Linux kernel mirror (for testing)
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linux
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
31struct 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
54struct 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
155struct device;
156struct 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
169struct tty_port;
170
171struct 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
190struct tty_port {
191 struct tty_struct *tty; /* Back pointer */
192 const struct tty_port_operations *ops; /* Port operations */
193 spinlock_t lock; /* Lock protecting tty field */
194 int blocked_open; /* Waiting to open */
195 int count; /* Usage count */
196 wait_queue_head_t open_wait; /* Open waiters */
197 wait_queue_head_t close_wait; /* Close waiters */
198 wait_queue_head_t delta_msr_wait; /* Modem status change */
199 unsigned long flags; /* TTY flags ASY_*/
200 unsigned char console:1; /* port is a console */
201 struct mutex mutex; /* Locking */
202 struct mutex buf_mutex; /* Buffer alloc lock */
203 unsigned char *xmit_buf; /* Optional buffer */
204 unsigned int close_delay; /* Close port delay */
205 unsigned int closing_wait; /* Delay for output */
206 int drain_delay; /* Set to zero if no pure time
207 based drain is needed else
208 set to size of fifo */
209 struct kref kref; /* Ref counter */
210};
211
212/*
213 * Where all of the state associated with a tty is kept while the tty
214 * is open. Since the termios state should be kept even if the tty
215 * has been closed --- for things like the baud rate, etc --- it is
216 * not stored here, but rather a pointer to the real state is stored
217 * here. Possible the winsize structure should have the same
218 * treatment, but (1) the default 80x24 is usually right and (2) it's
219 * most often used by a windowing system, which will set the correct
220 * size each time the window is created or resized anyway.
221 * - TYT, 9/14/92
222 */
223
224struct tty_operations;
225
226struct tty_struct {
227 int magic;
228 struct kref kref;
229 struct device *dev;
230 struct tty_driver *driver;
231 const struct tty_operations *ops;
232 int index;
233
234 /* Protects ldisc changes: Lock tty not pty */
235 struct mutex ldisc_mutex;
236 struct tty_ldisc *ldisc;
237
238 struct mutex legacy_mutex;
239 struct mutex termios_mutex;
240 spinlock_t ctrl_lock;
241 /* Termios values are protected by the termios mutex */
242 struct ktermios termios, termios_locked;
243 struct termiox *termiox; /* May be NULL for unsupported */
244 char name[64];
245 struct pid *pgrp; /* Protected by ctrl lock */
246 struct pid *session;
247 unsigned long flags;
248 int count;
249 struct winsize winsize; /* termios mutex */
250 unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
251 unsigned char low_latency:1, warned:1;
252 unsigned char ctrl_status; /* ctrl_lock */
253 unsigned int receive_room; /* Bytes free for queue */
254
255 struct tty_struct *link;
256 struct fasync_struct *fasync;
257 struct tty_bufhead buf; /* Locked internally */
258 int alt_speed; /* For magic substitution of 38400 bps */
259 wait_queue_head_t write_wait;
260 wait_queue_head_t read_wait;
261 struct work_struct hangup_work;
262 void *disc_data;
263 void *driver_data;
264 struct list_head tty_files;
265
266#define N_TTY_BUF_SIZE 4096
267
268 /*
269 * The following is data for the N_TTY line discipline. For
270 * historical reasons, this is included in the tty structure.
271 * Mostly locked by the BKL.
272 */
273 unsigned int column;
274 unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
275 unsigned char closing:1;
276 unsigned char echo_overrun:1;
277 unsigned short minimum_to_wake;
278 unsigned long overrun_time;
279 int num_overrun;
280 unsigned long process_char_map[256/(8*sizeof(unsigned long))];
281 char *read_buf;
282 int read_head;
283 int read_tail;
284 int read_cnt;
285 unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
286 unsigned char *echo_buf;
287 unsigned int echo_pos;
288 unsigned int echo_cnt;
289 int canon_data;
290 unsigned long canon_head;
291 unsigned int canon_column;
292 struct mutex atomic_read_lock;
293 struct mutex atomic_write_lock;
294 struct mutex output_lock;
295 struct mutex echo_lock;
296 unsigned char *write_buf;
297 int write_cnt;
298 spinlock_t read_lock;
299 /* If the tty has a pending do_SAK, queue it here - akpm */
300 struct work_struct SAK_work;
301 struct tty_port *port;
302};
303
304/* Each of a tty's open files has private_data pointing to tty_file_private */
305struct tty_file_private {
306 struct tty_struct *tty;
307 struct file *file;
308 struct list_head list;
309};
310
311/* tty magic number */
312#define TTY_MAGIC 0x5401
313
314/*
315 * These bits are used in the flags field of the tty structure.
