tty.h revision d7a855bd6ab25d10d5e3b6aeb53d9c57fa17b808
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
33struct 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
50static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
51{
52	return ((unsigned char *)b->data) + ofs;
53}
54
55static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
56{
57	return (char *)char_buf_ptr(b, ofs) + b->size;
58}
59
60struct 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
164struct device;
165struct 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
178struct tty_port;
179
180struct 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
198struct 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
235struct tty_operations;
236
237struct 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	int stopped;
265	int flow_stopped;
266	int hw_stopped;
267	int packet;
268	unsigned char ctrl_status;	/* ctrl_lock */
269	unsigned int receive_room;	/* Bytes free for queue */
270	int flow_change;
271
272	struct tty_struct *link;
273	struct fasync_struct *fasync;
274	int alt_speed;		/* For magic substitution of 38400 bps */
275	wait_queue_head_t write_wait;
276	wait_queue_head_t read_wait;
277	struct work_struct hangup_work;
278	void *disc_data;
279	void *driver_data;
280	struct list_head tty_files;
281
282#define N_TTY_BUF_SIZE 4096
283
284	unsigned char closing:1;
285	unsigned char *write_buf;
286	int write_cnt;
287	/* If the tty has a pending do_SAK, queue it here - akpm */
288	struct work_struct SAK_work;
289	struct tty_port *port;
290};
291
292/* Each of a tty's open files has private_data pointing to tty_file_private */
293struct tty_file_private {
294	struct tty_struct *tty;
295	struct file *file;
296	struct list_head list;
297};
298
299/* tty magic number */
300#define TTY_MAGIC		0x5401
301
302/*
303 * These bits are used in the flags field of the tty structure.
304 *
305 * So that interrupts won't be able to mess up the queues,
306 * copy_to_cooked must be atomic with respect to itself, as must
307 * tty->write.  Thus, you must use the inline functions set_bit() and
308 * clear_bit() to make things atomic.
309 */
310#define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
311#define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
312#define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
313#define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
314#define TTY_DEBUG 		4	/* Debugging */
315#define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
316#define TTY_CLOSING 		7	/* ->close() in progress */
317#define TTY_LDISC_OPEN	 	11	/* Line discipline is open */
318#define TTY_PTY_LOCK 		16	/* pty private */
319#define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
320#define TTY_HUPPED 		18	/* Post driver->hangup() */
321#define TTY_HUPPING 		21	/* ->hangup() in progress */
322#define TTY_LDISC_HALTED	22	/* Line discipline is halted */
323
324#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
325
326/* Values for tty->flow_change */
327#define TTY_THROTTLE_SAFE 1
328#define TTY_UNTHROTTLE_SAFE 2
329
330static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
331{
332	tty->flow_change = val;
333}
334
335static inline void tty_set_flow_change(struct tty_struct *tty, int val)
336{
337	tty->flow_change = val;
338	smp_mb();
339}
340
341#ifdef CONFIG_TTY
342extern void console_init(void);
343extern void tty_kref_put(struct tty_struct *tty);
344extern struct pid *tty_get_pgrp(struct tty_struct *tty);
345extern void tty_vhangup_self(void);
346extern void disassociate_ctty(int priv);
347extern dev_t tty_devnum(struct tty_struct *tty);
348extern void proc_clear_tty(struct task_struct *p);
349extern struct tty_struct *get_current_tty(void);
350/* tty_io.c */
351extern int __init tty_init(void);
352#else
353static inline void console_init(void)
354{ }
355static inline void tty_kref_put(struct tty_struct *tty)
356{ }
357static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
358{ return NULL; }
359static inline void tty_vhangup_self(void)
360{ }
361static inline void disassociate_ctty(int priv)
362{ }
363static inline dev_t tty_devnum(struct tty_struct *tty)
364{ return 0; }
365static inline void proc_clear_tty(struct task_struct *p)
366{ }
367static inline struct tty_struct *get_current_tty(void)
368{ return NULL; }
369/* tty_io.c */
370static inline int __init tty_init(void)
371{ return 0; }
372#endif
373
374extern void tty_write_flush(struct tty_struct *);
375
376extern struct ktermios tty_std_termios;
377
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}
397
398extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
399			      const char *routine);
400extern char *tty_name(struct tty_struct *tty, char *buf);
401extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
402extern int tty_check_change(struct tty_struct *tty);
403extern void stop_tty(struct tty_struct *tty);
404extern void start_tty(struct tty_struct *tty);
405extern int tty_register_driver(struct tty_driver *driver);
406extern int tty_unregister_driver(struct tty_driver *driver);
407extern struct device *tty_register_device(struct tty_driver *driver,
408					  unsigned index, struct device *dev);
409extern struct device *tty_register_device_attr(struct tty_driver *driver,
410				unsigned index, struct device *device,
411				void *drvdata,
412				const struct attribute_group **attr_grp);
413extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
414extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
415			     int buflen);
416extern void tty_write_message(struct tty_struct *tty, char *msg);
417extern int tty_put_char(struct tty_struct *tty, unsigned char c);
418extern int tty_chars_in_buffer(struct tty_struct *tty);
419extern int tty_write_room(struct tty_struct *tty);
420extern void tty_driver_flush_buffer(struct tty_struct *tty);
421extern void tty_throttle(struct tty_struct *tty);
422extern void tty_unthrottle(struct tty_struct *tty);
423extern int tty_throttle_safe(struct tty_struct *tty);
424extern int tty_unthrottle_safe(struct tty_struct *tty);
425extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
426extern void tty_driver_remove_tty(struct tty_driver *driver,
427				  struct tty_struct *tty);
428extern void tty_free_termios(struct tty_struct *tty);
429extern int is_current_pgrp_orphaned(void);
430extern int is_ignored(int sig);
431extern int tty_signal(int sig, struct tty_struct *tty);
432extern void tty_hangup(struct tty_struct *tty);
433extern void tty_vhangup(struct tty_struct *tty);
434extern void tty_unhangup(struct file *filp);
435extern int tty_hung_up_p(struct file *filp);
436extern void do_SAK(struct tty_struct *tty);
437extern void __do_SAK(struct tty_struct *tty);
438extern void no_tty(void);
439extern void tty_flush_to_ldisc(struct tty_struct *tty);
440extern void tty_buffer_free_all(struct tty_port *port);
441extern void tty_buffer_flush(struct tty_struct *tty);
442extern void tty_buffer_init(struct tty_port *port);
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);
449
450/**
451 *	tty_get_baud_rate	-	get tty bit rates
452 *	@tty: tty to query
453 *
454 *	Returns the baud rate as an integer for this terminal. The
455 *	termios lock must be held by the caller and the terminal bit
456 *	flags may be updated.
457 *
458 *	Locking: none
459 */
460static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
461{
462	return tty_termios_baud_rate(&tty->termios);
463}
464
465extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
466extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
467extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
468
469extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
470extern void tty_ldisc_deref(struct tty_ldisc *);
471extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
472extern void tty_ldisc_hangup(struct tty_struct *tty);
473extern const struct file_operations tty_ldiscs_proc_fops;
474
475extern void tty_wakeup(struct tty_struct *tty);
476extern void tty_ldisc_flush(struct tty_struct *tty);
477
478extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
479extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
480			unsigned int cmd, unsigned long arg);
481extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
482extern void tty_default_fops(struct file_operations *fops);
483extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
484extern int tty_alloc_file(struct file *file);
485extern void tty_add_file(struct tty_struct *tty, struct file *file);
486extern void tty_free_file(struct file *file);
487extern void free_tty_struct(struct tty_struct *tty);
488extern void deinitialize_tty_struct(struct tty_struct *tty);
489extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
490extern int tty_release(struct inode *inode, struct file *filp);
491extern int tty_init_termios(struct tty_struct *tty);
492extern int tty_standard_install(struct tty_driver *driver,
493		struct tty_struct *tty);
494
495extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
496extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
497
498extern struct mutex tty_mutex;
499extern spinlock_t tty_files_lock;
500
501extern void tty_write_unlock(struct tty_struct *tty);
502extern int tty_write_lock(struct tty_struct *tty, int ndelay);
503#define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
504
505extern void tty_port_init(struct tty_port *port);
506extern void tty_port_link_device(struct tty_port *port,
507		struct tty_driver *driver, unsigned index);
508extern struct device *tty_port_register_device(struct tty_port *port,
509		struct tty_driver *driver, unsigned index,
510		struct device *device);
511extern struct device *tty_port_register_device_attr(struct tty_port *port,
512		struct tty_driver *driver, unsigned index,
513		struct device *device, void *drvdata,
514		const struct attribute_group **attr_grp);
515extern int tty_port_alloc_xmit_buf(struct tty_port *port);
516extern void tty_port_free_xmit_buf(struct tty_port *port);
517extern void tty_port_destroy(struct tty_port *port);
518extern void tty_port_put(struct tty_port *port);
519
520static inline struct tty_port *tty_port_get(struct tty_port *port)
521{
522	if (port && kref_get_unless_zero(&port->kref))
523		return port;
524	return NULL;
525}
526
527/* If the cts flow control is enabled, return true. */
528static inline bool tty_port_cts_enabled(struct tty_port *port)
529{
530	return port->flags & ASYNC_CTS_FLOW;
531}
532
533extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
534extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
535extern int tty_port_carrier_raised(struct tty_port *port);
536extern void tty_port_raise_dtr_rts(struct tty_port *port);
537extern void tty_port_lower_dtr_rts(struct tty_port *port);
538extern void tty_port_hangup(struct tty_port *port);
539extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
