4c663cfc52
Many callers of the wait_event_timeout() and
wait_event_interruptible_timeout() expect that the return value will be
positive if the specified condition becomes true before the timeout
elapses. However, at the moment this isn't guaranteed. If the wake-up
handler is delayed enough, the time remaining until timeout will be
calculated as 0 - and passed back as a return value - even if the
condition became true before the timeout has passed.
Fix this by returning at least 1 if the condition becomes true. This
semantic is in line with what wait_for_condition_timeout() does; see
commit bb10ed09 ("sched: fix wait_for_completion_timeout() spurious
failure under heavy load").
Daniel said "We have 3 instances of this bug in drm/i915. One case even
where we switch between the interruptible and not interruptible
wait_event_timeout variants, foolishly presuming they have the same
semantics. I very much like this."
One such bug is reported at
https://bugs.freedesktop.org/show_bug.cgi?id=64133
Signed-off-by: Imre Deak <imre.deak@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Lukas Czerner <lczerner@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
906 lines
29 KiB
C
906 lines
29 KiB
C
#ifndef _LINUX_WAIT_H
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#define _LINUX_WAIT_H
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#include <linux/list.h>
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#include <linux/stddef.h>
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#include <linux/spinlock.h>
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#include <asm/current.h>
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#include <uapi/linux/wait.h>
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typedef struct __wait_queue wait_queue_t;
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typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
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int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
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struct __wait_queue {
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unsigned int flags;
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#define WQ_FLAG_EXCLUSIVE 0x01
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void *private;
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wait_queue_func_t func;
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struct list_head task_list;
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};
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struct wait_bit_key {
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void *flags;
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int bit_nr;
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};
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struct wait_bit_queue {
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struct wait_bit_key key;
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wait_queue_t wait;
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};
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struct __wait_queue_head {
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spinlock_t lock;
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struct list_head task_list;
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};
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typedef struct __wait_queue_head wait_queue_head_t;
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struct task_struct;
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/*
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* Macros for declaration and initialisaton of the datatypes
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*/
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#define __WAITQUEUE_INITIALIZER(name, tsk) { \
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.private = tsk, \
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.func = default_wake_function, \
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.task_list = { NULL, NULL } }
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#define DECLARE_WAITQUEUE(name, tsk) \
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wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
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#define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \
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.lock = __SPIN_LOCK_UNLOCKED(name.lock), \
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.task_list = { &(name).task_list, &(name).task_list } }
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#define DECLARE_WAIT_QUEUE_HEAD(name) \
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wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
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#define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
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{ .flags = word, .bit_nr = bit, }
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extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *);
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#define init_waitqueue_head(q) \
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do { \
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static struct lock_class_key __key; \
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\
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__init_waitqueue_head((q), #q, &__key); \
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} while (0)
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#ifdef CONFIG_LOCKDEP
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# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
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({ init_waitqueue_head(&name); name; })
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# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
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wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
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#else
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# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
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#endif
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static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
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{
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q->flags = 0;
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q->private = p;
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q->func = default_wake_function;
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}
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static inline void init_waitqueue_func_entry(wait_queue_t *q,
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wait_queue_func_t func)
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{
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q->flags = 0;
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q->private = NULL;
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q->func = func;
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}
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static inline int waitqueue_active(wait_queue_head_t *q)
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{
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return !list_empty(&q->task_list);
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}
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extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
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extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait);
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extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
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static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
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{
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list_add(&new->task_list, &head->task_list);
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}
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/*
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* Used for wake-one threads:
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*/
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static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
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wait_queue_t *wait)
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{
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wait->flags |= WQ_FLAG_EXCLUSIVE;
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__add_wait_queue(q, wait);
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}
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static inline void __add_wait_queue_tail(wait_queue_head_t *head,
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wait_queue_t *new)
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{
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list_add_tail(&new->task_list, &head->task_list);
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}
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static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q,
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wait_queue_t *wait)
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{
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wait->flags |= WQ_FLAG_EXCLUSIVE;
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__add_wait_queue_tail(q, wait);
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}
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static inline void __remove_wait_queue(wait_queue_head_t *head,
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wait_queue_t *old)
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{
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list_del(&old->task_list);
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}
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void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
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void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
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void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr,
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void *key);
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void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
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void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
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void __wake_up_bit(wait_queue_head_t *, void *, int);
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int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
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int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
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void wake_up_bit(void *, int);
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int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned);
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int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned);
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wait_queue_head_t *bit_waitqueue(void *, int);
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#define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
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#define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
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#define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
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#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1)
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#define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0)
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#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
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#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
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#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
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#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
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/*
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* Wakeup macros to be used to report events to the targets.
