1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_TTY_H
3#define _LINUX_TTY_H
4
5#include <linux/fs.h>
6#include <linux/major.h>
7#include <linux/termios.h>
8#include <linux/workqueue.h>
9#include <linux/tty_driver.h>
10#include <linux/tty_ldisc.h>
11#include <linux/mutex.h>
12#include <linux/tty_flags.h>
13#include <linux/seq_file.h>
14#include <uapi/linux/tty.h>
15#include <linux/rwsem.h>
16#include <linux/llist.h>
17
18
19/*
20 * Lock subclasses for tty locks
21 *
22 * TTY_LOCK_NORMAL is for normal ttys and master ptys.
23 * TTY_LOCK_SLAVE is for slave ptys only.
24 *
25 * Lock subclasses are necessary for handling nested locking with pty pairs.
26 * tty locks which use nested locking:
27 *
28 * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
29 * The stable lock order is master pty first, then slave pty.
30 * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
31 * Subclassing this lock enables the slave pty to hold its
32 * termios_rwsem when claiming the master tty_buffer lock.
33 * tty_buffer lock - slave ptys can claim nested buffer lock when handling
34 * signal chars. The stable lock order is slave pty, then
35 * master.
36 */
37
38enum {
39 TTY_LOCK_NORMAL = 0,
40 TTY_LOCK_SLAVE,
41};
42
43/*
44 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
45 * hardcoded at present.)
46 */
47#define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */
48#define NR_UNIX98_PTY_RESERVE 1024 /* Default reserve for main devpts */
49#define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */
50
51/*
52 * This character is the same as _POSIX_VDISABLE: it cannot be used as
53 * a c_cc[] character, but indicates that a particular special character
54 * isn't in use (eg VINTR has no character etc)
55 */
56#define __DISABLED_CHAR '\0'
57
58struct tty_buffer {
59 union {
60 struct tty_buffer *next;
61 struct llist_node free;
62 };
63 int used;
64 int size;
65 int commit;
66 int read;
67 int flags;
68 /* Data points here */
69 unsigned long data[0];
70};
71
72/* Values for .flags field of tty_buffer */
73#define TTYB_NORMAL 1 /* buffer has no flags buffer */
74
75static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
76{
77 return ((unsigned char *)b->data) + ofs;
78}
79
80static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
81{
82 return (char *)char_buf_ptr(b, ofs) + b->size;
83}
84
85struct tty_bufhead {
86 struct tty_buffer *head; /* Queue head */
87 struct work_struct work;
88 struct mutex lock;
89 atomic_t priority;
90 struct tty_buffer sentinel;
91 struct llist_head free; /* Free queue head */
92 atomic_t mem_used; /* In-use buffers excluding free list */
93 int mem_limit;
94 struct tty_buffer *tail; /* Active buffer */
95};
96/*
97 * When a break, frame error, or parity error happens, these codes are
98 * stuffed into the flags buffer.
99 */
100#define TTY_NORMAL 0
101#define TTY_BREAK 1
102#define TTY_FRAME 2
103#define TTY_PARITY 3
104#define TTY_OVERRUN 4
105
106#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
107#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
108#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
109#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
110#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
111#define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
112#define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
113#define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
114#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
115#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
116#define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
117#define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
118#define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
119#define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
120#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
