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		8c1007fdc7
		
	
	
	
	
		
			
			Sphinx emits various warnings all caused by a missing colon before code block: WARNING: Block quote ends without a blank line; unexpected unindent. ERROR: Unexpected indentation. WARNING: Block quote ends without a blank line; unexpected unindent. Add the colon, clearing sphinx warnings. Signed-off-by: Tobin C. Harding <tobin@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
		
			
				
	
	
		
			1135 lines
		
	
	
	
		
			40 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			1135 lines
		
	
	
	
		
			40 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
 | |
| #ifndef _LINUX_WAIT_H
 | |
| #define _LINUX_WAIT_H
 | |
| /*
 | |
|  * Linux wait queue related types and methods
 | |
|  */
 | |
| #include <linux/list.h>
 | |
| #include <linux/stddef.h>
 | |
| #include <linux/spinlock.h>
 | |
| 
 | |
| #include <asm/current.h>
 | |
| #include <uapi/linux/wait.h>
 | |
| 
 | |
| typedef struct wait_queue_entry wait_queue_entry_t;
 | |
| 
 | |
| typedef int (*wait_queue_func_t)(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key);
 | |
| int default_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key);
 | |
| 
 | |
| /* wait_queue_entry::flags */
 | |
| #define WQ_FLAG_EXCLUSIVE	0x01
 | |
| #define WQ_FLAG_WOKEN		0x02
 | |
| #define WQ_FLAG_BOOKMARK	0x04
 | |
| 
 | |
| /*
 | |
|  * A single wait-queue entry structure:
 | |
|  */
 | |
| struct wait_queue_entry {
 | |
| 	unsigned int		flags;
 | |
| 	void			*private;
 | |
| 	wait_queue_func_t	func;
 | |
| 	struct list_head	entry;
 | |
| };
 | |
| 
 | |
| struct wait_queue_head {
 | |
| 	spinlock_t		lock;
 | |
| 	struct list_head	head;
 | |
| };
 | |
| 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,				\
 | |
| 	.entry		= { NULL, NULL } }
 | |
| 
 | |
| #define DECLARE_WAITQUEUE(name, tsk)						\
 | |
| 	struct wait_queue_entry name = __WAITQUEUE_INITIALIZER(name, tsk)
 | |
| 
 | |
| #define __WAIT_QUEUE_HEAD_INITIALIZER(name) {					\
 | |
| 	.lock		= __SPIN_LOCK_UNLOCKED(name.lock),			\
 | |
| 	.head		= { &(name).head, &(name).head } }
 | |
| 
 | |
| #define DECLARE_WAIT_QUEUE_HEAD(name) \
 | |
| 	struct wait_queue_head name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
 | |
| 
 | |
| extern void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *);
 | |
| 
 | |
| #define init_waitqueue_head(wq_head)						\
 | |
| 	do {									\
 | |
| 		static struct lock_class_key __key;				\
 | |
| 										\
 | |
| 		__init_waitqueue_head((wq_head), #wq_head, &__key);		\
 | |
| 	} while (0)
 | |
| 
 | |
| #ifdef CONFIG_LOCKDEP
 | |
| # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
 | |
| 	({ init_waitqueue_head(&name); name; })
 | |
| # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
 | |
| 	struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
 | |
| #else
 | |
| # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
 | |
| #endif
 | |
| 
 | |
| static inline void init_waitqueue_entry(struct wait_queue_entry *wq_entry, struct task_struct *p)
 | |
| {
 | |
| 	wq_entry->flags		= 0;
 | |
| 	wq_entry->private	= p;
 | |
| 	wq_entry->func		= default_wake_function;
 | |
| }
 | |
| 
 | |
| static inline void
 | |
| init_waitqueue_func_entry(struct wait_queue_entry *wq_entry, wait_queue_func_t func)
 | |
| {
 | |
| 	wq_entry->flags		= 0;
 | |
| 	wq_entry->private	= NULL;
 | |
| 	wq_entry->func		= func;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * waitqueue_active -- locklessly test for waiters on the queue
 | |
|  * @wq_head: the waitqueue to test for waiters
 | |
|  *
 | |
|  * returns true if the wait list is not empty
 | |
|  *
 | |
|  * NOTE: this function is lockless and requires care, incorrect usage _will_
 | |
|  * lead to sporadic and non-obvious failure.
