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 * Lock subclasses for tty locks 19 * 20 * TTY_LOCK_NORMAL is for normal ttys and master ptys. 21 * TTY_LOCK_SLAVE is for slave ptys only. 22 * 23 * Lock subclasses are necessary for handling nested locking with pty pairs. 24 * tty locks which use nested locking: 25 * 26 * legacy_mutex - Nested tty locks are necessary for releasing pty pairs. 27 * The stable lock order is master pty first, then slave pty. 28 * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem. 29 * Subclassing this lock enables the slave pty to hold its 30 * termios_rwsem when claiming the master tty_buffer lock. 31 * tty_buffer lock - slave ptys can claim nested buffer lock when handling 32 * signal chars. The stable lock order is slave pty, then 33 * master. 34 */ 35 36enum { 37 TTY_LOCK_NORMAL = 0, 38 TTY_LOCK_SLAVE, 39}; 40 41/* 42 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are 43 * hardcoded at present.) 44 */ 45#define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */ 46#define NR_UNIX98_PTY_RESERVE 1024 /* Default reserve for main devpts */ 47#define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */ 48 49/* 50 * This character is the same as _POSIX_VDISABLE: it cannot be used as 51 * a c_cc[] character, but indicates that a particular special character 52 * isn't in use (eg VINTR has no character etc) 53 */ 54#define __DISABLED_CHAR '\0' 55 56struct tty_buffer { 57 union { 58 struct tty_buffer *next; 59 struct llist_node free; 60 }; 61 int used; 62 int size; 63 int commit; 64 int read; 65 int flags; 66 /* Data points here */ 67 unsigned long data[0]; 68}; 69 70/* Values for .flags field of tty_buffer */ 71#define TTYB_NORMAL 1 /* buffer has no flags buffer */ 72 73static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs) 74{ 75 return ((unsigned char *)b->data) + ofs; 76} 77 78static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs) 79{ 80 return (char *)char_buf_ptr(b, ofs) + b->size; 81} 82 83struct tty_bufhead { 84 struct tty_buffer *head; /* Queue head */ 85 struct work_struct work; 86 struct mutex lock; 87 atomic_t priority; 88 struct tty_buffer sentinel; 89 struct llist_head free; /* Free queue head */ 90 atomic_t mem_used; /* In-use buffers excluding free list */ 91 int mem_limit; 92 struct tty_buffer *tail; /* Active buffer */ 93}; 94/* 95 * When a break, frame error, or parity error happens, these codes are 96 * stuffed into the flags buffer. 97 */ 98#define TTY_NORMAL 0 99#define TTY_BREAK 1 100#define TTY_FRAME 2 101#define TTY_PARITY 3 102#define TTY_OVERRUN 4 103 104#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR]) 105#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT]) 106#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE]) 107#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL]) 108#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF]) 109#define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME]) 110#define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN]) 111#define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC]) 112#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART]) 113#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP]) 114#define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP]) 115#define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL]) 116#define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT]) 117#define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD]) 118#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE]) 119#define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT]) 120#define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2]) 121 122#define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f)) 123#define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f)) 124#define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f)) 125#define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f)) 126 127#define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK) 128#define I_BRKINT(tty) _I_FLAG((tty), BRKINT) 129#define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR) 130#define I_PARMRK(tty) _I_FLAG((tty), PARMRK) 131#define I_INPCK(tty) _I_FLAG((tty), INPCK) 132#define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP) 133#define I_INLCR(tty) _I_FLAG((tty), INLCR) 134#define I_IGNCR(tty) _I_FLAG((tty), IGNCR) 135#define I_ICRNL(tty) _I_FLAG((tty), ICRNL) 136#define I_IUCLC(tty) _I_FLAG((tty), IUCLC) 