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 14 15 16 /* 17 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are 18 * hardcoded at present.) 19 */ 20 #define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */ 21 #define NR_UNIX98_PTY_RESERVE 1024 /* Default reserve for main devpts */ 22 #define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */ 23 24 /* 25 * This character is the same as _POSIX_VDISABLE: it cannot be used as 26 * a c_cc[] character, but indicates that a particular special character 27 * isn't in use (eg VINTR has no character etc) 28 */ 29 #define __DISABLED_CHAR '\0' 30 31 struct tty_buffer { 32 struct tty_buffer *next; 33 char *char_buf_ptr; 34 unsigned char *flag_buf_ptr; 35 int used; 36 int size; 37 int commit; 38 int read; 39 /* Data points here */ 40 unsigned long data[0]; 41 }; 42 43 /* 44 * We default to dicing tty buffer allocations to this many characters 45 * in order to avoid multiple page allocations. We know the size of 46 * tty_buffer itself but it must also be taken into account that the 47 * the buffer is 256 byte aligned. See tty_buffer_find for the allocation 48 * logic this must match 49 */ 50 51 #define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF) 52 53 54 struct tty_bufhead { 55 struct work_struct work; 56 spinlock_t lock; 57 struct tty_buffer *head; /* Queue head */ 58 struct tty_buffer *tail; /* Active buffer */ 59 struct tty_buffer *free; /* Free queue head */ 60 int memory_used; /* Buffer space used excluding 61 free queue */ 62 }; 63 /* 64 * When a break, frame error, or parity error happens, these codes are 65 * stuffed into the flags buffer. 66 */ 67 #define TTY_NORMAL 0 68 #define TTY_BREAK 1 69 #define TTY_FRAME 2 70 #define TTY_PARITY 3 71 #define TTY_OVERRUN 4 72 73 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR]) 74 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT]) 75 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE]) 76 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL]) 77 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF]) 78 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME]) 79 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN]) 80 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC]) 81 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART]) 82 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP]) 83 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP]) 84 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL]) 85 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT]) 86 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD]) 87 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE]) 88 #define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT]) 89 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2]) 90 91 #define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f)) 92 #define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f)) 93 #define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f)) 94 #define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f)) 95 96 #define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK) 97 #define I_BRKINT(tty) _I_FLAG((tty), BRKINT) 98 #define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR) 99 #define I_PARMRK(tty) _I_FLAG((tty), PARMRK) 100 #define I_INPCK(tty) _I_FLAG((tty), INPCK) 101 #define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP) 102 #define I_INLCR(tty) _I_FLAG((tty), INLCR) 103 #define I_IGNCR(tty) _I_FLAG((tty), IGNCR) 104 #define I_ICRNL(tty) _I_FLAG((tty), ICRNL) 105 #define I_IUCLC(tty) _I_FLAG((tty), IUCLC) 106 #define I_IXON(tty) _I_FLAG((tty), IXON) 107 #define I_IXANY(tty) _I_FLAG((tty), IXANY) 108 #define I_IXOFF(tty) _I_FLAG((tty), IXOFF) 109 #define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL) 110 #define I_IUTF8(tty) _I_FLAG((tty), IUTF8) 111 112 #define O_OPOST(tty) _O_FLAG((tty), OPOST) 113 #define O_OLCUC(tty) _O_FLAG((tty), OLCUC) 114 #define O_ONLCR(tty) _O_FLAG((tty), ONLCR) 115 #define O_OCRNL(tty) _O_FLAG((tty), OCRNL) 116 #define O_ONOCR(tty) _O_FLAG((tty), ONOCR) 117 #define O_ONLRET(tty) _O_FLAG((tty), ONLRET) 118 #define