include/linux/tty.h

   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
  36 enum {
  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
  56 struct 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
  73 static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
  74 {
  75         return ((unsigned char *)b->data) + ofs;
  76 }
  77
  78 static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
  79 {
  80         return (char *)char_buf_ptr(b, ofs) + b->size;
  81 }
  82
  83 struct 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
 187 struct device;
 188 struct 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
 201 struct tty_port;
 202
 203 struct 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
 221 struct 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       delta_msr_wait; /* Modem status change */
 231         unsigned long           flags;          /* TTY flags ASY_*/
 232         unsigned char           console:1,      /* port is a console */
 233                                 low_latency:1;  /* optional: tune for latency */
 234         struct mutex            mutex;          /* Locking */
 235         struct mutex            buf_mutex;      /* Buffer alloc lock */
 236         unsigned char           *xmit_buf;      /* Optional buffer */
 237         unsigned int            close_delay;    /* Close port delay */
 238         unsigned int            closing_wait;   /* Delay for output */
 239         int                     drain_delay;    /* Set to zero if no pure time
 240                                                    based drain is needed else
 241                                                    set to size of fifo */
 242         struct kref             kref;           /* Ref counter */
 243 };
 244
 245 /*
 246  * Where all of the state associated with a tty is kept while the tty
 247  * is open.  Since the termios state should be kept even if the tty
 248  * has been closed --- for things like the baud rate, etc --- it is
 249  * not stored here, but rather a pointer to the real state is stored
 250  * here.  Possible the winsize structure should have the same
 251  * treatment, but (1) the default 80x24 is usually right and (2) it's
 252  * most often used by a windowing system, which will set the correct
 253  * size each time the window is created or resized anyway.
 254  *                                              - TYT, 9/14/92
 255  */
 256
 257 struct tty_operations;
 258
 259 struct tty_struct {
 260         int     magic;
 261         struct kref kref;
 262         struct device *dev;
 263         struct tty_driver *driver;
 264         const struct tty_operations *ops;
 265         int index;
 266
 267         /* Protects ldisc changes: Lock tty not pty */
 268         struct ld_semaphore ldisc_sem;
 269         struct tty_ldisc *ldisc;
 270
 271         struct mutex atomic_write_lock;
 272         struct mutex legacy_mutex;
 273         struct mutex throttle_mutex;
 274         struct rw_semaphore termios_rwsem;
 275         struct mutex winsize_mutex;
 276         spinlock_t ctrl_lock;
 277         spinlock_t flow_lock;
 278         /* Termios values are protected by the termios rwsem */
 279         struct ktermios termios, termios_locked;
 280         struct termiox *termiox;        /* May be NULL for unsupported */
 281         char name[64];
 282         struct pid *pgrp;               /* Protected by ctrl lock */
 283         struct pid *session;
 284         unsigned long flags;
 285         int count;
 286         struct winsize winsize;         /* winsize_mutex */
 287         unsigned long stopped:1,        /* flow_lock */
 288                       flow_stopped:1,
 289                       unused:BITS_PER_LONG - 2;
 290         int hw_stopped;
 291         unsigned long ctrl_status:8,    /* ctrl_lock */
 292                       packet:1,
 293                       unused_ctrl:BITS_PER_LONG - 9;
 294         unsigned int receive_room;      /* Bytes free for queue */
 295         int flow_change;
 296
 297         struct tty_struct *link;
 298         struct fasync_struct *fasync;
 299         int alt_speed;          /* For magic substitution of 38400 bps */
 300         wait_queue_head_t write_wait;
 301         wait_queue_head_t read_wait;
 302         struct work_struct hangup_work;
 303         void *disc_data;
 304         void *driver_data;
 305         struct list_head tty_files;
 306
 307 #define N_TTY_BUF_SIZE 4096
 308
 309         int closing;
 310         unsigned char *write_buf;
 311         int write_cnt;
 312         /* If the tty has a pending do_SAK, queue it here - akpm */
 313         struct work_struct SAK_work;
 314         struct tty_port *port;
 315 };
 316
 317 /* Each of a tty's open files has private_data pointing to tty_file_private */
 318 struct tty_file_private {
 319         struct tty_struct *tty;
 320         struct file *file;
 321         struct list_head list;
 322 };
 323
 324 /* tty magic number */
 325 #define TTY_MAGIC               0x5401
 326
 327 /*
 328  * These bits are used in the flags field of the tty structure.
