/** @file

  Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.<BR>

  This program and the accompanying materials are licensed and made available under
  the terms and conditions of the BSD License which accompanies this distribution.
  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include <Uefi.h>
#include <PiPei.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/IoLib.h>
#include <Library/DebugLib.h>
#include <Library/PeiServicesLib.h>
#include <Library/HobLib.h>
#include <IndustryStandard/Vtd.h>
#include <Ppi/IoMmu.h>
#include <Ppi/VtdInfo.h>
#include <Ppi/MemoryDiscovered.h>
#include <Ppi/EndOfPeiPhase.h>

#include "IntelVTdPmrPei.h"

EFI_GUID mVTdInfoGuid = {
  0x222f5e30, 0x5cd, 0x49c6, { 0x8a, 0xc, 0x36, 0xd6, 0x58, 0x41, 0xe0, 0x82 }
};

EFI_GUID mDmaBufferInfoGuid = {
  0x7b624ec7, 0xfb67, 0x4f9c, { 0xb6, 0xb0, 0x4d, 0xfa, 0x9c, 0x88, 0x20, 0x39 }
};

typedef struct {
  UINTN                             DmaBufferBase;
  UINTN                             DmaBufferSize;
  UINTN                             DmaBufferCurrentTop;
  UINTN                             DmaBufferCurrentBottom;
} DMA_BUFFER_INFO;

#define MAP_INFO_SIGNATURE  SIGNATURE_32 ('D', 'M', 'A', 'P')
typedef struct {
  UINT32                                    Signature;
  EDKII_IOMMU_OPERATION                     Operation;
  UINTN                                     NumberOfBytes;
  EFI_PHYSICAL_ADDRESS                      HostAddress;
  EFI_PHYSICAL_ADDRESS                      DeviceAddress;
} MAP_INFO;

/**

  PEI Memory Layout:

              +------------------+ <=============== PHMR.Limit (+ alignment) (1 << (HostAddressWidth + 1))
              |   Mem Resource   |
              |                  |

              +------------------+ <------- EfiMemoryTop
              |   PEI allocated  |
  =========== +==================+ <=============== PHMR.Base
       ^      |    Commom Buf    |
       |      |  --------------  |
  DMA Buffer  |   * DMA FREE *   |
       |      |  --------------  |
       V      |  Read/Write Buf  |
  =========== +==================+ <=============== PLMR.Limit (+ alignment)
              |   PEI allocated  |
              |  --------------  | <------- EfiFreeMemoryTop
              |   * PEI FREE *   |
              |  --------------  | <------- EfiFreeMemoryBottom
              |       hob        |
              |  --------------  |
              |      Stack       |
              +------------------+ <------- EfiMemoryBottom / Stack Bottom

              +------------------+
              |   Mem Alloc Hob  |
              +------------------+

              |                  |
              |   Mem Resource   |
              +------------------+ <=============== PLMR.Base (0)
**/

/**
  Set IOMMU attribute for a system memory.

  If the IOMMU PPI exists, the system memory cannot be used
  for DMA by default.

  When a device requests a DMA access for a system memory,
  the device driver need use SetAttribute() to update the IOMMU
  attribute to request DMA access (read and/or write).

  @param[in]  This              The PPI instance pointer.
  @param[in]  Mapping           The mapping value returned from Map().
  @param[in]  IoMmuAccess       The IOMMU access.

  @retval EFI_SUCCESS            The IoMmuAccess is set for the memory range specified by DeviceAddress and Length.
  @retval EFI_INVALID_PARAMETER  Mapping is not a value that was returned by Map().
  @retval EFI_INVALID_PARAMETER  IoMmuAccess specified an illegal combination of access.
  @retval EFI_UNSUPPORTED        The bit mask of IoMmuAccess is not supported by the IOMMU.
  @retval EFI_UNSUPPORTED        The IOMMU does not support the memory range specified by Mapping.
  @retval EFI_OUT_OF_RESOURCES   There are not enough resources available to modify the IOMMU access.
  @retval EFI_DEVICE_ERROR       The IOMMU device reported an error while attempting the operation.
  @retval EFI_NOT_AVAILABLE_YET  DMA protection has been enabled, but DMA buffer are
                                 not available to be allocated yet.

