diff options
| author | Jonathan Gray <jsg@cvs.openbsd.org> | 2015-06-29 04:16:33 +0000 |
|---|---|---|
| committer | Jonathan Gray <jsg@cvs.openbsd.org> | 2015-06-29 04:16:33 +0000 |
| commit | 918ad8934d2b0dff6db00ed5e04dba9f7a98ce00 (patch) | |
| tree | 5346352f246ef16020708eb2aeb5f33690e9e3aa /sys | |
| parent | 07cf13c26028613edda80f54efd12d444fe12351 (diff) | |
Implement membar_* for armv7 with the dmb instruction. The previous
sys/sys/atomic.h default of __sync_synchronize() resulted in "dmb sy",
a full system barrier for all memory operations. With this change
membar_producer() switches to "dmb st" (StoreStore).
earlier version ok rapha@
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/arch/arm/include/atomic.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/sys/arch/arm/include/atomic.h b/sys/arch/arm/include/atomic.h index ba80cb085eb..3f2db652bc8 100644 --- a/sys/arch/arm/include/atomic.h +++ b/sys/arch/arm/include/atomic.h @@ -1,4 +1,4 @@ -/* $OpenBSD: atomic.h,v 1.10 2014/11/14 09:56:06 dlg Exp $ */ +/* $OpenBSD: atomic.h,v 1.11 2015/06/29 04:16:32 jsg Exp $ */ /* Public Domain */ @@ -193,5 +193,19 @@ atomic_clearbits_int(volatile unsigned int *uip, unsigned int v) restore_interrupts(cpsr); } +#if defined(CPU_ARMv7) +#define __membar(_f) do { __asm __volatile(_f ::: "memory"); } while (0) + +#define membar_enter() __membar("dmb sy") +#define membar_exit() __membar("dmb sy") +#define membar_producer() __membar("dmb st") +#define membar_consumer() __membar("dmb sy") +#define membar_sync() __membar("dmb sy") + +#define virtio_membar_producer() __membar("dmb st") +#define virtio_membar_consumer() __membar("dmb sy") +#define virtio_membar_sync() __membar("dmb sy") +#endif /* CPU_ARMv7 */ + #endif /* defined(_KERNEL) */ #endif /* _ARM_ATOMIC_H_ */ |