[PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[Rebecca Cran]

Implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls for AArch64, and
add an MpServicesTest application to exercise it.

Changes from v3:

Removed Ard's 'Reviewed-by' line from the commits since the code has changed
sufficiently that it's no longer valid.

Rebecca Cran (3):
  ArmPkg: Add GET_MPIDR_AFFINITY_BITS and MPIDR_MT_BIT to ArmLib.h
  ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls
  MdeModulePkg: Add new Application/MpServicesTest application

 ArmPkg/ArmPkg.dsc                                            |    1 +
 MdeModulePkg/MdeModulePkg.dsc                                |    2 +
 ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf |   56 +
 MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf   |   40 +
 ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h     |  344 ++++
 ArmPkg/Include/Library/ArmLib.h                              |   16 +-
 MdeModulePkg/Application/MpServicesTest/Options.h            |   39 +
 ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c   | 1847 ++++++++++++++++++++
 MdeModulePkg/Application/MpServicesTest/MpServicesTest.c     |  560 ++++++
 MdeModulePkg/Application/MpServicesTest/Options.c            |  164 ++
 ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S                |   57 +
 11 files changed, 3119 insertions(+), 7 deletions(-)
 create mode 100644 ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
 create mode 100644 MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
 create mode 100644 ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h
 create mode 100644 MdeModulePkg/Application/MpServicesTest/Options.h
 create mode 100644 ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
 create mode 100644 MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
 create mode 100644 MdeModulePkg/Application/MpServicesTest/Options.c
 create mode 100644 ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S

-- 
2.30.2

[PATCH v4 1/3] ArmPkg: Add GET_MPIDR_AFFINITY_BITS and MPIDR_MT_BIT to ArmLib.h

[Rebecca Cran]

Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
---
 ArmPkg/Include/Library/ArmLib.h | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h
index 6566deebdde2..fa605f128bfd 100644
--- a/ArmPkg/Include/Library/ArmLib.h
+++ b/ArmPkg/Include/Library/ArmLib.h
@@ -108,14 +108,16 @@ typedef enum {
 
 #define ARM_CORE_MASK     ARM_CORE_AFF0
 #define ARM_CLUSTER_MASK  ARM_CORE_AFF1
-#define GET_CORE_ID(MpId)            ((MpId) & ARM_CORE_MASK)
-#define GET_CLUSTER_ID(MpId)         (((MpId) & ARM_CLUSTER_MASK) >> 8)
-#define GET_MPID(ClusterId, CoreId)  (((ClusterId) << 8) | (CoreId))
-#define GET_MPIDR_AFF0(MpId)         ((MpId) & ARM_CORE_AFF0)
-#define GET_MPIDR_AFF1(MpId)         (((MpId) & ARM_CORE_AFF1) >> 8)
-#define GET_MPIDR_AFF2(MpId)         (((MpId) & ARM_CORE_AFF2) >> 16)
-#define GET_MPIDR_AFF3(MpId)         (((MpId) & ARM_CORE_AFF3) >> 32)
+#define GET_CORE_ID(MpId)              ((MpId) & ARM_CORE_MASK)
+#define GET_CLUSTER_ID(MpId)           (((MpId) & ARM_CLUSTER_MASK) >> 8)
+#define GET_MPID(ClusterId, CoreId)    (((ClusterId) << 8) | (CoreId))
+#define GET_MPIDR_AFF0(MpId)           ((MpId) & ARM_CORE_AFF0)
+#define GET_MPIDR_AFF1(MpId)           (((MpId) & ARM_CORE_AFF1) >> 8)
+#define GET_MPIDR_AFF2(MpId)           (((MpId) & ARM_CORE_AFF2) >> 16)
+#define GET_MPIDR_AFF3(MpId)           (((MpId) & ARM_CORE_AFF3) >> 32)
+#define GET_MPIDR_AFFINITY_BITS(MpId)  ((MpId) & 0xFF00FFFFFF)
 #define PRIMARY_CORE_ID  (PcdGet32(PcdArmPrimaryCore) & ARM_CORE_MASK)
+#define MPIDR_MT_BIT     BIT24
 
 /** Reads the CCSIDR register for the specified cache.
 
-- 
2.30.2

[PATCH v4 2/3] ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls

[Rebecca Cran]

Add support for EFI_MP_SERVICES_PROTOCOL during the DXE phase under
AArch64.

PSCI_CPU_ON is called to power on the core, the supplied procedure is
executed and PSCI_CPU_OFF is called to power off the core.

Fixes contributed by Ard Biesheuvel.

Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
---
 ArmPkg/ArmPkg.dsc                                            |    1 +
 ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf |   56 +
 ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h     |  344 ++++
 ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c   | 1847 ++++++++++++++++++++
 ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S                |   57 +
 5 files changed, 2305 insertions(+)

diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
index ac24ebce4892..1e873b90c56d 100644
--- a/ArmPkg/ArmPkg.dsc
+++ b/ArmPkg/ArmPkg.dsc
@@ -164,6 +164,7 @@ [Components.common]
   ArmPkg/Universal/Smbios/OemMiscLibNull/OemMiscLibNull.inf
 
 [Components.AARCH64]
+  ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
   ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
   ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf
 
diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
new file mode 100644
index 000000000000..2c9ab99038f2
--- /dev/null
+++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
@@ -0,0 +1,56 @@
+## @file
+#  ARM MP services protocol driver
+#
+#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 1.27
+  BASE_NAME                      = ArmPsciMpServicesDxe
+  FILE_GUID                      = 007ab472-dc4a-4df8-a5c2-abb4a327278c
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+
+  ENTRY_POINT                    = ArmPsciMpServicesDxeInitialize
+
+[Sources.Common]
+  ArmPsciMpServicesDxe.c
+  MpFuncs.S
+  MpServicesInternal.h
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  ArmPlatformPkg/ArmPlatformPkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+
+[LibraryClasses]
+  ArmLib
+  ArmMmuLib
+  ArmSmcLib
+  BaseMemoryLib
+  CacheMaintenanceLib
+  CpuExceptionHandlerLib
+  DebugLib
+  HobLib
+  MemoryAllocationLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+  UefiLib
+
+[Protocols]
+  gEfiMpServiceProtocolGuid            ## PRODUCES
+  gEfiLoadedImageProtocolGuid          ## CONSUMES
+
+[Guids]
+  gArmMpCoreInfoGuid
+
+[Depex]
+  TRUE
+
+[BuildOptions]
+  GCC:*_*_*_CC_FLAGS = -mstrict-align
diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h
new file mode 100644
index 000000000000..5ba63700dd18
--- /dev/null
+++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h
@@ -0,0 +1,344 @@
+/** @file
+
+Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
+Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+Portions copyright (c) 2011, Apple Inc. All rights reserved.
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef MP_SERVICES_INTERNAL_H_
+#define MP_SERVICES_INTERNAL_H_
+
+#include <Protocol/Cpu.h>
+#include <Protocol/MpService.h>
+
+#include <Library/BaseLib.h>
+#include <Library/UefiLib.h>
+
+#define AP_STACK_SIZE  0x1000
+
+//
+// Internal Data Structures
+//
+
+//
+// AP state
+//
+// The state transitions for an AP when it processes a procedure are:
+//  Idle ----> Ready ----> Busy ----> Finished ----> Idle
+//       [BSP]       [BSP]      [AP]           [BSP]
+//
+typedef enum {
+  CpuStateIdle,
+  CpuStateReady,
+  CpuStateBlocked,
+  CpuStateBusy,
+  CpuStateFinished,
+  CpuStateDisabled
+} CPU_STATE;
+
+//
+// Define Individual Processor Data block.
+//
+typedef struct {
+  EFI_PROCESSOR_INFORMATION    Info;
+  EFI_AP_PROCEDURE             Procedure;
+  VOID                         *Parameter;
+  CPU_STATE                    State;
+  EFI_EVENT                    CheckThisAPEvent;
+  VOID                         *Ttbr0;
+  UINTN                        Tcr;
+  UINTN                        Mair;
+} CPU_AP_DATA;
+
+//
+// Define MP data block which consumes individual processor block.
+//
+typedef struct {
+  UINTN               NumberOfProcessors;
+  UINTN               NumberOfEnabledProcessors;
+  EFI_EVENT           CheckAllAPsEvent;
+  EFI_EVENT           WaitEvent;
+  UINTN               FinishCount;
+  UINTN               StartCount;
+  EFI_AP_PROCEDURE    Procedure;
+  VOID                *ProcedureArgument;
+  BOOLEAN             SingleThread;
+  UINTN               StartedNumber;
+  CPU_AP_DATA         *CpuData;
+  UINTN               Timeout;
+  UINTN               TimeTaken;
+  UINTN               *FailedList;
+  UINTN               FailedListIndex;
+  BOOLEAN             TimeoutActive;
+  BOOLEAN             *SingleApFinished;
+} CPU_MP_DATA;
+
+/** Secondary core entry point.
+
+**/
+VOID
+ApEntryPoint (
+  VOID
+  );
+
+/** C entry-point for the AP.
+    This function gets called from the assembly function ApEntryPoint.
+**/
+VOID
+ApProcedure (
+  VOID
+  );
+
+/** Turns on the specified core using PSCI and executes the user-supplied
+    function that's been configured via a previous call to SetApProcedure.
+
+   @param ProcessorIndex The index of the core to turn on.
+
+   @retval EFI_SUCCESS       The processor was successfully turned on.
+   @retval EFI_DEVICE_ERROR  An error occurred turning the processor on.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+DispatchCpu (
+  IN UINTN  ProcessorIndex
+  );
+
+/** Returns whether the specified processor is the BSP.
+
+   @param[in] ProcessorIndex The index the processor to check.
+
+   @return TRUE if the processor is the BSP, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorBSP (
+  UINTN  ProcessorIndex
+  );
+
+/** Returns whether the processor executing this function is the BSP.
+
+   @return Whether the current processor is the BSP.
+**/
+STATIC
+BOOLEAN
+IsCurrentProcessorBSP (
+  VOID
+  );
+
+/** Returns whether the specified processor is enabled.
+
+   @param[in] ProcessorIndex The index of the processor to check.
+
+   @return TRUE if the processor is enabled, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorEnabled (
+  UINTN  ProcessorIndex
+  );
+
+/** Configures the processor context with the user-supplied procedure and
+    argument.
+
+   @param CpuData           The processor context.
+   @param Procedure         The user-supplied procedure.
+   @param ProcedureArgument The user-supplied procedure argument.
+
+**/
+STATIC
+VOID
+SetApProcedure (
+  IN   CPU_AP_DATA       *CpuData,
+  IN   EFI_AP_PROCEDURE  Procedure,
+  IN   VOID              *ProcedureArgument
+  );
+
+/**
+  Get the Application Processors state.
+
+  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP
+
+  @return  The AP status
+**/
+CPU_STATE
+GetApState (
+  IN  CPU_AP_DATA  *CpuData
+  );
+
+/** Returns the index of the next processor that is blocked.
+
+   @param[out] NextNumber The index of the next blocked processor.
+
+   @retval EFI_SUCCESS   Successfully found the next blocked processor.
+   @retval EFI_NOT_FOUND There are no blocked processors.
+
+**/
+STATIC
+EFI_STATUS
+GetNextBlockedNumber (
+  OUT UINTN  *NextNumber
+  );
+
+/** Stalls the BSP for the minimum of gPollInterval and Timeout.
+
+   @param[in]  Timeout    The time limit in microseconds remaining for
+                          APs to return from Procedure.
+
+   @retval     StallTime  Time of execution stall.
+**/
+STATIC
+UINTN
+CalculateAndStallInterval (
+  IN UINTN  Timeout
+  );
+
+/** Sets up the state for the StartupAllAPs function.
+
+   @param SingleThread Whether the APs will execute sequentially.
+
+**/
+STATIC
+VOID
+StartupAllAPsPrepareState (
+  IN BOOLEAN  SingleThread
+  );
+
+/** Handles execution of StartupAllAPs when a WaitEvent has been specified.
+
+  @param Procedure         The user-supplied procedure.
+  @param ProcedureArgument The user-supplied procedure argument.
+  @param WaitEvent         The wait event to be signaled when the work is
+                           complete or a timeout has occurred.
+  @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+                               indicates an infinite timeout.
+  @param SingleThread          Whether the APs will execute sequentially.
+  @param FailedCpuList         User-supplied pointer for list of failed CPUs.
+
+   @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsWithWaitEvent (
+  IN EFI_AP_PROCEDURE  Procedure,
+  IN VOID              *ProcedureArgument,
+  IN EFI_EVENT         WaitEvent,
+  IN UINTN             TimeoutInMicroseconds,
+  IN BOOLEAN           SingleThread,
+  IN UINTN             **FailedCpuList
+  );
+
+/** Handles execution of StartupAllAPs when no wait event has been specified.
+
+   @param Procedure             The user-supplied procedure.
+   @param ProcedureArgument     The user-supplied procedure argument.
+   @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+                                indicates an infinite timeout.
+   @param SingleThread          Whether the APs will execute sequentially.
+   @param FailedCpuList         User-supplied pointer for list of failed CPUs.
+
+   @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsNoWaitEvent (
+  IN EFI_AP_PROCEDURE  Procedure,
+  IN VOID              *ProcedureArgument,
+  IN UINTN             TimeoutInMicroseconds,
+  IN BOOLEAN           SingleThread,
+  IN UINTN             **FailedCpuList
+  );
+
+/** Adds the specified processor the list of failed processors.
+
+   @param ProcessorIndex The processor index to add.
+   @param ApState         Processor state.
+
+**/
+STATIC
+VOID
+AddProcessorToFailedList (
+  UINTN      ProcessorIndex,
+  CPU_STATE  ApState
+  );
+
+/** Handles the StartupAllAPs case where the timeout has occurred.
+
+**/
+STATIC
+VOID
+ProcessStartupAllAPsTimeout (
+  VOID
+  );
+
+/**
+  If a timeout is specified in StartupAllAps(), a timer is set, which invokes
+  this procedure periodically to check whether all APs have finished.
+
+  @param[in] Event   The WaitEvent the user supplied.
+  @param[in] Context The event context.
+**/
+STATIC
+VOID
+EFIAPI
+CheckAllAPsStatus (
+  IN  EFI_EVENT  Event,
+  IN  VOID       *Context
+  );
+
+/** Invoked periodically via a timer to check the state of the processor.
+
+   @param Event   The event supplied by the timer expiration.
+   @param Context The processor context.
+
+**/
+STATIC
+VOID
+EFIAPI
+CheckThisAPStatus (
+  IN  EFI_EVENT  Event,
+  IN  VOID       *Context
+  );
+
+/**
+  This function is called by all processors (both BSP and AP) once and collects
+  MP related data.
+
+  @param BSP            TRUE if the processor is the BSP.
+  @param Mpidr          The MPIDR for the specified processor. This should be
+                        the full MPIDR and not only the affinity bits.
+  @param ProcessorIndex The index of the processor.
+
+  @return EFI_SUCCESS if the data for the processor collected and filled in.
+
+**/
+STATIC
+EFI_STATUS
+FillInProcessorInformation (
+  IN BOOLEAN  BSP,
+  IN UINTN    Mpidr,
+  IN UINTN    ProcessorIndex
+  );
+
+/**
+  Event notification function called when the EFI_EVENT_GROUP_READY_TO_BOOT is
+  signaled. After this point, non-blocking mode is no longer allowed.
+
+  @param  Event     Event whose notification function is being invoked.
+  @param  Context   The pointer to the notification function's context,
+                    which is implementation-dependent.
+
+**/
+STATIC
+VOID
+EFIAPI
+ReadyToBootSignaled (
+  IN  EFI_EVENT  Event,
+  IN  VOID       *Context
+  );
+
+#endif /* MP_SERVICES_INTERNAL_H_ */
diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
new file mode 100644
index 000000000000..ab439bffd722
--- /dev/null
+++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
@@ -0,0 +1,1847 @@
+/** @file
+  Construct MP Services Protocol.
+
+  The MP Services Protocol provides a generalized way of performing following tasks:
+    - Retrieving information of multi-processor environment and MP-related status of
+      specific processors.
+    - Dispatching user-provided function to APs.
+    - Maintain MP-related processor status.
+
+  The MP Services Protocol must be produced on any system with more than one logical
+  processor.
+
+  The Protocol is available only during boot time.
+
+  MP Services Protocol is hardware-independent. Most of the logic of this protocol
+  is architecturally neutral. It abstracts the multi-processor environment and
+  status of processors, and provides interfaces to retrieve information, maintain,
+  and dispatch.
+
+  MP Services Protocol may be consumed by ACPI module. The ACPI module may use this
+  protocol to retrieve data that are needed for an MP platform and report them to OS.
+  MP Services Protocol may also be used to program and configure processors, such
+  as MTRR synchronization for memory space attributes setting in DXE Services.
+  MP Services Protocol may be used by non-CPU DXE drivers to speed up platform boot
+  by taking advantage of the processing capabilities of the APs, for example, using
+  APs to help test system memory in parallel with other device initialization.
+  Diagnostics applications may also use this protocol for multi-processor.
+
+  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiDxe.h>
+
+#include <Library/ArmLib.h>
+#include <Library/ArmMmuLib.h>
+#include <Library/ArmPlatformLib.h>
+#include <Library/ArmSmcLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/CacheMaintenanceLib.h>
+#include <Library/CpuExceptionHandlerLib.h>
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+#include <IndustryStandard/ArmStdSmc.h>
+#include <Ppi/ArmMpCoreInfo.h>
+#include <Protocol/LoadedImage.h>
+
+#include "MpServicesInternal.h"
+
+#define POLL_INTERVAL_US  50000
+
+STATIC CPU_MP_DATA  mCpuMpData;
+STATIC BOOLEAN      mNonBlockingModeAllowed;
+UINT64              *gApStacksBase;
+UINT64              *gProcessorIDs;
+CONST UINT64        gApStackSize = AP_STACK_SIZE;
+
+STATIC
+BOOLEAN
+IsCurrentProcessorBSP (
+  VOID
+  );
+
+/** Turns on the specified core using PSCI and executes the user-supplied
+    function that's been configured via a previous call to SetApProcedure.
+
+    @param ProcessorIndex The index of the core to turn on.
+
+    @retval EFI_SUCCESS      Success.
+    @retval EFI_DEVICE_ERROR The processor could not be turned on.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+DispatchCpu (
+  IN UINTN  ProcessorIndex
+  )
+{
+  ARM_SMC_ARGS  Args;
+  EFI_STATUS    Status;
+
+  Status = EFI_SUCCESS;
+
+  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateBusy;
+
+  /* Turn the AP on */
+  if (sizeof (Args.Arg0) == sizeof (UINT32)) {
+    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH32;
+  } else {
+    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH64;
+  }
+
+  Args.Arg1 = gProcessorIDs[ProcessorIndex];
+  Args.Arg2 = (UINTN)ApEntryPoint;
+
+  mCpuMpData.CpuData[ProcessorIndex].Tcr   = ArmGetTCR ();
+  mCpuMpData.CpuData[ProcessorIndex].Mair  = ArmGetMAIR ();
+  mCpuMpData.CpuData[ProcessorIndex].Ttbr0 = ArmGetTTBR0BaseAddress ();
+  WriteBackDataCacheRange (&mCpuMpData.CpuData[ProcessorIndex], sizeof (CPU_AP_DATA));
+
+  ArmCallSmc (&Args);
+
+  if (Args.Arg0 != ARM_SMC_PSCI_RET_SUCCESS) {
+    DEBUG ((DEBUG_ERROR, "PSCI_CPU_ON call failed: %d\n", Args.Arg0));
+    Status = EFI_DEVICE_ERROR;
+  }
+
+  return Status;
+}
+
+/** Returns whether the specified processor is the BSP.
+
+  @param[in] ProcessorIndex The index the processor to check.
+
+  @return TRUE if the processor is the BSP, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorBSP (
+  UINTN  ProcessorIndex
+  )
+{
+  EFI_PROCESSOR_INFORMATION  *CpuInfo;
+
+  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
+
+  return (CpuInfo->StatusFlag & PROCESSOR_AS_BSP_BIT) != 0;
+}
+
+/** Get the Application Processors state.
+
+  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP.
+
+  @return The AP status.
+**/
+CPU_STATE
+GetApState (
+  IN  CPU_AP_DATA  *CpuData
+  )
+{
+  return CpuData->State;
+}
+
+/** Configures the processor context with the user-supplied procedure and
+    argument.
+
+   @param CpuData           The processor context.
+   @param Procedure         The user-supplied procedure.
+   @param ProcedureArgument The user-supplied procedure argument.
+
+**/
+STATIC
+VOID
+SetApProcedure (
+  IN   CPU_AP_DATA       *CpuData,
+  IN   EFI_AP_PROCEDURE  Procedure,
+  IN   VOID              *ProcedureArgument
+  )
+{
+  ASSERT (CpuData != NULL);
+  ASSERT (Procedure != NULL);
+
+  CpuData->Parameter = ProcedureArgument;
+  CpuData->Procedure = Procedure;
+}
+
+/** Returns the index of the next processor that is blocked.
+
+   @param[out] NextNumber The index of the next blocked processor.
+
+   @retval EFI_SUCCESS   Successfully found the next blocked processor.
+   @retval EFI_NOT_FOUND There are no blocked processors.
+
+**/
+STATIC
+EFI_STATUS
+GetNextBlockedNumber (
+  OUT UINTN  *NextNumber
+  )
+{
+  UINTN        Index;
+  CPU_STATE    State;
+  CPU_AP_DATA  *CpuData;
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
+    if (IsProcessorBSP (Index)) {
+      // Skip BSP
+      continue;
+    }
+
+    State = CpuData->State;
+
+    if (State == CpuStateBlocked) {
+      *NextNumber = Index;
+      return EFI_SUCCESS;
+    }
+  }
+
+  return EFI_NOT_FOUND;
+}
+
+/** Stalls the BSP for the minimum of POLL_INTERVAL_US and Timeout.
+
+   @param[in]  Timeout    The time limit in microseconds remaining for
+                          APs to return from Procedure.
+
+   @retval     StallTime  Time of execution stall.
+**/
+STATIC
+UINTN
+CalculateAndStallInterval (
+  IN UINTN  Timeout
+  )
+{
+  UINTN  StallTime;
+
+  if ((Timeout < POLL_INTERVAL_US) && (Timeout != 0)) {
+    StallTime = Timeout;
+  } else {
+    StallTime = POLL_INTERVAL_US;
+  }
+
+  gBS->Stall (StallTime);
+
+  return StallTime;
+}
+
+/**
+  This service retrieves the number of logical processor in the platform
+  and the number of those logical processors that are enabled on this boot.
+  This service may only be called from the BSP.
+
+  This function is used to retrieve the following information:
+    - The number of logical processors that are present in the system.
+    - The number of enabled logical processors in the system at the instant
+      this call is made.
+
+  Because MP Service Protocol provides services to enable and disable processors
+  dynamically, the number of enabled logical processors may vary during the
+  course of a boot session.
+
+  If this service is called from an AP, then EFI_DEVICE_ERROR is returned.
+  If NumberOfProcessors or NumberOfEnabledProcessors is NULL, then
+  EFI_INVALID_PARAMETER is returned. Otherwise, the total number of processors
+  is returned in NumberOfProcessors, the number of currently enabled processor
+  is returned in NumberOfEnabledProcessors, and EFI_SUCCESS is returned.
+
+  @param[in]  This                        A pointer to the
+                                          EFI_MP_SERVICES_PROTOCOL instance.
+  @param[out] NumberOfProcessors          Pointer to the total number of logical
+                                          processors in the system, including
+                                          the BSP and disabled APs.
+  @param[out] NumberOfEnabledProcessors   Pointer to the number of enabled
+                                          logical processors that exist in the
+                                          system, including the BSP.
+
+  @retval EFI_SUCCESS             The number of logical processors and enabled
+                                  logical processors was retrieved.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_INVALID_PARAMETER   NumberOfProcessors is NULL.
+  @retval EFI_INVALID_PARAMETER   NumberOfEnabledProcessors is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+GetNumberOfProcessors (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  OUT UINTN                     *NumberOfProcessors,
+  OUT UINTN                     *NumberOfEnabledProcessors
+  )
+{
+  if ((NumberOfProcessors == NULL) || (NumberOfEnabledProcessors == NULL)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  *NumberOfProcessors        = mCpuMpData.NumberOfProcessors;
+  *NumberOfEnabledProcessors = mCpuMpData.NumberOfEnabledProcessors;
+  return EFI_SUCCESS;
+}
+
+/**
+  Gets detailed MP-related information on the requested processor at the
+  instant this call is made. This service may only be called from the BSP.
+
+  This service retrieves detailed MP-related information about any processor
+  on the platform. Note the following:
+    - The processor information may change during the course of a boot session.
+    - The information presented here is entirely MP related.
+
+  Information regarding the number of caches and their sizes, frequency of
+  operation, slot numbers is all considered platform-related information and is
+  not provided by this service.
+
+  @param[in]  This                  A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                    instance.
+  @param[in]  ProcessorIndex        The index of the processor.
+  @param[out] ProcessorInfoBuffer   A pointer to the buffer where information
+                                    for the requested processor is deposited.
+
+  @retval EFI_SUCCESS             Processor information was returned.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_INVALID_PARAMETER   ProcessorInfoBuffer is NULL.
+  @retval EFI_NOT_FOUND           The processor with the handle specified by
+                                  ProcessorNumber does not exist in the platform.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+GetProcessorInfo (
+  IN  EFI_MP_SERVICES_PROTOCOL   *This,
+  IN  UINTN                      ProcessorIndex,
+  OUT EFI_PROCESSOR_INFORMATION  *ProcessorInfoBuffer
+  )
+{
+  if (ProcessorInfoBuffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  ProcessorIndex &= ~CPU_V2_EXTENDED_TOPOLOGY;
+
+  if (ProcessorIndex >= mCpuMpData.NumberOfProcessors) {
+    return EFI_NOT_FOUND;
+  }
+
+  CopyMem (
+    ProcessorInfoBuffer,
+    &mCpuMpData.CpuData[ProcessorIndex],
+    sizeof (EFI_PROCESSOR_INFORMATION)
+    );
+  return EFI_SUCCESS;
+}
+
+/**
+  This service executes a caller provided function on all enabled APs. APs can
+  run either simultaneously or one at a time in sequence. This service supports
+  both blocking and non-blocking requests. The non-blocking requests use EFI
+  events so the BSP can detect when the APs have finished. This service may only
+  be called from the BSP.
+
+  This function is used to dispatch all the enabled APs to the function
+  specified by Procedure.  If any enabled AP is busy, then EFI_NOT_READY is
+  returned immediately and Procedure is not started on any AP.
+
+  If SingleThread is TRUE, all the enabled APs execute the function specified by
+  Procedure one by one, in ascending order of processor handle number.
+  Otherwise, all the enabled APs execute the function specified by Procedure
+  simultaneously.
+
+  If WaitEvent is NULL, execution is in blocking mode. The BSP waits until all
+  APs finish or TimeoutInMicroseconds expires. Otherwise, execution is in
+  non-blocking mode, and the BSP returns from this service without waiting for
+  APs. If a non-blocking mode is requested after the UEFI Event
+  EFI_EVENT_GROUP_READY_TO_BOOT is signaled, then EFI_UNSUPPORTED must be
+  returned.
+
+  If the timeout specified by TimeoutInMicroseconds expires before all APs
+  return from Procedure, then Procedure on the failed APs is terminated.
+  All enabled APs are always available for further calls to
+  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
+  EFI_MP_SERVICES_PROTOCOL.StartupThisAP(). If FailedCpuList is not NULL, its
+  content points to the list of processor handle numbers in which Procedure was
+  terminated.
+
+  Note: It is the responsibility of the consumer of the
+  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() to make sure that the nature of the
+  code that is executed on the BSP and the dispatched APs is well controlled.
+  The MP Services Protocol does not guarantee that the Procedure function is
+  MP-safe. Hence, the tasks that can be run in parallel are limited to certain
+  independent tasks and well-controlled exclusive code. EFI services and
+  protocols may not be called by APs unless otherwise specified.
+
+  In blocking execution mode, BSP waits until all APs finish or
+  TimeoutInMicroseconds expires.
+
+  In non-blocking execution mode, BSP is freed to return to the caller and then
+  proceed to the next task without having to wait for APs. The following
+  sequence needs to occur in a non-blocking execution mode:
+
+    -# The caller that intends to use this MP Services Protocol in non-blocking
+       mode creates WaitEvent by calling the EFI CreateEvent() service.  The
+       caller invokes EFI_MP_SERVICES_PROTOCOL.StartupAllAPs(). If the parameter
+       WaitEvent is not NULL, then StartupAllAPs() executes in non-blocking
+       mode. It requests the function specified by Procedure to be started on
+       all the enabled APs, and releases the BSP to continue with other tasks.
+    -# The caller can use the CheckEvent() and WaitForEvent() services to check
+       the state of the WaitEvent created in step 1.
+    -# When the APs complete their task or TimeoutInMicroSecondss expires, the
+       MP Service signals WaitEvent by calling the EFI SignalEvent() function.
+       If FailedCpuList is not NULL, its content is available when WaitEvent is
+       signaled. If all APs returned from Procedure prior to the timeout, then
+       FailedCpuList is set to NULL. If not all APs return from Procedure before
+       the timeout, then FailedCpuList is filled in with the list of the failed
+       APs. The buffer is allocated by MP Service Protocol using AllocatePool().
+       It is the caller's responsibility to free the buffer with FreePool()
+       service.
+    -# This invocation of SignalEvent() function informs the caller that invoked
+       EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() that either all the APs
+       completed the specified task or a timeout occurred. The contents of
+       FailedCpuList can be examined to determine which APs did not complete the
+       specified task prior to the timeout.
+
+  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                      instance.
+  @param[in]  Procedure               A pointer to the function to be run on
+                                      enabled APs of the system. See type
+                                      EFI_AP_PROCEDURE.
+  @param[in]  SingleThread            If TRUE, then all the enabled APs execute
+                                      the function specified by Procedure one by
+                                      one, in ascending order of processor
+                                      handle number.  If FALSE, then all the
+                                      enabled APs execute the function specified
+                                      by Procedure simultaneously.
+  @param[in]  WaitEvent               The event created by the caller with
+                                      CreateEvent() service.  If it is NULL,
+                                      then execute in blocking mode. BSP waits
+                                      until all APs finish or
+                                      TimeoutInMicroseconds expires.  If it's
+                                      not NULL, then execute in non-blocking
+                                      mode. BSP requests the function specified
+                                      by Procedure to be started on all the
+                                      enabled APs, and go on executing
+                                      immediately. If all return from Procedure,
+                                      or TimeoutInMicroseconds expires, this
+                                      event is signaled. The BSP can use the
+                                      CheckEvent() or WaitForEvent()
+                                      services to check the state of event. Type
+                                      EFI_EVENT is defined in CreateEvent() in
+                                      the Unified Extensible Firmware Interface
+                                      Specification.
+  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds
+                                      for APs to return from Procedure, either
+                                      for blocking or non-blocking mode. Zero
+                                      means infinity.  If the timeout expires
+                                      before all APs return from Procedure, then
+                                      Procedure on the failed APs is terminated.
+                                      All enabled APs are available for next
+                                      function assigned by
+                                      EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+                                      If the timeout expires in blocking mode,
+                                      BSP returns EFI_TIMEOUT.  If the timeout
+                                      expires in non-blocking mode, WaitEvent
+                                      is signaled with SignalEvent().
+  @param[in]  ProcedureArgument       The parameter passed into Procedure for
+                                      all APs.
+  @param[out] FailedCpuList           If NULL, this parameter is ignored.
+                                      Otherwise, if all APs finish successfully,
+                                      then its content is set to NULL. If not
+                                      all APs finish before timeout expires,
+                                      then its content is set to address of the
+                                      buffer holding handle numbers of the
+                                      failed APs.
+                                      The buffer is allocated by MP Service
+                                      Protocol, and it's the caller's
+                                      responsibility to free the buffer with
+                                      FreePool() service.
+                                      In blocking mode, it is ready for
+                                      consumption when the call returns. In
+                                      non-blocking mode, it is ready when
+                                      WaitEvent is signaled. The list of failed
+                                      CPU is terminated by  END_OF_CPU_LIST.
+
+  @retval EFI_SUCCESS             In blocking mode, all APs have finished before
+                                  the timeout expired.
+  @retval EFI_SUCCESS             In non-blocking mode, function has been
+                                  dispatched to all enabled APs.
+  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
+                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+                                  signaled.
+  @retval EFI_DEVICE_ERROR        Caller processor is AP.
+  @retval EFI_NOT_STARTED         No enabled APs exist in the system.
+  @retval EFI_NOT_READY           Any enabled APs are busy.
+  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
+                                  all enabled APs have finished.
+  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+StartupAllAPs (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  EFI_AP_PROCEDURE          Procedure,
+  IN  BOOLEAN                   SingleThread,
+  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
+  IN  UINTN                     TimeoutInMicroseconds,
+  IN  VOID                      *ProcedureArgument      OPTIONAL,
+  OUT UINTN                     **FailedCpuList         OPTIONAL
+  )
+{
+  EFI_STATUS  Status;
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  if (mCpuMpData.NumberOfProcessors == 1) {
+    return EFI_NOT_STARTED;
+  }
+
+  if (Procedure == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
+    return EFI_UNSUPPORTED;
+  }
+
+  if (FailedCpuList != NULL) {
+    mCpuMpData.FailedList = AllocateZeroPool (
+                              (mCpuMpData.NumberOfProcessors + 1) *
+                              sizeof (UINTN)
+                              );
+    if (mCpuMpData.FailedList == NULL) {
+      return EFI_OUT_OF_RESOURCES;
+    }
+
+    SetMemN (
+      mCpuMpData.FailedList,
+      (mCpuMpData.NumberOfProcessors + 1) *
+      sizeof (UINTN),
+      END_OF_CPU_LIST
+      );
+    mCpuMpData.FailedListIndex = 0;
+    *FailedCpuList             = mCpuMpData.FailedList;
+  }
+
+  StartupAllAPsPrepareState (SingleThread);
+
+  if (WaitEvent != NULL) {
+    Status = StartupAllAPsWithWaitEvent (
+               Procedure,
+               ProcedureArgument,
+               WaitEvent,
+               TimeoutInMicroseconds,
+               SingleThread,
+               FailedCpuList
+               );
+
+    if (EFI_ERROR (Status) && (FailedCpuList != NULL)) {
+      if (mCpuMpData.FailedListIndex == 0) {
+        FreePool (*FailedCpuList);
+        *FailedCpuList = NULL;
+      }
+    }
+  } else {
+    Status = StartupAllAPsNoWaitEvent (
+               Procedure,
+               ProcedureArgument,
+               TimeoutInMicroseconds,
+               SingleThread,
+               FailedCpuList
+               );
+
+    if (FailedCpuList != NULL) {
+      if (mCpuMpData.FailedListIndex == 0) {
+        FreePool (*FailedCpuList);
+        *FailedCpuList = NULL;
+      }
+    }
+  }
+
+  return Status;
+}
+
+/**
+  This service lets the caller get one enabled AP to execute a caller-provided
+  function. The caller can request the BSP to either wait for the completion
+  of the AP or just proceed with the next task by using the EFI event mechanism.
+  See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on non-blocking
+  execution support.  This service may only be called from the BSP.
+
+  This function is used to dispatch one enabled AP to the function specified by
+  Procedure passing in the argument specified by ProcedureArgument.  If WaitEvent
+  is NULL, execution is in blocking mode. The BSP waits until the AP finishes or
+  TimeoutInMicroSecondss expires. Otherwise, execution is in non-blocking mode.
+  BSP proceeds to the next task without waiting for the AP. If a non-blocking mode
+  is requested after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled,
+  then EFI_UNSUPPORTED must be returned.
+
+  If the timeout specified by TimeoutInMicroseconds expires before the AP returns
+  from Procedure, then execution of Procedure by the AP is terminated. The AP is
+  available for subsequent calls to EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
+  EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+
+  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                      instance.
+  @param[in]  Procedure               A pointer to the function to be run on
+                                      enabled APs of the system. See type
+                                      EFI_AP_PROCEDURE.
+  @param[in]  ProcessorNumber         The handle number of the AP. The range is
+                                      from 0 to the total number of logical
+                                      processors minus 1. The total number of
+                                      logical processors can be retrieved by
+                                      EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @param[in]  WaitEvent               The event created by the caller with CreateEvent()
+                                      service.  If it is NULL, then execute in
+                                      blocking mode. BSP waits until all APs finish
+                                      or TimeoutInMicroseconds expires.  If it's
+                                      not NULL, then execute in non-blocking mode.
+                                      BSP requests the function specified by
+                                      Procedure to be started on all the enabled
+                                      APs, and go on executing immediately. If
+                                      all return from Procedure or TimeoutInMicroseconds
+                                      expires, this event is signaled. The BSP
+                                      can use the CheckEvent() or WaitForEvent()
+                                      services to check the state of event.  Type
+                                      EFI_EVENT is defined in CreateEvent() in
+                                      the Unified Extensible Firmware Interface
+                                      Specification.
+  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds for
+                                      APs to return from Procedure, either for
+                                      blocking or non-blocking mode. Zero means
+                                      infinity.  If the timeout expires before
+                                      all APs return from Procedure, then Procedure
+                                      on the failed APs is terminated. All enabled
+                                      APs are available for next function assigned
+                                      by EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+                                      If the timeout expires in blocking mode,
+                                      BSP returns EFI_TIMEOUT.  If the timeout
+                                      expires in non-blocking mode, WaitEvent
+                                      is signaled with SignalEvent().
+  @param[in]  ProcedureArgument       The parameter passed into Procedure for
+                                      all APs.
+  @param[out] Finished                If NULL, this parameter is ignored.  In
+                                      blocking mode, this parameter is ignored.
+                                      In non-blocking mode, if AP returns from
+                                      Procedure before the timeout expires, its
+                                      content is set to TRUE. Otherwise, the
+                                      value is set to FALSE. The caller can
+                                      determine if the AP returned from Procedure
+                                      by evaluating this value.
+
+  @retval EFI_SUCCESS             In blocking mode, specified AP finished before
+                                  the timeout expires.
+  @retval EFI_SUCCESS             In non-blocking mode, the function has been
+                                  dispatched to specified AP.
+  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
+                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+                                  signaled.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
+                                  the specified AP has finished.
+  @retval EFI_NOT_READY           The specified AP is busy.
+  @retval EFI_NOT_FOUND           The processor with the handle specified by
+                                  ProcessorNumber does not exist.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP or disabled AP.
+  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+StartupThisAP (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  EFI_AP_PROCEDURE          Procedure,
+  IN  UINTN                     ProcessorNumber,
+  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
+  IN  UINTN                     TimeoutInMicroseconds,
+  IN  VOID                      *ProcedureArgument      OPTIONAL,
+  OUT BOOLEAN                   *Finished               OPTIONAL
+  )
+{
+  EFI_STATUS   Status;
+  UINTN        Timeout;
+  CPU_AP_DATA  *CpuData;
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  if (Procedure == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
+    return EFI_NOT_FOUND;
+  }
+
+  CpuData = &mCpuMpData.CpuData[ProcessorNumber];
+
+  if (IsProcessorBSP (ProcessorNumber)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (!IsProcessorEnabled (ProcessorNumber)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (GetApState (CpuData) != CpuStateIdle) {
+    return EFI_NOT_READY;
+  }
+
+  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
+    return EFI_UNSUPPORTED;
+  }
+
+  Timeout = TimeoutInMicroseconds;
+
+  mCpuMpData.Timeout       = TimeoutInMicroseconds;
+  mCpuMpData.TimeTaken     = 0;
+  mCpuMpData.TimeoutActive = (BOOLEAN)(TimeoutInMicroseconds != 0);
+
+  mCpuMpData.StartCount  = 1;
+  mCpuMpData.FinishCount = 0;
+
+  SetApProcedure (
+    CpuData,
+    Procedure,
+    ProcedureArgument
+    );
+
+  Status = DispatchCpu (ProcessorNumber);
+  if (EFI_ERROR (Status)) {
+    CpuData->State = CpuStateIdle;
+    return EFI_NOT_READY;
+  }
+
+  if (WaitEvent != NULL) {
+    // Non Blocking
+    if (Finished != NULL) {
+      mCpuMpData.SingleApFinished = Finished;
+      *Finished                   = FALSE;
+    }
+
+    mCpuMpData.WaitEvent = WaitEvent;
+    Status               = gBS->SetTimer (
+                                  CpuData->CheckThisAPEvent,
+                                  TimerPeriodic,
+                                  POLL_INTERVAL_US
+                                  );
+
+    return EFI_SUCCESS;
+  }
+
+  // Blocking
+  while (TRUE) {
+    if (GetApState (CpuData) == CpuStateFinished) {
+      CpuData->State = CpuStateIdle;
+      break;
+    }
+
+    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
+      return EFI_TIMEOUT;
+    }
+
+    Timeout -= CalculateAndStallInterval (Timeout);
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  This service switches the requested AP to be the BSP from that point onward.
+  This service changes the BSP for all purposes.   This call can only be
+  performed by the current BSP.
+
+  This service switches the requested AP to be the BSP from that point onward.
+  This service changes the BSP for all purposes. The new BSP can take over the
+  execution of the old BSP and continue seamlessly from where the old one left
+  off. This service may not be supported after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT
+  is signaled.
+
+  If the BSP cannot be switched prior to the return from this service, then
+  EFI_UNSUPPORTED must be returned.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @param[in] ProcessorNumber   The handle number of AP that is to become the new
+                               BSP. The range is from 0 to the total number of
+                               logical processors minus 1. The total number of
+                               logical processors can be retrieved by
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @param[in] EnableOldBSP      If TRUE, then the old BSP will be listed as an
+                               enabled AP. Otherwise, it will be disabled.
+
+  @retval EFI_SUCCESS             BSP successfully switched.
+  @retval EFI_UNSUPPORTED         Switching the BSP cannot be completed prior to
+                                  this service returning.
+  @retval EFI_UNSUPPORTED         Switching the BSP is not supported.
+  @retval EFI_SUCCESS             The calling processor is an AP.
+  @retval EFI_NOT_FOUND           The processor with the handle specified by
+                                  ProcessorNumber does not exist.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the current BSP or
+                                  a disabled AP.
+  @retval EFI_NOT_READY           The specified AP is busy.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+SwitchBSP (
+  IN EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  UINTN                    ProcessorNumber,
+  IN  BOOLEAN                  EnableOldBSP
+  )
+{
+  return EFI_UNSUPPORTED;
+}
+
+/**
+  This service lets the caller enable or disable an AP from this point onward.
+  This service may only be called from the BSP.
+
+  This service allows the caller enable or disable an AP from this point onward.
+  The caller can optionally specify the health status of the AP by Health. If
+  an AP is being disabled, then the state of the disabled AP is implementation
+  dependent. If an AP is enabled, then the implementation must guarantee that a
+  complete initialization sequence is performed on the AP, so the AP is in a state
+  that is compatible with an MP operating system. This service may not be supported
+  after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled.
+
+  If the enable or disable AP operation cannot be completed prior to the return
+  from this service, then EFI_UNSUPPORTED must be returned.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @param[in] ProcessorNumber   The handle number of AP that is to become the new
+                               BSP. The range is from 0 to the total number of
+                               logical processors minus 1. The total number of
+                               logical processors can be retrieved by
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @param[in] EnableAP          Specifies the new state for the processor for
+                               enabled, FALSE for disabled.
+  @param[in] HealthFlag        If not NULL, a pointer to a value that specifies
+                               the new health status of the AP. This flag
+                               corresponds to StatusFlag defined in
+                               EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
+                               the PROCESSOR_HEALTH_STATUS_BIT is used. All other
+                               bits are ignored.  If it is NULL, this parameter
+                               is ignored.
+
+  @retval EFI_SUCCESS             The specified AP was enabled or disabled successfully.
+  @retval EFI_UNSUPPORTED         Enabling or disabling an AP cannot be completed
+                                  prior to this service returning.
+  @retval EFI_UNSUPPORTED         Enabling or disabling an AP is not supported.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_NOT_FOUND           Processor with the handle specified by ProcessorNumber
+                                  does not exist.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+EnableDisableAP (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  UINTN                     ProcessorNumber,
+  IN  BOOLEAN                   EnableAP,
+  IN  UINT32                    *HealthFlag OPTIONAL
+  )
+{
+  UINTN        StatusFlag;
+  CPU_AP_DATA  *CpuData;
+
+  StatusFlag = mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag;
+  CpuData    = &mCpuMpData.CpuData[ProcessorNumber];
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
+    return EFI_NOT_FOUND;
+  }
+
+  if (IsProcessorBSP (ProcessorNumber)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (GetApState (CpuData) != CpuStateIdle) {
+    return EFI_UNSUPPORTED;
+  }
+
+  if (EnableAP) {
+    if (!IsProcessorEnabled (ProcessorNumber)) {
+      mCpuMpData.NumberOfEnabledProcessors++;
+    }
+
+    StatusFlag |= PROCESSOR_ENABLED_BIT;
+  } else {
+    if (IsProcessorEnabled (ProcessorNumber)) {
+      mCpuMpData.NumberOfEnabledProcessors--;
+    }
+
+    StatusFlag &= ~PROCESSOR_ENABLED_BIT;
+  }
+
+  if (HealthFlag != NULL) {
+    StatusFlag &= ~PROCESSOR_HEALTH_STATUS_BIT;
+    StatusFlag |= (*HealthFlag & PROCESSOR_HEALTH_STATUS_BIT);
+  }
+
+  mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag = StatusFlag;
+  return EFI_SUCCESS;
+}
+
+/**
+  This return the handle number for the calling processor.  This service may be
+  called from the BSP and APs.
+
+  This service returns the processor handle number for the calling processor.
+  The returned value is in the range from 0 to the total number of logical
+  processors minus 1. The total number of logical processors can be retrieved
+  with EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors(). This service may be
+  called from the BSP and APs. If ProcessorNumber is NULL, then EFI_INVALID_PARAMETER
+  is returned. Otherwise, the current processors handle number is returned in
+  ProcessorNumber, and EFI_SUCCESS is returned.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @param[out] ProcessorNumber  The handle number of AP that is to become the new
+                               BSP. The range is from 0 to the total number of
+                               logical processors minus 1. The total number of
+                               logical processors can be retrieved by
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+
+  @retval EFI_SUCCESS             The current processor handle number was returned
+                                  in ProcessorNumber.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+WhoAmI (
+  IN EFI_MP_SERVICES_PROTOCOL  *This,
+  OUT UINTN                    *ProcessorNumber
+  )
+{
+  UINTN   Index;
+  UINT64  ProcessorId;
+
+  if (ProcessorNumber == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  ProcessorId = GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ());
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    if (ProcessorId == gProcessorIDs[Index]) {
+      *ProcessorNumber = Index;
+      break;
+    }
+  }
+
+  return EFI_SUCCESS;
+}
+
+STATIC EFI_MP_SERVICES_PROTOCOL  mMpServicesProtocol = {
+  GetNumberOfProcessors,
+  GetProcessorInfo,
+  StartupAllAPs,
+  StartupThisAP,
+  SwitchBSP,
+  EnableDisableAP,
+  WhoAmI
+};
+
+/** Adds the specified processor the list of failed processors.
+
+   @param ProcessorIndex The processor index to add.
+   @param ApState        Processor state.
+
+**/
+STATIC
+VOID
+AddProcessorToFailedList (
+  UINTN      ProcessorIndex,
+  CPU_STATE  ApState
+  )
+{
+  UINTN    Index;
+  BOOLEAN  Found;
+
+  Found = FALSE;
+
+  if ((mCpuMpData.FailedList == NULL) ||
+      (ApState == CpuStateIdle) ||
+      (ApState == CpuStateFinished) ||
+      IsProcessorBSP (ProcessorIndex))
+  {
+    return;
+  }
+
+  // If we are retrying make sure we don't double count
+  for (Index = 0; Index < mCpuMpData.FailedListIndex; Index++) {
+    if (mCpuMpData.FailedList[Index] == ProcessorIndex) {
+      Found = TRUE;
+      break;
+    }
+  }
+
+  /* If the CPU isn't already in the FailedList, add it */
+  if (!Found) {
+    mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = ProcessorIndex;
+  }
+}
+
+/** Handles the StartupAllAPs case where the timeout has occurred.
+
+**/
+STATIC
+VOID
+ProcessStartupAllAPsTimeout (
+  VOID
+  )
+{
+  CPU_AP_DATA  *CpuData;
+  UINTN        Index;
+
+  if (mCpuMpData.FailedList == NULL) {
+    return;
+  }
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
+    if (IsProcessorBSP (Index)) {
+      // Skip BSP
+      continue;
+    }
+
+    if (!IsProcessorEnabled (Index)) {
+      // Skip Disabled processors
+      continue;
+    }
+
+    CpuData = &mCpuMpData.CpuData[Index];
+    AddProcessorToFailedList (Index, GetApState (CpuData));
+  }
+}
+
+/** Updates the status of the APs.
+
+   @param[in] ProcessorIndex The index of the AP to update.
+**/
+STATIC
+VOID
+UpdateApStatus (
+  IN UINTN  ProcessorIndex
+  )
+{
+  EFI_STATUS   Status;
+  CPU_AP_DATA  *CpuData;
+  CPU_AP_DATA  *NextCpuData;
+  CPU_STATE    State;
+  UINTN        NextNumber;
+
+  CpuData = &mCpuMpData.CpuData[ProcessorIndex];
+
+  if (IsProcessorBSP (ProcessorIndex)) {
+    // Skip BSP
+    return;
+  }
+
+  if (!IsProcessorEnabled (ProcessorIndex)) {
+    // Skip Disabled processors
+    return;
+  }
+
+  State = GetApState (CpuData);
+
+  switch (State) {
+    case CpuStateFinished:
+      if (mCpuMpData.SingleThread) {
+        Status = GetNextBlockedNumber (&NextNumber);
+        if (!EFI_ERROR (Status)) {
+          NextCpuData = &mCpuMpData.CpuData[NextNumber];
+
+          NextCpuData->State = CpuStateReady;
+
+          SetApProcedure (
+            NextCpuData,
+            mCpuMpData.Procedure,
+            mCpuMpData.ProcedureArgument
+            );
+
+          Status = DispatchCpu (NextNumber);
+          if (!EFI_ERROR (Status)) {
+            mCpuMpData.StartCount++;
+          } else {
+            AddProcessorToFailedList (NextNumber, NextCpuData->State);
+          }
+        }
+      }
+
+      CpuData->State = CpuStateIdle;
+      mCpuMpData.FinishCount++;
+      break;
+
+    default:
+      break;
+  }
+}
+
+/**
+  If a timeout is specified in StartupAllAps(), a timer is set, which invokes
+  this procedure periodically to check whether all APs have finished.
+
+  @param[in] Event   The WaitEvent the user supplied.
+  @param[in] Context The event context.
+**/
+STATIC
+VOID
+EFIAPI
+CheckAllAPsStatus (
+  IN  EFI_EVENT  Event,
+  IN  VOID       *Context
+  )
+{
+  UINTN  Index;
+
+  mCpuMpData.TimeTaken += POLL_INTERVAL_US;
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    UpdateApStatus (Index);
+  }
+
+  if (mCpuMpData.TimeoutActive && (mCpuMpData.TimeTaken > mCpuMpData.Timeout)) {
+    ProcessStartupAllAPsTimeout ();
+
+    // Force terminal exit
+    mCpuMpData.FinishCount = mCpuMpData.StartCount;
+  }
+
+  if (mCpuMpData.FinishCount != mCpuMpData.StartCount) {
+    return;
+  }
+
+  gBS->SetTimer (
+         mCpuMpData.CheckAllAPsEvent,
+         TimerCancel,
+         0
+         );
+
+  if (mCpuMpData.FailedListIndex == 0) {
+    if (mCpuMpData.FailedList != NULL) {
+      // Since we don't have the original `FailedCpuList`
+      // pointer here to set to NULL, don't free the
+      // memory.
+    }
+  }
+
+  gBS->SignalEvent (mCpuMpData.WaitEvent);
+}
+
+/** Invoked periodically via a timer to check the state of the processor.
+
+   @param Event   The event supplied by the timer expiration.
+   @param Context The processor context.
+
+**/
+STATIC
+VOID
+EFIAPI
+CheckThisAPStatus (
+  IN  EFI_EVENT  Event,
+  IN  VOID       *Context
+  )
+{
+  EFI_STATUS   Status;
+  CPU_AP_DATA  *CpuData;
+  CPU_STATE    State;
+
+  CpuData = Context;
+
+  mCpuMpData.TimeTaken += POLL_INTERVAL_US;
+
+  State = GetApState (CpuData);
+
+  if (State == CpuStateFinished) {
+    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 0);
+    ASSERT_EFI_ERROR (Status);
+
+    if (mCpuMpData.SingleApFinished != NULL) {
+      *mCpuMpData.SingleApFinished = TRUE;
+    }
+
+    if (mCpuMpData.WaitEvent != NULL) {
+      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
+      ASSERT_EFI_ERROR (Status);
+    }
+
+    CpuData->State = CpuStateIdle;
+  }
+
+  if (mCpuMpData.TimeoutActive && (mCpuMpData.TimeTaken > mCpuMpData.Timeout)) {
+    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 0);
+    if (mCpuMpData.WaitEvent != NULL) {
+      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
+      ASSERT_EFI_ERROR (Status);
+    }
+  }
+}
+
+/**
+  This function is called by all processors (both BSP and AP) once and collects
+  MP related data.
+
+  @param BSP            TRUE if the processor is the BSP.
+  @param Mpidr          The MPIDR for the specified processor. This should be
+                        the full MPIDR and not only the affinity bits.
+  @param ProcessorIndex The index of the processor.
+
+  @return EFI_SUCCESS if the data for the processor collected and filled in.
+
+**/
+STATIC
+EFI_STATUS
+FillInProcessorInformation (
+  IN BOOLEAN  BSP,
+  IN UINTN    Mpidr,
+  IN UINTN    ProcessorIndex
+  )
+{
+  EFI_PROCESSOR_INFORMATION  *CpuInfo;
+
+  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
+
+  CpuInfo->ProcessorId = GET_MPIDR_AFFINITY_BITS (Mpidr);
+  CpuInfo->StatusFlag  = PROCESSOR_ENABLED_BIT | PROCESSOR_HEALTH_STATUS_BIT;
+
+  if (BSP) {
+    CpuInfo->StatusFlag |= PROCESSOR_AS_BSP_BIT;
+  }
+
+  if ((Mpidr & MPIDR_MT_BIT) > 0) {
+    CpuInfo->Location.Package = GET_MPIDR_AFF2 (Mpidr);
+    CpuInfo->Location.Core    = GET_MPIDR_AFF1 (Mpidr);
+    CpuInfo->Location.Thread  = GET_MPIDR_AFF0 (Mpidr);
+
+    CpuInfo->ExtendedInformation.Location2.Package = GET_MPIDR_AFF3 (Mpidr);
+    CpuInfo->ExtendedInformation.Location2.Die     = GET_MPIDR_AFF2 (Mpidr);
+    CpuInfo->ExtendedInformation.Location2.Core    = GET_MPIDR_AFF1 (Mpidr);
+    CpuInfo->ExtendedInformation.Location2.Thread  = GET_MPIDR_AFF0 (Mpidr);
+  } else {
+    CpuInfo->Location.Package = GET_MPIDR_AFF1 (Mpidr);
+    CpuInfo->Location.Core    = GET_MPIDR_AFF0 (Mpidr);
+    CpuInfo->Location.Thread  = 0;
+
+    CpuInfo->ExtendedInformation.Location2.Package = GET_MPIDR_AFF2 (Mpidr);
+    CpuInfo->ExtendedInformation.Location2.Die     = GET_MPIDR_AFF1 (Mpidr);
+    CpuInfo->ExtendedInformation.Location2.Core    = GET_MPIDR_AFF0 (Mpidr);
+    CpuInfo->ExtendedInformation.Location2.Thread  = 0;
+  }
+
+  mCpuMpData.CpuData[ProcessorIndex].State = BSP ? CpuStateBusy : CpuStateIdle;
+
+  mCpuMpData.CpuData[ProcessorIndex].Procedure = NULL;
+  mCpuMpData.CpuData[ProcessorIndex].Parameter = NULL;
+
+  return EFI_SUCCESS;
+}
+
+/** Initializes the MP Services system data
+
+   @param NumberOfProcessors The number of processors, both BSP and AP.
+   @param CoreInfo           CPU information gathered earlier during boot.
+
+**/
+STATIC
+EFI_STATUS
+MpServicesInitialize (
+  IN   UINTN                NumberOfProcessors,
+  IN   CONST ARM_CORE_INFO  *CoreInfo
+  )
+{
+  EFI_STATUS  Status;
+  UINTN       Index;
+  EFI_EVENT   ReadyToBootEvent;
+  BOOLEAN     IsBsp;
+
+  //
+  // Clear the data structure area first.
+  //
+  ZeroMem (&mCpuMpData, sizeof (CPU_MP_DATA));
+  //
+  // First BSP fills and inits all known values, including its own records.
+  //
+  mCpuMpData.NumberOfProcessors        = NumberOfProcessors;
+  mCpuMpData.NumberOfEnabledProcessors = NumberOfProcessors;
+
+  mCpuMpData.CpuData = AllocateZeroPool (
+                         mCpuMpData.NumberOfProcessors * sizeof (CPU_AP_DATA)
+                         );
+
+  if (mCpuMpData.CpuData == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  /* Allocate one extra for the sentinel entry at the end */
+  gProcessorIDs = AllocateZeroPool ((mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64));
+  ASSERT (gProcessorIDs != NULL);
+
+  Status = gBS->CreateEvent (
+                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
+                  TPL_CALLBACK,
+                  CheckAllAPsStatus,
+                  NULL,
+                  &mCpuMpData.CheckAllAPsEvent
+                  );
+  ASSERT_EFI_ERROR (Status);
+
+  gApStacksBase = AllocatePages (
+                    EFI_SIZE_TO_PAGES (
+                      mCpuMpData.NumberOfProcessors *
+                      gApStackSize
+                      )
+                    );
+  ASSERT (gApStacksBase != NULL);
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    if (GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ()) == CoreInfo[Index].Mpidr) {
+      IsBsp = TRUE;
+    } else {
+      IsBsp = FALSE;
+    }
+
+    FillInProcessorInformation (IsBsp, CoreInfo[Index].Mpidr, Index);
+
+    gProcessorIDs[Index] = mCpuMpData.CpuData[Index].Info.ProcessorId;
+
+    Status = gBS->CreateEvent (
+                    EVT_TIMER | EVT_NOTIFY_SIGNAL,
+                    TPL_CALLBACK,
+                    CheckThisAPStatus,
+                    (VOID *)&mCpuMpData.CpuData[Index],
+                    &mCpuMpData.CpuData[Index].CheckThisAPEvent
+                    );
+    ASSERT_EFI_ERROR (Status);
+  }
+
+  gProcessorIDs[Index] = MAX_UINT64;
+
+  //
+  // The global pointer variables as well as the gProcessorIDs array contents
+  // are accessed by the other cores so we must clean them to the PoC
+  //
+  WriteBackDataCacheRange (&gProcessorIDs, sizeof (UINT64 *));
+  WriteBackDataCacheRange (&gApStacksBase, sizeof (UINT64 *));
+
+  WriteBackDataCacheRange (
+    gProcessorIDs,
+    (mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64)
+    );
+
+  mNonBlockingModeAllowed = TRUE;
+
+  Status = EfiCreateEventReadyToBootEx (
+             TPL_CALLBACK,
+             ReadyToBootSignaled,
+             NULL,
+             &ReadyToBootEvent
+             );
+  ASSERT_EFI_ERROR (Status);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Event notification function called when the EFI_EVENT_GROUP_READY_TO_BOOT is
+  signaled. After this point, non-blocking mode is no longer allowed.
+
+  @param  Event     Event whose notification function is being invoked.
+  @param  Context   The pointer to the notification function's context,
+                    which is implementation-dependent.
+
+**/
+STATIC
+VOID
+EFIAPI
+ReadyToBootSignaled (
+  IN  EFI_EVENT  Event,
+  IN  VOID       *Context
+  )
+{
+  mNonBlockingModeAllowed = FALSE;
+}
+
+/** Initialize multi-processor support.
+
+  @param ImageHandle  Image handle.
+  @param SystemTable  System table.
+
+  @return EFI_SUCCESS on success, or an error code.
+
+**/
+EFI_STATUS
+EFIAPI
+ArmPsciMpServicesDxeInitialize (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS                 Status;
+  EFI_HANDLE                 Handle;
+  UINTN                      MaxCpus;
+  EFI_LOADED_IMAGE_PROTOCOL  *Image;
+  EFI_HOB_GENERIC_HEADER     *Hob;
+  VOID                       *HobData;
+  UINTN                      HobDataSize;
+  CONST ARM_CORE_INFO        *CoreInfo;
+
+  MaxCpus = 1;
+
+  Status = gBS->HandleProtocol (
+                  ImageHandle,
+                  &gEfiLoadedImageProtocolGuid,
+                  (VOID **)&Image
+                  );
+  ASSERT_EFI_ERROR (Status);
+
+  //
+  // Parts of the code in this driver may be executed by other cores running
+  // with the MMU off so we need to ensure that everything is clean to the
+  // point of coherency (PoC)
+  //
+  WriteBackDataCacheRange (Image->ImageBase, Image->ImageSize);
+
+  Hob = GetFirstGuidHob (&gArmMpCoreInfoGuid);
+  if (Hob != NULL) {
+    HobData     = GET_GUID_HOB_DATA (Hob);
+    HobDataSize = GET_GUID_HOB_DATA_SIZE (Hob);
+    CoreInfo    = (ARM_CORE_INFO *)HobData;
+    MaxCpus     = HobDataSize / sizeof (ARM_CORE_INFO);
+  }
+
+  if (MaxCpus == 1) {
+    DEBUG ((DEBUG_WARN, "Trying to use EFI_MP_SERVICES_PROTOCOL on a UP system"));
+    // We are not MP so nothing to do
+    return EFI_NOT_FOUND;
+  }
+
+  Status = MpServicesInitialize (MaxCpus, CoreInfo);
+  if (Status != EFI_SUCCESS) {
+    ASSERT_EFI_ERROR (Status);
+    return Status;
+  }
+
+  //
+  // Now install the MP services protocol.
+  //
+  Handle = NULL;
+  Status = gBS->InstallMultipleProtocolInterfaces (
+                  &Handle,
+                  &gEfiMpServiceProtocolGuid,
+                  &mMpServicesProtocol,
+                  NULL
+                  );
+  ASSERT_EFI_ERROR (Status);
+
+  return Status;
+}
+
+/** AP exception handler.
+
+  @param InterruptType The AArch64 CPU exception type.
+  @param SystemContext System context.
+
+**/
+STATIC
+VOID
+EFIAPI
+ApExceptionHandler (
+  IN CONST EFI_EXCEPTION_TYPE  InterruptType,
+  IN CONST EFI_SYSTEM_CONTEXT  SystemContext
+  )
+{
+  ARM_SMC_ARGS  Args;
+  UINT64        Mpidr;
+  UINTN         Index;
+  UINTN         ProcessorIndex;
+
+  Mpidr = GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ());
+
+  Index          = 0;
+  ProcessorIndex = MAX_UINT64;
+
+  do {
+    if (gProcessorIDs[Index] == Mpidr) {
+      ProcessorIndex = Index;
+      break;
+    }
+
+    Index++;
+  } while (gProcessorIDs[Index] != MAX_UINT64);
+
+  if (ProcessorIndex != MAX_UINT64) {
+    mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
+    ArmDataMemoryBarrier ();
+  }
+
+  Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
+  ArmCallSmc (&Args);
+
+  /* Should never be reached */
+  ASSERT (FALSE);
+  CpuDeadLoop ();
+}
+
+/** C entry-point for the AP.
+    This function gets called from the assembly function ApEntryPoint.
+
+**/
+VOID
+ApProcedure (
+  VOID
+  )
+{
+  ARM_SMC_ARGS      Args;
+  EFI_AP_PROCEDURE  UserApProcedure;
+  VOID              *UserApParameter;
+  UINTN             ProcessorIndex;
+
+  ProcessorIndex = 0;
+
+  WhoAmI (&mMpServicesProtocol, &ProcessorIndex);
+
+  /* Fetch the user-supplied procedure and parameter to execute */
+  UserApProcedure = mCpuMpData.CpuData[ProcessorIndex].Procedure;
+  UserApParameter = mCpuMpData.CpuData[ProcessorIndex].Parameter;
+
+  // Configure the MMU and caches
+  ArmSetTCR (mCpuMpData.CpuData[ProcessorIndex].Tcr);
+  ArmSetTTBR0 (mCpuMpData.CpuData[ProcessorIndex].Ttbr0);
+  ArmSetMAIR (mCpuMpData.CpuData[ProcessorIndex].Mair);
+  ArmDisableAlignmentCheck ();
+  ArmEnableStackAlignmentCheck ();
+  ArmEnableInstructionCache ();
+  ArmEnableDataCache ();
+  ArmEnableMmu ();
+
+  InitializeCpuExceptionHandlers (NULL);
+  RegisterCpuInterruptHandler (EXCEPT_AARCH64_SYNCHRONOUS_EXCEPTIONS, ApExceptionHandler);
+  RegisterCpuInterruptHandler (EXCEPT_AARCH64_IRQ, ApExceptionHandler);
+  RegisterCpuInterruptHandler (EXCEPT_AARCH64_FIQ, ApExceptionHandler);
+  RegisterCpuInterruptHandler (EXCEPT_AARCH64_SERROR, ApExceptionHandler);
+
+  UserApProcedure (UserApParameter);
+
+  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
+
+  ArmDataMemoryBarrier ();
+
+  /* Since we're finished with this AP, turn it off */
+  Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
+  ArmCallSmc (&Args);
+
+  /* Should never be reached */
+  ASSERT (FALSE);
+  CpuDeadLoop ();
+}
+
+/** Returns whether the processor executing this function is the BSP.
+
+    @return Whether the current processor is the BSP.
+**/
+STATIC
+BOOLEAN
+IsCurrentProcessorBSP (
+  VOID
+  )
+{
+  EFI_STATUS  Status;
+  UINTN       ProcessorIndex;
+
+  Status = WhoAmI (&mMpServicesProtocol, &ProcessorIndex);
+  if (EFI_ERROR (Status)) {
+    ASSERT_EFI_ERROR (Status);
+    return FALSE;
+  }
+
+  return IsProcessorBSP (ProcessorIndex);
+}
+
+/** Returns whether the specified processor is enabled.
+
+   @param[in] ProcessorIndex The index of the processor to check.
+
+   @return TRUE if the processor is enabled, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorEnabled (
+  UINTN  ProcessorIndex
+  )
+{
+  EFI_PROCESSOR_INFORMATION  *CpuInfo;
+
+  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
+
+  return (CpuInfo->StatusFlag & PROCESSOR_ENABLED_BIT) != 0;
+}
+
+/** Sets up the state for the StartupAllAPs function.
+
+   @param SingleThread Whether the APs will execute sequentially.
+
+**/
+STATIC
+VOID
+StartupAllAPsPrepareState (
+  IN BOOLEAN  SingleThread
+  )
+{
+  UINTN        Index;
+  CPU_STATE    APInitialState;
+  CPU_AP_DATA  *CpuData;
+
+  mCpuMpData.FinishCount  = 0;
+  mCpuMpData.StartCount   = 0;
+  mCpuMpData.SingleThread = SingleThread;
+
+  APInitialState = CpuStateReady;
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
+
+    //
+    // Get APs prepared, and put failing APs into FailedCpuList.
+    // If "SingleThread", only 1 AP will put into ready state, other AP will be
+    // put into ready state 1 by 1, until the previous 1 finished its task.
+    // If not "SingleThread", all APs are put into ready state from the
+    // beginning
+    //
+
+    if (IsProcessorBSP (Index)) {
+      // Skip BSP
+      continue;
+    }
+
+    if (!IsProcessorEnabled (Index)) {
+      // Skip Disabled processors
+      if (mCpuMpData.FailedList != NULL) {
+        mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = Index;
+      }
+
+      continue;
+    }
+
+    CpuData->State = APInitialState;
+
+    mCpuMpData.StartCount++;
+    if (SingleThread) {
+      APInitialState = CpuStateBlocked;
+    }
+  }
+}
+
+/** Handles execution of StartupAllAPs when a WaitEvent has been specified.
+
+  @param Procedure         The user-supplied procedure.
+  @param ProcedureArgument The user-supplied procedure argument.
+  @param WaitEvent         The wait event to be signaled when the work is
+                           complete or a timeout has occurred.
+  @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+                               indicates an infinite timeout.
+  @param SingleThread          Whether the APs will execute sequentially.
+  @param FailedCpuList         User-supplied pointer for list of failed CPUs.
+
+   @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsWithWaitEvent (
+  IN EFI_AP_PROCEDURE  Procedure,
+  IN VOID              *ProcedureArgument,
+  IN EFI_EVENT         WaitEvent,
+  IN UINTN             TimeoutInMicroseconds,
+  IN BOOLEAN           SingleThread,
+  IN UINTN             **FailedCpuList
+  )
+{
+  EFI_STATUS   Status;
+  UINTN        Index;
+  CPU_AP_DATA  *CpuData;
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
+    if (IsProcessorBSP (Index)) {
+      // Skip BSP
+      continue;
+    }
+
+    if (!IsProcessorEnabled (Index)) {
+      // Skip Disabled processors
+      continue;
+    }
+
+    if (GetApState (CpuData) == CpuStateReady) {
+      SetApProcedure (CpuData, Procedure, ProcedureArgument);
+      if ((mCpuMpData.StartCount == 0) || !SingleThread) {
+        Status = DispatchCpu (Index);
+        if (EFI_ERROR (Status)) {
+          AddProcessorToFailedList (Index, CpuData->State);
+          break;
+        }
+      }
+    }
+  }
+
+  if (EFI_ERROR (Status)) {
+    return EFI_NOT_READY;
+  }
+
+  //
+  // Save data into private data structure, and create timer to poll AP state
+  // before exiting
+  //
+  mCpuMpData.Procedure         = Procedure;
+  mCpuMpData.ProcedureArgument = ProcedureArgument;
+  mCpuMpData.WaitEvent         = WaitEvent;
+  mCpuMpData.Timeout           = TimeoutInMicroseconds;
+  mCpuMpData.TimeTaken         = 0;
+  mCpuMpData.TimeoutActive     = (BOOLEAN)(TimeoutInMicroseconds != 0);
+  Status                       = gBS->SetTimer (
+                                        mCpuMpData.CheckAllAPsEvent,
+                                        TimerPeriodic,
+                                        POLL_INTERVAL_US
+                                        );
+
+  return Status;
+}
+
+/** Handles execution of StartupAllAPs when no wait event has been specified.
+
+  @param Procedure             The user-supplied procedure.
+  @param ProcedureArgument     The user-supplied procedure argument.
+  @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+                                indicates an infinite timeout.
+  @param SingleThread          Whether the APs will execute sequentially.
+  @param FailedCpuList         User-supplied pointer for list of failed CPUs.
+
+  @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsNoWaitEvent (
+  IN EFI_AP_PROCEDURE  Procedure,
+  IN VOID              *ProcedureArgument,
+  IN UINTN             TimeoutInMicroseconds,
+  IN BOOLEAN           SingleThread,
+  IN UINTN             **FailedCpuList
+  )
+{
+  EFI_STATUS   Status;
+  UINTN        Index;
+  UINTN        NextIndex;
+  UINTN        Timeout;
+  CPU_AP_DATA  *CpuData;
+  BOOLEAN      DispatchError;
+
+  Timeout       = TimeoutInMicroseconds;
+  DispatchError = FALSE;
+
+  while (TRUE) {
+    for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+      CpuData = &mCpuMpData.CpuData[Index];
+      if (IsProcessorBSP (Index)) {
+        // Skip BSP
+        continue;
+      }
+
+      if (!IsProcessorEnabled (Index)) {
+        // Skip Disabled processors
+        continue;
+      }
+
+      switch (GetApState (CpuData)) {
+        case CpuStateReady:
+          SetApProcedure (CpuData, Procedure, ProcedureArgument);
+          Status = DispatchCpu (Index);
+          if (EFI_ERROR (Status)) {
+            AddProcessorToFailedList (Index, CpuData->State);
+            CpuData->State = CpuStateIdle;
+            mCpuMpData.StartCount--;
+            DispatchError = TRUE;
+
+            if (SingleThread) {
+              // Dispatch the next available AP
+              Status = GetNextBlockedNumber (&NextIndex);
+              if (!EFI_ERROR (Status)) {
+                mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
+              }
+            }
+          }
+
+          break;
+
+        case CpuStateFinished:
+          mCpuMpData.FinishCount++;
+          if (SingleThread) {
+            Status = GetNextBlockedNumber (&NextIndex);
+            if (!EFI_ERROR (Status)) {
+              mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
+            }
+          }
+
+          CpuData->State = CpuStateIdle;
+          break;
+
+        default:
+          break;
+      }
+    }
+
+    if (mCpuMpData.FinishCount == mCpuMpData.StartCount) {
+      Status = EFI_SUCCESS;
+      break;
+    }
+
+    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
+      Status = EFI_TIMEOUT;
+      break;
+    }
+
+    Timeout -= CalculateAndStallInterval (Timeout);
+  }
+
+  if (Status == EFI_TIMEOUT) {
+    // Add any remaining CPUs to the FailedCpuList
+    if (FailedCpuList != NULL) {
+      for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+        AddProcessorToFailedList (Index, mCpuMpData.CpuData[Index].State);
+      }
+    }
+  }
+
+  if (DispatchError) {
+    Status = EFI_NOT_READY;
+  }
+
+  return Status;
+}
diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S
new file mode 100644
index 000000000000..a90fa8a0075f
--- /dev/null
+++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S
@@ -0,0 +1,57 @@
+#===============================================================================
+#  Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#===============================================================================
+
+.text
+.align 3
+
+#include <AsmMacroIoLibV8.h>
+#include <IndustryStandard/ArmStdSmc.h>
+
+#include "MpServicesInternal.h"
+
+GCC_ASM_IMPORT (gApStacksBase)
+GCC_ASM_IMPORT (gProcessorIDs)
+GCC_ASM_IMPORT (ApProcedure)
+GCC_ASM_IMPORT (gApStackSize)
+
+GCC_ASM_EXPORT (ApEntryPoint)
+
+// Entry-point for the AP
+// VOID
+// ApEntryPoint (
+//   VOID
+//   );
+ASM_PFX(ApEntryPoint):
+  mrs x0, mpidr_el1
+  // Mask the non-affinity bits
+  bic x0, x0, 0x00ff000000
+  and x0, x0, 0xffffffffff
+  ldr x1, gProcessorIDs
+  mov x2, 0                   // x2 = processor index
+
+// Find index in gProcessorIDs for current processor
+1:
+  ldr x3, [x1, x2, lsl #3]    // x4 = gProcessorIDs + x2 * 8
+  cmp x3, #-1                 // check if we've reached the end of gProcessorIDs
+  beq ProcessorNotFound
+  add x2, x2, 1               // x2++
+  cmp x0, x3                  // if mpidr_el1 != gProcessorIDs[x] then loop
+  bne 1b
+
+// Calculate stack address
+  // x2 contains the index for the current processor plus 1
+  ldr x0, gApStacksBase
+  ldr x1, gApStackSize
+  mul x3, x2, x1              // x3 = (ProcessorIndex + 1) * gApStackSize
+  add sp, x0, x3              // sp = gApStacksBase + x3
+  mov x29, xzr
+  bl ApProcedure              // doesn't return
+
+ProcessorNotFound:
+// Turn off the processor
+  MOV32 (w0, ARM_SMC_ID_PSCI_CPU_OFF)
+  smc #0
+  b .
-- 
2.30.2

Re: [edk2-devel] [PATCH v4 2/3] ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls

[Kun Qin]

Hi Rebecca,

I have tried to use this for a few different scenarios and below is a 
few minor issues I have found and potential
changes (marked with [KQ]). Please let me know if I have any 
misunderstanding on the protocol itself.