 329  *
 330  * So that interrupts won't be able to mess up the queues,
 331  * copy_to_cooked must be atomic with respect to itself, as must
 332  * tty->write.  Thus, you must use the inline functions set_bit() and
 333  * clear_bit() to make things atomic.
 334  */
 335 #define TTY_THROTTLED           0       /* Call unthrottle() at threshold min */
 336 #define TTY_IO_ERROR            1       /* Cause an I/O error (may be no ldisc too) */
 337 #define TTY_OTHER_CLOSED        2       /* Other side (if any) has closed */
 338 #define TTY_EXCLUSIVE           3       /* Exclusive open mode */
 339 #define TTY_DEBUG               4       /* Debugging */
 340 #define TTY_DO_WRITE_WAKEUP     5       /* Call write_wakeup after queuing new */
 341 #define TTY_OTHER_DONE          6       /* Closed pty has completed input processing */
 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
 354 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
 355 {
 356         tty->flow_change = val;
 357 }
 358
 359 static 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
 366 extern void console_init(void);
 367 extern void tty_kref_put(struct tty_struct *tty);
 368 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
 369 extern void tty_vhangup_self(void);
 370 extern void disassociate_ctty(int priv);
 371 extern dev_t tty_devnum(struct tty_struct *tty);
 372 extern void proc_clear_tty(struct task_struct *p);
 373 extern struct tty_struct *get_current_tty(void);
 374 /* tty_io.c */
 375 extern int __init tty_init(void);
 376 #else
 377 static inline void console_init(void)
 378 { }
 379 static inline void tty_kref_put(struct tty_struct *tty)
 380 { }
 381 static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
 382 { return NULL; }
 383 static inline void tty_vhangup_self(void)
 384 { }
 385 static inline void disassociate_ctty(int priv)
 386 { }
 387 static inline dev_t tty_devnum(struct tty_struct *tty)
 388 { return 0; }
 389 static inline void proc_clear_tty(struct task_struct *p)
 390 { }
 391 static inline struct tty_struct *get_current_tty(void)
 392 { return NULL; }
 393 /* tty_io.c */
 394 static inline int __init tty_init(void)
 395 { return 0; }
 396 #endif
 397
 398 extern void tty_write_flush(struct tty_struct *);
 399
 400 extern struct ktermios tty_std_termios;
 401
 402 extern int vcs_init(void);
 403
 404 extern 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
 415 static 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
 422 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
 423                               const char *routine);
 424 extern const char *tty_name(const struct tty_struct *tty);
 425 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 426 extern int __tty_check_change(struct tty_struct *tty, int sig);
 427 extern int tty_check_change(struct tty_struct *tty);
 428 extern void __stop_tty(struct tty_struct *tty);
 429 extern void stop_tty(struct tty_struct *tty);
 430 extern void __start_tty(struct tty_struct *tty);
 431 extern void start_tty(struct tty_struct *tty);
 432 extern int tty_register_driver(struct tty_driver *driver);
 433 extern int tty_unregister_driver(struct tty_driver *driver);
 434 extern struct device *tty_register_device(struct tty_driver *driver,
 435                                           unsigned index, struct device *dev);
 436 extern struct device *tty_register_device_attr(struct tty_driver *driver,
 437                                 unsigned index, struct device *device,
 438                                 void *drvdata,
 439                                 const struct attribute_group **attr_grp);
 440 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 441 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
 442                              int buflen);
 443 extern void tty_write_message(struct tty_struct *tty, char *msg);
 444 extern int tty_send_xchar(struct tty_struct *tty, char ch);
 445 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
 446 extern int tty_chars_in_buffer(struct tty_struct *tty);
 447 extern int tty_write_room(struct tty_struct *tty);
 448 extern void tty_driver_flush_buffer(struct tty_struct *tty);
 449 extern void tty_throttle(struct tty_struct *tty);
 450 extern void tty_unthrottle(struct tty_struct *tty);
 451 extern int tty_throttle_safe(struct tty_struct *tty);
 452 extern int tty_unthrottle_safe(struct tty_struct *tty);
 453 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 454 extern void tty_driver_remove_tty(struct tty_driver *driver,
 455                                   struct tty_struct *tty);
 456 extern void tty_free_termios(struct tty_struct *tty);
 457 extern int is_current_pgrp_orphaned(void);
 458 extern int is_ignored(int sig);
 459 extern int tty_signal(int sig, struct tty_struct *tty);
