xref: /linux-6.15/include/linux/tty.h (revision a115bc07)
1 #ifndef _LINUX_TTY_H
2 #define _LINUX_TTY_H
3 
4 /*
5  * 'tty.h' defines some structures used by tty_io.c and some defines.
6  */
7 
8 #ifdef __KERNEL__
9 #include <linux/fs.h>
10 #include <linux/major.h>
11 #include <linux/termios.h>
12 #include <linux/workqueue.h>
13 #include <linux/tty_driver.h>
14 #include <linux/tty_ldisc.h>
15 #include <linux/mutex.h>
16 
17 #include <asm/system.h>
18 
19 
20 /*
21  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
22  * hardcoded at present.)
23  */
24 #define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
25 #define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
26 #define NR_LDISCS		20
27 
28 /* line disciplines */
29 #define N_TTY		0
30 #define N_SLIP		1
31 #define N_MOUSE		2
32 #define N_PPP		3
33 #define N_STRIP		4
34 #define N_AX25		5
35 #define N_X25		6	/* X.25 async */
36 #define N_6PACK		7
37 #define N_MASC		8	/* Reserved for Mobitex module <[email protected]> */
38 #define N_R3964		9	/* Reserved for Simatic R3964 module */
39 #define N_PROFIBUS_FDL	10	/* Reserved for Profibus */
40 #define N_IRDA		11	/* Linux IrDa - http://irda.sourceforge.net/ */
41 #define N_SMSBLOCK	12	/* SMS block mode - for talking to GSM data */
42 				/* cards about SMS messages */
43 #define N_HDLC		13	/* synchronous HDLC */
44 #define N_SYNC_PPP	14	/* synchronous PPP */
45 #define N_HCI		15	/* Bluetooth HCI UART */
46 #define N_GIGASET_M101	16	/* Siemens Gigaset M101 serial DECT adapter */
47 #define N_SLCAN		17	/* Serial / USB serial CAN Adaptors */
48 #define N_PPS		18	/* Pulse per Second */
49 
50 #define N_V253		19	/* Codec control over voice modem */
51 
52 /*
53  * This character is the same as _POSIX_VDISABLE: it cannot be used as
54  * a c_cc[] character, but indicates that a particular special character
55  * isn't in use (eg VINTR has no character etc)
56  */
57 #define __DISABLED_CHAR '\0'
58 
59 struct tty_buffer {
60 	struct tty_buffer *next;
61 	char *char_buf_ptr;
62 	unsigned char *flag_buf_ptr;
63 	int used;
64 	int size;
65 	int commit;
66 	int read;
67 	/* Data points here */
68 	unsigned long data[0];
69 };
70 
71 /*
72  * We default to dicing tty buffer allocations to this many characters
73  * in order to avoid multiple page allocations. We assume tty_buffer itself
74  * is under 256 bytes. See tty_buffer_find for the allocation logic this
75  * must match
76  */
77 
78 #define TTY_BUFFER_PAGE		((PAGE_SIZE  - 256) / 2)
79 
80 
81 struct tty_bufhead {
82 	struct delayed_work work;
83 	spinlock_t lock;
84 	struct tty_buffer *head;	/* Queue head */
85 	struct tty_buffer *tail;	/* Active buffer */
86 	struct tty_buffer *free;	/* Free queue head */
87 	int memory_used;		/* Buffer space used excluding
88 								free queue */
89 };
90 /*
91  * When a break, frame error, or parity error happens, these codes are
92  * stuffed into the flags buffer.
