xref: /linux-6.15/include/linux/tty.h (revision de2fe5e0)
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/config.h>
20 #include <linux/fs.h>
21 #include <linux/major.h>
22 #include <linux/termios.h>
23 #include <linux/workqueue.h>
24 #include <linux/tty_driver.h>
25 #include <linux/tty_ldisc.h>
26 #include <linux/screen_info.h>
27 #include <linux/mutex.h>
28 
29 #include <asm/system.h>
30 
31 
32 /*
33  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
34  * hardcoded at present.)
35  */
36 #define NR_PTYS	CONFIG_LEGACY_PTY_COUNT   /* Number of legacy ptys */
37 #define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
38 #define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
39 #define NR_LDISCS		16
40 
41 /*
42  * This character is the same as _POSIX_VDISABLE: it cannot be used as
43  * a c_cc[] character, but indicates that a particular special character
44  * isn't in use (eg VINTR has no character etc)
45  */
46 #define __DISABLED_CHAR '\0'
47 
48 /*
49  * This is the flip buffer used for the tty driver.  The buffer is
50  * located in the tty structure, and is used as a high speed interface
51  * between the tty driver and the tty line discipline.
52  */
53 #define TTY_FLIPBUF_SIZE 512
54 
55 struct tty_buffer {
56 	struct tty_buffer *next;
57 	char *char_buf_ptr;
58 	unsigned char *flag_buf_ptr;
59 	int used;
60 	int size;
61 	int active;
62 	int commit;
63 	int read;
64 	/* Data points here */
65 	unsigned long data[0];
66 };
67 
68 struct tty_bufhead {
69 	struct work_struct		work;
70 	struct semaphore pty_sem;
71 	spinlock_t lock;
72 	struct tty_buffer *head;	/* Queue head */
73 	struct tty_buffer *tail;	/* Active buffer */
74 	struct tty_buffer *free;	/* Free queue head */
75 };
76 /*
77  * The pty uses char_buf and flag_buf as a contiguous buffer
78  */
79 #define PTY_BUF_SIZE	4*TTY_FLIPBUF_SIZE
80 
81 /*
82  * When a break, frame error, or parity error happens, these codes are
83  * stuffed into the flags buffer.
84  */
85 #define TTY_NORMAL	0
86 #define TTY_BREAK	1
87 #define TTY_FRAME	2
88 #define TTY_PARITY	3
89 #define TTY_OVERRUN	4
90 
91 #define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
92 #define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
93 #define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
94 #define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
95 #define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
96 #define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
97 #define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
98 #define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
99 #define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
100 #define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
101 #define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
102 #define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
103 #define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
104 #define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
105 #define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
106 #define LNEXT_CHAR(tty)	((tty)->termios->c_cc[VLNEXT])
107 #define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])
108 
109 #define _I_FLAG(tty,f)	((tty)->termios->c_iflag & (f))
110 #define _O_FLAG(tty,f)	((tty)->termios->c_oflag & (f))
111 #define _C_FLAG(tty,f)	((tty)->termios->c_cflag & (f))
112 #define _L_FLAG(tty,f)	((tty)->termios->c_lflag & (f))
113 
114 #define I_IGNBRK(tty)	_I_FLAG((tty),IGNBRK)
115 #define I_BRKINT(tty)	_I_FLAG((tty),BRKINT)
116 #define I_IGNPAR(tty)	_I_FLAG((tty),IGNPAR)
117 #define I_PARMRK(tty)	_I_FLAG((tty),PARMRK)
118 #define I_INPCK(tty)	_I_FLAG((tty),INPCK)
119 #define I_ISTRIP(tty)	_I_FLAG((tty),ISTRIP)
120 #define I_INLCR(tty)	_I_FLAG((tty),INLCR)
121 #define I_IGNCR(tty)	_I_FLAG((tty),IGNCR)
122 #define I_ICRNL(tty)	_I_FLAG((tty),ICRNL)
