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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 #include <linux/rwsem.h>
14 #include <linux/llist.h>
15
16
17
18 /*
19 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
20 * hardcoded at present.)
21 */
22 #define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */
23 #define NR_UNIX98_PTY_RESERVE 1024 /* Default reserve for main devpts */
24 #define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */
25
26 /*
27 * This character is the same as _POSIX_VDISABLE: it cannot be used as
28 * a c_cc[] character, but indicates that a particular special character
29 * isn't in use (eg VINTR has no character etc)
30 */
31 #define __DISABLED_CHAR '\0'
32
33 struct tty_buffer {
34 union {
35 struct tty_buffer *next;
36 struct llist_node free;
37 };
38 int used;
39 int size;
40 int commit;
41 int read;
42 int flags;
43 /* Data points here */
44 unsigned long data[0];
45 };
46
47 /* Values for .flags field of tty_buffer */
48 #define TTYB_NORMAL 1 /* buffer has no flags buffer */
49
50 static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
51 {
52 return ((unsigned char *)b->data) + ofs;
53 }
54
55 static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
56 {
57 return (char *)char_buf_ptr(b, ofs) + b->size;
58 }
59
60 struct tty_bufhead {
61 struct tty_buffer *head; /* Queue head */
62 struct work_struct work;
63 struct mutex lock;
64 atomic_t priority;
65 struct tty_buffer sentinel;
66 struct llist_head free; /* Free queue head */
67 atomic_t mem_used; /* In-use buffers excluding free list */
68 int mem_limit;
69 struct tty_buffer *tail; /* Active buffer */
70 };
71 /*
72 * When a break, frame error, or parity error happens, these codes are
73 * stuffed into the flags buffer.
74 */
75 #define TTY_NORMAL 0
76 #define TTY_BREAK 1
77 #define TTY_FRAME 2
78 #define TTY_PARITY 3
79 #define TTY_OVERRUN 4
80
81 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
82 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
83 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
84 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
85 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
86 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
87 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
88 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
89 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
90 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
91 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
92 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
93 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
94 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
95 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
96 #define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
97 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
98
99 #define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
100 #define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
101 #define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
102 #define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
103
104 #define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK)
105 #define I_BRKINT(tty) _I_FLAG((tty), BRKINT)
106 #define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR)
107 #define I_PARMRK(tty) _I_FLAG((tty), PARMRK)
108 #define I_INPCK(tty) _I_FLAG((tty), INPCK)
109 #define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP)
110 #define I_INLCR(tty) _I_FLAG((tty), INLCR)
111 #define I_IGNCR(tty) _I_FLAG((tty), IGNCR)
112 #define I_ICRNL(tty) _I_FLAG((tty), ICRNL)
113 #define I_IUCLC(tty) _I_FLAG((tty), IUCLC)
114 #define I_IXON(tty) _I_FLAG((tty), IXON)
115 #define I_IXANY(tty) _I_FLAG((tty), IXANY)
116 #define I_IXOFF(tty) _I_FLAG((tty), IXOFF)
117 #define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL)
118 #define I_IUTF8(tty) _I_FLAG((tty), IUTF8)
119
120 #define O_OPOST(tty) _O_FLAG((tty), OPOST)
121 #define O_OLCUC(tty) _O_FLAG((tty), OLCUC)
122 #define O_ONLCR(tty) _O_FLAG((tty), ONLCR)
123 #define O_OCRNL(tty) _O_FLAG((tty), OCRNL)
124 #define O_ONOCR(tty) _O_FLAG((tty), ONOCR)
125 #define O_ONLRET(tty) _O_FLAG((tty), ONLRET)
126 #define O_OFILL(tty) _O_FLAG((tty), OFILL)
127 #define O_OFDEL(tty) _O_FLAG((tty), OFDEL)
128 #define O_NLDLY(tty) _O_FLAG((tty), NLDLY)
129 #define O_CRDLY(tty) _O_FLAG((tty), CRDLY)
130 #define O_TABDLY(tty) _O_FLAG((tty), TABDLY)
131 #define O_BSDLY(tty) _O_FLAG((tty), BSDLY)
132 #define O_VTDLY(tty) _O_FLAG((tty), VTDLY)
133 #define O_FFDLY(tty) _O_FLAG((tty), FFDLY)
