#define RWSEM_WAITING_FOR_WRITE 0x00000002
};
-#if RWSEM_DEBUG
-void rwsemtrace(struct rw_semaphore *sem, const char *str)
-{
- if (sem->debug)
- printk("[%d] %s({%d,%d})\n",
- current->pid, str, sem->activity,
- list_empty(&sem->wait_list) ? 0 : 1);
-}
-#endif
-
/*
* initialise the semaphore
*/
-void fastcall init_rwsem(struct rw_semaphore *sem)
+void __init_rwsem(struct rw_semaphore *sem, const char *name,
+ struct lock_class_key *key)
{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held semaphore:
+ */
+ debug_check_no_locks_freed((void *)sem, sizeof(*sem));
+ lockdep_init_map(&sem->dep_map, name, key, 0);
+#endif
sem->activity = 0;
spin_lock_init(&sem->wait_lock);
INIT_LIST_HEAD(&sem->wait_list);
-#if RWSEM_DEBUG
- sem->debug = 0;
-#endif
}
/*
struct task_struct *tsk;
int woken;
- rwsemtrace(sem, "Entering __rwsem_do_wake");
-
waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
if (!wakewrite) {
list_del(&waiter->list);
tsk = waiter->task;
/* Don't touch waiter after ->task has been NULLed */
- mb();
+ smp_mb();
waiter->task = NULL;
wake_up_process(tsk);
put_task_struct(tsk);
list_del(&waiter->list);
tsk = waiter->task;
- mb();
+ smp_mb();
waiter->task = NULL;
wake_up_process(tsk);
put_task_struct(tsk);
sem->activity += woken;
out:
- rwsemtrace(sem, "Leaving __rwsem_do_wake");
return sem;
}
list_del(&waiter->list);
tsk = waiter->task;
- mb();
+ smp_mb();
waiter->task = NULL;
wake_up_process(tsk);
put_task_struct(tsk);
struct rwsem_waiter waiter;
struct task_struct *tsk;
- rwsemtrace(sem, "Entering __down_read");
-
- spin_lock(&sem->wait_lock);
+ spin_lock_irq(&sem->wait_lock);
if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
/* granted */
sem->activity++;
- spin_unlock(&sem->wait_lock);
+ spin_unlock_irq(&sem->wait_lock);
goto out;
}
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
- spin_unlock(&sem->wait_lock);
+ spin_unlock_irq(&sem->wait_lock);
/* wait to be given the lock */
for (;;) {
}
tsk->state = TASK_RUNNING;
-
out:
- rwsemtrace(sem, "Leaving __down_read");
+ ;
}
/*
*/
int fastcall __down_read_trylock(struct rw_semaphore *sem)
{
+ unsigned long flags;
int ret = 0;
- rwsemtrace(sem, "Entering __down_read_trylock");
- spin_lock(&sem->wait_lock);
+
+ spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
/* granted */
ret = 1;
}
- spin_unlock(&sem->wait_lock);
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
- rwsemtrace(sem, "Leaving __down_read_trylock");
return ret;
}
* get a write lock on the semaphore
* - we increment the waiting count anyway to indicate an exclusive lock
*/
-void fastcall __sched __down_write(struct rw_semaphore *sem)
+void fastcall __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
{
struct rwsem_waiter waiter;
struct task_struct *tsk;
- rwsemtrace(sem, "Entering __down_write");
-
- spin_lock(&sem->wait_lock);
+ spin_lock_irq(&sem->wait_lock);
if (sem->activity == 0 && list_empty(&sem->wait_list)) {
/* granted */
sem->activity = -1;
- spin_unlock(&sem->wait_lock);
+ spin_unlock_irq(&sem->wait_lock);
goto out;
}
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
- spin_unlock(&sem->wait_lock);
+ spin_unlock_irq(&sem->wait_lock);
/* wait to be given the lock */
for (;;) {
}
tsk->state = TASK_RUNNING;
-
out:
- rwsemtrace(sem, "Leaving __down_write");
+ ;
+}
+
+void fastcall __sched __down_write(struct rw_semaphore *sem)
+{
+ __down_write_nested(sem, 0);
}
/*
*/
int fastcall __down_write_trylock(struct rw_semaphore *sem)
{
+ unsigned long flags;
int ret = 0;
- rwsemtrace(sem, "Entering __down_write_trylock");
- spin_lock(&sem->wait_lock);
+ spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->activity == 0 && list_empty(&sem->wait_list)) {
/* granted */
ret = 1;
}
- spin_unlock(&sem->wait_lock);
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
- rwsemtrace(sem, "Leaving __down_write_trylock");
return ret;
}
*/
void fastcall __up_read(struct rw_semaphore *sem)
{
- rwsemtrace(sem, "Entering __up_read");
+ unsigned long flags;
- spin_lock(&sem->wait_lock);
+ spin_lock_irqsave(&sem->wait_lock, flags);
if (--sem->activity == 0 && !list_empty(&sem->wait_list))
sem = __rwsem_wake_one_writer(sem);
- spin_unlock(&sem->wait_lock);
-
- rwsemtrace(sem, "Leaving __up_read");
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
}
/*
*/
void fastcall __up_write(struct rw_semaphore *sem)
{
- rwsemtrace(sem, "Entering __up_write");
+ unsigned long flags;
- spin_lock(&sem->wait_lock);
+ spin_lock_irqsave(&sem->wait_lock, flags);
sem->activity = 0;
if (!list_empty(&sem->wait_list))
sem = __rwsem_do_wake(sem, 1);
- spin_unlock(&sem->wait_lock);
-
- rwsemtrace(sem, "Leaving __up_write");
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
}
/*
*/
void fastcall __downgrade_write(struct rw_semaphore *sem)
{
- rwsemtrace(sem, "Entering __downgrade_write");
+ unsigned long flags;
- spin_lock(&sem->wait_lock);
+ spin_lock_irqsave(&sem->wait_lock, flags);
sem->activity = 1;
if (!list_empty(&sem->wait_list))
sem = __rwsem_do_wake(sem, 0);
- spin_unlock(&sem->wait_lock);
-
- rwsemtrace(sem, "Leaving __downgrade_write");
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
}
-EXPORT_SYMBOL(init_rwsem);
+EXPORT_SYMBOL(__init_rwsem);
EXPORT_SYMBOL(__down_read);
EXPORT_SYMBOL(__down_read_trylock);
+EXPORT_SYMBOL(__down_write_nested);
EXPORT_SYMBOL(__down_write);
EXPORT_SYMBOL(__down_write_trylock);
EXPORT_SYMBOL(__up_read);
EXPORT_SYMBOL(__up_write);
EXPORT_SYMBOL(__downgrade_write);
-#if RWSEM_DEBUG
-EXPORT_SYMBOL(rwsemtrace);
-#endif
git://git.onelab.eu / linux-2.6.git / blobdiff