xref: /linux-6.15/include/linux/tty.h (revision 4f3865fb)
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 /*
9  * These constants are also useful for user-level apps (e.g., VC
10  * resizing).
11  */
12 #define MIN_NR_CONSOLES 1       /* must be at least 1 */
13 #define MAX_NR_CONSOLES	63	/* serial lines start at 64 */
14 #define MAX_NR_USER_CONSOLES 63	/* must be root to allocate above this */
15 		/* Note: the ioctl VT_GETSTATE does not work for
16 		   consoles 16 and higher (since it returns a short) */
17 
18 #ifdef __KERNEL__
19 #include <linux/fs.h>
20 #include <linux/major.h>
21 #include <linux/termios.h>
22 #include <linux/workqueue.h>
23 #include <linux/tty_driver.h>
24 #include <linux/tty_ldisc.h>
25 #include <linux/screen_info.h>
26 #include <linux/mutex.h>
27 
28 #include <asm/system.h>
29 
30 
31 /*
32  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
33  * hardcoded at present.)
34  */
35 #define NR_PTYS	CONFIG_LEGACY_PTY_COUNT   /* Number of legacy ptys */
36 #define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
37 #define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
38 #define NR_LDISCS		16
39 
40 /*
41  * This character is the same as _POSIX_VDISABLE: it cannot be used as
42  * a c_cc[] character, but indicates that a particular special character
43  * isn't in use (eg VINTR has no character etc)
44  */
45 #define __DISABLED_CHAR '\0'
46 
47 /*
48  * This is the flip buffer used for the tty driver.  The buffer is
49  * located in the tty structure, and is used as a high speed interface
50  * between the tty driver and the tty line discipline.
51  */
52 #define TTY_FLIPBUF_SIZE 512
53 
54 struct tty_buffer {
55 	struct tty_buffer *next;
56 	char *char_buf_ptr;
57 	unsigned char *flag_buf_ptr;
58 	int used;
59 	int size;
60 	int active;
61 	int commit;
62 	int read;
63 	/* Data points here */
64 	unsigned long data[0];
65 };
66 
67 struct tty_bufhead {
68 	struct work_struct		work;
69 	struct semaphore pty_sem;
70 	spinlock_t lock;
71 	struct tty_buffer *head;	/* Queue head */
72 	struct tty_buffer *tail;	/* Active buffer */
73 	struct tty_buffer *free;	/* Free queue head */
74 };
75 /*
76  * The pty uses char_buf and flag_buf as a contiguous buffer
77  */
78 #define PTY_BUF_SIZE	4*TTY_FLIPBUF_SIZE
79 
80 /*
81  * When a break, frame error, or parity error happens, these codes are
82  * stuffed into the flags buffer.
83  */
84 #define TTY_NORMAL	0
85 #define TTY_BREAK	1
86 #define TTY_FRAME	2
87 #define TTY_PARITY	3
88 #define TTY_OVERRUN	4
89 
90 #define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
91 #define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
92 #define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
93 #define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
94 #define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
95 #define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
96 #define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
97 #define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
98 #define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
99 #define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
100 #define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
101 #define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
102 #define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
103 #define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
104 #define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
105 #define LNEXT_CHAR(tty)	((tty)->termios->c_cc[VLNEXT])
106 #define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])
107 
108 #define _I_FLAG(tty,f)	((tty)->termios->c_iflag & (f))
109 #define _O_FLAG(tty,f)	((tty)->termios->c_oflag & (f))
110 #define _C_FLAG(tty,f)	((tty)->termios->c_cflag & (f))
111 #define _L_FLAG(tty,f)	((tty)->termios->c_lflag & (f))
112 
113 #define I_IGNBRK(tty)	_I_FLAG((tty),IGNBRK)
114 #define I_BRKINT(tty)	_I_FLAG((tty),BRKINT)
115 #define I_IGNPAR(tty)	_I_FLAG((tty),IGNPAR)
116 #define I_PARMRK(tty)	_I_FLAG((tty),PARMRK)
