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1 #ifndef _LINUX_TTY_H
2 #define _LINUX_TTY_H
3 
4 #include <linux/fs.h>
5 #include <linux/major.h>
6 #include <linux/termios.h>
7 #include <linux/workqueue.h>
8 #include <linux/tty_driver.h>
9 #include <linux/tty_ldisc.h>
10 #include <linux/mutex.h>
11 #include <linux/tty_flags.h>
12 #include <uapi/linux/tty.h>
13 
14 
15 
16 /*
17  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
18  * hardcoded at present.)
19  */
20 #define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
21 #define NR_UNIX98_PTY_RESERVE	1024	  /* Default reserve for main devpts */
22 #define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
23 
24 /*
25  * This character is the same as _POSIX_VDISABLE: it cannot be used as
26  * a c_cc[] character, but indicates that a particular special character
27  * isn't in use (eg VINTR has no character etc)
28  */
29 #define __DISABLED_CHAR '\0'
30 
31 struct tty_buffer {
32 	struct tty_buffer *next;
33 	char *char_buf_ptr;
34 	unsigned char *flag_buf_ptr;
35 	int used;
36 	int size;
37 	int commit;
38 	int read;
39 	/* Data points here */
40 	unsigned long data[0];
41 };
42 
43 /*
44  * We default to dicing tty buffer allocations to this many characters
45  * in order to avoid multiple page allocations. We know the size of
46  * tty_buffer itself but it must also be taken into account that the
47  * the buffer is 256 byte aligned. See tty_buffer_find for the allocation
48  * logic this must match
49  */
50 
51 #define TTY_BUFFER_PAGE	(((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF)
52 
53 
54 struct tty_bufhead {
55 	struct work_struct work;
56 	spinlock_t lock;
57 	struct tty_buffer *head;	/* Queue head */
58 	struct tty_buffer *tail;	/* Active buffer */
59 	struct tty_buffer *free;	/* Free queue head */
60 	int memory_used;		/* Buffer space used excluding
61 								free queue */
62 };
63 /*
64  * When a break, frame error, or parity error happens, these codes are
65  * stuffed into the flags buffer.
66  */
67 #define TTY_NORMAL	0
68 #define TTY_BREAK	1
69 #define TTY_FRAME	2
70 #define TTY_PARITY	3
71 #define TTY_OVERRUN	4
72 
73 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
74 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
75 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
76 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
77 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
78 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
79 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
80 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
81 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
82 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
83 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
84 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
85 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
86 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
87 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
88 #define LNEXT_CHAR(tty)	((tty)->termios.c_cc[VLNEXT])
89 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
90 
91 #define _I_FLAG(tty, f)	((tty)->termios.c_iflag & (f))
92 #define _O_FLAG(tty, f)	((tty)->termios.c_oflag & (f))
93 #define _C_FLAG(tty, f)	((tty)->termios.c_cflag & (f))