Thanks,
Kun

On 1/4/2023 7:37 AM, Rebecca Cran wrote:
> Add support for EFI_MP_SERVICES_PROTOCOL during the DXE phase under
> AArch64.
>
> PSCI_CPU_ON is called to power on the core, the supplied procedure is
> executed and PSCI_CPU_OFF is called to power off the core.
>
> Fixes contributed by Ard Biesheuvel.
>
> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
> ---
>   ArmPkg/ArmPkg.dsc                                            |    1 +
>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf |   56 +
>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h     |  344 ++++
>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c   | 1847 ++++++++++++++++++++
>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S                |   57 +
>   5 files changed, 2305 insertions(+)
>
> diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
> index ac24ebce4892..1e873b90c56d 100644
> --- a/ArmPkg/ArmPkg.dsc
> +++ b/ArmPkg/ArmPkg.dsc
> @@ -164,6 +164,7 @@ [Components.common]
>     ArmPkg/Universal/Smbios/OemMiscLibNull/OemMiscLibNull.inf
>   
>   [Components.AARCH64]
> +  ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
>     ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
>     ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf
>   
> diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
> new file mode 100644
> index 000000000000..2c9ab99038f2
> --- /dev/null
> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
> @@ -0,0 +1,56 @@
> +## @file
> +#  ARM MP services protocol driver
> +#
> +#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 1.27
> +  BASE_NAME                      = ArmPsciMpServicesDxe
> +  FILE_GUID                      = 007ab472-dc4a-4df8-a5c2-abb4a327278c
> +  MODULE_TYPE                    = DXE_DRIVER
> +  VERSION_STRING                 = 1.0
> +
> +  ENTRY_POINT                    = ArmPsciMpServicesDxeInitialize
> +
> +[Sources.Common]
> +  ArmPsciMpServicesDxe.c
> +  MpFuncs.S
> +  MpServicesInternal.h
> +
> +[Packages]
> +  ArmPkg/ArmPkg.dec
> +  ArmPlatformPkg/ArmPlatformPkg.dec
> +  EmbeddedPkg/EmbeddedPkg.dec
> +  MdePkg/MdePkg.dec
> +  MdeModulePkg/MdeModulePkg.dec
> +
> +[LibraryClasses]
> +  ArmLib
> +  ArmMmuLib
> +  ArmSmcLib
> +  BaseMemoryLib
> +  CacheMaintenanceLib
> +  CpuExceptionHandlerLib
> +  DebugLib
> +  HobLib
> +  MemoryAllocationLib
> +  UefiBootServicesTableLib
> +  UefiDriverEntryPoint
> +  UefiLib
> +
> +[Protocols]
> +  gEfiMpServiceProtocolGuid            ## PRODUCES
> +  gEfiLoadedImageProtocolGuid          ## CONSUMES
> +
> +[Guids]
> +  gArmMpCoreInfoGuid
> +
> +[Depex]
> +  TRUE
> +
> +[BuildOptions]
> +  GCC:*_*_*_CC_FLAGS = -mstrict-align
> diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h
> new file mode 100644
> index 000000000000..5ba63700dd18
> --- /dev/null
> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h
> @@ -0,0 +1,344 @@
> +/** @file
> +
> +Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
> +Portions copyright (c) 2011, Apple Inc. All rights reserved.
> +
> +SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#ifndef MP_SERVICES_INTERNAL_H_
> +#define MP_SERVICES_INTERNAL_H_
> +
> +#include <Protocol/Cpu.h>
> +#include <Protocol/MpService.h>
> +
> +#include <Library/BaseLib.h>
> +#include <Library/UefiLib.h>
> +
> +#define AP_STACK_SIZE  0x1000
> +
> +//
> +// Internal Data Structures
> +//
> +
> +//
> +// AP state
> +//
> +// The state transitions for an AP when it processes a procedure are:
> +//  Idle ----> Ready ----> Busy ----> Finished ----> Idle
> +//       [BSP]       [BSP]      [AP]           [BSP]
> +//
> +typedef enum {
> +  CpuStateIdle,
> +  CpuStateReady,
> +  CpuStateBlocked,
> +  CpuStateBusy,
> +  CpuStateFinished,
> +  CpuStateDisabled
> +} CPU_STATE;
> +
> +//
> +// Define Individual Processor Data block.
> +//
> +typedef struct {
> +  EFI_PROCESSOR_INFORMATION    Info;
> +  EFI_AP_PROCEDURE             Procedure;
> +  VOID                         *Parameter;
> +  CPU_STATE                    State;
> +  EFI_EVENT                    CheckThisAPEvent;
> +  VOID                         *Ttbr0;
> +  UINTN                        Tcr;
> +  UINTN                        Mair;
> +} CPU_AP_DATA;
> +
> +//
> +// Define MP data block which consumes individual processor block.
> +//
> +typedef struct {
> +  UINTN               NumberOfProcessors;
> +  UINTN               NumberOfEnabledProcessors;
> +  EFI_EVENT           CheckAllAPsEvent;
> +  EFI_EVENT           WaitEvent;
> +  UINTN               FinishCount;
> +  UINTN               StartCount;
> +  EFI_AP_PROCEDURE    Procedure;
> +  VOID                *ProcedureArgument;
> +  BOOLEAN             SingleThread;
> +  UINTN               StartedNumber;
> +  CPU_AP_DATA         *CpuData;
> +  UINTN               Timeout;
> +  UINTN               TimeTaken;
> +  UINTN               *FailedList;
> +  UINTN               FailedListIndex;
> +  BOOLEAN             TimeoutActive;
> +  BOOLEAN             *SingleApFinished;
> +} CPU_MP_DATA;
> +
> +/** Secondary core entry point.
> +
> +**/
> +VOID
> +ApEntryPoint (
> +  VOID
> +  );
> +
> +/** C entry-point for the AP.
> +    This function gets called from the assembly function ApEntryPoint.
> +**/
> +VOID
> +ApProcedure (
> +  VOID
> +  );
> +
> +/** Turns on the specified core using PSCI and executes the user-supplied
> +    function that's been configured via a previous call to SetApProcedure.
> +
> +   @param ProcessorIndex The index of the core to turn on.
> +
> +   @retval EFI_SUCCESS       The processor was successfully turned on.
> +   @retval EFI_DEVICE_ERROR  An error occurred turning the processor on.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +DispatchCpu (
> +  IN UINTN  ProcessorIndex
> +  );
> +
> +/** Returns whether the specified processor is the BSP.
> +
> +   @param[in] ProcessorIndex The index the processor to check.
> +
> +   @return TRUE if the processor is the BSP, FALSE otherwise.
> +**/
> +STATIC
> +BOOLEAN
> +IsProcessorBSP (
> +  UINTN  ProcessorIndex
> +  );
> +
> +/** Returns whether the processor executing this function is the BSP.
> +
> +   @return Whether the current processor is the BSP.
> +**/
> +STATIC
> +BOOLEAN
> +IsCurrentProcessorBSP (
> +  VOID
> +  );
> +
> +/** Returns whether the specified processor is enabled.
> +
> +   @param[in] ProcessorIndex The index of the processor to check.
> +
> +   @return TRUE if the processor is enabled, FALSE otherwise.
> +**/
> +STATIC
> +BOOLEAN
> +IsProcessorEnabled (
> +  UINTN  ProcessorIndex
> +  );
> +
> +/** Configures the processor context with the user-supplied procedure and
> +    argument.
> +
> +   @param CpuData           The processor context.
> +   @param Procedure         The user-supplied procedure.
> +   @param ProcedureArgument The user-supplied procedure argument.
> +
> +**/
> +STATIC
> +VOID
> +SetApProcedure (
> +  IN   CPU_AP_DATA       *CpuData,
> +  IN   EFI_AP_PROCEDURE  Procedure,
> +  IN   VOID              *ProcedureArgument
> +  );
> +
> +/**
> +  Get the Application Processors state.
> +
> +  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP
> +
> +  @return  The AP status
> +**/
> +CPU_STATE
> +GetApState (
> +  IN  CPU_AP_DATA  *CpuData
> +  );
> +
> +/** Returns the index of the next processor that is blocked.
> +
> +   @param[out] NextNumber The index of the next blocked processor.
> +
> +   @retval EFI_SUCCESS   Successfully found the next blocked processor.
> +   @retval EFI_NOT_FOUND There are no blocked processors.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +GetNextBlockedNumber (
> +  OUT UINTN  *NextNumber
> +  );
> +
> +/** Stalls the BSP for the minimum of gPollInterval and Timeout.
> +
> +   @param[in]  Timeout    The time limit in microseconds remaining for
> +                          APs to return from Procedure.
> +
> +   @retval     StallTime  Time of execution stall.
> +**/
> +STATIC
> +UINTN
> +CalculateAndStallInterval (
> +  IN UINTN  Timeout
> +  );
> +
> +/** Sets up the state for the StartupAllAPs function.
> +
> +   @param SingleThread Whether the APs will execute sequentially.
> +
> +**/
> +STATIC
> +VOID
> +StartupAllAPsPrepareState (
> +  IN BOOLEAN  SingleThread
> +  );
> +
> +/** Handles execution of StartupAllAPs when a WaitEvent has been specified.
> +
> +  @param Procedure         The user-supplied procedure.
> +  @param ProcedureArgument The user-supplied procedure argument.
> +  @param WaitEvent         The wait event to be signaled when the work is
> +                           complete or a timeout has occurred.
> +  @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
> +                               indicates an infinite timeout.
> +  @param SingleThread          Whether the APs will execute sequentially.
> +  @param FailedCpuList         User-supplied pointer for list of failed CPUs.
> +
> +   @return EFI_SUCCESS on success.
> +**/
> +STATIC
> +EFI_STATUS
> +StartupAllAPsWithWaitEvent (
> +  IN EFI_AP_PROCEDURE  Procedure,
> +  IN VOID              *ProcedureArgument,
> +  IN EFI_EVENT         WaitEvent,
> +  IN UINTN             TimeoutInMicroseconds,
> +  IN BOOLEAN           SingleThread,
> +  IN UINTN             **FailedCpuList
> +  );
> +
> +/** Handles execution of StartupAllAPs when no wait event has been specified.
> +
> +   @param Procedure             The user-supplied procedure.
> +   @param ProcedureArgument     The user-supplied procedure argument.
> +   @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
> +                                indicates an infinite timeout.
> +   @param SingleThread          Whether the APs will execute sequentially.
> +   @param FailedCpuList         User-supplied pointer for list of failed CPUs.
> +
> +   @return EFI_SUCCESS on success.
> +**/
> +STATIC
> +EFI_STATUS
> +StartupAllAPsNoWaitEvent (
> +  IN EFI_AP_PROCEDURE  Procedure,
> +  IN VOID              *ProcedureArgument,
> +  IN UINTN             TimeoutInMicroseconds,
> +  IN BOOLEAN           SingleThread,
> +  IN UINTN             **FailedCpuList
> +  );
> +
> +/** Adds the specified processor the list of failed processors.
> +
> +   @param ProcessorIndex The processor index to add.
> +   @param ApState         Processor state.
> +
> +**/
> +STATIC
> +VOID
> +AddProcessorToFailedList (
> +  UINTN      ProcessorIndex,
> +  CPU_STATE  ApState
> +  );
> +
> +/** Handles the StartupAllAPs case where the timeout has occurred.
> +
> +**/
> +STATIC
> +VOID
> +ProcessStartupAllAPsTimeout (
> +  VOID
> +  );
> +
> +/**
> +  If a timeout is specified in StartupAllAps(), a timer is set, which invokes
> +  this procedure periodically to check whether all APs have finished.
> +
> +  @param[in] Event   The WaitEvent the user supplied.
> +  @param[in] Context The event context.
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +CheckAllAPsStatus (
> +  IN  EFI_EVENT  Event,
> +  IN  VOID       *Context
> +  );
> +
> +/** Invoked periodically via a timer to check the state of the processor.
> +
> +   @param Event   The event supplied by the timer expiration.
> +   @param Context The processor context.
> +
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +CheckThisAPStatus (
> +  IN  EFI_EVENT  Event,
> +  IN  VOID       *Context
> +  );
> +
> +/**
> +  This function is called by all processors (both BSP and AP) once and collects
> +  MP related data.
> +
> +  @param BSP            TRUE if the processor is the BSP.
> +  @param Mpidr          The MPIDR for the specified processor. This should be
> +                        the full MPIDR and not only the affinity bits.
> +  @param ProcessorIndex The index of the processor.
> +
> +  @return EFI_SUCCESS if the data for the processor collected and filled in.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +FillInProcessorInformation (
> +  IN BOOLEAN  BSP,
> +  IN UINTN    Mpidr,
> +  IN UINTN    ProcessorIndex
> +  );
> +
> +/**
> +  Event notification function called when the EFI_EVENT_GROUP_READY_TO_BOOT is
> +  signaled. After this point, non-blocking mode is no longer allowed.
> +
> +  @param  Event     Event whose notification function is being invoked.
> +  @param  Context   The pointer to the notification function's context,
> +                    which is implementation-dependent.
> +
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +ReadyToBootSignaled (
> +  IN  EFI_EVENT  Event,
> +  IN  VOID       *Context
> +  );
> +
> +#endif /* MP_SERVICES_INTERNAL_H_ */
> diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
> new file mode 100644
> index 000000000000..ab439bffd722
> --- /dev/null
> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
> @@ -0,0 +1,1847 @@
> +/** @file
> +  Construct MP Services Protocol.
> +
> +  The MP Services Protocol provides a generalized way of performing following tasks:
> +    - Retrieving information of multi-processor environment and MP-related status of
> +      specific processors.
> +    - Dispatching user-provided function to APs.
> +    - Maintain MP-related processor status.
> +
> +  The MP Services Protocol must be produced on any system with more than one logical
> +  processor.
> +
> +  The Protocol is available only during boot time.
> +
> +  MP Services Protocol is hardware-independent. Most of the logic of this protocol
> +  is architecturally neutral. It abstracts the multi-processor environment and
> +  status of processors, and provides interfaces to retrieve information, maintain,
> +  and dispatch.
> +
> +  MP Services Protocol may be consumed by ACPI module. The ACPI module may use this
> +  protocol to retrieve data that are needed for an MP platform and report them to OS.
> +  MP Services Protocol may also be used to program and configure processors, such
> +  as MTRR synchronization for memory space attributes setting in DXE Services.
> +  MP Services Protocol may be used by non-CPU DXE drivers to speed up platform boot
> +  by taking advantage of the processing capabilities of the APs, for example, using
> +  APs to help test system memory in parallel with other device initialization.
> +  Diagnostics applications may also use this protocol for multi-processor.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <PiDxe.h>
> +
> +#include <Library/ArmLib.h>
> +#include <Library/ArmMmuLib.h>
> +#include <Library/ArmPlatformLib.h>
> +#include <Library/ArmSmcLib.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Library/CacheMaintenanceLib.h>
> +#include <Library/CpuExceptionHandlerLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/HobLib.h>
> +#include <Library/MemoryAllocationLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Library/UefiLib.h>
> +#include <IndustryStandard/ArmStdSmc.h>
> +#include <Ppi/ArmMpCoreInfo.h>
> +#include <Protocol/LoadedImage.h>
> +
> +#include "MpServicesInternal.h"
> +
> +#define POLL_INTERVAL_US  50000
> +
> +STATIC CPU_MP_DATA  mCpuMpData;
> +STATIC BOOLEAN      mNonBlockingModeAllowed;
> +UINT64              *gApStacksBase;
> +UINT64              *gProcessorIDs;
> +CONST UINT64        gApStackSize = AP_STACK_SIZE;
> +
> +STATIC
> +BOOLEAN
> +IsCurrentProcessorBSP (
> +  VOID
> +  );
> +
> +/** Turns on the specified core using PSCI and executes the user-supplied
> +    function that's been configured via a previous call to SetApProcedure.
> +
> +    @param ProcessorIndex The index of the core to turn on.
> +
> +    @retval EFI_SUCCESS      Success.
> +    @retval EFI_DEVICE_ERROR The processor could not be turned on.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +DispatchCpu (
> +  IN UINTN  ProcessorIndex
> +  )
> +{
> +  ARM_SMC_ARGS  Args;
> +  EFI_STATUS    Status;
> +
> +  Status = EFI_SUCCESS;
> +
> +  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateBusy;
> +
> +  /* Turn the AP on */
> +  if (sizeof (Args.Arg0) == sizeof (UINT32)) {
> +    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH32;
> +  } else {
> +    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH64;
> +  }
> +
> +  Args.Arg1 = gProcessorIDs[ProcessorIndex];
> +  Args.Arg2 = (UINTN)ApEntryPoint;
> +
> +  mCpuMpData.CpuData[ProcessorIndex].Tcr   = ArmGetTCR ();
> +  mCpuMpData.CpuData[ProcessorIndex].Mair  = ArmGetMAIR ();
> +  mCpuMpData.CpuData[ProcessorIndex].Ttbr0 = ArmGetTTBR0BaseAddress ();
> +  WriteBackDataCacheRange (&mCpuMpData.CpuData[ProcessorIndex], sizeof (CPU_AP_DATA));
> +
> +  ArmCallSmc (&Args);
> +
> +  if (Args.Arg0 != ARM_SMC_PSCI_RET_SUCCESS) {
> +    DEBUG ((DEBUG_ERROR, "PSCI_CPU_ON call failed: %d\n", Args.Arg0));
> +    Status = EFI_DEVICE_ERROR;
> +  }
> +
> +  return Status;
> +}
> +
> +/** Returns whether the specified processor is the BSP.
> +
> +  @param[in] ProcessorIndex The index the processor to check.
> +
> +  @return TRUE if the processor is the BSP, FALSE otherwise.
> +**/
> +STATIC
> +BOOLEAN
> +IsProcessorBSP (
> +  UINTN  ProcessorIndex
> +  )
> +{
> +  EFI_PROCESSOR_INFORMATION  *CpuInfo;
> +
> +  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
> +
> +  return (CpuInfo->StatusFlag & PROCESSOR_AS_BSP_BIT) != 0;
> +}
> +
> +/** Get the Application Processors state.
> +
> +  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP.
> +
> +  @return The AP status.
> +**/
> +CPU_STATE
> +GetApState (
> +  IN  CPU_AP_DATA  *CpuData
> +  )
> +{
> +  return CpuData->State;
> +}
> +
> +/** Configures the processor context with the user-supplied procedure and
> +    argument.
> +
> +   @param CpuData           The processor context.
> +   @param Procedure         The user-supplied procedure.
> +   @param ProcedureArgument The user-supplied procedure argument.
> +
> +**/
> +STATIC
> +VOID
> +SetApProcedure (
> +  IN   CPU_AP_DATA       *CpuData,
> +  IN   EFI_AP_PROCEDURE  Procedure,
> +  IN   VOID              *ProcedureArgument
> +  )
> +{
> +  ASSERT (CpuData != NULL);
> +  ASSERT (Procedure != NULL);
> +
> +  CpuData->Parameter = ProcedureArgument;
> +  CpuData->Procedure = Procedure;
> +}
> +
> +/** Returns the index of the next processor that is blocked.
> +
> +   @param[out] NextNumber The index of the next blocked processor.
> +
> +   @retval EFI_SUCCESS   Successfully found the next blocked processor.
> +   @retval EFI_NOT_FOUND There are no blocked processors.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +GetNextBlockedNumber (
> +  OUT UINTN  *NextNumber
> +  )
> +{
> +  UINTN        Index;
> +  CPU_STATE    State;
> +  CPU_AP_DATA  *CpuData;
> +
> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
> +    CpuData = &mCpuMpData.CpuData[Index];
> +    if (IsProcessorBSP (Index)) {
> +      // Skip BSP
> +      continue;
> +    }
> +
> +    State = CpuData->State;
> +
> +    if (State == CpuStateBlocked) {
> +      *NextNumber = Index;
> +      return EFI_SUCCESS;
> +    }
> +  }
> +
> +  return EFI_NOT_FOUND;
> +}
> +
> +/** Stalls the BSP for the minimum of POLL_INTERVAL_US and Timeout.
> +
> +   @param[in]  Timeout    The time limit in microseconds remaining for
> +                          APs to return from Procedure.
> +
> +   @retval     StallTime  Time of execution stall.
> +**/
> +STATIC
> +UINTN
> +CalculateAndStallInterval (
> +  IN UINTN  Timeout
> +  )
> +{
> +  UINTN  StallTime;
> +
> +  if ((Timeout < POLL_INTERVAL_US) && (Timeout != 0)) {
> +    StallTime = Timeout;
> +  } else {
> +    StallTime = POLL_INTERVAL_US;
> +  }
> +
> +  gBS->Stall (StallTime);
> +
> +  return StallTime;
> +}
> +
> +/**
> +  This service retrieves the number of logical processor in the platform
> +  and the number of those logical processors that are enabled on this boot.
> +  This service may only be called from the BSP.
> +
> +  This function is used to retrieve the following information:
> +    - The number of logical processors that are present in the system.
> +    - The number of enabled logical processors in the system at the instant
> +      this call is made.
> +
> +  Because MP Service Protocol provides services to enable and disable processors
> +  dynamically, the number of enabled logical processors may vary during the
> +  course of a boot session.
> +
> +  If this service is called from an AP, then EFI_DEVICE_ERROR is returned.
> +  If NumberOfProcessors or NumberOfEnabledProcessors is NULL, then
> +  EFI_INVALID_PARAMETER is returned. Otherwise, the total number of processors
> +  is returned in NumberOfProcessors, the number of currently enabled processor
> +  is returned in NumberOfEnabledProcessors, and EFI_SUCCESS is returned.
> +
> +  @param[in]  This                        A pointer to the
> +                                          EFI_MP_SERVICES_PROTOCOL instance.
> +  @param[out] NumberOfProcessors          Pointer to the total number of logical
> +                                          processors in the system, including
> +                                          the BSP and disabled APs.
> +  @param[out] NumberOfEnabledProcessors   Pointer to the number of enabled
> +                                          logical processors that exist in the
> +                                          system, including the BSP.
> +
> +  @retval EFI_SUCCESS             The number of logical processors and enabled
> +                                  logical processors was retrieved.
> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
> +  @retval EFI_INVALID_PARAMETER   NumberOfProcessors is NULL.
> +  @retval EFI_INVALID_PARAMETER   NumberOfEnabledProcessors is NULL.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +GetNumberOfProcessors (
> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
> +  OUT UINTN                     *NumberOfProcessors,
> +  OUT UINTN                     *NumberOfEnabledProcessors
> +  )
> +{
> +  if ((NumberOfProcessors == NULL) || (NumberOfEnabledProcessors == NULL)) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  if (!IsCurrentProcessorBSP ()) {
> +    return EFI_DEVICE_ERROR;
> +  }
> +
> +  *NumberOfProcessors        = mCpuMpData.NumberOfProcessors;
> +  *NumberOfEnabledProcessors = mCpuMpData.NumberOfEnabledProcessors;
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  Gets detailed MP-related information on the requested processor at the
> +  instant this call is made. This service may only be called from the BSP.
> +
> +  This service retrieves detailed MP-related information about any processor
> +  on the platform. Note the following:
> +    - The processor information may change during the course of a boot session.
> +    - The information presented here is entirely MP related.
> +
> +  Information regarding the number of caches and their sizes, frequency of
> +  operation, slot numbers is all considered platform-related information and is
> +  not provided by this service.
> +
> +  @param[in]  This                  A pointer to the EFI_MP_SERVICES_PROTOCOL
> +                                    instance.
> +  @param[in]  ProcessorIndex        The index of the processor.
> +  @param[out] ProcessorInfoBuffer   A pointer to the buffer where information
> +                                    for the requested processor is deposited.
> +
> +  @retval EFI_SUCCESS             Processor information was returned.
> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
> +  @retval EFI_INVALID_PARAMETER   ProcessorInfoBuffer is NULL.
> +  @retval EFI_NOT_FOUND           The processor with the handle specified by
> +                                  ProcessorNumber does not exist in the platform.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +GetProcessorInfo (
> +  IN  EFI_MP_SERVICES_PROTOCOL   *This,
> +  IN  UINTN                      ProcessorIndex,
> +  OUT EFI_PROCESSOR_INFORMATION  *ProcessorInfoBuffer
> +  )
> +{
> +  if (ProcessorInfoBuffer == NULL) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  if (!IsCurrentProcessorBSP ()) {
> +    return EFI_DEVICE_ERROR;
> +  }
> +
> +  ProcessorIndex &= ~CPU_V2_EXTENDED_TOPOLOGY;
> +
> +  if (ProcessorIndex >= mCpuMpData.NumberOfProcessors) {
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  CopyMem (
> +    ProcessorInfoBuffer,
> +    &mCpuMpData.CpuData[ProcessorIndex],
> +    sizeof (EFI_PROCESSOR_INFORMATION)
> +    );
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  This service executes a caller provided function on all enabled APs. APs can
> +  run either simultaneously or one at a time in sequence. This service supports
> +  both blocking and non-blocking requests. The non-blocking requests use EFI
> +  events so the BSP can detect when the APs have finished. This service may only
> +  be called from the BSP.
> +
> +  This function is used to dispatch all the enabled APs to the function
> +  specified by Procedure.  If any enabled AP is busy, then EFI_NOT_READY is
> +  returned immediately and Procedure is not started on any AP.
> +
> +  If SingleThread is TRUE, all the enabled APs execute the function specified by
> +  Procedure one by one, in ascending order of processor handle number.
> +  Otherwise, all the enabled APs execute the function specified by Procedure
> +  simultaneously.
> +
> +  If WaitEvent is NULL, execution is in blocking mode. The BSP waits until all
> +  APs finish or TimeoutInMicroseconds expires. Otherwise, execution is in
> +  non-blocking mode, and the BSP returns from this service without waiting for
> +  APs. If a non-blocking mode is requested after the UEFI Event
> +  EFI_EVENT_GROUP_READY_TO_BOOT is signaled, then EFI_UNSUPPORTED must be
> +  returned.
> +
> +  If the timeout specified by TimeoutInMicroseconds expires before all APs
> +  return from Procedure, then Procedure on the failed APs is terminated.
> +  All enabled APs are always available for further calls to
> +  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
> +  EFI_MP_SERVICES_PROTOCOL.StartupThisAP(). If FailedCpuList is not NULL, its
> +  content points to the list of processor handle numbers in which Procedure was
> +  terminated.
> +
> +  Note: It is the responsibility of the consumer of the
> +  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() to make sure that the nature of the
> +  code that is executed on the BSP and the dispatched APs is well controlled.
> +  The MP Services Protocol does not guarantee that the Procedure function is
> +  MP-safe. Hence, the tasks that can be run in parallel are limited to certain
> +  independent tasks and well-controlled exclusive code. EFI services and
> +  protocols may not be called by APs unless otherwise specified.
> +
> +  In blocking execution mode, BSP waits until all APs finish or
> +  TimeoutInMicroseconds expires.
> +
> +  In non-blocking execution mode, BSP is freed to return to the caller and then
> +  proceed to the next task without having to wait for APs. The following
> +  sequence needs to occur in a non-blocking execution mode:
> +
> +    -# The caller that intends to use this MP Services Protocol in non-blocking
> +       mode creates WaitEvent by calling the EFI CreateEvent() service.  The
> +       caller invokes EFI_MP_SERVICES_PROTOCOL.StartupAllAPs(). If the parameter
> +       WaitEvent is not NULL, then StartupAllAPs() executes in non-blocking
> +       mode. It requests the function specified by Procedure to be started on
> +       all the enabled APs, and releases the BSP to continue with other tasks.
> +    -# The caller can use the CheckEvent() and WaitForEvent() services to check
> +       the state of the WaitEvent created in step 1.
> +    -# When the APs complete their task or TimeoutInMicroSecondss expires, the
> +       MP Service signals WaitEvent by calling the EFI SignalEvent() function.
> +       If FailedCpuList is not NULL, its content is available when WaitEvent is
> +       signaled. If all APs returned from Procedure prior to the timeout, then
> +       FailedCpuList is set to NULL. If not all APs return from Procedure before
> +       the timeout, then FailedCpuList is filled in with the list of the failed
> +       APs. The buffer is allocated by MP Service Protocol using AllocatePool().
> +       It is the caller's responsibility to free the buffer with FreePool()
> +       service.
> +    -# This invocation of SignalEvent() function informs the caller that invoked
> +       EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() that either all the APs
> +       completed the specified task or a timeout occurred. The contents of
> +       FailedCpuList can be examined to determine which APs did not complete the
> +       specified task prior to the timeout.
> +
> +  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
> +                                      instance.
> +  @param[in]  Procedure               A pointer to the function to be run on
> +                                      enabled APs of the system. See type
> +                                      EFI_AP_PROCEDURE.
> +  @param[in]  SingleThread            If TRUE, then all the enabled APs execute
> +                                      the function specified by Procedure one by
> +                                      one, in ascending order of processor
> +                                      handle number.  If FALSE, then all the
> +                                      enabled APs execute the function specified
> +                                      by Procedure simultaneously.
> +  @param[in]  WaitEvent               The event created by the caller with
> +                                      CreateEvent() service.  If it is NULL,
> +                                      then execute in blocking mode. BSP waits
> +                                      until all APs finish or
> +                                      TimeoutInMicroseconds expires.  If it's
> +                                      not NULL, then execute in non-blocking
> +                                      mode. BSP requests the function specified
> +                                      by Procedure to be started on all the
> +                                      enabled APs, and go on executing
> +                                      immediately. If all return from Procedure,
> +                                      or TimeoutInMicroseconds expires, this
> +                                      event is signaled. The BSP can use the
> +                                      CheckEvent() or WaitForEvent()
> +                                      services to check the state of event. Type
> +                                      EFI_EVENT is defined in CreateEvent() in
> +                                      the Unified Extensible Firmware Interface
> +                                      Specification.
> +  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds
> +                                      for APs to return from Procedure, either
> +                                      for blocking or non-blocking mode. Zero
> +                                      means infinity.  If the timeout expires
> +                                      before all APs return from Procedure, then
> +                                      Procedure on the failed APs is terminated.
> +                                      All enabled APs are available for next
> +                                      function assigned by
> +                                      EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
> +                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
> +                                      If the timeout expires in blocking mode,
> +                                      BSP returns EFI_TIMEOUT.  If the timeout
> +                                      expires in non-blocking mode, WaitEvent
> +                                      is signaled with SignalEvent().
> +  @param[in]  ProcedureArgument       The parameter passed into Procedure for
> +                                      all APs.
> +  @param[out] FailedCpuList           If NULL, this parameter is ignored.
> +                                      Otherwise, if all APs finish successfully,
> +                                      then its content is set to NULL. If not
> +                                      all APs finish before timeout expires,
> +                                      then its content is set to address of the
> +                                      buffer holding handle numbers of the
> +                                      failed APs.
> +                                      The buffer is allocated by MP Service
> +                                      Protocol, and it's the caller's
> +                                      responsibility to free the buffer with
> +                                      FreePool() service.
> +                                      In blocking mode, it is ready for
> +                                      consumption when the call returns. In
> +                                      non-blocking mode, it is ready when
> +                                      WaitEvent is signaled. The list of failed
> +                                      CPU is terminated by  END_OF_CPU_LIST.
> +
> +  @retval EFI_SUCCESS             In blocking mode, all APs have finished before
> +                                  the timeout expired.
> +  @retval EFI_SUCCESS             In non-blocking mode, function has been
> +                                  dispatched to all enabled APs.
> +  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
> +                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
> +                                  signaled.
> +  @retval EFI_DEVICE_ERROR        Caller processor is AP.
> +  @retval EFI_NOT_STARTED         No enabled APs exist in the system.
> +  @retval EFI_NOT_READY           Any enabled APs are busy.
> +  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
> +                                  all enabled APs have finished.
> +  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +StartupAllAPs (
> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
> +  IN  EFI_AP_PROCEDURE          Procedure,
> +  IN  BOOLEAN                   SingleThread,
> +  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
> +  IN  UINTN                     TimeoutInMicroseconds,
> +  IN  VOID                      *ProcedureArgument      OPTIONAL,
> +  OUT UINTN                     **FailedCpuList         OPTIONAL
> +  )
> +{
> +  EFI_STATUS  Status;
> +
> +  if (!IsCurrentProcessorBSP ()) {
> +    return EFI_DEVICE_ERROR;
> +  }
> +
> +  if (mCpuMpData.NumberOfProcessors == 1) {
> +    return EFI_NOT_STARTED;
> +  }
> +
> +  if (Procedure == NULL) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
> +    return EFI_UNSUPPORTED;
> +  }
> +
> +  if (FailedCpuList != NULL) {
> +    mCpuMpData.FailedList = AllocateZeroPool (
> +                              (mCpuMpData.NumberOfProcessors + 1) *
> +                              sizeof (UINTN)
> +                              );
> +    if (mCpuMpData.FailedList == NULL) {
> +      return EFI_OUT_OF_RESOURCES;
> +    }
> +
> +    SetMemN (
> +      mCpuMpData.FailedList,
> +      (mCpuMpData.NumberOfProcessors + 1) *
> +      sizeof (UINTN),
> +      END_OF_CPU_LIST
> +      );
> +    mCpuMpData.FailedListIndex = 0;
> +    *FailedCpuList             = mCpuMpData.FailedList;
> +  }
> +
> +  StartupAllAPsPrepareState (SingleThread);
> +
> +  if (WaitEvent != NULL) {
> +    Status = StartupAllAPsWithWaitEvent (
> +               Procedure,
> +               ProcedureArgument,
> +               WaitEvent,
> +               TimeoutInMicroseconds,
> +               SingleThread,
> +               FailedCpuList
> +               );
> +
> +    if (EFI_ERROR (Status) && (FailedCpuList != NULL)) {
> +      if (mCpuMpData.FailedListIndex == 0) {
> +        FreePool (*FailedCpuList);
> +        *FailedCpuList = NULL;
> +      }
> +    }
> +  } else {
> +    Status = StartupAllAPsNoWaitEvent (
> +               Procedure,
> +               ProcedureArgument,
> +               TimeoutInMicroseconds,
> +               SingleThread,
> +               FailedCpuList
> +               );
> +
> +    if (FailedCpuList != NULL) {
> +      if (mCpuMpData.FailedListIndex == 0) {
> +        FreePool (*FailedCpuList);
> +        *FailedCpuList = NULL;
> +      }
> +    }
> +  }
> +
> +  return Status;
> +}
> +
> +/**
> +  This service lets the caller get one enabled AP to execute a caller-provided
> +  function. The caller can request the BSP to either wait for the completion
> +  of the AP or just proceed with the next task by using the EFI event mechanism.
> +  See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on non-blocking
> +  execution support.  This service may only be called from the BSP.
> +
> +  This function is used to dispatch one enabled AP to the function specified by
> +  Procedure passing in the argument specified by ProcedureArgument.  If WaitEvent
> +  is NULL, execution is in blocking mode. The BSP waits until the AP finishes or
> +  TimeoutInMicroSecondss expires. Otherwise, execution is in non-blocking mode.
> +  BSP proceeds to the next task without waiting for the AP. If a non-blocking mode
> +  is requested after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled,
> +  then EFI_UNSUPPORTED must be returned.
> +
> +  If the timeout specified by TimeoutInMicroseconds expires before the AP returns
> +  from Procedure, then execution of Procedure by the AP is terminated. The AP is
> +  available for subsequent calls to EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
> +  EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
> +
> +  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
> +                                      instance.
> +  @param[in]  Procedure               A pointer to the function to be run on
> +                                      enabled APs of the system. See type
> +                                      EFI_AP_PROCEDURE.
> +  @param[in]  ProcessorNumber         The handle number of the AP. The range is
> +                                      from 0 to the total number of logical
> +                                      processors minus 1. The total number of
> +                                      logical processors can be retrieved by
> +                                      EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
> +  @param[in]  WaitEvent               The event created by the caller with CreateEvent()
> +                                      service.  If it is NULL, then execute in
> +                                      blocking mode. BSP waits until all APs finish
> +                                      or TimeoutInMicroseconds expires.  If it's
> +                                      not NULL, then execute in non-blocking mode.
> +                                      BSP requests the function specified by
> +                                      Procedure to be started on all the enabled
> +                                      APs, and go on executing immediately. If
> +                                      all return from Procedure or TimeoutInMicroseconds
> +                                      expires, this event is signaled. The BSP
> +                                      can use the CheckEvent() or WaitForEvent()
> +                                      services to check the state of event.  Type
> +                                      EFI_EVENT is defined in CreateEvent() in
> +                                      the Unified Extensible Firmware Interface
> +                                      Specification.
> +  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds for
> +                                      APs to return from Procedure, either for
> +                                      blocking or non-blocking mode. Zero means
> +                                      infinity.  If the timeout expires before
> +                                      all APs return from Procedure, then Procedure
> +                                      on the failed APs is terminated. All enabled
> +                                      APs are available for next function assigned
> +                                      by EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
> +                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
> +                                      If the timeout expires in blocking mode,
> +                                      BSP returns EFI_TIMEOUT.  If the timeout
> +                                      expires in non-blocking mode, WaitEvent
> +                                      is signaled with SignalEvent().
> +  @param[in]  ProcedureArgument       The parameter passed into Procedure for
> +                                      all APs.
> +  @param[out] Finished                If NULL, this parameter is ignored.  In
> +                                      blocking mode, this parameter is ignored.
> +                                      In non-blocking mode, if AP returns from
> +                                      Procedure before the timeout expires, its
> +                                      content is set to TRUE. Otherwise, the
> +                                      value is set to FALSE. The caller can
> +                                      determine if the AP returned from Procedure
> +                                      by evaluating this value.
> +
> +  @retval EFI_SUCCESS             In blocking mode, specified AP finished before
> +                                  the timeout expires.
> +  @retval EFI_SUCCESS             In non-blocking mode, the function has been
> +                                  dispatched to specified AP.
> +  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
> +                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
> +                                  signaled.
> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
> +  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
> +                                  the specified AP has finished.
> +  @retval EFI_NOT_READY           The specified AP is busy.
> +  @retval EFI_NOT_FOUND           The processor with the handle specified by
> +                                  ProcessorNumber does not exist.
> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP or disabled AP.
> +  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +StartupThisAP (
> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
> +  IN  EFI_AP_PROCEDURE          Procedure,
> +  IN  UINTN                     ProcessorNumber,
> +  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
> +  IN  UINTN                     TimeoutInMicroseconds,
> +  IN  VOID                      *ProcedureArgument      OPTIONAL,
> +  OUT BOOLEAN                   *Finished               OPTIONAL
> +  )
> +{
> +  EFI_STATUS   Status;
> +  UINTN        Timeout;
> +  CPU_AP_DATA  *CpuData;
> +
> +  if (!IsCurrentProcessorBSP ()) {
> +    return EFI_DEVICE_ERROR;
> +  }
> +
> +  if (Procedure == NULL) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  CpuData = &mCpuMpData.CpuData[ProcessorNumber];
> +
> +  if (IsProcessorBSP (ProcessorNumber)) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  if (!IsProcessorEnabled (ProcessorNumber)) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  if (GetApState (CpuData) != CpuStateIdle) {
> +    return EFI_NOT_READY;
> +  }
> +
> +  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
> +    return EFI_UNSUPPORTED;
> +  }
> +
> +  Timeout = TimeoutInMicroseconds;
> +
> +  mCpuMpData.Timeout       = TimeoutInMicroseconds;
> +  mCpuMpData.TimeTaken     = 0;
> +  mCpuMpData.TimeoutActive = (BOOLEAN)(TimeoutInMicroseconds != 0);

[KQ] Adding a timeout active flag is correct. However, I think each AP 
should have its own timeout related
data (that is Timeout, TimeTaken and TimeoutActive). Because i.e. if 
this StartupThisAp call is used on AP 1 in
a non-blocking mode, then a subsequent call on AP 2 is blocking, the 
common flag and timeout values will
impact both cores, and create unintended timeout events.

> +
> +  mCpuMpData.StartCount  = 1;
> +  mCpuMpData.FinishCount = 0;
> +
> +  SetApProcedure (
> +    CpuData,
> +    Procedure,
> +    ProcedureArgument
> +    );
> +
> +  Status = DispatchCpu (ProcessorNumber);
> +  if (EFI_ERROR (Status)) {
> +    CpuData->State = CpuStateIdle;
> +    return EFI_NOT_READY;
> +  }
> +
> +  if (WaitEvent != NULL) {
> +    // Non Blocking
> +    if (Finished != NULL) {
> +      mCpuMpData.SingleApFinished = Finished;
> +      *Finished                   = FALSE;
> +    }
> +
> +    mCpuMpData.WaitEvent = WaitEvent;
> +    Status               = gBS->SetTimer (
> +                                  CpuData->CheckThisAPEvent,
> +                                  TimerPeriodic,
> +                                  POLL_INTERVAL_US
> +                                  );
> +
> +    return EFI_SUCCESS;
> +  }
> +
> +  // Blocking
> +  while (TRUE) {
> +    if (GetApState (CpuData) == CpuStateFinished) {
> +      CpuData->State = CpuStateIdle;
> +      break;
> +    }
> +
> +    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
> +      return EFI_TIMEOUT;
> +    }
> +
> +    Timeout -= CalculateAndStallInterval (Timeout);
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  This service switches the requested AP to be the BSP from that point onward.
> +  This service changes the BSP for all purposes.   This call can only be
> +  performed by the current BSP.
> +
> +  This service switches the requested AP to be the BSP from that point onward.
> +  This service changes the BSP for all purposes. The new BSP can take over the
> +  execution of the old BSP and continue seamlessly from where the old one left
> +  off. This service may not be supported after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT
> +  is signaled.
> +
> +  If the BSP cannot be switched prior to the return from this service, then
> +  EFI_UNSUPPORTED must be returned.
> +
> +  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
> +  @param[in] ProcessorNumber   The handle number of AP that is to become the new
> +                               BSP. The range is from 0 to the total number of
> +                               logical processors minus 1. The total number of
> +                               logical processors can be retrieved by
> +                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
> +  @param[in] EnableOldBSP      If TRUE, then the old BSP will be listed as an
> +                               enabled AP. Otherwise, it will be disabled.
> +
> +  @retval EFI_SUCCESS             BSP successfully switched.
> +  @retval EFI_UNSUPPORTED         Switching the BSP cannot be completed prior to
> +                                  this service returning.
> +  @retval EFI_UNSUPPORTED         Switching the BSP is not supported.
> +  @retval EFI_SUCCESS             The calling processor is an AP.
> +  @retval EFI_NOT_FOUND           The processor with the handle specified by
> +                                  ProcessorNumber does not exist.
> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the current BSP or
> +                                  a disabled AP.
> +  @retval EFI_NOT_READY           The specified AP is busy.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +SwitchBSP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *This,
> +  IN  UINTN                    ProcessorNumber,
> +  IN  BOOLEAN                  EnableOldBSP
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +/**
> +  This service lets the caller enable or disable an AP from this point onward.
> +  This service may only be called from the BSP.
> +
> +  This service allows the caller enable or disable an AP from this point onward.
> +  The caller can optionally specify the health status of the AP by Health. If
> +  an AP is being disabled, then the state of the disabled AP is implementation
> +  dependent. If an AP is enabled, then the implementation must guarantee that a
> +  complete initialization sequence is performed on the AP, so the AP is in a state
> +  that is compatible with an MP operating system. This service may not be supported
> +  after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled.
> +
> +  If the enable or disable AP operation cannot be completed prior to the return
> +  from this service, then EFI_UNSUPPORTED must be returned.
> +
> +  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
> +  @param[in] ProcessorNumber   The handle number of AP that is to become the new
> +                               BSP. The range is from 0 to the total number of
> +                               logical processors minus 1. The total number of
> +                               logical processors can be retrieved by
> +                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
> +  @param[in] EnableAP          Specifies the new state for the processor for
> +                               enabled, FALSE for disabled.
> +  @param[in] HealthFlag        If not NULL, a pointer to a value that specifies
> +                               the new health status of the AP. This flag
> +                               corresponds to StatusFlag defined in
> +                               EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
> +                               the PROCESSOR_HEALTH_STATUS_BIT is used. All other
> +                               bits are ignored.  If it is NULL, this parameter
> +                               is ignored.
> +
> +  @retval EFI_SUCCESS             The specified AP was enabled or disabled successfully.
> +  @retval EFI_UNSUPPORTED         Enabling or disabling an AP cannot be completed
> +                                  prior to this service returning.
> +  @retval EFI_UNSUPPORTED         Enabling or disabling an AP is not supported.
> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
> +  @retval EFI_NOT_FOUND           Processor with the handle specified by ProcessorNumber
> +                                  does not exist.
> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +EnableDisableAP (
> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
> +  IN  UINTN                     ProcessorNumber,
> +  IN  BOOLEAN                   EnableAP,
> +  IN  UINT32                    *HealthFlag OPTIONAL
> +  )
> +{
> +  UINTN        StatusFlag;
> +  CPU_AP_DATA  *CpuData;
> +
> +  StatusFlag = mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag;
> +  CpuData    = &mCpuMpData.CpuData[ProcessorNumber];
> +
> +  if (!IsCurrentProcessorBSP ()) {
> +    return EFI_DEVICE_ERROR;
> +  }
> +
> +  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  if (IsProcessorBSP (ProcessorNumber)) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  if (GetApState (CpuData) != CpuStateIdle) {
> +    return EFI_UNSUPPORTED;
> +  }
> +
> +  if (EnableAP) {
> +    if (!IsProcessorEnabled (ProcessorNumber)) {
> +      mCpuMpData.NumberOfEnabledProcessors++;
> +    }
> +
> +    StatusFlag |= PROCESSOR_ENABLED_BIT;
> +  } else {
> +    if (IsProcessorEnabled (ProcessorNumber)) {
> +      mCpuMpData.NumberOfEnabledProcessors--;
> +    }
> +
> +    StatusFlag &= ~PROCESSOR_ENABLED_BIT;
> +  }
> +
> +  if (HealthFlag != NULL) {
> +    StatusFlag &= ~PROCESSOR_HEALTH_STATUS_BIT;
> +    StatusFlag |= (*HealthFlag & PROCESSOR_HEALTH_STATUS_BIT);
> +  }
> +
> +  mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag = StatusFlag;
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  This return the handle number for the calling processor.  This service may be
> +  called from the BSP and APs.
> +
> +  This service returns the processor handle number for the calling processor.
> +  The returned value is in the range from 0 to the total number of logical
> +  processors minus 1. The total number of logical processors can be retrieved
> +  with EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors(). This service may be
> +  called from the BSP and APs. If ProcessorNumber is NULL, then EFI_INVALID_PARAMETER
> +  is returned. Otherwise, the current processors handle number is returned in
> +  ProcessorNumber, and EFI_SUCCESS is returned.
> +
> +  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
> +  @param[out] ProcessorNumber  The handle number of AP that is to become the new
> +                               BSP. The range is from 0 to the total number of
> +                               logical processors minus 1. The total number of
> +                               logical processors can be retrieved by
> +                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
> +
> +  @retval EFI_SUCCESS             The current processor handle number was returned
> +                                  in ProcessorNumber.
> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber is NULL.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +WhoAmI (
> +  IN EFI_MP_SERVICES_PROTOCOL  *This,
> +  OUT UINTN                    *ProcessorNumber
> +  )
> +{
> +  UINTN   Index;
> +  UINT64  ProcessorId;
> +
> +  if (ProcessorNumber == NULL) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  ProcessorId = GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ());
> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
> +    if (ProcessorId == gProcessorIDs[Index]) {
> +      *ProcessorNumber = Index;
> +      break;
> +    }
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +STATIC EFI_MP_SERVICES_PROTOCOL  mMpServicesProtocol = {
> +  GetNumberOfProcessors,
> +  GetProcessorInfo,
> +  StartupAllAPs,
> +  StartupThisAP,
> +  SwitchBSP,
> +  EnableDisableAP,
> +  WhoAmI
> +};
> +
> +/** Adds the specified processor the list of failed processors.
> +
> +   @param ProcessorIndex The processor index to add.
> +   @param ApState        Processor state.
> +
> +**/
> +STATIC
> +VOID
> +AddProcessorToFailedList (
> +  UINTN      ProcessorIndex,
> +  CPU_STATE  ApState
> +  )
> +{
> +  UINTN    Index;
> +  BOOLEAN  Found;
> +
> +  Found = FALSE;
> +
> +  if ((mCpuMpData.FailedList == NULL) ||
> +      (ApState == CpuStateIdle) ||
> +      (ApState == CpuStateFinished) ||
> +      IsProcessorBSP (ProcessorIndex))
> +  {
> +    return;
> +  }
> +
> +  // If we are retrying make sure we don't double count
> +  for (Index = 0; Index < mCpuMpData.FailedListIndex; Index++) {
> +    if (mCpuMpData.FailedList[Index] == ProcessorIndex) {
> +      Found = TRUE;
> +      break;
> +    }
> +  }
> +
> +  /* If the CPU isn't already in the FailedList, add it */
> +  if (!Found) {
> +    mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = ProcessorIndex;
> +  }
> +}
> +
> +/** Handles the StartupAllAPs case where the timeout has occurred.
> +
> +**/
> +STATIC
> +VOID
> +ProcessStartupAllAPsTimeout (
> +  VOID
> +  )
> +{
> +  CPU_AP_DATA  *CpuData;
> +  UINTN        Index;
> +
> +  if (mCpuMpData.FailedList == NULL) {
> +    return;
> +  }
> +
> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
> +    CpuData = &mCpuMpData.CpuData[Index];
> +    if (IsProcessorBSP (Index)) {
> +      // Skip BSP
> +      continue;
> +    }
> +
> +    if (!IsProcessorEnabled (Index)) {
> +      // Skip Disabled processors
> +      continue;
> +    }
> +
> +    CpuData = &mCpuMpData.CpuData[Index];
> +    AddProcessorToFailedList (Index, GetApState (CpuData));
> +  }
> +}
> +
> +/** Updates the status of the APs.
> +
> +   @param[in] ProcessorIndex The index of the AP to update.
> +**/
> +STATIC
> +VOID
> +UpdateApStatus (
> +  IN UINTN  ProcessorIndex
> +  )
> +{
> +  EFI_STATUS   Status;
> +  CPU_AP_DATA  *CpuData;
> +  CPU_AP_DATA  *NextCpuData;
> +  CPU_STATE    State;
> +  UINTN        NextNumber;
> +
> +  CpuData = &mCpuMpData.CpuData[ProcessorIndex];
> +
> +  if (IsProcessorBSP (ProcessorIndex)) {
> +    // Skip BSP
> +    return;
> +  }
> +
> +  if (!IsProcessorEnabled (ProcessorIndex)) {
> +    // Skip Disabled processors
> +    return;
> +  }
> +
> +  State = GetApState (CpuData);
> +
> +  switch (State) {
> +    case CpuStateFinished:
> +      if (mCpuMpData.SingleThread) {
> +        Status = GetNextBlockedNumber (&NextNumber);
> +        if (!EFI_ERROR (Status)) {
> +          NextCpuData = &mCpuMpData.CpuData[NextNumber];
> +
> +          NextCpuData->State = CpuStateReady;
> +
> +          SetApProcedure (
> +            NextCpuData,
> +            mCpuMpData.Procedure,
> +            mCpuMpData.ProcedureArgument
> +            );
> +
> +          Status = DispatchCpu (NextNumber);
> +          if (!EFI_ERROR (Status)) {
> +            mCpuMpData.StartCount++;
> +          } else {
> +            AddProcessorToFailedList (NextNumber, NextCpuData->State);
> +          }
> +        }
> +      }
> +
> +      CpuData->State = CpuStateIdle;
> +      mCpuMpData.FinishCount++;
> +      break;
> +
> +    default:
> +      break;
> +  }
> +}
> +
> +/**
> +  If a timeout is specified in StartupAllAps(), a timer is set, which invokes
> +  this procedure periodically to check whether all APs have finished.
> +
> +  @param[in] Event   The WaitEvent the user supplied.
> +  @param[in] Context The event context.
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +CheckAllAPsStatus (
> +  IN  EFI_EVENT  Event,
> +  IN  VOID       *Context
> +  )
> +{
> +  UINTN  Index;
> +
> +  mCpuMpData.TimeTaken += POLL_INTERVAL_US;
> +
> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
> +    UpdateApStatus (Index);
> +  }
> +
> +  if (mCpuMpData.TimeoutActive && (mCpuMpData.TimeTaken > mCpuMpData.Timeout)) {
> +    ProcessStartupAllAPsTimeout ();
> +
> +    // Force terminal exit
> +    mCpuMpData.FinishCount = mCpuMpData.StartCount;
> +  }
> +
> +  if (mCpuMpData.FinishCount != mCpuMpData.StartCount) {
> +    return;
> +  }
> +
> +  gBS->SetTimer (
> +         mCpuMpData.CheckAllAPsEvent,
> +         TimerCancel,
> +         0
> +         );
> +
> +  if (mCpuMpData.FailedListIndex == 0) {
> +    if (mCpuMpData.FailedList != NULL) {
> +      // Since we don't have the original `FailedCpuList`
> +      // pointer here to set to NULL, don't free the
> +      // memory.
> +    }
> +  }
> +
> +  gBS->SignalEvent (mCpuMpData.WaitEvent);
> +}
> +
> +/** Invoked periodically via a timer to check the state of the processor.
> +
> +   @param Event   The event supplied by the timer expiration.
> +   @param Context The processor context.
> +
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +CheckThisAPStatus (
> +  IN  EFI_EVENT  Event,
> +  IN  VOID       *Context
> +  )
> +{
> +  EFI_STATUS   Status;
> +  CPU_AP_DATA  *CpuData;
> +  CPU_STATE    State;
> +
> +  CpuData = Context;
> +
> +  mCpuMpData.TimeTaken += POLL_INTERVAL_US;
> +
> +  State = GetApState (CpuData);
> +
> +  if (State == CpuStateFinished) {
> +    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 0);
> +    ASSERT_EFI_ERROR (Status);
> +
> +    if (mCpuMpData.SingleApFinished != NULL) {
> +      *mCpuMpData.SingleApFinished = TRUE;
> +    }
> +
> +    if (mCpuMpData.WaitEvent != NULL) {
> +      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
> +      ASSERT_EFI_ERROR (Status);
> +    }
> +
> +    CpuData->State = CpuStateIdle;
> +  }
> +
> +  if (mCpuMpData.TimeoutActive && (mCpuMpData.TimeTaken > mCpuMpData.Timeout)) {
[KQ] Similar to the other comment, this is probably better using a 
per-core data to track elapsed time.
On a side note, if this timeout ever occurs, this core will never be 
usable in next StartupThisAp calls due
to this AP state will not be set to Idle even if the AP procedure is 
complete. Is this the intended behavior?
> +    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 0);
> +    if (mCpuMpData.WaitEvent != NULL) {
> +      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
> +      ASSERT_EFI_ERROR (Status);
> +    }
> +  }
> +}
> +
> +/**
> +  This function is called by all processors (both BSP and AP) once and collects
> +  MP related data.
> +
> +  @param BSP            TRUE if the processor is the BSP.
> +  @param Mpidr          The MPIDR for the specified processor. This should be
> +                        the full MPIDR and not only the affinity bits.
> +  @param ProcessorIndex The index of the processor.
> +
> +  @return EFI_SUCCESS if the data for the processor collected and filled in.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +FillInProcessorInformation (
> +  IN BOOLEAN  BSP,
> +  IN UINTN    Mpidr,
> +  IN UINTN    ProcessorIndex
> +  )
> +{
> +  EFI_PROCESSOR_INFORMATION  *CpuInfo;
> +
> +  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
> +
> +  CpuInfo->ProcessorId = GET_MPIDR_AFFINITY_BITS (Mpidr);
> +  CpuInfo->StatusFlag  = PROCESSOR_ENABLED_BIT | PROCESSOR_HEALTH_STATUS_BIT;
> +
> +  if (BSP) {
> +    CpuInfo->StatusFlag |= PROCESSOR_AS_BSP_BIT;
> +  }
> +
> +  if ((Mpidr & MPIDR_MT_BIT) > 0) {
> +    CpuInfo->Location.Package = GET_MPIDR_AFF2 (Mpidr);
> +    CpuInfo->Location.Core    = GET_MPIDR_AFF1 (Mpidr);
> +    CpuInfo->Location.Thread  = GET_MPIDR_AFF0 (Mpidr);
> +
> +    CpuInfo->ExtendedInformation.Location2.Package = GET_MPIDR_AFF3 (Mpidr);
> +    CpuInfo->ExtendedInformation.Location2.Die     = GET_MPIDR_AFF2 (Mpidr);
> +    CpuInfo->ExtendedInformation.Location2.Core    = GET_MPIDR_AFF1 (Mpidr);
> +    CpuInfo->ExtendedInformation.Location2.Thread  = GET_MPIDR_AFF0 (Mpidr);
> +  } else {
> +    CpuInfo->Location.Package = GET_MPIDR_AFF1 (Mpidr);
> +    CpuInfo->Location.Core    = GET_MPIDR_AFF0 (Mpidr);
> +    CpuInfo->Location.Thread  = 0;
> +
> +    CpuInfo->ExtendedInformation.Location2.Package = GET_MPIDR_AFF2 (Mpidr);
> +    CpuInfo->ExtendedInformation.Location2.Die     = GET_MPIDR_AFF1 (Mpidr);
> +    CpuInfo->ExtendedInformation.Location2.Core    = GET_MPIDR_AFF0 (Mpidr);
> +    CpuInfo->ExtendedInformation.Location2.Thread  = 0;
> +  }
> +
> +  mCpuMpData.CpuData[ProcessorIndex].State = BSP ? CpuStateBusy : CpuStateIdle;
> +
> +  mCpuMpData.CpuData[ProcessorIndex].Procedure = NULL;
> +  mCpuMpData.CpuData[ProcessorIndex].Parameter = NULL;
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Initializes the MP Services system data
> +
> +   @param NumberOfProcessors The number of processors, both BSP and AP.
> +   @param CoreInfo           CPU information gathered earlier during boot.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +MpServicesInitialize (
> +  IN   UINTN                NumberOfProcessors,
> +  IN   CONST ARM_CORE_INFO  *CoreInfo
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINTN       Index;
> +  EFI_EVENT   ReadyToBootEvent;
> +  BOOLEAN     IsBsp;
> +
> +  //
> +  // Clear the data structure area first.
> +  //
> +  ZeroMem (&mCpuMpData, sizeof (CPU_MP_DATA));
> +  //
> +  // First BSP fills and inits all known values, including its own records.
> +  //
> +  mCpuMpData.NumberOfProcessors        = NumberOfProcessors;
> +  mCpuMpData.NumberOfEnabledProcessors = NumberOfProcessors;
> +
> +  mCpuMpData.CpuData = AllocateZeroPool (
> +                         mCpuMpData.NumberOfProcessors * sizeof (CPU_AP_DATA)
> +                         );
> +
> +  if (mCpuMpData.CpuData == NULL) {
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  /* Allocate one extra for the sentinel entry at the end */
> +  gProcessorIDs = AllocateZeroPool ((mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64));
> +  ASSERT (gProcessorIDs != NULL);
> +
> +  Status = gBS->CreateEvent (
> +                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
> +                  TPL_CALLBACK,
> +                  CheckAllAPsStatus,
> +                  NULL,
> +                  &mCpuMpData.CheckAllAPsEvent
> +                  );
> +  ASSERT_EFI_ERROR (Status);
> +
> +  gApStacksBase = AllocatePages (
> +                    EFI_SIZE_TO_PAGES (
> +                      mCpuMpData.NumberOfProcessors *
> +                      gApStackSize
> +                      )
> +                    );
> +  ASSERT (gApStacksBase != NULL);
> +
> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
> +    if (GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ()) == CoreInfo[Index].Mpidr) {
> +      IsBsp = TRUE;
> +    } else {
> +      IsBsp = FALSE;
> +    }
> +
> +    FillInProcessorInformation (IsBsp, CoreInfo[Index].Mpidr, Index);
> +
> +    gProcessorIDs[Index] = mCpuMpData.CpuData[Index].Info.ProcessorId;
> +
> +    Status = gBS->CreateEvent (
> +                    EVT_TIMER | EVT_NOTIFY_SIGNAL,
> +                    TPL_CALLBACK,
> +                    CheckThisAPStatus,
> +                    (VOID *)&mCpuMpData.CpuData[Index],
> +                    &mCpuMpData.CpuData[Index].CheckThisAPEvent
> +                    );
> +    ASSERT_EFI_ERROR (Status);
> +  }
> +
> +  gProcessorIDs[Index] = MAX_UINT64;
> +
> +  //
> +  // The global pointer variables as well as the gProcessorIDs array contents
> +  // are accessed by the other cores so we must clean them to the PoC
> +  //
> +  WriteBackDataCacheRange (&gProcessorIDs, sizeof (UINT64 *));
> +  WriteBackDataCacheRange (&gApStacksBase, sizeof (UINT64 *));
> +
> +  WriteBackDataCacheRange (
> +    gProcessorIDs,
> +    (mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64)
> +    );
> +
> +  mNonBlockingModeAllowed = TRUE;
> +
> +  Status = EfiCreateEventReadyToBootEx (
> +             TPL_CALLBACK,
> +             ReadyToBootSignaled,
> +             NULL,
> +             &ReadyToBootEvent
> +             );
> +  ASSERT_EFI_ERROR (Status);
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  Event notification function called when the EFI_EVENT_GROUP_READY_TO_BOOT is
> +  signaled. After this point, non-blocking mode is no longer allowed.
> +
> +  @param  Event     Event whose notification function is being invoked.
> +  @param  Context   The pointer to the notification function's context,
> +                    which is implementation-dependent.
> +
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +ReadyToBootSignaled (
> +  IN  EFI_EVENT  Event,
> +  IN  VOID       *Context
> +  )
> +{
> +  mNonBlockingModeAllowed = FALSE;
> +}
> +
> +/** Initialize multi-processor support.
> +
> +  @param ImageHandle  Image handle.
> +  @param SystemTable  System table.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +ArmPsciMpServicesDxeInitialize (
> +  IN EFI_HANDLE        ImageHandle,
> +  IN EFI_SYSTEM_TABLE  *SystemTable
> +  )
> +{
> +  EFI_STATUS                 Status;
> +  EFI_HANDLE                 Handle;
> +  UINTN                      MaxCpus;
> +  EFI_LOADED_IMAGE_PROTOCOL  *Image;
> +  EFI_HOB_GENERIC_HEADER     *Hob;
> +  VOID                       *HobData;
> +  UINTN                      HobDataSize;
> +  CONST ARM_CORE_INFO        *CoreInfo;
> +
> +  MaxCpus = 1;
> +
> +  Status = gBS->HandleProtocol (
> +                  ImageHandle,
> +                  &gEfiLoadedImageProtocolGuid,
> +                  (VOID **)&Image
> +                  );
> +  ASSERT_EFI_ERROR (Status);
> +
> +  //
> +  // Parts of the code in this driver may be executed by other cores running
> +  // with the MMU off so we need to ensure that everything is clean to the
> +  // point of coherency (PoC)
> +  //
> +  WriteBackDataCacheRange (Image->ImageBase, Image->ImageSize);
> +
> +  Hob = GetFirstGuidHob (&gArmMpCoreInfoGuid);
> +  if (Hob != NULL) {
> +    HobData     = GET_GUID_HOB_DATA (Hob);
> +    HobDataSize = GET_GUID_HOB_DATA_SIZE (Hob);
> +    CoreInfo    = (ARM_CORE_INFO *)HobData;
> +    MaxCpus     = HobDataSize / sizeof (ARM_CORE_INFO);
> +  }
> +
> +  if (MaxCpus == 1) {
> +    DEBUG ((DEBUG_WARN, "Trying to use EFI_MP_SERVICES_PROTOCOL on a UP system"));
> +    // We are not MP so nothing to do
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  Status = MpServicesInitialize (MaxCpus, CoreInfo);
> +  if (Status != EFI_SUCCESS) {
> +    ASSERT_EFI_ERROR (Status);
> +    return Status;
> +  }
> +
> +  //
> +  // Now install the MP services protocol.
> +  //
> +  Handle = NULL;
> +  Status = gBS->InstallMultipleProtocolInterfaces (
> +                  &Handle,
> +                  &gEfiMpServiceProtocolGuid,
> +                  &mMpServicesProtocol,
> +                  NULL
> +                  );
> +  ASSERT_EFI_ERROR (Status);
> +
> +  return Status;
> +}
> +
> +/** AP exception handler.
> +
> +  @param InterruptType The AArch64 CPU exception type.
> +  @param SystemContext System context.
> +
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +ApExceptionHandler (
> +  IN CONST EFI_EXCEPTION_TYPE  InterruptType,
> +  IN CONST EFI_SYSTEM_CONTEXT  SystemContext
> +  )
> +{
> +  ARM_SMC_ARGS  Args;
> +  UINT64        Mpidr;
> +  UINTN         Index;
> +  UINTN         ProcessorIndex;
> +
> +  Mpidr = GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ());
> +
> +  Index          = 0;
> +  ProcessorIndex = MAX_UINT64;
> +
> +  do {
> +    if (gProcessorIDs[Index] == Mpidr) {
> +      ProcessorIndex = Index;
> +      break;
> +    }
> +
> +    Index++;
> +  } while (gProcessorIDs[Index] != MAX_UINT64);
> +
> +  if (ProcessorIndex != MAX_UINT64) {
> +    mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
> +    ArmDataMemoryBarrier ();
> +  }
> +
> +  Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
> +  ArmCallSmc (&Args);
> +
> +  /* Should never be reached */
> +  ASSERT (FALSE);
> +  CpuDeadLoop ();
> +}
> +
> +/** C entry-point for the AP.
> +    This function gets called from the assembly function ApEntryPoint.
> +
> +**/
> +VOID
> +ApProcedure (
> +  VOID
> +  )
> +{
> +  ARM_SMC_ARGS      Args;
> +  EFI_AP_PROCEDURE  UserApProcedure;
> +  VOID              *UserApParameter;
> +  UINTN             ProcessorIndex;
> +
> +  ProcessorIndex = 0;
> +
> +  WhoAmI (&mMpServicesProtocol, &ProcessorIndex);
> +
> +  /* Fetch the user-supplied procedure and parameter to execute */
> +  UserApProcedure = mCpuMpData.CpuData[ProcessorIndex].Procedure;
> +  UserApParameter = mCpuMpData.CpuData[ProcessorIndex].Parameter;
> +
> +  // Configure the MMU and caches
> +  ArmSetTCR (mCpuMpData.CpuData[ProcessorIndex].Tcr);
> +  ArmSetTTBR0 (mCpuMpData.CpuData[ProcessorIndex].Ttbr0);
> +  ArmSetMAIR (mCpuMpData.CpuData[ProcessorIndex].Mair);
> +  ArmDisableAlignmentCheck ();
> +  ArmEnableStackAlignmentCheck ();
> +  ArmEnableInstructionCache ();
> +  ArmEnableDataCache ();
> +  ArmEnableMmu ();
> +
> +  InitializeCpuExceptionHandlers (NULL);
> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_SYNCHRONOUS_EXCEPTIONS, ApExceptionHandler);
> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_IRQ, ApExceptionHandler);
> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_FIQ, ApExceptionHandler);
> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_SERROR, ApExceptionHandler);
> +
> +  UserApProcedure (UserApParameter);
> +
> +  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
> +
> +  ArmDataMemoryBarrier ();
> +
> +  /* Since we're finished with this AP, turn it off */
> +  Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
> +  ArmCallSmc (&Args);
> +
> +  /* Should never be reached */
> +  ASSERT (FALSE);
> +  CpuDeadLoop ();
> +}
> +
> +/** Returns whether the processor executing this function is the BSP.
> +
> +    @return Whether the current processor is the BSP.
> +**/
> +STATIC
> +BOOLEAN
> +IsCurrentProcessorBSP (
> +  VOID
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINTN       ProcessorIndex;
> +
> +  Status = WhoAmI (&mMpServicesProtocol, &ProcessorIndex);
> +  if (EFI_ERROR (Status)) {
> +    ASSERT_EFI_ERROR (Status);
> +    return FALSE;
> +  }
> +
> +  return IsProcessorBSP (ProcessorIndex);
> +}
> +
> +/** Returns whether the specified processor is enabled.
> +
> +   @param[in] ProcessorIndex The index of the processor to check.
> +
> +   @return TRUE if the processor is enabled, FALSE otherwise.
> +**/
> +STATIC
> +BOOLEAN
> +IsProcessorEnabled (
> +  UINTN  ProcessorIndex
> +  )
> +{
> +  EFI_PROCESSOR_INFORMATION  *CpuInfo;
> +
> +  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
> +
> +  return (CpuInfo->StatusFlag & PROCESSOR_ENABLED_BIT) != 0;
> +}
> +
> +/** Sets up the state for the StartupAllAPs function.
> +
> +   @param SingleThread Whether the APs will execute sequentially.
> +
> +**/
> +STATIC
> +VOID
> +StartupAllAPsPrepareState (
> +  IN BOOLEAN  SingleThread
> +  )
> +{
> +  UINTN        Index;
> +  CPU_STATE    APInitialState;
> +  CPU_AP_DATA  *CpuData;
> +
> +  mCpuMpData.FinishCount  = 0;
> +  mCpuMpData.StartCount   = 0;
> +  mCpuMpData.SingleThread = SingleThread;
> +
> +  APInitialState = CpuStateReady;
> +
> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
> +    CpuData = &mCpuMpData.CpuData[Index];
> +
> +    //
> +    // Get APs prepared, and put failing APs into FailedCpuList.
> +    // If "SingleThread", only 1 AP will put into ready state, other AP will be
> +    // put into ready state 1 by 1, until the previous 1 finished its task.
> +    // If not "SingleThread", all APs are put into ready state from the
> +    // beginning
> +    //
> +
> +    if (IsProcessorBSP (Index)) {
> +      // Skip BSP
> +      continue;
> +    }
> +
> +    if (!IsProcessorEnabled (Index)) {
> +      // Skip Disabled processors
> +      if (mCpuMpData.FailedList != NULL) {
> +        mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = Index;
> +      }
> +
> +      continue;
> +    }
> +
> +    CpuData->State = APInitialState;
> +
> +    mCpuMpData.StartCount++;
> +    if (SingleThread) {
> +      APInitialState = CpuStateBlocked;
> +    }
> +  }
> +}
> +
> +/** Handles execution of StartupAllAPs when a WaitEvent has been specified.
> +
> +  @param Procedure         The user-supplied procedure.
> +  @param ProcedureArgument The user-supplied procedure argument.
> +  @param WaitEvent         The wait event to be signaled when the work is
> +                           complete or a timeout has occurred.
> +  @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
> +                               indicates an infinite timeout.
> +  @param SingleThread          Whether the APs will execute sequentially.
> +  @param FailedCpuList         User-supplied pointer for list of failed CPUs.
> +
> +   @return EFI_SUCCESS on success.
> +**/
> +STATIC
> +EFI_STATUS
> +StartupAllAPsWithWaitEvent (
> +  IN EFI_AP_PROCEDURE  Procedure,
> +  IN VOID              *ProcedureArgument,
> +  IN EFI_EVENT         WaitEvent,
> +  IN UINTN             TimeoutInMicroseconds,
> +  IN BOOLEAN           SingleThread,
> +  IN UINTN             **FailedCpuList
> +  )
> +{
> +  EFI_STATUS   Status;
> +  UINTN        Index;
> +  CPU_AP_DATA  *CpuData;
> +
> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
> +    CpuData = &mCpuMpData.CpuData[Index];
> +    if (IsProcessorBSP (Index)) {
> +      // Skip BSP
> +      continue;
> +    }
> +
> +    if (!IsProcessorEnabled (Index)) {
> +      // Skip Disabled processors
> +      continue;
> +    }
> +
> +    if (GetApState (CpuData) == CpuStateReady) {
> +      SetApProcedure (CpuData, Procedure, ProcedureArgument);
> +      if ((mCpuMpData.StartCount == 0) || !SingleThread) {
> +        Status = DispatchCpu (Index);
> +        if (EFI_ERROR (Status)) {
> +          AddProcessorToFailedList (Index, CpuData->State);
> +          break;
> +        }
> +      }
> +    }
> +  }
> +
> +  if (EFI_ERROR (Status)) {
> +    return EFI_NOT_READY;
> +  }
> +
> +  //
> +  // Save data into private data structure, and create timer to poll AP state
> +  // before exiting
> +  //
> +  mCpuMpData.Procedure         = Procedure;
> +  mCpuMpData.ProcedureArgument = ProcedureArgument;
> +  mCpuMpData.WaitEvent         = WaitEvent;
> +  mCpuMpData.Timeout           = TimeoutInMicroseconds;
> +  mCpuMpData.TimeTaken         = 0;
> +  mCpuMpData.TimeoutActive     = (BOOLEAN)(TimeoutInMicroseconds != 0);
> +  Status                       = gBS->SetTimer (
> +                                        mCpuMpData.CheckAllAPsEvent,
> +                                        TimerPeriodic,
> +                                        POLL_INTERVAL_US
> +                                        );
> +
> +  return Status;
> +}
> +
> +/** Handles execution of StartupAllAPs when no wait event has been specified.
> +
> +  @param Procedure             The user-supplied procedure.
> +  @param ProcedureArgument     The user-supplied procedure argument.
> +  @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
> +                                indicates an infinite timeout.
> +  @param SingleThread          Whether the APs will execute sequentially.
> +  @param FailedCpuList         User-supplied pointer for list of failed CPUs.
> +
> +  @return EFI_SUCCESS on success.
> +**/
> +STATIC
> +EFI_STATUS
> +StartupAllAPsNoWaitEvent (
> +  IN EFI_AP_PROCEDURE  Procedure,
> +  IN VOID              *ProcedureArgument,
> +  IN UINTN             TimeoutInMicroseconds,
> +  IN BOOLEAN           SingleThread,
> +  IN UINTN             **FailedCpuList
> +  )
> +{
> +  EFI_STATUS   Status;
> +  UINTN        Index;
> +  UINTN        NextIndex;
> +  UINTN        Timeout;
> +  CPU_AP_DATA  *CpuData;
> +  BOOLEAN      DispatchError;
> +
> +  Timeout       = TimeoutInMicroseconds;
> +  DispatchError = FALSE;
> +
> +  while (TRUE) {
> +    for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
> +      CpuData = &mCpuMpData.CpuData[Index];
> +      if (IsProcessorBSP (Index)) {
> +        // Skip BSP
> +        continue;
> +      }
> +
> +      if (!IsProcessorEnabled (Index)) {
> +        // Skip Disabled processors
> +        continue;
> +      }
> +
> +      switch (GetApState (CpuData)) {
> +        case CpuStateReady:
> +          SetApProcedure (CpuData, Procedure, ProcedureArgument);
> +          Status = DispatchCpu (Index);
> +          if (EFI_ERROR (Status)) {
> +            AddProcessorToFailedList (Index, CpuData->State);
> +            CpuData->State = CpuStateIdle;
> +            mCpuMpData.StartCount--;
> +            DispatchError = TRUE;
> +
> +            if (SingleThread) {
> +              // Dispatch the next available AP
> +              Status = GetNextBlockedNumber (&NextIndex);
> +              if (!EFI_ERROR (Status)) {
> +                mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
> +              }
> +            }
> +          }
> +
> +          break;
> +
> +        case CpuStateFinished:
> +          mCpuMpData.FinishCount++;
> +          if (SingleThread) {
> +            Status = GetNextBlockedNumber (&NextIndex);
> +            if (!EFI_ERROR (Status)) {
> +              mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
> +            }
> +          }
> +
> +          CpuData->State = CpuStateIdle;
> +          break;
> +
> +        default:
> +          break;
> +      }
> +    }
> +
> +    if (mCpuMpData.FinishCount == mCpuMpData.StartCount) {
> +      Status = EFI_SUCCESS;
> +      break;
> +    }
> +
> +    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
> +      Status = EFI_TIMEOUT;
> +      break;
> +    }
> +
> +    Timeout -= CalculateAndStallInterval (Timeout);
> +  }
> +
> +  if (Status == EFI_TIMEOUT) {
> +    // Add any remaining CPUs to the FailedCpuList
> +    if (FailedCpuList != NULL) {
> +      for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
> +        AddProcessorToFailedList (Index, mCpuMpData.CpuData[Index].State);
> +      }
> +    }
> +  }
> +
> +  if (DispatchError) {
> +    Status = EFI_NOT_READY;
> +  }
> +
> +  return Status;
> +}
> diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S
> new file mode 100644
> index 000000000000..a90fa8a0075f
> --- /dev/null
> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S
> @@ -0,0 +1,57 @@
> +#===============================================================================
> +#  Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#===============================================================================
> +
> +.text
> +.align 3
> +
> +#include <AsmMacroIoLibV8.h>
> +#include <IndustryStandard/ArmStdSmc.h>
> +
> +#include "MpServicesInternal.h"
> +
> +GCC_ASM_IMPORT (gApStacksBase)
> +GCC_ASM_IMPORT (gProcessorIDs)
> +GCC_ASM_IMPORT (ApProcedure)
> +GCC_ASM_IMPORT (gApStackSize)
> +
> +GCC_ASM_EXPORT (ApEntryPoint)
> +
> +// Entry-point for the AP
> +// VOID
> +// ApEntryPoint (
> +//   VOID
> +//   );
> +ASM_PFX(ApEntryPoint):
> +  mrs x0, mpidr_el1
> +  // Mask the non-affinity bits
> +  bic x0, x0, 0x00ff000000
> +  and x0, x0, 0xffffffffff
> +  ldr x1, gProcessorIDs
> +  mov x2, 0                   // x2 = processor index
> +
> +// Find index in gProcessorIDs for current processor
> +1:
> +  ldr x3, [x1, x2, lsl #3]    // x4 = gProcessorIDs + x2 * 8
> +  cmp x3, #-1                 // check if we've reached the end of gProcessorIDs
> +  beq ProcessorNotFound
> +  add x2, x2, 1               // x2++
> +  cmp x0, x3                  // if mpidr_el1 != gProcessorIDs[x] then loop
> +  bne 1b
> +
> +// Calculate stack address
> +  // x2 contains the index for the current processor plus 1
> +  ldr x0, gApStacksBase
> +  ldr x1, gApStackSize
> +  mul x3, x2, x1              // x3 = (ProcessorIndex + 1) * gApStackSize
> +  add sp, x0, x3              // sp = gApStacksBase + x3
> +  mov x29, xzr
> +  bl ApProcedure              // doesn't return
> +
> +ProcessorNotFound:
> +// Turn off the processor
> +  MOV32 (w0, ARM_SMC_ID_PSCI_CPU_OFF)
> +  smc #0
> +  b .