O_OFILL(tty) _O_FLAG((tty), OFILL) 119 #define O_OFDEL(tty) _O_FLAG((tty), OFDEL) 120 #define O_NLDLY(tty) _O_FLAG((tty), NLDLY) 121 #define O_CRDLY(tty) _O_FLAG((tty), CRDLY) 122 #define O_TABDLY(tty) _O_FLAG((tty), TABDLY) 123 #define O_BSDLY(tty) _O_FLAG((tty), BSDLY) 124 #define O_VTDLY(tty) _O_FLAG((tty), VTDLY) 125 #define O_FFDLY(tty) _O_FLAG((tty), FFDLY) 126 127 #define C_BAUD(tty) _C_FLAG((tty), CBAUD) 128 #define C_CSIZE(tty) _C_FLAG((tty), CSIZE) 129 #define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB) 130 #define C_CREAD(tty) _C_FLAG((tty), CREAD) 131 #define C_PARENB(tty) _C_FLAG((tty), PARENB) 132 #define C_PARODD(tty) _C_FLAG((tty), PARODD) 133 #define C_HUPCL(tty) _C_FLAG((tty), HUPCL) 134 #define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL) 135 #define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD) 136 #define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS) 137 138 #define L_ISIG(tty) _L_FLAG((tty), ISIG) 139 #define L_ICANON(tty) _L_FLAG((tty), ICANON) 140 #define L_XCASE(tty) _L_FLAG((tty), XCASE) 141 #define L_ECHO(tty) _L_FLAG((tty), ECHO) 142 #define L_ECHOE(tty) _L_FLAG((tty), ECHOE) 143 #define L_ECHOK(tty) _L_FLAG((tty), ECHOK) 144 #define L_ECHONL(tty) _L_FLAG((tty), ECHONL) 145 #define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH) 146 #define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP) 147 #define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL) 148 #define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT) 149 #define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE) 150 #define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO) 151 #define L_PENDIN(tty) _L_FLAG((tty), PENDIN) 152 #define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN) 153 #define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC) 154 155 struct device; 156 struct signal_struct; 157 158 /* 159 * Port level information. Each device keeps its own port level information 160 * so provide a common structure for those ports wanting to use common support 161 * routines. 162 * 163 * The tty port has a different lifetime to the tty so must be kept apart. 164 * In addition be careful as tty -> port mappings are valid for the life 165 * of the tty object but in many cases port -> tty mappings are valid only 166 * until a hangup so don't use the wrong path. 167 */ 168 169 struct tty_port; 170 171 struct tty_port_operations { 172 /* Return 1 if the carrier is raised */ 173 int (*carrier_raised)(struct tty_port *port); 174 /* Control the DTR line */ 175 void (*dtr_rts)(struct tty_port *port, int raise); 176 /* Called when the last close completes or a hangup finishes 177 IFF the port was initialized. Do not use to free resources. Called 178 under the port mutex to serialize against activate/shutdowns */ 179 void (*shutdown)(struct tty_port *port); 180 void (*drop)(struct tty_port *port); 181 /* Called under the port mutex from tty_port_open, serialized using 182 the port mutex */ 183 /* FIXME: long term getting the tty argument *out* of this would be 184 good for consoles */ 185 int (*activate)(struct tty_port *port, struct tty_struct *tty); 186 /* Called on the final put of a port */ 187 void (*destruct)(struct tty_port *port); 188 }; 189 190 struct tty_port { 191 struct tty_bufhead buf; /* Locked internally */ 192 struct tty_struct *tty; /* Back pointer */ 193 struct tty_struct *itty; /* internal back ptr */ 194 const struct tty_port_operations *ops; /* Port operations */ 195 spinlock_t lock; /* Lock protecting tty field */ 196 int blocked_open; /* Waiting to open */ 197 int count; /* Usage count */ 198 wait_queue_head_t open_wait; /* Open waiters */ 199 wait_queue_head_t close_wait; /* Close waiters */ 200 wait_queue_head_t delta_msr_wait; /* Modem status change */ 201 unsigned long flags; /* TTY flags ASY_*/ 202 unsigned long iflags; /* TTYP_ internal flags */ 203 #define TTYP_FLUSHING 1 /* Flushing to ldisc in progress */ 204 #define TTYP_FLUSHPENDING 2 /* Queued buffer flush pending */ 205 unsigned char console:1; /* port is a console */ 206 struct mutex mutex; /* Locking */ 207 struct mutex buf_mutex; /* Buffer alloc lock */ 208 unsigned