tty.h revision d7a68be4f265be10e24be931c257af30ca55566b
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 33struct 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 /* Data points here */ 43 unsigned long data[0]; 44}; 45 46static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs) 47{ 48 return ((unsigned char *)b->data) + ofs; 49} 50 51static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs) 52{ 53 return (char *)char_buf_ptr(b, ofs) + b->size; 54} 55 56/* 57 * We default to dicing tty buffer allocations to this many characters 58 * in order to avoid multiple page allocations. We know the size of 59 * tty_buffer itself but it must also be taken into account that the 60 * the buffer is 256 byte aligned. See tty_buffer_find for the allocation 61 * logic this must match 62 */ 63 64#define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF) 65 66 67struct tty_bufhead { 68 struct work_struct work; 69 struct mutex flush_mutex; 70 struct tty_buffer sentinel; 71 struct tty_buffer *head; /* Queue head */ 72 struct tty_buffer *tail; /* Active buffer */ 73 struct llist_head free; /* Free queue head */ 74 atomic_t memory_used; /* In-use buffers excluding free list */ 75}; 76/* 77 * When a break, frame error, or parity error happens, these codes are 78 * stuffed into the flags buffer. 79 */ 80#define TTY_NORMAL 0 81#define TTY_BREAK 1 82#define TTY_FRAME 2 83#define TTY_PARITY 3 84#define TTY_OVERRUN 4 85 86#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR]) 87#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT]) 88#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE]) 89#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL]) 90#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF]) 91#define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME]) 92#define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN]) 93#define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC]) 94#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART]) 95#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP]) 96#define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP]) 97#define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL]) 98#define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT]) 99#define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD]) 100#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE]) 101#define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT]) 102#define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2]) 103 104#define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f)) 105#define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f)) 106#define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f)) 107#define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f)) 108 109#define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK) 110#define I_BRKINT(tty) _I_FLAG((tty), BRKINT) 111#define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR) 112#define I_PARMRK(tty) _I_FLAG((tty), PARMRK) 113#define I_INPCK(tty) _I_FLAG((tty), INPCK) 114#define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP) 115#define I_INLCR(tty) _I_FLAG((tty), INLCR) 116#define I_IGNCR(tty) _I_FLAG((tty), IGNCR) 117#define I_ICRNL(tty) _I_FLAG((tty), ICRNL) 118#define I_IUCLC(tty) _I_FLAG((tty), IUCLC) 119#define I_IXON(tty) _I_FLAG((tty), IXON) 120#define I_IXANY(tty) _I_FLAG((tty), IXANY) 121#define I_IXOFF(tty) _I_FLAG((tty), IXOFF) 122#define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL) 123#define I_IUTF8(tty) _I_FLAG((tty), IUTF8) 124 125#define O_OPOST(tty) _O_FLAG((tty), OPOST) 126#define O_OLCUC(tty) _O_FLAG((tty), OLCUC) 127#define O_ONLCR(tty) _O_FLAG((tty), ONLCR) 128#define O_OCRNL(tty) _O_FLAG((tty), OCRNL) 129#define O_ONOCR(tty) _O_FLAG((tty), ONOCR) 130#define O_ONLRET(tty) _O_FLAG((tty), ONLRET) 131#define O_OFILL(tty) _O_FLAG((tty), OFILL) 132#define O_OFDEL(tty) _O_FLAG((tty), OFDEL) 133#define O_NLDLY(tty) _O_FLAG((tty), NLDLY) 134#define O_CRDLY(tty) _O_FLAG((tty), CRDLY) 135#define O_TABDLY(tty) _O_FLAG((tty), TABDLY) 136#define O_BSDLY(tty) _O_FLAG((tty), BSDLY) 137#define