121#define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
122#define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
123
124#define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
125#define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
126#define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
127#define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
128
129#define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK)
130#define I_BRKINT(tty) _I_FLAG((tty), BRKINT)
131#define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR)
132#define I_PARMRK(tty) _I_FLAG((tty), PARMRK)
133#define I_INPCK(tty) _I_FLAG((tty), INPCK)
134#define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP)
135#define I_INLCR(tty) _I_FLAG((tty), INLCR)
136#define I_IGNCR(tty) _I_FLAG((tty), IGNCR)
137#define I_ICRNL(tty) _I_FLAG((tty), ICRNL)
138#define I_IUCLC(tty) _I_FLAG((tty), IUCLC)
139#define I_IXON(tty) _I_FLAG((tty), IXON)
140#define I_IXANY(tty) _I_FLAG((tty), IXANY)
141#define I_IXOFF(tty) _I_FLAG((tty), IXOFF)
142#define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL)
143#define I_IUTF8(tty) _I_FLAG((tty), IUTF8)
144
145#define O_OPOST(tty) _O_FLAG((tty), OPOST)
146#define O_OLCUC(tty) _O_FLAG((tty), OLCUC)
147#define O_ONLCR(tty) _O_FLAG((tty), ONLCR)
148#define O_OCRNL(tty) _O_FLAG((tty), OCRNL)
149#define O_ONOCR(tty) _O_FLAG((tty), ONOCR)
150#define O_ONLRET(tty) _O_FLAG((tty), ONLRET)
151#define O_OFILL(tty) _O_FLAG((tty), OFILL)
152#define O_OFDEL(tty) _O_FLAG((tty), OFDEL)
153#define O_NLDLY(tty) _O_FLAG((tty), NLDLY)
154#define O_CRDLY(tty) _O_FLAG((tty), CRDLY)
155#define O_TABDLY(tty) _O_FLAG((tty), TABDLY)
156#define O_BSDLY(tty) _O_FLAG((tty), BSDLY)
157#define O_VTDLY(tty) _O_FLAG((tty), VTDLY)
158#define O_FFDLY(tty) _O_FLAG((tty), FFDLY)
159
160#define C_BAUD(tty) _C_FLAG((tty), CBAUD)
161#define C_CSIZE(tty) _C_FLAG((tty), CSIZE)
162#define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB)
163#define C_CREAD(tty) _C_FLAG((tty), CREAD)
164#define C_PARENB(tty) _C_FLAG((tty), PARENB)
165#define C_PARODD(tty) _C_FLAG((tty), PARODD)
166#define C_HUPCL(tty) _C_FLAG((tty), HUPCL)
167#define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL)
168#define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD)
169#define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS)
170#define C_CMSPAR(tty) _C_FLAG((tty), CMSPAR)
171
172#define L_ISIG(tty) _L_FLAG((tty), ISIG)
173#define L_ICANON(tty) _L_FLAG((tty), ICANON)
174#define L_XCASE(tty) _L_FLAG((tty), XCASE)
175#define L_ECHO(tty) _L_FLAG((tty), ECHO)
176#define L_ECHOE(tty) _L_FLAG((tty), ECHOE)
177#define L_ECHOK(tty) _L_FLAG((tty), ECHOK)
178#define L_ECHONL(tty) _L_FLAG((tty), ECHONL)
179#define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH)
180#define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP)
181#define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL)
182#define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT)
183#define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE)
184#define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO)
185#define L_PENDIN(tty) _L_FLAG((tty), PENDIN)
186#define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN)
187#define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC)
188
189struct device;
190struct signal_struct;
191
192/*
193 * Port level information. Each device keeps its own port level information
194 * so provide a common structure for those ports wanting to use common support
195 * routines.
196 *
197 * The tty port has a different lifetime to the tty so must be kept apart.
198 * In addition be careful as tty -> port mappings are valid for the life
199 * of the tty object but in many cases port -> tty mappings are valid only
200 * until a hangup so don't use the wrong path.
