audk/IntelFrameworkPkg/Include/Protocol/SmmCpuIo.h

/** @file
  SMM CPU I/O protocol as defined in the Intel Framework specification.

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

Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#ifndef _SMM_CPU_IO_H_
#define _SMM_CPU_IO_H_

#include <Protocol/SmmCpuIo2.h>

#define EFI_SMM_CPU_IO_GUID \
  { \
    0x5f439a0b, 0x45d8, 0x4682, {0xa4, 0xf4, 0xf0, 0x57, 0x6b, 0x51, 0x34, 0x41} \
  }

typedef struct _EFI_SMM_CPU_IO_INTERFACE EFI_SMM_CPU_IO_INTERFACE;

/**
  Provides the basic memory and I/O interfaces used to abstract 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_SMM_CPU_IO_INTERFACE 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_SMM_CPU_IO)(
  IN     EFI_SMM_CPU_IO_INTERFACE       *This,
  IN     EFI_SMM_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_SMM_CPU_IO  Read;
  ///
  /// This service provides the various modalities of memory and I/O write.
  ///
  EFI_SMM_CPU_IO  Write;
} EFI_SMM_IO_ACCESS;

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

extern EFI_GUID gEfiSmmCpuIoGuid;

#endif