Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) #include <linux/tty.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #include <linux/kallsyms.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) #include <linux/semaphore.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) /* Legacy tty mutex glue */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  * Getting the big tty mutex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) void tty_lock(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	tty_kref_get(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	mutex_lock(&tty->legacy_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) EXPORT_SYMBOL(tty_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) int tty_lock_interruptible(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	tty_kref_get(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	ret = mutex_lock_interruptible(&tty->legacy_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 		tty_kref_put(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) void tty_unlock(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	mutex_unlock(&tty->legacy_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	tty_kref_put(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) EXPORT_SYMBOL(tty_unlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) void tty_lock_slave(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	if (tty && tty != tty->link)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 		tty_lock(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) void tty_unlock_slave(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	if (tty && tty != tty->link)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 		tty_unlock(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) void tty_set_lock_subclass(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 	lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) }