316 *
317 * So that interrupts won't be able to mess up the queues,
318 * copy_to_cooked must be atomic with respect to itself, as must
319 * tty->write. Thus, you must use the inline functions set_bit() and
320 * clear_bit() to make things atomic.
321 */
322#define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */
323#define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */
324#define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */
325#define TTY_EXCLUSIVE 3 /* Exclusive open mode */
326#define TTY_DEBUG 4 /* Debugging */
327#define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */
328#define TTY_PUSH 6 /* n_tty private */
329#define TTY_CLOSING 7 /* ->close() in progress */
330#define TTY_LDISC 9 /* Line discipline attached */
331#define TTY_LDISC_CHANGING 10 /* Line discipline changing */
332#define TTY_LDISC_OPEN 11 /* Line discipline is open */
333#define TTY_HW_COOK_OUT 14 /* Hardware can do output cooking */
334#define TTY_HW_COOK_IN 15 /* Hardware can do input cooking */
335#define TTY_PTY_LOCK 16 /* pty private */
336#define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */
337#define TTY_HUPPED 18 /* Post driver->hangup() */
338#define TTY_FLUSHING 19 /* Flushing to ldisc in progress */
339#define TTY_FLUSHPENDING 20 /* Queued buffer flush pending */
340#define TTY_HUPPING 21 /* ->hangup() in progress */
341
342#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
343
344extern void tty_write_flush(struct tty_struct *);
345
346extern struct ktermios tty_std_termios;
347
348extern void console_init(void);
349extern int vcs_init(void);
350
351extern struct class *tty_class;
352
353/**
354 * tty_kref_get - get a tty reference
355 * @tty: tty device
356 *
357 * Return a new reference to a tty object. The caller must hold
358 * sufficient locks/counts to ensure that their existing reference cannot
359 * go away
360 */
361
362static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
363{
364 if (tty)
365 kref_get(&tty->kref);
366 return tty;
367}
368extern void tty_kref_put(struct tty_struct *tty);
369
370extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
371 const char *routine);
372extern char *tty_name(struct tty_struct *tty, char *buf);
373extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
374extern int tty_check_change(struct tty_struct *tty);
375extern void stop_tty(struct tty_struct *tty);
376extern void start_tty(struct tty_struct *tty);
377extern int tty_register_driver(struct tty_driver *driver);
378extern int tty_unregister_driver(struct tty_driver *driver);
379extern struct device *tty_register_device(struct tty_driver *driver,
380 unsigned index, struct device *dev);
381extern struct device *tty_register_device_attr(struct tty_driver *driver,
382 unsigned index, struct device *device,
383 void *drvdata,
384 const struct attribute_group **attr_grp);
385extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
386extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
387 int buflen);
388extern void tty_write_message(struct tty_struct *tty, char *msg);
389extern int tty_put_char(struct tty_struct *tty, unsigned char c);
390extern int tty_chars_in_buffer(struct tty_struct *tty);
391extern int tty_write_room(struct tty_struct *tty);
392extern void tty_driver_flush_buffer(struct tty_struct *tty);
393extern void tty_throttle(struct tty_struct *tty);
394extern void tty_unthrottle(struct tty_struct *tty);
395extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
396extern void tty_driver_remove_tty(struct tty_driver *driver,
397 struct tty_struct *tty);
398extern void tty_free_termios(struct tty_struct *tty);
399extern int is_current_pgrp_orphaned(void);
400extern struct pid *tty_get_pgrp(struct tty_struct *tty);
401extern int is_ignored(int sig);
402extern int tty_signal(int sig, struct tty_struct *tty);
403extern void tty_hangup(struct tty_struct *tty);
404extern void tty_vhangup(struct tty_struct *tty);
405extern void tty_vhangup_locked(struct tty_struct *tty);
406extern void tty_vhangup_self(void);
407extern void tty_unhangup(struct file *filp);
408extern int tty_hung_up_p(struct file *filp);
409extern void do_SAK(struct tty_struct *tty);
410extern void __do_SAK(struct tty_struct *tty);
411extern void disassociate_ctty(int priv);
412extern void no_tty(void);
413extern void tty_flip_buffer_push(struct tty_struct *tty);
414extern void tty_flush_to_ldisc(struct tty_struct *tty);
415extern void tty_buffer_free_all(struct tty_struct *tty);
416extern void tty_buffer_flush(struct tty_struct *tty);