134
135 #define C_BAUD(tty) _C_FLAG((tty), CBAUD)
136 #define C_CSIZE(tty) _C_FLAG((tty), CSIZE)
137 #define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB)
138 #define C_CREAD(tty) _C_FLAG((tty), CREAD)
139 #define C_PARENB(tty) _C_FLAG((tty), PARENB)
140 #define C_PARODD(tty) _C_FLAG((tty), PARODD)
141 #define C_HUPCL(tty) _C_FLAG((tty), HUPCL)
142 #define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL)
143 #define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD)
144 #define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS)
145 #define C_CMSPAR(tty) _C_FLAG((tty), CMSPAR)
146
147 #define L_ISIG(tty) _L_FLAG((tty), ISIG)
148 #define L_ICANON(tty) _L_FLAG((tty), ICANON)
149 #define L_XCASE(tty) _L_FLAG((tty), XCASE)
150 #define L_ECHO(tty) _L_FLAG((tty), ECHO)
151 #define L_ECHOE(tty) _L_FLAG((tty), ECHOE)
152 #define L_ECHOK(tty) _L_FLAG((tty), ECHOK)
153 #define L_ECHONL(tty) _L_FLAG((tty), ECHONL)
154 #define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH)
155 #define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP)
156 #define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL)
157 #define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT)
158 #define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE)
159 #define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO)
160 #define L_PENDIN(tty) _L_FLAG((tty), PENDIN)
161 #define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN)
162 #define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC)
163
164 struct device;
165 struct signal_struct;
166
167 /*
168 * Port level information. Each device keeps its own port level information
169 * so provide a common structure for those ports wanting to use common support
170 * routines.
171 *
172 * The tty port has a different lifetime to the tty so must be kept apart.
173 * In addition be careful as tty -> port mappings are valid for the life
174 * of the tty object but in many cases port -> tty mappings are valid only
175 * until a hangup so don't use the wrong path.
176 */
177
178 struct tty_port;
179
180 struct tty_port_operations {
181 /* Return 1 if the carrier is raised */
182 int (*carrier_raised)(struct tty_port *port);
183 /* Control the DTR line */
184 void (*dtr_rts)(struct tty_port *port, int raise);
185 /* Called when the last close completes or a hangup finishes
186 IFF the port was initialized. Do not use to free resources. Called
187 under the port mutex to serialize against activate/shutdowns */
188 void (*shutdown)(struct tty_port *port);
189 /* Called under the port mutex from tty_port_open, serialized using
190 the port mutex */
191 /* FIXME: long term getting the tty argument *out* of this would be
192 good for consoles */
193 int (*activate)(struct tty_port *port, struct tty_struct *tty);
194 /* Called on the final put of a port */
195 void (*destruct)(struct tty_port *port);
196 };
197
198 struct tty_port {
199 struct tty_bufhead buf; /* Locked internally */
200 struct tty_struct *tty; /* Back pointer */
201 struct tty_struct *itty; /* internal back ptr */
202 const struct tty_port_operations *ops; /* Port operations */
203 spinlock_t lock; /* Lock protecting tty field */
204 int blocked_open; /* Waiting to open */
205 int count; /* Usage count */
206 wait_queue_head_t open_wait; /* Open waiters */
207 wait_queue_head_t close_wait; /* Close waiters */
208 wait_queue_head_t delta_msr_wait; /* Modem status change */
209 unsigned long flags; /* TTY flags ASY_*/
210 unsigned char console:1, /* port is a console */
211 low_latency:1; /* optional: tune for latency */
212 struct mutex mutex; /* Locking */
213 struct mutex buf_mutex; /* Buffer alloc lock */
214 unsigned char *xmit_buf; /* Optional buffer */
215 unsigned int close_delay; /* Close port delay */
216 unsigned int closing_wait; /* Delay for output */
217 int drain_delay; /* Set to zero if no pure time
218 based drain is needed else
219 set to size of fifo */
220 struct kref kref; /* Ref counter */
221 };
222
223 /*
224 * Where all of the state associated with a tty is kept while the tty
225 * is open. Since the termios state should be kept even if the tty
226 * has been closed --- for things like the baud rate, etc --- it is
227 * not stored here, but rather a pointer to the real state is stored
228 * here. Possible the winsize structure should have the same
229 * treatment, but (1) the default 80x24 is usually right and (2) it's
230 * most often used by a windowing system, which will set the correct
231 * size each time the window is created or resized anyway.
