Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / include / linux / wait.h
diff --git a/kernel/include/linux/wait.h b/kernel/include/linux/wait.h
new file mode 100644 (file)
index 0000000..b3b54c2
--- /dev/null
@@ -0,0 +1,1156 @@
+#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>
+#include <linux/atomic.h>
+
+typedef struct __wait_queue wait_queue_t;
+typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
+int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
+
+/* __wait_queue::flags */
+#define WQ_FLAG_EXCLUSIVE      0x01
+#define WQ_FLAG_WOKEN          0x02
+
+struct __wait_queue {
+       unsigned int            flags;
+       void                    *private;
+       wait_queue_func_t       func;
+       struct list_head        task_list;
+};
+
+struct wait_bit_key {
+       void                    *flags;
+       int                     bit_nr;
+#define WAIT_ATOMIC_T_BIT_NR   -1
+       unsigned long           timeout;
+};
+
+struct wait_bit_queue {
+       struct wait_bit_key     key;
+       wait_queue_t            wait;
+};
+
+struct __wait_queue_head {
+       spinlock_t              lock;
+       struct list_head        task_list;
+};
+typedef struct __wait_queue_head wait_queue_head_t;
+
+struct task_struct;
+
+/*
+ * Macros for declaration and initialisaton of the datatypes
+ */
+
+#define __WAITQUEUE_INITIALIZER(name, tsk) {                           \
+       .private        = tsk,                                          \
+       .func           = default_wake_function,                        \
+       .task_list      = { NULL, NULL } }
+
+#define DECLARE_WAITQUEUE(name, tsk)                                   \
+       wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
+
+#define __WAIT_QUEUE_HEAD_INITIALIZER(name) {                          \
+       .lock           = __SPIN_LOCK_UNLOCKED(name.lock),              \
+       .task_list      = { &(name).task_list, &(name).task_list } }
+
+#define DECLARE_WAIT_QUEUE_HEAD(name) \
+       wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
+
+#define __WAIT_BIT_KEY_INITIALIZER(word, bit)                          \
+       { .flags = word, .bit_nr = bit, }
+
+#define __WAIT_ATOMIC_T_KEY_INITIALIZER(p)                             \
+       { .flags = p, .bit_nr = WAIT_ATOMIC_T_BIT_NR, }
+
+extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *);
+
+#define init_waitqueue_head(q)                         \
+       do {                                            \
+               static struct lock_class_key __key;     \
+                                                       \
+               __init_waitqueue_head((q), #q, &__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) \
+       wait_queue_head_t 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(wait_queue_t *q, struct task_struct *p)
+{
+       q->flags        = 0;
+       q->private      = p;
+       q->func         = default_wake_function;
+}
+
+static inline void
+init_waitqueue_func_entry(wait_queue_t *q, wait_queue_func_t func)
+{
+       q->flags        = 0;
+       q->private      = NULL;
+       q->func         = func;
+}
+
+static inline int waitqueue_active(wait_queue_head_t *q)
+{
+       return !list_empty(&q->task_list);
+}
+
+extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
+extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait);
+extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
+
+static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
+{
+       list_add(&new->task_list, &head->task_list);
+}
+
+/*
+ * Used for wake-one threads:
+ */
+static inline void
+__add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
+{
+       wait->flags |= WQ_FLAG_EXCLUSIVE;
+       __add_wait_queue(q, wait);
+}
+
+static inline void __add_wait_queue_tail(wait_queue_head_t *head,
+                                        wait_queue_t *new)
+{
+       list_add_tail(&new->task_list, &head->task_list);
+}
+
+static inline void
+__add_wait_queue_tail_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
+{
+       wait->flags |= WQ_FLAG_EXCLUSIVE;
+       __add_wait_queue_tail(q, wait);
+}
+
+static inline void
+__remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old)
+{
+       list_del(&old->task_list);
+}
+
+typedef int wait_bit_action_f(struct wait_bit_key *);
+void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
+void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
+void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
+void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
+void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
+void __wake_up_bit(wait_queue_head_t *, void *, int);
+int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, wait_bit_action_f *, unsigned);
+int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, wait_bit_action_f *, unsigned);
+void wake_up_bit(void *, int);
+void wake_up_atomic_t(atomic_t *);
+int out_of_line_wait_on_bit(void *, int, wait_bit_action_f *, unsigned);
+int out_of_line_wait_on_bit_timeout(void *, int, wait_bit_action_f *, unsigned, unsigned long);
+int out_of_line_wait_on_bit_lock(void *, int, wait_bit_action_f *, unsigned);
+int out_of_line_wait_on_atomic_t(atomic_t *, int (*)(atomic_t *), unsigned);
+wait_queue_head_t *bit_waitqueue(void *, int);
+
+#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 wake_up_poll(x, m)                                             \
+       __wake_up(x, TASK_NORMAL, 1, (void *) (m))
+#define wake_up_locked_poll(x, m)                                      \
+       __wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
+#define wake_up_interruptible_poll(x, m)                               \
+       __wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
+#define wake_up_interruptible_sync_poll(x, m)                          \
+       __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (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)  \
+
+/*
+ * 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, condition, state, exclusive, ret, cmd)       \
+({                                                                     \
+       __label__ __out;                                                \
+       wait_queue_t __wait;                                            \
+       long __ret = ret;       /* explicit shadow */                   \
+                                                                       \
+       INIT_LIST_HEAD(&__wait.task_list);                              \
+       if (exclusive)                                                  \
+               __wait.flags = WQ_FLAG_EXCLUSIVE;                       \
+       else                                                            \
