MdeModulePkg/Library/ArmFfaLib/ArmFfaPeiLib.c

/** @file
  Arm Ffa library code for PEI 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 <PiPei.h>
#include <Pi/PiPeiCis.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 <IndustryStandard/ArmFfaSvc.h>

#include <Guid/ArmFfaRxTxBufferInfo.h>

#include "ArmFfaCommon.h"
#include "ArmFfaRxTxMap.h"

STATIC UINT16   mPartId;
STATIC BOOLEAN  mIsFfaSupported;
STATIC BOOLEAN  mIsPermMemAvailable = FALSE;

/**
  Notification service to be called when gEfiPeiMemoryDiscoveredPpiGuid is installed.
  This function change reamp Rx/Tx buffer with permanent memory from
  temporary Rx/Tx buffer.

  Since, the Rx/Tx buffer is chanaged after gEfiPeiMemoryDiscoveredPpiGuid is installed,
  the Rx/Tx buffer should be gotten in each PEIM entrypoint
  via "ArmFfaGetRxTxBuffers()" for PEIM registered as shadow and
  call that function always then, it always gets proper Rx/Tx buffer.

  @param  PeiServices                 Indirect reference to the PEI Services Table.
  @param  NotifyDescriptor            Address of the notification descriptor data structure.
                                      Type EFI_PEI_NOTIFY_DESCRIPTOR is defined above.
  @param  Ppi                         Address of the PPI that was installed.

  @retval EFI_STATUS                  This function will install a PPI to PPI database.
                                      The status code will be the code for (*PeiServices)->InstallPpi.

**/
STATIC
EFI_STATUS
EFIAPI
PeiServicesMemoryDiscoveredNotifyCallback (
  IN EFI_PEI_SERVICES           **PeiServices,
  IN EFI_PEI_NOTIFY_DESCRIPTOR  *NotifyDescriptor,
  IN VOID                       *Ppi
  )
{
  EFI_HOB_GUID_TYPE          *RxTxBufferHob;
  ARM_FFA_RX_TX_BUFFER_INFO  *BufferInfo;

  RxTxBufferHob = GetFirstGuidHob (&gArmFfaRxTxBufferInfoGuid);
  ASSERT (RxTxBufferHob != NULL);
  BufferInfo = GET_GUID_HOB_DATA (RxTxBufferHob);

  return RemapFfaRxTxBuffer (BufferInfo);
}

STATIC EFI_PEI_NOTIFY_DESCRIPTOR  mNotifyOnPeiMemoryDiscovered = {
  (EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
  &gEfiPeiMemoryDiscoveredPpiGuid,
  PeiServicesMemoryDiscoveredNotifyCallback
};

/**
  ArmFfaLib Constructor.

  @param [in]   FileHandle        File Handle
  @param [in]   PeiServices       Pei Service Table

  @retval EFI_SUCCESS            Success
  @retval Others                 Error

**/
EFI_STATUS
EFIAPI
ArmFfaPeiLibConstructor (
  IN EFI_PEI_FILE_HANDLE     FileHandle,
  IN CONST EFI_PEI_SERVICES  **PeiServices
  )
{
  EFI_STATUS                 Status;
  EFI_HOB_GUID_TYPE          *RxTxBufferHob;
  ARM_FFA_RX_TX_BUFFER_INFO  *BufferInfo;
  VOID                       *Dummy;
  EFI_HOB_MEMORY_ALLOCATION  *RxTxBufferAllocationHob;
  UINTN                      Property1;
  UINTN                      Property2;
  UINT16                     PartId;
  BOOLEAN                    IsFfaSupported;

  Status = (**PeiServices).RegisterForShadow (FileHandle);
  if (Status == EFI_NOT_FOUND) {
    return Status;
  }

  /*
   * ArmFfaLibCommonInit() sets several pieces of information.
   * This function should only be called with globals when the PEIM is running in
   * permanent memory.
   */
  if (Status == EFI_ALREADY_STARTED) {
    mIsPermMemAvailable = TRUE;
    Status              = ArmFfaLibCommonInit (&mPartId, &mIsFfaSupported);
    if (EFI_ERROR (Status)) {
      if (!mIsFfaSupported) {
        /*
         * FF-A being unsupported doesn't mean a failure of loading the 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;
    }
  } else {
    /*
     * When permanent memory is unavailable, we need to use locals rather
     * than the globals.
     */
    Status = ArmFfaLibCommonInit (&PartId, &IsFfaSupported);
    if (EFI_ERROR (Status)) {
      if (!IsFfaSupported) {
        return EFI_SUCCESS;
      }

      return Status;
    }
  }

  RxTxBufferHob = GetFirstGuidHob (&gArmFfaRxTxBufferInfoGuid);
  if (RxTxBufferHob == NULL) {
    Status = ArmFfaLibRxTxMap ();
    if (EFI_ERROR (Status)) {
      if (Status != EFI_UNSUPPORTED) {
        return Status;
      }

