linux-vybrid_public/arch/s390/include/asm/barrier.h

/*
 * Copyright IBM Corp. 1999, 2009
 *
 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
 */

#ifndef __ASM_BARRIER_H
#define __ASM_BARRIER_H

/*
 * Force strict CPU ordering.
 * And yes, this is required on UP too when we're talking
 * to devices.
 *
 * This is very similar to the ppc eieio/sync instruction in that is
 * does a checkpoint syncronisation & makes sure that 
 * all memory ops have completed wrt other CPU's ( see 7-15 POP  DJB ).
 */

#define eieio()	asm volatile("bcr 15,0" : : : "memory")
#define SYNC_OTHER_CORES(x)   eieio()
#define mb()    eieio()
#define rmb()   eieio()
#define wmb()   eieio()
#define read_barrier_depends() do { } while(0)
#define smp_mb()       mb()
#define smp_rmb()      rmb()
#define smp_wmb()      wmb()
#define smp_read_barrier_depends()    read_barrier_depends()
#define smp_mb__before_clear_bit()     smp_mb()
#define smp_mb__after_clear_bit()      smp_mb()

#define set_mb(var, value)      do { var = value; mb(); } while (0)

#endif /* __ASM_BARRIER_H */