char *xmit_buf; /* Optional buffer */ 209 unsigned int close_delay; /* Close port delay */ 210 unsigned int closing_wait; /* Delay for output */ 211 int drain_delay; /* Set to zero if no pure time 212 based drain is needed else 213 set to size of fifo */ 214 struct kref kref; /* Ref counter */ 215 }; 216 217 /* 218 * Where all of the state associated with a tty is kept while the tty 219 * is open. Since the termios state should be kept even if the tty 220 * has been closed --- for things like the baud rate, etc --- it is 221 * not stored here, but rather a pointer to the real state is stored 222 * here. Possible the winsize structure should have the same 223 * treatment, but (1) the default 80x24 is usually right and (2) it's 224 * most often used by a windowing system, which will set the correct 225 * size each time the window is created or resized anyway. 226 * - TYT, 9/14/92 227 */ 228 229 struct tty_operations; 230 231 struct tty_struct { 232 int magic; 233 struct kref kref; 234 struct device *dev; 235 struct tty_driver *driver; 236 const struct tty_operations *ops; 237 int index; 238 239 /* Protects ldisc changes: Lock tty not pty */ 240 struct mutex ldisc_mutex; 241 struct tty_ldisc *ldisc; 242 243 struct mutex atomic_write_lock; 244 struct mutex legacy_mutex; 245 struct mutex termios_mutex; 246 spinlock_t ctrl_lock; 247 /* Termios values are protected by the termios mutex */ 248 struct ktermios termios, termios_locked; 249 struct termiox *termiox; /* May be NULL for unsupported */ 250 char name[64]; 251 struct pid *pgrp; /* Protected by ctrl lock */ 252 struct pid *session; 253 unsigned long flags; 254 int count; 255 struct winsize winsize; /* termios mutex */ 256 unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1; 257 unsigned char low_latency:1, warned:1; 258 unsigned char ctrl_status; /* ctrl_lock */ 259 unsigned int receive_room; /* Bytes free for queue */ 260 261 struct tty_struct *link; 262 struct fasync_struct *fasync; 263 int alt_speed; /* For magic substitution of 38400 bps */ 264 wait_queue_head_t write_wait; 265 wait_queue_head_t read_wait; 266 struct work_struct hangup_work; 267 void *disc_data; 268 void *driver_data; 269 struct list_head tty_files; 270 271 #define N_TTY_BUF_SIZE 4096 272 273 unsigned char closing:1; 274 unsigned short minimum_to_wake; 275 unsigned char *write_buf; 276 int write_cnt; 277 /* If the tty has a pending do_SAK, queue it here - akpm */ 278 struct work_struct SAK_work; 279 struct tty_port *port; 280 }; 281 282 /* Each of a tty's open files has private_data pointing to tty_file_private */ 283 struct tty_file_private { 284 struct tty_struct *tty; 285 struct file *file; 286 struct list_head list; 287 }; 288 289 /* tty magic number */ 290 #define TTY_MAGIC 0x5401 291 292 /* 293 * These bits are used in the flags field of the tty structure. 294 * 295 * So that interrupts won't be able to mess up the queues, 296 * copy_to_cooked must be atomic with respect to itself, as must 297 * tty->write. Thus, you must use the inline functions set_bit() and 298 * clear_bit() to make things atomic. 299 */ 300 #define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */ 301 #define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */ 302 #define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */ 303 #define TTY_EXCLUSIVE 3 /* Exclusive open mode */ 304 #define TTY_DEBUG 4 /* Debugging */ 305 #define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */ 306 #define TTY_PUSH 6 /* n_tty private */ 307 #define TTY_CLOSING 7 /* ->close() in progress */ 308 #define TTY_LDISC 9 /* Line discipline attached */ 309 #define TTY_LDISC_CHANGING 10 /* Line discipline changing */ 310 #define TTY_LDISC_OPEN 11 /* Line discipline is open */ 311 #define TTY_HW_COOK_OUT 14 /* Hardware can do output cooking */ 312 #define TTY_HW_COOK_IN 15 /* Hardware can do input cooking */ 313 #define TTY_PTY_LOCK 16 /* pty private */ 314 #define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ 315 #define TTY_HUPPED 18 /* Post driver->hangup() */ 316 #define TTY_HUPPING 21 /* ->hangup() in progress */ 317 318 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) 319 320 extern void