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[0];
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 struct 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
281 struct tty_operations;
282
283 struct 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 */
342 struct 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
__tty_set_flow_change(struct tty_struct * tty,int val)376 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
377 {
378 tty->flow_change = val;
379 }
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 smp_mb();
385 }
386
tty_io_nonblock(struct tty_struct * tty,struct file * file)387 static 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
tty_io_error(struct tty_struct * tty)393 static inline bool tty_io_error(struct tty_struct *tty)
394 {
395 return test_bit(TTY_IO_ERROR, &tty->flags);
396 }
397
tty_throttled(struct tty_struct * tty)398 static inline bool tty_throttled(struct tty_struct *tty)
399 {
400 return test_bit(TTY_THROTTLED, &tty->flags);
401 }
402
403 #ifdef CONFIG_TTY
404 extern void tty_kref_put(struct tty_struct *tty);
405 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
406 extern void tty_vhangup_self(void);
407 extern void disassociate_ctty(int priv);
408 extern dev_t tty_devnum(struct tty_struct *tty);
409 extern void proc_clear_tty(struct task_struct *p);
410 extern struct tty_struct *get_current_tty(void);
411 /* tty_io.c */
412 extern int __init tty_init(void);
413 extern const char *tty_name(const struct tty_struct *tty);
414 extern struct tty_struct *tty_kopen(dev_t device);
415 extern void tty_kclose(struct tty_struct *tty);
416 extern int tty_dev_name_to_number(const char *name, dev_t *number);
417 extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
418 extern void tty_ldisc_unlock(struct tty_struct *tty);
419 #else
tty_kref_put(struct tty_struct * tty)420 static inline void tty_kref_put(struct tty_struct *tty)
421 { }
tty_get_pgrp(struct tty_struct * tty)422 static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
423 { return NULL; }
tty_vhangup_self(void)424 static inline void tty_vhangup_self(void)
425 { }
disassociate_ctty(int priv)426 static inline void disassociate_ctty(int priv)
427 { }
tty_devnum(struct tty_struct * tty)428 static inline dev_t tty_devnum(struct tty_struct *tty)
429 { return 0; }
proc_clear_tty(struct task_struct * p)430 static inline void proc_clear_tty(struct task_struct *p)
431 { }
get_current_tty(void)432 static inline struct tty_struct *get_current_tty(void)
433 { return NULL; }
434 /* tty_io.c */
tty_init(void)435 static inline int __init tty_init(void)
436 { return 0; }
tty_name(const struct tty_struct * tty)437 static inline const char *tty_name(const struct tty_struct *tty)
438 { return "(none)"; }
tty_kopen(dev_t device)439 static inline struct tty_struct *tty_kopen(dev_t device)
440 { return ERR_PTR(-ENODEV); }
tty_kclose(struct tty_struct * tty)441 static inline void tty_kclose(struct tty_struct *tty)
442 { }
tty_dev_name_to_number(const char * name,dev_t * number)443 static inline int tty_dev_name_to_number(const char *name, dev_t *number)
444 { return -ENOTSUPP; }
445 #endif
446
447 extern struct ktermios tty_std_termios;
448
449 extern int vcs_init(void);
450
451 extern 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
tty_kref_get(struct tty_struct * tty)462 static 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
469 extern const char *tty_driver_name(const struct tty_struct *tty);
470 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
471 extern int __tty_check_change(struct tty_struct *tty, int sig);
472 extern int tty_check_change(struct tty_struct *tty);
473 extern void __stop_tty(struct tty_struct *tty);
474 extern void stop_tty(struct tty_struct *tty);
475 extern void __start_tty(struct tty_struct *tty);
476 extern void start_tty(struct tty_struct *tty);
477 extern int tty_register_driver(struct tty_driver *driver);
478 extern int tty_unregister_driver(struct tty_driver *driver);
479 extern struct device *tty_register_device(struct tty_driver *driver,
480 unsigned index, struct device *dev);
481 extern 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);
485 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
486 extern void tty_write_message(struct tty_struct *tty, char *msg);
487 extern int tty_send_xchar(struct tty_struct *tty, char ch);
488 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
489 extern int tty_chars_in_buffer(struct tty_struct *tty);
490 extern int tty_write_room(struct tty_struct *tty);
491 extern void tty_driver_flush_buffer(struct tty_struct *tty);
492 extern void tty_throttle(struct tty_struct *tty);
493 extern void tty_unthrottle(struct tty_struct *tty);
494 extern int tty_throttle_safe(struct tty_struct *tty);
495 extern int tty_unthrottle_safe(struct tty_struct *tty);
496 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
497 extern int is_current_pgrp_orphaned(void);
498 extern void tty_hangup(struct tty_struct *tty);