94 #define _L_FLAG(tty, f)	((tty)->termios.c_lflag & (f))
95 
96 #define I_IGNBRK(tty)	_I_FLAG((tty), IGNBRK)
97 #define I_BRKINT(tty)	_I_FLAG((tty), BRKINT)
98 #define I_IGNPAR(tty)	_I_FLAG((tty), IGNPAR)
99 #define I_PARMRK(tty)	_I_FLAG((tty), PARMRK)
100 #define I_INPCK(tty)	_I_FLAG((tty), INPCK)
101 #define I_ISTRIP(tty)	_I_FLAG((tty), ISTRIP)
102 #define I_INLCR(tty)	_I_FLAG((tty), INLCR)
103 #define I_IGNCR(tty)	_I_FLAG((tty), IGNCR)
104 #define I_ICRNL(tty)	_I_FLAG((tty), ICRNL)
105 #define I_IUCLC(tty)	_I_FLAG((tty), IUCLC)
106 #define I_IXON(tty)	_I_FLAG((tty), IXON)
107 #define I_IXANY(tty)	_I_FLAG((tty), IXANY)
108 #define I_IXOFF(tty)	_I_FLAG((tty), IXOFF)
109 #define I_IMAXBEL(tty)	_I_FLAG((tty), IMAXBEL)
110 #define I_IUTF8(tty)	_I_FLAG((tty), IUTF8)
111 
112 #define O_OPOST(tty)	_O_FLAG((tty), OPOST)
113 #define O_OLCUC(tty)	_O_FLAG((tty), OLCUC)
114 #define O_ONLCR(tty)	_O_FLAG((tty), ONLCR)
115 #define O_OCRNL(tty)	_O_FLAG((tty), OCRNL)
116 #define O_ONOCR(tty)	_O_FLAG((tty), ONOCR)
117 #define O_ONLRET(tty)	_O_FLAG((tty), ONLRET)
118 #define O_OFILL(tty)	_O_FLAG((tty), OFILL)
119 #define O_OFDEL(tty)	_O_FLAG((tty), OFDEL)
120 #define O_NLDLY(tty)	_O_FLAG((tty), NLDLY)
121 #define O_CRDLY(tty)	_O_FLAG((tty), CRDLY)
122 #define O_TABDLY(tty)	_O_FLAG((tty), TABDLY)
123 #define O_BSDLY(tty)	_O_FLAG((tty), BSDLY)
124 #define O_VTDLY(tty)	_O_FLAG((tty), VTDLY)
125 #define O_FFDLY(tty)	_O_FLAG((tty), FFDLY)
126 
127 #define C_BAUD(tty)	_C_FLAG((tty), CBAUD)
128 #define C_CSIZE(tty)	_C_FLAG((tty), CSIZE)
129 #define C_CSTOPB(tty)	_C_FLAG((tty), CSTOPB)
130 #define C_CREAD(tty)	_C_FLAG((tty), CREAD)
131 #define C_PARENB(tty)	_C_FLAG((tty), PARENB)
132 #define C_PARODD(tty)	_C_FLAG((tty), PARODD)
133 #define C_HUPCL(tty)	_C_FLAG((tty), HUPCL)
134 #define C_CLOCAL(tty)	_C_FLAG((tty), CLOCAL)
135 #define C_CIBAUD(tty)	_C_FLAG((tty), CIBAUD)
136 #define C_CRTSCTS(tty)	_C_FLAG((tty), CRTSCTS)
137 
138 #define L_ISIG(tty)	_L_FLAG((tty), ISIG)
139 #define L_ICANON(tty)	_L_FLAG((tty), ICANON)
140 #define L_XCASE(tty)	_L_FLAG((tty), XCASE)
141 #define L_ECHO(tty)	_L_FLAG((tty), ECHO)
142 #define L_ECHOE(tty)	_L_FLAG((tty), ECHOE)
143 #define L_ECHOK(tty)	_L_FLAG((tty), ECHOK)
144 #define L_ECHONL(tty)	_L_FLAG((tty), ECHONL)
145 #define L_NOFLSH(tty)	_L_FLAG((tty), NOFLSH)
146 #define L_TOSTOP(tty)	_L_FLAG((tty), TOSTOP)
147 #define L_ECHOCTL(tty)	_L_FLAG((tty), ECHOCTL)
148 #define L_ECHOPRT(tty)	_L_FLAG((tty), ECHOPRT)
149 #define L_ECHOKE(tty)	_L_FLAG((tty), ECHOKE)
150 #define L_FLUSHO(tty)	_L_FLAG((tty), FLUSHO)
151 #define L_PENDIN(tty)	_L_FLAG((tty), PENDIN)
152 #define L_IEXTEN(tty)	_L_FLAG((tty), IEXTEN)
153 #define L_EXTPROC(tty)	_L_FLAG((tty), EXTPROC)
154 
155 struct device;
156 struct signal_struct;
157 
158 /*
159  * Port level information. Each device keeps its own port level information
160  * so provide a common structure for those ports wanting to use common support
161  * routines.
162  *
163  * The tty port has a different lifetime to the tty so must be kept apart.
164  * In addition be careful as tty -> port mappings are valid for the life
165  * of the tty object but in many cases port -> tty mappings are valid only
166  * until a hangup so don't use the wrong path.
