tty.h revision 809850b7a5fcc0a96d023e1171a7944c60fd5a71
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 spinlock_t lock; 70 struct tty_buffer *head; /* Queue head */ 71 struct tty_buffer *tail; /* Active buffer */ 72 struct llist_head free; /* Free queue head */ 73 int memory_used; /* Buffer space used excluding 74 free queue */ 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_FLUSHING 1 /* Flushing to ldisc in progress */ 217#define TTYP_FLUSHPENDING 2 /* Queued buffer flush pending */ 218 unsigned char console:1, /* port is a console */ 219 low_latency:1; /* direct buffer flush */ 220 struct mutex mutex; /* Locking */ 221 struct mutex buf_mutex; /* Buffer alloc lock */ 222 unsigned char *xmit_buf; /* Optional buffer */ 223 unsigned int close_delay; /* Close port delay */ 224 unsigned int closing_wait; /* Delay for output */ 225 int drain_delay; /* Set to zero if no pure time 226 based drain is needed else 227 set to size of fifo */ 228 struct kref kref; /* Ref counter */ 229}; 230 231/* 232 * Where all of the state associated with a tty is kept while the tty 233 * is open. Since the termios state should be kept even if the tty 234 * has been closed --- for things like the baud rate, etc --- it is 235 * not stored here, but rather a pointer to the real state is stored 236 * here. Possible the winsize structure should have the same 237 * treatment, but (1) the default 80x24 is usually right and (2) it's 238 * most often used by a windowing system, which will set the correct 239 * size each time the window is created or resized anyway. 240 * - TYT, 9/14/92 241 */ 242 243struct tty_operations; 244 245struct tty_struct { 246 int magic; 247 struct kref kref; 248 struct device *dev; 249 struct tty_driver *driver; 250 const struct tty_operations *ops; 251 int index; 252 253 /* Protects ldisc changes: Lock tty not pty */ 254 struct ld_semaphore ldisc_sem; 255 struct tty_ldisc *ldisc; 256 257 struct mutex atomic_write_lock; 258 struct mutex legacy_mutex; 259 struct mutex throttle_mutex; 260 struct rw_semaphore termios_rwsem; 261 spinlock_t ctrl_lock; 262 /* Termios values are protected by the termios rwsem */ 263 struct ktermios termios, termios_locked; 264 struct termiox *termiox; /* May be NULL for unsupported */ 265 char name[64]; 266 struct pid *pgrp; /* Protected by ctrl lock */ 267 struct pid *session; 268 unsigned long flags; 269 int count; 270 struct winsize winsize; /* termios rwsem */ 271 unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1; 272 unsigned char ctrl_status; /* ctrl_lock */ 273 unsigned int receive_room; /* Bytes free for queue */ 274 int flow_change; 275 276 struct tty_struct *link; 277 struct fasync_struct *fasync; 278 int alt_speed; /* For magic substitution of 38400 bps */ 279 wait_queue_head_t write_wait; 280 wait_queue_head_t read_wait; 281 struct work_struct hangup_work; 282 void *disc_data; 283 void *driver_data; 284 struct list_head tty_files; 285 286#define N_TTY_BUF_SIZE 4096 287 288 unsigned char closing:1; 289 unsigned char *write_buf; 290 int write_cnt; 291 /* If the tty has a pending do_SAK, queue it here - akpm */ 292 struct work_struct SAK_work; 293 struct tty_port *port; 294}; 295 296/* Each of a tty's open files has private_data pointing to tty_file_private */ 297struct tty_file_private { 298 struct tty_struct *tty; 299 struct file *file; 300 struct list_head list; 301}; 302 303/* tty magic number */ 304#define TTY_MAGIC 0x5401 305 306/* 307 * These bits are used in the flags field of the tty structure. 308 * 309 * So that interrupts won't be able to mess up the queues, 310 * copy_to_cooked must be atomic with respect to itself, as must 311 * tty->write. Thus, you must use the inline functions set_bit() and 312 * clear_bit() to make things atomic. 313 */ 314#define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */ 315#define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */ 316#define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */ 317#define TTY_EXCLUSIVE 3 /* Exclusive open mode */ 318#define TTY_DEBUG 4 /* Debugging */ 319#define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */ 320#define TTY_PUSH 6 /* n_tty private */ 321#define TTY_CLOSING 7 /* ->close() in progress */ 322#define TTY_LDISC_OPEN 11 /* Line discipline is open */ 323#define TTY_PTY_LOCK 16 /* pty private */ 324#define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ 325#define TTY_HUPPED 18 /* Post driver->hangup() */ 326#define TTY_HUPPING 21 /* ->hangup() in progress */ 327#define TTY_LDISC_HALTED 22 /* Line discipline is halted */ 328 329#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) 330 331/* Values for tty->flow_change */ 332#define TTY_THROTTLE_SAFE 1 333#define TTY_UNTHROTTLE_SAFE 2 334 335static inline void __tty_set_flow_change(struct tty_struct *tty, int val) 336{ 337 tty->flow_change = val; 338} 339 340static inline void tty_set_flow_change(struct tty_struct *tty, int val) 341{ 342 tty->flow_change = val; 343 smp_mb(); 344} 345 346#ifdef CONFIG_TTY 347extern void console_init(void); 348extern void tty_kref_put(struct tty_struct *tty); 349extern struct pid *tty_get_pgrp(struct tty_struct *tty); 350extern void tty_vhangup_self(void); 351extern void disassociate_ctty(int priv); 352extern dev_t tty_devnum(struct tty_struct *tty); 353extern void proc_clear_tty(struct task_struct *p); 354extern struct tty_struct *get_current_tty(void); 355/* tty_io.c */ 356extern int __init tty_init(void); 357#else 358static inline void console_init(void) 359{ } 360static inline void tty_kref_put(struct tty_struct *tty) 361{ } 362static inline struct pid *tty_get_pgrp(struct tty_struct *tty) 363{ return NULL; } 364static inline void tty_vhangup_self(void) 365{ } 366static inline void disassociate_ctty(int priv) 367{ } 368static inline dev_t tty_devnum(struct tty_struct *tty) 369{ return 0; } 370static inline void proc_clear_tty(struct task_struct *p) 371{ } 372static inline struct tty_struct *get_current_tty(void) 373{ return NULL; } 374/* tty_io.c */ 375static inline int __init tty_init(void) 376{ return 0; } 377#endif 378 379extern void tty_write_flush(struct tty_struct *); 380 381extern struct ktermios tty_std_termios; 382 383extern int vcs_init(void); 384 385extern struct class *tty_class; 386 387/** 388 * tty_kref_get - get a tty reference 389 * @tty: tty device 390 * 391 * Return a new reference to a tty object. The caller must hold 392 * sufficient locks/counts to ensure that their existing reference cannot 393 * go away 394 */ 395 396static inline struct tty_struct *tty_kref_get(struct tty_struct *tty) 397{ 398 if (tty) 399 kref_get(&tty->kref); 400 return tty; 401} 402 403extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, 404 const char *routine); 405extern char *tty_name(struct tty_struct *tty, char *buf); 406extern void tty_wait_until_sent(struct tty_struct *tty, long timeout); 407extern int tty_check_change(struct tty_struct *tty); 408extern void stop_tty(struct tty_struct *tty); 409extern void start_tty(struct tty_struct *tty); 410extern int tty_register_driver(struct tty_driver *driver); 411extern int tty_unregister_driver(struct tty_driver *driver); 412extern struct device *tty_register_device(struct tty_driver *driver, 413 unsigned index, struct device *dev); 414extern struct device *tty_register_device_attr(struct tty_driver *driver, 415 unsigned index, struct device *device, 416 void *drvdata, 417 const struct attribute_group **attr_grp); 418extern void tty_unregister_device(struct tty_driver *driver, unsigned index); 419extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp, 420 int buflen); 421extern void tty_write_message(struct tty_struct *tty, char *msg); 422extern int tty_put_char(struct tty_struct *tty, unsigned char c); 423extern int tty_chars_in_buffer(struct tty_struct *tty); 424extern int tty_write_room(struct tty_struct *tty); 425extern void tty_driver_flush_buffer(struct tty_struct *tty); 426extern void tty_throttle(struct tty_struct *tty); 427extern void tty_unthrottle(struct tty_struct *tty); 428extern int tty_throttle_safe(struct tty_struct *tty); 429extern int tty_unthrottle_safe(struct tty_struct *tty); 430extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws); 431extern void tty_driver_remove_tty(struct tty_driver *driver, 432 struct tty_struct *tty); 433extern void tty_free_termios(struct tty_struct *tty); 434extern int is_current_pgrp_orphaned(void); 435extern int is_ignored(int sig); 436extern int tty_signal(int sig, struct tty_struct *tty); 437extern void tty_hangup(struct tty_struct *tty); 438extern void tty_vhangup(struct tty_struct *tty); 439extern void tty_vhangup_locked(struct tty_struct *tty); 440extern void tty_unhangup(struct file *filp); 441extern int tty_hung_up_p(struct file *filp); 442extern void do_SAK(struct tty_struct *tty); 443extern void __do_SAK(struct tty_struct *tty); 444extern void no_tty(void); 445extern void tty_flush_to_ldisc(struct tty_struct *tty); 446extern void tty_buffer_free_all(struct tty_port *port); 447extern void tty_buffer_flush(struct tty_struct *tty); 448extern void tty_buffer_init(struct tty_port *port); 449extern speed_t tty_termios_baud_rate(struct ktermios *termios); 450extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); 451extern void tty_termios_encode_baud_rate(struct ktermios *termios, 452 speed_t ibaud, speed_t obaud); 453extern void tty_encode_baud_rate(struct tty_struct *tty, 454 speed_t ibaud, speed_t obaud); 455 456/** 457 * tty_get_baud_rate - get tty bit rates 458 * @tty: tty to query 459 * 460 * Returns the baud rate as an integer for this terminal. The 461 * termios lock must be held by the caller and the terminal bit 462 * flags may be updated. 