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*/
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#define wake_up_poll(x, m) \
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__wake_up(x, TASK_NORMAL, 1, (void *) (m))
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#define wake_up_locked_poll(x, m) \
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__wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
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#define wake_up_interruptible_poll(x, m) \
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__wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
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#define wake_up_interruptible_sync_poll(x, m) \
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__wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))
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#define __wait_event(wq, condition) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
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if (condition) \
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break; \
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schedule(); \
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} \
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finish_wait(&wq, &__wait); \
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} while (0)
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/**
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* wait_event - sleep until a condition gets true
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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*
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* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
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* @condition evaluates to true. The @condition is checked each time
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* the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*/
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#define wait_event(wq, condition) \
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do { \
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if (condition) \
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break; \
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__wait_event(wq, condition); \
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} while (0)
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#define __wait_event_timeout(wq, condition, ret) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
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if (condition) \
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break; \
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ret = schedule_timeout(ret); \
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if (!ret) \
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break; \
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} \
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if (!ret && (condition)) \
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ret = 1; \
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finish_wait(&wq, &__wait); \
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} while (0)
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/**
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* wait_event_timeout - sleep until a condition gets true or a timeout elapses
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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* @timeout: timeout, in jiffies
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*
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* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
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* @condition evaluates to true. The @condition is checked each time
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* the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* The function returns 0 if the @timeout elapsed, or the remaining
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* jiffies (at least 1) if the @condition evaluated to %true before
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* the @timeout elapsed.
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*/
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#define wait_event_timeout(wq, condition, timeout) \
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({ \
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long __ret = timeout; \
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if (!(condition)) \
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__wait_event_timeout(wq, condition, __ret); \
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__ret; \
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})
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#define __wait_event_interruptible(wq, condition, ret) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
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if (condition) \
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break; \
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if (!signal_pending(current)) { \
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schedule(); \
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continue; \
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} \
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ret = -ERESTARTSYS; \
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break; \
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} \
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finish_wait(&wq, &__wait); \
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} while (0)
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/**
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* wait_event_interruptible - sleep until a condition gets true
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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*
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* The process is put to sleep (TASK_INTERRUPTIBLE) until the
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* @condition evaluates to true or a signal is received.
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* The @condition is checked each time the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* The function will return -ERESTARTSYS if it was interrupted by a
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* signal and 0 if @condition evaluated to true.
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*/
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#define wait_event_interruptible(wq, condition) \
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({ \
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int __ret = 0; \
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if (!(condition)) \
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__wait_event_interruptible(wq, condition, __ret); \
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__ret; \
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})
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#define __wait_event_interruptible_timeout(wq, condition, ret) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
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if (condition) \
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break; \
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if (!signal_pending(current)) { \
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ret = schedule_timeout(ret); \
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if (!ret) \
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break; \
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continue; \
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} \
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ret = -ERESTARTSYS; \
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break; \
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} \
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if (!ret && (condition)) \
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ret = 1; \
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finish_wait(&wq, &__wait); \
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} while (0)
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/**
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* wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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* @timeout: timeout, in jiffies
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*
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* The process is put to sleep (TASK_INTERRUPTIBLE) until the
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* @condition evaluates to true or a signal is received.
