1 /* Low-level functions for atomic operations. ARC version. 2 Copyright (C) 2020-2021 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 _ARC_BITS_ATOMIC_H 20 #define _ARC_BITS_ATOMIC_H 1 21 22 #define __HAVE_64B_ATOMICS 0 23 #define USE_ATOMIC_COMPILER_BUILTINS 1 24 25 /* ARC does have legacy atomic EX reg, [mem] instruction but the micro-arch 26 is not as optimal as LLOCK/SCOND specially for SMP. */ 27 #define ATOMIC_EXCHANGE_USES_CAS 1 28 29 #define __arch_compare_and_exchange_bool_8_acq(mem, newval, oldval) \ 30 (abort (), 0) 31 #define __arch_compare_and_exchange_bool_16_acq(mem, newval, oldval) \ 32 (abort (), 0) 33 #define __arch_compare_and_exchange_bool_64_acq(mem, newval, oldval) \ 34 (abort (), 0) 35 36 #define __arch_compare_and_exchange_val_8_int(mem, newval, oldval, model) \ 37 (abort (), (__typeof (*mem)) 0) 38 #define __arch_compare_and_exchange_val_16_int(mem, newval, oldval, model) \ 39 (abort (), (__typeof (*mem)) 0) 40 #define __arch_compare_and_exchange_val_64_int(mem, newval, oldval, model) \ 41 (abort (), (__typeof (*mem)) 0) 42 43 #define __arch_compare_and_exchange_val_32_int(mem, newval, oldval, model) \ 44 ({ \ 45 typeof (*mem) __oldval = (oldval); \ 46 __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \ 47 model, __ATOMIC_RELAXED); \ 48 __oldval; \ 49 }) 50 51 #define atomic_compare_and_exchange_val_acq(mem, new, old) \ 52 __atomic_val_bysize (__arch_compare_and_exchange_val, int, \ 53 mem, new, old, __ATOMIC_ACQUIRE) 54 55 #define atomic_full_barrier() ({ asm volatile ("dmb 3":::"memory"); }) 56 57 #endif /* _ARC_BITS_ATOMIC_H */ 58