diff options
Diffstat (limited to 'sys/arch/i386/include/atomic.h')
| -rw-r--r-- | sys/arch/i386/include/atomic.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/sys/arch/i386/include/atomic.h b/sys/arch/i386/include/atomic.h index 44a7be7f52f..35ea910c8fa 100644 --- a/sys/arch/i386/include/atomic.h +++ b/sys/arch/i386/include/atomic.h @@ -1,4 +1,4 @@ -/* $OpenBSD: atomic.h,v 1.5 2007/02/19 17:18:42 deraadt Exp $ */ +/* $OpenBSD: atomic.h,v 1.6 2007/05/25 15:55:27 art Exp $ */ /* $NetBSD: atomic.h,v 1.1.2.2 2000/02/21 18:54:07 sommerfeld Exp $ */ /*- @@ -92,6 +92,20 @@ i386_atomic_clearbits_l(volatile u_int32_t *ptr, unsigned long bits) __asm __volatile(LOCK " andl %1,%0" : "=m" (*ptr) : "ir" (bits)); } +/* + * cas = compare and set + */ +static __inline int +i486_atomic_cas_int(volatile u_int *ptr, u_int expect, u_int set) +{ + int res; + + __asm volatile(LOCK " cmpxchgl %2, %1" : "=a" (res), "=m" (*ptr) + : "r" (set), "a" (expect), "m" (*ptr) : "memory"); + + return (res); +} + #define atomic_setbits_int i386_atomic_setbits_l #define atomic_clearbits_int i386_atomic_clearbits_l |