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 spinlock_t flow_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 long stopped:1, /* flow_lock */ 266 flow_stopped:1, 267 unused:BITS_PER_LONG - 2; 268 int hw_stopped; 269 unsigned long ctrl_status:8, /* ctrl_lock */ 270 packet:1, 271 unused_ctrl:BITS_PER_LONG - 9; 272 unsigned int receive_room; /* Bytes free for queue */ 273 int flow_change; 274 275 struct tty_struct *link; 276 struct fasync_struct *fasync; 277 int alt_speed; /* For magic substitution of 38400 bps */ 278 wait_queue_head_t write_wait; 279 wait_queue_head_t read_wait; 280 struct work_struct hangup_work; 281 void *disc_data; 282 void *driver_data; 283 struct list_head tty_files; 284 285 #define N_TTY_BUF_SIZE 4096 286 287 int closing; 288 unsigned char *write_buf; 289 int write_cnt; 290 /* If the tty has a pending do_SAK, queue it here - akpm */ 291 struct work_struct SAK_work; 292 struct tty_port *port; 293 }; 294 295 /* Each of a tty's open files has private_data pointing to tty_file_private */ 296 struct tty_file_private { 297 struct tty_struct *tty; 298 struct file *file; 299 struct list_head list; 300 }; 301 302 /* tty magic number */ 303 #define TTY_MAGIC 0x5401 304 305 /* 306 * These bits are used in the flags field of the tty structure. 307 * 308 * So that interrupts won't be able to mess up the queues, 309 * copy_to_cooked must be atomic with respect to itself, as must 310 * tty->write. Thus, you must use the inline functions set_bit() and 311 * clear_bit() to make things atomic. 312 */ 313 #define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */ 314 #define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */ 315 #define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */ 316 #define TTY_EXCLUSIVE 3 /* Exclusive open mode */ 317 #define TTY_DEBUG 4 /* Debugging */ 318 #define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */ 319 #define TTY_LDISC_OPEN 11 /* Line discipline is open */ 320 #define TTY_PTY_LOCK 16 /* pty private */ 321 #define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ 322 #define TTY_HUPPED 18 /* Post driver->hangup() */ 323 #define TTY_LDISC_HALTED 22 /* Line discipline is halted */ 324 325 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) 326 327 /* Values for tty->flow_change */ 328 #define TTY_THROTTLE_SAFE 1 329 #define TTY_UNTHROTTLE_SAFE 2 330 331 static inline void __tty_set_flow_change(struct tty_struct *tty, int val) 332 { 333 tty->flow_change = val; 334 } 335 336 static inline void tty_set_flow_change(struct tty_struct *tty, int val) 337 { 338 tty->flow_change = val; 339 smp_mb(); 340 } 341 342 #ifdef CONFIG_TTY 343 extern void console_init(void); 344 extern void tty_kref_put(struct tty_struct *tty); 345 extern struct pid *tty_get_pgrp(struct tty_struct *tty); 346 extern void tty_vhangup_self(void); 347 extern void disassociate_ctty(int priv); 348 extern dev_t tty_devnum(struct tty_struct *tty); 349 extern void proc_clear_tty(struct task_struct *p); 350 extern struct tty_struct *get_current_tty(void); 351 /* tty_io.c */ 352 extern int __init tty_init(void); 353 #else 354 static inline void console_init(void) 355 { } 356 static inline void tty_kref_put(struct tty_struct *tty) 357 { } 358 static inline struct pid *tty_get_pgrp(struct tty_struct *tty) 359 { return NULL; } 360 static inline void tty_vhangup_self(void) 361 { } 362 static inline void disassociate_ctty(int priv) 363 { } 364 static inline dev_t tty_devnum(struct tty_struct *tty) 365 { return 0; } 366 static inline void proc_clear_tty(struct task_struct *p) 367 { } 368 static inline struct tty_struct *get_current_tty(void) 369 { return NULL; } 370 /* tty_io.c */ 371 static inline int __init tty_init(void) 372 { return 0; } 373 #endif 374 375 extern void tty_write_flush(struct tty_struct *); 376 377 extern struct ktermios tty_std_termios; 378 379 extern int vcs_init(void); 380 381 extern struct class *tty_class; 382 383 /** 384 * tty_kref_get - get a tty reference 385 * @tty: tty device 386 * 387 * Return