tools/virtio: use virt_xxx barriers

#if defined(__i386__) || defined(__x86_64__)

#define barrier() asm volatile("" ::: "memory")

#define mb() __sync_synchronize()

#define smp_mb()	mb()

# define dma_rmb()	barrier()

# define dma_wmb()	barrier()

# define smp_rmb()	barrier()

# define smp_wmb()	barrier()

#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 rmb() abort()

# define wmb() abort()

#else

#ifndef LINUX_COMPILER_H

#define LINUX_COMPILER_H

#define WRITE_ONCE(var, val) \

	(*((volatile typeof(val) *)(&(var))) = (val))

#define READ_ONCE(var) (*((volatile typeof(val) *)(&(var))))

#endif

#include <assert.h>

#include <stdarg.h>

#include <linux/compiler.h>

#include <linux/types.h>

#include <linux/printk.h>

#include <linux/bug.h>