Re: [edk2-devel] [PATCH v4 2/3] ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls

[Rebecca Cran]

On 1/6/23 15:11, Kun Qin wrote:

> On 1/4/2023 7:37 AM, Rebecca Cran wrote:
>> +  mCpuMpData.Timeout       = TimeoutInMicroseconds;
>> +  mCpuMpData.TimeTaken     = 0;
>> +  mCpuMpData.TimeoutActive = (BOOLEAN)(TimeoutInMicroseconds != 0);
> 
> [KQ] Adding a timeout active flag is correct. However, I think each AP 
> should have its own timeout related
> data (that is Timeout, TimeTaken and TimeoutActive). Because i.e. if 
> this StartupThisAp call is used on AP 1 in
> a non-blocking mode, then a subsequent call on AP 2 is blocking, the 
> common flag and timeout values will
> impact both cores, and create unintended timeout events.

Good catch! Thanks, I've fixed it by adding per-CPU fields for 
StartupThisAP.

>> +  if (mCpuMpData.TimeoutActive && (mCpuMpData.TimeTaken > 
>> mCpuMpData.Timeout)) {
> [KQ] Similar to the other comment, this is probably better using a 
> per-core data to track elapsed time.
> On a side note, if this timeout ever occurs, this core will never be 
> usable in next StartupThisAp calls due
> to this AP state will not be set to Idle even if the AP procedure is 
> complete. Is this the intended behavior?

No, it wasn't. I've added code to StartupThisAP and StartupAllAPs to 
accept CpuStateFinished or reset CPUs in that state back to Idle.

-- 
Rebecca Cran

Re: [edk2-devel] [PATCH v4 2/3] ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls

[Kun Qin]

Sorry, hit the send button too soon... One more comment under [KQ-2].

Thanks,
Kun

On 1/6/2023 2:11 PM, Kun Qin via groups.io wrote:
> Hi Rebecca,
>
> I have tried to use this for a few different scenarios and below is a 
> few minor issues I have found and potential
> changes (marked with [KQ]). Please let me know if I have any 
> misunderstanding on the protocol itself.
>
> Thanks,
> Kun
>
> On 1/4/2023 7:37 AM, Rebecca Cran wrote:
>> Add support for EFI_MP_SERVICES_PROTOCOL during the DXE phase under
>> AArch64.
>>
>> PSCI_CPU_ON is called to power on the core, the supplied procedure is
>> executed and PSCI_CPU_OFF is called to power off the core.
>>
>> Fixes contributed by Ard Biesheuvel.
>>
>> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
>> ---
>>   ArmPkg/ArmPkg.dsc |    1 +
>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf |   56 +
>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h |  344 ++++
>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c   | 1847 
>> ++++++++++++++++++++
>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S |   57 +
>>   5 files changed, 2305 insertions(+)
>>
>> diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
>> index ac24ebce4892..1e873b90c56d 100644
>> --- a/ArmPkg/ArmPkg.dsc
>> +++ b/ArmPkg/ArmPkg.dsc
>> @@ -164,6 +164,7 @@ [Components.common]
>>     ArmPkg/Universal/Smbios/OemMiscLibNull/OemMiscLibNull.inf
>>     [Components.AARCH64]
>> +  ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
>>     ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
>>     ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf
>>   diff --git 
>> a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf 
>> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
>> new file mode 100644
>> index 000000000000..2c9ab99038f2
>> --- /dev/null
>> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
>> @@ -0,0 +1,56 @@
>> +## @file
>> +#  ARM MP services protocol driver
>> +#
>> +#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>> reserved.<BR>
>> +#
>> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
>> +#
>> +##
>> +
>> +[Defines]
>> +  INF_VERSION                    = 1.27
>> +  BASE_NAME                      = ArmPsciMpServicesDxe
>> +  FILE_GUID                      = 007ab472-dc4a-4df8-a5c2-abb4a327278c
>> +  MODULE_TYPE                    = DXE_DRIVER
>> +  VERSION_STRING                 = 1.0
>> +
>> +  ENTRY_POINT                    = ArmPsciMpServicesDxeInitialize
>> +
>> +[Sources.Common]
>> +  ArmPsciMpServicesDxe.c
>> +  MpFuncs.S
>> +  MpServicesInternal.h
>> +
>> +[Packages]
>> +  ArmPkg/ArmPkg.dec
>> +  ArmPlatformPkg/ArmPlatformPkg.dec
>> +  EmbeddedPkg/EmbeddedPkg.dec
>> +  MdePkg/MdePkg.dec
>> +  MdeModulePkg/MdeModulePkg.dec
>> +
>> +[LibraryClasses]
>> +  ArmLib
>> +  ArmMmuLib
>> +  ArmSmcLib
>> +  BaseMemoryLib
>> +  CacheMaintenanceLib
>> +  CpuExceptionHandlerLib
>> +  DebugLib
>> +  HobLib
>> +  MemoryAllocationLib
>> +  UefiBootServicesTableLib
>> +  UefiDriverEntryPoint
>> +  UefiLib
>> +
>> +[Protocols]
>> +  gEfiMpServiceProtocolGuid            ## PRODUCES
>> +  gEfiLoadedImageProtocolGuid          ## CONSUMES
>> +
>> +[Guids]
>> +  gArmMpCoreInfoGuid
>> +
>> +[Depex]
>> +  TRUE
>> +
>> +[BuildOptions]
>> +  GCC:*_*_*_CC_FLAGS = -mstrict-align
>> diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h 
>> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h
>> new file mode 100644
>> index 000000000000..5ba63700dd18
>> --- /dev/null
>> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h
>> @@ -0,0 +1,344 @@
>> +/** @file
>> +
>> +Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>> reserved.<BR>
>> +Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
>> +Portions copyright (c) 2011, Apple Inc. All rights reserved.
>> +
>> +SPDX-License-Identifier: BSD-2-Clause-Patent
>> +
>> +**/
>> +
>> +#ifndef MP_SERVICES_INTERNAL_H_
>> +#define MP_SERVICES_INTERNAL_H_
>> +
>> +#include <Protocol/Cpu.h>
>> +#include <Protocol/MpService.h>
>> +
>> +#include <Library/BaseLib.h>
>> +#include <Library/UefiLib.h>
>> +
>> +#define AP_STACK_SIZE  0x1000
>> +
>> +//
>> +// Internal Data Structures
>> +//
>> +
>> +//
>> +// AP state
>> +//
>> +// The state transitions for an AP when it processes a procedure are:
>> +//  Idle ----> Ready ----> Busy ----> Finished ----> Idle
>> +//       [BSP]       [BSP]      [AP]           [BSP]
>> +//
>> +typedef enum {
>> +  CpuStateIdle,
>> +  CpuStateReady,
>> +  CpuStateBlocked,
>> +  CpuStateBusy,
>> +  CpuStateFinished,
>> +  CpuStateDisabled
>> +} CPU_STATE;
>> +
>> +//
>> +// Define Individual Processor Data block.
>> +//
>> +typedef struct {
>> +  EFI_PROCESSOR_INFORMATION    Info;
>> +  EFI_AP_PROCEDURE             Procedure;
>> +  VOID                         *Parameter;
>> +  CPU_STATE                    State;
>> +  EFI_EVENT                    CheckThisAPEvent;
>> +  VOID                         *Ttbr0;
>> +  UINTN                        Tcr;
>> +  UINTN                        Mair;
>> +} CPU_AP_DATA;
>> +
>> +//
>> +// Define MP data block which consumes individual processor block.
>> +//
>> +typedef struct {
>> +  UINTN               NumberOfProcessors;
>> +  UINTN               NumberOfEnabledProcessors;
>> +  EFI_EVENT           CheckAllAPsEvent;
>> +  EFI_EVENT           WaitEvent;
>> +  UINTN               FinishCount;
>> +  UINTN               StartCount;
>> +  EFI_AP_PROCEDURE    Procedure;
>> +  VOID                *ProcedureArgument;
>> +  BOOLEAN             SingleThread;
>> +  UINTN               StartedNumber;
>> +  CPU_AP_DATA         *CpuData;
>> +  UINTN               Timeout;
>> +  UINTN               TimeTaken;
>> +  UINTN               *FailedList;
>> +  UINTN               FailedListIndex;
>> +  BOOLEAN             TimeoutActive;
>> +  BOOLEAN             *SingleApFinished;
>> +} CPU_MP_DATA;
>> +
>> +/** Secondary core entry point.
>> +
>> +**/
>> +VOID
>> +ApEntryPoint (
>> +  VOID
>> +  );
>> +
>> +/** C entry-point for the AP.
>> +    This function gets called from the assembly function ApEntryPoint.
>> +**/
>> +VOID
>> +ApProcedure (
>> +  VOID
>> +  );
>> +
>> +/** Turns on the specified core using PSCI and executes the 
>> user-supplied
>> +    function that's been configured via a previous call to 
>> SetApProcedure.
>> +
>> +   @param ProcessorIndex The index of the core to turn on.
>> +
>> +   @retval EFI_SUCCESS       The processor was successfully turned on.
>> +   @retval EFI_DEVICE_ERROR  An error occurred turning the processor 
>> on.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +DispatchCpu (
>> +  IN UINTN  ProcessorIndex
>> +  );
>> +
>> +/** Returns whether the specified processor is the BSP.
>> +
>> +   @param[in] ProcessorIndex The index the processor to check.
>> +
>> +   @return TRUE if the processor is the BSP, FALSE otherwise.
>> +**/
>> +STATIC
>> +BOOLEAN
>> +IsProcessorBSP (
>> +  UINTN  ProcessorIndex
>> +  );
>> +
>> +/** Returns whether the processor executing this function is the BSP.
>> +
>> +   @return Whether the current processor is the BSP.
>> +**/
>> +STATIC
>> +BOOLEAN
>> +IsCurrentProcessorBSP (
>> +  VOID
>> +  );
>> +
>> +/** Returns whether the specified processor is enabled.
>> +
>> +   @param[in] ProcessorIndex The index of the processor to check.
>> +
>> +   @return TRUE if the processor is enabled, FALSE otherwise.
>> +**/
>> +STATIC
>> +BOOLEAN
>> +IsProcessorEnabled (
>> +  UINTN  ProcessorIndex
>> +  );
>> +
>> +/** Configures the processor context with the user-supplied 
>> procedure and
>> +    argument.
>> +
>> +   @param CpuData           The processor context.
>> +   @param Procedure         The user-supplied procedure.
>> +   @param ProcedureArgument The user-supplied procedure argument.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +SetApProcedure (
>> +  IN   CPU_AP_DATA       *CpuData,
>> +  IN   EFI_AP_PROCEDURE  Procedure,
>> +  IN   VOID              *ProcedureArgument
>> +  );
>> +
>> +/**
>> +  Get the Application Processors state.
>> +
>> +  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP
>> +
>> +  @return  The AP status
>> +**/
>> +CPU_STATE
>> +GetApState (
>> +  IN  CPU_AP_DATA  *CpuData
>> +  );
>> +
>> +/** Returns the index of the next processor that is blocked.
>> +
>> +   @param[out] NextNumber The index of the next blocked processor.
>> +
>> +   @retval EFI_SUCCESS   Successfully found the next blocked processor.
>> +   @retval EFI_NOT_FOUND There are no blocked processors.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +GetNextBlockedNumber (
>> +  OUT UINTN  *NextNumber
>> +  );
>> +
>> +/** Stalls the BSP for the minimum of gPollInterval and Timeout.
>> +
>> +   @param[in]  Timeout    The time limit in microseconds remaining for
>> +                          APs to return from Procedure.
>> +
>> +   @retval     StallTime  Time of execution stall.
>> +**/
>> +STATIC
>> +UINTN
>> +CalculateAndStallInterval (
>> +  IN UINTN  Timeout
>> +  );
>> +
>> +/** Sets up the state for the StartupAllAPs function.
>> +
>> +   @param SingleThread Whether the APs will execute sequentially.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +StartupAllAPsPrepareState (
>> +  IN BOOLEAN  SingleThread
>> +  );
>> +
>> +/** Handles execution of StartupAllAPs when a WaitEvent has been 
>> specified.
>> +
>> +  @param Procedure         The user-supplied procedure.
>> +  @param ProcedureArgument The user-supplied procedure argument.
>> +  @param WaitEvent         The wait event to be signaled when the 
>> work is
>> +                           complete or a timeout has occurred.
>> +  @param TimeoutInMicroseconds The timeout for the work to be 
>> completed. Zero
>> +                               indicates an infinite timeout.
>> +  @param SingleThread          Whether the APs will execute 
>> sequentially.
>> +  @param FailedCpuList         User-supplied pointer for list of 
>> failed CPUs.
>> +
>> +   @return EFI_SUCCESS on success.
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +StartupAllAPsWithWaitEvent (
>> +  IN EFI_AP_PROCEDURE  Procedure,
>> +  IN VOID              *ProcedureArgument,
>> +  IN EFI_EVENT         WaitEvent,
>> +  IN UINTN             TimeoutInMicroseconds,
>> +  IN BOOLEAN           SingleThread,
>> +  IN UINTN             **FailedCpuList
>> +  );
>> +
>> +/** Handles execution of StartupAllAPs when no wait event has been 
>> specified.
>> +
>> +   @param Procedure             The user-supplied procedure.
>> +   @param ProcedureArgument     The user-supplied procedure argument.
>> +   @param TimeoutInMicroseconds The timeout for the work to be 
>> completed. Zero
>> +                                indicates an infinite timeout.
>> +   @param SingleThread          Whether the APs will execute 
>> sequentially.
>> +   @param FailedCpuList         User-supplied pointer for list of 
>> failed CPUs.
>> +
>> +   @return EFI_SUCCESS on success.
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +StartupAllAPsNoWaitEvent (
>> +  IN EFI_AP_PROCEDURE  Procedure,
>> +  IN VOID              *ProcedureArgument,
>> +  IN UINTN             TimeoutInMicroseconds,
>> +  IN BOOLEAN           SingleThread,
>> +  IN UINTN             **FailedCpuList
>> +  );
>> +
>> +/** Adds the specified processor the list of failed processors.
>> +
>> +   @param ProcessorIndex The processor index to add.
>> +   @param ApState         Processor state.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +AddProcessorToFailedList (
>> +  UINTN      ProcessorIndex,
>> +  CPU_STATE  ApState
>> +  );
>> +
>> +/** Handles the StartupAllAPs case where the timeout has occurred.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +ProcessStartupAllAPsTimeout (
>> +  VOID
>> +  );
>> +
>> +/**
>> +  If a timeout is specified in StartupAllAps(), a timer is set, 
>> which invokes
>> +  this procedure periodically to check whether all APs have finished.
>> +
>> +  @param[in] Event   The WaitEvent the user supplied.
>> +  @param[in] Context The event context.
>> +**/
>> +STATIC
>> +VOID
>> +EFIAPI
>> +CheckAllAPsStatus (
>> +  IN  EFI_EVENT  Event,
>> +  IN  VOID       *Context
>> +  );
>> +
>> +/** Invoked periodically via a timer to check the state of the 
>> processor.
>> +
>> +   @param Event   The event supplied by the timer expiration.
>> +   @param Context The processor context.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +EFIAPI
>> +CheckThisAPStatus (
>> +  IN  EFI_EVENT  Event,
>> +  IN  VOID       *Context
>> +  );
>> +
>> +/**
>> +  This function is called by all processors (both BSP and AP) once 
>> and collects
>> +  MP related data.
>> +
>> +  @param BSP            TRUE if the processor is the BSP.
>> +  @param Mpidr          The MPIDR for the specified processor. This 
>> should be
>> +                        the full MPIDR and not only the affinity bits.
>> +  @param ProcessorIndex The index of the processor.
>> +
>> +  @return EFI_SUCCESS if the data for the processor collected and 
>> filled in.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +FillInProcessorInformation (
>> +  IN BOOLEAN  BSP,
>> +  IN UINTN    Mpidr,
>> +  IN UINTN    ProcessorIndex
>> +  );
>> +
>> +/**
>> +  Event notification function called when the 
>> EFI_EVENT_GROUP_READY_TO_BOOT is
>> +  signaled. After this point, non-blocking mode is no longer allowed.
>> +
>> +  @param  Event     Event whose notification function is being invoked.
>> +  @param  Context   The pointer to the notification function's context,
>> +                    which is implementation-dependent.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +EFIAPI
>> +ReadyToBootSignaled (
>> +  IN  EFI_EVENT  Event,
>> +  IN  VOID       *Context
>> +  );
>> +
>> +#endif /* MP_SERVICES_INTERNAL_H_ */
>> diff --git 
>> a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c 
>> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
>> new file mode 100644
>> index 000000000000..ab439bffd722
>> --- /dev/null
>> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
>> @@ -0,0 +1,1847 @@
>> +/** @file
>> +  Construct MP Services Protocol.
>> +
>> +  The MP Services Protocol provides a generalized way of performing 
>> following tasks:
>> +    - Retrieving information of multi-processor environment and 
>> MP-related status of
>> +      specific processors.
>> +    - Dispatching user-provided function to APs.
>> +    - Maintain MP-related processor status.
>> +
>> +  The MP Services Protocol must be produced on any system with more 
>> than one logical
>> +  processor.
>> +
>> +  The Protocol is available only during boot time.
>> +
>> +  MP Services Protocol is hardware-independent. Most of the logic of 
>> this protocol
>> +  is architecturally neutral. It abstracts the multi-processor 
>> environment and
>> +  status of processors, and provides interfaces to retrieve 
>> information, maintain,
>> +  and dispatch.
>> +
>> +  MP Services Protocol may be consumed by ACPI module. The ACPI 
>> module may use this
>> +  protocol to retrieve data that are needed for an MP platform and 
>> report them to OS.
>> +  MP Services Protocol may also be used to program and configure 
>> processors, such
>> +  as MTRR synchronization for memory space attributes setting in DXE 
>> Services.
>> +  MP Services Protocol may be used by non-CPU DXE drivers to speed 
>> up platform boot
>> +  by taking advantage of the processing capabilities of the APs, for 
>> example, using
>> +  APs to help test system memory in parallel with other device 
>> initialization.
>> +  Diagnostics applications may also use this protocol for 
>> multi-processor.
>> +
>> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>> reserved.<BR>
>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>> +
>> +**/
>> +
>> +#include <PiDxe.h>
>> +
>> +#include <Library/ArmLib.h>
>> +#include <Library/ArmMmuLib.h>
>> +#include <Library/ArmPlatformLib.h>
>> +#include <Library/ArmSmcLib.h>
>> +#include <Library/BaseMemoryLib.h>
>> +#include <Library/CacheMaintenanceLib.h>
>> +#include <Library/CpuExceptionHandlerLib.h>
>> +#include <Library/DebugLib.h>
>> +#include <Library/HobLib.h>
>> +#include <Library/MemoryAllocationLib.h>
>> +#include <Library/UefiBootServicesTableLib.h>
>> +#include <Library/UefiLib.h>
>> +#include <IndustryStandard/ArmStdSmc.h>
>> +#include <Ppi/ArmMpCoreInfo.h>
>> +#include <Protocol/LoadedImage.h>
>> +
>> +#include "MpServicesInternal.h"
>> +
>> +#define POLL_INTERVAL_US  50000
>> +
>> +STATIC CPU_MP_DATA  mCpuMpData;
>> +STATIC BOOLEAN      mNonBlockingModeAllowed;
>> +UINT64              *gApStacksBase;
>> +UINT64              *gProcessorIDs;
>> +CONST UINT64        gApStackSize = AP_STACK_SIZE;
>> +
>> +STATIC
>> +BOOLEAN
>> +IsCurrentProcessorBSP (
>> +  VOID
>> +  );
>> +
>> +/** Turns on the specified core using PSCI and executes the 
>> user-supplied
>> +    function that's been configured via a previous call to 
>> SetApProcedure.
>> +
>> +    @param ProcessorIndex The index of the core to turn on.
>> +
>> +    @retval EFI_SUCCESS      Success.
>> +    @retval EFI_DEVICE_ERROR The processor could not be turned on.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +DispatchCpu (
>> +  IN UINTN  ProcessorIndex
>> +  )
>> +{
>> +  ARM_SMC_ARGS  Args;
>> +  EFI_STATUS    Status;
>> +
>> +  Status = EFI_SUCCESS;
>> +
>> +  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateBusy;
>> +
>> +  /* Turn the AP on */
>> +  if (sizeof (Args.Arg0) == sizeof (UINT32)) {
>> +    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH32;
>> +  } else {
>> +    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH64;
>> +  }
>> +
>> +  Args.Arg1 = gProcessorIDs[ProcessorIndex];
>> +  Args.Arg2 = (UINTN)ApEntryPoint;
>> +
>> +  mCpuMpData.CpuData[ProcessorIndex].Tcr   = ArmGetTCR ();
>> +  mCpuMpData.CpuData[ProcessorIndex].Mair  = ArmGetMAIR ();
>> +  mCpuMpData.CpuData[ProcessorIndex].Ttbr0 = ArmGetTTBR0BaseAddress ();
>> +  WriteBackDataCacheRange (&mCpuMpData.CpuData[ProcessorIndex], 
>> sizeof (CPU_AP_DATA));
>> +
>> +  ArmCallSmc (&Args);
>> +
>> +  if (Args.Arg0 != ARM_SMC_PSCI_RET_SUCCESS) {
>> +    DEBUG ((DEBUG_ERROR, "PSCI_CPU_ON call failed: %d\n", Args.Arg0));
>> +    Status = EFI_DEVICE_ERROR;
>> +  }
>> +
>> +  return Status;
>> +}
>> +
>> +/** Returns whether the specified processor is the BSP.
>> +
>> +  @param[in] ProcessorIndex The index the processor to check.
>> +
>> +  @return TRUE if the processor is the BSP, FALSE otherwise.
>> +**/
>> +STATIC
>> +BOOLEAN
>> +IsProcessorBSP (
>> +  UINTN  ProcessorIndex
>> +  )
>> +{
>> +  EFI_PROCESSOR_INFORMATION  *CpuInfo;
>> +
>> +  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
>> +
>> +  return (CpuInfo->StatusFlag & PROCESSOR_AS_BSP_BIT) != 0;
>> +}
>> +
>> +/** Get the Application Processors state.
>> +
>> +  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP.
>> +
>> +  @return The AP status.
>> +**/
>> +CPU_STATE
>> +GetApState (
>> +  IN  CPU_AP_DATA  *CpuData
>> +  )
>> +{
>> +  return CpuData->State;
>> +}
>> +
>> +/** Configures the processor context with the user-supplied 
>> procedure and
>> +    argument.
>> +
>> +   @param CpuData           The processor context.
>> +   @param Procedure         The user-supplied procedure.
>> +   @param ProcedureArgument The user-supplied procedure argument.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +SetApProcedure (
>> +  IN   CPU_AP_DATA       *CpuData,
>> +  IN   EFI_AP_PROCEDURE  Procedure,
>> +  IN   VOID              *ProcedureArgument
>> +  )
>> +{
>> +  ASSERT (CpuData != NULL);
>> +  ASSERT (Procedure != NULL);
>> +
>> +  CpuData->Parameter = ProcedureArgument;
>> +  CpuData->Procedure = Procedure;
>> +}
>> +
>> +/** Returns the index of the next processor that is blocked.
>> +
>> +   @param[out] NextNumber The index of the next blocked processor.
>> +
>> +   @retval EFI_SUCCESS   Successfully found the next blocked processor.
>> +   @retval EFI_NOT_FOUND There are no blocked processors.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +GetNextBlockedNumber (
>> +  OUT UINTN  *NextNumber
>> +  )
>> +{
>> +  UINTN        Index;
>> +  CPU_STATE    State;
>> +  CPU_AP_DATA  *CpuData;
>> +
>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>> +    CpuData = &mCpuMpData.CpuData[Index];
>> +    if (IsProcessorBSP (Index)) {
>> +      // Skip BSP
>> +      continue;
>> +    }
>> +
>> +    State = CpuData->State;
>> +
>> +    if (State == CpuStateBlocked) {
>> +      *NextNumber = Index;
>> +      return EFI_SUCCESS;
>> +    }
>> +  }
>> +
>> +  return EFI_NOT_FOUND;
>> +}
>> +
>> +/** Stalls the BSP for the minimum of POLL_INTERVAL_US and Timeout.
>> +
>> +   @param[in]  Timeout    The time limit in microseconds remaining for
>> +                          APs to return from Procedure.
>> +
>> +   @retval     StallTime  Time of execution stall.
>> +**/
>> +STATIC
>> +UINTN
>> +CalculateAndStallInterval (
>> +  IN UINTN  Timeout
>> +  )
>> +{
>> +  UINTN  StallTime;
>> +
>> +  if ((Timeout < POLL_INTERVAL_US) && (Timeout != 0)) {
>> +    StallTime = Timeout;
>> +  } else {
>> +    StallTime = POLL_INTERVAL_US;
>> +  }
>> +
>> +  gBS->Stall (StallTime);
>> +
>> +  return StallTime;
>> +}
>> +
>> +/**
>> +  This service retrieves the number of logical processor in the 
>> platform
>> +  and the number of those logical processors that are enabled on 
>> this boot.
>> +  This service may only be called from the BSP.
>> +
>> +  This function is used to retrieve the following information:
>> +    - The number of logical processors that are present in the system.
>> +    - The number of enabled logical processors in the system at the 
>> instant
>> +      this call is made.
>> +
>> +  Because MP Service Protocol provides services to enable and 
>> disable processors
>> +  dynamically, the number of enabled logical processors may vary 
>> during the
>> +  course of a boot session.
>> +
>> +  If this service is called from an AP, then EFI_DEVICE_ERROR is 
>> returned.
>> +  If NumberOfProcessors or NumberOfEnabledProcessors is NULL, then
>> +  EFI_INVALID_PARAMETER is returned. Otherwise, the total number of 
>> processors
>> +  is returned in NumberOfProcessors, the number of currently enabled 
>> processor
>> +  is returned in NumberOfEnabledProcessors, and EFI_SUCCESS is 
>> returned.
>> +
>> +  @param[in]  This                        A pointer to the
>> + EFI_MP_SERVICES_PROTOCOL instance.
>> +  @param[out] NumberOfProcessors          Pointer to the total 
>> number of logical
>> +                                          processors in the system, 
>> including
>> +                                          the BSP and disabled APs.
>> +  @param[out] NumberOfEnabledProcessors   Pointer to the number of 
>> enabled
>> +                                          logical processors that 
>> exist in the
>> +                                          system, including the BSP.
>> +
>> +  @retval EFI_SUCCESS             The number of logical processors 
>> and enabled
>> +                                  logical processors was retrieved.
>> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
>> +  @retval EFI_INVALID_PARAMETER   NumberOfProcessors is NULL.
>> +  @retval EFI_INVALID_PARAMETER   NumberOfEnabledProcessors is NULL.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +GetNumberOfProcessors (
>> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
>> +  OUT UINTN                     *NumberOfProcessors,
>> +  OUT UINTN                     *NumberOfEnabledProcessors
>> +  )
>> +{
>> +  if ((NumberOfProcessors == NULL) || (NumberOfEnabledProcessors == 
>> NULL)) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  if (!IsCurrentProcessorBSP ()) {
>> +    return EFI_DEVICE_ERROR;
>> +  }
>> +
>> +  *NumberOfProcessors        = mCpuMpData.NumberOfProcessors;
>> +  *NumberOfEnabledProcessors = mCpuMpData.NumberOfEnabledProcessors;
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +  Gets detailed MP-related information on the requested processor at 
>> the
>> +  instant this call is made. This service may only be called from 
>> the BSP.
>> +
>> +  This service retrieves detailed MP-related information about any 
>> processor
>> +  on the platform. Note the following:
>> +    - The processor information may change during the course of a 
>> boot session.
>> +    - The information presented here is entirely MP related.
>> +
>> +  Information regarding the number of caches and their sizes, 
>> frequency of
>> +  operation, slot numbers is all considered platform-related 
>> information and is
>> +  not provided by this service.
>> +
>> +  @param[in]  This                  A pointer to the 
>> EFI_MP_SERVICES_PROTOCOL
>> +                                    instance.
>> +  @param[in]  ProcessorIndex        The index of the processor.
>> +  @param[out] ProcessorInfoBuffer   A pointer to the buffer where 
>> information
>> +                                    for the requested processor is 
>> deposited.
>> +
>> +  @retval EFI_SUCCESS             Processor information was returned.
>> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
>> +  @retval EFI_INVALID_PARAMETER   ProcessorInfoBuffer is NULL.
>> +  @retval EFI_NOT_FOUND           The processor with the handle 
>> specified by
>> +                                  ProcessorNumber does not exist in 
>> the platform.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +GetProcessorInfo (
>> +  IN  EFI_MP_SERVICES_PROTOCOL   *This,
>> +  IN  UINTN                      ProcessorIndex,
>> +  OUT EFI_PROCESSOR_INFORMATION  *ProcessorInfoBuffer
>> +  )
>> +{
>> +  if (ProcessorInfoBuffer == NULL) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  if (!IsCurrentProcessorBSP ()) {
>> +    return EFI_DEVICE_ERROR;
>> +  }
>> +
>> +  ProcessorIndex &= ~CPU_V2_EXTENDED_TOPOLOGY;
>> +
>> +  if (ProcessorIndex >= mCpuMpData.NumberOfProcessors) {
>> +    return EFI_NOT_FOUND;
>> +  }
>> +
>> +  CopyMem (
>> +    ProcessorInfoBuffer,
>> +    &mCpuMpData.CpuData[ProcessorIndex],
>> +    sizeof (EFI_PROCESSOR_INFORMATION)
>> +    );
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +  This service executes a caller provided function on all enabled 
>> APs. APs can
>> +  run either simultaneously or one at a time in sequence. This 
>> service supports
>> +  both blocking and non-blocking requests. The non-blocking requests 
>> use EFI
>> +  events so the BSP can detect when the APs have finished. This 
>> service may only
>> +  be called from the BSP.
>> +
>> +  This function is used to dispatch all the enabled APs to the function
>> +  specified by Procedure.  If any enabled AP is busy, then 
>> EFI_NOT_READY is
>> +  returned immediately and Procedure is not started on any AP.
>> +
>> +  If SingleThread is TRUE, all the enabled APs execute the function 
>> specified by
>> +  Procedure one by one, in ascending order of processor handle number.
>> +  Otherwise, all the enabled APs execute the function specified by 
>> Procedure
>> +  simultaneously.
>> +
>> +  If WaitEvent is NULL, execution is in blocking mode. The BSP waits 
>> until all
>> +  APs finish or TimeoutInMicroseconds expires. Otherwise, execution 
>> is in
>> +  non-blocking mode, and the BSP returns from this service without 
>> waiting for
>> +  APs. If a non-blocking mode is requested after the UEFI Event
>> +  EFI_EVENT_GROUP_READY_TO_BOOT is signaled, then EFI_UNSUPPORTED 
>> must be
>> +  returned.
>> +
>> +  If the timeout specified by TimeoutInMicroseconds expires before 
>> all APs
>> +  return from Procedure, then Procedure on the failed APs is 
>> terminated.
>> +  All enabled APs are always available for further calls to
>> +  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
>> +  EFI_MP_SERVICES_PROTOCOL.StartupThisAP(). If FailedCpuList is not 
>> NULL, its
>> +  content points to the list of processor handle numbers in which 
>> Procedure was
>> +  terminated.
>> +
>> +  Note: It is the responsibility of the consumer of the
>> +  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() to make sure that the 
>> nature of the
>> +  code that is executed on the BSP and the dispatched APs is well 
>> controlled.
>> +  The MP Services Protocol does not guarantee that the Procedure 
>> function is
>> +  MP-safe. Hence, the tasks that can be run in parallel are limited 
>> to certain
>> +  independent tasks and well-controlled exclusive code. EFI services 
>> and
>> +  protocols may not be called by APs unless otherwise specified.
>> +
>> +  In blocking execution mode, BSP waits until all APs finish or
>> +  TimeoutInMicroseconds expires.
>> +
>> +  In non-blocking execution mode, BSP is freed to return to the 
>> caller and then
>> +  proceed to the next task without having to wait for APs. The 
>> following
>> +  sequence needs to occur in a non-blocking execution mode:
>> +
>> +    -# The caller that intends to use this MP Services Protocol in 
>> non-blocking
>> +       mode creates WaitEvent by calling the EFI CreateEvent() 
>> service.  The
>> +       caller invokes EFI_MP_SERVICES_PROTOCOL.StartupAllAPs(). If 
>> the parameter
>> +       WaitEvent is not NULL, then StartupAllAPs() executes in 
>> non-blocking
>> +       mode. It requests the function specified by Procedure to be 
>> started on
>> +       all the enabled APs, and releases the BSP to continue with 
>> other tasks.
>> +    -# The caller can use the CheckEvent() and WaitForEvent() 
>> services to check
>> +       the state of the WaitEvent created in step 1.
>> +    -# When the APs complete their task or TimeoutInMicroSecondss 
>> expires, the
>> +       MP Service signals WaitEvent by calling the EFI SignalEvent() 
>> function.
>> +       If FailedCpuList is not NULL, its content is available when 
>> WaitEvent is
>> +       signaled. If all APs returned from Procedure prior to the 
>> timeout, then
>> +       FailedCpuList is set to NULL. If not all APs return from 
>> Procedure before
>> +       the timeout, then FailedCpuList is filled in with the list of 
>> the failed
>> +       APs. The buffer is allocated by MP Service Protocol using 
>> AllocatePool().
>> +       It is the caller's responsibility to free the buffer with 
>> FreePool()
>> +       service.
>> +    -# This invocation of SignalEvent() function informs the caller 
>> that invoked
>> +       EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() that either all the APs
>> +       completed the specified task or a timeout occurred. The 
>> contents of
>> +       FailedCpuList can be examined to determine which APs did not 
>> complete the
>> +       specified task prior to the timeout.
>> +
>> +  @param[in]  This                    A pointer to the 
>> EFI_MP_SERVICES_PROTOCOL
>> +                                      instance.
>> +  @param[in]  Procedure               A pointer to the function to 
>> be run on
>> +                                      enabled APs of the system. See 
>> type
>> +                                      EFI_AP_PROCEDURE.
>> +  @param[in]  SingleThread            If TRUE, then all the enabled 
>> APs execute
>> +                                      the function specified by 
>> Procedure one by
>> +                                      one, in ascending order of 
>> processor
>> +                                      handle number.  If FALSE, then 
>> all the
>> +                                      enabled APs execute the 
>> function specified
>> +                                      by Procedure simultaneously.
>> +  @param[in]  WaitEvent               The event created by the 
>> caller with
>> +                                      CreateEvent() service. If it 
>> is NULL,
>> +                                      then execute in blocking mode. 
>> BSP waits
>> +                                      until all APs finish or
>> +                                      TimeoutInMicroseconds 
>> expires.  If it's
>> +                                      not NULL, then execute in 
>> non-blocking
>> +                                      mode. BSP requests the 
>> function specified
>> +                                      by Procedure to be started on 
>> all the
>> +                                      enabled APs, and go on executing
>> +                                      immediately. If all return 
>> from Procedure,
>> +                                      or TimeoutInMicroseconds 
>> expires, this
>> +                                      event is signaled. The BSP can 
>> use the
>> +                                      CheckEvent() or WaitForEvent()
>> +                                      services to check the state of 
>> event. Type
>> +                                      EFI_EVENT is defined in 
>> CreateEvent() in
>> +                                      the Unified Extensible 
>> Firmware Interface
>> +                                      Specification.
>> +  @param[in]  TimeoutInMicroseconds   Indicates the time limit in 
>> microseconds
>> +                                      for APs to return from 
>> Procedure, either
>> +                                      for blocking or non-blocking 
>> mode. Zero
>> +                                      means infinity.  If the 
>> timeout expires
>> +                                      before all APs return from 
>> Procedure, then
>> +                                      Procedure on the failed APs is 
>> terminated.
>> +                                      All enabled APs are available 
>> for next
>> +                                      function assigned by
>> + EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
>> +                                      or 
>> EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
>> +                                      If the timeout expires in 
>> blocking mode,
>> +                                      BSP returns EFI_TIMEOUT. If 
>> the timeout
>> +                                      expires in non-blocking mode, 
>> WaitEvent
>> +                                      is signaled with SignalEvent().
>> +  @param[in]  ProcedureArgument       The parameter passed into 
>> Procedure for
>> +                                      all APs.
>> +  @param[out] FailedCpuList           If NULL, this parameter is 
>> ignored.
>> +                                      Otherwise, if all APs finish 
>> successfully,
>> +                                      then its content is set to 
>> NULL. If not
>> +                                      all APs finish before timeout 
>> expires,
>> +                                      then its content is set to 
>> address of the
>> +                                      buffer holding handle numbers 
>> of the
>> +                                      failed APs.
>> +                                      The buffer is allocated by MP 
>> Service
>> +                                      Protocol, and it's the caller's
>> +                                      responsibility to free the 
>> buffer with
>> +                                      FreePool() service.
>> +                                      In blocking mode, it is ready for
>> +                                      consumption when the call 
>> returns. In
>> +                                      non-blocking mode, it is ready 
>> when
>> +                                      WaitEvent is signaled. The 
>> list of failed
>> +                                      CPU is terminated by 
>> END_OF_CPU_LIST.
>> +
>> +  @retval EFI_SUCCESS             In blocking mode, all APs have 
>> finished before
>> +                                  the timeout expired.
>> +  @retval EFI_SUCCESS             In non-blocking mode, function has 
>> been
>> +                                  dispatched to all enabled APs.
>> +  @retval EFI_UNSUPPORTED         A non-blocking mode request was 
>> made after the
>> +                                  UEFI event 
>> EFI_EVENT_GROUP_READY_TO_BOOT was
>> +                                  signaled.
>> +  @retval EFI_DEVICE_ERROR        Caller processor is AP.
>> +  @retval EFI_NOT_STARTED         No enabled APs exist in the system.
>> +  @retval EFI_NOT_READY           Any enabled APs are busy.
>> +  @retval EFI_TIMEOUT             In blocking mode, the timeout 
>> expired before
>> +                                  all enabled APs have finished.
>> +  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +StartupAllAPs (
>> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
>> +  IN  EFI_AP_PROCEDURE          Procedure,
>> +  IN  BOOLEAN                   SingleThread,
>> +  IN  EFI_EVENT                 WaitEvent OPTIONAL,
>> +  IN  UINTN                     TimeoutInMicroseconds,
>> +  IN  VOID                      *ProcedureArgument OPTIONAL,
>> +  OUT UINTN                     **FailedCpuList OPTIONAL
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +
>> +  if (!IsCurrentProcessorBSP ()) {
>> +    return EFI_DEVICE_ERROR;
>> +  }
>> +
>> +  if (mCpuMpData.NumberOfProcessors == 1) {
>> +    return EFI_NOT_STARTED;
>> +  }
>> +
>> +  if (Procedure == NULL) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
>> +    return EFI_UNSUPPORTED;
>> +  }
>> +
>> +  if (FailedCpuList != NULL) {
>> +    mCpuMpData.FailedList = AllocateZeroPool (
>> +                              (mCpuMpData.NumberOfProcessors + 1) *
>> +                              sizeof (UINTN)
>> +                              );
>> +    if (mCpuMpData.FailedList == NULL) {
>> +      return EFI_OUT_OF_RESOURCES;
>> +    }
>> +
>> +    SetMemN (
>> +      mCpuMpData.FailedList,
>> +      (mCpuMpData.NumberOfProcessors + 1) *
>> +      sizeof (UINTN),
>> +      END_OF_CPU_LIST
>> +      );
>> +    mCpuMpData.FailedListIndex = 0;
>> +    *FailedCpuList             = mCpuMpData.FailedList;
>> +  }
>> +
>> +  StartupAllAPsPrepareState (SingleThread);
>> +
>> +  if (WaitEvent != NULL) {
>> +    Status = StartupAllAPsWithWaitEvent (
>> +               Procedure,
>> +               ProcedureArgument,
>> +               WaitEvent,
>> +               TimeoutInMicroseconds,
>> +               SingleThread,
>> +               FailedCpuList
>> +               );
>> +
>> +    if (EFI_ERROR (Status) && (FailedCpuList != NULL)) {
>> +      if (mCpuMpData.FailedListIndex == 0) {
>> +        FreePool (*FailedCpuList);
>> +        *FailedCpuList = NULL;
>> +      }
>> +    }
>> +  } else {
>> +    Status = StartupAllAPsNoWaitEvent (
>> +               Procedure,
>> +               ProcedureArgument,
>> +               TimeoutInMicroseconds,
>> +               SingleThread,
>> +               FailedCpuList
>> +               );
>> +
>> +    if (FailedCpuList != NULL) {
>> +      if (mCpuMpData.FailedListIndex == 0) {
>> +        FreePool (*FailedCpuList);
>> +        *FailedCpuList = NULL;
>> +      }
>> +    }
>> +  }
>> +
>> +  return Status;
>> +}
>> +
>> +/**
>> +  This service lets the caller get one enabled AP to execute a 
>> caller-provided
>> +  function. The caller can request the BSP to either wait for the 
>> completion
>> +  of the AP or just proceed with the next task by using the EFI 
>> event mechanism.
>> +  See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on 
>> non-blocking
>> +  execution support.  This service may only be called from the BSP.
>> +
>> +  This function is used to dispatch one enabled AP to the function 
>> specified by
>> +  Procedure passing in the argument specified by ProcedureArgument.  
>> If WaitEvent
>> +  is NULL, execution is in blocking mode. The BSP waits until the AP 
>> finishes or
>> +  TimeoutInMicroSecondss expires. Otherwise, execution is in 
>> non-blocking mode.
>> +  BSP proceeds to the next task without waiting for the AP. If a 
>> non-blocking mode
>> +  is requested after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is 
>> signaled,
>> +  then EFI_UNSUPPORTED must be returned.
>> +
>> +  If the timeout specified by TimeoutInMicroseconds expires before 
>> the AP returns
>> +  from Procedure, then execution of Procedure by the AP is 
>> terminated. The AP is
>> +  available for subsequent calls to 
>> EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
>> +  EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
>> +
>> +  @param[in]  This                    A pointer to the 
>> EFI_MP_SERVICES_PROTOCOL
>> +                                      instance.
>> +  @param[in]  Procedure               A pointer to the function to 
>> be run on
>> +                                      enabled APs of the system. See 
>> type
>> +                                      EFI_AP_PROCEDURE.
>> +  @param[in]  ProcessorNumber         The handle number of the AP. 
>> The range is
>> +                                      from 0 to the total number of 
>> logical
>> +                                      processors minus 1. The total 
>> number of
>> +                                      logical processors can be 
>> retrieved by
>> + EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
>> +  @param[in]  WaitEvent               The event created by the 
>> caller with CreateEvent()
>> +                                      service.  If it is NULL, then 
>> execute in
>> +                                      blocking mode. BSP waits until 
>> all APs finish
>> +                                      or TimeoutInMicroseconds 
>> expires.  If it's
>> +                                      not NULL, then execute in 
>> non-blocking mode.
>> +                                      BSP requests the function 
>> specified by
>> +                                      Procedure to be started on all 
>> the enabled
>> +                                      APs, and go on executing 
>> immediately. If
>> +                                      all return from Procedure or 
>> TimeoutInMicroseconds
>> +                                      expires, this event is 
>> signaled. The BSP
>> +                                      can use the CheckEvent() or 
>> WaitForEvent()
>> +                                      services to check the state of 
>> event.  Type
>> +                                      EFI_EVENT is defined in 
>> CreateEvent() in
>> +                                      the Unified Extensible 
>> Firmware Interface
>> +                                      Specification.
>> +  @param[in]  TimeoutInMicroseconds   Indicates the time limit in 
>> microseconds for
>> +                                      APs to return from Procedure, 
>> either for
>> +                                      blocking or non-blocking mode. 
>> Zero means
>> +                                      infinity.  If the timeout 
>> expires before
>> +                                      all APs return from Procedure, 
>> then Procedure
>> +                                      on the failed APs is 
>> terminated. All enabled
>> +                                      APs are available for next 
>> function assigned
>> +                                      by 
>> EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
>> +                                      or 
>> EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
>> +                                      If the timeout expires in 
>> blocking mode,
>> +                                      BSP returns EFI_TIMEOUT. If 
>> the timeout
>> +                                      expires in non-blocking mode, 
>> WaitEvent
>> +                                      is signaled with SignalEvent().
>> +  @param[in]  ProcedureArgument       The parameter passed into 
>> Procedure for
>> +                                      all APs.
>> +  @param[out] Finished                If NULL, this parameter is 
>> ignored.  In
>> +                                      blocking mode, this parameter 
>> is ignored.
>> +                                      In non-blocking mode, if AP 
>> returns from
>> +                                      Procedure before the timeout 
>> expires, its
>> +                                      content is set to TRUE. 
>> Otherwise, the
>> +                                      value is set to FALSE. The 
>> caller can
>> +                                      determine if the AP returned 
>> from Procedure
>> +                                      by evaluating this value.
>> +
>> +  @retval EFI_SUCCESS             In blocking mode, specified AP 
>> finished before
>> +                                  the timeout expires.
>> +  @retval EFI_SUCCESS             In non-blocking mode, the function 
>> has been
>> +                                  dispatched to specified AP.
>> +  @retval EFI_UNSUPPORTED         A non-blocking mode request was 
>> made after the
>> +                                  UEFI event 
>> EFI_EVENT_GROUP_READY_TO_BOOT was
>> +                                  signaled.
>> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
>> +  @retval EFI_TIMEOUT             In blocking mode, the timeout 
>> expired before
>> +                                  the specified AP has finished.
>> +  @retval EFI_NOT_READY           The specified AP is busy.
>> +  @retval EFI_NOT_FOUND           The processor with the handle 
>> specified by
>> +                                  ProcessorNumber does not exist.
>> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP 
>> or disabled AP.
>> +  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +StartupThisAP (
>> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
>> +  IN  EFI_AP_PROCEDURE          Procedure,
>> +  IN  UINTN                     ProcessorNumber,
>> +  IN  EFI_EVENT                 WaitEvent OPTIONAL,
>> +  IN  UINTN                     TimeoutInMicroseconds,
>> +  IN  VOID                      *ProcedureArgument OPTIONAL,
>> +  OUT BOOLEAN                   *Finished OPTIONAL
>> +  )
>> +{
>> +  EFI_STATUS   Status;
>> +  UINTN        Timeout;
>> +  CPU_AP_DATA  *CpuData;
>> +
>> +  if (!IsCurrentProcessorBSP ()) {
>> +    return EFI_DEVICE_ERROR;
>> +  }
>> +
>> +  if (Procedure == NULL) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
>> +    return EFI_NOT_FOUND;
>> +  }
>> +
>> +  CpuData = &mCpuMpData.CpuData[ProcessorNumber];
>> +
>> +  if (IsProcessorBSP (ProcessorNumber)) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  if (!IsProcessorEnabled (ProcessorNumber)) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  if (GetApState (CpuData) != CpuStateIdle) {
>> +    return EFI_NOT_READY;
>> +  }
>> +
>> +  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
>> +    return EFI_UNSUPPORTED;
>> +  }
>> +
>> +  Timeout = TimeoutInMicroseconds;
>> +
>> +  mCpuMpData.Timeout       = TimeoutInMicroseconds;
>> +  mCpuMpData.TimeTaken     = 0;
>> +  mCpuMpData.TimeoutActive = (BOOLEAN)(TimeoutInMicroseconds != 0);
>
> [KQ] Adding a timeout active flag is correct. However, I think each AP 
> should have its own timeout related
> data (that is Timeout, TimeTaken and TimeoutActive). Because i.e. if 
> this StartupThisAp call is used on AP 1 in
> a non-blocking mode, then a subsequent call on AP 2 is blocking, the 
> common flag and timeout values will
> impact both cores, and create unintended timeout events.
>
>> +
>> +  mCpuMpData.StartCount  = 1;
>> +  mCpuMpData.FinishCount = 0;
>> +
>> +  SetApProcedure (
>> +    CpuData,
>> +    Procedure,
>> +    ProcedureArgument
>> +    );
>> +
>> +  Status = DispatchCpu (ProcessorNumber);
>> +  if (EFI_ERROR (Status)) {
>> +    CpuData->State = CpuStateIdle;
>> +    return EFI_NOT_READY;
>> +  }
>> +
>> +  if (WaitEvent != NULL) {
>> +    // Non Blocking
>> +    if (Finished != NULL) {
>> +      mCpuMpData.SingleApFinished = Finished;
>> +      *Finished                   = FALSE;
>> +    }
>> +
>> +    mCpuMpData.WaitEvent = WaitEvent;
>> +    Status               = gBS->SetTimer (
>> +                                  CpuData->CheckThisAPEvent,
>> +                                  TimerPeriodic,
>> +                                  POLL_INTERVAL_US
>> +                                  );
>> +
>> +    return EFI_SUCCESS;
>> +  }
>> +
>> +  // Blocking
>> +  while (TRUE) {
>> +    if (GetApState (CpuData) == CpuStateFinished) {
>> +      CpuData->State = CpuStateIdle;
>> +      break;
>> +    }
>> +
>> +    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
[KQ-2] This will make the core never being able to accept the subsequent 
start up calls due to this CPU data state will
never be updated to CpuStateIdle. If this AP completes the job after 
timeout, ApProcedure will only be able to transition
its state to CpuStateFinished. Should we add a timer (when there is a 
timeout period specified) and use CpuData->CheckThisAPEvent
to check and try to sync the CPU states for this case?
>> +      return EFI_TIMEOUT;
>> +    }
>> +
>> +    Timeout -= CalculateAndStallInterval (Timeout);
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +  This service switches the requested AP to be the BSP from that 
>> point onward.
>> +  This service changes the BSP for all purposes.   This call can 
>> only be
>> +  performed by the current BSP.
>> +
>> +  This service switches the requested AP to be the BSP from that 
>> point onward.
>> +  This service changes the BSP for all purposes. The new BSP can 
>> take over the
>> +  execution of the old BSP and continue seamlessly from where the 
>> old one left
>> +  off. This service may not be supported after the UEFI Event 
>> EFI_EVENT_GROUP_READY_TO_BOOT
>> +  is signaled.
>> +
>> +  If the BSP cannot be switched prior to the return from this 
>> service, then
>> +  EFI_UNSUPPORTED must be returned.
>> +
>> +  @param[in] This              A pointer to the 
>> EFI_MP_SERVICES_PROTOCOL instance.
>> +  @param[in] ProcessorNumber   The handle number of AP that is to 
>> become the new
>> +                               BSP. The range is from 0 to the total 
>> number of
>> +                               logical processors minus 1. The total 
>> number of
>> +                               logical processors can be retrieved by
>> + EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
>> +  @param[in] EnableOldBSP      If TRUE, then the old BSP will be 
>> listed as an
>> +                               enabled AP. Otherwise, it will be 
>> disabled.
>> +
>> +  @retval EFI_SUCCESS             BSP successfully switched.
>> +  @retval EFI_UNSUPPORTED         Switching the BSP cannot be 
>> completed prior to
>> +                                  this service returning.
>> +  @retval EFI_UNSUPPORTED         Switching the BSP is not supported.
>> +  @retval EFI_SUCCESS             The calling processor is an AP.
>> +  @retval EFI_NOT_FOUND           The processor with the handle 
>> specified by
>> +                                  ProcessorNumber does not exist.
>> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the 
>> current BSP or
>> +                                  a disabled AP.
>> +  @retval EFI_NOT_READY           The specified AP is busy.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +SwitchBSP (
>> +  IN EFI_MP_SERVICES_PROTOCOL  *This,
>> +  IN  UINTN                    ProcessorNumber,
>> +  IN  BOOLEAN                  EnableOldBSP
>> +  )
>> +{
>> +  return EFI_UNSUPPORTED;
>> +}
>> +
>> +/**
>> +  This service lets the caller enable or disable an AP from this 
>> point onward.
>> +  This service may only be called from the BSP.
>> +
>> +  This service allows the caller enable or disable an AP from this 
>> point onward.
>> +  The caller can optionally specify the health status of the AP by 
>> Health. If
>> +  an AP is being disabled, then the state of the disabled AP is 
>> implementation
>> +  dependent. If an AP is enabled, then the implementation must 
>> guarantee that a
>> +  complete initialization sequence is performed on the AP, so the AP 
>> is in a state
>> +  that is compatible with an MP operating system. This service may 
>> not be supported
>> +  after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled.
>> +
>> +  If the enable or disable AP operation cannot be completed prior to 
>> the return
>> +  from this service, then EFI_UNSUPPORTED must be returned.
>> +
>> +  @param[in] This              A pointer to the 
>> EFI_MP_SERVICES_PROTOCOL instance.
>> +  @param[in] ProcessorNumber   The handle number of AP that is to 
>> become the new
>> +                               BSP. The range is from 0 to the total 
>> number of
>> +                               logical processors minus 1. The total 
>> number of
>> +                               logical processors can be retrieved by
>> + EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
>> +  @param[in] EnableAP          Specifies the new state for the 
>> processor for
>> +                               enabled, FALSE for disabled.
>> +  @param[in] HealthFlag        If not NULL, a pointer to a value 
>> that specifies
>> +                               the new health status of the AP. This 
>> flag
>> +                               corresponds to StatusFlag defined in
>> + EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
>> +                               the PROCESSOR_HEALTH_STATUS_BIT is 
>> used. All other
>> +                               bits are ignored.  If it is NULL, 
>> this parameter
>> +                               is ignored.
>> +
>> +  @retval EFI_SUCCESS             The specified AP was enabled or 
>> disabled successfully.
>> +  @retval EFI_UNSUPPORTED         Enabling or disabling an AP cannot 
>> be completed
>> +                                  prior to this service returning.
>> +  @retval EFI_UNSUPPORTED         Enabling or disabling an AP is not 
>> supported.
>> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
>> +  @retval EFI_NOT_FOUND           Processor with the handle 
>> specified by ProcessorNumber
>> +                                  does not exist.
>> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +EnableDisableAP (
>> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
>> +  IN  UINTN                     ProcessorNumber,
>> +  IN  BOOLEAN                   EnableAP,
>> +  IN  UINT32                    *HealthFlag OPTIONAL
>> +  )
>> +{
>> +  UINTN        StatusFlag;
>> +  CPU_AP_DATA  *CpuData;
>> +
>> +  StatusFlag = mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag;
>> +  CpuData    = &mCpuMpData.CpuData[ProcessorNumber];
>> +
>> +  if (!IsCurrentProcessorBSP ()) {
>> +    return EFI_DEVICE_ERROR;
>> +  }
>> +
>> +  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
>> +    return EFI_NOT_FOUND;
>> +  }
>> +
>> +  if (IsProcessorBSP (ProcessorNumber)) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  if (GetApState (CpuData) != CpuStateIdle) {
>> +    return EFI_UNSUPPORTED;
>> +  }
>> +
>> +  if (EnableAP) {
>> +    if (!IsProcessorEnabled (ProcessorNumber)) {
>> +      mCpuMpData.NumberOfEnabledProcessors++;
>> +    }
>> +
>> +    StatusFlag |= PROCESSOR_ENABLED_BIT;
>> +  } else {
>> +    if (IsProcessorEnabled (ProcessorNumber)) {
>> +      mCpuMpData.NumberOfEnabledProcessors--;
>> +    }
>> +
>> +    StatusFlag &= ~PROCESSOR_ENABLED_BIT;
>> +  }
>> +
>> +  if (HealthFlag != NULL) {
>> +    StatusFlag &= ~PROCESSOR_HEALTH_STATUS_BIT;
>> +    StatusFlag |= (*HealthFlag & PROCESSOR_HEALTH_STATUS_BIT);
>> +  }
>> +
>> +  mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag = StatusFlag;
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +  This return the handle number for the calling processor. This 
>> service may be
>> +  called from the BSP and APs.
>> +
>> +  This service returns the processor handle number for the calling 
>> processor.
>> +  The returned value is in the range from 0 to the total number of 
>> logical
>> +  processors minus 1. The total number of logical processors can be 
>> retrieved
>> +  with EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors(). This 
>> service may be
>> +  called from the BSP and APs. If ProcessorNumber is NULL, then 
>> EFI_INVALID_PARAMETER
>> +  is returned. Otherwise, the current processors handle number is 
>> returned in
>> +  ProcessorNumber, and EFI_SUCCESS is returned.
>> +
>> +  @param[in] This              A pointer to the 
>> EFI_MP_SERVICES_PROTOCOL instance.
>> +  @param[out] ProcessorNumber  The handle number of AP that is to 
>> become the new
>> +                               BSP. The range is from 0 to the total 
>> number of
>> +                               logical processors minus 1. The total 
>> number of
>> +                               logical processors can be retrieved by
>> + EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
>> +
>> +  @retval EFI_SUCCESS             The current processor handle 
>> number was returned
>> +                                  in ProcessorNumber.
>> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber is NULL.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +WhoAmI (
>> +  IN EFI_MP_SERVICES_PROTOCOL  *This,
>> +  OUT UINTN                    *ProcessorNumber
>> +  )
>> +{
>> +  UINTN   Index;
>> +  UINT64  ProcessorId;
>> +
>> +  if (ProcessorNumber == NULL) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  ProcessorId = GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ());
>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>> +    if (ProcessorId == gProcessorIDs[Index]) {
>> +      *ProcessorNumber = Index;
>> +      break;
>> +    }
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +STATIC EFI_MP_SERVICES_PROTOCOL  mMpServicesProtocol = {
>> +  GetNumberOfProcessors,
>> +  GetProcessorInfo,
>> +  StartupAllAPs,
>> +  StartupThisAP,
>> +  SwitchBSP,
>> +  EnableDisableAP,
>> +  WhoAmI
>> +};
>> +
>> +/** Adds the specified processor the list of failed processors.
>> +
>> +   @param ProcessorIndex The processor index to add.
>> +   @param ApState        Processor state.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +AddProcessorToFailedList (
>> +  UINTN      ProcessorIndex,
>> +  CPU_STATE  ApState
>> +  )
>> +{
>> +  UINTN    Index;
>> +  BOOLEAN  Found;
>> +
>> +  Found = FALSE;
>> +
>> +  if ((mCpuMpData.FailedList == NULL) ||
>> +      (ApState == CpuStateIdle) ||
>> +      (ApState == CpuStateFinished) ||
>> +      IsProcessorBSP (ProcessorIndex))
>> +  {
>> +    return;
>> +  }
>> +
>> +  // If we are retrying make sure we don't double count
>> +  for (Index = 0; Index < mCpuMpData.FailedListIndex; Index++) {
>> +    if (mCpuMpData.FailedList[Index] == ProcessorIndex) {
>> +      Found = TRUE;
>> +      break;
>> +    }
>> +  }
>> +
>> +  /* If the CPU isn't already in the FailedList, add it */
>> +  if (!Found) {
>> +    mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = 
>> ProcessorIndex;
>> +  }
>> +}
>> +
>> +/** Handles the StartupAllAPs case where the timeout has occurred.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +ProcessStartupAllAPsTimeout (
>> +  VOID
>> +  )
>> +{
>> +  CPU_AP_DATA  *CpuData;
>> +  UINTN        Index;
>> +
>> +  if (mCpuMpData.FailedList == NULL) {
>> +    return;
>> +  }
>> +
>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>> +    CpuData = &mCpuMpData.CpuData[Index];
>> +    if (IsProcessorBSP (Index)) {
>> +      // Skip BSP
>> +      continue;
>> +    }
>> +
>> +    if (!IsProcessorEnabled (Index)) {
>> +      // Skip Disabled processors
>> +      continue;
>> +    }
>> +
>> +    CpuData = &mCpuMpData.CpuData[Index];
>> +    AddProcessorToFailedList (Index, GetApState (CpuData));
>> +  }
>> +}
>> +
>> +/** Updates the status of the APs.
>> +
>> +   @param[in] ProcessorIndex The index of the AP to update.
>> +**/
>> +STATIC
>> +VOID
>> +UpdateApStatus (
>> +  IN UINTN  ProcessorIndex
>> +  )
>> +{
>> +  EFI_STATUS   Status;
>> +  CPU_AP_DATA  *CpuData;
>> +  CPU_AP_DATA  *NextCpuData;
>> +  CPU_STATE    State;
>> +  UINTN        NextNumber;
>> +
>> +  CpuData = &mCpuMpData.CpuData[ProcessorIndex];
>> +
>> +  if (IsProcessorBSP (ProcessorIndex)) {
>> +    // Skip BSP
>> +    return;
>> +  }
>> +
>> +  if (!IsProcessorEnabled (ProcessorIndex)) {
>> +    // Skip Disabled processors
>> +    return;
>> +  }
>> +
>> +  State = GetApState (CpuData);
>> +
>> +  switch (State) {
>> +    case CpuStateFinished:
>> +      if (mCpuMpData.SingleThread) {
>> +        Status = GetNextBlockedNumber (&NextNumber);
>> +        if (!EFI_ERROR (Status)) {
>> +          NextCpuData = &mCpuMpData.CpuData[NextNumber];
>> +
>> +          NextCpuData->State = CpuStateReady;
>> +
>> +          SetApProcedure (
>> +            NextCpuData,
>> +            mCpuMpData.Procedure,
>> +            mCpuMpData.ProcedureArgument
>> +            );
>> +
>> +          Status = DispatchCpu (NextNumber);
>> +          if (!EFI_ERROR (Status)) {
>> +            mCpuMpData.StartCount++;
>> +          } else {
>> +            AddProcessorToFailedList (NextNumber, NextCpuData->State);
>> +          }
>> +        }
>> +      }
>> +
>> +      CpuData->State = CpuStateIdle;
>> +      mCpuMpData.FinishCount++;
>> +      break;
>> +
>> +    default:
>> +      break;
>> +  }
>> +}
>> +
>> +/**
>> +  If a timeout is specified in StartupAllAps(), a timer is set, 
>> which invokes
>> +  this procedure periodically to check whether all APs have finished.
>> +
>> +  @param[in] Event   The WaitEvent the user supplied.
>> +  @param[in] Context The event context.
>> +**/
>> +STATIC
>> +VOID
>> +EFIAPI
>> +CheckAllAPsStatus (
>> +  IN  EFI_EVENT  Event,
>> +  IN  VOID       *Context
>> +  )
>> +{
>> +  UINTN  Index;
>> +
>> +  mCpuMpData.TimeTaken += POLL_INTERVAL_US;
>> +
>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>> +    UpdateApStatus (Index);
>> +  }
>> +
>> +  if (mCpuMpData.TimeoutActive && (mCpuMpData.TimeTaken > 
>> mCpuMpData.Timeout)) {
>> +    ProcessStartupAllAPsTimeout ();
>> +
>> +    // Force terminal exit
>> +    mCpuMpData.FinishCount = mCpuMpData.StartCount;
>> +  }
>> +
>> +  if (mCpuMpData.FinishCount != mCpuMpData.StartCount) {
>> +    return;
>> +  }
>> +
>> +  gBS->SetTimer (
>> +         mCpuMpData.CheckAllAPsEvent,
>> +         TimerCancel,
>> +         0
>> +         );
>> +
>> +  if (mCpuMpData.FailedListIndex == 0) {
>> +    if (mCpuMpData.FailedList != NULL) {
>> +      // Since we don't have the original `FailedCpuList`
>> +      // pointer here to set to NULL, don't free the
>> +      // memory.
>> +    }
>> +  }
>> +
>> +  gBS->SignalEvent (mCpuMpData.WaitEvent);
>> +}
>> +
>> +/** Invoked periodically via a timer to check the state of the 
>> processor.
>> +
>> +   @param Event   The event supplied by the timer expiration.
>> +   @param Context The processor context.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +EFIAPI
>> +CheckThisAPStatus (
>> +  IN  EFI_EVENT  Event,
>> +  IN  VOID       *Context
>> +  )
>> +{
>> +  EFI_STATUS   Status;
>> +  CPU_AP_DATA  *CpuData;
>> +  CPU_STATE    State;
>> +
>> +  CpuData = Context;
>> +
>> +  mCpuMpData.TimeTaken += POLL_INTERVAL_US;
>> +
>> +  State = GetApState (CpuData);
>> +
>> +  if (State == CpuStateFinished) {
>> +    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 0);
>> +    ASSERT_EFI_ERROR (Status);
>> +
>> +    if (mCpuMpData.SingleApFinished != NULL) {
>> +      *mCpuMpData.SingleApFinished = TRUE;
>> +    }
>> +
>> +    if (mCpuMpData.WaitEvent != NULL) {
>> +      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
>> +      ASSERT_EFI_ERROR (Status);
>> +    }
>> +
>> +    CpuData->State = CpuStateIdle;
>> +  }
>> +
>> +  if (mCpuMpData.TimeoutActive && (mCpuMpData.TimeTaken > 
>> mCpuMpData.Timeout)) {
> [KQ] Similar to the other comment, this is probably better using a 
> per-core data to track elapsed time.
> On a side note, if this timeout ever occurs, this core will never be 
> usable in next StartupThisAp calls due
> to this AP state will not be set to Idle even if the AP procedure is 
> complete. Is this the intended behavior?
>> +    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 0);
>> +    if (mCpuMpData.WaitEvent != NULL) {
>> +      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
>> +      ASSERT_EFI_ERROR (Status);
>> +    }
>> +  }
>> +}
>> +
>> +/**
>> +  This function is called by all processors (both BSP and AP) once 
>> and collects
>> +  MP related data.
>> +
>> +  @param BSP            TRUE if the processor is the BSP.
>> +  @param Mpidr          The MPIDR for the specified processor. This 
>> should be
>> +                        the full MPIDR and not only the affinity bits.
>> +  @param ProcessorIndex The index of the processor.
>> +
>> +  @return EFI_SUCCESS if the data for the processor collected and 
>> filled in.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +FillInProcessorInformation (
>> +  IN BOOLEAN  BSP,
>> +  IN UINTN    Mpidr,
>> +  IN UINTN    ProcessorIndex
>> +  )
>> +{
>> +  EFI_PROCESSOR_INFORMATION  *CpuInfo;
>> +
>> +  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
>> +
>> +  CpuInfo->ProcessorId = GET_MPIDR_AFFINITY_BITS (Mpidr);
>> +  CpuInfo->StatusFlag  = PROCESSOR_ENABLED_BIT | 
>> PROCESSOR_HEALTH_STATUS_BIT;
>> +
>> +  if (BSP) {
>> +    CpuInfo->StatusFlag |= PROCESSOR_AS_BSP_BIT;
>> +  }
>> +
>> +  if ((Mpidr & MPIDR_MT_BIT) > 0) {
>> +    CpuInfo->Location.Package = GET_MPIDR_AFF2 (Mpidr);
>> +    CpuInfo->Location.Core    = GET_MPIDR_AFF1 (Mpidr);
>> +    CpuInfo->Location.Thread  = GET_MPIDR_AFF0 (Mpidr);
>> +
>> +    CpuInfo->ExtendedInformation.Location2.Package = GET_MPIDR_AFF3 
>> (Mpidr);
>> +    CpuInfo->ExtendedInformation.Location2.Die     = GET_MPIDR_AFF2 
>> (Mpidr);
>> +    CpuInfo->ExtendedInformation.Location2.Core    = GET_MPIDR_AFF1 
>> (Mpidr);
>> +    CpuInfo->ExtendedInformation.Location2.Thread  = GET_MPIDR_AFF0 
>> (Mpidr);
>> +  } else {
>> +    CpuInfo->Location.Package = GET_MPIDR_AFF1 (Mpidr);
>> +    CpuInfo->Location.Core    = GET_MPIDR_AFF0 (Mpidr);
>> +    CpuInfo->Location.Thread  = 0;
>> +
>> +    CpuInfo->ExtendedInformation.Location2.Package = GET_MPIDR_AFF2 
>> (Mpidr);
>> +    CpuInfo->ExtendedInformation.Location2.Die     = GET_MPIDR_AFF1 
>> (Mpidr);
>> +    CpuInfo->ExtendedInformation.Location2.Core    = GET_MPIDR_AFF0 
>> (Mpidr);
>> +    CpuInfo->ExtendedInformation.Location2.Thread  = 0;
>> +  }
>> +
>> +  mCpuMpData.CpuData[ProcessorIndex].State = BSP ? CpuStateBusy : 
>> CpuStateIdle;
>> +
>> +  mCpuMpData.CpuData[ProcessorIndex].Procedure = NULL;
>> +  mCpuMpData.CpuData[ProcessorIndex].Parameter = NULL;
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/** Initializes the MP Services system data
>> +
>> +   @param NumberOfProcessors The number of processors, both BSP and AP.
>> +   @param CoreInfo           CPU information gathered earlier during 
>> boot.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +MpServicesInitialize (
>> +  IN   UINTN                NumberOfProcessors,
>> +  IN   CONST ARM_CORE_INFO  *CoreInfo
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  UINTN       Index;
>> +  EFI_EVENT   ReadyToBootEvent;
>> +  BOOLEAN     IsBsp;
>> +
>> +  //
>> +  // Clear the data structure area first.
>> +  //
>> +  ZeroMem (&mCpuMpData, sizeof (CPU_MP_DATA));
>> +  //
>> +  // First BSP fills and inits all known values, including its own 
>> records.
>> +  //
>> +  mCpuMpData.NumberOfProcessors        = NumberOfProcessors;
>> +  mCpuMpData.NumberOfEnabledProcessors = NumberOfProcessors;
>> +
>> +  mCpuMpData.CpuData = AllocateZeroPool (
>> +                         mCpuMpData.NumberOfProcessors * sizeof 
>> (CPU_AP_DATA)
>> +                         );
>> +
>> +  if (mCpuMpData.CpuData == NULL) {
>> +    return EFI_OUT_OF_RESOURCES;
>> +  }
>> +
>> +  /* Allocate one extra for the sentinel entry at the end */
>> +  gProcessorIDs = AllocateZeroPool ((mCpuMpData.NumberOfProcessors + 
>> 1) * sizeof (UINT64));
>> +  ASSERT (gProcessorIDs != NULL);
>> +
>> +  Status = gBS->CreateEvent (
>> +                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
>> +                  TPL_CALLBACK,
>> +                  CheckAllAPsStatus,
>> +                  NULL,
>> +                  &mCpuMpData.CheckAllAPsEvent
>> +                  );
>> +  ASSERT_EFI_ERROR (Status);
>> +
>> +  gApStacksBase = AllocatePages (
>> +                    EFI_SIZE_TO_PAGES (
>> +                      mCpuMpData.NumberOfProcessors *
>> +                      gApStackSize
>> +                      )
>> +                    );
>> +  ASSERT (gApStacksBase != NULL);
>> +
>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>> +    if (GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ()) == 
>> CoreInfo[Index].Mpidr) {
>> +      IsBsp = TRUE;
>> +    } else {
>> +      IsBsp = FALSE;
>> +    }
>> +
>> +    FillInProcessorInformation (IsBsp, CoreInfo[Index].Mpidr, Index);
>> +
>> +    gProcessorIDs[Index] = mCpuMpData.CpuData[Index].Info.ProcessorId;
>> +
>> +    Status = gBS->CreateEvent (
>> +                    EVT_TIMER | EVT_NOTIFY_SIGNAL,
>> +                    TPL_CALLBACK,
>> +                    CheckThisAPStatus,
>> +                    (VOID *)&mCpuMpData.CpuData[Index],
>> + &mCpuMpData.CpuData[Index].CheckThisAPEvent
>> +                    );
>> +    ASSERT_EFI_ERROR (Status);
>> +  }
>> +
>> +  gProcessorIDs[Index] = MAX_UINT64;
>> +
>> +  //
>> +  // The global pointer variables as well as the gProcessorIDs array 
>> contents
>> +  // are accessed by the other cores so we must clean them to the PoC
>> +  //
>> +  WriteBackDataCacheRange (&gProcessorIDs, sizeof (UINT64 *));
>> +  WriteBackDataCacheRange (&gApStacksBase, sizeof (UINT64 *));
>> +
>> +  WriteBackDataCacheRange (
>> +    gProcessorIDs,
>> +    (mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64)
>> +    );
>> +
>> +  mNonBlockingModeAllowed = TRUE;
>> +
>> +  Status = EfiCreateEventReadyToBootEx (
>> +             TPL_CALLBACK,
>> +             ReadyToBootSignaled,
>> +             NULL,
>> +             &ReadyToBootEvent
>> +             );
>> +  ASSERT_EFI_ERROR (Status);
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +  Event notification function called when the 
>> EFI_EVENT_GROUP_READY_TO_BOOT is
>> +  signaled. After this point, non-blocking mode is no longer allowed.
>> +
>> +  @param  Event     Event whose notification function is being invoked.
>> +  @param  Context   The pointer to the notification function's context,
>> +                    which is implementation-dependent.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +EFIAPI
>> +ReadyToBootSignaled (
>> +  IN  EFI_EVENT  Event,
>> +  IN  VOID       *Context
>> +  )
>> +{
>> +  mNonBlockingModeAllowed = FALSE;
>> +}
>> +
>> +/** Initialize multi-processor support.
>> +
>> +  @param ImageHandle  Image handle.
>> +  @param SystemTable  System table.
>> +
>> +  @return EFI_SUCCESS on success, or an error code.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +ArmPsciMpServicesDxeInitialize (
>> +  IN EFI_HANDLE        ImageHandle,
>> +  IN EFI_SYSTEM_TABLE  *SystemTable
>> +  )
>> +{
>> +  EFI_STATUS                 Status;
>> +  EFI_HANDLE                 Handle;
>> +  UINTN                      MaxCpus;
>> +  EFI_LOADED_IMAGE_PROTOCOL  *Image;
>> +  EFI_HOB_GENERIC_HEADER     *Hob;
>> +  VOID                       *HobData;
>> +  UINTN                      HobDataSize;
>> +  CONST ARM_CORE_INFO        *CoreInfo;
>> +
>> +  MaxCpus = 1;
>> +
>> +  Status = gBS->HandleProtocol (
>> +                  ImageHandle,
>> +                  &gEfiLoadedImageProtocolGuid,
>> +                  (VOID **)&Image
>> +                  );
>> +  ASSERT_EFI_ERROR (Status);
>> +
>> +  //
>> +  // Parts of the code in this driver may be executed by other cores 
>> running
>> +  // with the MMU off so we need to ensure that everything is clean 
>> to the
>> +  // point of coherency (PoC)
>> +  //
>> +  WriteBackDataCacheRange (Image->ImageBase, Image->ImageSize);
>> +
>> +  Hob = GetFirstGuidHob (&gArmMpCoreInfoGuid);
>> +  if (Hob != NULL) {
>> +    HobData     = GET_GUID_HOB_DATA (Hob);
>> +    HobDataSize = GET_GUID_HOB_DATA_SIZE (Hob);
>> +    CoreInfo    = (ARM_CORE_INFO *)HobData;
>> +    MaxCpus     = HobDataSize / sizeof (ARM_CORE_INFO);
>> +  }
>> +
>> +  if (MaxCpus == 1) {
>> +    DEBUG ((DEBUG_WARN, "Trying to use EFI_MP_SERVICES_PROTOCOL on a 
>> UP system"));
>> +    // We are not MP so nothing to do
>> +    return EFI_NOT_FOUND;
>> +  }
>> +
>> +  Status = MpServicesInitialize (MaxCpus, CoreInfo);
>> +  if (Status != EFI_SUCCESS) {
>> +    ASSERT_EFI_ERROR (Status);
>> +    return Status;
>> +  }
>> +
>> +  //
>> +  // Now install the MP services protocol.
>> +  //
>> +  Handle = NULL;
>> +  Status = gBS->InstallMultipleProtocolInterfaces (
>> +                  &Handle,
>> +                  &gEfiMpServiceProtocolGuid,
>> +                  &mMpServicesProtocol,
>> +                  NULL
>> +                  );
>> +  ASSERT_EFI_ERROR (Status);
>> +
>> +  return Status;
>> +}
>> +
>> +/** AP exception handler.
>> +
>> +  @param InterruptType The AArch64 CPU exception type.
>> +  @param SystemContext System context.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +EFIAPI
>> +ApExceptionHandler (
>> +  IN CONST EFI_EXCEPTION_TYPE  InterruptType,
>> +  IN CONST EFI_SYSTEM_CONTEXT  SystemContext
>> +  )
>> +{
>> +  ARM_SMC_ARGS  Args;
>> +  UINT64        Mpidr;
>> +  UINTN         Index;
>> +  UINTN         ProcessorIndex;
>> +
>> +  Mpidr = GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ());
>> +
>> +  Index          = 0;
>> +  ProcessorIndex = MAX_UINT64;
>> +
>> +  do {
>> +    if (gProcessorIDs[Index] == Mpidr) {
>> +      ProcessorIndex = Index;
>> +      break;
>> +    }
>> +
>> +    Index++;
>> +  } while (gProcessorIDs[Index] != MAX_UINT64);
>> +
>> +  if (ProcessorIndex != MAX_UINT64) {
>> +    mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
>> +    ArmDataMemoryBarrier ();
>> +  }
>> +
>> +  Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
>> +  ArmCallSmc (&Args);
>> +
>> +  /* Should never be reached */
>> +  ASSERT (FALSE);
>> +  CpuDeadLoop ();
>> +}
>> +
>> +/** C entry-point for the AP.
>> +    This function gets called from the assembly function ApEntryPoint.
>> +
>> +**/
>> +VOID
>> +ApProcedure (
>> +  VOID
>> +  )
>> +{
>> +  ARM_SMC_ARGS      Args;
>> +  EFI_AP_PROCEDURE  UserApProcedure;
>> +  VOID              *UserApParameter;
>> +  UINTN             ProcessorIndex;
>> +
>> +  ProcessorIndex = 0;
>> +
>> +  WhoAmI (&mMpServicesProtocol, &ProcessorIndex);
>> +
>> +  /* Fetch the user-supplied procedure and parameter to execute */
>> +  UserApProcedure = mCpuMpData.CpuData[ProcessorIndex].Procedure;
>> +  UserApParameter = mCpuMpData.CpuData[ProcessorIndex].Parameter;
>> +
>> +  // Configure the MMU and caches
>> +  ArmSetTCR (mCpuMpData.CpuData[ProcessorIndex].Tcr);
>> +  ArmSetTTBR0 (mCpuMpData.CpuData[ProcessorIndex].Ttbr0);
>> +  ArmSetMAIR (mCpuMpData.CpuData[ProcessorIndex].Mair);
>> +  ArmDisableAlignmentCheck ();
>> +  ArmEnableStackAlignmentCheck ();
>> +  ArmEnableInstructionCache ();
>> +  ArmEnableDataCache ();
>> +  ArmEnableMmu ();
>> +
>> +  InitializeCpuExceptionHandlers (NULL);
>> +  RegisterCpuInterruptHandler 
>> (EXCEPT_AARCH64_SYNCHRONOUS_EXCEPTIONS, ApExceptionHandler);
>> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_IRQ, ApExceptionHandler);
>> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_FIQ, ApExceptionHandler);
>> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_SERROR, 
>> ApExceptionHandler);
>> +
>> +  UserApProcedure (UserApParameter);
>> +
>> +  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
>> +
>> +  ArmDataMemoryBarrier ();
>> +
>> +  /* Since we're finished with this AP, turn it off */
>> +  Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
>> +  ArmCallSmc (&Args);
>> +
>> +  /* Should never be reached */
>> +  ASSERT (FALSE);
>> +  CpuDeadLoop ();
>> +}
>> +
>> +/** Returns whether the processor executing this function is the BSP.
>> +
>> +    @return Whether the current processor is the BSP.
>> +**/
>> +STATIC
>> +BOOLEAN
>> +IsCurrentProcessorBSP (
>> +  VOID
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  UINTN       ProcessorIndex;
>> +
>> +  Status = WhoAmI (&mMpServicesProtocol, &ProcessorIndex);
>> +  if (EFI_ERROR (Status)) {
>> +    ASSERT_EFI_ERROR (Status);
>> +    return FALSE;
>> +  }
>> +
>> +  return IsProcessorBSP (ProcessorIndex);
>> +}
>> +
>> +/** Returns whether the specified processor is enabled.
>> +
>> +   @param[in] ProcessorIndex The index of the processor to check.
>> +
>> +   @return TRUE if the processor is enabled, FALSE otherwise.
>> +**/
>> +STATIC
>> +BOOLEAN
>> +IsProcessorEnabled (
>> +  UINTN  ProcessorIndex
>> +  )
>> +{
>> +  EFI_PROCESSOR_INFORMATION  *CpuInfo;
>> +
>> +  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
>> +
>> +  return (CpuInfo->StatusFlag & PROCESSOR_ENABLED_BIT) != 0;
>> +}
>> +
>> +/** Sets up the state for the StartupAllAPs function.
>> +
>> +   @param SingleThread Whether the APs will execute sequentially.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +StartupAllAPsPrepareState (
>> +  IN BOOLEAN  SingleThread
>> +  )
>> +{
>> +  UINTN        Index;
>> +  CPU_STATE    APInitialState;
>> +  CPU_AP_DATA  *CpuData;
>> +
>> +  mCpuMpData.FinishCount  = 0;
>> +  mCpuMpData.StartCount   = 0;
>> +  mCpuMpData.SingleThread = SingleThread;
>> +
>> +  APInitialState = CpuStateReady;
>> +
>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>> +    CpuData = &mCpuMpData.CpuData[Index];
>> +
>> +    //
>> +    // Get APs prepared, and put failing APs into FailedCpuList.
>> +    // If "SingleThread", only 1 AP will put into ready state, other 
>> AP will be
>> +    // put into ready state 1 by 1, until the previous 1 finished 
>> its task.
>> +    // If not "SingleThread", all APs are put into ready state from the
>> +    // beginning
>> +    //
>> +
>> +    if (IsProcessorBSP (Index)) {
>> +      // Skip BSP
>> +      continue;
>> +    }
>> +
>> +    if (!IsProcessorEnabled (Index)) {
>> +      // Skip Disabled processors
>> +      if (mCpuMpData.FailedList != NULL) {
>> +        mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = Index;
>> +      }
>> +
>> +      continue;
>> +    }
>> +
>> +    CpuData->State = APInitialState;
>> +
>> +    mCpuMpData.StartCount++;
>> +    if (SingleThread) {
>> +      APInitialState = CpuStateBlocked;
>> +    }
>> +  }
>> +}
>> +
>> +/** Handles execution of StartupAllAPs when a WaitEvent has been 
>> specified.
>> +
>> +  @param Procedure         The user-supplied procedure.
>> +  @param ProcedureArgument The user-supplied procedure argument.
>> +  @param WaitEvent         The wait event to be signaled when the 
>> work is
>> +                           complete or a timeout has occurred.
>> +  @param TimeoutInMicroseconds The timeout for the work to be 
>> completed. Zero
>> +                               indicates an infinite timeout.
>> +  @param SingleThread          Whether the APs will execute 
>> sequentially.
>> +  @param FailedCpuList         User-supplied pointer for list of 
>> failed CPUs.
>> +
>> +   @return EFI_SUCCESS on success.
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +StartupAllAPsWithWaitEvent (
>> +  IN EFI_AP_PROCEDURE  Procedure,
>> +  IN VOID              *ProcedureArgument,
>> +  IN EFI_EVENT         WaitEvent,
>> +  IN UINTN             TimeoutInMicroseconds,
>> +  IN BOOLEAN           SingleThread,
>> +  IN UINTN             **FailedCpuList
>> +  )
>> +{
>> +  EFI_STATUS   Status;
>> +  UINTN        Index;
>> +  CPU_AP_DATA  *CpuData;
>> +
>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>> +    CpuData = &mCpuMpData.CpuData[Index];
>> +    if (IsProcessorBSP (Index)) {
>> +      // Skip BSP
>> +      continue;
>> +    }
>> +
>> +    if (!IsProcessorEnabled (Index)) {
>> +      // Skip Disabled processors
>> +      continue;
>> +    }
>> +
>> +    if (GetApState (CpuData) == CpuStateReady) {
>> +      SetApProcedure (CpuData, Procedure, ProcedureArgument);
>> +      if ((mCpuMpData.StartCount == 0) || !SingleThread) {
>> +        Status = DispatchCpu (Index);
>> +        if (EFI_ERROR (Status)) {
>> +          AddProcessorToFailedList (Index, CpuData->State);
>> +          break;
>> +        }
>> +      }
>> +    }
>> +  }
>> +
>> +  if (EFI_ERROR (Status)) {
>> +    return EFI_NOT_READY;
>> +  }
>> +
>> +  //
>> +  // Save data into private data structure, and create timer to poll 
>> AP state
>> +  // before exiting
>> +  //
>> +  mCpuMpData.Procedure         = Procedure;
>> +  mCpuMpData.ProcedureArgument = ProcedureArgument;
>> +  mCpuMpData.WaitEvent         = WaitEvent;
>> +  mCpuMpData.Timeout           = TimeoutInMicroseconds;
>> +  mCpuMpData.TimeTaken         = 0;
>> +  mCpuMpData.TimeoutActive     = (BOOLEAN)(TimeoutInMicroseconds != 0);
>> +  Status                       = gBS->SetTimer (
>> + mCpuMpData.CheckAllAPsEvent,
>> +                                        TimerPeriodic,
>> +                                        POLL_INTERVAL_US
>> +                                        );
>> +
>> +  return Status;
>> +}
>> +
>> +/** Handles execution of StartupAllAPs when no wait event has been 
>> specified.
>> +
>> +  @param Procedure             The user-supplied procedure.
>> +  @param ProcedureArgument     The user-supplied procedure argument.
>> +  @param TimeoutInMicroseconds The timeout for the work to be 
>> completed. Zero
>> +                                indicates an infinite timeout.
>> +  @param SingleThread          Whether the APs will execute 
>> sequentially.
>> +  @param FailedCpuList         User-supplied pointer for list of 
>> failed CPUs.
>> +
>> +  @return EFI_SUCCESS on success.
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +StartupAllAPsNoWaitEvent (
>> +  IN EFI_AP_PROCEDURE  Procedure,
>> +  IN VOID              *ProcedureArgument,
>> +  IN UINTN             TimeoutInMicroseconds,
>> +  IN BOOLEAN           SingleThread,
>> +  IN UINTN             **FailedCpuList
>> +  )
>> +{
>> +  EFI_STATUS   Status;
>> +  UINTN        Index;
>> +  UINTN        NextIndex;
>> +  UINTN        Timeout;
>> +  CPU_AP_DATA  *CpuData;
>> +  BOOLEAN      DispatchError;
>> +
>> +  Timeout       = TimeoutInMicroseconds;
>> +  DispatchError = FALSE;
>> +
>> +  while (TRUE) {
>> +    for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>> +      CpuData = &mCpuMpData.CpuData[Index];
>> +      if (IsProcessorBSP (Index)) {
>> +        // Skip BSP
>> +        continue;
>> +      }
>> +
>> +      if (!IsProcessorEnabled (Index)) {
>> +        // Skip Disabled processors
>> +        continue;
>> +      }
>> +
>> +      switch (GetApState (CpuData)) {
>> +        case CpuStateReady:
>> +          SetApProcedure (CpuData, Procedure, ProcedureArgument);
>> +          Status = DispatchCpu (Index);
>> +          if (EFI_ERROR (Status)) {
>> +            AddProcessorToFailedList (Index, CpuData->State);
>> +            CpuData->State = CpuStateIdle;
>> +            mCpuMpData.StartCount--;
>> +            DispatchError = TRUE;
>> +
>> +            if (SingleThread) {
>> +              // Dispatch the next available AP
>> +              Status = GetNextBlockedNumber (&NextIndex);
>> +              if (!EFI_ERROR (Status)) {
>> +                mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
>> +              }
>> +            }
>> +          }
>> +
>> +          break;
>> +
>> +        case CpuStateFinished:
>> +          mCpuMpData.FinishCount++;
>> +          if (SingleThread) {
>> +            Status = GetNextBlockedNumber (&NextIndex);
>> +            if (!EFI_ERROR (Status)) {
>> +              mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
>> +            }
>> +          }
>> +
>> +          CpuData->State = CpuStateIdle;
>> +          break;
>> +
>> +        default:
>> +          break;
>> +      }
>> +    }
>> +
>> +    if (mCpuMpData.FinishCount == mCpuMpData.StartCount) {
>> +      Status = EFI_SUCCESS;
>> +      break;
>> +    }
>> +
>> +    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
>> +      Status = EFI_TIMEOUT;
>> +      break;
>> +    }
>> +
>> +    Timeout -= CalculateAndStallInterval (Timeout);
>> +  }
>> +
>> +  if (Status == EFI_TIMEOUT) {
>> +    // Add any remaining CPUs to the FailedCpuList
>> +    if (FailedCpuList != NULL) {
>> +      for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>> +        AddProcessorToFailedList (Index, 
>> mCpuMpData.CpuData[Index].State);
>> +      }
>> +    }
>> +  }
>> +
>> +  if (DispatchError) {
>> +    Status = EFI_NOT_READY;
>> +  }
>> +
>> +  return Status;
>> +}
>> diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S 
>> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S
>> new file mode 100644
>> index 000000000000..a90fa8a0075f
>> --- /dev/null
>> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S
>> @@ -0,0 +1,57 @@
>> +#=============================================================================== 
>>
>> +#  Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights 
>> reserved.
>> +#
>> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
>> +#=============================================================================== 
>>
>> +
>> +.text
>> +.align 3
>> +
>> +#include <AsmMacroIoLibV8.h>
>> +#include <IndustryStandard/ArmStdSmc.h>
>> +
>> +#include "MpServicesInternal.h"
>> +
>> +GCC_ASM_IMPORT (gApStacksBase)
>> +GCC_ASM_IMPORT (gProcessorIDs)
>> +GCC_ASM_IMPORT (ApProcedure)
>> +GCC_ASM_IMPORT (gApStackSize)
>> +
>> +GCC_ASM_EXPORT (ApEntryPoint)
>> +
>> +// Entry-point for the AP
>> +// VOID
>> +// ApEntryPoint (
>> +//   VOID
>> +//   );
>> +ASM_PFX(ApEntryPoint):
>> +  mrs x0, mpidr_el1
>> +  // Mask the non-affinity bits
>> +  bic x0, x0, 0x00ff000000
>> +  and x0, x0, 0xffffffffff
>> +  ldr x1, gProcessorIDs
>> +  mov x2, 0                   // x2 = processor index
>> +
>> +// Find index in gProcessorIDs for current processor
>> +1:
>> +  ldr x3, [x1, x2, lsl #3]    // x4 = gProcessorIDs + x2 * 8
>> +  cmp x3, #-1                 // check if we've reached the end of 
>> gProcessorIDs
>> +  beq ProcessorNotFound
>> +  add x2, x2, 1               // x2++
>> +  cmp x0, x3                  // if mpidr_el1 != gProcessorIDs[x] 
>> then loop
>> +  bne 1b
>> +
>> +// Calculate stack address
>> +  // x2 contains the index for the current processor plus 1
>> +  ldr x0, gApStacksBase
>> +  ldr x1, gApStackSize
>> +  mul x3, x2, x1              // x3 = (ProcessorIndex + 1) * 
>> gApStackSize
>> +  add sp, x0, x3              // sp = gApStacksBase + x3
>> +  mov x29, xzr
>> +  bl ApProcedure              // doesn't return
>> +
>> +ProcessorNotFound:
>> +// Turn off the processor
>> +  MOV32 (w0, ARM_SMC_ID_PSCI_CPU_OFF)
>> +  smc #0
>> +  b .
>
>
> 
>
>