O_VTDLY(tty) _O_FLAG((tty), VTDLY) 138#define O_FFDLY(tty) _O_FLAG((tty), FFDLY) 139 140#define C_BAUD(tty) _C_FLAG((tty), CBAUD) 141#define C_CSIZE(tty) _C_FLAG((tty), CSIZE) 142#define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB) 143#define C_CREAD(tty) _C_FLAG((tty), CREAD) 144#define C_PARENB(tty) _C_FLAG((tty), PARENB) 145#define C_PARODD(tty) _C_FLAG((tty), PARODD) 146#define C_HUPCL(tty) _C_FLAG((tty), HUPCL) 147#define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL) 148#define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD) 149#define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS) 150 151#define L_ISIG(tty) _L_FLAG((tty), ISIG) 152#define L_ICANON(tty) _L_FLAG((tty), ICANON) 153#define L_XCASE(tty) _L_FLAG((tty), XCASE) 154#define L_ECHO(tty) _L_FLAG((tty), ECHO) 155#define L_ECHOE(tty) _L_FLAG((tty), ECHOE) 156#define L_ECHOK(tty) _L_FLAG((tty), ECHOK) 157#define L_ECHONL(tty) _L_FLAG((tty), ECHONL) 158#define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH) 159#define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP) 160#define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL) 161#define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT) 162#define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE) 163#define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO) 164#define L_PENDIN(tty) _L_FLAG((tty), PENDIN) 165#define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN) 166#define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC) 167 168struct device; 169struct signal_struct; 170 171/* 172 * Port level information. Each device keeps its own port level information 173 * so provide a common structure for those ports wanting to use common support 174 * routines. 175 * 176 * The tty port has a different lifetime to the tty so must be kept apart. 177 * In addition be careful as tty -> port mappings are valid for the life 178 * of the tty object but in many cases port -> tty mappings are valid only 179 * until a hangup so don't use the wrong path. 180 */ 181 182struct tty_port; 183 184struct tty_port_operations { 185 /* Return 1 if the carrier is raised */ 186 int (*carrier_raised)(struct tty_port *port); 187 /* Control the DTR line */ 188 void (*dtr_rts)(struct tty_port *port, int raise); 189 /* Called when the last close completes or a hangup finishes 190 IFF the port was initialized. Do not use to free resources. Called 191 under the port mutex to serialize against activate/shutdowns */ 192 void (*shutdown)(struct tty_port *port); 193 void (*drop)(struct tty_port *port); 194 /* Called under the port mutex from tty_port_open, serialized using 195 the port mutex */ 196 /* FIXME: long term getting the tty argument *out* of this would be 197 good for consoles */ 198 int (*activate)(struct tty_port *port, struct tty_struct *tty); 199 /* Called on the final put of a port */ 200 void (*destruct)(struct tty_port *port); 201}; 202 203struct tty_port { 204 struct tty_bufhead buf; /* Locked internally */ 205 struct tty_struct *tty; /* Back pointer */ 206 struct tty_struct *itty; /* internal back ptr */ 207 const struct tty_port_operations *ops; /* Port operations */ 208 spinlock_t lock; /* Lock protecting tty field */ 209 int blocked_open; /* Waiting to open */ 210 int count; /* Usage count */ 211 wait_queue_head_t open_wait; /* Open waiters */ 212 wait_queue_head_t close_wait; /* Close waiters */ 213 wait_queue_head_t delta_msr_wait; /* Modem status change */ 214 unsigned long flags; /* TTY flags ASY_*/ 215 unsigned long iflags; /* TTYP_ internal flags */ 216#define TTYP_FLUSHPENDING 2 /* Queued buffer flush pending */ 217 unsigned char console:1, /* port is a console */ 218 low_latency:1; /* direct buffer flush */ 219 struct mutex mutex; /* Locking */ 220 struct mutex buf_mutex; /* Buffer alloc lock */ 221 unsigned char *xmit_buf; /* Optional buffer */ 222 unsigned int close_delay; /* Close port delay */ 223 unsigned int closing_wait; /* Delay for output */ 224 int drain_delay; /* Set to zero if no pure time 225 based drain is needed else 226 set to size of fifo */ 227 struct kref kref; /* Ref counter */ 228}; 229 230/* 231 * Where all of the state associated with a tty is kept while the tty 232 * is open. Since the termios state should be kept even if the tty 233 * has been closed --- for things like the baud rate, etc --- it is 234 * not stored here, but rather a pointer to the real state is stored 235 * here. Possible the winsize structure should have the same 236 * treatment, but (1) the default 80x24 is usually right and (2) it's 237 * most often used by a windowing system, which will set the correct 238 * size each time the window is created or resized anyway. 