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