 | |
|  *
 | |
|  * Use either while holding wait_queue_head::lock or when used for wakeups
 | |
|  * with an extra smp_mb() like::
 | |
|  *
 | |
|  *      CPU0 - waker                    CPU1 - waiter
 | |
|  *
 | |
|  *                                      for (;;) {
 | |
|  *      @cond = true;                     prepare_to_wait(&wq_head, &wait, state);
 | |
|  *      smp_mb();                         // smp_mb() from set_current_state()
 | |
|  *      if (waitqueue_active(wq_head))         if (@cond)
 | |
|  *        wake_up(wq_head);                      break;
 | |
|  *                                        schedule();
 | |
|  *                                      }
 | |
|  *                                      finish_wait(&wq_head, &wait);
 | |
|  *
 | |
|  * Because without the explicit smp_mb() it's possible for the
 | |
|  * waitqueue_active() load to get hoisted over the @cond store such that we'll
 | |
|  * observe an empty wait list while the waiter might not observe @cond.
 | |
|  *
 | |
|  * Also note that this 'optimization' trades a spin_lock() for an smp_mb(),
 | |
|  * which (when the lock is uncontended) are of roughly equal cost.
 | |
|  */
 | |
| static inline int waitqueue_active(struct wait_queue_head *wq_head)
 | |
| {
 | |
| 	return !list_empty(&wq_head->head);
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * wq_has_sleeper - check if there are any waiting processes
 | |
|  * @wq_head: wait queue head
 | |
|  *
 | |
|  * Returns true if wq_head has waiting processes
 | |
|  *
 | |
|  * Please refer to the comment for waitqueue_active.
 | |
|  */
 | |
| static inline bool wq_has_sleeper(struct wait_queue_head *wq_head)
 | |
| {
 | |
| 	/*
 | |
| 	 * We need to be sure we are in sync with the
 | |
| 	 * add_wait_queue modifications to the wait queue.
 | |
| 	 *
 | |
| 	 * This memory barrier should be paired with one on the
 | |
| 	 * waiting side.
 | |
| 	 */
 | |
| 	smp_mb();
 | |
| 	return waitqueue_active(wq_head);
 | |
| }
 | |
| 
 | |
| extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 | |
| extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 | |
| extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 | |
| 
 | |
| static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 | |
| {
 | |
| 	list_add(&wq_entry->entry, &wq_head->head);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Used for wake-one threads:
 | |
|  */
 | |
| static inline void
 | |
| __add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 | |
| {
 | |
| 	wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
 | |
| 	__add_wait_queue(wq_head, wq_entry);
 | |
| }
 | |
| 
 | |
| static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 | |
| {
 | |
| 	list_add_tail(&wq_entry->entry, &wq_head->head);
 | |
| }
 | |
| 
 | |
| static inline void
 | |
| __add_wait_queue_entry_tail_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 | |
| {
 | |
| 	wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
 | |
| 	__add_wait_queue_entry_tail(wq_head, wq_entry);
 | |
| }
 | |
| 
 | |
| static inline void
 | |
| __remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 | |
| {
 | |
| 	list_del(&wq_entry->entry);
 | |
| }
 | |
| 
 | |
| void __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key);
 | |
| void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);
 | |
| void __wake_up_locked_key_bookmark(struct wait_queue_head *wq_head,
 | |
| 		unsigned int mode, void *key, wait_queue_entry_t *bookmark);
 | |
| void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key);
 | |
| void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr);
 | |
| void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode, int nr);
 | |
| 
 | |
| #define wake_up(x)			__wake_up(x, TASK_NORMAL, 1, NULL)
 | |
| #define wake_up_nr(x, nr)		__wake_up(x, TASK_NORMAL, nr, NULL)
 | |
| #define wake_up_all(x)			__wake_up(x, TASK_NORMAL, 0, NULL)
 | |
| #define wake_up_locked(x)		__wake_up_locked((x), TASK_NORMAL, 1)
 | |
| #define wake_up_all_locked(x)		__wake_up_locked((x), TASK_NORMAL, 0)
 | |
| 
 | |
| #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_interruptible_sync(x)	__wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
 | |
| 
 | |
| /*
 | |
|  * Wakeup macros to be used to report events to the targets.
