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
38 enum {
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
58 struct 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[];
70 };
71
72 /* Values for .flags field of tty_buffer */
73 #define TTYB_NORMAL 1 /* buffer has no flags buffer */
74
char_buf_ptr(struct tty_buffer * b,int ofs)75 static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
76 {
77 return ((unsigned char *)b->data) + ofs;
78 }
79
flag_buf_ptr(struct tty_buffer * b,int ofs)80 static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
81 {
82 return (char *)char_buf_ptr(b, ofs) + b->size;
83 }
84
85 struct 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
189 struct device;
190 struct 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
203 struct tty_port;
204
205 struct 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
223 struct 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
228 extern const struct tty_port_client_operations tty_port_default_client_ops;
229
230 struct tty_port {
231 struct tty_bufhead buf; /* Locked internally */
232 struct tty_struct *tty; /* Back pointer */
233 struct tty_struct *itty; /* internal back ptr */
234 const struct tty_port_operations *ops; /* Port operations */
235 const struct tty_port_client_operations *client_ops; /* Port client operations */
236 spinlock_t lock; /* Lock protecting tty field */
237 int blocked_open; /* Waiting to open */
238 int count; /* Usage count */
239 wait_queue_head_t open_wait; /* Open waiters */
240 wait_queue_head_t delta_msr_wait; /* Modem status change */
241 unsigned long flags; /* User TTY flags ASYNC_ */
242 unsigned long iflags; /* Internal flags TTY_PORT_ */
243 unsigned char console:1, /* port is a console */
244 low_latency:1; /* optional: tune for latency */
245 struct mutex mutex; /* Locking */
246 struct mutex buf_mutex; /* Buffer alloc lock */
247 unsigned char *xmit_buf; /* Optional buffer */
248 unsigned int close_delay; /* Close port delay */
249 unsigned int closing_wait; /* Delay for output */
250 int drain_delay; /* Set to zero if no pure time
251 based drain is needed else
252 set to size of fifo */
253 struct kref kref; /* Ref counter */
254 void *client_data;
255 };
256
257 /* tty_port::iflags bits -- use atomic bit ops */
258 #define TTY_PORT_INITIALIZED 0 /* device is initialized */
259 #define TTY_PORT_SUSPENDED 1 /* device is suspended */
260 #define TTY_PORT_ACTIVE 2 /* device is open */
261
262 /*
263 * uart drivers: use the uart_port::status field and the UPSTAT_* defines
264 * for s/w-based flow control steering and carrier detection status
265 */
266 #define TTY_PORT_CTS_FLOW 3 /* h/w flow control enabled */
267 #define TTY_PORT_CHECK_CD 4 /* carrier detect enabled */
268 #define TTY_PORT_KOPENED 5 /* device exclusively opened by
269 kernel */
270
271 /*
272 * Where all of the state associated with a tty is kept while the tty
273 * is open. Since the termios state should be kept even if the tty
274 * has been closed --- for things like the baud rate, etc --- it is
275 * not stored here, but rather a pointer to the real state is stored
276 * here. Possible the winsize structure should have the same
277 * treatment, but (1) the default 80x24 is usually right and (2) it's
278 * most often used by a windowing system, which will set the correct
279 * size each time the window is created or resized anyway.
280 * - TYT, 9/14/92
281 */
282
283 struct tty_operations;
284
285 struct tty_struct {
286 int magic;
287 struct kref kref;
288 struct device *dev;
289 struct tty_driver *driver;
290 const struct tty_operations *ops;
291 int index;
292
293 /* Protects ldisc changes: Lock tty not pty */
294 struct ld_semaphore ldisc_sem;
295 struct tty_ldisc *ldisc;
296
297 struct mutex atomic_write_lock;
298 struct mutex legacy_mutex;
299 struct mutex throttle_mutex;
300 struct rw_semaphore termios_rwsem;
301 struct mutex winsize_mutex;
302 spinlock_t ctrl_lock;
303 spinlock_t flow_lock;
304 /* Termios values are protected by the termios rwsem */
305 struct ktermios termios, termios_locked;
306 char name[64];
307 struct pid *pgrp; /* Protected by ctrl lock */
308 /*
309 * Writes protected by both ctrl lock and legacy mutex, readers must use
310 * at least one of them.
