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
  14
  15
  16 /*
  17  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
  18  * hardcoded at present.)
  19  */
  20 #define NR_UNIX98_PTY_DEFAULT   4096      /* Default maximum for Unix98 ptys */
  21 #define NR_UNIX98_PTY_RESERVE   1024      /* Default reserve for main devpts */
  22 #define NR_UNIX98_PTY_MAX       (1 << MINORBITS) /* Absolute limit */
  23
  24 /*
  25  * This character is the same as _POSIX_VDISABLE: it cannot be used as
  26  * a c_cc[] character, but indicates that a particular special character
  27  * isn't in use (eg VINTR has no character etc)
  28  */
  29 #define __DISABLED_CHAR '\0'
  30
  31 struct tty_buffer {
  32         struct tty_buffer *next;
  33         char *char_buf_ptr;
  34         unsigned char *flag_buf_ptr;
  35         int used;
  36         int size;
  37         int commit;
  38         int read;
  39         /* Data points here */
  40         unsigned long data[0];
  41 };
  42
  43 /*
  44  * We default to dicing tty buffer allocations to this many characters
  45  * in order to avoid multiple page allocations. We know the size of
  46  * tty_buffer itself but it must also be taken into account that the
  47  * the buffer is 256 byte aligned. See tty_buffer_find for the allocation
  48  * logic this must match
  49  */
  50
  51 #define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF)
  52
  53
  54 struct tty_bufhead {
  55         struct work_struct work;
  56         spinlock_t lock;
  57         struct tty_buffer *head;        /* Queue head */
  58         struct tty_buffer *tail;        /* Active buffer */
  59         struct tty_buffer *free;        /* Free queue head */
  60         int memory_used;                /* Buffer space used excluding
  61                                                                 free queue */
  62 };
  63 /*
  64  * When a break, frame error, or parity error happens, these codes are
  65  * stuffed into the flags buffer.
  66  */
  67 #define TTY_NORMAL      0
  68 #define TTY_BREAK       1
  69 #define TTY_FRAME       2
  70 #define TTY_PARITY      3
  71 #define TTY_OVERRUN     4
  72
  73 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
  74 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
  75 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
  76 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
  77 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
  78 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
  79 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
  80 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
  81 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
  82 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
  83 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
  84 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
  85 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
  86 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
  87 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
  88 #define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
  89 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
  90
  91 #define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
  92 #define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
  93 #define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
  94 #define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
