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 - 2010, 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 that 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.

**/

#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