 460 extern void tty_hangup(struct tty_struct *tty);
 461 extern void tty_vhangup(struct tty_struct *tty);
 462 extern int tty_hung_up_p(struct file *filp);
 463 extern void do_SAK(struct tty_struct *tty);
 464 extern void __do_SAK(struct tty_struct *tty);
 465 extern void no_tty(void);
 466 extern void tty_buffer_free_all(struct tty_port *port);
 467 extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
 468 extern void tty_buffer_init(struct tty_port *port);
 469 extern void tty_buffer_set_lock_subclass(struct tty_port *port);
 470 extern bool tty_buffer_restart_work(struct tty_port *port);
 471 extern bool tty_buffer_cancel_work(struct tty_port *port);
 472 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
 473 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 474 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
 475                                                 speed_t ibaud, speed_t obaud);
 476 extern void tty_encode_baud_rate(struct tty_struct *tty,
 477                                                 speed_t ibaud, speed_t obaud);
 478
 479 /**
 480  *      tty_get_baud_rate       -       get tty bit rates
 481  *      @tty: tty to query
 482  *
 483  *      Returns the baud rate as an integer for this terminal. The
 484  *      termios lock must be held by the caller and the terminal bit
 485  *      flags may be updated.
 486  *
 487  *      Locking: none
 488  */
 489 static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
 490 {
 491         return tty_termios_baud_rate(&tty->termios);
 492 }
 493
 494 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 495 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
 496 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 497
 498 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 499 extern void tty_ldisc_deref(struct tty_ldisc *);
 500 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
 501 extern void tty_ldisc_hangup(struct tty_struct *tty);
 502 extern const struct file_operations tty_ldiscs_proc_fops;
 503
 504 extern void tty_wakeup(struct tty_struct *tty);
 505 extern void tty_ldisc_flush(struct tty_struct *tty);
 506
 507 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 508 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 509                         unsigned int cmd, unsigned long arg);
 510 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
 511 extern void tty_default_fops(struct file_operations *fops);
 512 extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
 513 extern int tty_alloc_file(struct file *file);
 514 extern void tty_add_file(struct tty_struct *tty, struct file *file);
 515 extern void tty_free_file(struct file *file);
 516 extern void free_tty_struct(struct tty_struct *tty);
 517 extern void deinitialize_tty_struct(struct tty_struct *tty);
 518 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
 519 extern int tty_release(struct inode *inode, struct file *filp);
 520 extern int tty_init_termios(struct tty_struct *tty);
 521 extern int tty_standard_install(struct tty_driver *driver,
 522                 struct tty_struct *tty);
 523
 524 extern struct mutex tty_mutex;
 525 extern spinlock_t tty_files_lock;
 526
 527 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 528
 529 extern void tty_port_init(struct tty_port *port);
 530 extern void tty_port_link_device(struct tty_port *port,
 531                 struct tty_driver *driver, unsigned index);
 532 extern struct device *tty_port_register_device(struct tty_port *port,
 533                 struct tty_driver *driver, unsigned index,
 534                 struct device *device);
 535 extern struct device *tty_port_register_device_attr(struct tty_port *port,
 536                 struct tty_driver *driver, unsigned index,
 537                 struct device *device, void *drvdata,
 538                 const struct attribute_group **attr_grp);
 539 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 540 extern void tty_port_free_xmit_buf(struct tty_port *port);
 541 extern void tty_port_destroy(struct tty_port *port);
 542 extern void tty_port_put(struct tty_port *port);
 543
 544 static inline struct tty_port *tty_port_get(struct tty_port *port)
 545 {
 546         if (port && kref_get_unless_zero(&port->kref))
 547                 return port;
 548         return NULL;
 549 }
 550
 551 /* If the cts flow control is enabled, return true. */
 552 static inline bool tty_port_cts_enabled(struct tty_port *port)
 553 {
 554         return port->flags & ASYNC_CTS_FLOW;
 555 }
 556
 557 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
 558 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 559 extern int tty_port_carrier_raised(struct tty_port *port);
 560 extern void tty_port_raise_dtr_rts(struct tty_port *port);
