1 files changed, 0 insertions, 498 deletions
diff --git a/kernel/mutex.c b/kernel/mutex.c
deleted file mode 100644
index 200407c1502..00000000000
--- a/kernel/mutex.c
+++ /dev/null
@@ -1,498 +0,0 @@
-/*
- * kernel/mutex.c
- *
- * Mutexes: blocking mutual exclusion locks
- *
- * Started by Ingo Molnar:
- *
- *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- *
- * Many thanks to Arjan van de Ven, Thomas Gleixner, Steven Rostedt and
- * David Howells for suggestions and improvements.
- *
- *  - Adaptive spinning for mutexes by Peter Zijlstra. (Ported to mainline
- *    from the -rt tree, where it was originally implemented for rtmutexes
- *    by Steven Rostedt, based on work by Gregory Haskins, Peter Morreale
- *    and Sven Dietrich.
- *
- * Also see Documentation/mutex-design.txt.
- */
-#include <linux/mutex.h>
-#include <linux/sched.h>
-#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <linux/interrupt.h>
-#include <linux/debug_locks.h>
-
-/*
- * In the DEBUG case we are using the "NULL fastpath" for mutexes,
- * which forces all calls into the slowpath:
- */
-#ifdef CONFIG_DEBUG_MUTEXES
-# include "mutex-debug.h"
-# include <asm-generic/mutex-null.h>
-#else
-# include "mutex.h"
-# include <asm/mutex.h>
-#endif
-
-void
-__mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
-{
-	atomic_set(&lock->count, 1);
-	spin_lock_init(&lock->wait_lock);
-	INIT_LIST_HEAD(&lock->wait_list);
-	mutex_clear_owner(lock);
-
-	debug_mutex_init(lock, name, key);
-}
-
-EXPORT_SYMBOL(__mutex_init);
-
-#ifndef CONFIG_DEBUG_LOCK_ALLOC
-/*
- * We split the mutex lock/unlock logic into separate fastpath and
- * slowpath functions, to reduce the register pressure on the fastpath.
- * We also put the fastpath first in the kernel image, to make sure the
- * branch is predicted by the CPU as default-untaken.
- */
-static __used noinline void __sched
-__mutex_lock_slowpath(atomic_t *lock_count);
-
-/**
- * mutex_lock - acquire the mutex
- * @lock: the mutex to be acquired
- *
- * Lock the mutex exclusively for this task. If the mutex is not
- * available right now, it will sleep until it can get it.
- *
- * The mutex must later on be released by the same task that
- * acquired it. Recursive locking is not allowed. The task
- * may not exit without first unlocking the mutex. Also, kernel
- * memory where the mutex resides mutex must not be freed with
- * the mutex still locked. The mutex must first be initialized
- * (or statically defined) before it can be locked. memset()-ing
- * the mutex to 0 is not allowed.
- *
- * ( The CONFIG_DEBUG_MUTEXES .config option turns on debugging
- *   checks that will enforce the restrictions and will also do
- *   deadlock debugging. )
- *
- * This function is similar to (but not equivalent to) down().
- */
-void __sched mutex_lock(struct mutex *lock)
-{
-	might_sleep();
-	/*
-	 * The locking fastpath is the 1->0 transition from
-	 * 'unlocked' into 'locked' state.
-	 */
-	__mutex_fastpath_lock(&lock->count, __mutex_lock_slowpath);
-	mutex_set_owner(lock);
-}
-
-EXPORT_SYMBOL(mutex_lock);
-#endif
-
-static __used noinline void __sched __mutex_unlock_slowpath(atomic_t *lock_count);
-
-/**
- * mutex_unlock - release the mutex
- * @lock: the mutex to be released
- *
- * Unlock a mutex that has been locked by this task previously.
- *
- * This function must not be used in interrupt context. Unlocking
- * of a not locked mutex is not allowed.
- *
- * This function is similar to (but not equivalent to) up().
