#define RWSEM_WAITING_FOR_WRITE 0x00000002
};
-#if RWSEM_DEBUG
-void rwsemtrace(struct rw_semaphore *sem, const char *str)
+int rwsem_is_locked(struct rw_semaphore *sem)
{
- if (sem->debug)
- printk("[%d] %s({%d,%d})\n",
- current->pid, str, sem->activity,
- list_empty(&sem->wait_list) ? 0 : 1);
+ int ret = 1;
+ unsigned long flags;
+
+ if (spin_trylock_irqsave(&sem->wait_lock, flags)) {
+ ret = (sem->activity != 0);
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
+ }
+ return ret;
}
-#endif
+EXPORT_SYMBOL(rwsem_is_locked);
/*
* 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
}
+EXPORT_SYMBOL(__init_rwsem);
/*
* handle the lock release when processes blocked on it that can now run
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) {
sem->activity += woken;
out:
- rwsemtrace(sem, "Leaving __rwsem_do_wake");
return sem;
}
/*
* get a read lock on the semaphore
*/
-void fastcall __sched __down_read(struct rw_semaphore *sem)
+void __sched __down_read(struct rw_semaphore *sem)
{
struct rwsem_waiter waiter;
struct task_struct *tsk;
+ unsigned long flags;
- rwsemtrace(sem, "Entering __down_read");
-
- spin_lock_irq(&sem->wait_lock);
+ spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
/* granted */
sem->activity++;
- spin_unlock_irq(&sem->wait_lock);
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
goto out;
}
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
- spin_unlock_irq(&sem->wait_lock);
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
/* wait to be given the lock */
for (;;) {
}
tsk->state = TASK_RUNNING;
-
out:
- rwsemtrace(sem, "Leaving __down_read");
+ ;
}
/*
* trylock for reading -- returns 1 if successful, 0 if contention
*/
-int fastcall __down_read_trylock(struct rw_semaphore *sem)
+int __down_read_trylock(struct rw_semaphore *sem)
{
unsigned long flags;
int ret = 0;
- rwsemtrace(sem, "Entering __down_read_trylock");
spin_lock_irqsave(&sem->wait_lock, flags);
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 __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
{
struct rwsem_waiter waiter;
struct task_struct *tsk;
+ unsigned long flags;
- rwsemtrace(sem, "Entering __down_write");
-
- spin_lock_irq(&sem->wait_lock);
+ spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->activity == 0 && list_empty(&sem->wait_list)) {
/* granted */
sem->activity = -1;
- spin_unlock_irq(&sem->wait_lock);
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
goto out;
}
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
- spin_unlock_irq(&sem->wait_lock);
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
/* wait to be given the lock */
for (;;) {
}
tsk->state = TASK_RUNNING;
-
out:
- rwsemtrace(sem, "Leaving __down_write");
+ ;
+}
+
+void __sched __down_write(struct rw_semaphore *sem)
+{
+ __down_write_nested(sem, 0);
}
/*
* trylock for writing -- returns 1 if successful, 0 if contention
*/
-int fastcall __down_write_trylock(struct rw_semaphore *sem)
+int __down_write_trylock(struct rw_semaphore *sem)
{
unsigned long flags;
int ret = 0;
- rwsemtrace(sem, "Entering __down_write_trylock");
-
spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->activity == 0 && list_empty(&sem->wait_list)) {
spin_unlock_irqrestore(&sem->wait_lock, flags);
- rwsemtrace(sem, "Leaving __down_write_trylock");
return ret;
}
/*
* release a read lock on the semaphore
*/
-void fastcall __up_read(struct rw_semaphore *sem)
+void __up_read(struct rw_semaphore *sem)
{
unsigned long flags;
- rwsemtrace(sem, "Entering __up_read");
-
spin_lock_irqsave(&sem->wait_lock, flags);
if (--sem->activity == 0 && !list_empty(&sem->wait_list))
sem = __rwsem_wake_one_writer(sem);
spin_unlock_irqrestore(&sem->wait_lock, flags);
-
- rwsemtrace(sem, "Leaving __up_read");
}
/*
* release a write lock on the semaphore
*/
-void fastcall __up_write(struct rw_semaphore *sem)
+void __up_write(struct rw_semaphore *sem)
{
unsigned long flags;
- rwsemtrace(sem, "Entering __up_write");
-
spin_lock_irqsave(&sem->wait_lock, flags);
sem->activity = 0;
sem = __rwsem_do_wake(sem, 1);
spin_unlock_irqrestore(&sem->wait_lock, flags);
-
- rwsemtrace(sem, "Leaving __up_write");
}
/*
* downgrade a write lock into a read lock
* - just wake up any readers at the front of the queue
*/
-void fastcall __downgrade_write(struct rw_semaphore *sem)
+void __downgrade_write(struct rw_semaphore *sem)
{
unsigned long flags;
- rwsemtrace(sem, "Entering __downgrade_write");
-
spin_lock_irqsave(&sem->wait_lock, flags);
sem->activity = 1;
sem = __rwsem_do_wake(sem, 0);
spin_unlock_irqrestore(&sem->wait_lock, flags);
-
- rwsemtrace(sem, "Leaving __downgrade_write");
}
-EXPORT_SYMBOL(init_rwsem);
-EXPORT_SYMBOL(__down_read);
-EXPORT_SYMBOL(__down_read_trylock);
-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://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff