tty.h revision 3c80fe4ac9cfb13b1bfa4edf1544e8b656716694
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#include <linux/smp_lock.h>
17
18#include <asm/system.h>
19
20
21/*
22 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
23 * hardcoded at present.)
24 */
25#define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
26#define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
27#define NR_LDISCS		30
28
29/* line disciplines */
30#define N_TTY		0
31#define N_SLIP		1
32#define N_MOUSE		2
33#define N_PPP		3
34#define N_STRIP		4
35#define N_AX25		5
36#define N_X25		6	/* X.25 async */
37#define N_6PACK		7
38#define N_MASC		8	/* Reserved for Mobitex module <kaz@cafe.net> */
39#define N_R3964		9	/* Reserved for Simatic R3964 module */
40#define N_PROFIBUS_FDL	10	/* Reserved for Profibus */
41#define N_IRDA		11	/* Linux IrDa - http://irda.sourceforge.net/ */
42#define N_SMSBLOCK	12	/* SMS block mode - for talking to GSM data */
43				/* cards about SMS messages */
44#define N_HDLC		13	/* synchronous HDLC */
45#define N_SYNC_PPP	14	/* synchronous PPP */
46#define N_HCI		15	/* Bluetooth HCI UART */
47#define N_GIGASET_M101	16	/* Siemens Gigaset M101 serial DECT adapter */
48#define N_SLCAN		17	/* Serial / USB serial CAN Adaptors */
49#define N_PPS		18	/* Pulse per Second */
50#define N_V253		19	/* Codec control over voice modem */
51#define N_CAIF		20      /* CAIF protocol for talking to modems */
52#define N_GSM0710	21	/* GSM 0710 Mux */
53#define N_TI_WL	22	/* for TI's WL BT, FM, GPS combo chips */
54
55/*
56 * This character is the same as _POSIX_VDISABLE: it cannot be used as
57 * a c_cc[] character, but indicates that a particular special character
58 * isn't in use (eg VINTR has no character etc)
59 */
60#define __DISABLED_CHAR '\0'
61
62struct tty_buffer {
63	struct tty_buffer *next;
64	char *char_buf_ptr;
65	unsigned char *flag_buf_ptr;
66	int used;
67	int size;
68	int commit;
69	int read;
70	/* Data points here */
71	unsigned long data[0];
72};
73
74/*
75 * We default to dicing tty buffer allocations to this many characters
76 * in order to avoid multiple page allocations. We know the size of
77 * tty_buffer itself but it must also be taken into account that the
78 * the buffer is 256 byte aligned. See tty_buffer_find for the allocation
79 * logic this must match
80 */
81
82#define TTY_BUFFER_PAGE	(((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF)
83
84
85struct tty_bufhead {
86	struct delayed_work work;
87	spinlock_t lock;
88	struct tty_buffer *head;	/* Queue head */
89	struct tty_buffer *tail;	/* Active buffer */
90	struct tty_buffer *free;	/* Free queue head */
91	int memory_used;		/* Buffer space used excluding
92								free queue */
93};
94/*
95 * When a break, frame error, or parity error happens, these codes are
96 * stuffed into the flags buffer.