311 */
312 struct pid *session;
313 unsigned long flags;
314 int count;
315 struct winsize winsize; /* winsize_mutex */
316 unsigned long stopped:1, /* flow_lock */
317 flow_stopped:1,
318 unused:BITS_PER_LONG - 2;
319 int hw_stopped;
320 unsigned long ctrl_status:8, /* ctrl_lock */
321 packet:1,
322 unused_ctrl:BITS_PER_LONG - 9;
323 unsigned int receive_room; /* Bytes free for queue */
324 int flow_change;
325
326 struct tty_struct *link;
327 struct fasync_struct *fasync;
328 wait_queue_head_t write_wait;
329 wait_queue_head_t read_wait;
330 struct work_struct hangup_work;
331 void *disc_data;
332 void *driver_data;
333 spinlock_t files_lock; /* protects tty_files list */
334 struct list_head tty_files;
335
336 #define N_TTY_BUF_SIZE 4096
337
338 int closing;
339 unsigned char *write_buf;
340 int write_cnt;
341 /* If the tty has a pending do_SAK, queue it here - akpm */
342 struct work_struct SAK_work;
343 struct tty_port *port;
344 } __randomize_layout;
345
346 /* Each of a tty's open files has private_data pointing to tty_file_private */
347 struct tty_file_private {
348 struct tty_struct *tty;
349 struct file *file;
350 struct list_head list;
351 };
352
353 /* tty magic number */
354 #define TTY_MAGIC 0x5401
355
356 /*
357 * These bits are used in the flags field of the tty structure.
358 *
359 * So that interrupts won't be able to mess up the queues,
360 * copy_to_cooked must be atomic with respect to itself, as must
361 * tty->write. Thus, you must use the inline functions set_bit() and
362 * clear_bit() to make things atomic.
363 */
364 #define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */
365 #define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */
366 #define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */
367 #define TTY_EXCLUSIVE 3 /* Exclusive open mode */
368 #define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */
369 #define TTY_LDISC_OPEN 11 /* Line discipline is open */
370 #define TTY_PTY_LOCK 16 /* pty private */
371 #define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */
372 #define TTY_HUPPED 18 /* Post driver->hangup() */
373 #define TTY_HUPPING 19 /* Hangup in progress */
374 #define TTY_LDISC_CHANGING 20 /* Change pending - non-block IO */
375 #define TTY_LDISC_HALTED 22 /* Line discipline is halted */
376
377 /* Values for tty->flow_change */
378 #define TTY_THROTTLE_SAFE 1
379 #define TTY_UNTHROTTLE_SAFE 2
380
__tty_set_flow_change(struct tty_struct * tty,int val)381 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
382 {
383 tty->flow_change = val;
384 }
385
tty_set_flow_change(struct tty_struct * tty,int val)386 static inline void tty_set_flow_change(struct tty_struct *tty, int val)
387 {
388 tty->flow_change = val;
389 smp_mb();
390 }
391
tty_io_nonblock(struct tty_struct * tty,struct file * file)392 static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
393 {
394 return file->f_flags & O_NONBLOCK ||
395 test_bit(TTY_LDISC_CHANGING, &tty->flags);
396 }
397
tty_io_error(struct tty_struct * tty)398 static inline bool tty_io_error(struct tty_struct *tty)
399 {
400 return test_bit(TTY_IO_ERROR, &tty->flags);
401 }
402
tty_throttled(struct tty_struct * tty)403 static inline bool tty_throttled(struct tty_struct *tty)
404 {
405 return test_bit(TTY_THROTTLED, &tty->flags);
406 }
407
408 #ifdef CONFIG_TTY
409 extern void tty_kref_put(struct tty_struct *tty);
410 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
411 extern void tty_vhangup_self(void);
412 extern void disassociate_ctty(int priv);
413 extern dev_t tty_devnum(struct tty_struct *tty);
414 extern void proc_clear_tty(struct task_struct *p);
415 extern struct tty_struct *get_current_tty(void);
416 /* tty_io.c */
417 extern int __init tty_init(void);
418 extern const char *tty_name(const struct tty_struct *tty);
419 extern struct tty_struct *tty_kopen(dev_t device);
420 extern void tty_kclose(struct tty_struct *tty);
421 extern int tty_dev_name_to_number(const char *name, dev_t *number);
422 extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
