tty: Ldisc revamp

Move the line disciplines towards a conventional ->ops arrangement.  For
the moment the actual 'tty_ldisc' struct in the tty is kept as part of
the tty struct but this can then be changed if it turns out that when it
all settles down we want to refcount ldiscs separately to the tty.

Pull the ldisc code out of /proc and put it with our ldisc code.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 10 insertions, 6 deletions

diff --git a/include/linux/tty.h b/include/linux/tty.h
index 324a3b231d40..013711ea7385 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -185,6 +185,7 @@ struct tty_struct {
         struct tty_driver *driver;
         const struct tty_operations *ops;
         int index;
+        /* The ldisc objects are protected by tty_ldisc_lock at the moment */
         struct tty_ldisc ldisc;
         struct mutex termios_mutex;
         spinlock_t ctrl_lock;
@@ -289,7 +290,7 @@ extern void tty_wait_until_sent(struct tty_struct * tty, long timeout);
 extern int tty_check_change(struct tty_struct * tty);
 extern void stop_tty(struct tty_struct * tty);
 extern void start_tty(struct tty_struct * tty);
-extern int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc);
+extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 extern int tty_unregister_ldisc(int disc);
 extern int tty_register_driver(struct tty_driver *driver);
 extern int tty_unregister_driver(struct tty_driver *driver);
@@ -330,9 +331,7 @@ extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 extern void tty_ldisc_deref(struct tty_ldisc *);
 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
-
-extern struct tty_ldisc *tty_ldisc_get(int);
-extern void tty_ldisc_put(int);
+extern const struct file_operations tty_ldiscs_proc_fops;
 
 extern void tty_wakeup(struct tty_struct *tty);
 extern void tty_ldisc_flush(struct tty_struct *tty);
@@ -354,7 +353,7 @@ extern int tty_write_lock(struct tty_struct *tty, int ndelay);
 
 
 /* n_tty.c */
-extern struct tty_ldisc tty_ldisc_N_TTY;
+extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 
 /* tty_audit.c */
 #ifdef CONFIG_AUDIT
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index 6226504d9108..40f38d896777 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -104,7 +104,7 @@
 #include <linux/fs.h>
 #include <linux/wait.h>
 
-struct tty_ldisc {
+struct tty_ldisc_ops {
         int     magic;
         char    *name;
         int     num;
@@ -142,6 +142,11 @@ struct tty_ldisc {
         int refcount;
 };
 
+struct tty_ldisc {
+        struct tty_ldisc_ops *ops;
+        int refcount;
+};
+
 #define TTY_LDISC_MAGIC 0x5403
 
 #define LDISC_FLAG_DEFINED      0x00000001