137#define I_IXON(tty) _I_FLAG((tty), IXON) 138#define I_IXANY(tty) _I_FLAG((tty), IXANY) 139#define I_IXOFF(tty) _I_FLAG((tty), IXOFF) 140#define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL) 141#define I_IUTF8(tty) _I_FLAG((tty), IUTF8) 142 143#define O_OPOST(tty) _O_FLAG((tty), OPOST) 144#define O_OLCUC(tty) _O_FLAG((tty), OLCUC) 145#define O_ONLCR(tty) _O_FLAG((tty), ONLCR) 146#define O_OCRNL(tty) _O_FLAG((tty), OCRNL) 147#define O_ONOCR(tty) _O_FLAG((tty), ONOCR) 148#define O_ONLRET(tty) _O_FLAG((tty), ONLRET) 149#define O_OFILL(tty) _O_FLAG((tty), OFILL) 150#define O_OFDEL(tty) _O_FLAG((tty), OFDEL) 151#define O_NLDLY(tty) _O_FLAG((tty), NLDLY) 152#define O_CRDLY(tty) _O_FLAG((tty), CRDLY) 153#define O_TABDLY(tty) _O_FLAG((tty), TABDLY) 154#define O_BSDLY(tty) _O_FLAG((tty), BSDLY) 155#define O_VTDLY(tty) _O_FLAG((tty), VTDLY) 156#define O_FFDLY(tty) _O_FLAG((tty), FFDLY) 157 158#define C_BAUD(tty) _C_FLAG((tty), CBAUD) 159#define C_CSIZE(tty) _C_FLAG((tty), CSIZE) 160#define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB) 161#define C_CREAD(tty) _C_FLAG((tty), CREAD) 162#define C_PARENB(tty) _C_FLAG((tty), PARENB) 163#define C_PARODD(tty) _C_FLAG((tty), PARODD) 164#define C_HUPCL(tty) _C_FLAG((tty), HUPCL) 165#define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL) 166#define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD) 167#define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS) 168#define C_CMSPAR(tty) _C_FLAG((tty), CMSPAR) 169 170#define L_ISIG(tty) _L_FLAG((tty), ISIG) 171#define L_ICANON(tty) _L_FLAG((tty), ICANON) 172#define L_XCASE(tty) _L_FLAG((tty), XCASE) 173#define L_ECHO(tty) _L_FLAG((tty), ECHO) 174#define L_ECHOE(tty) _L_FLAG((tty), ECHOE) 175#define L_ECHOK(tty) _L_FLAG((tty), ECHOK) 176#define L_ECHONL(tty) _L_FLAG((tty), ECHONL) 177#define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH) 178#define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP) 179#define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL) 180#define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT) 181#define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE) 182#define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO) 183#define L_PENDIN(tty) _L_FLAG((tty), PENDIN) 184#define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN) 185#define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC) 186 187struct device; 188struct signal_struct; 189 190/* 191 * Port level information. Each device keeps its own port level information 192 * so provide a common structure for those ports wanting to use common support 193 * routines. 194 * 195 * The tty port has a different lifetime to the tty so must be kept apart. 196 * In addition be careful as tty -> port mappings are valid for the life 197 * of the tty object but in many cases port -> tty mappings are valid only 198 * until a hangup so don't use the wrong path. 199 */ 200 201struct tty_port; 202 203struct tty_port_operations { 204 /* Return 1 if the carrier is raised */ 205 int (*carrier_raised)(struct tty_port *port); 206 /* Control the DTR line */ 207 void (*dtr_rts)(struct tty_port *port, int raise); 208 /* Called when the last close completes or a hangup finishes 209 IFF the port was initialized. Do not use to free resources. Called 210 under the port mutex to serialize against activate/shutdowns */ 211 void (*shutdown)(struct tty_port *port); 212 /* Called under the port mutex from tty_port_open, serialized using 213 the port mutex */ 214 /* FIXME: long term getting the tty argument *out* of this would be 215 good for consoles */ 216 int (*activate)(struct tty_port *port, struct tty_struct *tty); 217 /* Called on the final put of a port */ 218 void (*destruct)(struct tty_port *port); 219}; 220 221struct tty_port { 222 struct tty_bufhead buf; /* Locked internally */ 223 struct tty_struct *tty; /* Back pointer */ 224 struct tty_struct *itty; /* internal back ptr */ 225 const struct tty_port_operations *ops; /* Port operations */ 226 spinlock_t lock; /* Lock protecting tty field */ 227 int blocked_open; /* Waiting to open */ 228 int count; /* Usage count */ 229 wait_queue_head_t open_wait; /* Open waiters */ 230 wait_queue_head_t close_wait; /* Close waiters */ 231 wait_queue_head_t delta_msr_wait; /* Modem status change */ 232 unsigned long flags; /* TTY flags ASY_*/ 233 unsigned char console:1, /* port is a console */ 234 low_latency:1; /* optional: tune for latency */ 235 struct mutex mutex; /* Locking */ 236 struct mutex buf_mutex; /* Buffer alloc lock */ 237 unsigned char *xmit_buf; /* Optional buffer */ 238 unsigned int close_delay; /* Close port delay */ 239 unsigned int closing_wait; /* Delay for output */ 240 int drain_delay; /* Set to zero if no pure time 241 based drain is needed else 242 set to size of fifo */ 243 struct kref kref; /* Ref counter */ 244}; 245 246/* 247 * Where all of the state associated with a tty is kept while the tty 248 * is open. Since the termios state should be kept even if the tty 249 * has been closed --- for things like the baud rate, etc --- it is 250 * not stored here, but rather a pointer to the real state is stored 251 * here. Possible the winsize structure should have the same 252 * treatment, but (1) the default 80x24 is usually right and (2) it's 253 * most often used by a windowing system, which will set the correct 254 * size each time the window is created or resized anyway. 255 * - TYT, 9/14/92 256 */ 257 258struct tty_operations; 259 260struct tty_struct { 261 int magic; 262 struct kref kref; 263 struct device *dev; 264 struct tty_driver *driver; 265 const struct tty_operations *ops; 266 int index; 267 268 /* Protects ldisc changes: Lock tty not pty */ 269 struct ld_semaphore ldisc_sem; 270 struct tty_ldisc *ldisc; 271 272 struct mutex atomic_write_lock; 273 struct mutex legacy_mutex; 274 struct mutex throttle_mutex; 275 struct rw_semaphore termios_rwsem; 276 struct mutex winsize_mutex; 277 spinlock_t ctrl_lock; 278 spinlock_t flow_lock; 279 /* Termios values are protected by the termios rwsem */ 280 struct ktermios termios, termios_locked; 281 struct termiox *termiox; /* May be NULL for unsupported */ 282 char name[64]; 283 struct pid *pgrp; /* Protected by ctrl lock */ 284 struct pid *session; 285 unsigned long flags; 286 int count; 287 struct winsize winsize; /* winsize_mutex */ 288 unsigned long stopped:1, /* flow_lock */ 289 flow_stopped:1, 290 unused:BITS_PER_LONG - 2; 291 int hw_stopped; 292 unsigned long ctrl_status:8, /* ctrl_lock */ 293 packet:1, 294 unused_ctrl:BITS_PER_LONG - 9; 295 unsigned int receive_room; /* Bytes free for queue */ 296 int flow_change; 297 298 struct tty_struct *link; 299 struct fasync_struct *fasync; 300 int alt_speed; /* For magic substitution of 38400 bps */ 301 wait_queue_head_t write_wait; 302 wait_queue_head_t read_wait; 303 struct work_struct hangup_work; 304 void *disc_data; 305 void *driver_data; 306 struct list_head tty_files; 307 308#define N_TTY_BUF_SIZE 4096 309 310 int closing; 311 unsigned char *write_buf; 312 int write_cnt; 313 /* If the tty has a pending do_SAK, queue it here - akpm */ 314 struct work_struct SAK_work; 315 struct tty_port *port; 316}; 317 318/* Each of a tty's open files has private_data pointing to tty_file_private */ 319struct tty_file_private { 320 struct tty_struct *tty; 321 struct file *file; 322 struct list_head list; 323}; 324 325/* tty magic number */ 326#define TTY_MAGIC 0x5401 327 328/* 329 * These bits are used in the flags field of the tty structure. 330 * 331 * So that interrupts won't be able to mess up the queues, 332 * copy_to_cooked must be atomic with respect to itself, as must 333 * tty->write. Thus, you must use the inline functions set_bit() and 334 * clear_bit() to make things atomic. 335 */ 336#define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */ 337#define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */ 338#define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */ 339#define TTY_EXCLUSIVE 3 /* Exclusive open mode */ 340#define TTY_DEBUG 4 /* Debugging */ 341#define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */ 342#define TTY_LDISC_OPEN 11 /* Line discipline is open */ 343#define TTY_PTY_LOCK 16 /* pty private */ 344#define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ 345#define TTY_HUPPED 18 /* Post driver->hangup() */ 346#define TTY_LDISC_HALTED 22 /* Line discipline is halted */ 347 348#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) 349 350/* Values for tty->flow_change */ 351#define TTY_THROTTLE_SAFE 1 352#define TTY_UNTHROTTLE_SAFE 2 353 354static inline void __tty_set_flow_change(struct tty_struct *tty, int val) 355{ 356 tty->flow_change = val; 357} 358 359static inline void tty_set_flow_change(struct tty_struct *tty, int val) 360{ 361 tty->flow_change = val; 362 smp_mb(); 363} 364 365#ifdef CONFIG_TTY 366extern void console_init(void); 367extern void