[PATCH] uml: Add throttling to console driver

This patch adds support for throttling and unthrottling input when the tty
driver can't handle it.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/include/line.h b/arch/um/include/line.h
index e6cc3ab..6f4d680 100644
--- a/arch/um/include/line.h
+++ b/arch/um/include/line.h
@@ -38,6 +38,7 @@
 	struct list_head chan_list;
 	int valid;
 	int count;
+	int throttled;
 	/*This lock is actually, mostly, local to*/
 	spinlock_t lock;
 
@@ -60,6 +61,7 @@
 	{ init_str :	str, \
 	  init_pri :	INIT_STATIC, \
 	  valid :	1, \
+	  throttled :	0, \
 	  lock :	SPIN_LOCK_UNLOCKED, \
 	  buffer :	NULL, \
 	  head :	NULL, \
@@ -88,6 +90,8 @@
 extern int line_write_room(struct tty_struct *tty);
 extern int line_ioctl(struct tty_struct *tty, struct file * file,
 		      unsigned int cmd, unsigned long arg);
+extern void line_throttle(struct tty_struct *tty);
+extern void line_unthrottle(struct tty_struct *tty);
 
 extern char *add_xterm_umid(char *base);
 extern int line_setup_irq(int fd, int input, int output, struct line *line,