EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseLib/Ebc/Synchronization.c

   1 /*++
   2
   3 Copyright (c) 2004 - 2006, Intel Corporation. All rights reserved.<BR>
   4 This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12
  13 Module Name:
  14
  15   Synchronization.c
  16
  17 Abstract:
  18
  19
  20 --*/
  21
  22 #include "BaseLibInternals.h"
  23
  24 UINT32
  25 EFIAPI
  26 InternalSyncCompareExchange32 (
  27   IN      volatile UINT32           *Value,
  28   IN      UINT32                    CompareValue,
  29   IN      UINT32                    ExchangeValue
  30   )
  31 {
  32   return *Value != CompareValue ? *Value :
  33            ((*Value = ExchangeValue), CompareValue);
  34 }
  35
  36 /**
  37   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
  38
  39   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
  40   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
  41   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
  42   The compare exchange operation must be performed using MP safe mechanisms.
  43
  44   @param  Value         A pointer to the 64-bit value for the compare exchange
  45                         operation.
  46   @param  CompareValue  64-bit value used in compare operation.
  47   @param  ExchangeValue 64-bit value used in exchange operation.
  48
  49   @return The original *Value before exchange.
  50
  51 **/
  52 UINT64
  53 EFIAPI
  54 InternalSyncCompareExchange64 (
  55   IN      volatile UINT64           *Value,
  56   IN      UINT64                    CompareValue,
  57   IN      UINT64                    ExchangeValue
  58   )
  59 {
  60   return *Value != CompareValue ? *Value :
  61            ((*Value = ExchangeValue), CompareValue);
  62 }
  63
  64 /**
  65   Performs an atomic increment of an 32-bit unsigned integer.
  66
  67   Performs an atomic increment of the 32-bit unsigned integer specified by
  68   Value and returns the incremented value. The increment operation must be
  69   performed using MP safe mechanisms. The state of the return value is not
  70   guaranteed to be MP safe.
  71
  72   @param  Value A pointer to the 32-bit value to increment.
  73
  74   @return The incremented value.
  75
  76 **/
  77 UINT32
  78 EFIAPI
  79 InternalSyncIncrement (
  80   IN      volatile UINT32           *Value
  81   )
  82 {
  83   return ++*Value;
  84 }
  85
  86 /**
  87   Performs an atomic decrement of an 32-bit unsigned integer.
  88
  89   Performs an atomic decrement of the 32-bit unsigned integer specified by
  90   Value and returns the decrement value. The decrement operation must be
  91   performed using MP safe mechanisms. The state of the return value is not
  92   guaranteed to be MP safe.
  93
  94   @param  Value A pointer to the 32-bit value to decrement.
  95
  96   @return The decrement value.
  97
  98 **/
  99 UINT32
 100 EFIAPI
 101 InternalSyncDecrement (
 102   IN      volatile UINT32           *Value
 103   )
 104 {
 105   return --*Value;
 106 }