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* The @condition is checked each time the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* Returns:
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* 0 if the @timeout elapsed, -%ERESTARTSYS if it was interrupted by
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* a signal, or the remaining jiffies (at least 1) if the @condition
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* evaluated to %true before the @timeout elapsed.
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*/
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#define wait_event_interruptible_timeout(wq, condition, timeout) \
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({ \
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long __ret = timeout; \
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if (!(condition)) \
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__wait_event_interruptible_timeout(wq, condition, __ret); \
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__ret; \
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})
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#define __wait_event_hrtimeout(wq, condition, timeout, state) \
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({ \
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int __ret = 0; \
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DEFINE_WAIT(__wait); \
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struct hrtimer_sleeper __t; \
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\
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hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \
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HRTIMER_MODE_REL); \
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hrtimer_init_sleeper(&__t, current); \
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if ((timeout).tv64 != KTIME_MAX) \
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hrtimer_start_range_ns(&__t.timer, timeout, \
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current->timer_slack_ns, \
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HRTIMER_MODE_REL); \
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\
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for (;;) { \
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prepare_to_wait(&wq, &__wait, state); \
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if (condition) \
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break; \
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if (state == TASK_INTERRUPTIBLE && \
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signal_pending(current)) { \
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__ret = -ERESTARTSYS; \
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break; \
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} \
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if (!__t.task) { \
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__ret = -ETIME; \
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break; \
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} \
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schedule(); \
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} \
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\
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hrtimer_cancel(&__t.timer); \
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destroy_hrtimer_on_stack(&__t.timer); \
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finish_wait(&wq, &__wait); \
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__ret; \
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})
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/**
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* wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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* @timeout: timeout, as a ktime_t
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*
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* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
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* @condition evaluates to true or a signal is received.
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* The @condition is checked each time the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* The function returns 0 if @condition became true, or -ETIME if the timeout
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* elapsed.
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*/
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#define wait_event_hrtimeout(wq, condition, timeout) \
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({ \
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int __ret = 0; \
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if (!(condition)) \
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__ret = __wait_event_hrtimeout(wq, condition, timeout, \
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TASK_UNINTERRUPTIBLE); \
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__ret; \
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})
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/**
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* wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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* @timeout: timeout, as a ktime_t
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*
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* The process is put to sleep (TASK_INTERRUPTIBLE) until the
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* @condition evaluates to true or a signal is received.
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* The @condition is checked each time the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* The function returns 0 if @condition became true, -ERESTARTSYS if it was
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* interrupted by a signal, or -ETIME if the timeout elapsed.
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*/
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#define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
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({ \
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long __ret = 0; \
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if (!(condition)) \
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__ret = __wait_event_hrtimeout(wq, condition, timeout, \
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TASK_INTERRUPTIBLE); \
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__ret; \
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})
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#define __wait_event_interruptible_exclusive(wq, condition, ret) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait_exclusive(&wq, &__wait, \
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TASK_INTERRUPTIBLE); \
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if (condition) { \
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finish_wait(&wq, &__wait); \
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break; \
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} \
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if (!signal_pending(current)) { \
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schedule(); \
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continue; \
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} \
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ret = -ERESTARTSYS; \
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abort_exclusive_wait(&wq, &__wait, \
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TASK_INTERRUPTIBLE, NULL); \
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break; \
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} \
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} while (0)
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#define wait_event_interruptible_exclusive(wq, condition) \
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({ \
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int __ret = 0; \
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if (!(condition)) \
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__wait_event_interruptible_exclusive(wq, condition, __ret);\
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__ret; \
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})
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|
|
#define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
|
|
({ \
|
|
int __ret = 0; \
|
|
DEFINE_WAIT(__wait); \
|
|
if (exclusive) \
|
|
__wait.flags |= WQ_FLAG_EXCLUSIVE; \
|
|
do { \
|
|
if (likely(list_empty(&__wait.task_list))) \
|
|
__add_wait_queue_tail(&(wq), &__wait); \
|
|
set_current_state(TASK_INTERRUPTIBLE); \
|
|
if (signal_pending(current)) { \
|
|
__ret = -ERESTARTSYS; \
|
|
break; \
|
|
} \
|
|
if (irq) \
|
|
spin_unlock_irq(&(wq).lock); \
|
|
else \
|
|
spin_unlock(&(wq).lock); \
|
|
schedule(); \
|
|
if (irq) \
|
|
spin_lock_irq(&(wq).lock); \
|
|
else \
|
|
spin_lock(&(wq).lock); \
|
|
} while (!(condition)); \
|
|
__remove_wait_queue(&(wq), &__wait); \
|
|
__set_current_state(TASK_RUNNING); \
|
|
__ret; \
|
|
})
|
|
|
|
|
|
/**
|
|
* wait_event_interruptible_locked - sleep until a condition gets true
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
*
|
|
* The process is put to sleep (TASK_INTERRUPTIBLE) until the
|
|
* @condition evaluates to true or a signal is received.