tty_kref_put(struct tty_struct *tty); 368extern struct pid *tty_get_pgrp(struct tty_struct *tty); 369extern void tty_vhangup_self(void); 370extern void disassociate_ctty(int priv); 371extern dev_t tty_devnum(struct tty_struct *tty); 372extern void proc_clear_tty(struct task_struct *p); 373extern struct tty_struct *get_current_tty(void); 374/* tty_io.c */ 375extern int __init tty_init(void); 376#else 377static inline void console_init(void) 378{ } 379static inline void tty_kref_put(struct tty_struct *tty) 380{ } 381static inline struct pid *tty_get_pgrp(struct tty_struct *tty) 382{ return NULL; } 383static inline void tty_vhangup_self(void) 384{ } 385static inline void disassociate_ctty(int priv) 386{ } 387static inline dev_t tty_devnum(struct tty_struct *tty) 388{ return 0; } 389static inline void proc_clear_tty(struct task_struct *p) 390{ } 391static inline struct tty_struct *get_current_tty(void) 392{ return NULL; } 393/* tty_io.c */ 394static inline int __init tty_init(void) 395{ return 0; } 396#endif 397 398extern void tty_write_flush(struct tty_struct *); 399 400extern struct ktermios tty_std_termios; 401 402extern int vcs_init(void); 403 404extern struct class *tty_class; 405 406/** 407 * tty_kref_get - get a tty reference 408 * @tty: tty device 409 * 410 * Return a new reference to a tty object. The caller must hold 411 * sufficient locks/counts to ensure that their existing reference cannot 412 * go away 413 */ 414 415static inline struct tty_struct *tty_kref_get(struct tty_struct *tty) 416{ 417 if (tty) 418 kref_get(&tty->kref); 419 return tty; 420} 421 422extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, 423 const char *routine); 424extern char *tty_name(struct tty_struct *tty, char *buf); 425extern void tty_wait_until_sent(struct tty_struct *tty, long timeout); 426extern int tty_check_change(struct tty_struct *tty); 427extern void __stop_tty(struct tty_struct *tty); 428extern void stop_tty(struct tty_struct *tty); 429extern void __start_tty(struct tty_struct *tty); 430extern void start_tty(struct tty_struct *tty); 431extern int tty_register_driver(struct tty_driver *driver); 432extern int tty_unregister_driver(struct tty_driver *driver); 433extern struct device *tty_register_device(struct tty_driver *driver, 434 unsigned index, struct device *dev); 435extern struct device *tty_register_device_attr(struct tty_driver *driver, 436 unsigned index, struct device *device, 437 void *drvdata, 438 const struct attribute_group **attr_grp); 439extern void tty_unregister_device(struct tty_driver *driver, unsigned index); 440extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp, 441 int buflen); 442extern void tty_write_message(struct tty_struct *tty, char *msg); 443extern int tty_send_xchar(struct tty_struct *tty, char ch); 444extern int tty_put_char(struct tty_struct *tty, unsigned char c); 445extern int tty_chars_in_buffer(struct tty_struct *tty); 446extern int tty_write_room(struct tty_struct *tty); 447extern void tty_driver_flush_buffer(struct tty_struct *tty); 448extern void tty_throttle(struct tty_struct *tty); 449extern void tty_unthrottle(struct tty_struct *tty); 450extern int tty_throttle_safe(struct tty_struct *tty); 451extern int tty_unthrottle_safe(struct tty_struct *tty); 452extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws); 453extern void tty_driver_remove_tty(struct tty_driver *driver, 454 struct tty_struct *tty); 455extern void tty_free_termios(struct tty_struct *tty); 456extern int is_current_pgrp_orphaned(void); 457extern int is_ignored(int sig); 458extern int tty_signal(int sig, struct tty_struct *tty); 459extern void tty_hangup(struct tty_struct *tty); 460extern void tty_vhangup(struct tty_struct *tty); 461extern int tty_hung_up_p(struct file *filp); 462extern void do_SAK(struct tty_struct *tty); 463extern void __do_SAK(struct tty_struct *tty); 464extern void no_tty(void); 465extern void tty_buffer_free_all(struct tty_port *port); 466extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld); 467extern void tty_buffer_init(struct tty_port *port); 468extern void tty_buffer_set_lock_subclass(struct tty_port *port); 469extern void tty_buffer_flush_work(struct tty_port *port); 470extern speed_t tty_termios_baud_rate(struct ktermios *termios); 471extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); 472extern void tty_termios_encode_baud_rate(struct ktermios *termios, 473 speed_t ibaud, speed_t obaud); 474extern void tty_encode_baud_rate(struct tty_struct *tty, 475 speed_t ibaud, speed_t obaud); 476 477/** 478 * tty_get_baud_rate - get tty bit rates 479 * @tty: tty to query 480 * 481 * Returns the baud rate as an integer for this terminal. The 482 * termios lock must be held by the caller and the terminal bit 483 * flags may be updated. 