LXR linux/include/linux/tty.h

   1#ifndef _LINUX_TTY_H
   2#define _LINUX_TTY_H
   3
   4/*
   5 * 'tty.h' defines some structures used by tty_io.c and some defines.
   6 */
   7
   8#ifdef __KERNEL__
   9#include <linux/fs.h>
  10#include <linux/major.h>
  11#include <linux/termios.h>
  12#include <linux/workqueue.h>
  13#include <linux/tty_driver.h>
  14#include <linux/tty_ldisc.h>
  15#include <linux/mutex.h>
  16
  17#include <asm/system.h>
  18
  19
  20/*
  21 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
  22 * hardcoded at present.)
  23 */
  24#define NR_UNIX98_PTY_DEFAULT   4096      /* Default maximum for Unix98 ptys */
  25#define NR_UNIX98_PTY_MAX       (1 << MINORBITS) /* Absolute limit */
  26#define NR_LDISCS               20
  27
  28/* line disciplines */
  29#define N_TTY           0
  30#define N_SLIP          1
  31#define N_MOUSE         2
  32#define N_PPP           3
  33#define N_STRIP         4
  34#define N_AX25          5
  35#define N_X25           6       /* X.25 async */
  36#define N_6PACK         7
  37#define N_MASC          8       /* Reserved for Mobitex module <kaz@cafe.net> */
  38#define N_R3964         9       /* Reserved for Simatic R3964 module */
  39#define N_PROFIBUS_FDL  10      /* Reserved for Profibus */
  40#define N_IRDA          11      /* Linux IrDa - http://irda.sourceforge.net/ */
  41#define N_SMSBLOCK      12      /* SMS block mode - for talking to GSM data */
  42                                /* cards about SMS messages */
  43#define N_HDLC          13      /* synchronous HDLC */
  44#define N_SYNC_PPP      14      /* synchronous PPP */
  45#define N_HCI           15      /* Bluetooth HCI UART */
  46#define N_GIGASET_M101  16      /* Siemens Gigaset M101 serial DECT adapter */
  47#define N_SLCAN         17      /* Serial / USB serial CAN Adaptors */
  48#define N_PPS           18      /* Pulse per Second */
  49
  50#define N_V253          19      /* Codec control over voice modem */
  51
  52/*
  53 * This character is the same as _POSIX_VDISABLE: it cannot be used as
  54 * a c_cc[] character, but indicates that a particular special character
  55 * isn't in use (eg VINTR has no character etc)
  56 */
  57#define __DISABLED_CHAR '\0'
  58
  59struct tty_buffer {
  60        struct tty_buffer *next;
  61        char *char_buf_ptr;
  62        unsigned char *flag_buf_ptr;
  63        int used;
  64        int size;
  65        int commit;
  66        int read;
  67        /* Data points here */
  68        unsigned long data[0];
  69};
  70
  71struct tty_bufhead {
  72        struct delayed_work work;
  73        spinlock_t lock;
  74        struct tty_buffer *head;        /* Queue head */
  75        struct tty_buffer *tail;        /* Active buffer */
  76        struct tty_buffer *free;        /* Free queue head */
  77        int memory_used;                /* Buffer space used excluding
  78                                                                free queue */
  79};
  80/*
  81 * When a break, frame error, or parity error happens, these codes are
  82 * stuffed into the flags buffer.
  83 */
  84#define TTY_NORMAL      0
  85#define TTY_BREAK       1
  86#define TTY_FRAME       2
  87#define TTY_PARITY      3
  88#define TTY_OVERRUN     4
  89
  90#define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
  91#define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
  92#define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
  93#define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
  94#define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
  95#define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
  96#define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
  97#define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
  98#define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
  99#define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
 100#define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
 101#define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
 102#define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
 103#define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