232 * - TYT, 9/14/92
233 */
234
235 struct tty_operations;
236
237 struct tty_struct {
238 int magic;
239 struct kref kref;
240 struct device *dev;
241 struct tty_driver *driver;
242 const struct tty_operations *ops;
243 int index;
244
245 /* Protects ldisc changes: Lock tty not pty */
246 struct ld_semaphore ldisc_sem;
247 struct tty_ldisc *ldisc;
248
249 struct mutex atomic_write_lock;
250 struct mutex legacy_mutex;
251 struct mutex throttle_mutex;
252 struct rw_semaphore termios_rwsem;
253 struct mutex winsize_mutex;
254 spinlock_t ctrl_lock;
255 /* Termios values are protected by the termios rwsem */
256 struct ktermios termios, termios_locked;
257 struct termiox *termiox; /* May be NULL for unsupported */
258 char name[64];
259 struct pid *pgrp; /* Protected by ctrl lock */
260 struct pid *session;
261 unsigned long flags;
262 int count;
263 struct winsize winsize; /* winsize_mutex */
264 unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
265 unsigned char ctrl_status; /* ctrl_lock */
266 unsigned int receive_room; /* Bytes free for queue */
267 int flow_change;
268
269 struct tty_struct *link;
270 struct fasync_struct *fasync;
271 int alt_speed; /* For magic substitution of 38400 bps */
272 wait_queue_head_t write_wait;
273 wait_queue_head_t read_wait;
274 struct work_struct hangup_work;
275 void *disc_data;
276 void *driver_data;
277 struct list_head tty_files;
278
279 #define N_TTY_BUF_SIZE 4096
280
281 unsigned char closing:1;
282 unsigned char *write_buf;
283 int write_cnt;
284 /* If the tty has a pending do_SAK, queue it here - akpm */
285 struct work_struct SAK_work;
286 struct tty_port *port;
287 };
288
289 /* Each of a tty's open files has private_data pointing to tty_file_private */
290 struct tty_file_private {
291 struct tty_struct *tty;
292 struct file *file;
293 struct list_head list;
294 };
295
296 /* tty magic number */
297 #define TTY_MAGIC 0x5401
298
299 /*
300 * These bits are used in the flags field of the tty structure.
301 *
302 * So that interrupts won't be able to mess up the queues,
303 * copy_to_cooked must be atomic with respect to itself, as must
304 * tty->write. Thus, you must use the inline functions set_bit() and
305 * clear_bit() to make things atomic.
