25 int rwsem_is_locked(struct rw_semaphore *sem)  in rwsem_is_locked()  argument
30 	if (raw_spin_trylock_irqsave(&sem->wait_lock, flags)) {  in rwsem_is_locked()
31 		ret = (sem->count != 0);  in rwsem_is_locked()
32 		raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in rwsem_is_locked()
41 void __init_rwsem(struct rw_semaphore *sem, const char *name,  in __init_rwsem()  argument
48 	debug_check_no_locks_freed((void *)sem, sizeof(*sem));  in __init_rwsem()
49 	lockdep_init_map(&sem->dep_map, name, key, 0);  in __init_rwsem()
51 	sem->count = 0;  in __init_rwsem()
52 	raw_spin_lock_init(&sem->wait_lock);  in __init_rwsem()
53 	INIT_LIST_HEAD(&sem->wait_list);  in __init_rwsem()
67 __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)  in __rwsem_do_wake()  argument
73 	waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);  in __rwsem_do_wake()
102 		if (next == &sem->wait_list)  in __rwsem_do_wake()
107 	sem->count += woken;  in __rwsem_do_wake()
110 	return sem;  in __rwsem_do_wake()
117 __rwsem_wake_one_writer(struct rw_semaphore *sem)  in __rwsem_wake_one_writer()  argument
121 	waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);  in __rwsem_wake_one_writer()
124 	return sem;  in __rwsem_wake_one_writer()
130 int __sched __down_read_common(struct rw_semaphore *sem, int state)  in __down_read_common()  argument
135 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_read_common()
137 	if (sem->count >= 0 && list_empty(&sem->wait_list)) {  in __down_read_common()
139 		sem->count++;  in __down_read_common()
140 		raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_read_common()
149 	list_add_tail(&waiter.list, &sem->wait_list);  in __down_read_common()
158 		raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_read_common()
160 		raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_read_common()
163 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_read_common()
174 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_read_common()
178 void __sched __down_read(struct rw_semaphore *sem)  in __down_read()  argument
180 	__down_read_common(sem, TASK_UNINTERRUPTIBLE);  in __down_read()
183 int __sched __down_read_killable(struct rw_semaphore *sem)  in __down_read_killable()  argument
185 	return __down_read_common(sem, TASK_KILLABLE);  in __down_read_killable()
191 int __down_read_trylock(struct rw_semaphore *sem)  in __down_read_trylock()  argument
197 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_read_trylock()
199 	if (sem->count >= 0 && list_empty(&sem->wait_list)) {  in __down_read_trylock()
201 		sem->count++;  in __down_read_trylock()
205 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_read_trylock()
213 int __sched __down_write_common(struct rw_semaphore *sem, int state)  in __down_write_common()  argument
219 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_write_common()
224 	list_add_tail(&waiter.list, &sem->wait_list);  in __down_write_common()
234 		if (sem->count == 0)  in __down_write_common()
240 		raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_write_common()
242 		raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_write_common()
245 	sem->count = -1;  in __down_write_common()
248 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_write_common()
254 	if (!list_empty(&sem->wait_list) && sem->count >= 0)  in __down_write_common()
255 		__rwsem_do_wake(sem, 0);  in __down_write_common()
256 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_write_common()
261 void __sched __down_write(struct rw_semaphore *sem)  in __down_write()  argument
263 	__down_write_common(sem, TASK_UNINTERRUPTIBLE);  in __down_write()
266 int __sched __down_write_killable(struct rw_semaphore *sem)  in __down_write_killable()  argument
268 	return __down_write_common(sem, TASK_KILLABLE);  in __down_write_killable()
274 int __down_write_trylock(struct rw_semaphore *sem)  in __down_write_trylock()  argument
279 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_write_trylock()
281 	if (sem->count == 0) {  in __down_write_trylock()
283 		sem->count = -1;  in __down_write_trylock()
287 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_write_trylock()
295 void __up_read(struct rw_semaphore *sem)  in __up_read()  argument
299 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __up_read()
301 	if (--sem->count == 0 && !list_empty(&sem->wait_list))  in __up_read()
302 		sem = __rwsem_wake_one_writer(sem);  in __up_read()
304 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __up_read()
310 void __up_write(struct rw_semaphore *sem)  in __up_write()  argument
314 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __up_write()
316 	sem->count = 0;  in __up_write()
317 	if (!list_empty(&sem->wait_list))  in __up_write()
318 		sem = __rwsem_do_wake(sem, 1);  in __up_write()
320 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __up_write()
327 void __downgrade_write(struct rw_semaphore *sem)  in __downgrade_write()  argument
331 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __downgrade_write()
333 	sem->count = 1;  in __downgrade_write()
334 	if (!list_empty(&sem->wait_list))  in __downgrade_write()
335 		sem = __rwsem_do_wake(sem, 0);  in __downgrade_write()
337 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __downgrade_write()