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 atomic_t priority; 65 struct tty_buffer sentinel; 66 struct llist_head free; /* Free queue head */ 67 atomic_t mem_used; /* In-use buffers excluding free list */ 68 int mem_limit; 69 struct tty_buffer *tail; /* Active buffer */ 70 }; 71 /* 72 * When a break, frame error, or parity error happens, these codes are 73 * stuffed into the flags buffer. 74 */ 75 #define TTY_NORMAL 0 76 #define TTY_BREAK 1 77 #define TTY_FRAME 2 78 #define TTY_PARITY 3 79 #define TTY_OVERRUN 4 80 81 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR]) 82 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT]) 83 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE]) 84 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL]) 85 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF]) 86 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME]) 87 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN]) 88 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC]) 89 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART]) 90 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP]) 91 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP]) 92 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL]) 93 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT]) 94 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD]) 95 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE]) 96 #define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT]) 97 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2]) 98 99 #define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f)) 100 #define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f)) 101 #define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f)) 102 #define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f)) 103 104 #define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK) 105 #define I_BRKINT(tty) _I_FLAG((tty), BRKINT) 106 #define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR) 107 #define I_PARMRK(tty) _I_FLAG((tty), PARMRK) 108 #define I_INPCK(tty) _I_FLAG((tty), INPCK) 109 #define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP) 110 #define I_INLCR(tty) _I_FLAG((tty), INLCR) 111 #define I_IGNCR(tty) _I_FLAG((tty), IGNCR) 112 #define I_ICRNL(tty) _I_FLAG((tty), ICRNL) 113 #define I_IUCLC(tty) _I_FLAG((tty), IUCLC) 114 #define I_IXON(tty) _I_FLAG((tty), IXON) 115 #define I_IXANY(tty) _I_FLAG((tty), IXANY) 116 #define I_IXOFF(tty) _I_FLAG((tty), IXOFF) 117 #define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL) 118 #define I_IUTF8(tty) _I_FLAG((tty), IUTF8) 119 120 #define O_OPOST(tty) _O_FLAG((tty), OPOST) 121 #define O_OLCUC(tty) _O_FLAG((tty), OLCUC) 122 #define O_ONLCR(tty) _O_FLAG((tty), ONLCR) 123 #define O_OCRNL(tty) _O_FLAG((tty), OCRNL) 124 #define O_ONOCR(tty) _O_FLAG((tty), ONOCR) 125 #define O_ONLRET(tty) _O_FLAG((tty), ONLRET) 126 #define O_OFILL(tty) _O_FLAG((tty), OFILL) 127 #define O_OFDEL(tty) _O_FLAG((tty), OFDEL) 128 #define O_NLDLY(tty) _O_FLAG((tty), NLDLY) 129 #define O_CRDLY(tty) _O_FLAG((tty), CRDLY) 130 #define O_TABDLY(tty) _O_FLAG((tty), TABDLY) 131 #define O_BSDLY(tty) _O_FLAG((tty), BSDLY) 132 #define O_VTDLY(tty) _O_FLAG((tty), VTDLY) 133 #define O_FFDLY(tty) _O_FLAG((tty), FFDLY) 134 135 #define C_BAUD(tty) _C_FLAG((tty), CBAUD) 136 #define C_CSIZE(tty) _C_FLAG((tty), CSIZE) 137 #define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB) 138 #define C_CREAD(tty) _C_FLAG((tty), CREAD) 139 #define C_PARENB(tty) _C_FLAG((tty), PARENB) 140 #define C_PARODD(tty) _C_FLAG((tty), PARODD) 141 #define C_HUPCL(tty) _C_FLAG((tty), HUPCL) 142 #define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL) 143 #define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD) 144 #define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS) 145 #define C_CMSPAR(tty) _C_FLAG((tty), CMSPAR) 146 147 #define L_ISIG(tty) _L_FLAG((tty), ISIG) 148 #define L_ICANON(tty) _L_FLAG((tty), ICANON) 149 #define L_XCASE(tty) _L_FLAG((tty), XCASE) 150 #define L_ECHO(tty) _L_FLAG((tty), ECHO) 151 #define L_ECHOE(tty) _L_FLAG((tty), ECHOE) 152 #define L_ECHOK(tty) _L_FLAG((tty), ECHOK) 153 #define