diff options
-rw-r--r-- | include/asm-ia64/spinlock.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/include/asm-ia64/spinlock.h b/include/asm-ia64/spinlock.h index 5b78611411c3..0c91a76c5ea3 100644 --- a/include/asm-ia64/spinlock.h +++ b/include/asm-ia64/spinlock.h | |||
@@ -201,6 +201,16 @@ static inline void __raw_write_unlock(raw_rwlock_t *x) | |||
201 | 201 | ||
202 | #endif /* !ASM_SUPPORTED */ | 202 | #endif /* !ASM_SUPPORTED */ |
203 | 203 | ||
204 | #define __raw_read_trylock(lock) generic__raw_read_trylock(lock) | 204 | static inline int __raw_read_trylock(raw_rwlock_t *x) |
205 | { | ||
206 | union { | ||
207 | raw_rwlock_t lock; | ||
208 | __u32 word; | ||
209 | } old, new; | ||
210 | old.lock = new.lock = *x; | ||
211 | old.lock.write_lock = new.lock.write_lock = 0; | ||
212 | ++new.lock.read_counter; | ||
213 | return (u32)ia64_cmpxchg4_acq((__u32 *)(x), new.word, old.word) == old.word; | ||
214 | } | ||
205 | 215 | ||
206 | #endif /* _ASM_IA64_SPINLOCK_H */ | 216 | #endif /* _ASM_IA64_SPINLOCK_H */ |