MdePkg/Include/Protocol/CpuIo2.h

   1 /** @file
   2   This files describes the CPU I/O 2 Protocol.
   3
   4   This protocol provides an I/O abstraction for a system processor. This protocol
   5   is used by a PCI root bridge I/O driver to perform memory-mapped I/O and I/O transactions.
   6   The I/O or memory primitives can be used by the consumer of the protocol to materialize
   7   bus-specific configuration cycles, such as the transitional configuration address and data
   8   ports for PCI. Only drivers that require direct access to the entire system should use this
   9   protocol.
  10
  11   Note: This is a boot-services only protocol and it may not be used by runtime drivers after
  12   ExitBootServices(). It is different from the Framework CPU I/O Protocol, which is a runtime
  13   protocol and can be used by runtime drivers after ExitBootServices().
  14
  15   Copyright (c) 2007 - 2010, Intel Corporation. All rights reserved.<BR>
  16   This program and the accompanying materials
  17   are licensed and made available under the terms and conditions of the BSD License
  18   which accompanies this distribution.  The full text of the license may be found at
  19   http://opensource.org/licenses/bsd-license.php
  20
  21   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  22   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  23
  24   @par Revision Reference:
  25   This Protocol is defined in UEFI Platform Initialization Specification 1.2
  26   Volume 5: Standards
  27
  28 **/
  29
  30 #ifndef __CPU_IO2_H__
  31 #define __CPU_IO2_H__
  32
  33 #define EFI_CPU_IO2_PROTOCOL_GUID \
  34   { \
  35     0xad61f191, 0xae5f, 0x4c0e, {0xb9, 0xfa, 0xe8, 0x69, 0xd2, 0x88, 0xc6, 0x4f} \
  36   }
  37
  38 typedef struct _EFI_CPU_IO2_PROTOCOL EFI_CPU_IO2_PROTOCOL;
  39
  40 ///
  41 /// Enumeration that defines the width of the I/O operation.
  42 ///
  43 typedef enum {
  44   EfiCpuIoWidthUint8,
  45   EfiCpuIoWidthUint16,
  46   EfiCpuIoWidthUint32,
  47   EfiCpuIoWidthUint64,
  48   EfiCpuIoWidthFifoUint8,
  49   EfiCpuIoWidthFifoUint16,
  50   EfiCpuIoWidthFifoUint32,
  51   EfiCpuIoWidthFifoUint64,
  52   EfiCpuIoWidthFillUint8,
  53   EfiCpuIoWidthFillUint16,
  54   EfiCpuIoWidthFillUint32,
  55   EfiCpuIoWidthFillUint64,
  56   EfiCpuIoWidthMaximum
  57 } EFI_CPU_IO_PROTOCOL_WIDTH;
  58
  59 /**
  60   Enables a driver to access registers in the PI CPU I/O space.
  61
  62   The Io.Read() and Io.Write() functions enable a driver to access PCI controller
  63   registers in the PI CPU I/O space.
  64
  65   The I/O operations are carried out exactly as requested. The caller is responsible
  66   for satisfying any alignment and I/O width restrictions that a PI System on a
  67   platform might require. For example on some platforms, width requests of
  68   EfiCpuIoWidthUint64 do not work. Misaligned buffers, on the other hand, will
  69   be handled by the driver.
  70
  71   If Width is EfiCpuIoWidthUint8, EfiCpuIoWidthUint16, EfiCpuIoWidthUint32,
  72   or EfiCpuIoWidthUint64, then both Address and Buffer are incremented for
  73   each of the Count operations that is performed.
  74
  75   If Width is EfiCpuIoWidthFifoUint8, EfiCpuIoWidthFifoUint16,
  76   EfiCpuIoWidthFifoUint32, or EfiCpuIoWidthFifoUint64, then only Buffer is
  77   incremented for each of the Count operations that is performed. The read or
  78   write operation is performed Count times on the same Address.
  79
  80   If Width is EfiCpuIoWidthFillUint8, EfiCpuIoWidthFillUint16,
  81   EfiCpuIoWidthFillUint32, or EfiCpuIoWidthFillUint64, then only Address is
  82   incremented for each of the Count operations that is performed. The read or
  83   write operation is performed Count times from the first element of Buffer.
  84
  85   @param[in]       This     A pointer to the EFI_CPU_IO2_PROTOCOL instance.
  86   @param[in]       Width    Signifies the width of the I/O or Memory operation.
  87   @param[in]       Address  The base address of the I/O operation.
  88   @param[in]       Count    The number of I/O operations to perform. The number
  89                             of bytes moved is Width size * Count, starting at Address.
  90   @param[in, out]  Buffer   For read operations, the destination buffer to store the results.
  91                             For write operations, the source buffer from which to write data.
  92
  93   @retval EFI_SUCCESS            The data was read from or written to the PI system.
  94   @retval EFI_INVALID_PARAMETER  Width is invalid for this PI system.
  95   @retval EFI_INVALID_PARAMETER  Buffer is NULL.
  96   @retval EFI_UNSUPPORTED        The Buffer is not aligned for the given Width.
  97   @retval EFI_UNSUPPORTED        The address range specified by Address, Width,
  98                                  and Count is not valid for this PI system.
  99
 100 **/
 101 typedef
 102 EFI_STATUS
 103 (EFIAPI *EFI_CPU_IO_PROTOCOL_IO_MEM)(
 104   IN     EFI_CPU_IO2_PROTOCOL              *This,
 105   IN     EFI_CPU_IO_PROTOCOL_WIDTH         Width,
 106   IN     UINT64                            Address,
 107   IN     UINTN                             Count,
 108   IN OUT VOID                              *Buffer
 109   );
 110
 111 ///
 112 /// Service for read and write accesses.
 113 ///
 114 typedef struct {
 115   ///
 116   /// This service provides the various modalities of memory and I/O read.
 117   ///
 118   EFI_CPU_IO_PROTOCOL_IO_MEM  Read;
 119   ///
 120   /// This service provides the various modalities of memory and I/O write.
 121   ///
 122   EFI_CPU_IO_PROTOCOL_IO_MEM  Write;
 123 } EFI_CPU_IO_PROTOCOL_ACCESS;
 124
 125 ///
 126 /// Provides the basic memory and I/O interfaces that are used to abstract
 127 /// accesses to devices in a system.
 128 ///
 129 struct _EFI_CPU_IO2_PROTOCOL {
 130   ///
 131   /// Enables a driver to access memory-mapped registers in the EFI system memory space.
 132   ///
 133   EFI_CPU_IO_PROTOCOL_ACCESS  Mem;
 134   ///
 135   /// Enables a driver to access registers in the EFI CPU I/O space.
 136   ///
 137   EFI_CPU_IO_PROTOCOL_ACCESS  Io;
 138 };
 139
 140 extern EFI_GUID gEfiCpuIo2ProtocolGuid;
 141
 142 #endif