MdePkg/Library/BaseSynchronizationLib/Ebc/Synchronization.c

   1 /** @file
   2   Implementation of synchronization functions on EBC.
   3
   4   Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 /**
  10   Performs an atomic compare exchange operation on a 16-bit
  11   unsigned integer.
  12
  13   Performs an atomic compare exchange operation on the 16-bit
  14   unsigned integer specified by Value.  If Value is equal to
  15   CompareValue, then Value is set to ExchangeValue and
  16   CompareValue is returned.  If Value is not equal to
  17   CompareValue, then Value is returned. The compare exchange
  18   operation must be performed using MP safe mechanisms.
  19
  20   @param  Value         A pointer to the 16-bit value for the
  21                         compare exchange operation.
  22   @param  CompareValue  16-bit value used in compare operation.
  23   @param  ExchangeValue 16-bit value used in exchange operation.
  24
  25   @return The original *Value before exchange.
  26
  27 **/
  28 UINT16
  29 EFIAPI
  30 InternalSyncCompareExchange16 (
  31   IN      volatile UINT16           *Value,
  32   IN      UINT16                    CompareValue,
  33   IN      UINT16                    ExchangeValue
  34   )
  35 {
  36   return *Value != CompareValue ? *Value :
  37            ((*Value = ExchangeValue), CompareValue);
  38 }
  39
  40 /**
  41   Performs an atomic compare exchange operation on a 32-bit
  42   unsigned integer.
  43
  44   Performs an atomic compare exchange operation on the 32-bit
  45   unsigned integer specified by Value.  If Value is equal to
  46   CompareValue, then Value is set to ExchangeValue and
  47   CompareValue is returned.  If Value is not equal to
  48   CompareValue, then Value is returned. The compare exchange
  49   operation must be performed using MP safe mechanisms.
  50
  51   @param  Value         A pointer to the 32-bit value for the
  52                         compare exchange operation.
  53   @param  CompareValue  32-bit value used in compare operation.
  54   @param  ExchangeValue 32-bit value used in exchange operation.
  55
  56   @return The original *Value before exchange.
  57
  58 **/
  59 UINT32
  60 EFIAPI
  61 InternalSyncCompareExchange32 (
  62   IN      volatile UINT32           *Value,
  63   IN      UINT32                    CompareValue,
  64   IN      UINT32                    ExchangeValue
  65   )
  66 {
  67   return *Value != CompareValue ? *Value :
  68            ((*Value = ExchangeValue), CompareValue);
  69 }
  70
  71 /**
  72   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
  73
  74   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
  75   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
  76   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
  77   The compare exchange operation must be performed using MP safe mechanisms.
  78
  79   @param  Value         A pointer to the 64-bit value for the compare exchange
  80                         operation.
  81   @param  CompareValue  64-bit value used in compare operation.
  82   @param  ExchangeValue 64-bit value used in exchange operation.
  83
  84   @return The original *Value before exchange.
  85
  86 **/
  87 UINT64
  88 EFIAPI
  89 InternalSyncCompareExchange64 (
  90   IN      volatile UINT64           *Value,
  91   IN      UINT64                    CompareValue,
  92   IN      UINT64                    ExchangeValue
  93   )
  94 {
  95   return *Value != CompareValue ? *Value :
  96            ((*Value = ExchangeValue), CompareValue);
  97 }
  98
  99 /**
 100   Performs an atomic increment of an 32-bit unsigned integer.
 101
 102   Performs an atomic increment of the 32-bit unsigned integer specified by
 103   Value and returns the incremented value. The increment operation must be
 104   performed using MP safe mechanisms. The state of the return value is not
 105   guaranteed to be MP safe.
 106
 107   @param  Value A pointer to the 32-bit value to increment.
 108
 109   @return The incremented value.
 110
 111 **/
 112 UINT32
 113 EFIAPI
 114 InternalSyncIncrement (
 115   IN      volatile UINT32           *Value
 116   )
 117 {
 118   return ++*Value;
 119 }
 120
 121 /**
 122   Performs an atomic decrement of an 32-bit unsigned integer.
 123
 124   Performs an atomic decrement of the 32-bit unsigned integer specified by
 125   Value and returns the decrement value. The decrement operation must be
 126   performed using MP safe mechanisms. The state of the return value is not
 127   guaranteed to be MP safe.
 128
 129   @param  Value A pointer to the 32-bit value to decrement.
 130
 131   @return The decrement value.
 132
 133 **/
 134 UINT32
 135 EFIAPI
 136 InternalSyncDecrement (
 137   IN      volatile UINT32           *Value
 138   )
 139 {
 140   return --*Value;
 141 }