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 /*
  19  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
  20  * hardcoded at present.)
  21  */
  22 #define NR_UNIX98_PTY_DEFAULT   4096      /* Default maximum for Unix98 ptys */
  23 #define NR_UNIX98_PTY_RESERVE   1024      /* Default reserve for main devpts */
  24 #define NR_UNIX98_PTY_MAX       (1 << MINORBITS) /* Absolute limit */
  25
  26 /*
  27  * This character is the same as _POSIX_VDISABLE: it cannot be used as
  28  * a c_cc[] character, but indicates that a particular special character
  29  * isn't in use (eg VINTR has no character etc)
  30  */
  31 #define __DISABLED_CHAR '\0'
  32
  33 struct tty_buffer {
  34         union {
  35                 struct tty_buffer *next;
  36                 struct llist_node free;
  37         };
  38         int used;
  39         int size;
  40         int commit;
  41         int read;
  42         int flags;
  43         /* Data points here */
  44         unsigned long data[0];
  45 };
  46
  47 /* Values for .flags field of tty_buffer */
  48 #define TTYB_NORMAL     1       /* buffer has no flags buffer */
  49
  50 static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
  51 {
  52         return ((unsigned char *)b->data) + ofs;
  53 }
  54
  55 static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
  56 {
  57         return (char *)char_buf_ptr(b, ofs) + b->size;
  58 }
  59
  60 struct tty_bufhead {
  61         struct tty_buffer *head;        /* Queue head */
  62         struct work_struct work;
  63         struct mutex       lock;
  64         atomic_t           priority;
  65         struct tty_buffer sentinel;
  66         struct llist_head free;         /* Free queue head */
  67         atomic_t           mem_used;    /* In-use buffers excluding free list */
  68         int                mem_limit;
  69         struct tty_buffer *tail;        /* Active buffer */
  70 };
  71 /*
  72  * When a break, frame error, or parity error happens, these codes are
  73  * stuffed into the flags buffer.
  74  */
  75 #define TTY_NORMAL      0
  76 #define TTY_BREAK       1
  77 #define TTY_FRAME       2
  78 #define TTY_PARITY      3
  79 #define TTY_OVERRUN     4
  80
  81 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
  82 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
  83 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
  84 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
  85 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
  86 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
  87 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
  88 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
  89 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
  90 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
  91 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
  92 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
  93 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
  94 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
  95 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
  96 #define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
  97 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
  98
  99 #define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
 100 #define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
 101 #define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