Re: [edk2-devel] [PATCH v4 2/3] ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls

[Kun Qin]

Hi Rebecca,

Thanks for working through the feedback as you mentioned on the other 
thread. But hopefully this email
finds you before the v5 gets published.

I ran through some more tests and found a few extra comments on this 
specific patch, which you might
have found during v5 preparation. I added some comments under [KQ-3].

Please let me know if any thoughts about them. Sorry again for the 
fragmented email.

Regards,
Kun

On 1/6/2023 2:16 PM, Kun Qin wrote:
> Sorry, hit the send button too soon... One more comment under [KQ-2].
>
> Thanks,
> Kun
>
> On 1/6/2023 2:11 PM, Kun Qin via groups.io wrote:
>> Hi Rebecca,
>>
>> I have tried to use this for a few different scenarios and below is a 
>> few minor issues I have found and potential
>> changes (marked with [KQ]). Please let me know if I have any 
>> misunderstanding on the protocol itself.
>>
>> Thanks,
>> Kun
>>
>> On 1/4/2023 7:37 AM, Rebecca Cran wrote:
>>> Add support for EFI_MP_SERVICES_PROTOCOL during the DXE phase under
>>> AArch64.
>>>
>>> PSCI_CPU_ON is called to power on the core, the supplied procedure is
>>> executed and PSCI_CPU_OFF is called to power off the core.
>>>
>>> Fixes contributed by Ard Biesheuvel.
>>>
>>> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
>>> ---
>>>   ArmPkg/ArmPkg.dsc |    1 +
>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf |   56 +
>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h | 344 ++++
>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c | 1847 
>>> ++++++++++++++++++++
>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S |   57 +
>>>   5 files changed, 2305 insertions(+)
>>>
>>> diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
>>> index ac24ebce4892..1e873b90c56d 100644
>>> --- a/ArmPkg/ArmPkg.dsc
>>> +++ b/ArmPkg/ArmPkg.dsc
>>> @@ -164,6 +164,7 @@ [Components.common]
>>>     ArmPkg/Universal/Smbios/OemMiscLibNull/OemMiscLibNull.inf
>>>     [Components.AARCH64]
>>> + ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
>>>     ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
>>>     ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf
>>>   diff --git 
>>> a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf 
>>> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
>>> new file mode 100644
>>> index 000000000000..2c9ab99038f2
>>> --- /dev/null
>>> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf
>>> @@ -0,0 +1,56 @@
>>> +## @file
>>> +#  ARM MP services protocol driver
>>> +#
>>> +#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>>> reserved.<BR>
>>> +#
>>> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
>>> +#
>>> +##
>>> +
>>> +[Defines]
>>> +  INF_VERSION                    = 1.27
>>> +  BASE_NAME                      = ArmPsciMpServicesDxe
>>> +  FILE_GUID                      = 
>>> 007ab472-dc4a-4df8-a5c2-abb4a327278c
>>> +  MODULE_TYPE                    = DXE_DRIVER
>>> +  VERSION_STRING                 = 1.0
>>> +
>>> +  ENTRY_POINT                    = ArmPsciMpServicesDxeInitialize
>>> +
>>> +[Sources.Common]
>>> +  ArmPsciMpServicesDxe.c
>>> +  MpFuncs.S
>>> +  MpServicesInternal.h
>>> +
>>> +[Packages]
>>> +  ArmPkg/ArmPkg.dec
>>> +  ArmPlatformPkg/ArmPlatformPkg.dec
>>> +  EmbeddedPkg/EmbeddedPkg.dec
>>> +  MdePkg/MdePkg.dec
>>> +  MdeModulePkg/MdeModulePkg.dec
>>> +
>>> +[LibraryClasses]
>>> +  ArmLib
>>> +  ArmMmuLib
>>> +  ArmSmcLib
>>> +  BaseMemoryLib
>>> +  CacheMaintenanceLib
>>> +  CpuExceptionHandlerLib
>>> +  DebugLib
>>> +  HobLib
>>> +  MemoryAllocationLib
>>> +  UefiBootServicesTableLib
>>> +  UefiDriverEntryPoint
>>> +  UefiLib
>>> +
>>> +[Protocols]
>>> +  gEfiMpServiceProtocolGuid            ## PRODUCES
>>> +  gEfiLoadedImageProtocolGuid          ## CONSUMES
>>> +
>>> +[Guids]
>>> +  gArmMpCoreInfoGuid
>>> +
>>> +[Depex]
>>> +  TRUE
>>> +
>>> +[BuildOptions]
>>> +  GCC:*_*_*_CC_FLAGS = -mstrict-align
>>> diff --git 
>>> a/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h 
>>> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h
>>> new file mode 100644
>>> index 000000000000..5ba63700dd18
>>> --- /dev/null
>>> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h
>>> @@ -0,0 +1,344 @@
>>> +/** @file
>>> +
>>> +Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>>> reserved.<BR>
>>> +Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
>>> +Portions copyright (c) 2011, Apple Inc. All rights reserved.
>>> +
>>> +SPDX-License-Identifier: BSD-2-Clause-Patent
>>> +
>>> +**/
>>> +
>>> +#ifndef MP_SERVICES_INTERNAL_H_
>>> +#define MP_SERVICES_INTERNAL_H_
>>> +
>>> +#include <Protocol/Cpu.h>
>>> +#include <Protocol/MpService.h>
>>> +
>>> +#include <Library/BaseLib.h>
>>> +#include <Library/UefiLib.h>
>>> +
>>> +#define AP_STACK_SIZE  0x1000
>>> +
>>> +//
>>> +// Internal Data Structures
>>> +//
>>> +
>>> +//
>>> +// AP state
>>> +//
>>> +// The state transitions for an AP when it processes a procedure are:
>>> +//  Idle ----> Ready ----> Busy ----> Finished ----> Idle
>>> +//       [BSP]       [BSP]      [AP]           [BSP]
>>> +//
>>> +typedef enum {
>>> +  CpuStateIdle,
>>> +  CpuStateReady,
>>> +  CpuStateBlocked,
>>> +  CpuStateBusy,
>>> +  CpuStateFinished,
>>> +  CpuStateDisabled
>>> +} CPU_STATE;
>>> +
>>> +//
>>> +// Define Individual Processor Data block.
>>> +//
>>> +typedef struct {
>>> +  EFI_PROCESSOR_INFORMATION    Info;
>>> +  EFI_AP_PROCEDURE             Procedure;
>>> +  VOID                         *Parameter;
>>> +  CPU_STATE                    State;
>>> +  EFI_EVENT                    CheckThisAPEvent;
>>> +  VOID                         *Ttbr0;
>>> +  UINTN                        Tcr;
>>> +  UINTN                        Mair;
>>> +} CPU_AP_DATA;
>>> +
>>> +//
>>> +// Define MP data block which consumes individual processor block.
>>> +//
>>> +typedef struct {
>>> +  UINTN               NumberOfProcessors;
>>> +  UINTN               NumberOfEnabledProcessors;
>>> +  EFI_EVENT           CheckAllAPsEvent;
>>> +  EFI_EVENT           WaitEvent;
>>> +  UINTN               FinishCount;
>>> +  UINTN               StartCount;
>>> +  EFI_AP_PROCEDURE    Procedure;
>>> +  VOID                *ProcedureArgument;
>>> +  BOOLEAN             SingleThread;
>>> +  UINTN               StartedNumber;
>>> +  CPU_AP_DATA         *CpuData;
>>> +  UINTN               Timeout;
>>> +  UINTN               TimeTaken;
>>> +  UINTN               *FailedList;
>>> +  UINTN               FailedListIndex;
>>> +  BOOLEAN             TimeoutActive;
>>> +  BOOLEAN             *SingleApFinished;
>>> +} CPU_MP_DATA;
>>> +
>>> +/** Secondary core entry point.
>>> +
>>> +**/
>>> +VOID
>>> +ApEntryPoint (
>>> +  VOID
>>> +  );
>>> +
>>> +/** C entry-point for the AP.
>>> +    This function gets called from the assembly function ApEntryPoint.
>>> +**/
>>> +VOID
>>> +ApProcedure (
>>> +  VOID
>>> +  );
>>> +
>>> +/** Turns on the specified core using PSCI and executes the 
>>> user-supplied
>>> +    function that's been configured via a previous call to 
>>> SetApProcedure.
>>> +
>>> +   @param ProcessorIndex The index of the core to turn on.
>>> +
>>> +   @retval EFI_SUCCESS       The processor was successfully turned on.
>>> +   @retval EFI_DEVICE_ERROR  An error occurred turning the 
>>> processor on.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +EFIAPI
>>> +DispatchCpu (
>>> +  IN UINTN  ProcessorIndex
>>> +  );
>>> +
>>> +/** Returns whether the specified processor is the BSP.
>>> +
>>> +   @param[in] ProcessorIndex The index the processor to check.
>>> +
>>> +   @return TRUE if the processor is the BSP, FALSE otherwise.
>>> +**/
>>> +STATIC
>>> +BOOLEAN
>>> +IsProcessorBSP (
>>> +  UINTN  ProcessorIndex
>>> +  );
>>> +
>>> +/** Returns whether the processor executing this function is the BSP.
>>> +
>>> +   @return Whether the current processor is the BSP.
>>> +**/
>>> +STATIC
>>> +BOOLEAN
>>> +IsCurrentProcessorBSP (
>>> +  VOID
>>> +  );
>>> +
>>> +/** Returns whether the specified processor is enabled.
>>> +
>>> +   @param[in] ProcessorIndex The index of the processor to check.
>>> +
>>> +   @return TRUE if the processor is enabled, FALSE otherwise.
>>> +**/
>>> +STATIC
>>> +BOOLEAN
>>> +IsProcessorEnabled (
>>> +  UINTN  ProcessorIndex
>>> +  );
>>> +
>>> +/** Configures the processor context with the user-supplied 
>>> procedure and
>>> +    argument.
>>> +
>>> +   @param CpuData           The processor context.
>>> +   @param Procedure         The user-supplied procedure.
>>> +   @param ProcedureArgument The user-supplied procedure argument.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +SetApProcedure (
>>> +  IN   CPU_AP_DATA       *CpuData,
>>> +  IN   EFI_AP_PROCEDURE  Procedure,
>>> +  IN   VOID              *ProcedureArgument
>>> +  );
>>> +
>>> +/**
>>> +  Get the Application Processors state.
>>> +
>>> +  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP
>>> +
>>> +  @return  The AP status
>>> +**/
>>> +CPU_STATE
>>> +GetApState (
>>> +  IN  CPU_AP_DATA  *CpuData
>>> +  );
>>> +
>>> +/** Returns the index of the next processor that is blocked.
>>> +
>>> +   @param[out] NextNumber The index of the next blocked processor.
>>> +
>>> +   @retval EFI_SUCCESS   Successfully found the next blocked 
>>> processor.
>>> +   @retval EFI_NOT_FOUND There are no blocked processors.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +GetNextBlockedNumber (
>>> +  OUT UINTN  *NextNumber
>>> +  );
>>> +
>>> +/** Stalls the BSP for the minimum of gPollInterval and Timeout.
>>> +
>>> +   @param[in]  Timeout    The time limit in microseconds remaining for
>>> +                          APs to return from Procedure.
>>> +
>>> +   @retval     StallTime  Time of execution stall.
>>> +**/
>>> +STATIC
>>> +UINTN
>>> +CalculateAndStallInterval (
>>> +  IN UINTN  Timeout
>>> +  );
>>> +
>>> +/** Sets up the state for the StartupAllAPs function.
>>> +
>>> +   @param SingleThread Whether the APs will execute sequentially.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +StartupAllAPsPrepareState (
>>> +  IN BOOLEAN  SingleThread
>>> +  );
>>> +
>>> +/** Handles execution of StartupAllAPs when a WaitEvent has been 
>>> specified.
>>> +
>>> +  @param Procedure         The user-supplied procedure.
>>> +  @param ProcedureArgument The user-supplied procedure argument.
>>> +  @param WaitEvent         The wait event to be signaled when the 
>>> work is
>>> +                           complete or a timeout has occurred.
>>> +  @param TimeoutInMicroseconds The timeout for the work to be 
>>> completed. Zero
>>> +                               indicates an infinite timeout.
>>> +  @param SingleThread          Whether the APs will execute 
>>> sequentially.
>>> +  @param FailedCpuList         User-supplied pointer for list of 
>>> failed CPUs.
>>> +
>>> +   @return EFI_SUCCESS on success.
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +StartupAllAPsWithWaitEvent (
>>> +  IN EFI_AP_PROCEDURE  Procedure,
>>> +  IN VOID              *ProcedureArgument,
>>> +  IN EFI_EVENT         WaitEvent,
>>> +  IN UINTN             TimeoutInMicroseconds,
>>> +  IN BOOLEAN           SingleThread,
>>> +  IN UINTN             **FailedCpuList
>>> +  );
>>> +
>>> +/** Handles execution of StartupAllAPs when no wait event has been 
>>> specified.
>>> +
>>> +   @param Procedure             The user-supplied procedure.
>>> +   @param ProcedureArgument     The user-supplied procedure argument.
>>> +   @param TimeoutInMicroseconds The timeout for the work to be 
>>> completed. Zero
>>> +                                indicates an infinite timeout.
>>> +   @param SingleThread          Whether the APs will execute 
>>> sequentially.
>>> +   @param FailedCpuList         User-supplied pointer for list of 
>>> failed CPUs.
>>> +
>>> +   @return EFI_SUCCESS on success.
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +StartupAllAPsNoWaitEvent (
>>> +  IN EFI_AP_PROCEDURE  Procedure,
>>> +  IN VOID              *ProcedureArgument,
>>> +  IN UINTN             TimeoutInMicroseconds,
>>> +  IN BOOLEAN           SingleThread,
>>> +  IN UINTN             **FailedCpuList
>>> +  );
>>> +
>>> +/** Adds the specified processor the list of failed processors.
>>> +
>>> +   @param ProcessorIndex The processor index to add.
>>> +   @param ApState         Processor state.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +AddProcessorToFailedList (
>>> +  UINTN      ProcessorIndex,
>>> +  CPU_STATE  ApState
>>> +  );
>>> +
>>> +/** Handles the StartupAllAPs case where the timeout has occurred.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +ProcessStartupAllAPsTimeout (
>>> +  VOID
>>> +  );
>>> +
>>> +/**
>>> +  If a timeout is specified in StartupAllAps(), a timer is set, 
>>> which invokes
>>> +  this procedure periodically to check whether all APs have finished.
>>> +
>>> +  @param[in] Event   The WaitEvent the user supplied.
>>> +  @param[in] Context The event context.
>>> +**/
>>> +STATIC
>>> +VOID
>>> +EFIAPI
>>> +CheckAllAPsStatus (
>>> +  IN  EFI_EVENT  Event,
>>> +  IN  VOID       *Context
>>> +  );
>>> +
>>> +/** Invoked periodically via a timer to check the state of the 
>>> processor.
>>> +
>>> +   @param Event   The event supplied by the timer expiration.
>>> +   @param Context The processor context.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +EFIAPI
>>> +CheckThisAPStatus (
>>> +  IN  EFI_EVENT  Event,
>>> +  IN  VOID       *Context
>>> +  );
>>> +
>>> +/**
>>> +  This function is called by all processors (both BSP and AP) once 
>>> and collects
>>> +  MP related data.
>>> +
>>> +  @param BSP            TRUE if the processor is the BSP.
>>> +  @param Mpidr          The MPIDR for the specified processor. This 
>>> should be
>>> +                        the full MPIDR and not only the affinity bits.
>>> +  @param ProcessorIndex The index of the processor.
>>> +
>>> +  @return EFI_SUCCESS if the data for the processor collected and 
>>> filled in.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +FillInProcessorInformation (
>>> +  IN BOOLEAN  BSP,
>>> +  IN UINTN    Mpidr,
>>> +  IN UINTN    ProcessorIndex
>>> +  );
>>> +
>>> +/**
>>> +  Event notification function called when the 
>>> EFI_EVENT_GROUP_READY_TO_BOOT is
>>> +  signaled. After this point, non-blocking mode is no longer allowed.
>>> +
>>> +  @param  Event     Event whose notification function is being 
>>> invoked.
>>> +  @param  Context   The pointer to the notification function's 
>>> context,
>>> +                    which is implementation-dependent.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +EFIAPI
>>> +ReadyToBootSignaled (
>>> +  IN  EFI_EVENT  Event,
>>> +  IN  VOID       *Context
>>> +  );
>>> +
>>> +#endif /* MP_SERVICES_INTERNAL_H_ */
>>> diff --git 
>>> a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c 
>>> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
>>> new file mode 100644
>>> index 000000000000..ab439bffd722
>>> --- /dev/null
>>> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
>>> @@ -0,0 +1,1847 @@
>>> +/** @file
>>> +  Construct MP Services Protocol.
>>> +
>>> +  The MP Services Protocol provides a generalized way of performing 
>>> following tasks:
>>> +    - Retrieving information of multi-processor environment and 
>>> MP-related status of
>>> +      specific processors.
>>> +    - Dispatching user-provided function to APs.
>>> +    - Maintain MP-related processor status.
>>> +
>>> +  The MP Services Protocol must be produced on any system with more 
>>> than one logical
>>> +  processor.
>>> +
>>> +  The Protocol is available only during boot time.
>>> +
>>> +  MP Services Protocol is hardware-independent. Most of the logic 
>>> of this protocol
>>> +  is architecturally neutral. It abstracts the multi-processor 
>>> environment and
>>> +  status of processors, and provides interfaces to retrieve 
>>> information, maintain,
>>> +  and dispatch.
>>> +
>>> +  MP Services Protocol may be consumed by ACPI module. The ACPI 
>>> module may use this
>>> +  protocol to retrieve data that are needed for an MP platform and 
>>> report them to OS.
>>> +  MP Services Protocol may also be used to program and configure 
>>> processors, such
>>> +  as MTRR synchronization for memory space attributes setting in 
>>> DXE Services.
>>> +  MP Services Protocol may be used by non-CPU DXE drivers to speed 
>>> up platform boot
>>> +  by taking advantage of the processing capabilities of the APs, 
>>> for example, using
>>> +  APs to help test system memory in parallel with other device 
>>> initialization.
>>> +  Diagnostics applications may also use this protocol for 
>>> multi-processor.
>>> +
>>> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>>> reserved.<BR>
>>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>>> +
>>> +**/
>>> +
>>> +#include <PiDxe.h>
>>> +
>>> +#include <Library/ArmLib.h>
>>> +#include <Library/ArmMmuLib.h>
>>> +#include <Library/ArmPlatformLib.h>
>>> +#include <Library/ArmSmcLib.h>
>>> +#include <Library/BaseMemoryLib.h>
>>> +#include <Library/CacheMaintenanceLib.h>
>>> +#include <Library/CpuExceptionHandlerLib.h>
>>> +#include <Library/DebugLib.h>
>>> +#include <Library/HobLib.h>
>>> +#include <Library/MemoryAllocationLib.h>
>>> +#include <Library/UefiBootServicesTableLib.h>
>>> +#include <Library/UefiLib.h>
>>> +#include <IndustryStandard/ArmStdSmc.h>
>>> +#include <Ppi/ArmMpCoreInfo.h>
>>> +#include <Protocol/LoadedImage.h>
>>> +
>>> +#include "MpServicesInternal.h"
>>> +
>>> +#define POLL_INTERVAL_US  50000
>>> +
>>> +STATIC CPU_MP_DATA  mCpuMpData;
>>> +STATIC BOOLEAN      mNonBlockingModeAllowed;
>>> +UINT64              *gApStacksBase;
>>> +UINT64              *gProcessorIDs;
>>> +CONST UINT64        gApStackSize = AP_STACK_SIZE;
>>> +
>>> +STATIC
>>> +BOOLEAN
>>> +IsCurrentProcessorBSP (
>>> +  VOID
>>> +  );
>>> +
>>> +/** Turns on the specified core using PSCI and executes the 
>>> user-supplied
>>> +    function that's been configured via a previous call to 
>>> SetApProcedure.
>>> +
>>> +    @param ProcessorIndex The index of the core to turn on.
>>> +
>>> +    @retval EFI_SUCCESS      Success.
>>> +    @retval EFI_DEVICE_ERROR The processor could not be turned on.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +EFIAPI
>>> +DispatchCpu (
>>> +  IN UINTN  ProcessorIndex
>>> +  )
>>> +{
>>> +  ARM_SMC_ARGS  Args;
>>> +  EFI_STATUS    Status;
>>> +
>>> +  Status = EFI_SUCCESS;
>>> +
>>> +  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateBusy;
>>> +
>>> +  /* Turn the AP on */
>>> +  if (sizeof (Args.Arg0) == sizeof (UINT32)) {
>>> +    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH32;
>>> +  } else {
>>> +    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH64;
>>> +  }
>>> +
>>> +  Args.Arg1 = gProcessorIDs[ProcessorIndex];
>>> +  Args.Arg2 = (UINTN)ApEntryPoint;
>>> +
>>> +  mCpuMpData.CpuData[ProcessorIndex].Tcr   = ArmGetTCR ();
>>> +  mCpuMpData.CpuData[ProcessorIndex].Mair  = ArmGetMAIR ();
>>> +  mCpuMpData.CpuData[ProcessorIndex].Ttbr0 = ArmGetTTBR0BaseAddress 
>>> ();
>>> +  WriteBackDataCacheRange (&mCpuMpData.CpuData[ProcessorIndex], 
>>> sizeof (CPU_AP_DATA));
>>> +
>>> +  ArmCallSmc (&Args);
>>> +
>>> +  if (Args.Arg0 != ARM_SMC_PSCI_RET_SUCCESS) {
>>> +    DEBUG ((DEBUG_ERROR, "PSCI_CPU_ON call failed: %d\n", Args.Arg0));
>>> +    Status = EFI_DEVICE_ERROR;
>>> +  }
>>> +
>>> +  return Status;
>>> +}
>>> +
>>> +/** Returns whether the specified processor is the BSP.
>>> +
>>> +  @param[in] ProcessorIndex The index the processor to check.
>>> +
>>> +  @return TRUE if the processor is the BSP, FALSE otherwise.
>>> +**/
>>> +STATIC
>>> +BOOLEAN
>>> +IsProcessorBSP (
>>> +  UINTN  ProcessorIndex
>>> +  )
>>> +{
>>> +  EFI_PROCESSOR_INFORMATION  *CpuInfo;
>>> +
>>> +  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
>>> +
>>> +  return (CpuInfo->StatusFlag & PROCESSOR_AS_BSP_BIT) != 0;
>>> +}
>>> +
>>> +/** Get the Application Processors state.
>>> +
>>> +  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP.
>>> +
>>> +  @return The AP status.
>>> +**/
>>> +CPU_STATE
>>> +GetApState (
>>> +  IN  CPU_AP_DATA  *CpuData
>>> +  )
>>> +{
>>> +  return CpuData->State;
>>> +}
>>> +
>>> +/** Configures the processor context with the user-supplied 
>>> procedure and
>>> +    argument.
>>> +
>>> +   @param CpuData           The processor context.
>>> +   @param Procedure         The user-supplied procedure.
>>> +   @param ProcedureArgument The user-supplied procedure argument.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +SetApProcedure (
>>> +  IN   CPU_AP_DATA       *CpuData,
>>> +  IN   EFI_AP_PROCEDURE  Procedure,
>>> +  IN   VOID              *ProcedureArgument
>>> +  )
>>> +{
>>> +  ASSERT (CpuData != NULL);
>>> +  ASSERT (Procedure != NULL);
>>> +
>>> +  CpuData->Parameter = ProcedureArgument;
>>> +  CpuData->Procedure = Procedure;
>>> +}
>>> +
>>> +/** Returns the index of the next processor that is blocked.
>>> +
>>> +   @param[out] NextNumber The index of the next blocked processor.
>>> +
>>> +   @retval EFI_SUCCESS   Successfully found the next blocked 
>>> processor.
>>> +   @retval EFI_NOT_FOUND There are no blocked processors.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +GetNextBlockedNumber (
>>> +  OUT UINTN  *NextNumber
>>> +  )
>>> +{
>>> +  UINTN        Index;
>>> +  CPU_STATE    State;
>>> +  CPU_AP_DATA  *CpuData;
>>> +
>>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>>> +    CpuData = &mCpuMpData.CpuData[Index];
>>> +    if (IsProcessorBSP (Index)) {
>>> +      // Skip BSP
>>> +      continue;
>>> +    }
>>> +
>>> +    State = CpuData->State;
>>> +
>>> +    if (State == CpuStateBlocked) {
>>> +      *NextNumber = Index;
>>> +      return EFI_SUCCESS;
>>> +    }
>>> +  }
>>> +
>>> +  return EFI_NOT_FOUND;
>>> +}
>>> +
>>> +/** Stalls the BSP for the minimum of POLL_INTERVAL_US and Timeout.
>>> +
>>> +   @param[in]  Timeout    The time limit in microseconds remaining for
>>> +                          APs to return from Procedure.
>>> +
>>> +   @retval     StallTime  Time of execution stall.
>>> +**/
>>> +STATIC
>>> +UINTN
>>> +CalculateAndStallInterval (
>>> +  IN UINTN  Timeout
>>> +  )
>>> +{
>>> +  UINTN  StallTime;
>>> +
>>> +  if ((Timeout < POLL_INTERVAL_US) && (Timeout != 0)) {
>>> +    StallTime = Timeout;
>>> +  } else {
>>> +    StallTime = POLL_INTERVAL_US;
>>> +  }
>>> +
>>> +  gBS->Stall (StallTime);
>>> +
>>> +  return StallTime;
>>> +}
>>> +
>>> +/**
>>> +  This service retrieves the number of logical processor in the 
>>> platform
>>> +  and the number of those logical processors that are enabled on 
>>> this boot.
>>> +  This service may only be called from the BSP.
>>> +
>>> +  This function is used to retrieve the following information:
>>> +    - The number of logical processors that are present in the system.
>>> +    - The number of enabled logical processors in the system at the 
>>> instant
>>> +      this call is made.
>>> +
>>> +  Because MP Service Protocol provides services to enable and 
>>> disable processors
>>> +  dynamically, the number of enabled logical processors may vary 
>>> during the
>>> +  course of a boot session.
>>> +
>>> +  If this service is called from an AP, then EFI_DEVICE_ERROR is 
>>> returned.
>>> +  If NumberOfProcessors or NumberOfEnabledProcessors is NULL, then
>>> +  EFI_INVALID_PARAMETER is returned. Otherwise, the total number of 
>>> processors
>>> +  is returned in NumberOfProcessors, the number of currently 
>>> enabled processor
>>> +  is returned in NumberOfEnabledProcessors, and EFI_SUCCESS is 
>>> returned.
>>> +
>>> +  @param[in]  This                        A pointer to the
>>> + EFI_MP_SERVICES_PROTOCOL instance.
>>> +  @param[out] NumberOfProcessors          Pointer to the total 
>>> number of logical
>>> +                                          processors in the system, 
>>> including
>>> +                                          the BSP and disabled APs.
>>> +  @param[out] NumberOfEnabledProcessors   Pointer to the number of 
>>> enabled
>>> +                                          logical processors that 
>>> exist in the
>>> +                                          system, including the BSP.
>>> +
>>> +  @retval EFI_SUCCESS             The number of logical processors 
>>> and enabled
>>> +                                  logical processors was retrieved.
>>> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
>>> +  @retval EFI_INVALID_PARAMETER   NumberOfProcessors is NULL.
>>> +  @retval EFI_INVALID_PARAMETER   NumberOfEnabledProcessors is NULL.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +EFIAPI
>>> +GetNumberOfProcessors (
>>> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
>>> +  OUT UINTN                     *NumberOfProcessors,
>>> +  OUT UINTN                     *NumberOfEnabledProcessors
>>> +  )
>>> +{
>>> +  if ((NumberOfProcessors == NULL) || (NumberOfEnabledProcessors == 
>>> NULL)) {
>>> +    return EFI_INVALID_PARAMETER;
>>> +  }
>>> +
>>> +  if (!IsCurrentProcessorBSP ()) {
>>> +    return EFI_DEVICE_ERROR;
>>> +  }
>>> +
>>> +  *NumberOfProcessors        = mCpuMpData.NumberOfProcessors;
>>> +  *NumberOfEnabledProcessors = mCpuMpData.NumberOfEnabledProcessors;
>>> +  return EFI_SUCCESS;
>>> +}
>>> +
>>> +/**
>>> +  Gets detailed MP-related information on the requested processor 
>>> at the
>>> +  instant this call is made. This service may only be called from 
>>> the BSP.
>>> +
>>> +  This service retrieves detailed MP-related information about any 
>>> processor
>>> +  on the platform. Note the following:
>>> +    - The processor information may change during the course of a 
>>> boot session.
>>> +    - The information presented here is entirely MP related.
>>> +
>>> +  Information regarding the number of caches and their sizes, 
>>> frequency of
>>> +  operation, slot numbers is all considered platform-related 
>>> information and is
>>> +  not provided by this service.
>>> +
>>> +  @param[in]  This                  A pointer to the 
>>> EFI_MP_SERVICES_PROTOCOL
>>> +                                    instance.
>>> +  @param[in]  ProcessorIndex        The index of the processor.
>>> +  @param[out] ProcessorInfoBuffer   A pointer to the buffer where 
>>> information
>>> +                                    for the requested processor is 
>>> deposited.
>>> +
>>> +  @retval EFI_SUCCESS             Processor information was returned.
>>> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
>>> +  @retval EFI_INVALID_PARAMETER   ProcessorInfoBuffer is NULL.
>>> +  @retval EFI_NOT_FOUND           The processor with the handle 
>>> specified by
>>> +                                  ProcessorNumber does not exist in 
>>> the platform.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +EFIAPI
>>> +GetProcessorInfo (
>>> +  IN  EFI_MP_SERVICES_PROTOCOL   *This,
>>> +  IN  UINTN                      ProcessorIndex,
>>> +  OUT EFI_PROCESSOR_INFORMATION  *ProcessorInfoBuffer
>>> +  )
>>> +{
>>> +  if (ProcessorInfoBuffer == NULL) {
>>> +    return EFI_INVALID_PARAMETER;
>>> +  }
>>> +
>>> +  if (!IsCurrentProcessorBSP ()) {
>>> +    return EFI_DEVICE_ERROR;
>>> +  }
>>> +
>>> +  ProcessorIndex &= ~CPU_V2_EXTENDED_TOPOLOGY;
>>> +
>>> +  if (ProcessorIndex >= mCpuMpData.NumberOfProcessors) {
>>> +    return EFI_NOT_FOUND;
>>> +  }
>>> +
>>> +  CopyMem (
>>> +    ProcessorInfoBuffer,
>>> +    &mCpuMpData.CpuData[ProcessorIndex],
>>> +    sizeof (EFI_PROCESSOR_INFORMATION)
>>> +    );
>>> +  return EFI_SUCCESS;
>>> +}
>>> +
>>> +/**
>>> +  This service executes a caller provided function on all enabled 
>>> APs. APs can
>>> +  run either simultaneously or one at a time in sequence. This 
>>> service supports
>>> +  both blocking and non-blocking requests. The non-blocking 
>>> requests use EFI
>>> +  events so the BSP can detect when the APs have finished. This 
>>> service may only
>>> +  be called from the BSP.
>>> +
>>> +  This function is used to dispatch all the enabled APs to the 
>>> function
>>> +  specified by Procedure.  If any enabled AP is busy, then 
>>> EFI_NOT_READY is
>>> +  returned immediately and Procedure is not started on any AP.
>>> +
>>> +  If SingleThread is TRUE, all the enabled APs execute the function 
>>> specified by
>>> +  Procedure one by one, in ascending order of processor handle number.
>>> +  Otherwise, all the enabled APs execute the function specified by 
>>> Procedure
>>> +  simultaneously.
>>> +
>>> +  If WaitEvent is NULL, execution is in blocking mode. The BSP 
>>> waits until all
>>> +  APs finish or TimeoutInMicroseconds expires. Otherwise, execution 
>>> is in
>>> +  non-blocking mode, and the BSP returns from this service without 
>>> waiting for
>>> +  APs. If a non-blocking mode is requested after the UEFI Event
>>> +  EFI_EVENT_GROUP_READY_TO_BOOT is signaled, then EFI_UNSUPPORTED 
>>> must be
>>> +  returned.
>>> +
>>> +  If the timeout specified by TimeoutInMicroseconds expires before 
>>> all APs
>>> +  return from Procedure, then Procedure on the failed APs is 
>>> terminated.
>>> +  All enabled APs are always available for further calls to
>>> +  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
>>> +  EFI_MP_SERVICES_PROTOCOL.StartupThisAP(). If FailedCpuList is not 
>>> NULL, its
>>> +  content points to the list of processor handle numbers in which 
>>> Procedure was
>>> +  terminated.
>>> +
>>> +  Note: It is the responsibility of the consumer of the
>>> +  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() to make sure that the 
>>> nature of the
>>> +  code that is executed on the BSP and the dispatched APs is well 
>>> controlled.
>>> +  The MP Services Protocol does not guarantee that the Procedure 
>>> function is
>>> +  MP-safe. Hence, the tasks that can be run in parallel are limited 
>>> to certain
>>> +  independent tasks and well-controlled exclusive code. EFI 
>>> services and
>>> +  protocols may not be called by APs unless otherwise specified.
>>> +
>>> +  In blocking execution mode, BSP waits until all APs finish or
>>> +  TimeoutInMicroseconds expires.
>>> +
>>> +  In non-blocking execution mode, BSP is freed to return to the 
>>> caller and then
>>> +  proceed to the next task without having to wait for APs. The 
>>> following
>>> +  sequence needs to occur in a non-blocking execution mode:
>>> +
>>> +    -# The caller that intends to use this MP Services Protocol in 
>>> non-blocking
>>> +       mode creates WaitEvent by calling the EFI CreateEvent() 
>>> service.  The
>>> +       caller invokes EFI_MP_SERVICES_PROTOCOL.StartupAllAPs(). If 
>>> the parameter
>>> +       WaitEvent is not NULL, then StartupAllAPs() executes in 
>>> non-blocking
>>> +       mode. It requests the function specified by Procedure to be 
>>> started on
>>> +       all the enabled APs, and releases the BSP to continue with 
>>> other tasks.
>>> +    -# The caller can use the CheckEvent() and WaitForEvent() 
>>> services to check
>>> +       the state of the WaitEvent created in step 1.
>>> +    -# When the APs complete their task or TimeoutInMicroSecondss 
>>> expires, the
>>> +       MP Service signals WaitEvent by calling the EFI 
>>> SignalEvent() function.
>>> +       If FailedCpuList is not NULL, its content is available when 
>>> WaitEvent is
>>> +       signaled. If all APs returned from Procedure prior to the 
>>> timeout, then
>>> +       FailedCpuList is set to NULL. If not all APs return from 
>>> Procedure before
>>> +       the timeout, then FailedCpuList is filled in with the list 
>>> of the failed
>>> +       APs. The buffer is allocated by MP Service Protocol using 
>>> AllocatePool().
>>> +       It is the caller's responsibility to free the buffer with 
>>> FreePool()
>>> +       service.
>>> +    -# This invocation of SignalEvent() function informs the caller 
>>> that invoked
>>> +       EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() that either all the 
>>> APs
>>> +       completed the specified task or a timeout occurred. The 
>>> contents of
>>> +       FailedCpuList can be examined to determine which APs did not 
>>> complete the
>>> +       specified task prior to the timeout.
>>> +
>>> +  @param[in]  This                    A pointer to the 
>>> EFI_MP_SERVICES_PROTOCOL
>>> +                                      instance.
>>> +  @param[in]  Procedure               A pointer to the function to 
>>> be run on
>>> +                                      enabled APs of the system. 
>>> See type
>>> +                                      EFI_AP_PROCEDURE.
>>> +  @param[in]  SingleThread            If TRUE, then all the enabled 
>>> APs execute
>>> +                                      the function specified by 
>>> Procedure one by
>>> +                                      one, in ascending order of 
>>> processor
>>> +                                      handle number.  If FALSE, 
>>> then all the
>>> +                                      enabled APs execute the 
>>> function specified
>>> +                                      by Procedure simultaneously.
>>> +  @param[in]  WaitEvent               The event created by the 
>>> caller with
>>> +                                      CreateEvent() service. If it 
>>> is NULL,
>>> +                                      then execute in blocking 
>>> mode. BSP waits
>>> +                                      until all APs finish or
>>> +                                      TimeoutInMicroseconds 
>>> expires.  If it's
>>> +                                      not NULL, then execute in 
>>> non-blocking
>>> +                                      mode. BSP requests the 
>>> function specified
>>> +                                      by Procedure to be started on 
>>> all the
>>> +                                      enabled APs, and go on executing
>>> +                                      immediately. If all return 
>>> from Procedure,
>>> +                                      or TimeoutInMicroseconds 
>>> expires, this
>>> +                                      event is signaled. The BSP 
>>> can use the
>>> +                                      CheckEvent() or WaitForEvent()
>>> +                                      services to check the state 
>>> of event. Type
>>> +                                      EFI_EVENT is defined in 
>>> CreateEvent() in
>>> +                                      the Unified Extensible 
>>> Firmware Interface
>>> +                                      Specification.
>>> +  @param[in]  TimeoutInMicroseconds   Indicates the time limit in 
>>> microseconds
>>> +                                      for APs to return from 
>>> Procedure, either
>>> +                                      for blocking or non-blocking 
>>> mode. Zero
>>> +                                      means infinity.  If the 
>>> timeout expires
>>> +                                      before all APs return from 
>>> Procedure, then
>>> +                                      Procedure on the failed APs 
>>> is terminated.
>>> +                                      All enabled APs are available 
>>> for next
>>> +                                      function assigned by
>>> + EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
>>> +                                      or 
>>> EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
>>> +                                      If the timeout expires in 
>>> blocking mode,
>>> +                                      BSP returns EFI_TIMEOUT. If 
>>> the timeout
>>> +                                      expires in non-blocking mode, 
>>> WaitEvent
>>> +                                      is signaled with SignalEvent().
>>> +  @param[in]  ProcedureArgument       The parameter passed into 
>>> Procedure for
>>> +                                      all APs.
>>> +  @param[out] FailedCpuList           If NULL, this parameter is 
>>> ignored.
>>> +                                      Otherwise, if all APs finish 
>>> successfully,
>>> +                                      then its content is set to 
>>> NULL. If not
>>> +                                      all APs finish before timeout 
>>> expires,
>>> +                                      then its content is set to 
>>> address of the
>>> +                                      buffer holding handle numbers 
>>> of the
>>> +                                      failed APs.
>>> +                                      The buffer is allocated by MP 
>>> Service
>>> +                                      Protocol, and it's the caller's
>>> +                                      responsibility to free the 
>>> buffer with
>>> +                                      FreePool() service.
>>> +                                      In blocking mode, it is ready 
>>> for
>>> +                                      consumption when the call 
>>> returns. In
>>> +                                      non-blocking mode, it is 
>>> ready when
>>> +                                      WaitEvent is signaled. The 
>>> list of failed
>>> +                                      CPU is terminated by 
>>> END_OF_CPU_LIST.
>>> +
>>> +  @retval EFI_SUCCESS             In blocking mode, all APs have 
>>> finished before
>>> +                                  the timeout expired.
>>> +  @retval EFI_SUCCESS             In non-blocking mode, function 
>>> has been
>>> +                                  dispatched to all enabled APs.
>>> +  @retval EFI_UNSUPPORTED         A non-blocking mode request was 
>>> made after the
>>> +                                  UEFI event 
>>> EFI_EVENT_GROUP_READY_TO_BOOT was
>>> +                                  signaled.
>>> +  @retval EFI_DEVICE_ERROR        Caller processor is AP.
>>> +  @retval EFI_NOT_STARTED         No enabled APs exist in the system.
>>> +  @retval EFI_NOT_READY           Any enabled APs are busy.
>>> +  @retval EFI_TIMEOUT             In blocking mode, the timeout 
>>> expired before
>>> +                                  all enabled APs have finished.
>>> +  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +EFIAPI
>>> +StartupAllAPs (
>>> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
>>> +  IN  EFI_AP_PROCEDURE          Procedure,
>>> +  IN  BOOLEAN                   SingleThread,
>>> +  IN  EFI_EVENT                 WaitEvent OPTIONAL,
>>> +  IN  UINTN                     TimeoutInMicroseconds,
>>> +  IN  VOID                      *ProcedureArgument OPTIONAL,
>>> +  OUT UINTN                     **FailedCpuList OPTIONAL
>>> +  )
>>> +{
>>> +  EFI_STATUS  Status;
>>> +
>>> +  if (!IsCurrentProcessorBSP ()) {
>>> +    return EFI_DEVICE_ERROR;
>>> +  }
>>> +
>>> +  if (mCpuMpData.NumberOfProcessors == 1) {
>>> +    return EFI_NOT_STARTED;
>>> +  }
>>> +
>>> +  if (Procedure == NULL) {
>>> +    return EFI_INVALID_PARAMETER;
>>> +  }
>>> +
>>> +  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
>>> +    return EFI_UNSUPPORTED;
>>> +  }
>>> +
>>> +  if (FailedCpuList != NULL) {
>>> +    mCpuMpData.FailedList = AllocateZeroPool (
>>> +                              (mCpuMpData.NumberOfProcessors + 1) *
>>> +                              sizeof (UINTN)
>>> +                              );
>>> +    if (mCpuMpData.FailedList == NULL) {
>>> +      return EFI_OUT_OF_RESOURCES;
>>> +    }
>>> +
>>> +    SetMemN (
>>> +      mCpuMpData.FailedList,
>>> +      (mCpuMpData.NumberOfProcessors + 1) *
>>> +      sizeof (UINTN),
>>> +      END_OF_CPU_LIST
>>> +      );
>>> +    mCpuMpData.FailedListIndex = 0;
>>> +    *FailedCpuList             = mCpuMpData.FailedList;
>>> +  }
>>> +
>>> +  StartupAllAPsPrepareState (SingleThread);
>>> +
>>> +  if (WaitEvent != NULL) {
>>> +    Status = StartupAllAPsWithWaitEvent (
>>> +               Procedure,
>>> +               ProcedureArgument,
>>> +               WaitEvent,
>>> +               TimeoutInMicroseconds,
>>> +               SingleThread,
>>> +               FailedCpuList
>>> +               );
>>> +
>>> +    if (EFI_ERROR (Status) && (FailedCpuList != NULL)) {
>>> +      if (mCpuMpData.FailedListIndex == 0) {
>>> +        FreePool (*FailedCpuList);
>>> +        *FailedCpuList = NULL;
>>> +      }
>>> +    }
>>> +  } else {
>>> +    Status = StartupAllAPsNoWaitEvent (
>>> +               Procedure,
>>> +               ProcedureArgument,
>>> +               TimeoutInMicroseconds,
>>> +               SingleThread,
>>> +               FailedCpuList
>>> +               );
>>> +
>>> +    if (FailedCpuList != NULL) {
>>> +      if (mCpuMpData.FailedListIndex == 0) {
>>> +        FreePool (*FailedCpuList);
>>> +        *FailedCpuList = NULL;
>>> +      }
>>> +    }
>>> +  }
>>> +
>>> +  return Status;
>>> +}
>>> +
>>> +/**
>>> +  This service lets the caller get one enabled AP to execute a 
>>> caller-provided
>>> +  function. The caller can request the BSP to either wait for the 
>>> completion
>>> +  of the AP or just proceed with the next task by using the EFI 
>>> event mechanism.
>>> +  See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on 
>>> non-blocking
>>> +  execution support.  This service may only be called from the BSP.
>>> +
>>> +  This function is used to dispatch one enabled AP to the function 
>>> specified by
>>> +  Procedure passing in the argument specified by 
>>> ProcedureArgument.  If WaitEvent
>>> +  is NULL, execution is in blocking mode. The BSP waits until the 
>>> AP finishes or
>>> +  TimeoutInMicroSecondss expires. Otherwise, execution is in 
>>> non-blocking mode.
>>> +  BSP proceeds to the next task without waiting for the AP. If a 
>>> non-blocking mode
>>> +  is requested after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT 
>>> is signaled,
>>> +  then EFI_UNSUPPORTED must be returned.
>>> +
>>> +  If the timeout specified by TimeoutInMicroseconds expires before 
>>> the AP returns
>>> +  from Procedure, then execution of Procedure by the AP is 
>>> terminated. The AP is
>>> +  available for subsequent calls to 
>>> EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
>>> +  EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
>>> +
>>> +  @param[in]  This                    A pointer to the 
>>> EFI_MP_SERVICES_PROTOCOL
>>> +                                      instance.
>>> +  @param[in]  Procedure               A pointer to the function to 
>>> be run on
>>> +                                      enabled APs of the system. 
>>> See type
>>> +                                      EFI_AP_PROCEDURE.
>>> +  @param[in]  ProcessorNumber         The handle number of the AP. 
>>> The range is
>>> +                                      from 0 to the total number of 
>>> logical
>>> +                                      processors minus 1. The total 
>>> number of
>>> +                                      logical processors can be 
>>> retrieved by
>>> + EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
>>> +  @param[in]  WaitEvent               The event created by the 
>>> caller with CreateEvent()
>>> +                                      service.  If it is NULL, then 
>>> execute in
>>> +                                      blocking mode. BSP waits 
>>> until all APs finish
>>> +                                      or TimeoutInMicroseconds 
>>> expires.  If it's
>>> +                                      not NULL, then execute in 
>>> non-blocking mode.
>>> +                                      BSP requests the function 
>>> specified by
>>> +                                      Procedure to be started on 
>>> all the enabled
>>> +                                      APs, and go on executing 
>>> immediately. If
>>> +                                      all return from Procedure or 
>>> TimeoutInMicroseconds
>>> +                                      expires, this event is 
>>> signaled. The BSP
>>> +                                      can use the CheckEvent() or 
>>> WaitForEvent()
>>> +                                      services to check the state 
>>> of event.  Type
>>> +                                      EFI_EVENT is defined in 
>>> CreateEvent() in
>>> +                                      the Unified Extensible 
>>> Firmware Interface
>>> +                                      Specification.
>>> +  @param[in]  TimeoutInMicroseconds   Indicates the time limit in 
>>> microseconds for
>>> +                                      APs to return from Procedure, 
>>> either for
>>> +                                      blocking or non-blocking 
>>> mode. Zero means
>>> +                                      infinity.  If the timeout 
>>> expires before
>>> +                                      all APs return from 
>>> Procedure, then Procedure
>>> +                                      on the failed APs is 
>>> terminated. All enabled
>>> +                                      APs are available for next 
>>> function assigned
>>> +                                      by 
>>> EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
>>> +                                      or 
>>> EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
>>> +                                      If the timeout expires in 
>>> blocking mode,
>>> +                                      BSP returns EFI_TIMEOUT. If 
>>> the timeout
>>> +                                      expires in non-blocking mode, 
>>> WaitEvent
>>> +                                      is signaled with SignalEvent().
>>> +  @param[in]  ProcedureArgument       The parameter passed into 
>>> Procedure for
>>> +                                      all APs.
>>> +  @param[out] Finished                If NULL, this parameter is 
>>> ignored.  In
>>> +                                      blocking mode, this parameter 
>>> is ignored.
>>> +                                      In non-blocking mode, if AP 
>>> returns from
>>> +                                      Procedure before the timeout 
>>> expires, its
>>> +                                      content is set to TRUE. 
>>> Otherwise, the
>>> +                                      value is set to FALSE. The 
>>> caller can
>>> +                                      determine if the AP returned 
>>> from Procedure
>>> +                                      by evaluating this value.
>>> +
>>> +  @retval EFI_SUCCESS             In blocking mode, specified AP 
>>> finished before
>>> +                                  the timeout expires.
>>> +  @retval EFI_SUCCESS             In non-blocking mode, the 
>>> function has been
>>> +                                  dispatched to specified AP.
>>> +  @retval EFI_UNSUPPORTED         A non-blocking mode request was 
>>> made after the
>>> +                                  UEFI event 
>>> EFI_EVENT_GROUP_READY_TO_BOOT was
>>> +                                  signaled.
>>> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
>>> +  @retval EFI_TIMEOUT             In blocking mode, the timeout 
>>> expired before
>>> +                                  the specified AP has finished.
>>> +  @retval EFI_NOT_READY           The specified AP is busy.
>>> +  @retval EFI_NOT_FOUND           The processor with the handle 
>>> specified by
>>> +                                  ProcessorNumber does not exist.
>>> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP 
>>> or disabled AP.
>>> +  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +EFIAPI
>>> +StartupThisAP (
>>> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
>>> +  IN  EFI_AP_PROCEDURE          Procedure,
>>> +  IN  UINTN                     ProcessorNumber,
>>> +  IN  EFI_EVENT                 WaitEvent OPTIONAL,
>>> +  IN  UINTN                     TimeoutInMicroseconds,
>>> +  IN  VOID                      *ProcedureArgument OPTIONAL,
>>> +  OUT BOOLEAN                   *Finished OPTIONAL
>>> +  )
>>> +{
>>> +  EFI_STATUS   Status;
>>> +  UINTN        Timeout;
>>> +  CPU_AP_DATA  *CpuData;
>>> +
>>> +  if (!IsCurrentProcessorBSP ()) {
>>> +    return EFI_DEVICE_ERROR;
>>> +  }
>>> +
>>> +  if (Procedure == NULL) {
>>> +    return EFI_INVALID_PARAMETER;
>>> +  }
>>> +
>>> +  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
>>> +    return EFI_NOT_FOUND;
>>> +  }
>>> +
>>> +  CpuData = &mCpuMpData.CpuData[ProcessorNumber];
>>> +
>>> +  if (IsProcessorBSP (ProcessorNumber)) {
>>> +    return EFI_INVALID_PARAMETER;
>>> +  }
>>> +
>>> +  if (!IsProcessorEnabled (ProcessorNumber)) {
>>> +    return EFI_INVALID_PARAMETER;
>>> +  }
>>> +
>>> +  if (GetApState (CpuData) != CpuStateIdle) {
>>> +    return EFI_NOT_READY;
>>> +  }
>>> +
>>> +  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
>>> +    return EFI_UNSUPPORTED;
>>> +  }
>>> +
>>> +  Timeout = TimeoutInMicroseconds;
>>> +
>>> +  mCpuMpData.Timeout       = TimeoutInMicroseconds;
>>> +  mCpuMpData.TimeTaken     = 0;
>>> +  mCpuMpData.TimeoutActive = (BOOLEAN)(TimeoutInMicroseconds != 0);
>>
>> [KQ] Adding a timeout active flag is correct. However, I think each 
>> AP should have its own timeout related
>> data (that is Timeout, TimeTaken and TimeoutActive). Because i.e. if 
>> this StartupThisAp call is used on AP 1 in
>> a non-blocking mode, then a subsequent call on AP 2 is blocking, the 
>> common flag and timeout values will
>> impact both cores, and create unintended timeout events.
>>
>>> +
>>> +  mCpuMpData.StartCount  = 1;
>>> +  mCpuMpData.FinishCount = 0;
>>> +
>>> +  SetApProcedure (
>>> +    CpuData,
>>> +    Procedure,
>>> +    ProcedureArgument
>>> +    );
>>> +
>>> +  Status = DispatchCpu (ProcessorNumber);
>>> +  if (EFI_ERROR (Status)) {
>>> +    CpuData->State = CpuStateIdle;
>>> +    return EFI_NOT_READY;
>>> +  }
>>> +
>>> +  if (WaitEvent != NULL) {
>>> +    // Non Blocking
>>> +    if (Finished != NULL) {
>>> +      mCpuMpData.SingleApFinished = Finished;
>>> +      *Finished                   = FALSE;
>>> +    }
>>> +
>>> +    mCpuMpData.WaitEvent = WaitEvent;
[KQ-3] Similar to the above [KQ] comment, for a wait event on the single 
AP, I think there should be a designated
wait event for each CPU available?
>>> +    Status               = gBS->SetTimer (
>>> + CpuData->CheckThisAPEvent,
>>> +                                  TimerPeriodic,
>>> +                                  POLL_INTERVAL_US
>>> +                                  );
>>> +
>>> +    return EFI_SUCCESS;
>>> +  }
>>> +
>>> +  // Blocking
>>> +  while (TRUE) {
>>> +    if (GetApState (CpuData) == CpuStateFinished) {
>>> +      CpuData->State = CpuStateIdle;
>>> +      break;
>>> +    }
>>> +
>>> +    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
> [KQ-2] This will make the core never being able to accept the 
> subsequent start up calls due to this CPU data state will
> never be updated to CpuStateIdle. If this AP completes the job after 
> timeout, ApProcedure will only be able to transition
> its state to CpuStateFinished. Should we add a timer (when there is a 
> timeout period specified) and use CpuData->CheckThisAPEvent
> to check and try to sync the CPU states for this case?
>>> +      return EFI_TIMEOUT;
>>> +    }
>>> +
>>> +    Timeout -= CalculateAndStallInterval (Timeout);
>>> +  }
>>> +
>>> +  return EFI_SUCCESS;
>>> +}
>>> +
>>> +/**
>>> +  This service switches the requested AP to be the BSP from that 
>>> point onward.
>>> +  This service changes the BSP for all purposes.   This call can 
>>> only be
>>> +  performed by the current BSP.
>>> +
>>> +  This service switches the requested AP to be the BSP from that 
>>> point onward.
>>> +  This service changes the BSP for all purposes. The new BSP can 
>>> take over the
>>> +  execution of the old BSP and continue seamlessly from where the 
>>> old one left
>>> +  off. This service may not be supported after the UEFI Event 
>>> EFI_EVENT_GROUP_READY_TO_BOOT
>>> +  is signaled.
>>> +
>>> +  If the BSP cannot be switched prior to the return from this 
>>> service, then
>>> +  EFI_UNSUPPORTED must be returned.
>>> +
>>> +  @param[in] This              A pointer to the 
>>> EFI_MP_SERVICES_PROTOCOL instance.
>>> +  @param[in] ProcessorNumber   The handle number of AP that is to 
>>> become the new
>>> +                               BSP. The range is from 0 to the 
>>> total number of
>>> +                               logical processors minus 1. The 
>>> total number of
>>> +                               logical processors can be retrieved by
>>> + EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
>>> +  @param[in] EnableOldBSP      If TRUE, then the old BSP will be 
>>> listed as an
>>> +                               enabled AP. Otherwise, it will be 
>>> disabled.
>>> +
>>> +  @retval EFI_SUCCESS             BSP successfully switched.
>>> +  @retval EFI_UNSUPPORTED         Switching the BSP cannot be 
>>> completed prior to
>>> +                                  this service returning.
>>> +  @retval EFI_UNSUPPORTED         Switching the BSP is not supported.
>>> +  @retval EFI_SUCCESS             The calling processor is an AP.
>>> +  @retval EFI_NOT_FOUND           The processor with the handle 
>>> specified by
>>> +                                  ProcessorNumber does not exist.
>>> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the 
>>> current BSP or
>>> +                                  a disabled AP.
>>> +  @retval EFI_NOT_READY           The specified AP is busy.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +EFIAPI
>>> +SwitchBSP (
>>> +  IN EFI_MP_SERVICES_PROTOCOL  *This,
>>> +  IN  UINTN                    ProcessorNumber,
>>> +  IN  BOOLEAN                  EnableOldBSP
>>> +  )
>>> +{
>>> +  return EFI_UNSUPPORTED;
>>> +}
>>> +
>>> +/**
>>> +  This service lets the caller enable or disable an AP from this 
>>> point onward.
>>> +  This service may only be called from the BSP.
>>> +
>>> +  This service allows the caller enable or disable an AP from this 
>>> point onward.
>>> +  The caller can optionally specify the health status of the AP by 
>>> Health. If
>>> +  an AP is being disabled, then the state of the disabled AP is 
>>> implementation
>>> +  dependent. If an AP is enabled, then the implementation must 
>>> guarantee that a
>>> +  complete initialization sequence is performed on the AP, so the 
>>> AP is in a state
>>> +  that is compatible with an MP operating system. This service may 
>>> not be supported
>>> +  after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled.
>>> +
>>> +  If the enable or disable AP operation cannot be completed prior 
>>> to the return
>>> +  from this service, then EFI_UNSUPPORTED must be returned.
>>> +
>>> +  @param[in] This              A pointer to the 
>>> EFI_MP_SERVICES_PROTOCOL instance.
>>> +  @param[in] ProcessorNumber   The handle number of AP that is to 
>>> become the new
>>> +                               BSP. The range is from 0 to the 
>>> total number of
>>> +                               logical processors minus 1. The 
>>> total number of
>>> +                               logical processors can be retrieved by
>>> + EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
>>> +  @param[in] EnableAP          Specifies the new state for the 
>>> processor for
>>> +                               enabled, FALSE for disabled.
>>> +  @param[in] HealthFlag        If not NULL, a pointer to a value 
>>> that specifies
>>> +                               the new health status of the AP. 
>>> This flag
>>> +                               corresponds to StatusFlag defined in
>>> + EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
>>> +                               the PROCESSOR_HEALTH_STATUS_BIT is 
>>> used. All other
>>> +                               bits are ignored.  If it is NULL, 
>>> this parameter
>>> +                               is ignored.
>>> +
>>> +  @retval EFI_SUCCESS             The specified AP was enabled or 
>>> disabled successfully.
>>> +  @retval EFI_UNSUPPORTED         Enabling or disabling an AP 
>>> cannot be completed
>>> +                                  prior to this service returning.
>>> +  @retval EFI_UNSUPPORTED         Enabling or disabling an AP is 
>>> not supported.
>>> +  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
>>> +  @retval EFI_NOT_FOUND           Processor with the handle 
>>> specified by ProcessorNumber
>>> +                                  does not exist.
>>> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +EFIAPI
>>> +EnableDisableAP (
>>> +  IN  EFI_MP_SERVICES_PROTOCOL  *This,
>>> +  IN  UINTN                     ProcessorNumber,
>>> +  IN  BOOLEAN                   EnableAP,
>>> +  IN  UINT32                    *HealthFlag OPTIONAL
>>> +  )
>>> +{
>>> +  UINTN        StatusFlag;
>>> +  CPU_AP_DATA  *CpuData;
>>> +
>>> +  StatusFlag = mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag;
>>> +  CpuData    = &mCpuMpData.CpuData[ProcessorNumber];
>>> +
>>> +  if (!IsCurrentProcessorBSP ()) {
>>> +    return EFI_DEVICE_ERROR;
>>> +  }
>>> +
>>> +  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
>>> +    return EFI_NOT_FOUND;
>>> +  }
>>> +
>>> +  if (IsProcessorBSP (ProcessorNumber)) {
>>> +    return EFI_INVALID_PARAMETER;
>>> +  }
>>> +
>>> +  if (GetApState (CpuData) != CpuStateIdle) {
>>> +    return EFI_UNSUPPORTED;
>>> +  }
>>> +
>>> +  if (EnableAP) {
>>> +    if (!IsProcessorEnabled (ProcessorNumber)) {
>>> +      mCpuMpData.NumberOfEnabledProcessors++;
>>> +    }
>>> +
>>> +    StatusFlag |= PROCESSOR_ENABLED_BIT;
>>> +  } else {
>>> +    if (IsProcessorEnabled (ProcessorNumber)) {
>>> +      mCpuMpData.NumberOfEnabledProcessors--;
>>> +    }
>>> +
>>> +    StatusFlag &= ~PROCESSOR_ENABLED_BIT;
>>> +  }
>>> +
>>> +  if (HealthFlag != NULL) {
>>> +    StatusFlag &= ~PROCESSOR_HEALTH_STATUS_BIT;
>>> +    StatusFlag |= (*HealthFlag & PROCESSOR_HEALTH_STATUS_BIT);
>>> +  }
>>> +
>>> +  mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag = StatusFlag;
>>> +  return EFI_SUCCESS;
>>> +}
>>> +
>>> +/**
>>> +  This return the handle number for the calling processor. This 
>>> service may be
>>> +  called from the BSP and APs.
>>> +
>>> +  This service returns the processor handle number for the calling 
>>> processor.
>>> +  The returned value is in the range from 0 to the total number of 
>>> logical
>>> +  processors minus 1. The total number of logical processors can be 
>>> retrieved
>>> +  with EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors(). This 
>>> service may be
>>> +  called from the BSP and APs. If ProcessorNumber is NULL, then 
>>> EFI_INVALID_PARAMETER
>>> +  is returned. Otherwise, the current processors handle number is 
>>> returned in
>>> +  ProcessorNumber, and EFI_SUCCESS is returned.
>>> +
>>> +  @param[in] This              A pointer to the 
>>> EFI_MP_SERVICES_PROTOCOL instance.
>>> +  @param[out] ProcessorNumber  The handle number of AP that is to 
>>> become the new
>>> +                               BSP. The range is from 0 to the 
>>> total number of
>>> +                               logical processors minus 1. The 
>>> total number of
>>> +                               logical processors can be retrieved by
>>> + EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
>>> +
>>> +  @retval EFI_SUCCESS             The current processor handle 
>>> number was returned
>>> +                                  in ProcessorNumber.
>>> +  @retval EFI_INVALID_PARAMETER   ProcessorNumber is NULL.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +EFIAPI
>>> +WhoAmI (
>>> +  IN EFI_MP_SERVICES_PROTOCOL  *This,
>>> +  OUT UINTN                    *ProcessorNumber
>>> +  )
>>> +{
>>> +  UINTN   Index;
>>> +  UINT64  ProcessorId;
>>> +
>>> +  if (ProcessorNumber == NULL) {
>>> +    return EFI_INVALID_PARAMETER;
>>> +  }
>>> +
>>> +  ProcessorId = GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ());
>>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>>> +    if (ProcessorId == gProcessorIDs[Index]) {
>>> +      *ProcessorNumber = Index;
>>> +      break;
>>> +    }
>>> +  }
>>> +
>>> +  return EFI_SUCCESS;
>>> +}
>>> +
>>> +STATIC EFI_MP_SERVICES_PROTOCOL  mMpServicesProtocol = {
>>> +  GetNumberOfProcessors,
>>> +  GetProcessorInfo,
>>> +  StartupAllAPs,
>>> +  StartupThisAP,
>>> +  SwitchBSP,
>>> +  EnableDisableAP,
>>> +  WhoAmI
>>> +};
>>> +
>>> +/** Adds the specified processor the list of failed processors.
>>> +
>>> +   @param ProcessorIndex The processor index to add.
>>> +   @param ApState        Processor state.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +AddProcessorToFailedList (
>>> +  UINTN      ProcessorIndex,
>>> +  CPU_STATE  ApState
>>> +  )
>>> +{
>>> +  UINTN    Index;
>>> +  BOOLEAN  Found;
>>> +
>>> +  Found = FALSE;
>>> +
>>> +  if ((mCpuMpData.FailedList == NULL) ||
>>> +      (ApState == CpuStateIdle) ||
>>> +      (ApState == CpuStateFinished) ||
>>> +      IsProcessorBSP (ProcessorIndex))
>>> +  {
>>> +    return;
>>> +  }
>>> +
>>> +  // If we are retrying make sure we don't double count
>>> +  for (Index = 0; Index < mCpuMpData.FailedListIndex; Index++) {
>>> +    if (mCpuMpData.FailedList[Index] == ProcessorIndex) {
>>> +      Found = TRUE;
>>> +      break;
>>> +    }
>>> +  }
>>> +
>>> +  /* If the CPU isn't already in the FailedList, add it */
>>> +  if (!Found) {
>>> +    mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = 
>>> ProcessorIndex;
>>> +  }
>>> +}
>>> +
>>> +/** Handles the StartupAllAPs case where the timeout has occurred.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +ProcessStartupAllAPsTimeout (
>>> +  VOID
>>> +  )
>>> +{
>>> +  CPU_AP_DATA  *CpuData;
>>> +  UINTN        Index;
>>> +
>>> +  if (mCpuMpData.FailedList == NULL) {
>>> +    return;
>>> +  }
>>> +
>>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>>> +    CpuData = &mCpuMpData.CpuData[Index];
>>> +    if (IsProcessorBSP (Index)) {
>>> +      // Skip BSP
>>> +      continue;
>>> +    }
>>> +
>>> +    if (!IsProcessorEnabled (Index)) {
>>> +      // Skip Disabled processors
>>> +      continue;
>>> +    }
>>> +
>>> +    CpuData = &mCpuMpData.CpuData[Index];
>>> +    AddProcessorToFailedList (Index, GetApState (CpuData));
>>> +  }
>>> +}
>>> +
>>> +/** Updates the status of the APs.
>>> +
>>> +   @param[in] ProcessorIndex The index of the AP to update.
>>> +**/
>>> +STATIC
>>> +VOID
>>> +UpdateApStatus (
>>> +  IN UINTN  ProcessorIndex
>>> +  )
>>> +{
>>> +  EFI_STATUS   Status;
>>> +  CPU_AP_DATA  *CpuData;
>>> +  CPU_AP_DATA  *NextCpuData;
>>> +  CPU_STATE    State;
>>> +  UINTN        NextNumber;
>>> +
>>> +  CpuData = &mCpuMpData.CpuData[ProcessorIndex];
>>> +
>>> +  if (IsProcessorBSP (ProcessorIndex)) {
>>> +    // Skip BSP
>>> +    return;
>>> +  }
>>> +
>>> +  if (!IsProcessorEnabled (ProcessorIndex)) {
>>> +    // Skip Disabled processors
>>> +    return;
>>> +  }
>>> +
>>> +  State = GetApState (CpuData);
>>> +
>>> +  switch (State) {
>>> +    case CpuStateFinished:
>>> +      if (mCpuMpData.SingleThread) {
>>> +        Status = GetNextBlockedNumber (&NextNumber);
>>> +        if (!EFI_ERROR (Status)) {
>>> +          NextCpuData = &mCpuMpData.CpuData[NextNumber];
>>> +
>>> +          NextCpuData->State = CpuStateReady;
>>> +
>>> +          SetApProcedure (
>>> +            NextCpuData,
>>> +            mCpuMpData.Procedure,
>>> +            mCpuMpData.ProcedureArgument
>>> +            );
>>> +
>>> +          Status = DispatchCpu (NextNumber);
>>> +          if (!EFI_ERROR (Status)) {
>>> +            mCpuMpData.StartCount++;
>>> +          } else {
>>> +            AddProcessorToFailedList (NextNumber, NextCpuData->State);
>>> +          }
>>> +        }
>>> +      }
>>> +
>>> +      CpuData->State = CpuStateIdle;
>>> +      mCpuMpData.FinishCount++;
>>> +      break;
>>> +
>>> +    default:
>>> +      break;
>>> +  }
>>> +}
>>> +
>>> +/**
>>> +  If a timeout is specified in StartupAllAps(), a timer is set, 
>>> which invokes
>>> +  this procedure periodically to check whether all APs have finished.
>>> +
>>> +  @param[in] Event   The WaitEvent the user supplied.
>>> +  @param[in] Context The event context.
>>> +**/
>>> +STATIC
>>> +VOID
>>> +EFIAPI
>>> +CheckAllAPsStatus (
>>> +  IN  EFI_EVENT  Event,
>>> +  IN  VOID       *Context
>>> +  )
>>> +{
>>> +  UINTN  Index;
>>> +
>>> +  mCpuMpData.TimeTaken += POLL_INTERVAL_US;
>>> +
>>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>>> +    UpdateApStatus (Index);
>>> +  }
>>> +
>>> +  if (mCpuMpData.TimeoutActive && (mCpuMpData.TimeTaken > 
>>> mCpuMpData.Timeout)) {
>>> +    ProcessStartupAllAPsTimeout ();
>>> +
>>> +    // Force terminal exit
>>> +    mCpuMpData.FinishCount = mCpuMpData.StartCount;
>>> +  }
>>> +
>>> +  if (mCpuMpData.FinishCount != mCpuMpData.StartCount) {
>>> +    return;
>>> +  }
>>> +
>>> +  gBS->SetTimer (
>>> +         mCpuMpData.CheckAllAPsEvent,
>>> +         TimerCancel,
>>> +         0
>>> +         );
>>> +
>>> +  if (mCpuMpData.FailedListIndex == 0) {
>>> +    if (mCpuMpData.FailedList != NULL) {
>>> +      // Since we don't have the original `FailedCpuList`
>>> +      // pointer here to set to NULL, don't free the
>>> +      // memory.
>>> +    }
>>> +  }
>>> +
>>> +  gBS->SignalEvent (mCpuMpData.WaitEvent);
>>> +}
>>> +
>>> +/** Invoked periodically via a timer to check the state of the 
>>> processor.
>>> +
>>> +   @param Event   The event supplied by the timer expiration.
>>> +   @param Context The processor context.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +EFIAPI
>>> +CheckThisAPStatus (
>>> +  IN  EFI_EVENT  Event,
>>> +  IN  VOID       *Context
>>> +  )
>>> +{
>>> +  EFI_STATUS   Status;
>>> +  CPU_AP_DATA  *CpuData;
>>> +  CPU_STATE    State;
>>> +
>>> +  CpuData = Context;
>>> +
>>> +  mCpuMpData.TimeTaken += POLL_INTERVAL_US;
>>> +
>>> +  State = GetApState (CpuData);
>>> +
>>> +  if (State == CpuStateFinished) {
>>> +    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 
>>> 0);
>>> +    ASSERT_EFI_ERROR (Status);
>>> +
>>> +    if (mCpuMpData.SingleApFinished != NULL) {
>>> +      *mCpuMpData.SingleApFinished = TRUE;
>>> +    }
>>> +
>>> +    if (mCpuMpData.WaitEvent != NULL) {
>>> +      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
>>> +      ASSERT_EFI_ERROR (Status);
>>> +    }
>>> +
>>> +    CpuData->State = CpuStateIdle;
>>> +  }
>>> +
>>> +  if (mCpuMpData.TimeoutActive && (mCpuMpData.TimeTaken > 
>>> mCpuMpData.Timeout)) {
>> [KQ] Similar to the other comment, this is probably better using a 
>> per-core data to track elapsed time.
>> On a side note, if this timeout ever occurs, this core will never be 
>> usable in next StartupThisAp calls due
>> to this AP state will not be set to Idle even if the AP procedure is 
>> complete. Is this the intended behavior?
>>> +    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 
>>> 0);
[KQ-3] Should we leave this timer keep checking the status of this AP 
even the time is up? Otherwise, there will
still be no mechanism to recover the CPU state to "Idle" if it ever 
times out and this CPU is essentially unusable for
the rest of this boot in UEFI.
>>> +    if (mCpuMpData.WaitEvent != NULL) {
[KQ-3] The same idea would apply that the event being signaled should be 
per CPU specific, instead
of the common event for "start all APs" call.
>>> +      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
[KQ-3] Then we probably want to set this to NULL after signalling this 
event, just to be on the safe side.
>>> +      ASSERT_EFI_ERROR (Status);
>>> +    }
>>> +  }
>>> +}
>>> +
>>> +/**
>>> +  This function is called by all processors (both BSP and AP) once 
>>> and collects
>>> +  MP related data.
>>> +
>>> +  @param BSP            TRUE if the processor is the BSP.
>>> +  @param Mpidr          The MPIDR for the specified processor. This 
>>> should be
>>> +                        the full MPIDR and not only the affinity bits.
>>> +  @param ProcessorIndex The index of the processor.
>>> +
>>> +  @return EFI_SUCCESS if the data for the processor collected and 
>>> filled in.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +FillInProcessorInformation (
>>> +  IN BOOLEAN  BSP,
>>> +  IN UINTN    Mpidr,
>>> +  IN UINTN    ProcessorIndex
>>> +  )
>>> +{
>>> +  EFI_PROCESSOR_INFORMATION  *CpuInfo;
>>> +
>>> +  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
>>> +
>>> +  CpuInfo->ProcessorId = GET_MPIDR_AFFINITY_BITS (Mpidr);
>>> +  CpuInfo->StatusFlag  = PROCESSOR_ENABLED_BIT | 
>>> PROCESSOR_HEALTH_STATUS_BIT;
>>> +
>>> +  if (BSP) {
>>> +    CpuInfo->StatusFlag |= PROCESSOR_AS_BSP_BIT;
>>> +  }
>>> +
>>> +  if ((Mpidr & MPIDR_MT_BIT) > 0) {
>>> +    CpuInfo->Location.Package = GET_MPIDR_AFF2 (Mpidr);
>>> +    CpuInfo->Location.Core    = GET_MPIDR_AFF1 (Mpidr);
>>> +    CpuInfo->Location.Thread  = GET_MPIDR_AFF0 (Mpidr);
>>> +
>>> +    CpuInfo->ExtendedInformation.Location2.Package = GET_MPIDR_AFF3 
>>> (Mpidr);
>>> +    CpuInfo->ExtendedInformation.Location2.Die     = GET_MPIDR_AFF2 
>>> (Mpidr);
>>> +    CpuInfo->ExtendedInformation.Location2.Core    = GET_MPIDR_AFF1 
>>> (Mpidr);
>>> +    CpuInfo->ExtendedInformation.Location2.Thread  = GET_MPIDR_AFF0 
>>> (Mpidr);
>>> +  } else {
>>> +    CpuInfo->Location.Package = GET_MPIDR_AFF1 (Mpidr);
>>> +    CpuInfo->Location.Core    = GET_MPIDR_AFF0 (Mpidr);
>>> +    CpuInfo->Location.Thread  = 0;
>>> +
>>> +    CpuInfo->ExtendedInformation.Location2.Package = GET_MPIDR_AFF2 
>>> (Mpidr);
>>> +    CpuInfo->ExtendedInformation.Location2.Die     = GET_MPIDR_AFF1 
>>> (Mpidr);
>>> +    CpuInfo->ExtendedInformation.Location2.Core    = GET_MPIDR_AFF0 
>>> (Mpidr);
>>> +    CpuInfo->ExtendedInformation.Location2.Thread  = 0;
>>> +  }
>>> +
>>> +  mCpuMpData.CpuData[ProcessorIndex].State = BSP ? CpuStateBusy : 
>>> CpuStateIdle;
>>> +
>>> +  mCpuMpData.CpuData[ProcessorIndex].Procedure = NULL;
>>> +  mCpuMpData.CpuData[ProcessorIndex].Parameter = NULL;
>>> +
>>> +  return EFI_SUCCESS;
>>> +}
>>> +
>>> +/** Initializes the MP Services system data
>>> +
>>> +   @param NumberOfProcessors The number of processors, both BSP and 
>>> AP.
>>> +   @param CoreInfo           CPU information gathered earlier 
>>> during boot.
>>> +
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +MpServicesInitialize (
>>> +  IN   UINTN                NumberOfProcessors,
>>> +  IN   CONST ARM_CORE_INFO  *CoreInfo
>>> +  )
>>> +{
>>> +  EFI_STATUS  Status;
>>> +  UINTN       Index;
>>> +  EFI_EVENT   ReadyToBootEvent;
>>> +  BOOLEAN     IsBsp;
>>> +
>>> +  //
>>> +  // Clear the data structure area first.
>>> +  //
>>> +  ZeroMem (&mCpuMpData, sizeof (CPU_MP_DATA));
>>> +  //
>>> +  // First BSP fills and inits all known values, including its own 
>>> records.
>>> +  //
>>> +  mCpuMpData.NumberOfProcessors        = NumberOfProcessors;
>>> +  mCpuMpData.NumberOfEnabledProcessors = NumberOfProcessors;
>>> +
>>> +  mCpuMpData.CpuData = AllocateZeroPool (
>>> +                         mCpuMpData.NumberOfProcessors * sizeof 
>>> (CPU_AP_DATA)
>>> +                         );
>>> +
>>> +  if (mCpuMpData.CpuData == NULL) {
>>> +    return EFI_OUT_OF_RESOURCES;
>>> +  }
>>> +
>>> +  /* Allocate one extra for the sentinel entry at the end */
>>> +  gProcessorIDs = AllocateZeroPool ((mCpuMpData.NumberOfProcessors 
>>> + 1) * sizeof (UINT64));
>>> +  ASSERT (gProcessorIDs != NULL);
>>> +
>>> +  Status = gBS->CreateEvent (
>>> +                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
>>> +                  TPL_CALLBACK,
>>> +                  CheckAllAPsStatus,
>>> +                  NULL,
>>> +                  &mCpuMpData.CheckAllAPsEvent
>>> +                  );
>>> +  ASSERT_EFI_ERROR (Status);
>>> +
>>> +  gApStacksBase = AllocatePages (
>>> +                    EFI_SIZE_TO_PAGES (
>>> +                      mCpuMpData.NumberOfProcessors *
>>> +                      gApStackSize
>>> +                      )
>>> +                    );
>>> +  ASSERT (gApStacksBase != NULL);
>>> +
>>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>>> +    if (GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ()) == 
>>> CoreInfo[Index].Mpidr) {
>>> +      IsBsp = TRUE;
>>> +    } else {
>>> +      IsBsp = FALSE;
>>> +    }
>>> +
>>> +    FillInProcessorInformation (IsBsp, CoreInfo[Index].Mpidr, Index);
>>> +
>>> +    gProcessorIDs[Index] = mCpuMpData.CpuData[Index].Info.ProcessorId;
>>> +
>>> +    Status = gBS->CreateEvent (
>>> +                    EVT_TIMER | EVT_NOTIFY_SIGNAL,
>>> +                    TPL_CALLBACK,
>>> +                    CheckThisAPStatus,
>>> +                    (VOID *)&mCpuMpData.CpuData[Index],
>>> + &mCpuMpData.CpuData[Index].CheckThisAPEvent
>>> +                    );
>>> +    ASSERT_EFI_ERROR (Status);
>>> +  }
>>> +
>>> +  gProcessorIDs[Index] = MAX_UINT64;
>>> +
>>> +  //
>>> +  // The global pointer variables as well as the gProcessorIDs 
>>> array contents
>>> +  // are accessed by the other cores so we must clean them to the PoC
>>> +  //
>>> +  WriteBackDataCacheRange (&gProcessorIDs, sizeof (UINT64 *));
>>> +  WriteBackDataCacheRange (&gApStacksBase, sizeof (UINT64 *));
>>> +
>>> +  WriteBackDataCacheRange (
>>> +    gProcessorIDs,
>>> +    (mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64)
>>> +    );
>>> +
>>> +  mNonBlockingModeAllowed = TRUE;
>>> +
>>> +  Status = EfiCreateEventReadyToBootEx (
>>> +             TPL_CALLBACK,
>>> +             ReadyToBootSignaled,
>>> +             NULL,
>>> +             &ReadyToBootEvent
>>> +             );
>>> +  ASSERT_EFI_ERROR (Status);
>>> +
>>> +  return EFI_SUCCESS;
>>> +}
>>> +
>>> +/**
>>> +  Event notification function called when the 
>>> EFI_EVENT_GROUP_READY_TO_BOOT is
>>> +  signaled. After this point, non-blocking mode is no longer allowed.
>>> +
>>> +  @param  Event     Event whose notification function is being 
>>> invoked.
>>> +  @param  Context   The pointer to the notification function's 
>>> context,
>>> +                    which is implementation-dependent.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +EFIAPI
>>> +ReadyToBootSignaled (
>>> +  IN  EFI_EVENT  Event,
>>> +  IN  VOID       *Context
>>> +  )
>>> +{
>>> +  mNonBlockingModeAllowed = FALSE;
>>> +}
>>> +
>>> +/** Initialize multi-processor support.
>>> +
>>> +  @param ImageHandle  Image handle.
>>> +  @param SystemTable  System table.
>>> +
>>> +  @return EFI_SUCCESS on success, or an error code.
>>> +
>>> +**/
>>> +EFI_STATUS
>>> +EFIAPI
>>> +ArmPsciMpServicesDxeInitialize (
>>> +  IN EFI_HANDLE        ImageHandle,
>>> +  IN EFI_SYSTEM_TABLE  *SystemTable
>>> +  )
>>> +{
>>> +  EFI_STATUS                 Status;
>>> +  EFI_HANDLE                 Handle;
>>> +  UINTN                      MaxCpus;
>>> +  EFI_LOADED_IMAGE_PROTOCOL  *Image;
>>> +  EFI_HOB_GENERIC_HEADER     *Hob;
>>> +  VOID                       *HobData;
>>> +  UINTN                      HobDataSize;
>>> +  CONST ARM_CORE_INFO        *CoreInfo;
>>> +
>>> +  MaxCpus = 1;
>>> +
>>> +  Status = gBS->HandleProtocol (
>>> +                  ImageHandle,
>>> +                  &gEfiLoadedImageProtocolGuid,
>>> +                  (VOID **)&Image
>>> +                  );
>>> +  ASSERT_EFI_ERROR (Status);
>>> +
>>> +  //
>>> +  // Parts of the code in this driver may be executed by other 
>>> cores running
>>> +  // with the MMU off so we need to ensure that everything is clean 
>>> to the
>>> +  // point of coherency (PoC)
>>> +  //
>>> +  WriteBackDataCacheRange (Image->ImageBase, Image->ImageSize);
>>> +
>>> +  Hob = GetFirstGuidHob (&gArmMpCoreInfoGuid);
>>> +  if (Hob != NULL) {
>>> +    HobData     = GET_GUID_HOB_DATA (Hob);
>>> +    HobDataSize = GET_GUID_HOB_DATA_SIZE (Hob);
>>> +    CoreInfo    = (ARM_CORE_INFO *)HobData;
>>> +    MaxCpus     = HobDataSize / sizeof (ARM_CORE_INFO);
>>> +  }
>>> +
>>> +  if (MaxCpus == 1) {
>>> +    DEBUG ((DEBUG_WARN, "Trying to use EFI_MP_SERVICES_PROTOCOL on 
>>> a UP system"));
>>> +    // We are not MP so nothing to do
>>> +    return EFI_NOT_FOUND;
>>> +  }
>>> +
>>> +  Status = MpServicesInitialize (MaxCpus, CoreInfo);
>>> +  if (Status != EFI_SUCCESS) {
>>> +    ASSERT_EFI_ERROR (Status);
>>> +    return Status;
>>> +  }
>>> +
>>> +  //
>>> +  // Now install the MP services protocol.
>>> +  //
>>> +  Handle = NULL;
>>> +  Status = gBS->InstallMultipleProtocolInterfaces (
>>> +                  &Handle,
>>> +                  &gEfiMpServiceProtocolGuid,
>>> +                  &mMpServicesProtocol,
>>> +                  NULL
>>> +                  );
>>> +  ASSERT_EFI_ERROR (Status);
>>> +
>>> +  return Status;
>>> +}
>>> +
>>> +/** AP exception handler.
>>> +
>>> +  @param InterruptType The AArch64 CPU exception type.
>>> +  @param SystemContext System context.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +EFIAPI
>>> +ApExceptionHandler (
>>> +  IN CONST EFI_EXCEPTION_TYPE  InterruptType,
>>> +  IN CONST EFI_SYSTEM_CONTEXT  SystemContext
>>> +  )
>>> +{
>>> +  ARM_SMC_ARGS  Args;
>>> +  UINT64        Mpidr;
>>> +  UINTN         Index;
>>> +  UINTN         ProcessorIndex;
>>> +
>>> +  Mpidr = GET_MPIDR_AFFINITY_BITS (ArmReadMpidr ());
>>> +
>>> +  Index          = 0;
>>> +  ProcessorIndex = MAX_UINT64;
>>> +
>>> +  do {
>>> +    if (gProcessorIDs[Index] == Mpidr) {
>>> +      ProcessorIndex = Index;
>>> +      break;
>>> +    }
>>> +
>>> +    Index++;
>>> +  } while (gProcessorIDs[Index] != MAX_UINT64);
>>> +
>>> +  if (ProcessorIndex != MAX_UINT64) {
>>> +    mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
>>> +    ArmDataMemoryBarrier ();
>>> +  }
>>> +
>>> +  Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
>>> +  ArmCallSmc (&Args);
>>> +
>>> +  /* Should never be reached */
>>> +  ASSERT (FALSE);
>>> +  CpuDeadLoop ();
>>> +}
>>> +
>>> +/** C entry-point for the AP.
>>> +    This function gets called from the assembly function ApEntryPoint.
>>> +
>>> +**/
>>> +VOID
>>> +ApProcedure (
>>> +  VOID
>>> +  )
>>> +{
>>> +  ARM_SMC_ARGS      Args;
>>> +  EFI_AP_PROCEDURE  UserApProcedure;
>>> +  VOID              *UserApParameter;
>>> +  UINTN             ProcessorIndex;
>>> +
>>> +  ProcessorIndex = 0;
>>> +
>>> +  WhoAmI (&mMpServicesProtocol, &ProcessorIndex);
>>> +
>>> +  /* Fetch the user-supplied procedure and parameter to execute */
>>> +  UserApProcedure = mCpuMpData.CpuData[ProcessorIndex].Procedure;
>>> +  UserApParameter = mCpuMpData.CpuData[ProcessorIndex].Parameter;
>>> +
>>> +  // Configure the MMU and caches
>>> +  ArmSetTCR (mCpuMpData.CpuData[ProcessorIndex].Tcr);
>>> +  ArmSetTTBR0 (mCpuMpData.CpuData[ProcessorIndex].Ttbr0);
>>> +  ArmSetMAIR (mCpuMpData.CpuData[ProcessorIndex].Mair);
>>> +  ArmDisableAlignmentCheck ();
>>> +  ArmEnableStackAlignmentCheck ();
>>> +  ArmEnableInstructionCache ();
>>> +  ArmEnableDataCache ();
>>> +  ArmEnableMmu ();
>>> +
>>> +  InitializeCpuExceptionHandlers (NULL);
>>> +  RegisterCpuInterruptHandler 
>>> (EXCEPT_AARCH64_SYNCHRONOUS_EXCEPTIONS, ApExceptionHandler);
>>> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_IRQ, 
>>> ApExceptionHandler);
>>> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_FIQ, 
>>> ApExceptionHandler);
>>> +  RegisterCpuInterruptHandler (EXCEPT_AARCH64_SERROR, 
>>> ApExceptionHandler);
>>> +
>>> +  UserApProcedure (UserApParameter);
>>> +
>>> +  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
>>> +
>>> +  ArmDataMemoryBarrier ();
>>> +
>>> +  /* Since we're finished with this AP, turn it off */
>>> +  Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
>>> +  ArmCallSmc (&Args);
>>> +
>>> +  /* Should never be reached */
>>> +  ASSERT (FALSE);
>>> +  CpuDeadLoop ();
>>> +}
>>> +
>>> +/** Returns whether the processor executing this function is the BSP.
>>> +
>>> +    @return Whether the current processor is the BSP.
>>> +**/
>>> +STATIC
>>> +BOOLEAN
>>> +IsCurrentProcessorBSP (
>>> +  VOID
>>> +  )
>>> +{
>>> +  EFI_STATUS  Status;
>>> +  UINTN       ProcessorIndex;
>>> +
>>> +  Status = WhoAmI (&mMpServicesProtocol, &ProcessorIndex);
>>> +  if (EFI_ERROR (Status)) {
>>> +    ASSERT_EFI_ERROR (Status);
>>> +    return FALSE;
>>> +  }
>>> +
>>> +  return IsProcessorBSP (ProcessorIndex);
>>> +}
>>> +
>>> +/** Returns whether the specified processor is enabled.
>>> +
>>> +   @param[in] ProcessorIndex The index of the processor to check.
>>> +
>>> +   @return TRUE if the processor is enabled, FALSE otherwise.
>>> +**/
>>> +STATIC
>>> +BOOLEAN
>>> +IsProcessorEnabled (
>>> +  UINTN  ProcessorIndex
>>> +  )
>>> +{
>>> +  EFI_PROCESSOR_INFORMATION  *CpuInfo;
>>> +
>>> +  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
>>> +
>>> +  return (CpuInfo->StatusFlag & PROCESSOR_ENABLED_BIT) != 0;
>>> +}
>>> +
>>> +/** Sets up the state for the StartupAllAPs function.
>>> +
>>> +   @param SingleThread Whether the APs will execute sequentially.
>>> +
>>> +**/
>>> +STATIC
>>> +VOID
>>> +StartupAllAPsPrepareState (
>>> +  IN BOOLEAN  SingleThread
>>> +  )
>>> +{
>>> +  UINTN        Index;
>>> +  CPU_STATE    APInitialState;
>>> +  CPU_AP_DATA  *CpuData;
>>> +
>>> +  mCpuMpData.FinishCount  = 0;
>>> +  mCpuMpData.StartCount   = 0;
>>> +  mCpuMpData.SingleThread = SingleThread;
>>> +
>>> +  APInitialState = CpuStateReady;
>>> +
>>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>>> +    CpuData = &mCpuMpData.CpuData[Index];
>>> +
>>> +    //
>>> +    // Get APs prepared, and put failing APs into FailedCpuList.
>>> +    // If "SingleThread", only 1 AP will put into ready state, 
>>> other AP will be
>>> +    // put into ready state 1 by 1, until the previous 1 finished 
>>> its task.
>>> +    // If not "SingleThread", all APs are put into ready state from 
>>> the
>>> +    // beginning
>>> +    //
>>> +
>>> +    if (IsProcessorBSP (Index)) {
>>> +      // Skip BSP
>>> +      continue;
>>> +    }
>>> +
>>> +    if (!IsProcessorEnabled (Index)) {
>>> +      // Skip Disabled processors
>>> +      if (mCpuMpData.FailedList != NULL) {
>>> +        mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = Index;
>>> +      }
>>> +
>>> +      continue;
>>> +    }
>>> +
>>> +    CpuData->State = APInitialState;
>>> +
>>> +    mCpuMpData.StartCount++;
>>> +    if (SingleThread) {
>>> +      APInitialState = CpuStateBlocked;
>>> +    }
>>> +  }
>>> +}
>>> +
>>> +/** Handles execution of StartupAllAPs when a WaitEvent has been 
>>> specified.
>>> +
>>> +  @param Procedure         The user-supplied procedure.
>>> +  @param ProcedureArgument The user-supplied procedure argument.
>>> +  @param WaitEvent         The wait event to be signaled when the 
>>> work is
>>> +                           complete or a timeout has occurred.
>>> +  @param TimeoutInMicroseconds The timeout for the work to be 
>>> completed. Zero
>>> +                               indicates an infinite timeout.
>>> +  @param SingleThread          Whether the APs will execute 
>>> sequentially.
>>> +  @param FailedCpuList         User-supplied pointer for list of 
>>> failed CPUs.
>>> +
>>> +   @return EFI_SUCCESS on success.
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +StartupAllAPsWithWaitEvent (
>>> +  IN EFI_AP_PROCEDURE  Procedure,
>>> +  IN VOID              *ProcedureArgument,
>>> +  IN EFI_EVENT         WaitEvent,
>>> +  IN UINTN             TimeoutInMicroseconds,
>>> +  IN BOOLEAN           SingleThread,
>>> +  IN UINTN             **FailedCpuList
>>> +  )
>>> +{
>>> +  EFI_STATUS   Status;
>>> +  UINTN        Index;
>>> +  CPU_AP_DATA  *CpuData;
>>> +
>>> +  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>>> +    CpuData = &mCpuMpData.CpuData[Index];
>>> +    if (IsProcessorBSP (Index)) {
>>> +      // Skip BSP
>>> +      continue;
>>> +    }
>>> +
>>> +    if (!IsProcessorEnabled (Index)) {
>>> +      // Skip Disabled processors
>>> +      continue;
>>> +    }
>>> +
>>> +    if (GetApState (CpuData) == CpuStateReady) {
>>> +      SetApProcedure (CpuData, Procedure, ProcedureArgument);
>>> +      if ((mCpuMpData.StartCount == 0) || !SingleThread) {
>>> +        Status = DispatchCpu (Index);
>>> +        if (EFI_ERROR (Status)) {
>>> +          AddProcessorToFailedList (Index, CpuData->State);
>>> +          break;
>>> +        }
>>> +      }
>>> +    }
>>> +  }
>>> +
>>> +  if (EFI_ERROR (Status)) {
>>> +    return EFI_NOT_READY;
>>> +  }
>>> +
>>> +  //
>>> +  // Save data into private data structure, and create timer to 
>>> poll AP state
>>> +  // before exiting
>>> +  //
>>> +  mCpuMpData.Procedure         = Procedure;
>>> +  mCpuMpData.ProcedureArgument = ProcedureArgument;
>>> +  mCpuMpData.WaitEvent         = WaitEvent;
>>> +  mCpuMpData.Timeout           = TimeoutInMicroseconds;
>>> +  mCpuMpData.TimeTaken         = 0;
>>> +  mCpuMpData.TimeoutActive     = (BOOLEAN)(TimeoutInMicroseconds != 
>>> 0);
>>> +  Status                       = gBS->SetTimer (
>>> + mCpuMpData.CheckAllAPsEvent,
>>> +                                        TimerPeriodic,
>>> +                                        POLL_INTERVAL_US
>>> +                                        );
>>> +
>>> +  return Status;
>>> +}
>>> +
>>> +/** Handles execution of StartupAllAPs when no wait event has been 
>>> specified.
>>> +
>>> +  @param Procedure             The user-supplied procedure.
>>> +  @param ProcedureArgument     The user-supplied procedure argument.
>>> +  @param TimeoutInMicroseconds The timeout for the work to be 
>>> completed. Zero
>>> +                                indicates an infinite timeout.
>>> +  @param SingleThread          Whether the APs will execute 
>>> sequentially.
>>> +  @param FailedCpuList         User-supplied pointer for list of 
>>> failed CPUs.
>>> +
>>> +  @return EFI_SUCCESS on success.
>>> +**/
>>> +STATIC
>>> +EFI_STATUS
>>> +StartupAllAPsNoWaitEvent (
>>> +  IN EFI_AP_PROCEDURE  Procedure,
>>> +  IN VOID              *ProcedureArgument,
>>> +  IN UINTN             TimeoutInMicroseconds,
>>> +  IN BOOLEAN           SingleThread,
>>> +  IN UINTN             **FailedCpuList
>>> +  )
>>> +{
>>> +  EFI_STATUS   Status;
>>> +  UINTN        Index;
>>> +  UINTN        NextIndex;
>>> +  UINTN        Timeout;
>>> +  CPU_AP_DATA  *CpuData;
>>> +  BOOLEAN      DispatchError;
>>> +
>>> +  Timeout       = TimeoutInMicroseconds;
>>> +  DispatchError = FALSE;
>>> +
>>> +  while (TRUE) {
>>> +    for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
>>> +      CpuData = &mCpuMpData.CpuData[Index];
>>> +      if (IsProcessorBSP (Index)) {
>>> +        // Skip BSP
>>> +        continue;
>>> +      }
>>> +
>>> +      if (!IsProcessorEnabled (Index)) {
>>> +        // Skip Disabled processors
>>> +        continue;
>>> +      }
>>> +
>>> +      switch (GetApState (CpuData)) {
>>> +        case CpuStateReady:
>>> +          SetApProcedure (CpuData, Procedure, ProcedureArgument);
>>> +          Status = DispatchCpu (Index);
>>> +          if (EFI_ERROR (Status)) {
>>> +            AddProcessorToFailedList (Index, CpuData->State);
>>> +            CpuData->State = CpuStateIdle;
>>> +            mCpuMpData.StartCount--;
>>> +            DispatchError = TRUE;
>>> +
>>> +            if (SingleThread) {
>>> +              // Dispatch the next available AP
>>> +              Status = GetNextBlockedNumber (&NextIndex);
>>> +              if (!EFI_ERROR (Status)) {
>>> +                mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
>>> +              }
>>> +            }
>>> +          }
>>> +
>>> +          break;
>>> +
>>> +        case CpuStateFinished:
>>> +          mCpuMpData.FinishCount++;
>>> +          if (SingleThread) {
>>> +            Status = GetNextBlockedNumber (&NextIndex);
>>> +            if (!EFI_ERROR (Status)) {
>>> +              mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
>>> +            }
>>> +          }
>>> +
>>> +          CpuData->State = CpuStateIdle;
>>> +          break;
>>> +
>>> +        default:
>>> +          break;
>>> +      }
>>> +    }
>>> +
>>> +    if (mCpuMpData.FinishCount == mCpuMpData.StartCount) {
>>> +      Status = EFI_SUCCESS;
>>> +      break;
>>> +    }
>>> +
>>> +    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
>>> +      Status = EFI_TIMEOUT;
>>> +      break;
>>> +    }
>>> +
>>> +    Timeout -= CalculateAndStallInterval (Timeout);
>>> +  }
>>> +
>>> +  if (Status == EFI_TIMEOUT) {
>>> +    // Add any remaining CPUs to the FailedCpuList
>>> +    if (FailedCpuList != NULL) {
>>> +      for (Index = 0; Index < mCpuMpData.NumberOfProcessors; 
>>> Index++) {
>>> +        AddProcessorToFailedList (Index, 
>>> mCpuMpData.CpuData[Index].State);
>>> +      }
>>> +    }
>>> +  }
>>> +
>>> +  if (DispatchError) {
>>> +    Status = EFI_NOT_READY;
>>> +  }
>>> +
>>> +  return Status;
>>> +}
>>> diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S 
>>> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S
>>> new file mode 100644
>>> index 000000000000..a90fa8a0075f
>>> --- /dev/null
>>> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S
>>> @@ -0,0 +1,57 @@
>>> +#=============================================================================== 
>>>
>>> +#  Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights 
>>> reserved.
>>> +#
>>> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
>>> +#=============================================================================== 
>>>
>>> +
>>> +.text
>>> +.align 3
>>> +
>>> +#include <AsmMacroIoLibV8.h>
>>> +#include <IndustryStandard/ArmStdSmc.h>
>>> +
>>> +#include "MpServicesInternal.h"
>>> +
>>> +GCC_ASM_IMPORT (gApStacksBase)
>>> +GCC_ASM_IMPORT (gProcessorIDs)
>>> +GCC_ASM_IMPORT (ApProcedure)
>>> +GCC_ASM_IMPORT (gApStackSize)
>>> +
>>> +GCC_ASM_EXPORT (ApEntryPoint)
>>> +
>>> +// Entry-point for the AP
>>> +// VOID
>>> +// ApEntryPoint (
>>> +//   VOID
>>> +//   );
>>> +ASM_PFX(ApEntryPoint):
>>> +  mrs x0, mpidr_el1
>>> +  // Mask the non-affinity bits
>>> +  bic x0, x0, 0x00ff000000
>>> +  and x0, x0, 0xffffffffff
>>> +  ldr x1, gProcessorIDs
>>> +  mov x2, 0                   // x2 = processor index
>>> +
>>> +// Find index in gProcessorIDs for current processor
>>> +1:
>>> +  ldr x3, [x1, x2, lsl #3]    // x4 = gProcessorIDs + x2 * 8
>>> +  cmp x3, #-1                 // check if we've reached the end of 
>>> gProcessorIDs
>>> +  beq ProcessorNotFound
>>> +  add x2, x2, 1               // x2++
>>> +  cmp x0, x3                  // if mpidr_el1 != gProcessorIDs[x] 
>>> then loop
>>> +  bne 1b
>>> +
>>> +// Calculate stack address
>>> +  // x2 contains the index for the current processor plus 1
>>> +  ldr x0, gApStacksBase
>>> +  ldr x1, gApStackSize
>>> +  mul x3, x2, x1              // x3 = (ProcessorIndex + 1) * 
>>> gApStackSize
>>> +  add sp, x0, x3              // sp = gApStacksBase + x3
>>> +  mov x29, xzr
>>> +  bl ApProcedure              // doesn't return
>>> +
>>> +ProcessorNotFound:
>>> +// Turn off the processor
>>> +  MOV32 (w0, ARM_SMC_ID_PSCI_CPU_OFF)
>>> +  smc #0
>>> +  b .
>>
>>
>> 
>>
>>