167  */
168 
169 struct tty_port;
170 
171 struct tty_port_operations {
172 	/* Return 1 if the carrier is raised */
173 	int (*carrier_raised)(struct tty_port *port);
174 	/* Control the DTR line */
175 	void (*dtr_rts)(struct tty_port *port, int raise);
176 	/* Called when the last close completes or a hangup finishes
177 	   IFF the port was initialized. Do not use to free resources. Called
178 	   under the port mutex to serialize against activate/shutdowns */
179 	void (*shutdown)(struct tty_port *port);
180 	void (*drop)(struct tty_port *port);
181 	/* Called under the port mutex from tty_port_open, serialized using
182 	   the port mutex */
183         /* FIXME: long term getting the tty argument *out* of this would be
184            good for consoles */
185 	int (*activate)(struct tty_port *port, struct tty_struct *tty);
186 	/* Called on the final put of a port */
187 	void (*destruct)(struct tty_port *port);
188 };
189 
190 struct tty_port {
191 	struct tty_bufhead	buf;		/* Locked internally */
192 	struct tty_struct	*tty;		/* Back pointer */
193 	struct tty_struct	*itty;		/* internal back ptr */
194 	const struct tty_port_operations *ops;	/* Port operations */
195 	spinlock_t		lock;		/* Lock protecting tty field */
196 	int			blocked_open;	/* Waiting to open */
197 	int			count;		/* Usage count */
198 	wait_queue_head_t	open_wait;	/* Open waiters */
199 	wait_queue_head_t	close_wait;	/* Close waiters */
200 	wait_queue_head_t	delta_msr_wait;	/* Modem status change */
201 	unsigned long		flags;		/* TTY flags ASY_*/
202 	unsigned long		iflags;		/* TTYP_ internal flags */
203 #define TTYP_FLUSHING			1  /* Flushing to ldisc in progress */
204 #define TTYP_FLUSHPENDING		2  /* Queued buffer flush pending */
205 	unsigned char		console:1,	/* port is a console */
206 				low_latency:1;	/* direct buffer flush */
207 	struct mutex		mutex;		/* Locking */
208 	struct mutex		buf_mutex;	/* Buffer alloc lock */
209 	unsigned char		*xmit_buf;	/* Optional buffer */
210 	unsigned int		close_delay;	/* Close port delay */
211 	unsigned int		closing_wait;	/* Delay for output */
212 	int			drain_delay;	/* Set to zero if no pure time
213 						   based drain is needed else
214 						   set to size of fifo */
215 	struct kref		kref;		/* Ref counter */
216 };
217 
218 /*
219  * Where all of the state associated with a tty is kept while the tty
220  * is open.  Since the termios state should be kept even if the tty
221  * has been closed --- for things like the baud rate, etc --- it is
222  * not stored here, but rather a pointer to the real state is stored
223  * here.  Possible the winsize structure should have the same
224  * treatment, but (1) the default 80x24 is usually right and (2) it's
225  * most often used by a windowing system, which will set the correct
226  * size each time the window is created or resized anyway.
227  * 						- TYT, 9/14/92
228  */
229 
230 struct tty_operations;
231 
232 struct tty_struct {
233 	int	magic;
234 	struct kref kref;
235 	struct device *dev;
236 	struct tty_driver *driver;
237 	const struct tty_operations *ops;
238 	int index;
239 
240 	/* Protects ldisc changes: Lock tty not pty */
241 	struct mutex ldisc_mutex;
242 	struct tty_ldisc *ldisc;
243 
244 	struct mutex atomic_write_lock;
245 	struct mutex legacy_mutex;
246 	struct mutex termios_mutex;
247 	spinlock_t ctrl_lock;
248 	/* Termios values are protected by the termios mutex */
249 	struct ktermios termios, termios_locked;
250 	struct termiox *termiox;	/* May be NULL for unsupported */
251 	char name[64];
252 	struct pid *pgrp;		/* Protected by ctrl lock */
253 	struct pid *session;
254 	unsigned long flags;
255 	int count;
256 	struct winsize winsize;		/* termios mutex */
257 	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
258 	unsigned char ctrl_status;	/* ctrl_lock */
259 	unsigned int receive_room;	/* Bytes free for queue */
260 	int flow_change;
261 
262 	struct tty_struct *link;
263 	struct fasync_struct *fasync;
264 	int alt_speed;		/* For magic substitution of 38400 bps */
265 	wait_queue_head_t write_wait;
266 	wait_queue_head_t read_wait;
267 	struct work_struct hangup_work;
268 	void *disc_data;
269 	void *driver_data;
270 	struct list_head tty_files;
271 
272 #define N_TTY_BUF_SIZE 4096
273 
274 	unsigned char closing:1;
275 	unsigned short minimum_to_wake;
276 	unsigned char *write_buf;
277 	int write_cnt;
278 	/* If the tty has a pending do_SAK, queue it here - akpm */
279 	struct work_struct SAK_work;
280 	struct tty_port *port;
281 };
282 
283 /* Each of a tty's open files has private_data pointing to tty_file_private */
284 struct tty_file_private {
285 	struct tty_struct *tty;
286 	struct file *file;
287 	struct list_head list;
288 };
289 
290 /* tty magic number */
291 #define TTY_MAGIC		0x5401
292 
293 /*
294  * These bits are used in the flags field of the tty structure.
295  *
296  * So that interrupts won't be able to mess up the queues,
297  * copy_to_cooked must be atomic with respect to itself, as must
298  * tty->write.  Thus, you must use the inline functions set_bit() and
299  * clear_bit() to make things atomic.
300  */
301 #define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
302 #define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
303 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
304 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
305 #define TTY_DEBUG 		4	/* Debugging */
306 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
307 #define TTY_PUSH 		6	/* n_tty private */
308 #define TTY_CLOSING 		7	/* ->close() in progress */
309 #define TTY_LDISC 		9	/* Line discipline attached */
310 #define TTY_LDISC_CHANGING 	10	/* Line discipline changing */
311 #define TTY_LDISC_OPEN	 	11	/* Line discipline is open */
312 #define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
313 #define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
314 #define TTY_PTY_LOCK 		16	/* pty private */
315 #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
316 #define TTY_HUPPED 		18	/* Post driver->hangup() */
317 #define TTY_HUPPING 		21	/* ->hangup() in progress */
318 #define TTY_LDISC_HALTED	22	/* Line discipline is halted */
319 
320 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
321 
322 /* Values for tty->flow_change */
323 #define TTY_THROTTLE_SAFE 1
324 #define TTY_UNTHROTTLE_SAFE 2
325 
__tty_set_flow_change(struct tty_struct * tty,int val)326 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
327 {
328 	tty->flow_change = val;
329 }
330 
tty_set_flow_change(struct tty_struct * tty,int val)331 static inline void tty_set_flow_change(struct tty_struct *tty, int val)
332 {
333 	tty->flow_change = val;
334 	smp_mb();
335 }
336 
337 #ifdef CONFIG_TTY
338 extern void console_init(void);
339 extern void tty_kref_put(struct tty_struct *tty);
340 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
341 extern void tty_vhangup_self(void);
342 extern void disassociate_ctty(int priv);
343 extern dev_t tty_devnum(struct tty_struct *tty);
344 extern void proc_clear_tty(struct task_struct *p);
345 extern struct tty_struct *get_current_tty(void);
346 /* tty_io.c */
347 extern int __init tty_init(void);
348 #else
console_init(void)349 static inline void console_init(void)
350 { }
tty_kref_put(struct tty_struct * tty)351 static inline void tty_kref_put(struct tty_struct *tty)
352 { }
tty_get_pgrp(struct tty_struct * tty)353 static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
354 { return NULL; }
tty_vhangup_self(void)355 static inline void tty_vhangup_self(void)
356 { }
disassociate_ctty(int priv)357 static inline void disassociate_ctty(int priv)
358 { }
tty_devnum(struct tty_struct * tty)359 static inline dev_t tty_devnum(struct tty_struct *tty)
360 { return 0; }
proc_clear_tty(struct task_struct * p)361 static inline void proc_clear_tty(struct task_struct *p)
362 { }
get_current_tty(void)363 static inline struct tty_struct *get_current_tty(void)
364 { return NULL; }
365 /* tty_io.c */
tty_init(void)366 static inline int __init tty_init(void)
367 { return 0; }
368 #endif
369 
370 extern void tty_write_flush(struct tty_struct *);
371 
372 extern struct ktermios tty_std_termios;
373 
374 extern int vcs_init(void);
375 
376 extern struct class *tty_class;
377 
378 /**
379  *	tty_kref_get		-	get a tty reference
380  *	@tty: tty device
381  *
382  *	Return a new reference to a tty object. The caller must hold
383  *	sufficient locks/counts to ensure that their existing reference cannot
384  *	go away
385  */
386 
tty_kref_get(struct tty_struct * tty)387 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
388 {
389 	if (tty)
390 		kref_get(&tty->kref);
391 	return tty;
392 }
393 
394 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
395 			      const char *routine);
396 extern char *tty_name(struct tty_struct *tty, char *buf);
397 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
398 extern int tty_check_change(struct tty_struct *tty);
399 extern void stop_tty(struct tty_struct *tty);
400 extern void start_tty(struct tty_struct *tty);
401 extern int tty_register_driver(struct tty_driver *driver);
402 extern int tty_unregister_driver(struct tty_driver *driver);
403 extern struct device *tty_register_device(struct tty_driver *driver,
404 					  unsigned index, struct device *dev);
405 extern struct device *tty_register_device_attr(struct tty_driver *driver,
406 				unsigned index, struct device *device,
407 				void *drvdata,
408 				const struct attribute_group **attr_grp);
409 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
410 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
411 			     int buflen);
412 extern void tty_write_message(struct tty_struct *tty, char *msg);
413 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
414 extern int tty_chars_in_buffer(struct tty_struct *tty);
415 extern int tty_write_room(struct tty_struct *tty);
416 extern void tty_driver_flush_buffer(struct tty_struct *tty);
417 extern void tty_throttle(struct tty_struct *tty);
418 extern void tty_unthrottle(struct tty_struct *tty);
419 extern int tty_throttle_safe(struct tty_struct *tty);
420 extern int tty_unthrottle_safe(struct tty_struct *tty);
421 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
422 extern void tty_driver_remove_tty(struct tty_driver *driver,
423 				  struct tty_struct *tty);
424 extern void tty_free_termios(struct tty_struct *tty);
425 extern int is_current_pgrp_orphaned(void);
426 extern int is_ignored(int sig);
427 extern int tty_signal(int sig, struct tty_struct *tty);
428 extern void tty_hangup(struct tty_struct *tty);
429 extern void tty_vhangup(struct tty_struct *tty);
430 extern void tty_vhangup_locked(struct tty_struct *tty);
431 extern void tty_unhangup(struct file *filp);
432 extern int tty_hung_up_p(struct file *filp);
433 extern void do_SAK(struct tty_struct *tty);
434 extern void __do_SAK(struct tty_struct *tty);
435 extern void no_tty(void);
436 extern void tty_flush_to_ldisc(struct tty_struct *tty);
437 extern void tty_buffer_free_all(struct tty_port *port);
438 extern void tty_buffer_flush(struct tty_struct *tty);
439 extern void tty_buffer_init(struct tty_port *port);
440 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
441 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
442 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
443 						speed_t ibaud, speed_t obaud);
444 extern void tty_encode_baud_rate(struct tty_struct *tty,
445 						speed_t ibaud, speed_t obaud);
446 
447 /**
448  *	tty_get_baud_rate	-	get tty bit rates
449  *	@tty: tty to query
450  *
451  *	Returns the baud rate as an integer for this terminal. The
452  *	termios lock must be held by the caller and the terminal bit
453  *	flags may be updated.
