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Commit 99f1fe18 authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
Browse files

tty: Clean up the tty_init_dev changes further 



Fix up the naming, style and extract some bits of code into the driver
specific code

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 23499705

drivers/char/pty.c

+48 −1
Original line number Diff line number Diff line
@@ -391,6 +391,41 @@ static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file, 
	return -ENOIOCTLCMD;

}



/**

 *	ptm_unix98_lookup	-	find a pty master

 *	@driver: ptm driver

 *	@idx: tty index

 *

 *	Look up a pty master device. Called under the tty_mutex for now.

 *	This provides our locking.

 */



static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, int idx)

{

	struct tty_struct *tty = devpts_get_tty(idx);

	if (tty)

		tty = tty->link;

	return tty;

}



/**

 *	pts_unix98_lookup	-	find a pty slave

 *	@driver: pts driver

 *	@idx: tty index

 *

 *	Look up a pty master device. Called under the tty_mutex for now.

 *	This provides our locking.

 */



static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, int idx)

{

	struct tty_struct *tty = devpts_get_tty(idx);

	/* Master must be open before slave */

	if (!tty)

		return ERR_PTR(-EIO);

	return tty;

}



static void pty_shutdown(struct tty_struct *tty)

{

	/* We have our own method as we don't use the tty index */
@@ -399,6 +434,7 @@ static void pty_shutdown(struct tty_struct *tty) 
}



static const struct tty_operations ptm_unix98_ops = {

	.lookup = ptm_unix98_lookup,

	.open = pty_open,

	.close = pty_close,

	.write = pty_write,
@@ -411,6 +447,17 @@ static const struct tty_operations ptm_unix98_ops = { 
	.shutdown = pty_shutdown

};



static const struct tty_operations pty_unix98_ops = {

	.lookup = pts_unix98_lookup,

	.open = pty_open,

	.close = pty_close,

	.write = pty_write,

	.write_room = pty_write_room,

	.flush_buffer = pty_flush_buffer,

	.chars_in_buffer = pty_chars_in_buffer,

	.unthrottle = pty_unthrottle,

	.set_termios = pty_set_termios,

};



/**

 *	ptmx_open		-	open a unix 98 pty master
@@ -517,7 +564,7 @@ static void __init unix98_pty_init(void) 
	pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |

		TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;

	pts_driver->other = ptm_driver;

	tty_set_operations(pts_driver, &pty_ops);

	tty_set_operations(pts_driver, &pty_unix98_ops);

	

	if (tty_register_driver(ptm_driver))

		panic("Couldn't register Unix98 ptm driver");

drivers/char/tty_io.c

+24 −40
Original line number Diff line number Diff line
@@ -1204,45 +1204,30 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p) 
	sprintf(p, "%s%d", driver->name, index + driver->name_base);

}



/*

 * 	find_tty() - find an existing tty, if any

/**

 *	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.

 *	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 *find_tty(struct tty_driver *driver, int idx)

struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, int idx)

{

	struct tty_struct *tty;



	/* 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)

			return ERR_PTR(-EIO);

	if (driver->ops->lookup)

		return driver->ops->lookup(driver, idx);



		/*

		 * tty is safe on because we are called with tty_mutex held

		 * and release_dev() won't change tty->count or tty->flags

		 * without grabbing tty_mutex.

		 */

		if (tty && driver->subtype == PTY_TYPE_MASTER)

			tty = tty->link;

	} else

		tty = driver->ttys[idx];

	return tty;

}



/*

 * 	fast_tty_open()	- fast re-open of an open tty

/**

 *	tty_reopen()	- fast re-open of an open tty

 *	@tty	- the tty to open

 *

 *	Return 0 on success, -errno on error.
@@ -1250,7 +1235,7 @@ struct tty_struct *find_tty(struct tty_driver *driver, int idx) 
 *	Locking: tty_mutex must be held from the time the tty was found

 *		 till this open completes.

 */

static int fast_tty_open(struct tty_struct *tty)

static int tty_reopen(struct tty_struct *tty)

{

	struct tty_driver *driver = tty->driver;
@@ -1271,9 +1256,7 @@ static int fast_tty_open(struct tty_struct *tty) 
	tty->count++;

	tty->driver = driver; /* N.B. why do this every time?? */



	/* FIXME */

	if (!test_bit(TTY_LDISC, &tty->flags))

		printk(KERN_ERR "fast_tty_open: no ldisc\n");

	WARN_ON(!test_bit(TTY_LDISC, &tty->flags));



	return 0;

}
@@ -1312,14 +1295,14 @@ int tty_init_dev(struct tty_driver *driver, int idx, 
	int retval = 0;



	/* check whether we're reopening an existing tty */

	tty = find_tty(driver, idx);

	tty = tty_driver_lookup_tty(driver, idx);

	if (IS_ERR(tty)) {

		retval = PTR_ERR(tty);

		goto end_init;

	}



	if (tty) {

		retval = fast_tty_open(tty);

		retval = tty_reopen(tty);

		if (retval)

			return retval;

		*ret_tty = tty;
@@ -1440,6 +1423,8 @@ 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;
@@ -1466,9 +1451,8 @@ int tty_init_dev(struct tty_driver *driver, int idx, 


	if (retval)

		goto release_mem_out;

success:

	*ret_tty = tty;



	*ret_tty = tty;

	/* All paths come through here to release the mutex */

end_init:

	return retval;

include/linux/tty_driver.h

+9 −0
Original line number Diff line number Diff line
@@ -7,6 +7,14 @@ 
 * defined; unless noted otherwise, they are optional, and can be

 * filled in with a null pointer.

 *

 * struct tty_struct * (*lookup)(struct tty_driver *self, int idx)

 *

 *	Return the tty device corresponding to idx, NULL if there is not

 *	one currently in use and an ERR_PTR value on error. Called under

 *	tty_mutex (for now!)

 *

 *	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.
@@ -203,6 +211,7 @@ struct tty_struct; 
struct tty_driver;



struct tty_operations {

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

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

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

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