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>

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>
Alan Cox · Linus Torvalds
1 parent e1e5770bb6
Showing 32 changed files with 286 additions and 246 deletions Side-by-side Diff
drivers/bluetooth/hci_ldisc.c
drivers/char/cyclades.c
drivers/char/epca.c
drivers/char/ip2/i2lib.c
drivers/char/ip2/ip2main.c
drivers/char/n_hdlc.c
drivers/char/n_r3964.c
drivers/char/n_tty.c
drivers/char/pcmcia/synclink_cs.c
drivers/char/pty.c
drivers/char/selection.c
drivers/char/synclink.c
drivers/char/synclink_gt.c
drivers/char/synclinkmp.c
drivers/char/tty_io.c
drivers/char/tty_ioctl.c
drivers/input/serio/serport.c
drivers/isdn/capi/capi.c
drivers/isdn/gigaset/ser-gigaset.c
drivers/net/hamradio/6pack.c
@@ -282,8 +282,8 @@
 	/* FIXME: why is this needed. Note don't use ldisc_ref here as the
 	   open path is before the ldisc is referencable */
  
-	if (tty->ldisc.flush_buffer)
-		tty->ldisc.flush_buffer(tty);
+	if (tty->ldisc.ops->flush_buffer)
+		tty->ldisc.ops->flush_buffer(tty);
 	tty_driver_flush_buffer(tty);
  
 	return 0;
@@ -514,7 +514,7 @@
  
 static int __init hci_uart_init(void)
 {
-	static struct tty_ldisc hci_uart_ldisc;
+	static struct tty_ldisc_ops hci_uart_ldisc;
 	int err;
  
 	BT_INFO("HCI UART driver ver %s", VERSION);
@@ -5246,7 +5246,8 @@
 					HZ, info->idle_stats.recv_bytes,
 					(cur_jifs - info->idle_stats.recv_idle)/
 					HZ, info->idle_stats.overruns,
-					(long)info->tty->ldisc.num);
+					/* FIXME: double check locking */
+					(long)info->tty->ldisc.ops->num);
 			else
 				size = sprintf(buf + len, "%3d %8lu %10lu %8lu "
 					"%10lu %8lu %9lu %6ld\n",
@@ -2262,8 +2262,8 @@
 			tty_wait_until_sent(tty, 0);
 		} else {
 			/* ldisc lock already held in ioctl */
-			if (tty->ldisc.flush_buffer)
-				tty->ldisc.flush_buffer(tty);
+			if (tty->ldisc.ops->flush_buffer)
+				tty->ldisc.ops->flush_buffer(tty);
 		}
 		unlock_kernel();
 		/* Fall Thru */
@@ -868,11 +868,11 @@
 		amountToMove = count;
 	}
 	// Move the first block
-	pCh->pTTY->ldisc.receive_buf( pCh->pTTY, 
+	pCh->pTTY->ldisc.ops->receive_buf( pCh->pTTY,
 		 &(pCh->Ibuf[stripIndex]), NULL, amountToMove );
 	// If we needed to wrap, do the second data move
 	if (count > amountToMove) {
-		pCh->pTTY->ldisc.receive_buf( pCh->pTTY, 
+		pCh->pTTY->ldisc.ops->receive_buf( pCh->pTTY,
 		 pCh->Ibuf, NULL, count - amountToMove );
 	}
 	// Bump and wrap the stripIndex all at once by the amount of data read. This
@@ -1289,11 +1289,12 @@
 // code duplicated from n_tty (ldisc)
 static inline void  isig(int sig, struct tty_struct *tty, int flush)
 {
+	/* FIXME: This is completely bogus */
 	if (tty->pgrp)
 		kill_pgrp(tty->pgrp, sig, 1);
 	if (flush || !L_NOFLSH(tty)) {
-		if ( tty->ldisc.flush_buffer )  
-			tty->ldisc.flush_buffer(tty);
+		if ( tty->ldisc.ops->flush_buffer )  
+			tty->ldisc.ops->flush_buffer(tty);
 		i2InputFlush( tty->driver_data );
 	}
 }
@@ -1342,7 +1343,7 @@
 		}
 		tmp = pCh->pTTY->real_raw;
 		pCh->pTTY->real_raw = 0;
-		pCh->pTTY->ldisc.receive_buf( pCh->pTTY, &brkc, &brkf, 1 );
+		pCh->pTTY->ldisc->ops.receive_buf( pCh->pTTY, &brkc, &brkf, 1 );
 		pCh->pTTY->real_raw = tmp;
 	}
 #endif /* NEVER_HAPPENS_AS_SETUP_XXX */
@@ -199,7 +199,7 @@
 #define tty2n_hdlc(tty)	((struct n_hdlc *) ((tty)->disc_data))
 #define n_hdlc2tty(n_hdlc)	((n_hdlc)->tty)
  
-static struct tty_ldisc n_hdlc_ldisc = {
+static struct tty_ldisc_ops n_hdlc_ldisc = {
 	.owner		= THIS_MODULE,
 	.magic		= TTY_LDISC_MAGIC,
 	.name		= "hdlc",
@@ -342,8 +342,8 @@
 #endif
  
 	/* Flush any pending characters in the driver and discipline. */
-	if (tty->ldisc.flush_buffer)
-		tty->ldisc.flush_buffer(tty);
+	if (tty->ldisc.ops->flush_buffer)
+		tty->ldisc.ops->flush_buffer(tty);
  
 	tty_driver_flush_buffer(tty);
  
@@ -143,7 +143,7 @@
 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 		char *fp, int count);
  
-static struct tty_ldisc tty_ldisc_N_R3964 = {
+static struct tty_ldisc_ops tty_ldisc_N_R3964 = {
 	.owner = THIS_MODULE,
 	.magic = TTY_LDISC_MAGIC,
 	.name = "R3964",
@@ -1573,7 +1573,7 @@
 	return mask;
 }
  