201 */
202
203struct tty_port;
204
205struct tty_port_operations {
206 /* Return 1 if the carrier is raised */
207 int (*carrier_raised)(struct tty_port *port);
208 /* Control the DTR line */
209 void (*dtr_rts)(struct tty_port *port, int raise);
210 /* Called when the last close completes or a hangup finishes
211 IFF the port was initialized. Do not use to free resources. Called
212 under the port mutex to serialize against activate/shutdowns */
213 void (*shutdown)(struct tty_port *port);
214 /* Called under the port mutex from tty_port_open, serialized using
215 the port mutex */
216 /* FIXME: long term getting the tty argument *out* of this would be
217 good for consoles */
218 int (*activate)(struct tty_port *port, struct tty_struct *tty);
219 /* Called on the final put of a port */
220 void (*destruct)(struct tty_port *port);
221};
222
223struct tty_port_client_operations {
224 int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t);
225 void (*write_wakeup)(struct tty_port *port);
226};
227
228struct tty_port {
229 struct tty_bufhead buf; /* Locked internally */
230 struct tty_struct *tty; /* Back pointer */
231 struct tty_struct *itty; /* internal back ptr */
232 const struct tty_port_operations *ops; /* Port operations */
233 const struct tty_port_client_operations *client_ops; /* Port client operations */
234 spinlock_t lock; /* Lock protecting tty field */
235 int blocked_open; /* Waiting to open */
236 int count; /* Usage count */
237 wait_queue_head_t open_wait; /* Open waiters */
238 wait_queue_head_t delta_msr_wait; /* Modem status change */
239 unsigned long flags; /* User TTY flags ASYNC_ */
240 unsigned long iflags; /* Internal flags TTY_PORT_ */
241 unsigned char console:1, /* port is a console */
242 low_latency:1; /* optional: tune for latency */
243 struct mutex mutex; /* Locking */
244 struct mutex buf_mutex; /* Buffer alloc lock */
245 unsigned char *xmit_buf; /* Optional buffer */
246 unsigned int close_delay; /* Close port delay */
247 unsigned int closing_wait; /* Delay for output */
248 int drain_delay; /* Set to zero if no pure time
249 based drain is needed else
250 set to size of fifo */
251 struct kref kref; /* Ref counter */
252 void *client_data;
253};
254
255/* tty_port::iflags bits -- use atomic bit ops */
256#define TTY_PORT_INITIALIZED 0 /* device is initialized */
257#define TTY_PORT_SUSPENDED 1 /* device is suspended */
258#define TTY_PORT_ACTIVE 2 /* device is open */
259
260/*
261 * uart drivers: use the uart_port::status field and the UPSTAT_* defines
262 * for s/w-based flow control steering and carrier detection status
263 */
264#define TTY_PORT_CTS_FLOW 3 /* h/w flow control enabled */
265#define TTY_PORT_CHECK_CD 4 /* carrier detect enabled */
266#define TTY_PORT_KOPENED 5 /* device exclusively opened by
267 kernel */
268
269/*
270 * Where all of the state associated with a tty is kept while the tty
271 * is open. Since the termios state should be kept even if the tty
272 * has been closed --- for things like the baud rate, etc --- it is
273 * not stored here, but rather a pointer to the real state is stored
274 * here. Possible the winsize structure should have the same
275 * treatment, but (1) the default 80x24 is usually right and (2) it's
276 * most often used by a windowing system, which will set the correct
277 * size each time the window is created or resized anyway.
278 * - TYT, 9/14/92
279 */
280
281struct tty_operations;
282
283struct tty_struct {
284 int magic;
285 struct kref kref;
286 struct device *dev;
287 struct tty_driver *driver;
288 const struct tty_operations *ops;
289 int index;
290
291 /* Protects ldisc changes: Lock tty not pty */
292 struct ld_semaphore ldisc_sem;
293 struct tty_ldisc *ldisc;
294
295 struct mutex atomic_write_lock;
296 struct mutex legacy_mutex;
297 struct mutex throttle_mutex;
298 struct rw_semaphore termios_rwsem;
299 struct mutex winsize_mutex;
300 spinlock_t ctrl_lock;
301 spinlock_t flow_lock;
302 /* Termios values are protected by the termios rwsem */
303 struct ktermios termios, termios_locked;
304 struct termiox *termiox; /* May be NULL for unsupported */
305 char name[64];
306 struct pid *pgrp; /* Protected by ctrl lock */
307 struct pid *session;
308 unsigned long flags;
309 int count;
310 struct winsize winsize; /* winsize_mutex */
311 unsigned long stopped:1, /* flow_lock */
312 flow_stopped:1,
313 unused:BITS_PER_LONG - 2;
314 int hw_stopped;
315 unsigned long ctrl_status:8, /* ctrl_lock */
316 packet:1,
317 unused_ctrl:BITS_PER_LONG - 9;
318 unsigned int receive_room; /* Bytes free for queue */
319 int flow_change;
320
321 struct tty_struct *link;
322 struct fasync_struct *fasync;
323 wait_queue_head_t write_wait;
324 wait_queue_head_t read_wait;
325 struct work_struct hangup_work;
326 void *disc_data;
327 void *driver_data;
328 spinlock_t files_lock; /* protects tty_files list */
329 struct list_head tty_files;
330
331#define N_TTY_BUF_SIZE 4096
332
333 int closing;
334 unsigned char *write_buf;
335 int write_cnt;
336 /* If the tty has a pending do_SAK, queue it here - akpm */
337 struct work_struct SAK_work;
338 struct tty_port *port;
339} __randomize_layout;
340
341/* Each of a tty's open files has private_data pointing to tty_file_private */
342struct tty_file_private {
343 struct tty_struct *tty;
344 struct file *file;
345 struct list_head list;
346};
347
348/* tty magic number */
349#define TTY_MAGIC 0x5401
350
351/*
352 * These bits are used in the flags field of the tty structure.
