linux-imx

// 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);

}