[PATCH 6/6] MdeModulePkg/DxeMain: Implement common event protocol

["Gao, Zhichao" <zhichao.gao@intel.com>]

From: Sean Brogan <sean.brogan@microsoft.com>

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1400

If an interrupt happens between CheckEvent and gIdleLoopEvent,
there would be a event pending during cpu sleep. So it is
required to check the gEventPending with the interrupt disabled.

Implement a protocol gEdkiiCommonEventProtocolGuid to support
all TPL event for PI drivers that use HW interrput. It has two
interface, one is to create event and the other one is to wait for
event.

Add 'volatile' specifier for gEfiCurrentTpl and gEventPending
because they may be changed out of the context (interrupt context).

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Liming gao <liming.gao@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Michael Turner <Michael.Turner@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
---
 MdeModulePkg/Core/Dxe/DxeMain.h               |  64 ++++++++++-
 MdeModulePkg/Core/Dxe/DxeMain.inf             |   1 +
 MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c       |  22 ++++
 .../Core/Dxe/DxeMain/DxeProtocolNotify.c      |   1 +
 MdeModulePkg/Core/Dxe/Event/Event.c           | 102 ++++++++++++++++--
 MdeModulePkg/Core/Dxe/Event/Event.h           |   2 +-
 6 files changed, 179 insertions(+), 13 deletions(-)

diff --git a/MdeModulePkg/Core/Dxe/DxeMain.h b/MdeModulePkg/Core/Dxe/DxeMain.h
index 6a64852730..355f66bc44 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain.h
+++ b/MdeModulePkg/Core/Dxe/DxeMain.h
@@ -38,6 +38,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Protocol/Security2.h>
 #include <Protocol/Reset.h>
 #include <Protocol/Cpu.h>
+#include <Protocol/Cpu2.h>
 #include <Protocol/Metronome.h>
 #include <Protocol/FirmwareVolumeBlock.h>
 #include <Protocol/Capsule.h>
@@ -47,6 +48,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Protocol/HiiPackageList.h>
 #include <Protocol/SmmBase2.h>
 #include <Protocol/PeCoffImageEmulator.h>
+#include <Protocol/CommonEvent.h>
 #include <Guid/MemoryTypeInformation.h>
 #include <Guid/FirmwareFileSystem2.h>
 #include <Guid/FirmwareFileSystem3.h>
@@ -274,10 +276,11 @@ extern EFI_METRONOME_ARCH_PROTOCOL              *gMetronome;
 extern EFI_TIMER_ARCH_PROTOCOL                  *gTimer;
 extern EFI_SECURITY_ARCH_PROTOCOL               *gSecurity;
 extern EFI_SECURITY2_ARCH_PROTOCOL              *gSecurity2;
+extern EFI_CPU2_PROTOCOL                        *gCpu2;
 extern EFI_BDS_ARCH_PROTOCOL                    *gBds;
 extern EFI_SMM_BASE2_PROTOCOL                   *gSmmBase2;
 
-extern EFI_TPL                                  gEfiCurrentTpl;
+extern volatile EFI_TPL                         gEfiCurrentTpl;
 
 extern EFI_GUID                                 *gDxeCoreFileName;
 extern EFI_LOADED_IMAGE_PROTOCOL                *gDxeCoreLoadedImage;
@@ -1714,6 +1717,65 @@ CoreCheckEvent (
   );
 