 102 #define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
 103
 104 #define I_IGNBRK(tty)   _I_FLAG((tty), IGNBRK)
 105 #define I_BRKINT(tty)   _I_FLAG((tty), BRKINT)
 106 #define I_IGNPAR(tty)   _I_FLAG((tty), IGNPAR)
 107 #define I_PARMRK(tty)   _I_FLAG((tty), PARMRK)
 108 #define I_INPCK(tty)    _I_FLAG((tty), INPCK)
 109 #define I_ISTRIP(tty)   _I_FLAG((tty), ISTRIP)
 110 #define I_INLCR(tty)    _I_FLAG((tty), INLCR)
 111 #define I_IGNCR(tty)    _I_FLAG((tty), IGNCR)
 112 #define I_ICRNL(tty)    _I_FLAG((tty), ICRNL)
 113 #define I_IUCLC(tty)    _I_FLAG((tty), IUCLC)
 114 #define I_IXON(tty)     _I_FLAG((tty), IXON)
 115 #define I_IXANY(tty)    _I_FLAG((tty), IXANY)
 116 #define I_IXOFF(tty)    _I_FLAG((tty), IXOFF)
 117 #define I_IMAXBEL(tty)  _I_FLAG((tty), IMAXBEL)
 118 #define I_IUTF8(tty)    _I_FLAG((tty), IUTF8)
 119
 120 #define O_OPOST(tty)    _O_FLAG((tty), OPOST)
 121 #define O_OLCUC(tty)    _O_FLAG((tty), OLCUC)
 122 #define O_ONLCR(tty)    _O_FLAG((tty), ONLCR)
 123 #define O_OCRNL(tty)    _O_FLAG((tty), OCRNL)
 124 #define O_ONOCR(tty)    _O_FLAG((tty), ONOCR)
 125 #define O_ONLRET(tty)   _O_FLAG((tty), ONLRET)
 126 #define O_OFILL(tty)    _O_FLAG((tty), OFILL)
 127 #define O_OFDEL(tty)    _O_FLAG((tty), OFDEL)
 128 #define O_NLDLY(tty)    _O_FLAG((tty), NLDLY)
 129 #define O_CRDLY(tty)    _O_FLAG((tty), CRDLY)
 130 #define O_TABDLY(tty)   _O_FLAG((tty), TABDLY)
 131 #define O_BSDLY(tty)    _O_FLAG((tty), BSDLY)
 132 #define O_VTDLY(tty)    _O_FLAG((tty), VTDLY)
 133 #define O_FFDLY(tty)    _O_FLAG((tty), FFDLY)
 134
 135 #define C_BAUD(tty)     _C_FLAG((tty), CBAUD)
 136 #define C_CSIZE(tty)    _C_FLAG((tty), CSIZE)
 137 #define C_CSTOPB(tty)   _C_FLAG((tty), CSTOPB)
 138 #define C_CREAD(tty)    _C_FLAG((tty), CREAD)
 139 #define C_PARENB(tty)   _C_FLAG((tty), PARENB)
 140 #define C_PARODD(tty)   _C_FLAG((tty), PARODD)
 141 #define C_HUPCL(tty)    _C_FLAG((tty), HUPCL)
 142 #define C_CLOCAL(tty)   _C_FLAG((tty), CLOCAL)
 143 #define C_CIBAUD(tty)   _C_FLAG((tty), CIBAUD)
 144 #define C_CRTSCTS(tty)  _C_FLAG((tty), CRTSCTS)
 145 #define C_CMSPAR(tty)   _C_FLAG((tty), CMSPAR)
 146
 147 #define L_ISIG(tty)     _L_FLAG((tty), ISIG)
 148 #define L_ICANON(tty)   _L_FLAG((tty), ICANON)
 149 #define L_XCASE(tty)    _L_FLAG((tty), XCASE)
 150 #define L_ECHO(tty)     _L_FLAG((tty), ECHO)
 151 #define L_ECHOE(tty)    _L_FLAG((tty), ECHOE)
 152 #define L_ECHOK(tty)    _L_FLAG((tty), ECHOK)
 153 #define L_ECHONL(tty)   _L_FLAG((tty), ECHONL)
 154 #define L_NOFLSH(tty)   _L_FLAG((tty), NOFLSH)
 155 #define L_TOSTOP(tty)   _L_FLAG((tty), TOSTOP)
 156 #define L_ECHOCTL(tty)  _L_FLAG((tty), ECHOCTL)
 157 #define L_ECHOPRT(tty)  _L_FLAG((tty), ECHOPRT)
 158 #define L_ECHOKE(tty)   _L_FLAG((tty), ECHOKE)
 159 #define L_FLUSHO(tty)   _L_FLAG((tty), FLUSHO)
 160 #define L_PENDIN(tty)   _L_FLAG((tty), PENDIN)
 161 #define L_IEXTEN(tty)   _L_FLAG((tty), IEXTEN)
 162 #define L_EXTPROC(tty)  _L_FLAG((tty), EXTPROC)
 163
 164 struct device;
 165 struct signal_struct;
 166
 167 /*
 168  * Port level information. Each device keeps its own port level information
 169  * so provide a common structure for those ports wanting to use common support
 170  * routines.
 171  *
 172  * The tty port has a different lifetime to the tty so must be kept apart.
 173  * In addition be careful as tty -> port mappings are valid for the life
 174  * of the tty object but in many cases port -> tty mappings are valid only
 175  * until a hangup so don't use the wrong path.
