drivers/tty/tty.h

   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  */
  38 enum {
  39         TTY_LOCK_NORMAL = 0,
  40         TTY_LOCK_SLAVE,
  41 };
  42
  43 /* Values for tty->flow_change */
  44 enum tty_flow_change {
  45         TTY_FLOW_NO_CHANGE,
  46         TTY_THROTTLE_SAFE,
  47         TTY_UNTHROTTLE_SAFE,
  48 };
  49
  50 static inline void __tty_set_flow_change(struct tty_struct *tty,
  51                                          enum tty_flow_change val)
  52 {
  53         tty->flow_change = val;
  54 }
  55
  56 static 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
  63 int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
  64 void tty_ldisc_unlock(struct tty_struct *tty);
  65
  66 int __tty_check_change(struct tty_struct *tty, int sig);
  67 int tty_check_change(struct tty_struct *tty);
  68 void __stop_tty(struct tty_struct *tty);
  69 void __start_tty(struct tty_struct *tty);
  70 void tty_write_unlock(struct tty_struct *tty);
  71 int tty_write_lock(struct tty_struct *tty, bool ndelay);
  72 void tty_vhangup_session(struct tty_struct *tty);
  73 void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
  74 int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
  75 void session_clear_tty(struct pid *session);
  76 void tty_buffer_free_all(struct tty_port *port);
  77 void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
  78 void tty_buffer_init(struct tty_port *port);
  79 void tty_buffer_set_lock_subclass(struct tty_port *port);
  80 bool tty_buffer_restart_work(struct tty_port *port);
  81 bool tty_buffer_cancel_work(struct tty_port *port);
  82 void tty_buffer_flush_work(struct tty_port *port);
  83 speed_t tty_termios_input_baud_rate(const struct ktermios *termios);
  84 void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
  85 int tty_ldisc_reinit(struct tty_struct *tty, int disc);
  86 long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
  87 long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
  88                        struct file *file, unsigned int cmd, unsigned long arg);
  89 void tty_default_fops(struct file_operations *fops);
  90 struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
  91 int tty_alloc_file(struct file *file);
  92 void tty_add_file(struct tty_struct *tty, struct file *file);
  93 void tty_free_file(struct file *file);
  94 int tty_release(struct inode *inode, struct file *filp);
  95
  96 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
  97
  98 int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
  99 void tty_ldisc_release(struct tty_struct *tty);
 100 int __must_check tty_ldisc_init(struct tty_struct *tty);
 101 void tty_ldisc_deinit(struct tty_struct *tty);
 102
 103 extern int tty_ldisc_autoload;
 104
 105 /* tty_audit.c */
 106 #ifdef CONFIG_AUDIT
 107 void tty_audit_add_data(const struct tty_struct *tty, const void *data,
 108                         size_t size);
 109 void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch);
 110 #else
 111 static inline void tty_audit_add_data(const struct tty_struct *tty,
 112                                       const void *data, size_t size)
 113 {
 114 }
 115 static inline void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch)
 116 {
 117 }
 118 #endif
 119
 120 ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
 121
 122 int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
 123                                            const u8 *chars, size_t cnt);
 124
 125 #endif