[PATCH] tty cleanups (12/12)

	* we allow tty_driver to cover more than 256 devices
	* pty.c cleaned up - now we only one driver for UNIX98 masters and
only one driver for UNIX98 slaves, so a lot of ugliness can be killed.
	* get_tty_driver() became an analog of get_gendisk() - it does
a lookup by device number and gives (pointer to tty_driver,index).
	* registration/unregistration of tty_driver updated
	* /proc/tty/drivers code updated (now one structure can be responsible
for several lines)

drivers/char/pty.c

@@ -52,16 +52,16 @@ static struct pty_struct pty_state[NR_PTYS];
 
 #ifdef CONFIG_UNIX98_PTYS
 /* These are global because they are accessed in tty_io.c */
-struct tty_driver ptm_driver[UNIX98_NR_MAJORS];
-struct tty_driver pts_driver[UNIX98_NR_MAJORS];
-
-static struct tty_struct *ptm_table[UNIX98_NR_MAJORS][NR_PTYS];
-static struct termios *ptm_termios[UNIX98_NR_MAJORS][NR_PTYS];
-static struct termios *ptm_termios_locked[UNIX98_NR_MAJORS][NR_PTYS];
-static struct tty_struct *pts_table[UNIX98_NR_MAJORS][NR_PTYS];
-static struct termios *pts_termios[UNIX98_NR_MAJORS][NR_PTYS];
-static struct termios *pts_termios_locked[UNIX98_NR_MAJORS][NR_PTYS];
-static struct pty_struct ptm_state[UNIX98_NR_MAJORS][NR_PTYS];
+struct tty_driver ptm_driver;
+struct tty_driver pts_driver;
+
+static struct tty_struct *ptm_table[UNIX98_NR_MAJORS*NR_PTYS];
+static struct termios *ptm_termios[UNIX98_NR_MAJORS*NR_PTYS];
+static struct termios *ptm_termios_locked[UNIX98_NR_MAJORS*NR_PTYS];
+static struct tty_struct *pts_table[UNIX98_NR_MAJORS*NR_PTYS];
+static struct termios *pts_termios[UNIX98_NR_MAJORS*NR_PTYS];
+static struct termios *pts_termios_locked[UNIX98_NR_MAJORS*NR_PTYS];
+static struct pty_struct ptm_state[UNIX98_NR_MAJORS*NR_PTYS];
 #endif
 
 static void pty_close(struct tty_struct * tty, struct file * filp)
@@ -87,12 +87,8 @@ static void pty_close(struct tty_struct * tty, struct file * filp)
 	if (tty->driver->subtype == PTY_TYPE_MASTER) {
 		set_bit(TTY_OTHER_CLOSED, &tty->flags);
 #ifdef CONFIG_UNIX98_PTYS
-		{
-			unsigned int major = MAJOR(tty->device) - UNIX98_PTY_MASTER_MAJOR;
-			if ( major < UNIX98_NR_MAJORS ) {
-				devpts_pty_kill( tty->index + tty->driver->name_base );
-			}
-		}
+		if (tty->driver == &ptm_driver)
+			devpts_pty_kill(tty->index);
 #endif
 		tty_vhangup(tty->link);
 	}
@@ -237,7 +233,7 @@ static int pty_chars_in_buffer(struct tty_struct *tty)
 #ifdef CONFIG_UNIX98_PTYS
 static int pty_get_device_number(struct tty_struct *tty, unsigned int *value)
 {
-	unsigned int result = tty->index + tty->driver->name_base;
+	unsigned int result = tty->index;
 	return put_user(result, value);
 }
 #endif
@@ -312,8 +308,6 @@ static int pty_open(struct tty_struct *tty, struct file * filp)
 	if (!tty || !tty->link)
 		goto out;
 	line = tty->index;
-	if ((line < 0) || (line >= NR_PTYS))
-		goto out;
 	pty = (struct pty_struct *)(tty->driver->driver_state) + line;
 	tty->driver_data = pty;
 