97 */
98#define TTY_NORMAL	0
99#define TTY_BREAK	1
100#define TTY_FRAME	2
101#define TTY_PARITY	3
102#define TTY_OVERRUN	4
103
104#define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
105#define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
106#define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
107#define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
108#define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
109#define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
110#define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
111#define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
112#define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
113#define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
114#define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
115#define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
116#define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
117#define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
118#define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
119#define LNEXT_CHAR(tty)	((tty)->termios->c_cc[VLNEXT])
120#define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])
121
122#define _I_FLAG(tty, f)	((tty)->termios->c_iflag & (f))
123#define _O_FLAG(tty, f)	((tty)->termios->c_oflag & (f))
124#define _C_FLAG(tty, f)	((tty)->termios->c_cflag & (f))
125#define _L_FLAG(tty, f)	((tty)->termios->c_lflag & (f))
126
127#define I_IGNBRK(tty)	_I_FLAG((tty), IGNBRK)
128#define I_BRKINT(tty)	_I_FLAG((tty), BRKINT)
129#define I_IGNPAR(tty)	_I_FLAG((tty), IGNPAR)
130#define I_PARMRK(tty)	_I_FLAG((tty), PARMRK)
131#define I_INPCK(tty)	_I_FLAG((tty), INPCK)
132#define I_ISTRIP(tty)	_I_FLAG((tty), ISTRIP)
133#define I_INLCR(tty)	_I_FLAG((tty), INLCR)
134#define I_IGNCR(tty)	_I_FLAG((tty), IGNCR)
135#define I_ICRNL(tty)	_I_FLAG((tty), ICRNL)
136#define I_IUCLC(tty)	_I_FLAG((tty), IUCLC)
137#define I_IXON(tty)	_I_FLAG((tty), IXON)
138#define I_IXANY(tty)	_I_FLAG((tty), IXANY)
139#define I_IXOFF(tty)	_I_FLAG((tty), IXOFF)
140#define I_IMAXBEL(tty)	_I_FLAG((tty), IMAXBEL)
141#define I_IUTF8(tty)	_I_FLAG((tty), IUTF8)
142
143#define O_OPOST(tty)	_O_FLAG((tty), OPOST)
144#define O_OLCUC(tty)	_O_FLAG((tty), OLCUC)
145#define O_ONLCR(tty)	_O_FLAG((tty), ONLCR)
146#define O_OCRNL(tty)	_O_FLAG((tty), OCRNL)
147#define O_ONOCR(tty)	_O_FLAG((tty), ONOCR)
148#define O_ONLRET(tty)	_O_FLAG((tty), ONLRET)
149#define O_OFILL(tty)	_O_FLAG((tty), OFILL)
150#define O_OFDEL(tty)	_O_FLAG((tty), OFDEL)
151#define O_NLDLY(tty)	_O_FLAG((tty), NLDLY)
152#define O_CRDLY(tty)	_O_FLAG((tty), CRDLY)
153#define O_TABDLY(tty)	_O_FLAG((tty), TABDLY)
154#define O_BSDLY(tty)	_O_FLAG((tty), BSDLY)
155#define O_VTDLY(tty)	_O_FLAG((tty), VTDLY)
156#define O_FFDLY(tty)	_O_FLAG((tty), FFDLY)
157
158#define C_BAUD(tty)	_C_FLAG((tty), CBAUD)
159#define C_CSIZE(tty)	_C_FLAG((tty), CSIZE)
160#define C_CSTOPB(tty)	_C_FLAG((tty), CSTOPB)
161#define C_CREAD(tty)	_C_FLAG((tty), CREAD)
162#define C_PARENB(tty)	_C_FLAG((tty), PARENB)
163#define C_PARODD(tty)	_C_FLAG((tty), PARODD)
164#define C_HUPCL(tty)	_C_FLAG((tty), HUPCL)
165#define C_CLOCAL(tty)	_C_FLAG((tty), CLOCAL)
166#define C_CIBAUD(tty)	_C_FLAG((tty), CIBAUD)
167#define C_CRTSCTS(tty)	_C_FLAG((tty), CRTSCTS)
168
169#define L_ISIG(tty)	_L_FLAG((tty), ISIG)
170#define L_ICANON(tty)	_L_FLAG((tty), ICANON)
171#define L_XCASE(tty)	_L_FLAG((tty), XCASE)
172#define L_ECHO(tty)	_L_FLAG((tty), ECHO)
173#define L_ECHOE(tty)	_L_FLAG((tty), ECHOE)
174#define L_ECHOK(tty)	_L_FLAG((tty), ECHOK)
175#define L_ECHONL(tty)	_L_FLAG((tty), ECHONL)
176#define L_NOFLSH(tty)	_L_FLAG((tty), NOFLSH)
177#define L_TOSTOP(tty)	_L_FLAG((tty), TOSTOP)
178#define L_ECHOCTL(tty)	_L_FLAG((tty), ECHOCTL)
179#define L_ECHOPRT(tty)	_L_FLAG((tty), ECHOPRT)
180#define L_ECHOKE(tty)	_L_FLAG((tty), ECHOKE)
181#define L_FLUSHO(tty)	_L_FLAG((tty), FLUSHO)
182#define L_PENDIN(tty)	_L_FLAG((tty), PENDIN)
183#define L_IEXTEN(tty)	_L_FLAG((tty), IEXTEN)
184#define L_EXTPROC(tty)	_L_FLAG((tty), EXTPROC)
185
186struct device;
187struct signal_struct;
188
189/*
190 * Port level information. Each device keeps its own port level information
191 * so provide a common structure for those ports wanting to use common support
192 * routines.