 | |
|  */
 | |
| #define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m))
 | |
| #define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m))
 | |
| #define wake_up_poll(x, m)							\
 | |
| 	__wake_up(x, TASK_NORMAL, 1, poll_to_key(m))
 | |
| #define wake_up_locked_poll(x, m)						\
 | |
| 	__wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m))
 | |
| #define wake_up_interruptible_poll(x, m)					\
 | |
| 	__wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m))
 | |
| #define wake_up_interruptible_sync_poll(x, m)					\
 | |
| 	__wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, poll_to_key(m))
 | |
| 
 | |
| #define ___wait_cond_timeout(condition)						\
 | |
| ({										\
 | |
| 	bool __cond = (condition);						\
 | |
| 	if (__cond && !__ret)							\
 | |
| 		__ret = 1;							\
 | |
| 	__cond || !__ret;							\
 | |
| })
 | |
| 
 | |
| #define ___wait_is_interruptible(state)						\
 | |
| 	(!__builtin_constant_p(state) ||					\
 | |
| 		state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE)		\
 | |
| 
 | |
| extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);
 | |
| 
 | |
| /*
 | |
|  * The below macro ___wait_event() has an explicit shadow of the __ret
 | |
|  * variable when used from the wait_event_*() macros.
 | |
|  *
 | |
|  * This is so that both can use the ___wait_cond_timeout() construct
 | |
|  * to wrap the condition.
 | |
|  *
 | |
|  * The type inconsistency of the wait_event_*() __ret variable is also
 | |
|  * on purpose; we use long where we can return timeout values and int
 | |
|  * otherwise.
 | |
|  */
 | |
| 
 | |
| #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd)		\
 | |
| ({										\
 | |
| 	__label__ __out;							\
 | |
| 	struct wait_queue_entry __wq_entry;					\
 | |
| 	long __ret = ret;	/* explicit shadow */				\
 | |
| 										\
 | |
| 	init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0);	\
 | |
| 	for (;;) {								\
 | |
| 		long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\
 | |
| 										\
 | |
| 		if (condition)							\
 | |
| 			break;							\
 | |
| 										\
 | |
| 		if (___wait_is_interruptible(state) && __int) {			\
 | |
| 			__ret = __int;						\
 | |
| 			goto __out;						\
 | |
| 		}								\
 | |
| 										\
 | |
| 		cmd;								\
 | |
| 	}									\
 | |
| 	finish_wait(&wq_head, &__wq_entry);					\
 | |
| __out:	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event(wq_head, condition)					\
 | |
| 	(void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,	\
 | |
| 			    schedule())
 | |
| 
 | |
| /**
 | |
|  * wait_event - sleep until a condition gets true
 | |
|  * @wq_head: 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_head 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_head, condition)						\
 | |
| do {										\
 | |
| 	might_sleep();								\
 | |
| 	if (condition)								\
 | |
| 		break;								\
 | |
| 	__wait_event(wq_head, condition);					\
 | |
| } while (0)
 | |
| 
 | |
| #define __io_wait_event(wq_head, condition)					\
 | |
| 	(void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,	\
 | |
| 			    io_schedule())
 | |
| 
 | |
| /*
 | |
|  * io_wait_event() -- like wait_event() but with io_schedule()
 | |
|  */
 | |
| #define io_wait_event(wq_head, condition)					\
 | |
| do {										\
 | |
| 	might_sleep();								\
 | |
| 	if (condition)								\
 | |
| 		break;								\
 | |
| 	__io_wait_event(wq_head, condition);					\
 | |
| } while (0)
 | |
| 
 | |
| #define __wait_event_freezable(wq_head, condition)				\
 | |
| 	___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,		\
 | |
| 			    freezable_schedule())
 | |
| 
 | |
| /**
 | |
|  * wait_event_freezable - sleep (or freeze) until a condition gets true
 | |
|  * @wq_head: the waitqueue to wait on
 | |
|  * @condition: a C expression for the event to wait for
 | |
|  *
 | |
|  * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute
 | |
|  * to system load) until the @condition evaluates to true. The
 | |
|  * @condition is checked each time the waitqueue @wq_head 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_freezable(wq_head, condition)				\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_freezable(wq_head, condition);		\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_timeout(wq_head, condition, timeout)			\