353 *
354 * So that interrupts won't be able to mess up the queues,
355 * copy_to_cooked must be atomic with respect to itself, as must
356 * tty->write. Thus, you must use the inline functions set_bit() and
357 * clear_bit() to make things atomic.
358 */
359#define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */
360#define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */
361#define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */
362#define TTY_EXCLUSIVE 3 /* Exclusive open mode */
363#define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */
364#define TTY_LDISC_OPEN 11 /* Line discipline is open */
365#define TTY_PTY_LOCK 16 /* pty private */
366#define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */
367#define TTY_HUPPED 18 /* Post driver->hangup() */
368#define TTY_HUPPING 19 /* Hangup in progress */
369#define TTY_LDISC_CHANGING 20 /* Change pending - non-block IO */
370#define TTY_LDISC_HALTED 22 /* Line discipline is halted */
371
372/* Values for tty->flow_change */
373#define TTY_THROTTLE_SAFE 1
374#define TTY_UNTHROTTLE_SAFE 2
375
376static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
377{
378 tty->flow_change = val;
379}
380
381static inline void tty_set_flow_change(struct tty_struct *tty, int val)
382{
383 tty->flow_change = val;
384 smp_mb();
385}
386
387static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
388{
389 return file->f_flags & O_NONBLOCK ||
390 test_bit(TTY_LDISC_CHANGING, &tty->flags);
391}
392
393static inline bool tty_io_error(struct tty_struct *tty)
394{
395 return test_bit(TTY_IO_ERROR, &tty->flags);
396}
397
398static inline bool tty_throttled(struct tty_struct *tty)
399{
400 return test_bit(TTY_THROTTLED, &tty->flags);
401}
402
403#ifdef CONFIG_TTY
404extern void tty_kref_put(struct tty_struct *tty);
405extern struct pid *tty_get_pgrp(struct tty_struct *tty);
406extern void tty_vhangup_self(void);
407extern void disassociate_ctty(int priv);
408extern dev_t tty_devnum(struct tty_struct *tty);
409extern void proc_clear_tty(struct task_struct *p);
410extern struct tty_struct *get_current_tty(void);
411/* tty_io.c */
412extern int __init tty_init(void);
413extern const char *tty_name(const struct tty_struct *tty);
414extern struct tty_struct *tty_kopen(dev_t device);
415extern void tty_kclose(struct tty_struct *tty);
416extern int tty_dev_name_to_number(const char *name, dev_t *number);
417extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
418extern void tty_ldisc_unlock(struct tty_struct *tty);
419#else
420static inline void tty_kref_put(struct tty_struct *tty)
421{ }
422static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
423{ return NULL; }
424static inline void tty_vhangup_self(void)
425{ }
426static inline void disassociate_ctty(int priv)
427{ }
428static inline dev_t tty_devnum(struct tty_struct *tty)
429{ return 0; }
430static inline void proc_clear_tty(struct task_struct *p)
431{ }
432static inline struct tty_struct *get_current_tty(void)
433{ return NULL; }
434/* tty_io.c */
435static inline int __init tty_init(void)
436{ return 0; }
437static inline const char *tty_name(const struct tty_struct *tty)
438{ return "(none)"; }
439static inline struct tty_struct *tty_kopen(dev_t device)
440{ return ERR_PTR(-ENODEV); }
441static inline void tty_kclose(struct tty_struct *tty)
442{ }
443static inline int tty_dev_name_to_number(const char *name, dev_t *number)
444{ return -ENOTSUPP; }
445#endif
446
447extern struct ktermios tty_std_termios;
448
449extern int vcs_init(void);
450
451extern struct class *tty_class;