Re: [edk2-devel] [PATCH v4 2/3] ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls

[Rebecca Cran]

On 1/12/23 19:01, Kun Qin wrote:

>>> On 1/4/2023 7:37 AM, Rebecca Cran wrote:
>>>> +  if (WaitEvent != NULL) {
>>>> +    // Non Blocking
>>>> +    if (Finished != NULL) {
>>>> +      mCpuMpData.SingleApFinished = Finished;
>>>> +      *Finished                   = FALSE;
>>>> +    }
>>>> +
>>>> +    mCpuMpData.WaitEvent = WaitEvent;
> [KQ-3] Similar to the above [KQ] comment, for a wait event on the single 
> AP, I think there should be a designated
> wait event for each CPU available?

Yes! I've made that change in the v5 patch series.

>>>> +    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 
>>>> 0);
> [KQ-3] Should we leave this timer keep checking the status of this AP 
> even the time is up? Otherwise, there will
> still be no mechanism to recover the CPU state to "Idle" if it ever 
> times out and this CPU is essentially unusable for
> the rest of this boot in UEFI.

I think I've fixed this by allowing CpuStateFinished as a starting 
state, or resetting CpuStateFinished back to CpuStateIdle (depending on 
the function being called).

>>>> +    if (mCpuMpData.WaitEvent != NULL) {
> [KQ-3] The same idea would apply that the event being signaled should be 
> per CPU specific, instead
> of the common event for "start all APs" call.
>>>> +      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
> [KQ-3] Then we probably want to set this to NULL after signalling this 
> event, just to be on the safe side.

Good point.

-- 
Rebecca Cran

Re: [edk2-devel] [PATCH v4 2/3] ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls

[Rebecca Cran]

On 1/6/23 15:16, Kun Qin wrote:

>>> +  // Blocking
>>> +  while (TRUE) {
>>> +    if (GetApState (CpuData) == CpuStateFinished) {
>>> +      CpuData->State = CpuStateIdle;
>>> +      break;
>>> +    }
>>> +
>>> +    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
> [KQ-2] This will make the core never being able to accept the subsequent 
> start up calls due to this CPU data state will
> never be updated to CpuStateIdle. If this AP completes the job after 
> timeout, ApProcedure will only be able to transition
> its state to CpuStateFinished. Should we add a timer (when there is a 
> timeout period specified) and use CpuData->CheckThisAPEvent
> to check and try to sync the CPU states for this case?

I think making a change to StartupThisAP and StartupAllAPs to reset any 
cores in CpuStateFinished back to CpuStateIdle should work?

-- 
Rebecca Cran

[PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Rebecca Cran]

The MpServicesTest application exercises the EFI_MP_SERVICES_PROTOCOL.

usage:
  MpServicesTest -A [-O]
  MpServicesTest -T <Timeout>
  MpServicesTest -S <Processor #>
  MpServicesTest -P
  MpServicesTest -U
  MpServicesTest -W
  MpServicesTest -E <Processor #>
  MpServicesTest -D <Processor #>
  MpServicesTest -h

Parameter:
  -A:  Run all APs.
  -O:  Run APs sequentially (use with -A).
  -T:  Specify timeout in milliseconds. Default is to wait forever.
  -S:  Specify the single AP to run.
  -P:  Print processor information.
  -U:  Set the specified AP to the Unhealthy status (use with -E/-D).
  -W:  Run WhoAmI and print index of BSP.
  -E:  Enable the specified AP.
  -D:  Disable the specified AP.
  -h:  Print this help page.

Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
---
 MdeModulePkg/MdeModulePkg.dsc                              |   2 +
 MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf |  40 ++
 MdeModulePkg/Application/MpServicesTest/Options.h          |  39 ++
 MdeModulePkg/Application/MpServicesTest/MpServicesTest.c   | 560 ++++++++++++++++++++
 MdeModulePkg/Application/MpServicesTest/Options.c          | 164 ++++++
 5 files changed, 805 insertions(+)

diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
index 659482ab737f..6992b3ae8db6 100644
--- a/MdeModulePkg/MdeModulePkg.dsc
+++ b/MdeModulePkg/MdeModulePkg.dsc
@@ -166,6 +166,7 @@ [LibraryClasses.common.UEFI_APPLICATION]
   MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
   DebugLib|MdePkg/Library/UefiDebugLibStdErr/UefiDebugLibStdErr.inf
   FileHandleLib|MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.inf
+  ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
 
 [LibraryClasses.common.MM_STANDALONE]
   HobLib|MdeModulePkg/Library/BaseHobLibNull/BaseHobLibNull.inf
@@ -445,6 +446,7 @@ [Components]
   MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
 
 [Components.IA32, Components.X64, Components.AARCH64]
+  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
   MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
   MdeModulePkg/Universal/EbcDxe/EbcDebugger.inf
   MdeModulePkg/Universal/EbcDxe/EbcDebuggerConfig.inf
diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
new file mode 100644
index 000000000000..07ee4afec845
--- /dev/null
+++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
@@ -0,0 +1,40 @@
+## @file
+#  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
+#
+#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 1.29
+  BASE_NAME                      = MpServicesTest
+  FILE_GUID                      = 43e9defa-7209-4b0d-b136-cc4ca02cb469
+  MODULE_TYPE                    = UEFI_APPLICATION
+  VERSION_STRING                 = 0.1
+  ENTRY_POINT                    = UefiMain
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
+#
+
+[Sources]
+  MpServicesTest.c
+  Options.c
+  Options.h
+
+[Packages]
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  BaseLib
+  ShellLib
+  UefiApplicationEntryPoint
+  UefiLib
+
+[Protocols]
+  gEfiMpServiceProtocolGuid    ## CONSUMES
+
diff --git a/MdeModulePkg/Application/MpServicesTest/Options.h b/MdeModulePkg/Application/MpServicesTest/Options.h
new file mode 100644
index 000000000000..cb28230ab095
--- /dev/null
+++ b/MdeModulePkg/Application/MpServicesTest/Options.h
@@ -0,0 +1,39 @@
+/** @file
+  Options handling code.
+
+  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef MPSERVICESTEST_OPTIONS_H_
+#define MPSERVICESTEST_OPTIONS_H_
+
+#define INFINITE_TIMEOUT  0
+
+typedef struct {
+  UINTN      Timeout;
+  UINTN      ProcessorIndex;
+  BOOLEAN    RunAllAPs;
+  BOOLEAN    RunSingleAP;
+  BOOLEAN    DisableProcessor;
+  BOOLEAN    EnableProcessor;
+  BOOLEAN    SetProcessorHealthy;
+  BOOLEAN    SetProcessorUnhealthy;
+  BOOLEAN    PrintProcessorInformation;
+  BOOLEAN    PrintBspProcessorIndex;
+  BOOLEAN    RunAPsSequentially;
+} MP_SERVICES_TEST_OPTIONS;
+
+/**
+  Parses any arguments provided on the command line.
+
+  @param Options  The arguments structure.
+
+  @return EFI_SUCCESS on success, or an error code.
+**/
+EFI_STATUS
+ParseArguments (
+  MP_SERVICES_TEST_OPTIONS  *Options
+  );
+
+#endif /* MPSERVICESTEST_OPTIONS_H_ */
diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
new file mode 100644
index 000000000000..3f3d9752d500
--- /dev/null
+++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
@@ -0,0 +1,560 @@
+/** @file
+  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
+
+  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Uefi.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/PrintLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+#include <Pi/PiMultiPhase.h>
+#include <Protocol/MpService.h>
+
+#include "Options.h"
+
+#define APFUNC_BUFFER_LEN  256
+
+typedef struct {
+  EFI_MP_SERVICES_PROTOCOL    *Mp;
+  CHAR16                      **Buffer;
+} APFUNC_ARG;
+
+/** The procedure to run with the MP Services interface.
+
+  @param Arg The procedure argument.
+
+**/
+STATIC
+VOID
+EFIAPI
+ApFunction (
+  IN OUT VOID  *Arg
+  )
+{
+  APFUNC_ARG  *Param;
+  UINTN       ProcessorId;
+
+  if (Arg != NULL) {
+    Param = Arg;
+
+    Param->Mp->WhoAmI (Param->Mp, &ProcessorId);
+    UnicodeSPrint (Param->Buffer[ProcessorId], APFUNC_BUFFER_LEN, L"Hello from CPU %ld\n", ProcessorId);
+  }
+}
+
+/**
+  Fetches the number of processors and which processor is the BSP.
+
+  @param Mp  MP Services Protocol.
+  @param NumProcessors Number of processors.
+  @param BspIndex      The index of the BSP.
+**/
+STATIC
+EFI_STATUS
+GetProcessorInformation (
+  IN  EFI_MP_SERVICES_PROTOCOL  *Mp,
+  OUT UINTN                     *NumProcessors,
+  OUT UINTN                     *BspIndex
+  )
+{
+  EFI_STATUS  Status;
+  UINTN       NumEnabledProcessors;
+
+  Status = Mp->GetNumberOfProcessors (Mp, NumProcessors, &NumEnabledProcessors);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Status = Mp->WhoAmI (Mp, BspIndex);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/** Displays information returned from MP Services Protocol.
+
+  @param Mp       The MP Services Protocol
+  @param BspIndex On return, contains the index of the BSP.
+
+  @return The number of CPUs in the system.
+
+**/
+STATIC
+UINTN
+PrintProcessorInformation (
+  IN   EFI_MP_SERVICES_PROTOCOL  *Mp,
+  OUT  UINTN                     *BspIndex
+  )
+{
+  EFI_STATUS                 Status;
+  EFI_PROCESSOR_INFORMATION  CpuInfo;
+  UINTN                      Index;
+  UINTN                      NumCpu;
+  UINTN                      NumEnabledCpu;
+
+  Status = Mp->GetNumberOfProcessors (Mp, &NumCpu, &NumEnabledCpu);
+  if (EFI_ERROR (Status)) {
+    Print (L"GetNumberOfProcessors failed: %r\n", Status);
+  } else {
+    Print (L"Number of CPUs: %ld, Enabled: %d\n", NumCpu, NumEnabledCpu);
+  }
+
+  for (Index = 0; Index < NumCpu; Index++) {
+    Status = Mp->GetProcessorInfo (Mp, CPU_V2_EXTENDED_TOPOLOGY | Index, &CpuInfo);
+    if (EFI_ERROR (Status)) {
+      Print (L"GetProcessorInfo for Processor %d failed: %r\n", Index, Status);
+    } else {
+      Print (
+        L"Processor %d:\n"
+        L"\tID: %016lx\n"
+        L"\tStatus: %s | ",
+        Index,
+        CpuInfo.ProcessorId,
+        (CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) ? L"BSP" : L"AP"
+        );
+
+      if ((CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) && (BspIndex != NULL)) {
+        *BspIndex = Index;
+      }
+
+      Print (L"%s | ", (CpuInfo.StatusFlag & PROCESSOR_ENABLED_BIT) ? L"Enabled" : L"Disabled");
+      Print (L"%s\n", (CpuInfo.StatusFlag & PROCESSOR_HEALTH_STATUS_BIT) ? L"Healthy" : L"Faulted");
+
+      Print (
+        L"\tLocation: Package %d, Core %d, Thread %d\n"
+        L"\tExtended Information: Package %d, Module %d, Tile %d, Die %d, Core %d, Thread %d\n\n",
+        CpuInfo.Location.Package,
+        CpuInfo.Location.Core,
+        CpuInfo.Location.Thread,
+        CpuInfo.ExtendedInformation.Location2.Package,
+        CpuInfo.ExtendedInformation.Location2.Module,
+        CpuInfo.ExtendedInformation.Location2.Tile,
+        CpuInfo.ExtendedInformation.Location2.Die,
+        CpuInfo.ExtendedInformation.Location2.Core,
+        CpuInfo.ExtendedInformation.Location2.Thread
+        );
+    }
+  }
+
+  return NumCpu;
+}
+
+/** Allocates memory in ApArg for the single AP specified.
+
+  @param ApArg          Pointer to the AP argument structure.
+  @param Mp             The MP Services Protocol.
+  @param ProcessorIndex The index of the AP.
+
+  @retval EFI_SUCCESS          Memory was successfully allocated.
+  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
+
+**/
+STATIC
+EFI_STATUS
+AllocateApFuncBufferSingleAP (
+  IN APFUNC_ARG                *ApArg,
+  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
+  IN UINTN                     ProcessorIndex
+  )
+{
+  ApArg->Mp = Mp;
+
+  ApArg->Buffer = AllocateZeroPool ((ProcessorIndex + 1) * sizeof (VOID *));
+  if (ApArg->Buffer == NULL) {
+    Print (L"Failed to allocate buffer for AP buffer\n");
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  ApArg->Buffer[ProcessorIndex] = AllocateZeroPool (APFUNC_BUFFER_LEN);
+  if (ApArg->Buffer[ProcessorIndex] == NULL) {
+    Print (L"Failed to allocate buffer for AP buffer\n");
+    FreePool (ApArg->Buffer);
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/** Allocates memory in ApArg for all APs.
+
+  @param ApArg   Pointer to the AP argument structure.
+  @param Mp      The MP Services Protocol.
+  @param NumCpus The number of CPUs.
+
+  @retval EFI_SUCCESS          Memory was successfully allocated.
+  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
+
+**/
+STATIC
+EFI_STATUS
+AllocateApFuncBufferAllAPs (
+  IN APFUNC_ARG                *ApArg,
+  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
+  IN UINTN                     NumCpus
+  )
+{
+  UINT32  Index;
+
+  ApArg->Mp = Mp;
+
+  ApArg->Buffer = AllocateZeroPool (NumCpus * sizeof (VOID *));
+  if (ApArg->Buffer == NULL) {
+    Print (L"Failed to allocate buffer for AP message\n");
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  for (Index = 0; Index < NumCpus; Index++) {
+    ApArg->Buffer[Index] = AllocateZeroPool (APFUNC_BUFFER_LEN);
+    if (ApArg->Buffer[Index] == NULL) {
+      Print (L"Failed to allocate buffer for AP message\n");
+      for (--Index; Index >= 0; Index++) {
+        FreePool (ApArg->Buffer[Index]);
+      }
+
+      FreePool (ApArg->Buffer);
+      return EFI_OUT_OF_RESOURCES;
+    }
+  }
+
+  return EFI_SUCCESS;
+}
+
+/** Frees memory in ApArg for all APs.
+
+  @param ApArg   Pointer to the AP argument structure.
+  @param NumCpus The number of CPUs.
+
+**/
+STATIC
+VOID
+FreeApFuncBuffer (
+  APFUNC_ARG  *ApArg,
+  UINTN       NumCpus
+  )
+{
+  UINTN  Index;
+
+  for (Index = 0; Index < NumCpus; Index++) {
+    if (ApArg->Buffer[Index] != NULL) {
+      FreePool (ApArg->Buffer[Index]);
+    }
+  }
+
+  FreePool (ApArg->Buffer);
+}
+
+/** Runs a specified AP.
+
+  @param Mp             The MP Services Protocol.
+  @param ProcessorIndex The processor index.
+  @param Timeout        Timeout in milliseconds.
+
+  @return EFI_SUCCESS on success, or an error code.
+
+**/
+STATIC
+EFI_STATUS
+StartupThisAP (
+  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
+  IN UINTN                     ProcessorIndex,
+  IN UINTN                     Timeout
+  )
+{
+  EFI_STATUS  Status;
+  APFUNC_ARG  ApArg;
+
+  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Print (
+    L"StartupThisAP on Processor %d with %d%s timeout...",
+    ProcessorIndex,
+    Timeout,
+    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
+    );
+  Status = Mp->StartupThisAP (
+                 Mp,
+                 ApFunction,
+                 ProcessorIndex,
+                 NULL,
+                 Timeout * 1000,
+                 &ApArg,
+                 NULL
+                 );
+  if (EFI_ERROR (Status)) {
+    Print (L"failed: %r\n", Status);
+    return Status;
+  } else {
+    Print (L"done.\n");
+    Print (ApArg.Buffer[ProcessorIndex]);
+  }
+
+  FreeApFuncBuffer (&ApArg, ProcessorIndex + 1);
+
+  return EFI_SUCCESS;
+}
+
+/** Runs all APs.
+
+  @param Mp                 The MP Services Protocol.
+  @param NumCpus            The number of CPUs in the system.
+  @param Timeout            Timeout in milliseconds.
+  @param RunAPsSequentially Run APs sequentially (FALSE: run simultaneously)
+
+  @return EFI_SUCCESS on success, or an error code.
+
+**/
+STATIC
+EFI_STATUS
+StartupAllAPs (
+  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
+  IN UINTN                     NumCpus,
+  IN UINTN                     Timeout,
+  IN BOOLEAN                   RunAPsSequentially
+  )
+{
+  EFI_STATUS  Status;
+  UINTN       Index;
+  APFUNC_ARG  ApArg;
+
+  Status = AllocateApFuncBufferAllAPs (&ApArg, Mp, NumCpus);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Print (
+    L"Running with SingleThread %s, %u%s timeout...",
+    (RunAPsSequentially) ? L"TRUE" : L"FALSE",
+    Timeout,
+    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
+    );
+
+  Status = Mp->StartupAllAPs (
+                 Mp,
+                 ApFunction,
+                 RunAPsSequentially,
+                 NULL,
+                 Timeout * 1000,
+                 &ApArg,
+                 NULL
+                 );
+
+  if (EFI_ERROR (Status)) {
+    Print (L"failed: %r\n", Status);
+
+    return Status;
+  } else {
+    Print (L"done.\n");
+
+    for (Index = 0; Index < NumCpus; Index++) {
+      Print (ApArg.Buffer[Index]);
+    }
+  }
+
+  FreeApFuncBuffer (&ApArg, NumCpus);
+  return EFI_SUCCESS;
+}
+
+/**
+  Enables the specified AP.
+
+  @param Mp               The MP Services Protocol.
+  @param ProcessorIndex   The processor to enable.
+  @param ProcessorHealthy The health status of the processor.
+
+  @return EFI_SUCCESS on success, or an error code.
+**/
+STATIC
+EFI_STATUS
+EnableAP (
+  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
+  UINTN                        ProcessorIndex,
+  BOOLEAN                      ProcessorHealthy
+  )
+{
+  EFI_STATUS  Status;
+  UINT32      HealthFlag;
+
+  if (ProcessorHealthy) {
+    Print (L"Enabling Processor %d with HealthFlag healthy...", ProcessorIndex);
+    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
+  } else {
+    Print (L"Enabling Processor %d with HealthFlag faulted...", ProcessorIndex);
+    HealthFlag = 0;
+  }
+
+  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, TRUE, &HealthFlag);
+  if (EFI_ERROR (Status)) {
+    Print (L"failed: %r\n", Status);
+    return Status;
+  } else {
+    Print (L"done.\n");
+  }
+
+  return Status;
+}
+
+/**
+  Disables the specified AP.
+
+  @param Mp               The MP Services Protocol.
+  @param ProcessorIndex   The processor to disable.
+  @param ProcessorHealthy The health status of the processor.
+
+  @return EFI_SUCCESS on success, or an error code.
+**/
+STATIC
+EFI_STATUS
+DisableAP (
+  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
+  UINTN                        ProcessorIndex,
+  BOOLEAN                      ProcessorHealthy
+  )
+{
+  EFI_STATUS  Status;
+  UINT32      HealthFlag;
+
+  if (ProcessorHealthy) {
+    Print (L"Disabling Processor %d with HealthFlag healthy...", ProcessorIndex);
+    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
+  } else {
+    Print (L"Disabling Processor %d with HealthFlag faulted...", ProcessorIndex);
+    HealthFlag = 0;
+  }
+
+  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, FALSE, &HealthFlag);
+  if (EFI_ERROR (Status)) {
+    Print (L"failed: %r\n", Status);
+    return Status;
+  } else {
+    Print (L"done.\n");
+  }
+
+  return Status;
+}
+
+/**
+  The user Entry Point for Application. The user code starts with this function
+  as the real entry point for the application.
+
+  @param[in] ImageHandle    The firmware allocated handle for the EFI image.
+  @param[in] SystemTable    A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS       The entry point is executed successfully.
+  @retval other             Some error occurs when executing this entry point.
+
+**/
+EFI_STATUS
+EFIAPI
+UefiMain (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS                Status;
+  EFI_MP_SERVICES_PROTOCOL  *Mp;
+  UINTN                     BspIndex;
+  UINTN                     CpuIndex;
+  UINTN                     NumCpus;
+  BOOLEAN                   ProcessorHealthy;
+  MP_SERVICES_TEST_OPTIONS  Options;
+
+  BspIndex = 0;
+
+  Status = gBS->LocateProtocol (
+                  &gEfiMpServiceProtocolGuid,
+                  NULL,
+                  (VOID **)&Mp
+                  );
+  if (EFI_ERROR (Status)) {
+    Print (L"Failed to locate EFI_MP_SERVICES_PROTOCOL (%r). Not installed on platform?\n", Status);
+    return EFI_NOT_FOUND;
+  }
+
+  Status = ParseArguments (&Options);
+  if (EFI_ERROR (Status)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Status = GetProcessorInformation (Mp, &NumCpus, &BspIndex);
+  if (EFI_ERROR (Status)) {
+    Print (L"Error: Failed to fetch processor information.\n");
+    return Status;
+  }
+
+  if (Options.PrintBspProcessorIndex) {
+    Status = Mp->WhoAmI (Mp, &CpuIndex);
+    if (EFI_ERROR (Status)) {
+      Print (L"WhoAmI failed: %r\n", Status);
+      return Status;
+    } else {
+      Print (L"BSP: %016lx\n", CpuIndex);
+    }
+  }
+
+  if (Options.PrintProcessorInformation) {
+    NumCpus = PrintProcessorInformation (Mp, &BspIndex);
+    if (NumCpus < 2) {
+      Print (L"Error: Uniprocessor system found.\n");
+      return EFI_INVALID_PARAMETER;
+    }
+  }
+
+  if (Options.RunSingleAP) {
+    Status = StartupThisAP (
+               Mp,
+               Options.ProcessorIndex,
+               Options.Timeout
+               );
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+  }
+
+  if (Options.RunAllAPs) {
+    Status = StartupAllAPs (Mp, NumCpus, Options.Timeout, Options.RunAPsSequentially);
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+  }
+
+  if (Options.EnableProcessor) {
+    ProcessorHealthy = TRUE;
+    if (Options.SetProcessorUnhealthy) {
+      ProcessorHealthy = FALSE;
+    }
+
+    Status = EnableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+  }
+
+  if (Options.DisableProcessor) {
+    ProcessorHealthy = TRUE;
+    if (Options.SetProcessorUnhealthy) {
+      ProcessorHealthy = FALSE;
+    }
+
+    Status = DisableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+  }
+
+  return EFI_SUCCESS;
+}
diff --git a/MdeModulePkg/Application/MpServicesTest/Options.c b/MdeModulePkg/Application/MpServicesTest/Options.c
new file mode 100644
index 000000000000..e820c061e1ec
--- /dev/null
+++ b/MdeModulePkg/Application/MpServicesTest/Options.c
@@ -0,0 +1,164 @@
+/** @file
+  Options handling code.
+
+  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
+  Copyright (c) 2010-2019  Finnbarr P. Murphy.   All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Uefi.h>
+#include <Library/BaseMemoryLib.h>
+#include <Protocol/ShellParameters.h>
+#include <Library/BaseLib.h>
+#include <Library/UefiLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+#include "Options.h"
+
+STATIC UINTN   Argc;
+STATIC CHAR16  **Argv;
+
+/**
+
+  This function provides argc and argv.
+
+  @return Status
+**/
+EFI_STATUS
+GetArg (
+  VOID
+  )
+{
+  EFI_STATUS                     Status;
+  EFI_SHELL_PARAMETERS_PROTOCOL  *ShellParameters;
+
+  Status = gBS->HandleProtocol (
+                  gImageHandle,
+                  &gEfiShellParametersProtocolGuid,
+                  (VOID **)&ShellParameters
+                  );
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Argc = ShellParameters->Argc;
+  Argv = ShellParameters->Argv;
+  return EFI_SUCCESS;
+}
+
+/**
+  Print app usage.
+**/
+STATIC
+VOID
+PrintUsage (
+  VOID
+  )
+{
+  Print (L"MpServicesTest:  usage\n");
+  Print (L"  MpServicesTest -A [-O]\n");
+  Print (L"  MpServicesTest -T <Timeout>\n");
+  Print (L"  MpServicesTest -S <Processor #>\n");
+  Print (L"  MpServicesTest -P\n");
+  Print (L"  MpServicesTest -U\n");
+  Print (L"  MpServicesTest -W\n");
+  Print (L"  MpServicesTest -E <Processor #>\n");
+  Print (L"  MpServicesTest -D <Processor #>\n");
+  Print (L"  MpServicesTest -h\n");
+  Print (L"Parameter:\n");
+  Print (L"  -A:  Run all APs.\n");
+  Print (L"  -O:  Run APs sequentially (use with -A).\n");
+  Print (L"  -T:  Specify timeout in milliseconds. Default is to wait forever.\n");
+  Print (L"  -S:  Specify the single AP to run.\n");
+  Print (L"  -P:  Print processor information.\n");
+  Print (L"  -U:  Set the specified AP to the Unhealthy status (use with -E/-D).\n");
+  Print (L"  -W:  Run WhoAmI and print index of BSP.\n");
+  Print (L"  -E:  Enable the specified AP.\n");
+  Print (L"  -D:  Disable the specified AP.\n");
+  Print (L"  -h:  Print this help page.\n");
+}
+
+/**
+  Parses any arguments provided on the command line.
+
+  @param Options  The arguments structure.
+
+  @return EFI_SUCCESS on success, or an error code.
+**/
+EFI_STATUS
+ParseArguments (
+  MP_SERVICES_TEST_OPTIONS  *Options
+  )
+{
+  EFI_STATUS    Status;
+  UINT32        ArgIndex;
+  CONST CHAR16  *Argument;
+  BOOLEAN       NeedsValue;
+  UINTN         *Value;
+
+  Status = GetArg ();
+  if (EFI_ERROR (Status)) {
+    Print (L"Please use the UEFI Shell to run this application!\n", Status);
+    return Status;
+  }
+
+  if (Argc == 1) {
+    PrintUsage ();
+  }
+
+  ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
+
+  for (ArgIndex = 1; ArgIndex < Argc; ArgIndex++) {
+    Argument   = Argv[ArgIndex];
+    NeedsValue = FALSE;
+
+    if (StrCmp (Argument, L"-A") == 0) {
+      Options->RunAllAPs = TRUE;
+    } else if (StrCmp (Argument, L"-O") == 0) {
+      Options->RunAPsSequentially = TRUE;
+    } else if (StrCmp (Argument, L"-T") == 0) {
+      NeedsValue = TRUE;
+      Value      = &Options->Timeout;
+    } else if (StrCmp (Argument, L"-S") == 0) {
+      Options->RunSingleAP = TRUE;
+      NeedsValue           = TRUE;
+      Value                = &Options->ProcessorIndex;
+    } else if (StrCmp (Argument, L"-P") == 0) {
+      Options->PrintProcessorInformation = TRUE;
+    } else if (StrCmp (Argument, L"-U") == 0) {
+      Options->SetProcessorUnhealthy = TRUE;
+    } else if (StrCmp (Argument, L"-W") == 0) {
+      Options->PrintBspProcessorIndex = TRUE;
+    } else if (StrCmp (Argument, L"-E") == 0) {
+      Options->EnableProcessor = TRUE;
+      NeedsValue               = TRUE;
+      Value                    = &Options->ProcessorIndex;
+    } else if (StrCmp (Argument, L"-D") == 0) {
+      Options->DisableProcessor = TRUE;
+      NeedsValue                = TRUE;
+      Value                     = &Options->ProcessorIndex;
+    } else {
+      PrintUsage ();
+      ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
+      return EFI_SUCCESS;
+    }
+
+    if (NeedsValue) {
+      if ((ArgIndex + 1) < Argc) {
+        Status = StrDecimalToUintnS (Argv[ArgIndex + 1], NULL, Value);
+        if (EFI_ERROR (Status)) {
+          Print (L"Error: option value must be a positive integer.\n");
+          PrintUsage ();
+          return EFI_INVALID_PARAMETER;
+        }
+
+        ArgIndex++;
+      } else {
+        PrintUsage ();
+        return EFI_INVALID_PARAMETER;
+      }
+    }
+  }
+
+  return EFI_SUCCESS;
+}
-- 
2.30.2

Re: [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Ard Biesheuvel]

On Wed, 4 Jan 2023 at 16:37, Rebecca Cran <rebecca@quicinc.com> wrote:
>
> The MpServicesTest application exercises the EFI_MP_SERVICES_PROTOCOL.
>
> usage:
>   MpServicesTest -A [-O]
>   MpServicesTest -T <Timeout>
>   MpServicesTest -S <Processor #>
>   MpServicesTest -P
>   MpServicesTest -U
>   MpServicesTest -W
>   MpServicesTest -E <Processor #>
>   MpServicesTest -D <Processor #>
>   MpServicesTest -h
>
> Parameter:
>   -A:  Run all APs.
>   -O:  Run APs sequentially (use with -A).
>   -T:  Specify timeout in milliseconds. Default is to wait forever.
>   -S:  Specify the single AP to run.
>   -P:  Print processor information.
>   -U:  Set the specified AP to the Unhealthy status (use with -E/-D).
>   -W:  Run WhoAmI and print index of BSP.
>   -E:  Enable the specified AP.
>   -D:  Disable the specified AP.
>   -h:  Print this help page.
>
> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Ard Biesheuvel <ardb@kernel.org>

However, I imagine this may violate some rules regarding dependencies
between packages, so I defer to the maintainers to suggest a way
forward here.


