ArmPkg: Add ArmFfaLib used in Dxe driver

Add ArmFfaLib used in Dxe driver

Signed-off-by: Levi Yun <yeoreum.yun@arm.com>

ArmPkg/ArmPkg.dsc

@@ -70,6 +70,7 @@
   ArmGicLib|ArmPkg/Drivers/ArmGic/ArmGicLib.inf
   ArmGicArchLib|ArmPkg/Library/ArmGicArchLib/ArmGicArchLib.inf
   ArmGenericTimerCounterLib|ArmPkg/Library/ArmGenericTimerPhyCounterLib/ArmGenericTimerPhyCounterLib.inf
+  ArmSvcLib|ArmPkg/Library/ArmSvcLib/ArmSvcLib.inf
   ArmSmcLib|ArmPkg/Library/ArmSmcLib/ArmSmcLib.inf
   ArmDisassemblerLib|ArmPkg/Library/ArmDisassemblerLib/ArmDisassemblerLib.inf
   OpteeLib|ArmPkg/Library/OpteeLib/OpteeLib.inf
@@ -87,6 +88,7 @@
   ArmLib|ArmPkg/Library/ArmLib/ArmBaseLib.inf
   ArmMmuLib|ArmPkg/Library/ArmMmuLib/ArmMmuBaseLib.inf
   ArmTransferListLib|ArmPkg/Library/ArmTransferListLib/ArmTransferListLib.inf
+  ArmFfaLib|ArmPkg/Library/ArmFfaLib/ArmFfaDxeLib.inf
 
   ArmMtlLib|ArmPkg/Library/ArmMtlNullLib/ArmMtlNullLib.inf
 
@@ -131,6 +133,7 @@
   ArmPkg/Library/ArmSvcLib/ArmSvcLib.inf
   ArmPkg/Library/OpteeLib/OpteeLib.inf
   ArmPkg/Library/ArmTransferListLib/ArmTransferListLib.inf
+  ArmPkg/Library/ArmFfaLib/ArmFfaDxeLib.inf
 
   ArmPkg/Filesystem/SemihostFs/SemihostFs.inf
 

ArmPkg/Library/ArmFfaLib/ArmFfaCommon.h

@@ -0,0 +1,76 @@
+/** @file
+  Arm FF-A ns common library Header file
+
+  Copyright (c) 2024, Arm Limited. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Glossary:
+     - FF-A - Firmware Framework for Arm A-profile
+     - spmc - Secure Partition Manager Core
+     - spmd - Secure Partition Manager Dispatcher
+
+  @par Reference(s):
+     - Arm Firmware Framework for Arm A-Profile [https://developer.arm.com/documentation/den0077/latest]
+
+**/
+
+#ifndef ARM_FFA_COMMON_LIB_H_
+#define ARM_FFA_COMMON_LIB_H_
+
+/**
+ * Arguments to call FF-A request via SMC/SVC.
+ */
+typedef struct ArmFfaArgs {
+  UINTN    Arg0;
+  UINTN    Arg1;
+  UINTN    Arg2;
+  UINTN    Arg3;
+  UINTN    Arg4;
+  UINTN    Arg5;
+  UINTN    Arg6;
+  UINTN    Arg7;
+} ARM_FFA_ARGS;
+
+extern BOOLEAN  gFfaSupported;
+extern UINT16   gPartId;
+
+/**
+  Convert FfArgs to EFI_STATUS.
+
+  @param [in] FfaArgs            Ffa arguments
+
+  @retval EFI_STATUS             return value correspond EFI_STATUS to FfaStatus
+
+**/
+EFI_STATUS
+EFIAPI
+FfaArgsToEfiStatus (
+  IN ARM_FFA_ARGS  *FfaArgs
+  );
+
+/**
+  Trigger FF-A ABI call according to PcdFfaLibConduitSmc.
+
+  @param [in out]  FfaArgs        Ffa arguments
+
+**/
+VOID
+EFIAPI
+ArmCallFfa (
+  IN OUT ARM_FFA_ARGS  *FfaArgs
+  );
+
+/**
+  Common ArmFfaLib Constructor.
+
+  @retval EFI_SUCCESS
+  @retval Others                  Error
+
+**/
+EFI_STATUS
+EFIAPI
+ArmFfaLibCommonInit (
+  IN VOID
+  );
+
+#endif