93  */
94 #define TTY_NORMAL	0
95 #define TTY_BREAK	1
96 #define TTY_FRAME	2
97 #define TTY_PARITY	3
98 #define TTY_OVERRUN	4
99 
100 #define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
101 #define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
102 #define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
103 #define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
104 #define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
105 #define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
106 #define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
107 #define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
108 #define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
109 #define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
110 #define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
111 #define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
112 #define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
113 #define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
114 #define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
115 #define LNEXT_CHAR(tty)	((tty)->termios->c_cc[VLNEXT])
116 #define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])
117 
118 #define _I_FLAG(tty, f)	((tty)->termios->c_iflag & (f))
119 #define _O_FLAG(tty, f)	((tty)->termios->c_oflag & (f))
120 #define _C_FLAG(tty, f)	((tty)->termios->c_cflag & (f))
121 #define _L_FLAG(tty, f)	((tty)->termios->c_lflag & (f))
122 
123 #define I_IGNBRK(tty)	_I_FLAG((tty), IGNBRK)
124 #define I_BRKINT(tty)	_I_FLAG((tty), BRKINT)
125 #define I_IGNPAR(tty)	_I_FLAG((tty), IGNPAR)
126 #define I_PARMRK(tty)	_I_FLAG((tty), PARMRK)
127 #define I_INPCK(tty)	_I_FLAG((tty), INPCK)
128 #define I_ISTRIP(tty)	_I_FLAG((tty), ISTRIP)
129 #define I_INLCR(tty)	_I_FLAG((tty), INLCR)
130 #define I_IGNCR(tty)	_I_FLAG((tty), IGNCR)
131 #define I_ICRNL(tty)	_I_FLAG((tty), ICRNL)
132 #define I_IUCLC(tty)	_I_FLAG((tty), IUCLC)
133 #define I_IXON(tty)	_I_FLAG((tty), IXON)
134 #define I_IXANY(tty)	_I_FLAG((tty), IXANY)
135 #define I_IXOFF(tty)	_I_FLAG((tty), IXOFF)
136 #define I_IMAXBEL(tty)	_I_FLAG((tty), IMAXBEL)
137 #define I_IUTF8(tty)	_I_FLAG((tty), IUTF8)
138 
139 #define O_OPOST(tty)	_O_FLAG((tty), OPOST)
140 #define O_OLCUC(tty)	_O_FLAG((tty), OLCUC)
141 #define O_ONLCR(tty)	_O_FLAG((tty), ONLCR)
142 #define O_OCRNL(tty)	_O_FLAG((tty), OCRNL)
143 #define O_ONOCR(tty)	_O_FLAG((tty), ONOCR)
144 #define O_ONLRET(tty)	_O_FLAG((tty), ONLRET)
145 #define O_OFILL(tty)	_O_FLAG((tty), OFILL)
146 #define O_OFDEL(tty)	_O_FLAG((tty), OFDEL)
147 #define O_NLDLY(tty)	_O_FLAG((tty), NLDLY)
148 #define O_CRDLY(tty)	_O_FLAG((tty), CRDLY)
149 #define O_TABDLY(tty)	_O_FLAG((tty), TABDLY)
150 #define O_BSDLY(tty)	_O_FLAG((tty), BSDLY)
151 #define O_VTDLY(tty)	_O_FLAG((tty), VTDLY)
152 #define O_FFDLY(tty)	_O_FLAG((tty), FFDLY)
153 
154 #define C_BAUD(tty)	_C_FLAG((tty), CBAUD)
155 #define C_CSIZE(tty)	_C_FLAG((tty), CSIZE)
156 #define C_CSTOPB(tty)	_C_FLAG((tty), CSTOPB)
157 #define C_CREAD(tty)	_C_FLAG((tty), CREAD)
158 #define C_PARENB(tty)	_C_FLAG((tty), PARENB)
159 #define C_PARODD(tty)	_C_FLAG((tty), PARODD)
160 #define C_HUPCL(tty)	_C_FLAG((tty), HUPCL)
161 #define C_CLOCAL(tty)	_C_FLAG((tty), CLOCAL)
162 #define C_CIBAUD(tty)	_C_FLAG((tty), CIBAUD)
163 #define C_CRTSCTS(tty)	_C_FLAG((tty), CRTSCTS)
164 
165 #define L_ISIG(tty)	_L_FLAG((tty), ISIG)
166 #define L_ICANON(tty)	_L_FLAG((tty), ICANON)
167 #define L_XCASE(tty)	_L_FLAG((tty), XCASE)
168 #define L_ECHO(tty)	_L_FLAG((tty), ECHO)