454  *
455  *	Locking: none
456  */
tty_get_baud_rate(struct tty_struct * tty)457 static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
458 {
459 	return tty_termios_baud_rate(&tty->termios);
460 }
461 
462 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
463 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
464 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
465 
466 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
467 extern void tty_ldisc_deref(struct tty_ldisc *);
468 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
469 extern void tty_ldisc_hangup(struct tty_struct *tty);
470 extern const struct file_operations tty_ldiscs_proc_fops;
471 
472 extern void tty_wakeup(struct tty_struct *tty);
473 extern void tty_ldisc_flush(struct tty_struct *tty);
474 
475 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
476 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
477 			unsigned int cmd, unsigned long arg);
478 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
479 extern void tty_default_fops(struct file_operations *fops);
480 extern struct tty_struct *alloc_tty_struct(void);
481 extern int tty_alloc_file(struct file *file);
482 extern void tty_add_file(struct tty_struct *tty, struct file *file);
483 extern void tty_free_file(struct file *file);
484 extern void free_tty_struct(struct tty_struct *tty);
485 extern void initialize_tty_struct(struct tty_struct *tty,
486 		struct tty_driver *driver, int idx);
487 extern void deinitialize_tty_struct(struct tty_struct *tty);
488 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
489 extern int tty_release(struct inode *inode, struct file *filp);
490 extern int tty_init_termios(struct tty_struct *tty);
491 extern int tty_standard_install(struct tty_driver *driver,
492 		struct tty_struct *tty);
493 
494 extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
495 extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
496 
497 extern struct mutex tty_mutex;
498 extern spinlock_t tty_files_lock;
499 
500 extern void tty_write_unlock(struct tty_struct *tty);
501 extern int tty_write_lock(struct tty_struct *tty, int ndelay);
502 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
503 
504 extern void tty_port_init(struct tty_port *port);
505 extern void tty_port_link_device(struct tty_port *port,
506 		struct tty_driver *driver, unsigned index);
507 extern struct device *tty_port_register_device(struct tty_port *port,
508 		struct tty_driver *driver, unsigned index,
509 		struct device *device);
510 extern struct device *tty_port_register_device_attr(struct tty_port *port,
511 		struct tty_driver *driver, unsigned index,
512 		struct device *device, void *drvdata,
513 		const struct attribute_group **attr_grp);
514 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
515 extern void tty_port_free_xmit_buf(struct tty_port *port);
516 extern void tty_port_destroy(struct tty_port *port);
517 extern void tty_port_put(struct tty_port *port);
518 
tty_port_get(struct tty_port * port)519 static inline struct tty_port *tty_port_get(struct tty_port *port)
520 {
521 	if (port)
522 		kref_get(&port->kref);
523 	return port;
524 }
525 
526 /* If the cts flow control is enabled, return true. */
tty_port_cts_enabled(struct tty_port * port)527 static inline bool tty_port_cts_enabled(struct tty_port *port)
528 {
529 	return port->flags & ASYNC_CTS_FLOW;
530 }
531 
532 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
533 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
534 extern int tty_port_carrier_raised(struct tty_port *port);
535 extern void tty_port_raise_dtr_rts(struct tty_port *port);
536 extern void tty_port_lower_dtr_rts(struct tty_port *port);
537 extern void tty_port_hangup(struct tty_port *port);
538 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
539 extern void tty_port_tty_wakeup(struct tty_port *port);
540 extern int tty_port_block_til_ready(struct tty_port *port,
541 				struct tty_struct *tty, struct file *filp);
542 extern int tty_port_close_start(struct tty_port *port,
543 				struct tty_struct *tty, struct file *filp);
544 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
545 extern void tty_port_close(struct tty_port *port,
546 				struct tty_struct *tty, struct file *filp);
547 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
548 				struct tty_struct *tty);
549 extern int tty_port_open(struct tty_port *port,
550 				struct tty_struct *tty, struct file *filp);
tty_port_users(struct tty_port * port)551 static inline int tty_port_users(struct tty_port *port)
552 {
553 	return port->count + port->blocked_open;
554 }
555 
556 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
557 extern int tty_unregister_ldisc(int disc);
558 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
559 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
560 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