 
+/**
+  Stops execution until an event is signaled.
+
+  Support all TPL.
+
+  @param  NumberOfEvents         The number of events in the UserEvents array
+  @param  UserEvents             An array of EFI_EVENT
+  @param  UserIndex              Pointer to the index of the event which
+                                 satisfied the wait condition
+
+  @retval EFI_SUCCESS            The event indicated by Index was signaled.
+  @retval EFI_INVALID_PARAMETER  The event indicated by Index has a notification
+                                 function or Event was not a valid type
+  @retval EFI_UNSUPPORTED        The current TPL is not TPL_APPLICATION
+
+**/
+EFI_STATUS
+EFIAPI
+CommonWaitForEvent (
+  IN UINTN        NumberOfEvents,
+  IN EFI_EVENT    *UserEvents,
+  OUT UINTN       *UserIndex
+  );
+
+
+/**
+  Creates an event in a group.
+
+  Support all TPL.
+
+  @param  Type                   The type of event to create and its mode and
+                                 attributes
+  @param  NotifyTpl              The task priority level of event notifications
+  @param  NotifyFunction         Pointer to the events notification function
+  @param  NotifyContext          Pointer to the notification functions context;
+                                 corresponds to parameter "Context" in the
+                                 notification function
+  @param  EventGroup             GUID for EventGroup if NULL act the same as
+                                 gBS->CreateEvent().
+  @param  Event                  Pointer to the newly created event if the call
+                                 succeeds; undefined otherwise
+
+  @retval EFI_SUCCESS            The event structure was created
+  @retval EFI_INVALID_PARAMETER  One of the parameters has an invalid value
+  @retval EFI_OUT_OF_RESOURCES   The event could not be allocated
+
+**/
+EFI_STATUS
+EFIAPI
+CommonCreateEventEx (
+  IN UINT32                   Type,
+  IN EFI_TPL                  NotifyTpl,
+  IN EFI_EVENT_NOTIFY         NotifyFunction, OPTIONAL
+  IN CONST VOID               *NotifyContext, OPTIONAL
+  IN CONST EFI_GUID           *EventGroup,    OPTIONAL
+  OUT EFI_EVENT               *Event
+  );
+
+
 /**
   Adds reserved memory, system memory, or memory-mapped I/O resources to the
   global coherency domain of the processor.
diff --git a/MdeModulePkg/Core/Dxe/DxeMain.inf b/MdeModulePkg/Core/Dxe/DxeMain.inf
index 61161bee28..d758ee431e 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain.inf
+++ b/MdeModulePkg/Core/Dxe/DxeMain.inf
@@ -171,6 +171,7 @@
   gEfiVariableArchProtocolGuid                  ## CONSUMES
   gEfiCapsuleArchProtocolGuid                   ## CONSUMES
   gEfiWatchdogTimerArchProtocolGuid             ## CONSUMES
+  gEdkiiCommonEventProtocolGuid                 ## SOMETIMES_CONSUMES
 
 [Pcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdLoadFixAddressBootTimeCodePageNumber    ## SOMETIMES_CONSUMES
diff --git a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
index 514d1aa75a..0e6a4b2ec5 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
+++ b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
@@ -13,12 +13,18 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 //
 EFI_HANDLE                                mDecompressHandle = NULL;
 
+//
+//  Common event protocol
+//
+EFI_HANDLE                                mCommonEventHalde = NULL;
+
 //
 // DXE Core globals for Architecture Protocols
 //
 EFI_SECURITY_ARCH_PROTOCOL        *gSecurity      = NULL;
 EFI_SECURITY2_ARCH_PROTOCOL       *gSecurity2     = NULL;
 EFI_CPU_ARCH_PROTOCOL             *gCpu           = NULL;
+EFI_CPU2_PROTOCOL                 *gCpu2          = NULL;
 EFI_METRONOME_ARCH_PROTOCOL       *gMetronome     = NULL;
 EFI_TIMER_ARCH_PROTOCOL           *gTimer         = NULL;
 EFI_BDS_ARCH_PROTOCOL             *gBds           = NULL;
@@ -211,6 +217,14 @@ EFI_DECOMPRESS_PROTOCOL  gEfiDecompress = {
   DxeMainUefiDecompress
 };
 
