tty: add throttle/unthrottle helpers

Something Arjan suggested which allows us to clean up the code nicely

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

7 files changed, 25 insertions, 25 deletions

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index a6c2619ec782..e5cd856a2fea 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -370,9 +370,7 @@ static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *f
 	hu->hdev->stat.byte_rx += count;
 	spin_unlock(&hu->rx_lock);
 
-	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
-					tty->ops->unthrottle)
-		tty->ops->unthrottle(tty);
+	tty_unthrottle(tty);
 }
 
 static int hci_uart_register_dev(struct hci_uart *hu)
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index abc93a93dcdd..19105ec203f7 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -147,10 +147,8 @@ static void put_tty_queue(unsigned char c, struct tty_struct *tty)
 
 static void check_unthrottle(struct tty_struct *tty)
 {
-	if (tty->count &&
-	    test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
-	    tty->ops->unthrottle)
-		tty->ops->unthrottle(tty);
+	if (tty->count)
+		tty_unthrottle(tty);
 }
 
 /**
@@ -982,12 +980,8 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 	 * mode.  We don't want to throttle the driver if we're in
 	 * canonical mode and don't have a newline yet!
 	 */
-	if (tty->receive_room < TTY_THRESHOLD_THROTTLE) {
-		/* 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);
-	}
+	if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
+		tty_throttle(tty);
 }
 
 int is_ignored(int sig)
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index c10d40c4c5ca..b1a757a5ee27 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -67,6 +67,22 @@ void tty_driver_flush_buffer(struct tty_struct *tty)
 
 EXPORT_SYMBOL(tty_driver_flush_buffer);
 
+void tty_throttle(struct tty_struct *tty)
+{
+	/* 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);
+}
+EXPORT_SYMBOL(tty_throttle);
+
+void tty_unthrottle(struct tty_struct *tty)
+{
+	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
+	    tty->ops->unthrottle)
+		tty->ops->unthrottle(tty);
+}
+EXPORT_SYMBOL(tty_unthrottle);
 
 /**
  *	tty_wait_until_sent	-	wait for I/O to finish
diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 82a36266dfc9..9d5721287d6f 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -491,9 +491,7 @@ static void sixpack_receive_buf(struct tty_struct *tty,
 	sixpack_decode(sp, buf, count1);
 
 	sp_put(sp);
-	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
-	    && tty->ops->unthrottle)
-		tty->ops->unthrottle(tty);
+	tty_unthrottle(tty);
 }
 
 /*
diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index ebcc5adee7cc..65166035aca0 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -936,9 +936,7 @@ static void mkiss_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 	}
 
 	mkiss_put(ax);
-	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
-	    && tty->ops->unthrottle)
-		tty->ops->unthrottle(tty);
+	tty_unthrottle(tty);
 }
 
 /*
diff --git a/drivers/net/ppp_async.c b/drivers/net/ppp_async.c
index 1c4b7e37912c..f1a52def1241 100644
--- a/drivers/net/ppp_async.c
+++ b/drivers/net/ppp_async.c
@@ -361,9 +361,7 @@ ppp_asynctty_receive(struct tty_struct *tty, const unsigned char *buf,
 	if (!skb_queue_empty(&ap->rqueue))
 		tasklet_schedule(&ap->tsk);
 	ap_put(ap);
-	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
-	    && tty->ops->unthrottle)
-		tty->ops->unthrottle(tty);
+	tty_unthrottle(tty);
 }
 
 static void
diff --git a/drivers/net/ppp_synctty.c b/drivers/net/ppp_synctty.c
index 48ed5fdbfe18..b8f0369a71e7 100644
--- a/drivers/net/ppp_synctty.c
+++ b/drivers/net/ppp_synctty.c
@@ -401,9 +401,7 @@ ppp_sync_receive(struct tty_struct *tty, const unsigned char *buf,
 	if (!skb_queue_empty(&ap->rqueue))
 		tasklet_schedule(&ap->tsk);
 	sp_put(ap);
-	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
-	    && tty->ops->unthrottle)
-		tty->ops->unthrottle(tty);
+	tty_unthrottle(tty);
 }
 
 static void