#include <linux/init.h>
#include <linux/module.h>
+/*
+ * Initialize an rwsem:
+ */
+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->count = RWSEM_UNLOCKED_VALUE;
+ spin_lock_init(&sem->wait_lock);
+ INIT_LIST_HEAD(&sem->wait_list);
+}
+
+EXPORT_SYMBOL(__init_rwsem);
+
struct rwsem_waiter {
struct list_head list;
struct task_struct *task;
#define RWSEM_WAITING_FOR_WRITE 0x00000002
};
-#if RWSEM_DEBUG
-#undef rwsemtrace
-void rwsemtrace(struct rw_semaphore *sem, const char *str)
-{
- printk("sem=%p\n", sem);
- printk("(sem)=%08lx\n", sem->count);
- if (sem->debug)
- printk("[%d] %s({%08lx})\n", current->pid, str, sem->count);
-}
-#endif
-
/*
* handle the lock release when processes blocked on it that can now run
* - if we come here from up_xxxx(), then:
struct list_head *next;
signed long oldcount, woken, loop;
- rwsemtrace(sem, "Entering __rwsem_do_wake");
-
if (downgrading)
goto dont_wake_writers;
next->prev = &sem->wait_list;
out:
- rwsemtrace(sem, "Leaving __rwsem_do_wake");
return sem;
/* undo the change to count, but check for a transition 1->0 */
/*
* wait for a lock to be granted
*/
-static inline struct rw_semaphore *
+static struct rw_semaphore __sched *
rwsem_down_failed_common(struct rw_semaphore *sem,
struct rwsem_waiter *waiter, signed long adjustment)
{
{
struct rwsem_waiter waiter;
- rwsemtrace(sem, "Entering rwsem_down_read_failed");
-
waiter.flags = RWSEM_WAITING_FOR_READ;
rwsem_down_failed_common(sem, &waiter,
RWSEM_WAITING_BIAS - RWSEM_ACTIVE_BIAS);
-
- rwsemtrace(sem, "Leaving rwsem_down_read_failed");
return sem;
}
{
struct rwsem_waiter waiter;
- rwsemtrace(sem, "Entering rwsem_down_write_failed");
-
waiter.flags = RWSEM_WAITING_FOR_WRITE;
rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_BIAS);
- rwsemtrace(sem, "Leaving rwsem_down_write_failed");
return sem;
}
{
unsigned long flags;
- rwsemtrace(sem, "Entering rwsem_wake");
-
spin_lock_irqsave(&sem->wait_lock, flags);
/* do nothing if list empty */
spin_unlock_irqrestore(&sem->wait_lock, flags);
- rwsemtrace(sem, "Leaving rwsem_wake");
-
return sem;
}
{
unsigned long flags;
- rwsemtrace(sem, "Entering rwsem_downgrade_wake");
-
spin_lock_irqsave(&sem->wait_lock, flags);
/* do nothing if list empty */
spin_unlock_irqrestore(&sem->wait_lock, flags);
- rwsemtrace(sem, "Leaving rwsem_downgrade_wake");
return sem;
}
EXPORT_SYMBOL(rwsem_down_write_failed);
EXPORT_SYMBOL(rwsem_wake);
EXPORT_SYMBOL(rwsem_downgrade_wake);
-#if RWSEM_DEBUG
-EXPORT_SYMBOL(rwsemtrace);
-#endif