**/
EFI_STATUS
EFIAPI
PeiIoMmuSetAttribute (
  IN EDKII_IOMMU_PPI       *This,
  IN VOID                  *Mapping,
  IN UINT64                IoMmuAccess
  )
{
  VOID                        *Hob;
  DMA_BUFFER_INFO             *DmaBufferInfo;

  Hob = GetFirstGuidHob (&mDmaBufferInfoGuid);
  DmaBufferInfo = GET_GUID_HOB_DATA(Hob);

  if (DmaBufferInfo->DmaBufferCurrentTop == 0) {
    return EFI_NOT_AVAILABLE_YET;
  }

  return EFI_SUCCESS;
}

/**
  Provides the controller-specific addresses required to access system memory from a
  DMA bus master.

  @param  This                  The PPI instance pointer.
  @param  Operation             Indicates if the bus master is going to read or write to system memory.
  @param  HostAddress           The system memory address to map to the PCI controller.
  @param  NumberOfBytes         On input the number of bytes to map. On output the number of bytes
                                that were mapped.
  @param  DeviceAddress         The resulting map address for the bus master PCI controller to use to
                                access the hosts HostAddress.
  @param  Mapping               A resulting value to pass to Unmap().

  @retval EFI_SUCCESS           The range was mapped for the returned NumberOfBytes.
  @retval EFI_UNSUPPORTED       The HostAddress cannot be mapped as a common buffer.
  @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
  @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.
  @retval EFI_DEVICE_ERROR      The system hardware could not map the requested address.
  @retval EFI_NOT_AVAILABLE_YET DMA protection has been enabled, but DMA buffer are
                                not available to be allocated yet.

**/
EFI_STATUS
EFIAPI
PeiIoMmuMap (
  IN     EDKII_IOMMU_PPI                            *This,
  IN     EDKII_IOMMU_OPERATION                      Operation,
  IN     VOID                                       *HostAddress,
  IN OUT UINTN                                      *NumberOfBytes,
  OUT    EFI_PHYSICAL_ADDRESS                       *DeviceAddress,
  OUT    VOID                                       **Mapping
  )
{
  MAP_INFO                    *MapInfo;
  UINTN                       Length;
  VOID                        *Hob;
  DMA_BUFFER_INFO             *DmaBufferInfo;

  Hob = GetFirstGuidHob (&mDmaBufferInfoGuid);
  DmaBufferInfo = GET_GUID_HOB_DATA(Hob);

  DEBUG ((DEBUG_VERBOSE, "PeiIoMmuMap - HostAddress - 0x%x, NumberOfBytes - %x\n", HostAddress, *NumberOfBytes));
  DEBUG ((DEBUG_VERBOSE, "  DmaBufferCurrentTop - %x\n", DmaBufferInfo->DmaBufferCurrentTop));
  DEBUG ((DEBUG_VERBOSE, "  DmaBufferCurrentBottom - %x\n", DmaBufferInfo->DmaBufferCurrentBottom));

  if (DmaBufferInfo->DmaBufferCurrentTop == 0) {
    return EFI_NOT_AVAILABLE_YET;
  }

  if (Operation == EdkiiIoMmuOperationBusMasterCommonBuffer ||
      Operation == EdkiiIoMmuOperationBusMasterCommonBuffer64) {
    *DeviceAddress = (UINTN)HostAddress;
    *Mapping = NULL;
    return EFI_SUCCESS;
  }

  Length = *NumberOfBytes + sizeof(MAP_INFO);
  if (Length > DmaBufferInfo->DmaBufferCurrentTop - DmaBufferInfo->DmaBufferCurrentBottom) {
    DEBUG ((DEBUG_ERROR, "PeiIoMmuMap - OUT_OF_RESOURCE\n"));
    ASSERT (FALSE);
    return EFI_OUT_OF_RESOURCES;
  }

