From fe6e29fdb1a7b94891bbdd3c67358fe4ed14639d Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@redhat.com>
Date: Mon, 13 Oct 2008 10:44:08 +0100
Subject: 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: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 drivers/char/tty_io.c | 46 +++++++---------------------------------------
 1 file changed, 7 insertions(+), 39 deletions(-)

(limited to 'drivers/char/tty_io.c')

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 9590839..502cad6 100644
--- a/drivers/char/tty_io.c
+++ b/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;
 	}
-- 
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