452
453/**
454 * tty_kref_get - get a tty reference
455 * @tty: tty device
456 *
457 * Return a new reference to a tty object. The caller must hold
458 * sufficient locks/counts to ensure that their existing reference cannot
459 * go away
460 */
461
462static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
463{
464 if (tty)
465 kref_get(&tty->kref);
466 return tty;
467}
468
469extern const char *tty_driver_name(const struct tty_struct *tty);
470extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
471extern int __tty_check_change(struct tty_struct *tty, int sig);
472extern int tty_check_change(struct tty_struct *tty);
473extern void __stop_tty(struct tty_struct *tty);
474extern void stop_tty(struct tty_struct *tty);
475extern void __start_tty(struct tty_struct *tty);
476extern void start_tty(struct tty_struct *tty);
477extern int tty_register_driver(struct tty_driver *driver);
478extern int tty_unregister_driver(struct tty_driver *driver);
479extern struct device *tty_register_device(struct tty_driver *driver,
480 unsigned index, struct device *dev);
481extern struct device *tty_register_device_attr(struct tty_driver *driver,
482 unsigned index, struct device *device,
483 void *drvdata,
484 const struct attribute_group **attr_grp);
485extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
486extern void tty_write_message(struct tty_struct *tty, char *msg);
487extern int tty_send_xchar(struct tty_struct *tty, char ch);
488extern int tty_put_char(struct tty_struct *tty, unsigned char c);
489extern int tty_chars_in_buffer(struct tty_struct *tty);
490extern int tty_write_room(struct tty_struct *tty);
491extern void tty_driver_flush_buffer(struct tty_struct *tty);
492extern void tty_throttle(struct tty_struct *tty);
493extern void tty_unthrottle(struct tty_struct *tty);
494extern int tty_throttle_safe(struct tty_struct *tty);
495extern int tty_unthrottle_safe(struct tty_struct *tty);
496extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
497extern int is_current_pgrp_orphaned(void);
498extern void tty_hangup(struct tty_struct *tty);
499extern void tty_vhangup(struct tty_struct *tty);
500extern void tty_vhangup_session(struct tty_struct *tty);
501extern int tty_hung_up_p(struct file *filp);
502extern void do_SAK(struct tty_struct *tty);
503extern void __do_SAK(struct tty_struct *tty);
504extern void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
505extern int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
506extern void session_clear_tty(struct pid *session);
507extern void no_tty(void);
508extern void tty_buffer_free_all(struct tty_port *port);
509extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
510extern void tty_buffer_init(struct tty_port *port);
511extern void tty_buffer_set_lock_subclass(struct tty_port *port);
512extern bool tty_buffer_restart_work(struct tty_port *port);
513extern bool tty_buffer_cancel_work(struct tty_port *port);
514extern void tty_buffer_flush_work(struct tty_port *port);
515extern speed_t tty_termios_baud_rate(struct ktermios *termios);
516extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
517extern void tty_termios_encode_baud_rate(struct ktermios *termios,
518 speed_t ibaud, speed_t obaud);
519extern void tty_encode_baud_rate(struct tty_struct *tty,
520 speed_t ibaud, speed_t obaud);
521
522/**
523 * tty_get_baud_rate - get tty bit rates
524 * @tty: tty to query
525 *
526 * Returns the baud rate as an integer for this terminal. The
527 * termios lock must be held by the caller and the terminal bit
528 * flags may be updated.