L_ECHONL(tty) _L_FLAG((tty), ECHONL) 154 #define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH) 155 #define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP) 156 #define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL) 157 #define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT) 158 #define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE) 159 #define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO) 160 #define L_PENDIN(tty) _L_FLAG((tty), PENDIN) 161 #define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN) 162 #define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC) 163 164 struct device; 165 struct signal_struct; 166 167 /* 168 * Port level information. Each device keeps its own port level information 169 * so provide a common structure for those ports wanting to use common support 170 * routines. 171 * 172 * The tty port has a different lifetime to the tty so must be kept apart. 173 * In addition be careful as tty -> port mappings are valid for the life 174 * of the tty object but in many cases port -> tty mappings are valid only 175 * until a hangup so don't use the wrong path. 176 */ 177 178 struct tty_port; 179 180 struct tty_port_operations { 181 /* Return 1 if the carrier is raised */ 182 int (*carrier_raised)(struct tty_port *port); 183 /* Control the DTR line */ 184 void (*dtr_rts)(struct tty_port *port, int raise); 185 /* Called when the last close completes or a hangup finishes 186 IFF the port was initialized. Do not use to free resources. Called 187 under the port mutex to serialize against activate/shutdowns */ 188 void (*shutdown)(struct tty_port *port); 189 /* Called under the port mutex from tty_port_open, serialized using 190 the port mutex */ 191 /* FIXME: long term getting the tty argument *out* of this would be 192 good for consoles */ 193 int (*activate)(struct tty_port *port, struct tty_struct *tty); 194 /* Called on the final put of a port */ 195 void (*destruct)(struct tty_port *port); 196 }; 197 198 struct tty_port { 199 struct tty_bufhead buf; /* Locked internally */ 200 struct tty_struct *tty; /* Back pointer */ 201 struct tty_struct *itty; /* internal back ptr */ 202 const struct tty_port_operations *ops; /* Port operations */ 203 spinlock_t lock; /* Lock protecting tty field */ 204 int blocked_open; /* Waiting to open */ 205 int count; /* Usage count */ 206 wait_queue_head_t open_wait; /* Open waiters */ 207 wait_queue_head_t close_wait; /* Close waiters */ 208 wait_queue_head_t delta_msr_wait; /* Modem status change */ 209 unsigned long flags; /* TTY flags ASY_*/ 210 unsigned char console:1, /* port is a console */ 211 low_latency:1; /* optional: tune for latency */ 212 struct mutex mutex; /* Locking */ 213 struct mutex buf_mutex; /* Buffer alloc lock */ 214 unsigned char *xmit_buf; /* Optional buffer */ 215 unsigned int close_delay; /* Close port delay */ 216 unsigned int closing_wait; /* Delay for output */ 217 int drain_delay; /* Set to zero if no pure time 218 based drain is needed else 219 set to size of fifo */ 220 struct kref kref; /* Ref counter */ 221 }; 222 223 /* 224 * Where all of the state associated with a tty is kept while the tty 225 * is open. Since the termios state should be kept even if the tty 226 * has been closed --- for things like the baud rate, etc --- it is 227 * not stored here, but rather a pointer to the real state is stored 228 * here. Possible the winsize structure should have the same 229 * treatment, but (1) the default 80x24 is usually right and (2) it's 230 * most often used by a windowing system, which will set the correct 231 * size each time the window is created or resized anyway. 