  *DeviceAddress = DmaBufferInfo->DmaBufferCurrentBottom;
  DmaBufferInfo->DmaBufferCurrentBottom += Length;

  MapInfo = (VOID *)(UINTN)(*DeviceAddress + *NumberOfBytes);
  MapInfo->Signature     = MAP_INFO_SIGNATURE;
  MapInfo->Operation     = Operation;
  MapInfo->NumberOfBytes = *NumberOfBytes;
  MapInfo->HostAddress   = (UINTN)HostAddress;
  MapInfo->DeviceAddress = *DeviceAddress;
  *Mapping = MapInfo;
  DEBUG ((DEBUG_VERBOSE, "  Op(%x):DeviceAddress - %x, Mapping - %x\n", Operation, (UINTN)*DeviceAddress, MapInfo));

  //
  // If this is a read operation from the Bus Master's point of view,
  // then copy the contents of the real buffer into the mapped buffer
  // so the Bus Master can read the contents of the real buffer.
  //
  if (Operation == EdkiiIoMmuOperationBusMasterRead ||
      Operation == EdkiiIoMmuOperationBusMasterRead64) {
    CopyMem (
      (VOID *) (UINTN) MapInfo->DeviceAddress,
      (VOID *) (UINTN) MapInfo->HostAddress,
      MapInfo->NumberOfBytes
      );
  }

  return EFI_SUCCESS;
}

/**
  Completes the Map() operation and releases any corresponding resources.

  @param  This                  The PPI instance pointer.
  @param  Mapping               The mapping value returned from Map().

  @retval EFI_SUCCESS           The range was unmapped.
  @retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by Map().
  @retval EFI_DEVICE_ERROR      The data was not committed to the target system memory.
  @retval EFI_NOT_AVAILABLE_YET DMA protection has been enabled, but DMA buffer are
                                not available to be allocated yet.

**/
EFI_STATUS
EFIAPI
PeiIoMmuUnmap (
  IN  EDKII_IOMMU_PPI                          *This,
  IN  VOID                                     *Mapping
  )
{
  MAP_INFO                    *MapInfo;
  UINTN                       Length;
  VOID                        *Hob;
  DMA_BUFFER_INFO             *DmaBufferInfo;

  Hob = GetFirstGuidHob (&mDmaBufferInfoGuid);
  DmaBufferInfo = GET_GUID_HOB_DATA(Hob);

  DEBUG ((DEBUG_VERBOSE, "PeiIoMmuUnmap - Mapping - %x\n", Mapping));
  DEBUG ((DEBUG_VERBOSE, "  DmaBufferCurrentTop - %x\n", DmaBufferInfo->DmaBufferCurrentTop));
  DEBUG ((DEBUG_VERBOSE, "  DmaBufferCurrentBottom - %x\n", DmaBufferInfo->DmaBufferCurrentBottom));

  if (DmaBufferInfo->DmaBufferCurrentTop == 0) {
    return EFI_NOT_AVAILABLE_YET;
  }

  if (Mapping == NULL) {
    return EFI_SUCCESS;
  }

  MapInfo = Mapping;
  ASSERT (MapInfo->Signature == MAP_INFO_SIGNATURE);
  DEBUG ((DEBUG_VERBOSE, "  Op(%x):DeviceAddress - %x, NumberOfBytes - %x\n", MapInfo->Operation, (UINTN)MapInfo->DeviceAddress, MapInfo->NumberOfBytes));

  //
  // If this is a write operation from the Bus Master's point of view,
  // then copy the contents of the mapped buffer into the real buffer
  // so the processor can read the contents of the real buffer.
  //
  if (MapInfo->Operation == EdkiiIoMmuOperationBusMasterWrite ||
      MapInfo->Operation == EdkiiIoMmuOperationBusMasterWrite64) {
    CopyMem (
      (VOID *) (UINTN) MapInfo->HostAddress,
      (VOID *) (UINTN) MapInfo->DeviceAddress,
      MapInfo->NumberOfBytes
      );
  }

  Length = MapInfo->NumberOfBytes + sizeof(MAP_INFO);
  if (DmaBufferInfo->DmaBufferCurrentBottom == MapInfo->DeviceAddress + Length) {
    DmaBufferInfo->DmaBufferCurrentBottom -= Length;
  }

  return EFI_SUCCESS;
}

/**
  Allocates pages that are suitable for an OperationBusMasterCommonBuffer or
  OperationBusMasterCommonBuffer64 mapping.

