1 /* Low-level functions for atomic operations. RISC-V version. 2 Copyright (C) 2014-2021 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 <https://www.gnu.org/licenses/>. */ 18 19 #ifndef _LINUX_RISCV_BITS_ATOMIC_H 20 #define _LINUX_RISCV_BITS_ATOMIC_H 1 21 22 #define atomic_full_barrier() __sync_synchronize () 23 24 #ifdef __riscv_atomic 25 26 # define __HAVE_64B_ATOMICS (__riscv_xlen >= 64) 27 # define USE_ATOMIC_COMPILER_BUILTINS 1 28 # define ATOMIC_EXCHANGE_USES_CAS 0 29 30 /* Compare and exchange. 31 For all "bool" routines, we return FALSE if exchange succesful. */ 32 33 # define __arch_compare_and_exchange_bool_8_int(mem, newval, oldval, model) \ 34 ({ \ 35 typeof (*mem) __oldval = (oldval); \ 36 !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ 37 model, __ATOMIC_RELAXED); \ 38 }) 39 40 # define __arch_compare_and_exchange_bool_16_int(mem, newval, oldval, model) \ 41 ({ \ 42 typeof (*mem) __oldval = (oldval); \ 43 !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ 44 model, __ATOMIC_RELAXED); \ 45 }) 46 47 # define __arch_compare_and_exchange_bool_32_int(mem, newval, oldval, model) \ 48 ({ \ 49 typeof (*mem) __oldval = (oldval); \ 50 !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ 51 model, __ATOMIC_RELAXED); \ 52 }) 53 54 # define __arch_compare_and_exchange_bool_64_int(mem, newval, oldval, model) \ 55 ({ \ 56 typeof (*mem) __oldval = (oldval); \ 57 !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ 58 model, __ATOMIC_RELAXED); \ 59 }) 60 61 # define __arch_compare_and_exchange_val_8_int(mem, newval, oldval, model) \ 62 ({ \ 63 typeof (*mem) __oldval = (oldval); \ 64 __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ 65 model, __ATOMIC_RELAXED); \ 66 __oldval; \ 67 }) 68 69 # define __arch_compare_and_exchange_val_16_int(mem, newval, oldval, model) \ 70 ({ \ 71 typeof (*mem) __oldval = (oldval); \ 72 __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ 73 model, __ATOMIC_RELAXED); \ 74 __oldval; \ 75 }) 76 77 # define __arch_compare_and_exchange_val_32_int(mem, newval, oldval, model) \ 78 ({ \ 79 typeof (*mem) __oldval = (oldval); \ 80 __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ 81 model, __ATOMIC_RELAXED); \ 82 __oldval; \ 83 }) 84 85 # define __arch_compare_and_exchange_val_64_int(mem, newval, oldval, model) \ 86 ({ \ 87 typeof (*mem) __oldval = (oldval); \ 88 __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ 89 model, __ATOMIC_RELAXED); \ 90 __oldval; \ 91 }) 92 93 /* Atomic compare and exchange. */ 94 95 # define atomic_compare_and_exchange_bool_acq(mem, new, old) \ 96 __atomic_bool_bysize (__arch_compare_and_exchange_bool, int, \ 97 mem, new, old, __ATOMIC_ACQUIRE) 98 99 # define atomic_compare_and_exchange_val_acq(mem, new, old) \ 100 __atomic_val_bysize (__arch_compare_and_exchange_val, int, \ 101 mem, new, old, __ATOMIC_ACQUIRE) 102 103 # define atomic_compare_and_exchange_val_rel(mem, new, old) \ 104 __atomic_val_bysize (__arch_compare_and_exchange_val, int, \ 105 mem, new, old, __ATOMIC_RELEASE) 106 107 /* Atomic exchange (without compare). */ 108 109 # define __arch_exchange_8_int(mem, newval, model) \ 110 __atomic_exchange_n (mem, newval, model) 111 112 # define __arch_exchange_16_int(mem, newval, model) \ 113 __atomic_exchange_n (mem, newval, model) 114 115 # define __arch_exchange_32_int(mem, newval, model) \ 116 __atomic_exchange_n (mem, newval, model) 117 118 # define __arch_exchange_64_int(mem, newval, model) \ 119 __atomic_exchange_n (mem, newval, model) 120 121 # define atomic_exchange_acq(mem, value) \ 122 __atomic_val_bysize (__arch_exchange, int, mem, value, __ATOMIC_ACQUIRE) 123 124 # define atomic_exchange_rel(mem, value) \ 125 __atomic_val_bysize (__arch_exchange, int, mem, value, __ATOMIC_RELEASE) 126 127 /* Atomically add value and return the previous (unincremented) value. */ 128 129 # define __arch_exchange_and_add_8_int(mem, value, model) \ 130 __atomic_fetch_add (mem, value, model) 131 132 # define __arch_exchange_and_add_16_int(mem, value, model) \ 133 __atomic_fetch_add (mem, value, model) 134 135 # define __arch_exchange_and_add_32_int(mem, value, model) \ 136 __atomic_fetch_add (mem, value, model) 137 138 # define __arch_exchange_and_add_64_int(mem, value, model) \ 139 __atomic_fetch_add (mem, value, model) 140 141 # define atomic_exchange_and_add_acq(mem, value) \ 142 __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, \ 143 __ATOMIC_ACQUIRE) 144 145 # define atomic_exchange_and_add_rel(mem, value) \ 146 __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, \ 147 __ATOMIC_RELEASE) 148 149 /* Miscellaneous. */ 150 151 # define asm_amo(which, ordering, mem, value) ({ \ 152 __atomic_check_size (mem); \ 153 typeof (*mem) __tmp; \ 154 if (sizeof (__tmp) == 4) \ 155 asm volatile (which ".w" ordering "\t%0, %z2, %1" \ 156 : "=r" (__tmp), "+A" (* (mem)) \ 157 : "rJ" (value)); \ 158 else if (sizeof (__tmp) == 8) \ 159 asm volatile (which ".d" ordering "\t%0, %z2, %1" \ 160 : "=r" (__tmp), "+A" (* (mem)) \ 161 : "rJ" (value)); \ 162 else \ 163 abort (); \ 164 __tmp; }) 165 166 # define atomic_max(mem, value) asm_amo ("amomaxu", ".aq", mem, value) 167 # define atomic_min(mem, value) asm_amo ("amominu", ".aq", mem, value) 168 169 # define atomic_bit_test_set(mem, bit) \ 170 ({ typeof (*mem) __mask = (typeof (*mem))1 << (bit); \ 171 asm_amo ("amoor", ".aq", mem, __mask) & __mask; }) 172 173 # define catomic_exchange_and_add(mem, value) \ 174 atomic_exchange_and_add (mem, value) 175 # define catomic_max(mem, value) atomic_max (mem, value) 176 177 #else /* __riscv_atomic */ 178 # error "ISAs that do not subsume the A extension are not supported" 179 #endif /* !__riscv_atomic */ 180 181 #endif /* bits/atomic.h */ 182