25 #define tty_ldisc_debug(tty, f, args...)	tty_debug(tty, f, ##args)  argument
27 #define tty_ldisc_debug(tty, f, args...)  argument
151 static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc)  in tty_ldisc_get()  argument
178 	ld->tty = tty;  in tty_ldisc_get()
262 struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)  in tty_ldisc_ref_wait()  argument
264 	ldsem_down_read(&tty->ldisc_sem, MAX_SCHEDULE_TIMEOUT);  in tty_ldisc_ref_wait()
265 	WARN_ON(!tty->ldisc);  in tty_ldisc_ref_wait()
266 	return tty->ldisc;  in tty_ldisc_ref_wait()
279 struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)  in tty_ldisc_ref()  argument
283 	if (ldsem_down_read_trylock(&tty->ldisc_sem)) {  in tty_ldisc_ref()
284 		ld = tty->ldisc;  in tty_ldisc_ref()
286 			ldsem_up_read(&tty->ldisc_sem);  in tty_ldisc_ref()
302 	ldsem_up_read(&ld->tty->ldisc_sem);  in tty_ldisc_deref()
308 __tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)  in __tty_ldisc_lock()  argument
310 	return ldsem_down_write(&tty->ldisc_sem, timeout);  in __tty_ldisc_lock()
314 __tty_ldisc_lock_nested(struct tty_struct *tty, unsigned long timeout)  in __tty_ldisc_lock_nested()  argument
316 	return ldsem_down_write_nested(&tty->ldisc_sem,  in __tty_ldisc_lock_nested()
320 static inline void __tty_ldisc_unlock(struct tty_struct *tty)  in __tty_ldisc_unlock()  argument
322 	ldsem_up_write(&tty->ldisc_sem);  in __tty_ldisc_unlock()
326 tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)  in tty_ldisc_lock()  argument
330 	ret = __tty_ldisc_lock(tty, timeout);  in tty_ldisc_lock()
333 	set_bit(TTY_LDISC_HALTED, &tty->flags);  in tty_ldisc_lock()
337 static void tty_ldisc_unlock(struct tty_struct *tty)  in tty_ldisc_unlock()  argument
339 	clear_bit(TTY_LDISC_HALTED, &tty->flags);  in tty_ldisc_unlock()
340 	__tty_ldisc_unlock(tty);  in tty_ldisc_unlock()
344 tty_ldisc_lock_pair_timeout(struct tty_struct *tty, struct tty_struct *tty2,  in tty_ldisc_lock_pair_timeout()  argument
349 	if (tty < tty2) {  in tty_ldisc_lock_pair_timeout()
350 		ret = __tty_ldisc_lock(tty, timeout);  in tty_ldisc_lock_pair_timeout()
354 				__tty_ldisc_unlock(tty);  in tty_ldisc_lock_pair_timeout()
358 		WARN_ON_ONCE(tty == tty2);  in tty_ldisc_lock_pair_timeout()
359 		if (tty2 && tty != tty2) {  in tty_ldisc_lock_pair_timeout()
362 				ret = __tty_ldisc_lock_nested(tty, timeout);  in tty_ldisc_lock_pair_timeout()
367 			ret = __tty_ldisc_lock(tty, timeout);  in tty_ldisc_lock_pair_timeout()
373 	set_bit(TTY_LDISC_HALTED, &tty->flags);  in tty_ldisc_lock_pair_timeout()
380 tty_ldisc_lock_pair(struct tty_struct *tty, struct tty_struct *tty2)  in tty_ldisc_lock_pair()  argument
382 	tty_ldisc_lock_pair_timeout(tty, tty2, MAX_SCHEDULE_TIMEOUT);  in tty_ldisc_lock_pair()
385 static void __lockfunc tty_ldisc_unlock_pair(struct tty_struct *tty,  in tty_ldisc_unlock_pair()  argument
388 	__tty_ldisc_unlock(tty);  in tty_ldisc_unlock_pair()
401 void tty_ldisc_flush(struct tty_struct *tty)  in tty_ldisc_flush()  argument
403 	struct tty_ldisc *ld = tty_ldisc_ref(tty);  in tty_ldisc_flush()
405 	tty_buffer_flush(tty, ld);  in tty_ldisc_flush()
423 static void tty_set_termios_ldisc(struct tty_struct *tty, int num)  in tty_set_termios_ldisc()  argument
