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   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10
  11
  12 /**
  13   Performs an atomic increment of an 32-bit unsigned integer.
  14
  15   Performs an atomic increment of the 32-bit unsigned integer specified by
  16   Value and returns the incremented value. The increment operation must be
  17   performed using MP safe mechanisms.
  18
  19   @param  Value A pointer to the 32-bit value to increment.
  20
  21   @return The incremented value.
  22
  23 **/
  24 UINT32
  25 EFIAPI
  26 InternalSyncIncrement (
  27   IN      volatile UINT32    *Value
  28   )
  29 {
  30   UINT32  Result;
  31
  32   __asm__ __volatile__ (
  33     "movl    $1, %%eax  \n\t"
  34     "lock               \n\t"
  35     "xadd    %%eax, %1  \n\t"
  36     "inc     %%eax      \n\t"
  37     : "=&a" (Result),         // %0
  38       "+m" (*Value)           // %1
  39     :                         // no inputs that aren't also outputs
  40     : "memory",
  41       "cc"
  42     );
  43
  44   return Result;
  45 }
  46
  47
  48 /**
  49   Performs an atomic decrement of an 32-bit unsigned integer.
  50
  51   Performs an atomic decrement of the 32-bit unsigned integer specified by
  52   Value and returns the decremented value. The decrement operation must be
  53   performed using MP safe mechanisms.
  54
  55   @param  Value A pointer to the 32-bit value to decrement.
  56
  57   @return The decremented value.
  58
  59 **/
  60 UINT32
  61 EFIAPI
  62 InternalSyncDecrement (
  63   IN      volatile UINT32       *Value
  64   )
  65 {
  66    UINT32  Result;
  67
  68   __asm__ __volatile__ (
  69     "movl    $-1, %%eax  \n\t"
  70     "lock                \n\t"
  71     "xadd    %%eax, %1   \n\t"
  72     "dec     %%eax       \n\t"
  73     : "=&a" (Result),          // %0
  74       "+m" (*Value)            // %1
  75     :                          // no inputs that aren't also outputs
  76     : "memory",
  77       "cc"
  78     );
  79
  80   return Result;
  81 }
  82
  83
  84 /**
  85   Performs an atomic compare exchange operation on a 16-bit unsigned integer.
  86
  87   Performs an atomic compare exchange operation on the 16-bit unsigned integer
  88   specified by Value.  If Value is equal to CompareValue, then Value is set to
  89   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
  90   then Value is returned.  The compare exchange operation must be performed using
  91   MP safe mechanisms.
  92
  93
  94   @param  Value         A pointer to the 16-bit value for the compare exchange
  95                         operation.
  96   @param  CompareValue  16-bit value used in compare operation.
  97   @param  ExchangeValue 16-bit value used in exchange operation.
  98
  99   @return The original *Value before exchange.
 100
 101 **/
 102 UINT16
 103 EFIAPI
 104 InternalSyncCompareExchange16 (
 105   IN OUT volatile  UINT16           *Value,
 106   IN      UINT16                    CompareValue,
 107   IN      UINT16                    ExchangeValue
 108   )
 109 {
 110   __asm__ __volatile__ (
 111     "lock                 \n\t"
 112     "cmpxchgw    %2, %1   \n\t"
 113     : "+a" (CompareValue),      // %0
 114       "+m" (*Value)             // %1
 115     : "r"  (ExchangeValue)      // %2
 116     : "memory",
 117       "cc"
 118     );
 119
 120   return CompareValue;
 121 }
 122
 123
 124 /**
 125   Performs an atomic compare exchange operation on a 32-bit unsigned integer.
 126
 127   Performs an atomic compare exchange operation on the 32-bit unsigned integer
 128   specified by Value.  If Value is equal to CompareValue, then Value is set to
 129   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
 130   then Value is returned.  The compare exchange operation must be performed using
 131   MP safe mechanisms.
 132
 133
 134   @param  Value         A pointer to the 32-bit value for the compare exchange
 135                         operation.
 136   @param  CompareValue  32-bit value used in compare operation.
 137   @param  ExchangeValue 32-bit value used in exchange operation.
 138
 139   @return The original *Value before exchange.
 140
 141 **/
 142 UINT32
 143 EFIAPI
 144 InternalSyncCompareExchange32 (
 145   IN OUT volatile  UINT32           *Value,
 146   IN      UINT32                    CompareValue,
 147   IN      UINT32                    ExchangeValue
 148   )
 149 {
 150   __asm__ __volatile__ (
 151     "lock                 \n\t"
 152     "cmpxchgl    %2, %1   \n\t"
 153     : "+a" (CompareValue),      // %0
 154       "+m" (*Value)             // %1
 155     : "r"  (ExchangeValue)      // %2
 156     : "memory",
 157       "cc"
 158     );
 159
 160   return CompareValue;
 161 }
 162
 163
 164 /**
 165   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
 166
 167   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
 168   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
 169   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
 170   The compare exchange operation must be performed using MP safe mechanisms.
 171
 172
 173   @param  Value         A pointer to the 64-bit value for the compare exchange
 174                         operation.
 175   @param  CompareValue  64-bit value used in compare operation.
 176   @param  ExchangeValue 64-bit value used in exchange operation.
 177
 178   @return The original *Value before exchange.
 179
 180 **/
 181 UINT64
 182 EFIAPI
 183 InternalSyncCompareExchange64 (
 184   IN OUT  volatile UINT64           *Value,
 185   IN      UINT64                    CompareValue,
 186   IN      UINT64                    ExchangeValue
 187   )
 188 {
 189   __asm__ __volatile__ (
 190     "lock                 \n\t"
 191     "cmpxchgq    %2, %1   \n\t"
 192     : "+a" (CompareValue),      // %0
 193       "+m" (*Value)             // %1
 194     : "r"  (ExchangeValue)      // %2
 195     : "memory",
 196       "cc"
 197     );
 198
 199   return CompareValue;
 200 }