  @param  This                  The PPI instance pointer.
  @param  MemoryType            The type of memory to allocate, EfiBootServicesData or
                                EfiRuntimeServicesData.
  @param  Pages                 The number of pages to allocate.
  @param  HostAddress           A pointer to store the base system memory address of the
                                allocated range.
  @param  Attributes            The requested bit mask of attributes for the allocated range.

  @retval EFI_SUCCESS           The requested memory pages were allocated.
  @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
                                MEMORY_WRITE_COMBINE, MEMORY_CACHED and DUAL_ADDRESS_CYCLE.
  @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
  @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.
  @retval EFI_NOT_AVAILABLE_YET DMA protection has been enabled, but DMA buffer are
                                not available to be allocated yet.

**/
EFI_STATUS
EFIAPI
PeiIoMmuAllocateBuffer (
  IN     EDKII_IOMMU_PPI                          *This,
  IN     EFI_MEMORY_TYPE                          MemoryType,
  IN     UINTN                                    Pages,
  IN OUT VOID                                     **HostAddress,
  IN     UINT64                                   Attributes
  )
{
  UINTN                       Length;
  VOID                        *Hob;
  DMA_BUFFER_INFO             *DmaBufferInfo;

  Hob = GetFirstGuidHob (&mDmaBufferInfoGuid);
  DmaBufferInfo = GET_GUID_HOB_DATA(Hob);

  DEBUG ((DEBUG_VERBOSE, "PeiIoMmuAllocateBuffer - page - %x\n", Pages));
  DEBUG ((DEBUG_VERBOSE, "  DmaBufferCurrentTop - %x\n", DmaBufferInfo->DmaBufferCurrentTop));
  DEBUG ((DEBUG_VERBOSE, "  DmaBufferCurrentBottom - %x\n", DmaBufferInfo->DmaBufferCurrentBottom));

  if (DmaBufferInfo->DmaBufferCurrentTop == 0) {
    return EFI_NOT_AVAILABLE_YET;
  }

  Length = EFI_PAGES_TO_SIZE(Pages);
  if (Length > DmaBufferInfo->DmaBufferCurrentTop - DmaBufferInfo->DmaBufferCurrentBottom) {
    DEBUG ((DEBUG_ERROR, "PeiIoMmuAllocateBuffer - OUT_OF_RESOURCE\n"));
    ASSERT (FALSE);
    return EFI_OUT_OF_RESOURCES;
  }
  *HostAddress = (VOID *)(UINTN)(DmaBufferInfo->DmaBufferCurrentTop - Length);
  DmaBufferInfo->DmaBufferCurrentTop -= Length;

  DEBUG ((DEBUG_VERBOSE, "PeiIoMmuAllocateBuffer - allocate - %x\n", *HostAddress));
  return EFI_SUCCESS;
}

/**
  Frees memory that was allocated with AllocateBuffer().

  @param  This                  The PPI instance pointer.
  @param  Pages                 The number of pages to free.
  @param  HostAddress           The base system memory address of the allocated range.

  @retval EFI_SUCCESS           The requested memory pages were freed.
  @retval EFI_INVALID_PARAMETER The memory range specified by HostAddress and Pages
                                was not allocated with AllocateBuffer().
  @retval EFI_NOT_AVAILABLE_YET DMA protection has been enabled, but DMA buffer are
                                not available to be allocated yet.