  95
  96 #define I_IGNBRK(tty)   _I_FLAG((tty), IGNBRK)
  97 #define I_BRKINT(tty)   _I_FLAG((tty), BRKINT)
  98 #define I_IGNPAR(tty)   _I_FLAG((tty), IGNPAR)
  99 #define I_PARMRK(tty)   _I_FLAG((tty), PARMRK)
 100 #define I_INPCK(tty)    _I_FLAG((tty), INPCK)
 101 #define I_ISTRIP(tty)   _I_FLAG((tty), ISTRIP)
 102 #define I_INLCR(tty)    _I_FLAG((tty), INLCR)
 103 #define I_IGNCR(tty)    _I_FLAG((tty), IGNCR)
 104 #define I_ICRNL(tty)    _I_FLAG((tty), ICRNL)
 105 #define I_IUCLC(tty)    _I_FLAG((tty), IUCLC)
 106 #define I_IXON(tty)     _I_FLAG((tty), IXON)
 107 #define I_IXANY(tty)    _I_FLAG((tty), IXANY)
 108 #define I_IXOFF(tty)    _I_FLAG((tty), IXOFF)
 109 #define I_IMAXBEL(tty)  _I_FLAG((tty), IMAXBEL)
 110 #define I_IUTF8(tty)    _I_FLAG((tty), IUTF8)
 111
 112 #define O_OPOST(tty)    _O_FLAG((tty), OPOST)
 113 #define O_OLCUC(tty)    _O_FLAG((tty), OLCUC)
 114 #define O_ONLCR(tty)    _O_FLAG((tty), ONLCR)
 115 #define O_OCRNL(tty)    _O_FLAG((tty), OCRNL)
 116 #define O_ONOCR(tty)    _O_FLAG((tty), ONOCR)
 117 #define O_ONLRET(tty)   _O_FLAG((tty), ONLRET)
 118 #define O_OFILL(tty)    _O_FLAG((tty), OFILL)
 119 #define O_OFDEL(tty)    _O_FLAG((tty), OFDEL)
 120 #define O_NLDLY(tty)    _O_FLAG((tty), NLDLY)
 121 #define O_CRDLY(tty)    _O_FLAG((tty), CRDLY)
 122 #define O_TABDLY(tty)   _O_FLAG((tty), TABDLY)
 123 #define O_BSDLY(tty)    _O_FLAG((tty), BSDLY)
 124 #define O_VTDLY(tty)    _O_FLAG((tty), VTDLY)
 125 #define O_FFDLY(tty)    _O_FLAG((tty), FFDLY)
 126
 127 #define C_BAUD(tty)     _C_FLAG((tty), CBAUD)
 128 #define C_CSIZE(tty)    _C_FLAG((tty), CSIZE)
 129 #define C_CSTOPB(tty)   _C_FLAG((tty), CSTOPB)
 130 #define C_CREAD(tty)    _C_FLAG((tty), CREAD)
 131 #define C_PARENB(tty)   _C_FLAG((tty), PARENB)
 132 #define C_PARODD(tty)   _C_FLAG((tty), PARODD)
 133 #define C_HUPCL(tty)    _C_FLAG((tty), HUPCL)
 134 #define C_CLOCAL(tty)   _C_FLAG((tty), CLOCAL)
 135 #define C_CIBAUD(tty)   _C_FLAG((tty), CIBAUD)
 136 #define C_CRTSCTS(tty)  _C_FLAG((tty), CRTSCTS)
 137
 138 #define L_ISIG(tty)     _L_FLAG((tty), ISIG)
 139 #define L_ICANON(tty)   _L_FLAG((tty), ICANON)
 140 #define L_XCASE(tty)    _L_FLAG((tty), XCASE)
 141 #define L_ECHO(tty)     _L_FLAG((tty), ECHO)
 142 #define L_ECHOE(tty)    _L_FLAG((tty), ECHOE)
 143 #define L_ECHOK(tty)    _L_FLAG((tty), ECHOK)
 144 #define L_ECHONL(tty)   _L_FLAG((tty), ECHONL)
 145 #define L_NOFLSH(tty)   _L_FLAG((tty), NOFLSH)
 146 #define L_TOSTOP(tty)   _L_FLAG((tty), TOSTOP)
 147 #define L_ECHOCTL(tty)  _L_FLAG((tty), ECHOCTL)
 148 #define L_ECHOPRT(tty)  _L_FLAG((tty), ECHOPRT)
 149 #define L_ECHOKE(tty)   _L_FLAG((tty), ECHOKE)
 150 #define L_FLUSHO(tty)   _L_FLAG((tty), FLUSHO)
 151 #define L_PENDIN(tty)   _L_FLAG((tty), PENDIN)
 152 #define L_IEXTEN(tty)   _L_FLAG((tty), IEXTEN)
 153 #define L_EXTPROC(tty)  _L_FLAG((tty), EXTPROC)
 154
 155 struct device;
 156 struct signal_struct;
 157
 158 /*
 159  * Port level information. Each device keeps its own port level information
 160  * so provide a common structure for those ports wanting to use common support
 161  * routines.
 162  *
 163  * The tty port has a different lifetime to the tty so must be kept apart.
 164  * In addition be careful as tty -> port mappings are valid for the life
 165  * of the tty object but in many cases port -> tty mappings are valid only
 166  * until a hangup so don't use the wrong path.
