sched: Move wait.c into kernel/sched/

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-5q5yqvdaen0rmapwloeaotx3@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 0 insertions, 401 deletions

diff --git a/kernel/wait.c b/kernel/wait.c
deleted file mode 100644
index de21c6305a44..000000000000
--- a/kernel/wait.c
+++ /dev/null
@@ -1,401 +0,0 @@
-/*
- * Generic waiting primitives.
- *
- * (C) 2004 Nadia Yvette Chambers, Oracle
- */
-#include <linux/init.h>
-#include <linux/export.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/wait.h>
-#include <linux/hash.h>
-
-void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *key)
-{
-	spin_lock_init(&q->lock);
-	lockdep_set_class_and_name(&q->lock, key, name);
-	INIT_LIST_HEAD(&q->task_list);
-}
-
-EXPORT_SYMBOL(__init_waitqueue_head);
-
-void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
-{
-	unsigned long flags;
-
-	wait->flags &= ~WQ_FLAG_EXCLUSIVE;
-	spin_lock_irqsave(&q->lock, flags);
-	__add_wait_queue(q, wait);
-	spin_unlock_irqrestore(&q->lock, flags);
-}
-EXPORT_SYMBOL(add_wait_queue);
-
-void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
-{
-	unsigned long flags;
-
-	wait->flags |= WQ_FLAG_EXCLUSIVE;
-	spin_lock_irqsave(&q->lock, flags);
-	__add_wait_queue_tail(q, wait);
-	spin_unlock_irqrestore(&q->lock, flags);
-}
-EXPORT_SYMBOL(add_wait_queue_exclusive);
-
-void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&q->lock, flags);
-	__remove_wait_queue(q, wait);
-	spin_unlock_irqrestore(&q->lock, flags);
-}
-EXPORT_SYMBOL(remove_wait_queue);
-
-
-/*
- * Note: we use "set_current_state()" _after_ the wait-queue add,
- * because we need a memory barrier there on SMP, so that any
- * wake-function that tests for the wait-queue being active
- * will be guaranteed to see waitqueue addition _or_ subsequent
- * tests in this thread will see the wakeup having taken place.
- *
- * The spin_unlock() itself is semi-permeable and only protects
- * one way (it only protects stuff inside the critical region and
- * stops them from bleeding out - it would still allow subsequent
- * loads to move into the critical region).
- */
-void
-prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state)
-{
-	unsigned long flags;
-
-	wait->flags &= ~WQ_FLAG_EXCLUSIVE;
-	spin_lock_irqsave(&q->lock, flags);
-	if (list_empty(&wait->task_list))
-		__add_wait_queue(q, wait);
-	set_current_state(state);
-	spin_unlock_irqrestore(&q->lock, flags);
-}
-EXPORT_SYMBOL(prepare_to_wait);
-
-void
-prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state)
-{
-	unsigned long flags;
-
-	wait->flags |= WQ_FLAG_EXCLUSIVE;
-	spin_lock_irqsave(&q->lock, flags);
-	if (list_empty(&wait->task_list))
-		__add_wait_queue_tail(q, wait);
-	set_current_state(state);
-	spin_unlock_irqrestore(&q->lock, flags);
-}
-EXPORT_SYMBOL(prepare_to_wait_exclusive);
-
-long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state)
-{
-	unsigned long flags;
-
-	if (signal_pending_state(state, current))
-		return -ERESTARTSYS;
-
-	wait->private = current;
-	wait->func = autoremove_wake_function;
-
-	spin_lock_irqsave(&q->lock, flags);
-	if (list_empty(&wait->task_list)) {
-		if (wait->flags & WQ_FLAG_EXCLUSIVE)
-			__add_wait_queue_tail(q, wait);
-		else
-			__add_wait_queue(q, wait);
-	}
-	set_current_state(state);
-	spin_unlock_irqrestore(&q->lock, flags);
-
-	return 0;
-}
-EXPORT_SYMBOL(prepare_to_wait_event);
-
-/**
- * finish_wait - clean up after waiting in a queue
- * @q: waitqueue waited on
- * @wait: wait descriptor
- *
- * Sets current thread back to running state and removes
- * the wait descriptor from the given waitqueue if still
- * queued.
- */
-void finish_wait(wait_queue_head_t *q, wait_queue_t *wait)
-{
-	unsigned long flags;
-
-	__set_current_state(TASK_RUNNING);
-	/*
-	 * We can check for list emptiness outside the lock
-	 * IFF:
-	 *  - we use the "careful" check that verifies both
-	 *    the next and prev pointers, so that there cannot
-	 *    be any half-pending updates in progress on other
-	 *    CPU's that we haven't seen yet (and that might
-	 *    still change the stack area.
-	 * and
-	 *  - all other users take the lock (ie we can only
-	 *    have _one_ other CPU that looks at or modifies
-	 *    the list).
