tty: simplify ktermios allocation

Copy the simplification from the pty unix98 special case to the generic one.
This allows us to kill off driver->termios_locked entirely which is nice. We
have to whack bits of the cris driver as it meddles in places it shouldn't
providing its own arrays that were never used anyway.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/char/tty_io.c

@@ -1235,27 +1235,20 @@ struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
 
 int tty_init_termios(struct tty_struct *tty)
 {
-	struct ktermios *tp, *ltp;
+	struct ktermios *tp;
 	int idx = tty->index;
 
 	tp = tty->driver->termios[idx];
-	ltp = tty->driver->termios_locked[idx];
 	if (tp == NULL) {
-		WARN_ON(ltp != NULL);
-		tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
-		ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL);
-		if (tp == NULL || ltp == NULL) {
-			kfree(tp);
-			kfree(ltp);
+		tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
+		if (tp == NULL)
 			return -ENOMEM;
-		}
 		memcpy(tp, &tty->driver->init_termios,
 						sizeof(struct ktermios));
 		tty->driver->termios[idx] = tp;
-		tty->driver->termios_locked[idx] = ltp;
 	}
 	tty->termios = tp;
-	tty->termios_locked = ltp;
+	tty->termios_locked = tp + 1;
 
 	/* Compatibility until drivers always set this */
 	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
@@ -1439,10 +1432,6 @@ void tty_free_termios(struct tty_struct *tty)
 		tp = tty->termios;
 		tty->driver->termios[idx] = NULL;
 		kfree(tp);
-
-		tp = tty->termios_locked;
-		tty->driver->termios_locked[idx] = NULL;
-		kfree(tp);
 	}
 }
 EXPORT_SYMBOL(tty_free_termios);
@@ -1575,12 +1564,6 @@ void tty_release_dev(struct file *filp)
 			       idx, tty->name);
 			return;
 		}
-		if (tty->termios_locked != tty->driver->termios_locked[idx]) {
-			printk(KERN_DEBUG "tty_release_dev: driver.termios_locked[%d] not "
-			       "termios_locked for (%s)\n",
-			       idx, tty->name);
-			return;
-		}
 	}
 #endif
 
@@ -1604,13 +1587,6 @@ void tty_release_dev(struct file *filp)
 			       idx, tty->name);
 			return;
 		}
-		if (o_tty->termios_locked !=
-		      tty->driver->other->termios_locked[idx]) {
-			printk(KERN_DEBUG "tty_release_dev: other->termios_locked["
-					  "%d] not o_termios_locked for (%s)\n",
-			       idx, tty->name);
-			return;
-		}
 		if (o_tty->link != tty) {
 			printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n");
 			return;
@@ -2930,18 +2906,13 @@ static void destruct_tty_driver(struct kref *kref)
 				driver->termios[i] = NULL;
 				kfree(tp);
 			}
-			tp = driver->termios_locked[i];
-			if (tp) {
-				driver->termios_locked[i] = NULL;
-				kfree(tp);
-			}
 			if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV))
 				tty_unregister_device(driver, i);
 		}
 		p = driver->ttys;
 		proc_tty_unregister_driver(driver);
 		driver->ttys = NULL;
-		driver->termios = driver->termios_locked = NULL;
+		driver->termios = NULL;
 		kfree(p);
 		cdev_del(&driver->cdev);
 	}
@@ -2978,7 +2949,7 @@ int tty_register_driver(struct tty_driver *driver)
 	void **p = NULL;
 
 	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
-		p = kzalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
+		p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL);
 		if (!p)
 			return -ENOMEM;
 	}
@@ -3002,12 +2973,9 @@ int tty_register_driver(struct tty_driver *driver)
 	if (p) {
 		driver->ttys = (struct tty_struct **)p;
 		driver->termios = (struct ktermios **)(p + driver->num);
-		driver->termios_locked = (struct ktermios **)
-							(p + driver->num * 2);
 	} else {
 		driver->ttys = NULL;
 		driver->termios = NULL;
-		driver->termios_locked = NULL;
 	}
 
 	cdev_init(&driver->cdev, &tty_fops);
@@ -3016,7 +2984,7 @@ int tty_register_driver(struct tty_driver *driver)
 	if (error) {
 		unregister_chrdev_region(dev, driver->num);
 		driver->ttys = NULL;
-		driver->termios = driver->termios_locked = NULL;
+		driver->termios = NULL;
 		kfree(p);
 		return error;
 	}

drivers/serial/crisv10.c

@@ -457,7 +457,6 @@ static struct e100_serial rs_table[] = {
 #define NR_PORTS (sizeof(rs_table)/sizeof(struct e100_serial))
 
 static struct ktermios *serial_termios[NR_PORTS];
-static struct ktermios *serial_termios_locked[NR_PORTS];
 #ifdef CONFIG_ETRAX_SERIAL_FAST_TIMER
 static struct fast_timer fast_timers[NR_PORTS];
 #endif
@@ -4448,8 +4447,6 @@ rs_init(void)
 	driver->init_termios.c_ispeed = 115200;
 	driver->init_termios.c_ospeed = 115200;
 	driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
-	driver->termios = serial_termios;
-	driver->termios_locked = serial_termios_locked;
 
 	tty_set_operations(driver, &rs_ops);
         serial_driver = driver;