X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fchar%2Ftty_io.c;h=888380f573dcfe622e98303dba398e63ef51c654;hb=8b0a88d5912ab549d5adac2c8498ecdaae5319a5;hp=f91704d57a4e3c288d70826c0bd717e523db86f3;hpb=feebed6515a113eeb33919e9557a8b9710ea627c;p=linux-2.6-omap-h63xx.git

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index f91704d57a4..888380f573d 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -49,7 +49,7 @@
  * implement CONFIG_VT and generalize console device interface.
  *	-- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
  *
- * Rewrote init_dev and release_dev to eliminate races.
+ * Rewrote tty_init_dev and tty_release_dev to eliminate races.
  *	-- Bill Hawes <whawes@star.net>, June 97
  *
  * Added devfs support.
@@ -136,11 +136,6 @@ LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
 DEFINE_MUTEX(tty_mutex);
 EXPORT_SYMBOL(tty_mutex);
 
-#ifdef CONFIG_UNIX98_PTYS
-extern struct tty_driver *ptm_driver;	/* Unix98 pty masters; for /dev/ptmx */
-static int ptmx_open(struct inode *, struct file *);
-#endif
-
 static void initialize_tty_struct(struct tty_struct *tty);
 
 static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
@@ -281,7 +276,7 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index)
 		if (device < base || device >= base + p->num)
 			continue;
 		*index = device - base;
-		return p;
+		return tty_driver_kref_get(p);
 	}
 	return NULL;
 }
@@ -325,7 +320,7 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line)
 
 		if (tty_line >= 0 && tty_line <= p->num && p->ops &&
 		    p->ops->poll_init && !p->ops->poll_init(p, tty_line, str)) {
-			res = p;
+			res = tty_driver_kref_get(p);
 			*line = tty_line;
 			break;
 		}
@@ -425,20 +420,6 @@ static const struct file_operations tty_fops = {
 	.fasync		= tty_fasync,
 };
 
-#ifdef CONFIG_UNIX98_PTYS
-static const struct file_operations ptmx_fops = {
-	.llseek		= no_llseek,
-	.read		= tty_read,
-	.write		= tty_write,
-	.poll		= tty_poll,
-	.unlocked_ioctl	= tty_ioctl,
-	.compat_ioctl	= tty_compat_ioctl,
-	.open		= ptmx_open,
-	.release	= tty_release,
-	.fasync		= tty_fasync,
-};
-#endif
-
 static const struct file_operations console_fops = {
 	.llseek		= no_llseek,
 	.read		= tty_read,
@@ -1208,7 +1189,7 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p)
 }
 
 /**
- *	pty_line_name	-	generate name for a tty
+ *	tty_line_name	-	generate name for a tty
  *	@driver: the tty driver in use
  *	@index: the minor number
  *	@p: output buffer of at least 7 bytes
@@ -1224,7 +1205,102 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p)
 }
 