- */
-void __sched mutex_unlock(struct mutex *lock)
-{
-	/*
-	 * The unlocking fastpath is the 0->1 transition from 'locked'
-	 * into 'unlocked' state:
-	 */
-#ifndef CONFIG_DEBUG_MUTEXES
-	/*
-	 * When debugging is enabled we must not clear the owner before time,
-	 * the slow path will always be taken, and that clears the owner field
-	 * after verifying that it was indeed current.
-	 */
-	mutex_clear_owner(lock);
-#endif
-	__mutex_fastpath_unlock(&lock->count, __mutex_unlock_slowpath);
-}
-
-EXPORT_SYMBOL(mutex_unlock);
-
-/*
- * Lock a mutex (possibly interruptible), slowpath:
- */
-static inline int __sched
-__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
-	       	unsigned long ip)
-{
-	struct task_struct *task = current;
-	struct mutex_waiter waiter;
-	unsigned long flags;
-
-	preempt_disable();
-	mutex_acquire(&lock->dep_map, subclass, 0, ip);
-
-#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
-	/*
-	 * Optimistic spinning.
-	 *
-	 * We try to spin for acquisition when we find that there are no
-	 * pending waiters and the lock owner is currently running on a
-	 * (different) CPU.
-	 *
-	 * The rationale is that if the lock owner is running, it is likely to
-	 * release the lock soon.
-	 *
-	 * Since this needs the lock owner, and this mutex implementation
-	 * doesn't track the owner atomically in the lock field, we need to
-	 * track it non-atomically.
-	 *
-	 * We can't do this for DEBUG_MUTEXES because that relies on wait_lock
-	 * to serialize everything.
-	 */
-
-	for (;;) {
-		struct thread_info *owner;
-
-		/*
-		 * If we own the BKL, then don't spin. The owner of
-		 * the mutex might be waiting on us to release the BKL.
-		 */
-		if (unlikely(current->lock_depth >= 0))
-			break;
-
-		/*
-		 * If there's an owner, wait for it to either
-		 * release the lock or go to sleep.
-		 */
-		owner = ACCESS_ONCE(lock->owner);
-		if (owner && !mutex_spin_on_owner(lock, owner))
-			break;
-
-		if (atomic_cmpxchg(&lock->count, 1, 0) == 1) {
-			lock_acquired(&lock->dep_map, ip);
-			mutex_set_owner(lock);
-			preempt_enable();
-			return 0;
-		}
-
-		/*
-		 * When there's no owner, we might have preempted between the
-		 * owner acquiring the lock and setting the owner field. If
-		 * we're an RT task that will live-lock because we won't let
-		 * the owner complete.
-		 */
-		if (!owner && (need_resched() || rt_task(task)))
-			break;
-
-		/*
-		 * The cpu_relax() call is a compiler barrier which forces
-		 * everything in this loop to be re-loaded. We don't need
-		 * memory barriers as we'll eventually observe the right
-		 * values at the cost of a few extra spins.
-		 */
-		cpu_relax();
-	}
-#endif
-	spin_lock_mutex(&lock->wait_lock, flags);
-
-	debug_mutex_lock_common(lock, &waiter);
-	debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));
-
-	/* add waiting tasks to the end of the waitqueue (FIFO): */
-	list_add_tail(&waiter.list, &lock->wait_list);
-	waiter.task = task;
-
-	if (atomic_xchg(&lock->count, -1) == 1)
-		goto done;
-
-	lock_contended(&lock->dep_map, ip);
-
-	for (;;) {
-		/*
-		 * Lets try to take the lock again - this is needed even if
-		 * we get here for the first time (shortly after failing to
-		 * acquire the lock), to make sure that we get a wakeup once
-		 * it's unlocked. Later on, if we sleep, this is the
-		 * operation that gives us the lock. We xchg it to -1, so
-		 * that when we release the lock, we properly wake up the
-		 * other waiters:
-		 */
-		if (atomic_xchg(&lock->count, -1) == 1)
-			break;
-
-		/*
-		 * got a signal? (This code gets eliminated in the
-		 * TASK_UNINTERRUPTIBLE case.)
