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1  /* SPDX-License-Identifier: GPL-2.0 */
2  #ifndef _LINUX_TTY_H
3  #define _LINUX_TTY_H
4  
5  #include <linux/fs.h>
6  #include <linux/major.h>
7  #include <linux/termios.h>
8  #include <linux/workqueue.h>
9  #include <linux/tty_driver.h>
10  #include <linux/tty_ldisc.h>
11  #include <linux/mutex.h>
12  #include <linux/tty_flags.h>
13  #include <linux/seq_file.h>
14  #include <uapi/linux/tty.h>
15  #include <linux/rwsem.h>
16  #include <linux/llist.h>
17  
18  
19  /*
20   * Lock subclasses for tty locks
21   *
22   * TTY_LOCK_NORMAL is for normal ttys and master ptys.
23   * TTY_LOCK_SLAVE is for slave ptys only.
24   *
25   * Lock subclasses are necessary for handling nested locking with pty pairs.
26   * tty locks which use nested locking:
27   *
28   * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
29   *		  The stable lock order is master pty first, then slave pty.
30   * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
31   *		   Subclassing this lock enables the slave pty to hold its
32   *		   termios_rwsem when claiming the master tty_buffer lock.
33   * tty_buffer lock - slave ptys can claim nested buffer lock when handling
34   *		     signal chars. The stable lock order is slave pty, then
35   *		     master.
36   */
37  
38  enum {
39  	TTY_LOCK_NORMAL = 0,
40  	TTY_LOCK_SLAVE,
41  };
42  
43  /*
44   * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
45   * hardcoded at present.)
46   */
47  #define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
48  #define NR_UNIX98_PTY_RESERVE	1024	  /* Default reserve for main devpts */
49  #define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
50  
51  /*
52   * This character is the same as _POSIX_VDISABLE: it cannot be used as
53   * a c_cc[] character, but indicates that a particular special character
54   * isn't in use (eg VINTR has no character etc)
55   */
56  #define __DISABLED_CHAR '\0'
57  
58  struct tty_buffer {
59  	union {
60  		struct tty_buffer *next;
61  		struct llist_node free;
62  	};
63  	int used;
64  	int size;
65  	int commit;
66  	int read;
67  	int flags;
68  	/* Data points here */
69  	unsigned long data[];
70  };
71  
72  /* Values for .flags field of tty_buffer */
73  #define TTYB_NORMAL	1	/* buffer has no flags buffer */
74  
char_buf_ptr(struct tty_buffer * b,int ofs)75  static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
76  {
77  	return ((unsigned char *)b->data) + ofs;
78  }
79  
flag_buf_ptr(struct tty_buffer * b,int ofs)80  static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
81  {
82  	return (char *)char_buf_ptr(b, ofs) + b->size;
83  }
84  
85  struct tty_bufhead {
86  	struct tty_buffer *head;	/* Queue head */
87  	struct work_struct work;
88  	struct mutex	   lock;
89  	atomic_t	   priority;
90  	struct tty_buffer sentinel;
91  	struct llist_head free;		/* Free queue head */
92  	atomic_t	   mem_used;    /* In-use buffers excluding free list */
93  	int		   mem_limit;
94  	struct tty_buffer *tail;	/* Active buffer */
95  };
96  /*
97   * When a break, frame error, or parity error happens, these codes are
98   * stuffed into the flags buffer.