193 *
194 * The tty port has a different lifetime to the tty so must be kept apart.
195 * In addition be careful as tty -> port mappings are valid for the life
196 * of the tty object but in many cases port -> tty mappings are valid only
197 * until a hangup so don't use the wrong path.
198 */
199
200struct tty_port;
201
202struct tty_port_operations {
203	/* Return 1 if the carrier is raised */
204	int (*carrier_raised)(struct tty_port *port);
205	/* Control the DTR line */
206	void (*dtr_rts)(struct tty_port *port, int raise);
207	/* Called when the last close completes or a hangup finishes
208	   IFF the port was initialized. Do not use to free resources. Called
209	   under the port mutex to serialize against activate/shutdowns */
210	void (*shutdown)(struct tty_port *port);
211	void (*drop)(struct tty_port *port);
212	/* Called under the port mutex from tty_port_open, serialized using
213	   the port mutex */
214        /* FIXME: long term getting the tty argument *out* of this would be
215           good for consoles */
216	int (*activate)(struct tty_port *port, struct tty_struct *tty);
217	/* Called on the final put of a port */
218	void (*destruct)(struct tty_port *port);
219};
220
221struct tty_port {
222	struct tty_struct	*tty;		/* Back pointer */
223	const struct tty_port_operations *ops;	/* Port operations */
224	spinlock_t		lock;		/* Lock protecting tty field */
225	int			blocked_open;	/* Waiting to open */
226	int			count;		/* Usage count */
227	wait_queue_head_t	open_wait;	/* Open waiters */
228	wait_queue_head_t	close_wait;	/* Close waiters */
229	wait_queue_head_t	delta_msr_wait;	/* Modem status change */
230	unsigned long		flags;		/* TTY flags ASY_*/
231	unsigned char		console:1;	/* port is a console */
232	struct mutex		mutex;		/* Locking */
233	struct mutex		buf_mutex;	/* Buffer alloc lock */
234	unsigned char		*xmit_buf;	/* Optional buffer */
235	unsigned int		close_delay;	/* Close port delay */
236	unsigned int		closing_wait;	/* Delay for output */
237	int			drain_delay;	/* Set to zero if no pure time
238						   based drain is needed else
239						   set to size of fifo */
240	struct kref		kref;		/* Ref counter */
241};
242
243/*
244 * Where all of the state associated with a tty is kept while the tty
245 * is open.  Since the termios state should be kept even if the tty
246 * has been closed --- for things like the baud rate, etc --- it is
247 * not stored here, but rather a pointer to the real state is stored
248 * here.  Possible the winsize structure should have the same
249 * treatment, but (1) the default 80x24 is usually right and (2) it's
250 * most often used by a windowing system, which will set the correct
251 * size each time the window is created or resized anyway.
252 * 						- TYT, 9/14/92
253 */
254
255struct tty_operations;
256
257struct tty_struct {
258	int	magic;
259	struct kref kref;
260	struct device *dev;
261	struct tty_driver *driver;
262	const struct tty_operations *ops;
263	int index;
264
265	/* Protects ldisc changes: Lock tty not pty */
266	struct mutex ldisc_mutex;
267	struct tty_ldisc *ldisc;
268
269	struct mutex termios_mutex;
270	spinlock_t ctrl_lock;
271	/* Termios values are protected by the termios mutex */
272	struct ktermios *termios, *termios_locked;
273	struct termiox *termiox;	/* May be NULL for unsupported */
274	char name[64];
275	struct pid *pgrp;		/* Protected by ctrl lock */
276	struct pid *session;
277	unsigned long flags;
278	int count;
279	struct winsize winsize;		/* termios mutex */
280	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
281	unsigned char low_latency:1, warned:1;
282	unsigned char ctrl_status;	/* ctrl_lock */
283	unsigned int receive_room;	/* Bytes free for queue */
284
285	struct tty_struct *link;
286	struct fasync_struct *fasync;
287	struct tty_bufhead buf;		/* Locked internally */
288	int alt_speed;		/* For magic substitution of 38400 bps */
289	wait_queue_head_t write_wait;
290	wait_queue_head_t read_wait;
291	struct work_struct hangup_work;
292	void *disc_data;
293	void *driver_data;
294	struct list_head tty_files;
295
296#define N_TTY_BUF_SIZE 4096
297
298	/*
299	 * The following is data for the N_TTY line discipline.  For
300	 * historical reasons, this is included in the tty structure.