123 #define I_IUCLC(tty)	_I_FLAG((tty),IUCLC)
124 #define I_IXON(tty)	_I_FLAG((tty),IXON)
125 #define I_IXANY(tty)	_I_FLAG((tty),IXANY)
126 #define I_IXOFF(tty)	_I_FLAG((tty),IXOFF)
127 #define I_IMAXBEL(tty)	_I_FLAG((tty),IMAXBEL)
128 #define I_IUTF8(tty)	_I_FLAG((tty),IUTF8)
129 
130 #define O_OPOST(tty)	_O_FLAG((tty),OPOST)
131 #define O_OLCUC(tty)	_O_FLAG((tty),OLCUC)
132 #define O_ONLCR(tty)	_O_FLAG((tty),ONLCR)
133 #define O_OCRNL(tty)	_O_FLAG((tty),OCRNL)
134 #define O_ONOCR(tty)	_O_FLAG((tty),ONOCR)
135 #define O_ONLRET(tty)	_O_FLAG((tty),ONLRET)
136 #define O_OFILL(tty)	_O_FLAG((tty),OFILL)
137 #define O_OFDEL(tty)	_O_FLAG((tty),OFDEL)
138 #define O_NLDLY(tty)	_O_FLAG((tty),NLDLY)
139 #define O_CRDLY(tty)	_O_FLAG((tty),CRDLY)
140 #define O_TABDLY(tty)	_O_FLAG((tty),TABDLY)
141 #define O_BSDLY(tty)	_O_FLAG((tty),BSDLY)
142 #define O_VTDLY(tty)	_O_FLAG((tty),VTDLY)
143 #define O_FFDLY(tty)	_O_FLAG((tty),FFDLY)
144 
145 #define C_BAUD(tty)	_C_FLAG((tty),CBAUD)
146 #define C_CSIZE(tty)	_C_FLAG((tty),CSIZE)
147 #define C_CSTOPB(tty)	_C_FLAG((tty),CSTOPB)
148 #define C_CREAD(tty)	_C_FLAG((tty),CREAD)
149 #define C_PARENB(tty)	_C_FLAG((tty),PARENB)
150 #define C_PARODD(tty)	_C_FLAG((tty),PARODD)
151 #define C_HUPCL(tty)	_C_FLAG((tty),HUPCL)
152 #define C_CLOCAL(tty)	_C_FLAG((tty),CLOCAL)
153 #define C_CIBAUD(tty)	_C_FLAG((tty),CIBAUD)
154 #define C_CRTSCTS(tty)	_C_FLAG((tty),CRTSCTS)
155 
156 #define L_ISIG(tty)	_L_FLAG((tty),ISIG)
157 #define L_ICANON(tty)	_L_FLAG((tty),ICANON)
158 #define L_XCASE(tty)	_L_FLAG((tty),XCASE)
159 #define L_ECHO(tty)	_L_FLAG((tty),ECHO)
160 #define L_ECHOE(tty)	_L_FLAG((tty),ECHOE)
161 #define L_ECHOK(tty)	_L_FLAG((tty),ECHOK)
162 #define L_ECHONL(tty)	_L_FLAG((tty),ECHONL)
163 #define L_NOFLSH(tty)	_L_FLAG((tty),NOFLSH)
164 #define L_TOSTOP(tty)	_L_FLAG((tty),TOSTOP)
165 #define L_ECHOCTL(tty)	_L_FLAG((tty),ECHOCTL)
166 #define L_ECHOPRT(tty)	_L_FLAG((tty),ECHOPRT)
167 #define L_ECHOKE(tty)	_L_FLAG((tty),ECHOKE)
168 #define L_FLUSHO(tty)	_L_FLAG((tty),FLUSHO)
169 #define L_PENDIN(tty)	_L_FLAG((tty),PENDIN)
170 #define L_IEXTEN(tty)	_L_FLAG((tty),IEXTEN)
171 
172 struct device;
173 /*
174  * Where all of the state associated with a tty is kept while the tty
175  * is open.  Since the termios state should be kept even if the tty
176  * has been closed --- for things like the baud rate, etc --- it is
177  * not stored here, but rather a pointer to the real state is stored
178  * here.  Possible the winsize structure should have the same
179  * treatment, but (1) the default 80x24 is usually right and (2) it's
180  * most often used by a windowing system, which will set the correct
181  * size each time the window is created or resized anyway.
182  * 						- TYT, 9/14/92
183  */
184 struct tty_struct {
185 	int	magic;
186 	struct tty_driver *driver;
187 	int index;
188 	struct tty_ldisc ldisc;
189 	struct semaphore termios_sem;
190 	struct termios *termios, *termios_locked;
191 	char name[64];
192 	int pgrp;
193 	int session;
194 	unsigned long flags;
195 	int count;
196 	struct winsize winsize;
197 	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
198 	unsigned char low_latency:1, warned:1;
199 	unsigned char ctrl_status;
200 	unsigned int receive_room;	/* Bytes free for queue */
201 
202 	struct tty_struct *link;
203 	struct fasync_struct *fasync;
204 	struct tty_bufhead buf;
205 	int max_flip_cnt;
206 	int alt_speed;		/* For magic substitution of 38400 bps */
207 	wait_queue_head_t write_wait;
208 	wait_queue_head_t read_wait;
209 	struct work_struct hangup_work;
210 	void *disc_data;
211 	void *driver_data;
212 	struct list_head tty_files;
213 
214 #define N_TTY_BUF_SIZE 4096
215 
216 	/*
217 	 * The following is data for the N_TTY line discipline.  For
218 	 * historical reasons, this is included in the tty structure.
