1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * TTY core internal functions
4 */
5
6#ifndef _TTY_INTERNAL_H
7#define _TTY_INTERNAL_H
8
9#define tty_msg(fn, tty, f, ...) \
10 fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
11
12#define tty_debug(tty, f, ...) tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
13#define tty_notice(tty, f, ...) tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
14#define tty_warn(tty, f, ...) tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
15#define tty_err(tty, f, ...) tty_msg(pr_err, tty, f, ##__VA_ARGS__)
16
17#define tty_info_ratelimited(tty, f, ...) \
18 tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
19
20/*
21 * Lock subclasses for tty locks
22 *
23 * TTY_LOCK_NORMAL is for normal ttys and master ptys.
24 * TTY_LOCK_SLAVE is for slave ptys only.
25 *
26 * Lock subclasses are necessary for handling nested locking with pty pairs.
27 * tty locks which use nested locking:
28 *
29 * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
30 * The stable lock order is master pty first, then slave pty.
31 * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
32 * Subclassing this lock enables the slave pty to hold its
33 * termios_rwsem when claiming the master tty_buffer lock.
34 * tty_buffer lock - slave ptys can claim nested buffer lock when handling
35 * signal chars. The stable lock order is slave pty, then
36 * master.
37 */
38enum {
39 TTY_LOCK_NORMAL = 0,
40 TTY_LOCK_SLAVE,
41};
42
43/* Values for tty->flow_change */
44enum tty_flow_change {
45 TTY_FLOW_NO_CHANGE,
46 TTY_THROTTLE_SAFE,
47 TTY_UNTHROTTLE_SAFE,
48};
49
50static inline void __tty_set_flow_change(struct tty_struct *tty,
51 enum tty_flow_change val)
52{
53 tty->flow_change = val;
54}
55
56static inline void tty_set_flow_change(struct tty_struct *tty,
57 enum tty_flow_change val)
58{
59 tty->flow_change = val;
60 smp_mb();
61}
62
63int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
64void tty_ldisc_unlock(struct tty_struct *tty);
65
66int __tty_check_change(struct tty_struct *tty, int sig);
67int tty_check_change(struct tty_struct *tty);
68void __stop_tty(struct tty_struct *tty);
69void __start_tty(struct tty_struct *tty);
70void tty_write_unlock(struct tty_struct *tty);
71int tty_write_lock(struct tty_struct *tty, bool ndelay);
72void tty_vhangup_session(struct tty_struct *tty);
73void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
74int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
75void session_clear_tty(struct pid *session);
76void tty_buffer_free_all(struct tty_port *port);
77void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
78void tty_buffer_init(struct tty_port *port);
79void tty_buffer_set_lock_subclass(struct tty_port *port);
80bool tty_buffer_restart_work(struct tty_port *port);
81bool tty_buffer_cancel_work(struct tty_port *port);
82void tty_buffer_flush_work(struct tty_port *port);
83speed_t tty_termios_input_baud_rate(const struct ktermios *termios);
84void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
85int tty_ldisc_reinit(struct tty_struct *tty, int disc);
86long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
87long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
88 struct file *file, unsigned int cmd, unsigned long arg);
89void tty_default_fops(struct file_operations *fops);
90struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
91int tty_alloc_file(struct file *file);
92void tty_add_file(struct tty_struct *tty, struct file *file);
93void tty_free_file(struct file *file);
94int tty_release(struct inode *inode, struct file *filp);
95
96#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
97
98int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
99void tty_ldisc_release(struct tty_struct *tty);
100int __must_check tty_ldisc_init(struct tty_struct *tty);
101void tty_ldisc_deinit(struct tty_struct *tty);
102
103extern int tty_ldisc_autoload;
104
105/* tty_audit.c */
106#ifdef CONFIG_AUDIT
107void tty_audit_add_data(const struct tty_struct *tty, const void *data,
108 size_t size);
109void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch);
110#else
111static inline void tty_audit_add_data(const struct tty_struct *tty,
112 const void *data, size_t size)
113{
114}
115static inline void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch)
116{
117}
118#endif
119
120ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
121
122int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
123 const u8 *chars, size_t cnt);
124
125#endif
126