301	 * Mostly locked by the BKL.
302	 */
303	unsigned int column;
304	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
305	unsigned char closing:1;
306	unsigned char echo_overrun:1;
307	unsigned short minimum_to_wake;
308	unsigned long overrun_time;
309	int num_overrun;
310	unsigned long process_char_map[256/(8*sizeof(unsigned long))];
311	char *read_buf;
312	int read_head;
313	int read_tail;
314	int read_cnt;
315	unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
316	unsigned char *echo_buf;
317	unsigned int echo_pos;
318	unsigned int echo_cnt;
319	int canon_data;
320	unsigned long canon_head;
321	unsigned int canon_column;
322	struct mutex atomic_read_lock;
323	struct mutex atomic_write_lock;
324	struct mutex output_lock;
325	struct mutex echo_lock;
326	unsigned char *write_buf;
327	int write_cnt;
328	spinlock_t read_lock;
329	/* If the tty has a pending do_SAK, queue it here - akpm */
330	struct work_struct SAK_work;
331	struct tty_port *port;
332};
333
334/* Each of a tty's open files has private_data pointing to tty_file_private */
335struct tty_file_private {
336	struct tty_struct *tty;
337	struct file *file;
338	struct list_head list;
339};
340
341/* tty magic number */
342#define TTY_MAGIC		0x5401
343
344/*
345 * These bits are used in the flags field of the tty structure.
346 *
347 * So that interrupts won't be able to mess up the queues,
348 * copy_to_cooked must be atomic with respect to itself, as must
349 * tty->write.  Thus, you must use the inline functions set_bit() and
350 * clear_bit() to make things atomic.
351 */
352#define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
353#define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
354#define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
355#define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
356#define TTY_DEBUG 		4	/* Debugging */
357#define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
358#define TTY_PUSH 		6	/* n_tty private */
359#define TTY_CLOSING 		7	/* ->close() in progress */
360#define TTY_LDISC 		9	/* Line discipline attached */
361#define TTY_LDISC_CHANGING 	10	/* Line discipline changing */
362#define TTY_LDISC_OPEN	 	11	/* Line discipline is open */
363#define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
364#define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
365#define TTY_PTY_LOCK 		16	/* pty private */
366#define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
367#define TTY_HUPPED 		18	/* Post driver->hangup() */
368#define TTY_FLUSHING		19	/* Flushing to ldisc in progress */
369#define TTY_FLUSHPENDING	20	/* Queued buffer flush pending */
370
371#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
372
373extern void tty_write_flush(struct tty_struct *);
374
375extern struct ktermios tty_std_termios;
376
377extern void console_init(void);
378extern int vcs_init(void);
379
380extern struct class *tty_class;
381
382/**
383 *	tty_kref_get		-	get a tty reference
384 *	@tty: tty device
385 *
386 *	Return a new reference to a tty object. The caller must hold
387 *	sufficient locks/counts to ensure that their existing reference cannot
388 *	go away
389 */
390
391static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
392{
393	if (tty)
394		kref_get(&tty->kref);
395	return tty;
396}
397extern void tty_kref_put(struct tty_struct *tty);
398
399extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
400			      const char *routine);
401extern char *tty_name(struct tty_struct *tty, char *buf);
402extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
403extern int tty_check_change(struct tty_struct *tty);
404extern void stop_tty(struct tty_struct *tty);
405extern void start_tty(struct tty_struct *tty);
406extern int tty_register_driver(struct tty_driver *driver);
407extern int tty_unregister_driver(struct tty_driver *driver);
408extern struct device *tty_register_device(struct tty_driver *driver,
409					  unsigned index, struct device *dev);
410extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
411extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
412			     int buflen);
413extern void tty_write_message(struct tty_struct *tty, char *msg);
414extern int tty_put_char(struct tty_struct *tty, unsigned char c);
415extern int tty_chars_in_buffer(struct tty_struct *tty);
416extern int tty_write_room(struct tty_struct *tty);
