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Commit 8b0a88d5 authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
Browse files

tty: More driver operations 



We have the lookup operation abstracted which is nice for pty cleanup but
we really want to abstract the add/remove entries as well so that we can
pull the pty code out of the tty core and create a clear defined interface
for the tty driver table.

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7d7b93c1

drivers/char/pty.c

+16 −0
Original line number Diff line number Diff line
@@ -433,8 +433,22 @@ static void pty_shutdown(struct tty_struct *tty) 
	kfree(tty->termios_locked);

}



/* We have no need to install and remove our tty objects as devpts does all

   the work for us */



static int pty_install(struct tty_driver *driver, struct tty_struct *tty)

{

	return 0;

}



static void pty_remove(struct tty_driver *driver, struct tty_struct *tty)

{

}



static const struct tty_operations ptm_unix98_ops = {

	.lookup = ptm_unix98_lookup,

	.install = pty_install,

	.remove = pty_remove,

	.open = pty_open,

	.close = pty_close,

	.write = pty_write,
@@ -449,6 +463,8 @@ static const struct tty_operations ptm_unix98_ops = { 


static const struct tty_operations pty_unix98_ops = {

	.lookup = pts_unix98_lookup,

	.install = pty_install,

	.remove = pty_remove,

	.open = pty_open,

	.close = pty_close,

	.write = pty_write,

drivers/char/tty_io.c

+47 −10
Original line number Diff line number Diff line
@@ -1189,7 +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
@@ -1227,6 +1227,44 @@ struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, int idx) 
}



/**

 *	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

 *
@@ -1423,11 +1461,7 @@ int tty_init_dev(struct tty_driver *driver, int idx, 
	 * All structures have been allocated, so now we install them.

	 * Failures after this point use release_tty to clean up, so

	 * there's no need to null out the local pointers.

	 *

	 * FIXME: We want a 'driver->install method ?

	 */

	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM))

		driver->ttys[idx] = tty;



	if (!*tp_loc)

		*tp_loc = tp;
@@ -1441,6 +1475,9 @@ int tty_init_dev(struct tty_driver *driver, int idx, 
	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
@@ -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);
@@ -1615,7 +1652,7 @@ void tty_release_dev(struct file *filp) 
				  "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 "tty_release_dev: driver.table[%d] not tty "

			       "for (%s)\n", idx, tty->name);

include/linux/tty_driver.h

+16 −0
Original line number Diff line number Diff line
@@ -15,6 +15,20 @@ 
 *

 *	Optional method. Default behaviour is to use the ttys array

 *

 * int (*install)(struct tty_driver *self, struct tty_struct *tty)

 *

 *	Install a new tty into the tty driver internal tables. Used in

 *	conjunction with lookup and remove methods.

 *

 *	Optional method. Default behaviour is to use the ttys array

 *

 * void (*remove)(struct tty_driver *self, struct tty_struct *tty)

 *

 *	Remove a closed tty from the tty driver internal tables. Used in

 *	conjunction with lookup and remove methods.

 *

 *	Optional method. Default behaviour is to use the ttys array

 *

 * int  (*open)(struct tty_struct * tty, struct file * filp);

 *

 * 	This routine is called when a particular tty device is opened.
@@ -212,6 +226,8 @@ struct tty_driver; 


struct tty_operations {

	struct tty_struct * (*lookup)(struct tty_driver *driver, int idx);

	int  (*install)(struct tty_driver *driver, struct tty_struct *tty);

	void (*remove)(struct tty_driver *driver, struct tty_struct *tty);

	int  (*open)(struct tty_struct * tty, struct file * filp);

	void (*close)(struct tty_struct * tty, struct file * filp);

	void (*shutdown)(struct tty_struct *tty);