-struct tty_ldisc tty_ldisc_N_TTY = {
+struct tty_ldisc_ops tty_ldisc_N_TTY = {
 	.magic           = TTY_LDISC_MAGIC,
 	.name            = "n_tty",
 	.open            = n_tty_open,
@@ -514,8 +514,8 @@
 		return;
 	ld = tty_ldisc_ref(tty);
 	if (ld) {
-		if (ld->receive_buf)
-			ld->receive_buf(tty, data, flags, count);
+		if (ld->ops->receive_buf)
+			ld->ops->receive_buf(tty, data, flags, count);
 		tty_ldisc_deref(ld);
 	}
 }
@@ -111,7 +111,7 @@
 	c = to->receive_room;
 	if (c > count)
 		c = count;
-	to->ldisc.receive_buf(to, buf, NULL, c);
+	to->ldisc.ops->receive_buf(to, buf, NULL, c);
  
 	return c;
 }
  
@@ -149,11 +149,11 @@
 	int count;
  
 	/* We should get the line discipline lock for "tty->link" */
-	if (!to || !to->ldisc.chars_in_buffer)
+	if (!to || !to->ldisc.ops->chars_in_buffer)
 		return 0;
  
 	/* The ldisc must report 0 if no characters available to be read */
-	count = to->ldisc.chars_in_buffer(to);
+	count = to->ldisc.ops->chars_in_buffer(to);
  
 	if (tty->driver->subtype == PTY_TYPE_SLAVE) return count;
  
@@ -186,8 +186,8 @@
 	if (!to)
 		return;
  
-	if (to->ldisc.flush_buffer)
-		to->ldisc.flush_buffer(to);
+	if (to->ldisc.ops->flush_buffer)
+		to->ldisc.ops->flush_buffer(to);
  
 	if (to->packet) {
 		spin_lock_irqsave(&tty->ctrl_lock, flags);
@@ -327,7 +327,8 @@
 		}
 		count = sel_buffer_lth - pasted;
 		count = min(count, tty->receive_room);
-		tty->ldisc.receive_buf(tty, sel_buffer + pasted, NULL, count);
+		tty->ldisc.ops->receive_buf(tty, sel_buffer + pasted,
+								NULL, count);
 		pasted += count;
 	}
 	remove_wait_queue(&vc->paste_wait, &wait);
@@ -975,8 +975,8 @@
 		return;
 	ld = tty_ldisc_ref(tty);
 	if (ld) {
-		if (ld->receive_buf)
-			ld->receive_buf(tty, data, flags, count);
+		if (ld->ops->receive_buf)
+			ld->ops->receive_buf(tty, data, flags, count);
 		tty_ldisc_deref(ld);
 	}
 }
@@ -641,8 +641,8 @@
 		return;
 	ld = tty_ldisc_ref(tty);
 	if (ld) {
-		if (ld->receive_buf)
-			ld->receive_buf(tty, data, flags, count);
+		if (ld->ops->receive_buf)
+			ld->ops->receive_buf(tty, data, flags, count);
 		tty_ldisc_deref(ld);
 	}
 }
@@ -712,8 +712,8 @@
 		return;
 	ld = tty_ldisc_ref(tty);
 	if (ld) {
-		if (ld->receive_buf)
-			ld->receive_buf(tty, data, flags, count);
+		if (ld->ops->receive_buf)
+			ld->ops->receive_buf(tty, data, flags, count);
 		tty_ldisc_deref(ld);
 	}
 }
@@ -95,8 +95,9 @@
 #include <linux/wait.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
+#include <linux/seq_file.h>
  
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 #include <asm/system.h>
  
 #include <linux/kbd_kern.h>
@@ -682,7 +683,7 @@
 static DEFINE_SPINLOCK(tty_ldisc_lock);
 static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
 /* Line disc dispatch table */
-static struct tty_ldisc tty_ldiscs[NR_LDISCS];
+static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
  
 /**
  *	tty_register_ldisc	-	install a line discipline
@@ -697,7 +698,7 @@
  *		takes tty_ldisc_lock to guard against ldisc races
  */
  
-int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc)
+int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc)
 {
 	unsigned long flags;
 	int ret = 0;
@@ -706,10 +707,9 @@
 		return -EINVAL;
  
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
-	tty_ldiscs[disc] = *new_ldisc;
-	tty_ldiscs[disc].num = disc;
-	tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED;
-	tty_ldiscs[disc].refcount = 0;
+	tty_ldiscs[disc] = new_ldisc;
+	new_ldisc->num = disc;
+	new_ldisc->refcount = 0;
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
  
 	return ret;
  
  
  
  
@@ -737,19 +737,56 @@
 		return -EINVAL;
  
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
-	if (tty_ldiscs[disc].refcount)
+	if (tty_ldiscs[disc]->refcount)
 		ret = -EBUSY;
 	else
-		tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED;
+		tty_ldiscs[disc] = NULL;
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
  
 	return ret;
 }
 EXPORT_SYMBOL(tty_unregister_ldisc);
  
+
 /**
+ *	tty_ldisc_try_get	-	try and reference an ldisc
+ *	@disc: ldisc number
+ *	@ld: tty ldisc structure to complete
+ *
+ *	Attempt to open and lock a line discipline into place. Return
+ *	the line discipline refcounted and assigned in ld. On an error
+ *	report the error code back
+ */
+
+static int tty_ldisc_try_get(int disc, struct tty_ldisc *ld)
+{
+	unsigned long flags;
+	struct tty_ldisc_ops *ldops;
+	int err = -EINVAL;
+	
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	ld->ops = NULL;
+	ldops = tty_ldiscs[disc];
+	/* Check the entry is defined */
+	if (ldops) {
+		/* If the module is being unloaded we can't use it */
+		if (!try_module_get(ldops->owner))
+			err = -EAGAIN;
+		else {
+			/* lock it */
+			ldops->refcount++;
+			ld->ops = ldops;
+			err = 0;
+		}
+	}
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	return err;
+}
+
+/**
  *	tty_ldisc_get		-	take a reference to an ldisc
  *	@disc: ldisc number
+ *	@ld: tty line discipline structure to use
  *
  *	Takes a reference to a line discipline. Deals with refcounts and
  *	module locking counts. Returns NULL if the discipline is not available.
  
  
  
@@ -760,32 +797,20 @@
  *		takes tty_ldisc_lock to guard against ldisc races
  */
  
-struct tty_ldisc *tty_ldisc_get(int disc)
+static int tty_ldisc_get(int disc, struct tty_ldisc *ld)
 {
-	unsigned long flags;
-	struct tty_ldisc *ld;
+	int err;
  
 	if (disc < N_TTY || disc >= NR_LDISCS)
-		return NULL;
-
-	spin_lock_irqsave(&tty_ldisc_lock, flags);
-
-	ld = &tty_ldiscs[disc];
-	/* Check the entry is defined */
-	if (ld->flags & LDISC_FLAG_DEFINED) {
-		/* If the module is being unloaded we can't use it */
-		if (!try_module_get(ld->owner))
-			ld = NULL;
-		else /* lock it */
-			ld->refcount++;
-	} else
-		ld = NULL;
-	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-	return ld;
+		return -EINVAL;
+	err = tty_ldisc_try_get(disc, ld);
+	if (err == -EAGAIN) {
+		request_module("tty-ldisc-%d", disc);
+		err = tty_ldisc_try_get(disc, ld);
+	}
+	return err;
 }
  
-EXPORT_SYMBOL_GPL(tty_ldisc_get);
-
 /**
  *	tty_ldisc_put		-	drop ldisc reference
  *	@disc: ldisc number
  
  
  
  
  
@@ -797,23 +822,68 @@
  *		takes tty_ldisc_lock to guard against ldisc races
  */
  
-void tty_ldisc_put(int disc)
+static void tty_ldisc_put(struct tty_ldisc_ops *ld)
 {
-	struct tty_ldisc *ld;
 	unsigned long flags;
+	int disc = ld->num;
  
 	BUG_ON(disc < N_TTY || disc >= NR_LDISCS);
  
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
-	ld = &tty_ldiscs[disc];
+	ld = tty_ldiscs[disc];
 	BUG_ON(ld->refcount == 0);
 	ld->refcount--;
 	module_put(ld->owner);
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 }
  
-EXPORT_SYMBOL_GPL(tty_ldisc_put);
+static void * tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
+{
+	return (*pos < NR_LDISCS) ? pos : NULL;
+}
  
+static void * tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	(*pos)++;
+	return (*pos < NR_LDISCS) ? pos : NULL;
+}
+
+static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
+{
+}
+
+static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
+{
+	int i = *(loff_t *)v;
+	struct tty_ldisc ld;
+	
+	if (tty_ldisc_get(i, &ld) < 0)
+		return 0;
+	seq_printf(m, "%-10s %2d\n", ld.ops->name ? ld.ops->name : "???", i);
+	tty_ldisc_put(ld.ops);
+	return 0;
+}
+
+static const struct seq_operations tty_ldiscs_seq_ops = {
+	.start	= tty_ldiscs_seq_start,
+	.next	= tty_ldiscs_seq_next,
+	.stop	= tty_ldiscs_seq_stop,
+	.show	= tty_ldiscs_seq_show,
+};
+
+static int proc_tty_ldiscs_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &tty_ldiscs_seq_ops);
+}
+
+const struct file_operations tty_ldiscs_proc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= proc_tty_ldiscs_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
 /**
  *	tty_ldisc_assign	-	set ldisc on a tty
  *	@tty: tty to assign
  
@@ -829,8 +899,8 @@
  
 static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
 {
+	ld->refcount = 0;
 	tty->ldisc = *ld;
-	tty->ldisc.refcount = 0;
 }
  
 /**
@@ -954,6 +1024,41 @@
 }
  
 /**
+ *	tty_ldisc_restore	-	helper for tty ldisc change
+ *	@tty: tty to recover
+ *	@old: previous ldisc
+ *
+ *	Restore the previous line discipline or N_TTY when a line discipline
+ *	change fails due to an open error
+ */
+
+static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
+{
+	char buf[64];
+	struct tty_ldisc new_ldisc;
+
+	/* There is an outstanding reference here so this is safe */
+	tty_ldisc_get(old->ops->num, old);
+	tty_ldisc_assign(tty, old);
+	tty_set_termios_ldisc(tty, old->ops->num);
+	if (old->ops->open && (old->ops->open(tty) < 0)) {
+		tty_ldisc_put(old->ops);
+		/* This driver is always present */
+		if (tty_ldisc_get(N_TTY, &new_ldisc) < 0)
+			panic("n_tty: get");
+		tty_ldisc_assign(tty, &new_ldisc);
+		tty_set_termios_ldisc(tty, N_TTY);
+		if (new_ldisc.ops->open) {
+			int r = new_ldisc.ops->open(tty);
+				if (r < 0)
+				panic("Couldn't open N_TTY ldisc for "
+				      "%s --- error %d.",
+				      tty_name(tty, buf), r);
+		}
+	}
+}
+
+/**
  *	tty_set_ldisc		-	set line discipline
  *	@tty: the terminal to set
  *	@ldisc: the line discipline
  
  
  
  
  
@@ -967,37 +1072,27 @@
  
 static int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 {
-	int retval = 0;
-	struct tty_ldisc o_ldisc;
-	char buf[64];
+	int retval;
+	struct tty_ldisc o_ldisc, new_ldisc;
 	int work;
 	unsigned long flags;
-	struct tty_ldisc *ld;
 	struct tty_struct *o_tty;
  
-	if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS))
-		return -EINVAL;
-
 restart:
+	/* This is a bit ugly for now but means we can break the 'ldisc
+	   is part of the tty struct' assumption later */
+	retval = tty_ldisc_get(ldisc, &new_ldisc);
+	if (retval)
+		return retval;
  
-	ld = tty_ldisc_get(ldisc);
-	/* Eduardo Blanco <ejbs@cs.cs.com.uy> */
-	/* Cyrus Durgin <cider@speakeasy.org> */
-	if (ld == NULL) {
-		request_module("tty-ldisc-%d", ldisc);
-		ld = tty_ldisc_get(ldisc);
-	}
-	if (ld == NULL)
-		return -EINVAL;
-
 	/*
 	 *	Problem: What do we do if this blocks ?
 	 */
  
 	tty_wait_until_sent(tty, 0);
  