417extern void tty_driver_flush_buffer(struct tty_struct *tty);
418extern void tty_throttle(struct tty_struct *tty);
419extern void tty_unthrottle(struct tty_struct *tty);
420extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
421extern void tty_shutdown(struct tty_struct *tty);
422extern void tty_free_termios(struct tty_struct *tty);
423extern int is_current_pgrp_orphaned(void);
424extern struct pid *tty_get_pgrp(struct tty_struct *tty);
425extern int is_ignored(int sig);
426extern int tty_signal(int sig, struct tty_struct *tty);
427extern void tty_hangup(struct tty_struct *tty);
428extern void tty_vhangup(struct tty_struct *tty);
429extern void tty_vhangup_locked(struct tty_struct *tty);
430extern void tty_vhangup_self(void);
431extern void tty_unhangup(struct file *filp);
432extern int tty_hung_up_p(struct file *filp);
433extern void do_SAK(struct tty_struct *tty);
434extern void __do_SAK(struct tty_struct *tty);
435extern void disassociate_ctty(int priv);
436extern void no_tty(void);
437extern void tty_flip_buffer_push(struct tty_struct *tty);
438extern void tty_flush_to_ldisc(struct tty_struct *tty);
439extern void tty_buffer_free_all(struct tty_struct *tty);
440extern void tty_buffer_flush(struct tty_struct *tty);
441extern void tty_buffer_init(struct tty_struct *tty);
442extern speed_t tty_get_baud_rate(struct tty_struct *tty);
443extern speed_t tty_termios_baud_rate(struct ktermios *termios);
444extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
445extern void tty_termios_encode_baud_rate(struct ktermios *termios,
446						speed_t ibaud, speed_t obaud);
447extern void tty_encode_baud_rate(struct tty_struct *tty,
448						speed_t ibaud, speed_t obaud);
449extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
450extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
451
452extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
453extern void tty_ldisc_deref(struct tty_ldisc *);
454extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
455extern void tty_ldisc_hangup(struct tty_struct *tty);
456extern const struct file_operations tty_ldiscs_proc_fops;
457
458extern void tty_wakeup(struct tty_struct *tty);
459extern void tty_ldisc_flush(struct tty_struct *tty);
460
461extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
462extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
463			unsigned int cmd, unsigned long arg);
464extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
465extern dev_t tty_devnum(struct tty_struct *tty);
466extern void proc_clear_tty(struct task_struct *p);
467extern struct tty_struct *get_current_tty(void);
468extern void tty_default_fops(struct file_operations *fops);
469extern struct tty_struct *alloc_tty_struct(void);
470extern int tty_add_file(struct tty_struct *tty, struct file *file);
471extern void free_tty_struct(struct tty_struct *tty);
472extern void initialize_tty_struct(struct tty_struct *tty,
473		struct tty_driver *driver, int idx);
474extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
475								int first_ok);
476extern int tty_release(struct inode *inode, struct file *filp);
477extern int tty_init_termios(struct tty_struct *tty);
478
479extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
480extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
481
482extern struct mutex tty_mutex;
483extern spinlock_t tty_files_lock;
484
485extern void tty_write_unlock(struct tty_struct *tty);
486extern int tty_write_lock(struct tty_struct *tty, int ndelay);
487#define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
488
489extern void tty_port_init(struct tty_port *port);
490extern int tty_port_alloc_xmit_buf(struct tty_port *port);
491extern void tty_port_free_xmit_buf(struct tty_port *port);
492extern void tty_port_put(struct tty_port *port);
493
494static inline struct tty_port *tty_port_get(struct tty_port *port)
495{
496	if (port)
497		kref_get(&port->kref);
498	return port;
499}
500
501extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
502extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
503extern int tty_port_carrier_raised(struct tty_port *port);
504extern void tty_port_raise_dtr_rts(struct tty_port *port);
505extern void tty_port_lower_dtr_rts(struct tty_port *port);
506extern void tty_port_hangup(struct tty_port *port);
507extern int tty_port_block_til_ready(struct tty_port *port,
508				struct tty_struct *tty, struct file *filp);