tty_write_flush(struct tty_struct *); 321 322 extern struct ktermios tty_std_termios; 323 324 extern void console_init(void); 325 extern int vcs_init(void); 326 327 extern struct class *tty_class; 328 329 /** 330 * tty_kref_get - get a tty reference 331 * @tty: tty device 332 * 333 * Return a new reference to a tty object. The caller must hold 334 * sufficient locks/counts to ensure that their existing reference cannot 335 * go away 336 */ 337 338 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty) 339 { 340 if (tty) 341 kref_get(&tty->kref); 342 return tty; 343 } 344 extern void tty_kref_put(struct tty_struct *tty); 345 346 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, 347 const char *routine); 348 extern char *tty_name(struct tty_struct *tty, char *buf); 349 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout); 350 extern int tty_check_change(struct tty_struct *tty); 351 extern void stop_tty(struct tty_struct *tty); 352 extern void start_tty(struct tty_struct *tty); 353 extern int tty_register_driver(struct tty_driver *driver); 354 extern int tty_unregister_driver(struct tty_driver *driver); 355 extern struct device *tty_register_device(struct tty_driver *driver, 356 unsigned index, struct device *dev); 357 extern struct device *tty_register_device_attr(struct tty_driver *driver, 358 unsigned index, struct device *device, 359 void *drvdata, 360 const struct attribute_group **attr_grp); 361 extern void tty_unregister_device(struct tty_driver *driver, unsigned index); 362 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp, 363 int buflen); 364 extern void tty_write_message(struct tty_struct *tty, char *msg); 365 extern int tty_put_char(struct tty_struct *tty, unsigned char c); 366 extern int tty_chars_in_buffer(struct tty_struct *tty); 367 extern int tty_write_room(struct tty_struct *tty); 368 extern void tty_driver_flush_buffer(struct tty_struct *tty); 369 extern void tty_throttle(struct tty_struct *tty); 370 extern void tty_unthrottle(struct tty_struct *tty); 371 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws); 372 extern void tty_driver_remove_tty(struct tty_driver *driver, 373 struct tty_struct *tty); 374 extern void tty_free_termios(struct tty_struct *tty); 375 extern int is_current_pgrp_orphaned(void); 376 extern struct pid *tty_get_pgrp(struct tty_struct *tty); 377 extern int is_ignored(int sig); 378 extern int tty_signal(int sig, struct tty_struct *tty); 379 extern void tty_hangup(struct tty_struct *tty); 380 extern void tty_vhangup(struct tty_struct *tty); 381 extern void tty_vhangup_locked(struct tty_struct *tty); 382 extern void tty_vhangup_self(void); 383 extern void tty_unhangup(struct file *filp); 384 extern int tty_hung_up_p(struct file *filp); 385 extern void do_SAK(struct tty_struct *tty); 386 extern void __do_SAK(struct tty_struct *tty); 387 extern void disassociate_ctty(int priv); 388 extern void no_tty(void); 389 extern void tty_flip_buffer_push(struct tty_struct *tty); 390 extern void tty_flush_to_ldisc(struct tty_struct *tty); 391 extern void tty_buffer_free_all(struct tty_port *port); 392 extern void tty_buffer_flush(struct tty_struct *tty); 393 extern void tty_buffer_init(struct tty_port *port); 394 extern speed_t tty_get_baud_rate(struct tty_struct *tty); 395 extern speed_t tty_termios_baud_rate(struct ktermios *termios); 396 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); 397 extern void tty_termios_encode_baud_rate(struct ktermios *termios, 398 speed_t ibaud, speed_t obaud); 399 extern void tty_encode_baud_rate(struct tty_struct *tty, 400 speed_t ibaud, speed_t obaud); 401 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old); 402 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b); 403 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt); 404 405 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *); 406 extern void tty_ldisc_deref(struct tty_ldisc *); 407 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *); 408 extern void tty_ldisc_hangup(struct tty_struct *tty); 409 extern const struct file_operations tty_ldiscs_proc_fops; 410 411 extern void tty_wakeup(struct tty_struct *tty); 412 extern void tty_ldisc_flush(struct