@@ -424,49 +418,41 @@ int __init pty_init(void)
 #ifdef CONFIG_UNIX98_PTYS
 	devfs_mk_dir("pts");
 	printk("pty: %d Unix98 ptys configured\n", UNIX98_NR_MAJORS*NR_PTYS);
-	for ( i = 0 ; i < UNIX98_NR_MAJORS ; i++ ) {
-		int j;
-
-		ptm_driver[i] = pty_driver;
-		ptm_driver[i].name = "ptm";
-		ptm_driver[i].proc_entry = 0;
-		ptm_driver[i].major = UNIX98_PTY_MASTER_MAJOR+i;
-		ptm_driver[i].minor_start = 0;
-		ptm_driver[i].name_base = i*NR_PTYS;
-		ptm_driver[i].num = NR_PTYS;
-		ptm_driver[i].other = &pts_driver[i];
-		ptm_driver[i].flags |= TTY_DRIVER_NO_DEVFS;
-		ptm_driver[i].table = ptm_table[i];
-		ptm_driver[i].termios = ptm_termios[i];
-		ptm_driver[i].termios_locked = ptm_termios_locked[i];
-		ptm_driver[i].driver_state = ptm_state[i];
-
-		for (j = 0; j < NR_PTYS; j++)
-			init_waitqueue_head(&ptm_state[i][j].open_wait);
-		
-		pts_driver[i] = pty_slave_driver;
-		pts_driver[i].name = "pts";
-		pts_driver[i].proc_entry = 0;
-		pts_driver[i].major = UNIX98_PTY_SLAVE_MAJOR+i;
-		pts_driver[i].minor_start = 0;
-		pts_driver[i].name_base = i*NR_PTYS;
-		pts_driver[i].num = ptm_driver[i].num;
-		pts_driver[i].flags |= TTY_DRIVER_NO_DEVFS;
-		pts_driver[i].other = &ptm_driver[i];
-		pts_driver[i].table = pts_table[i];
-		pts_driver[i].termios = pts_termios[i];
-		pts_driver[i].termios_locked = pts_termios_locked[i];
-		pts_driver[i].driver_state = ptm_state[i];
-		
-		ptm_driver[i].ioctl = pty_unix98_ioctl;
-		
-		if (tty_register_driver(&ptm_driver[i]))
-			panic("Couldn't register Unix98 ptm driver major %d",
-			      ptm_driver[i].major);
-		if (tty_register_driver(&pts_driver[i]))
-			panic("Couldn't register Unix98 pts driver major %d",
-			      pts_driver[i].major);
-	}
+	ptm_driver = pty_driver;
+	ptm_driver.name = "ptm";
+	ptm_driver.proc_entry = 0;
+	ptm_driver.major = UNIX98_PTY_MASTER_MAJOR;
+	ptm_driver.minor_start = 0;
+	ptm_driver.num = UNIX98_NR_MAJORS * NR_PTYS;
+	ptm_driver.other = &pts_driver;
+	ptm_driver.flags |= TTY_DRIVER_NO_DEVFS;
+	ptm_driver.table = ptm_table;
+	ptm_driver.termios = ptm_termios;
+	ptm_driver.termios_locked = ptm_termios_locked;
+	ptm_driver.driver_state = ptm_state;
+
+	for (i = 0; i < UNIX98_NR_MAJORS*NR_PTYS; i++)
+		init_waitqueue_head(&ptm_state[i].open_wait);
+	
+	pts_driver = pty_slave_driver;
+	pts_driver.name = "pts";
+	pts_driver.proc_entry = 0;
+	pts_driver.major = UNIX98_PTY_SLAVE_MAJOR;
+	pts_driver.minor_start = 0;
+	pts_driver.num = UNIX98_NR_MAJORS * NR_PTYS;
+	pts_driver.other = &ptm_driver;
+	pts_driver.flags |= TTY_DRIVER_NO_DEVFS;
+	pts_driver.table = pts_table;
+	pts_driver.termios = pts_termios;
+	pts_driver.termios_locked = pts_termios_locked;
+	pts_driver.driver_state = ptm_state;
+	
+	ptm_driver.ioctl = pty_unix98_ioctl;
+	
+	if (tty_register_driver(&ptm_driver))
+		panic("Couldn't register Unix98 ptm driver");
+	if (tty_register_driver(&pts_driver))
+		panic("Couldn't register Unix98 pts driver");
 #endif
 	return 0;
 }