306 */
307 #define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */
308 #define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */
309 #define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */
310 #define TTY_EXCLUSIVE 3 /* Exclusive open mode */
311 #define TTY_DEBUG 4 /* Debugging */
312 #define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */
313 #define TTY_CLOSING 7 /* ->close() in progress */
314 #define TTY_LDISC_OPEN 11 /* Line discipline is open */
315 #define TTY_PTY_LOCK 16 /* pty private */
316 #define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */
317 #define TTY_HUPPED 18 /* Post driver->hangup() */
318 #define TTY_HUPPING 21 /* ->hangup() in progress */
319 #define TTY_LDISC_HALTED 22 /* Line discipline is halted */
320
321 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
322
323 /* Values for tty->flow_change */
324 #define TTY_THROTTLE_SAFE 1
325 #define TTY_UNTHROTTLE_SAFE 2
326
327 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
328 {
329 tty->flow_change = val;
330 }
331
332 static inline void tty_set_flow_change(struct tty_struct *tty, int val)
333 {
334 tty->flow_change = val;
335 smp_mb();
336 }
337
338 #ifdef CONFIG_TTY
339 extern void console_init(void);
340 extern void tty_kref_put(struct tty_struct *tty);
341 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
342 extern void tty_vhangup_self(void);
343 extern void disassociate_ctty(int priv);
344 extern dev_t tty_devnum(struct tty_struct *tty);
345 extern void proc_clear_tty(struct task_struct *p);
346 extern struct tty_struct *get_current_tty(void);
347 /* tty_io.c */
348 extern int __init tty_init(void);
349 #else
350 static inline void console_init(void)
351 { }
352 static inline void tty_kref_put(struct tty_struct *tty)
353 { }
354 static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
355 { return NULL; }
356 static inline void tty_vhangup_self(void)
357 { }
358 static inline void disassociate_ctty(int priv)
359 { }
360 static inline dev_t tty_devnum(struct tty_struct *tty)
361 { return 0; }
362 static inline void proc_clear_tty(struct task_struct *p)
363 { }
364 static inline struct tty_struct *get_current_tty(void)
365 { return NULL; }
366 /* tty_io.c */
367 static inline int __init tty_init(void)
368 { return 0; }
369 #endif
370
371 extern void tty_write_flush(struct tty_struct *);
372
373 extern struct ktermios tty_std_termios;
374
375 extern int vcs_init(void);
376
377 extern struct class *tty_class;
378
379 /**
380 * tty_kref_get - get a tty reference
381 * @tty: tty device
382 *
383 * Return a new reference to a tty object. The caller must hold
384 * sufficient locks/counts to ensure that their existing reference cannot
385 * go away
386 */
387
388 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
389 {
390 if (tty)
391 kref_get(&tty->kref);
392 return tty;
393 }
394
395 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
396 const char *routine);
397 extern char *tty_name(struct tty_struct *tty, char *buf);
398 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
399 extern int tty_check_change(struct tty_struct *tty);
400 extern void stop_tty(struct tty_struct *tty);
401 extern void start_tty(struct tty_struct *tty);
402 extern int tty_register_driver(struct tty_driver *driver);
403 extern int tty_unregister_driver(struct tty_driver *driver);
404 extern struct device *tty_register_device(struct tty_driver *driver,
405 unsigned index, struct device *dev);
406 extern struct device *tty_register_device_attr(struct tty_driver *driver,
407 unsigned index, struct device *device,
408 void *drvdata,
409 const struct attribute_group **attr_grp);
410 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
411 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
412 int buflen);
413 extern void tty_write_message(struct tty_struct *tty, char *msg);
414 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
415 extern int tty_chars_in_buffer(struct tty_struct *tty);
416 extern int tty_write_room(struct tty_struct *tty);
417 extern void tty_driver_flush_buffer(struct tty_struct *tty);
418 extern void tty_throttle(struct tty_struct *tty);
419 extern void tty_unthrottle(struct tty_struct *tty);
420 extern int tty_throttle_safe(struct tty_struct *tty);
421 extern int tty_unthrottle_safe(struct tty_struct *tty);
422 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
423 extern void tty_driver_remove_tty(struct tty_driver *driver,
424 struct tty_struct *tty);
425 extern void tty_free_termios(struct tty_struct *tty);
426 extern int is_current_pgrp_orphaned(void);
427 extern int is_ignored(int sig);
428 extern int tty_signal(int sig, struct tty_struct *tty);
