path: root/UefiCpuPkg/CpuIoPei/CpuIoPei.c

/** @file
  Produces the CPU I/O PPI.

Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2017, AMD Incorporated. 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 "CpuIoPei.h"

//
// Instance of CPU I/O PPI
//
EFI_PEI_CPU_IO_PPI  gCpuIoPpi = {
  {
    CpuMemoryServiceRead,
    CpuMemoryServiceWrite
  },
  {
    CpuIoServiceRead,
    CpuIoServiceWrite
  },
  CpuIoRead8,
  CpuIoRead16,
  CpuIoRead32,
  CpuIoRead64,
  CpuIoWrite8,
  CpuIoWrite16,
  CpuIoWrite32,
  CpuIoWrite64,
  CpuMemRead8,
  CpuMemRead16,
  CpuMemRead32,
  CpuMemRead64,
  CpuMemWrite8,
  CpuMemWrite16,
  CpuMemWrite32,
  CpuMemWrite64
};

//
// PPI Descriptor used to install the CPU I/O PPI
//
EFI_PEI_PPI_DESCRIPTOR gPpiList = {
  (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
  &gEfiPeiCpuIoPpiInstalledGuid,
  NULL
};
  
//
// Lookup table for increment values based on transfer widths
//
UINT8 mInStride[] = {
  1, // EfiPeiCpuIoWidthUint8
  2, // EfiPeiCpuIoWidthUint16
  4, // EfiPeiCpuIoWidthUint32
  8, // EfiPeiCpuIoWidthUint64
  0, // EfiPeiCpuIoWidthFifoUint8
  0, // EfiPeiCpuIoWidthFifoUint16
  0, // EfiPeiCpuIoWidthFifoUint32
  0, // EfiPeiCpuIoWidthFifoUint64
  1, // EfiPeiCpuIoWidthFillUint8
  2, // EfiPeiCpuIoWidthFillUint16
  4, // EfiPeiCpuIoWidthFillUint32
  8  // EfiPeiCpuIoWidthFillUint64
};

//
// Lookup table for increment values based on transfer widths
//
UINT8 mOutStride[] = {
  1, // EfiPeiCpuIoWidthUint8
  2, // EfiPeiCpuIoWidthUint16
  4, // EfiPeiCpuIoWidthUint32
  8, // EfiPeiCpuIoWidthUint64
  1, // EfiPeiCpuIoWidthFifoUint8
  2, // EfiPeiCpuIoWidthFifoUint16
  4, // EfiPeiCpuIoWidthFifoUint32
  8, // EfiPeiCpuIoWidthFifoUint64
  0, // EfiPeiCpuIoWidthFillUint8
  0, // EfiPeiCpuIoWidthFillUint16
  0, // EfiPeiCpuIoWidthFillUint32
  0  // EfiPeiCpuIoWidthFillUint64
};

/**
  Check parameters to a CPU I/O PPI service request.

  @param[in]  MmioOperation  TRUE for an MMIO operation, FALSE for I/O Port operation.
  @param[in]  Width          The width of the access. Enumerated in bytes.
  @param[in]  Address        The physical address of the access.
  @param[in]  Count          The number of accesses to perform.
  @param[in]  Buffer         A pointer to the buffer of data.

  @retval EFI_SUCCESS            The parameters for this request pass the checks.
  @retval EFI_INVALID_PARAMETER  Width is invalid for this EFI system.
  @retval EFI_INVALID_PARAMETER  Buffer is NULL.
  @retval EFI_UNSUPPORTED        The address range specified by Address, Width, 
                                 and Count is not valid for this EFI system.
                                 
**/
EFI_STATUS
CpuIoCheckParameter (
  IN BOOLEAN                   MmioOperation,
  IN EFI_PEI_CPU_IO_PPI_WIDTH  Width,
  IN UINT64                    Address,
  IN UINTN                     Count,
  IN VOID                      *Buffer
  )
{
  UINT64  MaxCount;
  UINT64  Limit;

  //
  // Check to see if Buffer is NULL
  //
  if (Buffer == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Check to see if Width is in the valid range
  //
  if ((UINT32)Width >= EfiPeiCpuIoWidthMaximum) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // For FIFO type, the target address won't increase during the access,
  // so treat Count as 1
  //
  if (Width >= EfiPeiCpuIoWidthFifoUint8 && Width <= EfiPeiCpuIoWidthFifoUint64) {
    Count = 1;
  }