|
|
* The @condition is checked each time the waitqueue @wq is woken up.
|
|
*
|
|
* It must be called with wq.lock being held. This spinlock is
|
|
* unlocked while sleeping but @condition testing is done while lock
|
|
* is held and when this macro exits the lock is held.
|
|
*
|
|
* The lock is locked/unlocked using spin_lock()/spin_unlock()
|
|
* functions which must match the way they are locked/unlocked outside
|
|
* of this macro.
|
|
*
|
|
* wake_up_locked() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* The function will return -ERESTARTSYS if it was interrupted by a
|
|
* signal and 0 if @condition evaluated to true.
|
|
*/
|
|
#define wait_event_interruptible_locked(wq, condition) \
|
|
((condition) \
|
|
? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0))
|
|
|
|
/**
|
|
* wait_event_interruptible_locked_irq - sleep until a condition gets true
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
*
|
|
* The process is put to sleep (TASK_INTERRUPTIBLE) until the
|
|
* @condition evaluates to true or a signal is received.
|
|
* The @condition is checked each time the waitqueue @wq is woken up.
|
|
*
|
|
* It must be called with wq.lock being held. This spinlock is
|
|
* unlocked while sleeping but @condition testing is done while lock
|
|
* is held and when this macro exits the lock is held.
|
|
*
|
|
* The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
|
|
* functions which must match the way they are locked/unlocked outside
|
|
* of this macro.
|
|
*
|
|
* wake_up_locked() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* The function will return -ERESTARTSYS if it was interrupted by a
|
|
* signal and 0 if @condition evaluated to true.
|
|
*/
|
|
#define wait_event_interruptible_locked_irq(wq, condition) \
|
|
((condition) \
|
|
? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1))
|
|
|
|
/**
|
|
* wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
*
|
|
* The process is put to sleep (TASK_INTERRUPTIBLE) until the
|
|
* @condition evaluates to true or a signal is received.
|
|
* The @condition is checked each time the waitqueue @wq is woken up.
|
|
*
|
|
* It must be called with wq.lock being held. This spinlock is
|
|
* unlocked while sleeping but @condition testing is done while lock
|
|
* is held and when this macro exits the lock is held.
|
|
*
|
|
* The lock is locked/unlocked using spin_lock()/spin_unlock()
|
|
* functions which must match the way they are locked/unlocked outside
|
|
* of this macro.
|
|
*
|
|
* The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
|
|
* set thus when other process waits process on the list if this
|
|
* process is awaken further processes are not considered.
|
|
*
|
|
* wake_up_locked() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* The function will return -ERESTARTSYS if it was interrupted by a
|
|
* signal and 0 if @condition evaluated to true.
|
|
*/
|
|
#define wait_event_interruptible_exclusive_locked(wq, condition) \
|
|
((condition) \
|
|
? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0))
|
|
|
|
/**
|
|
* wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
*
|
|
* The process is put to sleep (TASK_INTERRUPTIBLE) until the
|
|
* @condition evaluates to true or a signal is received.