 | |
| 	___wait_event(wq_head, ___wait_cond_timeout(condition),			\
 | |
| 		      TASK_UNINTERRUPTIBLE, 0, timeout,				\
 | |
| 		      __ret = schedule_timeout(__ret))
 | |
| 
 | |
| /**
 | |
|  * wait_event_timeout - sleep until a condition gets true or a timeout elapses
 | |
|  * @wq_head: 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_head is woken up.
 | |
|  *
 | |
|  * wake_up() has to be called after changing any variable that could
 | |
|  * change the result of the wait condition.
 | |
|  *
 | |
|  * Returns:
 | |
|  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 | |
|  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 | |
|  * or the remaining jiffies (at least 1) if the @condition evaluated
 | |
|  * to %true before the @timeout elapsed.
 | |
|  */
 | |
| #define wait_event_timeout(wq_head, condition, timeout)				\
 | |
| ({										\
 | |
| 	long __ret = timeout;							\
 | |
| 	might_sleep();								\
 | |
| 	if (!___wait_cond_timeout(condition))					\
 | |
| 		__ret = __wait_event_timeout(wq_head, condition, timeout);	\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_freezable_timeout(wq_head, condition, timeout)		\
 | |
| 	___wait_event(wq_head, ___wait_cond_timeout(condition),			\
 | |
| 		      TASK_INTERRUPTIBLE, 0, timeout,				\
 | |
| 		      __ret = freezable_schedule_timeout(__ret))
 | |
| 
 | |
| /*
 | |
|  * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid
 | |
|  * increasing load and is freezable.
 | |
|  */
 | |
| #define wait_event_freezable_timeout(wq_head, condition, timeout)		\
 | |
| ({										\
 | |
| 	long __ret = timeout;							\
 | |
| 	might_sleep();								\
 | |
| 	if (!___wait_cond_timeout(condition))					\
 | |
| 		__ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2)		\
 | |
| 	(void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0,	\
 | |
| 			    cmd1; schedule(); cmd2)
 | |
| /*
 | |
|  * Just like wait_event_cmd(), except it sets exclusive flag
 | |
|  */
 | |
| #define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2)		\
 | |
| do {										\
 | |
| 	if (condition)								\
 | |
| 		break;								\
 | |
| 	__wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2);		\
 | |
| } while (0)
 | |
| 
 | |
| #define __wait_event_cmd(wq_head, condition, cmd1, cmd2)			\
 | |
| 	(void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,	\
 | |
| 			    cmd1; schedule(); cmd2)
 | |
| 
 | |
| /**
 | |
|  * wait_event_cmd - sleep until a condition gets true
 | |
|  * @wq_head: the waitqueue to wait on
 | |
|  * @condition: a C expression for the event to wait for
 | |
|  * @cmd1: the command will be executed before sleep
 | |
|  * @cmd2: the command will be executed after sleep
 | |
|  *
 | |
|  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 | |
|  * @condition evaluates to true. The @condition is checked each time
 | |
|  * the waitqueue @wq_head 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_cmd(wq_head, condition, cmd1, cmd2)				\
 | |
| do {										\
 | |
| 	if (condition)								\
 | |
| 		break;								\
 | |
| 	__wait_event_cmd(wq_head, condition, cmd1, cmd2);			\
 | |
| } while (0)
 | |
| 
 | |
| #define __wait_event_interruptible(wq_head, condition)				\
 | |
| 	___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,		\
 | |
| 		      schedule())
 | |
| 
 | |
| /**
 | |
|  * wait_event_interruptible - sleep until a condition gets true
 | |
|  * @wq_head: 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_head 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_head, condition)				\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_interruptible(wq_head, condition);		\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_interruptible_timeout(wq_head, condition, timeout)		\
 | |
| 	___wait_event(wq_head, ___wait_cond_timeout(condition),			\
 | |
| 		      TASK_INTERRUPTIBLE, 0, timeout,				\
 | |
| 		      __ret = schedule_timeout(__ret))
 | |
| 
 | |
| /**
 | |
|  * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
 | |
|  * @wq_head: 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_head is woken up.
