1. added functions header for BaseUefiDecompressLi

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ipf / Synchronization.c

/** @file\r
  Implementation of synchronization functions on Itanium.\r
\r
  Copyright (c) 2006, Intel Corporation<BR>\r
  All rights reserved. This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
  Module Name:  Synchronization.c\r
\r
**/\r
\r
/**\r
  Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
\r
  Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
  specified by Value.  If Value is equal to CompareValue, then Value is set to \r
  ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,\r
  then Value is returned.  The compare exchange operation must be performed using \r
  MP safe mechanisms.\r
\r
  @param  Value         A pointer to the 32-bit value for the compare exchange\r
                        operation.\r
  @param  CompareValue  32-bit value used in compare operation.\r
  @param  ExchangeValue 32-bit value used in exchange operation.\r
\r
  @return The original *Value before exchange.\r
\r
**/\r
UINT32\r
EFIAPI\r
InternalSyncCompareExchange32 (\r
  IN      volatile UINT32           *Value,\r
  IN      UINT32                    CompareValue,\r
  IN      UINT32                    ExchangeValue\r
  );\r
\r
/**\r
  Performs an atomic increment of an 32-bit unsigned integer.\r
\r
  Performs an atomic increment of the 32-bit unsigned integer specified by\r
  Value and returns the incremented value. The increment operation must be\r
  performed using MP safe mechanisms. The state of the return value is not\r
  guaranteed to be MP safe.\r
\r
  @param  Value A pointer to the 32-bit value to increment.\r
\r
  @return The incremented value.\r
\r
**/\r
UINT32\r
EFIAPI\r
InternalSyncIncrement (\r
  IN      volatile UINT32           *Value\r
  )\r
{\r
  UINT32                            OriginalValue;\r
\r
  do {\r
    OriginalValue = *Value;\r
  } while (OriginalValue != InternalSyncCompareExchange32 (\r
                              Value,\r
                              OriginalValue,\r
                              OriginalValue + 1\r
                              ));\r
  return OriginalValue + 1;\r
}\r
\r
/**\r
  Performs an atomic decrement of an 32-bit unsigned integer.\r
\r
  Performs an atomic decrement of the 32-bit unsigned integer specified by\r
  Value and returns the decrement value. The decrement operation must be\r
  performed using MP safe mechanisms. The state of the return value is not\r
  guaranteed to be MP safe.\r
\r
  @param  Value A pointer to the 32-bit value to decrement.\r
\r
  @return The decrement value.\r
\r
**/\r
UINT32\r
EFIAPI\r
InternalSyncDecrement (\r
  IN      volatile UINT32           *Value\r
  )\r
{\r
  UINT32                            OriginalValue;\r
\r
  do {\r
    OriginalValue = *Value;\r
  } while (OriginalValue != InternalSyncCompareExchange32 (\r
                              Value,\r
                              OriginalValue,\r
                              OriginalValue - 1\r
                              ));\r
  return OriginalValue - 1;\r
}\r