s390/3270: introduce device notifier

Add a notifier to create / destroy the device nodes for the tty view
and the fullscreen view. Only device nodes for online devices are
created and the device names will follow the convention as outlined
in Documentation/devices.txt: 3270/tty<x> for the tty nodes,
3270/tub<x> for hte fullscreen nodes and 3270/tub for the fullscreen
control node.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 33 insertions, 16 deletions

diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
index 5e4b6fc49ae3..48767e6bab9d 100644
--- a/drivers/s390/char/tty3270.c
+++ b/drivers/s390/char/tty3270.c
@@ -829,9 +829,8 @@ tty3270_del_views(void)
 {
 	int i;
 
-	for (i = 0; i < tty3270_max_index; i++) {
-		struct raw3270_view *view =
-			raw3270_find_view(&tty3270_fn, i + RAW3270_FIRSTMINOR);
+	for (i = RAW3270_FIRSTMINOR; i <= tty3270_max_index; i++) {
+		struct raw3270_view *view = raw3270_find_view(&tty3270_fn, i);
 		if (!IS_ERR(view))
 			raw3270_del_view(view);
 	}
@@ -855,8 +854,7 @@ static int tty3270_install(struct tty_driver *driver, struct tty_struct *tty)
 	int i, rc;
 
 	/* Check if the tty3270 is already there. */
-	view = raw3270_find_view(&tty3270_fn,
-				  tty->index + RAW3270_FIRSTMINOR);
+	view = raw3270_find_view(&tty3270_fn, tty->index);
 	if (!IS_ERR(view)) {
 		tp = container_of(view, struct tty3270, view);
 		tty->driver_data = tp;
@@ -868,8 +866,8 @@ static int tty3270_install(struct tty_driver *driver, struct tty_struct *tty)
 		tp->inattr = TF_INPUT;
 		return tty_port_install(&tp->port, driver, tty);
 	}
-	if (tty3270_max_index < tty->index + 1)
-		tty3270_max_index = tty->index + 1;
+	if (tty3270_max_index < tty->index)
+		tty3270_max_index = tty->index;
 
 	/* Quick exit if there is no device for tty->index. */
 	if (PTR_ERR(view) == -ENODEV)
@@ -880,8 +878,7 @@ static int tty3270_install(struct tty_driver *driver, struct tty_struct *tty)
 	if (IS_ERR(tp))
 		return PTR_ERR(tp);
 
-	rc = raw3270_add_view(&tp->view, &tty3270_fn,
-			      tty->index + RAW3270_FIRSTMINOR);
+	rc = raw3270_add_view(&tp->view, &tty3270_fn, tty->index);
 	if (rc) {
 		tty3270_free_view(tp);
 		return rc;
@@ -1788,6 +1785,22 @@ static const struct tty_operations tty3270_ops = {
 	.set_termios = tty3270_set_termios
 };
 
+void tty3270_create_cb(int minor)
+{
+	tty_register_device(tty3270_driver, minor, NULL);
+}
+
+void tty3270_destroy_cb(int minor)
+{
+	tty_unregister_device(tty3270_driver, minor);
+}
+
+struct raw3270_notifier tty3270_notifier =
+{
+	.create = tty3270_create_cb,
+	.destroy = tty3270_destroy_cb,
+};
+
 /*
  * 3270 tty registration code called from tty_init().
  * Most kernel services (incl. kmalloc) are available at this poimt.
@@ -1797,23 +1810,25 @@ static int __init tty3270_init(void)
 	struct tty_driver *driver;
 	int ret;
 
-	driver = alloc_tty_driver(RAW3270_MAXDEVS);
-	if (!driver)
-		return -ENOMEM;
+	driver = tty_alloc_driver(RAW3270_MAXDEVS,
+				  TTY_DRIVER_REAL_RAW |
+				  TTY_DRIVER_DYNAMIC_DEV |
+				  TTY_DRIVER_RESET_TERMIOS);
+	if (IS_ERR(driver))
+		return PTR_ERR(driver);
 
 	/*
 	 * Initialize the tty_driver structure
 	 * Entries in tty3270_driver that are NOT initialized:
 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
 	 */
-	driver->driver_name = "ttyTUB";
-	driver->name = "ttyTUB";
+	driver->driver_name = "tty3270";
+	driver->name = "3270/tty";
 	driver->major = IBM_TTY3270_MAJOR;
-	driver->minor_start = RAW3270_FIRSTMINOR;
+	driver->minor_start = 0;
 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
 	driver->subtype = SYSTEM_TYPE_TTY;
 	driver->init_termios = tty_std_termios;
-	driver->flags = TTY_DRIVER_RESET_TERMIOS;
 	tty_set_operations(driver, &tty3270_ops);
 	ret = tty_register_driver(driver);
 	if (ret) {
@@ -1821,6 +1836,7 @@ static int __init tty3270_init(void)
 		return ret;
 	}
 	tty3270_driver = driver;
+	raw3270_register_notifier(&tty3270_notifier);
 	return 0;
 }
 
@@ -1829,6 +1845,7 @@ tty3270_exit(void)
 {
 	struct tty_driver *driver;
 
+	raw3270_unregister_notifier(&tty3270_notifier);
 	driver = tty3270_driver;
 	tty3270_driver = NULL;
 	tty_unregister_driver(driver);