+//
+// Common event protocol
+//
+EDKII_COMMON_EVENT_PROTOCOL gEdkiiCommonEvent = {
+  CommonCreateEventEx,
+  CommonWaitForEvent
+};
+
 //
 // For Loading modules at fixed address feature, the configuration table is to cache the top address below which to load
 // Runtime code&boot time code
@@ -475,6 +489,14 @@ DxeMain (
   //
   CoreNotifyOnProtocolInstallation ();
 
+  Status = CoreInstallProtocolInterface (
+              &mCommonEventHalde,
+              &gEdkiiCommonEventProtocolGuid,
+              EFI_NATIVE_INTERFACE,
+              &gEdkiiCommonEvent
+              );
+  ASSERT_EFI_ERROR (Status);
+
   //
   // Produce Firmware Volume Protocols, one for each FV in the HOB list.
   //
diff --git a/MdeModulePkg/Core/Dxe/DxeMain/DxeProtocolNotify.c b/MdeModulePkg/Core/Dxe/DxeMain/DxeProtocolNotify.c
index 29a55d02e6..77af8185b8 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain/DxeProtocolNotify.c
+++ b/MdeModulePkg/Core/Dxe/DxeMain/DxeProtocolNotify.c
@@ -41,6 +41,7 @@ EFI_CORE_PROTOCOL_NOTIFY_ENTRY  mArchProtocols[] = {
 EFI_CORE_PROTOCOL_NOTIFY_ENTRY  mOptionalProtocols[] = {
   { &gEfiSecurity2ArchProtocolGuid,        (VOID **)&gSecurity2,     NULL, NULL, FALSE },
   { &gEfiSmmBase2ProtocolGuid,             (VOID **)&gSmmBase2,      NULL, NULL, FALSE },
+  { &gEdkiiCommonEventProtocolGuid,        (VOID **)&gCpu2,          NULL, NULL, FALSE },
   { NULL,                                  (VOID **)NULL,            NULL, NULL, FALSE }
 };
 
diff --git a/MdeModulePkg/Core/Dxe/Event/Event.c b/MdeModulePkg/Core/Dxe/Event/Event.c
index 21db38aaf0..d271d2faf3 100644
--- a/MdeModulePkg/Core/Dxe/Event/Event.c
+++ b/MdeModulePkg/Core/Dxe/Event/Event.c
@@ -14,7 +14,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 ///
 /// gEfiCurrentTpl - Current Task priority level
 ///
-EFI_TPL  gEfiCurrentTpl = TPL_APPLICATION;
+volatile EFI_TPL  gEfiCurrentTpl = TPL_APPLICATION;
 
 ///
 /// gEventQueueLock - Protects the event queues
@@ -29,7 +29,7 @@ LIST_ENTRY      gEventQueue[TPL_HIGH_LEVEL + 1];
 ///
 /// gEventPending - A bitmask of the EventQueues that are pending
 ///
-UINTN           gEventPending = 0;
+volatile UINTN  gEventPending = 0;
 
 ///
 /// gEventSignalQueue - A list of events to signal based on EventGroup type
@@ -658,16 +658,44 @@ CoreWaitForEvent (
   OUT UINTN       *UserIndex
   )
 {
-  EFI_STATUS      Status;
-  UINTN           Index;
-
-  //
+   //
   // Can only WaitForEvent at TPL_APPLICATION
   //
   if (gEfiCurrentTpl != TPL_APPLICATION) {
     return EFI_UNSUPPORTED;
   }
 
+  return CommonWaitForEvent (NumberOfEvents, UserEvents, UserIndex);
+}
+
+
+/**
+  Stops execution until an event is signaled.
+
+  Support all TPL.
+
+  @param  NumberOfEvents         The number of events in the UserEvents array
+  @param  UserEvents             An array of EFI_EVENT
+  @param  UserIndex              Pointer to the index of the event which
+                                 satisfied the wait condition
+
+  @retval EFI_SUCCESS            The event indicated by Index was signaled.
+  @retval EFI_INVALID_PARAMETER  The event indicated by Index has a notification
+                                 function or Event was not a valid type
+  @retval EFI_UNSUPPORTED        The current TPL is not TPL_APPLICATION
+
+**/
+EFI_STATUS
+EFIAPI
+CommonWaitForEvent (
+  IN UINTN        NumberOfEvents,
+  IN EFI_EVENT    *UserEvents,
+  OUT UINTN       *UserIndex
+  )
+{
+  EFI_STATUS      Status;
+  UINTN           Index;
+
   if (NumberOfEvents == 0) {
     return EFI_INVALID_PARAMETER;
   }
@@ -678,7 +706,7 @@ CoreWaitForEvent (
 