-		 */
-		if (unlikely(signal_pending_state(state, task))) {
-			mutex_remove_waiter(lock, &waiter,
-					    task_thread_info(task));
-			mutex_release(&lock->dep_map, 1, ip);
-			spin_unlock_mutex(&lock->wait_lock, flags);
-
-			debug_mutex_free_waiter(&waiter);
-			preempt_enable();
-			return -EINTR;
-		}
-		__set_task_state(task, state);
-
-		/* didnt get the lock, go to sleep: */
-		spin_unlock_mutex(&lock->wait_lock, flags);
-		preempt_enable_no_resched();
-		schedule();
-		preempt_disable();
-		spin_lock_mutex(&lock->wait_lock, flags);
-	}
-
-done:
-	lock_acquired(&lock->dep_map, ip);
-	/* got the lock - rejoice! */
-	mutex_remove_waiter(lock, &waiter, current_thread_info());
-	mutex_set_owner(lock);
-
-	/* set it to 0 if there are no waiters left: */
-	if (likely(list_empty(&lock->wait_list)))
-		atomic_set(&lock->count, 0);
-
-	spin_unlock_mutex(&lock->wait_lock, flags);
-
-	debug_mutex_free_waiter(&waiter);
-	preempt_enable();
-
-	return 0;
-}
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-void __sched
-mutex_lock_nested(struct mutex *lock, unsigned int subclass)
-{
-	might_sleep();
-	__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, _RET_IP_);
-}
-
-EXPORT_SYMBOL_GPL(mutex_lock_nested);
-
-int __sched
-mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass)
-{
-	might_sleep();
-	return __mutex_lock_common(lock, TASK_KILLABLE, subclass, _RET_IP_);
-}
-EXPORT_SYMBOL_GPL(mutex_lock_killable_nested);
-
-int __sched
-mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
-{
-	might_sleep();
-	return __mutex_lock_common(lock, TASK_INTERRUPTIBLE,
-				   subclass, _RET_IP_);
-}
-
-EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
-#endif
-
-/*
- * Release the lock, slowpath:
- */
-static inline void
-__mutex_unlock_common_slowpath(atomic_t *lock_count, int nested)
-{
-	struct mutex *lock = container_of(lock_count, struct mutex, count);
-	unsigned long flags;
-
-	spin_lock_mutex(&lock->wait_lock, flags);
-	mutex_release(&lock->dep_map, nested, _RET_IP_);
-	debug_mutex_unlock(lock);
-
-	/*
-	 * some architectures leave the lock unlocked in the fastpath failure
-	 * case, others need to leave it locked. In the later case we have to
-	 * unlock it here
-	 */
-	if (__mutex_slowpath_needs_to_unlock())
-		atomic_set(&lock->count, 1);
-
-	if (!list_empty(&lock->wait_list)) {
-		/* get the first entry from the wait-list: */
-		struct mutex_waiter *waiter =
-				list_entry(lock->wait_list.next,
-					   struct mutex_waiter, list);
-
-		debug_mutex_wake_waiter(lock, waiter);
-
-		wake_up_process(waiter->task);
-	}
-
-	spin_unlock_mutex(&lock->wait_lock, flags);
-}
-
-/*
- * Release the lock, slowpath:
- */
-static __used noinline void
-__mutex_unlock_slowpath(atomic_t *lock_count)
-{
-	__mutex_unlock_common_slowpath(lock_count, 1);
-}
-
-#ifndef CONFIG_DEBUG_LOCK_ALLOC
-/*
- * Here come the less common (and hence less performance-critical) APIs:
- * mutex_lock_interruptible() and mutex_trylock().
- */
-static noinline int __sched
-__mutex_lock_killable_slowpath(atomic_t *lock_count);
-
-static noinline int __sched
-__mutex_lock_interruptible_slowpath(atomic_t *lock_count);
-
-/**
- * mutex_lock_interruptible - acquire the mutex, interruptible
- * @lock: the mutex to be acquired
- *
- * Lock the mutex like mutex_lock(), and return 0 if the mutex has
- * been acquired or sleep until the mutex becomes available. If a
- * signal arrives while waiting for the lock then this function
- * returns -EINTR.