117 #define I_INPCK(tty)	_I_FLAG((tty),INPCK)
118 #define I_ISTRIP(tty)	_I_FLAG((tty),ISTRIP)
119 #define I_INLCR(tty)	_I_FLAG((tty),INLCR)
120 #define I_IGNCR(tty)	_I_FLAG((tty),IGNCR)
121 #define I_ICRNL(tty)	_I_FLAG((tty),ICRNL)
122 #define I_IUCLC(tty)	_I_FLAG((tty),IUCLC)
123 #define I_IXON(tty)	_I_FLAG((tty),IXON)
124 #define I_IXANY(tty)	_I_FLAG((tty),IXANY)
125 #define I_IXOFF(tty)	_I_FLAG((tty),IXOFF)
126 #define I_IMAXBEL(tty)	_I_FLAG((tty),IMAXBEL)
127 #define I_IUTF8(tty)	_I_FLAG((tty),IUTF8)
128 
129 #define O_OPOST(tty)	_O_FLAG((tty),OPOST)
130 #define O_OLCUC(tty)	_O_FLAG((tty),OLCUC)
131 #define O_ONLCR(tty)	_O_FLAG((tty),ONLCR)
132 #define O_OCRNL(tty)	_O_FLAG((tty),OCRNL)
133 #define O_ONOCR(tty)	_O_FLAG((tty),ONOCR)
134 #define O_ONLRET(tty)	_O_FLAG((tty),ONLRET)
135 #define O_OFILL(tty)	_O_FLAG((tty),OFILL)
136 #define O_OFDEL(tty)	_O_FLAG((tty),OFDEL)
137 #define O_NLDLY(tty)	_O_FLAG((tty),NLDLY)
138 #define O_CRDLY(tty)	_O_FLAG((tty),CRDLY)
139 #define O_TABDLY(tty)	_O_FLAG((tty),TABDLY)
140 #define O_BSDLY(tty)	_O_FLAG((tty),BSDLY)
141 #define O_VTDLY(tty)	_O_FLAG((tty),VTDLY)
142 #define O_FFDLY(tty)	_O_FLAG((tty),FFDLY)
143 
144 #define C_BAUD(tty)	_C_FLAG((tty),CBAUD)
145 #define C_CSIZE(tty)	_C_FLAG((tty),CSIZE)
146 #define C_CSTOPB(tty)	_C_FLAG((tty),CSTOPB)
147 #define C_CREAD(tty)	_C_FLAG((tty),CREAD)
148 #define C_PARENB(tty)	_C_FLAG((tty),PARENB)
149 #define C_PARODD(tty)	_C_FLAG((tty),PARODD)
150 #define C_HUPCL(tty)	_C_FLAG((tty),HUPCL)
151 #define C_CLOCAL(tty)	_C_FLAG((tty),CLOCAL)
152 #define C_CIBAUD(tty)	_C_FLAG((tty),CIBAUD)
153 #define C_CRTSCTS(tty)	_C_FLAG((tty),CRTSCTS)
154 
155 #define L_ISIG(tty)	_L_FLAG((tty),ISIG)
156 #define L_ICANON(tty)	_L_FLAG((tty),ICANON)
157 #define L_XCASE(tty)	_L_FLAG((tty),XCASE)
158 #define L_ECHO(tty)	_L_FLAG((tty),ECHO)
159 #define L_ECHOE(tty)	_L_FLAG((tty),ECHOE)
160 #define L_ECHOK(tty)	_L_FLAG((tty),ECHOK)
161 #define L_ECHONL(tty)	_L_FLAG((tty),ECHONL)
162 #define L_NOFLSH(tty)	_L_FLAG((tty),NOFLSH)
163 #define L_TOSTOP(tty)	_L_FLAG((tty),TOSTOP)
164 #define L_ECHOCTL(tty)	_L_FLAG((tty),ECHOCTL)
165 #define L_ECHOPRT(tty)	_L_FLAG((tty),ECHOPRT)
166 #define L_ECHOKE(tty)	_L_FLAG((tty),ECHOKE)
167 #define L_FLUSHO(tty)	_L_FLAG((tty),FLUSHO)
168 #define L_PENDIN(tty)	_L_FLAG((tty),PENDIN)
169 #define L_IEXTEN(tty)	_L_FLAG((tty),IEXTEN)
170 
171 struct device;
172 /*
173  * Where all of the state associated with a tty is kept while the tty
174  * is open.  Since the termios state should be kept even if the tty
175  * has been closed --- for things like the baud rate, etc --- it is
176  * not stored here, but rather a pointer to the real state is stored
177  * here.  Possible the winsize structure should have the same
178  * treatment, but (1) the default 80x24 is usually right and (2) it's
179  * most often used by a windowing system, which will set the correct
180  * size each time the window is created or resized anyway.
181  * 						- TYT, 9/14/92
182  */
183 struct tty_struct {
184 	int	magic;
185 	struct tty_driver *driver;
186 	int index;
187 	struct tty_ldisc ldisc;
188 	struct semaphore termios_sem;
189 	struct termios *termios, *termios_locked;
190 	char name[64];
191 	int pgrp;
192 	int session;
193 	unsigned long flags;
194 	int count;
195 	struct winsize winsize;
196 	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
197 	unsigned char low_latency:1, warned:1;
198 	unsigned char ctrl_status;
199 	unsigned int receive_room;	/* Bytes free for queue */
200 
201 	struct tty_struct *link;
202 	struct fasync_struct *fasync;
203 	struct tty_bufhead buf;
204 	int max_flip_cnt;
205 	int alt_speed;		/* For magic substitution of 38400 bps */
206 	wait_queue_head_t write_wait;
207 	wait_queue_head_t read_wait;
208 	struct work_struct hangup_work;
209 	void *disc_data;
210 	void *driver_data;
211 	struct list_head tty_files;
212 
213 #define N_TTY_BUF_SIZE 4096
214 
215 	/*
216 	 * The following is data for the N_TTY line discipline.  For
217 	 * historical reasons, this is included in the tty structure.