-	 */
-	if (!list_empty_careful(&wait->task_list)) {
-		spin_lock_irqsave(&q->lock, flags);
-		list_del_init(&wait->task_list);
-		spin_unlock_irqrestore(&q->lock, flags);
-	}
-}
-EXPORT_SYMBOL(finish_wait);
-
-/**
- * abort_exclusive_wait - abort exclusive waiting in a queue
- * @q: waitqueue waited on
- * @wait: wait descriptor
- * @mode: runstate of the waiter to be woken
- * @key: key to identify a wait bit queue or %NULL
- *
- * Sets current thread back to running state and removes
- * the wait descriptor from the given waitqueue if still
- * queued.
- *
- * Wakes up the next waiter if the caller is concurrently
- * woken up through the queue.
- *
- * This prevents waiter starvation where an exclusive waiter
- * aborts and is woken up concurrently and no one wakes up
- * the next waiter.
- */
-void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
-			unsigned int mode, void *key)
-{
-	unsigned long flags;
-
-	__set_current_state(TASK_RUNNING);
-	spin_lock_irqsave(&q->lock, flags);
-	if (!list_empty(&wait->task_list))
-		list_del_init(&wait->task_list);
-	else if (waitqueue_active(q))
-		__wake_up_locked_key(q, mode, key);
-	spin_unlock_irqrestore(&q->lock, flags);
-}
-EXPORT_SYMBOL(abort_exclusive_wait);
-
-int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
-{
-	int ret = default_wake_function(wait, mode, sync, key);
-
-	if (ret)
-		list_del_init(&wait->task_list);
-	return ret;
-}
-EXPORT_SYMBOL(autoremove_wake_function);
-
-int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *arg)
-{
-	struct wait_bit_key *key = arg;
-	struct wait_bit_queue *wait_bit
-		= container_of(wait, struct wait_bit_queue, wait);
-
-	if (wait_bit->key.flags != key->flags ||
-			wait_bit->key.bit_nr != key->bit_nr ||
-			test_bit(key->bit_nr, key->flags))
-		return 0;
-	else
-		return autoremove_wake_function(wait, mode, sync, key);
-}
-EXPORT_SYMBOL(wake_bit_function);
-
-/*
- * To allow interruptible waiting and asynchronous (i.e. nonblocking)
- * waiting, the actions of __wait_on_bit() and __wait_on_bit_lock() are
- * permitted return codes. Nonzero return codes halt waiting and return.
- */
-int __sched
-__wait_on_bit(wait_queue_head_t *wq, struct wait_bit_queue *q,
-			int (*action)(void *), unsigned mode)
-{
-	int ret = 0;
-
-	do {
-		prepare_to_wait(wq, &q->wait, mode);
-		if (test_bit(q->key.bit_nr, q->key.flags))
-			ret = (*action)(q->key.flags);
-	} while (test_bit(q->key.bit_nr, q->key.flags) && !ret);
-	finish_wait(wq, &q->wait);
-	return ret;
-}
-EXPORT_SYMBOL(__wait_on_bit);
-
-int __sched out_of_line_wait_on_bit(void *word, int bit,
-					int (*action)(void *), unsigned mode)
-{
-	wait_queue_head_t *wq = bit_waitqueue(word, bit);
-	DEFINE_WAIT_BIT(wait, word, bit);
-
-	return __wait_on_bit(wq, &wait, action, mode);
-}
-EXPORT_SYMBOL(out_of_line_wait_on_bit);
-
-int __sched
-__wait_on_bit_lock(wait_queue_head_t *wq, struct wait_bit_queue *q,
-			int (*action)(void *), unsigned mode)
-{
-	do {
-		int ret;
-
-		prepare_to_wait_exclusive(wq, &q->wait, mode);
-		if (!test_bit(q->key.bit_nr, q->key.flags))
-			continue;
-		ret = action(q->key.flags);
-		if (!ret)
-			continue;
-		abort_exclusive_wait(wq, &q->wait, mode, &q->key);
-		return ret;
-	} while (test_and_set_bit(q->key.bit_nr, q->key.flags));
-	finish_wait(wq, &q->wait);
-	return 0;
-}
-EXPORT_SYMBOL(__wait_on_bit_lock);
-
-int __sched out_of_line_wait_on_bit_lock(void *word, int bit,
-					int (*action)(void *), unsigned mode)
-{
-	wait_queue_head_t *wq = bit_waitqueue(word, bit);
-	DEFINE_WAIT_BIT(wait, word, bit);
-
-	return __wait_on_bit_lock(wq, &wait, action, mode);
-}
-EXPORT_SYMBOL(out_of_line_wait_on_bit_lock);
-
-void __wake_up_bit(wait_queue_head_t *wq, void *word, int bit)
-{
-	struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit);
-	if (waitqueue_active(wq))
-		__wake_up(wq, TASK_NORMAL, 1, &key);
-}
-EXPORT_SYMBOL(__wake_up_bit);
-
-/**
- * wake_up_bit - wake up a waiter on a bit
- * @word: the word being waited on, a kernel virtual address
- * @bit: the bit of the word being waited on
- *
- * There is a standard hashed waitqueue table for generic use. This
- * is the part of the hashtable's accessor API that wakes up waiters
- * on a bit. For instance, if one were to have waiters on a bitflag,
- * one would call wake_up_bit() after clearing the bit.