  //
  // Check to see if Width is in the valid range for I/O Port operations
  //
  Width = (EFI_PEI_CPU_IO_PPI_WIDTH) (Width & 0x03);
  if (!MmioOperation && (Width == EfiPeiCpuIoWidthUint64)) {
    return EFI_INVALID_PARAMETER;
  }
  
  //
  // Check to see if any address associated with this transfer exceeds the maximum 
  // allowed address.  The maximum address implied by the parameters passed in is
  // Address + Size * Count.  If the following condition is met, then the transfer
  // is not supported.
  //
  //    Address + Size * Count > (MmioOperation ? MAX_ADDRESS : MAX_IO_PORT_ADDRESS) + 1
  //
  // Since MAX_ADDRESS can be the maximum integer value supported by the CPU and Count 
  // can also be the maximum integer value supported by the CPU, this range
  // check must be adjusted to avoid all overflow conditions.
  //   
  // The following form of the range check is equivalent but assumes that 
  // MAX_ADDRESS and MAX_IO_PORT_ADDRESS are of the form (2^n - 1).
  //
  Limit = (MmioOperation ? MAX_ADDRESS : MAX_IO_PORT_ADDRESS);
  if (Count == 0) {
    if (Address > Limit) {
      return EFI_UNSUPPORTED;
    }
  } else {  
    MaxCount = RShiftU64 (Limit, Width);
    if (MaxCount < (Count - 1)) {
      return EFI_UNSUPPORTED;
    }
    if (Address > LShiftU64 (MaxCount - Count + 1, Width)) {
      return EFI_UNSUPPORTED;
    }
  }
  
  return EFI_SUCCESS;
}

/**
  Reads memory-mapped registers.

  @param[in]  PeiServices  An indirect pointer to the PEI Services Table
                           published by the PEI Foundation.
  @param[in]  This         Pointer to local data for the interface.
  @param[in]  Width        The width of the access. Enumerated in bytes.
  @param[in]  Address      The physical address of the access.
  @param[in]  Count        The number of accesses to perform.
  @param[out] Buffer       A pointer to the buffer of data.

  @retval EFI_SUCCESS            The function completed successfully.
  @retval EFI_INVALID_PARAMETER  Width is invalid for this EFI system.
  @retval EFI_INVALID_PARAMETER  Buffer is NULL.
  @retval EFI_UNSUPPORTED        The address range specified by Address, Width, 
                                 and Count is not valid for this EFI system.

**/
EFI_STATUS
EFIAPI
CpuMemoryServiceRead (
  IN  CONST EFI_PEI_SERVICES    **PeiServices,
  IN  CONST EFI_PEI_CPU_IO_PPI  *This,
  IN  EFI_PEI_CPU_IO_PPI_WIDTH  Width,
  IN  UINT64                    Address,
  IN  UINTN                     Count,
  OUT VOID                      *Buffer
  )
{
  EFI_STATUS                Status;
  UINT8                     InStride;
  UINT8                     OutStride;
  EFI_PEI_CPU_IO_PPI_WIDTH  OperationWidth;
  BOOLEAN                   Aligned;
  UINT8                     *Uint8Buffer;

  Status = CpuIoCheckParameter (TRUE, Width, Address, Count, Buffer);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Select loop based on the width of the transfer
  //
  InStride = mInStride[Width];
  OutStride = mOutStride[Width];
  OperationWidth = (EFI_PEI_CPU_IO_PPI_WIDTH) (Width & 0x03);
  Aligned = (BOOLEAN)(((UINTN)Buffer & (mInStride[OperationWidth] - 1)) == 0x00);
  for (Uint8Buffer = Buffer; Count > 0; Address += InStride, Uint8Buffer += OutStride, Count--) {
    if (OperationWidth == EfiPeiCpuIoWidthUint8) {
      *Uint8Buffer = MmioRead8 ((UINTN)Address);
    } else if (OperationWidth == EfiPeiCpuIoWidthUint16) {
      if (Aligned) {
        *((UINT16 *)Uint8Buffer) = MmioRead16 ((UINTN)Address);
      } else {
        WriteUnaligned16 ((UINT16 *)Uint8Buffer, MmioRead16 ((UINTN)Address));
      }
    } else if (OperationWidth == EfiPeiCpuIoWidthUint32) {
      if (Aligned) {
        *((UINT32 *)Uint8Buffer) = MmioRead32 ((UINTN)Address);
      } else {
        WriteUnaligned32 ((UINT32 *)Uint8Buffer, MmioRead32 ((UINTN)Address));
      }
    } else if (OperationWidth == EfiPeiCpuIoWidthUint64) {
      if (Aligned) {
        *((UINT64 *)Uint8Buffer) = MmioRead64 ((UINTN)Address);
      } else {
        WriteUnaligned64 ((UINT64 *)Uint8Buffer, MmioRead64 ((UINTN)Address));
      }
    }
  }
  return EFI_SUCCESS;
}