**/
EFI_STATUS
EFIAPI
PeiIoMmuFreeBuffer (
  IN  EDKII_IOMMU_PPI                          *This,
  IN  UINTN                                    Pages,
  IN  VOID                                     *HostAddress
  )
{
  UINTN                       Length;
  VOID                        *Hob;
  DMA_BUFFER_INFO             *DmaBufferInfo;

  Hob = GetFirstGuidHob (&mDmaBufferInfoGuid);
  DmaBufferInfo = GET_GUID_HOB_DATA(Hob);

  DEBUG ((DEBUG_VERBOSE, "PeiIoMmuFreeBuffer - page - %x, HostAddr - %x\n", Pages, HostAddress));
  DEBUG ((DEBUG_VERBOSE, "  DmaBufferCurrentTop - %x\n", DmaBufferInfo->DmaBufferCurrentTop));
  DEBUG ((DEBUG_VERBOSE, "  DmaBufferCurrentBottom - %x\n", DmaBufferInfo->DmaBufferCurrentBottom));

  if (DmaBufferInfo->DmaBufferCurrentTop == 0) {
    return EFI_NOT_AVAILABLE_YET;
  }

  Length = EFI_PAGES_TO_SIZE(Pages);
  if ((UINTN)HostAddress == DmaBufferInfo->DmaBufferCurrentTop) {
    DmaBufferInfo->DmaBufferCurrentTop += Length;
  }

  return EFI_SUCCESS;
}

EDKII_IOMMU_PPI mIoMmuPpi = {
  EDKII_IOMMU_PPI_REVISION,
  PeiIoMmuSetAttribute,
  PeiIoMmuMap,
  PeiIoMmuUnmap,
  PeiIoMmuAllocateBuffer,
  PeiIoMmuFreeBuffer,
};

CONST EFI_PEI_PPI_DESCRIPTOR mIoMmuPpiList = {
  EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,
  &gEdkiiIoMmuPpiGuid,
  (VOID *) &mIoMmuPpi
};

/**
  Initialize DMA protection.

  @param VTdInfo        The VTd engine context information.

  @retval EFI_SUCCESS           the DMA protection is initialized.
  @retval EFI_OUT_OF_RESOURCES  no enough resource to initialize DMA protection.
**/
EFI_STATUS
InitDmaProtection (
  IN   VTD_INFO                    *VTdInfo
  )
{
  EFI_STATUS                  Status;
  UINT32                      LowMemoryAlignment;
  UINT64                      HighMemoryAlignment;
  UINTN                       MemoryAlignment;
  UINTN                       LowBottom;
  UINTN                       LowTop;
  UINTN                       HighBottom;
  UINT64                      HighTop;
  DMA_BUFFER_INFO             *DmaBufferInfo;
  VOID                        *Hob;
  EFI_PEI_PPI_DESCRIPTOR      *OldDescriptor;
  EDKII_IOMMU_PPI             *OldIoMmuPpi;

  Hob = GetFirstGuidHob (&mDmaBufferInfoGuid);
  DmaBufferInfo = GET_GUID_HOB_DATA(Hob);

  DEBUG ((DEBUG_INFO, " DmaBufferSize : 0x%x\n", DmaBufferInfo->DmaBufferSize));

  LowMemoryAlignment = GetLowMemoryAlignment (VTdInfo, VTdInfo->EngineMask);
  HighMemoryAlignment = GetHighMemoryAlignment (VTdInfo, VTdInfo->EngineMask);
  if (LowMemoryAlignment < HighMemoryAlignment) {
    MemoryAlignment = (UINTN)HighMemoryAlignment;
  } else {
    MemoryAlignment = LowMemoryAlignment;
  }
  ASSERT (DmaBufferInfo->DmaBufferSize == ALIGN_VALUE(DmaBufferInfo->DmaBufferSize, MemoryAlignment));
  DmaBufferInfo->DmaBufferBase = (UINTN)AllocateAlignedPages (EFI_SIZE_TO_PAGES(DmaBufferInfo->DmaBufferSize), MemoryAlignment);
  ASSERT (DmaBufferInfo->DmaBufferBase != 0);
  if (DmaBufferInfo->DmaBufferBase == 0) {
    DEBUG ((DEBUG_INFO, " InitDmaProtection : OutOfResource\n"));
    return EFI_OUT_OF_RESOURCES;
  }