169 #define L_ECHOE(tty)	_L_FLAG((tty), ECHOE)
170 #define L_ECHOK(tty)	_L_FLAG((tty), ECHOK)
171 #define L_ECHONL(tty)	_L_FLAG((tty), ECHONL)
172 #define L_NOFLSH(tty)	_L_FLAG((tty), NOFLSH)
173 #define L_TOSTOP(tty)	_L_FLAG((tty), TOSTOP)
174 #define L_ECHOCTL(tty)	_L_FLAG((tty), ECHOCTL)
175 #define L_ECHOPRT(tty)	_L_FLAG((tty), ECHOPRT)
176 #define L_ECHOKE(tty)	_L_FLAG((tty), ECHOKE)
177 #define L_FLUSHO(tty)	_L_FLAG((tty), FLUSHO)
178 #define L_PENDIN(tty)	_L_FLAG((tty), PENDIN)
179 #define L_IEXTEN(tty)	_L_FLAG((tty), IEXTEN)
180 
181 struct device;
182 struct signal_struct;
183 
184 /*
185  * Port level information. Each device keeps its own port level information
186  * so provide a common structure for those ports wanting to use common support
187  * routines.
188  *
189  * The tty port has a different lifetime to the tty so must be kept apart.
190  * In addition be careful as tty -> port mappings are valid for the life
191  * of the tty object but in many cases port -> tty mappings are valid only
192  * until a hangup so don't use the wrong path.
193  */
194 
195 struct tty_port;
196 
197 struct tty_port_operations {
198 	/* Return 1 if the carrier is raised */
199 	int (*carrier_raised)(struct tty_port *port);
200 	/* Control the DTR line */
201 	void (*dtr_rts)(struct tty_port *port, int raise);
202 	/* Called when the last close completes or a hangup finishes
203 	   IFF the port was initialized. Do not use to free resources. Called
204 	   under the port mutex to serialize against activate/shutdowns */
205 	void (*shutdown)(struct tty_port *port);
206 	void (*drop)(struct tty_port *port);
207 	/* Called under the port mutex from tty_port_open, serialized using
208 	   the port mutex */
209         /* FIXME: long term getting the tty argument *out* of this would be
210            good for consoles */
211 	int (*activate)(struct tty_port *port, struct tty_struct *tty);
212 	/* Called on the final put of a port */
213 	void (*destruct)(struct tty_port *port);
214 };
215 
216 struct tty_port {
217 	struct tty_struct	*tty;		/* Back pointer */
218 	const struct tty_port_operations *ops;	/* Port operations */
219 	spinlock_t		lock;		/* Lock protecting tty field */
220 	int			blocked_open;	/* Waiting to open */
221 	int			count;		/* Usage count */
222 	wait_queue_head_t	open_wait;	/* Open waiters */
223 	wait_queue_head_t	close_wait;	/* Close waiters */
224 	wait_queue_head_t	delta_msr_wait;	/* Modem status change */
225 	unsigned long		flags;		/* TTY flags ASY_*/
226 	struct mutex		mutex;		/* Locking */
227 	struct mutex		buf_mutex;	/* Buffer alloc lock */
228 	unsigned char		*xmit_buf;	/* Optional buffer */
229 	unsigned int		close_delay;	/* Close port delay */
230 	unsigned int		closing_wait;	/* Delay for output */
231 	int			drain_delay;	/* Set to zero if no pure time
232 						   based drain is needed else
233 						   set to size of fifo */
234 	struct kref		kref;		/* Ref counter */
235 };
236 
237 /*
238  * Where all of the state associated with a tty is kept while the tty
239  * is open.  Since the termios state should be kept even if the tty
240  * has been closed --- for things like the baud rate, etc --- it is
241  * not stored here, but rather a pointer to the real state is stored
242  * here.  Possible the winsize structure should have the same
243  * treatment, but (1) the default 80x24 is usually right and (2) it's
244  * most often used by a windowing system, which will set the correct
245  * size each time the window is created or resized anyway.