 167  */
 168
 169 struct tty_port;
 170
 171 struct tty_port_operations {
 172         /* Return 1 if the carrier is raised */
 173         int (*carrier_raised)(struct tty_port *port);
 174         /* Control the DTR line */
 175         void (*dtr_rts)(struct tty_port *port, int raise);
 176         /* Called when the last close completes or a hangup finishes
 177            IFF the port was initialized. Do not use to free resources. Called
 178            under the port mutex to serialize against activate/shutdowns */
 179         void (*shutdown)(struct tty_port *port);
 180         void (*drop)(struct tty_port *port);
 181         /* Called under the port mutex from tty_port_open, serialized using
 182            the port mutex */
 183         /* FIXME: long term getting the tty argument *out* of this would be
 184            good for consoles */
 185         int (*activate)(struct tty_port *port, struct tty_struct *tty);
 186         /* Called on the final put of a port */
 187         void (*destruct)(struct tty_port *port);
 188 };
 189
 190 struct tty_port {
 191         struct tty_struct       *tty;           /* Back pointer */
 192         const struct tty_port_operations *ops;  /* Port operations */
 193         spinlock_t              lock;           /* Lock protecting tty field */
 194         int                     blocked_open;   /* Waiting to open */
 195         int                     count;          /* Usage count */
 196         wait_queue_head_t       open_wait;      /* Open waiters */
 197         wait_queue_head_t       close_wait;     /* Close waiters */
 198         wait_queue_head_t       delta_msr_wait; /* Modem status change */
 199         unsigned long           flags;          /* TTY flags ASY_*/
 200         unsigned char           console:1;      /* port is a console */
 201         struct mutex            mutex;          /* Locking */
 202         struct mutex            buf_mutex;      /* Buffer alloc lock */
 203         unsigned char           *xmit_buf;      /* Optional buffer */
 204         unsigned int            close_delay;    /* Close port delay */
 205         unsigned int            closing_wait;   /* Delay for output */
 206         int                     drain_delay;    /* Set to zero if no pure time
 207                                                    based drain is needed else
 208                                                    set to size of fifo */
 209         struct kref             kref;           /* Ref counter */
 210 };
 211
 212 /*
 213  * Where all of the state associated with a tty is kept while the tty
 214  * is open.  Since the termios state should be kept even if the tty
 215  * has been closed --- for things like the baud rate, etc --- it is
 216  * not stored here, but rather a pointer to the real state is stored
 217  * here.  Possible the winsize structure should have the same
 218  * treatment, but (1) the default 80x24 is usually right and (2) it's
 219  * most often used by a windowing system, which will set the correct
 220  * size each time the window is created or resized anyway.
 221  *                                              - TYT, 9/14/92
 222  */
 223
 224 struct tty_operations;
 225
 226 struct tty_struct {
 227         int     magic;
 228         struct kref kref;
 229         struct device *dev;
 230         struct tty_driver *driver;
 231         const struct tty_operations *ops;
 232         int index;
 233
 234         /* Protects ldisc changes: Lock tty not pty */
 235         struct mutex ldisc_mutex;
 236         struct tty_ldisc *ldisc;
 237
 238         struct mutex legacy_mutex;
 239         struct mutex termios_mutex;
 240         spinlock_t ctrl_lock;
 241         /* Termios values are protected by the termios mutex */
 242         struct ktermios termios, termios_locked;
 243         struct termiox *termiox;        /* May be NULL for unsupported */
 244         char name[64];
 245         struct pid *pgrp;               /* Protected by ctrl lock */
 246         struct pid *session;
 247         unsigned long flags;
 248         int count;
 249         struct winsize winsize;         /* termios mutex */
 250         unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
 251         unsigned char low_latency:1, warned:1;
 252         unsigned char ctrl_status;      /* ctrl_lock */
 253         unsigned int receive_room;      /* Bytes free for queue */
 254
 255         struct tty_struct *link;
 256         struct fasync_struct *fasync;
 257         struct tty_bufhead buf;         /* Locked internally */
 258         int alt_speed;          /* For magic substitution of 38400 bps */
 259         wait_queue_head_t write_wait;
 260         wait_queue_head_t read_wait;
 261         struct work_struct hangup_work;
 262         void *disc_data;
 263         void *driver_data;
 264         struct list_head tty_files;
 265
 266 #define N_TTY_BUF_SIZE 4096
 267
 268         /*
 269          * The following is data for the N_TTY line discipline.  For
 270          * historical reasons, this is included in the tty structure.