> ---
>  MdeModulePkg/MdeModulePkg.dsc                              |   2 +
>  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf |  40 ++
>  MdeModulePkg/Application/MpServicesTest/Options.h          |  39 ++
>  MdeModulePkg/Application/MpServicesTest/MpServicesTest.c   | 560 ++++++++++++++++++++
>  MdeModulePkg/Application/MpServicesTest/Options.c          | 164 ++++++
>  5 files changed, 805 insertions(+)
>
> diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
> index 659482ab737f..6992b3ae8db6 100644
> --- a/MdeModulePkg/MdeModulePkg.dsc
> +++ b/MdeModulePkg/MdeModulePkg.dsc
> @@ -166,6 +166,7 @@ [LibraryClasses.common.UEFI_APPLICATION]
>    MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>    DebugLib|MdePkg/Library/UefiDebugLibStdErr/UefiDebugLibStdErr.inf
>    FileHandleLib|MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.inf
> +  ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
>
>  [LibraryClasses.common.MM_STANDALONE]
>    HobLib|MdeModulePkg/Library/BaseHobLibNull/BaseHobLibNull.inf
> @@ -445,6 +446,7 @@ [Components]
>    MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
>
>  [Components.IA32, Components.X64, Components.AARCH64]
> +  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>    MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
>    MdeModulePkg/Universal/EbcDxe/EbcDebugger.inf
>    MdeModulePkg/Universal/EbcDxe/EbcDebuggerConfig.inf
> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> new file mode 100644
> index 000000000000..07ee4afec845
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> @@ -0,0 +1,40 @@
> +## @file
> +#  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
> +#
> +#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 1.29
> +  BASE_NAME                      = MpServicesTest
> +  FILE_GUID                      = 43e9defa-7209-4b0d-b136-cc4ca02cb469
> +  MODULE_TYPE                    = UEFI_APPLICATION
> +  VERSION_STRING                 = 0.1
> +  ENTRY_POINT                    = UefiMain
> +
> +#
> +# The following information is for reference only and not required by the build tools.
> +#
> +#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
> +#
> +
> +[Sources]
> +  MpServicesTest.c
> +  Options.c
> +  Options.h
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> +  BaseLib
> +  ShellLib
> +  UefiApplicationEntryPoint
> +  UefiLib
> +
> +[Protocols]
> +  gEfiMpServiceProtocolGuid    ## CONSUMES
> +
> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.h b/MdeModulePkg/Application/MpServicesTest/Options.h
> new file mode 100644
> index 000000000000..cb28230ab095
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/Options.h
> @@ -0,0 +1,39 @@
> +/** @file
> +  Options handling code.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#ifndef MPSERVICESTEST_OPTIONS_H_
> +#define MPSERVICESTEST_OPTIONS_H_
> +
> +#define INFINITE_TIMEOUT  0
> +
> +typedef struct {
> +  UINTN      Timeout;
> +  UINTN      ProcessorIndex;
> +  BOOLEAN    RunAllAPs;
> +  BOOLEAN    RunSingleAP;
> +  BOOLEAN    DisableProcessor;
> +  BOOLEAN    EnableProcessor;
> +  BOOLEAN    SetProcessorHealthy;
> +  BOOLEAN    SetProcessorUnhealthy;
> +  BOOLEAN    PrintProcessorInformation;
> +  BOOLEAN    PrintBspProcessorIndex;
> +  BOOLEAN    RunAPsSequentially;
> +} MP_SERVICES_TEST_OPTIONS;
> +
> +/**
> +  Parses any arguments provided on the command line.
> +
> +  @param Options  The arguments structure.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +EFI_STATUS
> +ParseArguments (
> +  MP_SERVICES_TEST_OPTIONS  *Options
> +  );
> +
> +#endif /* MPSERVICESTEST_OPTIONS_H_ */
> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
> new file mode 100644
> index 000000000000..3f3d9752d500
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
> @@ -0,0 +1,560 @@
> +/** @file
> +  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#include <Uefi.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/MemoryAllocationLib.h>
> +#include <Library/PrintLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Library/UefiLib.h>
> +#include <Pi/PiMultiPhase.h>
> +#include <Protocol/MpService.h>
> +
> +#include "Options.h"
> +
> +#define APFUNC_BUFFER_LEN  256
> +
> +typedef struct {
> +  EFI_MP_SERVICES_PROTOCOL    *Mp;
> +  CHAR16                      **Buffer;
> +} APFUNC_ARG;
> +
> +/** The procedure to run with the MP Services interface.
> +
> +  @param Arg The procedure argument.
> +
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +ApFunction (
> +  IN OUT VOID  *Arg
> +  )
> +{
> +  APFUNC_ARG  *Param;
> +  UINTN       ProcessorId;
> +
> +  if (Arg != NULL) {
> +    Param = Arg;
> +
> +    Param->Mp->WhoAmI (Param->Mp, &ProcessorId);
> +    UnicodeSPrint (Param->Buffer[ProcessorId], APFUNC_BUFFER_LEN, L"Hello from CPU %ld\n", ProcessorId);
> +  }
> +}
> +
> +/**
> +  Fetches the number of processors and which processor is the BSP.
> +
> +  @param Mp  MP Services Protocol.
> +  @param NumProcessors Number of processors.
> +  @param BspIndex      The index of the BSP.
> +**/
> +STATIC
> +EFI_STATUS
> +GetProcessorInformation (
> +  IN  EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  OUT UINTN                     *NumProcessors,
> +  OUT UINTN                     *BspIndex
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINTN       NumEnabledProcessors;
> +
> +  Status = Mp->GetNumberOfProcessors (Mp, NumProcessors, &NumEnabledProcessors);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Status = Mp->WhoAmI (Mp, BspIndex);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Displays information returned from MP Services Protocol.
> +
> +  @param Mp       The MP Services Protocol
> +  @param BspIndex On return, contains the index of the BSP.
> +
> +  @return The number of CPUs in the system.
> +
> +**/
> +STATIC
> +UINTN
> +PrintProcessorInformation (
> +  IN   EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  OUT  UINTN                     *BspIndex
> +  )
> +{
> +  EFI_STATUS                 Status;
> +  EFI_PROCESSOR_INFORMATION  CpuInfo;
> +  UINTN                      Index;
> +  UINTN                      NumCpu;
> +  UINTN                      NumEnabledCpu;
> +
> +  Status = Mp->GetNumberOfProcessors (Mp, &NumCpu, &NumEnabledCpu);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"GetNumberOfProcessors failed: %r\n", Status);
> +  } else {
> +    Print (L"Number of CPUs: %ld, Enabled: %d\n", NumCpu, NumEnabledCpu);
> +  }
> +
> +  for (Index = 0; Index < NumCpu; Index++) {
> +    Status = Mp->GetProcessorInfo (Mp, CPU_V2_EXTENDED_TOPOLOGY | Index, &CpuInfo);
> +    if (EFI_ERROR (Status)) {
> +      Print (L"GetProcessorInfo for Processor %d failed: %r\n", Index, Status);
> +    } else {
> +      Print (
> +        L"Processor %d:\n"
> +        L"\tID: %016lx\n"
> +        L"\tStatus: %s | ",
> +        Index,
> +        CpuInfo.ProcessorId,
> +        (CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) ? L"BSP" : L"AP"
> +        );
> +
> +      if ((CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) && (BspIndex != NULL)) {
> +        *BspIndex = Index;
> +      }
> +
> +      Print (L"%s | ", (CpuInfo.StatusFlag & PROCESSOR_ENABLED_BIT) ? L"Enabled" : L"Disabled");
> +      Print (L"%s\n", (CpuInfo.StatusFlag & PROCESSOR_HEALTH_STATUS_BIT) ? L"Healthy" : L"Faulted");
> +
> +      Print (
> +        L"\tLocation: Package %d, Core %d, Thread %d\n"
> +        L"\tExtended Information: Package %d, Module %d, Tile %d, Die %d, Core %d, Thread %d\n\n",
> +        CpuInfo.Location.Package,
> +        CpuInfo.Location.Core,
> +        CpuInfo.Location.Thread,
> +        CpuInfo.ExtendedInformation.Location2.Package,
> +        CpuInfo.ExtendedInformation.Location2.Module,
> +        CpuInfo.ExtendedInformation.Location2.Tile,
> +        CpuInfo.ExtendedInformation.Location2.Die,
> +        CpuInfo.ExtendedInformation.Location2.Core,
> +        CpuInfo.ExtendedInformation.Location2.Thread
> +        );
> +    }
> +  }
> +
> +  return NumCpu;
> +}
> +
> +/** Allocates memory in ApArg for the single AP specified.
> +
> +  @param ApArg          Pointer to the AP argument structure.
> +  @param Mp             The MP Services Protocol.
> +  @param ProcessorIndex The index of the AP.
> +
> +  @retval EFI_SUCCESS          Memory was successfully allocated.
> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +AllocateApFuncBufferSingleAP (
> +  IN APFUNC_ARG                *ApArg,
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     ProcessorIndex
> +  )
> +{
> +  ApArg->Mp = Mp;
> +
> +  ApArg->Buffer = AllocateZeroPool ((ProcessorIndex + 1) * sizeof (VOID *));
> +  if (ApArg->Buffer == NULL) {
> +    Print (L"Failed to allocate buffer for AP buffer\n");
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  ApArg->Buffer[ProcessorIndex] = AllocateZeroPool (APFUNC_BUFFER_LEN);
> +  if (ApArg->Buffer[ProcessorIndex] == NULL) {
> +    Print (L"Failed to allocate buffer for AP buffer\n");
> +    FreePool (ApArg->Buffer);
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Allocates memory in ApArg for all APs.
> +
> +  @param ApArg   Pointer to the AP argument structure.
> +  @param Mp      The MP Services Protocol.
> +  @param NumCpus The number of CPUs.
> +
> +  @retval EFI_SUCCESS          Memory was successfully allocated.
> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +AllocateApFuncBufferAllAPs (
> +  IN APFUNC_ARG                *ApArg,
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     NumCpus
> +  )
> +{
> +  UINT32  Index;
> +
> +  ApArg->Mp = Mp;
> +
> +  ApArg->Buffer = AllocateZeroPool (NumCpus * sizeof (VOID *));
> +  if (ApArg->Buffer == NULL) {
> +    Print (L"Failed to allocate buffer for AP message\n");
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  for (Index = 0; Index < NumCpus; Index++) {
> +    ApArg->Buffer[Index] = AllocateZeroPool (APFUNC_BUFFER_LEN);
> +    if (ApArg->Buffer[Index] == NULL) {
> +      Print (L"Failed to allocate buffer for AP message\n");
> +      for (--Index; Index >= 0; Index++) {
> +        FreePool (ApArg->Buffer[Index]);
> +      }
> +
> +      FreePool (ApArg->Buffer);
> +      return EFI_OUT_OF_RESOURCES;
> +    }
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Frees memory in ApArg for all APs.
> +
> +  @param ApArg   Pointer to the AP argument structure.
> +  @param NumCpus The number of CPUs.
> +
> +**/
> +STATIC
> +VOID
> +FreeApFuncBuffer (
> +  APFUNC_ARG  *ApArg,
> +  UINTN       NumCpus
> +  )
> +{
> +  UINTN  Index;
> +
> +  for (Index = 0; Index < NumCpus; Index++) {
> +    if (ApArg->Buffer[Index] != NULL) {
> +      FreePool (ApArg->Buffer[Index]);
> +    }
> +  }
> +
> +  FreePool (ApArg->Buffer);
> +}
> +
> +/** Runs a specified AP.
> +
> +  @param Mp             The MP Services Protocol.
> +  @param ProcessorIndex The processor index.
> +  @param Timeout        Timeout in milliseconds.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +StartupThisAP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     ProcessorIndex,
> +  IN UINTN                     Timeout
> +  )
> +{
> +  EFI_STATUS  Status;
> +  APFUNC_ARG  ApArg;
> +
> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Print (
> +    L"StartupThisAP on Processor %d with %d%s timeout...",
> +    ProcessorIndex,
> +    Timeout,
> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
> +    );
> +  Status = Mp->StartupThisAP (
> +                 Mp,
> +                 ApFunction,
> +                 ProcessorIndex,
> +                 NULL,
> +                 Timeout * 1000,
> +                 &ApArg,
> +                 NULL
> +                 );
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +    return Status;
> +  } else {
> +    Print (L"done.\n");
> +    Print (ApArg.Buffer[ProcessorIndex]);
> +  }
> +
> +  FreeApFuncBuffer (&ApArg, ProcessorIndex + 1);
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Runs all APs.
> +
> +  @param Mp                 The MP Services Protocol.
> +  @param NumCpus            The number of CPUs in the system.
> +  @param Timeout            Timeout in milliseconds.
> +  @param RunAPsSequentially Run APs sequentially (FALSE: run simultaneously)
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +StartupAllAPs (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     NumCpus,
> +  IN UINTN                     Timeout,
> +  IN BOOLEAN                   RunAPsSequentially
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINTN       Index;
> +  APFUNC_ARG  ApArg;
> +
> +  Status = AllocateApFuncBufferAllAPs (&ApArg, Mp, NumCpus);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Print (
> +    L"Running with SingleThread %s, %u%s timeout...",
> +    (RunAPsSequentially) ? L"TRUE" : L"FALSE",
> +    Timeout,
> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
> +    );
> +
> +  Status = Mp->StartupAllAPs (
> +                 Mp,
> +                 ApFunction,
> +                 RunAPsSequentially,
> +                 NULL,
> +                 Timeout * 1000,
> +                 &ApArg,
> +                 NULL
> +                 );
> +
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +
> +    return Status;
> +  } else {
> +    Print (L"done.\n");
> +
> +    for (Index = 0; Index < NumCpus; Index++) {
> +      Print (ApArg.Buffer[Index]);
> +    }
> +  }
> +
> +  FreeApFuncBuffer (&ApArg, NumCpus);
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  Enables the specified AP.
> +
> +  @param Mp               The MP Services Protocol.
> +  @param ProcessorIndex   The processor to enable.
> +  @param ProcessorHealthy The health status of the processor.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +STATIC
> +EFI_STATUS
> +EnableAP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  UINTN                        ProcessorIndex,
> +  BOOLEAN                      ProcessorHealthy
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINT32      HealthFlag;
> +
> +  if (ProcessorHealthy) {
> +    Print (L"Enabling Processor %d with HealthFlag healthy...", ProcessorIndex);
> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
> +  } else {
> +    Print (L"Enabling Processor %d with HealthFlag faulted...", ProcessorIndex);
> +    HealthFlag = 0;
> +  }
> +
> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, TRUE, &HealthFlag);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +    return Status;
> +  } else {
> +    Print (L"done.\n");
> +  }
> +
> +  return Status;
> +}
> +
> +/**
> +  Disables the specified AP.
> +
> +  @param Mp               The MP Services Protocol.
> +  @param ProcessorIndex   The processor to disable.
> +  @param ProcessorHealthy The health status of the processor.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +STATIC
> +EFI_STATUS
> +DisableAP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  UINTN                        ProcessorIndex,
> +  BOOLEAN                      ProcessorHealthy
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINT32      HealthFlag;
> +
> +  if (ProcessorHealthy) {
> +    Print (L"Disabling Processor %d with HealthFlag healthy...", ProcessorIndex);
> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
> +  } else {
> +    Print (L"Disabling Processor %d with HealthFlag faulted...", ProcessorIndex);
> +    HealthFlag = 0;
> +  }
> +
> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, FALSE, &HealthFlag);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +    return Status;
> +  } else {
> +    Print (L"done.\n");
> +  }
> +
> +  return Status;
> +}
> +
> +/**
> +  The user Entry Point for Application. The user code starts with this function
> +  as the real entry point for the application.
> +
> +  @param[in] ImageHandle    The firmware allocated handle for the EFI image.
> +  @param[in] SystemTable    A pointer to the EFI System Table.
> +
> +  @retval EFI_SUCCESS       The entry point is executed successfully.
> +  @retval other             Some error occurs when executing this entry point.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +UefiMain (
> +  IN EFI_HANDLE        ImageHandle,
> +  IN EFI_SYSTEM_TABLE  *SystemTable
> +  )
> +{
> +  EFI_STATUS                Status;
> +  EFI_MP_SERVICES_PROTOCOL  *Mp;
> +  UINTN                     BspIndex;
> +  UINTN                     CpuIndex;
> +  UINTN                     NumCpus;
> +  BOOLEAN                   ProcessorHealthy;
> +  MP_SERVICES_TEST_OPTIONS  Options;
> +
> +  BspIndex = 0;
> +
> +  Status = gBS->LocateProtocol (
> +                  &gEfiMpServiceProtocolGuid,
> +                  NULL,
> +                  (VOID **)&Mp
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    Print (L"Failed to locate EFI_MP_SERVICES_PROTOCOL (%r). Not installed on platform?\n", Status);
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  Status = ParseArguments (&Options);
> +  if (EFI_ERROR (Status)) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  Status = GetProcessorInformation (Mp, &NumCpus, &BspIndex);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"Error: Failed to fetch processor information.\n");
> +    return Status;
> +  }
> +
> +  if (Options.PrintBspProcessorIndex) {
> +    Status = Mp->WhoAmI (Mp, &CpuIndex);
> +    if (EFI_ERROR (Status)) {
> +      Print (L"WhoAmI failed: %r\n", Status);
> +      return Status;
> +    } else {
> +      Print (L"BSP: %016lx\n", CpuIndex);
> +    }
> +  }
> +
> +  if (Options.PrintProcessorInformation) {
> +    NumCpus = PrintProcessorInformation (Mp, &BspIndex);
> +    if (NumCpus < 2) {
> +      Print (L"Error: Uniprocessor system found.\n");
> +      return EFI_INVALID_PARAMETER;
> +    }
> +  }
> +
> +  if (Options.RunSingleAP) {
> +    Status = StartupThisAP (
> +               Mp,
> +               Options.ProcessorIndex,
> +               Options.Timeout
> +               );
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  if (Options.RunAllAPs) {
> +    Status = StartupAllAPs (Mp, NumCpus, Options.Timeout, Options.RunAPsSequentially);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  if (Options.EnableProcessor) {
> +    ProcessorHealthy = TRUE;
> +    if (Options.SetProcessorUnhealthy) {
> +      ProcessorHealthy = FALSE;
> +    }
> +
> +    Status = EnableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  if (Options.DisableProcessor) {
> +    ProcessorHealthy = TRUE;
> +    if (Options.SetProcessorUnhealthy) {
> +      ProcessorHealthy = FALSE;
> +    }
> +
> +    Status = DisableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.c b/MdeModulePkg/Application/MpServicesTest/Options.c
> new file mode 100644
> index 000000000000..e820c061e1ec
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/Options.c
> @@ -0,0 +1,164 @@
> +/** @file
> +  Options handling code.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  Copyright (c) 2010-2019  Finnbarr P. Murphy.   All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#include <Uefi.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Protocol/ShellParameters.h>
> +#include <Library/BaseLib.h>
> +#include <Library/UefiLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +
> +#include "Options.h"
> +
> +STATIC UINTN   Argc;
> +STATIC CHAR16  **Argv;
> +
> +/**
> +
> +  This function provides argc and argv.
> +
> +  @return Status
> +**/
> +EFI_STATUS
> +GetArg (
> +  VOID
> +  )
> +{
> +  EFI_STATUS                     Status;
> +  EFI_SHELL_PARAMETERS_PROTOCOL  *ShellParameters;
> +
> +  Status = gBS->HandleProtocol (
> +                  gImageHandle,
> +                  &gEfiShellParametersProtocolGuid,
> +                  (VOID **)&ShellParameters
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Argc = ShellParameters->Argc;
> +  Argv = ShellParameters->Argv;
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  Print app usage.
> +**/
> +STATIC
> +VOID
> +PrintUsage (
> +  VOID
> +  )
> +{
> +  Print (L"MpServicesTest:  usage\n");
> +  Print (L"  MpServicesTest -A [-O]\n");
> +  Print (L"  MpServicesTest -T <Timeout>\n");
> +  Print (L"  MpServicesTest -S <Processor #>\n");
> +  Print (L"  MpServicesTest -P\n");
> +  Print (L"  MpServicesTest -U\n");
> +  Print (L"  MpServicesTest -W\n");
> +  Print (L"  MpServicesTest -E <Processor #>\n");
> +  Print (L"  MpServicesTest -D <Processor #>\n");
> +  Print (L"  MpServicesTest -h\n");
> +  Print (L"Parameter:\n");
> +  Print (L"  -A:  Run all APs.\n");
> +  Print (L"  -O:  Run APs sequentially (use with -A).\n");
> +  Print (L"  -T:  Specify timeout in milliseconds. Default is to wait forever.\n");
> +  Print (L"  -S:  Specify the single AP to run.\n");
> +  Print (L"  -P:  Print processor information.\n");
> +  Print (L"  -U:  Set the specified AP to the Unhealthy status (use with -E/-D).\n");
> +  Print (L"  -W:  Run WhoAmI and print index of BSP.\n");
> +  Print (L"  -E:  Enable the specified AP.\n");
> +  Print (L"  -D:  Disable the specified AP.\n");
> +  Print (L"  -h:  Print this help page.\n");
> +}
> +
> +/**
> +  Parses any arguments provided on the command line.
> +
> +  @param Options  The arguments structure.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +EFI_STATUS
> +ParseArguments (
> +  MP_SERVICES_TEST_OPTIONS  *Options
> +  )
> +{
> +  EFI_STATUS    Status;
> +  UINT32        ArgIndex;
> +  CONST CHAR16  *Argument;
> +  BOOLEAN       NeedsValue;
> +  UINTN         *Value;
> +
> +  Status = GetArg ();
> +  if (EFI_ERROR (Status)) {
> +    Print (L"Please use the UEFI Shell to run this application!\n", Status);
> +    return Status;
> +  }
> +
> +  if (Argc == 1) {
> +    PrintUsage ();
> +  }
> +
> +  ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
> +
> +  for (ArgIndex = 1; ArgIndex < Argc; ArgIndex++) {
> +    Argument   = Argv[ArgIndex];
> +    NeedsValue = FALSE;
> +
> +    if (StrCmp (Argument, L"-A") == 0) {
> +      Options->RunAllAPs = TRUE;
> +    } else if (StrCmp (Argument, L"-O") == 0) {
> +      Options->RunAPsSequentially = TRUE;
> +    } else if (StrCmp (Argument, L"-T") == 0) {
> +      NeedsValue = TRUE;
> +      Value      = &Options->Timeout;
> +    } else if (StrCmp (Argument, L"-S") == 0) {
> +      Options->RunSingleAP = TRUE;
> +      NeedsValue           = TRUE;
> +      Value                = &Options->ProcessorIndex;
> +    } else if (StrCmp (Argument, L"-P") == 0) {
> +      Options->PrintProcessorInformation = TRUE;
> +    } else if (StrCmp (Argument, L"-U") == 0) {
> +      Options->SetProcessorUnhealthy = TRUE;
> +    } else if (StrCmp (Argument, L"-W") == 0) {
> +      Options->PrintBspProcessorIndex = TRUE;
> +    } else if (StrCmp (Argument, L"-E") == 0) {
> +      Options->EnableProcessor = TRUE;
> +      NeedsValue               = TRUE;
> +      Value                    = &Options->ProcessorIndex;
> +    } else if (StrCmp (Argument, L"-D") == 0) {
> +      Options->DisableProcessor = TRUE;
> +      NeedsValue                = TRUE;
> +      Value                     = &Options->ProcessorIndex;
> +    } else {
> +      PrintUsage ();
> +      ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
> +      return EFI_SUCCESS;
> +    }
> +
> +    if (NeedsValue) {
> +      if ((ArgIndex + 1) < Argc) {
> +        Status = StrDecimalToUintnS (Argv[ArgIndex + 1], NULL, Value);
> +        if (EFI_ERROR (Status)) {
> +          Print (L"Error: option value must be a positive integer.\n");
> +          PrintUsage ();
> +          return EFI_INVALID_PARAMETER;
> +        }
> +
> +        ArgIndex++;
> +      } else {
> +        PrintUsage ();
> +        return EFI_INVALID_PARAMETER;
> +      }
> +    }
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> --
> 2.30.2
>

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Laszlo Ersek]

On 1/6/23 10:40, Ard Biesheuvel wrote:
> On Wed, 4 Jan 2023 at 16:37, Rebecca Cran <rebecca@quicinc.com> wrote:
>>
>> The MpServicesTest application exercises the EFI_MP_SERVICES_PROTOCOL.
>>
>> usage:
>>   MpServicesTest -A [-O]
>>   MpServicesTest -T <Timeout>
>>   MpServicesTest -S <Processor #>
>>   MpServicesTest -P
>>   MpServicesTest -U
>>   MpServicesTest -W
>>   MpServicesTest -E <Processor #>
>>   MpServicesTest -D <Processor #>
>>   MpServicesTest -h
>>
>> Parameter:
>>   -A:  Run all APs.
>>   -O:  Run APs sequentially (use with -A).
>>   -T:  Specify timeout in milliseconds. Default is to wait forever.
>>   -S:  Specify the single AP to run.
>>   -P:  Print processor information.
>>   -U:  Set the specified AP to the Unhealthy status (use with -E/-D).
>>   -W:  Run WhoAmI and print index of BSP.
>>   -E:  Enable the specified AP.
>>   -D:  Disable the specified AP.
>>   -h:  Print this help page.
>>
>> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
>
> Acked-by: Ard Biesheuvel <ardb@kernel.org>
> Tested-by: Ard Biesheuvel <ardb@kernel.org>
>
> However, I imagine this may violate some rules regarding dependencies
> between packages, so I defer to the maintainers to suggest a way
> forward here.

The application does not in fact need ShellLib. Squash this patch:

> diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
> index 6992b3ae8db6..24c9b3d5b4b3 100644
> --- a/MdeModulePkg/MdeModulePkg.dsc
> +++ b/MdeModulePkg/MdeModulePkg.dsc
> @@ -166,7 +166,6 @@ [LibraryClasses.common.UEFI_APPLICATION]
>    MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>    DebugLib|MdePkg/Library/UefiDebugLibStdErr/UefiDebugLibStdErr.inf
>    FileHandleLib|MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.inf
> -  ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
>
>  [LibraryClasses.common.MM_STANDALONE]
>    HobLib|MdeModulePkg/Library/BaseHobLibNull/BaseHobLibNull.inf
> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> index 07ee4afec845..fb19e487c129 100644
> --- a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> @@ -31,10 +31,9 @@ [Packages]
>
>  [LibraryClasses]
>    BaseLib
> -  ShellLib
>    UefiApplicationEntryPoint
>    UefiLib
>
>  [Protocols]
> -  gEfiMpServiceProtocolGuid    ## CONSUMES
> -
> +  gEfiMpServiceProtocolGuid       ## CONSUMES
> +  gEfiShellParametersProtocolGuid ## CONSUMES

The ShellLib dependency was incorrectly used for bringing in
"gEfiShellParametersProtocolGuid". But "gEfiShellParametersProtocolGuid"
is a standard protocol GUID, it is declared in "MdePkg/MdePkg.dec". So
you just need to spell it out in the [Protocols] section.

And then (IIUC) no invalid cross-Pkg dependency remains.

(The INF file was not right in the first place: the ShellLib class comes
from "ShellPkg/ShellPkg.dec", but that DEC file is not listed in the INF
file's [Packages] section.)

Laszlo

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Rebecca Cran]

On 1/6/23 04:02, Laszlo Ersek wrote:

> The ShellLib dependency was incorrectly used for bringing in
> "gEfiShellParametersProtocolGuid". But "gEfiShellParametersProtocolGuid"
> is a standard protocol GUID, it is declared in "MdePkg/MdePkg.dec". So
> you just need to spell it out in the [Protocols] section.
> 
> And then (IIUC) no invalid cross-Pkg dependency remains.
> 
> (The INF file was not right in the first place: the ShellLib class comes
> from "ShellPkg/ShellPkg.dec", but that DEC file is not listed in the INF
> file's [Packages] section.)

Oh, thanks!

-- 
Rebecca Cran

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Kun Qin]

Hi Rebecca,

Thanks for sharing this patch. I found a few minor issues when running 
this test app. Please see comments with [KQ] below.

Regards,
Kun

On 1/4/2023 7:37 AM, Rebecca Cran wrote:
> The MpServicesTest application exercises the EFI_MP_SERVICES_PROTOCOL.
>
> usage:
>    MpServicesTest -A [-O]
>    MpServicesTest -T <Timeout>
>    MpServicesTest -S <Processor #>
>    MpServicesTest -P
>    MpServicesTest -U
>    MpServicesTest -W
>    MpServicesTest -E <Processor #>
>    MpServicesTest -D <Processor #>
>    MpServicesTest -h
>
> Parameter:
>    -A:  Run all APs.
>    -O:  Run APs sequentially (use with -A).
>    -T:  Specify timeout in milliseconds. Default is to wait forever.
>    -S:  Specify the single AP to run.
>    -P:  Print processor information.
>    -U:  Set the specified AP to the Unhealthy status (use with -E/-D).
>    -W:  Run WhoAmI and print index of BSP.
>    -E:  Enable the specified AP.
>    -D:  Disable the specified AP.
>    -h:  Print this help page.
>
> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
> ---
>   MdeModulePkg/MdeModulePkg.dsc                              |   2 +
>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf |  40 ++
>   MdeModulePkg/Application/MpServicesTest/Options.h          |  39 ++
>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.c   | 560 ++++++++++++++++++++
>   MdeModulePkg/Application/MpServicesTest/Options.c          | 164 ++++++
>   5 files changed, 805 insertions(+)
>
> diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
> index 659482ab737f..6992b3ae8db6 100644
> --- a/MdeModulePkg/MdeModulePkg.dsc
> +++ b/MdeModulePkg/MdeModulePkg.dsc
> @@ -166,6 +166,7 @@ [LibraryClasses.common.UEFI_APPLICATION]
>     MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>     DebugLib|MdePkg/Library/UefiDebugLibStdErr/UefiDebugLibStdErr.inf
>     FileHandleLib|MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.inf
> +  ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
>   
>   [LibraryClasses.common.MM_STANDALONE]
>     HobLib|MdeModulePkg/Library/BaseHobLibNull/BaseHobLibNull.inf
> @@ -445,6 +446,7 @@ [Components]
>     MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
>   
>   [Components.IA32, Components.X64, Components.AARCH64]
> +  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>     MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
>     MdeModulePkg/Universal/EbcDxe/EbcDebugger.inf
>     MdeModulePkg/Universal/EbcDxe/EbcDebuggerConfig.inf
> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> new file mode 100644
> index 000000000000..07ee4afec845
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> @@ -0,0 +1,40 @@
> +## @file
> +#  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
> +#
> +#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 1.29
> +  BASE_NAME                      = MpServicesTest
> +  FILE_GUID                      = 43e9defa-7209-4b0d-b136-cc4ca02cb469
> +  MODULE_TYPE                    = UEFI_APPLICATION
> +  VERSION_STRING                 = 0.1
> +  ENTRY_POINT                    = UefiMain
> +
> +#
> +# The following information is for reference only and not required by the build tools.
> +#
> +#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
> +#
> +
> +[Sources]
> +  MpServicesTest.c
> +  Options.c
> +  Options.h
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> +  BaseLib
> +  ShellLib
> +  UefiApplicationEntryPoint
> +  UefiLib
> +
> +[Protocols]
> +  gEfiMpServiceProtocolGuid    ## CONSUMES
> +
> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.h b/MdeModulePkg/Application/MpServicesTest/Options.h
> new file mode 100644
> index 000000000000..cb28230ab095
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/Options.h
> @@ -0,0 +1,39 @@
> +/** @file
> +  Options handling code.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#ifndef MPSERVICESTEST_OPTIONS_H_
> +#define MPSERVICESTEST_OPTIONS_H_
> +
> +#define INFINITE_TIMEOUT  0
> +
> +typedef struct {
> +  UINTN      Timeout;
> +  UINTN      ProcessorIndex;
> +  BOOLEAN    RunAllAPs;
> +  BOOLEAN    RunSingleAP;
> +  BOOLEAN    DisableProcessor;
> +  BOOLEAN    EnableProcessor;
> +  BOOLEAN    SetProcessorHealthy;
> +  BOOLEAN    SetProcessorUnhealthy;
> +  BOOLEAN    PrintProcessorInformation;
> +  BOOLEAN    PrintBspProcessorIndex;
> +  BOOLEAN    RunAPsSequentially;
> +} MP_SERVICES_TEST_OPTIONS;
> +
> +/**
> +  Parses any arguments provided on the command line.
> +
> +  @param Options  The arguments structure.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +EFI_STATUS
> +ParseArguments (
> +  MP_SERVICES_TEST_OPTIONS  *Options
> +  );
> +
> +#endif /* MPSERVICESTEST_OPTIONS_H_ */
> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
> new file mode 100644
> index 000000000000..3f3d9752d500
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
> @@ -0,0 +1,560 @@
> +/** @file
> +  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#include <Uefi.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/MemoryAllocationLib.h>
> +#include <Library/PrintLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Library/UefiLib.h>
> +#include <Pi/PiMultiPhase.h>
> +#include <Protocol/MpService.h>
> +
> +#include "Options.h"
> +
> +#define APFUNC_BUFFER_LEN  256
> +
> +typedef struct {
> +  EFI_MP_SERVICES_PROTOCOL    *Mp;
> +  CHAR16                      **Buffer;
> +} APFUNC_ARG;
> +
> +/** The procedure to run with the MP Services interface.
> +
> +  @param Arg The procedure argument.
> +
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +ApFunction (
> +  IN OUT VOID  *Arg
> +  )
> +{
> +  APFUNC_ARG  *Param;
> +  UINTN       ProcessorId;
> +
> +  if (Arg != NULL) {
> +    Param = Arg;
> +
> +    Param->Mp->WhoAmI (Param->Mp, &ProcessorId);
> +    UnicodeSPrint (Param->Buffer[ProcessorId], APFUNC_BUFFER_LEN, L"Hello from CPU %ld\n", ProcessorId);
> +  }
> +}
> +
> +/**
> +  Fetches the number of processors and which processor is the BSP.
> +
> +  @param Mp  MP Services Protocol.
> +  @param NumProcessors Number of processors.
> +  @param BspIndex      The index of the BSP.
> +**/
> +STATIC
> +EFI_STATUS
> +GetProcessorInformation (
> +  IN  EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  OUT UINTN                     *NumProcessors,
> +  OUT UINTN                     *BspIndex
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINTN       NumEnabledProcessors;
> +
> +  Status = Mp->GetNumberOfProcessors (Mp, NumProcessors, &NumEnabledProcessors);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Status = Mp->WhoAmI (Mp, BspIndex);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Displays information returned from MP Services Protocol.
> +
> +  @param Mp       The MP Services Protocol
> +  @param BspIndex On return, contains the index of the BSP.
> +
> +  @return The number of CPUs in the system.
> +
> +**/
> +STATIC
> +UINTN
> +PrintProcessorInformation (
> +  IN   EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  OUT  UINTN                     *BspIndex
> +  )
> +{
> +  EFI_STATUS                 Status;
> +  EFI_PROCESSOR_INFORMATION  CpuInfo;
> +  UINTN                      Index;
> +  UINTN                      NumCpu;
> +  UINTN                      NumEnabledCpu;
[KQ] The NumCpu and NumEnabledCpu probably should be initialized to 0s? 
Otherwise if the
GetNumberOfProcessors function somehow fails, the rest of the call will 
essentially be no-op,
instead of running into undefined number of CPUs.
> +
> +  Status = Mp->GetNumberOfProcessors (Mp, &NumCpu, &NumEnabledCpu);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"GetNumberOfProcessors failed: %r\n", Status);
> +  } else {
> +    Print (L"Number of CPUs: %ld, Enabled: %d\n", NumCpu, NumEnabledCpu);
> +  }
> +
> +  for (Index = 0; Index < NumCpu; Index++) {
> +    Status = Mp->GetProcessorInfo (Mp, CPU_V2_EXTENDED_TOPOLOGY | Index, &CpuInfo);
> +    if (EFI_ERROR (Status)) {
> +      Print (L"GetProcessorInfo for Processor %d failed: %r\n", Index, Status);
> +    } else {
> +      Print (
> +        L"Processor %d:\n"
> +        L"\tID: %016lx\n"
> +        L"\tStatus: %s | ",
> +        Index,
> +        CpuInfo.ProcessorId,
> +        (CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) ? L"BSP" : L"AP"
> +        );
> +
> +      if ((CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) && (BspIndex != NULL)) {
> +        *BspIndex = Index;
> +      }
> +
> +      Print (L"%s | ", (CpuInfo.StatusFlag & PROCESSOR_ENABLED_BIT) ? L"Enabled" : L"Disabled");
> +      Print (L"%s\n", (CpuInfo.StatusFlag & PROCESSOR_HEALTH_STATUS_BIT) ? L"Healthy" : L"Faulted");
> +
> +      Print (
> +        L"\tLocation: Package %d, Core %d, Thread %d\n"
> +        L"\tExtended Information: Package %d, Module %d, Tile %d, Die %d, Core %d, Thread %d\n\n",
> +        CpuInfo.Location.Package,
> +        CpuInfo.Location.Core,
> +        CpuInfo.Location.Thread,
> +        CpuInfo.ExtendedInformation.Location2.Package,
> +        CpuInfo.ExtendedInformation.Location2.Module,
> +        CpuInfo.ExtendedInformation.Location2.Tile,
> +        CpuInfo.ExtendedInformation.Location2.Die,
> +        CpuInfo.ExtendedInformation.Location2.Core,
> +        CpuInfo.ExtendedInformation.Location2.Thread
> +        );
> +    }
> +  }
> +
> +  return NumCpu;
> +}
> +
> +/** Allocates memory in ApArg for the single AP specified.
> +
> +  @param ApArg          Pointer to the AP argument structure.
> +  @param Mp             The MP Services Protocol.
> +  @param ProcessorIndex The index of the AP.
> +
> +  @retval EFI_SUCCESS          Memory was successfully allocated.
> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +AllocateApFuncBufferSingleAP (
> +  IN APFUNC_ARG                *ApArg,
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     ProcessorIndex
> +  )
> +{
> +  ApArg->Mp = Mp;
> +
> +  ApArg->Buffer = AllocateZeroPool ((ProcessorIndex + 1) * sizeof (VOID *));
> +  if (ApArg->Buffer == NULL) {
> +    Print (L"Failed to allocate buffer for AP buffer\n");
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  ApArg->Buffer[ProcessorIndex] = AllocateZeroPool (APFUNC_BUFFER_LEN);
> +  if (ApArg->Buffer[ProcessorIndex] == NULL) {
> +    Print (L"Failed to allocate buffer for AP buffer\n");
> +    FreePool (ApArg->Buffer);
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Allocates memory in ApArg for all APs.
> +
> +  @param ApArg   Pointer to the AP argument structure.
> +  @param Mp      The MP Services Protocol.
> +  @param NumCpus The number of CPUs.
> +
> +  @retval EFI_SUCCESS          Memory was successfully allocated.
> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +AllocateApFuncBufferAllAPs (
> +  IN APFUNC_ARG                *ApArg,
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     NumCpus
> +  )
> +{
> +  UINT32  Index;
[KQ] The Index of UINT32 compared to NumCpus of UINTN could make some 
compilers unhappy.
> +
> +  ApArg->Mp = Mp;
> +
> +  ApArg->Buffer = AllocateZeroPool (NumCpus * sizeof (VOID *));
> +  if (ApArg->Buffer == NULL) {
> +    Print (L"Failed to allocate buffer for AP message\n");
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  for (Index = 0; Index < NumCpus; Index++) {
> +    ApArg->Buffer[Index] = AllocateZeroPool (APFUNC_BUFFER_LEN);
> +    if (ApArg->Buffer[Index] == NULL) {
> +      Print (L"Failed to allocate buffer for AP message\n");
> +      for (--Index; Index >= 0; Index++) {
[KQ] This Index increment could cause the loop not ending as expected.
> +        FreePool (ApArg->Buffer[Index]);
> +      }
> +
> +      FreePool (ApArg->Buffer);
> +      return EFI_OUT_OF_RESOURCES;
> +    }
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Frees memory in ApArg for all APs.
> +
> +  @param ApArg   Pointer to the AP argument structure.
> +  @param NumCpus The number of CPUs.
> +
> +**/
> +STATIC
> +VOID
> +FreeApFuncBuffer (
> +  APFUNC_ARG  *ApArg,
> +  UINTN       NumCpus
> +  )
> +{
> +  UINTN  Index;
> +
> +  for (Index = 0; Index < NumCpus; Index++) {
> +    if (ApArg->Buffer[Index] != NULL) {
> +      FreePool (ApArg->Buffer[Index]);
> +    }
> +  }
> +
> +  FreePool (ApArg->Buffer);
> +}
> +
> +/** Runs a specified AP.
> +
> +  @param Mp             The MP Services Protocol.
> +  @param ProcessorIndex The processor index.
> +  @param Timeout        Timeout in milliseconds.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +StartupThisAP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     ProcessorIndex,
> +  IN UINTN                     Timeout
> +  )
> +{
> +  EFI_STATUS  Status;
> +  APFUNC_ARG  ApArg;
> +
> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
[KQ] I guess the above double calls are not intended?
> +  Print (
> +    L"StartupThisAP on Processor %d with %d%s timeout...",
> +    ProcessorIndex,
> +    Timeout,
> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
> +    );
> +  Status = Mp->StartupThisAP (
> +                 Mp,
> +                 ApFunction,
> +                 ProcessorIndex,
> +                 NULL,
> +                 Timeout * 1000,
> +                 &ApArg,
> +                 NULL
> +                 );
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +    return Status;
> +  } else {
> +    Print (L"done.\n");
> +    Print (ApArg.Buffer[ProcessorIndex]);
> +  }
> +
> +  FreeApFuncBuffer (&ApArg, ProcessorIndex + 1);
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Runs all APs.
> +
> +  @param Mp                 The MP Services Protocol.
> +  @param NumCpus            The number of CPUs in the system.
> +  @param Timeout            Timeout in milliseconds.
> +  @param RunAPsSequentially Run APs sequentially (FALSE: run simultaneously)
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +StartupAllAPs (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     NumCpus,
> +  IN UINTN                     Timeout,
> +  IN BOOLEAN                   RunAPsSequentially
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINTN       Index;
> +  APFUNC_ARG  ApArg;
> +
> +  Status = AllocateApFuncBufferAllAPs (&ApArg, Mp, NumCpus);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Print (
> +    L"Running with SingleThread %s, %u%s timeout...",
> +    (RunAPsSequentially) ? L"TRUE" : L"FALSE",
> +    Timeout,
> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
> +    );
> +
> +  Status = Mp->StartupAllAPs (
> +                 Mp,
> +                 ApFunction,
> +                 RunAPsSequentially,
> +                 NULL,
> +                 Timeout * 1000,
> +                 &ApArg,
> +                 NULL
> +                 );
> +
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +
> +    return Status;
> +  } else {
> +    Print (L"done.\n");
> +
> +    for (Index = 0; Index < NumCpus; Index++) {
> +      Print (ApArg.Buffer[Index]);
> +    }
> +  }
> +
> +  FreeApFuncBuffer (&ApArg, NumCpus);
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  Enables the specified AP.
> +
> +  @param Mp               The MP Services Protocol.
> +  @param ProcessorIndex   The processor to enable.
> +  @param ProcessorHealthy The health status of the processor.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +STATIC
> +EFI_STATUS
> +EnableAP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  UINTN                        ProcessorIndex,
> +  BOOLEAN                      ProcessorHealthy
[KQ] These parameters should have the "IN" attributes?
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINT32      HealthFlag;
> +
> +  if (ProcessorHealthy) {
> +    Print (L"Enabling Processor %d with HealthFlag healthy...", ProcessorIndex);
> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
> +  } else {
> +    Print (L"Enabling Processor %d with HealthFlag faulted...", ProcessorIndex);
> +    HealthFlag = 0;
> +  }
> +
> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, TRUE, &HealthFlag);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +    return Status;
> +  } else {
> +    Print (L"done.\n");
> +  }
> +
> +  return Status;
> +}
> +
> +/**
> +  Disables the specified AP.
> +
> +  @param Mp               The MP Services Protocol.
> +  @param ProcessorIndex   The processor to disable.
> +  @param ProcessorHealthy The health status of the processor.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +STATIC
> +EFI_STATUS
> +DisableAP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  UINTN                        ProcessorIndex,
> +  BOOLEAN                      ProcessorHealthy
[KQ] These parameters should have the "IN" attributes?
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINT32      HealthFlag;
> +
> +  if (ProcessorHealthy) {
> +    Print (L"Disabling Processor %d with HealthFlag healthy...", ProcessorIndex);
> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
> +  } else {
> +    Print (L"Disabling Processor %d with HealthFlag faulted...", ProcessorIndex);
> +    HealthFlag = 0;
> +  }
> +
> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, FALSE, &HealthFlag);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +    return Status;
> +  } else {
> +    Print (L"done.\n");
> +  }
> +
> +  return Status;
> +}
> +
> +/**
> +  The user Entry Point for Application. The user code starts with this function
> +  as the real entry point for the application.
> +
> +  @param[in] ImageHandle    The firmware allocated handle for the EFI image.
> +  @param[in] SystemTable    A pointer to the EFI System Table.
> +
> +  @retval EFI_SUCCESS       The entry point is executed successfully.
> +  @retval other             Some error occurs when executing this entry point.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +UefiMain (
> +  IN EFI_HANDLE        ImageHandle,
> +  IN EFI_SYSTEM_TABLE  *SystemTable
> +  )
> +{
> +  EFI_STATUS                Status;
> +  EFI_MP_SERVICES_PROTOCOL  *Mp;
> +  UINTN                     BspIndex;
> +  UINTN                     CpuIndex;
> +  UINTN                     NumCpus;
> +  BOOLEAN                   ProcessorHealthy;
> +  MP_SERVICES_TEST_OPTIONS  Options;
> +
> +  BspIndex = 0;
> +
> +  Status = gBS->LocateProtocol (
> +                  &gEfiMpServiceProtocolGuid,
> +                  NULL,
> +                  (VOID **)&Mp
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    Print (L"Failed to locate EFI_MP_SERVICES_PROTOCOL (%r). Not installed on platform?\n", Status);
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  Status = ParseArguments (&Options);
> +  if (EFI_ERROR (Status)) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  Status = GetProcessorInformation (Mp, &NumCpus, &BspIndex);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"Error: Failed to fetch processor information.\n");
> +    return Status;
> +  }
> +
> +  if (Options.PrintBspProcessorIndex) {
> +    Status = Mp->WhoAmI (Mp, &CpuIndex);
> +    if (EFI_ERROR (Status)) {
> +      Print (L"WhoAmI failed: %r\n", Status);
> +      return Status;
> +    } else {
> +      Print (L"BSP: %016lx\n", CpuIndex);
> +    }
> +  }
> +
> +  if (Options.PrintProcessorInformation) {
> +    NumCpus = PrintProcessorInformation (Mp, &BspIndex);
> +    if (NumCpus < 2) {
> +      Print (L"Error: Uniprocessor system found.\n");
> +      return EFI_INVALID_PARAMETER;
> +    }
> +  }
> +
> +  if (Options.RunSingleAP) {
> +    Status = StartupThisAP (
> +               Mp,
> +               Options.ProcessorIndex,
> +               Options.Timeout
> +               );
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  if (Options.RunAllAPs) {
> +    Status = StartupAllAPs (Mp, NumCpus, Options.Timeout, Options.RunAPsSequentially);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  if (Options.EnableProcessor) {
> +    ProcessorHealthy = TRUE;
> +    if (Options.SetProcessorUnhealthy) {
> +      ProcessorHealthy = FALSE;
> +    }
> +
> +    Status = EnableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  if (Options.DisableProcessor) {
> +    ProcessorHealthy = TRUE;
> +    if (Options.SetProcessorUnhealthy) {
> +      ProcessorHealthy = FALSE;
> +    }
> +
> +    Status = DisableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.c b/MdeModulePkg/Application/MpServicesTest/Options.c
> new file mode 100644
> index 000000000000..e820c061e1ec
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/Options.c
> @@ -0,0 +1,164 @@
> +/** @file
> +  Options handling code.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  Copyright (c) 2010-2019  Finnbarr P. Murphy.   All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#include <Uefi.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Protocol/ShellParameters.h>
> +#include <Library/BaseLib.h>
> +#include <Library/UefiLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +
> +#include "Options.h"
> +
> +STATIC UINTN   Argc;
> +STATIC CHAR16  **Argv;
> +
> +/**
> +
> +  This function provides argc and argv.
> +
> +  @return Status
> +**/
> +EFI_STATUS
> +GetArg (
> +  VOID
> +  )
> +{
> +  EFI_STATUS                     Status;
> +  EFI_SHELL_PARAMETERS_PROTOCOL  *ShellParameters;
> +
> +  Status = gBS->HandleProtocol (
> +                  gImageHandle,
> +                  &gEfiShellParametersProtocolGuid,
> +                  (VOID **)&ShellParameters
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Argc = ShellParameters->Argc;
> +  Argv = ShellParameters->Argv;
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  Print app usage.
> +**/
> +STATIC
> +VOID
> +PrintUsage (
> +  VOID
> +  )
> +{
> +  Print (L"MpServicesTest:  usage\n");
> +  Print (L"  MpServicesTest -A [-O]\n");
> +  Print (L"  MpServicesTest -T <Timeout>\n");
> +  Print (L"  MpServicesTest -S <Processor #>\n");
> +  Print (L"  MpServicesTest -P\n");
> +  Print (L"  MpServicesTest -U\n");
> +  Print (L"  MpServicesTest -W\n");
> +  Print (L"  MpServicesTest -E <Processor #>\n");
> +  Print (L"  MpServicesTest -D <Processor #>\n");
> +  Print (L"  MpServicesTest -h\n");
> +  Print (L"Parameter:\n");
> +  Print (L"  -A:  Run all APs.\n");
> +  Print (L"  -O:  Run APs sequentially (use with -A).\n");
> +  Print (L"  -T:  Specify timeout in milliseconds. Default is to wait forever.\n");
> +  Print (L"  -S:  Specify the single AP to run.\n");
> +  Print (L"  -P:  Print processor information.\n");
> +  Print (L"  -U:  Set the specified AP to the Unhealthy status (use with -E/-D).\n");
> +  Print (L"  -W:  Run WhoAmI and print index of BSP.\n");
> +  Print (L"  -E:  Enable the specified AP.\n");
> +  Print (L"  -D:  Disable the specified AP.\n");
> +  Print (L"  -h:  Print this help page.\n");
> +}
> +
> +/**
> +  Parses any arguments provided on the command line.
> +
> +  @param Options  The arguments structure.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +EFI_STATUS
> +ParseArguments (
> +  MP_SERVICES_TEST_OPTIONS  *Options
> +  )
> +{
> +  EFI_STATUS    Status;
> +  UINT32        ArgIndex;
[KQ] Similar to the other comment, ArgIndex is of UINT32 is compared to 
Argc of UINTN could make some compilers unhappy.
> +  CONST CHAR16  *Argument;
> +  BOOLEAN       NeedsValue;
> +  UINTN         *Value;
> +
> +  Status = GetArg ();
> +  if (EFI_ERROR (Status)) {
> +    Print (L"Please use the UEFI Shell to run this application!\n", Status);
> +    return Status;
> +  }
> +
> +  if (Argc == 1) {
> +    PrintUsage ();
> +  }
> +
> +  ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
> +
> +  for (ArgIndex = 1; ArgIndex < Argc; ArgIndex++) {
> +    Argument   = Argv[ArgIndex];
> +    NeedsValue = FALSE;
> +
> +    if (StrCmp (Argument, L"-A") == 0) {
> +      Options->RunAllAPs = TRUE;
> +    } else if (StrCmp (Argument, L"-O") == 0) {
> +      Options->RunAPsSequentially = TRUE;
> +    } else if (StrCmp (Argument, L"-T") == 0) {
> +      NeedsValue = TRUE;
> +      Value      = &Options->Timeout;
> +    } else if (StrCmp (Argument, L"-S") == 0) {
> +      Options->RunSingleAP = TRUE;
> +      NeedsValue           = TRUE;
> +      Value                = &Options->ProcessorIndex;
> +    } else if (StrCmp (Argument, L"-P") == 0) {
> +      Options->PrintProcessorInformation = TRUE;
> +    } else if (StrCmp (Argument, L"-U") == 0) {
> +      Options->SetProcessorUnhealthy = TRUE;
> +    } else if (StrCmp (Argument, L"-W") == 0) {
> +      Options->PrintBspProcessorIndex = TRUE;
> +    } else if (StrCmp (Argument, L"-E") == 0) {
> +      Options->EnableProcessor = TRUE;
> +      NeedsValue               = TRUE;
> +      Value                    = &Options->ProcessorIndex;
> +    } else if (StrCmp (Argument, L"-D") == 0) {
> +      Options->DisableProcessor = TRUE;
> +      NeedsValue                = TRUE;
> +      Value                     = &Options->ProcessorIndex;
> +    } else {
> +      PrintUsage ();
> +      ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
> +      return EFI_SUCCESS;
> +    }
> +
> +    if (NeedsValue) {
> +      if ((ArgIndex + 1) < Argc) {
> +        Status = StrDecimalToUintnS (Argv[ArgIndex + 1], NULL, Value);
> +        if (EFI_ERROR (Status)) {
> +          Print (L"Error: option value must be a positive integer.\n");
> +          PrintUsage ();
> +          return EFI_INVALID_PARAMETER;
> +        }
> +
> +        ArgIndex++;
> +      } else {
> +        PrintUsage ();
> +        return EFI_INVALID_PARAMETER;
> +      }
> +    }
> +  }
> +
> +  return EFI_SUCCESS;
> +}

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Rebecca Cran]

Thanks! I've fixed all the issues you noted and will send out a v5 patch 
in the next couple of days.

-- 
Rebecca Cran

On 1/6/23 15:33, Kun Qin wrote:
> Hi Rebecca,
> 
> Thanks for sharing this patch. I found a few minor issues when running 
> this test app. Please see comments with [KQ] below.
> 
> Regards,
> Kun
> 
> On 1/4/2023 7:37 AM, Rebecca Cran wrote:
>> The MpServicesTest application exercises the EFI_MP_SERVICES_PROTOCOL.
>>
>> usage:
>>    MpServicesTest -A [-O]
>>    MpServicesTest -T <Timeout>
>>    MpServicesTest -S <Processor #>
>>    MpServicesTest -P
>>    MpServicesTest -U
>>    MpServicesTest -W
>>    MpServicesTest -E <Processor #>
>>    MpServicesTest -D <Processor #>
>>    MpServicesTest -h
>>
>> Parameter:
>>    -A:  Run all APs.
>>    -O:  Run APs sequentially (use with -A).
>>    -T:  Specify timeout in milliseconds. Default is to wait forever.
>>    -S:  Specify the single AP to run.
>>    -P:  Print processor information.
>>    -U:  Set the specified AP to the Unhealthy status (use with -E/-D).
>>    -W:  Run WhoAmI and print index of BSP.
>>    -E:  Enable the specified AP.
>>    -D:  Disable the specified AP.
>>    -h:  Print this help page.
>>
>> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
>> ---
>>   MdeModulePkg/MdeModulePkg.dsc                              |   2 +
>>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf |  40 ++
>>   MdeModulePkg/Application/MpServicesTest/Options.h          |  39 ++
>>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.c   | 560 
>> ++++++++++++++++++++
>>   MdeModulePkg/Application/MpServicesTest/Options.c          | 164 ++++++
>>   5 files changed, 805 insertions(+)
>>
>> diff --git a/MdeModulePkg/MdeModulePkg.dsc 
>> b/MdeModulePkg/MdeModulePkg.dsc
>> index 659482ab737f..6992b3ae8db6 100644
>> --- a/MdeModulePkg/MdeModulePkg.dsc
>> +++ b/MdeModulePkg/MdeModulePkg.dsc
>> @@ -166,6 +166,7 @@ [LibraryClasses.common.UEFI_APPLICATION]
>>     
>> MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>>     DebugLib|MdePkg/Library/UefiDebugLibStdErr/UefiDebugLibStdErr.inf
>>     FileHandleLib|MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.inf
>> +  ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
>>   [LibraryClasses.common.MM_STANDALONE]
>>     HobLib|MdeModulePkg/Library/BaseHobLibNull/BaseHobLibNull.inf
>> @@ -445,6 +446,7 @@ [Components]
>>     
>> MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
>>   [Components.IA32, Components.X64, Components.AARCH64]
>> +  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>>     MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
>>     MdeModulePkg/Universal/EbcDxe/EbcDebugger.inf
>>     MdeModulePkg/Universal/EbcDxe/EbcDebuggerConfig.inf
>> diff --git 
>> a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf 
>> b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>> new file mode 100644
>> index 000000000000..07ee4afec845
>> --- /dev/null
>> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>> @@ -0,0 +1,40 @@
>> +## @file
>> +#  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
>> +#
>> +#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>> reserved.<BR>
>> +#
>> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
>> +#
>> +##
>> +
>> +[Defines]
>> +  INF_VERSION                    = 1.29
>> +  BASE_NAME                      = MpServicesTest
>> +  FILE_GUID                      = 43e9defa-7209-4b0d-b136-cc4ca02cb469
>> +  MODULE_TYPE                    = UEFI_APPLICATION
>> +  VERSION_STRING                 = 0.1
>> +  ENTRY_POINT                    = UefiMain
>> +
>> +#
>> +# The following information is for reference only and not required by 
>> the build tools.
>> +#
>> +#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
>> +#
>> +
>> +[Sources]
>> +  MpServicesTest.c
>> +  Options.c
>> +  Options.h
>> +
>> +[Packages]
>> +  MdePkg/MdePkg.dec
>> +
>> +[LibraryClasses]
>> +  BaseLib
>> +  ShellLib
>> +  UefiApplicationEntryPoint
>> +  UefiLib
>> +
>> +[Protocols]
>> +  gEfiMpServiceProtocolGuid    ## CONSUMES
>> +
>> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.h 
>> b/MdeModulePkg/Application/MpServicesTest/Options.h
>> new file mode 100644
>> index 000000000000..cb28230ab095
>> --- /dev/null
>> +++ b/MdeModulePkg/Application/MpServicesTest/Options.h
>> @@ -0,0 +1,39 @@
>> +/** @file
>> +  Options handling code.
>> +
>> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>> reserved.<BR>
>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>> +**/
>> +
>> +#ifndef MPSERVICESTEST_OPTIONS_H_
>> +#define MPSERVICESTEST_OPTIONS_H_
>> +
>> +#define INFINITE_TIMEOUT  0
>> +
>> +typedef struct {
>> +  UINTN      Timeout;
>> +  UINTN      ProcessorIndex;
>> +  BOOLEAN    RunAllAPs;
>> +  BOOLEAN    RunSingleAP;
>> +  BOOLEAN    DisableProcessor;
>> +  BOOLEAN    EnableProcessor;
>> +  BOOLEAN    SetProcessorHealthy;
>> +  BOOLEAN    SetProcessorUnhealthy;
>> +  BOOLEAN    PrintProcessorInformation;
>> +  BOOLEAN    PrintBspProcessorIndex;
>> +  BOOLEAN    RunAPsSequentially;
>> +} MP_SERVICES_TEST_OPTIONS;
>> +
>> +/**
>> +  Parses any arguments provided on the command line.
>> +
>> +  @param Options  The arguments structure.
>> +
>> +  @return EFI_SUCCESS on success, or an error code.
>> +**/
>> +EFI_STATUS
>> +ParseArguments (
>> +  MP_SERVICES_TEST_OPTIONS  *Options
>> +  );
>> +
>> +#endif /* MPSERVICESTEST_OPTIONS_H_ */
>> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c 
>> b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
>> new file mode 100644
>> index 000000000000..3f3d9752d500
>> --- /dev/null
>> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
>> @@ -0,0 +1,560 @@
>> +/** @file
>> +  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
>> +
>> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>> reserved.<BR>
>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>> +**/
>> +
>> +#include <Uefi.h>
>> +#include <Library/BaseMemoryLib.h>
>> +#include <Library/DebugLib.h>
>> +#include <Library/MemoryAllocationLib.h>
>> +#include <Library/PrintLib.h>
>> +#include <Library/UefiBootServicesTableLib.h>
>> +#include <Library/UefiLib.h>
>> +#include <Pi/PiMultiPhase.h>
>> +#include <Protocol/MpService.h>
>> +
>> +#include "Options.h"
>> +
>> +#define APFUNC_BUFFER_LEN  256
>> +
>> +typedef struct {
>> +  EFI_MP_SERVICES_PROTOCOL    *Mp;
>> +  CHAR16                      **Buffer;
>> +} APFUNC_ARG;
>> +
>> +/** The procedure to run with the MP Services interface.
>> +
>> +  @param Arg The procedure argument.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +EFIAPI
>> +ApFunction (
>> +  IN OUT VOID  *Arg
>> +  )
>> +{
>> +  APFUNC_ARG  *Param;
>> +  UINTN       ProcessorId;
>> +
>> +  if (Arg != NULL) {
>> +    Param = Arg;
>> +
>> +    Param->Mp->WhoAmI (Param->Mp, &ProcessorId);
>> +    UnicodeSPrint (Param->Buffer[ProcessorId], APFUNC_BUFFER_LEN, 
>> L"Hello from CPU %ld\n", ProcessorId);
>> +  }
>> +}
>> +
>> +/**
>> +  Fetches the number of processors and which processor is the BSP.
>> +
>> +  @param Mp  MP Services Protocol.
>> +  @param NumProcessors Number of processors.
>> +  @param BspIndex      The index of the BSP.
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +GetProcessorInformation (
>> +  IN  EFI_MP_SERVICES_PROTOCOL  *Mp,
>> +  OUT UINTN                     *NumProcessors,
>> +  OUT UINTN                     *BspIndex
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  UINTN       NumEnabledProcessors;
>> +
>> +  Status = Mp->GetNumberOfProcessors (Mp, NumProcessors, 
>> &NumEnabledProcessors);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  Status = Mp->WhoAmI (Mp, BspIndex);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/** Displays information returned from MP Services Protocol.
>> +
>> +  @param Mp       The MP Services Protocol
>> +  @param BspIndex On return, contains the index of the BSP.
>> +
>> +  @return The number of CPUs in the system.
>> +
>> +**/
>> +STATIC
>> +UINTN
>> +PrintProcessorInformation (
>> +  IN   EFI_MP_SERVICES_PROTOCOL  *Mp,
>> +  OUT  UINTN                     *BspIndex
>> +  )
>> +{
>> +  EFI_STATUS                 Status;
>> +  EFI_PROCESSOR_INFORMATION  CpuInfo;
>> +  UINTN                      Index;
>> +  UINTN                      NumCpu;
>> +  UINTN                      NumEnabledCpu;
> [KQ] The NumCpu and NumEnabledCpu probably should be initialized to 0s? 
> Otherwise if the
> GetNumberOfProcessors function somehow fails, the rest of the call will 
> essentially be no-op,
> instead of running into undefined number of CPUs.
>> +
>> +  Status = Mp->GetNumberOfProcessors (Mp, &NumCpu, &NumEnabledCpu);
>> +  if (EFI_ERROR (Status)) {
>> +    Print (L"GetNumberOfProcessors failed: %r\n", Status);
>> +  } else {
>> +    Print (L"Number of CPUs: %ld, Enabled: %d\n", NumCpu, 
>> NumEnabledCpu);
>> +  }
>> +
>> +  for (Index = 0; Index < NumCpu; Index++) {
>> +    Status = Mp->GetProcessorInfo (Mp, CPU_V2_EXTENDED_TOPOLOGY | 
>> Index, &CpuInfo);
>> +    if (EFI_ERROR (Status)) {
>> +      Print (L"GetProcessorInfo for Processor %d failed: %r\n", 
>> Index, Status);
>> +    } else {
>> +      Print (
>> +        L"Processor %d:\n"
>> +        L"\tID: %016lx\n"
>> +        L"\tStatus: %s | ",
>> +        Index,
>> +        CpuInfo.ProcessorId,
>> +        (CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) ? L"BSP" : L"AP"
>> +        );
>> +
>> +      if ((CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) && (BspIndex != 
>> NULL)) {
>> +        *BspIndex = Index;
>> +      }
>> +
>> +      Print (L"%s | ", (CpuInfo.StatusFlag & PROCESSOR_ENABLED_BIT) ? 
>> L"Enabled" : L"Disabled");
>> +      Print (L"%s\n", (CpuInfo.StatusFlag & 
>> PROCESSOR_HEALTH_STATUS_BIT) ? L"Healthy" : L"Faulted");
>> +
>> +      Print (
>> +        L"\tLocation: Package %d, Core %d, Thread %d\n"
>> +        L"\tExtended Information: Package %d, Module %d, Tile %d, Die 
>> %d, Core %d, Thread %d\n\n",
>> +        CpuInfo.Location.Package,
>> +        CpuInfo.Location.Core,
>> +        CpuInfo.Location.Thread,
>> +        CpuInfo.ExtendedInformation.Location2.Package,
>> +        CpuInfo.ExtendedInformation.Location2.Module,
>> +        CpuInfo.ExtendedInformation.Location2.Tile,
>> +        CpuInfo.ExtendedInformation.Location2.Die,
>> +        CpuInfo.ExtendedInformation.Location2.Core,
>> +        CpuInfo.ExtendedInformation.Location2.Thread
>> +        );
>> +    }
>> +  }
>> +
>> +  return NumCpu;
>> +}
>> +
>> +/** Allocates memory in ApArg for the single AP specified.
>> +
>> +  @param ApArg          Pointer to the AP argument structure.
>> +  @param Mp             The MP Services Protocol.
>> +  @param ProcessorIndex The index of the AP.
>> +
>> +  @retval EFI_SUCCESS          Memory was successfully allocated.
>> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +AllocateApFuncBufferSingleAP (
>> +  IN APFUNC_ARG                *ApArg,
>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>> +  IN UINTN                     ProcessorIndex
>> +  )
>> +{
>> +  ApArg->Mp = Mp;
>> +
>> +  ApArg->Buffer = AllocateZeroPool ((ProcessorIndex + 1) * sizeof 
>> (VOID *));
>> +  if (ApArg->Buffer == NULL) {
>> +    Print (L"Failed to allocate buffer for AP buffer\n");
>> +    return EFI_OUT_OF_RESOURCES;
>> +  }
>> +
>> +  ApArg->Buffer[ProcessorIndex] = AllocateZeroPool (APFUNC_BUFFER_LEN);
>> +  if (ApArg->Buffer[ProcessorIndex] == NULL) {
>> +    Print (L"Failed to allocate buffer for AP buffer\n");
>> +    FreePool (ApArg->Buffer);
>> +    return EFI_OUT_OF_RESOURCES;
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/** Allocates memory in ApArg for all APs.
>> +
>> +  @param ApArg   Pointer to the AP argument structure.
>> +  @param Mp      The MP Services Protocol.
>> +  @param NumCpus The number of CPUs.
>> +
>> +  @retval EFI_SUCCESS          Memory was successfully allocated.
>> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +AllocateApFuncBufferAllAPs (
>> +  IN APFUNC_ARG                *ApArg,
>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>> +  IN UINTN                     NumCpus
>> +  )
>> +{
>> +  UINT32  Index;
> [KQ] The Index of UINT32 compared to NumCpus of UINTN could make some 
> compilers unhappy.
>> +
>> +  ApArg->Mp = Mp;
>> +
>> +  ApArg->Buffer = AllocateZeroPool (NumCpus * sizeof (VOID *));
>> +  if (ApArg->Buffer == NULL) {
>> +    Print (L"Failed to allocate buffer for AP message\n");
>> +    return EFI_OUT_OF_RESOURCES;
>> +  }
>> +
>> +  for (Index = 0; Index < NumCpus; Index++) {
>> +    ApArg->Buffer[Index] = AllocateZeroPool (APFUNC_BUFFER_LEN);
>> +    if (ApArg->Buffer[Index] == NULL) {
>> +      Print (L"Failed to allocate buffer for AP message\n");
>> +      for (--Index; Index >= 0; Index++) {
> [KQ] This Index increment could cause the loop not ending as expected.
>> +        FreePool (ApArg->Buffer[Index]);
>> +      }
>> +
>> +      FreePool (ApArg->Buffer);
>> +      return EFI_OUT_OF_RESOURCES;
>> +    }
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/** Frees memory in ApArg for all APs.
>> +
>> +  @param ApArg   Pointer to the AP argument structure.
>> +  @param NumCpus The number of CPUs.
>> +
>> +**/
>> +STATIC
>> +VOID
>> +FreeApFuncBuffer (
>> +  APFUNC_ARG  *ApArg,
>> +  UINTN       NumCpus
>> +  )
>> +{
>> +  UINTN  Index;
>> +
>> +  for (Index = 0; Index < NumCpus; Index++) {
>> +    if (ApArg->Buffer[Index] != NULL) {
>> +      FreePool (ApArg->Buffer[Index]);
>> +    }
>> +  }
>> +
>> +  FreePool (ApArg->Buffer);
>> +}
>> +
>> +/** Runs a specified AP.
>> +
>> +  @param Mp             The MP Services Protocol.
>> +  @param ProcessorIndex The processor index.
>> +  @param Timeout        Timeout in milliseconds.
>> +
>> +  @return EFI_SUCCESS on success, or an error code.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +StartupThisAP (
>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>> +  IN UINTN                     ProcessorIndex,
>> +  IN UINTN                     Timeout
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  APFUNC_ARG  ApArg;
>> +
>> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
> [KQ] I guess the above double calls are not intended?
>> +  Print (
>> +    L"StartupThisAP on Processor %d with %d%s timeout...",
>> +    ProcessorIndex,
>> +    Timeout,
>> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
>> +    );
>> +  Status = Mp->StartupThisAP (
>> +                 Mp,
>> +                 ApFunction,
>> +                 ProcessorIndex,
>> +                 NULL,
>> +                 Timeout * 1000,
>> +                 &ApArg,
>> +                 NULL
>> +                 );
>> +  if (EFI_ERROR (Status)) {
>> +    Print (L"failed: %r\n", Status);
>> +    return Status;
>> +  } else {
>> +    Print (L"done.\n");
>> +    Print (ApArg.Buffer[ProcessorIndex]);
>> +  }
>> +
>> +  FreeApFuncBuffer (&ApArg, ProcessorIndex + 1);
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/** Runs all APs.
>> +
>> +  @param Mp                 The MP Services Protocol.
>> +  @param NumCpus            The number of CPUs in the system.
>> +  @param Timeout            Timeout in milliseconds.
>> +  @param RunAPsSequentially Run APs sequentially (FALSE: run 
>> simultaneously)
>> +
>> +  @return EFI_SUCCESS on success, or an error code.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +StartupAllAPs (
>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>> +  IN UINTN                     NumCpus,
>> +  IN UINTN                     Timeout,
>> +  IN BOOLEAN                   RunAPsSequentially
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  UINTN       Index;
>> +  APFUNC_ARG  ApArg;
>> +
>> +  Status = AllocateApFuncBufferAllAPs (&ApArg, Mp, NumCpus);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  Print (
>> +    L"Running with SingleThread %s, %u%s timeout...",
>> +    (RunAPsSequentially) ? L"TRUE" : L"FALSE",
>> +    Timeout,
>> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
>> +    );
>> +
>> +  Status = Mp->StartupAllAPs (
>> +                 Mp,
>> +                 ApFunction,
>> +                 RunAPsSequentially,
>> +                 NULL,
>> +                 Timeout * 1000,
>> +                 &ApArg,
>> +                 NULL
>> +                 );
>> +
>> +  if (EFI_ERROR (Status)) {
>> +    Print (L"failed: %r\n", Status);
>> +
>> +    return Status;
>> +  } else {
>> +    Print (L"done.\n");
>> +
>> +    for (Index = 0; Index < NumCpus; Index++) {
>> +      Print (ApArg.Buffer[Index]);
>> +    }
>> +  }
>> +
>> +  FreeApFuncBuffer (&ApArg, NumCpus);
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +  Enables the specified AP.
>> +
>> +  @param Mp               The MP Services Protocol.
>> +  @param ProcessorIndex   The processor to enable.
>> +  @param ProcessorHealthy The health status of the processor.
>> +
>> +  @return EFI_SUCCESS on success, or an error code.
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EnableAP (
>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>> +  UINTN                        ProcessorIndex,
>> +  BOOLEAN                      ProcessorHealthy
> [KQ] These parameters should have the "IN" attributes?
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  UINT32      HealthFlag;
>> +
>> +  if (ProcessorHealthy) {
>> +    Print (L"Enabling Processor %d with HealthFlag healthy...", 
>> ProcessorIndex);
>> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
>> +  } else {
>> +    Print (L"Enabling Processor %d with HealthFlag faulted...", 
>> ProcessorIndex);
>> +    HealthFlag = 0;
>> +  }
>> +
>> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, TRUE, &HealthFlag);
>> +  if (EFI_ERROR (Status)) {
>> +    Print (L"failed: %r\n", Status);
>> +    return Status;
>> +  } else {
>> +    Print (L"done.\n");
>> +  }
>> +
>> +  return Status;
>> +}
>> +
>> +/**
>> +  Disables the specified AP.
>> +
>> +  @param Mp               The MP Services Protocol.
>> +  @param ProcessorIndex   The processor to disable.
>> +  @param ProcessorHealthy The health status of the processor.
>> +
>> +  @return EFI_SUCCESS on success, or an error code.
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +DisableAP (
>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>> +  UINTN                        ProcessorIndex,
>> +  BOOLEAN                      ProcessorHealthy
> [KQ] These parameters should have the "IN" attributes?
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  UINT32      HealthFlag;
>> +
>> +  if (ProcessorHealthy) {
>> +    Print (L"Disabling Processor %d with HealthFlag healthy...", 
>> ProcessorIndex);
>> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
>> +  } else {
>> +    Print (L"Disabling Processor %d with HealthFlag faulted...", 
>> ProcessorIndex);
>> +    HealthFlag = 0;
>> +  }
>> +
>> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, FALSE, &HealthFlag);
>> +  if (EFI_ERROR (Status)) {
>> +    Print (L"failed: %r\n", Status);
>> +    return Status;
>> +  } else {
>> +    Print (L"done.\n");
>> +  }
>> +
>> +  return Status;
>> +}
>> +
>> +/**
>> +  The user Entry Point for Application. The user code starts with 
>> this function
>> +  as the real entry point for the application.
>> +
>> +  @param[in] ImageHandle    The firmware allocated handle for the EFI 
>> image.
>> +  @param[in] SystemTable    A pointer to the EFI System Table.
>> +
>> +  @retval EFI_SUCCESS       The entry point is executed successfully.
>> +  @retval other             Some error occurs when executing this 
>> entry point.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +UefiMain (
>> +  IN EFI_HANDLE        ImageHandle,
>> +  IN EFI_SYSTEM_TABLE  *SystemTable
>> +  )
>> +{
>> +  EFI_STATUS                Status;
>> +  EFI_MP_SERVICES_PROTOCOL  *Mp;
>> +  UINTN                     BspIndex;
>> +  UINTN                     CpuIndex;
>> +  UINTN                     NumCpus;
>> +  BOOLEAN                   ProcessorHealthy;
>> +  MP_SERVICES_TEST_OPTIONS  Options;
>> +
>> +  BspIndex = 0;
>> +
>> +  Status = gBS->LocateProtocol (
>> +                  &gEfiMpServiceProtocolGuid,
>> +                  NULL,
>> +                  (VOID **)&Mp
>> +                  );
>> +  if (EFI_ERROR (Status)) {
>> +    Print (L"Failed to locate EFI_MP_SERVICES_PROTOCOL (%r). Not 
>> installed on platform?\n", Status);
>> +    return EFI_NOT_FOUND;
>> +  }
>> +
>> +  Status = ParseArguments (&Options);
>> +  if (EFI_ERROR (Status)) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  Status = GetProcessorInformation (Mp, &NumCpus, &BspIndex);
>> +  if (EFI_ERROR (Status)) {
>> +    Print (L"Error: Failed to fetch processor information.\n");
>> +    return Status;
>> +  }
>> +
>> +  if (Options.PrintBspProcessorIndex) {
>> +    Status = Mp->WhoAmI (Mp, &CpuIndex);
>> +    if (EFI_ERROR (Status)) {
>> +      Print (L"WhoAmI failed: %r\n", Status);
>> +      return Status;
>> +    } else {
>> +      Print (L"BSP: %016lx\n", CpuIndex);
>> +    }
>> +  }
>> +
>> +  if (Options.PrintProcessorInformation) {
>> +    NumCpus = PrintProcessorInformation (Mp, &BspIndex);
>> +    if (NumCpus < 2) {
>> +      Print (L"Error: Uniprocessor system found.\n");
>> +      return EFI_INVALID_PARAMETER;
>> +    }
>> +  }
>> +
>> +  if (Options.RunSingleAP) {
>> +    Status = StartupThisAP (
>> +               Mp,
>> +               Options.ProcessorIndex,
>> +               Options.Timeout
>> +               );
>> +    if (EFI_ERROR (Status)) {
>> +      return Status;
>> +    }
>> +  }
>> +
>> +  if (Options.RunAllAPs) {
>> +    Status = StartupAllAPs (Mp, NumCpus, Options.Timeout, 
>> Options.RunAPsSequentially);
>> +    if (EFI_ERROR (Status)) {
>> +      return Status;
>> +    }
>> +  }
>> +
>> +  if (Options.EnableProcessor) {
>> +    ProcessorHealthy = TRUE;
>> +    if (Options.SetProcessorUnhealthy) {
>> +      ProcessorHealthy = FALSE;
>> +    }
>> +
>> +    Status = EnableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
>> +    if (EFI_ERROR (Status)) {
>> +      return Status;
>> +    }
>> +  }
>> +
>> +  if (Options.DisableProcessor) {
>> +    ProcessorHealthy = TRUE;
>> +    if (Options.SetProcessorUnhealthy) {
>> +      ProcessorHealthy = FALSE;
>> +    }
>> +
>> +    Status = DisableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
>> +    if (EFI_ERROR (Status)) {
>> +      return Status;
>> +    }
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.c 
>> b/MdeModulePkg/Application/MpServicesTest/Options.c
>> new file mode 100644
>> index 000000000000..e820c061e1ec
>> --- /dev/null
>> +++ b/MdeModulePkg/Application/MpServicesTest/Options.c
>> @@ -0,0 +1,164 @@
>> +/** @file
>> +  Options handling code.
>> +
>> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights 
>> reserved.<BR>
>> +  Copyright (c) 2010-2019  Finnbarr P. Murphy.   All rights 
>> reserved.<BR>
>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>> +**/
>> +
>> +#include <Uefi.h>
>> +#include <Library/BaseMemoryLib.h>
>> +#include <Protocol/ShellParameters.h>
>> +#include <Library/BaseLib.h>
>> +#include <Library/UefiLib.h>
>> +#include <Library/UefiBootServicesTableLib.h>
>> +
>> +#include "Options.h"
>> +
>> +STATIC UINTN   Argc;
>> +STATIC CHAR16  **Argv;
>> +
>> +/**
>> +
>> +  This function provides argc and argv.
>> +
>> +  @return Status
>> +**/
>> +EFI_STATUS
>> +GetArg (
>> +  VOID
>> +  )
>> +{
>> +  EFI_STATUS                     Status;
>> +  EFI_SHELL_PARAMETERS_PROTOCOL  *ShellParameters;
>> +
>> +  Status = gBS->HandleProtocol (
>> +                  gImageHandle,
>> +                  &gEfiShellParametersProtocolGuid,
>> +                  (VOID **)&ShellParameters
>> +                  );
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  Argc = ShellParameters->Argc;
>> +  Argv = ShellParameters->Argv;
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +  Print app usage.
>> +**/
>> +STATIC
>> +VOID
>> +PrintUsage (
>> +  VOID
>> +  )
>> +{
>> +  Print (L"MpServicesTest:  usage\n");
>> +  Print (L"  MpServicesTest -A [-O]\n");
>> +  Print (L"  MpServicesTest -T <Timeout>\n");
>> +  Print (L"  MpServicesTest -S <Processor #>\n");
>> +  Print (L"  MpServicesTest -P\n");
>> +  Print (L"  MpServicesTest -U\n");
>> +  Print (L"  MpServicesTest -W\n");
>> +  Print (L"  MpServicesTest -E <Processor #>\n");
>> +  Print (L"  MpServicesTest -D <Processor #>\n");
>> +  Print (L"  MpServicesTest -h\n");
>> +  Print (L"Parameter:\n");
>> +  Print (L"  -A:  Run all APs.\n");
>> +  Print (L"  -O:  Run APs sequentially (use with -A).\n");
>> +  Print (L"  -T:  Specify timeout in milliseconds. Default is to wait 
>> forever.\n");
>> +  Print (L"  -S:  Specify the single AP to run.\n");
>> +  Print (L"  -P:  Print processor information.\n");
>> +  Print (L"  -U:  Set the specified AP to the Unhealthy status (use 
>> with -E/-D).\n");
>> +  Print (L"  -W:  Run WhoAmI and print index of BSP.\n");
>> +  Print (L"  -E:  Enable the specified AP.\n");
>> +  Print (L"  -D:  Disable the specified AP.\n");
>> +  Print (L"  -h:  Print this help page.\n");
>> +}
>> +
>> +/**
>> +  Parses any arguments provided on the command line.
>> +
>> +  @param Options  The arguments structure.
>> +
>> +  @return EFI_SUCCESS on success, or an error code.
>> +**/
>> +EFI_STATUS
>> +ParseArguments (
>> +  MP_SERVICES_TEST_OPTIONS  *Options
>> +  )
>> +{
>> +  EFI_STATUS    Status;
>> +  UINT32        ArgIndex;
> [KQ] Similar to the other comment, ArgIndex is of UINT32 is compared to 
> Argc of UINTN could make some compilers unhappy.
>> +  CONST CHAR16  *Argument;
>> +  BOOLEAN       NeedsValue;
>> +  UINTN         *Value;
>> +
>> +  Status = GetArg ();
>> +  if (EFI_ERROR (Status)) {
>> +    Print (L"Please use the UEFI Shell to run this application!\n", 
>> Status);
>> +    return Status;
>> +  }
>> +
>> +  if (Argc == 1) {
>> +    PrintUsage ();
>> +  }
>> +
>> +  ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
>> +
>> +  for (ArgIndex = 1; ArgIndex < Argc; ArgIndex++) {
>> +    Argument   = Argv[ArgIndex];
>> +    NeedsValue = FALSE;
>> +
>> +    if (StrCmp (Argument, L"-A") == 0) {
>> +      Options->RunAllAPs = TRUE;
>> +    } else if (StrCmp (Argument, L"-O") == 0) {
>> +      Options->RunAPsSequentially = TRUE;
>> +    } else if (StrCmp (Argument, L"-T") == 0) {
>> +      NeedsValue = TRUE;
>> +      Value      = &Options->Timeout;
>> +    } else if (StrCmp (Argument, L"-S") == 0) {
>> +      Options->RunSingleAP = TRUE;
>> +      NeedsValue           = TRUE;
>> +      Value                = &Options->ProcessorIndex;
>> +    } else if (StrCmp (Argument, L"-P") == 0) {
>> +      Options->PrintProcessorInformation = TRUE;
>> +    } else if (StrCmp (Argument, L"-U") == 0) {
>> +      Options->SetProcessorUnhealthy = TRUE;
>> +    } else if (StrCmp (Argument, L"-W") == 0) {
>> +      Options->PrintBspProcessorIndex = TRUE;
>> +    } else if (StrCmp (Argument, L"-E") == 0) {
>> +      Options->EnableProcessor = TRUE;
>> +      NeedsValue               = TRUE;
>> +      Value                    = &Options->ProcessorIndex;
>> +    } else if (StrCmp (Argument, L"-D") == 0) {
>> +      Options->DisableProcessor = TRUE;
>> +      NeedsValue                = TRUE;
>> +      Value                     = &Options->ProcessorIndex;
>> +    } else {
>> +      PrintUsage ();
>> +      ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
>> +      return EFI_SUCCESS;
>> +    }
>> +
>> +    if (NeedsValue) {
>> +      if ((ArgIndex + 1) < Argc) {
>> +        Status = StrDecimalToUintnS (Argv[ArgIndex + 1], NULL, Value);
>> +        if (EFI_ERROR (Status)) {
>> +          Print (L"Error: option value must be a positive integer.\n");
>> +          PrintUsage ();
>> +          return EFI_INVALID_PARAMETER;
>> +        }
>> +
>> +        ArgIndex++;
>> +      } else {
>> +        PrintUsage ();
>> +        return EFI_INVALID_PARAMETER;
>> +      }
>> +    }
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Ni, Ray]

Rebecca,
Have you reviewed UefiCpuPkg\Test\UnitTest\EfiMpServicesPpiProtocol? It's based on UnitTestFrameworkPkg for unit testing on MP PPI and MP protocol.
Do you think if the MpServicesTest app and the EfiMpServicesPpiProtocol have some overlapped functionalities?