484 * 485 * Locking: none 486 */ 487static inline speed_t tty_get_baud_rate(struct tty_struct *tty) 488{ 489 return tty_termios_baud_rate(&tty->termios); 490} 491 492extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old); 493extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b); 494extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt); 495 496extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *); 497extern void tty_ldisc_deref(struct tty_ldisc *); 498extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *); 499extern void tty_ldisc_hangup(struct tty_struct *tty); 500extern const struct file_operations tty_ldiscs_proc_fops; 501 502extern void tty_wakeup(struct tty_struct *tty); 503extern void tty_ldisc_flush(struct tty_struct *tty); 504 505extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 506extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file, 507 unsigned int cmd, unsigned long arg); 508extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); 509extern void tty_default_fops(struct file_operations *fops); 510extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx); 511extern int tty_alloc_file(struct file *file); 512extern void tty_add_file(struct tty_struct *tty, struct file *file); 513extern void tty_free_file(struct file *file); 514extern void free_tty_struct(struct tty_struct *tty); 515extern void deinitialize_tty_struct(struct tty_struct *tty); 516extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); 517extern int tty_release(struct inode *inode, struct file *filp); 518extern int tty_init_termios(struct tty_struct *tty); 519extern int tty_standard_install(struct tty_driver *driver, 520 struct tty_struct *tty); 521 522extern struct mutex tty_mutex; 523extern spinlock_t tty_files_lock; 524 525#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) 526 527extern void tty_port_init(struct tty_port *port); 528extern void tty_port_link_device(struct tty_port *port, 529 struct tty_driver *driver, unsigned index); 530extern struct device *tty_port_register_device(struct tty_port *port, 531 struct tty_driver *driver, unsigned index, 532 struct device *device); 533extern struct device *tty_port_register_device_attr(struct tty_port *port, 534 struct tty_driver *driver, unsigned index, 535 struct device *device, void *drvdata, 536 const struct attribute_group **attr_grp); 537extern int tty_port_alloc_xmit_buf(struct tty_port *port); 538extern void tty_port_free_xmit_buf(struct tty_port *port); 539extern void tty_port_destroy(struct tty_port *port); 540extern void tty_port_put(struct tty_port *port); 541 542static inline struct tty_port *tty_port_get(struct tty_port *port) 543{ 544 if (port && kref_get_unless_zero(&port->kref)) 545 return port; 546 return NULL; 547} 548 549/* If the cts flow control is enabled, return true. */ 550static inline bool tty_port_cts_enabled(struct tty_port *port) 551{ 552 return port->flags & ASYNC_CTS_FLOW; 553} 554 555extern struct tty_struct *tty_port_tty_get(struct tty_port *port); 556extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); 557extern int tty_port_carrier_raised(struct tty_port *port); 558extern void tty_port_raise_dtr_rts(struct tty_port *port); 559extern void tty_port_lower_dtr_rts(struct tty_port *port); 560extern void tty_port_hangup(struct tty_port *port); 561extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal); 562extern void tty_port_tty_wakeup(struct tty_port *port); 563extern int tty_port_block_til_ready(struct tty_port *port, 564 struct tty_struct *tty, struct file *filp); 565extern int tty_port_close_start(struct tty_port *port, 566 struct tty_struct *tty, struct file *filp); 567extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty); 568extern void tty_port_close(struct tty_port *port, 569 struct tty_struct *tty, struct file *filp); 570extern int tty_port_install(struct tty_port *port, struct tty_driver *driver, 571 struct tty_struct *tty); 572extern int tty_port_open(struct tty_port *port, 573 struct tty_struct *tty, struct file *filp); 574static inline int tty_port_users(struct tty_port *port) 575{ 576 return port->count + port->blocked_open; 577} 578 579extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc); 