|
|
* The @condition is checked each time the waitqueue @wq is woken up.
|
|
*
|
|
* It must be called with wq.lock being held. This spinlock is
|
|
* unlocked while sleeping but @condition testing is done while lock
|
|
* is held and when this macro exits the lock is held.
|
|
*
|
|
* The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
|
|
* functions which must match the way they are locked/unlocked outside
|
|
* of this macro.
|
|
*
|
|
* The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
|
|
* set thus when other process waits process on the list if this
|
|
* process is awaken further processes are not considered.
|
|
*
|
|
* wake_up_locked() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* The function will return -ERESTARTSYS if it was interrupted by a
|
|
* signal and 0 if @condition evaluated to true.
|
|
*/
|
|
#define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
|
|
((condition) \
|
|
? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))
|
|
|
|
|
|
|
|
#define __wait_event_killable(wq, condition, ret) \
|
|
do { \
|
|
DEFINE_WAIT(__wait); \
|
|
\
|
|
for (;;) { \
|
|
prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \
|
|
if (condition) \
|
|
break; \
|
|
if (!fatal_signal_pending(current)) { \
|
|
schedule(); \
|
|
continue; \
|
|
} \
|
|
ret = -ERESTARTSYS; \
|
|
break; \
|
|
} \
|
|
finish_wait(&wq, &__wait); \
|
|
} while (0)
|
|
|
|
/**
|
|
* wait_event_killable - sleep until a condition gets true
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
*
|
|
* The process is put to sleep (TASK_KILLABLE) until the
|
|
* @condition evaluates to true or a signal is received.
|
|
* The @condition is checked each time the waitqueue @wq is woken up.
|
|
*
|
|
* wake_up() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* The function will return -ERESTARTSYS if it was interrupted by a
|
|
* signal and 0 if @condition evaluated to true.
|
|
*/
|
|
#define wait_event_killable(wq, condition) \
|
|
({ \
|
|
int __ret = 0; \
|
|
if (!(condition)) \
|
|
__wait_event_killable(wq, condition, __ret); \
|
|
__ret; \
|
|
})
|
|
|
|
|
|
#define __wait_event_lock_irq(wq, condition, lock, cmd) \
|
|
do { \
|
|
DEFINE_WAIT(__wait); \
|
|
\
|
|
for (;;) { \
|
|
prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
|
|
if (condition) \
|
|
break; \
|
|
spin_unlock_irq(&lock); \
|
|
cmd; \
|
|
schedule(); \
|
|
spin_lock_irq(&lock); \
|
|
} \
|
|
finish_wait(&wq, &__wait); \
|
|
} while (0)
|
|
|
|
/**
|
|
* wait_event_lock_irq_cmd - sleep until a condition gets true. The
|
|
* condition is checked under the lock. This
|
|
* is expected to be called with the lock
|
|
* taken.
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
* @lock: a locked spinlock_t, which will be released before cmd
|
|
* and schedule() and reacquired afterwards.
|
|
* @cmd: a command which is invoked outside the critical section before
|
|
* sleep
|
|
*
|
|
* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
|
|
* @condition evaluates to true. The @condition is checked each time
|
|
* the waitqueue @wq is woken up.
|
|
*
|
|
* wake_up() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* This is supposed to be called while holding the lock. The lock is
|
|
* dropped before invoking the cmd and going to sleep and is reacquired
|
|
* afterwards.
|
|
*/
|
|
#define wait_event_lock_irq_cmd(wq, condition, lock, cmd) \
|
|
do { \
|
|
if (condition) \
|
|
break; \
|
|
__wait_event_lock_irq(wq, condition, lock, cmd); \
|
|
} while (0)
|
|
|
|
/**
|
|
* wait_event_lock_irq - sleep until a condition gets true. The
|
|
* condition is checked under the lock. This
|
|
* is expected to be called with the lock
|
|
* taken.