 561 extern void tty_port_lower_dtr_rts(struct tty_port *port);
 562 extern void tty_port_hangup(struct tty_port *port);
 563 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
 564 extern void tty_port_tty_wakeup(struct tty_port *port);
 565 extern int tty_port_block_til_ready(struct tty_port *port,
 566                                 struct tty_struct *tty, struct file *filp);
 567 extern int tty_port_close_start(struct tty_port *port,
 568                                 struct tty_struct *tty, struct file *filp);
 569 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
 570 extern void tty_port_close(struct tty_port *port,
 571                                 struct tty_struct *tty, struct file *filp);
 572 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
 573                                 struct tty_struct *tty);
 574 extern int tty_port_open(struct tty_port *port,
 575                                 struct tty_struct *tty, struct file *filp);
 576 static inline int tty_port_users(struct tty_port *port)
 577 {
 578         return port->count + port->blocked_open;
 579 }
 580
 581 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 582 extern int tty_unregister_ldisc(int disc);
 583 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
 584 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 585 extern void tty_ldisc_release(struct tty_struct *tty);
 586 extern void tty_ldisc_init(struct tty_struct *tty);
 587 extern void tty_ldisc_deinit(struct tty_struct *tty);
 588 extern void tty_ldisc_begin(void);
 589
 590 static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 591                                         char *f, int count)
 592 {
 593         if (ld->ops->receive_buf2)
 594                 count = ld->ops->receive_buf2(ld->tty, p, f, count);
 595         else {
 596                 count = min_t(int, count, ld->tty->receive_room);
 597                 if (count)
 598                         ld->ops->receive_buf(ld->tty, p, f, count);
 599         }
 600         return count;
 601 }
 602
 603
 604 /* n_tty.c */
 605 extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 606 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 607
 608 /* tty_audit.c */
 609 #ifdef CONFIG_AUDIT
 610 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
 611                                size_t size, unsigned icanon);
 612 extern void tty_audit_exit(void);
 613 extern void tty_audit_fork(struct signal_struct *sig);
 614 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
 615 extern void tty_audit_push(struct tty_struct *tty);
 616 extern int tty_audit_push_current(void);
 617 #else
 618 static inline void tty_audit_add_data(struct tty_struct *tty,
 619                 unsigned char *data, size_t size, unsigned icanon)
 620 {
 621 }
 622 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 623 {
 624 }
 625 static inline void tty_audit_exit(void)
 626 {
 627 }
 628 static inline void tty_audit_fork(struct signal_struct *sig)
 629 {
 630 }
 631 static inline void tty_audit_push(struct tty_struct *tty)
 632 {
 633 }
 634 static inline int tty_audit_push_current(void)
 635 {
 636         return 0;
 637 }
 638 #endif
 639
 640 /* tty_ioctl.c */
 641 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 642                        unsigned int cmd, unsigned long arg);
 643 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
 644                        unsigned int cmd, unsigned long arg);
 645
 646 /* vt.c */
 647
 648 extern int vt_ioctl(struct tty_struct *tty,
 649                     unsigned int cmd, unsigned long arg);
 650
 651 extern long vt_compat_ioctl(struct tty_struct *tty,
 652                      unsigned int cmd, unsigned long arg);
 653
 654 /* tty_mutex.c */
 655 /* functions for preparation of BKL removal */
 656 extern void __lockfunc tty_lock(struct tty_struct *tty);
 657 extern void __lockfunc tty_unlock(struct tty_struct *tty);
 658 extern void __lockfunc tty_lock_slave(struct tty_struct *tty);
 659 extern void __lockfunc tty_unlock_slave(struct tty_struct *tty);
 660 extern void tty_set_lock_subclass(struct tty_struct *tty);
 661
 662 #ifdef CONFIG_PROC_FS
 663 extern void proc_tty_register_driver(struct tty_driver *);
 664 extern void proc_tty_unregister_driver(struct tty_driver *);
 665 #else
 666 static inline void proc_tty_register_driver(struct tty_driver *d) {}
 667 static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
 668 #endif
 669
 670 #define tty_debug(tty, f, args...)                                      \
 671         do {                                                            \
 672                 printk(KERN_DEBUG "%s: %s: " f, __func__,               \
 673                        tty_name(tty), ##args);                          \
 674         } while (0)
 675
 676 #endif