425 	down_write(&tty->termios_rwsem);  in tty_set_termios_ldisc()
426 	tty->termios.c_line = num;  in tty_set_termios_ldisc()
427 	up_write(&tty->termios_rwsem);  in tty_set_termios_ldisc()
441 static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)  in tty_ldisc_open()  argument
443 	WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));  in tty_ldisc_open()
447 		ret = ld->ops->open(tty);  in tty_ldisc_open()
449 			clear_bit(TTY_LDISC_OPEN, &tty->flags);  in tty_ldisc_open()
451 		tty_ldisc_debug(tty, "%p: opened\n", tty->ldisc);  in tty_ldisc_open()
466 static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)  in tty_ldisc_close()  argument
468 	WARN_ON(!test_bit(TTY_LDISC_OPEN, &tty->flags));  in tty_ldisc_close()
469 	clear_bit(TTY_LDISC_OPEN, &tty->flags);  in tty_ldisc_close()
471 		ld->ops->close(tty);  in tty_ldisc_close()
472 	tty_ldisc_debug(tty, "%p: closed\n", tty->ldisc);  in tty_ldisc_close()
484 static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)  in tty_ldisc_restore()  argument
490 	old = tty_ldisc_get(tty, old->ops->num);  in tty_ldisc_restore()
492 	tty->ldisc = old;  in tty_ldisc_restore()
493 	tty_set_termios_ldisc(tty, old->ops->num);  in tty_ldisc_restore()
494 	if (tty_ldisc_open(tty, old) < 0) {  in tty_ldisc_restore()
497 		new_ldisc = tty_ldisc_get(tty, N_TTY);  in tty_ldisc_restore()
500 		tty->ldisc = new_ldisc;  in tty_ldisc_restore()
501 		tty_set_termios_ldisc(tty, N_TTY);  in tty_ldisc_restore()
502 		r = tty_ldisc_open(tty, new_ldisc);  in tty_ldisc_restore()
506 			      tty_name(tty), r);  in tty_ldisc_restore()
521 int tty_set_ldisc(struct tty_struct *tty, int ldisc)  in tty_set_ldisc()  argument
526 	new_ldisc = tty_ldisc_get(tty, ldisc);  in tty_set_ldisc()
530 	tty_lock(tty);  in tty_set_ldisc()
531 	retval = tty_ldisc_lock(tty, 5 * HZ);  in tty_set_ldisc()
534 		tty_unlock(tty);  in tty_set_ldisc()
542 	if (tty->ldisc->ops->num == ldisc) {  in tty_set_ldisc()
543 		tty_ldisc_unlock(tty);  in tty_set_ldisc()
545 		tty_unlock(tty);  in tty_set_ldisc()
549 	old_ldisc = tty->ldisc;  in tty_set_ldisc()
551 	if (test_bit(TTY_HUPPED, &tty->flags)) {  in tty_set_ldisc()
554 		tty_ldisc_unlock(tty);  in tty_set_ldisc()
556 		tty_unlock(tty);  in tty_set_ldisc()
561 	tty_ldisc_close(tty, old_ldisc);  in tty_set_ldisc()
564 	tty->ldisc = new_ldisc;  in tty_set_ldisc()
565 	tty_set_termios_ldisc(tty, ldisc);  in tty_set_ldisc()
567 	retval = tty_ldisc_open(tty, new_ldisc);  in tty_set_ldisc()
571 		tty_ldisc_restore(tty, old_ldisc);  in tty_set_ldisc()
574 	if (tty->ldisc->ops->num != old_ldisc->ops->num && tty->ops->set_ldisc) {  in tty_set_ldisc()
575 		down_read(&tty->termios_rwsem);  in tty_set_ldisc()
576 		tty->ops->set_ldisc(tty);  in tty_set_ldisc()
577 		up_read(&tty->termios_rwsem);  in tty_set_ldisc()
591 	tty_ldisc_unlock(tty);  in tty_set_ldisc()
595 	tty_buffer_restart_work(tty->port);  in tty_set_ldisc()
597 	tty_unlock(tty);  in tty_set_ldisc()
608 static void tty_reset_termios(struct tty_struct *tty)  in tty_reset_termios()  argument
610 	down_write(&tty->termios_rwsem);  in tty_reset_termios()
611 	tty->termios = tty->driver->init_termios;  in tty_reset_termios()
612 	tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);  in tty_reset_termios()