+               __wait.flags = 0;                                       \
+                                                                       \
+       for (;;) {                                                      \
+               long __int = prepare_to_wait_event(&wq, &__wait, state);\
+                                                                       \
+               if (condition)                                          \
+                       break;                                          \
+                                                                       \
+               if (___wait_is_interruptible(state) && __int) {         \
+                       __ret = __int;                                  \
+                       if (exclusive) {                                \
+                               abort_exclusive_wait(&wq, &__wait,      \
+                                                    state, NULL);      \
+                               goto __out;                             \
+                       }                                               \
+                       break;                                          \
+               }                                                       \
+                                                                       \
+               cmd;                                                    \
+       }                                                               \
+       finish_wait(&wq, &__wait);                                      \
+__out: __ret;                                                          \
+})
+
+#define __wait_event(wq, condition)                                    \
+       (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0,  \
+                           schedule())
+
+/**
+ * wait_event - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define wait_event(wq, condition)                                      \
+do {                                                                   \
+       might_sleep();                                                  \
+       if (condition)                                                  \
+               break;                                                  \
+       __wait_event(wq, condition);                                    \
+} while (0)
+
+#define __io_wait_event(wq, condition)                                 \
+       (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0,  \
+                           io_schedule())
+
+/*
+ * io_wait_event() -- like wait_event() but with io_schedule()
+ */
+#define io_wait_event(wq, condition)                                   \
+do {                                                                   \
+       might_sleep();                                                  \
+       if (condition)                                                  \
+               break;                                                  \
+       __io_wait_event(wq, condition);                                 \
+} while (0)
+
+#define __wait_event_freezable(wq, condition)                          \
+       ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0,          \
+                           schedule(); try_to_freeze())
+
+/**
+ * wait_event - sleep (or freeze) 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 -- so as not to contribute
+ * to system load) until the @condition evaluates to true. The
+ * @condition is checked each time the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define wait_event_freezable(wq, condition)                            \
+({                                                                     \
+       int __ret = 0;                                                  \
+       might_sleep();                                                  \
+       if (!(condition))                                               \
+               __ret = __wait_event_freezable(wq, condition);          \
+       __ret;                                                          \
+})
+
+#define __wait_event_timeout(wq, condition, timeout)                   \
+       ___wait_event(wq, ___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: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @timeout: timeout, in jiffies
+ *
+ * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ *
+ * 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, condition, timeout)                     \
+({                                                                     \
+       long __ret = timeout;                                           \
+       might_sleep();                                                  \
+       if (!___wait_cond_timeout(condition))                           \
+               __ret = __wait_event_timeout(wq, condition, timeout);   \
+       __ret;                                                          \
+})
+
+#define __wait_event_freezable_timeout(wq, condition, timeout)         \
+       ___wait_event(wq, ___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, condition, timeout)           \
+({                                                                     \
+       long __ret = timeout;                                           \
+       might_sleep();                                                  \
+       if (!___wait_cond_timeout(condition))                           \
+               __ret = __wait_event_freezable_timeout(wq, condition, timeout); \
+       __ret;                                                          \
+})
+
+#define __wait_event_cmd(wq, condition, cmd1, cmd2)                    \
+       (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0,  \
+                           cmd1; schedule(); cmd2)
+
+/**
+ * wait_event_cmd - sleep until a condition gets true
+ * @wq: 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 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, condition, cmd1, cmd2)                      \
+do {                                                                   \
+       if (condition)                                                  \
+               break;                                                  \
+       __wait_event_cmd(wq, condition, cmd1, cmd2);                    \
+} while (0)
+
+#define __wait_event_interruptible(wq, condition)                      \
+       ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0,          \
+                     schedule())
+
+/**
+ * wait_event_interruptible - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_INTERRUPTIBLE) until the
+ * @condition evaluates to true or a signal is received.