ArmPkg/Library/ArmFfaLib/ArmFfaDxeLib.c

@@ -0,0 +1,158 @@
+/** @file
+  Arm Ffa library code for Dxe Driver
+
+  Copyright (c) 2024, Arm Limited. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+   @par Glossary:
+     - FF-A - Firmware Framework for Arm A-profile
+
+   @par Reference(s):
+     - Arm Firmware Framework for Arm A-Profile [https://developer.arm.com/documentation/den0077/latest]
+
+**/
+
+#include <Uefi.h>
+#include <Pi/PiMultiPhase.h>
+
+#include <Library/ArmLib.h>
+#include <Library/ArmSmcLib.h>
+#include <Library/ArmFfaLib.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/PcdLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+#include <IndustryStandard/ArmFfaSvc.h>
+
+#include "ArmFfaCommon.h"
+#include "ArmFfaRxTxMap.h"
+
+STATIC EFI_EVENT  mFfaExitBootServiceEvent;
+
+/**
+  Unmap RX/TX buffer on Exit Boot Service.
+
+  @param [in]   Event      Registered exit boot service event.
+  @param [in]   Context    Additional data.
+
+**/
+STATIC
+VOID
+EFIAPI
+ArmFfaLibExitBootServiceEvent (
+  IN EFI_EVENT  Event,
+  IN VOID       *Context
+  )
+{
+  ArmFfaLibRxTxUnmap ();
+}
+
+/**
+  ArmFfaLib Constructor.
+
+  @param [in]   ImageHandle      Image Handle
+  @param [in]   SystemTable      System Table
+
+  @retval EFI_SUCCESS            Success
+  @retval EFI_INVALID_PARAMETER  Invalid alignment of Rx/Tx buffer
+  @retval EFI_OUT_OF_RESOURCES   Out of memory
+  @retval Others                 Error
+
+**/
+EFI_STATUS
+EFIAPI
+ArmFfaDxeLibConstructor (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS                 Status;
+  EFI_HOB_GUID_TYPE          *RxTxBufferHob;
+  ARM_FFA_RX_TX_BUFFER_INFO  *BufferInfo;
+
+  Status = ArmFfaLibCommonInit ();
+  if (EFI_ERROR (Status)) {
+    if (Status == EFI_UNSUPPORTED) {
+      /*
+       * EFI_UNSUPPORTED return from ArmFfaLibCommonInit() means
+       * FF-A interface doesn't support.
+       * However, It doesn't make failure of loading driver/library instance
+       * (i.e) ArmPkg's MmCommunication Dxe/PEI Driver uses as well as SpmMm.
+       * So If FF-A is not supported the the MmCommunication Dxe/PEI falls
+       * back to SpmMm.
+       * For this case, return EFI_SUCCESS.
+       */
+      return EFI_SUCCESS;
+    }
+
+    return Status;
+  }
+
+  if (PcdGetBool (PcdFfaExitBootEventRegistered)) {
+    return EFI_SUCCESS;
+  }
+
+  /*
+   * If PEIM uses ArmFfaPeiLib, the Rx/Tx buffers is already mapped in PEI phase.
+   * In this case, get Rx/Tx buffer info from Hob.
+   */
+  RxTxBufferHob = GetFirstGuidHob (&gArmFfaRxTxBufferInfoGuid);
+  if (RxTxBufferHob != NULL) {
+    BufferInfo = GET_GUID_HOB_DATA (RxTxBufferHob);
+    PcdSet64S (PcdFfaTxBuffer, (UINTN)BufferInfo->TxBufferAddr);
+    PcdSet64S (PcdFfaRxBuffer, (UINTN)BufferInfo->RxBufferAddr);
+  } else {
+    Status = ArmFfaLibRxTxMap ();
+
+    /*
+     * When first Dxe instance (library or driver) which uses ArmFfaLib loaded,
+     * It already maps Rx/Tx buffer.
+     * From Next Dxe instance which uses ArmFfaLib it doesn't need to map Rx/Tx
+     * buffer again but it uses the mapped one.
+     * ArmFfaLibRxTxMap() returns EFI_ALREADY_STARTED when the Rx/Tx buffers
+     * already maps.
+     */
+    if ((Status != EFI_SUCCESS) && (Status != EFI_ALREADY_STARTED)) {
+      DEBUG ((
+        DEBUG_ERROR,
+        "%a: Failed to Map Rx/Tx buffer. Status: %r\n",
+        __func__,
+        Status
+        ));
+      return Status;
+    }
+  }
+
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_CALLBACK,
+                  ArmFfaLibExitBootServiceEvent,
+                  NULL,
+                  &gEfiEventExitBootServicesGuid,
+                  &mFfaExitBootServiceEvent
+                  );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: Failed to register ExitBootService event. Status: %r\n",
+      __func__,
+      Status
+      ));
+    goto ErrorHandler;
+  }
+
+  PcdSetBoolS (PcdFfaExitBootEventRegistered, TRUE);
+
+  return EFI_SUCCESS;
+
+ErrorHandler:
+  if (RxTxBufferHob != NULL) {
+    ArmFfaLibRxTxUnmap ();
+  }
+
+  return Status;
+}

