[linux-2.6-block.git] / include / linux / wait.h

#ifndef _LINUX_WAIT_H
#define _LINUX_WAIT_H

#define WNOHANG		0x00000001
#define WUNTRACED	0x00000002
#define WSTOPPED	WUNTRACED
#define WEXITED		0x00000004
#define WCONTINUED	0x00000008
#define WNOWAIT		0x01000000	/* Don't reap, just poll status.  */

#define __WNOTHREAD	0x20000000	/* Don't wait on children of other threads in this group */
#define __WALL		0x40000000	/* Wait on all children, regardless of type */
#define __WCLONE	0x80000000	/* Wait only on non-SIGCHLD children */

/* First argument to waitid: */
#define P_ALL		0
#define P_PID		1
#define P_PGID		2

#ifdef __KERNEL__

#include <linux/list.h>
#include <linux/stddef.h>
#include <linux/spinlock.h>
#include <asm/system.h>
#include <asm/current.h>

typedef struct __wait_queue wait_queue_t;
typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key);
int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);

struct __wait_queue {
	unsigned int flags;
#define WQ_FLAG_EXCLUSIVE	0x01
	void *private;
	wait_queue_func_t func;
	struct list_head task_list;
};

struct wait_bit_key {
	void *flags;
	int bit_nr;
};

struct wait_bit_queue {
	struct wait_bit_key key;
	wait_queue_t wait;
};

struct __wait_queue_head {
	spinlock_t lock;
	struct list_head task_list;
};
typedef struct __wait_queue_head wait_queue_head_t;

struct task_struct;

/*
 * Macros for declaration and initialisaton of the datatypes
 */

#define __WAITQUEUE_INITIALIZER(name, tsk) {				\
	.private	= tsk,						\
	.func		= default_wake_function,			\
	.task_list	= { NULL, NULL } }

#define DECLARE_WAITQUEUE(name, tsk)					\
	wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)

#define __WAIT_QUEUE_HEAD_INITIALIZER(name) {				\
	.lock		= __SPIN_LOCK_UNLOCKED(name.lock),		\
	.task_list	= { &(name).task_list, &(name).task_list } }

#define DECLARE_WAIT_QUEUE_HEAD(name) \
	wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)

#define __WAIT_BIT_KEY_INITIALIZER(word, bit)				\
	{ .flags = word, .bit_nr = bit, }

/*
 * lockdep: we want one lock-class for all waitqueue locks.
 */
extern struct lock_class_key waitqueue_lock_key;

static inline void init_waitqueue_head(wait_queue_head_t *q)
{
	spin_lock_init(&q->lock);
	lockdep_set_class(&q->lock, &waitqueue_lock_key);
	INIT_LIST_HEAD(&q->task_list);
}

static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
{
	q->flags = 0;
	q->private = p;
	q->func = default_wake_function;
}

static inline void init_waitqueue_func_entry(wait_queue_t *q,
					wait_queue_func_t func)
{
	q->flags = 0;
	q->private = NULL;
	q->func = func;
}

static inline int waitqueue_active(wait_queue_head_t *q)
{
	return !list_empty(&q->task_list);
}

/*
 * Used to distinguish between sync and async io wait context:
 * sync i/o typically specifies a NULL wait queue entry or a wait
 * queue entry bound to a task (current task) to wake up.
 * aio specifies a wait queue entry with an async notification
 * callback routine, not associated with any task.
 */
#define is_sync_wait(wait)	(!(wait) || ((wait)->private))

extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait));
extern void FASTCALL(remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));

static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
{
	list_add(&new->task_list, &head->task_list);
}

/*
 * Used for wake-one threads:
 */
static inline void __add_wait_queue_tail(wait_queue_head_t *head,
						wait_queue_t *new)
{
	list_add_tail(&new->task_list, &head->task_list);
}

static inline void __remove_wait_queue(wait_queue_head_t *head,
							wait_queue_t *old)
{
	list_del(&old->task_list);
}

void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key));
extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode));
extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr));
void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int));
int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
void FASTCALL(wake_up_bit(void *, int));
int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned));
int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned));
wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int));

#define wake_up(x)			__wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL)
#define wake_up_nr(x, nr)		__wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL)
#define wake_up_all(x)			__wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL)
#define wake_up_interruptible(x)	__wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
#define wake_up_interruptible_nr(x, nr)	__wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
#define wake_up_interruptible_all(x)	__wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
#define	wake_up_locked(x)		__wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE)
#define wake_up_interruptible_sync(x)   __wake_up_sync((x),TASK_INTERRUPTIBLE, 1)

