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author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2011-05-08 23:11:02 +0200 |
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committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2011-05-08 23:11:02 +0200 |
commit | cded208c7ea6d107dcbfdb2e2d4622daf41c2886 (patch) | |
tree | a04a03736b0a928c2954382f924aadb105ee39cc /libdde_linux26/contrib/kernel/.svn/text-base/mutex.c.svn-base | |
parent | fc82e00ca1e174cb961dea6ad37622e9b26cd899 (diff) |
remove .svn directories
Diffstat (limited to 'libdde_linux26/contrib/kernel/.svn/text-base/mutex.c.svn-base')
-rw-r--r-- | libdde_linux26/contrib/kernel/.svn/text-base/mutex.c.svn-base | 387 |
1 files changed, 0 insertions, 387 deletions
diff --git a/libdde_linux26/contrib/kernel/.svn/text-base/mutex.c.svn-base b/libdde_linux26/contrib/kernel/.svn/text-base/mutex.c.svn-base deleted file mode 100644 index 4f45d4b6..00000000 --- a/libdde_linux26/contrib/kernel/.svn/text-base/mutex.c.svn-base +++ /dev/null @@ -1,387 +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. - * - * 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 - -/*** - * mutex_init - initialize the mutex - * @lock: the mutex to be initialized - * @key: the lock_class_key for the class; used by mutex lock debugging - * - * Initialize the mutex to unlocked state. - * - * It is not allowed to initialize an already locked mutex. - */ -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); - - 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 inline __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); -} - -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: - */ - __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 int old_val; - unsigned long flags; - - spin_lock_mutex(&lock->wait_lock, flags); - - debug_mutex_lock_common(lock, &waiter); - mutex_acquire(&lock->dep_map, subclass, 0, ip); - 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; - - old_val = atomic_xchg(&lock->count, -1); - if (old_val == 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: - */ - old_val = atomic_xchg(&lock->count, -1); - if (old_val == 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); - return -EINTR; - } - __set_task_state(task, state); - - /* didnt get the lock, go to sleep: */ - spin_unlock_mutex(&lock->wait_lock, flags); - schedule(); - spin_lock_mutex(&lock->wait_lock, flags); - } - -done: - lock_acquired(&lock->dep_map, ip); - /* got the lock - rejoice! */ - mutex_remove_waiter(lock, &waiter, task_thread_info(task)); - debug_mutex_set_owner(lock, task_thread_info(task)); - - /* 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); - - 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); - } - - debug_mutex_clear_owner(lock); - - 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, interruptable - * @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) -{ - might_sleep(); - return __mutex_fastpath_lock_retval - (&lock->count, __mutex_lock_interruptible_slowpath); -} - -EXPORT_SYMBOL(mutex_lock_interruptible); - -int __sched mutex_lock_killable(struct mutex *lock) -{ - might_sleep(); - return __mutex_fastpath_lock_retval - (&lock->count, __mutex_lock_killable_slowpath); -} -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)) { - debug_mutex_set_owner(lock, current_thread_info()); - 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 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 to 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) -{ - return __mutex_fastpath_trylock(&lock->count, - __mutex_trylock_slowpath); -} - -EXPORT_SYMBOL(mutex_trylock); |