ArmPkg/Library/ArmFfaLib/ArmFfaDxeLib.inf

@@ -0,0 +1,46 @@
+## @file
+#  Provides FF-A ABI Library used in Dxe Driver.
+#
+#  Copyright (c) 2024, Arm Limited. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = ArmFfaDxeLib
+  FILE_GUID                      = e2a8e040-5346-11ef-8454-eff3c163f615
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = ArmFfaLib|DXE_DRIVER DXE_RUNTIME_DRIVER UEFI_APPLICATION UEFI_DRIVER
+  CONSTRUCTOR                    = ArmFfaDxeLibConstructor
+
+[Sources]
+  ArmFfaCommon.h
+  ArmFfaCommon.c
+  ArmFfaRxTxMap.h
+  ArmFfaRxTxMap.c
+  ArmFfaDxeLib.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  ArmPkg/ArmPkg.dec
+
+[LibraryClasses]
+  ArmSmcLib
+  ArmSvcLib
+  BaseLib
+  BaseMemoryLib
+  DebugLib
+  HobLib
+
+[Pcd]
+  gArmTokenSpaceGuid.PcdFfaLibConduitSmc
+  gArmTokenSpaceGuid.PcdFfaTxBuffer
+  gArmTokenSpaceGuid.PcdFfaRxBuffer
+  gArmTokenSpaceGuid.PcdFfaTxRxPageCount
+  gArmTokenSpaceGuid.PcdFfaExitBootEventRegistered
+
+[Guids]
+  gArmFfaRxTxBufferInfoGuid
+  gEfiEventExitBootServicesGuid