#define __wait_event(wq, condition) 					\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE);	\
		if (condition)						\
			break;						\
		schedule();						\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

/**
 * wait_event - 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_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.
 */
#define wait_event(wq, condition) 					\
do {									\
	if (condition)	 						\
		break;							\
	__wait_event(wq, condition);					\
} while (0)

#define __wait_event_timeout(wq, condition, ret)			\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE);	\
		if (condition)						\
			break;						\
		ret = schedule_timeout(ret);				\
		if (!ret)						\
			break;						\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

/**
 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
 * @wq: the waitqueue to wait on
 * @condition: a C expression for the event to wait for
 * @timeout: timeout, in jiffies
 *
 * 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.
 *
 * The function returns 0 if the @timeout elapsed, and the remaining
 * jiffies if the condition evaluated to true before the timeout elapsed.
 */
#define wait_event_timeout(wq, condition, timeout)			\
({									\
	long __ret = timeout;						\
	if (!(condition)) 						\
		__wait_event_timeout(wq, condition, __ret);		\
	__ret;								\
})

#define __wait_event_interruptible(wq, condition, ret)			\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE);	\
		if (condition)						\
			break;						\
		if (!signal_pending(current)) {				\
			schedule();					\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		break;							\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

/**
 * wait_event_interruptible - 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.
 *
 * 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_interruptible(wq, condition)				\
({									\
	int __ret = 0;							\
	if (!(condition))						\
		__wait_event_interruptible(wq, condition, __ret);	\
	__ret;								\
})

#define __wait_event_interruptible_timeout(wq, condition, ret)		\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE);	\
		if (condition)						\
			break;						\
		if (!signal_pending(current)) {				\
			ret = schedule_timeout(ret);			\
			if (!ret)					\
				break;					\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		break;							\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

/**
 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
 * @wq: the waitqueue to wait on
 * @condition: a C expression for the event to wait for
 * @timeout: timeout, in jiffies
 *
 * 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.
 *
 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
 * was interrupted by a signal, and the remaining jiffies otherwise
 * if the condition evaluated to true before the timeout elapsed.
 */
#define wait_event_interruptible_timeout(wq, condition, timeout)	\
({									\
	long __ret = timeout;						\
	if (!(condition))						\
		__wait_event_interruptible_timeout(wq, condition, __ret); \
	__ret;								\
})

#define __wait_event_interruptible_exclusive(wq, condition, ret)	\
do {									\
	DEFINE_WAIT(__wait);						\
									\
	for (;;) {							\
		prepare_to_wait_exclusive(&wq, &__wait,			\
					TASK_INTERRUPTIBLE);		\
		if (condition)						\
			break;						\
		if (!signal_pending(current)) {				\
			schedule();					\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		break;							\
	}								\
	finish_wait(&wq, &__wait);					\
} while (0)

#define wait_event_interruptible_exclusive(wq, condition)		\
({									\
	int __ret = 0;							\
	if (!(condition))						\
		__wait_event_interruptible_exclusive(wq, condition, __ret);\
	__ret;								\
})

/*
 * Must be called with the spinlock in the wait_queue_head_t held.
 */
static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
						   wait_queue_t * wait)
{
	wait->flags |= WQ_FLAG_EXCLUSIVE;
	__add_wait_queue_tail(q,  wait);
}

/*
 * Must be called with the spinlock in the wait_queue_head_t held.
 */
static inline void remove_wait_queue_locked(wait_queue_head_t *q,
					    wait_queue_t * wait)
{
	__remove_wait_queue(q,  wait);
}

/*
 * 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 during 2.7.
 */
extern void FASTCALL(sleep_on(wait_queue_head_t *q));
extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q,
				      signed long timeout));
extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q));
extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q,
						    signed long timeout));

/*
 * Waitqueues which are removed from the waitqueue_head at wakeup time
 */
void FASTCALL(prepare_to_wait(wait_queue_head_t *q,
				wait_queue_t *wait, int state));
void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
				wait_queue_t *wait, int state));
void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait));
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(name)						\
	wait_queue_t name = {						\
		.private	= current,				\
		.func		= autoremove_wake_function,		\
		.task_list	= LIST_HEAD_INIT((name).task_list),	\
	}

