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| author | Steven Whitehouse <swhiteho@redhat.com> | 2006-09-04 10:31:36 -0400 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2006-09-04 10:31:36 -0400 |
| commit | 31e77ac55f18db0ec1c724840927562ef3093ef6 (patch) | |
| tree | 01bb0ac2868debd2246df4c5e5617a2ce9f09600 /include/asm-arm/spinlock.h | |
| parent | 5029996547a9f3988459e11955c13259495308ef (diff) | |
| parent | c336923b668fdcf0312efbec3b44895d713f4d81 (diff) | |
| download | talos-op-linux-31e77ac55f18db0ec1c724840927562ef3093ef6.tar.gz talos-op-linux-31e77ac55f18db0ec1c724840927562ef3093ef6.zip | |
Merge branch 'master' into gfs2
Diffstat (limited to 'include/asm-arm/spinlock.h')
| -rw-r--r-- | include/asm-arm/spinlock.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/include/asm-arm/spinlock.h b/include/asm-arm/spinlock.h index 406ca97a8ab2..e2f1d75171df 100644 --- a/include/asm-arm/spinlock.h +++ b/include/asm-arm/spinlock.h @@ -199,7 +199,21 @@ static inline void __raw_read_unlock(raw_rwlock_t *rw) : "cc"); } -#define __raw_read_trylock(lock) generic__raw_read_trylock(lock) +static inline int __raw_read_trylock(raw_rwlock_t *rw) +{ + unsigned long tmp tmp2 = 1; + + __asm__ __volatile__( +"1: ldrex %0, [%2]\n" +" adds %0, %0, #1\n" +" strexpl %1, %0, [%2]\n" + : "=&r" (tmp), "+r" (tmp2) + : "r" (&rw->lock) + : "cc"); + + smp_mb(); + return tmp2 == 0; +} /* read_can_lock - would read_trylock() succeed? */ #define __raw_read_can_lock(x) ((x)->lock < 0x80000000) |
