sysdeps/arm/atomic-machine.h

   1 /* Atomic operations.  Pure ARM version.
   2    Copyright (C) 2002-2016 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library.  If not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <stdint.h>
  20
  21 typedef int8_t atomic8_t;
  22 typedef uint8_t uatomic8_t;
  23 typedef int_fast8_t atomic_fast8_t;
  24 typedef uint_fast8_t uatomic_fast8_t;
  25
  26 typedef int32_t atomic32_t;
  27 typedef uint32_t uatomic32_t;
  28 typedef int_fast32_t atomic_fast32_t;
  29 typedef uint_fast32_t uatomic_fast32_t;
  30
  31 typedef intptr_t atomicptr_t;
  32 typedef uintptr_t uatomicptr_t;
  33 typedef intmax_t atomic_max_t;
  34 typedef uintmax_t uatomic_max_t;
  35
  36 #define __HAVE_64B_ATOMICS 0
  37 #define USE_ATOMIC_COMPILER_BUILTINS 0
  38
  39 void __arm_link_error (void);
  40
  41 #ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
  42 # define atomic_full_barrier() __sync_synchronize ()
  43 #else
  44 # define atomic_full_barrier() __arm_assisted_full_barrier ()
  45 #endif
  46
  47 /* An OS-specific atomic-machine.h file will define this macro if
  48    the OS can provide something.  If not, we'll fail to build
  49    with a compiler that doesn't supply the operation.  */
  50 #ifndef __arm_assisted_full_barrier
  51 # define __arm_assisted_full_barrier()  __arm_link_error()
  52 #endif
  53
  54 /* Use the atomic builtins provided by GCC in case the backend provides
  55    a pattern to do this efficiently.  */
  56 #ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
  57
  58 # define atomic_exchange_acq(mem, value)                                \
  59   __atomic_val_bysize (__arch_exchange, int, mem, value, __ATOMIC_ACQUIRE)
  60
  61 # define atomic_exchange_rel(mem, value)                                \
  62   __atomic_val_bysize (__arch_exchange, int, mem, value, __ATOMIC_RELEASE)
  63
  64 /* Atomic exchange (without compare).  */
  65
  66 # define __arch_exchange_8_int(mem, newval, model)      \
  67   (__arm_link_error (), (typeof (*mem)) 0)
  68
  69 # define __arch_exchange_16_int(mem, newval, model)     \
  70   (__arm_link_error (), (typeof (*mem)) 0)
  71
  72 # define __arch_exchange_32_int(mem, newval, model)     \
  73   __atomic_exchange_n (mem, newval, model)
  74
  75 # define __arch_exchange_64_int(mem, newval, model)     \
  76   (__arm_link_error (), (typeof (*mem)) 0)
  77
  78 /* Compare and exchange with "acquire" semantics, ie barrier after.  */
  79
  80 # define atomic_compare_and_exchange_bool_acq(mem, new, old)    \
  81   __atomic_bool_bysize (__arch_compare_and_exchange_bool, int,  \
  82                         mem, new, old, __ATOMIC_ACQUIRE)
  83
  84 # define atomic_compare_and_exchange_val_acq(mem, new, old)     \
  85   __atomic_val_bysize (__arch_compare_and_exchange_val, int,    \
  86                        mem, new, old, __ATOMIC_ACQUIRE)
  87
  88 /* Compare and exchange with "release" semantics, ie barrier before.  */
  89
  90 # define atomic_compare_and_exchange_val_rel(mem, new, old)      \
  91   __atomic_val_bysize (__arch_compare_and_exchange_val, int,    \
  92                        mem, new, old, __ATOMIC_RELEASE)
  93
  94 /* Compare and exchange.
  95    For all "bool" routines, we return FALSE if exchange succesful.  */
  96
  97 # define __arch_compare_and_exchange_bool_8_int(mem, newval, oldval, model) \
  98   ({__arm_link_error (); 0; })
  99
 100 # define __arch_compare_and_exchange_bool_16_int(mem, newval, oldval, model) \
 101   ({__arm_link_error (); 0; })
 102
 103 # define __arch_compare_and_exchange_bool_32_int(mem, newval, oldval, model) \
 104   ({                                                                    \
 105     typeof (*mem) __oldval = (oldval);                                  \
 106     !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0,   \
 107                                   model, __ATOMIC_RELAXED);             \
 108   })
 109
 110 # define __arch_compare_and_exchange_bool_64_int(mem, newval, oldval, model) \
 111   ({__arm_link_error (); 0; })
 112
 113 # define __arch_compare_and_exchange_val_8_int(mem, newval, oldval, model) \
 114   ({__arm_link_error (); oldval; })
 115
 116 # define __arch_compare_and_exchange_val_16_int(mem, newval, oldval, model) \
 117   ({__arm_link_error (); oldval; })
 118
 119 # define __arch_compare_and_exchange_val_32_int(mem, newval, oldval, model) \
 120   ({                                                                    \
 121     typeof (*mem) __oldval = (oldval);                                  \
 122     __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0,    \
 123                                  model, __ATOMIC_RELAXED);              \
 124     __oldval;                                                           \
 125   })
 126
 127 # define __arch_compare_and_exchange_val_64_int(mem, newval, oldval, model) \
 128   ({__arm_link_error (); oldval; })
 129
 130 #else
 131 # define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \
 132   __arm_assisted_compare_and_exchange_val_32_acq ((mem), (newval), (oldval))
 133 #endif
 134
 135 #ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
 136 /* We don't support atomic operations on any non-word types.
 137    So make them link errors.  */
 138 # define __arch_compare_and_exchange_val_8_acq(mem, newval, oldval) \
 139   ({ __arm_link_error (); oldval; })
 140
 141 # define __arch_compare_and_exchange_val_16_acq(mem, newval, oldval) \
 142   ({ __arm_link_error (); oldval; })
 143
 144 # define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
 145   ({ __arm_link_error (); oldval; })
 146 #endif
 147
 148 /* An OS-specific atomic-machine.h file will define this macro if
 149    the OS can provide something.  If not, we'll fail to build
 150    with a compiler that doesn't supply the operation.  */
 151 #ifndef __arm_assisted_compare_and_exchange_val_32_acq
 152 # define __arm_assisted_compare_and_exchange_val_32_acq(mem, newval, oldval) \
 153   ({ __arm_link_error (); oldval; })
 154 #endif