1// SPDX-License-Identifier: GPL-2.0
2#include <linux/tty.h>
3#include <linux/module.h>
4#include <linux/kallsyms.h>
5#include <linux/semaphore.h>
6#include <linux/sched.h>
7#include "tty.h"
8
9/* Legacy tty mutex glue */
10
11/*
12 * Getting the big tty mutex.
13 */
14
15void tty_lock(struct tty_struct *tty)
16{
17 tty_kref_get(tty);
18 mutex_lock(lock: &tty->legacy_mutex);
19}
20EXPORT_SYMBOL(tty_lock);
21
22int tty_lock_interruptible(struct tty_struct *tty)
23{
24 int ret;
25
26 tty_kref_get(tty);
27 ret = mutex_lock_interruptible(lock: &tty->legacy_mutex);
28 if (ret)
29 tty_kref_put(tty);
30 return ret;
31}
32
33void tty_unlock(struct tty_struct *tty)
34{
35 mutex_unlock(lock: &tty->legacy_mutex);
36 tty_kref_put(tty);
37}
38EXPORT_SYMBOL(tty_unlock);
39
40void tty_lock_slave(struct tty_struct *tty)
41{
42 if (tty && tty != tty->link)
43 tty_lock(tty);
44}
45
46void tty_unlock_slave(struct tty_struct *tty)
47{
48 if (tty && tty != tty->link)
49 tty_unlock(tty);
50}
51
52void tty_set_lock_subclass(struct tty_struct *tty)
53{
54 lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
55}
56