[edk2-platforms][PATCH v2 11/32] AmperePlatformPkg: Add AcpiPccLib to support ACPI PCCT Table

["Nhi Pham" <nhi@os.amperecomputing.com>]

The AcpiPccLib provides functions to allocate and get the physical
address of PCC shared memory.

Cc: Thang Nguyen <thang@os.amperecomputing.com>
Cc: Chuong Tran <chuong@os.amperecomputing.com>
Cc: Phong Vo <phong@os.amperecomputing.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>

Signed-off-by: Nhi Pham <nhi@os.amperecomputing.com>
---
 Silicon/Ampere/AmpereSiliconPkg/AmpereSiliconPkg.dec                |   2 +
 Platform/Ampere/AmperePlatformPkg/Library/AcpiPccLib/AcpiPccLib.inf |  41 ++++
 Silicon/Ampere/AmpereSiliconPkg/Include/Library/AcpiPccLib.h        | 166 ++++++++++++++
 Platform/Ampere/AmperePlatformPkg/Library/AcpiPccLib/AcpiPccLib.c   | 241 ++++++++++++++++++++
 4 files changed, 450 insertions(+)

diff --git a/Silicon/Ampere/AmpereSiliconPkg/AmpereSiliconPkg.dec b/Silicon/Ampere/AmpereSiliconPkg/AmpereSiliconPkg.dec
index a72205aa5316..8193ff617600 100755
--- a/Silicon/Ampere/AmpereSiliconPkg/AmpereSiliconPkg.dec
+++ b/Silicon/Ampere/AmpereSiliconPkg/AmpereSiliconPkg.dec
@@ -25,6 +25,8 @@ [Includes.common]
   Include                        # Root include for the package
 
 [LibraryClasses]
+  ##  @libraryclass  Provides functions to create the ACPI PCCT Table which which advertises PCC mailbox channel information.
+  AcpiPccLib|Silicon/Ampere/AmpereSiliconPkg/Include/Library/AcpiPccLib.h
 
 [Guids]
   gAmpereTokenSpaceGuid = { 0xdbd4436e, 0x89cb, 0x44dc, { 0xb5, 0xc0, 0x49, 0xc3, 0x91, 0x35, 0xbf, 0xdf } }
diff --git a/Platform/Ampere/AmperePlatformPkg/Library/AcpiPccLib/AcpiPccLib.inf b/Platform/Ampere/AmperePlatformPkg/Library/AcpiPccLib/AcpiPccLib.inf
new file mode 100755
index 000000000000..9f38e1e77145
--- /dev/null
+++ b/Platform/Ampere/AmperePlatformPkg/Library/AcpiPccLib/AcpiPccLib.inf
@@ -0,0 +1,41 @@
+## @file
+#
+# Copyright (c) 2020 - 2021, Ampere Computing LLC. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                   = 0x0001001B
+  BASE_NAME                     = AcpiPccLib
+  FILE_GUID                     = 790519F0-F344-11E3-AC10-0800200C9A66
+  MODULE_TYPE                   = BASE
+  VERSION_STRING                = 1.0
+  LIBRARY_CLASS                 = AcpiPccLib
+
+[Sources.common]
+  AcpiPccLib.c
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  ArmPlatformPkg/ArmPlatformPkg.dec
+  MdePkg/MdePkg.dec
+  Silicon/Ampere/AmpereAltraPkg/AmpereAltraPkg.dec
+  Silicon/Ampere/AmpereSiliconPkg/AmpereSiliconPkg.dec
+
+[LibraryClasses]
+  ArmLib
+  BaseLib
+  BaseMemoryLib
+  DebugLib
+  IoLib
+  MailboxInterfaceLib
+  PrintLib
+  SystemFirmwareInterfaceLib
+  TimerLib
+  UefiBootServicesTableLib
+
+[Pcd]
+  gAmpereTokenSpaceGuid.PcdPmproDbBaseReg
