[linux-2.6-block.git] / drivers / tty / tty_mutex.c

// SPDX-License-Identifier: GPL-2.0
#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 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 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 tty_lock_slave(struct tty_struct *tty)
{
	if (tty && tty != tty->link)
		tty_lock(tty);
}

void 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);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
b07471fa AB	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
89c8d91e AC	8	/* Legacy tty mutex glue */
89c8d91e AC	9
b07471fa AB	10	/*
	11	* Getting the big tty mutex.
	12	*/
89c8d91e	13
c2bb524b	14	void tty_lock(struct tty_struct *tty)
b07471fa	15	{
6d029c68	16	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
89c8d91e	17	return;
89c8d91e	18	tty_kref_get(tty);
2febdb63	19	mutex_lock(&tty->legacy_mutex);
b07471fa AB	20	}
	21	EXPORT_SYMBOL(tty_lock);
	22
0bfd464d PH	23	int tty_lock_interruptible(struct tty_struct *tty)
0bfd464d PH	24	{
e9036d06 PH	25	int ret;
e9036d06 PH	26
0bfd464d PH	27	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
	28	return -EIO;
	29	tty_kref_get(tty);
e9036d06 PH	30	ret = mutex_lock_interruptible(&tty->legacy_mutex);
	31	if (ret)
	32	tty_kref_put(tty);
	33	return ret;
0bfd464d PH	34	}
0bfd464d PH	35
c2bb524b	36	void tty_unlock(struct tty_struct *tty)
b07471fa	37	{
6d029c68	38	if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
89c8d91e	39	return;
89c8d91e AC	40	mutex_unlock(&tty->legacy_mutex);
89c8d91e AC	41	tty_kref_put(tty);
b07471fa AB	42	}
b07471fa AB	43	EXPORT_SYMBOL(tty_unlock);
89c8d91e	44
c2bb524b	45	void tty_lock_slave(struct tty_struct *tty)
89c8d91e	46	{
eef15e2a	47	if (tty && tty != tty->link)
2febdb63	48	tty_lock(tty);
89c8d91e	49	}
89c8d91e	50
c2bb524b	51	void tty_unlock_slave(struct tty_struct *tty)
89c8d91e	52	{
2aff5e2b PH	53	if (tty && tty != tty->link)
2aff5e2b PH	54	tty_unlock(tty);
89c8d91e	55	}
2febdb63 PH	56
	57	void tty_set_lock_subclass(struct tty_struct *tty)
	58	{
3abf87cd	59	lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
2febdb63	60	}