#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);			\
	} 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 /* __KERNEL__ */

#endif
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_WAIT_H
	2	#define _LINUX_WAIT_H
	3
	4	#define WNOHANG 0x00000001
	5	#define WUNTRACED 0x00000002
	6	#define WSTOPPED WUNTRACED
	7	#define WEXITED 0x00000004
	8	#define WCONTINUED 0x00000008
	9	#define WNOWAIT 0x01000000 /* Don't reap, just poll status. */
	10
	11	#define __WNOTHREAD 0x20000000 /* Don't wait on children of other threads in this group */
	12	#define __WALL 0x40000000 /* Wait on all children, regardless of type */
	13	#define __WCLONE 0x80000000 /* Wait only on non-SIGCHLD children */
	14
	15	/* First argument to waitid: */
	16	#define P_ALL 0
	17	#define P_PID 1
	18	#define P_PGID 2
	19
	20	#ifdef __KERNEL__
	21
1da177e4 LT	22	#include <linux/list.h>
	23	#include <linux/stddef.h>
	24	#include <linux/spinlock.h>
	25	#include <asm/system.h>
	26	#include <asm/current.h>
	27
	28	typedef struct __wait_queue wait_queue_t;
	29	typedef int (wait_queue_func_t)(wait_queue_t wait, unsigned mode, int sync, void *key);
	30	int default_wake_function(wait_queue_t wait, unsigned mode, int sync, void key);
	31
	32	struct __wait_queue {
	33	unsigned int flags;
	34	#define WQ_FLAG_EXCLUSIVE 0x01
c43dc2fd	35	void *private;
1da177e4 LT	36	wait_queue_func_t func;
	37	struct list_head task_list;
	38	};
	39
	40	struct wait_bit_key {
	41	void *flags;
	42	int bit_nr;
	43	};
	44
	45	struct wait_bit_queue {
	46	struct wait_bit_key key;
	47	wait_queue_t wait;
	48	};
	49
	50	struct __wait_queue_head {
	51	spinlock_t lock;
	52	struct list_head task_list;
	53	};
	54	typedef struct __wait_queue_head wait_queue_head_t;
	55
8c65b4a6	56	struct task_struct;
1da177e4 LT	57
	58	/*
	59	* Macros for declaration and initialisaton of the datatypes
	60	*/
	61
	62	#define __WAITQUEUE_INITIALIZER(name, tsk) { \
c43dc2fd	63	.private = tsk, \
1da177e4 LT	64	.func = default_wake_function, \
	65	.task_list = { NULL, NULL } }
	66
	67	#define DECLARE_WAITQUEUE(name, tsk) \
	68	wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
	69
	70	#define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \
e4d91918	71	.lock = __SPIN_LOCK_UNLOCKED(name.lock), \
1da177e4 LT	72	.task_list = { &(name).task_list, &(name).task_list } }
	73
	74	#define DECLARE_WAIT_QUEUE_HEAD(name) \
	75	wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
	76
	77	#define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
	78	{ .flags = word, .bit_nr = bit, }
	79
eb4542b9 IM	80	/*
	81	* lockdep: we want one lock-class for all waitqueue locks.
	82	*/
	83	extern struct lock_class_key waitqueue_lock_key;
	84
1da177e4 LT	85	static inline void init_waitqueue_head(wait_queue_head_t *q)
	86	{
	87	spin_lock_init(&q->lock);
eb4542b9	88	lockdep_set_class(&q->lock, &waitqueue_lock_key);
1da177e4 LT	89	INIT_LIST_HEAD(&q->task_list);
	90	}
	91
	92	static inline void init_waitqueue_entry(wait_queue_t q, struct task_struct p)
	93	{
	94	q->flags = 0;
c43dc2fd	95	q->private = p;
1da177e4 LT	96	q->func = default_wake_function;
	97	}
	98
	99	static inline void init_waitqueue_func_entry(wait_queue_t *q,
	100	wait_queue_func_t func)
	101	{
	102	q->flags = 0;
c43dc2fd	103	q->private = NULL;
1da177e4 LT	104	q->func = func;
	105	}
	106
	107	static inline int waitqueue_active(wait_queue_head_t *q)
	108	{
	109	return !list_empty(&q->task_list);
	110	}
	111
	112	/*
	113	* Used to distinguish between sync and async io wait context:
	114	* sync i/o typically specifies a NULL wait queue entry or a wait
	115	* queue entry bound to a task (current task) to wake up.
	116	* aio specifies a wait queue entry with an async notification
	117	* callback routine, not associated with any task.
	118	*/
c43dc2fd	119	#define is_sync_wait(wait) (!(wait) \|\| ((wait)->private))
1da177e4 LT	120
	121	extern void FASTCALL(add_wait_queue(wait_queue_head_t q, wait_queue_t wait));
