linux_dsm_epyc7002/drivers/tty/tty_mutex.c
Alan Cox d29f3ef39b tty_lock: Localise the lock
In each remaining case the tty_lock is associated with a specific tty. This
means we can now lock on a per tty basis. We do need tty_lock_pair() for
the pty case. Uglier but still a step in the right direction.

[fixed up calls in 3 missing drivers - gregkh]

Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-04 16:58:47 -07:00

63 lines
1.2 KiB
C

#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 (tty->magic != TTY_MAGIC) {
printk(KERN_ERR "L Bad %p\n", tty);
WARN_ON(1);
return;
}
tty_kref_get(tty);
mutex_lock(&tty->legacy_mutex);
}
EXPORT_SYMBOL(tty_lock);
void __lockfunc tty_unlock(struct tty_struct *tty)
{
if (tty->magic != TTY_MAGIC) {
printk(KERN_ERR "U Bad %p\n", tty);
WARN_ON(1);
return;
}
mutex_unlock(&tty->legacy_mutex);
tty_kref_put(tty);
}
EXPORT_SYMBOL(tty_unlock);
/*
* Getting the big tty mutex for a pair of ttys with lock ordering
* On a non pty/tty pair tty2 can be NULL which is just fine.
*/
void __lockfunc tty_lock_pair(struct tty_struct *tty,
struct tty_struct *tty2)
{
if (tty < tty2) {
tty_lock(tty);
tty_lock(tty2);
} else {
if (tty2 && tty2 != tty)
tty_lock(tty2);
tty_lock(tty);
}
}
EXPORT_SYMBOL(tty_lock_pair);
void __lockfunc tty_unlock_pair(struct tty_struct *tty,
struct tty_struct *tty2)
{
tty_unlock(tty);
if (tty2 && tty2 != tty)
tty_unlock(tty2);
}
EXPORT_SYMBOL(tty_unlock_pair);