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| author |   miod <miod@openbsd.org> | 2013-12-22 18:32:40 +0000 |
|---|---|---|
| committer | miod <miod@openbsd.org> | 2013-12-22 18:32:40 +0000 |
| commit | 1f99c46e2161a26fffe44eee602374d0142c2644 (patch) | |
| tree | c0108965f581ff302103948ab18c81e650860829 | |
| parent | Set the primary CPU's PAL revision to the OSF/1 PAL revision after switching (diff) | |
| download | wireguard-openbsd-1f99c46e2161a26fffe44eee602374d0142c2644.tar.xz wireguard-openbsd-1f99c46e2161a26fffe44eee602374d0142c2644.zip | |
MP-safe rw_cas() implementation for rwlocks.
| -rw-r--r-- | sys/arch/alpha/include/lock.h | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/sys/arch/alpha/include/lock.h b/sys/arch/alpha/include/lock.h index cec638a8adb..fcaf38cb4c6 100644 --- a/sys/arch/alpha/include/lock.h +++ b/sys/arch/alpha/include/lock.h @@ -1,4 +1,4 @@ -/* $OpenBSD: lock.h,v 1.4 2013/05/21 20:05:30 tedu Exp $ */ +/* $OpenBSD: lock.h,v 1.5 2013/12/22 18:32:40 miod Exp $ */ /* $NetBSD: lock.h,v 1.16 2001/12/17 23:34:57 thorpej Exp $ */ /*- @@ -63,4 +63,28 @@ do { \ } while (0) #endif /* MULTIPROCESSOR */ +#define rw_cas __cpu_cas +static inline int +__cpu_cas(volatile unsigned long *addr, unsigned long old, unsigned long new) +{ + unsigned long t0, v0; + + __asm __volatile( + "1: ldq_l %1, 0(%2) \n" /* v0 = *addr */ + " cmpeq %1, %3, %0 \n" /* t0 = v0 == old */ + " beq %0, 2f \n" + " mov %4, %0 \n" /* t0 = new */ + " stq_c %0, 0(%2) \n" /* *addr = new */ + " beq %0, 3f \n" + " mb \n" + "2: br 4f \n" + "3: br 1b \n" /* update failed */ + "4: \n" + : "=&r" (t0), "=&r" (v0) + : "r" (addr), "r" (old), "r" (new) + : "memory"); + + return (v0 != old); +} + #endif /* _MACHINE_LOCK_H_ */ |