561 extern void tty_ldisc_init(struct tty_struct *tty);
562 extern void tty_ldisc_deinit(struct tty_struct *tty);
563 extern void tty_ldisc_begin(void);
564 
565 
566 /* n_tty.c */
567 extern struct tty_ldisc_ops tty_ldisc_N_TTY;
568 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
569 
570 /* tty_audit.c */
571 #ifdef CONFIG_AUDIT
572 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
573 			       size_t size, unsigned icanon);
574 extern void tty_audit_exit(void);
575 extern void tty_audit_fork(struct signal_struct *sig);
576 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
577 extern void tty_audit_push(struct tty_struct *tty);
578 extern int tty_audit_push_current(void);
579 #else
tty_audit_add_data(struct tty_struct * tty,unsigned char * data,size_t size,unsigned icanon)580 static inline void tty_audit_add_data(struct tty_struct *tty,
581 		unsigned char *data, size_t size, unsigned icanon)
582 {
583 }
tty_audit_tiocsti(struct tty_struct * tty,char ch)584 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
585 {
586 }
tty_audit_exit(void)587 static inline void tty_audit_exit(void)
588 {
589 }
tty_audit_fork(struct signal_struct * sig)590 static inline void tty_audit_fork(struct signal_struct *sig)
591 {
592 }
tty_audit_push(struct tty_struct * tty)593 static inline void tty_audit_push(struct tty_struct *tty)
594 {
595 }
tty_audit_push_current(void)596 static inline int tty_audit_push_current(void)
597 {
598 	return 0;
599 }
600 #endif
601 
602 /* tty_ioctl.c */
603 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
604 		       unsigned int cmd, unsigned long arg);
605 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
606 		       unsigned int cmd, unsigned long arg);
607 
608 /* serial.c */
609 
610 extern void serial_console_init(void);
611 
612 /* pcxx.c */
613 
614 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
615 
616 /* vt.c */
617 
618 extern int vt_ioctl(struct tty_struct *tty,
619 		    unsigned int cmd, unsigned long arg);
620 
621 extern long vt_compat_ioctl(struct tty_struct *tty,
622 		     unsigned int cmd, unsigned long arg);
623 
624 /* tty_mutex.c */
625 /* functions for preparation of BKL removal */
626 extern void __lockfunc tty_lock(struct tty_struct *tty);
627 extern void __lockfunc tty_unlock(struct tty_struct *tty);
628 extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
629 				struct tty_struct *tty2);
630 extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
631 				struct tty_struct *tty2);
632 
633 /*
634  * this shall be called only from where BTM is held (like close)
635  *
636  * We need this to ensure nobody waits for us to finish while we are waiting.
637  * Without this we were encountering system stalls.
638  *
639  * This should be indeed removed with BTM removal later.
640  *
641  * Locking: BTM required. Nobody is allowed to hold port->mutex.
642  */
tty_wait_until_sent_from_close(struct tty_struct * tty,long timeout)643 static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
644 		long timeout)
645 {
646 	tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
647 	tty_wait_until_sent(tty, timeout);
648 	tty_lock(tty);
649 }
650 
651 /*
652  * wait_event_interruptible_tty -- wait for a condition with the tty lock held
653  *
654  * The condition we are waiting for might take a long time to
655  * become true, or might depend on another thread taking the
656  * BTM. In either case, we need to drop the BTM to guarantee
657  * forward progress. This is a leftover from the conversion
658  * from the BKL and should eventually get removed as the BTM
659  * falls out of use.
660  *
661  * Do not use in new code.
662  */
663 #define wait_event_interruptible_tty(tty, wq, condition)		\
664 ({									\
665 	int __ret = 0;							\
666 	if (!(condition)) {						\
667 		__wait_event_interruptible_tty(tty, wq, condition, __ret);	\
668 	}								\
669 	__ret;								\
670 })
671 
672 #define __wait_event_interruptible_tty(tty, wq, condition, ret)		\
673 do {									\
674 	DEFINE_WAIT(__wait);						\
675 									\
676 	for (;;) {							\
677 		prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE);	\
678 		if (condition)						\
679 			break;						\
680 		if (!signal_pending(current)) {				\
681 			tty_unlock(tty);					\
682 			schedule();					\
683 			tty_lock(tty);					\
684 			continue;					\
685 		}							\
686 		ret = -ERESTARTSYS;					\
687 		break;							\
688 	}								\
689 	finish_wait(&wq, &__wait);					\
690 } while (0)
691 
692 #ifdef CONFIG_PROC_FS
693 extern void proc_tty_register_driver(struct tty_driver *);
694 extern void proc_tty_unregister_driver(struct tty_driver *);
695 #else
proc_tty_register_driver(struct tty_driver * d)696 static inline void proc_tty_register_driver(struct tty_driver *d) {}
proc_tty_unregister_driver(struct tty_driver * d)697 static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
698 #endif
699 
700 #endif
701