239 * - TYT, 9/14/92 240 */ 241 242struct tty_operations; 243 244struct tty_struct { 245 int magic; 246 struct kref kref; 247 struct device *dev; 248 struct tty_driver *driver; 249 const struct tty_operations *ops; 250 int index; 251 252 /* Protects ldisc changes: Lock tty not pty */ 253 struct ld_semaphore ldisc_sem; 254 struct tty_ldisc *ldisc; 255 256 struct mutex atomic_write_lock; 257 struct mutex legacy_mutex; 258 struct mutex throttle_mutex; 259 struct rw_semaphore termios_rwsem; 260 spinlock_t ctrl_lock; 261 /* Termios values are protected by the termios rwsem */ 262 struct ktermios termios, termios_locked; 263 struct termiox *termiox; /* May be NULL for unsupported */ 264 char name[64]; 265 struct pid *pgrp; /* Protected by ctrl lock */ 266 struct pid *session; 267 unsigned long flags; 268 int count; 269 struct winsize winsize; /* termios rwsem */ 270 unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1; 271 unsigned char ctrl_status; /* ctrl_lock */ 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 unsigned char closing:1; 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 */ 296struct 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_PUSH 6 /* n_tty private */ 320#define TTY_CLOSING 7 /* ->close() in progress */ 321#define TTY_LDISC_OPEN 11 /* Line discipline is open */ 322#define TTY_PTY_LOCK 16 /* pty private */ 323#define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ 324#define TTY_HUPPED 18 /* Post driver->hangup() */ 325#define TTY_HUPPING 21 /* ->hangup() in progress */ 326#define TTY_LDISC_HALTED 22 /* Line discipline is halted */ 327 328#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) 329 330/* Values for tty->flow_change */ 331#define TTY_THROTTLE_SAFE 1 332#define TTY_UNTHROTTLE_SAFE 2 333 334static inline void __tty_set_flow_change(struct tty_struct *tty, int val) 335{ 336 tty->flow_change = val; 337} 338 339static inline void tty_set_flow_change(struct tty_struct *tty, int val) 340{ 341 tty->flow_change = val; 342 smp_mb(); 343} 344 345#ifdef CONFIG_TTY 346extern void console_init(void); 347extern void tty_kref_put(struct tty_struct *tty); 348extern struct pid *tty_get_pgrp(struct tty_struct *tty); 349extern void tty_vhangup_self(void); 350extern void disassociate_ctty(int priv); 351extern dev_t tty_devnum(struct tty_struct *tty); 352extern void proc_clear_tty(struct task_struct *p); 353extern struct tty_struct *get_current_tty(void); 354/* tty_io.c */ 355extern int __init tty_init(void); 356#else 357static inline void console_init(void) 358{ } 359static inline void tty_kref_put(struct tty_struct *tty) 360{ } 361static inline struct pid *tty_get_pgrp(struct tty_struct *tty) 362{ return NULL; } 363static inline void tty_vhangup_self(void) 364{ } 365static inline void disassociate_ctty(int priv) 366{ } 367static inline dev_t tty_devnum(struct tty_struct *tty) 368{ return 0; } 369static inline void proc_clear_tty(struct task_struct *p) 370{ } 371static inline struct tty_struct *get_current_tty(void) 372{ return NULL; } 373/* tty_io.c */ 374static inline int __init tty_init(void) 375{ return 0; } 376#endif 377 378extern void tty_write_flush(struct tty_struct *); 379 380extern struct ktermios tty_std_termios; 381 382extern int vcs_init(void); 383 384extern struct class *tty_class; 385 386/** 387 * tty_kref_get - get a tty reference 388 * @tty: tty device 389 * 390 * Return a new reference to a tty object. The caller must hold 391 * sufficient locks/counts to ensure that their existing reference cannot 392 * go away 393 */ 394 395static inline struct tty_struct *tty_kref_get(struct tty_struct *tty) 396{ 397 if (tty) 398 kref_get(&tty->kref); 399 return tty; 400} 401 402extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, 403 const char *routine); 404extern char *tty_name(struct tty_struct *tty, char *buf); 405extern void tty_wait_until_sent(struct tty_struct *tty, long timeout); 406extern int tty_check_change(struct tty_struct *tty); 407extern void stop_tty(struct tty_struct *tty); 408extern void start_tty(struct tty_struct *tty); 409extern int tty_register_driver(struct tty_driver *driver); 410extern int tty_unregister_driver(struct tty_driver *driver); 411extern struct device *tty_register_device(struct tty_driver *driver, 412 unsigned index, struct device *dev); 413extern struct device *tty_register_device_attr(struct tty_driver *driver, 414 unsigned index, struct device *device, 415 void *drvdata, 416 const struct attribute_group **attr_grp); 417extern void tty_unregister_device(struct tty_driver *driver, unsigned index); 418extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp, 419 int buflen); 420extern void tty_write_message(struct tty_struct *tty, char *msg); 421extern int tty_put_char(struct tty_struct *tty, unsigned char c); 422extern int tty_chars_in_buffer(struct tty_struct *tty); 423extern int tty_write_room(struct tty_struct *tty); 424extern void tty_driver_flush_buffer(struct tty_struct *tty); 425extern void tty_throttle(struct tty_struct *tty); 426extern void tty_unthrottle(struct tty_struct *tty); 427extern int tty_throttle_safe(struct tty_struct *tty); 428extern int tty_unthrottle_safe(struct tty_struct *tty); 429extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws); 430extern void tty_driver_remove_tty(struct tty_driver *driver, 431 struct tty_struct *tty); 432extern void tty_free_termios(struct tty_struct *tty); 433extern int is_current_pgrp_orphaned(void); 434extern int is_ignored(int sig); 435extern int tty_signal(int sig, struct tty_struct *tty); 436extern void tty_hangup(struct tty_struct *tty); 437extern void tty_vhangup(struct tty_struct *tty); 438extern void tty_vhangup_locked(struct tty_struct *tty); 439extern void tty_unhangup(struct file *filp); 440extern int tty_hung_up_p(struct file *filp); 441extern void do_SAK(struct tty_struct *tty); 442extern void __do_SAK(struct tty_struct *tty); 443extern void no_tty(void); 444extern void tty_flush_to_ldisc(struct tty_struct *tty); 445extern void tty_buffer_free_all(struct tty_port *port); 446extern void tty_buffer_flush(struct tty_struct *tty); 447extern void tty_buffer_init(struct tty_port *port); 448extern speed_t tty_termios_baud_rate(struct ktermios *termios); 449extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); 450extern void tty_termios_encode_baud_rate(struct ktermios *termios, 451 speed_t ibaud, speed_t obaud); 452extern void tty_encode_baud_rate(struct tty_struct *tty, 453 speed_t ibaud, speed_t obaud); 454 455/** 456 * tty_get_baud_rate - get tty bit rates 457 * @tty: tty to query 458 * 459 * Returns the baud rate as an integer for this terminal. The 460 * termios lock must be held by the caller and the terminal bit 461 * flags may be updated. 462 * 463 * Locking: none 464 */ 465static inline speed_t tty_get_baud_rate(struct tty_struct *tty) 466{ 467 return tty_termios_baud_rate(&tty->termios); 468} 469 470extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old); 471extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b); 472extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt); 473 474extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *); 475extern void tty_ldisc_deref(struct tty_ldisc *); 476extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *); 477extern void tty_ldisc_hangup(struct tty_struct *tty); 478extern const struct file_operations tty_ldiscs_proc_fops; 479 480extern void tty_wakeup(struct tty_struct *tty); 481extern void tty_ldisc_flush(struct tty_struct *tty); 482 483extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 484extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 485 unsigned int cmd, unsigned long arg); 486extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); 487extern void tty_default_fops(struct