diff options
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/arch/m88k/include/lock.h | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/sys/arch/m88k/include/lock.h b/sys/arch/m88k/include/lock.h index 7d377703b7a..baa0439d728 100644 --- a/sys/arch/m88k/include/lock.h +++ b/sys/arch/m88k/include/lock.h @@ -1,6 +1,6 @@ #ifndef _M88K_LOCK_H_ #define _M88K_LOCK_H_ -/* $OpenBSD: lock.h,v 1.3 2007/05/19 16:58:43 miod Exp $ */ +/* $OpenBSD: lock.h,v 1.4 2007/10/27 20:35:21 miod Exp $ */ /* * Copyright (c) 2005, Miodrag Vallat. @@ -44,7 +44,13 @@ __cpu_simple_lock_init(__cpu_simple_lock_t *l) static __inline__ void __cpu_simple_lock(__cpu_simple_lock_t *l) { - __cpu_simple_lock_t old; + /* + * The local __cpu_simple_lock_t is not declared volatile, so that + * stores to it can be optimized away, since we will use a register + * and only spin on it. xmem will do the right thing regardless of + * the volatile qualifier. + */ + u_int old; do { old = __SIMPLELOCK_LOCKED; @@ -56,7 +62,12 @@ __cpu_simple_lock(__cpu_simple_lock_t *l) static __inline__ int __cpu_simple_lock_try(__cpu_simple_lock_t *l) { - __cpu_simple_lock_t old = __SIMPLELOCK_LOCKED; + /* + * The local __cpu_simple_lock_t is not declared volatile, so that + * there are not pipeline synchronization around stores to it. + * xmem will do the right thing regardless of the volatile qualifier. + */ + u_int old = __SIMPLELOCK_LOCKED; __asm__ __volatile__ ("xmem %0, %1, r0" : "+r" (old) : "r" (l)); |