+ * The @condition is checked each time the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ *
+ * The function will return -ERESTARTSYS if it was interrupted by a
+ * signal and 0 if @condition evaluated to true.
+ */
+#define wait_event_interruptible(wq, condition)                                \
+({                                                                     \
+       int __ret = 0;                                                  \
+       might_sleep();                                                  \
+       if (!(condition))                                               \
+               __ret = __wait_event_interruptible(wq, condition);      \
+       __ret;                                                          \
+})
+
+#define __wait_event_interruptible_timeout(wq, condition, timeout)     \
+       ___wait_event(wq, ___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: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @timeout: timeout, in jiffies
+ *
+ * The process is put to sleep (TASK_INTERRUPTIBLE) until the
+ * @condition evaluates to true or a signal is received.
+ * The @condition is checked each time the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ *
+ * 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, condition, timeout)       \
+({                                                                     \
+       long __ret = timeout;                                           \
+       might_sleep();                                                  \
+       if (!___wait_cond_timeout(condition))                           \
+               __ret = __wait_event_interruptible_timeout(wq,          \
+                                               condition, timeout);    \
+       __ret;                                                          \
+})
+
+#define __wait_event_hrtimeout(wq, 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).tv64 != KTIME_MAX)                                \
+               hrtimer_start_range_ns(&__t.timer, timeout,             \
+                                      current->timer_slack_ns,         \
+                                      HRTIMER_MODE_REL);               \
+                                                                       \
+       __ret = ___wait_event(wq, 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: 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 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, condition, timeout)                   \
+({                                                                     \
+       int __ret = 0;                                                  \
+       might_sleep();                                                  \
+       if (!(condition))                                               \
+               __ret = __wait_event_hrtimeout(wq, 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_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;                                                          \
+})
+
+
+#define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
+({                                                                     \
+       int __ret = 0;                                                  \
+       DEFINE_WAIT(__wait);                                            \
+       if (exclusive)                                                  \
+               __wait.flags |= WQ_FLAG_EXCLUSIVE;                      \
+       do {                                                            \
+               if (likely(list_empty(&__wait.task_list)))              \
+                       __add_wait_queue_tail(&(wq), &__wait);          \
+               set_current_state(TASK_INTERRUPTIBLE);                  \
+               if (signal_pending(current)) {                          \
+                       __ret = -ERESTARTSYS;                           \
+                       break;                                          \
+               }                                                       \
+               if (irq)                                                \
+                       spin_unlock_irq(&(wq).lock);                    \
+               else                                                    \
+                       spin_unlock(&(wq).lock);                        \
+               schedule();                                             \
+               if (irq)                                                \
+                       spin_lock_irq(&(wq).lock);                      \
+               else                                                    \
+                       spin_lock(&(wq).lock);                          \
+       } 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, 0))
+
+/**
+ * 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, 1))
+
+/**
+ * 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, 0))
+
+/**
+ * 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, 1))
+
+
+#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: 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 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, condition)                             \
+({                                                                     \
+       int __ret = 0;                                                  \
+       might_sleep();                                                  \
+       if (!(condition))                                               \
+               __ret = __wait_event_killable(wq, condition);           \
+       __ret;                                                          \
+})
+
+
+#define __wait_event_lock_irq(wq, condition, lock, cmd)                        \
+       (void)___wait_event(wq, 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: 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 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, condition, lock, cmd)              \
+do {                                                                   \
+       if (condition)                                                  \
+               break;                                                  \
+       __wait_event_lock_irq(wq, 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: 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 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, condition, lock)                       \
+do {                                                                   \
+       if (condition)                                                  \
+               break;                                                  \
+       __wait_event_lock_irq(wq, condition, lock, );                   \
+} while (0)
+
+
+#define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd)  \