   for(;;) {
 
-    for(Index = 0; Index < NumberOfEvents; Index++) {
+    for (Index = 0; Index < NumberOfEvents; Index++) {
 
       Status = CoreCheckEvent (UserEvents[Index]);
 
@@ -693,14 +721,66 @@ CoreWaitForEvent (
       }
     }
 
-    //
-    // Signal the Idle event
-    //
-    CoreSignalEvent (gIdleLoopEvent);
+    if (gCpu != NULL && gCpu2 != NULL) {
+      //
+      // None of the events checked above are ready/signaled yet,
+      // disable interrupts before checking for all pending events
+      //
+      gCpu->DisableInterrupt (gCpu);
+
+      if (((UINTN) HighBitSet64 (gEventPending)) > gEfiCurrentTpl) {
+        //
+        // There are pending events, enable interrupts for these events to be processed
+        //
+        gCpu->EnableInterrupt (gCpu);
+      } else {
+        //
+        // No events are pending, enable interrupts, sleep the CPU and wait for an interrupt
+        //
+        gCpu2->EnableAndWaitForInterrupt (gCpu2);
+      }
+    }
   }
 }
 
 
+/**
+  Creates an event in a group.
+
+  Support all TPL.
+
+  @param  Type                   The type of event to create and its mode and
+                                 attributes
+  @param  NotifyTpl              The task priority level of event notifications
+  @param  NotifyFunction         Pointer to the events notification function
+  @param  NotifyContext          Pointer to the notification functions context;
+                                 corresponds to parameter "Context" in the
+                                 notification function
+  @param  EventGroup             GUID for EventGroup if NULL act the same as
+                                 gBS->CreateEvent().
+  @param  Event                  Pointer to the newly created event if the call
+                                 succeeds; undefined otherwise
+
+  @retval EFI_SUCCESS            The event structure was created
+  @retval EFI_INVALID_PARAMETER  One of the parameters has an invalid value
+  @retval EFI_OUT_OF_RESOURCES   The event could not be allocated
+
+**/
+EFI_STATUS
+EFIAPI
+CommonCreateEventEx (
+  IN UINT32                   Type,
+  IN EFI_TPL                  NotifyTpl,
+  IN EFI_EVENT_NOTIFY         NotifyFunction, OPTIONAL
+  IN CONST VOID               *NotifyContext, OPTIONAL
+  IN CONST EFI_GUID           *EventGroup,    OPTIONAL
+  OUT EFI_EVENT               *Event
+  )
+{
+  return CoreCreateEventInternal (Type, NotifyTpl, NotifyFunction, NotifyContext, EventGroup, Event);
+}
+
+
 /**
   Closes an event and frees the event structure.
 
diff --git a/MdeModulePkg/Core/Dxe/Event/Event.h b/MdeModulePkg/Core/Dxe/Event/Event.h
index 8141c5003e..050df26ec9 100644
--- a/MdeModulePkg/Core/Dxe/Event/Event.h
+++ b/MdeModulePkg/Core/Dxe/Event/Event.h
@@ -12,7 +12,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 
 #define VALID_TPL(a)            ((a) <= TPL_HIGH_LEVEL)
-extern  UINTN                   gEventPending;
+extern  volatile UINTN          gEventPending;
 
 ///
 /// Set if Event is part of an event group
-- 
2.21.0.windows.1