 176  */
 177
 178 struct tty_port;
 179
 180 struct tty_port_operations {
 181         /* Return 1 if the carrier is raised */
 182         int (*carrier_raised)(struct tty_port *port);
 183         /* Control the DTR line */
 184         void (*dtr_rts)(struct tty_port *port, int raise);
 185         /* Called when the last close completes or a hangup finishes
 186            IFF the port was initialized. Do not use to free resources. Called
 187            under the port mutex to serialize against activate/shutdowns */
 188         void (*shutdown)(struct tty_port *port);
 189         /* Called under the port mutex from tty_port_open, serialized using
 190            the port mutex */
 191         /* FIXME: long term getting the tty argument *out* of this would be
 192            good for consoles */
 193         int (*activate)(struct tty_port *port, struct tty_struct *tty);
 194         /* Called on the final put of a port */
 195         void (*destruct)(struct tty_port *port);
 196 };
 197
 198 struct tty_port {
 199         struct tty_bufhead      buf;            /* Locked internally */
 200         struct tty_struct       *tty;           /* Back pointer */
 201         struct tty_struct       *itty;          /* internal back ptr */
 202         const struct tty_port_operations *ops;  /* Port operations */
 203         spinlock_t              lock;           /* Lock protecting tty field */
 204         int                     blocked_open;   /* Waiting to open */
 205         int                     count;          /* Usage count */
 206         wait_queue_head_t       open_wait;      /* Open waiters */
 207         wait_queue_head_t       close_wait;     /* Close waiters */
 208         wait_queue_head_t       delta_msr_wait; /* Modem status change */
 209         unsigned long           flags;          /* TTY flags ASY_*/
 210         unsigned char           console:1,      /* port is a console */
 211                                 low_latency:1;  /* optional: tune for latency */
 212         struct mutex            mutex;          /* Locking */
 213         struct mutex            buf_mutex;      /* Buffer alloc lock */
 214         unsigned char           *xmit_buf;      /* Optional buffer */
 215         unsigned int            close_delay;    /* Close port delay */
 216         unsigned int            closing_wait;   /* Delay for output */
 217         int                     drain_delay;    /* Set to zero if no pure time
 218                                                    based drain is needed else
 219                                                    set to size of fifo */
 220         struct kref             kref;           /* Ref counter */
 221 };
 222
 223 /*
 224  * Where all of the state associated with a tty is kept while the tty
 225  * is open.  Since the termios state should be kept even if the tty
 226  * has been closed --- for things like the baud rate, etc --- it is
 227  * not stored here, but rather a pointer to the real state is stored
 228  * here.  Possible the winsize structure should have the same
 229  * treatment, but (1) the default 80x24 is usually right and (2) it's
 230  * most often used by a windowing system, which will set the correct
 231  * size each time the window is created or resized anyway.
 232  *                                              - TYT, 9/14/92
 233  */
 234
 235 struct tty_operations;
 236
 237 struct tty_struct {
 238         int     magic;
 239         struct kref kref;
 240         struct device *dev;
 241         struct tty_driver *driver;
 242         const struct tty_operations *ops;
 243         int index;
 244
 245         /* Protects ldisc changes: Lock tty not pty */
 246         struct ld_semaphore ldisc_sem;
 247         struct tty_ldisc *ldisc;
 248
 249         struct mutex atomic_write_lock;
 250         struct mutex legacy_mutex;
 251         struct mutex throttle_mutex;
 252         struct rw_semaphore termios_rwsem;
 253         struct mutex winsize_mutex;
 254         spinlock_t ctrl_lock;
 255         /* Termios values are protected by the termios rwsem */
 256         struct ktermios termios, termios_locked;
 257         struct termiox *termiox;        /* May be NULL for unsupported */
 258         char name[64];
 259         struct pid *pgrp;               /* Protected by ctrl lock */
 260         struct pid *session;
 261         unsigned long flags;
 262         int count;
 263         struct winsize winsize;         /* winsize_mutex */
 264         unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
 265         unsigned char ctrl_status;      /* ctrl_lock */
 266         unsigned int receive_room;      /* Bytes free for queue */
 267         int flow_change;
 268
 269         struct tty_struct *link;
 270         struct fasync_struct *fasync;
 271         int alt_speed;          /* For magic substitution of 38400 bps */
 272         wait_queue_head_t write_wait;
 273         wait_queue_head_t read_wait;
 274         struct work_struct hangup_work;
 275         void *disc_data;
 276         void *driver_data;
 277         struct list_head tty_files;
 278
 279 #define N_TTY_BUF_SIZE 4096
 280
 281         unsigned char closing:1;
 282         unsigned char *write_buf;
 283         int write_cnt;
 284         /* If the tty has a pending do_SAK, queue it here - akpm */
 285         struct work_struct SAK_work;
 286         struct tty_port *port;
 287 };
 288
 289 /* Each of a tty's open files has private_data pointing to tty_file_private */
 290 struct tty_file_private {
 291         struct tty_struct *tty;
 292         struct file *file;
 293         struct list_head list;
 294 };
 295
 296 /* tty magic number */
 297 #define TTY_MAGIC               0x5401
 298
 299 /*
 300  * These bits are used in the flags field of the tty structure.
