extern struct tty_driver *ptm_driver;  /* Unix98 pty masters; for /dev/ptmx */
 extern int pty_limit;          /* Config limit on Unix98 ptys */
 static DEFINE_IDR(allocated_ptys);
-static DECLARE_MUTEX(allocated_ptys_lock);
+static DEFINE_MUTEX(allocated_ptys_lock);
 static int ptmx_open(struct inode *, struct file *);
 #endif
 
 #ifdef CONFIG_UNIX98_PTYS
        /* Make this pty number available for reallocation */
        if (devpts) {
-               down(&allocated_ptys_lock);
+               mutex_lock(&allocated_ptys_lock);
                idr_remove(&allocated_ptys, idx);
-               up(&allocated_ptys_lock);
+               mutex_unlock(&allocated_ptys_lock);
        }
 #endif
 
        nonseekable_open(inode, filp);
 
        /* find a device that is not in use. */
-       down(&allocated_ptys_lock);
+       mutex_lock(&allocated_ptys_lock);
        if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
-               up(&allocated_ptys_lock);
+               mutex_unlock(&allocated_ptys_lock);
                return -ENOMEM;
        }
        idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
        if (idr_ret < 0) {
-               up(&allocated_ptys_lock);
+               mutex_unlock(&allocated_ptys_lock);
                if (idr_ret == -EAGAIN)
                        return -ENOMEM;
                return -EIO;
        }
        if (index >= pty_limit) {
                idr_remove(&allocated_ptys, index);
-               up(&allocated_ptys_lock);
+               mutex_unlock(&allocated_ptys_lock);
                return -EIO;
        }
-       up(&allocated_ptys_lock);
+       mutex_unlock(&allocated_ptys_lock);
 
        mutex_lock(&tty_mutex);
        retval = init_dev(ptm_driver, index, &tty);
        release_dev(filp);
        return retval;
 out:
-       down(&allocated_ptys_lock);
+       mutex_lock(&allocated_ptys_lock);
        idr_remove(&allocated_ptys, index);
-       up(&allocated_ptys_lock);
+       mutex_unlock(&allocated_ptys_lock);
        return retval;
 }
 #endif