diff options
-rw-r--r-- | include/linux/rwsem-spinlock.h | 6 | ||||
-rw-r--r-- | lib/rwsem-spinlock.c | 13 |
2 files changed, 14 insertions, 5 deletions
diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h index 6c3c0f6c261f..bdfcc2527970 100644 --- a/include/linux/rwsem-spinlock.h +++ b/include/linux/rwsem-spinlock.h | |||
@@ -68,11 +68,7 @@ extern int __down_write_trylock(struct rw_semaphore *sem); | |||
68 | extern void __up_read(struct rw_semaphore *sem); | 68 | extern void __up_read(struct rw_semaphore *sem); |
69 | extern void __up_write(struct rw_semaphore *sem); | 69 | extern void __up_write(struct rw_semaphore *sem); |
70 | extern void __downgrade_write(struct rw_semaphore *sem); | 70 | extern void __downgrade_write(struct rw_semaphore *sem); |
71 | 71 | extern int rwsem_is_locked(struct rw_semaphore *sem); | |
72 | static inline int rwsem_is_locked(struct rw_semaphore *sem) | ||
73 | { | ||
74 | return (sem->activity != 0); | ||
75 | } | ||
76 | 72 | ||
77 | #endif /* __KERNEL__ */ | 73 | #endif /* __KERNEL__ */ |
78 | #endif /* _LINUX_RWSEM_SPINLOCK_H */ | 74 | #endif /* _LINUX_RWSEM_SPINLOCK_H */ |
diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c index 39a74110f55b..ccf95bff7984 100644 --- a/lib/rwsem-spinlock.c +++ b/lib/rwsem-spinlock.c | |||
@@ -17,6 +17,19 @@ struct rwsem_waiter { | |||
17 | #define RWSEM_WAITING_FOR_WRITE 0x00000002 | 17 | #define RWSEM_WAITING_FOR_WRITE 0x00000002 |
18 | }; | 18 | }; |
19 | 19 | ||
20 | int rwsem_is_locked(struct rw_semaphore *sem) | ||
21 | { | ||
22 | int ret = 1; | ||
23 | unsigned long flags; | ||
24 | |||
25 | if (spin_trylock_irqsave(&sem->wait_lock, flags)) { | ||
26 | ret = (sem->activity != 0); | ||
27 | spin_unlock_irqrestore(&sem->wait_lock, flags); | ||
28 | } | ||
29 | return ret; | ||
30 | } | ||
31 | EXPORT_SYMBOL(rwsem_is_locked); | ||
32 | |||
20 | /* | 33 | /* |
21 | * initialise the semaphore | 34 | * initialise the semaphore |
22 | */ | 35 | */ |