499 extern void tty_vhangup(struct tty_struct *tty);
500 extern void tty_vhangup_session(struct tty_struct *tty);
501 extern int tty_hung_up_p(struct file *filp);
502 extern void do_SAK(struct tty_struct *tty);
503 extern void __do_SAK(struct tty_struct *tty);
504 extern void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
505 extern int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
506 extern void session_clear_tty(struct pid *session);
507 extern void no_tty(void);
508 extern void tty_buffer_free_all(struct tty_port *port);
509 extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
510 extern void tty_buffer_init(struct tty_port *port);
511 extern void tty_buffer_set_lock_subclass(struct tty_port *port);
512 extern bool tty_buffer_restart_work(struct tty_port *port);
513 extern bool tty_buffer_cancel_work(struct tty_port *port);
514 extern void tty_buffer_flush_work(struct tty_port *port);
515 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
516 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
517 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
518 speed_t ibaud, speed_t obaud);
519 extern 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 */
tty_get_baud_rate(struct tty_struct * tty)532 static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
533 {
534 return tty_termios_baud_rate(&tty->termios);
535 }
536
537 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
538 extern int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
539 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
540
541 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
542 extern void tty_ldisc_deref(struct tty_ldisc *);
543 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
544 extern void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
545 extern int tty_ldisc_reinit(struct tty_struct *tty, int disc);
546 extern const struct seq_operations tty_ldiscs_seq_ops;
547
548 extern void tty_wakeup(struct tty_struct *tty);
549 extern void tty_ldisc_flush(struct tty_struct *tty);
550
551 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
552 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
553 unsigned int cmd, unsigned long arg);
554 extern long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
555 struct file *file, unsigned int cmd, unsigned long arg);
556 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
557 extern void tty_default_fops(struct file_operations *fops);
558 extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
559 extern int tty_alloc_file(struct file *file);
560 extern void tty_add_file(struct tty_struct *tty, struct file *file);
561 extern void tty_free_file(struct file *file);
562 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
563 extern void tty_release_struct(struct tty_struct *tty, int idx);
564 extern int tty_release(struct inode *inode, struct file *filp);
565 extern void tty_init_termios(struct tty_struct *tty);
566 extern void tty_save_termios(struct tty_struct *tty);
567 extern int tty_standard_install(struct tty_driver *driver,
568 struct tty_struct *tty);
569
570 extern struct mutex tty_mutex;
571
572 #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
573
574 extern void tty_port_init(struct tty_port *port);
575 extern void tty_port_link_device(struct tty_port *port,
576 struct tty_driver *driver, unsigned index);
577 extern struct device *tty_port_register_device(struct tty_port *port,
578 struct tty_driver *driver, unsigned index,
579 struct device *device);
580 extern 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);
584 extern struct device *tty_port_register_device_serdev(struct tty_port *port,
585 struct tty_driver *driver, unsigned index,
586 struct device *device);
587 extern 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);
591 extern void tty_port_unregister_device(struct tty_port *port,
592 struct tty_driver *driver, unsigned index);
593 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
594 extern void tty_port_free_xmit_buf(struct tty_port *port);
595 extern void tty_port_destroy(struct tty_port *port);
596 extern void tty_port_put(struct tty_port *port);
597
tty_port_get(struct tty_port * port)598 static 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. */
tty_port_cts_enabled(struct tty_port * port)606 static inline bool tty_port_cts_enabled(struct tty_port *port)
607 {
608 return test_bit(TTY_PORT_CTS_FLOW, &port->iflags);
609 }
610
tty_port_set_cts_flow(struct tty_port * port,bool val)611 static 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
tty_port_active(struct tty_port * port)619 static inline bool tty_port_active(struct tty_port *port)
620 {
621 return test_bit(TTY_PORT_ACTIVE, &port->iflags);
622 }
623
tty_port_set_active(struct tty_port * port,bool val)624 static 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
tty_port_check_carrier(struct tty_port * port)632 static inline bool tty_port_check_carrier(struct tty_port *port)
633 {