a new reference to a tty object. The caller must hold 388 * sufficient locks/counts to ensure that their existing reference cannot 389 * go away 390 */ 391 392 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty) 393 { 394 if (tty) 395 kref_get(&tty->kref); 396 return tty; 397 } 398 399 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, 400 const char *routine); 401 extern char *tty_name(struct tty_struct *tty, char *buf); 402 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout); 403 extern int tty_check_change(struct tty_struct *tty); 404 extern void __stop_tty(struct tty_struct *tty); 405 extern void stop_tty(struct tty_struct *tty); 406 extern void __start_tty(struct tty_struct *tty); 407 extern void start_tty(struct tty_struct *tty); 408 extern int tty_register_driver(struct tty_driver *driver); 409 extern int tty_unregister_driver(struct tty_driver *driver); 410 extern struct device *tty_register_device(struct tty_driver *driver, 411 unsigned index, struct device *dev); 412 extern struct device *tty_register_device_attr(struct tty_driver *driver, 413 unsigned index, struct device *device, 414 void *drvdata, 415 const struct attribute_group **attr_grp); 416 extern void tty_unregister_device(struct tty_driver *driver, unsigned index); 417 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp, 418 int buflen); 419 extern void tty_write_message(struct tty_struct *tty, char *msg); 420 extern int tty_send_xchar(struct tty_struct *tty, char ch); 421 extern int tty_put_char(struct tty_struct *tty, unsigned char c); 422 extern int tty_chars_in_buffer(struct tty_struct *tty); 423 extern int tty_write_room(struct tty_struct *tty); 424 extern void tty_driver_flush_buffer(struct tty_struct *tty); 425 extern void tty_throttle(struct tty_struct *tty); 426 extern void tty_unthrottle(struct tty_struct *tty); 427 extern int tty_throttle_safe(struct tty_struct *tty); 428 extern int tty_unthrottle_safe(struct tty_struct *tty); 429 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws); 430 extern void tty_driver_remove_tty(struct tty_driver *driver, 431 struct tty_struct *tty); 432 extern void tty_free_termios(struct tty_struct *tty); 433 extern int is_current_pgrp_orphaned(void); 434 extern int is_ignored(int sig); 435 extern int tty_signal(int sig, struct tty_struct *tty); 436 extern void tty_hangup(struct tty_struct *tty); 437 extern void tty_vhangup(struct tty_struct *tty); 438 extern int tty_hung_up_p(struct file *filp); 439 extern void do_SAK(struct tty_struct *tty); 440 extern void __do_SAK(struct tty_struct *tty); 441 extern void no_tty(void); 442 extern void tty_flush_to_ldisc(struct tty_struct *tty); 443 extern void tty_buffer_free_all(struct tty_port *port); 444 extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld); 445 extern void tty_buffer_init(struct tty_port *port); 446 extern speed_t tty_termios_baud_rate(struct ktermios *termios); 447 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); 448 extern void tty_termios_encode_baud_rate(struct ktermios *termios, 449 speed_t ibaud, speed_t obaud); 450 extern void tty_encode_baud_rate(struct tty_struct *tty, 451 speed_t ibaud, speed_t obaud); 452 453 /** 454 * tty_get_baud_rate - get tty bit rates 455 * @tty: tty to query 456 * 457 * Returns the baud rate as an integer for this terminal. The 458 * termios lock must be held by the caller and the terminal bit 459 * flags may be updated. 