  DEBUG ((DEBUG_INFO, " DmaBufferBase : 0x%x\n", DmaBufferInfo->DmaBufferBase));

  DmaBufferInfo->DmaBufferCurrentTop = DmaBufferInfo->DmaBufferBase + DmaBufferInfo->DmaBufferSize;
  DmaBufferInfo->DmaBufferCurrentBottom = DmaBufferInfo->DmaBufferBase;

  //
  // (Re)Install PPI.
  //
  Status = PeiServicesLocatePpi (
             &gEdkiiIoMmuPpiGuid,
             0,
             &OldDescriptor,
             (VOID **) &OldIoMmuPpi
             );
  if (!EFI_ERROR (Status)) {
    Status = PeiServicesReInstallPpi (OldDescriptor, &mIoMmuPpiList);
  } else {
    Status = PeiServicesInstallPpi (&mIoMmuPpiList);
  }
  ASSERT_EFI_ERROR (Status);

  LowBottom = 0;
  LowTop = DmaBufferInfo->DmaBufferBase;
  HighBottom = DmaBufferInfo->DmaBufferBase + DmaBufferInfo->DmaBufferSize;
  HighTop = LShiftU64 (1, VTdInfo->HostAddressWidth + 1);

  Status = SetDmaProtectedRange (
             VTdInfo,
             VTdInfo->EngineMask,
             (UINT32)LowBottom,
             (UINT32)(LowTop - LowBottom),
             HighBottom,
             HighTop - HighBottom
             );

  if (EFI_ERROR(Status)) {
    FreePages ((VOID *)DmaBufferInfo->DmaBufferBase, EFI_SIZE_TO_PAGES(DmaBufferInfo->DmaBufferSize));
  }

  return Status;
}

/**
  Initializes the Intel VTd Info.

  @retval EFI_SUCCESS            Usb bot driver is successfully initialized.
  @retval EFI_OUT_OF_RESOURCES   Can't initialize the driver.

**/
EFI_STATUS
InitVTdInfo (
  VOID
  )
{
  EFI_STATUS                  Status;
  EFI_ACPI_DMAR_HEADER        *AcpiDmarTable;
  VOID                        *Hob;

  Status = PeiServicesLocatePpi (
             &gEdkiiVTdInfoPpiGuid,
             0,
             NULL,
             (VOID **)&AcpiDmarTable
             );
  ASSERT_EFI_ERROR(Status);

  DumpAcpiDMAR (AcpiDmarTable);

  //
  // Clear old VTdInfo Hob.
  //
  Hob = GetFirstGuidHob (&mVTdInfoGuid);
  if (Hob != NULL) {
    ZeroMem (&((EFI_HOB_GUID_TYPE *)Hob)->Name, sizeof(EFI_GUID));
  }

  //
  // Get DMAR information to local VTdInfo
  //
  Status = ParseDmarAcpiTableDrhd (AcpiDmarTable);
  if (EFI_ERROR(Status)) {
    return Status;
  }

  //
  // NOTE: Do not parse RMRR here, because RMRR may cause PMR programming.
  //

  return EFI_SUCCESS;
}

/**
  Initializes the Intel VTd PMR for all memory.

  @retval EFI_SUCCESS            Usb bot driver is successfully initialized.
  @retval EFI_OUT_OF_RESOURCES   Can't initialize the driver.

**/
EFI_STATUS
InitVTdPmrForAll (
  VOID
  )
{
  EFI_STATUS                  Status;
  VOID                        *Hob;
  VTD_INFO                    *VTdInfo;
  UINTN                       LowBottom;
  UINTN                       LowTop;
  UINTN                       HighBottom;
  UINT64                      HighTop;

  Hob = GetFirstGuidHob (&mVTdInfoGuid);
  VTdInfo = GET_GUID_HOB_DATA(Hob);

  LowBottom = 0;
  LowTop = 0;
  HighBottom = 0;
  HighTop = LShiftU64 (1, VTdInfo->HostAddressWidth + 1);

  Status = SetDmaProtectedRange (
             VTdInfo,
             VTdInfo->EngineMask,
             (UINT32)LowBottom,
             (UINT32)(LowTop - LowBottom),
             HighBottom,
             HighTop - HighBottom
             );

  return Status;
}

/**
  Initializes the Intel VTd PMR for DMA buffer.