 | |
|  *
 | |
|  * wake_up() has to be called after changing any variable that could
 | |
|  * change the result of the wait condition.
 | |
|  *
 | |
|  * Returns:
 | |
|  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 | |
|  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 | |
|  * the remaining jiffies (at least 1) if the @condition evaluated
 | |
|  * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
 | |
|  * interrupted by a signal.
 | |
|  */
 | |
| #define wait_event_interruptible_timeout(wq_head, condition, timeout)		\
 | |
| ({										\
 | |
| 	long __ret = timeout;							\
 | |
| 	might_sleep();								\
 | |
| 	if (!___wait_cond_timeout(condition))					\
 | |
| 		__ret = __wait_event_interruptible_timeout(wq_head,		\
 | |
| 						condition, timeout);		\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_hrtimeout(wq_head, condition, timeout, state)		\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	struct hrtimer_sleeper __t;						\
 | |
| 										\
 | |
| 	hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);	\
 | |
| 	hrtimer_init_sleeper(&__t, current);					\
 | |
| 	if ((timeout) != KTIME_MAX)						\
 | |
| 		hrtimer_start_range_ns(&__t.timer, timeout,			\
 | |
| 				       current->timer_slack_ns,			\
 | |
| 				       HRTIMER_MODE_REL);			\
 | |
| 										\
 | |
| 	__ret = ___wait_event(wq_head, condition, state, 0, 0,			\
 | |
| 		if (!__t.task) {						\
 | |
| 			__ret = -ETIME;						\
 | |
| 			break;							\
 | |
| 		}								\
 | |
| 		schedule());							\
 | |
| 										\
 | |
| 	hrtimer_cancel(&__t.timer);						\
 | |
| 	destroy_hrtimer_on_stack(&__t.timer);					\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| /**
 | |
|  * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
 | |
|  * @wq_head: the waitqueue to wait on
 | |
|  * @condition: a C expression for the event to wait for
 | |
|  * @timeout: timeout, as a ktime_t
 | |
|  *
 | |
|  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 | |
|  * @condition evaluates to true or a signal is received.
 | |
|  * The @condition is checked each time the waitqueue @wq_head 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 @condition became true, or -ETIME if the timeout
 | |
|  * elapsed.
 | |
|  */
 | |
| #define wait_event_hrtimeout(wq_head, condition, timeout)			\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_hrtimeout(wq_head, condition, timeout,	\
 | |
| 					       TASK_UNINTERRUPTIBLE);		\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| /**
 | |
|  * wait_event_interruptible_hrtimeout - 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, as a ktime_t
 | |
|  *
 | |
|  * 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 @condition became true, -ERESTARTSYS if it was
 | |
|  * interrupted by a signal, or -ETIME if the timeout elapsed.