ArmPkg/Library/ArmFfaLib/ArmFfaRxTxMap.c

@@ -0,0 +1,272 @@
+/** @file
+  Arm Ffa library common code.
+
+  Copyright (c) 2024, Arm Limited. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+   @par Glossary:
+     - FF-A - Firmware Framework for Arm A-profile
+
+   @par Reference(s):
+     - Arm Firmware Framework for Arm A-Profile [https://developer.arm.com/documentation/den0077/latest]
+
+**/
+#include <Uefi.h>
+#include <Pi/PiMultiPhase.h>
+
+#include <Library/ArmLib.h>
+#include <Library/ArmFfaLib.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/PcdLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+#include <IndustryStandard/ArmFfaSvc.h>
+
+#include "ArmFfaCommon.h"
+#include "ArmFfaRxTxMap.h"
+
+/**
+  Get mapped Rx/Tx buffers.
+
+  @param [out]   TxBuffer         Address of TxBuffer
+  @param [out]   TxBufferSize     Size of TxBuffer
+  @param [out]   RxBuffer         Address of RxBuffer
+  @param [out]   RxBufferSize     Size of RxBuffer
+
+  @retval EFI_SUCCESS
+  @retval Others             Error.
+
+**/
+EFI_STATUS
+EFIAPI
+ArmFfaLibGetRxTxBuffers (
+  OUT VOID    **TxBuffer OPTIONAL,
+  OUT UINT64  *TxBufferSize OPTIONAL,
+  OUT VOID    **RxBuffer OPTIONAL,
+  OUT UINT64  *RxBufferSize OPTIONAL
+  )
+{
+  UINTN  TxBufferAddr;
+  UINTN  RxBufferAddr;
+
+  TxBufferAddr = (UINTN)PcdGet64 (PcdFfaTxBuffer);
+  RxBufferAddr = (UINTN)PcdGet64 (PcdFfaRxBuffer);
+
+  if ((TxBufferAddr == 0x00) || (RxBufferAddr == 0x00)) {
+    return EFI_NOT_READY;
+  }
+
+  if (TxBuffer != NULL) {
+    *TxBuffer = (VOID *)TxBufferAddr;
+  }
+
+  if (TxBufferSize != NULL) {
+    *TxBufferSize = PcdGet64 (PcdFfaTxRxPageCount) * EFI_PAGE_SIZE;
+  }
+
+  if (RxBuffer != NULL) {
+    *RxBuffer = (VOID *)RxBufferAddr;
+  }
+
+  if (RxBufferSize != NULL) {
+    *RxBufferSize = PcdGet64 (PcdFfaTxRxPageCount) * EFI_PAGE_SIZE;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Mapping Rx/Tx buffers.
+  This function is only called in ArmFfaLibConstructor because
+  Rx/Tx buffer is registered only once per partition.
+
+  @retval EFI_SUCCESS
+  @retval EFI_ALREADY_STARTED     Rx/Tx buffer already mapped.
+  @retval EFI_OUT_OF_RESOURCE     Out of memory
+  @retval EFI_INVALID_PARAMETER   Invalid alignment of Rx/Tx buffer
+  @retval Others                  Error
+
+**/
+EFI_STATUS
+EFIAPI
+ArmFfaLibRxTxMap (
+  IN VOID
+  )
+{
+  EFI_STATUS    Status;
+  ARM_FFA_ARGS  FfaArgs;
+  UINTN         Property1;
+  UINTN         Property2;
+  UINTN         MinSizeAndAlign;
+  UINTN         MaxSize;
+  VOID          *Buffers;
+  VOID          *TxBuffer;
+  VOID          *RxBuffer;
+  UINT64        BufferSize;
+
+  TxBuffer   = (VOID *)(UINTN)PcdGet64 (PcdFfaTxBuffer);
+  RxBuffer   = (VOID *)(UINTN)PcdGet64 (PcdFfaRxBuffer);
+  BufferSize = PcdGet64 (PcdFfaTxRxPageCount) * EFI_PAGE_SIZE;
+
+  /*
+   * If someone already mapped Rx/Tx Buffers, return EFI_ALREADY_STARTED.
+   * return EFI_ALREADY_STARTED.
+   */
+  if ((TxBuffer != NULL) && (RxBuffer != NULL)) {
+    return EFI_ALREADY_STARTED;
+  }
+
+  Status = ArmFfaLibGetFeatures (
+             ARM_FID_FFA_RXTX_MAP,
+             FFA_RXTX_MAP_INPUT_PROPERTY_DEFAULT,
+             &Property1,
+             &Property2
+             );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: Failed to get RX/TX buffer property... Status: %r\n",
+      __func__,
+      Status
+      ));
+    return Status;
+  }
+
+  ZeroMem (&FfaArgs, sizeof (ARM_FFA_ARGS));
+
+  MinSizeAndAlign =
+    ((Property1 >>