99   */
100  #define TTY_NORMAL	0
101  #define TTY_BREAK	1
102  #define TTY_FRAME	2
103  #define TTY_PARITY	3
104  #define TTY_OVERRUN	4
105  
106  #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
107  #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
108  #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
109  #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
110  #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
111  #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
112  #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
113  #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
114  #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
115  #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
116  #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
117  #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
118  #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
119  #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
120  #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
121  #define LNEXT_CHAR(tty)	((tty)->termios.c_cc[VLNEXT])
122  #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
123  
124  #define _I_FLAG(tty, f)	((tty)->termios.c_iflag & (f))
125  #define _O_FLAG(tty, f)	((tty)->termios.c_oflag & (f))
126  #define _C_FLAG(tty, f)	((tty)->termios.c_cflag & (f))
127  #define _L_FLAG(tty, f)	((tty)->termios.c_lflag & (f))
128  
129  #define I_IGNBRK(tty)	_I_FLAG((tty), IGNBRK)
130  #define I_BRKINT(tty)	_I_FLAG((tty), BRKINT)
131  #define I_IGNPAR(tty)	_I_FLAG((tty), IGNPAR)
132  #define I_PARMRK(tty)	_I_FLAG((tty), PARMRK)
133  #define I_INPCK(tty)	_I_FLAG((tty), INPCK)
134  #define I_ISTRIP(tty)	_I_FLAG((tty), ISTRIP)
135  #define I_INLCR(tty)	_I_FLAG((tty), INLCR)
136  #define I_IGNCR(tty)	_I_FLAG((tty), IGNCR)
137  #define I_ICRNL(tty)	_I_FLAG((tty), ICRNL)
138  #define I_IUCLC(tty)	_I_FLAG((tty), IUCLC)
139  #define I_IXON(tty)	_I_FLAG((tty), IXON)
140  #define I_IXANY(tty)	_I_FLAG((tty), IXANY)
141  #define I_IXOFF(tty)	_I_FLAG((tty), IXOFF)
142  #define I_IMAXBEL(tty)	_I_FLAG((tty), IMAXBEL)
143  #define I_IUTF8(tty)	_I_FLAG((tty), IUTF8)
144  
145  #define O_OPOST(tty)	_O_FLAG((tty), OPOST)
146  #define O_OLCUC(tty)	_O_FLAG((tty), OLCUC)
147  #define O_ONLCR(tty)	_O_FLAG((tty), ONLCR)
148  #define O_OCRNL(tty)	_O_FLAG((tty), OCRNL)
149  #define O_ONOCR(tty)	_O_FLAG((tty), ONOCR)
150  #define O_ONLRET(tty)	_O_FLAG((tty), ONLRET)
151  #define O_OFILL(tty)	_O_FLAG((tty), OFILL)
152  #define O_OFDEL(tty)	_O_FLAG((tty), OFDEL)
153  #define O_NLDLY(tty)	_O_FLAG((tty), NLDLY)
154  #define O_CRDLY(tty)	_O_FLAG((tty), CRDLY)
155  #define O_TABDLY(tty)	_O_FLAG((tty), TABDLY)
156  #define O_BSDLY(tty)	_O_FLAG((tty), BSDLY)
157  #define O_VTDLY(tty)	_O_FLAG((tty), VTDLY)
158  #define O_FFDLY(tty)	_O_FLAG((tty), FFDLY)
159  
160  #define C_BAUD(tty)	_C_FLAG((tty), CBAUD)
161  #define C_CSIZE(tty)	_C_FLAG((tty), CSIZE)
162  #define C_CSTOPB(tty)	_C_FLAG((tty), CSTOPB)
163  #define C_CREAD(tty)	_C_FLAG((tty), CREAD)
164  #define C_PARENB(tty)	_C_FLAG((tty), PARENB)
165  #define C_PARODD(tty)	_C_FLAG((tty), PARODD)
166  #define C_HUPCL(tty)	_C_FLAG((tty), HUPCL)
167  #define C_CLOCAL(tty)	_C_FLAG((tty), CLOCAL)
168  #define C_CIBAUD(tty)	_C_FLAG((tty), CIBAUD)
169  #define C_CRTSCTS(tty)	_C_FLAG((tty), CRTSCTS)
170  #define C_CMSPAR(tty)	_C_FLAG((tty), CMSPAR)
171  
172  #define L_ISIG(tty)	_L_FLAG((tty), ISIG)
173  #define L_ICANON(tty)	_L_FLAG((tty), ICANON)
174  #define L_XCASE(tty)	_L_FLAG((tty), XCASE)
175  #define L_ECHO(tty)	_L_FLAG((tty), ECHO)
176  #define L_ECHOE(tty)	_L_FLAG((tty), ECHOE)
177  #define L_ECHOK(tty)	_L_FLAG((tty), ECHOK)
178  #define L_ECHONL(tty)	_L_FLAG((tty), ECHONL)
179  #define L_NOFLSH(tty)	_L_FLAG((tty), NOFLSH)
180  #define L_TOSTOP(tty)	_L_FLAG((tty), TOSTOP)
181  #define L_ECHOCTL(tty)	_L_FLAG((tty), ECHOCTL)
182  #define L_ECHOPRT(tty)	_L_FLAG((tty), ECHOPRT)
183  #define L_ECHOKE(tty)	_L_FLAG((tty), ECHOKE)
184  #define L_FLUSHO(tty)	_L_FLAG((tty), FLUSHO)
185  #define L_PENDIN(tty)	_L_FLAG((tty), PENDIN)
186  #define L_IEXTEN(tty)	_L_FLAG((tty), IEXTEN)
187  #define L_EXTPROC(tty)	_L_FLAG((tty), EXTPROC)
188  
189  struct device;
190  struct signal_struct;
191  
192  /*
193   * Port level information. Each device keeps its own port level information
194   * so provide a common structure for those ports wanting to use common support
195   * routines.
