OvmfPkg/QemuVideoDxe/UnalignedIoInternal.h

   1 /** @file
   2   Unaligned port I/O, with implementations for various x86 compilers and a
   3   dummy for platforms which do not support unaligned port I/O.
   4
   5   Copyright (c) 2017, Phil Dennis-Jordan.<BR>
   6   This program and the accompanying materials are licensed and made available
   7   under the terms and conditions of the BSD License which accompanies this
   8   distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php.
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #ifndef _UNALIGNED_IO_INTERNAL_H_
  17 #define _UNALIGNED_IO_INTERNAL_H_
  18
  19 /**
  20   Performs a 32-bit write to the specified, possibly unaligned I/O-type address.
  21
  22   Writes the 32-bit I/O port specified by Port with the value specified by Value
  23   and returns Value. This function must guarantee that all I/O read and write
  24   operations are serialized.
  25
  26   If 32-bit unaligned I/O port operations are not supported, then ASSERT().
  27
  28   @param[in]  Port   I/O port address
  29   @param[in]  Value  32-bit word to write
  30
  31   @return The value written to the I/O port.
  32
  33 **/
  34 UINT32
  35 UnalignedIoWrite32 (
  36   IN      UINTN                     Port,
  37   IN      UINT32                    Value
  38   );
  39
  40 /**
  41   Reads a 32-bit word from the specified, possibly unaligned I/O-type address.
  42
  43   Reads the 32-bit I/O port specified by Port. The 32-bit read value is
  44   returned. This function must guarantee that all I/O read and write operations
  45   are serialized.
  46
  47   If 32-bit unaligned I/O port operations are not supported, then ASSERT().
  48
  49   @param[in]  Port  The I/O port to read.
  50
  51   @return The value read.
  52
  53 **/
  54 UINT32
  55 UnalignedIoRead32 (
  56   IN      UINTN                     Port
  57   );
  58
  59 #endif