MdePkg/Include/Protocol/MmCpuIo.h

/** @file
  MM CPU I/O 2 protocol as defined in the PI 1.5 specification.

  This protocol provides CPU I/O and memory access within MM.

  Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#ifndef _MM_CPU_IO_H_
#define _MM_CPU_IO_H_

#define EFI_MM_CPU_IO_PROTOCOL_GUID \
  { \
    0x3242A9D8, 0xCE70, 0x4AA0, { 0x95, 0x5D, 0x5E, 0x7B, 0x14, 0x0D, 0xE4, 0xD2 } \
  }

typedef struct _EFI_MM_CPU_IO_PROTOCOL EFI_MM_CPU_IO_PROTOCOL;

///
/// Width of the MM CPU I/O operations
///
typedef enum {
  MM_IO_UINT8  = 0,
  MM_IO_UINT16 = 1,
  MM_IO_UINT32 = 2,
  MM_IO_UINT64 = 3
} EFI_MM_IO_WIDTH;

/**
  Provides the basic memory and I/O interfaces used toabstract accesses to devices.

  The I/O operations are carried out exactly as requested.  The caller is
  responsible for any alignment and I/O width issues that the bus, device,
  platform, or type of I/O might require.

  @param[in]      This     The EFI_MM_CPU_IO_PROTOCOL instance.
  @param[in]      Width    Signifies the width of the I/O operations.
  @param[in]      Address  The base address of the I/O operations.  The caller is
                           responsible for aligning the Address if required.
  @param[in]      Count    The number of I/O operations to perform.
  @param[in,out]  Buffer   For read operations, the destination buffer to store
                           the results.  For write operations, the source buffer
                           from which to write data.

  @retval EFI_SUCCESS            The data was read from or written to the device.
  @retval EFI_UNSUPPORTED        The Address is not valid for this system.
  @retval EFI_INVALID_PARAMETER  Width or Count, or both, were invalid.
  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack
                                 of resources.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_MM_CPU_IO)(
  IN     CONST EFI_MM_CPU_IO_PROTOCOL    *This,
  IN     EFI_MM_IO_WIDTH                 Width,
  IN     UINT64                          Address,
  IN     UINTN                           Count,
  IN OUT VOID                            *Buffer
  );

typedef struct {
  ///
  /// This service provides the various modalities of memory and I/O read.
  ///
  EFI_MM_CPU_IO    Read;
  ///
  /// This service provides the various modalities of memory and I/O write.
  ///
  EFI_MM_CPU_IO    Write;
} EFI_MM_IO_ACCESS;

///
/// MM CPU I/O Protocol provides CPU I/O and memory access within MM.
///
struct _EFI_MM_CPU_IO_PROTOCOL {
  ///
  /// Allows reads and writes to memory-mapped I/O space.
  ///
  EFI_MM_IO_ACCESS    Mem;
  ///
  /// Allows reads and writes to I/O space.
  ///
  EFI_MM_IO_ACCESS    Io;
};

extern EFI_GUID  gEfiMmCpuIoProtocolGuid;

#endif