+  gAmpereTokenSpaceGuid.PcdSmproDbBaseReg
diff --git a/Silicon/Ampere/AmpereSiliconPkg/Include/Library/AcpiPccLib.h b/Silicon/Ampere/AmpereSiliconPkg/Include/Library/AcpiPccLib.h
new file mode 100644
index 000000000000..d8ae48e7612a
--- /dev/null
+++ b/Silicon/Ampere/AmpereSiliconPkg/Include/Library/AcpiPccLib.h
@@ -0,0 +1,166 @@
+/** @file
+
+  Copyright (c) 2020 - 2021, Ampere Computing LLC. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef ACPI_PCC_LIB_H_
+#define ACPI_PCC_LIB_H_
+
+#include <Library/MailboxInterfaceLib.h>
+#include <Library/SystemFirmwareInterfaceLib.h>
+
+// Send a message with dummy payload is to advertise the shared memory address
+#define DB_PCC_PAYLOAD_DUMMY         0x0F000000
+
+#define DB_PCC_MSG_PAYLOAD_SIZE      12 // Number of Bytes
+
+//
+// ACPI Platform Communication Channel (PCC)
+//
+#define ACPI_PCC_SUBSPACE_SHARED_MEM_SIGNATURE  0x50434300 // "PCC"
+#define ACPI_PCC_SUBSPACE_SHARED_MEM_SIZE       0x4000     // Number of Bytes
+
+//
+// Reserved Doorbell Mask
+// Bit 0 --> 31 correspond to Doorbell 0 --> 31
+//
+// List of reserved Doorbells
+//  1. Doorbell 4: PCIe Hot-plug
+//
+#define ACPI_PCC_AVAILABLE_DOORBELL_MASK        0xEFFFEFFF
+#define ACPI_PCC_NUMBER_OF_RESERVED_DOORBELLS   1
+
+// Supported doorbells in the platform
+#define ACPI_PCC_MAX_DOORBELL              (NUMBER_OF_DOORBELLS_PER_SOCKET * PLATFORM_CPU_MAX_SOCKET)
+
+// Valid doorbells for use
+#define ACPI_PCC_MAX_SUBPACE_PER_SOCKET    (NUMBER_OF_DOORBELLS_PER_SOCKET - ACPI_PCC_NUMBER_OF_RESERVED_DOORBELLS)
+#define ACPI_PCC_MAX_SUBPACE               (ACPI_PCC_MAX_SUBPACE_PER_SOCKET * PLATFORM_CPU_MAX_SOCKET)
+
+#define ACPI_PCC_NOMINAL_LATENCY_US                1000 // us
+#define ACPI_PCC_MAX_PERIODIC_ACCESS_RATE          0    // no limitation
+#define ACPI_PCC_MIN_REQ_TURNAROUND_TIME_US        0
+
+// Polling interval for PCC Command Complete
+#define ACPI_PCC_COMMAND_POLL_INTERVAL_US          10
+
+#define ACPI_PCC_COMMAND_POLL_COUNT  (ACPI_PCC_NOMINAL_LATENCY_US / ACPI_PCC_COMMAND_POLL_INTERVAL_US)
+
+//
+// PCC subspace 2 (PMpro Doorbell Channel 2) is used for ACPI CPPC
+//
+#define ACPI_PCC_CPPC_DOORBELL_ID                  (PMproDoorbellChannel2)
+
+#define ACPI_PCC_CPPC_NOMINAL_LATENCY_US           100
+#define ACPI_PCC_CPPC_MIN_REQ_TURNAROUND_TIME_US   110
+
+
+/**
+  Allocate memory pages for the PCC shared memory region.
+
+  @param  PccSharedMemoryPtr     Pointer to the shared memory address.
+  @param  NumberOfSubspaces      Number of subspaces slot in the shared memory region.
+
+  @retval EFI_SUCCESS            Send the message successfully.
+  @retval EFI_INVALID_PARAMETER  TheNumberOfSubspaces is out of the valid range.
+  @retval Otherwise              Return errors from call to gBS->AllocatePages().