423 extern void tty_ldisc_unlock(struct tty_struct *tty);
424 extern ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
425 #else
tty_kref_put(struct tty_struct * tty)426 static inline void tty_kref_put(struct tty_struct *tty)
427 { }
tty_get_pgrp(struct tty_struct * tty)428 static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
429 { return NULL; }
tty_vhangup_self(void)430 static inline void tty_vhangup_self(void)
431 { }
disassociate_ctty(int priv)432 static inline void disassociate_ctty(int priv)
433 { }
tty_devnum(struct tty_struct * tty)434 static inline dev_t tty_devnum(struct tty_struct *tty)
435 { return 0; }
proc_clear_tty(struct task_struct * p)436 static inline void proc_clear_tty(struct task_struct *p)
437 { }
get_current_tty(void)438 static inline struct tty_struct *get_current_tty(void)
439 { return NULL; }
440 /* tty_io.c */
tty_init(void)441 static inline int __init tty_init(void)
442 { return 0; }
tty_name(const struct tty_struct * tty)443 static inline const char *tty_name(const struct tty_struct *tty)
444 { return "(none)"; }
tty_kopen(dev_t device)445 static inline struct tty_struct *tty_kopen(dev_t device)
446 { return ERR_PTR(-ENODEV); }
tty_kclose(struct tty_struct * tty)447 static inline void tty_kclose(struct tty_struct *tty)
448 { }
tty_dev_name_to_number(const char * name,dev_t * number)449 static inline int tty_dev_name_to_number(const char *name, dev_t *number)
450 { return -ENOTSUPP; }
451 #endif
452
453 extern struct ktermios tty_std_termios;
454
455 extern int vcs_init(void);
456
457 extern struct class *tty_class;
458
459 /**
460 * tty_kref_get - get a tty reference
461 * @tty: tty device
462 *
463 * Return a new reference to a tty object. The caller must hold
464 * sufficient locks/counts to ensure that their existing reference cannot
465 * go away
466 */
467
tty_kref_get(struct tty_struct * tty)468 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
469 {
470 if (tty)
471 kref_get(&tty->kref);
472 return tty;
473 }
474
475 extern const char *tty_driver_name(const struct tty_struct *tty);
476 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
477 extern int __tty_check_change(struct tty_struct *tty, int sig);
478 extern int tty_check_change(struct tty_struct *tty);
479 extern void __stop_tty(struct tty_struct *tty);
480 extern void stop_tty(struct tty_struct *tty);
481 extern void __start_tty(struct tty_struct *tty);
482 extern void start_tty(struct tty_struct *tty);
483 extern int tty_register_driver(struct tty_driver *driver);
484 extern int tty_unregister_driver(struct tty_driver *driver);
485 extern struct device *tty_register_device(struct tty_driver *driver,
486 unsigned index, struct device *dev);
487 extern struct device *tty_register_device_attr(struct tty_driver *driver,
488 unsigned index, struct device *device,
489 void *drvdata,
490 const struct attribute_group **attr_grp);
491 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
492 extern void tty_write_message(struct tty_struct *tty, char *msg);
493 extern int tty_send_xchar(struct tty_struct *tty, char ch);
494 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
495 extern int tty_chars_in_buffer(struct tty_struct *tty);
496 extern int tty_write_room(struct tty_struct *tty);
497 extern void tty_driver_flush_buffer(struct tty_struct *tty);
498 extern void tty_throttle(struct tty_struct *tty);
499 extern void tty_unthrottle(struct tty_struct *tty);
500 extern int tty_throttle_safe(struct tty_struct *tty);
501 extern int tty_unthrottle_safe(struct tty_struct *tty);
502 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
503 extern int is_current_pgrp_orphaned(void);
504 extern void tty_hangup(struct tty_struct *tty);
505 extern void tty_vhangup(struct tty_struct *tty);
506 extern void tty_vhangup_session(struct tty_struct *tty);
507 extern int tty_hung_up_p(struct file *filp);
508 extern void do_SAK(struct tty_struct *tty);
509 extern void __do_SAK(struct tty_struct *tty);