drivers/char/tty_io.c

@@ -126,8 +126,8 @@ LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
 struct tty_ldisc ldiscs[NR_LDISCS];	/* line disc dispatch table	*/
 
 #ifdef CONFIG_UNIX98_PTYS
-extern struct tty_driver ptm_driver[];	/* Unix98 pty masters; for /dev/ptmx */
-extern struct tty_driver pts_driver[];	/* Unix98 pty slaves;  for /dev/ptmx */
+extern struct tty_driver ptm_driver;	/* Unix98 pty masters; for /dev/ptmx */
+extern struct tty_driver pts_driver;	/* Unix98 pty slaves;  for /dev/ptmx */
 #endif
 
 extern void disable_early_printk(void);
@@ -313,21 +313,15 @@ static int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 /*
  * This routine returns a tty driver structure, given a device number
  */
-struct tty_driver *get_tty_driver(kdev_t device)
+struct tty_driver *get_tty_driver(dev_t device, int *index)
 {
-	int	major, minor;
 	struct tty_driver *p;
 
-	minor = minor(device);
-	major = major(device);
-
 	list_for_each_entry(p, &tty_drivers, tty_drivers) {
-		if (p->major != major)
-			continue;
-		if (minor < p->minor_start)
-			continue;
-		if (minor >= p->minor_start + p->num)
+		dev_t base = MKDEV(p->major, p->minor_start);
+		if (device < base || device >= base + p->num)
 			continue;
+		*index = device - base;
 		return p;
 	}
 	return NULL;
@@ -1345,32 +1339,24 @@ static int tty_open(struct inode * inode, struct file * filp)
 
 	if (IS_PTMX_DEV(device)) {
 #ifdef CONFIG_UNIX98_PTYS
-		/* find a free pty. */
-		int major;
-
 		/* find a device that is not in use. */
 		retval = -1;
-		for (major = 0 ; major < UNIX98_NR_MAJORS ; major++) {
-			driver = &ptm_driver[major];
+		driver = &ptm_driver;
 		for (index = 0; index < driver->num ; index++)
 			if (!init_dev(driver, index, &tty))
 				goto ptmx_found; /* ok! */
-			}
-		}
 		return -EIO; /* no free ptys */
-
 	ptmx_found:
 		set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
-		devpts_pty_new(driver->other->name_base + index, MKDEV(driver->other->major, index + driver->other->minor_start));
+		devpts_pty_new(index, MKDEV(pts_driver.major, pts_driver.minor_start) + index);
 		noctty = 1;
 #else
 		return -ENODEV;
 #endif  /* CONFIG_UNIX_98_PTYS */
 	} else {
-		driver = get_tty_driver(device);
+		driver = get_tty_driver(kdev_t_to_nr(device), &index);
 		if (!driver)
 			return -ENODEV;
-		index = minor(device) - driver->minor_start;
 
 		retval = init_dev(driver, index, &tty);
 		if (retval)
@@ -2094,21 +2080,18 @@ static void tty_default_put_char(struct tty_struct *tty, unsigned char ch)
 #ifdef CONFIG_DEVFS_FS
 static void tty_register_devfs(struct tty_driver *driver, unsigned index)
 {
-	umode_t mode = S_IFCHR | S_IRUSR | S_IWUSR;
-	unsigned minor = driver->minor_start + index;
-	kdev_t dev = mk_kdev(driver->major, minor);
+	dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
 	char buf[32];
 
