tty: Eliminate global symbol tty_ldisc_N_TTY

Reduce global tty symbols; move and rename tty_ldisc_begin() as
n_tty_init() and redefine the N_TTY ldisc ops as file scope.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/n_tty.c

@@ -2497,7 +2497,7 @@ static void n_tty_fasync(struct tty_struct *tty, int on)
 	}
 }
 
-struct tty_ldisc_ops tty_ldisc_N_TTY = {
+static struct tty_ldisc_ops n_tty_ops = {
 	.magic           = TTY_LDISC_MAGIC,
 	.name            = "n_tty",
 	.open            = n_tty_open,
@@ -2518,14 +2518,18 @@ struct tty_ldisc_ops tty_ldisc_N_TTY = {
  *	n_tty_inherit_ops	-	inherit N_TTY methods
  *	@ops: struct tty_ldisc_ops where to save N_TTY methods
  *
- *	Enables a 'subclass' line discipline to 'inherit' N_TTY
- *	methods.
+ *	Enables a 'subclass' line discipline to 'inherit' N_TTY methods.
  */
 
 void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
 {
-	*ops = tty_ldisc_N_TTY;
+	*ops = n_tty_ops;
 	ops->owner = NULL;
 	ops->refcount = ops->flags = 0;
 }
 EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
+
+void __init n_tty_init(void)
+{
+	tty_register_ldisc(N_TTY, &n_tty_ops);
+}

drivers/tty/tty_io.c

@@ -3576,7 +3576,7 @@ void __init console_init(void)
 	initcall_t *call;
 
 	/* Setup the default TTY line discipline. */
-	tty_ldisc_begin();
+	n_tty_init();
 
 	/*
 	 * set up the console device so that later boot sequences can

drivers/tty/tty_ldisc.c

@@ -824,9 +824,3 @@ void tty_ldisc_deinit(struct tty_struct *tty)
 		tty_ldisc_put(tty->ldisc);
 	tty->ldisc = NULL;
 }
-
-void tty_ldisc_begin(void)
-{
-	/* Setup the default TTY line discipline. */
-	(void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
-}

include/linux/tty.h

@@ -576,7 +576,6 @@ extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 extern void tty_ldisc_release(struct tty_struct *tty);
 extern void tty_ldisc_init(struct tty_struct *tty);
 extern void tty_ldisc_deinit(struct tty_struct *tty);
-extern void tty_ldisc_begin(void);
 
 static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 					char *f, int count)
@@ -593,8 +592,8 @@ static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 
 
 /* n_tty.c */
-extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
+extern void __init n_tty_init(void);
 
 /* tty_audit.c */
 #ifdef CONFIG_AUDIT