232 * - TYT, 9/14/92 233 */ 234 235 struct tty_operations; 236 237 struct tty_struct { 238 int magic; 239 struct kref kref; 240 struct device *dev; 241 struct tty_driver *driver; 242 const struct tty_operations *ops; 243 int index; 244 245 /* Protects ldisc changes: Lock tty not pty */ 246 struct ld_semaphore ldisc_sem; 247 struct tty_ldisc *ldisc; 248 249 struct mutex atomic_write_lock; 250 struct mutex legacy_mutex; 251 struct mutex throttle_mutex; 252 struct rw_semaphore termios_rwsem; 253 struct mutex winsize_mutex; 254 spinlock_t ctrl_lock; 255 /* Termios values are protected by the termios rwsem */ 256 struct ktermios termios, termios_locked; 257 struct termiox *termiox; /* May be NULL for unsupported */ 258 char name[64]; 259 struct pid *pgrp; /* Protected by ctrl lock */ 260 struct pid *session; 261 unsigned long flags; 262 int count; 263 struct winsize winsize; /* winsize_mutex */ 264 unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1; 265 unsigned char ctrl_status; /* ctrl_lock */ 266 unsigned int receive_room; /* Bytes free for queue */ 267 int flow_change; 268 269 struct tty_struct *link; 270 struct fasync_struct *fasync; 271 int alt_speed; /* For magic substitution of 38400 bps */ 272 wait_queue_head_t write_wait; 273 wait_queue_head_t read_wait; 274 struct work_struct hangup_work; 275 void *disc_data; 276 void *driver_data; 277 struct list_head tty_files; 278 279 #define N_TTY_BUF_SIZE 4096 280 281 unsigned char closing:1; 282 unsigned char *write_buf; 283 int write_cnt; 284 /* If the tty has a pending do_SAK, queue it here - akpm */ 285 struct work_struct SAK_work; 286 struct tty_port *port; 287 }; 288 289 /* Each of a tty's open files has private_data pointing to tty_file_private */ 290 struct tty_file_private { 291 struct tty_struct *tty; 292 struct file *file; 293 struct list_head list; 294 }; 295 296 /* tty magic number */ 297 #define TTY_MAGIC 0x5401 298 299 /* 300 * These bits are used in the flags field of the tty structure. 301 * 302 * So that interrupts won't be able to mess up the queues, 303 * copy_to_cooked must be atomic with respect to itself, as must 304 * tty->write. Thus, you must use the inline functions set_bit() and 305 * clear_bit() to make things atomic. 306 */ 307 #define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */ 308 #define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */ 309 #define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */ 310 #define TTY_EXCLUSIVE 3 /* Exclusive open mode */ 311 #define TTY_DEBUG 4 /* Debugging */ 312 #define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */ 313 #define TTY_CLOSING 7 /* ->close() in progress */ 314 #define TTY_LDISC_OPEN 11 /* Line discipline is open */ 315 #define TTY_PTY_LOCK 16 /* pty private */ 316 #define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ 317 #define TTY_HUPPED 18 /* Post driver->hangup() */ 318 #define TTY_HUPPING 21 /* ->hangup() in progress */ 319 #define TTY_LDISC_HALTED 22 /* Line discipline is halted */ 320 321 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) 322 323 /* Values for tty->flow_change */ 324 #define TTY_THROTTLE_SAFE 1 325 #define TTY_UNTHROTTLE_SAFE 2 326 327 static inline void __tty_set_flow_change(struct tty_struct *tty, int val) 328 { 329 tty->flow_change = val; 330 } 331 332 static inline void tty_set_flow_change(struct tty_struct *tty, int val) 333 { 334 tty->flow_change = val; 335 smp_mb(); 336 } 337 338 #ifdef CONFIG_TTY 339 extern void console_init(void); 340 extern void tty_kref_put(struct tty_struct *tty); 341 extern struct pid *tty_get_pgrp(struct tty_struct *tty); 342 extern void tty_vhangup_self(void); 343 extern void disassociate_ctty(int priv); 344 extern dev_t tty_devnum(struct tty_struct *tty); 345 extern void proc_clear_tty(struct task_struct *p); 346 extern struct tty_struct *get_current_tty(void); 347 /* tty_io.c */ 348 extern int __init tty_init(void); 349 #else 350 static inline void console_init(void) 351 { } 352 static inline void tty_kref_put(struct tty_struct *tty) 353 { } 354 static inline struct pid *tty_get_pgrp(struct tty_struct *tty) 355 { return NULL; } 356 static inline void tty_vhangup_self(void) 357 { } 358 static inline void disassociate_ctty(int priv) 359 { } 360 static inline dev_t tty_devnum(struct tty_struct *tty) 361 { return 0; } 362 static inline void proc_clear_tty(struct task_struct *p) 363 { } 364 static inline struct tty_struct *get_current_tty(void) 365 { return NULL; } 366 /* tty_io.c */ 367 static inline int __init tty_init(void) 368 { return 0; } 369 #endif 370 371 extern void tty_write_flush(struct tty_struct *); 372 373 extern struct ktermios tty_std_termios; 374 375 extern int vcs_init(void); 376 377 extern