463 * 464 * Locking: none 465 */ 466static inline speed_t tty_get_baud_rate(struct tty_struct *tty) 467{ 468 return tty_termios_baud_rate(&tty->termios); 469} 470 471extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old); 472extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b); 473extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt); 474 475extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *); 476extern void tty_ldisc_deref(struct tty_ldisc *); 477extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *); 478extern void tty_ldisc_hangup(struct tty_struct *tty); 479extern const struct file_operations tty_ldiscs_proc_fops; 480 481extern void tty_wakeup(struct tty_struct *tty); 482extern void tty_ldisc_flush(struct tty_struct *tty); 483 484extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 485extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 486 unsigned int cmd, unsigned long arg); 487extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); 488extern void tty_default_fops(struct file_operations *fops); 489extern struct tty_struct *alloc_tty_struct(void); 490extern int tty_alloc_file(struct file *file); 491extern void tty_add_file(struct tty_struct *tty, struct file *file); 492extern void tty_free_file(struct file *file); 493extern void free_tty_struct(struct tty_struct *tty); 494extern void initialize_tty_struct(struct tty_struct *tty, 495 struct tty_driver *driver, int idx); 496extern void deinitialize_tty_struct(struct tty_struct *tty); 497extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); 498extern int tty_release(struct inode *inode, struct file *filp); 499extern int tty_init_termios(struct tty_struct *tty); 500extern int tty_standard_install(struct tty_driver *driver, 501 struct tty_struct *tty); 502 503extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty); 504extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty); 505 506extern struct mutex tty_mutex; 507extern spinlock_t tty_files_lock; 508 509extern void tty_write_unlock(struct tty_struct *tty); 510extern int tty_write_lock(struct tty_struct *tty, int ndelay); 511#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) 512 513extern void tty_port_init(struct tty_port *port); 514extern void tty_port_link_device(struct tty_port *port, 515 struct tty_driver *driver, unsigned index); 516extern struct device *tty_port_register_device(struct tty_port *port, 517 struct tty_driver *driver, unsigned index, 518 struct device *device); 519extern struct device *tty_port_register_device_attr(struct tty_port *port, 520 struct tty_driver *driver, unsigned index, 521 struct device *device, void *drvdata, 522 const struct attribute_group **attr_grp); 523extern int tty_port_alloc_xmit_buf(struct tty_port *port); 524extern void tty_port_free_xmit_buf(struct tty_port *port); 525extern void tty_port_destroy(struct tty_port *port); 526extern void tty_port_put(struct tty_port *port); 527 528static inline struct tty_port *tty_port_get(struct tty_port *port) 529{ 530 if (port) 531 kref_get(&port->kref); 532 return port; 533} 534 535/* If the cts flow control is enabled, return true. */ 536static inline bool tty_port_cts_enabled(struct tty_port *port) 537{ 538 return port->flags & ASYNC_CTS_FLOW; 539} 540 541extern struct tty_struct *tty_port_tty_get(struct tty_port *port); 542extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); 543extern int tty_port_carrier_raised(struct tty_port *port); 544extern void tty_port_raise_dtr_rts(struct tty_port *port); 545extern void tty_port_lower_dtr_rts(struct tty_port *port); 546extern void tty_port_hangup(struct tty_port *port); 547extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal); 548extern void tty_port_tty_wakeup(struct tty_port *port); 549extern int tty_port_block_til_ready(struct tty_port *port, 550 struct tty_struct *tty, struct file *filp); 551extern int tty_port_close_start(struct tty_port *port, 552 struct tty_struct *tty, struct file *filp); 553extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty); 554extern void tty_port_close(struct tty_port *port, 555 struct tty_struct *tty, struct file *filp); 556extern int tty_port_install(struct tty_port *port, struct tty_driver *driver, 557 struct tty_struct *tty); 558extern int tty_port_open(struct tty_port *port, 559 struct tty_struct *tty, struct file *filp); 560static inline int tty_port_users(struct tty_port *port) 561{ 562 return port->count + port->blocked_open; 563} 564 565extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc); 566extern int tty_unregister_ldisc(int disc); 567extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); 568extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); 569extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty); 570extern void tty_ldisc_init(struct tty_struct *tty); 571extern void tty_ldisc_deinit(struct tty_struct *tty); 572extern void tty_ldisc_begin(void); 573 574static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p, 575 char *f, int count) 576{ 577 if (ld->ops->receive_buf2) 578 count = ld->ops->receive_buf2(ld->tty, p, f, count); 579 else { 580 count = min_t(int, count, ld->tty->receive_room); 581 if (count) 582 ld->ops->receive_buf(ld->tty, p, f, count); 583 } 584 return count; 585} 586 587 588/* n_tty.c */ 589extern struct tty_ldisc_ops tty_ldisc_N_TTY; 590extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops); 591 592/* tty_audit.c */ 593#ifdef CONFIG_AUDIT 594extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, 595 size_t size, unsigned icanon); 596extern void tty_audit_exit(void); 597extern void tty_audit_fork(struct signal_struct *sig); 598extern void tty_audit_tiocsti(struct tty_struct *tty, char ch); 599extern void tty_audit_push(struct tty_struct *tty); 600extern int tty_audit_push_current(void); 601#else 602static inline void tty_audit_add_data(struct tty_struct *tty, 603 unsigned char *data, size_t size, unsigned icanon) 604{ 605} 606static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch) 607{ 608} 609static inline void tty_audit_exit(void) 610{ 611} 612static inline void tty_audit_fork(struct signal_struct *sig) 613{ 614} 615static inline void tty_audit_push(struct tty_struct *tty) 616{ 617} 618static inline int tty_audit_push_current(void) 619{ 620 return 0; 621} 622#endif 623 624/* tty_ioctl.c */ 625extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, 626 unsigned int cmd, unsigned long arg); 627extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file, 628 unsigned int cmd, unsigned long arg); 629 630/* serial.c */ 631 632extern void serial_console_init(void); 633 634/* pcxx.c */ 635 636extern int pcxe_open(struct tty_struct *tty, struct file *filp); 637 638/* vt.c */ 639 640extern int vt_ioctl(struct tty_struct *tty, 641 unsigned int cmd, unsigned long arg); 642 643extern long vt_compat_ioctl(struct tty_struct *tty, 644 unsigned int cmd, unsigned long arg); 645 646/* tty_mutex.c */ 647/* functions for preparation of BKL removal */ 648extern void __lockfunc tty_lock(struct tty_struct *tty); 649extern void __lockfunc tty_unlock(struct tty_struct *tty); 650extern void __lockfunc tty_lock_pair(struct tty_struct *tty, 651 struct tty_struct *tty2); 652extern void __lockfunc tty_unlock_pair(struct tty_struct *tty, 653 struct tty_struct *tty2); 654 655/* 656 * this shall be called only from where BTM is held (like close) 657 * 658 * We need this to ensure nobody waits for us to finish while we are waiting. 659 * Without this we were encountering system stalls. 660 * 661 * This should be indeed removed with BTM removal later. 662 * 663 * Locking: BTM required. Nobody is allowed to hold port->mutex. 664 */ 665static inline void tty_wait_until_sent_from_close(struct tty_struct *tty, 666 long timeout) 667{ 668 tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */ 669 tty_wait_until_sent(tty, timeout); 670 tty_lock(tty); 671} 672 673/* 674 * wait_event_interruptible_tty -- wait for a condition with the tty lock held 675 * 676 * The condition we are waiting for might take a long time to 677 * become true, or might depend on another thread taking the 678 * BTM. In either case, we need to drop the BTM to guarantee 679 * forward progress. This is a leftover from the conversion 680 * from the BKL and should eventually get removed as the BTM 681 * falls out of use. 682 * 683 * Do not use in new code. 684 */ 685#define wait_event_interruptible_tty(tty, wq, condition) \ 686({ \ 687 int __ret = 0; \ 688 if (!(condition)) { \ 689 __wait_event_interruptible_tty(tty, wq, condition, __ret); \ 690 } \ 691 __ret; \ 692}) 693 694#define __wait_event_interruptible_tty(tty, wq, condition, ret) \ 695do { \ 696 DEFINE_WAIT(__wait); \ 697 \ 698 for (;;) { \ 699 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ 700 if (condition) \ 701 break; \ 702 if (!signal_pending(current)) { \ 703 tty_unlock(tty); \ 704 schedule(); \ 705 tty_lock(tty); \ 706 continue; \ 707 } \ 708 ret = -ERESTARTSYS; \ 709 break; \ 710 } \ 711 finish_wait(&wq, &__wait); \ 712} while (0) 713 714#ifdef CONFIG_PROC_FS 715extern void proc_tty_register_driver(struct tty_driver *); 716extern void proc_tty_unregister_driver(struct tty_driver *); 717#else 718static inline void proc_tty_register_driver(struct tty_driver *d) {} 719static inline void proc_tty_unregister_driver(struct tty_driver *d) {} 720#endif 721 722#endif 723