+       ___wait_event(wq, 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: 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 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, condition, lock, cmd)        \
+({                                                                     \
+       int __ret = 0;                                                  \
+       if (!(condition))                                               \
+               __ret = __wait_event_interruptible_lock_irq(wq,         \
+                                               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: 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 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, condition, lock)         \
+({                                                                     \
+       int __ret = 0;                                                  \
+       if (!(condition))                                               \
+               __ret = __wait_event_interruptible_lock_irq(wq,         \
+                                               condition, lock,);      \
+       __ret;                                                          \
+})
+
+#define __wait_event_interruptible_lock_irq_timeout(wq, condition,     \
+                                                   lock, timeout)      \
+       ___wait_event(wq, ___wait_cond_timeout(condition),              \
+                     TASK_INTERRUPTIBLE, 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: 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 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, condition, lock, \
+                                                 timeout)              \
+({                                                                     \
+       long __ret = timeout;                                           \
+       if (!___wait_cond_timeout(condition))                           \
+               __ret = __wait_event_interruptible_lock_irq_timeout(    \
+                                       wq, condition, lock, timeout);  \
+       __ret;                                                          \
+})
+
+/*
+ * Waitqueues which are removed from the waitqueue_head at wakeup time
+ */
+void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
+void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
+long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state);
+void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
+void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key);
+long wait_woken(wait_queue_t *wait, unsigned mode, long timeout);
+int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
+int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
+int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
+
+#define DEFINE_WAIT_FUNC(name, function)                               \
+       wait_queue_t name = {                                           \
+               .private        = current,                              \
+               .func           = function,                             \
+               .task_list      = LIST_HEAD_INIT((name).task_list),     \
+       }
+
+#define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
+
+#define DEFINE_WAIT_BIT(name, word, bit)                               \
+       struct wait_bit_queue name = {                                  \
+               .key = __WAIT_BIT_KEY_INITIALIZER(word, bit),           \
+               .wait   = {                                             \
+                       .private        = current,                      \
+                       .func           = wake_bit_function,            \
+                       .task_list      =                               \
+                               LIST_HEAD_INIT((name).wait.task_list),  \
+               },                                                      \
+       }
+
+#define init_wait(wait)                                                        \
+       do {                                                            \
+               (wait)->private = current;                              \
+               (wait)->func = autoremove_wake_function;                \
+               INIT_LIST_HEAD(&(wait)->task_list);                     \
+               (wait)->flags = 0;                                      \
+       } while (0)
+
+
+extern int bit_wait(struct wait_bit_key *);
+extern int bit_wait_io(struct wait_bit_key *);
+extern int bit_wait_timeout(struct wait_bit_key *);
+extern int bit_wait_io_timeout(struct wait_bit_key *);
+
+/**
+ * wait_on_bit - wait for a bit to be cleared
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @mode: the task state to sleep in
+ *
+ * There is a standard hashed waitqueue table for generic use. This
+ * is the part of the hashtable's accessor API that waits on a bit.
+ * For instance, if one were to have waiters on a bitflag, one would
+ * call wait_on_bit() in threads waiting for the bit to clear.
+ * One uses wait_on_bit() where one is waiting for the bit to clear,
+ * but has no intention of setting it.
+ * Returned value will be zero if the bit was cleared, or non-zero
+ * if the process received a signal and the mode permitted wakeup
+ * on that signal.
+ */
+static inline int
+wait_on_bit(void *word, int bit, unsigned mode)
+{
+       might_sleep();
+       if (!test_bit(bit, word))
+               return 0;
+       return out_of_line_wait_on_bit(word, bit,
+                                      bit_wait,
+                                      mode);
+}
+
+/**
+ * wait_on_bit_io - wait for a bit to be cleared
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @mode: the task state to sleep in
+ *
+ * Use the standard hashed waitqueue table to wait for a bit
+ * to be cleared.  This is similar to wait_on_bit(), but calls
+ * io_schedule() instead of schedule() for the actual waiting.
+ *
+ * Returned value will be zero if the bit was cleared, or non-zero
+ * if the process received a signal and the mode permitted wakeup
+ * on that signal.
+ */
+static inline int
+wait_on_bit_io(void *word, int bit, unsigned mode)
+{
+       might_sleep();
+       if (!test_bit(bit, word))
+               return 0;
+       return out_of_line_wait_on_bit(word, bit,
+                                      bit_wait_io,
+                                      mode);
+}
+
+/**
+ * wait_on_bit_timeout - wait for a bit to be cleared or a timeout elapses
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @mode: the task state to sleep in
+ * @timeout: timeout, in jiffies
+ *
+ * Use the standard hashed waitqueue table to wait for a bit
+ * to be cleared. This is similar to wait_on_bit(), except also takes a
+ * timeout parameter.
+ *
+ * Returned value will be zero if the bit was cleared before the
+ * @timeout elapsed, or non-zero if the @timeout elapsed or process
+ * received a signal and the mode permitted wakeup on that signal.