struct class *tty_class; 378 379 /** 380 * tty_kref_get - get a tty reference 381 * @tty: tty device 382 * 383 * Return a new reference to a tty object. The caller must hold 384 * sufficient locks/counts to ensure that their existing reference cannot 385 * go away 386 */ 387 388 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty) 389 { 390 if (tty) 391 kref_get(&tty->kref); 392 return tty; 393 } 394 395 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, 396 const char *routine); 397 extern char *tty_name(struct tty_struct *tty, char *buf); 398 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout); 399 extern int tty_check_change(struct tty_struct *tty); 400 extern void stop_tty(struct tty_struct *tty); 401 extern void start_tty(struct tty_struct *tty); 402 extern int tty_register_driver(struct tty_driver *driver); 403 extern int tty_unregister_driver(struct tty_driver *driver); 404 extern struct device *tty_register_device(struct tty_driver *driver, 405 unsigned index, struct device *dev); 406 extern struct device *tty_register_device_attr(struct tty_driver *driver, 407 unsigned index, struct device *device, 408 void *drvdata, 409 const struct attribute_group **attr_grp); 410 extern void tty_unregister_device(struct tty_driver *driver, unsigned index); 411 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp, 412 int buflen); 413 extern void tty_write_message(struct tty_struct *tty, char *msg); 414 extern int tty_put_char(struct tty_struct *tty, unsigned char c); 415 extern int tty_chars_in_buffer(struct tty_struct *tty); 416 extern int tty_write_room(struct tty_struct *tty); 417 extern void tty_driver_flush_buffer(struct tty_struct *tty); 418 extern void tty_throttle(struct tty_struct *tty); 419 extern void tty_unthrottle(struct tty_struct *tty); 420 extern int tty_throttle_safe(struct tty_struct *tty); 421 extern int tty_unthrottle_safe(struct tty_struct *tty); 422 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws); 423 extern void tty_driver_remove_tty(struct tty_driver *driver, 424 struct tty_struct *tty); 425 extern void tty_free_termios(struct tty_struct *tty); 426 extern int is_current_pgrp_orphaned(void); 427 extern int is_ignored(int sig); 428 extern int tty_signal(int sig, struct tty_struct *tty); 429 extern void tty_hangup(struct tty_struct *tty); 430 extern void tty_vhangup(struct tty_struct *tty); 431 extern void tty_unhangup(struct file *filp); 432 extern int tty_hung_up_p(struct file *filp); 433 extern void do_SAK(struct tty_struct *tty); 434 extern void __do_SAK(struct tty_struct *tty); 435 extern void no_tty(void); 436 extern void tty_flush_to_ldisc(struct tty_struct *tty); 437 extern void tty_buffer_free_all(struct tty_port *port); 438 extern void tty_buffer_flush(struct tty_struct *tty); 439 extern void tty_buffer_init(struct tty_port *port); 440 extern speed_t tty_termios_baud_rate(struct ktermios *termios); 441 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); 442 extern void tty_termios_encode_baud_rate(struct ktermios *termios, 443 speed_t ibaud, speed_t obaud); 444 extern void tty_encode_baud_rate(struct tty_struct *tty, 445 speed_t ibaud, speed_t obaud); 446 447 /** 448 * tty_get_baud_rate - get tty bit rates 449 * @tty: tty to query 450 * 451 * Returns the baud rate as an integer for this terminal. The 452 * termios lock must be held by the caller and the terminal bit 453 * flags may be updated. 454 * 455 * Locking: none 456 */ 457 static inline speed_t tty_get_baud_rate(struct tty_struct *tty) 458 { 459 return tty_termios_baud_rate(&tty->termios); 460 } 461 462 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old); 463 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b); 464 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt); 465 466 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *); 467 extern void tty_ldisc_deref(struct tty_ldisc *); 468 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *); 469 extern void tty_ldisc_hangup(struct tty_struct *tty); 470 extern const struct file_operations tty_ldiscs_proc_fops; 471 472 extern void tty_wakeup(struct tty_struct *tty); 473 extern void tty_ldisc_flush(struct tty_struct *tty); 474 475 