+      ARM_FFA_BUFFER_MINSIZE_AND_ALIGN_SHIFT) &
+     ARM_FFA_BUFFER_MINSIZE_AND_ALIGN_MASK);
+
+  switch (MinSizeAndAlign) {
+    case ARM_FFA_BUFFER_MINSIZE_AND_ALIGN_4K:
+      MinSizeAndAlign = SIZE_4KB;
+      break;
+    case ARM_FFA_BUFFER_MINSIZE_AND_ALIGN_16K:
+      MinSizeAndAlign = SIZE_16KB;
+      break;
+    case ARM_FFA_BUFFER_MINSIZE_AND_ALIGN_64K:
+      MinSizeAndAlign = SIZE_64KB;
+      break;
+    default:
+      DEBUG ((DEBUG_ERROR, "%a: Invalid MinSizeAndAlign: 0x%x\n", __func__, MinSizeAndAlign));
+      return EFI_UNSUPPORTED;
+  }
+
+  MaxSize =
+    (((Property1 >>
+       ARM_FFA_BUFFER_MAXSIZE_PAGE_COUNT_SHIFT) &
+      ARM_FFA_BUFFER_MAXSIZE_PAGE_COUNT_MASK));
+
+  MaxSize = ((MaxSize == 0) ? MAX_UINTN : (MaxSize * MinSizeAndAlign));
+
+  if ((MinSizeAndAlign > (PcdGet64 (PcdFfaTxRxPageCount) * EFI_PAGE_SIZE)) ||
+      (MaxSize < (PcdGet64 (PcdFfaTxRxPageCount) * EFI_PAGE_SIZE)))
+  {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: Buffer is too small! MinSize: 0x%x, MaxSize: 0x%x, PageCount: %d\n",
+      __func__,
+      MinSizeAndAlign,
+      MaxSize,
+      PcdGet64 (PcdFfaTxRxPageCount)
+      ));
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Buffers = AllocateAlignedPages ((PcdGet64 (PcdFfaTxRxPageCount) * 2), MinSizeAndAlign);
+  if (Buffers == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  TxBuffer = Buffers;
+  RxBuffer = Buffers + BufferSize;
+
+  FfaArgs.Arg0 = ARM_FID_FFA_RXTX_MAP;
+  FfaArgs.Arg1 = (UINTN)TxBuffer;
+  FfaArgs.Arg2 = (UINTN)RxBuffer;
+
+  /*
+   * PcdFfaTxRxPageCount sets with count of EFI_PAGE_SIZE granularity
+   * But, PageCounts for Tx/Rx buffer should set with
+   * count of Tx/Rx Buffer's MinSizeAndAlign. granularity.
+   */
+  FfaArgs.Arg3 = PcdGet64 (PcdFfaTxRxPageCount) / EFI_SIZE_TO_PAGES (MinSizeAndAlign);
+
+  ArmCallFfa (&FfaArgs);
+
+  Status = FfaArgsToEfiStatus (&FfaArgs);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: Failed to map Rx/Tx buffer. Status: %r\n",
+      __func__,
+      Status
+      ));
+    goto ErrorHandler;
+  }
+
+  PcdSet64S (PcdFfaTxBuffer, (UINTN)TxBuffer);
+  PcdSet64S (PcdFfaRxBuffer, (UINTN)RxBuffer);
+
+  return EFI_SUCCESS;
+
+ErrorHandler:
+  FreeAlignedPages (Buffers, (PcdGet64 (PcdFfaTxRxPageCount) * 2));
+  TxBuffer = NULL;
+  RxBuffer = NULL;
+
+  return Status;
+}
+
+/**
+  Unmap Rx/Tx buffer.
+  This function is only called in Exit boot service because
+  Rx/Tx buffer is registered only once per partition.
+
+  @retval EFI_SUCCESS
+  @retval EFI_INVALID_PARAMETERS               Already unregistered
+  @retval EFI_UNSUPPORTED                      Not supported
+
+**/
+EFI_STATUS
+EFIAPI
+ArmFfaLibRxTxUnmap (
+  IN VOID
+  )
+{
+  EFI_STATUS    Status;
+  ARM_FFA_ARGS  FfaArgs;
+  VOID          *Buffers;
+
+  ZeroMem (&FfaArgs, sizeof (ARM_FFA_ARGS));
+
+  FfaArgs.Arg0 = ARM_FID_FFA_RXTX_UNMAP;
+  FfaArgs.Arg1 = (gPartId << ARM_FFA_SOURCE_EP_SHIFT);
+
+  ArmCallFfa (&FfaArgs);
+
+  Status = FfaArgsToEfiStatus (&FfaArgs);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  /*
+   * Rx/Tx Buffer are allocated with continuous pages.
+   * and start address of these pages is set on PcdFfaTxBuffer.
+   * See ArmFfaLibRxTxMap().
+   */
+  Buffers = (VOID *)(UINTN)PcdGet64 (PcdFfaTxBuffer);
+  if (Buffers != NULL) {
+    FreeAlignedPages (Buffers, (PcdGet64 (PcdFfaTxRxPageCount) * 2));
+  }
+
+  PcdSet64S (PcdFfaTxBuffer, 0x00);
+  PcdSet64S (PcdFfaRxBuffer, 0x00);
+
+  return EFI_SUCCESS;
+}