+ */
+static inline int
+wait_on_bit_timeout(void *word, int bit, unsigned mode, unsigned long timeout)
+{
+       might_sleep();
+       if (!test_bit(bit, word))
+               return 0;
+       return out_of_line_wait_on_bit_timeout(word, bit,
+                                              bit_wait_timeout,
+                                              mode, timeout);
+}
+
+/**
+ * wait_on_bit_action - wait for a bit to be cleared
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @action: the function used to sleep, which may take special actions
+ * @mode: the task state to sleep in
+ *
+ * Use the standard hashed waitqueue table to wait for a bit
+ * to be cleared, and allow the waiting action to be specified.
+ * This is like wait_on_bit() but allows fine control of how the waiting
+ * is done.
+ *
+ * Returned value will be zero if the bit was cleared, or non-zero
+ * if the process received a signal and the mode permitted wakeup
+ * on that signal.
+ */
+static inline int
+wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
+{
+       might_sleep();
+       if (!test_bit(bit, word))
+               return 0;
+       return out_of_line_wait_on_bit(word, bit, action, mode);
+}
+
+/**
+ * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @mode: the task state to sleep in
+ *
+ * There is a standard hashed waitqueue table for generic use. This
+ * is the part of the hashtable's accessor API that waits on a bit
+ * when one intends to set it, for instance, trying to lock bitflags.
+ * For instance, if one were to have waiters trying to set bitflag
+ * and waiting for it to clear before setting it, one would call
+ * wait_on_bit() in threads waiting to be able to set the bit.
+ * One uses wait_on_bit_lock() where one is waiting for the bit to
+ * clear with the intention of setting it, and when done, clearing it.
+ *
+ * Returns zero if the bit was (eventually) found to be clear and was
+ * set.  Returns non-zero if a signal was delivered to the process and
+ * the @mode allows that signal to wake the process.
+ */
+static inline int
+wait_on_bit_lock(void *word, int bit, unsigned mode)
+{
+       might_sleep();
+       if (!test_and_set_bit(bit, word))
+               return 0;
+       return out_of_line_wait_on_bit_lock(word, bit, bit_wait, mode);
+}
+
+/**
+ * wait_on_bit_lock_io - wait for a bit to be cleared, when wanting to set it
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @mode: the task state to sleep in
+ *
+ * Use the standard hashed waitqueue table to wait for a bit
+ * to be cleared and then to atomically set it.  This is similar
+ * to wait_on_bit(), but calls io_schedule() instead of schedule()
+ * for the actual waiting.
+ *
+ * Returns zero if the bit was (eventually) found to be clear and was
+ * set.  Returns non-zero if a signal was delivered to the process and
+ * the @mode allows that signal to wake the process.
+ */
+static inline int
+wait_on_bit_lock_io(void *word, int bit, unsigned mode)
+{
+       might_sleep();
+       if (!test_and_set_bit(bit, word))
+               return 0;
+       return out_of_line_wait_on_bit_lock(word, bit, bit_wait_io, mode);
+}
+
+/**
+ * wait_on_bit_lock_action - wait for a bit to be cleared, when wanting to set it
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @action: the function used to sleep, which may take special actions
+ * @mode: the task state to sleep in
+ *
+ * Use the standard hashed waitqueue table to wait for a bit
+ * to be cleared and then to set it, and allow the waiting action
+ * to be specified.
+ * This is like wait_on_bit() but allows fine control of how the waiting
+ * is done.
+ *
+ * Returns zero if the bit was (eventually) found to be clear and was
+ * set.  Returns non-zero if a signal was delivered to the process and
+ * the @mode allows that signal to wake the process.
+ */
+static inline int
+wait_on_bit_lock_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
+{
+       might_sleep();
+       if (!test_and_set_bit(bit, word))
+               return 0;
+       return out_of_line_wait_on_bit_lock(word, bit, action, mode);
+}
+
+/**
+ * wait_on_atomic_t - Wait for an atomic_t to become 0
+ * @val: The atomic value being waited on, a kernel virtual address
+ * @action: the function used to sleep, which may take special actions
+ * @mode: the task state to sleep in
+ *
+ * Wait for an atomic_t to become 0.  We abuse the bit-wait waitqueue table for
+ * the purpose of getting a waitqueue, but we set the key to a bit number
+ * outside of the target 'word'.
+ */
+static inline
+int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode)
+{
+       might_sleep();
+       if (atomic_read(val) == 0)
+               return 0;
+       return out_of_line_wait_on_atomic_t(val, action, mode);
+}
+
+#endif /* _LINUX_WAIT_H */