+
+**/
+EFI_STATUS
+EFIAPI
+AcpiPccAllocateSharedMemory (
+  OUT EFI_PHYSICAL_ADDRESS *PccSharedMemPointer,
+  IN  UINT16               NumberOfSubspaces
+  );
+
+/**
+  Free the whole shared memory region that is allocated by
+  the AcpiPccAllocateSharedMemory() function.
+
+**/
+VOID
+EFIAPI
+AcpiPccFreeSharedMemory (
+  VOID
+  );
+
+/**
+  Send a PCC message to the platform (SMpro/PMpro).
+
+  @param  Socket    The Socket ID.
+  @param  Doorbell  The Doorbell index from supported Doorbells per socket.
+  @param  Subspace  The Subspace index in the shared memory region.
+
+  @retval EFI_SUCCESS            Send the message successfully.
+  @retval EFI_INVALID_PARAMETER  The Socket, Doorbell or Subspace is out of the valid range.
+                                 The data buffer is NULL or the size of data buffer is zero.
+  @retval EFI_NOT_READY          The shared memory region is NULL.
+  @retval EFI_TIMEOUT            Timeout occurred when polling the PCC Command Complete bit.
+
+**/
+EFI_STATUS
+EFIAPI
+AcpiPccSendMessage (
+  IN UINT8  Socket,
+  IN UINT16 Doorbell,
+  IN UINT16 Subspace,
+  IN VOID   *DataBuffer,
+  IN UINT32 DataSize
+  );
+
+/**
+  Initialize the shared memory in the SMpro/PMpro Doorbell handler.
+  This function is to advertise the shared memory region address to the platform (SMpro/PMpro).
+
+  @param  Socket    The Socket ID.
+  @param  Doorbell  The Doorbell index from supported Doorbells per socket.
+  @param  Subspace  The Subspace index in the shared memory region.
+
+  @retval EFI_SUCCESS            Initialize successfully.
+  @retval EFI_INVALID_PARAMETER  The Socket, Doorbell or Subspace is out of the valid range.
+
+**/
+EFI_STATUS
+EFIAPI
+AcpiPccInitSharedMemory (
+  IN UINT8  Socket,
+  IN UINT16 Doorbell,
+  IN UINT16 Subspace
+  );
+
+/**
+  Unmask the Doorbell interrupt.
+
+  @param  Socket    The Socket ID.
+  @param  Doorbell  The Doorbell index from supported Doorbells per socket.
+
+  @retval EFI_SUCCESS            Unmask the Doorbell interrupt successfully.
+  @retval EFI_INVALID_PARAMETER  The Socket or Doorbell is out of the valid range.
+
+**/
+EFI_STATUS
+EFIAPI
+AcpiPccUnmaskDoorbellInterrupt (
+  IN UINT8  Socket,
+  IN UINT16 Doorbell
+  );
+
+/**
+  Check whether the Doorbell is reserved or not.
+
+  @param  Doorbell   The Doorbell index from supported Doorbells.
+
+  @retval TRUE         The Doorbell is reserved for private use or invalid.
+  @retval FALSE        The Doorbell is available.