-	if (tty->ldisc.num == ldisc) {
-		tty_ldisc_put(ldisc);
+	if (tty->ldisc.ops->num == ldisc) {
+		tty_ldisc_put(new_ldisc.ops);
 		return 0;
 	}
  
@@ -1024,7 +1119,7 @@
 			/* Free the new ldisc we grabbed. Must drop the lock
 			   first. */
 			spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-			tty_ldisc_put(ldisc);
+			tty_ldisc_put(o_ldisc.ops);
 			/*
 			 * There are several reasons we may be busy, including
 			 * random momentary I/O traffic. We must therefore
@@ -1038,7 +1133,7 @@
 		}
 		if (o_tty && o_tty->ldisc.refcount) {
 			spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-			tty_ldisc_put(ldisc);
+			tty_ldisc_put(o_tty->ldisc.ops);
 			if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0)
 				return -ERESTARTSYS;
 			goto restart;
  
@@ -1049,8 +1144,9 @@
 	 *	another ldisc change
 	 */
 	if (!test_bit(TTY_LDISC, &tty->flags)) {
+		struct tty_ldisc *ld;
 		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-		tty_ldisc_put(ldisc);
+		tty_ldisc_put(new_ldisc.ops);
 		ld = tty_ldisc_ref_wait(tty);
 		tty_ldisc_deref(ld);
 		goto restart;
@@ -1060,7 +1156,7 @@
 	if (o_tty)
 		clear_bit(TTY_LDISC, &o_tty->flags);
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-
+	
 	/*
 	 *	From this point on we know nobody has an ldisc
 	 *	usage reference, nor can they obtain one until
  
  
  
  
  
  
@@ -1070,45 +1166,30 @@
 	work = cancel_delayed_work(&tty->buf.work);
 	/*
 	 * Wait for ->hangup_work and ->buf.work handlers to terminate
+	 * MUST NOT hold locks here.
 	 */
 	flush_scheduled_work();
 	/* Shutdown the current discipline. */
-	if (tty->ldisc.close)
-		(tty->ldisc.close)(tty);
+	if (o_ldisc.ops->close)
+		(o_ldisc.ops->close)(tty);
  
 	/* Now set up the new line discipline. */
-	tty_ldisc_assign(tty, ld);
+	tty_ldisc_assign(tty, &new_ldisc);
 	tty_set_termios_ldisc(tty, ldisc);
-	if (tty->ldisc.open)
-		retval = (tty->ldisc.open)(tty);
+	if (new_ldisc.ops->open)
+		retval = (new_ldisc.ops->open)(tty);
 	if (retval < 0) {
-		tty_ldisc_put(ldisc);
-		/* There is an outstanding reference here so this is safe */
-		tty_ldisc_assign(tty, tty_ldisc_get(o_ldisc.num));
-		tty_set_termios_ldisc(tty, tty->ldisc.num);
-		if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) {
-			tty_ldisc_put(o_ldisc.num);
-			/* This driver is always present */
-			tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
-			tty_set_termios_ldisc(tty, N_TTY);
-			if (tty->ldisc.open) {
-				int r = tty->ldisc.open(tty);
-
-				if (r < 0)
-					panic("Couldn't open N_TTY ldisc for "
-					      "%s --- error %d.",
-					      tty_name(tty, buf), r);
-			}
-		}
+		tty_ldisc_put(new_ldisc.ops);
+		tty_ldisc_restore(tty, &o_ldisc);
 	}
 	/* At this point we hold a reference to the new ldisc and a
 	   a reference to the old ldisc. If we ended up flipping back
 	   to the existing ldisc we have two references to it */
  
-	if (tty->ldisc.num != o_ldisc.num && tty->ops->set_ldisc)
+	if (tty->ldisc.ops->num != o_ldisc.ops->num && tty->ops->set_ldisc)
 		tty->ops->set_ldisc(tty);
  
-	tty_ldisc_put(o_ldisc.num);
+	tty_ldisc_put(o_ldisc.ops);
  
 	/*
 	 *	Allow ldisc referencing to occur as soon as the driver
@@ -1335,8 +1416,8 @@
 	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
 		ld = tty_ldisc_ref(tty);
 		if (ld) {
-			if (ld->write_wakeup)
-				ld->write_wakeup(tty);
+			if (ld->ops->write_wakeup)
+				ld->ops->write_wakeup(tty);
 			tty_ldisc_deref(ld);
 		}
 	}
@@ -1357,8 +1438,8 @@
 {
 	struct tty_ldisc *ld = tty_ldisc_ref(tty);
 	if (ld) {
-		if (ld->flush_buffer)
-			ld->flush_buffer(tty);
+		if (ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
 		tty_ldisc_deref(ld);
 	}
 	tty_buffer_flush(tty);
@@ -1386,7 +1467,7 @@
  *	do_tty_hangup		-	actual handler for hangup events
  *	@work: tty device
  *
- *	This can be called by the "eventd" kernel thread.  That is process
+k *	This can be called by the "eventd" kernel thread.  That is process
  *	synchronous but doesn't hold any locks, so we need to make sure we
  *	have the appropriate locks for what we're doing.
  *
  
@@ -1449,14 +1530,14 @@
 	ld = tty_ldisc_ref(tty);
 	if (ld != NULL) {
 		/* We may have no line discipline at this point */
-		if (ld->flush_buffer)
-			ld->flush_buffer(tty);
+		if (ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
 		tty_driver_flush_buffer(tty);
 		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
-		    ld->write_wakeup)
-			ld->write_wakeup(tty);
-		if (ld->hangup)
-			ld->hangup(tty);
+		    ld->ops->write_wakeup)
+			ld->ops->write_wakeup(tty);
+		if (ld->ops->hangup)
+			ld->ops->hangup(tty);
 	}
 	/*
 	 * FIXME: Once we trust the LDISC code better we can wait here for
@@ -1825,8 +1906,8 @@
 	/* We want to wait for the line discipline to sort out in this
 	   situation */
 	ld = tty_ldisc_ref_wait(tty);
-	if (ld->read)
-		i = (ld->read)(tty, file, buf, count);
+	if (ld->ops->read)
+		i = (ld->ops->read)(tty, file, buf, count);
 	else
 		i = -EIO;
 	tty_ldisc_deref(ld);
  