 | |
|  */
 | |
| #define wait_event_interruptible_hrtimeout(wq, condition, timeout)		\
 | |
| ({										\
 | |
| 	long __ret = 0;								\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_hrtimeout(wq, condition, timeout,		\
 | |
| 					       TASK_INTERRUPTIBLE);		\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_interruptible_exclusive(wq, condition)			\
 | |
| 	___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0,			\
 | |
| 		      schedule())
 | |
| 
 | |
| #define wait_event_interruptible_exclusive(wq, condition)			\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_interruptible_exclusive(wq, condition);	\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_killable_exclusive(wq, condition)				\
 | |
| 	___wait_event(wq, condition, TASK_KILLABLE, 1, 0,			\
 | |
| 		      schedule())
 | |
| 
 | |
| #define wait_event_killable_exclusive(wq, condition)				\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_killable_exclusive(wq, condition);		\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| 
 | |
| #define __wait_event_freezable_exclusive(wq, condition)				\
 | |
| 	___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0,			\
 | |
| 			freezable_schedule())
 | |
| 
 | |
| #define wait_event_freezable_exclusive(wq, condition)				\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_freezable_exclusive(wq, condition);	\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| /**
 | |
|  * wait_event_idle - wait for a condition without contributing to system load
 | |
|  * @wq_head: the waitqueue to wait on
 | |
|  * @condition: a C expression for the event to wait for
 | |
|  *
 | |
|  * The process is put to sleep (TASK_IDLE) until the
 | |
|  * @condition evaluates to true.
 | |
|  * The @condition is checked each time the waitqueue @wq_head 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_idle(wq_head, condition)					\
 | |
| do {										\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule());	\
 | |
| } while (0)
 | |
| 
 | |
| /**
 | |
|  * wait_event_idle_exclusive - wait for a condition with contributing to system load
 | |
|  * @wq_head: the waitqueue to wait on
 | |
|  * @condition: a C expression for the event to wait for
 | |
|  *
 | |
|  * The process is put to sleep (TASK_IDLE) until the
 | |
|  * @condition evaluates to true.
 | |
|  * The @condition is checked each time the waitqueue @wq_head is woken up.
 | |
|  *
 | |
|  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 | |
|  * set thus if other processes wait on the same list, when this
 | |
|  * process is woken further processes are not considered.
 | |
|  *
 | |
|  * wake_up() has to be called after changing any variable that could
 | |
|  * change the result of the wait condition.
 | |
|  *
 | |
|  */
 | |
| #define wait_event_idle_exclusive(wq_head, condition)				\
 | |
| do {										\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule());	\
 | |
| } while (0)
 | |
| 
 | |
| #define __wait_event_idle_timeout(wq_head, condition, timeout)			\
 | |
| 	___wait_event(wq_head, ___wait_cond_timeout(condition),			\
 | |
| 		      TASK_IDLE, 0, timeout,					\
 | |
| 		      __ret = schedule_timeout(__ret))
 | |
| 
 | |
| /**
 | |
|  * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses
 | |
|  * @wq_head: 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_IDLE) until the
 | |
|  * @condition evaluates to true. The @condition is checked each time
 | |
|  * the waitqueue @wq_head is woken up.
 | |
|  *
 | |
|  * wake_up() has to be called after changing any variable that could
 | |
|  * change the result of the wait condition.
 | |
|  *
 | |
|  * Returns:
 | |
|  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 | |
|  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 | |
|  * or the remaining jiffies (at least 1) if the @condition evaluated
 | |
|  * to %true before the @timeout elapsed.
 | |
|  */
 | |
| #define wait_event_idle_timeout(wq_head, condition, timeout)			\
 | |
| ({										\
 | |
| 	long __ret = timeout;							\
 | |
| 	might_sleep();								\
 | |
| 	if (!___wait_cond_timeout(condition))					\
 | |
| 		__ret = __wait_event_idle_timeout(wq_head, condition, timeout);	\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout)	\
 | |
| 	___wait_event(wq_head, ___wait_cond_timeout(condition),			\
 | |
| 		      TASK_IDLE, 1, timeout,					\
 | |
| 		      __ret = schedule_timeout(__ret))
 | |
| 
 | |
| /**
 | |
|  * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses
 | |
|  * @wq_head: 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_IDLE) until the
 | |
|  * @condition evaluates to true. The @condition is checked each time
 | |
|  * the waitqueue @wq_head is woken up.