196   *
197   * The tty port has a different lifetime to the tty so must be kept apart.
198   * In addition be careful as tty -> port mappings are valid for the life
199   * of the tty object but in many cases port -> tty mappings are valid only
200   * until a hangup so don't use the wrong path.
201   */
202  
203  struct tty_port;
204  
205  struct tty_port_operations {
206  	/* Return 1 if the carrier is raised */
207  	int (*carrier_raised)(struct tty_port *port);
208  	/* Control the DTR line */
209  	void (*dtr_rts)(struct tty_port *port, int raise);
210  	/* Called when the last close completes or a hangup finishes
211  	   IFF the port was initialized. Do not use to free resources. Called
212  	   under the port mutex to serialize against activate/shutdowns */
213  	void (*shutdown)(struct tty_port *port);
214  	/* Called under the port mutex from tty_port_open, serialized using
215  	   the port mutex */
216          /* FIXME: long term getting the tty argument *out* of this would be
217             good for consoles */
218  	int (*activate)(struct tty_port *port, struct tty_struct *tty);
219  	/* Called on the final put of a port */
220  	void (*destruct)(struct tty_port *port);
221  };
222  
223  struct tty_port_client_operations {
224  	int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t);
225  	void (*write_wakeup)(struct tty_port *port);
226  };
227  
228  extern const struct tty_port_client_operations tty_port_default_client_ops;
229  
230  struct tty_port {
231  	struct tty_bufhead	buf;		/* Locked internally */
232  	struct tty_struct	*tty;		/* Back pointer */
233  	struct tty_struct	*itty;		/* internal back ptr */
234  	const struct tty_port_operations *ops;	/* Port operations */
235  	const struct tty_port_client_operations *client_ops; /* Port client operations */
236  	spinlock_t		lock;		/* Lock protecting tty field */
237  	int			blocked_open;	/* Waiting to open */
238  	int			count;		/* Usage count */
239  	wait_queue_head_t	open_wait;	/* Open waiters */
240  	wait_queue_head_t	delta_msr_wait;	/* Modem status change */
241  	unsigned long		flags;		/* User TTY flags ASYNC_ */
242  	unsigned long		iflags;		/* Internal flags TTY_PORT_ */
243  	unsigned char		console:1,	/* port is a console */
244  				low_latency:1;	/* optional: tune for latency */
245  	struct mutex		mutex;		/* Locking */
246  	struct mutex		buf_mutex;	/* Buffer alloc lock */
247  	unsigned char		*xmit_buf;	/* Optional buffer */
248  	unsigned int		close_delay;	/* Close port delay */
249  	unsigned int		closing_wait;	/* Delay for output */
250  	int			drain_delay;	/* Set to zero if no pure time
251  						   based drain is needed else
252  						   set to size of fifo */
253  	struct kref		kref;		/* Ref counter */
254  	void 			*client_data;
255  };
256  
257  /* tty_port::iflags bits -- use atomic bit ops */
258  #define TTY_PORT_INITIALIZED	0	/* device is initialized */
259  #define TTY_PORT_SUSPENDED	1	/* device is suspended */
260  #define TTY_PORT_ACTIVE		2	/* device is open */
261  
262  /*
263   * uart drivers: use the uart_port::status field and the UPSTAT_* defines
264   * for s/w-based flow control steering and carrier detection status
265   */
266  #define TTY_PORT_CTS_FLOW	3	/* h/w flow control enabled */
267  #define TTY_PORT_CHECK_CD	4	/* carrier detect enabled */
268  #define TTY_PORT_KOPENED	5	/* device exclusively opened by
269  					   kernel */
270  
271  /*
272   * Where all of the state associated with a tty is kept while the tty
273   * is open.  Since the termios state should be kept even if the tty
274   * has been closed --- for things like the baud rate, etc --- it is
275   * not stored here, but rather a pointer to the real state is stored
276   * here.  Possible the winsize structure should have the same
277   * treatment, but (1) the default 80x24 is usually right and (2) it's
278   * most often used by a windowing system, which will set the correct
279   * size each time the window is created or resized anyway.