@@ -1978,10 +2059,10 @@
 		printk(KERN_ERR "tty driver %s lacks a write_room method.\n",
 			tty->driver->name);
 	ld = tty_ldisc_ref_wait(tty);
-	if (!ld->write)
+	if (!ld->ops->write)
 		ret = -EIO;
 	else
-		ret = do_tty_write(ld->write, tty, file, buf, count);
+		ret = do_tty_write(ld->ops->write, tty, file, buf, count);
 	tty_ldisc_deref(ld);
 	return ret;
 }
@@ -2076,6 +2157,7 @@
 	struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc;
 	struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc;
 	int retval = 0;
+	struct tty_ldisc *ld;
  
 	/* check whether we're reopening an existing tty */
 	if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
  
  
  
@@ -2224,17 +2306,19 @@
 	 * If we fail here just call release_tty to clean up.  No need
 	 * to decrement the use counts, as release_tty doesn't care.
 	 */
+	 
+	ld = &tty->ldisc;
  
-	if (tty->ldisc.open) {
-		retval = (tty->ldisc.open)(tty);
+	if (ld->ops->open) {
+		retval = (ld->ops->open)(tty);
 		if (retval)
 			goto release_mem_out;
 	}
-	if (o_tty && o_tty->ldisc.open) {
-		retval = (o_tty->ldisc.open)(o_tty);
+	if (o_tty && o_tty->ldisc.ops->open) {
+		retval = (o_tty->ldisc.ops->open)(o_tty);
 		if (retval) {
-			if (tty->ldisc.close)
-				(tty->ldisc.close)(tty);
+			if (ld->ops->close)
+				(ld->ops->close)(tty);
 			goto release_mem_out;
 		}
 		tty_ldisc_enable(o_tty);
@@ -2378,6 +2462,7 @@
 static void release_dev(struct file *filp)
 {
 	struct tty_struct *tty, *o_tty;
+	struct tty_ldisc ld;
 	int	pty_master, tty_closing, o_tty_closing, do_sleep;
 	int	devpts;
 	int	idx;
  
  
  
@@ -2611,26 +2696,27 @@
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 	/*
 	 * Shutdown the current line discipline, and reset it to N_TTY.
-	 * N.B. why reset ldisc when we're releasing the memory??
 	 *
 	 * FIXME: this MUST get fixed for the new reflocking
 	 */
-	if (tty->ldisc.close)
-		(tty->ldisc.close)(tty);
-	tty_ldisc_put(tty->ldisc.num);
+	if (tty->ldisc.ops->close)
+		(tty->ldisc.ops->close)(tty);
+	tty_ldisc_put(tty->ldisc.ops);
  
 	/*
 	 *	Switch the line discipline back
 	 */
-	tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
+	WARN_ON(tty_ldisc_get(N_TTY, &ld));
+	tty_ldisc_assign(tty, &ld);
 	tty_set_termios_ldisc(tty, N_TTY);
 	if (o_tty) {
 		/* FIXME: could o_tty be in setldisc here ? */
 		clear_bit(TTY_LDISC, &o_tty->flags);
-		if (o_tty->ldisc.close)
-			(o_tty->ldisc.close)(o_tty);
-		tty_ldisc_put(o_tty->ldisc.num);
-		tty_ldisc_assign(o_tty, tty_ldisc_get(N_TTY));
+		if (o_tty->ldisc.ops->close)
+			(o_tty->ldisc.ops->close)(o_tty);
+		tty_ldisc_put(o_tty->ldisc.ops);
+		WARN_ON(tty_ldisc_get(N_TTY, &ld));
+		tty_ldisc_assign(o_tty, &ld);
 		tty_set_termios_ldisc(o_tty, N_TTY);
 	}
 	/*
@@ -2899,8 +2985,8 @@
 		return 0;
  
 	ld = tty_ldisc_ref_wait(tty);
-	if (ld->poll)
-		ret = (ld->poll)(tty, filp, wait);
+	if (ld->ops->poll)
+		ret = (ld->ops->poll)(tty, filp, wait);
 	tty_ldisc_deref(ld);
 	return ret;
 }
@@ -2974,7 +3060,7 @@
 	if (get_user(ch, p))
 		return -EFAULT;
 	ld = tty_ldisc_ref_wait(tty);
-	ld->receive_buf(tty, &ch, &mbz, 1);
+	ld->ops->receive_buf(tty, &ch, &mbz, 1);
 	tty_ldisc_deref(ld);
 	return 0;
 }
@@ -3528,7 +3614,7 @@
 	case TIOCGSID:
 		return tiocgsid(tty, real_tty, p);
 	case TIOCGETD:
-		return put_user(tty->ldisc.num, (int __user *)p);
+		return put_user(tty->ldisc.ops->num, (int __user *)p);
 	case TIOCSETD:
 		return tiocsetd(tty, p);
 #ifdef CONFIG_VT
@@ -3581,8 +3667,8 @@
 	}
 	ld = tty_ldisc_ref_wait(tty);
 	retval = -EINVAL;
-	if (ld->ioctl) {
-		retval = ld->ioctl(tty, file, cmd, arg);
+	if (ld->ops->ioctl) {
+		retval = ld->ops->ioctl(tty, file, cmd, arg);
 		if (retval == -ENOIOCTLCMD)
 			retval = -EINVAL;
 	}
@@ -3609,8 +3695,8 @@
 	}
  
 	ld = tty_ldisc_ref_wait(tty);
-	if (ld->compat_ioctl)
-		retval = ld->compat_ioctl(tty, file, cmd, arg);
+	if (ld->ops->compat_ioctl)
+		retval = ld->ops->compat_ioctl(tty, file, cmd, arg);
 	tty_ldisc_deref(ld);
  
 	return retval;
@@ -3782,7 +3868,8 @@
 			flag_buf = head->flag_buf_ptr + head->read;
 			head->read += count;
 			spin_unlock_irqrestore(&tty->buf.lock, flags);
-			disc->receive_buf(tty, char_buf, flag_buf, count);
+			disc->ops->receive_buf(tty, char_buf,
+							flag_buf, count);
 			spin_lock_irqsave(&tty->buf.lock, flags);
 		}
 		/* Restore the queue head */
  
