MdePkg/Library/BaseSynchronizationLib/X64/GccInline.c

   1 /** @file
   2   GCC inline implementation of BaseSynchronizationLib processor specific functions.
   3
   4   Copyright (c) 2006 - 2018, 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   Performs an atomic increment of an 32-bit unsigned integer.
  20
  21   Performs an atomic increment of the 32-bit unsigned integer specified by
  22   Value and returns the incremented value. The increment operation must be
  23   performed using MP safe mechanisms.
  24
  25   @param  Value A pointer to the 32-bit value to increment.
  26
  27   @return The incremented value.
  28
  29 **/
  30 UINT32
  31 EFIAPI
  32 InternalSyncIncrement (
  33   IN      volatile UINT32    *Value
  34   )
  35 {
  36   UINT32  Result;
  37
  38   __asm__ __volatile__ (
  39     "movl    $1, %%eax  \n\t"
  40     "lock               \n\t"
  41     "xadd    %%eax, %1  \n\t"
  42     "inc     %%eax      \n\t"
  43     : "=a" (Result),          // %0
  44       "+m" (*Value)           // %1
  45     :                         // no inputs that aren't also outputs
  46     : "memory",
  47       "cc"
  48     );
  49
  50   return Result;
  51 }
  52
  53
  54 /**
  55   Performs an atomic decrement of an 32-bit unsigned integer.
  56
  57   Performs an atomic decrement of the 32-bit unsigned integer specified by
  58   Value and returns the decremented value. The decrement operation must be
  59   performed using MP safe mechanisms.
  60
  61   @param  Value A pointer to the 32-bit value to decrement.
  62
  63   @return The decremented value.
  64
  65 **/
  66 UINT32
  67 EFIAPI
  68 InternalSyncDecrement (
  69   IN      volatile UINT32       *Value
  70   )
  71 {
  72    UINT32  Result;
  73
  74   __asm__ __volatile__ (
  75     "movl    $-1, %%eax  \n\t"
  76     "lock                \n\t"
  77     "xadd    %%eax, %1   \n\t"
  78     "dec     %%eax       \n\t"
  79     : "=a" (Result),           // %0
  80       "+m" (*Value)            // %1
  81     :                          // no inputs that aren't also outputs
  82     : "memory",
  83       "cc"
  84     );
  85
  86   return Result;
  87 }
  88
  89
  90 /**
  91   Performs an atomic compare exchange operation on a 16-bit unsigned integer.
  92
  93   Performs an atomic compare exchange operation on the 16-bit unsigned integer
  94   specified by Value.  If Value is equal to CompareValue, then Value is set to
  95   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
  96   then Value is returned.  The compare exchange operation must be performed using
  97   MP safe mechanisms.
  98
  99
 100   @param  Value         A pointer to the 16-bit value for the compare exchange
 101                         operation.
 102   @param  CompareValue  16-bit value used in compare operation.
 103   @param  ExchangeValue 16-bit value used in exchange operation.
 104
 105   @return The original *Value before exchange.
 106
 107 **/
 108 UINT16
 109 EFIAPI
 110 InternalSyncCompareExchange16 (
 111   IN OUT volatile  UINT16           *Value,
 112   IN      UINT16                    CompareValue,
 113   IN      UINT16                    ExchangeValue
 114   )
 115 {
 116   __asm__ __volatile__ (
 117     "lock                 \n\t"
 118     "cmpxchgw    %2, %1   \n\t"
 119     : "+a" (CompareValue),      // %0
 120       "+m" (*Value)             // %1
 121     : "r"  (ExchangeValue)      // %2
 122     : "memory",
 123       "cc"
 124     );
 125
 126   return CompareValue;
 127 }
 128
 129
 130 /**
 131   Performs an atomic compare exchange operation on a 32-bit unsigned integer.
 132
 133   Performs an atomic compare exchange operation on the 32-bit unsigned integer
 134   specified by Value.  If Value is equal to CompareValue, then Value is set to
 135   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
 136   then Value is returned.  The compare exchange operation must be performed using
 137   MP safe mechanisms.
 138
 139
 140   @param  Value         A pointer to the 32-bit value for the compare exchange
 141                         operation.
 142   @param  CompareValue  32-bit value used in compare operation.
 143   @param  ExchangeValue 32-bit value used in exchange operation.
 144
 145   @return The original *Value before exchange.
 146
 147 **/
 148 UINT32
 149 EFIAPI
 150 InternalSyncCompareExchange32 (
 151   IN OUT volatile  UINT32           *Value,
 152   IN      UINT32                    CompareValue,
 153   IN      UINT32                    ExchangeValue
 154   )
 155 {
 156   __asm__ __volatile__ (
 157     "lock                 \n\t"
 158     "cmpxchgl    %2, %1   \n\t"
 159     : "+a" (CompareValue),      // %0
 160       "+m" (*Value)             // %1
 161     : "r"  (ExchangeValue)      // %2
 162     : "memory",
 163       "cc"
 164     );
 165
 166   return CompareValue;
 167 }
 168
 169
 170 /**
 171   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
 172
 173   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
 174   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
 175   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
 176   The compare exchange operation must be performed using MP safe mechanisms.
 177
 178
 179   @param  Value         A pointer to the 64-bit value for the compare exchange
 180                         operation.
 181   @param  CompareValue  64-bit value used in compare operation.
 182   @param  ExchangeValue 64-bit value used in exchange operation.
 183
 184   @return The original *Value before exchange.
 185
 186 **/
 187 UINT64
 188 EFIAPI
 189 InternalSyncCompareExchange64 (
 190   IN OUT  volatile UINT64           *Value,
 191   IN      UINT64                    CompareValue,
 192   IN      UINT64                    ExchangeValue
 193   )
 194 {
 195   __asm__ __volatile__ (
 196     "lock                 \n\t"
 197     "cmpxchgq    %2, %1   \n\t"
 198     : "+a" (CompareValue),      // %0
 199       "+m" (*Value)             // %1
 200     : "r"  (ExchangeValue)      // %2
 201     : "memory",
 202       "cc"
 203     );
 204
 205   return CompareValue;
 206 }