510 extern void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
511 extern int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
512 extern void session_clear_tty(struct pid *session);
513 extern void no_tty(void);
514 extern void tty_buffer_free_all(struct tty_port *port);
515 extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
516 extern void tty_buffer_init(struct tty_port *port);
517 extern void tty_buffer_set_lock_subclass(struct tty_port *port);
518 extern bool tty_buffer_restart_work(struct tty_port *port);
519 extern bool tty_buffer_cancel_work(struct tty_port *port);
520 extern void tty_buffer_flush_work(struct tty_port *port);
521 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
522 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
523 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
524 speed_t ibaud, speed_t obaud);
525 extern void tty_encode_baud_rate(struct tty_struct *tty,
526 speed_t ibaud, speed_t obaud);
527
528 /**
529 * tty_get_baud_rate - get tty bit rates
530 * @tty: tty to query
531 *
532 * Returns the baud rate as an integer for this terminal. The
533 * termios lock must be held by the caller and the terminal bit
534 * flags may be updated.
535 *
536 * Locking: none
537 */
tty_get_baud_rate(struct tty_struct * tty)538 static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
539 {
540 return tty_termios_baud_rate(&tty->termios);
541 }
542
543 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
544 extern int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
545 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
546
547 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
548 extern void tty_ldisc_deref(struct tty_ldisc *);
549 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
550 extern void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
551 extern int tty_ldisc_reinit(struct tty_struct *tty, int disc);
552 extern const struct seq_operations tty_ldiscs_seq_ops;
553
554 extern void tty_wakeup(struct tty_struct *tty);
555 extern void tty_ldisc_flush(struct tty_struct *tty);
556
557 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
558 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
559 unsigned int cmd, unsigned long arg);
560 extern long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
561 struct file *file, unsigned int cmd, unsigned long arg);
562 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
563 extern void tty_default_fops(struct file_operations *fops);
564 extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
565 extern int tty_alloc_file(struct file *file);
566 extern void tty_add_file(struct tty_struct *tty, struct file *file);
567 extern void tty_free_file(struct file *file);
568 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
569 extern void tty_release_struct(struct tty_struct *tty, int idx);
570 extern int tty_release(struct inode *inode, struct file *filp);
571 extern void tty_init_termios(struct tty_struct *tty);
572 extern void tty_save_termios(struct tty_struct *tty);
573 extern int tty_standard_install(struct tty_driver *driver,
574 struct tty_struct *tty);
575
576 extern struct mutex tty_mutex;
577
578 #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
579
580 extern void tty_port_init(struct tty_port *port);
581 extern void tty_port_link_device(struct tty_port *port,
582 struct tty_driver *driver, unsigned index);
583 extern struct device *tty_port_register_device(struct tty_port *port,
584 struct tty_driver *driver, unsigned index,
585 struct device *device);
586 extern struct device *tty_port_register_device_attr(struct tty_port *port,
587 struct tty_driver *driver, unsigned index,
588 struct device *device, void *drvdata,
589 const struct attribute_group **attr_grp);
590 extern struct device *tty_port_register_device_serdev(struct tty_port *port,
591 struct tty_driver *driver, unsigned index,
592 struct device *device);
593 extern struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
594 struct tty_driver *driver, unsigned index,