/**
  Writes memory-mapped registers.

  @param[in]  PeiServices  An indirect pointer to the PEI Services Table
                           published by the PEI Foundation.
  @param[in]  This         Pointer to local data for the interface.
  @param[in]  Width        The width of the access. Enumerated in bytes.
  @param[in]  Address      The physical address of the access.
  @param[in]  Count        The number of accesses to perform.
  @param[in]  Buffer       A pointer to the buffer of data.

  @retval EFI_SUCCESS            The function completed successfully.
  @retval EFI_INVALID_PARAMETER  Width is invalid for this EFI system.
  @retval EFI_INVALID_PARAMETER  Buffer is NULL.
  @retval EFI_UNSUPPORTED        The address range specified by Address, Width, 
                                 and Count is not valid for this EFI system.

**/
EFI_STATUS
EFIAPI
CpuMemoryServiceWrite (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN EFI_PEI_CPU_IO_PPI_WIDTH  Width,
  IN UINT64                    Address,
  IN UINTN                     Count,
  IN VOID                      *Buffer
  )
{
  EFI_STATUS                Status;
  UINT8                     InStride;
  UINT8                     OutStride;
  EFI_PEI_CPU_IO_PPI_WIDTH  OperationWidth;
  BOOLEAN                   Aligned;
  UINT8                     *Uint8Buffer;

  Status = CpuIoCheckParameter (TRUE, Width, Address, Count, Buffer);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Select loop based on the width of the transfer
  //
  InStride = mInStride[Width];
  OutStride = mOutStride[Width];
  OperationWidth = (EFI_PEI_CPU_IO_PPI_WIDTH) (Width & 0x03);
  Aligned = (BOOLEAN)(((UINTN)Buffer & (mInStride[OperationWidth] - 1)) == 0x00);
  for (Uint8Buffer = Buffer; Count > 0; Address += InStride, Uint8Buffer += OutStride, Count--) {
    if (OperationWidth == EfiPeiCpuIoWidthUint8) {
      MmioWrite8 ((UINTN)Address, *Uint8Buffer);
    } else if (OperationWidth == EfiPeiCpuIoWidthUint16) {
      if (Aligned) {
        MmioWrite16 ((UINTN)Address, *((UINT16 *)Uint8Buffer));
      } else {
        MmioWrite16 ((UINTN)Address, ReadUnaligned16 ((UINT16 *)Uint8Buffer));
      }
    } else if (OperationWidth == EfiPeiCpuIoWidthUint32) {
      if (Aligned) {
        MmioWrite32 ((UINTN)Address, *((UINT32 *)Uint8Buffer));
      } else {
        MmioWrite32 ((UINTN)Address, ReadUnaligned32 ((UINT32 *)Uint8Buffer));
      }
    } else if (OperationWidth == EfiPeiCpuIoWidthUint64) {
      if (Aligned) {
        MmioWrite64 ((UINTN)Address, *((UINT64 *)Uint8Buffer));
      } else {
        MmioWrite64 ((UINTN)Address, ReadUnaligned64 ((UINT64 *)Uint8Buffer));
      }
    }
  }
  return EFI_SUCCESS;
}

/**
  Reads I/O registers.

  @param[in]  PeiServices  An indirect pointer to the PEI Services Table
                           published by the PEI Foundation.
  @param[in]  This         Pointer to local data for the interface.
  @param[in]  Width        The width of the access. Enumerated in bytes.
  @param[in]  Address      The physical address of the access.
  @param[in]  Count        The number of accesses to perform.
  @param[out] Buffer       A pointer to the buffer of data.