file_operations *fops); 488extern struct tty_struct *alloc_tty_struct(void); 489extern int tty_alloc_file(struct file *file); 490extern void tty_add_file(struct tty_struct *tty, struct file *file); 491extern void tty_free_file(struct file *file); 492extern void free_tty_struct(struct tty_struct *tty); 493extern void initialize_tty_struct(struct tty_struct *tty, 494 struct tty_driver *driver, int idx); 495extern void deinitialize_tty_struct(struct tty_struct *tty); 496extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); 497extern int tty_release(struct inode *inode, struct file *filp); 498extern int tty_init_termios(struct tty_struct *tty); 499extern int tty_standard_install(struct tty_driver *driver, 500 struct tty_struct *tty); 501 502extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty); 503extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty); 504 505extern struct mutex tty_mutex; 506extern spinlock_t tty_files_lock; 507 508extern void tty_write_unlock(struct tty_struct *tty); 509extern int tty_write_lock(struct tty_struct *tty, int ndelay); 510#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) 511 512extern void tty_port_init(struct tty_port *port); 513extern void tty_port_link_device(struct tty_port *port, 514 struct tty_driver *driver, unsigned index); 515extern struct device *tty_port_register_device(struct tty_port *port, 516 struct tty_driver *driver, unsigned index, 517 struct device *device); 518extern struct device *tty_port_register_device_attr(struct tty_port *port, 519 struct tty_driver *driver, unsigned index, 520 struct device *device, void *drvdata, 521 const struct attribute_group **attr_grp); 522extern int tty_port_alloc_xmit_buf(struct tty_port *port); 523extern void tty_port_free_xmit_buf(struct tty_port *port); 524extern void tty_port_destroy(struct tty_port *port); 525extern void tty_port_put(struct tty_port *port); 526 527static inline struct tty_port *tty_port_get(struct tty_port *port) 528{ 529 if (port) 530 kref_get(&port->kref); 531 return port; 532} 533 534/* If the cts flow control is enabled, return true. */ 535static inline bool tty_port_cts_enabled(struct tty_port *port) 536{ 537 return port->flags & ASYNC_CTS_FLOW; 538} 539 540extern struct tty_struct *tty_port_tty_get(struct tty_port *port); 541extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); 542extern int tty_port_carrier_raised(struct tty_port *port); 543extern void tty_port_raise_dtr_rts(struct tty_port *port); 544extern void tty_port_lower_dtr_rts(struct tty_port *port); 545extern void tty_port_hangup(struct tty_port *port); 546extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal); 547extern void tty_port_tty_wakeup(struct tty_port *port); 548extern int tty_port_block_til_ready(struct tty_port *port, 549 struct tty_struct *tty, struct file *filp); 550extern int tty_port_close_start(struct tty_port *port, 551 struct tty_struct *tty, struct file *filp); 552extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty); 553extern void tty_port_close(struct tty_port *port, 554 struct tty_struct *tty, struct file *filp); 555extern int tty_port_install(struct tty_port *port, struct tty_driver *driver, 556 struct tty_struct *tty); 557extern int tty_port_open(struct tty_port *port, 558 struct tty_struct *tty, struct file *filp); 559static inline int tty_port_users(struct tty_port *port) 560{ 561 return port->count + port->blocked_open; 562} 563 564extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc); 565extern int tty_unregister_ldisc(int disc); 566extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); 567extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); 568extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty); 569extern void tty_ldisc_init(struct tty_struct *tty); 570extern void tty_ldisc_deinit(struct tty_struct *tty); 571extern void tty_ldisc_begin(void); 572 573static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p, 574 char *f, int count) 575{ 576 if (ld->ops->receive_buf2) 577 count = ld->ops->receive_buf2(ld->tty, p, f, count); 578 else { 579 count = min_t(int, count, ld->tty->receive_room); 580 if (count) 581 