 301  *
 302  * So that interrupts won't be able to mess up the queues,
 303  * copy_to_cooked must be atomic with respect to itself, as must
 304  * tty->write.  Thus, you must use the inline functions set_bit() and
 305  * clear_bit() to make things atomic.
 306  */
 307 #define TTY_THROTTLED           0       /* Call unthrottle() at threshold min */
 308 #define TTY_IO_ERROR            1       /* Cause an I/O error (may be no ldisc too) */
 309 #define TTY_OTHER_CLOSED        2       /* Other side (if any) has closed */
 310 #define TTY_EXCLUSIVE           3       /* Exclusive open mode */
 311 #define TTY_DEBUG               4       /* Debugging */
 312 #define TTY_DO_WRITE_WAKEUP     5       /* Call write_wakeup after queuing new */
 313 #define TTY_CLOSING             7       /* ->close() in progress */
 314 #define TTY_LDISC_OPEN          11      /* Line discipline is open */
 315 #define TTY_PTY_LOCK            16      /* pty private */
 316 #define TTY_NO_WRITE_SPLIT      17      /* Preserve write boundaries to driver */
 317 #define TTY_HUPPED              18      /* Post driver->hangup() */
 318 #define TTY_HUPPING             21      /* ->hangup() in progress */
 319 #define TTY_LDISC_HALTED        22      /* Line discipline is halted */
 320
 321 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
 322
 323 /* Values for tty->flow_change */
 324 #define TTY_THROTTLE_SAFE 1
 325 #define TTY_UNTHROTTLE_SAFE 2
 326
 327 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
 328 {
 329         tty->flow_change = val;
 330 }
 331
 332 static inline void tty_set_flow_change(struct tty_struct *tty, int val)
 333 {
 334         tty->flow_change = val;
 335         smp_mb();
 336 }
 337
 338 #ifdef CONFIG_TTY
 339 extern void console_init(void);
 340 extern void tty_kref_put(struct tty_struct *tty);
 341 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
 342 extern void tty_vhangup_self(void);
 343 extern void disassociate_ctty(int priv);
 344 extern dev_t tty_devnum(struct tty_struct *tty);
 345 extern void proc_clear_tty(struct task_struct *p);
 346 extern struct tty_struct *get_current_tty(void);
 347 /* tty_io.c */
 348 extern int __init tty_init(void);
 349 #else
 350 static inline void console_init(void)
 351 { }
 352 static inline void tty_kref_put(struct tty_struct *tty)
 353 { }
 354 static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
 355 { return NULL; }
 356 static inline void tty_vhangup_self(void)
 357 { }
 358 static inline void disassociate_ctty(int priv)
 359 { }
 360 static inline dev_t tty_devnum(struct tty_struct *tty)
 361 { return 0; }
 362 static inline void proc_clear_tty(struct task_struct *p)
 363 { }
 364 static inline struct tty_struct *get_current_tty(void)
 365 { return NULL; }
 366 /* tty_io.c */
 367 static inline int __init tty_init(void)
 368 { return 0; }
 369 #endif
 370
 371 extern void tty_write_flush(struct tty_struct *);
 372
 373 extern struct ktermios tty_std_termios;
 374
 375 extern int vcs_init(void);
 376
 377 extern struct class *tty_class;
 378
 379 /**
 380  *      tty_kref_get            -       get a tty reference
 381  *      @tty: tty device
 382  *
 383  *      Return a new reference to a tty object. The caller must hold
 384  *      sufficient locks/counts to ensure that their existing reference cannot
 385  *      go away
 386  */
 387
 388 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
 389 {