595 struct device *device, void *drvdata,
596 const struct attribute_group **attr_grp);
597 extern void tty_port_unregister_device(struct tty_port *port,
598 struct tty_driver *driver, unsigned index);
599 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
600 extern void tty_port_free_xmit_buf(struct tty_port *port);
601 extern void tty_port_destroy(struct tty_port *port);
602 extern void tty_port_put(struct tty_port *port);
603
tty_port_get(struct tty_port * port)604 static inline struct tty_port *tty_port_get(struct tty_port *port)
605 {
606 if (port && kref_get_unless_zero(&port->kref))
607 return port;
608 return NULL;
609 }
610
611 /* If the cts flow control is enabled, return true. */
tty_port_cts_enabled(struct tty_port * port)612 static inline bool tty_port_cts_enabled(struct tty_port *port)
613 {
614 return test_bit(TTY_PORT_CTS_FLOW, &port->iflags);
615 }
616
tty_port_set_cts_flow(struct tty_port * port,bool val)617 static inline void tty_port_set_cts_flow(struct tty_port *port, bool val)
618 {
619 if (val)
620 set_bit(TTY_PORT_CTS_FLOW, &port->iflags);
621 else
622 clear_bit(TTY_PORT_CTS_FLOW, &port->iflags);
623 }
624
tty_port_active(struct tty_port * port)625 static inline bool tty_port_active(struct tty_port *port)
626 {
627 return test_bit(TTY_PORT_ACTIVE, &port->iflags);
628 }
629
tty_port_set_active(struct tty_port * port,bool val)630 static inline void tty_port_set_active(struct tty_port *port, bool val)
631 {
632 if (val)
633 set_bit(TTY_PORT_ACTIVE, &port->iflags);
634 else
635 clear_bit(TTY_PORT_ACTIVE, &port->iflags);
636 }
637
tty_port_check_carrier(struct tty_port * port)638 static inline bool tty_port_check_carrier(struct tty_port *port)
639 {
640 return test_bit(TTY_PORT_CHECK_CD, &port->iflags);
641 }
642
tty_port_set_check_carrier(struct tty_port * port,bool val)643 static inline void tty_port_set_check_carrier(struct tty_port *port, bool val)
644 {
645 if (val)
646 set_bit(TTY_PORT_CHECK_CD, &port->iflags);
647 else
648 clear_bit(TTY_PORT_CHECK_CD, &port->iflags);
649 }
650
tty_port_suspended(struct tty_port * port)651 static inline bool tty_port_suspended(struct tty_port *port)
652 {
653 return test_bit(TTY_PORT_SUSPENDED, &port->iflags);
654 }
655
tty_port_set_suspended(struct tty_port * port,bool val)656 static inline void tty_port_set_suspended(struct tty_port *port, bool val)
657 {
658 if (val)
659 set_bit(TTY_PORT_SUSPENDED, &port->iflags);
660 else
661 clear_bit(TTY_PORT_SUSPENDED, &port->iflags);
662 }
663
tty_port_initialized(struct tty_port * port)664 static inline bool tty_port_initialized(struct tty_port *port)
665 {
666 return test_bit(TTY_PORT_INITIALIZED, &port->iflags);
667 }
668
tty_port_set_initialized(struct tty_port * port,bool val)669 static inline void tty_port_set_initialized(struct tty_port *port, bool val)
670 {
671 if (val)
672 set_bit(TTY_PORT_INITIALIZED, &port->iflags);
673 else
674 clear_bit(TTY_PORT_INITIALIZED, &port->iflags);
675 }
676
tty_port_kopened(struct tty_port * port)677 static inline bool tty_port_kopened(struct tty_port *port)
678 {
679 return test_bit(TTY_PORT_KOPENED, &port->iflags);
680 }
681
tty_port_set_kopened(struct tty_port * port,bool val)682 static inline void tty_port_set_kopened(struct tty_port *port, bool val)
683 {
684 if (val)
685 set_bit(TTY_PORT_KOPENED, &port->iflags);
686 else
687 clear_bit(TTY_PORT_KOPENED, &port->iflags);
688 }
689
690 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
691 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
692 extern int tty_port_carrier_raised(struct tty_port *port);
693 extern void tty_port_raise_dtr_rts(struct tty_port *port);
694 extern void tty_port_lower_dtr_rts(struct tty_port *port);
695 extern void tty_port_hangup(struct tty_port *port);
696 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
697 extern void tty_port_tty_wakeup(struct tty_port *port);
698 extern int tty_port_block_til_ready(struct tty_port *port,
699 struct tty_struct *tty, struct file *filp);
700 extern int tty_port_close_start(struct tty_port *port,
