MdePkg/Library/BaseSynchronizationLib/X64/GccInline.c

   1 /** @file
   2   GCC inline implementation of BaseSynchronizationLib processor specific functions.
   3
   4   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
   5   Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this 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
  17
  18
  19 /**
  20   Performs an atomic increment of an 32-bit unsigned integer.
  21
  22   Performs an atomic increment of the 32-bit unsigned integer specified by
  23   Value and returns the incremented value. The increment operation must be
  24   performed using MP safe mechanisms. The state of the return value is not
  25   guaranteed to be MP safe.
  26
  27   @param  Value A pointer to the 32-bit value to increment.
  28
  29   @return The incremented value.
  30
  31 **/
  32 UINT32
  33 EFIAPI
  34 InternalSyncIncrement (
  35   IN      volatile UINT32    *Value
  36   )
  37 {
  38   UINT32  Result;
  39
  40   __asm__ __volatile__ (
  41     "lock               \n\t"
  42     "incl    %2         \n\t"
  43     "mov     %2, %%eax      "
  44     : "=a" (Result),          // %0
  45       "=m" (*Value)           // %1
  46     : "m"  (*Value)           // %2
  47     : "memory",
  48       "cc"
  49     );
  50
  51   return Result;
  52 }
  53
  54
  55 /**
  56   Performs an atomic decrement of an 32-bit unsigned integer.
  57
  58   Performs an atomic decrement of the 32-bit unsigned integer specified by
  59   Value and returns the decremented value. The decrement operation must be
  60   performed using MP safe mechanisms. The state of the return value is not
  61   guaranteed to be MP safe.
  62
  63   @param  Value A pointer to the 32-bit value to decrement.
  64
  65   @return The decremented value.
  66
  67 **/
  68 UINT32
  69 EFIAPI
  70 InternalSyncDecrement (
  71   IN      volatile UINT32       *Value
  72   )
  73 {
  74    UINT32  Result;
  75
  76   __asm__ __volatile__ (
  77     "lock               \n\t"
  78     "decl    %2         \n\t"
  79     "mov     %2, %%eax      "
  80     : "=a" (Result),          // %0
  81       "=m" (*Value)           // %1
  82     : "m"  (*Value)           // %2
  83     : "memory",
  84       "cc"
  85     );
  86
  87   return Result;
  88 }
  89
  90
  91 /**
  92   Performs an atomic compare exchange operation on a 32-bit unsigned integer.
  93
  94   Performs an atomic compare exchange operation on the 32-bit unsigned integer
  95   specified by Value.  If Value is equal to CompareValue, then Value is set to
  96   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
  97   then Value is returned.  The compare exchange operation must be performed using
  98   MP safe mechanisms.
  99
 100
 101   @param  Value         A pointer to the 32-bit value for the compare exchange
 102                         operation.
 103   @param  CompareValue  32-bit value used in compare operation.
 104   @param  ExchangeValue 32-bit value used in exchange operation.
 105
 106   @return The original *Value before exchange.
 107
 108 **/
 109 UINT32
 110 EFIAPI
 111 InternalSyncCompareExchange32 (
 112   IN OUT volatile  UINT32           *Value,
 113   IN      UINT32                    CompareValue,
 114   IN      UINT32                    ExchangeValue
 115   )
 116 {
 117
 118
 119   __asm__ __volatile__ (
 120     "lock                 \n\t"
 121     "cmpxchgl    %3, %1       "
 122     : "=a" (CompareValue),    // %0
 123       "=m" (*Value)           // %1
 124     : "a"  (CompareValue),    // %2
 125       "r"  (ExchangeValue),   // %3
 126       "m"  (*Value)
 127     : "memory",
 128       "cc"
 129     );
 130
 131   return CompareValue;
 132 }
 133
 134
 135 /**
 136   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
 137
 138   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
 139   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
 140   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
 141   The compare exchange operation must be performed using MP safe mechanisms.
 142
 143
 144   @param  Value         A pointer to the 64-bit value for the compare exchange
 145                         operation.
 146   @param  CompareValue  64-bit value used in compare operation.
 147   @param  ExchangeValue 64-bit value used in exchange operation.
 148
 149   @return The original *Value before exchange.
 150
 151 **/
 152 UINT64
 153 EFIAPI
 154 InternalSyncCompareExchange64 (
 155   IN OUT  volatile UINT64           *Value,
 156   IN      UINT64                    CompareValue,
 157   IN      UINT64                    ExchangeValue
 158   )
 159 {
 160
 161   __asm__ __volatile__ (
 162     "lock                 \n\t"
 163     "cmpxchgq    %3, %1       "
 164     : "=a" (CompareValue),    // %0
 165       "=m" (*Value)           // %1
 166     : "a"  (CompareValue),    // %2
 167       "r"  (ExchangeValue),   // %3
 168       "m"  (*Value)
 169     : "memory",
 170       "cc"
 171     );
 172
 173   return CompareValue;
 174 }
 175
 176