429 extern void tty_hangup(struct tty_struct *tty);
430 extern void tty_vhangup(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 */
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
519 static inline struct tty_port *tty_port_get(struct tty_port *port)
520 {
521 if (port && kref_get_unless_zero(&port->kref))
522 return port;
523 return NULL;
524 }
525
526 /* If the cts flow control is enabled, return true. */
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);
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 static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
566 char *f, int count)
567 {
568 if (ld->ops->receive_buf2)
569 count = ld->ops->receive_buf2(ld->tty, p, f, count);
570 else {
571 count = min_t(int, count, ld->tty->receive_room);
572 if (count)
573 ld->ops->receive_buf(ld->tty, p, f, count);
574 }
575 return count;
576 }
577
578
579 /* n_tty.c */
580 extern struct tty_ldisc_ops tty_ldisc_N_TTY;
581 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
582
583 /* tty_audit.c */
584 #ifdef CONFIG_AUDIT
585 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
586 size_t size, unsigned icanon);
587 extern void tty_audit_exit(void);
588 extern void tty_audit_fork(struct signal_struct *sig);
589 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
590 extern void tty_audit_push(struct tty_struct *tty);
591 extern int tty_audit_push_current(void);
592 #else
593 static inline void tty_audit_add_data(struct tty_struct *tty,
594 unsigned char *data, size_t size, unsigned icanon)
595 {
596 }
597 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
598 {
599 }
600 static inline void tty_audit_exit(void)
601 {
602 }
603 static inline void tty_audit_fork(struct signal_struct *sig)
604 {
605 }
606 static inline void tty_audit_push(struct tty_struct *tty)
607 {
608 }
609 static inline int tty_audit_push_current(void)
610 {
611 return 0;
612 }
613 #endif
614
615 /* tty_ioctl.c */
616 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
617 unsigned int cmd, unsigned long arg);
618 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
619 unsigned int cmd, unsigned long arg);
620
621 /* serial.c */
622
623 extern void serial_console_init(void);
624
625 /* pcxx.c */
626
627 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
628
629 /* vt.c */
630
631 extern int vt_ioctl(struct tty_struct *tty,
632 unsigned int cmd, unsigned long arg);
633
634 extern long vt_compat_ioctl(struct tty_struct *tty,
635 unsigned int cmd, unsigned long arg);
636
637 /* tty_mutex.c */
638 /* functions for preparation of BKL removal */
639 extern void __lockfunc tty_lock(struct tty_struct *tty);
640 extern void __lockfunc tty_unlock(struct tty_struct *tty);
641 extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
642 struct tty_struct *tty2);
643 extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
644 struct tty_struct *tty2);
645
646 /*
647 * this shall be called only from where BTM is held (like close)
648 *
649 * We need this to ensure nobody waits for us to finish while we are waiting.
650 * Without this we were encountering system stalls.
651 *
652 * This should be indeed removed with BTM removal later.
653 *
654 * Locking: BTM required. Nobody is allowed to hold port->mutex.
655 */
656 static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
657 long timeout)
658 {
659 tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
660 tty_wait_until_sent(tty, timeout);
661 tty_lock(tty);
662 }
663
664 /*
665 * wait_event_interruptible_tty -- wait for a condition with the tty lock held
666 *
667 * The condition we are waiting for might take a long time to
668 * become true, or might depend on another thread taking the
669 * BTM. In either case, we need to drop the BTM to guarantee
670 * forward progress. This is a leftover from the conversion
671 * from the BKL and should eventually get removed as the BTM
672 * falls out of use.
673 *
674 * Do not use in new code.
675 */
676 #define wait_event_interruptible_tty(tty, wq, condition) \
677 ({ \
678 int __ret = 0; \
679 if (!(condition)) \
680 __ret = __wait_event_interruptible_tty(tty, wq, \
681 condition); \
682 __ret; \
683 })
684
685 #define __wait_event_interruptible_tty(tty, wq, condition) \
686 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
687 tty_unlock(tty); \
688 schedule(); \
689 tty_lock(tty))
690
691 #ifdef CONFIG_PROC_FS
692 extern void proc_tty_register_driver(struct tty_driver *);
693 extern void proc_tty_unregister_driver(struct tty_driver *);
694 #else
695 static inline void proc_tty_register_driver(struct tty_driver *d) {}
696 static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
697 #endif
698
699 #endif