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 33 struct 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 50 static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs) 51 { 52 return ((unsigned char *)b->data) + ofs; 53 } 54 55 static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs) 56 { 57 return (char *)char_buf_ptr(b, ofs) + b->size; 58 } 59 60 struct tty_bufhead { 61 struct tty_buffer *head; /* Queue head */ 62 struct work_struct work; 63 struct mutex lock; 64 spinlock_t flush_lock; 65 atomic_t priority; 66 struct tty_buffer sentinel; 67 struct llist_head free; /* Free queue head */ 68 atomic_t mem_used; /* In-use buffers excluding free list */ 69 int mem_limit; 70 struct tty_buffer *tail; /* Active buffer */ 71 }; 72 /* 73 * When a break, frame error, or parity error happens, these codes are 74 * stuffed into the flags buffer. 75 */ 76 #define TTY_NORMAL 0 77 #define TTY_BREAK 1 78 #define TTY_FRAME 2 79 #define TTY_PARITY 3 80 #define TTY_OVERRUN 4 81 82 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR]) 83 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT]) 84 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE]) 85 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL]) 86 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF]) 87 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME]) 88 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN]) 89 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC]) 90 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART]) 91 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP]) 92 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP]) 93 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL]) 94 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT]) 95 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD]) 96 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE]) 97 #define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT]) 98 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2]) 99 100 #define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f)) 101 #define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f)) 102 #define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f)) 103 #define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f)) 104 105 #define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK) 106 #define I_BRKINT(tty) _I_FLAG((tty), BRKINT) 107 #define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR) 108 #define I_PARMRK(tty) _I_FLAG((tty), PARMRK) 109 #define I_INPCK(tty) _I_FLAG((tty), INPCK) 110 #define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP) 111 #define I_INLCR(tty) _I_FLAG((tty), INLCR) 112 #define I_IGNCR(tty) _I_FLAG((tty), IGNCR) 113 #define I_ICRNL(tty) _I_FLAG((tty), ICRNL) 114 #define I_IUCLC(tty) _I_FLAG((tty), IUCLC) 115 #define I_IXON(tty) _I_FLAG((tty), IXON) 116 #define I_IXANY(tty) _I_FLAG((tty), IXANY) 117 #define I_IXOFF(tty) _I_FLAG((tty), IXOFF) 118 #define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL) 119 #define I_IUTF8(tty) _I_FLAG((tty), IUTF8) 120 121 #define O_OPOST(tty) _O_FLAG((tty), OPOST) 122 #define O_OLCUC(tty) _O_FLAG((tty), OLCUC) 123 #define O_ONLCR(tty) _O_FLAG((tty), ONLCR) 124 #define O_OCRNL(tty) _O_FLAG((tty), OCRNL) 125 #define O_ONOCR(tty) _O_FLAG((tty), ONOCR) 126 #define O_ONLRET(tty) _O_FLAG((tty), ONLRET) 127 #define O_OFILL(tty) _O_FLAG((tty), OFILL) 128 #define O_OFDEL(tty) _O_FLAG((tty), OFDEL) 129 #define O_NLDLY(tty) _O_FLAG((tty), NLDLY) 130 #define O_CRDLY(tty) _O_FLAG((tty), CRDLY) 131 #define O_TABDLY(tty) _O_FLAG((tty), TABDLY) 132 #define O_BSDLY(tty) _O_FLAG((tty), BSDLY) 133 #define O_VTDLY(tty) _O_FLAG((tty), VTDLY) 134 #define O_FFDLY(tty) _O_FLAG((tty), FFDLY) 135 136 #define C_BAUD(tty) _C_FLAG((tty), CBAUD) 137 #define C_CSIZE(tty) _C_FLAG((tty), CSIZE) 138 #define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB) 139 #define C_CREAD(tty) _C_FLAG((tty), CREAD) 140 #define C_PARENB(tty) _C_FLAG((tty), PARENB) 141 #define C_PARODD(tty) _C_FLAG((tty), PARODD) 142 #define C_HUPCL(tty) _C_FLAG((tty), HUPCL) 143 #define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL) 144 #define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD) 145 #define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS) 146 #define C_CMSPAR(tty) _C_FLAG((tty), CMSPAR) 147 148 #define L_ISIG(tty) _L_FLAG((tty), ISIG) 149 #define L_ICANON(tty) _L_FLAG((tty), ICANON) 150 #define L_XCASE(tty) _L_FLAG((tty), XCASE) 151 #define L_ECHO(tty) _L_FLAG((tty), ECHO) 152 #define L_ECHOE(tty) _L_FLAG((tty), ECHOE) 153 #define L_ECHOK(tty) _L_FLAG((tty), ECHOK) 154 #define L_ECHONL(tty) _L_FLAG((tty), ECHONL) 