+
+**/
+BOOLEAN
+EFIAPI
+AcpiPccIsDoorbellReserved (
+  IN UINT16 Doorbell
+  );
+
+#endif /* ACPI_PCC_LIB_H_ */
diff --git a/Platform/Ampere/AmperePlatformPkg/Library/AcpiPccLib/AcpiPccLib.c b/Platform/Ampere/AmperePlatformPkg/Library/AcpiPccLib/AcpiPccLib.c
new file mode 100644
index 000000000000..48e0b9e876ef
--- /dev/null
+++ b/Platform/Ampere/AmperePlatformPkg/Library/AcpiPccLib/AcpiPccLib.c
@@ -0,0 +1,241 @@
+/** @file
+
+  Copyright (c) 2020 - 2021, Ampere Computing LLC. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+
+#include <IndustryStandard/Acpi.h>
+#include <Library/AcpiPccLib.h>
+#include <Library/ArmLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/IoLib.h>
+#include <Library/PrintLib.h>
+#include <Library/TimerLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Platform/Ac01.h>
+
+STATIC EFI_PHYSICAL_ADDRESS mPccSharedMemoryAddress;
+STATIC UINTN                mPccSharedMemorySize;
+
+EFI_STATUS
+AcpiPccGetSharedMemoryAddress (
+  IN  UINT8  Socket,
+  IN  UINT16 Subspace,
+  OUT VOID   **SharedMemoryAddress
+  )
+{
+  if (Socket >= PLATFORM_CPU_MAX_SOCKET
+      || Subspace >= ACPI_PCC_MAX_SUBPACE)
+  {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (mPccSharedMemoryAddress == 0) {
+    return EFI_NOT_READY;
+  }
+
+  *SharedMemoryAddress = (VOID *)(mPccSharedMemoryAddress + ACPI_PCC_SUBSPACE_SHARED_MEM_SIZE * Subspace);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Allocate memory pages for the PCC shared memory region.
+
+  @param  PccSharedMemoryPtr     Pointer to the shared memory address.
+  @param  NumberOfSubspaces      Number of subspaces slot in the shared memory region.
+
+  @retval EFI_SUCCESS            Send the message successfully.
+  @retval EFI_INVALID_PARAMETER  TheNumberOfSubspaces is out of the valid range.
+  @retval Otherwise              Return errors from call to gBS->AllocatePages().
+
+**/
+EFI_STATUS
+EFIAPI
+AcpiPccAllocateSharedMemory (
+  OUT EFI_PHYSICAL_ADDRESS *PccSharedMemoryPtr,
+  IN  UINT16               NumberOfSubspaces
+  )
+{
+  EFI_STATUS Status;
+
+  if (NumberOfSubspaces > ACPI_PCC_MAX_SUBPACE) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  mPccSharedMemorySize = ACPI_PCC_SUBSPACE_SHARED_MEM_SIZE * NumberOfSubspaces;
+
+  Status = gBS->AllocatePages (
+                  AllocateAnyPages,
+                  EfiRuntimeServicesData,
+                  EFI_SIZE_TO_PAGES (mPccSharedMemorySize),
+                  &mPccSharedMemoryAddress
+                  );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "Failed to allocate PCC shared memory\n"));
+    mPccSharedMemorySize = 0;
+    return Status;
+  }
+
+  *PccSharedMemoryPtr = mPccSharedMemoryAddress;
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Free the whole shared memory region that is allocated by
+  the AcpiPccAllocateSharedMemory() function.
+
+**/
+VOID
+EFIAPI
+AcpiPccFreeSharedMemory (
+  VOID
+  )
+{
+  if (mPccSharedMemoryAddress != 0 && mPccSharedMemorySize != 0)
+  {
+    gBS->FreePages (
+           mPccSharedMemoryAddress,
+           EFI_SIZE_TO_PAGES (mPccSharedMemorySize)
+           );
+
+    mPccSharedMemoryAddress = 0;
+  }
+}
+
+/**
+  Initialize the shared memory in the SMpro/PMpro Doorbell handler.
+  This function is to advertise the shared memory region address to the platform (SMpro/PMpro).
+
+  @param  Socket    The Socket ID.
+  @param  Doorbell  The Doorbell index from supported Doorbells per socket.
+  @param  Subspace  The Subspace index in the shared memory region.
+
+  @retval EFI_SUCCESS            Initialize successfully.
+  @retval EFI_INVALID_PARAMETER  The Socket, Doorbell or Subspace is out of the valid range.