  @retval EFI_SUCCESS            The function completed successfully.
  @retval EFI_INVALID_PARAMETER  Width is invalid for this EFI system.
  @retval EFI_INVALID_PARAMETER  Buffer is NULL.
  @retval EFI_UNSUPPORTED        The address range specified by Address, Width, 
                                 and Count is not valid for this EFI system.

**/
EFI_STATUS
EFIAPI
CpuIoServiceRead (
  IN  CONST EFI_PEI_SERVICES    **PeiServices,
  IN  CONST EFI_PEI_CPU_IO_PPI  *This,
  IN  EFI_PEI_CPU_IO_PPI_WIDTH  Width,
  IN  UINT64                    Address,
  IN  UINTN                     Count,
  OUT VOID                      *Buffer
  )
{
  EFI_STATUS                Status;
  UINT8                     InStride;
  UINT8                     OutStride;
  EFI_PEI_CPU_IO_PPI_WIDTH  OperationWidth;
  BOOLEAN                   Aligned;
  UINT8                     *Uint8Buffer;

  Status = CpuIoCheckParameter (FALSE, Width, Address, Count, Buffer);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Select loop based on the width of the transfer
  //
  InStride = mInStride[Width];
  OutStride = mOutStride[Width];
  OperationWidth = (EFI_PEI_CPU_IO_PPI_WIDTH) (Width & 0x03);

  //
  // Fifo operations supported for (mInStride[Width] == 0)
  //
  if (InStride == 0) {
    switch (OperationWidth) {
    case EfiPeiCpuIoWidthUint8:
      IoReadFifo8 ((UINTN)Address, Count, Buffer);
      return EFI_SUCCESS;
    case EfiPeiCpuIoWidthUint16:
      IoReadFifo16 ((UINTN)Address, Count, Buffer);
      return EFI_SUCCESS;
    case EfiPeiCpuIoWidthUint32:
      IoReadFifo32 ((UINTN)Address, Count, Buffer);
      return EFI_SUCCESS;
    default:
      //
      // The CpuIoCheckParameter call above will ensure that this
      // path is not taken.
      //
      ASSERT (FALSE);
      break;
    }
  }

  Aligned = (BOOLEAN)(((UINTN)Buffer & (mInStride[OperationWidth] - 1)) == 0x00);
  for (Uint8Buffer = Buffer; Count > 0; Address += InStride, Uint8Buffer += OutStride, Count--) {
    if (OperationWidth == EfiPeiCpuIoWidthUint8) {
      *Uint8Buffer = IoRead8 ((UINTN)Address);
    } else if (OperationWidth == EfiPeiCpuIoWidthUint16) {
      if (Aligned) {
        *((UINT16 *)Uint8Buffer) = IoRead16 ((UINTN)Address);
      } else {
        WriteUnaligned16 ((UINT16 *)Uint8Buffer, IoRead16 ((UINTN)Address));
      }
    } else if (OperationWidth == EfiPeiCpuIoWidthUint32) {
      if (Aligned) {
        *((UINT32 *)Uint8Buffer) = IoRead32 ((UINTN)Address);
      } else {
        WriteUnaligned32 ((UINT32 *)Uint8Buffer, IoRead32 ((UINTN)Address));
      }
    }
  }

  return EFI_SUCCESS;
}

/**
  Write I/O registers.

  @param[in]  PeiServices  An indirect pointer to the PEI Services Table
                           published by the PEI Foundation.
  @param[in]  This         Pointer to local data for the interface.
  @param[in]  Width        The width of the access. Enumerated in bytes.
  @param[in]  Address      The physical address of the access.
  @param[in]  Count        The number of accesses to perform.
  @param[in]  Buffer       A pointer to the buffer of data.

  @retval EFI_SUCCESS            The function completed successfully.
  @retval EFI_INVALID_PARAMETER  Width is invalid for this EFI system.
  @retval EFI_INVALID_PARAMETER  Buffer is NULL.
  @retval EFI_UNSUPPORTED        The address range specified by Address, Width, 
                                 and Count is not valid for this EFI system.