 /**
- *	init_dev		-	initialise a tty device
+ *	tty_driver_lookup_tty() - find an existing tty, if any
+ *	@driver: the driver for the tty
+ *	@idx:	 the minor number
+ *
+ *	Return the tty, if found or ERR_PTR() otherwise.
+ *
+ *	Locking: tty_mutex must be held. If tty is found, the mutex must
+ *	be held until the 'fast-open' is also done. Will change once we
+ *	have refcounting in the driver and per driver locking
+ */
+struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, int idx)
+{
+	struct tty_struct *tty;
+
+	if (driver->ops->lookup)
+		return driver->ops->lookup(driver, idx);
+
+	tty = driver->ttys[idx];
+	return tty;
+}
+
+/**
+ *	tty_driver_install_tty() - install a tty entry in the driver
+ *	@driver: the driver for the tty
+ *	@tty: the tty
+ *
+ *	Install a tty object into the driver tables. The tty->index field
+ *	will be set by the time this is called.
+ *
+ *	Locking: tty_mutex for now
+ */
+static int tty_driver_install_tty(struct tty_driver *driver,
+						struct tty_struct *tty)
+{
+	if (driver->ops->install)
+		return driver->ops->install(driver, tty);
+	driver->ttys[tty->index] = tty;
+	return 0;
+}
+
+/**
+ *	tty_driver_remove_tty() - remove a tty from the driver tables
+ *	@driver: the driver for the tty
+ *	@idx:	 the minor number
+ *
+ *	Remvoe a tty object from the driver tables. The tty->index field
+ *	will be set by the time this is called.
+ *
+ *	Locking: tty_mutex for now
+ */
+static void tty_driver_remove_tty(struct tty_driver *driver,
+						struct tty_struct *tty)
+{
+	if (driver->ops->remove)
+		driver->ops->remove(driver, tty);
+	else
+		driver->ttys[tty->index] = NULL;
+}
+
+/*
+ * 	tty_reopen()	- fast re-open of an open tty
+ * 	@tty	- the tty to open
+ *
+ *	Return 0 on success, -errno on error.
+ *
+ *	Locking: tty_mutex must be held from the time the tty was found
+ *		 till this open completes.
+ */
+static int tty_reopen(struct tty_struct *tty)
+{
+	struct tty_driver *driver = tty->driver;
+
+	if (test_bit(TTY_CLOSING, &tty->flags))
+		return -EIO;
+
+	if (driver->type == TTY_DRIVER_TYPE_PTY &&
+	    driver->subtype == PTY_TYPE_MASTER) {
+		/*
+		 * special case for PTY masters: only one open permitted,
+		 * and the slave side open count is incremented as well.
+		 */
+		if (tty->count)
+			return -EIO;
+
+		tty->link->count++;
+	}
+	tty->count++;
+	tty->driver = driver; /* N.B. why do this every time?? */
+
+	WARN_ON(!test_bit(TTY_LDISC, &tty->flags));
+
+	return 0;
+}
+
+/**
+ *	tty_init_dev		-	initialise a tty device
  *	@driver: tty driver we are opening a device on
  *	@idx: device index
  *	@ret_tty: returned tty structure
@@ -1248,7 +1324,7 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p)
  * relaxed for the (most common) case of reopening a tty.
  */
 
-static int init_dev(struct tty_driver *driver, int idx,
+int tty_init_dev(struct tty_driver *driver, int idx,
 	struct tty_struct **ret_tty, int first_ok)
 {
 	struct tty_struct *tty, *o_tty;
@@ -1257,29 +1333,21 @@ static int init_dev(struct tty_driver *driver, int idx,
 	int retval = 0;
 
 	/* check whether we're reopening an existing tty */
-	if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
-		tty = devpts_get_tty(idx);
-		/*
-		 * If we don't have a tty here on a slave open, it's because
-		 * the master already started the close process and there's
-		 * no relation between devpts file and tty anymore.
-		 */
-		if (!tty && driver->subtype == PTY_TYPE_SLAVE) {
-			retval = -EIO;
-			goto end_init;
-		}
-		/*
-		 * It's safe from now on because init_dev() is called with
-		 * tty_mutex held and release_dev() won't change tty->count
-		 * or tty->flags without having to grab tty_mutex
-		 */
-		if (tty && driver->subtype == PTY_TYPE_MASTER)
-			tty = tty->link;
-	} else {
-		tty = driver->ttys[idx];
+	tty = tty_driver_lookup_tty(driver, idx);
+	if (IS_ERR(tty)) {
+		retval = PTR_ERR(tty);
+		goto end_init;
+	}
+
+	if (tty) {
+		retval = tty_reopen(tty);
+		if (retval)
+			return retval;
+		*ret_tty = tty;
+		return 0;
 	}
-	if (tty) goto fast_track;
 
+	/* Check if pty master is being opened multiple times */
 	if (driver->subtype == PTY_TYPE_MASTER &&
 		(driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) {
 		retval = -EIO;
@@ -1380,7 +1448,7 @@ static int init_dev(struct tty_driver *driver, int idx,
 			*o_ltp_loc = o_ltp;
 		o_tty->termios = *o_tp_loc;
 		o_tty->termios_locked = *o_ltp_loc;
-		driver->other->refcount++;
+		tty_driver_kref_get(driver->other);
 		if (driver->subtype == PTY_TYPE_MASTER)
 			o_tty->count++;
 
@@ -1394,8 +1462,6 @@ static int init_dev(struct tty_driver *driver, int idx,
 	 * Failures after this point use release_tty to clean up, so
 	 * there's no need to null out the local pointers.
 	 */
-	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM))
-		driver->ttys[idx] = tty;
 
 	if (!*tp_loc)
 		*tp_loc = tp;
@@ -1406,9 +1472,12 @@ static int init_dev(struct tty_driver *driver, int idx,
 	/* Compatibility until drivers always set this */
 	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
 	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
-	driver->refcount++;
+	tty_driver_kref_get(driver);
 	tty->count++;
 