155 #define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH) 156 #define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP) 157 #define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL) 158 #define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT) 159 #define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE) 160 #define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO) 161 #define L_PENDIN(tty) _L_FLAG((tty), PENDIN) 162 #define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN) 163 #define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC) 164 165 struct device; 166 struct signal_struct; 167 168 /* 169 * Port level information. Each device keeps its own port level information 170 * so provide a common structure for those ports wanting to use common support 171 * routines. 172 * 173 * The tty port has a different lifetime to the tty so must be kept apart. 174 * In addition be careful as tty -> port mappings are valid for the life 175 * of the tty object but in many cases port -> tty mappings are valid only 176 * until a hangup so don't use the wrong path. 177 */ 178 179 struct tty_port; 180 181 struct tty_port_operations { 182 /* Return 1 if the carrier is raised */ 183 int (*carrier_raised)(struct tty_port *port); 184 /* Control the DTR line */ 185 void (*dtr_rts)(struct tty_port *port, int raise); 186 /* Called when the last close completes or a hangup finishes 187 IFF the port was initialized. Do not use to free resources. Called 188 under the port mutex to serialize against activate/shutdowns */ 189 void (*shutdown)(struct tty_port *port); 190 /* Called under the port mutex from tty_port_open, serialized using 191 the port mutex */ 192 /* FIXME: long term getting the tty argument *out* of this would be 193 good for consoles */ 194 int (*activate)(struct tty_port *port, struct tty_struct *tty); 195 /* Called on the final put of a port */ 196 void (*destruct)(struct tty_port *port); 197 }; 198 199 struct tty_port { 200 struct tty_bufhead buf; /* Locked internally */ 201 struct tty_struct *tty; /* Back pointer */ 202 struct tty_struct *itty; /* internal back ptr */ 203 const struct tty_port_operations *ops; /* Port operations */ 204 spinlock_t lock; /* Lock protecting tty field */ 205 int blocked_open; /* Waiting to open */ 206 int count; /* Usage count */ 207 wait_queue_head_t open_wait; /* Open waiters */ 208 wait_queue_head_t close_wait; /* Close waiters */ 209 wait_queue_head_t delta_msr_wait; /* Modem status change */ 210 unsigned long flags; /* TTY flags ASY_*/ 211 unsigned char console:1, /* port is a console */ 212 low_latency:1; /* optional: tune for latency */ 213 struct mutex mutex; /* Locking */ 214 struct mutex buf_mutex; /* Buffer alloc lock */ 215 unsigned char *xmit_buf; /* Optional buffer */ 216 unsigned int close_delay; /* Close port delay */ 217 unsigned int closing_wait; /* Delay for output */ 218 int drain_delay; /* Set to zero if no pure time 219 based drain is needed else 220 set to size of fifo */ 221 struct kref kref; /* Ref counter */ 222 }; 223 224 /* 225 * Where all of the state associated with a tty is kept while the tty 226 * is open. Since the termios state should be kept even if the tty 227 * has been closed --- for things like the baud rate, etc --- it is 228 * not stored here, but rather a pointer to the real state is stored 229 * here. Possible the winsize structure should have the same 230 * treatment, but (1) the default 80x24 is usually right and (2) it's 231 * most often used by a windowing system, which will set the correct 232 * size each time the window is created or resized anyway. 233 * - TYT, 9/14/92 234 */ 235 236 struct tty_operations; 237 238 struct tty_struct { 239 int magic; 240 struct kref kref; 241 struct device *dev; 242 struct tty_driver *driver; 243 const struct tty_operations *ops; 244 int index; 245 246 /* Protects ldisc changes: Lock tty not pty */ 247 struct ld_semaphore ldisc_sem; 248 struct tty_ldisc *ldisc; 249 250 struct mutex atomic_write_lock; 251 struct mutex legacy_mutex; 252 struct mutex throttle_mutex; 253 struct rw_semaphore termios_rwsem; 254 struct mutex winsize_mutex; 255 spinlock_t ctrl_lock; 256 /* Termios values are protected by the termios rwsem */ 257 struct ktermios termios, termios_locked; 258 struct termiox *termiox; /* May be NULL for unsupported */ 259 char name[64]; 260 struct pid *pgrp; /* Protected by ctrl lock */ 261 struct pid *session; 262 unsigned long flags; 263 int count; 264 struct winsize winsize; /* winsize_mutex */ 265 unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1; 266 unsigned char ctrl_status; /* ctrl_lock */ 267 unsigned int receive_room; /* Bytes