**/
EFI_STATUS
EFIAPI
CpuIoServiceWrite (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN EFI_PEI_CPU_IO_PPI_WIDTH  Width,
  IN UINT64                    Address,
  IN UINTN                     Count,
  IN VOID                      *Buffer
  )
{
  EFI_STATUS                Status;
  UINT8                     InStride;
  UINT8                     OutStride;
  EFI_PEI_CPU_IO_PPI_WIDTH  OperationWidth;
  BOOLEAN                   Aligned;
  UINT8                     *Uint8Buffer;

  //
  // Make sure the parameters are valid
  //
  Status = CpuIoCheckParameter (FALSE, Width, Address, Count, Buffer);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Select loop based on the width of the transfer
  //
  InStride = mInStride[Width];
  OutStride = mOutStride[Width];
  OperationWidth = (EFI_PEI_CPU_IO_PPI_WIDTH) (Width & 0x03);

  //
  // Fifo operations supported for (mInStride[Width] == 0)
  //
  if (InStride == 0) {
    switch (OperationWidth) {
    case EfiPeiCpuIoWidthUint8:
      IoWriteFifo8 ((UINTN)Address, Count, Buffer);
      return EFI_SUCCESS;
    case EfiPeiCpuIoWidthUint16:
      IoWriteFifo16 ((UINTN)Address, Count, Buffer);
      return EFI_SUCCESS;
    case EfiPeiCpuIoWidthUint32:
      IoWriteFifo32 ((UINTN)Address, Count, Buffer);
      return EFI_SUCCESS;
    default:
      //
      // The CpuIoCheckParameter call above will ensure that this
      // path is not taken.
      //
      ASSERT (FALSE);
      break;
    }
  }

  Aligned = (BOOLEAN)(((UINTN)Buffer & (mInStride[OperationWidth] - 1)) == 0x00);
  for (Uint8Buffer = (UINT8 *)Buffer; Count > 0; Address += InStride, Uint8Buffer += OutStride, Count--) {
    if (OperationWidth == EfiPeiCpuIoWidthUint8) {
      IoWrite8 ((UINTN)Address, *Uint8Buffer);
    } else if (OperationWidth == EfiPeiCpuIoWidthUint16) {
      if (Aligned) {
        IoWrite16 ((UINTN)Address, *((UINT16 *)Uint8Buffer));
      } else {
        IoWrite16 ((UINTN)Address, ReadUnaligned16 ((UINT16 *)Uint8Buffer));
      }
    } else if (OperationWidth == EfiPeiCpuIoWidthUint32) {
      if (Aligned) {
        IoWrite32 ((UINTN)Address, *((UINT32 *)Uint8Buffer));
      } else {
        IoWrite32 ((UINTN)Address, ReadUnaligned32 ((UINT32 *)Uint8Buffer));
      }
    }
  }
  
  return EFI_SUCCESS;
}

/**
  8-bit I/O read operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.

  @return  An 8-bit value returned from the I/O space.
**/
UINT8
EFIAPI
CpuIoRead8 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address
  )
{
  return IoRead8 ((UINTN)Address);
}

/**
  16-bit I/O read operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.

  @return  A 16-bit value returned from the I/O space.

**/
UINT16
EFIAPI
CpuIoRead16 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address
  )
{
  return IoRead16 ((UINTN)Address);
}

/**
  32-bit I/O read operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.

  @return  A 32-bit value returned from the I/O space.

**/
UINT32
EFIAPI
CpuIoRead32 (
  IN CONST EFI_PEI_SERVICES     **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI   *This,
  IN UINT64                     Address
  )
{
  return IoRead32 ((UINTN)Address);
}

/**
  64-bit I/O read operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.

  @return  A 64-bit value returned from the I/O space.

**/
UINT64
EFIAPI
CpuIoRead64 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address
  )
{
  return IoRead64 ((UINTN)Address);
}

/**
  8-bit I/O write operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.
  @param[in] Data         The data to write.

**/
VOID
EFIAPI
CpuIoWrite8 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address,
  IN UINT8                     Data
  )
{
  IoWrite8 ((UINTN)Address, Data);
}

/**
  16-bit I/O write operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.
  @param[in] Data         The data to write.