+	if (tty_driver_install_tty(driver, tty) < 0)
+		goto release_mem_out;
+
 	/*
 	 * Structures all installed ... call the ldisc open routines.
 	 * If we fail here just call release_tty to clean up.  No need
@@ -1419,40 +1488,8 @@ static int init_dev(struct tty_driver *driver, int idx,
 
 	if (retval)
 		goto release_mem_out;
-	goto success;
 
-	/*
-	 * This fast open can be used if the tty is already open.
-	 * No memory is allocated, and the only failures are from
-	 * attempting to open a closing tty or attempting multiple
-	 * opens on a pty master.
-	 */
-fast_track:
-	if (test_bit(TTY_CLOSING, &tty->flags)) {
-		retval = -EIO;
-		goto end_init;
-	}
-	if (driver->type == TTY_DRIVER_TYPE_PTY &&
-	    driver->subtype == PTY_TYPE_MASTER) {
-		/*
-		 * special case for PTY masters: only one open permitted,
-		 * and the slave side open count is incremented as well.
-		 */
-		if (tty->count) {
-			retval = -EIO;
-			goto end_init;
-		}
-		tty->link->count++;
-	}
-	tty->count++;
-	tty->driver = driver; /* N.B. why do this every time?? */
-
-	/* FIXME */
-	if (!test_bit(TTY_LDISC, &tty->flags))
-		printk(KERN_ERR "init_dev but no ldisc\n");
-success:
 	*ret_tty = tty;
-
 	/* All paths come through here to release the mutex */
 end_init:
 	return retval;
@@ -1476,7 +1513,7 @@ fail_no_mem:
 	/* call the tty release_tty routine to clean out this slot */
 release_mem_out:
 	if (printk_ratelimit())
-		printk(KERN_INFO "init_dev: ldisc open failed, "
+		printk(KERN_INFO "tty_init_dev: ldisc open failed, "
 				 "clearing slot %d\n", idx);
 	release_tty(tty, idx);
 	goto end_init;
@@ -1502,7 +1539,7 @@ EXPORT_SYMBOL(tty_free_termios);
 
 void tty_shutdown(struct tty_struct *tty)
 {
-	tty->driver->ttys[tty->index] = NULL;
+	tty_driver_remove_tty(tty->driver, tty);
 	tty_free_termios(tty);
 }
 EXPORT_SYMBOL(tty_shutdown);
@@ -1530,8 +1567,7 @@ static void release_one_tty(struct kref *kref)
 	else
 		tty_shutdown(tty);
 	tty->magic = 0;
-	/* FIXME: locking on tty->driver->refcount */
-	tty->driver->refcount--;
+	tty_driver_kref_put(driver);
 	module_put(driver->owner);
 
 	file_list_lock();
@@ -1587,7 +1623,7 @@ static void release_tty(struct tty_struct *tty, int idx)
  * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
  * lead to double frees or releasing memory still in use.
  */
-static void release_dev(struct file *filp)
+void tty_release_dev(struct file *filp)
 {
 	struct tty_struct *tty, *o_tty;
 	int	pty_master, tty_closing, o_tty_closing, do_sleep;
@@ -1597,10 +1633,10 @@ static void release_dev(struct file *filp)
 
 	tty = (struct tty_struct *)filp->private_data;
 	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode,
-							"release_dev"))
+							"tty_release_dev"))
 		return;
 
-	check_tty_count(tty, "release_dev");
+	check_tty_count(tty, "tty_release_dev");
 
 	tty_fasync(-1, filp, 0);
 
@@ -1612,24 +1648,24 @@ static void release_dev(struct file *filp)
 
 #ifdef TTY_PARANOIA_CHECK
 	if (idx < 0 || idx >= tty->driver->num) {
-		printk(KERN_DEBUG "release_dev: bad idx when trying to "
+		printk(KERN_DEBUG "tty_release_dev: bad idx when trying to "
 				  "free (%s)\n", tty->name);
 		return;
 	}
-	if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+	if (!devpts) {
 		if (tty != tty->driver->ttys[idx]) {
-			printk(KERN_DEBUG "release_dev: driver.table[%d] not tty "
+			printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty "
 			       "for (%s)\n", idx, tty->name);
 			return;
 		}
 		if (tty->termios != tty->driver->termios[idx]) {
-			printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios "
+			printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios "
 			       "for (%s)\n",
 			       idx, tty->name);
 			return;
 		}
 		if (tty->termios_locked != tty->driver->termios_locked[idx]) {
-			printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not "
+			printk(KERN_DEBUG "tty_release_dev: driver.termios_locked[%d] not "
 			       "termios_locked for (%s)\n",
 			       idx, tty->name);
 			return;
@@ -1638,7 +1674,7 @@ static void release_dev(struct file *filp)
 #endif
 