 390         if (tty)
 391                 kref_get(&tty->kref);
 392         return tty;
 393 }
 394
 395 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
 396                               const char *routine);
 397 extern char *tty_name(struct tty_struct *tty, char *buf);
 398 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 399 extern int tty_check_change(struct tty_struct *tty);
 400 extern void stop_tty(struct tty_struct *tty);
 401 extern void start_tty(struct tty_struct *tty);
 402 extern int tty_register_driver(struct tty_driver *driver);
 403 extern int tty_unregister_driver(struct tty_driver *driver);
 404 extern struct device *tty_register_device(struct tty_driver *driver,
 405                                           unsigned index, struct device *dev);
 406 extern struct device *tty_register_device_attr(struct tty_driver *driver,
 407                                 unsigned index, struct device *device,
 408                                 void *drvdata,
 409                                 const struct attribute_group **attr_grp);
 410 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 411 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
 412                              int buflen);
 413 extern void tty_write_message(struct tty_struct *tty, char *msg);
 414 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
 415 extern int tty_chars_in_buffer(struct tty_struct *tty);
 416 extern int tty_write_room(struct tty_struct *tty);
 417 extern void tty_driver_flush_buffer(struct tty_struct *tty);
 418 extern void tty_throttle(struct tty_struct *tty);
 419 extern void tty_unthrottle(struct tty_struct *tty);
 420 extern int tty_throttle_safe(struct tty_struct *tty);
 421 extern int tty_unthrottle_safe(struct tty_struct *tty);
 422 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 423 extern void tty_driver_remove_tty(struct tty_driver *driver,
 424                                   struct tty_struct *tty);
 425 extern void tty_free_termios(struct tty_struct *tty);
 426 extern int is_current_pgrp_orphaned(void);
 427 extern int is_ignored(int sig);
 428 extern int tty_signal(int sig, struct tty_struct *tty);
 429 extern void tty_hangup(struct tty_struct *tty);
 430 extern void tty_vhangup(struct tty_struct *tty);
 431 extern void tty_unhangup(struct file *filp);
 432 extern int tty_hung_up_p(struct file *filp);
 433 extern void do_SAK(struct tty_struct *tty);
 434 extern void __do_SAK(struct tty_struct *tty);
 435 extern void no_tty(void);
 436 extern void tty_flush_to_ldisc(struct tty_struct *tty);
 437 extern void tty_buffer_free_all(struct tty_port *port);
 438 extern void tty_buffer_flush(struct tty_struct *tty);
 439 extern void tty_buffer_init(struct tty_port *port);
 440 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
 441 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 442 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
 443                                                 speed_t ibaud, speed_t obaud);
 444 extern void tty_encode_baud_rate(struct tty_struct *tty,
 445                                                 speed_t ibaud, speed_t obaud);
 446
 447 /**
 448  *      tty_get_baud_rate       -       get tty bit rates
 449  *      @tty: tty to query
 450  *
 451  *      Returns the baud rate as an integer for this terminal. The
 452  *      termios lock must be held by the caller and the terminal bit
 453  *      flags may be updated.
