25 #define tty_ldisc_debug(tty, f, args...) ({				       \  argument
27 	printk(KERN_DEBUG "%s: %s: " f, __func__, tty_name(tty, __b), ##args); \
30 #define tty_ldisc_debug(tty, f, args...)  argument
154 static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc)  in tty_ldisc_get()  argument
181 	ld->tty = tty;  in tty_ldisc_get()
265 struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)  in tty_ldisc_ref_wait()  argument
267 	ldsem_down_read(&tty->ldisc_sem, MAX_SCHEDULE_TIMEOUT);  in tty_ldisc_ref_wait()
268 	WARN_ON(!tty->ldisc);  in tty_ldisc_ref_wait()
269 	return tty->ldisc;  in tty_ldisc_ref_wait()
282 struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)  in tty_ldisc_ref()  argument
286 	if (ldsem_down_read_trylock(&tty->ldisc_sem)) {  in tty_ldisc_ref()
287 		ld = tty->ldisc;  in tty_ldisc_ref()
289 			ldsem_up_read(&tty->ldisc_sem);  in tty_ldisc_ref()
305 	ldsem_up_read(&ld->tty->ldisc_sem);  in tty_ldisc_deref()
311 __tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)  in __tty_ldisc_lock()  argument
313 	return ldsem_down_write(&tty->ldisc_sem, timeout);  in __tty_ldisc_lock()
317 __tty_ldisc_lock_nested(struct tty_struct *tty, unsigned long timeout)  in __tty_ldisc_lock_nested()  argument
319 	return ldsem_down_write_nested(&tty->ldisc_sem,  in __tty_ldisc_lock_nested()
323 static inline void __tty_ldisc_unlock(struct tty_struct *tty)  in __tty_ldisc_unlock()  argument
325 	return ldsem_up_write(&tty->ldisc_sem);  in __tty_ldisc_unlock()
329 tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)  in tty_ldisc_lock()  argument
333 	ret = __tty_ldisc_lock(tty, timeout);  in tty_ldisc_lock()
336 	set_bit(TTY_LDISC_HALTED, &tty->flags);  in tty_ldisc_lock()
340 static void tty_ldisc_unlock(struct tty_struct *tty)  in tty_ldisc_unlock()  argument
342 	clear_bit(TTY_LDISC_HALTED, &tty->flags);  in tty_ldisc_unlock()
343 	__tty_ldisc_unlock(tty);  in tty_ldisc_unlock()
347 tty_ldisc_lock_pair_timeout(struct tty_struct *tty, struct tty_struct *tty2,  in tty_ldisc_lock_pair_timeout()  argument
352 	if (tty < tty2) {  in tty_ldisc_lock_pair_timeout()
353 		ret = __tty_ldisc_lock(tty, timeout);  in tty_ldisc_lock_pair_timeout()
357 				__tty_ldisc_unlock(tty);  in tty_ldisc_lock_pair_timeout()
361 		WARN_ON_ONCE(tty == tty2);  in tty_ldisc_lock_pair_timeout()
362 		if (tty2 && tty != tty2) {  in tty_ldisc_lock_pair_timeout()
365 				ret = __tty_ldisc_lock_nested(tty, timeout);  in tty_ldisc_lock_pair_timeout()
370 			ret = __tty_ldisc_lock(tty, timeout);  in tty_ldisc_lock_pair_timeout()
376 	set_bit(TTY_LDISC_HALTED, &tty->flags);  in tty_ldisc_lock_pair_timeout()
383 tty_ldisc_lock_pair(struct tty_struct *tty, struct tty_struct *tty2)  in tty_ldisc_lock_pair()  argument
385 	tty_ldisc_lock_pair_timeout(tty, tty2, MAX_SCHEDULE_TIMEOUT);  in tty_ldisc_lock_pair()
388 static void __lockfunc tty_ldisc_unlock_pair(struct tty_struct *tty,  in tty_ldisc_unlock_pair()  argument
391 	__tty_ldisc_unlock(tty);  in tty_ldisc_unlock_pair()
404 void tty_ldisc_flush(struct tty_struct *tty)  in tty_ldisc_flush()  argument
406 	struct tty_ldisc *ld = tty_ldisc_ref(tty);  in tty_ldisc_flush()
408 	tty_buffer_flush(tty, ld);  in tty_ldisc_flush()
426 static void tty_set_termios_ldisc(struct tty_struct *tty, int num)  in tty_set_termios_ldisc()  argument