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
* @lock: a locked spinlock_t, which will be released before schedule()
|
|
* and reacquired afterwards.
|
|
*
|
|
* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
|
|
* @condition evaluates to true. The @condition is checked each time
|
|
* the waitqueue @wq is woken up.
|
|
*
|
|
* wake_up() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* This is supposed to be called while holding the lock. The lock is
|
|
* dropped before going to sleep and is reacquired afterwards.
|
|
*/
|
|
#define wait_event_lock_irq(wq, condition, lock) \
|
|
do { \
|
|
if (condition) \
|
|
break; \
|
|
__wait_event_lock_irq(wq, condition, lock, ); \
|
|
} while (0)
|
|
|
|
|
|
#define __wait_event_interruptible_lock_irq(wq, condition, \
|
|
lock, ret, cmd) \
|
|
do { \
|
|
DEFINE_WAIT(__wait); \
|
|
\
|
|
for (;;) { \
|
|
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
|
|
if (condition) \
|
|
break; \
|
|
if (signal_pending(current)) { \
|
|
ret = -ERESTARTSYS; \
|
|
break; \
|
|
} \
|
|
spin_unlock_irq(&lock); \
|
|
cmd; \
|
|
schedule(); \
|
|
spin_lock_irq(&lock); \
|
|
} \
|
|
finish_wait(&wq, &__wait); \
|
|
} while (0)
|
|
|
|
/**
|
|
* wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
|
|
* The condition is checked under the lock. This is expected to
|
|
* be called with the lock taken.
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
* @lock: a locked spinlock_t, which will be released before cmd and
|
|
* schedule() and reacquired afterwards.
|
|
* @cmd: a command which is invoked outside the critical section before
|
|
* sleep
|
|
*
|
|
* The process is put to sleep (TASK_INTERRUPTIBLE) until the
|
|
* @condition evaluates to true or a signal is received. The @condition is
|
|
* checked each time the waitqueue @wq is woken up.
|
|
*
|
|
* wake_up() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* This is supposed to be called while holding the lock. The lock is
|
|
* dropped before invoking the cmd and going to sleep and is reacquired
|
|
* afterwards.
|
|
*
|
|
* The macro will return -ERESTARTSYS if it was interrupted by a signal
|
|
* and 0 if @condition evaluated to true.
|
|
*/
|
|
#define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \
|
|
({ \
|
|
int __ret = 0; \
|
|
\
|
|
if (!(condition)) \
|
|
__wait_event_interruptible_lock_irq(wq, condition, \
|
|
lock, __ret, cmd); \
|
|
__ret; \
|
|
})
|
|
|
|
/**
|
|
* wait_event_interruptible_lock_irq - sleep until a condition gets true.
|
|
* The condition is checked under the lock. This is expected
|
|
* to be called with the lock taken.
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
* @lock: a locked spinlock_t, which will be released before schedule()
|
|
* and reacquired afterwards.
|
|
*
|
|
* The process is put to sleep (TASK_INTERRUPTIBLE) until the
|
|
* @condition evaluates to true or signal is received. The @condition is
|
|
* checked each time the waitqueue @wq is woken up.
|
|
*
|
|
* wake_up() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* This is supposed to be called while holding the lock. The lock is
|
|
* dropped before going to sleep and is reacquired afterwards.
|
|
*
|
|
* The macro will return -ERESTARTSYS if it was interrupted by a signal
|
|
* and 0 if @condition evaluated to true.
|
|
*/
|
|
#define wait_event_interruptible_lock_irq(wq, condition, lock) \
|
|
({ \
|
|
int __ret = 0; \
|
|
\
|
|
if (!(condition)) \
|
|
__wait_event_interruptible_lock_irq(wq, condition, \
|
|
lock, __ret, ); \
|
|
__ret; \
|
|
})
|
|
|
|
|
|
/*
|
|
* These are the old interfaces to sleep waiting for an event.