 454  *
 455  *      Locking: none
 456  */
 457 static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
 458 {
 459         return tty_termios_baud_rate(&tty->termios);
 460 }
 461
 462 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 463 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
 464 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 465
 466 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 467 extern void tty_ldisc_deref(struct tty_ldisc *);
 468 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
 469 extern void tty_ldisc_hangup(struct tty_struct *tty);
 470 extern const struct file_operations tty_ldiscs_proc_fops;
 471
 472 extern void tty_wakeup(struct tty_struct *tty);
 473 extern void tty_ldisc_flush(struct tty_struct *tty);
 474
 475 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 476 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 477                         unsigned int cmd, unsigned long arg);
 478 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
 479 extern void tty_default_fops(struct file_operations *fops);
 480 extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
 481 extern int tty_alloc_file(struct file *file);
 482 extern void tty_add_file(struct tty_struct *tty, struct file *file);
 483 extern void tty_free_file(struct file *file);
 484 extern void free_tty_struct(struct tty_struct *tty);
 485 extern void deinitialize_tty_struct(struct tty_struct *tty);
 486 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
 487 extern int tty_release(struct inode *inode, struct file *filp);
 488 extern int tty_init_termios(struct tty_struct *tty);
 489 extern int tty_standard_install(struct tty_driver *driver,
 490                 struct tty_struct *tty);
 491
 492 extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
 493 extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
 494
 495 extern struct mutex tty_mutex;
 496 extern spinlock_t tty_files_lock;
 497
 498 extern void tty_write_unlock(struct tty_struct *tty);
 499 extern int tty_write_lock(struct tty_struct *tty, int ndelay);
 500 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 501
 502 extern void tty_port_init(struct tty_port *port);
 503 extern void tty_port_link_device(struct tty_port *port,
 504                 struct tty_driver *driver, unsigned index);
 505 extern struct device *tty_port_register_device(struct tty_port *port,
 506                 struct tty_driver *driver, unsigned index,
 507                 struct device *device);
 508 extern struct device *tty_port_register_device_attr(struct tty_port *port,
 509                 struct tty_driver *driver, unsigned index,
 510                 struct device *device, void *drvdata,
 511                 const struct attribute_group **attr_grp);
 512 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 513 extern void tty_port_free_xmit_buf(struct tty_port *port);
 514 extern void tty_port_destroy(struct tty_port *port);
 515 extern void tty_port_put(struct tty_port *port);
 516
 517 static inline struct tty_port *tty_port_get(struct tty_port *port)
 518 {
 519         if (port && kref_get_unless_zero(&port->kref))
 520                 return port;
 521         return NULL;
 522 }
 523
 524 /* If the cts flow control is enabled, return true. */
 525 static inline bool tty_port_cts_enabled(struct tty_port *port)
 526 {
 527         return port->flags & ASYNC_CTS_FLOW;
 528 }
 529
 530 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
 531 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 532 extern int tty_port_carrier_raised(struct tty_port *port);
 533 extern void tty_port_raise_dtr_rts(struct tty_port *port);
 534 extern void tty_port_lower_dtr_rts(struct tty_port *port);
 535 extern void tty_port_hangup(struct tty_port *port);
 536 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
 537 extern void tty_port_tty_wakeup(struct tty_port *port);
 538 extern int tty_port_block_til_ready(struct tty_port *port,
 539                                 struct tty_struct *tty, struct file *filp);
 540 extern int tty_port_close_start(struct tty_port *port,
 541                                 struct tty_struct *tty, struct file *filp);
 542 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
 543 extern void tty_port_close(struct tty_port *port,
 544                                 struct tty_struct *tty, struct file *filp);
 545 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
 546                                 struct tty_struct *tty);
 547 extern int tty_port_open(struct tty_port *port,
 548                                 struct tty_struct *tty, struct file *filp);
 549 static inline int tty_port_users(struct tty_port *port)
 550 {
 551         return port->count + port->blocked_open;
 552 }
 553
 554 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 555 extern int tty_unregister_ldisc(int disc);
 556 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
 557 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 558 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
 559 extern void tty_ldisc_init(struct tty_struct *tty);
 560 extern void tty_ldisc_deinit(struct tty_struct *tty);
 561 extern void tty_ldisc_begin(void);