280   * 						- TYT, 9/14/92
281   */
282  
283  struct tty_operations;
284  
285  struct tty_struct {
286  	int	magic;
287  	struct kref kref;
288  	struct device *dev;
289  	struct tty_driver *driver;
290  	const struct tty_operations *ops;
291  	int index;
292  
293  	/* Protects ldisc changes: Lock tty not pty */
294  	struct ld_semaphore ldisc_sem;
295  	struct tty_ldisc *ldisc;
296  
297  	struct mutex atomic_write_lock;
298  	struct mutex legacy_mutex;
299  	struct mutex throttle_mutex;
300  	struct rw_semaphore termios_rwsem;
301  	struct mutex winsize_mutex;
302  	spinlock_t ctrl_lock;
303  	spinlock_t flow_lock;
304  	/* Termios values are protected by the termios rwsem */
305  	struct ktermios termios, termios_locked;
306  	char name[64];
307  	struct pid *pgrp;		/* Protected by ctrl lock */
308  	/*
309  	 * Writes protected by both ctrl lock and legacy mutex, readers must use
310  	 * at least one of them.
311  	 */
312  	struct pid *session;
313  	unsigned long flags;
314  	int count;
315  	struct winsize winsize;		/* winsize_mutex */
316  	unsigned long stopped:1,	/* flow_lock */
317  		      flow_stopped:1,
318  		      unused:BITS_PER_LONG - 2;
319  	int hw_stopped;
320  	unsigned long ctrl_status:8,	/* ctrl_lock */
321  		      packet:1,
322  		      unused_ctrl:BITS_PER_LONG - 9;
323  	unsigned int receive_room;	/* Bytes free for queue */
324  	int flow_change;
325  
326  	struct tty_struct *link;
327  	struct fasync_struct *fasync;
328  	wait_queue_head_t write_wait;
329  	wait_queue_head_t read_wait;
330  	struct work_struct hangup_work;
331  	void *disc_data;
332  	void *driver_data;
333  	spinlock_t files_lock;		/* protects tty_files list */
334  	struct list_head tty_files;
335  
336  #define N_TTY_BUF_SIZE 4096
337  
338  	int closing;
339  	unsigned char *write_buf;
340  	int write_cnt;
341  	/* If the tty has a pending do_SAK, queue it here - akpm */
342  	struct work_struct SAK_work;
343  	struct tty_port *port;
344  } __randomize_layout;
345  
346  /* Each of a tty's open files has private_data pointing to tty_file_private */
347  struct tty_file_private {
348  	struct tty_struct *tty;
349  	struct file *file;
350  	struct list_head list;
351  };
352  
353  /* tty magic number */
354  #define TTY_MAGIC		0x5401
355  
356  /*
357   * These bits are used in the flags field of the tty structure.
358   *
359   * So that interrupts won't be able to mess up the queues,
360   * copy_to_cooked must be atomic with respect to itself, as must
361   * tty->write.  Thus, you must use the inline functions set_bit() and
362   * clear_bit() to make things atomic.
363   */
364  #define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
365  #define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
366  #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
367  #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
368  #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
369  #define TTY_LDISC_OPEN	 	11	/* Line discipline is open */
370  #define TTY_PTY_LOCK 		16	/* pty private */
371  #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
372  #define TTY_HUPPED 		18	/* Post driver->hangup() */
373  #define TTY_HUPPING		19	/* Hangup in progress */
374  #define TTY_LDISC_CHANGING	20	/* Change pending - non-block IO */
375  #define TTY_LDISC_HALTED	22	/* Line discipline is halted */
376  
377  /* Values for tty->flow_change */
378  #define TTY_THROTTLE_SAFE 1
379  #define TTY_UNTHROTTLE_SAFE 2
380  
__tty_set_flow_change(struct tty_struct * tty,int val)381  static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
382  {
383  	tty->flow_change = val;
384  }
385  
tty_set_flow_change(struct tty_struct * tty,int val)386  static inline void tty_set_flow_change(struct tty_struct *tty, int val)
387  {
388  	tty->flow_change = val;
389  	smp_mb();
390  }
391  
tty_io_nonblock(struct tty_struct * tty,struct file * file)392  static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
393  {
394  	return file->f_flags & O_NONBLOCK ||
395  		test_bit(TTY_LDISC_CHANGING, &tty->flags);
396  }
397  
tty_io_error(struct tty_struct * tty)398  static inline bool tty_io_error(struct tty_struct *tty)
399  {
400  	return test_bit(TTY_IO_ERROR, &tty->flags);
401  }
402  
tty_throttled(struct tty_struct * tty)403  static inline bool tty_throttled(struct tty_struct *tty)
404  {
405  	return test_bit(TTY_THROTTLED, &tty->flags);