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 476 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 477 unsigned int cmd, unsigned long arg); 478 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); 479 extern void tty_default_fops(struct file_operations *fops); 480 extern struct tty_struct *alloc_tty_struct(void); 481 extern int tty_alloc_file(struct file *file); 482 extern void tty_add_file(struct tty_struct *tty, struct file *file); 483 extern void tty_free_file(struct file *file); 484 extern void free_tty_struct(struct tty_struct *tty); 485 extern void initialize_tty_struct(struct tty_struct *tty, 486 struct tty_driver *driver, int idx); 487 extern void deinitialize_tty_struct(struct tty_struct *tty); 488 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); 489 extern int tty_release(struct inode *inode, struct file *filp); 490 extern int tty_init_termios(struct tty_struct *tty); 491 extern int tty_standard_install(struct tty_driver *driver, 492 struct tty_struct *tty); 493 494 extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty); 495 extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty); 496 497 extern struct mutex tty_mutex; 498 extern spinlock_t tty_files_lock; 499 500 extern void tty_write_unlock(struct tty_struct *tty); 501 extern int tty_write_lock(struct tty_struct *tty, int ndelay); 502 #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) 503 504 extern void tty_port_init(struct tty_port *port); 505 extern void tty_port_link_device(struct tty_port *port, 506 struct tty_driver *driver, unsigned index); 507 extern struct device *tty_port_register_device(struct tty_port *port, 508 struct tty_driver *driver, unsigned index, 509 struct device *device); 510 extern struct device *tty_port_register_device_attr(struct tty_port *port, 511 struct tty_driver *driver, unsigned index, 512 struct device *device, void *drvdata, 513 const struct attribute_group **attr_grp); 514 extern int tty_port_alloc_xmit_buf(struct tty_port *port); 515 extern void tty_port_free_xmit_buf(struct tty_port *port); 516 extern void tty_port_destroy(struct tty_port *port); 517 extern void tty_port_put(struct tty_port *port); 518 519 static inline struct tty_port *tty_port_get(struct tty_port *port) 520 { 521 if (port && kref_get_unless_zero(&port->kref)) 522 return port; 523 return NULL; 524 } 525 526 /* If the cts flow control is enabled, return true. */ 527 static inline bool tty_port_cts_enabled(struct tty_port *port) 528 { 529 return port->flags & ASYNC_CTS_FLOW; 530 } 531 532 extern struct tty_struct *tty_port_tty_get(struct tty_port *port); 533 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); 534 extern int tty_port_carrier_raised(struct tty_port *port); 535 extern void tty_port_raise_dtr_rts(struct tty_port *port); 536 extern void tty_port_lower_dtr_rts(struct tty_port *port); 537 extern void tty_port_hangup(struct tty_port *port); 538 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal); 539 extern void tty_port_tty_wakeup(struct tty_port *port); 540 extern int tty_port_block_til_ready(struct tty_port *port, 541 struct tty_struct *tty, struct file *filp); 542 extern int tty_port_close_start(struct tty_port *port, 543 struct tty_struct *tty, struct file *filp); 544 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty); 545 extern void tty_port_close(struct tty_port *port, 546 struct tty_struct *tty, struct file *filp); 547 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver, 548 struct tty_struct *tty); 549 extern int tty_port_open(struct tty_port *port, 550 struct tty_struct *tty, struct file *filp); 551 static inline int tty_port_users(struct tty_port *port) 552 { 553 return port->count + port->blocked_open; 554 } 555 556 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc); 557 extern int tty_unregister_ldisc(int disc); 558 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); 559 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); 560 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty); 561 extern void tty_ldisc_init(struct tty_struct *tty); 562 extern void tty_ldisc_deinit(struct tty_struct *tty); 563 extern void tty_ldisc_begin(void); 564 565 