- *
- * This function is similar to (but not equivalent to) down_interruptible().
- */
-int __sched mutex_lock_interruptible(struct mutex *lock)
-{
-	int ret;
-
-	might_sleep();
-	ret =  __mutex_fastpath_lock_retval
-			(&lock->count, __mutex_lock_interruptible_slowpath);
-	if (!ret)
-		mutex_set_owner(lock);
-
-	return ret;
-}
-
-EXPORT_SYMBOL(mutex_lock_interruptible);
-
-int __sched mutex_lock_killable(struct mutex *lock)
-{
-	int ret;
-
-	might_sleep();
-	ret = __mutex_fastpath_lock_retval
-			(&lock->count, __mutex_lock_killable_slowpath);
-	if (!ret)
-		mutex_set_owner(lock);
-
-	return ret;
-}
-EXPORT_SYMBOL(mutex_lock_killable);
-
-static __used noinline void __sched
-__mutex_lock_slowpath(atomic_t *lock_count)
-{
-	struct mutex *lock = container_of(lock_count, struct mutex, count);
-
-	__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, _RET_IP_);
-}
-
-static noinline int __sched
-__mutex_lock_killable_slowpath(atomic_t *lock_count)
-{
-	struct mutex *lock = container_of(lock_count, struct mutex, count);
-
-	return __mutex_lock_common(lock, TASK_KILLABLE, 0, _RET_IP_);
-}
-
-static noinline int __sched
-__mutex_lock_interruptible_slowpath(atomic_t *lock_count)
-{
-	struct mutex *lock = container_of(lock_count, struct mutex, count);
-
-	return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0, _RET_IP_);
-}
-#endif
-
-/*
- * Spinlock based trylock, we take the spinlock and check whether we
- * can get the lock:
- */
-static inline int __mutex_trylock_slowpath(atomic_t *lock_count)
-{
-	struct mutex *lock = container_of(lock_count, struct mutex, count);
-	unsigned long flags;
-	int prev;
-
-	spin_lock_mutex(&lock->wait_lock, flags);
-
-	prev = atomic_xchg(&lock->count, -1);
-	if (likely(prev == 1)) {
-		mutex_set_owner(lock);
-		mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
-	}
-
-	/* Set it back to 0 if there are no waiters: */
-	if (likely(list_empty(&lock->wait_list)))
-		atomic_set(&lock->count, 0);
-
-	spin_unlock_mutex(&lock->wait_lock, flags);
-
-	return prev == 1;
-}
-
-/**
- * mutex_trylock - try to acquire the mutex, without waiting
- * @lock: the mutex to be acquired
- *
- * Try to acquire the mutex atomically. Returns 1 if the mutex
- * has been acquired successfully, and 0 on contention.
- *
- * NOTE: this function follows the spin_trylock() convention, so
- * it is negated from the down_trylock() return values! Be careful
- * about this when converting semaphore users to mutexes.
- *
- * This function must not be used in interrupt context. The
- * mutex must be released by the same task that acquired it.
- */
-int __sched mutex_trylock(struct mutex *lock)
-{
-	int ret;
-
-	ret = __mutex_fastpath_trylock(&lock->count, __mutex_trylock_slowpath);
-	if (ret)
-		mutex_set_owner(lock);
-
-	return ret;
-}
-EXPORT_SYMBOL(mutex_trylock);
-
-/**
- * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
- * @cnt: the atomic which we are to dec
- * @lock: the mutex to return holding if we dec to 0
- *
- * return true and hold lock if we dec to 0, return false otherwise
- */
-int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
-{
-	/* dec if we can't possibly hit 0 */
-	if (atomic_add_unless(cnt, -1, 1))
-		return 0;
-	/* we might hit 0, so take the lock */
-	mutex_lock(lock);
-	if (!atomic_dec_and_test(cnt)) {
-		/* when we actually did the dec, we didn't hit 0 */
-		mutex_unlock(lock);
-		return 0;
-	}
-	/* we hit 0, and we hold the lock */
-	return 1;
-}
-EXPORT_SYMBOL(atomic_dec_and_mutex_lock);