580extern int tty_unregister_ldisc(int disc); 581extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); 582extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); 583extern void tty_ldisc_release(struct tty_struct *tty); 584extern void tty_ldisc_init(struct tty_struct *tty); 585extern void tty_ldisc_deinit(struct tty_struct *tty); 586extern void tty_ldisc_begin(void); 587 588static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p, 589 char *f, int count) 590{ 591 if (ld->ops->receive_buf2) 592 count = ld->ops->receive_buf2(ld->tty, p, f, count); 593 else { 594 count = min_t(int, count, ld->tty->receive_room); 595 if (count && ld->ops->receive_buf) 596 ld->ops->receive_buf(ld->tty, p, f, count); 597 } 598 return count; 599} 600 601 602/* n_tty.c */ 603extern struct tty_ldisc_ops tty_ldisc_N_TTY; 604extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops); 605 606/* tty_audit.c */ 607#ifdef CONFIG_AUDIT 608extern void tty_audit_add_data(struct tty_struct *tty, const void *data, 609 size_t size, unsigned icanon); 610extern void tty_audit_exit(void); 611extern void tty_audit_fork(struct signal_struct *sig); 612extern void tty_audit_tiocsti(struct tty_struct *tty, char ch); 613extern void tty_audit_push(struct tty_struct *tty); 614extern int tty_audit_push_current(void); 615#else 616static inline void tty_audit_add_data(struct tty_struct *tty, const void *data, 617 size_t size, unsigned icanon) 618{ 619} 620static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch) 621{ 622} 623static inline void tty_audit_exit(void) 624{ 625} 626static inline void tty_audit_fork(struct signal_struct *sig) 627{ 628} 629static inline void tty_audit_push(struct tty_struct *tty) 630{ 631} 632static inline int tty_audit_push_current(void) 633{ 634 return 0; 635} 636#endif 637 638/* tty_ioctl.c */ 639extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, 640 unsigned int cmd, unsigned long arg); 641extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file, 642 unsigned int cmd, unsigned long arg); 643 644/* vt.c */ 645 646extern int vt_ioctl(struct tty_struct *tty, 647 unsigned int cmd, unsigned long arg); 648 649extern long vt_compat_ioctl(struct tty_struct *tty, 650 unsigned int cmd, unsigned long arg); 651 652/* tty_mutex.c */ 653/* functions for preparation of BKL removal */ 654extern void __lockfunc tty_lock(struct tty_struct *tty); 655extern void __lockfunc tty_unlock(struct tty_struct *tty); 656extern void __lockfunc tty_lock_slave(struct tty_struct *tty); 657extern void __lockfunc tty_unlock_slave(struct tty_struct *tty); 658extern void tty_set_lock_subclass(struct tty_struct *tty); 659/* 660 * this shall be called only from where BTM is held (like close) 661 * 662 * We need this to ensure nobody waits for us to finish while we are waiting. 663 * Without this we were encountering system stalls. 664 * 665 * This should be indeed removed with BTM removal later. 666 * 667 * Locking: BTM required. Nobody is allowed to hold port->mutex. 668 */ 669static inline void tty_wait_until_sent_from_close(struct tty_struct *tty, 670 long timeout) 671{ 672 tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */ 673 tty_wait_until_sent(tty, timeout); 674 tty_lock(tty); 675} 676 677/* 678 * wait_event_interruptible_tty -- wait for a condition with the tty lock held 679 * 680 * The condition we are waiting for might take a long time to 681 * become true, or might depend on another thread taking the 682 * BTM. In either case, we need to drop the BTM to guarantee 683 * forward progress. This is a leftover from the conversion 684 * from the BKL and should eventually get removed as the BTM 685 * falls out of use. 686 * 687 * Do not use in new code. 688 */ 689#define wait_event_interruptible_tty(tty, wq, condition) \ 690({ \ 691 int __ret = 0; \ 692 if (!(condition)) \ 693 __ret = __wait_event_interruptible_tty(tty, wq, \ 694 condition); \ 695 __ret; \ 696}) 697 698#define __wait_event_interruptible_tty(tty, wq, condition) \ 699 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ 700 tty_unlock(tty); \ 701 schedule(); \ 702 tty_lock(tty)) 703 704#ifdef CONFIG_PROC_FS 705extern void proc_tty_register_driver(struct tty_driver *); 706extern void proc_tty_unregister_driver(struct tty_driver *); 707#else 708static inline void proc_tty_register_driver(struct tty_driver *d) {} 709static inline void proc_tty_unregister_driver(struct tty_driver *d) {} 710#endif 711 712#endif 713