529 *
530 * Locking: none
531 */
532static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
533{
534 return tty_termios_baud_rate(&tty->termios);
535}
536
537extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
538extern int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
539extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
540
541extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
542extern void tty_ldisc_deref(struct tty_ldisc *);
543extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
544extern void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
545extern int tty_ldisc_reinit(struct tty_struct *tty, int disc);
546extern const struct seq_operations tty_ldiscs_seq_ops;
547
548extern void tty_wakeup(struct tty_struct *tty);
549extern void tty_ldisc_flush(struct tty_struct *tty);
550
551extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
552extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
553 unsigned int cmd, unsigned long arg);
554extern long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
555 struct file *file, unsigned int cmd, unsigned long arg);
556extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
557extern void tty_default_fops(struct file_operations *fops);
558extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
559extern int tty_alloc_file(struct file *file);
560extern void tty_add_file(struct tty_struct *tty, struct file *file);
561extern void tty_free_file(struct file *file);
562extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
563extern void tty_release_struct(struct tty_struct *tty, int idx);
564extern int tty_release(struct inode *inode, struct file *filp);
565extern void tty_init_termios(struct tty_struct *tty);
566extern void tty_save_termios(struct tty_struct *tty);
567extern int tty_standard_install(struct tty_driver *driver,
568 struct tty_struct *tty);
569
570extern struct mutex tty_mutex;
571
572#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
573
574extern void tty_port_init(struct tty_port *port);
575extern void tty_port_link_device(struct tty_port *port,
576 struct tty_driver *driver, unsigned index);
577extern struct device *tty_port_register_device(struct tty_port *port,
578 struct tty_driver *driver, unsigned index,
579 struct device *device);
580extern struct device *tty_port_register_device_attr(struct tty_port *port,
581 struct tty_driver *driver, unsigned index,
582 struct device *device, void *drvdata,
583 const struct attribute_group **attr_grp);
584extern struct device *tty_port_register_device_serdev(struct tty_port *port,
585 struct tty_driver *driver, unsigned index,
586 struct device *device);
587extern struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
588 struct tty_driver *driver, unsigned index,
589 struct device *device, void *drvdata,
590 const struct attribute_group **attr_grp);
591extern void tty_port_unregister_device(struct tty_port *port,
592 struct tty_driver *driver, unsigned index);
593extern int tty_port_alloc_xmit_buf(struct tty_port *port);
594extern void tty_port_free_xmit_buf(struct tty_port *port);
595extern void tty_port_destroy(struct tty_port *port);
596extern void tty_port_put(struct tty_port *port);
597
598static inline struct tty_port *tty_port_get(struct tty_port *port)
599{
600 if (port && kref_get_unless_zero(&port->kref))
601 return port;
602 return NULL;
603}
604
605/* If the cts flow control is enabled, return true. */
606static inline bool tty_port_cts_enabled(struct tty_port *port)
607{
608 return test_bit(TTY_PORT_CTS_FLOW, &port->iflags);
609}
610
611static inline void tty_port_set_cts_flow(struct tty_port *port, bool val)
612{
613 if (val)
614 set_bit(TTY_PORT_CTS_FLOW, &port->iflags);
615 else
616 clear_bit(TTY_PORT_CTS_FLOW, &port->iflags);
617}
618
619static inline bool tty_port_active(struct tty_port *port)
620{
621 return test_bit(TTY_PORT_ACTIVE, &port->iflags);
622}
623
624static inline void tty_port_set_active(struct tty_port *port, bool val)
625{
626 if (val)
627 set_bit(TTY_PORT_ACTIVE, &port->iflags);
628 else
629 clear_bit(TTY_PORT_ACTIVE, &port->iflags);
630}
631
632static inline bool tty_port_check_carrier(struct tty_port *port)
633{
634 return test_bit(TTY_PORT_CHECK_CD, &port->iflags);
635}
636
637static inline void tty_port_set_check_carrier(struct tty_port *port, bool val)
638{
639 if (val)
640 set_bit(TTY_PORT_CHECK_CD, &port->iflags);
641 else
642 clear_bit(TTY_PORT_CHECK_CD, &port->iflags);
643}
644
645static inline bool tty_port_suspended(struct tty_port *port)
646{
647 return test_bit(TTY_PORT_SUSPENDED, &port->iflags);
648}
649
650static inline void tty_port_set_suspended(struct tty_port *port, bool val)
651{
652 if (val)
653 set_bit(TTY_PORT_SUSPENDED, &port->iflags);
654 else
655 clear_bit(TTY_PORT_SUSPENDED, &port->iflags);
656}
657
658static inline bool tty_port_initialized(struct tty_port *port)
659{