	122	extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t q, wait_queue_t wait));
	123	extern void FASTCALL(remove_wait_queue(wait_queue_head_t q, wait_queue_t wait));
	124
	125	static inline void __add_wait_queue(wait_queue_head_t head, wait_queue_t new)
	126	{
	127	list_add(&new->task_list, &head->task_list);
	128	}
	129
	130	/*
	131	* Used for wake-one threads:
	132	*/
	133	static inline void __add_wait_queue_tail(wait_queue_head_t *head,
	134	wait_queue_t *new)
	135	{
	136	list_add_tail(&new->task_list, &head->task_list);
	137	}
	138
	139	static inline void __remove_wait_queue(wait_queue_head_t *head,
	140	wait_queue_t *old)
	141	{
	142	list_del(&old->task_list);
	143	}
	144
	145	void FASTCALL(__wake_up(wait_queue_head_t q, unsigned int mode, int nr, void key));
	146	extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode));
	147	extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr));
	148	void FASTCALL(__wake_up_bit(wait_queue_head_t , void , int));
	149	int FASTCALL(__wait_on_bit(wait_queue_head_t , struct wait_bit_queue , int ()(void ), unsigned));
	150	int FASTCALL(__wait_on_bit_lock(wait_queue_head_t , struct wait_bit_queue , int ()(void ), unsigned));
	151	void FASTCALL(wake_up_bit(void *, int));
	152	int FASTCALL(out_of_line_wait_on_bit(void , int, int ()(void *), unsigned));
	153	int FASTCALL(out_of_line_wait_on_bit_lock(void , int, int ()(void *), unsigned));
	154	wait_queue_head_t FASTCALL(bit_waitqueue(void , int));
	155
	156	#define wake_up(x) __wake_up(x, TASK_UNINTERRUPTIBLE \| TASK_INTERRUPTIBLE, 1, NULL)
	157	#define wake_up_nr(x, nr) __wake_up(x, TASK_UNINTERRUPTIBLE \| TASK_INTERRUPTIBLE, nr, NULL)
	158	#define wake_up_all(x) __wake_up(x, TASK_UNINTERRUPTIBLE \| TASK_INTERRUPTIBLE, 0, NULL)
	159	#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
	160	#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
	161	#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
	162	#define wake_up_locked(x) __wake_up_locked((x), TASK_UNINTERRUPTIBLE \| TASK_INTERRUPTIBLE)
	163	#define wake_up_interruptible_sync(x) __wake_up_sync((x),TASK_INTERRUPTIBLE, 1)
	164
	165	#define __wait_event(wq, condition) \
	166	do { \
	167	DEFINE_WAIT(__wait); \
	168	\
	169	for (;;) { \
	170	prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
	171	if (condition) \
	172	break; \
	173	schedule(); \
	174	} \
	175	finish_wait(&wq, &__wait); \
	176	} while (0)
	177
	178	/**
	179	* wait_event - sleep until a condition gets true
	180	* @wq: the waitqueue to wait on
	181	* @condition: a C expression for the event to wait for
	182	*
	183	* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
184	* @condition evaluates to true. The @condition is checked each time
185	* the waitqueue @wq is woken up.
186	*
187	* wake_up() has to be called after changing any variable that could
188	* change the result of the wait condition.
189	*/
190	#define wait_event(wq, condition) \
191	do { \
192	if (condition) \
193	break; \
194	__wait_event(wq, condition); \
195	} while (0)
196
197	#define __wait_event_timeout(wq, condition, ret) \
198	do { \
199	DEFINE_WAIT(__wait); \
200	\
201	for (;;) { \
202	prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
203	if (condition) \
204	break; \
205	ret = schedule_timeout(ret); \
206	if (!ret) \
207	break; \
208	} \
209	finish_wait(&wq, &__wait); \
210	} while (0)
211
212	/**
213	* wait_event_timeout - sleep until a condition gets true or a timeout elapses
214	* @wq: the waitqueue to wait on
215	* @condition: a C expression for the event to wait for
216	* @timeout: timeout, in jiffies
217	*
218	* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
219	* @condition evaluates to true. The @condition is checked each time
220	* the waitqueue @wq is woken up.
221	*
222	* wake_up() has to be called after changing any variable that could
223	* change the result of the wait condition.
224	*
225	* The function returns 0 if the @timeout elapsed, and the remaining
