1. 根目录:
2. arch
3. h8300
4. include
5. asm
6. barrier.h

#ifndef _H8300_BARRIER_H
#define _H8300_BARRIER_H

#define nop()  asm volatile ("nop"::)

/*
 * Force strict CPU ordering.
 * Not really required on H8...
 */
#define mb()   asm volatile (""   : : :"memory")
#define rmb()  asm volatile (""   : : :"memory")
#define wmb()  asm volatile (""   : : :"memory")
#define set_mb(var, value) do { xchg(&var, value); } while (0)

#ifdef CONFIG_SMP
#define smp_mb()	mb()
#define smp_rmb()	rmb()
#define smp_wmb()	wmb()
#define smp_read_barrier_depends()	read_barrier_depends()
#else
#define smp_mb()	barrier()
#define smp_rmb()	barrier()
#define smp_wmb()	barrier()
#define smp_read_barrier_depends()	do { } while(0)
#endif

#endif /* _H8300_BARRIER_H */