**/
VOID
EFIAPI
CpuIoWrite16 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address,
  IN UINT16                    Data
  )
{
  IoWrite16 ((UINTN)Address, Data);
}

/**
  32-bit I/O write operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.
  @param[in] Data         The data to write.

**/
VOID
EFIAPI
CpuIoWrite32 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address,
  IN UINT32                    Data
  )
{
  IoWrite32 ((UINTN)Address, Data);
}

/**
  64-bit I/O write operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.
  @param[in] Data         The data to write.

**/
VOID
EFIAPI
CpuIoWrite64 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address,
  IN UINT64                    Data
  )
{
  IoWrite64 ((UINTN)Address, Data);
}

/**
  8-bit memory read operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.

  @return  An 8-bit value returned from the memory space.

**/
UINT8
EFIAPI
CpuMemRead8 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address
  )
{
  return MmioRead8 ((UINTN)Address);
}

/**
  16-bit memory read operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.

  @return  A 16-bit value returned from the memory space.

**/
UINT16
EFIAPI
CpuMemRead16 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address
  )
{
  return MmioRead16 ((UINTN)Address);
}

/**
  32-bit memory read operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.

  @return  A 32-bit value returned from the memory space.

**/
UINT32
EFIAPI
CpuMemRead32 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address
  )
{
  return MmioRead32 ((UINTN)Address);
}

/**
  64-bit memory read operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.

  @return  A 64-bit value returned from the memory space.

**/
UINT64
EFIAPI
CpuMemRead64 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address
  )
{
  return MmioRead64 ((UINTN)Address);
}

/**
  8-bit memory write operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.
  @param[in] Data         The data to write.

**/
VOID
EFIAPI
CpuMemWrite8 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address,
  IN  UINT8                    Data
  )
{
  MmioWrite8 ((UINTN)Address, Data);
}

/**
  16-bit memory write operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.
  @param[in] Data         The data to write.

**/
VOID
EFIAPI
CpuMemWrite16 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address,
  IN UINT16                    Data
  )
{
  MmioWrite16 ((UINTN)Address, Data);
}

/**
  32-bit memory write operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.
  @param[in] Data         The data to write.

**/
VOID
EFIAPI
CpuMemWrite32 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address,
  IN UINT32                    Data
  )
{
  MmioWrite32 ((UINTN)Address, Data);
}

/**
  64-bit memory write operations.

  @param[in] PeiServices  An indirect pointer to the PEI Services Table published 
                          by the PEI Foundation.
  @param[in] This         Pointer to local data for the interface.
  @param[in] Address      The physical address of the access.
  @param[in] Data         The data to write.

**/
VOID
EFIAPI
CpuMemWrite64 (
  IN CONST EFI_PEI_SERVICES    **PeiServices,
  IN CONST EFI_PEI_CPU_IO_PPI  *This,
  IN UINT64                    Address,
  IN UINT64                    Data
  )
{
  MmioWrite64 ((UINTN)Address, Data);
}

/**
  The Entry point of the CPU I/O PEIM

  This function is the Entry point of the CPU I/O PEIM which installs CpuIoPpi.

  @param[in]  FileHandle   Pointer to image file handle.
  @param[in]  PeiServices  Pointer to PEI Services Table   

  @retval EFI_SUCCESS  CPU I/O PPI successfully installed

**/
EFI_STATUS
EFIAPI
CpuIoInitialize (
  IN EFI_PEI_FILE_HANDLE     FileHandle,
  IN CONST EFI_PEI_SERVICES  **PeiServices
  )
{
  EFI_STATUS  Status;

  //
  // Register so it will be automatically shadowed to memory
  //
  Status = PeiServicesRegisterForShadow (FileHandle);
  
  //
  // Make CpuIo pointer in PeiService table point to gCpuIoPpi
  //
  (*((EFI_PEI_SERVICES **)PeiServices))->CpuIo = &gCpuIoPpi;
  
  if (Status == EFI_ALREADY_STARTED) {
    //
    // Shadow completed and running from memory
    //
    DEBUG ((EFI_D_INFO, "CpuIO PPI has been loaded into memory.  Reinstalled PPI=0x%x\n", &gCpuIoPpi));
  } else {
    Status = PeiServicesInstallPpi (&gPpiList);
    ASSERT_EFI_ERROR (Status);
  }
  
  return EFI_SUCCESS;
}