aboutsummaryrefslogtreecommitdiff
path: root/drivers/tty/tty_mutex.c
blob: dfa9ec03fa8e06dfe03a6e0ae04c62a2ac774103 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/semaphore.h>
#include <linux/sched.h>

/* Legacy tty mutex glue */

/*
 * Getting the big tty mutex.
 */

void __lockfunc tty_lock(struct tty_struct *tty)
{
	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
		return;
	tty_kref_get(tty);
	mutex_lock(&tty->legacy_mutex);
}
EXPORT_SYMBOL(tty_lock);

int tty_lock_interruptible(struct tty_struct *tty)
{
	int ret;

	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
		return -EIO;
	tty_kref_get(tty);
	ret = mutex_lock_interruptible(&tty->legacy_mutex);
	if (ret)
		tty_kref_put(tty);
	return ret;
}

void __lockfunc tty_unlock(struct tty_struct *tty)
{
	if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
		return;
	mutex_unlock(&tty->legacy_mutex);
	tty_kref_put(tty);
}
EXPORT_SYMBOL(tty_unlock);

void __lockfunc tty_lock_slave(struct tty_struct *tty)
{
	if (tty && tty != tty->link)
		tty_lock(tty);
}

void __lockfunc tty_unlock_slave(struct tty_struct *tty)
{
	if (tty && tty != tty->link)
		tty_unlock(tty);
}

void tty_set_lock_subclass(struct tty_struct *tty)
{
	lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
}