246  * 						- TYT, 9/14/92
247  */
248 
249 struct tty_operations;
250 
251 struct tty_struct {
252 	int	magic;
253 	struct kref kref;
254 	struct tty_driver *driver;
255 	const struct tty_operations *ops;
256 	int index;
257 
258 	/* Protects ldisc changes: Lock tty not pty */
259 	struct mutex ldisc_mutex;
260 	struct tty_ldisc *ldisc;
261 
262 	struct mutex termios_mutex;
263 	spinlock_t ctrl_lock;
264 	/* Termios values are protected by the termios mutex */
265 	struct ktermios *termios, *termios_locked;
266 	struct termiox *termiox;	/* May be NULL for unsupported */
267 	char name[64];
268 	struct pid *pgrp;		/* Protected by ctrl lock */
269 	struct pid *session;
270 	unsigned long flags;
271 	int count;
272 	struct winsize winsize;		/* termios mutex */
273 	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
274 	unsigned char low_latency:1, warned:1;
275 	unsigned char ctrl_status;	/* ctrl_lock */
276 	unsigned int receive_room;	/* Bytes free for queue */
277 
278 	struct tty_struct *link;
279 	struct fasync_struct *fasync;
280 	struct tty_bufhead buf;		/* Locked internally */
281 	int alt_speed;		/* For magic substitution of 38400 bps */
282 	wait_queue_head_t write_wait;
283 	wait_queue_head_t read_wait;
284 	struct work_struct hangup_work;
285 	void *disc_data;
286 	void *driver_data;
287 	struct list_head tty_files;
288 
289 #define N_TTY_BUF_SIZE 4096
290 
291 	/*
292 	 * The following is data for the N_TTY line discipline.  For
293 	 * historical reasons, this is included in the tty structure.
294 	 * Mostly locked by the BKL.
295 	 */
296 	unsigned int column;
297 	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
298 	unsigned char closing:1;
299 	unsigned char echo_overrun:1;
300 	unsigned short minimum_to_wake;
301 	unsigned long overrun_time;
302 	int num_overrun;
303 	unsigned long process_char_map[256/(8*sizeof(unsigned long))];
304 	char *read_buf;
305 	int read_head;
306 	int read_tail;
307 	int read_cnt;
308 	unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
309 	unsigned char *echo_buf;
310 	unsigned int echo_pos;
311 	unsigned int echo_cnt;
312 	int canon_data;
313 	unsigned long canon_head;
314 	unsigned int canon_column;
315 	struct mutex atomic_read_lock;
316 	struct mutex atomic_write_lock;
317 	struct mutex output_lock;
318 	struct mutex echo_lock;
319 	unsigned char *write_buf;
320 	int write_cnt;
321 	spinlock_t read_lock;
322 	/* If the tty has a pending do_SAK, queue it here - akpm */
323 	struct work_struct SAK_work;
324 	struct tty_port *port;
325 };
326 
327 /* tty magic number */
328 #define TTY_MAGIC		0x5401
329 
330 /*
331  * These bits are used in the flags field of the tty structure.
332  *
333  * So that interrupts won't be able to mess up the queues,
334  * copy_to_cooked must be atomic with respect to itself, as must
335  * tty->write.  Thus, you must use the inline functions set_bit() and
336  * clear_bit() to make things atomic.