 271          * Mostly locked by the BKL.
 272          */
 273         unsigned int column;
 274         unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
 275         unsigned char closing:1;
 276         unsigned char echo_overrun:1;
 277         unsigned short minimum_to_wake;
 278         unsigned long overrun_time;
 279         int num_overrun;
 280         unsigned long process_char_map[256/(8*sizeof(unsigned long))];
 281         char *read_buf;
 282         int read_head;
 283         int read_tail;
 284         int read_cnt;
 285         unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
 286         unsigned char *echo_buf;
 287         unsigned int echo_pos;
 288         unsigned int echo_cnt;
 289         int canon_data;
 290         unsigned long canon_head;
 291         unsigned int canon_column;
 292         struct mutex atomic_read_lock;
 293         struct mutex atomic_write_lock;
 294         struct mutex output_lock;
 295         struct mutex echo_lock;
 296         unsigned char *write_buf;
 297         int write_cnt;
 298         spinlock_t read_lock;
 299         /* If the tty has a pending do_SAK, queue it here - akpm */
 300         struct work_struct SAK_work;
 301         struct tty_port *port;
 302 };
 303
 304 /* Each of a tty's open files has private_data pointing to tty_file_private */
 305 struct tty_file_private {
 306         struct tty_struct *tty;
 307         struct file *file;
 308         struct list_head list;
 309 };
 310
 311 /* tty magic number */
 312 #define TTY_MAGIC               0x5401
 313
 314 /*
 315  * These bits are used in the flags field of the tty structure.
 316  *
 317  * So that interrupts won't be able to mess up the queues,
 318  * copy_to_cooked must be atomic with respect to itself, as must
 319  * tty->write.  Thus, you must use the inline functions set_bit() and
 320  * clear_bit() to make things atomic.
 321  */
 322 #define TTY_THROTTLED           0       /* Call unthrottle() at threshold min */
 323 #define TTY_IO_ERROR            1       /* Cause an I/O error (may be no ldisc too) */
 324 #define TTY_OTHER_CLOSED        2       /* Other side (if any) has closed */
 325 #define TTY_EXCLUSIVE           3       /* Exclusive open mode */
 326 #define TTY_DEBUG               4       /* Debugging */
 327 #define TTY_DO_WRITE_WAKEUP     5       /* Call write_wakeup after queuing new */
 328 #define TTY_PUSH                6       /* n_tty private */
 329 #define TTY_CLOSING             7       /* ->close() in progress */
 330 #define TTY_LDISC               9       /* Line discipline attached */
 331 #define TTY_LDISC_CHANGING      10      /* Line discipline changing */
 332 #define TTY_LDISC_OPEN          11      /* Line discipline is open */
 333 #define TTY_HW_COOK_OUT         14      /* Hardware can do output cooking */
 334 #define TTY_HW_COOK_IN          15      /* Hardware can do input cooking */
 335 #define TTY_PTY_LOCK            16      /* pty private */
 336 #define TTY_NO_WRITE_SPLIT      17      /* Preserve write boundaries to driver */
 337 #define TTY_HUPPED              18      /* Post driver->hangup() */
 338 #define TTY_FLUSHING            19      /* Flushing to ldisc in progress */
 339 #define TTY_FLUSHPENDING        20      /* Queued buffer flush pending */
 340 #define TTY_HUPPING             21      /* ->hangup() in progress */
 341
 342 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
 343
 344 extern void tty_write_flush(struct tty_struct *);
 345
 346 extern struct ktermios tty_std_termios;
 347
 348 extern void console_init(void);
 349 extern int vcs_init(void);
 350
 351 extern struct class *tty_class;
 352
 353 /**
 354  *      tty_kref_get            -       get a tty reference
 355  *      @tty: tty device
 356  *
 357  *      Return a new reference to a tty object. The caller must hold
 358  *      sufficient locks/counts to ensure that their existing reference cannot
 359  *      go away
 360  */
 361
 362 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
 363 {
 364         if (tty)
 365                 kref_get(&tty->kref);
 366         return tty;
 367 }
 368 extern void tty_kref_put(struct tty_struct *tty);
 369
 370 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
 371                               const char *routine);
 372 extern char *tty_name(struct tty_struct *tty, char *buf);
 373 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 374 extern int tty_check_change(struct tty_struct *tty);
 375 extern void stop_tty(struct tty_struct *tty);
 376 extern void start_tty(struct tty_struct *tty);