tty_struct *tty); 413 414 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 415 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 416 unsigned int cmd, unsigned long arg); 417 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); 418 extern dev_t tty_devnum(struct tty_struct *tty); 419 extern void proc_clear_tty(struct task_struct *p); 420 extern struct tty_struct *get_current_tty(void); 421 extern void tty_default_fops(struct file_operations *fops); 422 extern struct tty_struct *alloc_tty_struct(void); 423 extern int tty_alloc_file(struct file *file); 424 extern void tty_add_file(struct tty_struct *tty, struct file *file); 425 extern void tty_free_file(struct file *file); 426 extern void free_tty_struct(struct tty_struct *tty); 427 extern void initialize_tty_struct(struct tty_struct *tty, 428 struct tty_driver *driver, int idx); 429 extern void deinitialize_tty_struct(struct tty_struct *tty); 430 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); 431 extern int tty_release(struct inode *inode, struct file *filp); 432 extern int tty_init_termios(struct tty_struct *tty); 433 extern int tty_standard_install(struct tty_driver *driver, 434 struct tty_struct *tty); 435 436 extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty); 437 extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty); 438 439 extern struct mutex tty_mutex; 440 extern spinlock_t tty_files_lock; 441 442 extern void tty_write_unlock(struct tty_struct *tty); 443 extern int tty_write_lock(struct tty_struct *tty, int ndelay); 444 #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) 445 446 extern void tty_port_init(struct tty_port *port); 447 extern void tty_port_link_device(struct tty_port *port, 448 struct tty_driver *driver, unsigned index); 449 extern struct device *tty_port_register_device(struct tty_port *port, 450 struct tty_driver *driver, unsigned index, 451 struct device *device); 452 extern struct device *tty_port_register_device_attr(struct tty_port *port, 453 struct tty_driver *driver, unsigned index, 454 struct device *device, void *drvdata, 455 const struct attribute_group **attr_grp); 456 extern int tty_port_alloc_xmit_buf(struct tty_port *port); 457 extern void tty_port_free_xmit_buf(struct tty_port *port); 458 extern void tty_port_destroy(struct tty_port *port); 459 extern void tty_port_put(struct tty_port *port); 460 461 static inline struct tty_port *tty_port_get(struct tty_port *port) 462 { 463 if (port) 464 kref_get(&port->kref); 465 return port; 466 } 467 468 /* If the cts flow control is enabled, return true. */ 469 static inline bool tty_port_cts_enabled(struct tty_port *port) 470 { 471 return port->flags & ASYNC_CTS_FLOW; 472 } 473 474 extern struct tty_struct *tty_port_tty_get(struct tty_port *port); 475 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); 476 extern int tty_port_carrier_raised(struct tty_port *port); 477 extern void tty_port_raise_dtr_rts(struct tty_port *port); 478 extern void tty_port_lower_dtr_rts(struct tty_port *port); 479 extern void tty_port_hangup(struct tty_port *port); 480 extern int tty_port_block_til_ready(struct tty_port *port, 481 struct tty_struct *tty, struct file *filp); 482 extern int tty_port_close_start(struct tty_port *port, 483 struct tty_struct *tty, struct file *filp); 484 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty); 485 extern void tty_port_close(struct tty_port *port, 486 struct tty_struct *tty, struct file *filp); 487 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver, 488 struct tty_struct *tty); 489 extern int tty_port_open(struct tty_port *port, 490 struct tty_struct *tty, struct file *filp); 491 static inline int tty_port_users(struct tty_port *port) 492 { 493 return port->count + port->blocked_open; 494 } 495 496 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc); 497 extern int tty_unregister_ldisc(int disc); 498 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); 499 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); 500 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty); 501 extern void tty_ldisc_init(struct tty_struct *tty); 502 extern void tty_ldisc_deinit(struct tty_struct *tty); 