337  */
338 #define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
339 #define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
340 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
341 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
342 #define TTY_DEBUG 		4	/* Debugging */
343 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
344 #define TTY_PUSH 		6	/* n_tty private */
345 #define TTY_CLOSING 		7	/* ->close() in progress */
346 #define TTY_LDISC 		9	/* Line discipline attached */
347 #define TTY_LDISC_CHANGING 	10	/* Line discipline changing */
348 #define TTY_LDISC_OPEN	 	11	/* Line discipline is open */
349 #define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
350 #define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
351 #define TTY_PTY_LOCK 		16	/* pty private */
352 #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
353 #define TTY_HUPPED 		18	/* Post driver->hangup() */
354 #define TTY_FLUSHING		19	/* Flushing to ldisc in progress */
355 #define TTY_FLUSHPENDING	20	/* Queued buffer flush pending */
356 
357 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
358 
359 extern void tty_write_flush(struct tty_struct *);
360 
361 extern struct ktermios tty_std_termios;
362 
363 extern void console_init(void);
364 extern int vcs_init(void);
365 
366 extern struct class *tty_class;
367 
368 /**
369  *	tty_kref_get		-	get a tty reference
370  *	@tty: tty device
371  *
372  *	Return a new reference to a tty object. The caller must hold
373  *	sufficient locks/counts to ensure that their existing reference cannot
374  *	go away
375  */
376 
377 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
378 {
379 	if (tty)
380 		kref_get(&tty->kref);
381 	return tty;
382 }
383 extern void tty_kref_put(struct tty_struct *tty);
384 
385 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
386 			      const char *routine);
387 extern char *tty_name(struct tty_struct *tty, char *buf);
388 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
389 extern int tty_check_change(struct tty_struct *tty);
390 extern void stop_tty(struct tty_struct *tty);
391 extern void start_tty(struct tty_struct *tty);
392 extern int tty_register_driver(struct tty_driver *driver);
393 extern int tty_unregister_driver(struct tty_driver *driver);
394 extern struct device *tty_register_device(struct tty_driver *driver,
395 					  unsigned index, struct device *dev);
396 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
397 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
398 			     int buflen);
399 extern void tty_write_message(struct tty_struct *tty, char *msg);
400 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
401 extern int tty_chars_in_buffer(struct tty_struct *tty);
402 extern int tty_write_room(struct tty_struct *tty);
403 extern void tty_driver_flush_buffer(struct tty_struct *tty);
404 extern void tty_throttle(struct tty_struct *tty);
405 extern void tty_unthrottle(struct tty_struct *tty);
406 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
407 extern void tty_shutdown(struct tty_struct *tty);
408 extern void tty_free_termios(struct tty_struct *tty);
409 extern int is_current_pgrp_orphaned(void);
410 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
411 extern int is_ignored(int sig);
412 extern int tty_signal(int sig, struct tty_struct *tty);
413 extern void tty_hangup(struct tty_struct *tty);
414 extern void tty_vhangup(struct tty_struct *tty);
415 extern void tty_vhangup_self(void);
416 extern void tty_unhangup(struct file *filp);
417 extern int tty_hung_up_p(struct file *filp);
418 extern void do_SAK(struct tty_struct *tty);
419 extern void __do_SAK(struct tty_struct *tty);
420 extern void disassociate_ctty(int priv);
421 extern void no_tty(void);
422 extern void tty_flip_buffer_push(struct tty_struct *tty);
423 extern void tty_flush_to_ldisc(struct tty_struct *tty);
424 extern void tty_buffer_free_all(struct tty_struct *tty);
425 extern void tty_buffer_flush(struct tty_struct *tty);
426 extern void tty_buffer_init(struct tty_struct *tty);
427 extern speed_t tty_get_baud_rate(struct tty_struct *tty);
428 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
429 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
430 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
431 						speed_t ibaud, speed_t obaud);
432 extern void tty_encode_baud_rate(struct tty_struct *tty,
433 						speed_t ibaud, speed_t obaud);
434 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
435 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
436 
437 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
438 extern void tty_ldisc_deref(struct tty_ldisc *);
439 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
440 extern void tty_ldisc_hangup(struct tty_struct *tty);
441 extern const struct file_operations tty_ldiscs_proc_fops;
442 
443 extern void tty_wakeup(struct tty_struct *tty);