-	if ((minor < driver->minor_start) || 
-	    (minor >= driver->minor_start + driver->num)) {
-		printk(KERN_ERR "Attempt to register invalid minor number "
-		       "with devfs (%d:%d).\n", (int)driver->major,(int)minor);
+	if (index >= driver->num) {
+		printk(KERN_ERR "Attempt to register invalid tty line number "
+		       "with devfs (%d).\n", index);
 		return;
 	}
 
 	tty_line_name(driver, index, buf);
-	devfs_register(NULL, buf, 0, driver->major, minor, mode,
-		       &tty_fops, NULL);
+	devfs_register(NULL, buf, 0, MAJOR(dev), MINOR(dev),
+		S_IFCHR | S_IRUSR | S_IWUSR, &tty_fops, NULL);
 }
 
 static void tty_unregister_devfs(struct tty_driver *driver, int index)
@@ -2138,6 +2121,53 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index)
 EXPORT_SYMBOL(tty_register_device);
 EXPORT_SYMBOL(tty_unregister_device);
 
+/* that should be handled by register_chrdev_region() */
+static int get_range(struct tty_driver *driver)
+{
+	dev_t from = MKDEV(driver->major, driver->minor_start);
+	dev_t to = from + driver->num;
+	dev_t n, next;
+	int error = 0;
+
+	for (n = from; MAJOR(n) < MAJOR(to); n = next) {
+		next = MKDEV(MAJOR(n)+1, 0);
+		error = register_chrdev_region(MAJOR(n), MINOR(n),
+			       next - n, driver->name, &tty_fops);
+		if (error)
+			goto fail;
+	}
+	if (n != to)
+		error = register_chrdev_region(MAJOR(n), MINOR(n),
+			       to - n, driver->name, &tty_fops);
+	if (!error)
+		return 0;
+fail:
+	to = n;
+	for (n = from; MAJOR(n) < MAJOR(to); n = next) {
+		next = MKDEV(MAJOR(n)+1, 0);
+		unregister_chrdev_region(MAJOR(n), MINOR(n),
+			       next - n, driver->name);
+	}
+	return error;
+}
+
+/* that should be handled by unregister_chrdev_region() */
+static void put_range(struct tty_driver *driver)
+{
+	dev_t from = MKDEV(driver->major, driver->minor_start);
+	dev_t to = from + driver->num;
+	dev_t n, next;
+
+	for (n = from; MAJOR(n) < MAJOR(to); n = next) {
+		next = MKDEV(MAJOR(n)+1, 0);
+		unregister_chrdev_region(MAJOR(n), MINOR(n),
+			       next - n, driver->name);
+	}
+	if (n != to)
+		unregister_chrdev_region(MAJOR(n), MINOR(n),
+			       to - n, driver->name);
+}
+
 /*
  * Called by a tty driver to register itself.
  */
@@ -2149,12 +2179,16 @@ int tty_register_driver(struct tty_driver *driver)
 	if (driver->flags & TTY_DRIVER_INSTALLED)
 		return 0;
 
-	error = register_chrdev_region(driver->major, driver->minor_start,
+	if (!driver->major) {
+		error = register_chrdev_region(0, driver->minor_start,
 				       driver->num, driver->name, &tty_fops);
+		if (error > 0)
+			driver->major = error;
+	} else {
+		error = get_range(driver);
+	}
 	if (error < 0)
 		return error;
-	else if(driver->major == 0)
-		driver->major = error;
 
 	if (!driver->put_char)
 		driver->put_char = tty_default_put_char;
@@ -2174,16 +2208,13 @@ int tty_register_driver(struct tty_driver *driver)
  */
 int tty_unregister_driver(struct tty_driver *driver)
 {
-	int retval, i;
+	int i;
 	struct termios *tp;
 
 	if (*driver->refcount)
 		return -EBUSY;
 