 #ifdef TTY_DEBUG_HANGUP
-	printk(KERN_DEBUG "release_dev of %s (tty count=%d)...",
+	printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...",
 	       tty_name(tty, buf), tty->count);
 #endif
 
@@ -1646,26 +1682,26 @@ static void release_dev(struct file *filp)
 	if (tty->driver->other &&
 	     !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
 		if (o_tty != tty->driver->other->ttys[idx]) {
-			printk(KERN_DEBUG "release_dev: other->table[%d] "
+			printk(KERN_DEBUG "tty_release_dev: other->table[%d] "
 					  "not o_tty for (%s)\n",
 			       idx, tty->name);
 			return;
 		}
 		if (o_tty->termios != tty->driver->other->termios[idx]) {
-			printk(KERN_DEBUG "release_dev: other->termios[%d] "
+			printk(KERN_DEBUG "tty_release_dev: other->termios[%d] "
 					  "not o_termios for (%s)\n",
 			       idx, tty->name);
 			return;
 		}
 		if (o_tty->termios_locked !=
 		      tty->driver->other->termios_locked[idx]) {
-			printk(KERN_DEBUG "release_dev: other->termios_locked["
+			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 "release_dev: bad pty pointers\n");
+			printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n");
 			return;
 		}
 	}
@@ -1723,7 +1759,7 @@ static void release_dev(struct file *filp)
 		if (!do_sleep)
 			break;
 
-		printk(KERN_WARNING "release_dev: %s: read/write wait queue "
+		printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue "
 				    "active!\n", tty_name(tty, buf));
 		mutex_unlock(&tty_mutex);
 		schedule();
@@ -1736,14 +1772,14 @@ static void release_dev(struct file *filp)
 	 */
 	if (pty_master) {
 		if (--o_tty->count < 0) {
-			printk(KERN_WARNING "release_dev: bad pty slave count "
+			printk(KERN_WARNING "tty_release_dev: bad pty slave count "
 					    "(%d) for %s\n",
 			       o_tty->count, tty_name(o_tty, buf));
 			o_tty->count = 0;
 		}
 	}
 	if (--tty->count < 0) {
-		printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n",
+		printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n",
 		       tty->count, tty_name(tty, buf));
 		tty->count = 0;
 	}
@@ -1825,7 +1861,7 @@ static void release_dev(struct file *filp)
  *	The termios state of a pty is reset on first open so that
  *	settings don't persist across reuse.
  *
- *	Locking: tty_mutex protects tty, get_tty_driver and init_dev work.
+ *	Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work.
  *		 tty->count should protect the rest.
  *		 ->siglock protects ->signal/->sighand
  */
@@ -1854,7 +1890,7 @@ retry_open:
 			mutex_unlock(&tty_mutex);
 			return -ENXIO;
 		}
-		driver = tty->driver;
+		driver = tty_driver_kref_get(tty->driver);
 		index = tty->index;
 		filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
 		/* noctty = 1; */
@@ -1865,14 +1901,14 @@ retry_open:
 #ifdef CONFIG_VT
 	if (device == MKDEV(TTY_MAJOR, 0)) {
 		extern struct tty_driver *console_driver;
-		driver = console_driver;
+		driver = tty_driver_kref_get(console_driver);
 		index = fg_console;
 		noctty = 1;
 		goto got_driver;
 	}
 #endif
 	if (device == MKDEV(TTYAUX_MAJOR, 1)) {
-		driver = console_device(&index);
+		driver = tty_driver_kref_get(console_device(&index));
 		if (driver) {
 			/* Don't let /dev/console block */
 			filp->f_flags |= O_NONBLOCK;
@@ -1889,8 +1925,9 @@ retry_open:
 		return -ENODEV;
 	}
 got_driver:
-	retval = init_dev(driver, index, &tty, 0);
+	retval = tty_init_dev(driver, index, &tty, 0);
 	mutex_unlock(&tty_mutex);
+	tty_driver_kref_put(driver);
 	if (retval)
 		return retval;
 
