forked from mirrors/linux
7e43c84e3e
Use LIST_HEAD_INIT rather than doing it by hand in DEFINE_WAIT. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
458 lines
14 KiB
C
458 lines
14 KiB
C
#ifndef _LINUX_WAIT_H
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#define _LINUX_WAIT_H
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#define WNOHANG 0x00000001
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#define WUNTRACED 0x00000002
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#define WSTOPPED WUNTRACED
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#define WEXITED 0x00000004
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#define WCONTINUED 0x00000008
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#define WNOWAIT 0x01000000 /* Don't reap, just poll status. */
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#define __WNOTHREAD 0x20000000 /* Don't wait on children of other threads in this group */
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#define __WALL 0x40000000 /* Wait on all children, regardless of type */
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#define __WCLONE 0x80000000 /* Wait only on non-SIGCHLD children */
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/* First argument to waitid: */
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#define P_ALL 0
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#define P_PID 1
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#define P_PGID 2
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#ifdef __KERNEL__
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#include <linux/config.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/system.h>
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#include <asm/current.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 sync, void *key);
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int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, 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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struct task_struct * task;
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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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/*
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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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.task = 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, \
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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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static inline void init_waitqueue_head(wait_queue_head_t *q)
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{
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spin_lock_init(&q->lock);
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INIT_LIST_HEAD(&q->task_list);
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}
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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->task = 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->task = 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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/*
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* Used to distinguish between sync and async io wait context:
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* sync i/o typically specifies a NULL wait queue entry or a wait
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* queue entry bound to a task (current task) to wake up.
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* aio specifies a wait queue entry with an async notification
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* callback routine, not associated with any task.
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*/
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#define is_sync_wait(wait) (!(wait) || ((wait)->task))
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extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
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extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait));
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extern void FASTCALL(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_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 __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 FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key));
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extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode));
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extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr));
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void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int));
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int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
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int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
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void FASTCALL(wake_up_bit(void *, int));
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int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned));
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int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned));
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wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int));
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#define wake_up(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL)
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#define wake_up_nr(x, nr) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL)
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#define wake_up_all(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL)
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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_locked(x) __wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE)
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#define wake_up_interruptible_sync(x) __wake_up_sync((x),TASK_INTERRUPTIBLE, 1)
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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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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, and the remaining
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* jiffies if the condition evaluated to true before 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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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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* The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
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* was interrupted by a signal, and the remaining jiffies otherwise
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* if the condition 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_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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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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#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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/*
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* Must be called with the spinlock in the wait_queue_head_t held.
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*/
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static inline void add_wait_queue_exclusive_locked(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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/*
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* Must be called with the spinlock in the wait_queue_head_t held.
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*/
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static inline void remove_wait_queue_locked(wait_queue_head_t *q,
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wait_queue_t * wait)
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{
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__remove_wait_queue(q, wait);
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}
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/*
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* These are the old interfaces to sleep waiting for an event.
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* They are racy. DO NOT use them, use the wait_event* interfaces above.
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* We plan to remove these interfaces during 2.7.
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*/
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extern void FASTCALL(sleep_on(wait_queue_head_t *q));
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extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q,
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signed long timeout));
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extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q));
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extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q,
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signed long timeout));
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/*
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* Waitqueues which are removed from the waitqueue_head at wakeup time
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*/
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void FASTCALL(prepare_to_wait(wait_queue_head_t *q,
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wait_queue_t *wait, int state));
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void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
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wait_queue_t *wait, int state));
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void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait));
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int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
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int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
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#define DEFINE_WAIT(name) \
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wait_queue_t name = { \
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.task = current, \
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.func = autoremove_wake_function, \
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.task_list = LIST_HEAD_INIT((name).task_list), \
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}
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#define DEFINE_WAIT_BIT(name, word, bit) \
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struct wait_bit_queue name = { \
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.key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
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.wait = { \
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.task = current, \
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.func = wake_bit_function, \
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.task_list = \
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LIST_HEAD_INIT((name).wait.task_list), \
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}, \
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}
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#define init_wait(wait) \
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do { \
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(wait)->task = current; \
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(wait)->func = autoremove_wake_function; \
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INIT_LIST_HEAD(&(wait)->task_list); \
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} while (0)
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/**
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* wait_on_bit - wait for a bit to be cleared
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* @word: the word being waited on, a kernel virtual address
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* @bit: the bit of the word being waited on
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* @action: the function used to sleep, which may take special actions
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* @mode: the task state to sleep in
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*
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* There is a standard hashed waitqueue table for generic use. This
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* is the part of the hashtable's accessor API that waits on a bit.
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* For instance, if one were to have waiters on a bitflag, one would
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* call wait_on_bit() in threads waiting for the bit to clear.
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* One uses wait_on_bit() where one is waiting for the bit to clear,
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* but has no intention of setting it.
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*/
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static inline int wait_on_bit(void *word, int bit,
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int (*action)(void *), unsigned mode)
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{
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if (!test_bit(bit, word))
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return 0;
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return out_of_line_wait_on_bit(word, bit, action, mode);
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}
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/**
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* wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
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* @word: the word being waited on, a kernel virtual address
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* @bit: the bit of the word being waited on
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* @action: the function used to sleep, which may take special actions
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* @mode: the task state to sleep in
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*
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* There is a standard hashed waitqueue table for generic use. This
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* is the part of the hashtable's accessor API that waits on a bit
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* when one intends to set it, for instance, trying to lock bitflags.
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* For instance, if one were to have waiters trying to set bitflag
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* and waiting for it to clear before setting it, one would call
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* wait_on_bit() in threads waiting to be able to set the bit.
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* One uses wait_on_bit_lock() where one is waiting for the bit to
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* clear with the intention of setting it, and when done, clearing it.
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*/
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static inline int wait_on_bit_lock(void *word, int bit,
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int (*action)(void *), unsigned mode)
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{
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if (!test_and_set_bit(bit, word))
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return 0;
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return out_of_line_wait_on_bit_lock(word, bit, action, mode);
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}
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#endif /* __KERNEL__ */
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#endif
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