226	* jiffies if the condition evaluated to true before the timeout elapsed.
227	*/
228	#define wait_event_timeout(wq, condition, timeout) \
229	({ \
230	long __ret = timeout; \
231	if (!(condition)) \
232	__wait_event_timeout(wq, condition, __ret); \
233	__ret; \
234	})
235
236	#define __wait_event_interruptible(wq, condition, ret) \
237	do { \
238	DEFINE_WAIT(__wait); \
239	\
240	for (;;) { \
241	prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
242	if (condition) \
243	break; \
244	if (!signal_pending(current)) { \
245	schedule(); \
246	continue; \
247	} \
248	ret = -ERESTARTSYS; \
249	break; \
250	} \
251	finish_wait(&wq, &__wait); \
252	} while (0)
253
254	/**
255	* wait_event_interruptible - sleep until a condition gets true
256	* @wq: the waitqueue to wait on
257	* @condition: a C expression for the event to wait for
258	*
259	* The process is put to sleep (TASK_INTERRUPTIBLE) until the
260	* @condition evaluates to true or a signal is received.
261	* The @condition is checked each time the waitqueue @wq is woken up.
262	*
263	* wake_up() has to be called after changing any variable that could
264	* change the result of the wait condition.
265	*
266	* The function will return -ERESTARTSYS if it was interrupted by a
267	* signal and 0 if @condition evaluated to true.
268	*/
269	#define wait_event_interruptible(wq, condition) \
270	({ \
271	int __ret = 0; \
272	if (!(condition)) \
273	__wait_event_interruptible(wq, condition, __ret); \
274	__ret; \
275	})
276
277	#define __wait_event_interruptible_timeout(wq, condition, ret) \
278	do { \
279	DEFINE_WAIT(__wait); \
280	\
281	for (;;) { \
282	prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
283	if (condition) \
284	break; \
285	if (!signal_pending(current)) { \
286	ret = schedule_timeout(ret); \
287	if (!ret) \
288	break; \
289	continue; \
290	} \
291	ret = -ERESTARTSYS; \
292	break; \
293	} \
294	finish_wait(&wq, &__wait); \
295	} while (0)
296
297	/**
298	* wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
299	* @wq: the waitqueue to wait on
300	* @condition: a C expression for the event to wait for
301	* @timeout: timeout, in jiffies
302	*
303	* The process is put to sleep (TASK_INTERRUPTIBLE) until the
304	* @condition evaluates to true or a signal is received.
305	* The @condition is checked each time the waitqueue @wq is woken up.
306	*
307	* wake_up() has to be called after changing any variable that could
308	* change the result of the wait condition.
309	*
310	* The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
311	* was interrupted by a signal, and the remaining jiffies otherwise
312	* if the condition evaluated to true before the timeout elapsed.
313	*/
314	#define wait_event_interruptible_timeout(wq, condition, timeout) \
315	({ \
316	long __ret = timeout; \
317	if (!(condition)) \
318	__wait_event_interruptible_timeout(wq, condition, __ret); \
319	__ret; \
320	})
321
322	#define __wait_event_interruptible_exclusive(wq, condition, ret) \
323	do { \
324	DEFINE_WAIT(__wait); \
325	\
326	for (;;) { \
327	prepare_to_wait_exclusive(&wq, &__wait, \
328	TASK_INTERRUPTIBLE); \
329	if (condition) \
330	break; \
331	if (!signal_pending(current)) { \
332	schedule(); \
333	continue; \
334	} \
335	ret = -ERESTARTSYS; \
336	break; \
337	} \
338	finish_wait(&wq, &__wait); \
339	} while (0)
340
341	#define wait_event_interruptible_exclusive(wq, condition) \
342	({ \
343	int __ret = 0; \
344	if (!(condition)) \
345	__wait_event_interruptible_exclusive(wq, condition, __ret);\
346	__ret; \
347	})
348
349	/*
350	* Must be called with the spinlock in the wait_queue_head_t held.
351	*/
352	static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
353	wait_queue_t * wait)
354	{
355	wait->flags \|= WQ_FLAG_EXCLUSIVE;
356	__add_wait_queue_tail(q, wait);
357	}
358
359	/*
360	* Must be called with the spinlock in the wait_queue_head_t held.
361	*/
362	static inline void remove_wait_queue_locked(wait_queue_head_t *q,
363	wait_queue_t * wait)
364	{
