linux/tools/virtio/asm/barrier.h
Michael S. Tsirkin 770f359ced tools/virtio: make asm/barrier.h self contained
We are using abort() so let's include stdlib.h

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-17 06:05:29 -04:00

23 lines
726 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#include <stdlib.h>
#if defined(__i386__) || defined(__x86_64__)
#define barrier() asm volatile("" ::: "memory")
#define virt_mb() __sync_synchronize()
#define virt_rmb() barrier()
#define virt_wmb() barrier()
/* Atomic store should be enough, but gcc generates worse code in that case. */
#define virt_store_mb(var, value) do { \
typeof(var) virt_store_mb_value = (value); \
__atomic_exchange(&(var), &virt_store_mb_value, &virt_store_mb_value, \
__ATOMIC_SEQ_CST); \
barrier(); \
} while (0);
/* Weak barriers should be used. If not - it's a bug */
# define mb() abort()
# define dma_rmb() abort()
# define dma_wmb() abort()
#else
#error Please fill in barrier macros
#endif