struct tty_port {
struct tty_struct *tty; /* Back pointer */
+ spinlock_t lock; /* Lock protecting tty field */
int blocked_open; /* Waiting to open */
int count; /* Usage count */
wait_queue_head_t open_wait; /* Open waiters */
extern void tty_port_init(struct tty_port *port);
extern int tty_port_alloc_xmit_buf(struct tty_port *port);
extern void tty_port_free_xmit_buf(struct tty_port *port);
+extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
+extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
extern int tty_unregister_ldisc(int disc);