406  }
407  
408  #ifdef CONFIG_TTY
409  extern void tty_kref_put(struct tty_struct *tty);
410  extern struct pid *tty_get_pgrp(struct tty_struct *tty);
411  extern void tty_vhangup_self(void);
412  extern void disassociate_ctty(int priv);
413  extern dev_t tty_devnum(struct tty_struct *tty);
414  extern void proc_clear_tty(struct task_struct *p);
415  extern struct tty_struct *get_current_tty(void);
416  /* tty_io.c */
417  extern int __init tty_init(void);
418  extern const char *tty_name(const struct tty_struct *tty);
419  extern struct tty_struct *tty_kopen(dev_t device);
420  extern void tty_kclose(struct tty_struct *tty);
421  extern int tty_dev_name_to_number(const char *name, dev_t *number);
422  extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
423  extern void tty_ldisc_unlock(struct tty_struct *tty);
424  extern ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
425  #else
tty_kref_put(struct tty_struct * tty)426  static inline void tty_kref_put(struct tty_struct *tty)
427  { }
tty_get_pgrp(struct tty_struct * tty)428  static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
429  { return NULL; }
tty_vhangup_self(void)430  static inline void tty_vhangup_self(void)
431  { }
disassociate_ctty(int priv)432  static inline void disassociate_ctty(int priv)
433  { }
tty_devnum(struct tty_struct * tty)434  static inline dev_t tty_devnum(struct tty_struct *tty)
435  { return 0; }
proc_clear_tty(struct task_struct * p)436  static inline void proc_clear_tty(struct task_struct *p)
437  { }
get_current_tty(void)438  static inline struct tty_struct *get_current_tty(void)
439  { return NULL; }
440  /* tty_io.c */
tty_init(void)441  static inline int __init tty_init(void)
442  { return 0; }
tty_name(const struct tty_struct * tty)443  static inline const char *tty_name(const struct tty_struct *tty)
444  { return "(none)"; }
tty_kopen(dev_t device)445  static inline struct tty_struct *tty_kopen(dev_t device)
446  { return ERR_PTR(-ENODEV); }
tty_kclose(struct tty_struct * tty)447  static inline void tty_kclose(struct tty_struct *tty)
448  { }
tty_dev_name_to_number(const char * name,dev_t * number)449  static inline int tty_dev_name_to_number(const char *name, dev_t *number)
450  { return -ENOTSUPP; }
451  #endif
452  
453  extern struct ktermios tty_std_termios;
454  
455  extern int vcs_init(void);
456  
457  extern struct class *tty_class;
458  
459  /**
460   *	tty_kref_get		-	get a tty reference
461   *	@tty: tty device
462   *
463   *	Return a new reference to a tty object. The caller must hold
464   *	sufficient locks/counts to ensure that their existing reference cannot
465   *	go away
466   */
467  
tty_kref_get(struct tty_struct * tty)468  static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
469  {
470  	if (tty)
471  		kref_get(&tty->kref);
472  	return tty;
473  }
474  
475  extern const char *tty_driver_name(const struct tty_struct *tty);
476  extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
477  extern int __tty_check_change(struct tty_struct *tty, int sig);
478  extern int tty_check_change(struct tty_struct *tty);
479  extern void __stop_tty(struct tty_struct *tty);
480  extern void stop_tty(struct tty_struct *tty);
481  extern void __start_tty(struct tty_struct *tty);
482  extern void start_tty(struct tty_struct *tty);
483  extern int tty_register_driver(struct tty_driver *driver);
484  extern int tty_unregister_driver(struct tty_driver *driver);
485  extern struct device *tty_register_device(struct tty_driver *driver,
486  					  unsigned index, struct device *dev);
487  extern struct device *tty_register_device_attr(struct tty_driver *driver,
488  				unsigned index, struct device *device,
489  				void *drvdata,
490  				const struct attribute_group **attr_grp);
491  extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
492  extern void tty_write_message(struct tty_struct *tty, char *msg);
493  extern int tty_send_xchar(struct tty_struct *tty, char ch);
494  extern int tty_put_char(struct tty_struct *tty, unsigned char c);
495  extern int tty_chars_in_buffer(struct tty_struct *tty);
496  extern int tty_write_room(struct tty_struct *tty);
497  extern void tty_driver_flush_buffer(struct tty_struct *tty);
498  extern void tty_throttle(struct tty_struct *tty);
499  extern void tty_unthrottle(struct tty_struct *tty);
500  extern int tty_throttle_safe(struct tty_struct *tty);
