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, %2  \n\t"
  42     "inc     %%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   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, %2   \n\t"
  78     "dec     %%eax                  "
  79     : "=a" (Result),          // %0
  80       "=m" (*Value)           // %1
  81     : "m"  (*Value)           // %2
  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
 117
 118   __asm__ __volatile__ (
 119     "lock                 \n\t"
 120     "cmpxchgw    %3, %1       "
 121     : "=a" (CompareValue),
 122       "=m" (*Value)
 123     : "a"  (CompareValue),
 124       "r"  (ExchangeValue),
 125       "m"  (*Value)
 126     : "memory",
 127       "cc"
 128     );
 129
 130   return CompareValue;
 131 }
 132
 133
 134 /**
 135   Performs an atomic compare exchange operation on a 32-bit unsigned integer.
 136
 137   Performs an atomic compare exchange operation on the 32-bit unsigned integer
 138   specified by Value.  If Value is equal to CompareValue, then Value is set to
 139   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
 140   then Value is returned.  The compare exchange operation must be performed using
 141   MP safe mechanisms.
 142
 143
 144   @param  Value         A pointer to the 32-bit value for the compare exchange
 145                         operation.
 146   @param  CompareValue  32-bit value used in compare operation.
 147   @param  ExchangeValue 32-bit value used in exchange operation.
 148
 149   @return The original *Value before exchange.
 150
 151 **/
 152 UINT32
 153 EFIAPI
 154 InternalSyncCompareExchange32 (
 155   IN OUT volatile  UINT32           *Value,
 156   IN      UINT32                    CompareValue,
 157   IN      UINT32                    ExchangeValue
 158   )
 159 {
 160
 161
 162   __asm__ __volatile__ (
 163     "lock                 \n\t"
 164     "cmpxchgl    %3, %1       "
 165     : "=a" (CompareValue),    // %0
 166       "=m" (*Value)           // %1
 167     : "a"  (CompareValue),    // %2
 168       "r"  (ExchangeValue),   // %3
 169       "m"  (*Value)
 170     : "memory",
 171       "cc"
 172     );
 173
 174   return CompareValue;
 175 }
 176
 177
 178 /**
 179   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
 180
 181   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
 182   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
 183   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
 184   The compare exchange operation must be performed using MP safe mechanisms.
 185
 186
 187   @param  Value         A pointer to the 64-bit value for the compare exchange
 188                         operation.
 189   @param  CompareValue  64-bit value used in compare operation.
 190   @param  ExchangeValue 64-bit value used in exchange operation.
 191
 192   @return The original *Value before exchange.
 193
 194 **/
 195 UINT64
 196 EFIAPI
 197 InternalSyncCompareExchange64 (
 198   IN OUT  volatile UINT64           *Value,
 199   IN      UINT64                    CompareValue,
 200   IN      UINT64                    ExchangeValue
 201   )
 202 {
 203
 204   __asm__ __volatile__ (
 205     "lock                 \n\t"
 206     "cmpxchgq    %3, %1       "
 207     : "=a" (CompareValue),    // %0
 208       "=m" (*Value)           // %1
 209     : "a"  (CompareValue),    // %2
 210       "r"  (ExchangeValue),   // %3
 211       "m"  (*Value)
 212     : "memory",
 213       "cc"
 214     );
 215
 216   return CompareValue;
 217 }
 218
 219