417extern void tty_buffer_init(struct tty_struct *tty);
418extern speed_t tty_get_baud_rate(struct tty_struct *tty);
419extern speed_t tty_termios_baud_rate(struct ktermios *termios);
420extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
421extern void tty_termios_encode_baud_rate(struct ktermios *termios,
422 speed_t ibaud, speed_t obaud);
423extern void tty_encode_baud_rate(struct tty_struct *tty,
424 speed_t ibaud, speed_t obaud);
425extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
426extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
427extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
428
429extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
430extern void tty_ldisc_deref(struct tty_ldisc *);
431extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
432extern void tty_ldisc_hangup(struct tty_struct *tty);
433extern const struct file_operations tty_ldiscs_proc_fops;
434
435extern void tty_wakeup(struct tty_struct *tty);
436extern void tty_ldisc_flush(struct tty_struct *tty);
437
438extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
439extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
440 unsigned int cmd, unsigned long arg);
441extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
442extern dev_t tty_devnum(struct tty_struct *tty);
443extern void proc_clear_tty(struct task_struct *p);
444extern struct tty_struct *get_current_tty(void);
445extern void tty_default_fops(struct file_operations *fops);
446extern struct tty_struct *alloc_tty_struct(void);
447extern int tty_alloc_file(struct file *file);
448extern void tty_add_file(struct tty_struct *tty, struct file *file);
449extern void tty_free_file(struct file *file);
450extern void free_tty_struct(struct tty_struct *tty);
451extern void initialize_tty_struct(struct tty_struct *tty,
452 struct tty_driver *driver, int idx);
453extern void deinitialize_tty_struct(struct tty_struct *tty);
454extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
455extern int tty_release(struct inode *inode, struct file *filp);
456extern int tty_init_termios(struct tty_struct *tty);
457extern int tty_standard_install(struct tty_driver *driver,
458 struct tty_struct *tty);
459
460extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
461extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
462
463extern struct mutex tty_mutex;
464extern spinlock_t tty_files_lock;
465
466extern void tty_write_unlock(struct tty_struct *tty);
467extern int tty_write_lock(struct tty_struct *tty, int ndelay);
468#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
469
470extern void tty_port_init(struct tty_port *port);
471extern void tty_port_link_device(struct tty_port *port,
472 struct tty_driver *driver, unsigned index);
473extern struct device *tty_port_register_device(struct tty_port *port,
474 struct tty_driver *driver, unsigned index,
475 struct device *device);
476extern struct device *tty_port_register_device_attr(struct tty_port *port,
477 struct tty_driver *driver, unsigned index,
478 struct device *device, void *drvdata,
479 const struct attribute_group **attr_grp);
480extern int tty_port_alloc_xmit_buf(struct tty_port *port);
481extern void tty_port_free_xmit_buf(struct tty_port *port);
482extern void tty_port_put(struct tty_port *port);
483
484static inline struct tty_port *tty_port_get(struct tty_port *port)
485{
486 if (port)
487 kref_get(&port->kref);
488 return port;
489}
490
491/* If the cts flow control is enabled, return true. */
492static inline bool tty_port_cts_enabled(struct tty_port *port)
493{
494 return port->flags & ASYNC_CTS_FLOW;
495}
496
497extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
498extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
499extern int tty_port_carrier_raised(struct tty_port *port);
500extern void tty_port_raise_dtr_rts(struct tty_port *port);
501extern void tty_port_lower_dtr_rts(struct tty_port *port);
502extern void tty_port_hangup(struct tty_port *port);
503extern int tty_port_block_til_ready(struct tty_port *port,
504 struct tty_struct *tty, struct file *filp);
505extern int tty_port_close_start(struct tty_port *port,
506 struct tty_struct *tty, struct file *filp);
507extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
508extern void tty_port_close(struct tty_port *port,
509 struct tty_struct *tty, struct file *filp);
510extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
511 struct tty_struct *tty);
512extern int tty_port_open(struct tty_port *port,
513 struct tty_struct *tty, struct file *filp);
