diff options
Diffstat (limited to 'include/asm-generic/barrier.h')
| -rw-r--r-- | include/asm-generic/barrier.h | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h index 639d7a4d033..d12a90f9368 100644 --- a/include/asm-generic/barrier.h +++ b/include/asm-generic/barrier.h @@ -1,4 +1,5 @@ -/* Generic barrier definitions, based on MN10300 definitions. +/* + * Generic barrier definitions, originally based on MN10300 definitions. * * It should be possible to use these on really simple architectures, * but it serves more as a starting point for new ports. @@ -16,35 +17,50 @@ #ifndef __ASSEMBLY__ -#define nop() asm volatile ("nop") +#include <linux/compiler.h> + +#ifndef nop +#define nop() asm volatile ("nop") +#endif /* - * Force strict CPU ordering. - * And yes, this is required on UP too when we're talking - * to devices. + * Force strict CPU ordering. And yes, this is required on UP too when we're + * talking to devices. * - * This implementation only contains a compiler barrier. + * Fall back to compiler barriers if nothing better is provided. */ -#define mb() asm volatile ("": : :"memory") +#ifndef mb +#define mb() barrier() +#endif + +#ifndef rmb #define rmb() mb() -#define wmb() asm volatile ("": : :"memory") +#endif + +#ifndef wmb +#define wmb() mb() +#endif + +#ifndef read_barrier_depends +#define read_barrier_depends() do { } while (0) +#endif #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 -#define set_mb(var, value) do { var = value; mb(); } while (0) -#define set_wmb(var, value) do { var = value; wmb(); } while (0) - -#define read_barrier_depends() do {} while (0) -#define smp_read_barrier_depends() do {} while (0) +#ifndef set_mb +#define set_mb(var, value) do { (var) = (value); mb(); } while (0) +#endif #endif /* !__ASSEMBLY__ */ #endif /* __ASM_GENERIC_BARRIER_H */ |