@@ -3843,9 +3930,12 @@
  
 static void initialize_tty_struct(struct tty_struct *tty)
 {
+	struct tty_ldisc ld;
 	memset(tty, 0, sizeof(struct tty_struct));
 	tty->magic = TTY_MAGIC;
-	tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
+	if (tty_ldisc_get(N_TTY, &ld) < 0)
+		panic("n_tty: init_tty");
+	tty_ldisc_assign(tty, &ld);
 	tty->session = NULL;
 	tty->pgrp = NULL;
 	tty->overrun_time = jiffies;
@@ -491,8 +491,8 @@
  
 	ld = tty_ldisc_ref(tty);
 	if (ld != NULL) {
-		if (ld->set_termios)
-			(ld->set_termios)(tty, &old_termios);
+		if (ld->ops->set_termios)
+			(ld->ops->set_termios)(tty, &old_termios);
 		tty_ldisc_deref(ld);
 	}
 	mutex_unlock(&tty->termios_mutex);
@@ -552,8 +552,8 @@
 	ld = tty_ldisc_ref(tty);
  
 	if (ld != NULL) {
-		if ((opt & TERMIOS_FLUSH) && ld->flush_buffer)
-			ld->flush_buffer(tty);
+		if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
 		tty_ldisc_deref(ld);
 	}
  
  
@@ -959,12 +959,12 @@
 	ld = tty_ldisc_ref(tty);
 	switch (arg) {
 	case TCIFLUSH:
-		if (ld && ld->flush_buffer)
-			ld->flush_buffer(tty);
+		if (ld && ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
 		break;
 	case TCIOFLUSH:
-		if (ld && ld->flush_buffer)
-			ld->flush_buffer(tty);
+		if (ld && ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
 		/* fall through */
 	case TCOFLUSH:
 		tty_driver_flush_buffer(tty);
@@ -216,7 +216,7 @@
  * The line discipline structure.
  */
  
-static struct tty_ldisc serport_ldisc = {
+static struct tty_ldisc_ops serport_ldisc = {
 	.owner =	THIS_MODULE,
 	.name =		"input",
 	.open =		serport_ldisc_open,
@@ -466,7 +466,7 @@
 	ld = tty_ldisc_ref(mp->tty);
 	if (ld == NULL)
 		return -1;
-	if (ld->receive_buf == NULL) {
+	if (ld->ops->receive_buf == NULL) {
 #if defined(_DEBUG_DATAFLOW) || defined(_DEBUG_TTYFUNCS)
 		printk(KERN_DEBUG "capi: ldisc has no receive_buf function\n");
 #endif
@@ -501,7 +501,7 @@
 	printk(KERN_DEBUG "capi: DATA_B3_RESP %u len=%d => ldisc\n",
 				datahandle, skb->len);
 #endif
-	ld->receive_buf(mp->tty, skb->data, NULL, skb->len);
+	ld->ops->receive_buf(mp->tty, skb->data, NULL, skb->len);
 	kfree_skb(skb);
 	tty_ldisc_deref(ld);
 	return 0;
@@ -766,7 +766,7 @@
 	cs_put(cs);
 }
  
-static struct tty_ldisc gigaset_ldisc = {
+static struct tty_ldisc_ops gigaset_ldisc = {
 	.owner		= THIS_MODULE,
 	.magic		= TTY_LDISC_MAGIC,
 	.name		= "ser_gigaset",
@@ -783,7 +783,7 @@
 	return err;
 }
  
-static struct tty_ldisc sp_ldisc = {
+static struct tty_ldisc_ops sp_ldisc = {
 	.owner		= THIS_MODULE,
 	.magic		= TTY_LDISC_MAGIC,
 	.name		= "6pack",
@@ -969,7 +969,7 @@
 	mkiss_put(ax);
 }
  
-static struct tty_ldisc ax_ldisc = {
+static struct tty_ldisc_ops ax_ldisc = {
 	.owner		= THIS_MODULE,
 	.magic		= TTY_LDISC_MAGIC,
 	.name		= "mkiss",
@@ -533,7 +533,7 @@
  
 /* ------------------------------------------------------- */
  
-static struct tty_ldisc irda_ldisc = {
+static struct tty_ldisc_ops irda_ldisc = {
 	.magic		= TTY_LDISC_MAGIC,
  	.name		= "irda",
 	.flags		= 0,
@@ -378,7 +378,7 @@
 }
  
  
-static struct tty_ldisc ppp_ldisc = {
+static struct tty_ldisc_ops ppp_ldisc = {
 	.owner  = THIS_MODULE,
 	.magic	= TTY_LDISC_MAGIC,
 	.name	= "ppp",
@@ -418,7 +418,7 @@
 }
  
  
-static struct tty_ldisc ppp_sync_ldisc = {
+static struct tty_ldisc_ops ppp_sync_ldisc = {
 	.owner	= THIS_MODULE,
 	.magic	= TTY_LDISC_MAGIC,
 	.name	= "pppsync",
@@ -1301,7 +1301,7 @@
 #endif
 /* VSV changes end */
  
-static struct tty_ldisc	sl_ldisc = {
+static struct tty_ldisc_ops sl_ldisc = {
 	.owner 		= THIS_MODULE,
 	.magic 		= TTY_LDISC_MAGIC,
 	.name 		= "slip",
@@ -688,9 +688,9 @@
 				if (cpc_tty->tty) {
 					ld = tty_ldisc_ref(cpc_tty->tty);
 					if (ld) {
-						if (ld->receive_buf) {
+						if (ld->ops->receive_buf) {
 							CPC_TTY_DBG("%s: call line disc. receive_buf\n",cpc_tty->name);
-							ld->receive_buf(cpc_tty->tty, (char *)(buf->data), &flags, buf->size);
+							ld->ops->receive_buf(cpc_tty->tty, (char *)(buf->data), &flags, buf->size);
 						}
 						tty_ldisc_deref(ld);
 					}
@@ -754,7 +754,7 @@
 	dev->flags		= IFF_NOARP;
 }
  