free for queue */ 268 int flow_change; 269 270 struct tty_struct *link; 271 struct fasync_struct *fasync; 272 int alt_speed; /* For magic substitution of 38400 bps */ 273 wait_queue_head_t write_wait; 274 wait_queue_head_t read_wait; 275 struct work_struct hangup_work; 276 void *disc_data; 277 void *driver_data; 278 struct list_head tty_files; 279 280 #define N_TTY_BUF_SIZE 4096 281 282 unsigned char closing:1; 283 unsigned char *write_buf; 284 int write_cnt; 285 /* If the tty has a pending do_SAK, queue it here - akpm */ 286 struct work_struct SAK_work; 287 struct tty_port *port; 288 }; 289 290 /* Each of a tty's open files has private_data pointing to tty_file_private */ 291 struct tty_file_private { 292 struct tty_struct *tty; 293 struct file *file; 294 struct list_head list; 295 }; 296 297 /* tty magic number */ 298 #define TTY_MAGIC 0x5401 299 300 /* 301 * These bits are used in the flags field of the tty structure. 302 * 303 * So that interrupts won't be able to mess up the queues, 304 * copy_to_cooked must be atomic with respect to itself, as must 305 * tty->write. Thus, you must use the inline functions set_bit() and 306 * clear_bit() to make things atomic. 307 */ 308 #define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */ 309 #define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */ 310 #define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */ 311 #define TTY_EXCLUSIVE 3 /* Exclusive open mode */ 312 #define TTY_DEBUG 4 /* Debugging */ 313 #define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */ 314 #define TTY_CLOSING 7 /* ->close() in progress */ 315 #define TTY_LDISC_OPEN 11 /* Line discipline is open */ 316 #define TTY_PTY_LOCK 16 /* pty private */ 317 #define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ 318 #define TTY_HUPPED 18 /* Post driver->hangup() */ 319 #define TTY_HUPPING 21 /* ->hangup() in progress */ 320 #define TTY_LDISC_HALTED 22 /* Line discipline is halted */ 321 322 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) 323 324 /* Values for tty->flow_change */ 325 #define TTY_THROTTLE_SAFE 1 326 #define TTY_UNTHROTTLE_SAFE 2 327 328 static inline void __tty_set_flow_change(struct tty_struct *tty, int val) 329 { 330 tty->flow_change = val; 331 } 332 333 static inline void tty_set_flow_change(struct tty_struct *tty, int val) 334 { 335 tty->flow_change = val; 336 smp_mb(); 337 } 338 339 #ifdef CONFIG_TTY 340 extern void console_init(void); 341 extern void tty_kref_put(struct tty_struct *tty); 342 extern struct pid *tty_get_pgrp(struct tty_struct *tty); 343 extern void tty_vhangup_self(void); 344 extern void disassociate_ctty(int priv); 345 extern dev_t tty_devnum(struct tty_struct *tty); 346 extern void proc_clear_tty(struct task_struct *p); 347 extern struct tty_struct *get_current_tty(void); 348 /* tty_io.c */ 349 extern int __init tty_init(void); 350 #else 351 static inline void console_init(void) 352 { } 353 static inline void tty_kref_put(struct tty_struct *tty) 354 { } 355 static inline struct pid *tty_get_pgrp(struct tty_struct *tty) 356 { return NULL; } 357 static inline void tty_vhangup_self(void) 358 { } 359 static inline void disassociate_ctty(int priv) 360 { } 361 static inline dev_t tty_devnum(struct tty_struct *tty) 362 { return 0; } 363 static inline void proc_clear_tty(struct task_struct *p) 364 { } 365 static inline struct tty_struct *get_current_tty(void) 366 { return NULL; } 367 /* tty_io.c */ 368 static inline int __init tty_init(void) 369 { return 0; } 370 #endif 371 372 extern void tty_write_flush(struct tty_struct *); 373 374 extern struct ktermios tty_std_termios; 375 376 extern int vcs_init(void); 377 378 extern struct class *tty_class; 379 380 /** 381 * tty_kref_get - get a tty reference 382 * @tty: tty device 383 * 384 * Return a new reference to a tty object. The caller must hold 385 * sufficient locks/counts to ensure that their existing reference cannot 386 * go away 387 */ 388 389 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty) 390 { 391 if (tty) 392 kref_get(&tty->kref); 393 return tty; 394 } 395 396 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, 397 const char *routine); 398 extern char *tty_name(struct tty_struct *tty, char *buf); 399 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout); 400 extern int tty_check_change(struct tty_struct *tty); 401 extern void stop_tty(struct tty_struct *tty); 402 extern void start_tty(struct tty_struct *tty); 403 extern int tty_register_driver(struct tty_driver *driver); 404 extern int tty_unregister_driver(struct tty_driver *driver); 405 extern struct device *tty_register_device(struct tty_driver *driver, 406 unsigned index, struct device *dev); 