tty: set tty_ldisc_ops::num statically

There is no reason to pass the ldisc number to tty_register_ldisc
separately. Just set it in the already defined tty_ldisc_ops in all the
ldiscs.

This simplifies tty_register_ldisc a bit too (no need to set the num
member there).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210505091928.22010-15-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

5 files changed, 11 insertions, 8 deletions

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 477403ecc445..654e439ff6c8 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2857,6 +2857,7 @@ static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc)
 /* Line discipline for real tty */
 static struct tty_ldisc_ops tty_ldisc_packet = {
 	.owner		 = THIS_MODULE,
+	.num		 = N_GSM0710,
 	.name            = "n_gsm",
 	.open            = gsmld_open,
 	.close           = gsmld_close,
@@ -3242,7 +3243,7 @@ static const struct tty_operations gsmtty_ops = {
 static int __init gsm_init(void)
 {
 	/* Fill in our line protocol discipline, and register it */
-	int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet);
+	int status = tty_register_ldisc(&tty_ldisc_packet);
 	if (status != 0) {
 		pr_err("n_gsm: can't register line discipline (err = %d)\n",
 								status);
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 62b1d1a6e0f1..2256039911f5 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -788,6 +788,7 @@ static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *buf_list)
 
 static struct tty_ldisc_ops n_hdlc_ldisc = {
 	.owner		= THIS_MODULE,
+	.num		= N_HDLC,
 	.name		= "hdlc",
 	.open		= n_hdlc_tty_open,
 	.close		= n_hdlc_tty_close,
@@ -807,7 +808,7 @@ static int __init n_hdlc_init(void)
 	/* range check maxframe arg */
 	maxframe = clamp(maxframe, 4096, MAX_HDLC_FRAME_SIZE);
 
-	status = tty_register_ldisc(N_HDLC, &n_hdlc_ldisc);
+	status = tty_register_ldisc(&n_hdlc_ldisc);
 	if (!status)
 		pr_info("N_HDLC line discipline registered with maxframe=%d\n",
 				maxframe);
diff --git a/drivers/tty/n_null.c b/drivers/tty/n_null.c
index 2ff373d2f98d..ee229c812dce 100644
--- a/drivers/tty/n_null.c
+++ b/drivers/tty/n_null.c
@@ -40,6 +40,7 @@ static void n_null_receivebuf(struct tty_struct *tty,
 
 static struct tty_ldisc_ops null_ldisc = {
 	.owner		=	THIS_MODULE,
+	.num		=	N_NULL,
 	.name		=	"n_null",
 	.open		=	n_null_open,
 	.close		=	n_null_close,
@@ -50,7 +51,7 @@ static struct tty_ldisc_ops null_ldisc = {
 
 static int __init n_null_init(void)
 {
-	BUG_ON(tty_register_ldisc(N_NULL, &null_ldisc));
+	BUG_ON(tty_register_ldisc(&null_ldisc));
 	return 0;
 }
 
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 8ce712eec026..2fe27905c398 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2424,6 +2424,7 @@ static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
 
 static struct tty_ldisc_ops n_tty_ops = {
 	.owner		 = THIS_MODULE,
+	.num		 = N_TTY,
 	.name            = "n_tty",
 	.open            = n_tty_open,
 	.close           = n_tty_close,
@@ -2455,5 +2456,5 @@ EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
 
 void __init n_tty_init(void)
 {
-	tty_register_ldisc(N_TTY, &n_tty_ops);
+	tty_register_ldisc(&n_tty_ops);
 }
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 03f414172f34..9aff04bee4cd 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -59,17 +59,16 @@ static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
  *		takes tty_ldiscs_lock to guard against ldisc races
  */
 
-int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc)
+int tty_register_ldisc(struct tty_ldisc_ops *new_ldisc)
 {
 	unsigned long flags;
 	int ret = 0;
 
-	if (disc < N_TTY || disc >= NR_LDISCS)
+	if (new_ldisc->num < N_TTY || new_ldisc->num >= NR_LDISCS)
 		return -EINVAL;
 
 	raw_spin_lock_irqsave(&tty_ldiscs_lock, flags);
-	tty_ldiscs[disc] = new_ldisc;
-	new_ldisc->num = disc;
+	tty_ldiscs[new_ldisc->num] = new_ldisc;
 	new_ldisc->refcount = 0;
 	raw_spin_unlock_irqrestore(&tty_ldiscs_lock, flags);