 562
 563 static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 564                                         char *f, int count)
 565 {
 566         if (ld->ops->receive_buf2)
 567                 count = ld->ops->receive_buf2(ld->tty, p, f, count);
 568         else {
 569                 count = min_t(int, count, ld->tty->receive_room);
 570                 if (count)
 571                         ld->ops->receive_buf(ld->tty, p, f, count);
 572         }
 573         return count;
 574 }
 575
 576
 577 /* n_tty.c */
 578 extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 579 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 580
 581 /* tty_audit.c */
 582 #ifdef CONFIG_AUDIT
 583 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
 584                                size_t size, unsigned icanon);
 585 extern void tty_audit_exit(void);
 586 extern void tty_audit_fork(struct signal_struct *sig);
 587 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
 588 extern void tty_audit_push(struct tty_struct *tty);
 589 extern int tty_audit_push_current(void);
 590 #else
 591 static inline void tty_audit_add_data(struct tty_struct *tty,
 592                 unsigned char *data, size_t size, unsigned icanon)
 593 {
 594 }
 595 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 596 {
 597 }
 598 static inline void tty_audit_exit(void)
 599 {
 600 }
 601 static inline void tty_audit_fork(struct signal_struct *sig)
 602 {
 603 }
 604 static inline void tty_audit_push(struct tty_struct *tty)
 605 {
 606 }
 607 static inline int tty_audit_push_current(void)
 608 {
 609         return 0;
 610 }
 611 #endif
 612
 613 /* tty_ioctl.c */
 614 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 615                        unsigned int cmd, unsigned long arg);
 616 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
 617                        unsigned int cmd, unsigned long arg);
 618
 619 /* serial.c */
 620
 621 extern void serial_console_init(void);
 622
 623 /* pcxx.c */
 624
 625 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
 626
 627 /* vt.c */
 628
 629 extern int vt_ioctl(struct tty_struct *tty,
 630                     unsigned int cmd, unsigned long arg);
 631
 632 extern long vt_compat_ioctl(struct tty_struct *tty,
 633                      unsigned int cmd, unsigned long arg);
 634
 635 /* tty_mutex.c */
 636 /* functions for preparation of BKL removal */
 637 extern void __lockfunc tty_lock(struct tty_struct *tty);
 638 extern void __lockfunc tty_unlock(struct tty_struct *tty);
 639 extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
 640                                 struct tty_struct *tty2);
 641 extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
 642                                 struct tty_struct *tty2);
 643
 644 /*
 645  * this shall be called only from where BTM is held (like close)
 646  *
 647  * We need this to ensure nobody waits for us to finish while we are waiting.
 648  * Without this we were encountering system stalls.
 649  *
 650  * This should be indeed removed with BTM removal later.
 651  *
 652  * Locking: BTM required. Nobody is allowed to hold port->mutex.
 653  */
 654 static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
 655                 long timeout)
 656 {
 657         tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
 658         tty_wait_until_sent(tty, timeout);
 659         tty_lock(tty);
 660 }
 661
 662 /*
 663  * wait_event_interruptible_tty -- wait for a condition with the tty lock held
 664  *
 665  * The condition we are waiting for might take a long time to
 666  * become true, or might depend on another thread taking the
 667  * BTM. In either case, we need to drop the BTM to guarantee
 668  * forward progress. This is a leftover from the conversion
 669  * from the BKL and should eventually get removed as the BTM
 670  * falls out of use.
 671  *
 672  * Do not use in new code.
 673  */
 674 #define wait_event_interruptible_tty(tty, wq, condition)                \
 675 ({                                                                      \
 676         int __ret = 0;                                                  \
 677         if (!(condition))                                               \
 678                 __ret = __wait_event_interruptible_tty(tty, wq,         \
 679                                                        condition);      \
 680         __ret;                                                          \
 681 })
 682
 683 #define __wait_event_interruptible_tty(tty, wq, condition)              \
 684         ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0,          \
 685                         tty_unlock(tty);                                \
 686                         schedule();                                     \
 687                         tty_lock(tty))
 688
 689 #ifdef CONFIG_PROC_FS
 690 extern void proc_tty_register_driver(struct tty_driver *);
 691 extern void proc_tty_unregister_driver(struct tty_driver *);
 692 #else
 693 static inline void proc_tty_register_driver(struct tty_driver *d) {}
 694 static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
 695 #endif
 696
 697 #endif