365	__remove_wait_queue(q, wait);
366	}
367
368	/*
369	* These are the old interfaces to sleep waiting for an event.
370	* They are racy. DO NOT use them, use the wait_event* interfaces above.
371	* We plan to remove these interfaces during 2.7.
372	*/
373	extern void FASTCALL(sleep_on(wait_queue_head_t *q));
374	extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q,
375	signed long timeout));
376	extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q));
377	extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q,
378	signed long timeout));
379
380	/*
381	* Waitqueues which are removed from the waitqueue_head at wakeup time
382	*/
383	void FASTCALL(prepare_to_wait(wait_queue_head_t *q,
384	wait_queue_t *wait, int state));
385	void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
386	wait_queue_t *wait, int state));
387	void FASTCALL(finish_wait(wait_queue_head_t q, wait_queue_t wait));
388	int autoremove_wake_function(wait_queue_t wait, unsigned mode, int sync, void key);
389	int wake_bit_function(wait_queue_t wait, unsigned mode, int sync, void key);
390
391	#define DEFINE_WAIT(name) \
392	wait_queue_t name = { \
c43dc2fd	393	.private = current, \
1da177e4	394	.func = autoremove_wake_function, \
7e43c84e	395	.task_list = LIST_HEAD_INIT((name).task_list), \
1da177e4 LT	396	}
	397
	398	#define DEFINE_WAIT_BIT(name, word, bit) \
	399	struct wait_bit_queue name = { \
	400	.key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
	401	.wait = { \
c43dc2fd	402	.private = current, \
1da177e4 LT	403	.func = wake_bit_function, \
	404	.task_list = \
	405	LIST_HEAD_INIT((name).wait.task_list), \
	406	}, \
	407	}
	408
	409	#define init_wait(wait) \
	410	do { \
c43dc2fd	411	(wait)->private = current; \
1da177e4 LT	412	(wait)->func = autoremove_wake_function; \
	413	INIT_LIST_HEAD(&(wait)->task_list); \
	414	} while (0)
	415
	416	/**
	417	* wait_on_bit - wait for a bit to be cleared
	418	* @word: the word being waited on, a kernel virtual address
	419	* @bit: the bit of the word being waited on
	420	* @action: the function used to sleep, which may take special actions
	421	* @mode: the task state to sleep in
	422	*
	423	* There is a standard hashed waitqueue table for generic use. This
	424	* is the part of the hashtable's accessor API that waits on a bit.
	425	* For instance, if one were to have waiters on a bitflag, one would
	426	* call wait_on_bit() in threads waiting for the bit to clear.
	427	* One uses wait_on_bit() where one is waiting for the bit to clear,
	428	* but has no intention of setting it.
	429	*/
	430	static inline int wait_on_bit(void *word, int bit,
	431	int (action)(void ), unsigned mode)
	432	{
	433	if (!test_bit(bit, word))
	434	return 0;
	435	return out_of_line_wait_on_bit(word, bit, action, mode);
	436	}
	437
	438	/**
	439	* wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
	440	* @word: the word being waited on, a kernel virtual address
	441	* @bit: the bit of the word being waited on
	442	* @action: the function used to sleep, which may take special actions
	443	* @mode: the task state to sleep in
	444	*
	445	* There is a standard hashed waitqueue table for generic use. This
	446	* is the part of the hashtable's accessor API that waits on a bit
	447	* when one intends to set it, for instance, trying to lock bitflags.
	448	* For instance, if one were to have waiters trying to set bitflag
	449	* and waiting for it to clear before setting it, one would call
	450	* wait_on_bit() in threads waiting to be able to set the bit.
	451	* One uses wait_on_bit_lock() where one is waiting for the bit to
	452	* clear with the intention of setting it, and when done, clearing it.
	453	*/
	454	static inline int wait_on_bit_lock(void *word, int bit,
	455	int (action)(void ), unsigned mode)
	456	{
	457	if (!test_and_set_bit(bit, word))
	458	return 0;
	459	return out_of_line_wait_on_bit_lock(word, bit, action, mode);
	460	}
	461
	462	#endif /* __KERNEL__ */
	463
	464	#endif