 377 extern int tty_register_driver(struct tty_driver *driver);
 378 extern int tty_unregister_driver(struct tty_driver *driver);
 379 extern struct device *tty_register_device(struct tty_driver *driver,
 380                                           unsigned index, struct device *dev);
 381 extern struct device *tty_register_device_attr(struct tty_driver *driver,
 382                                 unsigned index, struct device *device,
 383                                 void *drvdata,
 384                                 const struct attribute_group **attr_grp);
 385 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 386 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
 387                              int buflen);
 388 extern void tty_write_message(struct tty_struct *tty, char *msg);
 389 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
 390 extern int tty_chars_in_buffer(struct tty_struct *tty);
 391 extern int tty_write_room(struct tty_struct *tty);
 392 extern void tty_driver_flush_buffer(struct tty_struct *tty);
 393 extern void tty_throttle(struct tty_struct *tty);
 394 extern void tty_unthrottle(struct tty_struct *tty);
 395 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 396 extern void tty_driver_remove_tty(struct tty_driver *driver,
 397                                   struct tty_struct *tty);
 398 extern void tty_free_termios(struct tty_struct *tty);
 399 extern int is_current_pgrp_orphaned(void);
 400 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
 401 extern int is_ignored(int sig);
 402 extern int tty_signal(int sig, struct tty_struct *tty);
 403 extern void tty_hangup(struct tty_struct *tty);
 404 extern void tty_vhangup(struct tty_struct *tty);
 405 extern void tty_vhangup_locked(struct tty_struct *tty);
 406 extern void tty_vhangup_self(void);
 407 extern void tty_unhangup(struct file *filp);
 408 extern int tty_hung_up_p(struct file *filp);
 409 extern void do_SAK(struct tty_struct *tty);
 410 extern void __do_SAK(struct tty_struct *tty);
 411 extern void disassociate_ctty(int priv);
 412 extern void no_tty(void);
 413 extern void tty_flip_buffer_push(struct tty_struct *tty);
 414 extern void tty_flush_to_ldisc(struct tty_struct *tty);
 415 extern void tty_buffer_free_all(struct tty_struct *tty);
 416 extern void tty_buffer_flush(struct tty_struct *tty);
 417 extern void tty_buffer_init(struct tty_struct *tty);
 418 extern speed_t tty_get_baud_rate(struct tty_struct *tty);
 419 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
 420 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 421 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
 422                                                 speed_t ibaud, speed_t obaud);
 423 extern void tty_encode_baud_rate(struct tty_struct *tty,
 424                                                 speed_t ibaud, speed_t obaud);
 425 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 426 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
 427 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 428
 429 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 430 extern void tty_ldisc_deref(struct tty_ldisc *);
 431 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
 432 extern void tty_ldisc_hangup(struct tty_struct *tty);
 433 extern const struct file_operations tty_ldiscs_proc_fops;
 434
 435 extern void tty_wakeup(struct tty_struct *tty);
 436 extern void tty_ldisc_flush(struct tty_struct *tty);
 437
 438 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 439 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 440                         unsigned int cmd, unsigned long arg);
 441 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
 442 extern dev_t tty_devnum(struct tty_struct *tty);
 443 extern void proc_clear_tty(struct task_struct *p);
 444 extern struct tty_struct *get_current_tty(void);
 445 extern void tty_default_fops(struct file_operations *fops);
 446 extern struct tty_struct *alloc_tty_struct(void);
 447 extern int tty_alloc_file(struct file *file);
 448 extern void tty_add_file(struct tty_struct *tty, struct file *file);
 449 extern void tty_free_file(struct file *file);
 450 extern void free_tty_struct(struct tty_struct *tty);
 451 extern void initialize_tty_struct(struct tty_struct *tty,
 452                 struct tty_driver *driver, int idx);
 453 extern void deinitialize_tty_struct(struct tty_struct *tty);
 454 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
 455 extern int tty_release(struct inode *inode, struct file *filp);
 456 extern int tty_init_termios(struct tty_struct *tty);