501  extern int tty_unthrottle_safe(struct tty_struct *tty);
502  extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
503  extern int is_current_pgrp_orphaned(void);
504  extern void tty_hangup(struct tty_struct *tty);
505  extern void tty_vhangup(struct tty_struct *tty);
506  extern void tty_vhangup_session(struct tty_struct *tty);
507  extern int tty_hung_up_p(struct file *filp);
508  extern void do_SAK(struct tty_struct *tty);
509  extern void __do_SAK(struct tty_struct *tty);
510  extern void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
511  extern int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
512  extern void session_clear_tty(struct pid *session);
513  extern void no_tty(void);
514  extern void tty_buffer_free_all(struct tty_port *port);
515  extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
516  extern void tty_buffer_init(struct tty_port *port);
517  extern void tty_buffer_set_lock_subclass(struct tty_port *port);
518  extern bool tty_buffer_restart_work(struct tty_port *port);
519  extern bool tty_buffer_cancel_work(struct tty_port *port);
520  extern void tty_buffer_flush_work(struct tty_port *port);
521  extern speed_t tty_termios_baud_rate(struct ktermios *termios);
522  extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
523  extern void tty_termios_encode_baud_rate(struct ktermios *termios,
524  						speed_t ibaud, speed_t obaud);
525  extern void tty_encode_baud_rate(struct tty_struct *tty,
526  						speed_t ibaud, speed_t obaud);
527  
528  /**
529   *	tty_get_baud_rate	-	get tty bit rates
530   *	@tty: tty to query
531   *
532   *	Returns the baud rate as an integer for this terminal. The
533   *	termios lock must be held by the caller and the terminal bit
534   *	flags may be updated.
535   *
536   *	Locking: none
537   */
tty_get_baud_rate(struct tty_struct * tty)538  static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
539  {
540  	return tty_termios_baud_rate(&tty->termios);
541  }
542  
543  extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
544  extern int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
545  extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
546  
547  extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
548  extern void tty_ldisc_deref(struct tty_ldisc *);
549  extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
550  extern void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
551  extern int tty_ldisc_reinit(struct tty_struct *tty, int disc);
552  extern const struct seq_operations tty_ldiscs_seq_ops;
553  
554  extern void tty_wakeup(struct tty_struct *tty);
555  extern void tty_ldisc_flush(struct tty_struct *tty);
556  
557  extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
558  extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
559  			unsigned int cmd, unsigned long arg);
560  extern long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
561  			      struct file *file, unsigned int cmd, unsigned long arg);
562  extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
563  extern void tty_default_fops(struct file_operations *fops);
564  extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
565  extern int tty_alloc_file(struct file *file);
566  extern void tty_add_file(struct tty_struct *tty, struct file *file);
567  extern void tty_free_file(struct file *file);
568  extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
569  extern void tty_release_struct(struct tty_struct *tty, int idx);
570  extern int tty_release(struct inode *inode, struct file *filp);
571  extern void tty_init_termios(struct tty_struct *tty);
572  extern void tty_save_termios(struct tty_struct *tty);
573  extern int tty_standard_install(struct tty_driver *driver,
574  		struct tty_struct *tty);
575  
576  extern struct mutex tty_mutex;
577  
578  #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
579  
580  extern void tty_port_init(struct tty_port *port);
581  extern void tty_port_link_device(struct tty_port *port,
582  		struct tty_driver *driver, unsigned index);
583  extern struct device *tty_port_register_device(struct tty_port *port,
584  		struct tty_driver *driver, unsigned index,
585  		struct device *device);
586  extern struct device *tty_port_register_device_attr(struct tty_port *port,
587  		struct tty_driver *driver, unsigned index,
588  		struct device *device, void *drvdata,