 | |
|  *
 | |
|  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 | |
|  * set thus if other processes wait on the same list, when this
 | |
|  * process is woken further processes are not considered.
 | |
|  *
 | |
|  * wake_up() has to be called after changing any variable that could
 | |
|  * change the result of the wait condition.
 | |
|  *
 | |
|  * Returns:
 | |
|  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 | |
|  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 | |
|  * or the remaining jiffies (at least 1) if the @condition evaluated
 | |
|  * to %true before the @timeout elapsed.
 | |
|  */
 | |
| #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout)		\
 | |
| ({										\
 | |
| 	long __ret = timeout;							\
 | |
| 	might_sleep();								\
 | |
| 	if (!___wait_cond_timeout(condition))					\
 | |
| 		__ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *);
 | |
| extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);
 | |
| 
 | |
| #define __wait_event_interruptible_locked(wq, condition, exclusive, fn)		\
 | |
| ({										\
 | |
| 	int __ret;								\
 | |
| 	DEFINE_WAIT(__wait);							\
 | |
| 	if (exclusive)								\
 | |
| 		__wait.flags |= WQ_FLAG_EXCLUSIVE;				\
 | |
| 	do {									\
 | |
| 		__ret = fn(&(wq), &__wait);					\
 | |
| 		if (__ret)							\
 | |
| 			break;							\
 | |
| 	} 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, do_wait_intr))
 | |
| 
 | |
| /**
 | |
|  * 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, do_wait_intr_irq))
 | |
| 
 | |
| /**
 | |
|  * 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, do_wait_intr))
 | |
| 
 | |
| /**
 | |
|  * 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, do_wait_intr_irq))
 | |
| 
 | |
| 
 | |
| #define __wait_event_killable(wq, condition)					\
 | |
| 	___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
 | |
| 
 | |
| /**
 | |
|  * wait_event_killable - sleep until a condition gets true
 | |
|  * @wq_head: 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_head 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_head, condition)					\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	might_sleep();								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_killable(wq_head, condition);		\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_killable_timeout(wq_head, condition, timeout)		\
 | |
| 	___wait_event(wq_head, ___wait_cond_timeout(condition),			\
 | |
| 		      TASK_KILLABLE, 0, timeout,				\
 | |
| 		      __ret = schedule_timeout(__ret))
 | |
| 
 | |
| /**
 | |
|  * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses
 | |
|  * @wq_head: 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_KILLABLE) until the
 | |
|  * @condition evaluates to true or a kill signal is received.
 | |
|  * The @condition is checked each time the waitqueue @wq_head is woken up.
 | |
|  *
 | |
|  * wake_up() has to be called after changing any variable that could
 | |
|  * change the result of the wait condition.
 | |
|  *
 | |
|  * Returns:
 | |
|  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 | |
|  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 | |
|  * the remaining jiffies (at least 1) if the @condition evaluated
 | |
|  * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
 | |
|  * interrupted by a kill signal.
 | |
|  *
 | |
|  * Only kill signals interrupt this process.