509extern int tty_port_close_start(struct tty_port *port,
510				struct tty_struct *tty, struct file *filp);
511extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
512extern void tty_port_close(struct tty_port *port,
513				struct tty_struct *tty, struct file *filp);
514extern int tty_port_open(struct tty_port *port,
515				struct tty_struct *tty, struct file *filp);
516static inline int tty_port_users(struct tty_port *port)
517{
518	return port->count + port->blocked_open;
519}
520
521extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
522extern int tty_unregister_ldisc(int disc);
523extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
524extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
525extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
526extern void tty_ldisc_init(struct tty_struct *tty);
527extern void tty_ldisc_begin(void);
528/* This last one is just for the tty layer internals and shouldn't be used elsewhere */
529extern void tty_ldisc_enable(struct tty_struct *tty);
530
531
532/* n_tty.c */
533extern struct tty_ldisc_ops tty_ldisc_N_TTY;
534extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
535
536/* tty_audit.c */
537#ifdef CONFIG_AUDIT
538extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
539			       size_t size);
540extern void tty_audit_exit(void);
541extern void tty_audit_fork(struct signal_struct *sig);
542extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
543extern void tty_audit_push(struct tty_struct *tty);
544extern int tty_audit_push_task(struct task_struct *tsk,
545			       uid_t loginuid, u32 sessionid);
546#else
547static inline void tty_audit_add_data(struct tty_struct *tty,
548				      unsigned char *data, size_t size)
549{
550}
551static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
552{
553}
554static inline void tty_audit_exit(void)
555{
556}
557static inline void tty_audit_fork(struct signal_struct *sig)
558{
559}
560static inline void tty_audit_push(struct tty_struct *tty)
561{
562}
563static inline int tty_audit_push_task(struct task_struct *tsk,
564				      uid_t loginuid, u32 sessionid)
565{
566	return 0;
567}
568#endif
569
570/* tty_io.c */
571extern int __init tty_init(void);
572
573/* tty_ioctl.c */
574extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
575		       unsigned int cmd, unsigned long arg);
576
577/* serial.c */
578
579extern void serial_console_init(void);
580
581/* pcxx.c */
582
583extern int pcxe_open(struct tty_struct *tty, struct file *filp);
584
585/* vt.c */
586
587extern int vt_ioctl(struct tty_struct *tty, struct file *file,
588		    unsigned int cmd, unsigned long arg);
589
590extern long vt_compat_ioctl(struct tty_struct *tty, struct file * file,
591		     unsigned int cmd, unsigned long arg);
592
593/* tty_mutex.c */
594/* functions for preparation of BKL removal */
595extern void __lockfunc tty_lock(void) __acquires(tty_lock);
596extern void __lockfunc tty_unlock(void) __releases(tty_lock);
597extern struct task_struct *__big_tty_mutex_owner;
598#define tty_locked()		(current == __big_tty_mutex_owner)
599
600/*
601 * wait_event_interruptible_tty -- wait for a condition with the tty lock held
602 *
603 * The condition we are waiting for might take a long time to
604 * become true, or might depend on another thread taking the
605 * BTM. In either case, we need to drop the BTM to guarantee
606 * forward progress. This is a leftover from the conversion
607 * from the BKL and should eventually get removed as the BTM
608 * falls out of use.
609 *
610 * Do not use in new code.
611 */
612#define wait_event_interruptible_tty(wq, condition)			\
613({									\
614	int __ret = 0;							\
615	if (!(condition)) {						\
616		__wait_event_interruptible_tty(wq, condition, __ret);	\
617	}								\
618	__ret;								\
619})
620
621#define __wait_event_interruptible_tty(wq, condition, ret)		\
622do {									\
623	DEFINE_WAIT(__wait);						\
624									\
625	for (;;) {							\
626		prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE);	\
627		if (condition)						\
628			break;						\
629		if (!signal_pending(current)) {				\
630			tty_unlock();					\
631			schedule();					\
632			tty_lock();					\
633			continue;					\
634		}							\
635		ret = -ERESTARTSYS;					\
636		break;							\
637	}								\
638	finish_wait(&wq, &__wait);					\
639} while (0)
640
641
642#endif /* __KERNEL__ */
643#endif
644