MdePkg/Library/BaseSynchronizationLib/Ia32/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. The state of the return value is not
  24   guaranteed to be MP safe.
  25
  26   @param  Value A pointer to the 32-bit value to increment.
  27
  28   @return The incremented value.
  29
  30 **/
  31 UINT32
  32 EFIAPI
  33 InternalSyncIncrement (
  34   IN      volatile UINT32    *Value
  35   )
  36 {
  37   UINT32  Result;
  38
  39   __asm__ __volatile__ (
  40     "lock               \n\t"
  41     "incl    %2         \n\t"
  42     "movl    %2, %%eax      "
  43     : "=a" (Result),          // %0
  44       "=m" (*Value)           // %1
  45     : "m"  (*Value)           // %2
  46     : "memory",
  47       "cc"
  48     );
  49
  50   return Result;
  51
  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     "movl    %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   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
 117   __asm__ __volatile__ (
 118     "                     \n\t"
 119     "lock                 \n\t"
 120     "cmpxchgw    %1, %2   \n\t"
 121     : "=a" (CompareValue)
 122     : "q"  (ExchangeValue),
 123       "m"  (*Value),
 124       "0"  (CompareValue)
 125     : "memory",
 126       "cc"
 127     );
 128
 129   return CompareValue;
 130 }
 131
 132 /**
 133   Performs an atomic compare exchange operation on a 32-bit unsigned integer.
 134
 135   Performs an atomic compare exchange operation on the 32-bit unsigned integer
 136   specified by Value.  If Value is equal to CompareValue, then Value is set to
 137   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
 138   then Value is returned.  The compare exchange operation must be performed using
 139   MP safe mechanisms.
 140
 141
 142   @param  Value         A pointer to the 32-bit value for the compare exchange
 143                         operation.
 144   @param  CompareValue  32-bit value used in compare operation.
 145   @param  ExchangeValue 32-bit value used in exchange operation.
 146
 147   @return The original *Value before exchange.
 148
 149 **/
 150 UINT32
 151 EFIAPI
 152 InternalSyncCompareExchange32 (
 153   IN OUT volatile  UINT32           *Value,
 154   IN      UINT32                    CompareValue,
 155   IN      UINT32                    ExchangeValue
 156   )
 157 {
 158
 159   __asm__ __volatile__ (
 160     "                     \n\t"
 161     "lock                 \n\t"
 162     "cmpxchgl    %1, %2   \n\t"
 163     : "=a" (CompareValue)     // %0
 164     : "q"  (ExchangeValue),   // %1
 165       "m"  (*Value),          // %2
 166       "0"  (CompareValue)     // %4
 167     : "memory",
 168       "cc"
 169     );
 170
 171   return CompareValue;
 172 }
 173
 174 /**
 175   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
 176
 177   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
 178   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
 179   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
 180   The compare exchange operation must be performed using MP safe mechanisms.
 181
 182
 183   @param  Value         A pointer to the 64-bit value for the compare exchange
 184                         operation.
 185   @param  CompareValue  64-bit value used in compare operation.
 186   @param  ExchangeValue 64-bit value used in exchange operation.
 187
 188   @return The original *Value before exchange.
 189
 190 **/
 191 UINT64
 192 EFIAPI
 193 InternalSyncCompareExchange64 (
 194   IN OUT  volatile UINT64           *Value,
 195   IN      UINT64                    CompareValue,
 196   IN      UINT64                    ExchangeValue
 197   )
 198 {
 199   __asm__ __volatile__ (
 200     "                       \n\t"
 201     "push        %%ebx      \n\t"
 202     "movl        %2,%%ebx   \n\t"
 203     "lock                   \n\t"
 204     "cmpxchg8b   (%1)       \n\t"
 205     "pop         %%ebx      \n\t"
 206     : "+A"  (CompareValue)                    // %0
 207     : "S"   (Value),                          // %1
 208       "r"   ((UINT32) ExchangeValue),         // %2
 209       "c"   ((UINT32) (ExchangeValue >> 32))  // %3
 210     : "memory",
 211       "cc"
 212     );
 213
 214   return CompareValue;
 215 }