  @retval EFI_SUCCESS            Usb bot driver is successfully initialized.
  @retval EFI_OUT_OF_RESOURCES   Can't initialize the driver.

**/
EFI_STATUS
InitVTdPmrForDma (
  VOID
  )
{
  EFI_STATUS                  Status;
  VOID                        *Hob;
  VTD_INFO                    *VTdInfo;

  Hob = GetFirstGuidHob (&mVTdInfoGuid);
  VTdInfo = GET_GUID_HOB_DATA(Hob);

  //
  // If there is RMRR memory, parse it here.
  //
  ParseDmarAcpiTableRmrr (VTdInfo);

  //
  // Allocate a range in PEI memory as DMA buffer
  // Mark others to be DMA protected.
  //
  Status = InitDmaProtection (VTdInfo);

  return Status;
}

/**
  This function handles S3 resume task at the end of PEI

  @param[in] PeiServices    Pointer to PEI Services Table.
  @param[in] NotifyDesc     Pointer to the descriptor for the Notification event that
                            caused this function to execute.
  @param[in] Ppi            Pointer to the PPI data associated with this function.

  @retval EFI_STATUS        Always return EFI_SUCCESS
**/
EFI_STATUS
EFIAPI
S3EndOfPeiNotify(
  IN EFI_PEI_SERVICES          **PeiServices,
  IN EFI_PEI_NOTIFY_DESCRIPTOR *NotifyDesc,
  IN VOID                      *Ppi
  )
{
  VOID                        *Hob;
  VTD_INFO                    *VTdInfo;
  UINT64                      EngineMask;

  DEBUG((DEBUG_INFO, "VTdPmr S3EndOfPeiNotify\n"));

  if ((PcdGet8(PcdVTdPolicyPropertyMask) & BIT1) == 0) {
    Hob = GetFirstGuidHob (&mVTdInfoGuid);
    if (Hob == NULL) {
      return EFI_SUCCESS;
    }
    VTdInfo = GET_GUID_HOB_DATA(Hob);

    EngineMask = LShiftU64 (1, VTdInfo->VTdEngineCount) - 1;
    DisableDmaProtection (VTdInfo, EngineMask);
  }
  return EFI_SUCCESS;
}

EFI_PEI_NOTIFY_DESCRIPTOR mS3EndOfPeiNotifyDesc = {
  (EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
  &gEfiEndOfPeiSignalPpiGuid,
  S3EndOfPeiNotify
};

/**
  This function handles VTd engine setup

  @param[in] PeiServices    Pointer to PEI Services Table.
  @param[in] NotifyDesc     Pointer to the descriptor for the Notification event that
                            caused this function to execute.
  @param[in] Ppi            Pointer to the PPI data associated with this function.

  @retval EFI_STATUS        Always return EFI_SUCCESS
**/
EFI_STATUS
EFIAPI
VTdInfoNotify (
  IN EFI_PEI_SERVICES          **PeiServices,
  IN EFI_PEI_NOTIFY_DESCRIPTOR *NotifyDesc,
  IN VOID                      *Ppi
  )
{
  EFI_STATUS                  Status;
  VOID                        *MemoryDiscovered;
  UINT64                      EnabledEngineMask;
  VOID                        *Hob;
  VTD_INFO                    *VTdInfo;
  BOOLEAN                     MemoryInitialized;

  DEBUG ((DEBUG_INFO, "VTdInfoNotify\n"));