 457 extern int tty_standard_install(struct tty_driver *driver,
 458                 struct tty_struct *tty);
 459
 460 extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
 461 extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
 462
 463 extern struct mutex tty_mutex;
 464 extern spinlock_t tty_files_lock;
 465
 466 extern void tty_write_unlock(struct tty_struct *tty);
 467 extern int tty_write_lock(struct tty_struct *tty, int ndelay);
 468 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 469
 470 extern void tty_port_init(struct tty_port *port);
 471 extern void tty_port_link_device(struct tty_port *port,
 472                 struct tty_driver *driver, unsigned index);
 473 extern struct device *tty_port_register_device(struct tty_port *port,
 474                 struct tty_driver *driver, unsigned index,
 475                 struct device *device);
 476 extern struct device *tty_port_register_device_attr(struct tty_port *port,
 477                 struct tty_driver *driver, unsigned index,
 478                 struct device *device, void *drvdata,
 479                 const struct attribute_group **attr_grp);
 480 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 481 extern void tty_port_free_xmit_buf(struct tty_port *port);
 482 extern void tty_port_put(struct tty_port *port);
 483
 484 static inline struct tty_port *tty_port_get(struct tty_port *port)
 485 {
 486         if (port)
 487                 kref_get(&port->kref);
 488         return port;
 489 }
 490
 491 /* If the cts flow control is enabled, return true. */
 492 static inline bool tty_port_cts_enabled(struct tty_port *port)
 493 {
 494         return port->flags & ASYNC_CTS_FLOW;
 495 }
 496
 497 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
 498 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 499 extern int tty_port_carrier_raised(struct tty_port *port);
 500 extern void tty_port_raise_dtr_rts(struct tty_port *port);
 501 extern void tty_port_lower_dtr_rts(struct tty_port *port);
 502 extern void tty_port_hangup(struct tty_port *port);
 503 extern int tty_port_block_til_ready(struct tty_port *port,
 504                                 struct tty_struct *tty, struct file *filp);
 505 extern int tty_port_close_start(struct tty_port *port,
 506                                 struct tty_struct *tty, struct file *filp);
 507 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
 508 extern void tty_port_close(struct tty_port *port,
 509                                 struct tty_struct *tty, struct file *filp);
 510 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
 511                                 struct tty_struct *tty);
 512 extern int tty_port_open(struct tty_port *port,
 513                                 struct tty_struct *tty, struct file *filp);
 514 static inline int tty_port_users(struct tty_port *port)
 515 {
 516         return port->count + port->blocked_open;
 517 }
 518
 519 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 520 extern int tty_unregister_ldisc(int disc);
 521 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
 522 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 523 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
 524 extern void tty_ldisc_init(struct tty_struct *tty);
 525 extern void tty_ldisc_deinit(struct tty_struct *tty);
 526 extern void tty_ldisc_begin(void);
 527 /* This last one is just for the tty layer internals and shouldn't be used elsewhere */
 528 extern void tty_ldisc_enable(struct tty_struct *tty);
 529
 530
 531 /* n_tty.c */
 532 extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 533 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 534
 535 /* tty_audit.c */
 536 #ifdef CONFIG_AUDIT
 537 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
 538                                size_t size);
 539 extern void tty_audit_exit(void);
 540 extern void tty_audit_fork(struct signal_struct *sig);
 541 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
 542 extern void tty_audit_push(struct tty_struct *tty);
 543 extern int tty_audit_push_task(struct task_struct *tsk,
 544                                kuid_t loginuid, u32 sessionid);
 545 #else
 546 static inline void tty_audit_add_data(struct tty_struct *tty,
 547                                       unsigned char *data, size_t size)
 548 {
 549 }
 550 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 551 {
 552 }
 553 static inline void tty_audit_exit(void)
 554 {
 555 }
 556 static inline void tty_audit_fork(struct signal_struct *sig)
 557 {
 558 }
 559 static inline void tty_audit_push(struct tty_struct *tty)
 560 {
 561 }