Thanks,
Ray

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Rebecca Cran
> Sent: Sunday, January 8, 2023 12:56 PM
> To: Kun Qin <kuqin12@gmail.com>; devel@edk2.groups.io; Sami Mujawar <sami.mujawar@arm.com>; Ard Biesheuvel
> <ardb+tianocore@kernel.org>; Leif Lindholm <quic_llindhol@quicinc.com>; Wang, Jian J <jian.j.wang@intel.com>; Gao,
> Liming <gaoliming@byosoft.com.cn>; Tiger Liu <TigerLiu@zhaoxin.com>
> Subject: Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application
> 
> Thanks! I've fixed all the issues you noted and will send out a v5 patch
> in the next couple of days.
> 
> --
> Rebecca Cran
> 
> On 1/6/23 15:33, Kun Qin wrote:
> > Hi Rebecca,
> >
> > Thanks for sharing this patch. I found a few minor issues when running
> > this test app. Please see comments with [KQ] below.
> >
> > Regards,
> > Kun
> >
> > On 1/4/2023 7:37 AM, Rebecca Cran wrote:
> >> The MpServicesTest application exercises the EFI_MP_SERVICES_PROTOCOL.
> >>
> >> usage:
> >>    MpServicesTest -A [-O]
> >>    MpServicesTest -T <Timeout>
> >>    MpServicesTest -S <Processor #>
> >>    MpServicesTest -P
> >>    MpServicesTest -U
> >>    MpServicesTest -W
> >>    MpServicesTest -E <Processor #>
> >>    MpServicesTest -D <Processor #>
> >>    MpServicesTest -h
> >>
> >> Parameter:
> >>    -A:  Run all APs.
> >>    -O:  Run APs sequentially (use with -A).
> >>    -T:  Specify timeout in milliseconds. Default is to wait forever.
> >>    -S:  Specify the single AP to run.
> >>    -P:  Print processor information.
> >>    -U:  Set the specified AP to the Unhealthy status (use with -E/-D).
> >>    -W:  Run WhoAmI and print index of BSP.
> >>    -E:  Enable the specified AP.
> >>    -D:  Disable the specified AP.
> >>    -h:  Print this help page.
> >>
> >> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
> >> ---
> >>   MdeModulePkg/MdeModulePkg.dsc                              |   2 +
> >>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf |  40 ++
> >>   MdeModulePkg/Application/MpServicesTest/Options.h          |  39 ++
> >>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.c   | 560
> >> ++++++++++++++++++++
> >>   MdeModulePkg/Application/MpServicesTest/Options.c          | 164 ++++++
> >>   5 files changed, 805 insertions(+)
> >>
> >> diff --git a/MdeModulePkg/MdeModulePkg.dsc
> >> b/MdeModulePkg/MdeModulePkg.dsc
> >> index 659482ab737f..6992b3ae8db6 100644
> >> --- a/MdeModulePkg/MdeModulePkg.dsc
> >> +++ b/MdeModulePkg/MdeModulePkg.dsc
> >> @@ -166,6 +166,7 @@ [LibraryClasses.common.UEFI_APPLICATION]
> >>
> >> MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
> >>     DebugLib|MdePkg/Library/UefiDebugLibStdErr/UefiDebugLibStdErr.inf
> >>     FileHandleLib|MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.inf
> >> +  ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
> >>   [LibraryClasses.common.MM_STANDALONE]
> >>     HobLib|MdeModulePkg/Library/BaseHobLibNull/BaseHobLibNull.inf
> >> @@ -445,6 +446,7 @@ [Components]
> >>
> >> MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
> >>   [Components.IA32, Components.X64, Components.AARCH64]
> >> +  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> >>     MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
> >>     MdeModulePkg/Universal/EbcDxe/EbcDebugger.inf
> >>     MdeModulePkg/Universal/EbcDxe/EbcDebuggerConfig.inf
> >> diff --git
> >> a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> >> b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> >> new file mode 100644
> >> index 000000000000..07ee4afec845
> >> --- /dev/null
> >> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> >> @@ -0,0 +1,40 @@
> >> +## @file
> >> +#  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
> >> +#
> >> +#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights
> >> reserved.<BR>
> >> +#
> >> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> >> +#
> >> +##
> >> +
> >> +[Defines]
> >> +  INF_VERSION                    = 1.29
> >> +  BASE_NAME                      = MpServicesTest
> >> +  FILE_GUID                      = 43e9defa-7209-4b0d-b136-cc4ca02cb469
> >> +  MODULE_TYPE                    = UEFI_APPLICATION
> >> +  VERSION_STRING                 = 0.1
> >> +  ENTRY_POINT                    = UefiMain
> >> +
> >> +#
> >> +# The following information is for reference only and not required by
> >> the build tools.
> >> +#
> >> +#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
> >> +#
> >> +
> >> +[Sources]
> >> +  MpServicesTest.c
> >> +  Options.c
> >> +  Options.h
> >> +
> >> +[Packages]
> >> +  MdePkg/MdePkg.dec
> >> +
> >> +[LibraryClasses]
> >> +  BaseLib
> >> +  ShellLib
> >> +  UefiApplicationEntryPoint
> >> +  UefiLib
> >> +
> >> +[Protocols]
> >> +  gEfiMpServiceProtocolGuid    ## CONSUMES
> >> +
> >> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.h
> >> b/MdeModulePkg/Application/MpServicesTest/Options.h
> >> new file mode 100644
> >> index 000000000000..cb28230ab095
> >> --- /dev/null
> >> +++ b/MdeModulePkg/Application/MpServicesTest/Options.h
> >> @@ -0,0 +1,39 @@
> >> +/** @file
> >> +  Options handling code.
> >> +
> >> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights
> >> reserved.<BR>
> >> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> >> +**/
> >> +
> >> +#ifndef MPSERVICESTEST_OPTIONS_H_
> >> +#define MPSERVICESTEST_OPTIONS_H_
> >> +
> >> +#define INFINITE_TIMEOUT  0
> >> +
> >> +typedef struct {
> >> +  UINTN      Timeout;
> >> +  UINTN      ProcessorIndex;
> >> +  BOOLEAN    RunAllAPs;
> >> +  BOOLEAN    RunSingleAP;
> >> +  BOOLEAN    DisableProcessor;
> >> +  BOOLEAN    EnableProcessor;
> >> +  BOOLEAN    SetProcessorHealthy;
> >> +  BOOLEAN    SetProcessorUnhealthy;
> >> +  BOOLEAN    PrintProcessorInformation;
> >> +  BOOLEAN    PrintBspProcessorIndex;
> >> +  BOOLEAN    RunAPsSequentially;
> >> +} MP_SERVICES_TEST_OPTIONS;
> >> +
> >> +/**
> >> +  Parses any arguments provided on the command line.
> >> +
> >> +  @param Options  The arguments structure.
> >> +
> >> +  @return EFI_SUCCESS on success, or an error code.
> >> +**/
> >> +EFI_STATUS
> >> +ParseArguments (
> >> +  MP_SERVICES_TEST_OPTIONS  *Options
> >> +  );
> >> +
> >> +#endif /* MPSERVICESTEST_OPTIONS_H_ */
> >> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
> >> b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
> >> new file mode 100644
> >> index 000000000000..3f3d9752d500
> >> --- /dev/null
> >> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
> >> @@ -0,0 +1,560 @@
> >> +/** @file
> >> +  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
> >> +
> >> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights
> >> reserved.<BR>
> >> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> >> +**/
> >> +
> >> +#include <Uefi.h>
> >> +#include <Library/BaseMemoryLib.h>
> >> +#include <Library/DebugLib.h>
> >> +#include <Library/MemoryAllocationLib.h>
> >> +#include <Library/PrintLib.h>
> >> +#include <Library/UefiBootServicesTableLib.h>
> >> +#include <Library/UefiLib.h>
> >> +#include <Pi/PiMultiPhase.h>
> >> +#include <Protocol/MpService.h>
> >> +
> >> +#include "Options.h"
> >> +
> >> +#define APFUNC_BUFFER_LEN  256
> >> +
> >> +typedef struct {
> >> +  EFI_MP_SERVICES_PROTOCOL    *Mp;
> >> +  CHAR16                      **Buffer;
> >> +} APFUNC_ARG;
> >> +
> >> +/** The procedure to run with the MP Services interface.
> >> +
> >> +  @param Arg The procedure argument.
> >> +
> >> +**/
> >> +STATIC
> >> +VOID
> >> +EFIAPI
> >> +ApFunction (
> >> +  IN OUT VOID  *Arg
> >> +  )
> >> +{
> >> +  APFUNC_ARG  *Param;
> >> +  UINTN       ProcessorId;
> >> +
> >> +  if (Arg != NULL) {
> >> +    Param = Arg;
> >> +
> >> +    Param->Mp->WhoAmI (Param->Mp, &ProcessorId);
> >> +    UnicodeSPrint (Param->Buffer[ProcessorId], APFUNC_BUFFER_LEN,
> >> L"Hello from CPU %ld\n", ProcessorId);
> >> +  }
> >> +}
> >> +
> >> +/**
> >> +  Fetches the number of processors and which processor is the BSP.
> >> +
> >> +  @param Mp  MP Services Protocol.
> >> +  @param NumProcessors Number of processors.
> >> +  @param BspIndex      The index of the BSP.
> >> +**/
> >> +STATIC
> >> +EFI_STATUS
> >> +GetProcessorInformation (
> >> +  IN  EFI_MP_SERVICES_PROTOCOL  *Mp,
> >> +  OUT UINTN                     *NumProcessors,
> >> +  OUT UINTN                     *BspIndex
> >> +  )
> >> +{
> >> +  EFI_STATUS  Status;
> >> +  UINTN       NumEnabledProcessors;
> >> +
> >> +  Status = Mp->GetNumberOfProcessors (Mp, NumProcessors,
> >> &NumEnabledProcessors);
> >> +  if (EFI_ERROR (Status)) {
> >> +    return Status;
> >> +  }
> >> +
> >> +  Status = Mp->WhoAmI (Mp, BspIndex);
> >> +  if (EFI_ERROR (Status)) {
> >> +    return Status;
> >> +  }
> >> +
> >> +  return EFI_SUCCESS;
> >> +}
> >> +
> >> +/** Displays information returned from MP Services Protocol.
> >> +
> >> +  @param Mp       The MP Services Protocol
> >> +  @param BspIndex On return, contains the index of the BSP.
> >> +
> >> +  @return The number of CPUs in the system.
> >> +
> >> +**/
> >> +STATIC
> >> +UINTN
> >> +PrintProcessorInformation (
> >> +  IN   EFI_MP_SERVICES_PROTOCOL  *Mp,
> >> +  OUT  UINTN                     *BspIndex
> >> +  )
> >> +{
> >> +  EFI_STATUS                 Status;
> >> +  EFI_PROCESSOR_INFORMATION  CpuInfo;
> >> +  UINTN                      Index;
> >> +  UINTN                      NumCpu;
> >> +  UINTN                      NumEnabledCpu;
> > [KQ] The NumCpu and NumEnabledCpu probably should be initialized to 0s?
> > Otherwise if the
> > GetNumberOfProcessors function somehow fails, the rest of the call will
> > essentially be no-op,
> > instead of running into undefined number of CPUs.
> >> +
> >> +  Status = Mp->GetNumberOfProcessors (Mp, &NumCpu, &NumEnabledCpu);
> >> +  if (EFI_ERROR (Status)) {
> >> +    Print (L"GetNumberOfProcessors failed: %r\n", Status);
> >> +  } else {
> >> +    Print (L"Number of CPUs: %ld, Enabled: %d\n", NumCpu,
> >> NumEnabledCpu);
> >> +  }
> >> +
> >> +  for (Index = 0; Index < NumCpu; Index++) {
> >> +    Status = Mp->GetProcessorInfo (Mp, CPU_V2_EXTENDED_TOPOLOGY |
> >> Index, &CpuInfo);
> >> +    if (EFI_ERROR (Status)) {
> >> +      Print (L"GetProcessorInfo for Processor %d failed: %r\n",
> >> Index, Status);
> >> +    } else {
> >> +      Print (
> >> +        L"Processor %d:\n"
> >> +        L"\tID: %016lx\n"
> >> +        L"\tStatus: %s | ",
> >> +        Index,
> >> +        CpuInfo.ProcessorId,
> >> +        (CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) ? L"BSP" : L"AP"
> >> +        );
> >> +
> >> +      if ((CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) && (BspIndex !=
> >> NULL)) {
> >> +        *BspIndex = Index;
> >> +      }
> >> +
> >> +      Print (L"%s | ", (CpuInfo.StatusFlag & PROCESSOR_ENABLED_BIT) ?
> >> L"Enabled" : L"Disabled");
> >> +      Print (L"%s\n", (CpuInfo.StatusFlag &
> >> PROCESSOR_HEALTH_STATUS_BIT) ? L"Healthy" : L"Faulted");
> >> +
> >> +      Print (
> >> +        L"\tLocation: Package %d, Core %d, Thread %d\n"
> >> +        L"\tExtended Information: Package %d, Module %d, Tile %d, Die
> >> %d, Core %d, Thread %d\n\n",
> >> +        CpuInfo.Location.Package,
> >> +        CpuInfo.Location.Core,
> >> +        CpuInfo.Location.Thread,
> >> +        CpuInfo.ExtendedInformation.Location2.Package,
> >> +        CpuInfo.ExtendedInformation.Location2.Module,
> >> +        CpuInfo.ExtendedInformation.Location2.Tile,
> >> +        CpuInfo.ExtendedInformation.Location2.Die,
> >> +        CpuInfo.ExtendedInformation.Location2.Core,
> >> +        CpuInfo.ExtendedInformation.Location2.Thread
> >> +        );
> >> +    }
> >> +  }
> >> +
> >> +  return NumCpu;
> >> +}
> >> +
> >> +/** Allocates memory in ApArg for the single AP specified.
> >> +
> >> +  @param ApArg          Pointer to the AP argument structure.
> >> +  @param Mp             The MP Services Protocol.
> >> +  @param ProcessorIndex The index of the AP.
> >> +
> >> +  @retval EFI_SUCCESS          Memory was successfully allocated.
> >> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
> >> +
> >> +**/
> >> +STATIC
> >> +EFI_STATUS
> >> +AllocateApFuncBufferSingleAP (
> >> +  IN APFUNC_ARG                *ApArg,
> >> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> >> +  IN UINTN                     ProcessorIndex
> >> +  )
> >> +{
> >> +  ApArg->Mp = Mp;
> >> +
> >> +  ApArg->Buffer = AllocateZeroPool ((ProcessorIndex + 1) * sizeof
> >> (VOID *));
> >> +  if (ApArg->Buffer == NULL) {
> >> +    Print (L"Failed to allocate buffer for AP buffer\n");
> >> +    return EFI_OUT_OF_RESOURCES;
> >> +  }
> >> +
> >> +  ApArg->Buffer[ProcessorIndex] = AllocateZeroPool (APFUNC_BUFFER_LEN);
> >> +  if (ApArg->Buffer[ProcessorIndex] == NULL) {
> >> +    Print (L"Failed to allocate buffer for AP buffer\n");
> >> +    FreePool (ApArg->Buffer);
> >> +    return EFI_OUT_OF_RESOURCES;
> >> +  }
> >> +
> >> +  return EFI_SUCCESS;
> >> +}
> >> +
> >> +/** Allocates memory in ApArg for all APs.
> >> +
> >> +  @param ApArg   Pointer to the AP argument structure.
> >> +  @param Mp      The MP Services Protocol.
> >> +  @param NumCpus The number of CPUs.
> >> +
> >> +  @retval EFI_SUCCESS          Memory was successfully allocated.
> >> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
> >> +
> >> +**/
> >> +STATIC
> >> +EFI_STATUS
> >> +AllocateApFuncBufferAllAPs (
> >> +  IN APFUNC_ARG                *ApArg,
> >> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> >> +  IN UINTN                     NumCpus
> >> +  )
> >> +{
> >> +  UINT32  Index;
> > [KQ] The Index of UINT32 compared to NumCpus of UINTN could make some
> > compilers unhappy.
> >> +
> >> +  ApArg->Mp = Mp;
> >> +
> >> +  ApArg->Buffer = AllocateZeroPool (NumCpus * sizeof (VOID *));
> >> +  if (ApArg->Buffer == NULL) {
> >> +    Print (L"Failed to allocate buffer for AP message\n");
> >> +    return EFI_OUT_OF_RESOURCES;
> >> +  }
> >> +
> >> +  for (Index = 0; Index < NumCpus; Index++) {
> >> +    ApArg->Buffer[Index] = AllocateZeroPool (APFUNC_BUFFER_LEN);
> >> +    if (ApArg->Buffer[Index] == NULL) {
> >> +      Print (L"Failed to allocate buffer for AP message\n");
> >> +      for (--Index; Index >= 0; Index++) {
> > [KQ] This Index increment could cause the loop not ending as expected.
> >> +        FreePool (ApArg->Buffer[Index]);
> >> +      }
> >> +
> >> +      FreePool (ApArg->Buffer);
> >> +      return EFI_OUT_OF_RESOURCES;
> >> +    }
> >> +  }
> >> +
> >> +  return EFI_SUCCESS;
> >> +}
> >> +
> >> +/** Frees memory in ApArg for all APs.
> >> +
> >> +  @param ApArg   Pointer to the AP argument structure.
> >> +  @param NumCpus The number of CPUs.
> >> +
> >> +**/
> >> +STATIC
> >> +VOID
> >> +FreeApFuncBuffer (
> >> +  APFUNC_ARG  *ApArg,
> >> +  UINTN       NumCpus
> >> +  )
> >> +{
> >> +  UINTN  Index;
> >> +
> >> +  for (Index = 0; Index < NumCpus; Index++) {
> >> +    if (ApArg->Buffer[Index] != NULL) {
> >> +      FreePool (ApArg->Buffer[Index]);
> >> +    }
> >> +  }
> >> +
> >> +  FreePool (ApArg->Buffer);
> >> +}
> >> +
> >> +/** Runs a specified AP.
> >> +
> >> +  @param Mp             The MP Services Protocol.
> >> +  @param ProcessorIndex The processor index.
> >> +  @param Timeout        Timeout in milliseconds.
> >> +
> >> +  @return EFI_SUCCESS on success, or an error code.
> >> +
> >> +**/
> >> +STATIC
> >> +EFI_STATUS
> >> +StartupThisAP (
> >> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> >> +  IN UINTN                     ProcessorIndex,
> >> +  IN UINTN                     Timeout
> >> +  )
> >> +{
> >> +  EFI_STATUS  Status;
> >> +  APFUNC_ARG  ApArg;
> >> +
> >> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
> >> +  if (EFI_ERROR (Status)) {
> >> +    return Status;
> >> +  }
> >> +
> >> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
> >> +  if (EFI_ERROR (Status)) {
> >> +    return Status;
> >> +  }
> >> +
> > [KQ] I guess the above double calls are not intended?
> >> +  Print (
> >> +    L"StartupThisAP on Processor %d with %d%s timeout...",
> >> +    ProcessorIndex,
> >> +    Timeout,
> >> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
> >> +    );
> >> +  Status = Mp->StartupThisAP (
> >> +                 Mp,
> >> +                 ApFunction,
> >> +                 ProcessorIndex,
> >> +                 NULL,
> >> +                 Timeout * 1000,
> >> +                 &ApArg,
> >> +                 NULL
> >> +                 );
> >> +  if (EFI_ERROR (Status)) {
> >> +    Print (L"failed: %r\n", Status);
> >> +    return Status;
> >> +  } else {
> >> +    Print (L"done.\n");
> >> +    Print (ApArg.Buffer[ProcessorIndex]);
> >> +  }
> >> +
> >> +  FreeApFuncBuffer (&ApArg, ProcessorIndex + 1);
> >> +
> >> +  return EFI_SUCCESS;
> >> +}
> >> +
> >> +/** Runs all APs.
> >> +
> >> +  @param Mp                 The MP Services Protocol.
> >> +  @param NumCpus            The number of CPUs in the system.
> >> +  @param Timeout            Timeout in milliseconds.
> >> +  @param RunAPsSequentially Run APs sequentially (FALSE: run
> >> simultaneously)
> >> +
> >> +  @return EFI_SUCCESS on success, or an error code.
> >> +
> >> +**/
> >> +STATIC
> >> +EFI_STATUS
> >> +StartupAllAPs (
> >> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> >> +  IN UINTN                     NumCpus,
> >> +  IN UINTN                     Timeout,
> >> +  IN BOOLEAN                   RunAPsSequentially
> >> +  )
> >> +{
> >> +  EFI_STATUS  Status;
> >> +  UINTN       Index;
> >> +  APFUNC_ARG  ApArg;
> >> +
> >> +  Status = AllocateApFuncBufferAllAPs (&ApArg, Mp, NumCpus);
> >> +  if (EFI_ERROR (Status)) {
> >> +    return Status;
> >> +  }
> >> +
> >> +  Print (
> >> +    L"Running with SingleThread %s, %u%s timeout...",
> >> +    (RunAPsSequentially) ? L"TRUE" : L"FALSE",
> >> +    Timeout,
> >> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
> >> +    );
> >> +
> >> +  Status = Mp->StartupAllAPs (
> >> +                 Mp,
> >> +                 ApFunction,
> >> +                 RunAPsSequentially,
> >> +                 NULL,
> >> +                 Timeout * 1000,
> >> +                 &ApArg,
> >> +                 NULL
> >> +                 );
> >> +
> >> +  if (EFI_ERROR (Status)) {
> >> +    Print (L"failed: %r\n", Status);
> >> +
> >> +    return Status;
> >> +  } else {
> >> +    Print (L"done.\n");
> >> +
> >> +    for (Index = 0; Index < NumCpus; Index++) {
> >> +      Print (ApArg.Buffer[Index]);
> >> +    }
> >> +  }
> >> +
> >> +  FreeApFuncBuffer (&ApArg, NumCpus);
> >> +  return EFI_SUCCESS;
> >> +}
> >> +
> >> +/**
> >> +  Enables the specified AP.
> >> +
> >> +  @param Mp               The MP Services Protocol.
> >> +  @param ProcessorIndex   The processor to enable.
> >> +  @param ProcessorHealthy The health status of the processor.
> >> +
> >> +  @return EFI_SUCCESS on success, or an error code.
> >> +**/
> >> +STATIC
> >> +EFI_STATUS
> >> +EnableAP (
> >> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> >> +  UINTN                        ProcessorIndex,
> >> +  BOOLEAN                      ProcessorHealthy
> > [KQ] These parameters should have the "IN" attributes?
> >> +  )
> >> +{
> >> +  EFI_STATUS  Status;
> >> +  UINT32      HealthFlag;
> >> +
> >> +  if (ProcessorHealthy) {
> >> +    Print (L"Enabling Processor %d with HealthFlag healthy...",
> >> ProcessorIndex);
> >> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
> >> +  } else {
> >> +    Print (L"Enabling Processor %d with HealthFlag faulted...",
> >> ProcessorIndex);
> >> +    HealthFlag = 0;
> >> +  }
> >> +
> >> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, TRUE, &HealthFlag);
> >> +  if (EFI_ERROR (Status)) {
> >> +    Print (L"failed: %r\n", Status);
> >> +    return Status;
> >> +  } else {
> >> +    Print (L"done.\n");
> >> +  }
> >> +
> >> +  return Status;
> >> +}
> >> +
> >> +/**
> >> +  Disables the specified AP.
> >> +
> >> +  @param Mp               The MP Services Protocol.
> >> +  @param ProcessorIndex   The processor to disable.
> >> +  @param ProcessorHealthy The health status of the processor.
> >> +
> >> +  @return EFI_SUCCESS on success, or an error code.
> >> +**/
> >> +STATIC
> >> +EFI_STATUS
> >> +DisableAP (
> >> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> >> +  UINTN                        ProcessorIndex,
> >> +  BOOLEAN                      ProcessorHealthy
> > [KQ] These parameters should have the "IN" attributes?
> >> +  )
> >> +{
> >> +  EFI_STATUS  Status;
> >> +  UINT32      HealthFlag;
> >> +
> >> +  if (ProcessorHealthy) {
> >> +    Print (L"Disabling Processor %d with HealthFlag healthy...",
> >> ProcessorIndex);
> >> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
> >> +  } else {
> >> +    Print (L"Disabling Processor %d with HealthFlag faulted...",
> >> ProcessorIndex);
> >> +    HealthFlag = 0;
> >> +  }
> >> +
> >> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, FALSE, &HealthFlag);
> >> +  if (EFI_ERROR (Status)) {
> >> +    Print (L"failed: %r\n", Status);
> >> +    return Status;
> >> +  } else {
> >> +    Print (L"done.\n");
> >> +  }
> >> +
> >> +  return Status;
> >> +}
> >> +
> >> +/**
> >> +  The user Entry Point for Application. The user code starts with
> >> this function
> >> +  as the real entry point for the application.
> >> +
> >> +  @param[in] ImageHandle    The firmware allocated handle for the EFI
> >> image.
> >> +  @param[in] SystemTable    A pointer to the EFI System Table.
> >> +
> >> +  @retval EFI_SUCCESS       The entry point is executed successfully.
> >> +  @retval other             Some error occurs when executing this
> >> entry point.
> >> +
> >> +**/
> >> +EFI_STATUS
> >> +EFIAPI
> >> +UefiMain (
> >> +  IN EFI_HANDLE        ImageHandle,
> >> +  IN EFI_SYSTEM_TABLE  *SystemTable
> >> +  )
> >> +{
> >> +  EFI_STATUS                Status;
> >> +  EFI_MP_SERVICES_PROTOCOL  *Mp;
> >> +  UINTN                     BspIndex;
> >> +  UINTN                     CpuIndex;
> >> +  UINTN                     NumCpus;
> >> +  BOOLEAN                   ProcessorHealthy;
> >> +  MP_SERVICES_TEST_OPTIONS  Options;
> >> +
> >> +  BspIndex = 0;
> >> +
> >> +  Status = gBS->LocateProtocol (
> >> +                  &gEfiMpServiceProtocolGuid,
> >> +                  NULL,
> >> +                  (VOID **)&Mp
> >> +                  );
> >> +  if (EFI_ERROR (Status)) {
> >> +    Print (L"Failed to locate EFI_MP_SERVICES_PROTOCOL (%r). Not
> >> installed on platform?\n", Status);
> >> +    return EFI_NOT_FOUND;
> >> +  }
> >> +
> >> +  Status = ParseArguments (&Options);
> >> +  if (EFI_ERROR (Status)) {
> >> +    return EFI_INVALID_PARAMETER;
> >> +  }
> >> +
> >> +  Status = GetProcessorInformation (Mp, &NumCpus, &BspIndex);
> >> +  if (EFI_ERROR (Status)) {
> >> +    Print (L"Error: Failed to fetch processor information.\n");
> >> +    return Status;
> >> +  }
> >> +
> >> +  if (Options.PrintBspProcessorIndex) {
> >> +    Status = Mp->WhoAmI (Mp, &CpuIndex);
> >> +    if (EFI_ERROR (Status)) {
> >> +      Print (L"WhoAmI failed: %r\n", Status);
> >> +      return Status;
> >> +    } else {
> >> +      Print (L"BSP: %016lx\n", CpuIndex);
> >> +    }
> >> +  }
> >> +
> >> +  if (Options.PrintProcessorInformation) {
> >> +    NumCpus = PrintProcessorInformation (Mp, &BspIndex);
> >> +    if (NumCpus < 2) {
> >> +      Print (L"Error: Uniprocessor system found.\n");
> >> +      return EFI_INVALID_PARAMETER;
> >> +    }
> >> +  }
> >> +
> >> +  if (Options.RunSingleAP) {
> >> +    Status = StartupThisAP (
> >> +               Mp,
> >> +               Options.ProcessorIndex,
> >> +               Options.Timeout
> >> +               );
> >> +    if (EFI_ERROR (Status)) {
> >> +      return Status;
> >> +    }
> >> +  }
> >> +
> >> +  if (Options.RunAllAPs) {
> >> +    Status = StartupAllAPs (Mp, NumCpus, Options.Timeout,
> >> Options.RunAPsSequentially);
> >> +    if (EFI_ERROR (Status)) {
> >> +      return Status;
> >> +    }
> >> +  }
> >> +
> >> +  if (Options.EnableProcessor) {
> >> +    ProcessorHealthy = TRUE;
> >> +    if (Options.SetProcessorUnhealthy) {
> >> +      ProcessorHealthy = FALSE;
> >> +    }
> >> +
> >> +    Status = EnableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
> >> +    if (EFI_ERROR (Status)) {
> >> +      return Status;
> >> +    }
> >> +  }
> >> +
> >> +  if (Options.DisableProcessor) {
> >> +    ProcessorHealthy = TRUE;
> >> +    if (Options.SetProcessorUnhealthy) {
> >> +      ProcessorHealthy = FALSE;
> >> +    }
> >> +
> >> +    Status = DisableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
> >> +    if (EFI_ERROR (Status)) {
> >> +      return Status;
> >> +    }
> >> +  }
> >> +
> >> +  return EFI_SUCCESS;
> >> +}
> >> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.c
> >> b/MdeModulePkg/Application/MpServicesTest/Options.c
> >> new file mode 100644
> >> index 000000000000..e820c061e1ec
> >> --- /dev/null
> >> +++ b/MdeModulePkg/Application/MpServicesTest/Options.c
> >> @@ -0,0 +1,164 @@
> >> +/** @file
> >> +  Options handling code.
> >> +
> >> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights
> >> reserved.<BR>
> >> +  Copyright (c) 2010-2019  Finnbarr P. Murphy.   All rights
> >> reserved.<BR>
> >> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> >> +**/
> >> +
> >> +#include <Uefi.h>
> >> +#include <Library/BaseMemoryLib.h>
> >> +#include <Protocol/ShellParameters.h>
> >> +#include <Library/BaseLib.h>
> >> +#include <Library/UefiLib.h>
> >> +#include <Library/UefiBootServicesTableLib.h>
> >> +
> >> +#include "Options.h"
> >> +
> >> +STATIC UINTN   Argc;
> >> +STATIC CHAR16  **Argv;
> >> +
> >> +/**
> >> +
> >> +  This function provides argc and argv.
> >> +
> >> +  @return Status
> >> +**/
> >> +EFI_STATUS
> >> +GetArg (
> >> +  VOID
> >> +  )
> >> +{
> >> +  EFI_STATUS                     Status;
> >> +  EFI_SHELL_PARAMETERS_PROTOCOL  *ShellParameters;
> >> +
> >> +  Status = gBS->HandleProtocol (
> >> +                  gImageHandle,
> >> +                  &gEfiShellParametersProtocolGuid,
> >> +                  (VOID **)&ShellParameters
> >> +                  );
> >> +  if (EFI_ERROR (Status)) {
> >> +    return Status;
> >> +  }
> >> +
> >> +  Argc = ShellParameters->Argc;
> >> +  Argv = ShellParameters->Argv;
> >> +  return EFI_SUCCESS;
> >> +}
> >> +
> >> +/**
> >> +  Print app usage.
> >> +**/
> >> +STATIC
> >> +VOID
> >> +PrintUsage (
> >> +  VOID
> >> +  )
> >> +{
> >> +  Print (L"MpServicesTest:  usage\n");
> >> +  Print (L"  MpServicesTest -A [-O]\n");
> >> +  Print (L"  MpServicesTest -T <Timeout>\n");
> >> +  Print (L"  MpServicesTest -S <Processor #>\n");
> >> +  Print (L"  MpServicesTest -P\n");
> >> +  Print (L"  MpServicesTest -U\n");
> >> +  Print (L"  MpServicesTest -W\n");
> >> +  Print (L"  MpServicesTest -E <Processor #>\n");
> >> +  Print (L"  MpServicesTest -D <Processor #>\n");
> >> +  Print (L"  MpServicesTest -h\n");
> >> +  Print (L"Parameter:\n");
> >> +  Print (L"  -A:  Run all APs.\n");
> >> +  Print (L"  -O:  Run APs sequentially (use with -A).\n");
> >> +  Print (L"  -T:  Specify timeout in milliseconds. Default is to wait
> >> forever.\n");
> >> +  Print (L"  -S:  Specify the single AP to run.\n");
> >> +  Print (L"  -P:  Print processor information.\n");
> >> +  Print (L"  -U:  Set the specified AP to the Unhealthy status (use
> >> with -E/-D).\n");
> >> +  Print (L"  -W:  Run WhoAmI and print index of BSP.\n");
> >> +  Print (L"  -E:  Enable the specified AP.\n");
> >> +  Print (L"  -D:  Disable the specified AP.\n");
> >> +  Print (L"  -h:  Print this help page.\n");
> >> +}
> >> +
> >> +/**
> >> +  Parses any arguments provided on the command line.
> >> +
> >> +  @param Options  The arguments structure.
> >> +
> >> +  @return EFI_SUCCESS on success, or an error code.
> >> +**/
> >> +EFI_STATUS
> >> +ParseArguments (
> >> +  MP_SERVICES_TEST_OPTIONS  *Options
> >> +  )
> >> +{
> >> +  EFI_STATUS    Status;
> >> +  UINT32        ArgIndex;
> > [KQ] Similar to the other comment, ArgIndex is of UINT32 is compared to
> > Argc of UINTN could make some compilers unhappy.
> >> +  CONST CHAR16  *Argument;
> >> +  BOOLEAN       NeedsValue;
> >> +  UINTN         *Value;
> >> +
> >> +  Status = GetArg ();
> >> +  if (EFI_ERROR (Status)) {
> >> +    Print (L"Please use the UEFI Shell to run this application!\n",
> >> Status);
> >> +    return Status;
> >> +  }
> >> +
> >> +  if (Argc == 1) {
> >> +    PrintUsage ();
> >> +  }
> >> +
> >> +  ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
> >> +
> >> +  for (ArgIndex = 1; ArgIndex < Argc; ArgIndex++) {
> >> +    Argument   = Argv[ArgIndex];
> >> +    NeedsValue = FALSE;
> >> +
> >> +    if (StrCmp (Argument, L"-A") == 0) {
> >> +      Options->RunAllAPs = TRUE;
> >> +    } else if (StrCmp (Argument, L"-O") == 0) {
> >> +      Options->RunAPsSequentially = TRUE;
> >> +    } else if (StrCmp (Argument, L"-T") == 0) {
> >> +      NeedsValue = TRUE;
> >> +      Value      = &Options->Timeout;
> >> +    } else if (StrCmp (Argument, L"-S") == 0) {
> >> +      Options->RunSingleAP = TRUE;
> >> +      NeedsValue           = TRUE;
> >> +      Value                = &Options->ProcessorIndex;
> >> +    } else if (StrCmp (Argument, L"-P") == 0) {
> >> +      Options->PrintProcessorInformation = TRUE;
> >> +    } else if (StrCmp (Argument, L"-U") == 0) {
> >> +      Options->SetProcessorUnhealthy = TRUE;
> >> +    } else if (StrCmp (Argument, L"-W") == 0) {
> >> +      Options->PrintBspProcessorIndex = TRUE;
> >> +    } else if (StrCmp (Argument, L"-E") == 0) {
> >> +      Options->EnableProcessor = TRUE;
> >> +      NeedsValue               = TRUE;
> >> +      Value                    = &Options->ProcessorIndex;
> >> +    } else if (StrCmp (Argument, L"-D") == 0) {
> >> +      Options->DisableProcessor = TRUE;
> >> +      NeedsValue                = TRUE;
> >> +      Value                     = &Options->ProcessorIndex;
> >> +    } else {
> >> +      PrintUsage ();
> >> +      ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
> >> +      return EFI_SUCCESS;
> >> +    }
> >> +
> >> +    if (NeedsValue) {
> >> +      if ((ArgIndex + 1) < Argc) {
> >> +        Status = StrDecimalToUintnS (Argv[ArgIndex + 1], NULL, Value);
> >> +        if (EFI_ERROR (Status)) {
> >> +          Print (L"Error: option value must be a positive integer.\n");
> >> +          PrintUsage ();
> >> +          return EFI_INVALID_PARAMETER;
> >> +        }
> >> +
> >> +        ArgIndex++;
> >> +      } else {
> >> +        PrintUsage ();
> >> +        return EFI_INVALID_PARAMETER;
> >> +      }
> >> +    }
> >> +  }
> >> +
> >> +  return EFI_SUCCESS;
> >> +}
> 
> 
> 
> 

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Rebecca Cran]

Thanks, I hadn't seen that. Unless people want the additional control 
this application provides via the command-line options, I can drop this 
patch.

-- 
Rebecca Cran

On 1/8/23 18:32, Ni, Ray wrote:
> Rebecca,
> Have you reviewed UefiCpuPkg\Test\UnitTest\EfiMpServicesPpiProtocol? It's based on UnitTestFrameworkPkg for unit testing on MP PPI and MP protocol.
> Do you think if the MpServicesTest app and the EfiMpServicesPpiProtocol have some overlapped functionalities?
> 
> 
> 
> Thanks,
> Ray
> 
>> -----Original Message-----
>> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Rebecca Cran
>> Sent: Sunday, January 8, 2023 12:56 PM
>> To: Kun Qin <kuqin12@gmail.com>; devel@edk2.groups.io; Sami Mujawar <sami.mujawar@arm.com>; Ard Biesheuvel
>> <ardb+tianocore@kernel.org>; Leif Lindholm <quic_llindhol@quicinc.com>; Wang, Jian J <jian.j.wang@intel.com>; Gao,
>> Liming <gaoliming@byosoft.com.cn>; Tiger Liu <TigerLiu@zhaoxin.com>
>> Subject: Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application
>>
>> Thanks! I've fixed all the issues you noted and will send out a v5 patch
>> in the next couple of days.
>>
>> --
>> Rebecca Cran
>>
>> On 1/6/23 15:33, Kun Qin wrote:
>>> Hi Rebecca,
>>>
>>> Thanks for sharing this patch. I found a few minor issues when running
>>> this test app. Please see comments with [KQ] below.
>>>
>>> Regards,
>>> Kun
>>>
>>> On 1/4/2023 7:37 AM, Rebecca Cran wrote:
>>>> The MpServicesTest application exercises the EFI_MP_SERVICES_PROTOCOL.
>>>>
>>>> usage:
>>>>     MpServicesTest -A [-O]
>>>>     MpServicesTest -T <Timeout>
>>>>     MpServicesTest -S <Processor #>
>>>>     MpServicesTest -P
>>>>     MpServicesTest -U
>>>>     MpServicesTest -W
>>>>     MpServicesTest -E <Processor #>
>>>>     MpServicesTest -D <Processor #>
>>>>     MpServicesTest -h
>>>>
>>>> Parameter:
>>>>     -A:  Run all APs.
>>>>     -O:  Run APs sequentially (use with -A).
>>>>     -T:  Specify timeout in milliseconds. Default is to wait forever.
>>>>     -S:  Specify the single AP to run.
>>>>     -P:  Print processor information.
>>>>     -U:  Set the specified AP to the Unhealthy status (use with -E/-D).
>>>>     -W:  Run WhoAmI and print index of BSP.
>>>>     -E:  Enable the specified AP.
>>>>     -D:  Disable the specified AP.
>>>>     -h:  Print this help page.
>>>>
>>>> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
>>>> ---
>>>>    MdeModulePkg/MdeModulePkg.dsc                              |   2 +
>>>>    MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf |  40 ++
>>>>    MdeModulePkg/Application/MpServicesTest/Options.h          |  39 ++
>>>>    MdeModulePkg/Application/MpServicesTest/MpServicesTest.c   | 560
>>>> ++++++++++++++++++++
>>>>    MdeModulePkg/Application/MpServicesTest/Options.c          | 164 ++++++
>>>>    5 files changed, 805 insertions(+)
>>>>
>>>> diff --git a/MdeModulePkg/MdeModulePkg.dsc
>>>> b/MdeModulePkg/MdeModulePkg.dsc
>>>> index 659482ab737f..6992b3ae8db6 100644
>>>> --- a/MdeModulePkg/MdeModulePkg.dsc
>>>> +++ b/MdeModulePkg/MdeModulePkg.dsc
>>>> @@ -166,6 +166,7 @@ [LibraryClasses.common.UEFI_APPLICATION]
>>>>
>>>> MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>>>>      DebugLib|MdePkg/Library/UefiDebugLibStdErr/UefiDebugLibStdErr.inf
>>>>      FileHandleLib|MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.inf
>>>> +  ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
>>>>    [LibraryClasses.common.MM_STANDALONE]
>>>>      HobLib|MdeModulePkg/Library/BaseHobLibNull/BaseHobLibNull.inf
>>>> @@ -445,6 +446,7 @@ [Components]
>>>>
>>>> MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
>>>>    [Components.IA32, Components.X64, Components.AARCH64]
>>>> +  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>>>>      MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
>>>>      MdeModulePkg/Universal/EbcDxe/EbcDebugger.inf
>>>>      MdeModulePkg/Universal/EbcDxe/EbcDebuggerConfig.inf
>>>> diff --git
>>>> a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>>>> b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>>>> new file mode 100644
>>>> index 000000000000..07ee4afec845
>>>> --- /dev/null
>>>> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>>>> @@ -0,0 +1,40 @@
>>>> +## @file
>>>> +#  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
>>>> +#
>>>> +#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights
>>>> reserved.<BR>
>>>> +#
>>>> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
>>>> +#
>>>> +##
>>>> +
>>>> +[Defines]
>>>> +  INF_VERSION                    = 1.29
>>>> +  BASE_NAME                      = MpServicesTest
>>>> +  FILE_GUID                      = 43e9defa-7209-4b0d-b136-cc4ca02cb469
>>>> +  MODULE_TYPE                    = UEFI_APPLICATION
>>>> +  VERSION_STRING                 = 0.1
>>>> +  ENTRY_POINT                    = UefiMain
>>>> +
>>>> +#
>>>> +# The following information is for reference only and not required by
>>>> the build tools.
>>>> +#
>>>> +#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
>>>> +#
>>>> +
>>>> +[Sources]
>>>> +  MpServicesTest.c
>>>> +  Options.c
>>>> +  Options.h
>>>> +
>>>> +[Packages]
>>>> +  MdePkg/MdePkg.dec
>>>> +
>>>> +[LibraryClasses]
>>>> +  BaseLib
>>>> +  ShellLib
>>>> +  UefiApplicationEntryPoint
>>>> +  UefiLib
>>>> +
>>>> +[Protocols]
>>>> +  gEfiMpServiceProtocolGuid    ## CONSUMES
>>>> +
>>>> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.h
>>>> b/MdeModulePkg/Application/MpServicesTest/Options.h
>>>> new file mode 100644
>>>> index 000000000000..cb28230ab095
>>>> --- /dev/null
>>>> +++ b/MdeModulePkg/Application/MpServicesTest/Options.h
>>>> @@ -0,0 +1,39 @@
>>>> +/** @file
>>>> +  Options handling code.
>>>> +
>>>> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights
>>>> reserved.<BR>
>>>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>>>> +**/
>>>> +
>>>> +#ifndef MPSERVICESTEST_OPTIONS_H_
>>>> +#define MPSERVICESTEST_OPTIONS_H_
>>>> +
>>>> +#define INFINITE_TIMEOUT  0
>>>> +
>>>> +typedef struct {
>>>> +  UINTN      Timeout;
>>>> +  UINTN      ProcessorIndex;
>>>> +  BOOLEAN    RunAllAPs;
>>>> +  BOOLEAN    RunSingleAP;
>>>> +  BOOLEAN    DisableProcessor;
>>>> +  BOOLEAN    EnableProcessor;
>>>> +  BOOLEAN    SetProcessorHealthy;
>>>> +  BOOLEAN    SetProcessorUnhealthy;
>>>> +  BOOLEAN    PrintProcessorInformation;
>>>> +  BOOLEAN    PrintBspProcessorIndex;
>>>> +  BOOLEAN    RunAPsSequentially;
>>>> +} MP_SERVICES_TEST_OPTIONS;
>>>> +
>>>> +/**
>>>> +  Parses any arguments provided on the command line.
>>>> +
>>>> +  @param Options  The arguments structure.
>>>> +
>>>> +  @return EFI_SUCCESS on success, or an error code.
>>>> +**/
>>>> +EFI_STATUS
>>>> +ParseArguments (
>>>> +  MP_SERVICES_TEST_OPTIONS  *Options
>>>> +  );
>>>> +
>>>> +#endif /* MPSERVICESTEST_OPTIONS_H_ */
>>>> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
>>>> b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
>>>> new file mode 100644
>>>> index 000000000000..3f3d9752d500
>>>> --- /dev/null
>>>> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
>>>> @@ -0,0 +1,560 @@
>>>> +/** @file
>>>> +  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
>>>> +
>>>> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights
>>>> reserved.<BR>
>>>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>>>> +**/
>>>> +
>>>> +#include <Uefi.h>
>>>> +#include <Library/BaseMemoryLib.h>
>>>> +#include <Library/DebugLib.h>
>>>> +#include <Library/MemoryAllocationLib.h>
>>>> +#include <Library/PrintLib.h>
>>>> +#include <Library/UefiBootServicesTableLib.h>
>>>> +#include <Library/UefiLib.h>
>>>> +#include <Pi/PiMultiPhase.h>
>>>> +#include <Protocol/MpService.h>
>>>> +
>>>> +#include "Options.h"
>>>> +
>>>> +#define APFUNC_BUFFER_LEN  256
>>>> +
>>>> +typedef struct {
>>>> +  EFI_MP_SERVICES_PROTOCOL    *Mp;
>>>> +  CHAR16                      **Buffer;
>>>> +} APFUNC_ARG;
>>>> +
>>>> +/** The procedure to run with the MP Services interface.
>>>> +
>>>> +  @param Arg The procedure argument.
>>>> +
>>>> +**/
>>>> +STATIC
>>>> +VOID
>>>> +EFIAPI
>>>> +ApFunction (
>>>> +  IN OUT VOID  *Arg
>>>> +  )
>>>> +{
>>>> +  APFUNC_ARG  *Param;
>>>> +  UINTN       ProcessorId;
>>>> +
>>>> +  if (Arg != NULL) {
>>>> +    Param = Arg;
>>>> +
>>>> +    Param->Mp->WhoAmI (Param->Mp, &ProcessorId);
>>>> +    UnicodeSPrint (Param->Buffer[ProcessorId], APFUNC_BUFFER_LEN,
>>>> L"Hello from CPU %ld\n", ProcessorId);
>>>> +  }
>>>> +}
>>>> +
>>>> +/**
>>>> +  Fetches the number of processors and which processor is the BSP.
>>>> +
>>>> +  @param Mp  MP Services Protocol.
>>>> +  @param NumProcessors Number of processors.
>>>> +  @param BspIndex      The index of the BSP.
>>>> +**/
>>>> +STATIC
>>>> +EFI_STATUS
>>>> +GetProcessorInformation (
>>>> +  IN  EFI_MP_SERVICES_PROTOCOL  *Mp,
>>>> +  OUT UINTN                     *NumProcessors,
>>>> +  OUT UINTN                     *BspIndex
>>>> +  )
>>>> +{
>>>> +  EFI_STATUS  Status;
>>>> +  UINTN       NumEnabledProcessors;
>>>> +
>>>> +  Status = Mp->GetNumberOfProcessors (Mp, NumProcessors,
>>>> &NumEnabledProcessors);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    return Status;
>>>> +  }
>>>> +
>>>> +  Status = Mp->WhoAmI (Mp, BspIndex);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    return Status;
>>>> +  }
>>>> +
>>>> +  return EFI_SUCCESS;
>>>> +}
>>>> +
>>>> +/** Displays information returned from MP Services Protocol.
>>>> +
>>>> +  @param Mp       The MP Services Protocol
>>>> +  @param BspIndex On return, contains the index of the BSP.
>>>> +
>>>> +  @return The number of CPUs in the system.
>>>> +
>>>> +**/
>>>> +STATIC
>>>> +UINTN
>>>> +PrintProcessorInformation (
>>>> +  IN   EFI_MP_SERVICES_PROTOCOL  *Mp,
>>>> +  OUT  UINTN                     *BspIndex
>>>> +  )
>>>> +{
>>>> +  EFI_STATUS                 Status;
>>>> +  EFI_PROCESSOR_INFORMATION  CpuInfo;
>>>> +  UINTN                      Index;
>>>> +  UINTN                      NumCpu;
>>>> +  UINTN                      NumEnabledCpu;
>>> [KQ] The NumCpu and NumEnabledCpu probably should be initialized to 0s?
>>> Otherwise if the
>>> GetNumberOfProcessors function somehow fails, the rest of the call will
>>> essentially be no-op,
>>> instead of running into undefined number of CPUs.
>>>> +
>>>> +  Status = Mp->GetNumberOfProcessors (Mp, &NumCpu, &NumEnabledCpu);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    Print (L"GetNumberOfProcessors failed: %r\n", Status);
>>>> +  } else {
>>>> +    Print (L"Number of CPUs: %ld, Enabled: %d\n", NumCpu,
>>>> NumEnabledCpu);
>>>> +  }
>>>> +
>>>> +  for (Index = 0; Index < NumCpu; Index++) {
>>>> +    Status = Mp->GetProcessorInfo (Mp, CPU_V2_EXTENDED_TOPOLOGY |
>>>> Index, &CpuInfo);
>>>> +    if (EFI_ERROR (Status)) {
>>>> +      Print (L"GetProcessorInfo for Processor %d failed: %r\n",
>>>> Index, Status);
>>>> +    } else {
>>>> +      Print (
>>>> +        L"Processor %d:\n"
>>>> +        L"\tID: %016lx\n"
>>>> +        L"\tStatus: %s | ",
>>>> +        Index,
>>>> +        CpuInfo.ProcessorId,
>>>> +        (CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) ? L"BSP" : L"AP"
>>>> +        );
>>>> +
>>>> +      if ((CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) && (BspIndex !=
>>>> NULL)) {
>>>> +        *BspIndex = Index;
>>>> +      }
>>>> +
>>>> +      Print (L"%s | ", (CpuInfo.StatusFlag & PROCESSOR_ENABLED_BIT) ?
>>>> L"Enabled" : L"Disabled");
>>>> +      Print (L"%s\n", (CpuInfo.StatusFlag &
>>>> PROCESSOR_HEALTH_STATUS_BIT) ? L"Healthy" : L"Faulted");
>>>> +
>>>> +      Print (
>>>> +        L"\tLocation: Package %d, Core %d, Thread %d\n"
>>>> +        L"\tExtended Information: Package %d, Module %d, Tile %d, Die
>>>> %d, Core %d, Thread %d\n\n",
>>>> +        CpuInfo.Location.Package,
>>>> +        CpuInfo.Location.Core,
>>>> +        CpuInfo.Location.Thread,
>>>> +        CpuInfo.ExtendedInformation.Location2.Package,
>>>> +        CpuInfo.ExtendedInformation.Location2.Module,
>>>> +        CpuInfo.ExtendedInformation.Location2.Tile,
>>>> +        CpuInfo.ExtendedInformation.Location2.Die,
>>>> +        CpuInfo.ExtendedInformation.Location2.Core,
>>>> +        CpuInfo.ExtendedInformation.Location2.Thread
>>>> +        );
>>>> +    }
>>>> +  }
>>>> +
>>>> +  return NumCpu;
>>>> +}
>>>> +
>>>> +/** Allocates memory in ApArg for the single AP specified.
>>>> +
>>>> +  @param ApArg          Pointer to the AP argument structure.
>>>> +  @param Mp             The MP Services Protocol.
>>>> +  @param ProcessorIndex The index of the AP.
>>>> +
>>>> +  @retval EFI_SUCCESS          Memory was successfully allocated.
>>>> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
>>>> +
>>>> +**/
>>>> +STATIC
>>>> +EFI_STATUS
>>>> +AllocateApFuncBufferSingleAP (
>>>> +  IN APFUNC_ARG                *ApArg,
>>>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>>>> +  IN UINTN                     ProcessorIndex
>>>> +  )
>>>> +{
>>>> +  ApArg->Mp = Mp;
>>>> +
>>>> +  ApArg->Buffer = AllocateZeroPool ((ProcessorIndex + 1) * sizeof
>>>> (VOID *));
>>>> +  if (ApArg->Buffer == NULL) {
>>>> +    Print (L"Failed to allocate buffer for AP buffer\n");
>>>> +    return EFI_OUT_OF_RESOURCES;
>>>> +  }
>>>> +
>>>> +  ApArg->Buffer[ProcessorIndex] = AllocateZeroPool (APFUNC_BUFFER_LEN);
>>>> +  if (ApArg->Buffer[ProcessorIndex] == NULL) {
>>>> +    Print (L"Failed to allocate buffer for AP buffer\n");
>>>> +    FreePool (ApArg->Buffer);
>>>> +    return EFI_OUT_OF_RESOURCES;
>>>> +  }
>>>> +
>>>> +  return EFI_SUCCESS;
>>>> +}
>>>> +
>>>> +/** Allocates memory in ApArg for all APs.
>>>> +
>>>> +  @param ApArg   Pointer to the AP argument structure.
>>>> +  @param Mp      The MP Services Protocol.
>>>> +  @param NumCpus The number of CPUs.
>>>> +
>>>> +  @retval EFI_SUCCESS          Memory was successfully allocated.
>>>> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
>>>> +
>>>> +**/
>>>> +STATIC
>>>> +EFI_STATUS
>>>> +AllocateApFuncBufferAllAPs (
>>>> +  IN APFUNC_ARG                *ApArg,
>>>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>>>> +  IN UINTN                     NumCpus
>>>> +  )
>>>> +{
>>>> +  UINT32  Index;
>>> [KQ] The Index of UINT32 compared to NumCpus of UINTN could make some
>>> compilers unhappy.
>>>> +
>>>> +  ApArg->Mp = Mp;
>>>> +
>>>> +  ApArg->Buffer = AllocateZeroPool (NumCpus * sizeof (VOID *));
>>>> +  if (ApArg->Buffer == NULL) {
>>>> +    Print (L"Failed to allocate buffer for AP message\n");
>>>> +    return EFI_OUT_OF_RESOURCES;
>>>> +  }
>>>> +
>>>> +  for (Index = 0; Index < NumCpus; Index++) {
>>>> +    ApArg->Buffer[Index] = AllocateZeroPool (APFUNC_BUFFER_LEN);
>>>> +    if (ApArg->Buffer[Index] == NULL) {
>>>> +      Print (L"Failed to allocate buffer for AP message\n");
>>>> +      for (--Index; Index >= 0; Index++) {
>>> [KQ] This Index increment could cause the loop not ending as expected.
>>>> +        FreePool (ApArg->Buffer[Index]);
>>>> +      }
>>>> +
>>>> +      FreePool (ApArg->Buffer);
>>>> +      return EFI_OUT_OF_RESOURCES;
>>>> +    }
>>>> +  }
>>>> +
>>>> +  return EFI_SUCCESS;
>>>> +}
>>>> +
>>>> +/** Frees memory in ApArg for all APs.
>>>> +
>>>> +  @param ApArg   Pointer to the AP argument structure.
>>>> +  @param NumCpus The number of CPUs.
>>>> +
>>>> +**/
>>>> +STATIC
>>>> +VOID
>>>> +FreeApFuncBuffer (
>>>> +  APFUNC_ARG  *ApArg,
>>>> +  UINTN       NumCpus
>>>> +  )
>>>> +{
>>>> +  UINTN  Index;
>>>> +
>>>> +  for (Index = 0; Index < NumCpus; Index++) {
>>>> +    if (ApArg->Buffer[Index] != NULL) {
>>>> +      FreePool (ApArg->Buffer[Index]);
>>>> +    }
>>>> +  }
>>>> +
>>>> +  FreePool (ApArg->Buffer);
>>>> +}
>>>> +
>>>> +/** Runs a specified AP.
>>>> +
>>>> +  @param Mp             The MP Services Protocol.
>>>> +  @param ProcessorIndex The processor index.
>>>> +  @param Timeout        Timeout in milliseconds.
>>>> +
>>>> +  @return EFI_SUCCESS on success, or an error code.
>>>> +
>>>> +**/
>>>> +STATIC
>>>> +EFI_STATUS
>>>> +StartupThisAP (
>>>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>>>> +  IN UINTN                     ProcessorIndex,
>>>> +  IN UINTN                     Timeout
>>>> +  )
>>>> +{
>>>> +  EFI_STATUS  Status;
>>>> +  APFUNC_ARG  ApArg;
>>>> +
>>>> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    return Status;
>>>> +  }
>>>> +
>>>> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    return Status;
>>>> +  }
>>>> +
>>> [KQ] I guess the above double calls are not intended?
>>>> +  Print (
>>>> +    L"StartupThisAP on Processor %d with %d%s timeout...",
>>>> +    ProcessorIndex,
>>>> +    Timeout,
>>>> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
>>>> +    );
>>>> +  Status = Mp->StartupThisAP (
>>>> +                 Mp,
>>>> +                 ApFunction,
>>>> +                 ProcessorIndex,
>>>> +                 NULL,
>>>> +                 Timeout * 1000,
>>>> +                 &ApArg,
>>>> +                 NULL
>>>> +                 );
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    Print (L"failed: %r\n", Status);
>>>> +    return Status;
>>>> +  } else {
>>>> +    Print (L"done.\n");
>>>> +    Print (ApArg.Buffer[ProcessorIndex]);
>>>> +  }
>>>> +
>>>> +  FreeApFuncBuffer (&ApArg, ProcessorIndex + 1);
>>>> +
>>>> +  return EFI_SUCCESS;
>>>> +}
>>>> +
>>>> +/** Runs all APs.
>>>> +
>>>> +  @param Mp                 The MP Services Protocol.
>>>> +  @param NumCpus            The number of CPUs in the system.
>>>> +  @param Timeout            Timeout in milliseconds.
>>>> +  @param RunAPsSequentially Run APs sequentially (FALSE: run
>>>> simultaneously)
>>>> +
>>>> +  @return EFI_SUCCESS on success, or an error code.
>>>> +
>>>> +**/
>>>> +STATIC
>>>> +EFI_STATUS
>>>> +StartupAllAPs (
>>>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>>>> +  IN UINTN                     NumCpus,
>>>> +  IN UINTN                     Timeout,
>>>> +  IN BOOLEAN                   RunAPsSequentially
>>>> +  )
>>>> +{
>>>> +  EFI_STATUS  Status;
>>>> +  UINTN       Index;
>>>> +  APFUNC_ARG  ApArg;
>>>> +
>>>> +  Status = AllocateApFuncBufferAllAPs (&ApArg, Mp, NumCpus);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    return Status;
>>>> +  }
>>>> +
>>>> +  Print (
>>>> +    L"Running with SingleThread %s, %u%s timeout...",
>>>> +    (RunAPsSequentially) ? L"TRUE" : L"FALSE",
>>>> +    Timeout,
>>>> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
>>>> +    );
>>>> +
>>>> +  Status = Mp->StartupAllAPs (
>>>> +                 Mp,
>>>> +                 ApFunction,
>>>> +                 RunAPsSequentially,
>>>> +                 NULL,
>>>> +                 Timeout * 1000,
>>>> +                 &ApArg,
>>>> +                 NULL
>>>> +                 );
>>>> +
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    Print (L"failed: %r\n", Status);
>>>> +
>>>> +    return Status;
>>>> +  } else {
>>>> +    Print (L"done.\n");
>>>> +
>>>> +    for (Index = 0; Index < NumCpus; Index++) {
>>>> +      Print (ApArg.Buffer[Index]);
>>>> +    }
>>>> +  }
>>>> +
>>>> +  FreeApFuncBuffer (&ApArg, NumCpus);
>>>> +  return EFI_SUCCESS;
>>>> +}
>>>> +
>>>> +/**
>>>> +  Enables the specified AP.
>>>> +
>>>> +  @param Mp               The MP Services Protocol.
>>>> +  @param ProcessorIndex   The processor to enable.
>>>> +  @param ProcessorHealthy The health status of the processor.
>>>> +
>>>> +  @return EFI_SUCCESS on success, or an error code.
>>>> +**/
>>>> +STATIC
>>>> +EFI_STATUS
>>>> +EnableAP (
>>>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>>>> +  UINTN                        ProcessorIndex,
>>>> +  BOOLEAN                      ProcessorHealthy
>>> [KQ] These parameters should have the "IN" attributes?
>>>> +  )
>>>> +{
>>>> +  EFI_STATUS  Status;
>>>> +  UINT32      HealthFlag;
>>>> +
>>>> +  if (ProcessorHealthy) {
>>>> +    Print (L"Enabling Processor %d with HealthFlag healthy...",
>>>> ProcessorIndex);
>>>> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
>>>> +  } else {
>>>> +    Print (L"Enabling Processor %d with HealthFlag faulted...",
>>>> ProcessorIndex);
>>>> +    HealthFlag = 0;
>>>> +  }
>>>> +
>>>> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, TRUE, &HealthFlag);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    Print (L"failed: %r\n", Status);
>>>> +    return Status;
>>>> +  } else {
>>>> +    Print (L"done.\n");
>>>> +  }
>>>> +
>>>> +  return Status;
>>>> +}
>>>> +
>>>> +/**
>>>> +  Disables the specified AP.
>>>> +
>>>> +  @param Mp               The MP Services Protocol.
>>>> +  @param ProcessorIndex   The processor to disable.
>>>> +  @param ProcessorHealthy The health status of the processor.
>>>> +
>>>> +  @return EFI_SUCCESS on success, or an error code.
>>>> +**/
>>>> +STATIC
>>>> +EFI_STATUS
>>>> +DisableAP (
>>>> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
>>>> +  UINTN                        ProcessorIndex,
>>>> +  BOOLEAN                      ProcessorHealthy
>>> [KQ] These parameters should have the "IN" attributes?
>>>> +  )
>>>> +{
>>>> +  EFI_STATUS  Status;
>>>> +  UINT32      HealthFlag;
>>>> +
>>>> +  if (ProcessorHealthy) {
>>>> +    Print (L"Disabling Processor %d with HealthFlag healthy...",
>>>> ProcessorIndex);
>>>> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
>>>> +  } else {
>>>> +    Print (L"Disabling Processor %d with HealthFlag faulted...",
>>>> ProcessorIndex);
>>>> +    HealthFlag = 0;
>>>> +  }
>>>> +
>>>> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, FALSE, &HealthFlag);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    Print (L"failed: %r\n", Status);
>>>> +    return Status;
>>>> +  } else {
>>>> +    Print (L"done.\n");
>>>> +  }
>>>> +
>>>> +  return Status;
>>>> +}
>>>> +
>>>> +/**
>>>> +  The user Entry Point for Application. The user code starts with
>>>> this function
>>>> +  as the real entry point for the application.
>>>> +
>>>> +  @param[in] ImageHandle    The firmware allocated handle for the EFI
>>>> image.
>>>> +  @param[in] SystemTable    A pointer to the EFI System Table.
>>>> +
>>>> +  @retval EFI_SUCCESS       The entry point is executed successfully.
>>>> +  @retval other             Some error occurs when executing this
>>>> entry point.
>>>> +
>>>> +**/
>>>> +EFI_STATUS
>>>> +EFIAPI
>>>> +UefiMain (
>>>> +  IN EFI_HANDLE        ImageHandle,
>>>> +  IN EFI_SYSTEM_TABLE  *SystemTable
>>>> +  )
>>>> +{
>>>> +  EFI_STATUS                Status;
>>>> +  EFI_MP_SERVICES_PROTOCOL  *Mp;
>>>> +  UINTN                     BspIndex;
>>>> +  UINTN                     CpuIndex;
>>>> +  UINTN                     NumCpus;
>>>> +  BOOLEAN                   ProcessorHealthy;
>>>> +  MP_SERVICES_TEST_OPTIONS  Options;
>>>> +
>>>> +  BspIndex = 0;
>>>> +
>>>> +  Status = gBS->LocateProtocol (
>>>> +                  &gEfiMpServiceProtocolGuid,
>>>> +                  NULL,
>>>> +                  (VOID **)&Mp
>>>> +                  );
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    Print (L"Failed to locate EFI_MP_SERVICES_PROTOCOL (%r). Not
>>>> installed on platform?\n", Status);
>>>> +    return EFI_NOT_FOUND;
>>>> +  }
>>>> +
>>>> +  Status = ParseArguments (&Options);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    return EFI_INVALID_PARAMETER;
>>>> +  }
>>>> +
>>>> +  Status = GetProcessorInformation (Mp, &NumCpus, &BspIndex);
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    Print (L"Error: Failed to fetch processor information.\n");
>>>> +    return Status;
>>>> +  }
>>>> +
>>>> +  if (Options.PrintBspProcessorIndex) {
>>>> +    Status = Mp->WhoAmI (Mp, &CpuIndex);
>>>> +    if (EFI_ERROR (Status)) {
>>>> +      Print (L"WhoAmI failed: %r\n", Status);
>>>> +      return Status;
>>>> +    } else {
>>>> +      Print (L"BSP: %016lx\n", CpuIndex);
>>>> +    }
>>>> +  }
>>>> +
>>>> +  if (Options.PrintProcessorInformation) {
>>>> +    NumCpus = PrintProcessorInformation (Mp, &BspIndex);
>>>> +    if (NumCpus < 2) {
>>>> +      Print (L"Error: Uniprocessor system found.\n");
>>>> +      return EFI_INVALID_PARAMETER;
>>>> +    }
>>>> +  }
>>>> +
>>>> +  if (Options.RunSingleAP) {
>>>> +    Status = StartupThisAP (
>>>> +               Mp,
>>>> +               Options.ProcessorIndex,
>>>> +               Options.Timeout
>>>> +               );
>>>> +    if (EFI_ERROR (Status)) {
>>>> +      return Status;
>>>> +    }
>>>> +  }
>>>> +
>>>> +  if (Options.RunAllAPs) {
>>>> +    Status = StartupAllAPs (Mp, NumCpus, Options.Timeout,
>>>> Options.RunAPsSequentially);
>>>> +    if (EFI_ERROR (Status)) {
>>>> +      return Status;
>>>> +    }
>>>> +  }
>>>> +
>>>> +  if (Options.EnableProcessor) {
>>>> +    ProcessorHealthy = TRUE;
>>>> +    if (Options.SetProcessorUnhealthy) {
>>>> +      ProcessorHealthy = FALSE;
>>>> +    }
>>>> +
>>>> +    Status = EnableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
>>>> +    if (EFI_ERROR (Status)) {
>>>> +      return Status;
>>>> +    }
>>>> +  }
>>>> +
>>>> +  if (Options.DisableProcessor) {
>>>> +    ProcessorHealthy = TRUE;
>>>> +    if (Options.SetProcessorUnhealthy) {
>>>> +      ProcessorHealthy = FALSE;
>>>> +    }
>>>> +
>>>> +    Status = DisableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
>>>> +    if (EFI_ERROR (Status)) {
>>>> +      return Status;
>>>> +    }
>>>> +  }
>>>> +
>>>> +  return EFI_SUCCESS;
>>>> +}
>>>> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.c
>>>> b/MdeModulePkg/Application/MpServicesTest/Options.c
>>>> new file mode 100644
>>>> index 000000000000..e820c061e1ec
>>>> --- /dev/null
>>>> +++ b/MdeModulePkg/Application/MpServicesTest/Options.c
>>>> @@ -0,0 +1,164 @@
>>>> +/** @file
>>>> +  Options handling code.
>>>> +
>>>> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights
>>>> reserved.<BR>
>>>> +  Copyright (c) 2010-2019  Finnbarr P. Murphy.   All rights
>>>> reserved.<BR>
>>>> +  SPDX-License-Identifier: BSD-2-Clause-Patent
>>>> +**/
>>>> +
>>>> +#include <Uefi.h>
>>>> +#include <Library/BaseMemoryLib.h>
>>>> +#include <Protocol/ShellParameters.h>
>>>> +#include <Library/BaseLib.h>
>>>> +#include <Library/UefiLib.h>
>>>> +#include <Library/UefiBootServicesTableLib.h>
>>>> +
>>>> +#include "Options.h"
>>>> +
>>>> +STATIC UINTN   Argc;
>>>> +STATIC CHAR16  **Argv;
>>>> +
>>>> +/**
>>>> +
>>>> +  This function provides argc and argv.
>>>> +
>>>> +  @return Status
>>>> +**/
>>>> +EFI_STATUS
>>>> +GetArg (
>>>> +  VOID
>>>> +  )
>>>> +{
>>>> +  EFI_STATUS                     Status;
>>>> +  EFI_SHELL_PARAMETERS_PROTOCOL  *ShellParameters;
>>>> +
>>>> +  Status = gBS->HandleProtocol (
>>>> +                  gImageHandle,
>>>> +                  &gEfiShellParametersProtocolGuid,
>>>> +                  (VOID **)&ShellParameters
>>>> +                  );
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    return Status;
>>>> +  }
>>>> +
>>>> +  Argc = ShellParameters->Argc;
>>>> +  Argv = ShellParameters->Argv;
>>>> +  return EFI_SUCCESS;
>>>> +}
>>>> +
>>>> +/**
>>>> +  Print app usage.
>>>> +**/
>>>> +STATIC
>>>> +VOID
>>>> +PrintUsage (
>>>> +  VOID
>>>> +  )
>>>> +{
>>>> +  Print (L"MpServicesTest:  usage\n");
>>>> +  Print (L"  MpServicesTest -A [-O]\n");
>>>> +  Print (L"  MpServicesTest -T <Timeout>\n");
>>>> +  Print (L"  MpServicesTest -S <Processor #>\n");
>>>> +  Print (L"  MpServicesTest -P\n");
>>>> +  Print (L"  MpServicesTest -U\n");
>>>> +  Print (L"  MpServicesTest -W\n");
>>>> +  Print (L"  MpServicesTest -E <Processor #>\n");
>>>> +  Print (L"  MpServicesTest -D <Processor #>\n");
>>>> +  Print (L"  MpServicesTest -h\n");
>>>> +  Print (L"Parameter:\n");
>>>> +  Print (L"  -A:  Run all APs.\n");
>>>> +  Print (L"  -O:  Run APs sequentially (use with -A).\n");
>>>> +  Print (L"  -T:  Specify timeout in milliseconds. Default is to wait
>>>> forever.\n");
>>>> +  Print (L"  -S:  Specify the single AP to run.\n");
>>>> +  Print (L"  -P:  Print processor information.\n");
>>>> +  Print (L"  -U:  Set the specified AP to the Unhealthy status (use
>>>> with -E/-D).\n");
>>>> +  Print (L"  -W:  Run WhoAmI and print index of BSP.\n");
>>>> +  Print (L"  -E:  Enable the specified AP.\n");
>>>> +  Print (L"  -D:  Disable the specified AP.\n");
>>>> +  Print (L"  -h:  Print this help page.\n");
>>>> +}
>>>> +
>>>> +/**
>>>> +  Parses any arguments provided on the command line.
>>>> +
>>>> +  @param Options  The arguments structure.
>>>> +
>>>> +  @return EFI_SUCCESS on success, or an error code.
>>>> +**/
>>>> +EFI_STATUS
>>>> +ParseArguments (
>>>> +  MP_SERVICES_TEST_OPTIONS  *Options
>>>> +  )
>>>> +{
>>>> +  EFI_STATUS    Status;
>>>> +  UINT32        ArgIndex;
>>> [KQ] Similar to the other comment, ArgIndex is of UINT32 is compared to
>>> Argc of UINTN could make some compilers unhappy.
>>>> +  CONST CHAR16  *Argument;
>>>> +  BOOLEAN       NeedsValue;
>>>> +  UINTN         *Value;
>>>> +
>>>> +  Status = GetArg ();
>>>> +  if (EFI_ERROR (Status)) {
>>>> +    Print (L"Please use the UEFI Shell to run this application!\n",
>>>> Status);
>>>> +    return Status;
>>>> +  }
>>>> +
>>>> +  if (Argc == 1) {
>>>> +    PrintUsage ();
>>>> +  }
>>>> +
>>>> +  ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
>>>> +
>>>> +  for (ArgIndex = 1; ArgIndex < Argc; ArgIndex++) {
>>>> +    Argument   = Argv[ArgIndex];
>>>> +    NeedsValue = FALSE;
>>>> +
>>>> +    if (StrCmp (Argument, L"-A") == 0) {
>>>> +      Options->RunAllAPs = TRUE;
>>>> +    } else if (StrCmp (Argument, L"-O") == 0) {
>>>> +      Options->RunAPsSequentially = TRUE;
>>>> +    } else if (StrCmp (Argument, L"-T") == 0) {
>>>> +      NeedsValue = TRUE;
>>>> +      Value      = &Options->Timeout;
>>>> +    } else if (StrCmp (Argument, L"-S") == 0) {
>>>> +      Options->RunSingleAP = TRUE;
>>>> +      NeedsValue           = TRUE;
>>>> +      Value                = &Options->ProcessorIndex;
>>>> +    } else if (StrCmp (Argument, L"-P") == 0) {
>>>> +      Options->PrintProcessorInformation = TRUE;
>>>> +    } else if (StrCmp (Argument, L"-U") == 0) {
>>>> +      Options->SetProcessorUnhealthy = TRUE;
>>>> +    } else if (StrCmp (Argument, L"-W") == 0) {
>>>> +      Options->PrintBspProcessorIndex = TRUE;
>>>> +    } else if (StrCmp (Argument, L"-E") == 0) {
>>>> +      Options->EnableProcessor = TRUE;
>>>> +      NeedsValue               = TRUE;
>>>> +      Value                    = &Options->ProcessorIndex;
>>>> +    } else if (StrCmp (Argument, L"-D") == 0) {
>>>> +      Options->DisableProcessor = TRUE;
>>>> +      NeedsValue                = TRUE;
>>>> +      Value                     = &Options->ProcessorIndex;
>>>> +    } else {
>>>> +      PrintUsage ();
>>>> +      ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
>>>> +      return EFI_SUCCESS;
>>>> +    }
>>>> +
>>>> +    if (NeedsValue) {
>>>> +      if ((ArgIndex + 1) < Argc) {
>>>> +        Status = StrDecimalToUintnS (Argv[ArgIndex + 1], NULL, Value);
>>>> +        if (EFI_ERROR (Status)) {
>>>> +          Print (L"Error: option value must be a positive integer.\n");
>>>> +          PrintUsage ();
>>>> +          return EFI_INVALID_PARAMETER;
>>>> +        }
>>>> +
>>>> +        ArgIndex++;
>>>> +      } else {
>>>> +        PrintUsage ();
>>>> +        return EFI_INVALID_PARAMETER;
>>>> +      }
>>>> +    }
>>>> +  }
>>>> +
>>>> +  return EFI_SUCCESS;
>>>> +}
>>
>>
>> 
>>
> 

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Ard Biesheuvel]

On Mon, 9 Jan 2023 at 15:25, Rebecca Cran <quic_rcran@quicinc.com> wrote:
>
> Thanks, I hadn't seen that. Unless people want the additional control
> this application provides via the command-line options, I can drop this
> patch.
>
> --
> Rebecca Cran
>
> On 1/8/23 18:32, Ni, Ray wrote:
> > Rebecca,
> > Have you reviewed UefiCpuPkg\Test\UnitTest\EfiMpServicesPpiProtocol? It's based on UnitTestFrameworkPkg for unit testing on MP PPI and MP protocol.
> > Do you think if the MpServicesTest app and the EfiMpServicesPpiProtocol have some overlapped functionalities?
> >

Having a shell app to run against the MP services protocol is rather
useful. Does a unit test provide the same functionality?

