barrier.h (1128B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2#include <stdlib.h> 3#if defined(__i386__) || defined(__x86_64__) 4#define barrier() asm volatile("" ::: "memory") 5#define virt_mb() __sync_synchronize() 6#define virt_rmb() barrier() 7#define virt_wmb() barrier() 8/* Atomic store should be enough, but gcc generates worse code in that case. */ 9#define virt_store_mb(var, value) do { \ 10 typeof(var) virt_store_mb_value = (value); \ 11 __atomic_exchange(&(var), &virt_store_mb_value, &virt_store_mb_value, \ 12 __ATOMIC_SEQ_CST); \ 13 barrier(); \ 14} while (0); 15/* Weak barriers should be used. If not - it's a bug */ 16# define mb() abort() 17# define dma_rmb() abort() 18# define dma_wmb() abort() 19#elif defined(__aarch64__) 20#define dmb(opt) asm volatile("dmb " #opt : : : "memory") 21#define virt_mb() __sync_synchronize() 22#define virt_rmb() dmb(ishld) 23#define virt_wmb() dmb(ishst) 24#define virt_store_mb(var, value) do { WRITE_ONCE(var, value); dmb(ish); } while (0) 25/* Weak barriers should be used. If not - it's a bug */ 26# define mb() abort() 27# define dma_rmb() abort() 28# define dma_wmb() abort() 29#else 30#error Please fill in barrier macros 31#endif 32