locking/mutex: Improve documentation

__mutex_lock_interruptible_slowpath(struct mutex *lock);

/**

 * mutex_lock_interruptible - acquire the mutex, interruptible

 * @lock: the mutex to be acquired

 * mutex_lock_interruptible() - Acquire the mutex, interruptible by signals.

 * @lock: The mutex to be acquired.

 *

 * Lock the mutex like mutex_lock(), and return 0 if the mutex has

 * been acquired or sleep until the mutex becomes available. If a

 * signal arrives while waiting for the lock then this function

 * returns -EINTR.

 * Lock the mutex like mutex_lock().  If a signal is delivered while the

 * process is sleeping, this function will return without acquiring the

 * mutex.

 *

 * This function is similar to (but not equivalent to) down_interruptible().

 * Context: Process context.

 * Return: 0 if the lock was successfully acquired or %-EINTR if a

 * signal arrived.

 */

int __sched mutex_lock_interruptible(struct mutex *lock)

{

EXPORT_SYMBOL(mutex_lock_interruptible);

/**

 * mutex_lock_killable() - Acquire the mutex, interruptible by fatal signals.

 * @lock: The mutex to be acquired.

 *

 * Lock the mutex like mutex_lock().  If a signal which will be fatal to

 * the current process is delivered while the process is sleeping, this

 * function will return without acquiring the mutex.

 *

 * Context: Process context.

 * Return: 0 if the lock was successfully acquired or %-EINTR if a

 * fatal signal arrived.

 */

int __sched mutex_lock_killable(struct mutex *lock)

{

	might_sleep();

}

EXPORT_SYMBOL(mutex_lock_killable);

/**

 * mutex_lock_io() - Acquire the mutex and mark the process as waiting for I/O

 * @lock: The mutex to be acquired.

 *

 * Lock the mutex like mutex_lock().  While the task is waiting for this

 * mutex, it will be accounted as being in the IO wait state by the

 * scheduler.

 *

 * Context: Process context.

 */

void __sched mutex_lock_io(struct mutex *lock)

{

	int token;