428 	down_write(&tty->termios_rwsem);  in tty_set_termios_ldisc()
429 	tty->termios.c_line = num;  in tty_set_termios_ldisc()
430 	up_write(&tty->termios_rwsem);  in tty_set_termios_ldisc()
444 static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)  in tty_ldisc_open()  argument
446 	WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));  in tty_ldisc_open()
450 		ret = ld->ops->open(tty);  in tty_ldisc_open()
452 			clear_bit(TTY_LDISC_OPEN, &tty->flags);  in tty_ldisc_open()
467 static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)  in tty_ldisc_close()  argument
469 	WARN_ON(!test_bit(TTY_LDISC_OPEN, &tty->flags));  in tty_ldisc_close()
470 	clear_bit(TTY_LDISC_OPEN, &tty->flags);  in tty_ldisc_close()
472 		ld->ops->close(tty);  in tty_ldisc_close()
484 static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)  in tty_ldisc_restore()  argument
491 	old = tty_ldisc_get(tty, old->ops->num);  in tty_ldisc_restore()
493 	tty->ldisc = old;  in tty_ldisc_restore()
494 	tty_set_termios_ldisc(tty, old->ops->num);  in tty_ldisc_restore()
495 	if (tty_ldisc_open(tty, old) < 0) {  in tty_ldisc_restore()
498 		new_ldisc = tty_ldisc_get(tty, N_TTY);  in tty_ldisc_restore()
501 		tty->ldisc = new_ldisc;  in tty_ldisc_restore()
502 		tty_set_termios_ldisc(tty, N_TTY);  in tty_ldisc_restore()
503 		r = tty_ldisc_open(tty, new_ldisc);  in tty_ldisc_restore()
507 			      tty_name(tty, buf), r);  in tty_ldisc_restore()
522 int tty_set_ldisc(struct tty_struct *tty, int ldisc)  in tty_set_ldisc()  argument
527 	new_ldisc = tty_ldisc_get(tty, ldisc);  in tty_set_ldisc()
531 	tty_lock(tty);  in tty_set_ldisc()
532 	retval = tty_ldisc_lock(tty, 5 * HZ);  in tty_set_ldisc()
535 		tty_unlock(tty);  in tty_set_ldisc()
543 	if (tty->ldisc->ops->num == ldisc) {  in tty_set_ldisc()
544 		tty_ldisc_unlock(tty);  in tty_set_ldisc()
546 		tty_unlock(tty);  in tty_set_ldisc()
550 	old_ldisc = tty->ldisc;  in tty_set_ldisc()
552 	if (test_bit(TTY_HUPPED, &tty->flags)) {  in tty_set_ldisc()
555 		tty_ldisc_unlock(tty);  in tty_set_ldisc()
557 		tty_unlock(tty);  in tty_set_ldisc()
562 	tty_ldisc_close(tty, old_ldisc);  in tty_set_ldisc()
565 	tty->ldisc = new_ldisc;  in tty_set_ldisc()
566 	tty_set_termios_ldisc(tty, ldisc);  in tty_set_ldisc()
568 	retval = tty_ldisc_open(tty, new_ldisc);  in tty_set_ldisc()
572 		tty_ldisc_restore(tty, old_ldisc);  in tty_set_ldisc()
575 	if (tty->ldisc->ops->num != old_ldisc->ops->num && tty->ops->set_ldisc) {  in tty_set_ldisc()
576 		down_read(&tty->termios_rwsem);  in tty_set_ldisc()
577 		tty->ops->set_ldisc(tty);  in tty_set_ldisc()
578 		up_read(&tty->termios_rwsem);  in tty_set_ldisc()
592 	tty_ldisc_unlock(tty);  in tty_set_ldisc()
596 	schedule_work(&tty->port->buf.work);  in tty_set_ldisc()
598 	tty_unlock(tty);  in tty_set_ldisc()
609 static void tty_reset_termios(struct tty_struct *tty)  in tty_reset_termios()  argument
611 	down_write(&tty->termios_rwsem);  in tty_reset_termios()
612 	tty->termios = tty->driver->init_termios;  in tty_reset_termios()
613 	tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);  in tty_reset_termios()
614 	tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);  in tty_reset_termios()