460 * 461 * Locking: none 462 */ 463 static inline speed_t tty_get_baud_rate(struct tty_struct *tty) 464 { 465 return tty_termios_baud_rate(&tty->termios); 466 } 467 468 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old); 469 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b); 470 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt); 471 472 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *); 473 extern void tty_ldisc_deref(struct tty_ldisc *); 474 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *); 475 extern void tty_ldisc_hangup(struct tty_struct *tty); 476 extern const struct file_operations tty_ldiscs_proc_fops; 477 478 extern void tty_wakeup(struct tty_struct *tty); 479 extern void tty_ldisc_flush(struct tty_struct *tty); 480 481 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 482 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 483 unsigned int cmd, unsigned long arg); 484 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); 485 extern void tty_default_fops(struct file_operations *fops); 486 extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx); 487 extern int tty_alloc_file(struct file *file); 488 extern void tty_add_file(struct tty_struct *tty, struct file *file); 489 extern void tty_free_file(struct file *file); 490 extern void free_tty_struct(struct tty_struct *tty); 491 extern void deinitialize_tty_struct(struct tty_struct *tty); 492 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); 493 extern int tty_release(struct inode *inode, struct file *filp); 494 extern int tty_init_termios(struct tty_struct *tty); 495 extern int tty_standard_install(struct tty_driver *driver, 496 struct tty_struct *tty); 497 498 extern struct mutex tty_mutex; 499 extern spinlock_t tty_files_lock; 500 501 #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) 502 503 extern void tty_port_init(struct tty_port *port); 504 extern void tty_port_link_device(struct tty_port *port, 505 struct tty_driver *driver, unsigned index); 506 extern struct device *tty_port_register_device(struct tty_port *port, 507 struct tty_driver *driver, unsigned index, 508 struct device *device); 509 extern struct device *tty_port_register_device_attr(struct tty_port *port, 510 struct tty_driver *driver, unsigned index, 511 struct device *device, void *drvdata, 512 const struct attribute_group **attr_grp); 513 extern int tty_port_alloc_xmit_buf(struct tty_port *port); 514 extern void tty_port_free_xmit_buf(struct tty_port *port); 515 extern void tty_port_destroy(struct tty_port *port); 516 extern void tty_port_put(struct tty_port *port); 517 518 static inline struct tty_port *tty_port_get(struct tty_port *port) 519 { 520 if (port && kref_get_unless_zero(&port->kref)) 521 return port; 522 return NULL; 523 } 524 525 /* If the cts flow control is enabled, return true. */ 526 static inline bool tty_port_cts_enabled(struct tty_port *port) 527 { 528 return port->flags & ASYNC_CTS_FLOW; 529 } 530 531 extern struct tty_struct *tty_port_tty_get(struct tty_port *port); 532 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); 533 extern int tty_port_carrier_raised(struct tty_port *port); 534 extern void tty_port_raise_dtr_rts(struct tty_port *port); 535 extern void tty_port_lower_dtr_rts(struct tty_port *port); 536 extern void tty_port_hangup(struct tty_port *port); 537 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal); 538 extern void tty_port_tty_wakeup(struct tty_port *port); 539 extern int tty_port_block_til_ready(struct tty_port *port, 540 struct tty_struct *tty, struct file *filp); 541 extern int tty_port_close_start(struct tty_port *port, 542 struct tty_struct *tty, struct file *filp); 543 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty); 544 extern void tty_port_close(struct tty_port *port, 545 struct tty_struct *tty, struct file *filp); 546 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver, 547 struct tty_struct *tty); 548 extern int tty_port_open(struct tty_port *port, 549 struct tty_struct *tty, struct file *filp); 550 static inline int tty_port_users(struct tty_port *port) 551 { 552 return port->count + port->blocked_open; 553 } 554 555 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc); 556 extern int tty_unregister_ldisc(int disc); 557 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); 558 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); 559 extern void tty_ldisc_release(struct tty_struct *tty); 560 extern void tty_ldisc_init(struct tty_struct *tty); 561 extern void tty_ldisc_deinit(struct tty_struct *tty); 562 extern void tty_ldisc_begin(void); 563 564 static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p, 