 | |
|  */
 | |
| #define wait_event_killable_timeout(wq_head, condition, timeout)		\
 | |
| ({										\
 | |
| 	long __ret = timeout;							\
 | |
| 	might_sleep();								\
 | |
| 	if (!___wait_cond_timeout(condition))					\
 | |
| 		__ret = __wait_event_killable_timeout(wq_head,			\
 | |
| 						condition, timeout);		\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| 
 | |
| #define __wait_event_lock_irq(wq_head, condition, lock, cmd)			\
 | |
| 	(void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,	\
 | |
| 			    spin_unlock_irq(&lock);				\
 | |
| 			    cmd;						\
 | |
| 			    schedule();						\
 | |
| 			    spin_lock_irq(&lock))
 | |
| 
 | |
| /**
 | |
|  * 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_head: 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_head 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_head, condition, lock, cmd)			\
 | |
| do {										\
 | |
| 	if (condition)								\
 | |
| 		break;								\
 | |
| 	__wait_event_lock_irq(wq_head, 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_head: 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_head 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_head, condition, lock)				\
 | |
| do {										\
 | |
| 	if (condition)								\
 | |
| 		break;								\
 | |
| 	__wait_event_lock_irq(wq_head, condition, lock, );			\
 | |
| } while (0)
 | |
| 
 | |
| 
 | |
| #define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd)	\
 | |
| 	___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,		\
 | |
| 		      spin_unlock_irq(&lock);					\
 | |
| 		      cmd;							\
 | |
| 		      schedule();						\
 | |
| 		      spin_lock_irq(&lock))
 | |
| 
 | |
| /**
 | |
|  * 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_head: 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_head 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_head, condition, lock, cmd)	\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_interruptible_lock_irq(wq_head,		\
 | |
| 						condition, lock, 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_head: 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_head 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_head, condition, lock)		\
 | |
| ({										\
 | |
| 	int __ret = 0;								\
 | |
| 	if (!(condition))							\
 | |
| 		__ret = __wait_event_interruptible_lock_irq(wq_head,		\
 | |
| 						condition, lock,);		\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state)	\
 | |
| 	___wait_event(wq_head, ___wait_cond_timeout(condition),			\
 | |
| 		      state, 0, timeout,					\
 | |
| 		      spin_unlock_irq(&lock);					\
 | |
| 		      __ret = schedule_timeout(__ret);				\
 | |
| 		      spin_lock_irq(&lock));
 | |
| 
 | |
| /**
 | |
|  * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
 | |
|  *		true or a timeout elapses. The condition is checked under
 | |
|  *		the lock. This is expected to be called with the lock taken.
 | |
|  * @wq_head: 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.
 | |
|  * @timeout: timeout, in jiffies
 | |
|  *
 | |
|  * 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_head 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 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_lock_irq_timeout(wq_head, condition, lock,	\
 | |
| 						  timeout)			\
 | |
| ({										\
 | |
| 	long __ret = timeout;							\
 | |
| 	if (!___wait_cond_timeout(condition))					\
 | |
| 		__ret = __wait_event_lock_irq_timeout(				\
 | |
| 					wq_head, condition, lock, timeout,	\
 | |
| 					TASK_INTERRUPTIBLE);			\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| #define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout)		\
 | |
| ({										\
 | |
| 	long __ret = timeout;							\
 | |
| 	if (!___wait_cond_timeout(condition))					\
 | |
| 		__ret = __wait_event_lock_irq_timeout(				\
 | |
| 					wq_head, condition, lock, timeout,	\
 | |
| 					TASK_UNINTERRUPTIBLE);			\
 | |
| 	__ret;									\
 | |
| })
 | |
| 
 | |
| /*
 | |
|  * Waitqueues which are removed from the waitqueue_head at wakeup time
 | |
|  */
 | |
| void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
 | |
| void prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
 | |
| long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
 | |
| void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 | |
| long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);
 | |
| int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
 | |
| int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
 | |
| 
 | |
| #define DEFINE_WAIT_FUNC(name, function)					\
 | |
| 	struct wait_queue_entry name = {					\
 | |
| 		.private	= current,					\
 | |
| 		.func		= function,					\
 | |
| 		.entry		= LIST_HEAD_INIT((name).entry),			\
 | |
| 	}
 | |
| 
 | |
| #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
 | |
| 
 | |
| #define init_wait(wait)								\
 | |
| 	do {									\
 | |
| 		(wait)->private = current;					\
 | |
| 		(wait)->func = autoremove_wake_function;			\
 | |
| 		INIT_LIST_HEAD(&(wait)->entry);					\
 | |
| 		(wait)->flags = 0;						\
 | |
| 	} while (0)
 | |
| 
 | |
| #endif /* _LINUX_WAIT_H */
 |