@@ -1920,7 +1957,7 @@ got_driver:
 		printk(KERN_DEBUG "error %d in opening %s...", retval,
 		       tty->name);
 #endif
-		release_dev(filp);
+		tty_release_dev(filp);
 		if (retval != -ERESTARTSYS)
 			return retval;
 		if (signal_pending(current))
@@ -1959,69 +1996,6 @@ static int tty_open(struct inode *inode, struct file *filp)
 
 
 
-#ifdef CONFIG_UNIX98_PTYS
-/**
- *	ptmx_open		-	open a unix 98 pty master
- *	@inode: inode of device file
- *	@filp: file pointer to tty
- *
- *	Allocate a unix98 pty master device from the ptmx driver.
- *
- *	Locking: tty_mutex protects theinit_dev work. tty->count should
- * 		protect the rest.
- *		allocated_ptys_lock handles the list of free pty numbers
- */
-
-static int __ptmx_open(struct inode *inode, struct file *filp)
-{
-	struct tty_struct *tty;
-	int retval;
-	int index;
-
-	nonseekable_open(inode, filp);
-
-	/* find a device that is not in use. */
-	index = devpts_new_index();
-	if (index < 0)
-		return index;
-
-	mutex_lock(&tty_mutex);
-	retval = init_dev(ptm_driver, index, &tty, 1);
-	mutex_unlock(&tty_mutex);
-
-	if (retval)
-		goto out;
-
-	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
-	filp->private_data = tty;
-	file_move(filp, &tty->tty_files);
-
-	retval = devpts_pty_new(tty->link);
-	if (retval)
-		goto out1;
-
-	check_tty_count(tty, "ptmx_open");
-	retval = ptm_driver->ops->open(tty, filp);
-	if (!retval)
-		return 0;
-out1:
-	release_dev(filp);
-	return retval;
-out:
-	devpts_kill_index(index);
-	return retval;
-}
-
-static int ptmx_open(struct inode *inode, struct file *filp)
-{
-	int ret;
-
-	lock_kernel();
-	ret = __ptmx_open(inode, filp);
-	unlock_kernel();
-	return ret;
-}
-#endif
 
 /**
  *	tty_release		-	vfs callback for close
@@ -2032,13 +2006,13 @@ static int ptmx_open(struct inode *inode, struct file *filp)
  *	this tty. There may however be several such references.
  *
  *	Locking:
- *		Takes bkl. See release_dev
+ *		Takes bkl. See tty_release_dev
  */
 
 static int tty_release(struct inode *inode, struct file *filp)
 {
 	lock_kernel();
-	release_dev(filp);
+	tty_release_dev(filp);
 	unlock_kernel();
 	return 0;
 }
@@ -2929,10 +2903,9 @@ int tty_put_char(struct tty_struct *tty, unsigned char ch)
 		return tty->ops->put_char(tty, ch);
 	return tty->ops->write(tty, &ch, 1);
 }
-
 EXPORT_SYMBOL_GPL(tty_put_char);
 
-static struct class *tty_class;
+struct class *tty_class;
 
 /**
  *	tty_register_device - register a tty device
@@ -2972,6 +2945,7 @@ struct device *tty_register_device(struct tty_driver *driver, unsigned index,
 
 	return device_create_drvdata(tty_class, device, dev, NULL, name);
 }
+EXPORT_SYMBOL(tty_register_device);
 
 /**
  * 	tty_unregister_device - unregister a tty device
@@ -2989,8 +2963,6 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index)
 	device_destroy(tty_class,
 		MKDEV(driver->major, driver->minor_start) + index);
 }
-
-EXPORT_SYMBOL(tty_register_device);
 EXPORT_SYMBOL(tty_unregister_device);
 
 struct tty_driver *alloc_tty_driver(int lines)
@@ -2999,27 +2971,70 @@ struct tty_driver *alloc_tty_driver(int lines)
 
 	driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL);
 	if (driver) {
+		kref_init(&driver->kref);
 		driver->magic = TTY_DRIVER_MAGIC;
 		driver->num = lines;
 		/* later we'll move allocation of tables here */
 	}
 	return driver;
 }
+EXPORT_SYMBOL(alloc_tty_driver);
 
-void put_tty_driver(struct tty_driver *driver)
+static void destruct_tty_driver(struct kref *kref)
 {
+	struct tty_driver *driver = container_of(kref, struct tty_driver, kref);
+	int i;
+	struct ktermios *tp;
+	void *p;
+
+	if (driver->flags & TTY_DRIVER_INSTALLED) {
+		/*
+		 * Free the termios and termios_locked structures because
+		 * we don't want to get memory leaks when modular tty
+		 * drivers are removed from the kernel.
+		 */
+		for (i = 0; i < driver->num; i++) {
+			tp = driver->termios[i];
+			if (tp) {
+				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;
+		kfree(p);
+		cdev_del(&driver->cdev);
+	}
 	kfree(driver);
 }
 