565 char *f, int count) 566 { 567 if (ld->ops->receive_buf2) 568 count = ld->ops->receive_buf2(ld->tty, p, f, count); 569 else { 570 count = min_t(int, count, ld->tty->receive_room); 571 if (count) 572 ld->ops->receive_buf(ld->tty, p, f, count); 573 } 574 return count; 575 } 576 577 578 /* n_tty.c */ 579 extern struct tty_ldisc_ops tty_ldisc_N_TTY; 580 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops); 581 582 /* tty_audit.c */ 583 #ifdef CONFIG_AUDIT 584 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, 585 size_t size, unsigned icanon); 586 extern void tty_audit_exit(void); 587 extern void tty_audit_fork(struct signal_struct *sig); 588 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch); 589 extern void tty_audit_push(struct tty_struct *tty); 590 extern int tty_audit_push_current(void); 591 #else 592 static inline void tty_audit_add_data(struct tty_struct *tty, 593 unsigned char *data, size_t size, unsigned icanon) 594 { 595 } 596 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch) 597 { 598 } 599 static inline void tty_audit_exit(void) 600 { 601 } 602 static inline void tty_audit_fork(struct signal_struct *sig) 603 { 604 } 605 static inline void tty_audit_push(struct tty_struct *tty) 606 { 607 } 608 static inline int tty_audit_push_current(void) 609 { 610 return 0; 611 } 612 #endif 613 614 /* tty_ioctl.c */ 615 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, 616 unsigned int cmd, unsigned long arg); 617 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file, 618 unsigned int cmd, unsigned long arg); 619 620 /* vt.c */ 621 622 extern int vt_ioctl(struct tty_struct *tty, 623 unsigned int cmd, unsigned long arg); 624 625 extern long vt_compat_ioctl(struct tty_struct *tty, 626 unsigned int cmd, unsigned long arg); 627 628 /* tty_mutex.c */ 629 /* functions for preparation of BKL removal */ 630 extern void __lockfunc tty_lock(struct tty_struct *tty); 631 extern void __lockfunc tty_unlock(struct tty_struct *tty); 632 extern void __lockfunc tty_lock_slave(struct tty_struct *tty); 633 extern void __lockfunc tty_unlock_slave(struct tty_struct *tty); 634 extern void tty_set_lock_subclass(struct tty_struct *tty); 635 /* 636 * this shall be called only from where BTM is held (like close) 637 * 638 * We need this to ensure nobody waits for us to finish while we are waiting. 639 * Without this we were encountering system stalls. 640 * 641 * This should be indeed removed with BTM removal later. 642 * 643 * Locking: BTM required. Nobody is allowed to hold port->mutex. 644 */ 645 static inline void tty_wait_until_sent_from_close(struct tty_struct *tty, 646 long timeout) 647 { 648 tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */ 649 tty_wait_until_sent(tty, timeout); 650 tty_lock(tty); 651 } 652 653 /* 654 * wait_event_interruptible_tty -- wait for a condition with the tty lock held 655 * 656 * The condition we are waiting for might take a long time to 657 * become true, or might depend on another thread taking the 658 * BTM. In either case, we need to drop the BTM to guarantee 659 * forward progress. This is a leftover from the conversion 660 * from the BKL and should eventually get removed as the BTM 661 * falls out of use. 662 * 663 * Do not use in new code. 664 */ 665 #define wait_event_interruptible_tty(tty, wq, condition) \ 666 ({ \ 667 int __ret = 0; \ 668 if (!(condition)) \ 669 __ret = __wait_event_interruptible_tty(tty, wq, \ 670 condition); \ 671 __ret; \ 672 }) 673 674 #define __wait_event_interruptible_tty(tty, wq, condition) \ 675 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ 676 tty_unlock(tty); \ 677 schedule(); \ 678 tty_lock(tty)) 679 680 #ifdef CONFIG_PROC_FS 681 extern void proc_tty_register_driver(struct tty_driver *); 682 extern void proc_tty_unregister_driver(struct tty_driver *); 683 #else 684 static inline void proc_tty_register_driver(struct tty_driver *d) {} 685 static inline void proc_tty_unregister_driver(struct tty_driver *d) {} 686 #endif 687 688 #endif 689