diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/wait.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/kernel/wait.c b/kernel/wait.c index 78256a812ca0..29057f707dbd 100644 --- a/kernel/wait.c +++ b/kernel/wait.c @@ -143,6 +143,43 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *arg) } EXPORT_SYMBOL(wake_bit_function); +/* + * To allow interruptible waiting and asynchronous (i.e. nonblocking) + * waiting, the actions of __wait_on_bit() and __wait_on_bit_lock() are + * permitted return codes. Nonzero return codes halt waiting and return. + */ +int __sched fastcall +__wait_on_bit(wait_queue_head_t *wq, struct wait_bit_queue *q, + void *word, int bit, int (*action)(void *), unsigned mode) +{ + int ret = 0; + + prepare_to_wait(wq, &q->wait, mode); + if (test_bit(bit, word)) + ret = (*action)(word); + finish_wait(wq, &q->wait); + return ret; +} +EXPORT_SYMBOL(__wait_on_bit); + +int __sched fastcall +__wait_on_bit_lock(wait_queue_head_t *wq, struct wait_bit_queue *q, + void *word, int bit, int (*action)(void *), unsigned mode) +{ + int ret = 0; + + while (test_and_set_bit(bit, word)) { + prepare_to_wait_exclusive(wq, &q->wait, mode); + if (test_bit(bit, word)) { + if ((ret = (*action)(word))) + break; + } + } + finish_wait(wq, &q->wait); + return ret; +} +EXPORT_SYMBOL(__wait_on_bit_lock); + void fastcall __wake_up_bit(wait_queue_head_t *wq, void *word, int bit) { struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit); |