kernel-ark/arch/s390/include/asm/barrier.h
Heiko Carstens e5b8d7553f s390/barrier: make use of fast-bcr facility
If the kernel gets compiled for at least z196, make use of
the fast-BCR facility.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16 14:42:45 +02:00

39 lines
891 B
C

/*
* 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.
*/
static inline void mb(void)
{
#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
/* Fast-BCR without checkpoint synchronization */
asm volatile("bcr 14,0" : : : "memory");
#else
asm volatile("bcr 15,0" : : : "memory");
#endif
}
#define rmb() mb()
#define wmb() mb()
#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 */