drivers/tty/tty_mutex.c

   1 #include <linux/tty.h>
   2 #include <linux/module.h>
   3 #include <linux/kallsyms.h>
   4 #include <linux/semaphore.h>
   5 #include <linux/sched.h>
   6
   7 /*
   8  * The 'big tty mutex'
   9  *
  10  * This mutex is taken and released by tty_lock() and tty_unlock(),
  11  * replacing the older big kernel lock.
  12  * It can no longer be taken recursively, and does not get
  13  * released implicitly while sleeping.
  14  *
  15  * Don't use in new code.
  16  */
  17 static DEFINE_MUTEX(big_tty_mutex);
  18
  19 /*
  20  * Getting the big tty mutex.
  21  */
  22 void __lockfunc tty_lock(void)
  23 {
  24         mutex_lock(&big_tty_mutex);
  25 }
  26 EXPORT_SYMBOL(tty_lock);
  27
  28 void __lockfunc tty_unlock(void)
  29 {
  30         mutex_unlock(&big_tty_mutex);
  31 }
  32 EXPORT_SYMBOL(tty_unlock);