  //
  // Check if memory is initialized.
  //
  MemoryInitialized = FALSE;
  Status = PeiServicesLocatePpi (
             &gEfiPeiMemoryDiscoveredPpiGuid,
             0,
             NULL,
             &MemoryDiscovered
             );
  if (!EFI_ERROR(Status)) {
    MemoryInitialized = TRUE;
  }

  DEBUG ((DEBUG_INFO, "MemoryInitialized - %x\n", MemoryInitialized));

  if (!MemoryInitialized) {
    //
    // If the memory is not initialized,
    // Protect all system memory
    //
    InitVTdInfo ();
    InitVTdPmrForAll ();

    //
    // Install PPI.
    //
    Status = PeiServicesInstallPpi (&mIoMmuPpiList);
    ASSERT_EFI_ERROR(Status);
  } else {
    //
    // If the memory is initialized,
    // Allocate DMA buffer and protect rest system memory
    //

    //
    // NOTE: We need reinit VTdInfo because previous information might be overriden.
    //
    InitVTdInfo ();

    Hob = GetFirstGuidHob (&mVTdInfoGuid);
    VTdInfo = GET_GUID_HOB_DATA(Hob);

    //
    // NOTE: We need check if PMR is enabled or not.
    //
    EnabledEngineMask = GetDmaProtectionEnabledEngineMask (VTdInfo, VTdInfo->EngineMask);
    if (EnabledEngineMask != 0) {
      EnableVTdTranslationProtection (VTdInfo, EnabledEngineMask);
      DisableDmaProtection (VTdInfo, EnabledEngineMask);
    }
    InitVTdPmrForDma ();
    if (EnabledEngineMask != 0) {
      DisableVTdTranslationProtection (VTdInfo, EnabledEngineMask);
    }

  }

  return EFI_SUCCESS;
}

EFI_PEI_NOTIFY_DESCRIPTOR mVTdInfoNotifyDesc = {
  (EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
  &gEdkiiVTdInfoPpiGuid,
  VTdInfoNotify
};

/**
  Initializes the Intel VTd PMR PEIM.

  @param  FileHandle  Handle of the file being invoked.
  @param  PeiServices Describes the list of possible PEI Services.

  @retval EFI_SUCCESS            Usb bot driver is successfully initialized.
  @retval EFI_OUT_OF_RESOURCES   Can't initialize the driver.

**/
EFI_STATUS
EFIAPI
IntelVTdPmrInitialize (
  IN EFI_PEI_FILE_HANDLE       FileHandle,
  IN CONST EFI_PEI_SERVICES    **PeiServices
  )
{
  EFI_STATUS                  Status;
  EFI_BOOT_MODE               BootMode;
  DMA_BUFFER_INFO             *DmaBufferInfo;

  DEBUG ((DEBUG_INFO, "IntelVTdPmrInitialize\n"));

  if ((PcdGet8(PcdVTdPolicyPropertyMask) & BIT0) == 0) {
    return EFI_UNSUPPORTED;
  }

  DmaBufferInfo = BuildGuidHob (&mDmaBufferInfoGuid, sizeof(DMA_BUFFER_INFO));
  ASSERT(DmaBufferInfo != NULL);
  if (DmaBufferInfo == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
  ZeroMem (DmaBufferInfo, sizeof(DMA_BUFFER_INFO));

  PeiServicesGetBootMode (&BootMode);

  if (BootMode == BOOT_ON_S3_RESUME) {
    DmaBufferInfo->DmaBufferSize = PcdGet32 (PcdVTdPeiDmaBufferSizeS3);
  } else {
    DmaBufferInfo->DmaBufferSize = PcdGet32 (PcdVTdPeiDmaBufferSize);
  }

  Status = PeiServicesNotifyPpi (&mVTdInfoNotifyDesc);
  ASSERT_EFI_ERROR (Status);

  //
  // Register EndOfPei Notify for S3
  //
  if (BootMode == BOOT_ON_S3_RESUME) {
    Status = PeiServicesNotifyPpi (&mS3EndOfPeiNotifyDesc);
    ASSERT_EFI_ERROR (Status);
  }

  return EFI_SUCCESS;
}