634 return test_bit(TTY_PORT_CHECK_CD, &port->iflags);
635 }
636
tty_port_set_check_carrier(struct tty_port * port,bool val)637 static 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
tty_port_suspended(struct tty_port * port)645 static inline bool tty_port_suspended(struct tty_port *port)
646 {
647 return test_bit(TTY_PORT_SUSPENDED, &port->iflags);
648 }
649
tty_port_set_suspended(struct tty_port * port,bool val)650 static 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
tty_port_initialized(struct tty_port * port)658 static inline bool tty_port_initialized(struct tty_port *port)
659 {
660 return test_bit(TTY_PORT_INITIALIZED, &port->iflags);
661 }
662
tty_port_set_initialized(struct tty_port * port,bool val)663 static 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
tty_port_kopened(struct tty_port * port)671 static inline bool tty_port_kopened(struct tty_port *port)
672 {
673 return test_bit(TTY_PORT_KOPENED, &port->iflags);
674 }
675
tty_port_set_kopened(struct tty_port * port,bool val)676 static 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
684 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
685 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
686 extern int tty_port_carrier_raised(struct tty_port *port);
687 extern void tty_port_raise_dtr_rts(struct tty_port *port);
688 extern void tty_port_lower_dtr_rts(struct tty_port *port);
689 extern void tty_port_hangup(struct tty_port *port);
690 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
691 extern void tty_port_tty_wakeup(struct tty_port *port);
692 extern int tty_port_block_til_ready(struct tty_port *port,
693 struct tty_struct *tty, struct file *filp);
694 extern int tty_port_close_start(struct tty_port *port,
695 struct tty_struct *tty, struct file *filp);
696 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
697 extern void tty_port_close(struct tty_port *port,
698 struct tty_struct *tty, struct file *filp);
699 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
700 struct tty_struct *tty);
701 extern int tty_port_open(struct tty_port *port,
702 struct tty_struct *tty, struct file *filp);
tty_port_users(struct tty_port * port)703 static inline int tty_port_users(struct tty_port *port)
704 {
705 return port->count + port->blocked_open;
706 }
707
708 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
709 extern int tty_unregister_ldisc(int disc);
710 extern int tty_set_ldisc(struct tty_struct *tty, int disc);
711 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
712 extern void tty_ldisc_release(struct tty_struct *tty);
713 extern int __must_check tty_ldisc_init(struct tty_struct *tty);
714 extern void tty_ldisc_deinit(struct tty_struct *tty);
715 extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
716 char *f, int count);
717
718 /* n_tty.c */
719 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
720 #ifdef CONFIG_TTY
721 extern void __init n_tty_init(void);
722 #else
n_tty_init(void)723 static inline void n_tty_init(void) { }
724 #endif
725
726 /* tty_audit.c */
727 #ifdef CONFIG_AUDIT
728 extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
729 size_t size);
730 extern void tty_audit_exit(void);
731 extern void tty_audit_fork(struct signal_struct *sig);
732 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
733 extern int tty_audit_push(void);
734 #else
tty_audit_add_data(struct tty_struct * tty,const void * data,size_t size)735 static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
736 size_t size)
737 {
738 }
tty_audit_tiocsti(struct tty_struct * tty,char ch)739 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
740 {
741 }
tty_audit_exit(void)742 static inline void tty_audit_exit(void)
743 {
744 }
tty_audit_fork(struct signal_struct * sig)745 static inline void tty_audit_fork(struct signal_struct *sig)
746 {
747 }
tty_audit_push(void)748 static inline int tty_audit_push(void)
749 {
750 return 0;
751 }
752 #endif
753
754 /* tty_ioctl.c */
755 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
756 unsigned int cmd, unsigned long arg);
757
758 /* vt.c */
759
760 extern int vt_ioctl(struct tty_struct *tty,
761 unsigned int cmd, unsigned long arg);
762
763 extern 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 */
768 extern void tty_lock(struct tty_struct *tty);
769 extern int tty_lock_interruptible(struct tty_struct *tty);
770 extern void tty_unlock(struct tty_struct *tty);
771 extern void tty_lock_slave(struct tty_struct *tty);
772 extern void tty_unlock_slave(struct tty_struct *tty);
773 extern void tty_set_lock_subclass(struct tty_struct *tty);
774
775 #ifdef CONFIG_PROC_FS
776 extern void proc_tty_register_driver(struct tty_driver *);
777 extern void proc_tty_unregister_driver(struct tty_driver *);
778 #else
proc_tty_register_driver(struct tty_driver * d)779 static inline void proc_tty_register_driver(struct tty_driver *d) {}
proc_tty_unregister_driver(struct tty_driver * d)780 static 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
