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/* 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
#define WQ_FLAG_CUSTOM 0x08
#define WQ_FLAG_DONE 0x10
#define WQ_FLAG_PRIORITY 0x20
/*
* 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 = LIST_HEAD_INIT(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_single_sleeper - check if there is only one sleeper
* @wq_head: wait queue head
*
* Returns true of wq_head has only one sleeper on the list.
*
* Please refer to the comment for waitqueue_active.
*/
static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head)
{
return list_is_singular(&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 add_wait_queue_priority(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)
{
struct list_head *head = &wq_head->head;
struct wait_queue_entry *wq;
list_for_each_entry(wq, &wq_head->head, entry) {
if (!(wq->flags & WQ_FLAG_PRIORITY))
break;
head = &wq->entry;
}
list_add(&wq_entry->entry, 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, void *key);
void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, unsigned int mode, 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);
void __wake_up_pollfree(struct wait_queue_head *wq_head);
#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)
/*
* 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, poll_to_key(m))
#define wake_up_interruptible_sync_poll_locked(x, m) \
__wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
/**
* wake_up_pollfree - signal that a polled waitqueue is going away
* @wq_head: the wait queue head
*
* In the very rare cases where a ->poll() implementation uses a waitqueue whose
* lifetime is tied to a task rather than to the 'struct file' being polled,
* this function must be called before the waitqueue is freed so that
* non-blocking polls (e.g. epoll) are notified that the queue is going away.
*
* The caller must also RCU-delay the freeing of the wait_queue_head, e.g. via
* an explicit synchronize_rcu() or call_rcu(), or via SLAB_TYPESAFE_BY_RCU.
*/
static inline void wake_up_pollfree(struct wait_queue_head *wq_head)
{
/*
* For performance reasons, we don't always take the queue lock here.
* Therefore, we might race with someone removing the last entry from
* the queue, and proceed while they still hold the queue lock.
* However, rcu_read_lock() is required to be held in such cases, so we
* can safely proceed with an RCU-delayed free.
*/
if (waitqueue_active(wq_head))
__wake_up_pollfree(wq_head);
}
#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_sleeper_on_stack(&__t, CLOCK_MONOTONIC, \
HRTIMER_MODE_REL); \
if ((timeout) != KTIME_MAX) { \
hrtimer_set_expires_range_ns(&__t.timer, timeout, \
current->timer_slack_ns); \
hrtimer_sleeper_start_expires(&__t, 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);
bool 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)
typedef int (*task_call_f)(struct task_struct *p, void *arg);
extern int task_call_func(struct task_struct *p, task_call_f func, void *arg);
#endif /* _LINUX_WAIT_H */
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