660 return test_bit(TTY_PORT_INITIALIZED, &port->iflags);
661}
662
663static inline void tty_port_set_initialized(struct tty_port *port, bool val)
664{
665 if (val)
666 set_bit(TTY_PORT_INITIALIZED, &port->iflags);
667 else
668 clear_bit(TTY_PORT_INITIALIZED, &port->iflags);
669}
670
671static inline bool tty_port_kopened(struct tty_port *port)
672{
673 return test_bit(TTY_PORT_KOPENED, &port->iflags);
674}
675
676static inline void tty_port_set_kopened(struct tty_port *port, bool val)
677{
678 if (val)
679 set_bit(TTY_PORT_KOPENED, &port->iflags);
680 else
681 clear_bit(TTY_PORT_KOPENED, &port->iflags);
682}
683
684extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
685extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
686extern int tty_port_carrier_raised(struct tty_port *port);
687extern void tty_port_raise_dtr_rts(struct tty_port *port);
688extern void tty_port_lower_dtr_rts(struct tty_port *port);
689extern void tty_port_hangup(struct tty_port *port);
690extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
691extern void tty_port_tty_wakeup(struct tty_port *port);
692extern int tty_port_block_til_ready(struct tty_port *port,
693 struct tty_struct *tty, struct file *filp);
694extern int tty_port_close_start(struct tty_port *port,
695 struct tty_struct *tty, struct file *filp);
696extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
697extern void tty_port_close(struct tty_port *port,
698 struct tty_struct *tty, struct file *filp);
699extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
700 struct tty_struct *tty);
701extern int tty_port_open(struct tty_port *port,
702 struct tty_struct *tty, struct file *filp);
703static inline int tty_port_users(struct tty_port *port)
704{
705 return port->count + port->blocked_open;
706}
707
708extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
709extern int tty_unregister_ldisc(int disc);
710extern int tty_set_ldisc(struct tty_struct *tty, int disc);
711extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
712extern void tty_ldisc_release(struct tty_struct *tty);
713extern int __must_check tty_ldisc_init(struct tty_struct *tty);
714extern void tty_ldisc_deinit(struct tty_struct *tty);
715extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
716 char *f, int count);
717
718/* n_tty.c */
719extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
720#ifdef CONFIG_TTY
721extern void __init n_tty_init(void);
722#else
723static inline void n_tty_init(void) { }
724#endif
725
726/* tty_audit.c */
727#ifdef CONFIG_AUDIT
728extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
729 size_t size);
730extern void tty_audit_exit(void);
731extern void tty_audit_fork(struct signal_struct *sig);
732extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
733extern int tty_audit_push(void);
734#else
735static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
736 size_t size)
737{
738}
739static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
740{
741}
742static inline void tty_audit_exit(void)
743{
744}
745static inline void tty_audit_fork(struct signal_struct *sig)
746{
747}
748static inline int tty_audit_push(void)
749{
750 return 0;
751}
752#endif
753
754/* tty_ioctl.c */
755extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
756 unsigned int cmd, unsigned long arg);
757
758/* vt.c */
759
760extern int vt_ioctl(struct tty_struct *tty,
761 unsigned int cmd, unsigned long arg);
762
763extern long vt_compat_ioctl(struct tty_struct *tty,
764 unsigned int cmd, unsigned long arg);
765
766/* tty_mutex.c */
767/* functions for preparation of BKL removal */
768extern void tty_lock(struct tty_struct *tty);
769extern int tty_lock_interruptible(struct tty_struct *tty);
770extern void tty_unlock(struct tty_struct *tty);
771extern void tty_lock_slave(struct tty_struct *tty);
772extern void tty_unlock_slave(struct tty_struct *tty);
773extern void tty_set_lock_subclass(struct tty_struct *tty);
774
775#ifdef CONFIG_PROC_FS
776extern void proc_tty_register_driver(struct tty_driver *);
777extern void proc_tty_unregister_driver(struct tty_driver *);
778#else
779static inline void proc_tty_register_driver(struct tty_driver *d) {}
780static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
781#endif
782
783#define tty_msg(fn, tty, f, ...) \
784 fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
785
786#define tty_debug(tty, f, ...) tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
787#define tty_info(tty, f, ...) tty_msg(pr_info, tty, f, ##__VA_ARGS__)
788#define tty_notice(tty, f, ...) tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
789#define tty_warn(tty, f, ...) tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
790#define tty_err(tty, f, ...) tty_msg(pr_err, tty, f, ##__VA_ARGS__)
791
792#define tty_info_ratelimited(tty, f, ...) \
793 tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
794
795#endif
796