540extern void tty_port_tty_wakeup(struct tty_port *port);
541extern int tty_port_block_til_ready(struct tty_port *port,
542				struct tty_struct *tty, struct file *filp);
543extern int tty_port_close_start(struct tty_port *port,
544				struct tty_struct *tty, struct file *filp);
545extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
546extern void tty_port_close(struct tty_port *port,
547				struct tty_struct *tty, struct file *filp);
548extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
549				struct tty_struct *tty);
550extern int tty_port_open(struct tty_port *port,
551				struct tty_struct *tty, struct file *filp);
552static inline int tty_port_users(struct tty_port *port)
553{
554	return port->count + port->blocked_open;
555}
556
557extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
558extern int tty_unregister_ldisc(int disc);
559extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
560extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
561extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
562extern void tty_ldisc_init(struct tty_struct *tty);
563extern void tty_ldisc_deinit(struct tty_struct *tty);
564extern void tty_ldisc_begin(void);
565
566static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
567					char *f, int count)
568{
569	if (ld->ops->receive_buf2)
570		count = ld->ops->receive_buf2(ld->tty, p, f, count);
571	else {
572		count = min_t(int, count, ld->tty->receive_room);
573		if (count)
574			ld->ops->receive_buf(ld->tty, p, f, count);
575	}
576	return count;
577}
578
579
580/* n_tty.c */
581extern struct tty_ldisc_ops tty_ldisc_N_TTY;
582extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
583
584/* tty_audit.c */
585#ifdef CONFIG_AUDIT
586extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
587			       size_t size, unsigned icanon);
588extern void tty_audit_exit(void);
589extern void tty_audit_fork(struct signal_struct *sig);
590extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
591extern void tty_audit_push(struct tty_struct *tty);
592extern int tty_audit_push_current(void);
593#else
594static inline void tty_audit_add_data(struct tty_struct *tty,
595		unsigned char *data, size_t size, unsigned icanon)
596{
597}
598static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
599{
600}
601static inline void tty_audit_exit(void)
602{
603}
604static inline void tty_audit_fork(struct signal_struct *sig)
605{
606}
607static inline void tty_audit_push(struct tty_struct *tty)
608{
609}
610static inline int tty_audit_push_current(void)
611{
612	return 0;
613}
614#endif
615
616/* tty_ioctl.c */
617extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
618		       unsigned int cmd, unsigned long arg);
619extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
620		       unsigned int cmd, unsigned long arg);
621
622/* serial.c */
623
624extern void serial_console_init(void);
625
626/* pcxx.c */
627
628extern int pcxe_open(struct tty_struct *tty, struct file *filp);
629
630/* vt.c */
631
632extern int vt_ioctl(struct tty_struct *tty,
633		    unsigned int cmd, unsigned long arg);
634
635extern long vt_compat_ioctl(struct tty_struct *tty,
636		     unsigned int cmd, unsigned long arg);
637
638/* tty_mutex.c */
639/* functions for preparation of BKL removal */
640extern void __lockfunc tty_lock(struct tty_struct *tty);
641extern void __lockfunc tty_unlock(struct tty_struct *tty);
642extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
643				struct tty_struct *tty2);
644extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
645				struct tty_struct *tty2);
646
647/*
648 * this shall be called only from where BTM is held (like close)
649 *
650 * We need this to ensure nobody waits for us to finish while we are waiting.
651 * Without this we were encountering system stalls.
652 *
653 * This should be indeed removed with BTM removal later.
654 *
655 * Locking: BTM required. Nobody is allowed to hold port->mutex.
656 */
657static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
658		long timeout)
659{
660	tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
661	tty_wait_until_sent(tty, timeout);
662	tty_lock(tty);
663}
664
665/*
666 * wait_event_interruptible_tty -- wait for a condition with the tty lock held
667 *
668 * The condition we are waiting for might take a long time to
669 * become true, or might depend on another thread taking the
670 * BTM. In either case, we need to drop the BTM to guarantee
671 * forward progress. This is a leftover from the conversion
672 * from the BKL and should eventually get removed as the BTM
673 * falls out of use.
674 *
675 * Do not use in new code.
676 */
677#define wait_event_interruptible_tty(tty, wq, condition)		\
678({									\
679	int __ret = 0;							\
680	if (!(condition))						\
681		__ret = __wait_event_interruptible_tty(tty, wq,		\
682						       condition);	\
683	__ret;								\
684})
685
686#define __wait_event_interruptible_tty(tty, wq, condition)		\
687	___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0,		\
688			tty_unlock(tty);				\
689			schedule();					\
690			tty_lock(tty))
691
692#ifdef CONFIG_PROC_FS
693extern void proc_tty_register_driver(struct tty_driver *);
694extern void proc_tty_unregister_driver(struct tty_driver *);
695#else
696static inline void proc_tty_register_driver(struct tty_driver *d) {}
697static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
698#endif
699
700#endif
701