23 int rwsem_is_locked(struct rw_semaphore *sem)  in rwsem_is_locked()  argument
28 	if (raw_spin_trylock_irqsave(&sem->wait_lock, flags)) {  in rwsem_is_locked()
29 		ret = (sem->count != 0);  in rwsem_is_locked()
30 		raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in rwsem_is_locked()
39 void __init_rwsem(struct rw_semaphore *sem, const char *name,  in __init_rwsem()  argument
46 	debug_check_no_locks_freed((void *)sem, sizeof(*sem));  in __init_rwsem()
47 	lockdep_init_map(&sem->dep_map, name, key, 0);  in __init_rwsem()
49 	sem->count = 0;  in __init_rwsem()
50 	raw_spin_lock_init(&sem->wait_lock);  in __init_rwsem()
51 	INIT_LIST_HEAD(&sem->wait_list);  in __init_rwsem()
65 __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)  in __rwsem_do_wake()  argument
71 	waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);  in __rwsem_do_wake()
100 		if (next == &sem->wait_list)  in __rwsem_do_wake()
105 	sem->count += woken;  in __rwsem_do_wake()
108 	return sem;  in __rwsem_do_wake()
115 __rwsem_wake_one_writer(struct rw_semaphore *sem)  in __rwsem_wake_one_writer()  argument
119 	waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);  in __rwsem_wake_one_writer()
122 	return sem;  in __rwsem_wake_one_writer()
128 void __sched __down_read(struct rw_semaphore *sem)  in __down_read()  argument
134 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_read()
136 	if (sem->count >= 0 && list_empty(&sem->wait_list)) {  in __down_read()
138 		sem->count++;  in __down_read()
139 		raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_read()
151 	list_add_tail(&waiter.list, &sem->wait_list);  in __down_read()
154 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_read()
172 int __down_read_trylock(struct rw_semaphore *sem)  in __down_read_trylock()  argument
178 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_read_trylock()
180 	if (sem->count >= 0 && list_empty(&sem->wait_list)) {  in __down_read_trylock()
182 		sem->count++;  in __down_read_trylock()
186 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_read_trylock()
194 void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)  in __down_write_nested()  argument
200 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_write_nested()
206 	list_add_tail(&waiter.list, &sem->wait_list);  in __down_write_nested()
216 		if (sem->count == 0)  in __down_write_nested()
219 		raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_write_nested()
221 		raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_write_nested()
224 	sem->count = -1;  in __down_write_nested()
227 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_write_nested()
230 void __sched __down_write(struct rw_semaphore *sem)  in __down_write()  argument
232 	__down_write_nested(sem, 0);  in __down_write()
238 int __down_write_trylock(struct rw_semaphore *sem)  in __down_write_trylock()  argument
243 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __down_write_trylock()
245 	if (sem->count == 0) {  in __down_write_trylock()
247 		sem->count = -1;  in __down_write_trylock()
251 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __down_write_trylock()
259 void __up_read(struct rw_semaphore *sem)  in __up_read()  argument
263 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __up_read()
265 	if (--sem->count == 0 && !list_empty(&sem->wait_list))  in __up_read()
266 		sem = __rwsem_wake_one_writer(sem);  in __up_read()
268 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __up_read()
274 void __up_write(struct rw_semaphore *sem)  in __up_write()  argument
278 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __up_write()
280 	sem->count = 0;  in __up_write()
281 	if (!list_empty(&sem->wait_list))  in __up_write()
282 		sem = __rwsem_do_wake(sem, 1);  in __up_write()
284 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __up_write()
291 void __downgrade_write(struct rw_semaphore *sem)  in __downgrade_write()  argument
295 	raw_spin_lock_irqsave(&sem->wait_lock, flags);  in __downgrade_write()
297 	sem->count = 1;  in __downgrade_write()
298 	if (!list_empty(&sem->wait_list))  in __downgrade_write()
299 		sem = __rwsem_do_wake(sem, 0);  in __downgrade_write()
301 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);  in __downgrade_write()