diff options
Diffstat (limited to 'include/linux/tty.h')
| -rw-r--r-- | include/linux/tty.h | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/include/linux/tty.h b/include/linux/tty.h index 013711ea738..d7c695b65c0 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -166,6 +166,29 @@ struct tty_bufhead { struct device; struct signal_struct; + +/* + * Port level information. Each device keeps its own port level information + * so provide a common structure for those ports wanting to use common support + * routines. + * + * The tty port has a different lifetime to the tty so must be kept apart. + * In addition be careful as tty -> port mappings are valid for the life + * of the tty object but in many cases port -> tty mappings are valid only + * until a hangup so don't use the wrong path. + */ + +struct tty_port { + struct tty_struct *tty; /* Back pointer */ + int blocked_open; /* Waiting to open */ + int count; /* Usage count */ + wait_queue_head_t open_wait; /* Open waiters */ + wait_queue_head_t close_wait; /* Close waiters */ + unsigned long flags; /* TTY flags ASY_*/ + struct mutex mutex; /* Locking */ + unsigned char *xmit_buf; /* Optional buffer */ +}; + /* * Where all of the state associated with a tty is kept while the tty * is open. Since the termios state should be kept even if the tty @@ -214,7 +237,7 @@ struct tty_struct { struct list_head tty_files; #define N_TTY_BUF_SIZE 4096 - + /* * The following is data for the N_TTY line discipline. For * historical reasons, this is included in the tty structure. @@ -242,6 +265,7 @@ struct tty_struct { spinlock_t read_lock; /* If the tty has a pending do_SAK, queue it here - akpm */ struct work_struct SAK_work; + struct tty_port *port; }; /* tty magic number */ @@ -350,6 +374,10 @@ extern void tty_write_unlock(struct tty_struct *tty); extern int tty_write_lock(struct tty_struct *tty, int ndelay); #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) +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); + /* n_tty.c */ |