-static struct tty_ldisc x25_ldisc = {
+static struct tty_ldisc_ops x25_ldisc = {
 	.owner		= THIS_MODULE,
 	.magic		= TTY_LDISC_MAGIC,
 	.name		= "X.25",
@@ -136,54 +136,6 @@
 	.release	= seq_release,
 };
  
-static void * tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
-{
-	return (*pos < NR_LDISCS) ? pos : NULL;
-}
-
-static void * tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
-{
-	(*pos)++;
-	return (*pos < NR_LDISCS) ? pos : NULL;
-}
-
-static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
-{
-}
-
-static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
-{
-	int i = *(loff_t *)v;
-	struct tty_ldisc *ld;
-	
-	ld = tty_ldisc_get(i);
-	if (ld == NULL)
-		return 0;
-	seq_printf(m, "%-10s %2d\n", ld->name ? ld->name : "???", i);
-	tty_ldisc_put(i);
-	return 0;
-}
-
-static const struct seq_operations tty_ldiscs_seq_ops = {
-	.start	= tty_ldiscs_seq_start,
-	.next	= tty_ldiscs_seq_next,
-	.stop	= tty_ldiscs_seq_stop,
-	.show	= tty_ldiscs_seq_show,
-};
-
-static int proc_tty_ldiscs_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &tty_ldiscs_seq_ops);
-}
-
-static const struct file_operations tty_ldiscs_proc_fops = {
-	.owner		= THIS_MODULE,
-	.open		= proc_tty_ldiscs_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
 /*
  * This function is called by tty_register_driver() to handle
  * registering the driver's /proc handler into /proc/tty/driver/<foo>
@@ -185,6 +185,7 @@
 	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 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);
  
@@ -330,10 +331,8 @@
 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 const struct file_operations tty_ldiscs_proc_fops;
  
-extern struct tty_ldisc *tty_ldisc_get(int);
-extern void tty_ldisc_put(int);
-
 extern void tty_wakeup(struct tty_struct *tty);
 extern void tty_ldisc_flush(struct tty_struct *tty);
  
@@ -354,7 +353,7 @@
  
  
 /* 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
@@ -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;
@@ -139,6 +139,11 @@
  
 	struct  module *owner;
  
+	int refcount;
+};
+
+struct tty_ldisc {
+	struct tty_ldisc_ops *ops;
 	int refcount;
 };
  
@@ -617,14 +617,7 @@
 		return;
  
 	BT_DBG("dev %p tty %p", dev, tty);
-
-	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && tty->ldisc.write_wakeup)
-		(tty->ldisc.write_wakeup)(tty);
-
-	wake_up_interruptible(&tty->write_wait);
-#ifdef SERIAL_HAVE_POLL_WAIT
-	wake_up_interruptible(&tty->poll_wait);
-#endif
+	tty_wakeup(tty);
 }
  
 static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
@@ -1005,9 +998,7 @@
 		return;
  
 	skb_queue_purge(&dev->dlc->tx_queue);
-
-	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && tty->ldisc.write_wakeup)
-		tty->ldisc.write_wakeup(tty);
+	tty_wakeup(tty);
 }
  
 static void rfcomm_tty_send_xchar(struct tty_struct *tty, char ch)
@@ -650,12 +650,7 @@
 	}
  
 	/* Check if user (still) wants to be waken up */
-	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
-	    tty->ldisc.write_wakeup)
-	{
-		(tty->ldisc.write_wakeup)(tty);
-	}
-	wake_up_interruptible(&tty->write_wait);
+	tty_wakeup(tty);
 }
  
 /*
@@ -1141,6 +1136,7 @@
 				      struct sk_buff *skb)
 {
 	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;
+	struct tty_ldisc *ld;
  
 	IRDA_DEBUG(2, "%s()\n", __func__ );
  
@@ -1173,7 +1169,11 @@
 	 * involve the flip buffers, since we are not running in an interrupt
 	 * handler
 	 */
-	self->tty->ldisc.receive_buf(self->tty, skb->data, NULL, skb->len);
+
+	ld = tty_ldisc_ref(self->tty);
+	if (ld)
+		ld->ops->receive_buf(self->tty, skb->data, NULL, skb->len);
+	tty_ldisc_deref(ld);
  