589  		const struct attribute_group **attr_grp);
590  extern struct device *tty_port_register_device_serdev(struct tty_port *port,
591  		struct tty_driver *driver, unsigned index,
592  		struct device *device);
593  extern struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
594  		struct tty_driver *driver, unsigned index,
595  		struct device *device, void *drvdata,
596  		const struct attribute_group **attr_grp);
597  extern void tty_port_unregister_device(struct tty_port *port,
598  		struct tty_driver *driver, unsigned index);
599  extern int tty_port_alloc_xmit_buf(struct tty_port *port);
600  extern void tty_port_free_xmit_buf(struct tty_port *port);
601  extern void tty_port_destroy(struct tty_port *port);
602  extern void tty_port_put(struct tty_port *port);
603  
tty_port_get(struct tty_port * port)604  static inline struct tty_port *tty_port_get(struct tty_port *port)
605  {
606  	if (port && kref_get_unless_zero(&port->kref))
607  		return port;
608  	return NULL;
609  }
610  
611  /* If the cts flow control is enabled, return true. */
tty_port_cts_enabled(struct tty_port * port)612  static inline bool tty_port_cts_enabled(struct tty_port *port)
613  {
614  	return test_bit(TTY_PORT_CTS_FLOW, &port->iflags);
615  }
616  
tty_port_set_cts_flow(struct tty_port * port,bool val)617  static inline void tty_port_set_cts_flow(struct tty_port *port, bool val)
618  {
619  	if (val)
620  		set_bit(TTY_PORT_CTS_FLOW, &port->iflags);
621  	else
622  		clear_bit(TTY_PORT_CTS_FLOW, &port->iflags);
623  }
624  
tty_port_active(struct tty_port * port)625  static inline bool tty_port_active(struct tty_port *port)
626  {
627  	return test_bit(TTY_PORT_ACTIVE, &port->iflags);
628  }
629  
tty_port_set_active(struct tty_port * port,bool val)630  static inline void tty_port_set_active(struct tty_port *port, bool val)
631  {
632  	if (val)
633  		set_bit(TTY_PORT_ACTIVE, &port->iflags);
634  	else
635  		clear_bit(TTY_PORT_ACTIVE, &port->iflags);
636  }
637  
tty_port_check_carrier(struct tty_port * port)638  static inline bool tty_port_check_carrier(struct tty_port *port)
639  {
640  	return test_bit(TTY_PORT_CHECK_CD, &port->iflags);
641  }
642  
tty_port_set_check_carrier(struct tty_port * port,bool val)643  static inline void tty_port_set_check_carrier(struct tty_port *port, bool val)
644  {
645  	if (val)
646  		set_bit(TTY_PORT_CHECK_CD, &port->iflags);
647  	else
648  		clear_bit(TTY_PORT_CHECK_CD, &port->iflags);
649  }
650  
tty_port_suspended(struct tty_port * port)651  static inline bool tty_port_suspended(struct tty_port *port)
652  {
653  	return test_bit(TTY_PORT_SUSPENDED, &port->iflags);
654  }
655  
tty_port_set_suspended(struct tty_port * port,bool val)656  static inline void tty_port_set_suspended(struct tty_port *port, bool val)
657  {
658  	if (val)
659  		set_bit(TTY_PORT_SUSPENDED, &port->iflags);
660  	else
661  		clear_bit(TTY_PORT_SUSPENDED, &port->iflags);
662  }
663  
tty_port_initialized(struct tty_port * port)664  static inline bool tty_port_initialized(struct tty_port *port)
665  {
666  	return test_bit(TTY_PORT_INITIALIZED, &port->iflags);
667  }
668  
tty_port_set_initialized(struct tty_port * port,bool val)669  static inline void tty_port_set_initialized(struct tty_port *port, bool val)
670  {
671  	if (val)
672  		set_bit(TTY_PORT_INITIALIZED, &port->iflags);
673  	else
674  		clear_bit(TTY_PORT_INITIALIZED, &port->iflags);
675  }
676  
tty_port_kopened(struct tty_port * port)677  static inline bool tty_port_kopened(struct tty_port *port)
678  {
679  	return test_bit(TTY_PORT_KOPENED, &port->iflags);
680  }
681  
tty_port_set_kopened(struct tty_port * port,bool val)682  static inline void tty_port_set_kopened(struct tty_port *port, bool val)
683  {
684  	if (val)
685  		set_bit(TTY_PORT_KOPENED, &port->iflags);
686  	else
687  		clear_bit(TTY_PORT_KOPENED, &port->iflags);
688  }
689  
690  extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
691  extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
692  extern int tty_port_carrier_raised(struct tty_port *port);
693  extern void tty_port_raise_dtr_rts(struct tty_port *port);
694  extern void tty_port_lower_dtr_rts(struct tty_port *port);
695  extern void tty_port_hangup(struct tty_port *port);
696  extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
697  extern void tty_port_tty_wakeup(struct tty_port *port);