219 	 */
220 	unsigned int column;
221 	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
222 	unsigned char closing:1;
223 	unsigned short minimum_to_wake;
224 	unsigned long overrun_time;
225 	int num_overrun;
226 	unsigned long process_char_map[256/(8*sizeof(unsigned long))];
227 	char *read_buf;
228 	int read_head;
229 	int read_tail;
230 	int read_cnt;
231 	unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
232 	int canon_data;
233 	unsigned long canon_head;
234 	unsigned int canon_column;
235 	struct mutex atomic_read_lock;
236 	struct mutex atomic_write_lock;
237 	unsigned char *write_buf;
238 	int write_cnt;
239 	spinlock_t read_lock;
240 	/* If the tty has a pending do_SAK, queue it here - akpm */
241 	struct work_struct SAK_work;
242 };
243 
244 /* tty magic number */
245 #define TTY_MAGIC		0x5401
246 
247 /*
248  * These bits are used in the flags field of the tty structure.
249  *
250  * So that interrupts won't be able to mess up the queues,
251  * copy_to_cooked must be atomic with respect to itself, as must
252  * tty->write.  Thus, you must use the inline functions set_bit() and
253  * clear_bit() to make things atomic.
254  */
255 #define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
256 #define TTY_IO_ERROR 		1	/* Canse an I/O error (may be no ldisc too) */
257 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
258 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
259 #define TTY_DEBUG 		4	/* Debugging */
260 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
261 #define TTY_PUSH 		6	/* n_tty private */
262 #define TTY_CLOSING 		7	/* ->close() in progress */
263 #define TTY_DONT_FLIP 		8	/* Defer buffer flip */
264 #define TTY_LDISC 		9	/* Line discipline attached */
265 #define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
266 #define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
267 #define TTY_PTY_LOCK 		16	/* pty private */
268 #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
269 #define TTY_HUPPED 		18	/* Post driver->hangup() */
270 
271 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
272 
273 extern void tty_write_flush(struct tty_struct *);
274 
275 extern struct termios tty_std_termios;
276 extern int fg_console, last_console, want_console;
277 
278 extern int kmsg_redirect;
279 
280 extern void console_init(void);
281 extern int vcs_init(void);
282 
283 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
284 			      const char *routine);
285 extern char *tty_name(struct tty_struct *tty, char *buf);
286 extern void tty_wait_until_sent(struct tty_struct * tty, long timeout);
287 extern int tty_check_change(struct tty_struct * tty);
288 extern void stop_tty(struct tty_struct * tty);
289 extern void start_tty(struct tty_struct * tty);
290 extern int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc);
291 extern int tty_unregister_ldisc(int disc);
292 extern int tty_register_driver(struct tty_driver *driver);
293 extern int tty_unregister_driver(struct tty_driver *driver);
294 extern void tty_register_device(struct tty_driver *driver, unsigned index, struct device *dev);
295 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
296 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
297 			     int buflen);
298 extern void tty_write_message(struct tty_struct *tty, char *msg);
299 
300 extern int is_orphaned_pgrp(int pgrp);
301 extern int is_ignored(int sig);
302 extern int tty_signal(int sig, struct tty_struct *tty);
303 extern void tty_hangup(struct tty_struct * tty);
304 extern void tty_vhangup(struct tty_struct * tty);
305 extern void tty_unhangup(struct file *filp);
306 extern int tty_hung_up_p(struct file * filp);
307 extern void do_SAK(struct tty_struct *tty);
308 extern void disassociate_ctty(int priv);
309 extern void tty_flip_buffer_push(struct tty_struct *tty);
310 extern int tty_get_baud_rate(struct tty_struct *tty);
311 extern int tty_termios_baud_rate(struct termios *termios);
312 
313 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
314 extern void tty_ldisc_deref(struct tty_ldisc *);
315 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
316 
317 extern struct tty_ldisc *tty_ldisc_get(int);
318 extern void tty_ldisc_put(int);
319 
320 extern void tty_wakeup(struct tty_struct *tty);
321 extern void tty_ldisc_flush(struct tty_struct *tty);
322 
323 extern struct mutex tty_mutex;
324 
325 /* n_tty.c */
326 extern struct tty_ldisc tty_ldisc_N_TTY;
327 
328 /* tty_ioctl.c */
329 extern int n_tty_ioctl(struct tty_struct * tty, struct file * file,
330 		       unsigned int cmd, unsigned long arg);
331 
332 /* serial.c */
333 
334 extern void serial_console_init(void);
335 
336 /* pcxx.c */
337 
338 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
339 
340 /* printk.c */
341 
342 extern void console_print(const char *);
343 
344 /* vt.c */
345 
346 extern int vt_ioctl(struct tty_struct *tty, struct file * file,
347 		    unsigned int cmd, unsigned long arg);
348 
349 static inline dev_t tty_devnum(struct tty_struct *tty)
350 {
351 	return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
352 }
353 
354 #endif /* __KERNEL__ */
355 #endif
356