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
33