I am not talking about CI here but about diagnostics on an actual system.

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Ni, Ray]

UefiCpuPkg\Test\UnitTest\EfiMpServicesPpiProtocol\EfiMpServiceProtocolShellUnitTest.inf
can be used to build the shell app.

> -----Original Message-----
> From: Ard Biesheuvel <ardb@kernel.org>
> Sent: Tuesday, January 10, 2023 1:13 AM
> To: devel@edk2.groups.io; quic_rcran@quicinc.com
> Cc: Ni, Ray <ray.ni@intel.com>; Kun Qin <kuqin12@gmail.com>; Sami Mujawar <sami.mujawar@arm.com>; Ard Biesheuvel
> <ardb+tianocore@kernel.org>; Leif Lindholm <quic_llindhol@quicinc.com>; Wang, Jian J <jian.j.wang@intel.com>; Gao,
> Liming <gaoliming@byosoft.com.cn>; Tiger Liu <TigerLiu@zhaoxin.com>
> Subject: Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application
> 
> On Mon, 9 Jan 2023 at 15:25, Rebecca Cran <quic_rcran@quicinc.com> wrote:
> >
> > Thanks, I hadn't seen that. Unless people want the additional control
> > this application provides via the command-line options, I can drop this
> > patch.
> >
> > --
> > Rebecca Cran
> >
> > On 1/8/23 18:32, Ni, Ray wrote:
> > > Rebecca,
> > > Have you reviewed UefiCpuPkg\Test\UnitTest\EfiMpServicesPpiProtocol? It's based on UnitTestFrameworkPkg for unit
> testing on MP PPI and MP protocol.
> > > Do you think if the MpServicesTest app and the EfiMpServicesPpiProtocol have some overlapped functionalities?
> > >
> 
> Having a shell app to run against the MP services protocol is rather
> useful. Does a unit test provide the same functionality?
> 
> I am not talking about CI here but about diagnostics on an actual system.

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Rebecca Cran]

This is the current output of the EfiMpServiceProtocolShellUnitTest.
Many of the failures appear to be because one of the tests runs an 
infinite loop on the APs, and so subsequent requests to power them on 
fail because they're already running:

FS0:\> MpProtocolUnitTest.efi
InstallProtocolInterface: 5B1B31A1-9562-11D2-8E3F-00A0C969723B FCBC0DC0
add-symbol-file 
/home/rcran/src/upstream/uefi/Build/ArmJuno/NOOPT_GCC5/AARCH64/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServiceProtocolShellUnitTest/DEBUG/MpProtocolUnitTest.dll 
0xF8E7D000
Loading driver at 0x000F8E7C000 EntryPoint=0x000F8E7D000 
MpProtocolUnitTest.efi
InstallProtocolInterface: BC62157E-3E33-4FEC-9920-2D3B36D750DF FCBC0B18
ProtectUefiImageCommon - 0xFCBC0DC0
   - 0x00000000F8E7C000 - 0x0000000000014000
SetUefiImageMemoryAttributes - 0x00000000F8E7C000 - 0x0000000000001000 
(0x0000000000004008)
SetUefiImageMemoryAttributes - 0x00000000F8E7D000 - 0x0000000000011000 
(0x0000000000020008)
SetUefiImageMemoryAttributes - 0x00000000F8E8E000 - 0x0000000000002000 
(0x0000000000004008)
InstallProtocolInterface: 752F3136-4E16-4FDC-A22A-E5F46812F4CA FEFFF2A0
EfiMpServiceProtocol Unit Test v0.1
Adding Common Test case
Running All Test Suites
InitUTContext: BspNumber = 0x2
InitUTContext: NumberOfProcessors = 0x6, NumberOfEnabledProcessors = 0x6
NumberOfDisabledAPs: 0
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
PSCI_CPU_ON call failed: -4
CheckUTContext: New NumberOfEnabledProcessors = 0x5
CheckUTContext: AP(0x0) is disabled unexpectedly and reenable it.
SaveFrameworkState - Could not save state! Unsupported
---------------------------------------------------------
------------- UNIT TEST FRAMEWORK RESULTS ---------------
---------------------------------------------------------
/////////////////////////////////////////////////////////
   SUITE: Identify the currently executing processor
    PACKAGE: MpServices.WhoAmI
/////////////////////////////////////////////////////////
*********************************************************
   CLASS NAME: TestWhoAmI1
   TEST:    Test WhoAmI 1
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Suite Stats
  Passed:  1  (100)
  Failed:  0  (0)
  Not Run: 0  (0)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/////////////////////////////////////////////////////////
   SUITE: Retrieve the number of logical processor
    PACKAGE: MpServices.GetNumberOfProcessors
/////////////////////////////////////////////////////////
*********************************************************
   CLASS NAME: TestGetNumberOfProcessors1
   TEST:    Test GetNumberOfProcessors 1
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
*********************************************************
   CLASS NAME: TestGetNumberOfProcessors2
   TEST:    Test GetNumberOfProcessors 2
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
*********************************************************
   CLASS NAME: TestGetNumberOfProcessors3
   TEST:    Test GetNumberOfProcessors 3
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Suite Stats
  Passed:  3  (100)
  Failed:  0  (0)
  Not Run: 0  (0)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/////////////////////////////////////////////////////////
   SUITE: Get detailed information on the requested logical processor
    PACKAGE: MpServices.GetProcessorInfo
/////////////////////////////////////////////////////////
*********************************************************
   CLASS NAME: TestGetProcessorInfo1
   TEST:    Test GetProcessorInfo 1
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
*********************************************************
   CLASS NAME: TestGetProcessorInfo2
   TEST:    Test GetProcessorInfo 2
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Suite Stats
  Passed:  2  (100)
  Failed:  0  (0)
  Not Run: 0  (0)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/////////////////////////////////////////////////////////
   SUITE: Caller enables or disables an AP from this point onward
    PACKAGE: MpServices.EnableDisableAP
/////////////////////////////////////////////////////////
*********************************************************
   CLASS NAME: TestEnableDisableAP1
   TEST:    Test EnableDisableAP 1
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
*********************************************************
   CLASS NAME: TestEnableDisableAP2
   TEST:    Test EnableDisableAP 2
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
*********************************************************
   CLASS NAME: TestEnableDisableAP3
   TEST:    Test EnableDisableAP 3
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Suite Stats
  Passed:  3  (100)
  Failed:  0  (0)
  Not Run: 0  (0)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/////////////////////////////////////////////////////////
   SUITE: Get the requested AP to execute a caller-provided function
    PACKAGE: MpServices.StartupThisAP
/////////////////////////////////////////////////////////
*********************************************************
   CLASS NAME: TestStartupThisAP1
   TEST:    Test StartupThisAP 1
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
*********************************************************
   CLASS NAME: TestStartupThisAP2
   TEST:    Test StartupThisAP 2
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
*********************************************************
   CLASS NAME: TestStartupThisAP3
   TEST:    Test StartupThisAP 3
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
*********************************************************
   CLASS NAME: TestStartupThisAP4
   TEST:    Test StartupThisAP 4
   STATUS:  FAILED
   FAILURE: ASSERT_NOTEFIERROR FAILURE
   FAILURE MESSAGE:
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1118
   LOG:
[ERROR]       [ASSERT FAIL] 
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1118: 
Status 'Status' is EFI_ERROR (Unsupported)!
**********************************************************
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Suite Stats
  Passed:  3  (75)
  Failed:  1  (25)
  Not Run: 0  (0)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/////////////////////////////////////////////////////////
   SUITE: Execute a caller provided function on all enabled APs
    PACKAGE: MpServices.StartupAllAPs
/////////////////////////////////////////////////////////
*********************************************************
   CLASS NAME: TestStartupAllAPs1
   TEST:    Test StartupAllAPs 1
   STATUS:  FAILED
   FAILURE: ASSERT_NOTEFIERROR FAILURE
   FAILURE MESSAGE:
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1181
   LOG:
[ERROR]       [ASSERT FAIL] 
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1181: 
Status 'Status' is EFI_ERROR (Not Ready)!
**********************************************************
*********************************************************
   CLASS NAME: TestStartupAllAPs2
   TEST:    Test StartupAllAPs 2
   STATUS:  FAILED
   FAILURE: ASSERT_NOTEFIERROR FAILURE
   FAILURE MESSAGE:
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1224
   LOG:
[ERROR]       [ASSERT FAIL] 
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1224: 
Status 'Status' is EFI_ERROR (Not Ready)!
**********************************************************
*********************************************************
   CLASS NAME: TestStartupAllAPs3
   TEST:    Test StartupAllAPs 3
   STATUS:  FAILED
   FAILURE: ASSERT_NOTEFIERROR FAILURE
   FAILURE MESSAGE:
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1275
   LOG:
[ERROR]       [ASSERT FAIL] 
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1275: 
Status 'Status' is EFI_ERROR (Not Ready)!
**********************************************************
*********************************************************
   CLASS NAME: TestStartupAllAPs4
   TEST:    Test StartupAllAPs 4
   STATUS:  FAILED
   FAILURE: ASSERT_STATUSEQUAL FAILURE
   FAILURE MESSAGE:
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1311
   LOG:
[ERROR]       [ASSERT FAIL] 
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1311: 
Status 'Status' is Not Ready, should be Time out!
**********************************************************
*********************************************************
   CLASS NAME: TestStartupAllAPs5
   TEST:    Test StartupAllAPs 5
   STATUS:  PASSED
   FAILURE: NO FAILURE
   FAILURE MESSAGE:

**********************************************************
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Suite Stats
  Passed:  1  (20)
  Failed:  4  (80)
  Not Run: 0  (0)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/////////////////////////////////////////////////////////
   SUITE: Switch the requested AP to be the BSP from that point onward
    PACKAGE: MpServices.SwitchBSP
/////////////////////////////////////////////////////////
*********************************************************
   CLASS NAME: TestSwitchBSP1
   TEST:    Test SwitchBSP 1
   STATUS:  FAILED
   FAILURE: ASSERT_NOTEFIERROR FAILURE
   FAILURE MESSAGE:
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1426
   LOG:
[ERROR]       [ASSERT FAIL] 
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1426: 
Status 'Status' is EFI_ERROR (Unsupported)!
**********************************************************
*********************************************************
   CLASS NAME: TestSwitchBSP2
   TEST:    Test SwitchBSP 2
   STATUS:  FAILED
   FAILURE: ASSERT_NOTEFIERROR FAILURE
   FAILURE MESSAGE:
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1492
   LOG:
[ERROR]       [ASSERT FAIL] 
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1492: 
Status 'Status' is EFI_ERROR (Not Ready)!
**********************************************************
*********************************************************
   CLASS NAME: TestSwitchBSP3
   TEST:    Test SwitchBSP 3
   STATUS:  FAILED
   FAILURE: ASSERT_STATUSEQUAL FAILURE
   FAILURE MESSAGE:
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1540
   LOG:
[ERROR]       [ASSERT FAIL] 
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1540: 
Status 'Status' is Unsupported, should be Invalid Parameter!
**********************************************************
*********************************************************
   CLASS NAME: TestSwitchBSP4
   TEST:    Test SwitchBSP 4
   STATUS:  FAILED
   FAILURE: ASSERT_NOTEFIERROR FAILURE
   FAILURE MESSAGE:
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1591
   LOG:
[ERROR]       [ASSERT FAIL] 
/home/rcran/src/upstream/uefi/edk2/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServicesUnitTestCommon.c:1591: 
Status 'Status' is EFI_ERROR (Unsupported)!
**********************************************************
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Suite Stats
  Passed:  0  (0)
  Failed:  4  (100)
  Not Run: 0  (0)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
=========================================================
Total Stats
  Passed:  13  (59)
  Failed:  9  (40)
  Not Run: 0  (0)
=========================================================
SetUefiImageMemoryAttributes - 0x00000000F8E7C000 - 0x0000000000014000 
(0x0000000000000008)
remove-symbol-file 
/home/rcran/src/upstream/uefi/Build/ArmJuno/NOOPT_GCC5/AARCH64/UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServiceProtocolShellUnitTest/DEBUG/MpProtocolUnitTest.dll 
0xF8E7D000


On 1/9/23 18:08, Ni, Ray wrote:
> UefiCpuPkg\Test\UnitTest\EfiMpServicesPpiProtocol\EfiMpServiceProtocolShellUnitTest.inf
> can be used to build the shell app.
> 
>> -----Original Message-----
>> From: Ard Biesheuvel <ardb@kernel.org>
>> Sent: Tuesday, January 10, 2023 1:13 AM
>> To: devel@edk2.groups.io; quic_rcran@quicinc.com
>> Cc: Ni, Ray <ray.ni@intel.com>; Kun Qin <kuqin12@gmail.com>; Sami Mujawar <sami.mujawar@arm.com>; Ard Biesheuvel
>> <ardb+tianocore@kernel.org>; Leif Lindholm <quic_llindhol@quicinc.com>; Wang, Jian J <jian.j.wang@intel.com>; Gao,
>> Liming <gaoliming@byosoft.com.cn>; Tiger Liu <TigerLiu@zhaoxin.com>
>> Subject: Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application
>>
>> On Mon, 9 Jan 2023 at 15:25, Rebecca Cran <quic_rcran@quicinc.com> wrote:
>>>
>>> Thanks, I hadn't seen that. Unless people want the additional control
>>> this application provides via the command-line options, I can drop this
>>> patch.
>>>
>>> --
>>> Rebecca Cran
>>>
>>> On 1/8/23 18:32, Ni, Ray wrote:
>>>> Rebecca,
>>>> Have you reviewed UefiCpuPkg\Test\UnitTest\EfiMpServicesPpiProtocol? It's based on UnitTestFrameworkPkg for unit
>> testing on MP PPI and MP protocol.
>>>> Do you think if the MpServicesTest app and the EfiMpServicesPpiProtocol have some overlapped functionalities?
>>>>
>>
>> Having a shell app to run against the MP services protocol is rather
>> useful. Does a unit test provide the same functionality?
>>
>> I am not talking about CI here but about diagnostics on an actual system.
> 
> 
> 
> 
> 

Re: [edk2-devel] [PATCH v4 3/3] MdeModulePkg: Add new Application/MpServicesTest application

[Laszlo Ersek]

I've taken an interest in this utility, because I think it should be
utilized in CI, if possible, for testing the firmware's multiprocessing
capabilities. (+Oliver +Gerd.) Some superficial comments below (I'm not
requesting v5, because I'm joining this review very-very late; feel free
to update it if you wish later on).

On 1/4/23 16:37, Rebecca Cran wrote:
> The MpServicesTest application exercises the EFI_MP_SERVICES_PROTOCOL.
> 
> usage:
>   MpServicesTest -A [-O]
>   MpServicesTest -T <Timeout>
>   MpServicesTest -S <Processor #>
>   MpServicesTest -P
>   MpServicesTest -U
>   MpServicesTest -W
>   MpServicesTest -E <Processor #>
>   MpServicesTest -D <Processor #>
>   MpServicesTest -h
> 
> Parameter:
>   -A:  Run all APs.
>   -O:  Run APs sequentially (use with -A).
>   -T:  Specify timeout in milliseconds. Default is to wait forever.
>   -S:  Specify the single AP to run.
>   -P:  Print processor information.
>   -U:  Set the specified AP to the Unhealthy status (use with -E/-D).
>   -W:  Run WhoAmI and print index of BSP.
>   -E:  Enable the specified AP.
>   -D:  Disable the specified AP.
>   -h:  Print this help page.
> 
> Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
> ---
>  MdeModulePkg/MdeModulePkg.dsc                              |   2 +
>  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf |  40 ++
>  MdeModulePkg/Application/MpServicesTest/Options.h          |  39 ++
>  MdeModulePkg/Application/MpServicesTest/MpServicesTest.c   | 560 ++++++++++++++++++++
>  MdeModulePkg/Application/MpServicesTest/Options.c          | 164 ++++++
>  5 files changed, 805 insertions(+)
> 
> diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
> index 659482ab737f..6992b3ae8db6 100644
> --- a/MdeModulePkg/MdeModulePkg.dsc
> +++ b/MdeModulePkg/MdeModulePkg.dsc
> @@ -166,6 +166,7 @@ [LibraryClasses.common.UEFI_APPLICATION]
>    MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>    DebugLib|MdePkg/Library/UefiDebugLibStdErr/UefiDebugLibStdErr.inf
>    FileHandleLib|MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.inf
> +  ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
>  
>  [LibraryClasses.common.MM_STANDALONE]
>    HobLib|MdeModulePkg/Library/BaseHobLibNull/BaseHobLibNull.inf
> @@ -445,6 +446,7 @@ [Components]
>    MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
>  
>  [Components.IA32, Components.X64, Components.AARCH64]
> +  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
>    MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
>    MdeModulePkg/Universal/EbcDxe/EbcDebugger.inf
>    MdeModulePkg/Universal/EbcDxe/EbcDebuggerConfig.inf
> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> new file mode 100644
> index 000000000000..07ee4afec845
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf
> @@ -0,0 +1,40 @@
> +## @file
> +#  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
> +#
> +#  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 1.29
> +  BASE_NAME                      = MpServicesTest
> +  FILE_GUID                      = 43e9defa-7209-4b0d-b136-cc4ca02cb469
> +  MODULE_TYPE                    = UEFI_APPLICATION
> +  VERSION_STRING                 = 0.1
> +  ENTRY_POINT                    = UefiMain
> +
> +#
> +# The following information is for reference only and not required by the build tools.
> +#
> +#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
> +#
> +
> +[Sources]
> +  MpServicesTest.c
> +  Options.c
> +  Options.h
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> +  BaseLib
> +  ShellLib
> +  UefiApplicationEntryPoint
> +  UefiLib
> +
> +[Protocols]
> +  gEfiMpServiceProtocolGuid    ## CONSUMES
> +
> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.h b/MdeModulePkg/Application/MpServicesTest/Options.h
> new file mode 100644
> index 000000000000..cb28230ab095
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/Options.h
> @@ -0,0 +1,39 @@
> +/** @file
> +  Options handling code.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#ifndef MPSERVICESTEST_OPTIONS_H_
> +#define MPSERVICESTEST_OPTIONS_H_
> +
> +#define INFINITE_TIMEOUT  0
> +
> +typedef struct {
> +  UINTN      Timeout;
> +  UINTN      ProcessorIndex;
> +  BOOLEAN    RunAllAPs;
> +  BOOLEAN    RunSingleAP;
> +  BOOLEAN    DisableProcessor;
> +  BOOLEAN    EnableProcessor;
> +  BOOLEAN    SetProcessorHealthy;
> +  BOOLEAN    SetProcessorUnhealthy;
> +  BOOLEAN    PrintProcessorInformation;
> +  BOOLEAN    PrintBspProcessorIndex;
> +  BOOLEAN    RunAPsSequentially;
> +} MP_SERVICES_TEST_OPTIONS;
> +
> +/**
> +  Parses any arguments provided on the command line.
> +
> +  @param Options  The arguments structure.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +EFI_STATUS
> +ParseArguments (
> +  MP_SERVICES_TEST_OPTIONS  *Options
> +  );
> +
> +#endif /* MPSERVICESTEST_OPTIONS_H_ */
> diff --git a/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
> new file mode 100644
> index 000000000000..3f3d9752d500
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/MpServicesTest.c
> @@ -0,0 +1,560 @@
> +/** @file
> +  UEFI Application to exercise EFI_MP_SERVICES_PROTOCOL.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#include <Uefi.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/MemoryAllocationLib.h>
> +#include <Library/PrintLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Library/UefiLib.h>
> +#include <Pi/PiMultiPhase.h>
> +#include <Protocol/MpService.h>
> +
> +#include "Options.h"
> +
> +#define APFUNC_BUFFER_LEN  256
> +
> +typedef struct {
> +  EFI_MP_SERVICES_PROTOCOL    *Mp;
> +  CHAR16                      **Buffer;
> +} APFUNC_ARG;

While you need to allocate Buffer dynamically, I think you need not
allocate the string pointed-to by Buffer[N] dynamically; can you just do:

  CHAR16 (*Buffer)[APFUNC_BUFFER_LEN];

?

It is indeed one of those rare cases when we don't want an array of
pointers, but a pointer to an array. (Effectively an array of arrays.)

It's quite funny that I explained precisely this syntax to my son a few
hours ago. :)

> +
> +/** The procedure to run with the MP Services interface.
> +
> +  @param Arg The procedure argument.
> +
> +**/
> +STATIC
> +VOID
> +EFIAPI
> +ApFunction (
> +  IN OUT VOID  *Arg
> +  )
> +{
> +  APFUNC_ARG  *Param;
> +  UINTN       ProcessorId;
> +
> +  if (Arg != NULL) {
> +    Param = Arg;
> +
> +    Param->Mp->WhoAmI (Param->Mp, &ProcessorId);
> +    UnicodeSPrint (Param->Buffer[ProcessorId], APFUNC_BUFFER_LEN, L"Hello from CPU %ld\n", ProcessorId);

- "%d" is not a proper conversion specifier for UINTN. The proper way to
format UINTN in decimal is to cast the UINTN to UINT64, and then use
"%Lu" (or "%lu", equivalently).

- you need to make sure that the application is built with the
MdePkg/Library/BasePrintLib instance, and not with the
MdeModulePkg/Library/DxePrintLibPrint2Protocol instance. Protocol usage
from multiple processors is generally not permitted (there are exceptions).

> +  }
> +}
> +
> +/**
> +  Fetches the number of processors and which processor is the BSP.
> +
> +  @param Mp  MP Services Protocol.
> +  @param NumProcessors Number of processors.
> +  @param BspIndex      The index of the BSP.
> +**/
> +STATIC
> +EFI_STATUS
> +GetProcessorInformation (
> +  IN  EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  OUT UINTN                     *NumProcessors,
> +  OUT UINTN                     *BspIndex
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINTN       NumEnabledProcessors;
> +
> +  Status = Mp->GetNumberOfProcessors (Mp, NumProcessors, &NumEnabledProcessors);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Status = Mp->WhoAmI (Mp, BspIndex);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Displays information returned from MP Services Protocol.
> +
> +  @param Mp       The MP Services Protocol
> +  @param BspIndex On return, contains the index of the BSP.
> +
> +  @return The number of CPUs in the system.
> +
> +**/
> +STATIC
> +UINTN
> +PrintProcessorInformation (
> +  IN   EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  OUT  UINTN                     *BspIndex
> +  )
> +{
> +  EFI_STATUS                 Status;
> +  EFI_PROCESSOR_INFORMATION  CpuInfo;
> +  UINTN                      Index;
> +  UINTN                      NumCpu;
> +  UINTN                      NumEnabledCpu;
> +
> +  Status = Mp->GetNumberOfProcessors (Mp, &NumCpu, &NumEnabledCpu);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"GetNumberOfProcessors failed: %r\n", Status);
> +  } else {
> +    Print (L"Number of CPUs: %ld, Enabled: %d\n", NumCpu, NumEnabledCpu);

Same formatting comment about %d.

> +  }
> +
> +  for (Index = 0; Index < NumCpu; Index++) {

If getting NumCpu above failed, this is undefined behavior (NumCpu will
have indeterminate value).

> +    Status = Mp->GetProcessorInfo (Mp, CPU_V2_EXTENDED_TOPOLOGY | Index, &CpuInfo);
> +    if (EFI_ERROR (Status)) {
> +      Print (L"GetProcessorInfo for Processor %d failed: %r\n", Index, Status);
> +    } else {
> +      Print (
> +        L"Processor %d:\n"

Same comment -- Index is UINTN.

> +        L"\tID: %016lx\n"
> +        L"\tStatus: %s | ",
> +        Index,
> +        CpuInfo.ProcessorId,
> +        (CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) ? L"BSP" : L"AP"

I *think* the edk2 coding style requries an explicit comparison against
0 here, such as in (a & b) != 0; but if Uncrustify is fine with this,
who am I to complain? :)

> +        );
> +
> +      if ((CpuInfo.StatusFlag & PROCESSOR_AS_BSP_BIT) && (BspIndex != NULL)) {

Same comment here.

> +        *BspIndex = Index;
> +      }
> +
> +      Print (L"%s | ", (CpuInfo.StatusFlag & PROCESSOR_ENABLED_BIT) ? L"Enabled" : L"Disabled");
> +      Print (L"%s\n", (CpuInfo.StatusFlag & PROCESSOR_HEALTH_STATUS_BIT) ? L"Healthy" : L"Faulted");
> +
> +      Print (
> +        L"\tLocation: Package %d, Core %d, Thread %d\n"
> +        L"\tExtended Information: Package %d, Module %d, Tile %d, Die %d, Core %d, Thread %d\n\n",
> +        CpuInfo.Location.Package,
> +        CpuInfo.Location.Core,
> +        CpuInfo.Location.Thread,
> +        CpuInfo.ExtendedInformation.Location2.Package,
> +        CpuInfo.ExtendedInformation.Location2.Module,
> +        CpuInfo.ExtendedInformation.Location2.Tile,
> +        CpuInfo.ExtendedInformation.Location2.Die,
> +        CpuInfo.ExtendedInformation.Location2.Core,
> +        CpuInfo.ExtendedInformation.Location2.Thread

All UINT32's, please use %u for them

BTW was this built for all of ARM / AARCH64 / IA32 / X64?

> +        );
> +    }
> +  }
> +
> +  return NumCpu;

If getting NumCpu at the top failed, this returns an indeterminate value
-- undefined behavior.

I think this function can actually return VOID. See near the call site,
later, why.


> +}
> +
> +/** Allocates memory in ApArg for the single AP specified.
> +
> +  @param ApArg          Pointer to the AP argument structure.
> +  @param Mp             The MP Services Protocol.
> +  @param ProcessorIndex The index of the AP.
> +
> +  @retval EFI_SUCCESS          Memory was successfully allocated.
> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +AllocateApFuncBufferSingleAP (
> +  IN APFUNC_ARG                *ApArg,
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     ProcessorIndex
> +  )
> +{
> +  ApArg->Mp = Mp;
> +
> +  ApArg->Buffer = AllocateZeroPool ((ProcessorIndex + 1) * sizeof (VOID *));

The way to write this with the least thinking is always

  Ptr = Allocate[Zero]Pool (NumberOfElements * sizeof *Ptr);

by which I want to highlight the "sizeof *Ptr" part. Will always have
the correct size, even if you change the element (or otherwise
pointed-to) type, and survives renaming the type, too.

Will translate transparently to my suggestion at the top, i.e. if you
change the element type from pointer to array.

Just a suggestion.

> +  if (ApArg->Buffer == NULL) {
> +    Print (L"Failed to allocate buffer for AP buffer\n");
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  ApArg->Buffer[ProcessorIndex] = AllocateZeroPool (APFUNC_BUFFER_LEN);
> +  if (ApArg->Buffer[ProcessorIndex] == NULL) {
> +    Print (L"Failed to allocate buffer for AP buffer\n");
> +    FreePool (ApArg->Buffer);
> +    return EFI_OUT_OF_RESOURCES;
> +  }

Then this separate allocation can be dropped.

> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Allocates memory in ApArg for all APs.
> +
> +  @param ApArg   Pointer to the AP argument structure.
> +  @param Mp      The MP Services Protocol.
> +  @param NumCpus The number of CPUs.
> +
> +  @retval EFI_SUCCESS          Memory was successfully allocated.
> +  @retval EFI_OUT_OF_RESOURCES Failed to allocate memory.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +AllocateApFuncBufferAllAPs (
> +  IN APFUNC_ARG                *ApArg,
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     NumCpus
> +  )
> +{
> +  UINT32  Index;
> +
> +  ApArg->Mp = Mp;
> +
> +  ApArg->Buffer = AllocateZeroPool (NumCpus * sizeof (VOID *));

Same recommendation here.

> +  if (ApArg->Buffer == NULL) {
> +    Print (L"Failed to allocate buffer for AP message\n");
> +    return EFI_OUT_OF_RESOURCES;
> +  }
> +
> +  for (Index = 0; Index < NumCpus; Index++) {
> +    ApArg->Buffer[Index] = AllocateZeroPool (APFUNC_BUFFER_LEN);
> +    if (ApArg->Buffer[Index] == NULL) {
> +      Print (L"Failed to allocate buffer for AP message\n");
> +      for (--Index; Index >= 0; Index++) {
> +        FreePool (ApArg->Buffer[Index]);
> +      }
> +
> +      FreePool (ApArg->Buffer);
> +      return EFI_OUT_OF_RESOURCES;
> +    }
> +  }

And then you can remove the second set of allocations (one fewer
indirections, again).

... Which is useful for a different reason too: your rollback
(releasing) logic is wrong. Note that "Index" has type UINT32, and
because of that, your loop controlling expression

  Index >= 0

is a tautology; it can never evaluate to false.

Plus, I don't really understand the "Index++" as the third expression in
there. Probably a typo and you meant "Index--".


Anyway, I do love this pattern; however, I like to write it like this:

{
  for (Index = 0; Index < NumCpus; Index++) {
    VOID *Buf;

    Buf = AllocateZeroPool (APFUNC_BUFFER_LEN);
    if (Buf == NULL) {
      Status = EFI_OUT_OF_RESOURCES;
      goto Release;
    }
    ApArg->Buffer[Index] = Buf;
  }

  return EFI_SUCCESS;

Release:
  while (Index > 0) {
    --Index;
    FreePool (ApArg->Buffer[Index]);
    ApArg->Buffer[Index] = NULL;
  }
  return Status;
}

(I've omitted the freeing of ApArg->Buffer itself.)

Worth noting:

- due to the goto and the separate Status variable, it composes well
with further rollback steps if you need to extend the set of allocated
resources later

- the release loop counts down exactly as many times as it needs to.
This pattern is *required* for *precisely reversing* the original "for"
loop that did the allocations.

Some people counter-propose this:

  for (; Index-- > 0; ) {
    FreePool (ApArg->Buffer[Index]);
    ApArg->Buffer[Index] = NULL;
  }

where they jokingly call the "-- >" tokens (operators), read together as
"-->", the "downto" operator.

But this is not identical: when this latter loop completes, it will set
Index to (UINT32)-1, rather than 0, and so Index will no longer reflect
the number of elements present in the array. The problem is that, even
when Index is already zero and so we don't enter the loop body, the
post-decrement still happens.

The while loop I propose does set Index to the number of elements left
in the array: it ends with Index==0.

Anyway, end of detour.


One more note: if you change the element type like I propose, then both
functions coalesce to just one. You can no longer allocate the buffer
just for the Nth processor, you simply can't avoid allocating the
buffers for all the previous processors too.

But that's a plus!

> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Frees memory in ApArg for all APs.
> +
> +  @param ApArg   Pointer to the AP argument structure.
> +  @param NumCpus The number of CPUs.
> +
> +**/
> +STATIC
> +VOID
> +FreeApFuncBuffer (
> +  APFUNC_ARG  *ApArg,
> +  UINTN       NumCpus
> +  )
> +{
> +  UINTN  Index;
> +
> +  for (Index = 0; Index < NumCpus; Index++) {
> +    if (ApArg->Buffer[Index] != NULL) {
> +      FreePool (ApArg->Buffer[Index]);
> +    }
> +  }
> +
> +  FreePool (ApArg->Buffer);
> +}
> +
> +/** Runs a specified AP.
> +
> +  @param Mp             The MP Services Protocol.
> +  @param ProcessorIndex The processor index.
> +  @param Timeout        Timeout in milliseconds.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +StartupThisAP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     ProcessorIndex,
> +  IN UINTN                     Timeout
> +  )
> +{
> +  EFI_STATUS  Status;
> +  APFUNC_ARG  ApArg;
> +
> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Status = AllocateApFuncBufferSingleAP (&ApArg, Mp, ProcessorIndex);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }

This looks like a copy-paste error to me. It leaks memory, I believe.

> +
> +  Print (
> +    L"StartupThisAP on Processor %d with %d%s timeout...",
> +    ProcessorIndex,
> +    Timeout,

Both are UINTNs, so %d is not a good match for printing them.

> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
> +    );
> +  Status = Mp->StartupThisAP (
> +                 Mp,
> +                 ApFunction,
> +                 ProcessorIndex,
> +                 NULL,
> +                 Timeout * 1000,
> +                 &ApArg,
> +                 NULL
> +                 );
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +    return Status;

you leak the buffers here, suggest reworking with gotos

> +  } else {

else-after-return is a wart, I suggest dropping the "else" and unnesting
its branch body.

> +    Print (L"done.\n");
> +    Print (ApArg.Buffer[ProcessorIndex]);
> +  }
> +
> +  FreeApFuncBuffer (&ApArg, ProcessorIndex + 1);
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/** Runs all APs.
> +
> +  @param Mp                 The MP Services Protocol.
> +  @param NumCpus            The number of CPUs in the system.
> +  @param Timeout            Timeout in milliseconds.
> +  @param RunAPsSequentially Run APs sequentially (FALSE: run simultaneously)
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +StartupAllAPs (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  IN UINTN                     NumCpus,
> +  IN UINTN                     Timeout,
> +  IN BOOLEAN                   RunAPsSequentially
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINTN       Index;
> +  APFUNC_ARG  ApArg;
> +
> +  Status = AllocateApFuncBufferAllAPs (&ApArg, Mp, NumCpus);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Print (
> +    L"Running with SingleThread %s, %u%s timeout...",
> +    (RunAPsSequentially) ? L"TRUE" : L"FALSE",
> +    Timeout,

%u is not a good fit for UINTN

> +    (Timeout == INFINITE_TIMEOUT) ? L" (infinite)" : L"ms"
> +    );
> +
> +  Status = Mp->StartupAllAPs (
> +                 Mp,
> +                 ApFunction,
> +                 RunAPsSequentially,
> +                 NULL,
> +                 Timeout * 1000,
> +                 &ApArg,
> +                 NULL
> +                 );
> +
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +
> +    return Status;

you leak the buffers here, suggest reworking with goto

> +  } else {
> +    Print (L"done.\n");
> +
> +    for (Index = 0; Index < NumCpus; Index++) {
> +      Print (ApArg.Buffer[Index]);

Hm, I think this deserves a code comment. The array includes an entry
for the BSP too, and that entry will never be populated. But that's OK,
because it is NUL-initialized, so this Print will not output any
characters for that entry.

> +    }
> +  }
> +
> +  FreeApFuncBuffer (&ApArg, NumCpus);
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  Enables the specified AP.
> +
> +  @param Mp               The MP Services Protocol.
> +  @param ProcessorIndex   The processor to enable.
> +  @param ProcessorHealthy The health status of the processor.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +STATIC
> +EFI_STATUS
> +EnableAP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  UINTN                        ProcessorIndex,
> +  BOOLEAN                      ProcessorHealthy
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINT32      HealthFlag;
> +
> +  if (ProcessorHealthy) {
> +    Print (L"Enabling Processor %d with HealthFlag healthy...", ProcessorIndex);
> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
> +  } else {
> +    Print (L"Enabling Processor %d with HealthFlag faulted...", ProcessorIndex);
> +    HealthFlag = 0;
> +  }

%d vs. UINTN

> +
> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, TRUE, &HealthFlag);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +    return Status;
> +  } else {

else-after-return

> +    Print (L"done.\n");
> +  }
> +
> +  return Status;
> +}
> +
> +/**
> +  Disables the specified AP.
> +
> +  @param Mp               The MP Services Protocol.
> +  @param ProcessorIndex   The processor to disable.
> +  @param ProcessorHealthy The health status of the processor.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +STATIC
> +EFI_STATUS
> +DisableAP (
> +  IN EFI_MP_SERVICES_PROTOCOL  *Mp,
> +  UINTN                        ProcessorIndex,
> +  BOOLEAN                      ProcessorHealthy
> +  )
> +{
> +  EFI_STATUS  Status;
> +  UINT32      HealthFlag;
> +
> +  if (ProcessorHealthy) {
> +    Print (L"Disabling Processor %d with HealthFlag healthy...", ProcessorIndex);
> +    HealthFlag = PROCESSOR_HEALTH_STATUS_BIT;
> +  } else {
> +    Print (L"Disabling Processor %d with HealthFlag faulted...", ProcessorIndex);
> +    HealthFlag = 0;
> +  }

%d vs UINTN

> +
> +  Status = Mp->EnableDisableAP (Mp, ProcessorIndex, FALSE, &HealthFlag);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"failed: %r\n", Status);
> +    return Status;
> +  } else {

else-after-return

> +    Print (L"done.\n");
> +  }
> +
> +  return Status;
> +}
> +
> +/**
> +  The user Entry Point for Application. The user code starts with this function
> +  as the real entry point for the application.
> +
> +  @param[in] ImageHandle    The firmware allocated handle for the EFI image.
> +  @param[in] SystemTable    A pointer to the EFI System Table.
> +
> +  @retval EFI_SUCCESS       The entry point is executed successfully.
> +  @retval other             Some error occurs when executing this entry point.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +UefiMain (
> +  IN EFI_HANDLE        ImageHandle,
> +  IN EFI_SYSTEM_TABLE  *SystemTable
> +  )
> +{
> +  EFI_STATUS                Status;
> +  EFI_MP_SERVICES_PROTOCOL  *Mp;
> +  UINTN                     BspIndex;
> +  UINTN                     CpuIndex;
> +  UINTN                     NumCpus;
> +  BOOLEAN                   ProcessorHealthy;
> +  MP_SERVICES_TEST_OPTIONS  Options;
> +
> +  BspIndex = 0;
> +
> +  Status = gBS->LocateProtocol (
> +                  &gEfiMpServiceProtocolGuid,
> +                  NULL,
> +                  (VOID **)&Mp
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    Print (L"Failed to locate EFI_MP_SERVICES_PROTOCOL (%r). Not installed on platform?\n", Status);
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  Status = ParseArguments (&Options);
> +  if (EFI_ERROR (Status)) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  Status = GetProcessorInformation (Mp, &NumCpus, &BspIndex);
> +  if (EFI_ERROR (Status)) {
> +    Print (L"Error: Failed to fetch processor information.\n");
> +    return Status;
> +  }

I suggest reordering these two steps (ParseArguments and
GetProcessorInformation), and then passing NumCpus to ParseArguments.
I'll explain below why.

> +
> +  if (Options.PrintBspProcessorIndex) {
> +    Status = Mp->WhoAmI (Mp, &CpuIndex);
> +    if (EFI_ERROR (Status)) {
> +      Print (L"WhoAmI failed: %r\n", Status);
> +      return Status;
> +    } else {

else-after-return

> +      Print (L"BSP: %016lx\n", CpuIndex);

%lx is not good for UINTN on 32-bit (ARM, IA32).

> +    }
> +  }
> +
> +  if (Options.PrintProcessorInformation) {
> +    NumCpus = PrintProcessorInformation (Mp, &BspIndex);
> +    if (NumCpus < 2) {
> +      Print (L"Error: Uniprocessor system found.\n");
> +      return EFI_INVALID_PARAMETER;
> +    }

I don't understand the logic here.

First, why it's important that we have at least one AP.

Second, if it *is* important, then why only in case the user wants to
print the information?

Also, you are overwriting "NumCpus", which you fetched above with
GetProcessorInformation().

I think it's not needed for PrintProcessorInformation() to return a value.

Same for BspIndex -- you are overwriting it.

But, most surprisingly, "BspIndex" is not used for anything later on. So
I think neither GetProcessorInformation() nor
PrintProcessorInformation() need to output it.

Hm, maybe you wanted to remove "CpuIndex" instead (with the accompanying
WhoAmI() call), and rely on the output of GetProcessorInformation() instead?

> +  }
> +
> +  if (Options.RunSingleAP) {
> +    Status = StartupThisAP (
> +               Mp,
> +               Options.ProcessorIndex,
> +               Options.Timeout
> +               );
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  if (Options.RunAllAPs) {
> +    Status = StartupAllAPs (Mp, NumCpus, Options.Timeout, Options.RunAPsSequentially);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  if (Options.EnableProcessor) {
> +    ProcessorHealthy = TRUE;
> +    if (Options.SetProcessorUnhealthy) {
> +      ProcessorHealthy = FALSE;
> +    }
> +
> +    Status = EnableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  if (Options.DisableProcessor) {
> +    ProcessorHealthy = TRUE;
> +    if (Options.SetProcessorUnhealthy) {
> +      ProcessorHealthy = FALSE;
> +    }
> +
> +    Status = DisableAP (Mp, Options.ProcessorIndex, ProcessorHealthy);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  return EFI_SUCCESS;
> +}
> diff --git a/MdeModulePkg/Application/MpServicesTest/Options.c b/MdeModulePkg/Application/MpServicesTest/Options.c
> new file mode 100644
> index 000000000000..e820c061e1ec
> --- /dev/null
> +++ b/MdeModulePkg/Application/MpServicesTest/Options.c
> @@ -0,0 +1,164 @@
> +/** @file
> +  Options handling code.
> +
> +  Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.<BR>
> +  Copyright (c) 2010-2019  Finnbarr P. Murphy.   All rights reserved.<BR>
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#include <Uefi.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Protocol/ShellParameters.h>
> +#include <Library/BaseLib.h>
> +#include <Library/UefiLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +
> +#include "Options.h"
> +
> +STATIC UINTN   Argc;
> +STATIC CHAR16  **Argv;
> +
> +/**
> +
> +  This function provides argc and argv.
> +
> +  @return Status
> +**/
> +EFI_STATUS
> +GetArg (
> +  VOID
> +  )
> +{
> +  EFI_STATUS                     Status;
> +  EFI_SHELL_PARAMETERS_PROTOCOL  *ShellParameters;
> +
> +  Status = gBS->HandleProtocol (
> +                  gImageHandle,
> +                  &gEfiShellParametersProtocolGuid,
> +                  (VOID **)&ShellParameters
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Argc = ShellParameters->Argc;
> +  Argv = ShellParameters->Argv;
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  Print app usage.
> +**/
> +STATIC
> +VOID
> +PrintUsage (
> +  VOID
> +  )
> +{
> +  Print (L"MpServicesTest:  usage\n");
> +  Print (L"  MpServicesTest -A [-O]\n");
> +  Print (L"  MpServicesTest -T <Timeout>\n");
> +  Print (L"  MpServicesTest -S <Processor #>\n");
> +  Print (L"  MpServicesTest -P\n");
> +  Print (L"  MpServicesTest -U\n");
> +  Print (L"  MpServicesTest -W\n");
> +  Print (L"  MpServicesTest -E <Processor #>\n");
> +  Print (L"  MpServicesTest -D <Processor #>\n");
> +  Print (L"  MpServicesTest -h\n");
> +  Print (L"Parameter:\n");
> +  Print (L"  -A:  Run all APs.\n");
> +  Print (L"  -O:  Run APs sequentially (use with -A).\n");
> +  Print (L"  -T:  Specify timeout in milliseconds. Default is to wait forever.\n");
> +  Print (L"  -S:  Specify the single AP to run.\n");
> +  Print (L"  -P:  Print processor information.\n");
> +  Print (L"  -U:  Set the specified AP to the Unhealthy status (use with -E/-D).\n");
> +  Print (L"  -W:  Run WhoAmI and print index of BSP.\n");
> +  Print (L"  -E:  Enable the specified AP.\n");
> +  Print (L"  -D:  Disable the specified AP.\n");
> +  Print (L"  -h:  Print this help page.\n");
> +}
> +
> +/**
> +  Parses any arguments provided on the command line.
> +
> +  @param Options  The arguments structure.
> +
> +  @return EFI_SUCCESS on success, or an error code.
> +**/
> +EFI_STATUS
> +ParseArguments (
> +  MP_SERVICES_TEST_OPTIONS  *Options
> +  )
> +{
> +  EFI_STATUS    Status;
> +  UINT32        ArgIndex;
> +  CONST CHAR16  *Argument;
> +  BOOLEAN       NeedsValue;
> +  UINTN         *Value;

I propose removing "NeedsValue". The same can be expressed by

  Value != NULL

> +
> +  Status = GetArg ();
> +  if (EFI_ERROR (Status)) {
> +    Print (L"Please use the UEFI Shell to run this application!\n", Status);
> +    return Status;
> +  }
> +
> +  if (Argc == 1) {
> +    PrintUsage ();
> +  }
> +
> +  ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));
> +
> +  for (ArgIndex = 1; ArgIndex < Argc; ArgIndex++) {
> +    Argument   = Argv[ArgIndex];
> +    NeedsValue = FALSE;

i.e., Value = NULL

> +
> +    if (StrCmp (Argument, L"-A") == 0) {
> +      Options->RunAllAPs = TRUE;
> +    } else if (StrCmp (Argument, L"-O") == 0) {
> +      Options->RunAPsSequentially = TRUE;
> +    } else if (StrCmp (Argument, L"-T") == 0) {
> +      NeedsValue = TRUE;
> +      Value      = &Options->Timeout;
> +    } else if (StrCmp (Argument, L"-S") == 0) {
> +      Options->RunSingleAP = TRUE;
> +      NeedsValue           = TRUE;
> +      Value                = &Options->ProcessorIndex;
> +    } else if (StrCmp (Argument, L"-P") == 0) {
> +      Options->PrintProcessorInformation = TRUE;
> +    } else if (StrCmp (Argument, L"-U") == 0) {
> +      Options->SetProcessorUnhealthy = TRUE;
> +    } else if (StrCmp (Argument, L"-W") == 0) {
> +      Options->PrintBspProcessorIndex = TRUE;
> +    } else if (StrCmp (Argument, L"-E") == 0) {
> +      Options->EnableProcessor = TRUE;
> +      NeedsValue               = TRUE;
> +      Value                    = &Options->ProcessorIndex;
> +    } else if (StrCmp (Argument, L"-D") == 0) {
> +      Options->DisableProcessor = TRUE;
> +      NeedsValue                = TRUE;
> +      Value                     = &Options->ProcessorIndex;
> +    } else {
> +      PrintUsage ();
> +      ZeroMem (Options, sizeof (MP_SERVICES_TEST_OPTIONS));

This ZeroMem() looks pointless.

> +      return EFI_SUCCESS;
> +    }
> +
> +    if (NeedsValue) {
> +      if ((ArgIndex + 1) < Argc) {
> +        Status = StrDecimalToUintnS (Argv[ArgIndex + 1], NULL, Value);

Side comment: StrDecimalToUintnS() is not a flawless function; see
<https://bugzilla.tianocore.org/show_bug.cgi?id=2693>. But that's not
too important here.

> +        if (EFI_ERROR (Status)) {
> +          Print (L"Error: option value must be a positive integer.\n");
> +          PrintUsage ();
> +          return EFI_INVALID_PARAMETER;
> +        }

I've got a suggestion for this location. I suggest introducing MaxVal
(UINTN) and setting them appropriately whenever you set the Value
pointer to non-NULL.

Then, after parsing the option-argument here, I suggest performing a
<=MaxVal range check (i.e. inclusive).

Here's why: Value is effectively "untrusted" input. But consider how you
use each of the two possible UINTN option-arguments:

- Timeout is multiplied by 1000 in the functions StartupThisAP and
StartupAllAPs. You don't want an integer overflow there, so best set
MaxVal=MAX_UINTN/1000.

- ProcessorIndex is passed to EnableAP, DisableAP, and StartupThisAP. In
all three functions, the underlying MP protocol members perform range
checking, so that's fine. However, in StartupThisAP, we also use
ProcessorIndex -- indirectly -- for memory allocation. In that
calculation, we use addition and then multiplication -- this can lead to
integer overflow. So best set MaxVal = NumCpus-1. (I don't expect we'll
ever see more than a few thousand CPUs, and with such a count, the
buffer size calculation will not overflow.)

(I probably won't have time or energy to review the next version or the
incremental updates; I just figured I'd raise these.)

Laszlo


> +
> +        ArgIndex++;
> +      } else {
> +        PrintUsage ();
> +        return EFI_INVALID_PARAMETER;
> +      }
> +    }
> +  }
> +
> +  return EFI_SUCCESS;
> +}

Re: [PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[Ard Biesheuvel]

On Wed, 4 Jan 2023 at 16:37, Rebecca Cran <rebecca@quicinc.com> wrote:
>
> Implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls for AArch64, and
> add an MpServicesTest application to exercise it.
>
> Changes from v3:
>
> Removed Ard's 'Reviewed-by' line from the commits since the code has changed
> sufficiently that it's no longer valid.
>
> Rebecca Cran (3):
>   ArmPkg: Add GET_MPIDR_AFFINITY_BITS and MPIDR_MT_BIT to ArmLib.h
>   ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls
>   MdeModulePkg: Add new Application/MpServicesTest application
>
>  ArmPkg/ArmPkg.dsc                                            |    1 +
>  MdeModulePkg/MdeModulePkg.dsc                                |    2 +
>  ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf |   56 +
>  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf   |   40 +
>  ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h     |  344 ++++
>  ArmPkg/Include/Library/ArmLib.h                              |   16 +-
>  MdeModulePkg/Application/MpServicesTest/Options.h            |   39 +
>  ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c   | 1847 ++++++++++++++++++++
>  MdeModulePkg/Application/MpServicesTest/MpServicesTest.c     |  560 ++++++
>  MdeModulePkg/Application/MpServicesTest/Options.c            |  164 ++
>  ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S                |   57 +
>  11 files changed, 3119 insertions(+), 7 deletions(-)

Hello Rebecca,

Thanks for reposting this.

Running the secondaries with MMU and caches on is a huge improvement.
I would suggest, though, that we enable the MMU first thing out of
reset, and do so from asm code so we don't have to reason about the
stack (pushing something with the MMU off and popping it with the MMU
on requires cache maintenance as well, and there is no way this can be
done from the code itself without help from the compiler)

So I propose adding the diff below - note that only the variables
holding TCR, MAIR and TTBR0 need cache maintenance now (in addition to
the executable image) - everything else will be accessed by the
secondaries with the MMU enabled.

https://paste.debian.net/1266242/

WIth a tweak to the RPI4 platform that I sent out separately, this all
works fine for me (both with and without the diff above applied)

-- 
Ard.

Re: [PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[Ard Biesheuvel]

On Thu, 5 Jan 2023 at 18:39, Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Wed, 4 Jan 2023 at 16:37, Rebecca Cran <rebecca@quicinc.com> wrote:
> >
> > Implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls for AArch64, and
> > add an MpServicesTest application to exercise it.
> >
> > Changes from v3:
> >
> > Removed Ard's 'Reviewed-by' line from the commits since the code has changed
> > sufficiently that it's no longer valid.
> >
> > Rebecca Cran (3):
> >   ArmPkg: Add GET_MPIDR_AFFINITY_BITS and MPIDR_MT_BIT to ArmLib.h
> >   ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls
> >   MdeModulePkg: Add new Application/MpServicesTest application
> >
> >  ArmPkg/ArmPkg.dsc                                            |    1 +
> >  MdeModulePkg/MdeModulePkg.dsc                                |    2 +
> >  ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf |   56 +
> >  MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf   |   40 +
> >  ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h     |  344 ++++
> >  ArmPkg/Include/Library/ArmLib.h                              |   16 +-
> >  MdeModulePkg/Application/MpServicesTest/Options.h            |   39 +
> >  ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c   | 1847 ++++++++++++++++++++
> >  MdeModulePkg/Application/MpServicesTest/MpServicesTest.c     |  560 ++++++
> >  MdeModulePkg/Application/MpServicesTest/Options.c            |  164 ++
> >  ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S                |   57 +
> >  11 files changed, 3119 insertions(+), 7 deletions(-)
>
> Hello Rebecca,
>
> Thanks for reposting this.
>
> Running the secondaries with MMU and caches on is a huge improvement.
> I would suggest, though, that we enable the MMU first thing out of
> reset, and do so from asm code so we don't have to reason about the
> stack (pushing something with the MMU off and popping it with the MMU
> on requires cache maintenance as well, and there is no way this can be
> done from the code itself without help from the compiler)
>
> So I propose adding the diff below - note that only the variables
> holding TCR, MAIR and TTBR0 need cache maintenance now (in addition to
> the executable image) - everything else will be accessed by the
> secondaries with the MMU enabled.
>
> https://paste.debian.net/1266242/
>
> WIth a tweak to the RPI4 platform that I sent out separately, this all
> works fine for me (both with and without the diff above applied)
>

Actually, maybe better to retain the hunk below. I saw some weird
hangs without them

diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
index ab439bffd722..eb634a25b33a 100644
--- a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
+++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
@@ -1345,18 +1345,6 @@ MpServicesInitialize (

   gProcessorIDs[Index] = MAX_UINT64;

-  //
-  // The global pointer variables as well as the gProcessorIDs array contents
-  // are accessed by the other cores so we must clean them to the PoC
-  //
-  WriteBackDataCacheRange (&gProcessorIDs, sizeof (UINT64 *));
-  WriteBackDataCacheRange (&gApStacksBase, sizeof (UINT64 *));
-
-  WriteBackDataCacheRange (
-    gProcessorIDs,
-    (mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64)
-    );
-
   mNonBlockingModeAllowed = TRUE;

   Status = EfiCreateEventReadyToBootEx (

Re: [edk2-devel] [PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[Kun Qin]

Hi Ard/Rebecca,

Thanks for bringing this to the mailing list. But somehow I cannot find 
the patches sent along with this
v4 cover letter. Could you please point me to them?

I have been running the previous version of this patch and noticed a 
minor issue when the wait event is
specified but the timeout is 0. In this case the CheckApStatus function 
could fall into the timeout scenario
regardless and signal the event timeout incorrectly. I attempted a 
simple fix here:
https://github.com/kuqin12/mu_silicon_arm_tiano/commit/591462cc32e621c1da470a8319f7deda723e8509

Please let me know if I misunderstood anything for the above case. 
Thanks in advance!

Regards,
Kun

On 1/5/2023 9:59 AM, Ard Biesheuvel wrote:
> On Thu, 5 Jan 2023 at 18:39, Ard Biesheuvel <ardb@kernel.org> wrote:
>> On Wed, 4 Jan 2023 at 16:37, Rebecca Cran <rebecca@quicinc.com> wrote:
>>> Implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls for AArch64, and
>>> add an MpServicesTest application to exercise it.
>>>
>>> Changes from v3:
>>>
>>> Removed Ard's 'Reviewed-by' line from the commits since the code has changed
>>> sufficiently that it's no longer valid.
>>>
>>> Rebecca Cran (3):
>>>    ArmPkg: Add GET_MPIDR_AFFINITY_BITS and MPIDR_MT_BIT to ArmLib.h
>>>    ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls
>>>    MdeModulePkg: Add new Application/MpServicesTest application
>>>
>>>   ArmPkg/ArmPkg.dsc                                            |    1 +
>>>   MdeModulePkg/MdeModulePkg.dsc                                |    2 +
>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf |   56 +
>>>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf   |   40 +
>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h     |  344 ++++
>>>   ArmPkg/Include/Library/ArmLib.h                              |   16 +-
>>>   MdeModulePkg/Application/MpServicesTest/Options.h            |   39 +
>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c   | 1847 ++++++++++++++++++++
>>>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.c     |  560 ++++++
>>>   MdeModulePkg/Application/MpServicesTest/Options.c            |  164 ++
>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S                |   57 +
>>>   11 files changed, 3119 insertions(+), 7 deletions(-)
>> Hello Rebecca,
>>
>> Thanks for reposting this.
>>
>> Running the secondaries with MMU and caches on is a huge improvement.
>> I would suggest, though, that we enable the MMU first thing out of
>> reset, and do so from asm code so we don't have to reason about the
>> stack (pushing something with the MMU off and popping it with the MMU
>> on requires cache maintenance as well, and there is no way this can be
>> done from the code itself without help from the compiler)
>>
>> So I propose adding the diff below - note that only the variables
>> holding TCR, MAIR and TTBR0 need cache maintenance now (in addition to
>> the executable image) - everything else will be accessed by the
>> secondaries with the MMU enabled.
>>
>> https://paste.debian.net/1266242/
>>
>> WIth a tweak to the RPI4 platform that I sent out separately, this all
>> works fine for me (both with and without the diff above applied)
>>
> Actually, maybe better to retain the hunk below. I saw some weird
> hangs without them
>
> diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
> index ab439bffd722..eb634a25b33a 100644
> --- a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
> @@ -1345,18 +1345,6 @@ MpServicesInitialize (
>
>     gProcessorIDs[Index] = MAX_UINT64;
>
> -  //
> -  // The global pointer variables as well as the gProcessorIDs array contents
> -  // are accessed by the other cores so we must clean them to the PoC
> -  //
> -  WriteBackDataCacheRange (&gProcessorIDs, sizeof (UINT64 *));
> -  WriteBackDataCacheRange (&gApStacksBase, sizeof (UINT64 *));
> -
> -  WriteBackDataCacheRange (
> -    gProcessorIDs,
> -    (mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64)
> -    );
> -
>     mNonBlockingModeAllowed = TRUE;
>
>     Status = EfiCreateEventReadyToBootEx (
>
>
> 
>
>

Re: [edk2-devel] [PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[Rebecca Cran]

The patches aren't attached to the cover letter, but are separate 
emails. You should be able to find them by looking for "PATCH v4 1/3", 
"PATCH v4 2/3" etc.

I've made several changes to the WaitEvent handling in the latest patch: 
could you check if the problem has been fixed please?

-- 
Rebecca Cran

On 1/5/23 22:11, Kun Qin wrote:
> Hi Ard/Rebecca,
> 
> Thanks for bringing this to the mailing list. But somehow I cannot find 
> the patches sent along with this
> v4 cover letter. Could you please point me to them?
> 
> I have been running the previous version of this patch and noticed a 
> minor issue when the wait event is
> specified but the timeout is 0. In this case the CheckApStatus function 
> could fall into the timeout scenario
> regardless and signal the event timeout incorrectly. I attempted a 
> simple fix here:
> https://github.com/kuqin12/mu_silicon_arm_tiano/commit/591462cc32e621c1da470a8319f7deda723e8509
> 
> Please let me know if I misunderstood anything for the above case. 
> Thanks in advance!
> 
> Regards,
> Kun
> 
> On 1/5/2023 9:59 AM, Ard Biesheuvel wrote:
>> On Thu, 5 Jan 2023 at 18:39, Ard Biesheuvel <ardb@kernel.org> wrote:
>>> On Wed, 4 Jan 2023 at 16:37, Rebecca Cran <rebecca@quicinc.com> wrote:
>>>> Implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls for AArch64, and
>>>> add an MpServicesTest application to exercise it.
>>>>
>>>> Changes from v3:
>>>>
>>>> Removed Ard's 'Reviewed-by' line from the commits since the code has 
>>>> changed
>>>> sufficiently that it's no longer valid.
>>>>
>>>> Rebecca Cran (3):
>>>>    ArmPkg: Add GET_MPIDR_AFFINITY_BITS and MPIDR_MT_BIT to ArmLib.h
>>>>    ArmPkg: implement EFI_MP_SERVICES_PROTOCOL based on PSCI calls
>>>>    MdeModulePkg: Add new Application/MpServicesTest application
>>>>
>>>>   ArmPkg/ArmPkg.dsc                                            |    1 +
>>>>   MdeModulePkg/MdeModulePkg.dsc                                |    2 +
>>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.inf |   56 +
>>>>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.inf   |   40 +
>>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpServicesInternal.h     |  
>>>> 344 ++++
>>>>   ArmPkg/Include/Library/ArmLib.h                              |   
>>>> 16 +-
>>>>   MdeModulePkg/Application/MpServicesTest/Options.h            |   39 +
>>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c   | 
>>>> 1847 ++++++++++++++++++++
>>>>   MdeModulePkg/Application/MpServicesTest/MpServicesTest.c     |  
>>>> 560 ++++++
>>>>   MdeModulePkg/Application/MpServicesTest/Options.c            |  
>>>> 164 ++
>>>>   ArmPkg/Drivers/ArmPsciMpServicesDxe/MpFuncs.S                |   57 +
>>>>   11 files changed, 3119 insertions(+), 7 deletions(-)
>>> Hello Rebecca,
>>>
>>> Thanks for reposting this.
>>>
>>> Running the secondaries with MMU and caches on is a huge improvement.
>>> I would suggest, though, that we enable the MMU first thing out of
>>> reset, and do so from asm code so we don't have to reason about the
>>> stack (pushing something with the MMU off and popping it with the MMU
>>> on requires cache maintenance as well, and there is no way this can be
>>> done from the code itself without help from the compiler)
>>>
>>> So I propose adding the diff below - note that only the variables
>>> holding TCR, MAIR and TTBR0 need cache maintenance now (in addition to
>>> the executable image) - everything else will be accessed by the
>>> secondaries with the MMU enabled.
>>>
>>> https://paste.debian.net/1266242/
>>>
>>> WIth a tweak to the RPI4 platform that I sent out separately, this all
>>> works fine for me (both with and without the diff above applied)
>>>
>> Actually, maybe better to retain the hunk below. I saw some weird
>> hangs without them
>>
>> diff --git a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
>> b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
>> index ab439bffd722..eb634a25b33a 100644
>> --- a/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
>> +++ b/ArmPkg/Drivers/ArmPsciMpServicesDxe/ArmPsciMpServicesDxe.c
>> @@ -1345,18 +1345,6 @@ MpServicesInitialize (
>>
>>     gProcessorIDs[Index] = MAX_UINT64;
>>
>> -  //
>> -  // The global pointer variables as well as the gProcessorIDs array 
>> contents
>> -  // are accessed by the other cores so we must clean them to the PoC
>> -  //
>> -  WriteBackDataCacheRange (&gProcessorIDs, sizeof (UINT64 *));
>> -  WriteBackDataCacheRange (&gApStacksBase, sizeof (UINT64 *));
>> -
>> -  WriteBackDataCacheRange (
>> -    gProcessorIDs,
>> -    (mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64)
>> -    );
>> -
>>     mNonBlockingModeAllowed = TRUE;
>>
>>     Status = EfiCreateEventReadyToBootEx (
>>
>>
>> 
>>
>>

Re: [edk2-devel] [PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[Kun Qin]

Hi Rebecca,

Thanks for the information. Somehow these patches (i.e. 
https://edk2.groups.io/g/devel/message/98106) just landed on groups.io 
last night.

I will test the latest version of your patches and reply back here.

Regards,
Kun

On 1/6/2023 10:42 AM, Rebecca Cran wrote:
> The patches aren't attached to the cover letter, but are separate 
> emails. You should be able to find them by looking for "PATCH v4 1/3", 
> "PATCH v4 2/3" etc.
>
> I've made several changes to the WaitEvent handling in the latest 
> patch: could you check if the problem has been fixed please?
>

Re: [PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[Rebecca Cran]

On 1/5/23 10:39, Ard Biesheuvel wrote:

> So I propose adding the diff below - note that only the variables
> holding TCR, MAIR and TTBR0 need cache maintenance now (in addition to
> the executable image) - everything else will be accessed by the
> secondaries with the MMU enabled.
> 
> https://paste.debian.net/1266242/
> 
> WIth a tweak to the RPI4 platform that I sent out separately, this all
> works fine for me (both with and without the diff above applied)
> 

Sorry I didn't get around to working on this before the paste.debian.org 
link expired. I think I remember what the code was doing though, so I'll 
try and recreate it.

-- 
Rebecca Cran

Re: [edk2-devel] [PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[Patrik Berglund]

Hello Rebecca,

I have tested the v4 set on a single-chip N1SDP.
I had to fix N1SDP for the same reasons as in
https://edk2.groups.io/g/devel/message/93633 and I post that fix to the 
list separately.

I think it works but here is the output:

Shell> MpServicesTest -P
Number of CPUs: 4, Enabled: 4
Processor 0:
	ID: 0000000000000000
	Status: BSP | Enabled | Healthy
	Location: Package 0, Core 0, Thread 0
	Extended Information: Package 0, Module 0, Tile 0, Die 0, Core 0, Thread 0

Processor 1:
	ID: 0000000000000100
	Status: AP | Enabled | Healthy
	Location: Package 1, Core 0, Thread 0
	Extended Information: Package 0, Module 0, Tile 0, Die 1, Core 0, Thread 0

Processor 2:
	ID: 0000000000010000
	Status: AP | Enabled | Healthy
	Location: Package 0, Core 0, Thread 0
	Extended Information: Package 1, Module 0, Tile 0, Die 0, Core 0, Thread 0

Processor 3:
	ID: 0000000000010100
	Status: AP | Enabled | Healthy
	Location: Package 1, Core 0, Thread 0
	Extended Information: Package 1, Module 0, Tile 0, Die 1, Core 0, Thread 0

Shell> MpServicesTest -A
Running with SingleThread FALSE, 0 (infinite) timeout...done.
Hello from CPU 1
Hello from CPU 2
Hello from CPU 3
Shell>


One suggestion on the MpServicesTest utility, maybe check the AP number 
to give a bit friendlier error message if the user pass the BSP?

Regards,
Patrik

Re: [edk2-devel] [PATCH v4 0/3] ArmPkg,MdeModulePkg: Implement EFI_MP_SERVICES_PROTOCOL for AArch64 and add an MpServicesTest application to exercise it

[Rebecca Cran]

Thanks!

I'm dropping the MpServicesTest patch and people will be able to use the 
application from 
UefiCpuPkg/Test/UnitTest/EfiMpServicesPpiProtocol/EfiMpServiceProtocolShellUnitTest.inf 
instead.

-- 
Rebecca Cran

On 1/11/23 09:41, Patrik Berglund wrote:
> Hello Rebecca,
> 
> I have tested the v4 set on a single-chip N1SDP.
> I had to fix N1SDP for the same reasons as in
> https://edk2.groups.io/g/devel/message/93633 and I post that fix to the 
> list separately.
> 
> I think it works but here is the output:
> 
> Shell> MpServicesTest -P
> Number of CPUs: 4, Enabled: 4
> Processor 0:
>      ID: 0000000000000000
>      Status: BSP | Enabled | Healthy
>      Location: Package 0, Core 0, Thread 0
>      Extended Information: Package 0, Module 0, Tile 0, Die 0, Core 0, 
> Thread 0
> 
> Processor 1:
>      ID: 0000000000000100
>      Status: AP | Enabled | Healthy
>      Location: Package 1, Core 0, Thread 0
>      Extended Information: Package 0, Module 0, Tile 0, Die 1, Core 0, 
> Thread 0
> 
> Processor 2:
>      ID: 0000000000010000
>      Status: AP | Enabled | Healthy
>      Location: Package 0, Core 0, Thread 0
>      Extended Information: Package 1, Module 0, Tile 0, Die 0, Core 0, 
> Thread 0
> 
> Processor 3:
>      ID: 0000000000010100
>      Status: AP | Enabled | Healthy
>      Location: Package 1, Core 0, Thread 0
>      Extended Information: Package 1, Module 0, Tile 0, Die 1, Core 0, 
> Thread 0
> 
> Shell> MpServicesTest -A
> Running with SingleThread FALSE, 0 (infinite) timeout...done.
> Hello from CPU 1
> Hello from CPU 2
> Hello from CPU 3
> Shell>
> 
> 
> One suggestion on the MpServicesTest utility, maybe check the AP number 
> to give a bit friendlier error message if the user pass the BSP?