615 	up_write(&tty->termios_rwsem);  in tty_reset_termios()
628 static int tty_ldisc_reinit(struct tty_struct *tty, int ldisc)  in tty_ldisc_reinit()  argument
630 	struct tty_ldisc *ld = tty_ldisc_get(tty, ldisc);  in tty_ldisc_reinit()
635 	tty_ldisc_close(tty, tty->ldisc);  in tty_ldisc_reinit()
636 	tty_ldisc_put(tty->ldisc);  in tty_ldisc_reinit()
640 	tty->ldisc = ld;  in tty_ldisc_reinit()
641 	tty_set_termios_ldisc(tty, ldisc);  in tty_ldisc_reinit()
661 void tty_ldisc_hangup(struct tty_struct *tty)  in tty_ldisc_hangup()  argument
664 	int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;  in tty_ldisc_hangup()
667 	tty_ldisc_debug(tty, "closing ldisc: %p\n", tty->ldisc);  in tty_ldisc_hangup()
669 	ld = tty_ldisc_ref(tty);  in tty_ldisc_hangup()
672 			ld->ops->flush_buffer(tty);  in tty_ldisc_hangup()
673 		tty_driver_flush_buffer(tty);  in tty_ldisc_hangup()
674 		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&  in tty_ldisc_hangup()
676 			ld->ops->write_wakeup(tty);  in tty_ldisc_hangup()
678 			ld->ops->hangup(tty);  in tty_ldisc_hangup()
682 	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);  in tty_ldisc_hangup()
683 	wake_up_interruptible_poll(&tty->read_wait, POLLIN);  in tty_ldisc_hangup()
691 	tty_ldisc_lock(tty, MAX_SCHEDULE_TIMEOUT);  in tty_ldisc_hangup()
693 	if (tty->ldisc) {  in tty_ldisc_hangup()
701 			if (!tty_ldisc_reinit(tty, tty->termios.c_line))  in tty_ldisc_hangup()
702 				err = tty_ldisc_open(tty, tty->ldisc);  in tty_ldisc_hangup()
709 			BUG_ON(tty_ldisc_reinit(tty, N_TTY));  in tty_ldisc_hangup()
710 			WARN_ON(tty_ldisc_open(tty, tty->ldisc));  in tty_ldisc_hangup()
713 	tty_ldisc_unlock(tty);  in tty_ldisc_hangup()
715 		tty_reset_termios(tty);  in tty_ldisc_hangup()
717 	tty_ldisc_debug(tty, "re-opened ldisc: %p\n", tty->ldisc);  in tty_ldisc_hangup()
730 int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)  in tty_ldisc_setup()  argument
732 	struct tty_ldisc *ld = tty->ldisc;  in tty_ldisc_setup()
735 	retval = tty_ldisc_open(tty, ld);  in tty_ldisc_setup()
742 			tty_ldisc_close(tty, ld);  in tty_ldisc_setup()
749 static void tty_ldisc_kill(struct tty_struct *tty)  in tty_ldisc_kill()  argument
754 	tty_ldisc_close(tty, tty->ldisc);  in tty_ldisc_kill()
755 	tty_ldisc_put(tty->ldisc);  in tty_ldisc_kill()
757 	tty->ldisc = NULL;  in tty_ldisc_kill()
760 	tty_set_termios_ldisc(tty, N_TTY);  in tty_ldisc_kill()
772 void tty_ldisc_release(struct tty_struct *tty)  in tty_ldisc_release()  argument
774 	struct tty_struct *o_tty = tty->link;  in tty_ldisc_release()
781 	tty_ldisc_debug(tty, "closing ldisc: %p\n", tty->ldisc);  in tty_ldisc_release()
783 	tty_ldisc_lock_pair(tty, o_tty);  in tty_ldisc_release()
784 	tty_ldisc_kill(tty);  in tty_ldisc_release()
787 	tty_ldisc_unlock_pair(tty, o_tty);  in tty_ldisc_release()
792 	tty_ldisc_debug(tty, "ldisc closed\n");  in tty_ldisc_release()
803 void tty_ldisc_init(struct tty_struct *tty)  in tty_ldisc_init()  argument
805 	struct tty_ldisc *ld = tty_ldisc_get(tty, N_TTY);  in tty_ldisc_init()
808 	tty->ldisc = ld;  in tty_ldisc_init()
818 void tty_ldisc_deinit(struct tty_struct *tty)  in tty_ldisc_deinit()  argument
820 	tty_ldisc_put(tty->ldisc);  in tty_ldisc_deinit()
821 	tty->ldisc = NULL;  in tty_ldisc_deinit()