 562 static inline int tty_audit_push_task(struct task_struct *tsk,
 563                                       kuid_t loginuid, u32 sessionid)
 564 {
 565         return 0;
 566 }
 567 #endif
 568
 569 /* tty_io.c */
 570 extern int __init tty_init(void);
 571
 572 /* tty_ioctl.c */
 573 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 574                        unsigned int cmd, unsigned long arg);
 575 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
 576                        unsigned int cmd, unsigned long arg);
 577
 578 /* serial.c */
 579
 580 extern void serial_console_init(void);
 581
 582 /* pcxx.c */
 583
 584 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
 585
 586 /* vt.c */
 587
 588 extern int vt_ioctl(struct tty_struct *tty,
 589                     unsigned int cmd, unsigned long arg);
 590
 591 extern long vt_compat_ioctl(struct tty_struct *tty,
 592                      unsigned int cmd, unsigned long arg);
 593
 594 /* tty_mutex.c */
 595 /* functions for preparation of BKL removal */
 596 extern void __lockfunc tty_lock(struct tty_struct *tty);
 597 extern void __lockfunc tty_unlock(struct tty_struct *tty);
 598 extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
 599                                 struct tty_struct *tty2);
 600 extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
 601                                 struct tty_struct *tty2);
 602
 603 /*
 604  * this shall be called only from where BTM is held (like close)
 605  *
 606  * We need this to ensure nobody waits for us to finish while we are waiting.
 607  * Without this we were encountering system stalls.
 608  *
 609  * This should be indeed removed with BTM removal later.
 610  *
 611  * Locking: BTM required. Nobody is allowed to hold port->mutex.
 612  */
 613 static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
 614                 long timeout)
 615 {
 616         tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
 617         tty_wait_until_sent(tty, timeout);
 618         tty_lock(tty);
 619 }
 620
 621 /*
 622  * wait_event_interruptible_tty -- wait for a condition with the tty lock held
 623  *
 624  * The condition we are waiting for might take a long time to
 625  * become true, or might depend on another thread taking the
 626  * BTM. In either case, we need to drop the BTM to guarantee
 627  * forward progress. This is a leftover from the conversion
 628  * from the BKL and should eventually get removed as the BTM
 629  * falls out of use.
 630  *
 631  * Do not use in new code.
 632  */
 633 #define wait_event_interruptible_tty(tty, wq, condition)                \
 634 ({                                                                      \
 635         int __ret = 0;                                                  \
 636         if (!(condition)) {                                             \
 637                 __wait_event_interruptible_tty(tty, wq, condition, __ret);      \
 638         }                                                               \
 639         __ret;                                                          \
 640 })
 641
 642 #define __wait_event_interruptible_tty(tty, wq, condition, ret)         \
 643 do {                                                                    \
 644         DEFINE_WAIT(__wait);                                            \
 645                                                                         \
 646         for (;;) {                                                      \
 647                 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE);      \
 648                 if (condition)                                          \
 649                         break;                                          \
 650                 if (!signal_pending(current)) {                         \
 651                         tty_unlock(tty);                                        \
 652                         schedule();                                     \
 653                         tty_lock(tty);                                  \
 654                         continue;                                       \
 655                 }                                                       \
 656                 ret = -ERESTARTSYS;                                     \
 657                 break;                                                  \
 658         }                                                               \
 659         finish_wait(&wq, &__wait);                                      \
 660 } while (0)
 661
 662
 663 #endif