|
|
* They are racy. DO NOT use them, use the wait_event* interfaces above.
|
|
* We plan to remove these interfaces.
|
|
*/
|
|
extern void sleep_on(wait_queue_head_t *q);
|
|
extern long sleep_on_timeout(wait_queue_head_t *q,
|
|
signed long timeout);
|
|
extern void interruptible_sleep_on(wait_queue_head_t *q);
|
|
extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
|
|
signed long timeout);
|
|
|
|
/*
|
|
* Waitqueues which are removed from the waitqueue_head at wakeup time
|
|
*/
|
|
void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
|
|
void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
|
|
void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
|
|
void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
|
|
unsigned int mode, void *key);
|
|
int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
|
|
int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
|
|
|
|
#define DEFINE_WAIT_FUNC(name, function) \
|
|
wait_queue_t name = { \
|
|
.private = current, \
|
|
.func = function, \
|
|
.task_list = LIST_HEAD_INIT((name).task_list), \
|
|
}
|
|
|
|
#define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
|
|
|
|
#define DEFINE_WAIT_BIT(name, word, bit) \
|
|
struct wait_bit_queue name = { \
|
|
.key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
|
|
.wait = { \
|
|
.private = current, \
|
|
.func = wake_bit_function, \
|
|
.task_list = \
|
|
LIST_HEAD_INIT((name).wait.task_list), \
|
|
}, \
|
|
}
|
|
|
|
#define init_wait(wait) \
|
|
do { \
|
|
(wait)->private = current; \
|
|
(wait)->func = autoremove_wake_function; \
|
|
INIT_LIST_HEAD(&(wait)->task_list); \
|
|
(wait)->flags = 0; \
|
|
} while (0)
|
|
|
|
/**
|
|
* wait_on_bit - wait for a bit to be cleared
|
|
* @word: the word being waited on, a kernel virtual address
|
|
* @bit: the bit of the word being waited on
|
|
* @action: the function used to sleep, which may take special actions
|
|
* @mode: the task state to sleep in
|
|
*
|
|
* There is a standard hashed waitqueue table for generic use. This
|
|
* is the part of the hashtable's accessor API that waits on a bit.
|
|
* For instance, if one were to have waiters on a bitflag, one would
|
|
* call wait_on_bit() in threads waiting for the bit to clear.
|
|
* One uses wait_on_bit() where one is waiting for the bit to clear,
|
|
* but has no intention of setting it.
|
|
*/
|
|
static inline int wait_on_bit(void *word, int bit,
|
|
int (*action)(void *), unsigned mode)
|
|
{
|
|
if (!test_bit(bit, word))
|
|
return 0;
|
|
return out_of_line_wait_on_bit(word, bit, action, mode);
|
|
}
|
|
|
|
/**
|
|
* wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
|
|
* @word: the word being waited on, a kernel virtual address
|
|
* @bit: the bit of the word being waited on
|
|
* @action: the function used to sleep, which may take special actions
|
|
* @mode: the task state to sleep in
|
|
*
|
|
* There is a standard hashed waitqueue table for generic use. This
|
|
* is the part of the hashtable's accessor API that waits on a bit
|
|
* when one intends to set it, for instance, trying to lock bitflags.
|
|
* For instance, if one were to have waiters trying to set bitflag
|
|
* and waiting for it to clear before setting it, one would call
|
|
* wait_on_bit() in threads waiting to be able to set the bit.
|
|
* One uses wait_on_bit_lock() where one is waiting for the bit to
|
|
* clear with the intention of setting it, and when done, clearing it.
|
|
*/
|
|
static inline int wait_on_bit_lock(void *word, int bit,
|
|
int (*action)(void *), unsigned mode)
|
|
{
|
|
if (!test_and_set_bit(bit, word))
|
|
return 0;
|
|
return out_of_line_wait_on_bit_lock(word, bit, action, mode);
|
|
}
|
|
|
|
#endif
|