698  extern int tty_port_block_til_ready(struct tty_port *port,
699  				struct tty_struct *tty, struct file *filp);
700  extern int tty_port_close_start(struct tty_port *port,
701  				struct tty_struct *tty, struct file *filp);
702  extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
703  extern void tty_port_close(struct tty_port *port,
704  				struct tty_struct *tty, struct file *filp);
705  extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
706  				struct tty_struct *tty);
707  extern int tty_port_open(struct tty_port *port,
708  				struct tty_struct *tty, struct file *filp);
tty_port_users(struct tty_port * port)709  static inline int tty_port_users(struct tty_port *port)
710  {
711  	return port->count + port->blocked_open;
712  }
713  
714  extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
715  extern int tty_unregister_ldisc(int disc);
716  extern int tty_set_ldisc(struct tty_struct *tty, int disc);
717  extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
718  extern void tty_ldisc_release(struct tty_struct *tty);
719  extern int __must_check tty_ldisc_init(struct tty_struct *tty);
720  extern void tty_ldisc_deinit(struct tty_struct *tty);
721  extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
722  				 char *f, int count);
723  
724  /* n_tty.c */
725  extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
726  #ifdef CONFIG_TTY
727  extern void __init n_tty_init(void);
728  #else
n_tty_init(void)729  static inline void n_tty_init(void) { }
730  #endif
731  
732  /* tty_audit.c */
733  #ifdef CONFIG_AUDIT
734  extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
735  			       size_t size);
736  extern void tty_audit_exit(void);
737  extern void tty_audit_fork(struct signal_struct *sig);
738  extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
739  extern int tty_audit_push(void);
740  #else
tty_audit_add_data(struct tty_struct * tty,const void * data,size_t size)741  static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
742  				      size_t size)
743  {
744  }
tty_audit_tiocsti(struct tty_struct * tty,char ch)745  static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
746  {
747  }
tty_audit_exit(void)748  static inline void tty_audit_exit(void)
749  {
750  }
tty_audit_fork(struct signal_struct * sig)751  static inline void tty_audit_fork(struct signal_struct *sig)
752  {
753  }
tty_audit_push(void)754  static inline int tty_audit_push(void)
755  {
756  	return 0;
757  }
758  #endif
759  
760  /* tty_ioctl.c */
761  extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
762  		       unsigned int cmd, unsigned long arg);
763  
764  /* vt.c */
765  
766  extern int vt_ioctl(struct tty_struct *tty,
767  		    unsigned int cmd, unsigned long arg);
768  
769  extern long vt_compat_ioctl(struct tty_struct *tty,
770  		     unsigned int cmd, unsigned long arg);
771  
772  /* tty_mutex.c */
773  /* functions for preparation of BKL removal */
774  extern void tty_lock(struct tty_struct *tty);
775  extern int  tty_lock_interruptible(struct tty_struct *tty);
776  extern void tty_unlock(struct tty_struct *tty);
777  extern void tty_lock_slave(struct tty_struct *tty);
778  extern void tty_unlock_slave(struct tty_struct *tty);
779  extern void tty_set_lock_subclass(struct tty_struct *tty);
780  
781  #ifdef CONFIG_PROC_FS
782  extern void proc_tty_register_driver(struct tty_driver *);
783  extern void proc_tty_unregister_driver(struct tty_driver *);
784  #else
proc_tty_register_driver(struct tty_driver * d)785  static inline void proc_tty_register_driver(struct tty_driver *d) {}
proc_tty_unregister_driver(struct tty_driver * d)786  static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
787  #endif
788  
789  #define tty_msg(fn, tty, f, ...) \
790  	fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
791  
792  #define tty_debug(tty, f, ...)	tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
793  #define tty_info(tty, f, ...)	tty_msg(pr_info, tty, f, ##__VA_ARGS__)
794  #define tty_notice(tty, f, ...)	tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
795  #define tty_warn(tty, f, ...)	tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
796  #define tty_err(tty, f, ...)	tty_msg(pr_err, tty, f, ##__VA_ARGS__)
797  
798  #define tty_info_ratelimited(tty, f, ...) \
799  		tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
800  
801  #endif
802