-	retval = unregister_chrdev_region(driver->major, driver->minor_start,
-					  driver->num, driver->name);
-	if (retval)
-		return retval;
+	put_range(driver);
 
 	list_del(&driver->tty_drivers);
 

drivers/s390/char/con3215.c

@@ -1182,7 +1182,6 @@ tty3215_init(void)
 	tty3215_driver.owner = THIS_MODULE;
 	tty3215_driver.driver_name = "tty3215";
 	tty3215_driver.name = "ttyS";
-	tty3215_driver.name_base = 0;
 	tty3215_driver.major = TTY_MAJOR;
 	tty3215_driver.minor_start = 64;
 	tty3215_driver.num = NR_3215;

drivers/s390/char/sclp_tty.c

@@ -761,7 +761,6 @@ sclp_tty_init(void)
 	sclp_tty_driver.owner = THIS_MODULE;
 	sclp_tty_driver.driver_name = "sclp_line";
 	sclp_tty_driver.name = "ttyS";
-	sclp_tty_driver.name_base = 0;
 	sclp_tty_driver.major = TTY_MAJOR;
 	sclp_tty_driver.minor_start = 64;
 	sclp_tty_driver.num = 1;

fs/proc/proc_tty.c

@@ -29,39 +29,18 @@ static struct proc_dir_entry *proc_tty_ldisc, *proc_tty_driver;
 /*
  * This is the handler for /proc/tty/drivers
  */
-static int show_tty_driver(struct seq_file *m, void *v)
+static void show_tty_range(struct seq_file *m, struct tty_driver *p,
+	dev_t from, int num)
 {
-	struct tty_driver *p = v;
- 
-	if (&p->tty_drivers == tty_drivers.next) {
-		/* pseudo-drivers first */
-		seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
-		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
-		seq_printf(m, "system:/dev/tty\n");
-		seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
-		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
-		seq_printf(m, "system:console\n");
-#ifdef CONFIG_UNIX98_PTYS
-		seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
-		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
-		seq_printf(m, "system\n");
-#endif
-#ifdef CONFIG_VT
-		seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
-		seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
-		seq_printf(m, "system:vtmaster\n");
-#endif
-	}
-
 	seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown");
 	seq_printf(m, "/dev/%-8s ", p->name);
 	if (p->num > 1) {
 		char	range[20];
-		sprintf(range, "%d-%d", p->minor_start,
-			p->minor_start + p->num - 1);
-		seq_printf(m, "%3d %7s ", p->major, range);
+		sprintf(range, "%d-%d", MINOR(from),
+			MINOR(from) + num - 1);
+		seq_printf(m, "%3d %7s ", MAJOR(from), range);
 	} else {
-		seq_printf(m, "%3d %7d ", p->major, p->minor_start);
+		seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from));
 	}
 	switch (p->type) {
 	case TTY_DRIVER_TYPE_SYSTEM:
@@ -93,6 +72,41 @@ static int show_tty_driver(struct seq_file *m, void *v)
 		seq_printf(m, "type:%d.%d", p->type, p->subtype);
 	}
 	seq_putc(m, '\n');
+}
+
+static int show_tty_driver(struct seq_file *m, void *v)
+{
+	struct tty_driver *p = v;
+	dev_t from = MKDEV(p->major, p->minor_start);
+	dev_t to = from + p->num;
+
+	if (&p->tty_drivers == tty_drivers.next) {
+		/* pseudo-drivers first */
+		seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
+		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
+		seq_printf(m, "system:/dev/tty\n");
+		seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
+		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
+		seq_printf(m, "system:console\n");
+#ifdef CONFIG_UNIX98_PTYS
+		seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
+		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
+		seq_printf(m, "system\n");
+#endif
+#ifdef CONFIG_VT
+		seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
+		seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
+		seq_printf(m, "system:vtmaster\n");
+#endif
+	}
+
+	while (MAJOR(from) < MAJOR(to)) {
+		dev_t next = MKDEV(MAJOR(from)+1, 0);
+		show_tty_range(m, p, from, next - from);
+		from = next;
+	}
+	if (from != to)
+		show_tty_range(m, p, from, to - from);
 	return 0;
 }