v4.19.13 snapshot.
diff --git a/include/linux/wait.h b/include/linux/wait.h
new file mode 100644
index 0000000..ed7c122
--- /dev/null
+++ b/include/linux/wait.h
@@ -0,0 +1,1135 @@
+/* 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, \
+ schedule(); try_to_freeze())
+
+/**
+ * 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 = schedule_timeout(__ret); try_to_freeze())
+
+/*
+ * 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, \
+ schedule(); try_to_freeze())
+
+#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 */