serial: move port users helper

This little helper is now tty_port specific and useful generally so move it

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/tty.h b/include/linux/tty.h
index 0daa8a72b176..a0e03309a379 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -467,6 +467,11 @@ extern int tty_port_close_start(struct tty_port *port,
 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
 extern void tty_port_close(struct tty_port *port,
                                 struct tty_struct *tty, struct file *filp);
+extern inline int tty_port_users(struct tty_port *port)
+{
+        return port->count + port->blocked_open;
+}
+
 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 extern int tty_unregister_ldisc(int disc);
 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);