701 struct tty_struct *tty, struct file *filp);
702 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
703 extern void tty_port_close(struct tty_port *port,
704 struct tty_struct *tty, struct file *filp);
705 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
706 struct tty_struct *tty);
707 extern int tty_port_open(struct tty_port *port,
708 struct tty_struct *tty, struct file *filp);
tty_port_users(struct tty_port * port)709 static inline int tty_port_users(struct tty_port *port)
710 {
711 return port->count + port->blocked_open;
712 }
713
714 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
715 extern int tty_unregister_ldisc(int disc);
716 extern int tty_set_ldisc(struct tty_struct *tty, int disc);
717 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
718 extern void tty_ldisc_release(struct tty_struct *tty);
719 extern int __must_check tty_ldisc_init(struct tty_struct *tty);
720 extern void tty_ldisc_deinit(struct tty_struct *tty);
721 extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
722 char *f, int count);
723
724 /* n_tty.c */
725 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
726 #ifdef CONFIG_TTY
727 extern void __init n_tty_init(void);
728 #else
n_tty_init(void)729 static inline void n_tty_init(void) { }
730 #endif
731
732 /* tty_audit.c */
733 #ifdef CONFIG_AUDIT
734 extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
735 size_t size);
736 extern void tty_audit_exit(void);
737 extern void tty_audit_fork(struct signal_struct *sig);
738 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
739 extern int tty_audit_push(void);
740 #else
tty_audit_add_data(struct tty_struct * tty,const void * data,size_t size)741 static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
742 size_t size)
743 {
744 }
tty_audit_tiocsti(struct tty_struct * tty,char ch)745 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
746 {
747 }
tty_audit_exit(void)748 static inline void tty_audit_exit(void)
749 {
750 }
tty_audit_fork(struct signal_struct * sig)751 static inline void tty_audit_fork(struct signal_struct *sig)
752 {
753 }
tty_audit_push(void)754 static inline int tty_audit_push(void)
755 {
756 return 0;
757 }
758 #endif
759
760 /* tty_ioctl.c */
761 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
762 unsigned int cmd, unsigned long arg);
763
764 /* vt.c */
765
766 extern int vt_ioctl(struct tty_struct *tty,
767 unsigned int cmd, unsigned long arg);
768
769 extern long vt_compat_ioctl(struct tty_struct *tty,
770 unsigned int cmd, unsigned long arg);
771
772 /* tty_mutex.c */
773 /* functions for preparation of BKL removal */
774 extern void tty_lock(struct tty_struct *tty);
775 extern int tty_lock_interruptible(struct tty_struct *tty);
776 extern void tty_unlock(struct tty_struct *tty);
777 extern void tty_lock_slave(struct tty_struct *tty);
778 extern void tty_unlock_slave(struct tty_struct *tty);
779 extern void tty_set_lock_subclass(struct tty_struct *tty);
780
781 #ifdef CONFIG_PROC_FS
782 extern void proc_tty_register_driver(struct tty_driver *);
783 extern void proc_tty_unregister_driver(struct tty_driver *);
784 #else
proc_tty_register_driver(struct tty_driver * d)785 static inline void proc_tty_register_driver(struct tty_driver *d) {}
proc_tty_unregister_driver(struct tty_driver * d)786 static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
787 #endif
788
789 #define tty_msg(fn, tty, f, ...) \
790 fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
791
792 #define tty_debug(tty, f, ...) tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
793 #define tty_info(tty, f, ...) tty_msg(pr_info, tty, f, ##__VA_ARGS__)
794 #define tty_notice(tty, f, ...) tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
795 #define tty_warn(tty, f, ...) tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
796 #define tty_err(tty, f, ...) tty_msg(pr_err, tty, f, ##__VA_ARGS__)
797
798 #define tty_info_ratelimited(tty, f, ...) \
799 tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
800
801 #endif
802