ArmPkg/Library/ArmFfaLib/ArmFfaRxTxMap.h

@@ -0,0 +1,71 @@
+/** @file
+  Arm FF-A ns common library Header file
+
+  Copyright (c) 2024, Arm Limited. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Glossary:
+     - FF-A - Firmware Framework for Arm A-profile
+     - spmc - Secure Partition Manager Core
+     - spmd - Secure Partition Manager Dispatcher
+
+  @par Reference(s):
+     - Arm Firmware Framework for Arm A-Profile [https://developer.arm.com/documentation/den0077/latest]
+
+**/
+
+#ifndef ARM_FFA_RX_TX_MAP_LIB_H_
+#define ARM_FFA_RX_TX_MAP_LIB_H_
+
+/**
+ * Guid Hob Data for gArmFfaRxTxBufferInfoGuid Guid Hob.
+ */
+typedef struct ArmFfaRxTxBuffersInfo {
+  /// Tx Buffer Address.
+  VOID      *TxBufferAddr;
+
+  /// Tx Buffer Size.
+  UINT64    TxBufferSize;
+
+  /// Rx Buffer Address.
+  VOID      *RxBufferAddr;
+
+  /// Rx Buffer Size.
+  UINT64    RxBufferSize;
+} ARM_FFA_RX_TX_BUFFER_INFO;
+
+/**
+  Mapping Rx/Tx buffers.
+  This function is only called in ArmFfaLibConstructor because
+  Rx/Tx buffer is registered only once per partition.
+
+  @retval EFI_SUCCESS
+  @retval EFI_ALREADY_STARTED     Rx/Tx buffer already mapped in PEI phase
+  @retval EFI_OUT_OF_RESOURCE     Out of memory
+  @retval EFI_INVALID_PARAMETER   Invalid alignment of Rx/Tx buffer
+  @retval Others                  Error
+
+**/
+EFI_STATUS
+EFIAPI
+ArmFfaLibRxTxMap (
+  IN VOID
+  );
+
+/**
+  Unmap Rx/Tx buffer.
+  This function is only called in Exit boot service because
+  Rx/Tx buffer is registered only once per partition.
+
+  @retval EFI_SUCCESS
+  @retval EFI_INVALID_PARAMETERS               Already unregistered
+  @retval EFI_UNSUPPORTED                      Not supported
+
+**/
+EFI_STATUS
+EFIAPI
+ArmFfaLibRxTxUnmap (
+  IN VOID
+  );
+
+#endif