444 extern void tty_ldisc_flush(struct tty_struct *tty);
445 
446 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
447 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
448 			unsigned int cmd, unsigned long arg);
449 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
450 extern dev_t tty_devnum(struct tty_struct *tty);
451 extern void proc_clear_tty(struct task_struct *p);
452 extern struct tty_struct *get_current_tty(void);
453 extern void tty_default_fops(struct file_operations *fops);
454 extern struct tty_struct *alloc_tty_struct(void);
455 extern void free_tty_struct(struct tty_struct *tty);
456 extern void initialize_tty_struct(struct tty_struct *tty,
457 		struct tty_driver *driver, int idx);
458 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
459 								int first_ok);
460 extern int tty_release(struct inode *inode, struct file *filp);
461 extern int tty_init_termios(struct tty_struct *tty);
462 
463 extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
464 extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
465 
466 extern struct mutex tty_mutex;
467 
468 extern void tty_write_unlock(struct tty_struct *tty);
469 extern int tty_write_lock(struct tty_struct *tty, int ndelay);
470 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
471 
472 extern void tty_port_init(struct tty_port *port);
473 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
474 extern void tty_port_free_xmit_buf(struct tty_port *port);
475 extern void tty_port_put(struct tty_port *port);
476 
477 static inline struct tty_port *tty_port_get(struct tty_port *port)
478 {
479 	if (port)
480 		kref_get(&port->kref);
481 	return port;
482 }
483 
484 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
485 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
486 extern int tty_port_carrier_raised(struct tty_port *port);
487 extern void tty_port_raise_dtr_rts(struct tty_port *port);
488 extern void tty_port_lower_dtr_rts(struct tty_port *port);
489 extern void tty_port_hangup(struct tty_port *port);
490 extern int tty_port_block_til_ready(struct tty_port *port,
491 				struct tty_struct *tty, struct file *filp);
492 extern int tty_port_close_start(struct tty_port *port,
493 				struct tty_struct *tty, struct file *filp);
494 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
495 extern void tty_port_close(struct tty_port *port,
496 				struct tty_struct *tty, struct file *filp);
497 extern int tty_port_open(struct tty_port *port,
498 				struct tty_struct *tty, struct file *filp);
499 static inline int tty_port_users(struct tty_port *port)
500 {
501 	return port->count + port->blocked_open;
502 }
503 
504 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
505 extern int tty_unregister_ldisc(int disc);
506 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
507 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
508 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
509 extern void tty_ldisc_init(struct tty_struct *tty);
510 extern void tty_ldisc_begin(void);
511 /* This last one is just for the tty layer internals and shouldn't be used elsewhere */
512 extern void tty_ldisc_enable(struct tty_struct *tty);
513 
514 
515 /* n_tty.c */
516 extern struct tty_ldisc_ops tty_ldisc_N_TTY;
517 
518 /* tty_audit.c */
519 #ifdef CONFIG_AUDIT
520 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
521 			       size_t size);
522 extern void tty_audit_exit(void);
523 extern void tty_audit_fork(struct signal_struct *sig);
524 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
525 extern void tty_audit_push(struct tty_struct *tty);
526 extern void tty_audit_push_task(struct task_struct *tsk,
527 					uid_t loginuid, u32 sessionid);
528 #else
529 static inline void tty_audit_add_data(struct tty_struct *tty,
530 				      unsigned char *data, size_t size)
531 {
532 }
533 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
534 {
535 }
536 static inline void tty_audit_exit(void)
537 {
538 }
539 static inline void tty_audit_fork(struct signal_struct *sig)
540 {
541 }
542 static inline void tty_audit_push(struct tty_struct *tty)
543 {
544 }
545 static inline void tty_audit_push_task(struct task_struct *tsk,
546 					uid_t loginuid, u32 sessionid)
547 {
548 }
549 #endif
550 
551 /* tty_ioctl.c */
552 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
553 		       unsigned int cmd, unsigned long arg);
554 
555 /* serial.c */
556 
557 extern void serial_console_init(void);
558 
559 /* pcxx.c */
560 
561 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
562 
563 /* vt.c */
564 
565 extern int vt_ioctl(struct tty_struct *tty, struct file *file,
566 		    unsigned int cmd, unsigned long arg);
567 
568 extern long vt_compat_ioctl(struct tty_struct *tty, struct file * file,
569 		     unsigned int cmd, unsigned long arg);
570 
571 #endif /* __KERNEL__ */
572 #endif
573