 	/* No need to kfree_skb - see ircomm_ttp_data_indication() */
...	...	@@ -282,8 +282,8 @@
282	282	/* FIXME: why is this needed. Note don't use ldisc_ref here as the
283	283	open path is before the ldisc is referencable */
284	284
285		- if (tty->ldisc.flush_buffer)
286		- tty->ldisc.flush_buffer(tty);
	285	+ if (tty->ldisc.ops->flush_buffer)
	286	+ tty->ldisc.ops->flush_buffer(tty);
287	287	tty_driver_flush_buffer(tty);
288	288
289	289	return 0;
...	...	@@ -514,7 +514,7 @@
514	514
515	515	static int __init hci_uart_init(void)
516	516	{
517		- static struct tty_ldisc hci_uart_ldisc;
	517	+ static struct tty_ldisc_ops hci_uart_ldisc;
518	518	int err;
519	519
520	520	BT_INFO("HCI UART driver ver %s", VERSION);
...	...	@@ -5246,7 +5246,8 @@
5246	5246	HZ, info->idle_stats.recv_bytes,
5247	5247	(cur_jifs - info->idle_stats.recv_idle)/
5248	5248	HZ, info->idle_stats.overruns,
5249		- (long)info->tty->ldisc.num);
	5249	+ /* FIXME: double check locking */
	5250	+ (long)info->tty->ldisc.ops->num);
5250	5251	else
5251	5252	size = sprintf(buf + len, "%3d %8lu %10lu %8lu "
5252	5253	"%10lu %8lu %9lu %6ld\n",
...	...	@@ -2262,8 +2262,8 @@
2262	2262	tty_wait_until_sent(tty, 0);
2263	2263	} else {
2264	2264	/* ldisc lock already held in ioctl */
2265		- if (tty->ldisc.flush_buffer)
2266		- tty->ldisc.flush_buffer(tty);
	2265	+ if (tty->ldisc.ops->flush_buffer)
	2266	+ tty->ldisc.ops->flush_buffer(tty);
2267	2267	}
2268	2268	unlock_kernel();
2269	2269	/* Fall Thru */
...	...	@@ -868,11 +868,11 @@
868	868	amountToMove = count;
869	869	}
870	870	// Move the first block
871		- pCh->pTTY->ldisc.receive_buf( pCh->pTTY,
	871	+ pCh->pTTY->ldisc.ops->receive_buf( pCh->pTTY,
872	872	&(pCh->Ibuf[stripIndex]), NULL, amountToMove );
873	873	// If we needed to wrap, do the second data move
874	874	if (count > amountToMove) {
875		- pCh->pTTY->ldisc.receive_buf( pCh->pTTY,
	875	+ pCh->pTTY->ldisc.ops->receive_buf( pCh->pTTY,
876	876	pCh->Ibuf, NULL, count - amountToMove );
877	877	}
878	878	// Bump and wrap the stripIndex all at once by the amount of data read. This
...	...	@@ -1289,11 +1289,12 @@
1289	1289	// code duplicated from n_tty (ldisc)
1290	1290	static inline void isig(int sig, struct tty_struct *tty, int flush)
1291	1291	{
	1292	+ /* FIXME: This is completely bogus */
1292	1293	if (tty->pgrp)
1293	1294	kill_pgrp(tty->pgrp, sig, 1);
1294	1295	if (flush \|\| !L_NOFLSH(tty)) {
1295		- if ( tty->ldisc.flush_buffer )
1296		- tty->ldisc.flush_buffer(tty);
	1296	+ if ( tty->ldisc.ops->flush_buffer )
	1297	+ tty->ldisc.ops->flush_buffer(tty);
1297	1298	i2InputFlush( tty->driver_data );
1298	1299	}
1299	1300	}
...	...	@@ -1342,7 +1343,7 @@
1342	1343	}
1343	1344	tmp = pCh->pTTY->real_raw;
1344	1345	pCh->pTTY->real_raw = 0;
1345		- pCh->pTTY->ldisc.receive_buf( pCh->pTTY, &brkc, &brkf, 1 );
	1346	+ pCh->pTTY->ldisc->ops.receive_buf( pCh->pTTY, &brkc, &brkf, 1 );
1346	1347	pCh->pTTY->real_raw = tmp;
1347	1348	}
1348	1349	#endif /* NEVER_HAPPENS_AS_SETUP_XXX */
...	...	@@ -199,7 +199,7 @@
199	199	#define tty2n_hdlc(tty) ((struct n_hdlc *) ((tty)->disc_data))
200	200	#define n_hdlc2tty(n_hdlc) ((n_hdlc)->tty)
201	201
202		-static struct tty_ldisc n_hdlc_ldisc = {
	202	+static struct tty_ldisc_ops n_hdlc_ldisc = {
203	203	.owner = THIS_MODULE,
204	204	.magic = TTY_LDISC_MAGIC,
205	205	.name = "hdlc",
...	...	@@ -342,8 +342,8 @@
342	342	#endif
343	343
344	344	/* Flush any pending characters in the driver and discipline. */
345		- if (tty->ldisc.flush_buffer)
346		- tty->ldisc.flush_buffer(tty);
	345	+ if (tty->ldisc.ops->flush_buffer)
	346	+ tty->ldisc.ops->flush_buffer(tty);
347	347
348	348	tty_driver_flush_buffer(tty);
349	349
...	...	@@ -143,7 +143,7 @@
143	143	static void r3964_receive_buf(struct tty_struct tty, const unsigned char cp,
144	144	char *fp, int count);
145	145
146		-static struct tty_ldisc tty_ldisc_N_R3964 = {
	146	+static struct tty_ldisc_ops tty_ldisc_N_R3964 = {
147	147	.owner = THIS_MODULE,
148	148	.magic = TTY_LDISC_MAGIC,
149	149	.name = "R3964",
...	...	@@ -1573,7 +1573,7 @@
1573	1573	return mask;
1574	1574	}
1575	1575
1576		-struct tty_ldisc tty_ldisc_N_TTY = {
	1576	+struct tty_ldisc_ops tty_ldisc_N_TTY = {
1577	1577	.magic = TTY_LDISC_MAGIC,
1578	1578	.name = "n_tty",
1579	1579	.open = n_tty_open,
...	...	@@ -514,8 +514,8 @@
514	514	return;
515	515	ld = tty_ldisc_ref(tty);
516	516	if (ld) {
517		- if (ld->receive_buf)
518		- ld->receive_buf(tty, data, flags, count);
	517	+ if (ld->ops->receive_buf)
	518	+ ld->ops->receive_buf(tty, data, flags, count);
519	519	tty_ldisc_deref(ld);
520	520	}
521	521	}
...	...	@@ -111,7 +111,7 @@
111	111	c = to->receive_room;
112	112	if (c > count)
113	113	c = count;
114		- to->ldisc.receive_buf(to, buf, NULL, c);
	114	+ to->ldisc.ops->receive_buf(to, buf, NULL, c);
115	115
116	116	return c;
117	117	}
118	118
...	...	@@ -149,11 +149,11 @@
149	149	int count;
150	150
151	151	/* We should get the line discipline lock for "tty->link" */
152		- if (!to \|\| !to->ldisc.chars_in_buffer)
	152	+ if (!to \|\| !to->ldisc.ops->chars_in_buffer)
153	153	return 0;
154	154
155	155	/* The ldisc must report 0 if no characters available to be read */
156		- count = to->ldisc.chars_in_buffer(to);
	156	+ count = to->ldisc.ops->chars_in_buffer(to);
157	157
158	158	if (tty->driver->subtype == PTY_TYPE_SLAVE) return count;
159	159
...	...	@@ -186,8 +186,8 @@
186	186	if (!to)
187	187	return;
188	188
189		- if (to->ldisc.flush_buffer)
190		- to->ldisc.flush_buffer(to);
	189	+ if (to->ldisc.ops->flush_buffer)
	190	+ to->ldisc.ops->flush_buffer(to);
191	191
192	192	if (to->packet) {
193	193	spin_lock_irqsave(&tty->ctrl_lock, flags);