218 	 */
219 	unsigned int column;
220 	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
221 	unsigned char closing:1;
222 	unsigned short minimum_to_wake;
223 	unsigned long overrun_time;
224 	int num_overrun;
225 	unsigned long process_char_map[256/(8*sizeof(unsigned long))];
226 	char *read_buf;
227 	int read_head;
228 	int read_tail;
229 	int read_cnt;
230 	unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
231 	int canon_data;
232 	unsigned long canon_head;
233 	unsigned int canon_column;
234 	struct mutex atomic_read_lock;
235 	struct mutex atomic_write_lock;
236 	unsigned char *write_buf;
237 	int write_cnt;
238 	spinlock_t read_lock;
239 	/* If the tty has a pending do_SAK, queue it here - akpm */
240 	struct work_struct SAK_work;
241 };
242 
243 /* tty magic number */
244 #define TTY_MAGIC		0x5401
245 
246 /*
247  * These bits are used in the flags field of the tty structure.
248  *
249  * So that interrupts won't be able to mess up the queues,
250  * copy_to_cooked must be atomic with respect to itself, as must
251  * tty->write.  Thus, you must use the inline functions set_bit() and
252  * clear_bit() to make things atomic.
253  */
254 #define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
255 #define TTY_IO_ERROR 		1	/* Canse an I/O error (may be no ldisc too) */
256 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
257 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
258 #define TTY_DEBUG 		4	/* Debugging */
259 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
260 #define TTY_PUSH 		6	/* n_tty private */
261 #define TTY_CLOSING 		7	/* ->close() in progress */
262 #define TTY_DONT_FLIP 		8	/* Defer buffer flip */
263 #define TTY_LDISC 		9	/* Line discipline attached */
264 #define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
265 #define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
266 #define TTY_PTY_LOCK 		16	/* pty private */
267 #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
268 #define TTY_HUPPED 		18	/* Post driver->hangup() */
269 
270 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
271 
272 extern void tty_write_flush(struct tty_struct *);
273 
274 extern struct termios tty_std_termios;
275 extern int fg_console, last_console, want_console;
276 
277 extern int kmsg_redirect;
278 
279 extern void console_init(void);
280 extern int vcs_init(void);
281 
282 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
283 			      const char *routine);
284 extern char *tty_name(struct tty_struct *tty, char *buf);
285 extern void tty_wait_until_sent(struct tty_struct * tty, long timeout);
286 extern int tty_check_change(struct tty_struct * tty);
287 extern void stop_tty(struct tty_struct * tty);
288 extern void start_tty(struct tty_struct * tty);
289 extern int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc);
290 extern int tty_unregister_ldisc(int disc);
291 extern int tty_register_driver(struct tty_driver *driver);
292 extern int tty_unregister_driver(struct tty_driver *driver);
293 extern struct class_device *tty_register_device(struct tty_driver *driver,
294 						unsigned index,
295 						struct device *dev);
296 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
297 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
298 			     int buflen);
299 extern void tty_write_message(struct tty_struct *tty, char *msg);
300 
301 extern int is_orphaned_pgrp(int pgrp);
302 extern int is_ignored(int sig);
303 extern int tty_signal(int sig, struct tty_struct *tty);
304 extern void tty_hangup(struct tty_struct * tty);
305 extern void tty_vhangup(struct tty_struct * tty);
306 extern void tty_unhangup(struct file *filp);
307 extern int tty_hung_up_p(struct file * filp);
308 extern void do_SAK(struct tty_struct *tty);
309 extern void disassociate_ctty(int priv);
310 extern void tty_flip_buffer_push(struct tty_struct *tty);
311 extern int tty_get_baud_rate(struct tty_struct *tty);
312 extern int tty_termios_baud_rate(struct termios *termios);
313 
314 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
315 extern void tty_ldisc_deref(struct tty_ldisc *);
316 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
317 
318 extern struct tty_ldisc *tty_ldisc_get(int);
319 extern void tty_ldisc_put(int);
320 
321 extern void tty_wakeup(struct tty_struct *tty);
322 extern void tty_ldisc_flush(struct tty_struct *tty);
323 
324 extern struct mutex tty_mutex;
325 
326 /* n_tty.c */
327 extern struct tty_ldisc tty_ldisc_N_TTY;
328 
329 /* tty_ioctl.c */
330 extern int n_tty_ioctl(struct tty_struct * tty, struct file * file,
331 		       unsigned int cmd, unsigned long arg);
332 
333 /* serial.c */
334 
335 extern void serial_console_init(void);
336 
337 /* pcxx.c */
338 
339 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
340 
341 /* printk.c */
342 
343 extern void console_print(const char *);
344 
345 /* vt.c */
346 
347 extern int vt_ioctl(struct tty_struct *tty, struct file * file,
348 		    unsigned int cmd, unsigned long arg);
349 
350 static inline dev_t tty_devnum(struct tty_struct *tty)
351 {
352 	return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
353 }
354 
355 #endif /* __KERNEL__ */
356 #endif
357