      /*
       * When ARM_FID_FFA_PARTITION_INFO_GET_REGS is supported,
       * Rx/Tx buffer might not be required to request service to
       * secure partition.
       * So, consider EFI_UNSUPPORTED for Rx/Tx buffer as SUCCESS.
       */
      Status = ArmFfaLibGetFeatures (
                 ARM_FID_FFA_PARTITION_INFO_GET_REGS,
                 0x00,
                 &Property1,
                 &Property2
                 );
      if (!EFI_ERROR (Status)) {
        DEBUG ((DEBUG_INFO, "%a Rx/Tx buffer doesn't support.\n", __func__));
      }

      return Status;
    }

    BufferInfo = BuildGuidHob (
                   &gArmFfaRxTxBufferInfoGuid,
                   sizeof (ARM_FFA_RX_TX_BUFFER_INFO)
                   );
    if (BufferInfo == NULL) {
      ArmFfaLibRxTxUnmap ();
      return EFI_OUT_OF_RESOURCES;
    }

    UpdateRxTxBufferInfo (BufferInfo);

    /*
     * When permanent memory is used, gEfiPeiMemoryDiscoveredPpiGuid
     * is installed. If gEfiPeiMemoryDiscoveredPpiGuid is found,
     * It doesn't need to remap Rx/Tx buffer.
     */
    Status = (*PeiServices)->LocatePpi (
                               PeiServices,
                               &gEfiPeiMemoryDiscoveredPpiGuid,
                               0,
                               NULL,
                               &Dummy
                               );
    BufferInfo->RemapRequired = EFI_ERROR (Status);
  } else {
    BufferInfo = GET_GUID_HOB_DATA (RxTxBufferHob);
  }

  if (BufferInfo->RemapRequired) {
    /*
     * If RxTxBufferAllocationHob can be found with gArmFfaRxTxBufferInfoGuid,
     * This Rx/Tx buffer is mapped by ArmFfaSecLib.
     */
    RxTxBufferAllocationHob = FindRxTxBufferAllocationHob (TRUE);

    /*
     * Below case Rx/Tx buffer mapped by ArmPeiLib but in temporary memory.
     */
    if (RxTxBufferAllocationHob == NULL) {
      RxTxBufferAllocationHob = FindRxTxBufferAllocationHob (FALSE);
      ASSERT (RxTxBufferAllocationHob != NULL);
      BufferInfo->RemapOffset =
        (UINTN)(BufferInfo->TxBufferAddr -
                RxTxBufferAllocationHob->AllocDescriptor.MemoryBaseAddress);

      CopyGuid (
        &RxTxBufferAllocationHob->AllocDescriptor.Name,
        &gArmFfaRxTxBufferInfoGuid
        );
    }

    Status = (*PeiServices)->NotifyPpi (PeiServices, &mNotifyOnPeiMemoryDiscovered);

    /*
     * Failed to register NotifyPpi.
     * In this case, return ERROR to make failure of load for PPI
     * and postpone to remap to other PEIM.
     */
    if (EFI_ERROR (Status)) {
      return Status;
    }

    /*
     * Change RemapRequired to FALSE here to prevent other PEIM from
     * registering notification again.
     */
    BufferInfo->RemapRequired = FALSE;
  }

  return EFI_SUCCESS;
}

/**
  Return partition or VM ID

  @param[out] PartId  The partition or VM ID

  @retval EFI_SUCCESS  Partition ID or VM ID returned
  @retval Others       Errors

**/
EFI_STATUS
EFIAPI
ArmFfaLibGetPartId (
  OUT UINT16  *PartId
  )
{
  if (mIsPermMemAvailable) {
    *PartId = mPartId;
    return EFI_SUCCESS;
  } else {
    return ArmFfaLibPartitionIdGet (PartId);
  }
}

/**
  Check FF-A support or not.

  @retval TRUE                   Supported
  @retval FALSE                  Not supported

**/
BOOLEAN
EFIAPI
IsFfaSupported (
  IN VOID
  )
{
  if (mIsPermMemAvailable) {
    return mIsFfaSupported;
  }

  return ArmFfaLibIsFfaSupported ();
}

/**
  Callback for when Unmap is called to handle any post unmap
  functionality. In PEI the Rx/Tx buffer HOB needs to be
  invalidated.

**/
VOID
EFIAPI
UnmapCallback (
  IN VOID
  )
{
  EFI_HOB_MEMORY_ALLOCATION  *RxTxBufferAllocationHob;

  /*
   * Rx/Tx buffers are allocated with continuous pages.
   * See ArmFfaLibRxTxMap(). If HOB is not found, the Rx/Tx
   * buffers were not successfully mapped.
   */
  RxTxBufferAllocationHob = FindRxTxBufferAllocationHob (TRUE);
  if (RxTxBufferAllocationHob == NULL) {
    return;
  }

  /*
   * Invalidate the HOB.
   */
  ZeroMem (RxTxBufferAllocationHob, sizeof (ARM_FFA_RX_TX_BUFFER_INFO));
}