- *
- * In order for this to function properly, as it uses waitqueue_active()
- * internally, some kind of memory barrier must be done prior to calling
- * this. Typically, this will be smp_mb__after_clear_bit(), but in some
- * cases where bitflags are manipulated non-atomically under a lock, one
- * may need to use a less regular barrier, such fs/inode.c's smp_mb(),
- * because spin_unlock() does not guarantee a memory barrier.
- */
-void wake_up_bit(void *word, int bit)
-{
-	__wake_up_bit(bit_waitqueue(word, bit), word, bit);
-}
-EXPORT_SYMBOL(wake_up_bit);
-
-wait_queue_head_t *bit_waitqueue(void *word, int bit)
-{
-	const int shift = BITS_PER_LONG == 32 ? 5 : 6;
-	const struct zone *zone = page_zone(virt_to_page(word));
-	unsigned long val = (unsigned long)word << shift | bit;
-
-	return &zone->wait_table[hash_long(val, zone->wait_table_bits)];
-}
-EXPORT_SYMBOL(bit_waitqueue);
-
-/*
- * Manipulate the atomic_t address to produce a better bit waitqueue table hash
- * index (we're keying off bit -1, but that would produce a horrible hash
- * value).
- */
-static inline wait_queue_head_t *atomic_t_waitqueue(atomic_t *p)
-{
-	if (BITS_PER_LONG == 64) {
-		unsigned long q = (unsigned long)p;
-		return bit_waitqueue((void *)(q & ~1), q & 1);
-	}
-	return bit_waitqueue(p, 0);
-}
-
-static int wake_atomic_t_function(wait_queue_t *wait, unsigned mode, int sync,
-				  void *arg)
-{
-	struct wait_bit_key *key = arg;
-	struct wait_bit_queue *wait_bit
-		= container_of(wait, struct wait_bit_queue, wait);
-	atomic_t *val = key->flags;
-
-	if (wait_bit->key.flags != key->flags ||
-	    wait_bit->key.bit_nr != key->bit_nr ||
-	    atomic_read(val) != 0)
-		return 0;
-	return autoremove_wake_function(wait, mode, sync, key);
-}
-
-/*
- * To allow interruptible waiting and asynchronous (i.e. nonblocking) waiting,
- * the actions of __wait_on_atomic_t() are permitted return codes.  Nonzero
- * return codes halt waiting and return.
- */
-static __sched
-int __wait_on_atomic_t(wait_queue_head_t *wq, struct wait_bit_queue *q,
-		       int (*action)(atomic_t *), unsigned mode)
-{
-	atomic_t *val;
-	int ret = 0;
-
-	do {
-		prepare_to_wait(wq, &q->wait, mode);
-		val = q->key.flags;
-		if (atomic_read(val) == 0)
-			break;
-		ret = (*action)(val);
-	} while (!ret && atomic_read(val) != 0);
-	finish_wait(wq, &q->wait);
-	return ret;
-}
-
-#define DEFINE_WAIT_ATOMIC_T(name, p)					\
-	struct wait_bit_queue name = {					\
-		.key = __WAIT_ATOMIC_T_KEY_INITIALIZER(p),		\
-		.wait	= {						\
-			.private	= current,			\
-			.func		= wake_atomic_t_function,	\
-			.task_list	=				\
-				LIST_HEAD_INIT((name).wait.task_list),	\
-		},							\
-	}
-
-__sched int out_of_line_wait_on_atomic_t(atomic_t *p, int (*action)(atomic_t *),
-					 unsigned mode)
-{
-	wait_queue_head_t *wq = atomic_t_waitqueue(p);
-	DEFINE_WAIT_ATOMIC_T(wait, p);
-
-	return __wait_on_atomic_t(wq, &wait, action, mode);
-}
-EXPORT_SYMBOL(out_of_line_wait_on_atomic_t);
-
-/**
- * wake_up_atomic_t - Wake up a waiter on a atomic_t
- * @p: The atomic_t being waited on, a kernel virtual address
- *
- * Wake up anyone waiting for the atomic_t to go to zero.
- *
- * Abuse the bit-waker function and its waitqueue hash table set (the atomic_t
- * check is done by the waiter's wake function, not the by the waker itself).
- */
-void wake_up_atomic_t(atomic_t *p)
-{
-	__wake_up_bit(atomic_t_waitqueue(p), p, WAIT_ATOMIC_T_BIT_NR);
-}
-EXPORT_SYMBOL(wake_up_atomic_t);