+
+**/
+EFI_STATUS
+EFIAPI
+AcpiPccInitSharedMemory (
+  IN UINT8  Socket,
+  IN UINT16 Doorbell,
+  IN UINT16 Subspace
+  )
+{
+  EFI_STATUS                                            Status;
+  EFI_ACPI_6_3_PCCT_GENERIC_SHARED_MEMORY_REGION_HEADER *PcctSharedMemoryRegion;
+  UINT32                                                CommunicationData;
+  UINTN                                                 Timeout;
+
+  if (Socket >= PLATFORM_CPU_MAX_SOCKET
+      || Doorbell >= NUMBER_OF_DOORBELLS_PER_SOCKET
+      || Subspace >= ACPI_PCC_MAX_SUBPACE)
+  {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Status = AcpiPccGetSharedMemoryAddress (Socket, Subspace, (VOID **)&PcctSharedMemoryRegion);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  //
+  // Zero shared memory region for each PCC subspace
+  //
+  SetMem (
+    (VOID *)PcctSharedMemoryRegion,
+    sizeof (EFI_ACPI_6_3_PCCT_GENERIC_SHARED_MEMORY_REGION_HEADER) + DB_PCC_MSG_PAYLOAD_SIZE,
+    0
+    );
+
+  // Advertise shared memory address to Platform (SMpro/PMpro)
+  // by ringing the doorbell with dummy PCC message
+  //
+  CommunicationData = DB_PCC_PAYLOAD_DUMMY;
+
+  //
+  // Write Data into Communication Space Region
+  //
+  CopyMem ((VOID *)(PcctSharedMemoryRegion + 1), &CommunicationData, sizeof (CommunicationData));
+
+  PcctSharedMemoryRegion->Status.CommandComplete = 0;
+  PcctSharedMemoryRegion->Signature = ACPI_PCC_SUBSPACE_SHARED_MEM_SIGNATURE | Subspace;
+
+  Status = MailboxMsgSetPccSharedMem (Socket, Doorbell, TRUE, (UINT64)PcctSharedMemoryRegion);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: Failed to send mailbox message!\n", __FUNCTION__));
+    ASSERT_EFI_ERROR (Status);
+    return Status;
+  }
+
+  //
+  // Polling CMD_COMPLETE bit
+  //
+  Timeout = ACPI_PCC_COMMAND_POLL_COUNT;
+  while (PcctSharedMemoryRegion->Status.CommandComplete != 1) {
+    if (--Timeout <= 0) {
+      DEBUG ((DEBUG_ERROR, "%a - Timeout occurred when polling the PCC Status Complete\n", __FUNCTION__));
+      return EFI_TIMEOUT;
+    }
+    MicroSecondDelay (ACPI_PCC_COMMAND_POLL_INTERVAL_US);
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Unmask the Doorbell interrupt.
+
+  @param  Socket    The Socket ID.
+  @param  Doorbell  The Doorbell index from supported Doorbells per socket.
+
+  @retval EFI_SUCCESS            Unmask the Doorbell interrupt successfully.
+  @retval EFI_INVALID_PARAMETER  The Socket or Doorbell is out of the valid range.
+
+**/
+EFI_STATUS
+EFIAPI
+AcpiPccUnmaskDoorbellInterrupt (
+  IN UINT8  Socket,
+  IN UINT16 Doorbell
+  )
+{
+  return MailboxUnmaskInterrupt (Socket, Doorbell);
+}
+
+/**
+  Check whether the Doorbell is reserved or not.
+
+  @param  Doorbell   The Doorbell index from supported Doorbells.
+
+  @retval TRUE         The Doorbell is reserved for private use or invalid.
+  @retval FALSE        The Doorbell is available.
+
+**/
+BOOLEAN
+EFIAPI
+AcpiPccIsDoorbellReserved (
+  IN UINT16 Doorbell
+  )
+{
+  if (Doorbell >= ACPI_PCC_MAX_DOORBELL) {
+    ASSERT (FALSE);
+    return TRUE;
+  }
+
+  if (((1 << Doorbell) & ACPI_PCC_AVAILABLE_DOORBELL_MASK) == 0) {
+    //
+    // The doorbell is reserved for private use.
+    //
+    return TRUE;
+  }
+
+  return FALSE;
+}
-- 
2.17.1