265 static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)  in tty_ldisc_assign()  argument
268 	tty->ldisc = *ld;  in tty_ldisc_assign()
283 static int tty_ldisc_try(struct tty_struct *tty)  in tty_ldisc_try()  argument
290 	ld = &tty->ldisc;  in tty_ldisc_try()
291 	if (test_bit(TTY_LDISC, &tty->flags)) {  in tty_ldisc_try()
315 struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)  in tty_ldisc_ref_wait()  argument
318 	wait_event(tty_ldisc_wait, tty_ldisc_try(tty));  in tty_ldisc_ref_wait()
319 	WARN_ON(tty->ldisc.refcount == 0);  in tty_ldisc_ref_wait()
320 	return &tty->ldisc;  in tty_ldisc_ref_wait()
336 struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)  in tty_ldisc_ref()  argument
338 	if (tty_ldisc_try(tty))  in tty_ldisc_ref()
339 		return &tty->ldisc;  in tty_ldisc_ref()
385 void tty_ldisc_enable(struct tty_struct *tty)  in tty_ldisc_enable()  argument
387 	set_bit(TTY_LDISC, &tty->flags);  in tty_ldisc_enable()
388 	clear_bit(TTY_LDISC_CHANGING, &tty->flags);  in tty_ldisc_enable()
404 static void tty_set_termios_ldisc(struct tty_struct *tty, int num)  in tty_set_termios_ldisc()  argument
406 	mutex_lock(&tty->termios_mutex);  in tty_set_termios_ldisc()
407 	tty->termios->c_line = num;  in tty_set_termios_ldisc()
408 	mutex_unlock(&tty->termios_mutex);  in tty_set_termios_ldisc()
421 static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)  in tty_ldisc_restore()  argument
428 	tty_ldisc_assign(tty, old);  in tty_ldisc_restore()
429 	tty_set_termios_ldisc(tty, old->ops->num);  in tty_ldisc_restore()
430 	if (old->ops->open && (old->ops->open(tty) < 0)) {  in tty_ldisc_restore()
435 		tty_ldisc_assign(tty, &new_ldisc);  in tty_ldisc_restore()
436 		tty_set_termios_ldisc(tty, N_TTY);  in tty_ldisc_restore()
438 			int r = new_ldisc.ops->open(tty);  in tty_ldisc_restore()
442 				      tty_name(tty, buf), r);  in tty_ldisc_restore()
459 int tty_set_ldisc(struct tty_struct *tty, int ldisc)  in tty_set_ldisc()  argument
478 	tty_wait_until_sent(tty, 0);  in tty_set_ldisc()
480 	if (tty->ldisc.ops->num == ldisc) {  in tty_set_ldisc()
490 	tty->receive_room = 0;  in tty_set_ldisc()
492 	o_ldisc = tty->ldisc;  in tty_set_ldisc()
493 	o_tty = tty->link;  in tty_set_ldisc()
505 	clear_bit(TTY_LDISC, &tty->flags);  in tty_set_ldisc()
510 	if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) {  in tty_set_ldisc()
511 		if (tty->ldisc.refcount) {  in tty_set_ldisc()
523 			if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0)  in tty_set_ldisc()
539 	if (test_bit(TTY_LDISC_CHANGING, &tty->flags)) {  in tty_set_ldisc()
543 		ld = tty_ldisc_ref_wait(tty);  in tty_set_ldisc()
552 	set_bit(TTY_LDISC_CHANGING, &tty->flags);  in tty_set_ldisc()
563 	work = cancel_delayed_work(&tty->buf.work);  in tty_set_ldisc()
571 		(o_ldisc.ops->close)(tty);  in tty_set_ldisc()
574 	tty_ldisc_assign(tty, &new_ldisc);  in tty_set_ldisc()
575 	tty_set_termios_ldisc(tty, ldisc);  in tty_set_ldisc()
577 		retval = (new_ldisc.ops->open)(tty);  in tty_set_ldisc()
580 		tty_ldisc_restore(tty, &o_ldisc);  in tty_set_ldisc()
586 	if (tty->ldisc.ops->num != o_ldisc.ops->num && tty->ops->set_ldisc)  in tty_set_ldisc()
587 		tty->ops->set_ldisc(tty);  in tty_set_ldisc()
596 	tty_ldisc_enable(tty);  in tty_set_ldisc()
603 		schedule_delayed_work(&tty->buf.work, 1);  in tty_set_ldisc()
617 int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)  in tty_ldisc_setup()  argument
619 	struct tty_ldisc *ld = &tty->ldisc;  in tty_ldisc_setup()
623 		retval = (ld->ops->open)(tty);  in tty_ldisc_setup()
631 				(ld->ops->close)(tty);  in tty_ldisc_setup()
636 	tty_ldisc_enable(tty);  in tty_ldisc_setup()
649 void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)  in tty_ldisc_release()  argument
658 	clear_bit(TTY_LDISC, &tty->flags);  in tty_ldisc_release()
659 	cancel_delayed_work(&tty->buf.work);  in tty_ldisc_release()
673 	while (tty->ldisc.refcount) {  in tty_ldisc_release()
675 		wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0);  in tty_ldisc_release()
684 	if (tty->ldisc.ops->close)  in tty_ldisc_release()
685 		(tty->ldisc.ops->close)(tty);  in tty_ldisc_release()
686 	tty_ldisc_put(tty->ldisc.ops);  in tty_ldisc_release()
692 	tty_ldisc_assign(tty, &ld);  in tty_ldisc_release()
693 	tty_set_termios_ldisc(tty, N_TTY);  in tty_ldisc_release()
714 void tty_ldisc_init(struct tty_struct *tty)  in tty_ldisc_init()  argument
719 	tty_ldisc_assign(tty, &ld);  in tty_ldisc_init()