407 extern struct device *tty_register_device_attr(struct tty_driver *driver, 408 unsigned index, struct device *device, 409 void *drvdata, 410 const struct attribute_group **attr_grp); 411 extern void tty_unregister_device(struct tty_driver *driver, unsigned index); 412 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp, 413 int buflen); 414 extern void tty_write_message(struct tty_struct *tty, char *msg); 415 extern int tty_put_char(struct tty_struct *tty, unsigned char c); 416 extern int tty_chars_in_buffer(struct tty_struct *tty); 417 extern int tty_write_room(struct tty_struct *tty); 418 extern void tty_driver_flush_buffer(struct tty_struct *tty); 419 extern void tty_throttle(struct tty_struct *tty); 420 extern void tty_unthrottle(struct tty_struct *tty); 421 extern int tty_throttle_safe(struct tty_struct *tty); 422 extern int tty_unthrottle_safe(struct tty_struct *tty); 423 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws); 424 extern void tty_driver_remove_tty(struct tty_driver *driver, 425 struct tty_struct *tty); 426 extern void tty_free_termios(struct tty_struct *tty); 427 extern int is_current_pgrp_orphaned(void); 428 extern int is_ignored(int sig); 429 extern int tty_signal(int sig, struct tty_struct *tty); 430 extern void tty_hangup(struct tty_struct *tty); 431 extern void tty_vhangup(struct tty_struct *tty); 432 extern void tty_unhangup(struct file *filp); 433 extern int tty_hung_up_p(struct file *filp); 434 extern void do_SAK(struct tty_struct *tty); 435 extern void __do_SAK(struct tty_struct *tty); 436 extern void no_tty(void); 437 extern void tty_flush_to_ldisc(struct tty_struct *tty); 438 extern void tty_buffer_free_all(struct tty_port *port); 439 extern void tty_buffer_flush(struct tty_struct *tty); 440 extern void tty_buffer_init(struct tty_port *port); 441 extern speed_t tty_termios_baud_rate(struct ktermios *termios); 442 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); 443 extern void tty_termios_encode_baud_rate(struct ktermios *termios, 444 speed_t ibaud, speed_t obaud); 445 extern void tty_encode_baud_rate(struct tty_struct *tty, 446 speed_t ibaud, speed_t obaud); 447 448 /** 449 * tty_get_baud_rate - get tty bit rates 450 * @tty: tty to query 451 * 452 * Returns the baud rate as an integer for this terminal. The 453 * termios lock must be held by the caller and the terminal bit 454 * flags may be updated. 455 * 456 * Locking: none 457 */ 458 static inline speed_t tty_get_baud_rate(struct tty_struct *tty) 459 { 460 return tty_termios_baud_rate(&tty->termios); 461 } 462 463 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old); 464 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b); 465 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt); 466 467 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *); 468 extern void tty_ldisc_deref(struct tty_ldisc *); 469 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *); 470 extern void tty_ldisc_hangup(struct tty_struct *tty); 471 extern const struct file_operations tty_ldiscs_proc_fops; 472 473 extern void tty_wakeup(struct tty_struct *tty); 474 extern void tty_ldisc_flush(struct tty_struct *tty); 475 476 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 477 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 478 unsigned int cmd, unsigned long arg); 479 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); 480 extern void tty_default_fops(struct file_operations *fops); 481 extern struct tty_struct *alloc_tty_struct(void); 482 extern int tty_alloc_file(struct file *file); 483 extern void tty_add_file(struct tty_struct *tty, struct file *file); 484 extern void tty_free_file(struct file *file); 485 extern void free_tty_struct(struct tty_struct *tty); 486 extern void initialize_tty_struct(struct tty_struct *tty, 487 struct tty_driver *driver, int idx); 488 extern void deinitialize_tty_struct(struct tty_struct *tty); 489 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); 490 extern int tty_release(struct inode *inode, struct file *filp); 491 extern int tty_init_termios(struct tty_struct *tty); 492 extern int tty_standard_install(struct tty_driver *driver, 493 struct tty_struct *tty); 494 495 extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty); 496 extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty); 497 498 extern struct mutex tty_mutex; 499 extern spinlock_t tty_files_lock; 500 501 extern void tty_write_unlock(struct tty_struct *tty); 502 extern int tty_write_lock(struct tty_struct *tty, int ndelay); 503 #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) 504 505 extern void tty_port_init(struct tty_port *port); 506 extern void tty_port_link_device(struct tty_port *port, 507 struct tty_driver *driver, unsigned index); 508 extern struct device *tty_port_register_device(struct tty_port *port, 509 struct tty_driver *driver, unsigned index, 510 struct device *device); 511 extern 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); 515 extern int tty_port_alloc_xmit_buf(struct tty_port *port); 516 extern void tty_port_free_xmit_buf(struct tty_port *port); 517 extern void tty_port_destroy(struct tty_port *port); 518 extern void tty_port_put(struct tty_port *port); 519 520 static 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. */ 528 static inline bool tty_port_cts_enabled(struct tty_port *port) 529 { 530 return port->flags & ASYNC_CTS_FLOW; 531 } 532 533 extern struct tty_struct *tty_port_tty_get(struct tty_port *port); 534 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); 535 extern int tty_port_carrier_raised(struct tty_port *port); 536 extern void tty_port_raise_dtr_rts(struct tty_port *port); 537 extern void tty_port_lower_dtr_rts(struct tty_port *port); 538 extern void tty_port_hangup(struct tty_port *port); 539 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal); 540 extern void tty_port_tty_wakeup(struct tty_port *port); 541 extern int tty_port_block_til_ready(struct tty_port *port, 542 struct tty_struct *tty, struct file *filp); 543 extern int tty_port_close_start(struct tty_port *port, 544 struct tty_struct *tty, struct file *filp); 545 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty); 546 extern void tty_port_close(struct tty_port *port, 547 struct tty_struct *tty, struct file *filp); 548 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver, 549 struct tty_struct *tty); 550 extern int tty_port_open(struct tty_port *port, 551 struct tty_struct *tty, struct file *filp); 552 static inline int tty_port_users(struct tty_port *port) 553 { 554 return port->count + port->blocked_open; 555 } 556 557 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc); 558 extern int tty_unregister_ldisc(int disc); 559 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); 560 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); 561 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty); 562 extern void tty_ldisc_init(struct tty_struct *tty); 563 extern void tty_ldisc_deinit(struct tty_struct *tty); 564 extern void tty_ldisc_begin(void); 565 566 static 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 */ 581 extern struct tty_ldisc_ops tty_ldisc_N_TTY; 582 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops); 583 584 /* tty_audit.c */ 585 #ifdef CONFIG_AUDIT 586 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, 587 size_t size, unsigned icanon); 588 extern void tty_audit_exit(void); 589 extern void tty_audit_fork(struct signal_struct *sig); 590 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch); 591 extern void tty_audit_push(struct tty_struct *tty); 592 extern int tty_audit_push_current(void); 593 #else 594 static inline void tty_audit_add_data(struct tty_struct *tty, 595 unsigned char *data, size_t size, unsigned icanon) 596 { 597 } 598 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch) 599 { 600 } 601 static inline void tty_audit_exit(void) 602 { 603 } 604 static inline void tty_audit_fork(struct signal_struct *sig) 605 { 606 } 607 static inline void tty_audit_push(struct tty_struct *tty) 608 { 609 } 610 static inline int tty_audit_push_current(void) 611 { 612 return 0; 613 } 614 #endif 615 616 /* tty_ioctl.c */ 617 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, 618 unsigned int cmd, unsigned long arg); 619 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file, 620 unsigned int cmd, unsigned long arg); 621 622 /* serial.c */ 623 624 extern void serial_console_init(void); 625 626 /* pcxx.c */ 627 628 extern int pcxe_open(struct tty_struct *tty, struct file *filp); 629 630 /* vt.c */ 631 632 extern int vt_ioctl(struct tty_struct *tty, 633 unsigned int cmd, unsigned long arg); 634 635 extern 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 */ 640 extern void __lockfunc tty_lock(struct tty_struct *tty); 641 extern void __lockfunc tty_unlock(struct tty_struct *tty); 642 extern void __lockfunc tty_lock_pair(struct tty_struct *tty, 643 struct tty_struct *tty2); 644 extern 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 */ 657 static 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 693 extern void proc_tty_register_driver(struct tty_driver *); 694 extern void proc_tty_unregister_driver(struct tty_driver *); 695 #else 696 static inline void proc_tty_register_driver(struct tty_driver *d) {} 697 static inline void proc_tty_unregister_driver(struct tty_driver *d) {} 698 #endif 699 700 #endif 701