+void tty_driver_kref_put(struct tty_driver *driver)
+{
+	kref_put(&driver->kref, destruct_tty_driver);
+}
+EXPORT_SYMBOL(tty_driver_kref_put);
+
 void tty_set_operations(struct tty_driver *driver,
 			const struct tty_operations *op)
 {
 	driver->ops = op;
 };
+EXPORT_SYMBOL(tty_set_operations);
 
-EXPORT_SYMBOL(alloc_tty_driver);
+void put_tty_driver(struct tty_driver *d)
+{
+	tty_driver_kref_put(d);
+}
 EXPORT_SYMBOL(put_tty_driver);
-EXPORT_SYMBOL(tty_set_operations);
 
 /*
  * Called by a tty driver to register itself.
@@ -3031,9 +3046,6 @@ int tty_register_driver(struct tty_driver *driver)
 	dev_t dev;
 	void **p = NULL;
 
-	if (driver->flags & TTY_DRIVER_INSTALLED)
-		return 0;
-
 	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
 		p = kzalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
 		if (!p)
@@ -3087,6 +3099,7 @@ int tty_register_driver(struct tty_driver *driver)
 		    tty_register_device(driver, i, NULL);
 	}
 	proc_tty_register_driver(driver);
+	driver->flags |= TTY_DRIVER_INSTALLED;
 	return 0;
 }
 
@@ -3097,46 +3110,19 @@ EXPORT_SYMBOL(tty_register_driver);
  */
 int tty_unregister_driver(struct tty_driver *driver)
 {
-	int i;
-	struct ktermios *tp;
-	void *p;
-
+#if 0
+	/* FIXME */
 	if (driver->refcount)
 		return -EBUSY;
-
+#endif
 	unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
 				driver->num);
 	mutex_lock(&tty_mutex);
 	list_del(&driver->tty_drivers);
 	mutex_unlock(&tty_mutex);
-
-	/*
-	 * Free the termios and termios_locked structures because
-	 * we don't want to get memory leaks when modular tty
-	 * drivers are removed from the kernel.
-	 */
-	for (i = 0; i < driver->num; i++) {
-		tp = driver->termios[i];
-		if (tp) {
-			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;
-	kfree(p);
-	cdev_del(&driver->cdev);
 	return 0;
 }
+
 EXPORT_SYMBOL(tty_unregister_driver);
 
 dev_t tty_devnum(struct tty_struct *tty)
@@ -3197,6 +3183,11 @@ struct tty_struct *get_current_tty(void)
 }
 EXPORT_SYMBOL_GPL(get_current_tty);
 
+void tty_default_fops(struct file_operations *fops)
+{
+	*fops = tty_fops;
+}
+
 /*
  * Initialize the console device. This is called *early*, so
  * we can't necessarily depend on lots of kernel help here.
@@ -3234,12 +3225,6 @@ postcore_initcall(tty_class_init);
 /* 3/2004 jmc: why do these devices exist? */
 
 static struct cdev tty_cdev, console_cdev;
-#ifdef CONFIG_UNIX98_PTYS
-static struct cdev ptmx_cdev;
-#endif
-#ifdef CONFIG_VT
-static struct cdev vc0_cdev;
-#endif
 
 /*
  * Ok, now we can initialize the rest of the tty devices and can count
@@ -3251,32 +3236,18 @@ static int __init tty_init(void)
 	if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
 	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
 		panic("Couldn't register /dev/tty driver\n");
-	device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
+	device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
 			      "tty");
 
 	cdev_init(&console_cdev, &console_fops);
 	if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
 	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
 		panic("Couldn't register /dev/console driver\n");
-	device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
+	device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
 			      "console");
 
-#ifdef CONFIG_UNIX98_PTYS
-	cdev_init(&ptmx_cdev, &ptmx_fops);
-	if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
-	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
-		panic("Couldn't register /dev/ptmx driver\n");
-	device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
-#endif
-
 #ifdef CONFIG_VT
-	cdev_init(&vc0_cdev, &console_fops);
-	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
-	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
-		panic("Couldn't register /dev/tty0 driver\n");
-	device_create_drvdata(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
-
-	vty_init();
+	vty_init(&console_fops);
 #endif
 	return 0;
 }