diff options
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/sched/wait_bit.c | 110 |
1 files changed, 26 insertions, 84 deletions
diff --git a/kernel/sched/wait_bit.c b/kernel/sched/wait_bit.c index 4239c78f5cd3..c67c6d24adc2 100644 --- a/kernel/sched/wait_bit.c +++ b/kernel/sched/wait_bit.c @@ -149,106 +149,48 @@ void wake_up_bit(void *word, int bit) } EXPORT_SYMBOL(wake_up_bit); -/* - * Manipulate the atomic_t address to produce a better bit waitqueue table hash - * index (we're keying off bit -1, but that would produce a horrible hash - * value). - */ -static inline wait_queue_head_t *atomic_t_waitqueue(atomic_t *p) +wait_queue_head_t *__var_waitqueue(void *p) { - if (BITS_PER_LONG == 64) { - unsigned long q = (unsigned long)p; - - return bit_waitqueue((void *)(q & ~1), q & 1); - } - return bit_waitqueue(p, 0); + return bit_wait_table + hash_ptr(p, WAIT_TABLE_BITS); } +EXPORT_SYMBOL(__var_waitqueue); -static int wake_atomic_t_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, - void *arg) +static int +var_wake_function(struct wait_queue_entry *wq_entry, unsigned int mode, + int sync, void *arg) { struct wait_bit_key *key = arg; - struct wait_bit_queue_entry *wait_bit = container_of(wq_entry, struct wait_bit_queue_entry, wq_entry); - atomic_t *val = key->flags; + struct wait_bit_queue_entry *wbq_entry = + container_of(wq_entry, struct wait_bit_queue_entry, wq_entry); - if (wait_bit->key.flags != key->flags || - wait_bit->key.bit_nr != key->bit_nr || - atomic_read(val) != 0) + if (wbq_entry->key.flags != key->flags || + wbq_entry->key.bit_nr != key->bit_nr) return 0; return autoremove_wake_function(wq_entry, mode, sync, key); } -/* - * To allow interruptible waiting and asynchronous (i.e. nonblocking) waiting, - * the actions of __wait_on_atomic_t() are permitted return codes. Nonzero - * return codes halt waiting and return. - */ -static __sched -int __wait_on_atomic_t(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_entry, - wait_atomic_t_action_f action, unsigned int mode) +void init_wait_var_entry(struct wait_bit_queue_entry *wbq_entry, void *var, int flags) { - atomic_t *val; - int ret = 0; - - do { - prepare_to_wait(wq_head, &wbq_entry->wq_entry, mode); - val = wbq_entry->key.flags; - if (atomic_read(val) == 0) - break; - ret = (*action)(val, mode); - } while (!ret && atomic_read(val) != 0); - finish_wait(wq_head, &wbq_entry->wq_entry); - - return ret; + *wbq_entry = (struct wait_bit_queue_entry){ + .key = { + .flags = (var), + .bit_nr = -1, + }, + .wq_entry = { + .private = current, + .func = var_wake_function, + .entry = LIST_HEAD_INIT(wbq_entry->wq_entry.entry), + }, + }; } +EXPORT_SYMBOL(init_wait_var_entry); -#define DEFINE_WAIT_ATOMIC_T(name, p) \ - struct wait_bit_queue_entry name = { \ - .key = __WAIT_ATOMIC_T_KEY_INITIALIZER(p), \ - .wq_entry = { \ - .private = current, \ - .func = wake_atomic_t_function, \ - .entry = \ - LIST_HEAD_INIT((name).wq_entry.entry), \ - }, \ - } - -__sched int out_of_line_wait_on_atomic_t(atomic_t *p, - wait_atomic_t_action_f action, - unsigned int mode) -{ - struct wait_queue_head *wq_head = atomic_t_waitqueue(p); - DEFINE_WAIT_ATOMIC_T(wq_entry, p); - - return __wait_on_atomic_t(wq_head, &wq_entry, action, mode); -} -EXPORT_SYMBOL(out_of_line_wait_on_atomic_t); - -__sched int atomic_t_wait(atomic_t *counter, unsigned int mode) -{ - schedule(); - if (signal_pending_state(mode, current)) - return -EINTR; - - return 0; -} -EXPORT_SYMBOL(atomic_t_wait); - -/** - * wake_up_atomic_t - Wake up a waiter on a atomic_t - * @p: The atomic_t being waited on, a kernel virtual address - * - * Wake up anyone waiting for the atomic_t to go to zero. - * - * Abuse the bit-waker function and its waitqueue hash table set (the atomic_t - * check is done by the waiter's wake function, not the by the waker itself). - */ -void wake_up_atomic_t(atomic_t *p) +void wake_up_var(void *var) { - __wake_up_bit(atomic_t_waitqueue(p), p, WAIT_ATOMIC_T_BIT_NR); + __wake_up_bit(__var_waitqueue(var), var, -1); } -EXPORT_SYMBOL(wake_up_atomic_t); +EXPORT_SYMBOL(wake_up_var); __sched int bit_wait(struct wait_bit_key *word, int mode) { |