static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p, 566 char *f, int count) 567 { 568 if (ld->ops->receive_buf2) 569 count = ld->ops->receive_buf2(ld->tty, p, f, count); 570 else { 571 count = min_t(int, count, ld->tty->receive_room); 572 if (count) 573 ld->ops->receive_buf(ld->tty, p, f, count); 574 } 575 return count; 576 } 577 578 579 /* n_tty.c */ 580 extern struct tty_ldisc_ops tty_ldisc_N_TTY; 581 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops); 582 583 /* tty_audit.c */ 584 #ifdef CONFIG_AUDIT 585 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, 586 size_t size, unsigned icanon); 587 extern void tty_audit_exit(void); 588 extern void tty_audit_fork(struct signal_struct *sig); 589 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch); 590 extern void tty_audit_push(struct tty_struct *tty); 591 extern int tty_audit_push_current(void); 592 #else 593 static inline void tty_audit_add_data(struct tty_struct *tty, 594 unsigned char *data, size_t size, unsigned icanon) 595 { 596 } 597 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch) 598 { 599 } 600 static inline void tty_audit_exit(void) 601 { 602 } 603 static inline void tty_audit_fork(struct signal_struct *sig) 604 { 605 } 606 static inline void tty_audit_push(struct tty_struct *tty) 607 { 608 } 609 static inline int tty_audit_push_current(void) 610 { 611 return 0; 612 } 613 #endif 614 615 /* tty_ioctl.c */ 616 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, 617 unsigned int cmd, unsigned long arg); 618 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file, 619 unsigned int cmd, unsigned long arg); 620 621 /* serial.c */ 622 623 extern void serial_console_init(void); 624 625 /* pcxx.c */ 626 627 extern int pcxe_open(struct tty_struct *tty, struct file *filp); 628 629 /* vt.c */ 630 631 extern int vt_ioctl(struct tty_struct *tty, 632 unsigned int cmd, unsigned long arg); 633 634 extern long vt_compat_ioctl(struct tty_struct *tty, 635 unsigned int cmd, unsigned long arg); 636 637 /* tty_mutex.c */ 638 /* functions for preparation of BKL removal */ 639 extern void __lockfunc tty_lock(struct tty_struct *tty); 640 extern void __lockfunc tty_unlock(struct tty_struct *tty); 641 extern void __lockfunc tty_lock_pair(struct tty_struct *tty, 642 struct tty_struct *tty2); 643 extern void __lockfunc tty_unlock_pair(struct tty_struct *tty, 644 struct tty_struct *tty2); 645 646 /* 647 * this shall be called only from where BTM is held (like close) 648 * 649 * We need this to ensure nobody waits for us to finish while we are waiting. 650 * Without this we were encountering system stalls. 651 * 652 * This should be indeed removed with BTM removal later. 653 * 654 * Locking: BTM required. Nobody is allowed to hold port->mutex. 655 */ 656 static inline void tty_wait_until_sent_from_close(struct tty_struct *tty, 657 long timeout) 658 { 659 tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */ 660 tty_wait_until_sent(tty, timeout); 661 tty_lock(tty); 662 } 663 664 /* 665 * wait_event_interruptible_tty -- wait for a condition with the tty lock held 666 * 667 * The condition we are waiting for might take a long time to 668 * become true, or might depend on another thread taking the 669 * BTM. In either case, we need to drop the BTM to guarantee 670 * forward progress. This is a leftover from the conversion 671 * from the BKL and should eventually get removed as the BTM 672 * falls out of use. 673 * 674 * Do not use in new code. 675 */ 676 #define wait_event_interruptible_tty(tty, wq, condition) \ 677 ({ \ 678 int __ret = 0; \ 679 if (!(condition)) \ 680 __ret = __wait_event_interruptible_tty(tty, wq, \ 681 condition); \ 682 __ret; \ 683 }) 684 685 #define __wait_event_interruptible_tty(tty, wq, condition) \ 686 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ 687 tty_unlock(tty); \ 688 schedule(); \ 689 tty_lock(tty)) 690 691 #ifdef CONFIG_PROC_FS 692 extern void proc_tty_register_driver(struct tty_driver *); 693 extern void proc_tty_unregister_driver(struct tty_driver *); 694 #else 695 static inline void proc_tty_register_driver(struct tty_driver *d) {} 696 static inline void proc_tty_unregister_driver(struct tty_driver *d) {} 697 #endif 698 699 #endif 700