1 files changed, 60 insertions, 36 deletions

diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index 41f7449d0464..507a25d692bb 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -54,7 +54,7 @@
  *	to be no queue on the device.
  */
 
-int tty_chars_in_buffer(struct tty_struct *tty)
+unsigned int tty_chars_in_buffer(struct tty_struct *tty)
 {
 	if (tty->ops->chars_in_buffer)
 		return tty->ops->chars_in_buffer(tty);
@@ -73,7 +73,7 @@ EXPORT_SYMBOL(tty_chars_in_buffer);
  *	returned and data may be lost as there will be no flow control.
  */
  
-int tty_write_room(struct tty_struct *tty)
+unsigned int tty_write_room(struct tty_struct *tty)
 {
 	if (tty->ops->write_room)
 		return tty->ops->write_room(tty);
@@ -97,28 +97,6 @@ void tty_driver_flush_buffer(struct tty_struct *tty)
 EXPORT_SYMBOL(tty_driver_flush_buffer);
 
 /**
- *	tty_throttle		-	flow control
- *	@tty: terminal
- *
- *	Indicate that a tty should stop transmitting data down the stack.
- *	Takes the termios rwsem to protect against parallel throttle/unthrottle
- *	and also to ensure the driver can consistently reference its own
- *	termios data at this point when implementing software flow control.
- */
-
-void tty_throttle(struct tty_struct *tty)
-{
-	down_write(&tty->termios_rwsem);
-	/* check TTY_THROTTLED first so it indicates our state */
-	if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
-	    tty->ops->throttle)
-		tty->ops->throttle(tty);
-	tty->flow_change = 0;
-	up_write(&tty->termios_rwsem);
-}
-EXPORT_SYMBOL(tty_throttle);
-
-/**
  *	tty_unthrottle		-	flow control
  *	@tty: terminal
  *
@@ -146,10 +124,11 @@ EXPORT_SYMBOL(tty_unthrottle);
  *	tty_throttle_safe	-	flow control
  *	@tty: terminal
  *
- *	Similar to tty_throttle() but will only attempt throttle
- *	if tty->flow_change is TTY_THROTTLE_SAFE. Prevents an accidental
- *	throttle due to race conditions when throttling is conditional
- *	on factors evaluated prior to throttling.
+ *	Indicate that a tty should stop transmitting data down the stack.
+ *	tty_throttle_safe will only attempt throttle if tty->flow_change is
+ *	TTY_THROTTLE_SAFE. Prevents an accidental throttle due to race
+ *	conditions when throttling is conditional on factors evaluated prior to
+ *	throttling.
  *
  *	Returns 0 if tty is throttled (or was already throttled)
  */
@@ -301,6 +280,51 @@ int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
 EXPORT_SYMBOL(tty_termios_hw_change);
 
 /**
+ *	tty_get_char_size	-	get size of a character
+ *	@cflag: termios cflag value
+ *
+ *	Get the size (in bits) of a character depending on @cflag's %CSIZE
+ *	setting.
+ */
+unsigned char tty_get_char_size(unsigned int cflag)
+{
+	switch (cflag & CSIZE) {
+	case CS5:
+		return 5;
+	case CS6:
+		return 6;
+	case CS7:
+		return 7;
+	case CS8:
+	default:
+		return 8;
+	}
+}
+EXPORT_SYMBOL_GPL(tty_get_char_size);
+
+/**
+ *	tty_get_frame_size	-	get size of a frame
+ *	@cflag: termios cflag value
+ *
+ *	Get the size (in bits) of a frame depending on @cflag's %CSIZE, %CSTOPB,
+ *	and %PARENB setting. The result is a sum of character size, start and
+ *	stop bits -- one bit each -- second stop bit (if set), and parity bit
+ *	(if set).
+ */
+unsigned char tty_get_frame_size(unsigned int cflag)
+{
+	unsigned char bits = 2 + tty_get_char_size(cflag);
+
+	if (cflag & CSTOPB)
+		bits++;
+	if (cflag & PARENB)
+		bits++;
+
+	return bits;
+}
+EXPORT_SYMBOL_GPL(tty_get_frame_size);
+
+/**
  *	tty_set_termios		-	update termios values
  *	@tty: tty to update
  *	@new_termios: desired new value
@@ -846,20 +870,20 @@ int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 			return retval;
 		switch (arg) {
 		case TCOOFF:
-			spin_lock_irq(&tty->flow_lock);
-			if (!tty->flow_stopped) {
-				tty->flow_stopped = 1;
+			spin_lock_irq(&tty->flow.lock);
+			if (!tty->flow.tco_stopped) {
+				tty->flow.tco_stopped = true;
 				__stop_tty(tty);
 			}
-			spin_unlock_irq(&tty->flow_lock);
+			spin_unlock_irq(&tty->flow.lock);
 			break;
 		case TCOON:
-			spin_lock_irq(&tty->flow_lock);
-			if (tty->flow_stopped) {
-				tty->flow_stopped = 0;
+			spin_lock_irq(&tty->flow.lock);
+			if (tty->flow.tco_stopped) {
+				tty->flow.tco_stopped = false;
 				__start_tty(tty);
 			}
-			spin_unlock_irq(&tty->flow_lock);
+			spin_unlock_irq(&tty->flow.lock);
 			break;
 		case TCIOFF:
 			if (STOP_CHAR(tty) != __DISABLED_CHAR)