tty: extract tty_flip_buffer_commit() from tty_flip_buffer_push()

We will need this new helper in the next patch.

Cc: Hillf Danton <[email protected]>
Cc: 一只狗 <[email protected]>
Cc: Dan Carpenter <[email protected]>
Signed-off-by: Jiri Slaby <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Jiri Slaby

drivers/tty/tty_buffer.c

@@ -532,6 +532,15 @@ static void flush_to_ldisc(struct work_struct *work)
 
 }
 
+static inline void tty_flip_buffer_commit(struct tty_buffer *tail)
+{
+	/*
+	 * Paired w/ acquire in flush_to_ldisc(); ensures flush_to_ldisc() sees
+	 * buffer data.
+	 */
+	smp_store_release(&tail->commit, tail->used);
+}
+
 /**
  * tty_flip_buffer_push		-	push terminal buffers
  * @port: tty port to push
@@ -546,11 +555,7 @@ void tty_flip_buffer_push(struct tty_port *port)
 {
 	struct tty_bufhead *buf = &port->buf;
 
-	/*
-	 * Paired w/ acquire in flush_to_ldisc(); ensures flush_to_ldisc() sees
-	 * buffer data.
-	 */
-	smp_store_release(&buf->tail->commit, buf->tail->used);
+	tty_flip_buffer_commit(buf->tail);
 	queue_work(system_unbound_wq, &buf->work);
 }
 EXPORT_SYMBOL(tty_flip_buffer_push);