514static inline int tty_port_users(struct tty_port *port)
515{
516 return port->count + port->blocked_open;
517}
518
519extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
520extern int tty_unregister_ldisc(int disc);
521extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
522extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
523extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
524extern void tty_ldisc_init(struct tty_struct *tty);
525extern void tty_ldisc_deinit(struct tty_struct *tty);
526extern void tty_ldisc_begin(void);
527/* This last one is just for the tty layer internals and shouldn't be used elsewhere */
528extern void tty_ldisc_enable(struct tty_struct *tty);
529
530
531/* n_tty.c */
532extern struct tty_ldisc_ops tty_ldisc_N_TTY;
533extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
534
535/* tty_audit.c */
536#ifdef CONFIG_AUDIT
537extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
538 size_t size);
539extern void tty_audit_exit(void);
540extern void tty_audit_fork(struct signal_struct *sig);
541extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
542extern void tty_audit_push(struct tty_struct *tty);
543extern int tty_audit_push_task(struct task_struct *tsk,
544 kuid_t loginuid, u32 sessionid);
545#else
546static inline void tty_audit_add_data(struct tty_struct *tty,
547 unsigned char *data, size_t size)
548{
549}
550static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
551{
552}
553static inline void tty_audit_exit(void)
554{
555}
556static inline void tty_audit_fork(struct signal_struct *sig)
557{
558}
559static inline void tty_audit_push(struct tty_struct *tty)
560{
561}
562static inline int tty_audit_push_task(struct task_struct *tsk,
563 kuid_t loginuid, u32 sessionid)
564{
565 return 0;
566}
567#endif
568
569/* tty_io.c */
570extern int __init tty_init(void);
571
572/* tty_ioctl.c */
573extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
574 unsigned int cmd, unsigned long arg);
575extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
576 unsigned int cmd, unsigned long arg);
577
578/* serial.c */
579
580extern void serial_console_init(void);
581
582/* pcxx.c */
583
584extern int pcxe_open(struct tty_struct *tty, struct file *filp);
585
586/* vt.c */
587
588extern int vt_ioctl(struct tty_struct *tty,
589 unsigned int cmd, unsigned long arg);
590
591extern long vt_compat_ioctl(struct tty_struct *tty,
592 unsigned int cmd, unsigned long arg);
593
594/* tty_mutex.c */
595/* functions for preparation of BKL removal */
596extern void __lockfunc tty_lock(struct tty_struct *tty);
597extern void __lockfunc tty_unlock(struct tty_struct *tty);
598extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
599 struct tty_struct *tty2);
600extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
601 struct tty_struct *tty2);
602
603/*
604 * this shall be called only from where BTM is held (like close)
605 *
606 * We need this to ensure nobody waits for us to finish while we are waiting.
607 * Without this we were encountering system stalls.
608 *
609 * This should be indeed removed with BTM removal later.
610 *
611 * Locking: BTM required. Nobody is allowed to hold port->mutex.
612 */
613static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
614 long timeout)
615{
616 tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
617 tty_wait_until_sent(tty, timeout);
618 tty_lock(tty);
619}
620
621/*
622 * wait_event_interruptible_tty -- wait for a condition with the tty lock held
623 *
624 * The condition we are waiting for might take a long time to
625 * become true, or might depend on another thread taking the
626 * BTM. In either case, we need to drop the BTM to guarantee
627 * forward progress. This is a leftover from the conversion
628 * from the BKL and should eventually get removed as the BTM
629 * falls out of use.
630 *
631 * Do not use in new code.
632 */
633#define wait_event_interruptible_tty(tty, wq, condition) \
634({ \
635 int __ret = 0; \
636 if (!(condition)) { \
637 __wait_event_interruptible_tty(tty, wq, condition, __ret); \
638 } \
639 __ret; \
640})
641
642#define __wait_event_interruptible_tty(tty, wq, condition, ret) \
643do { \
644 DEFINE_WAIT(__wait); \
645 \
646 for (;;) { \
647 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
648 if (condition) \
649 break; \
650 if (!signal_pending(current)) { \
651 tty_unlock(tty); \
652 schedule(); \
653 tty_lock(tty); \
654 continue; \
655 } \
656 ret = -ERESTARTSYS; \
657 break; \
658 } \
659 finish_wait(&wq, &__wait); \
660} while (0)
661
662
663#endif