503 extern void tty_ldisc_begin(void); 504 /* This last one is just for the tty layer internals and shouldn't be used elsewhere */ 505 extern void tty_ldisc_enable(struct tty_struct *tty); 506 507 508 /* n_tty.c */ 509 extern struct tty_ldisc_ops tty_ldisc_N_TTY; 510 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops); 511 512 /* tty_audit.c */ 513 #ifdef CONFIG_AUDIT 514 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, 515 size_t size, unsigned icanon); 516 extern void tty_audit_exit(void); 517 extern void tty_audit_fork(struct signal_struct *sig); 518 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch); 519 extern void tty_audit_push(struct tty_struct *tty); 520 extern int tty_audit_push_task(struct task_struct *tsk, 521 kuid_t loginuid, u32 sessionid); 522 #else 523 static inline void tty_audit_add_data(struct tty_struct *tty, 524 unsigned char *data, size_t size, unsigned icanon) 525 { 526 } 527 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch) 528 { 529 } 530 static inline void tty_audit_exit(void) 531 { 532 } 533 static inline void tty_audit_fork(struct signal_struct *sig) 534 { 535 } 536 static inline void tty_audit_push(struct tty_struct *tty) 537 { 538 } 539 static inline int tty_audit_push_task(struct task_struct *tsk, 540 kuid_t loginuid, u32 sessionid) 541 { 542 return 0; 543 } 544 #endif 545 546 /* tty_io.c */ 547 extern int __init tty_init(void); 548 549 /* tty_ioctl.c */ 550 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, 551 unsigned int cmd, unsigned long arg); 552 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file, 553 unsigned int cmd, unsigned long arg); 554 555 /* serial.c */ 556 557 extern void serial_console_init(void); 558 559 /* pcxx.c */ 560 561 extern int pcxe_open(struct tty_struct *tty, struct file *filp); 562 563 /* vt.c */ 564 565 extern int vt_ioctl(struct tty_struct *tty, 566 unsigned int cmd, unsigned long arg); 567 568 extern long vt_compat_ioctl(struct tty_struct *tty, 569 unsigned int cmd, unsigned long arg); 570 571 /* tty_mutex.c */ 572 /* functions for preparation of BKL removal */ 573 extern void __lockfunc tty_lock(struct tty_struct *tty); 574 extern void __lockfunc tty_unlock(struct tty_struct *tty); 575 extern void __lockfunc tty_lock_pair(struct tty_struct *tty, 576 struct tty_struct *tty2); 577 extern void __lockfunc tty_unlock_pair(struct tty_struct *tty, 578 struct tty_struct *tty2); 579 580 /* 581 * this shall be called only from where BTM is held (like close) 582 * 583 * We need this to ensure nobody waits for us to finish while we are waiting. 584 * Without this we were encountering system stalls. 585 * 586 * This should be indeed removed with BTM removal later. 587 * 588 * Locking: BTM required. Nobody is allowed to hold port->mutex. 589 */ 590 static inline void tty_wait_until_sent_from_close(struct tty_struct *tty, 591 long timeout) 592 { 593 tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */ 594 tty_wait_until_sent(tty, timeout); 595 tty_lock(tty); 596 } 597 598 /* 599 * wait_event_interruptible_tty -- wait for a condition with the tty lock held 600 * 601 * The condition we are waiting for might take a long time to 602 * become true, or might depend on another thread taking the 603 * BTM. In either case, we need to drop the BTM to guarantee 604 * forward progress. This is a leftover from the conversion 605 * from the BKL and should eventually get removed as the BTM 606 * falls out of use. 607 * 608 * Do not use in new code. 609 */ 610 #define wait_event_interruptible_tty(tty, wq, condition) \ 611 ({ \ 612 int __ret = 0; \ 613 if (!(condition)) { \ 614 __wait_event_interruptible_tty(tty, wq, condition, __ret); \ 615 } \ 616 __ret; \ 617 }) 618 619 #define __wait_event_interruptible_tty(tty, wq, condition, ret) \ 620 do { \ 621 DEFINE_WAIT(__wait); \ 622 \ 623 for (;;) { \ 624 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ 625 if (condition) \ 626 break; \ 627 if (!signal_pending(current)) { \ 628 tty_unlock(tty); \ 629 schedule(); \ 630 tty_lock(tty); \ 631 continue; \ 632 } \ 633 ret = -ERESTARTSYS; \ 634 break; \ 635 } \ 636 finish_wait(&wq, &__wait); \ 637 } while (0) 638 639 640 #endif 641