ld->ops->receive_buf(ld->tty, p, f, count); 582 } 583 return count; 584} 585 586 587/* n_tty.c */ 588extern struct tty_ldisc_ops tty_ldisc_N_TTY; 589extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops); 590 591/* tty_audit.c */ 592#ifdef CONFIG_AUDIT 593extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, 594 size_t size, unsigned icanon); 595extern void tty_audit_exit(void); 596extern void tty_audit_fork(struct signal_struct *sig); 597extern void tty_audit_tiocsti(struct tty_struct *tty, char ch); 598extern void tty_audit_push(struct tty_struct *tty); 599extern int tty_audit_push_current(void); 600#else 601static inline void tty_audit_add_data(struct tty_struct *tty, 602 unsigned char *data, size_t size, unsigned icanon) 603{ 604} 605static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch) 606{ 607} 608static inline void tty_audit_exit(void) 609{ 610} 611static inline void tty_audit_fork(struct signal_struct *sig) 612{ 613} 614static inline void tty_audit_push(struct tty_struct *tty) 615{ 616} 617static inline int tty_audit_push_current(void) 618{ 619 return 0; 620} 621#endif 622 623/* tty_ioctl.c */ 624extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, 625 unsigned int cmd, unsigned long arg); 626extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file, 627 unsigned int cmd, unsigned long arg); 628 629/* serial.c */ 630 631extern void serial_console_init(void); 632 633/* pcxx.c */ 634 635extern int pcxe_open(struct tty_struct *tty, struct file *filp); 636 637/* vt.c */ 638 639extern int vt_ioctl(struct tty_struct *tty, 640 unsigned int cmd, unsigned long arg); 641 642extern long vt_compat_ioctl(struct tty_struct *tty, 643 unsigned int cmd, unsigned long arg); 644 645/* tty_mutex.c */ 646/* functions for preparation of BKL removal */ 647extern void __lockfunc tty_lock(struct tty_struct *tty); 648extern void __lockfunc tty_unlock(struct tty_struct *tty); 649extern void __lockfunc tty_lock_pair(struct tty_struct *tty, 650 struct tty_struct *tty2); 651extern void __lockfunc tty_unlock_pair(struct tty_struct *tty, 652 struct tty_struct *tty2); 653 654/* 655 * this shall be called only from where BTM is held (like close) 656 * 657 * We need this to ensure nobody waits for us to finish while we are waiting. 658 * Without this we were encountering system stalls. 659 * 660 * This should be indeed removed with BTM removal later. 661 * 662 * Locking: BTM required. Nobody is allowed to hold port->mutex. 663 */ 664static inline void tty_wait_until_sent_from_close(struct tty_struct *tty, 665 long timeout) 666{ 667 tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */ 668 tty_wait_until_sent(tty, timeout); 669 tty_lock(tty); 670} 671 672/* 673 * wait_event_interruptible_tty -- wait for a condition with the tty lock held 674 * 675 * The condition we are waiting for might take a long time to 676 * become true, or might depend on another thread taking the 677 * BTM. In either case, we need to drop the BTM to guarantee 678 * forward progress. This is a leftover from the conversion 679 * from the BKL and should eventually get removed as the BTM 680 * falls out of use. 681 * 682 * Do not use in new code. 683 */ 684#define wait_event_interruptible_tty(tty, wq, condition) \ 685({ \ 686 int __ret = 0; \ 687 if (!(condition)) { \ 688 __wait_event_interruptible_tty(tty, wq, condition, __ret); \ 689 } \ 690 __ret; \ 691}) 692 693#define __wait_event_interruptible_tty(tty, wq, condition, ret) \ 694do { \ 695 DEFINE_WAIT(__wait); \ 696 \ 697 for (;;) { \ 698 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ 699 if (condition) \ 700 break; \ 701 if (!signal_pending(current)) { \ 702 tty_unlock(tty); \ 703 schedule(); \ 704 tty_lock(tty); \ 705 continue; \ 706 } \ 707 ret = -ERESTARTSYS; \ 708 break; \ 709 } \ 710 finish_wait(&wq, &__wait); \ 711} while (0) 712 713#ifdef CONFIG_PROC_FS 714extern void proc_tty_register_driver(struct tty_driver *); 715extern void proc_tty_unregister_driver(struct tty_driver *); 716#else 717static inline void proc_tty_register_driver(struct tty_driver *d) {} 718static inline void proc_tty_unregister_driver(struct tty_driver *d) {} 719#endif 720 721#endif 722