613 	tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);  in tty_reset_termios()
614 	up_write(&tty->termios_rwsem);  in tty_reset_termios()
627 static int tty_ldisc_reinit(struct tty_struct *tty, int ldisc)  in tty_ldisc_reinit()  argument
629 	struct tty_ldisc *ld = tty_ldisc_get(tty, ldisc);  in tty_ldisc_reinit()
634 	tty_ldisc_close(tty, tty->ldisc);  in tty_ldisc_reinit()
635 	tty_ldisc_put(tty->ldisc);  in tty_ldisc_reinit()
639 	tty->ldisc = ld;  in tty_ldisc_reinit()
640 	tty_set_termios_ldisc(tty, ldisc);  in tty_ldisc_reinit()
660 void tty_ldisc_hangup(struct tty_struct *tty)  in tty_ldisc_hangup()  argument
663 	int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;  in tty_ldisc_hangup()
666 	tty_ldisc_debug(tty, "%p: closing\n", tty->ldisc);  in tty_ldisc_hangup()
668 	ld = tty_ldisc_ref(tty);  in tty_ldisc_hangup()
671 			ld->ops->flush_buffer(tty);  in tty_ldisc_hangup()
672 		tty_driver_flush_buffer(tty);  in tty_ldisc_hangup()
673 		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&  in tty_ldisc_hangup()
675 			ld->ops->write_wakeup(tty);  in tty_ldisc_hangup()
677 			ld->ops->hangup(tty);  in tty_ldisc_hangup()
681 	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);  in tty_ldisc_hangup()
682 	wake_up_interruptible_poll(&tty->read_wait, POLLIN);  in tty_ldisc_hangup()
690 	tty_ldisc_lock(tty, MAX_SCHEDULE_TIMEOUT);  in tty_ldisc_hangup()
692 	if (tty->ldisc) {  in tty_ldisc_hangup()
700 			if (!tty_ldisc_reinit(tty, tty->termios.c_line))  in tty_ldisc_hangup()
701 				err = tty_ldisc_open(tty, tty->ldisc);  in tty_ldisc_hangup()
708 			BUG_ON(tty_ldisc_reinit(tty, N_TTY));  in tty_ldisc_hangup()
709 			WARN_ON(tty_ldisc_open(tty, tty->ldisc));  in tty_ldisc_hangup()
712 	tty_ldisc_unlock(tty);  in tty_ldisc_hangup()
714 		tty_reset_termios(tty);  in tty_ldisc_hangup()
716 	tty_ldisc_debug(tty, "%p: re-opened\n", tty->ldisc);  in tty_ldisc_hangup()
729 int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)  in tty_ldisc_setup()  argument
731 	struct tty_ldisc *ld = tty->ldisc;  in tty_ldisc_setup()
734 	retval = tty_ldisc_open(tty, ld);  in tty_ldisc_setup()
741 			tty_ldisc_close(tty, ld);  in tty_ldisc_setup()
748 static void tty_ldisc_kill(struct tty_struct *tty)  in tty_ldisc_kill()  argument
753 	tty_ldisc_close(tty, tty->ldisc);  in tty_ldisc_kill()
754 	tty_ldisc_put(tty->ldisc);  in tty_ldisc_kill()
756 	tty->ldisc = NULL;  in tty_ldisc_kill()
759 	tty_set_termios_ldisc(tty, N_TTY);  in tty_ldisc_kill()
771 void tty_ldisc_release(struct tty_struct *tty)  in tty_ldisc_release()  argument
773 	struct tty_struct *o_tty = tty->link;  in tty_ldisc_release()
780 	tty_ldisc_lock_pair(tty, o_tty);  in tty_ldisc_release()
781 	tty_ldisc_kill(tty);  in tty_ldisc_release()
784 	tty_ldisc_unlock_pair(tty, o_tty);  in tty_ldisc_release()
789 	tty_ldisc_debug(tty, "released\n");  in tty_ldisc_release()
800 void tty_ldisc_init(struct tty_struct *tty)  in tty_ldisc_init()  argument
802 	struct tty_ldisc *ld = tty_ldisc_get(tty, N_TTY);  in tty_ldisc_init()
805 	tty->ldisc = ld;  in tty_ldisc_init()
815 void tty_ldisc_deinit(struct tty_struct *tty)  in tty_ldisc_deinit()  argument
817 	tty_ldisc_put(tty->ldisc);  in tty_ldisc_deinit()
818 	tty->ldisc = NULL;  in tty_ldisc_deinit()