 104#define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
 105#define LNEXT_CHAR(tty) ((tty)->termios->c_cc[VLNEXT])
 106#define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])
 107
 108#define _I_FLAG(tty, f) ((tty)->termios->c_iflag & (f))
 109#define _O_FLAG(tty, f) ((tty)->termios->c_oflag & (f))
 110#define _C_FLAG(tty, f) ((tty)->termios->c_cflag & (f))
 111#define _L_FLAG(tty, f) ((tty)->termios->c_lflag & (f))
 112
 113#define I_IGNBRK(tty)   _I_FLAG((tty), IGNBRK)
 114#define I_BRKINT(tty)   _I_FLAG((tty), BRKINT)
 115#define I_IGNPAR(tty)   _I_FLAG((tty), IGNPAR)
 116#define I_PARMRK(tty)   _I_FLAG((tty), PARMRK)
 117#define I_INPCK(tty)    _I_FLAG((tty), INPCK)
 118#define I_ISTRIP(tty)   _I_FLAG((tty), ISTRIP)
 119#define I_INLCR(tty)    _I_FLAG((tty), INLCR)
 120#define I_IGNCR(tty)    _I_FLAG((tty), IGNCR)
 121#define I_ICRNL(tty)    _I_FLAG((tty), ICRNL)
 122#define I_IUCLC(tty)    _I_FLAG((tty), IUCLC)
 123#define I_IXON(tty)     _I_FLAG((tty), IXON)
 124#define I_IXANY(tty)    _I_FLAG((tty), IXANY)
 125#define I_IXOFF(tty)    _I_FLAG((tty), IXOFF)
 126#define I_IMAXBEL(tty)  _I_FLAG((tty), IMAXBEL)
 127#define I_IUTF8(tty)    _I_FLAG((tty), IUTF8)
 128
 129#define O_OPOST(tty)    _O_FLAG((tty), OPOST)
 130#define O_OLCUC(tty)    _O_FLAG((tty), OLCUC)
 131#define O_ONLCR(tty)    _O_FLAG((tty), ONLCR)
 132#define O_OCRNL(tty)    _O_FLAG((tty), OCRNL)
 133#define O_ONOCR(tty)    _O_FLAG((tty), ONOCR)
 134#define O_ONLRET(tty)   _O_FLAG((tty), ONLRET)
 135#define O_OFILL(tty)    _O_FLAG((tty), OFILL)
 136#define O_OFDEL(tty)    _O_FLAG((tty), OFDEL)
 137#define O_NLDLY(tty)    _O_FLAG((tty), NLDLY)
 138#define O_CRDLY(tty)    _O_FLAG((tty), CRDLY)
 139#define O_TABDLY(tty)   _O_FLAG((tty), TABDLY)
 140#define O_BSDLY(tty)    _O_FLAG((tty), BSDLY)
 141#define O_VTDLY(tty)    _O_FLAG((tty), VTDLY)
 142#define O_FFDLY(tty)    _O_FLAG((tty), FFDLY)
 143
 144#define C_BAUD(tty)     _C_FLAG((tty), CBAUD)
 145#define C_CSIZE(tty)    _C_FLAG((tty), CSIZE)
 146#define C_CSTOPB(tty)   _C_FLAG((tty), CSTOPB)
 147#define C_CREAD(tty)    _C_FLAG((tty), CREAD)
 148#define C_PARENB(tty)   _C_FLAG((tty), PARENB)
 149#define C_PARODD(tty)   _C_FLAG((tty), PARODD)
 150#define C_HUPCL(tty)    _C_FLAG((tty), HUPCL)
 151#define C_CLOCAL(tty)   _C_FLAG((tty), CLOCAL)
 152#define C_CIBAUD(tty)   _C_FLAG((tty), CIBAUD)
 153#define C_CRTSCTS(tty)  _C_FLAG((tty), CRTSCTS)
 154
 155#define L_ISIG(tty)     _L_FLAG((tty), ISIG)
 156#define L_ICANON(tty)   _L_FLAG((tty), ICANON)
 157#define L_XCASE(tty)    _L_FLAG((tty), XCASE)
 158#define L_ECHO(tty)     _L_FLAG((tty), ECHO)
 159#define L_ECHOE(tty)    _L_FLAG((tty), ECHOE)
 160#define L_ECHOK(tty)    _L_FLAG((tty), ECHOK)
 161#define L_ECHONL(tty)   _L_FLAG((tty), ECHONL)
 162#define L_NOFLSH(tty)   _L_FLAG((tty), NOFLSH)
 163#define L_TOSTOP(tty)   _L_FLAG((tty), TOSTOP)
 164#define L_ECHOCTL(tty)  _L_FLAG((tty), ECHOCTL)
 165#define L_ECHOPRT(tty)  _L_FLAG((tty), ECHOPRT)
 166#define L_ECHOKE(tty)   _L_FLAG((tty), ECHOKE)
 167#define L_FLUSHO(tty)   _L_FLAG((tty), FLUSHO)
 168#define L_PENDIN(tty)   _L_FLAG((tty), PENDIN)
 169#define L_IEXTEN(tty)   _L_FLAG((tty), IEXTEN)
 170
 171struct device;
 172struct signal_struct;
 173
 174/*
 175 * Port level information. Each device keeps its own port level information
 176 * so provide a common structure for those ports wanting to use common support
 177 * routines.
 178 *
 179 * The tty port has a different lifetime to the tty so must be kept apart.
 180 * In addition be careful as tty -> port mappings are valid for the life
 181 * of the tty object but in many cases port -> tty mappings are valid only
 182 * until a hangup so don't use the wrong path.
 183 */
 184
 185struct tty_port;
 186
 187struct tty_port_operations {
 188        /* Return 1 if the carrier is raised */
 189        int (*carrier_raised)(struct tty_port *port);
 190        /* Control the DTR line */
 191        void (*dtr_rts)(struct tty_port *port, int raise);
 192        /* Called when the last close completes or a hangup finishes
 193           IFF the port was initialized. Do not use to free resources */
 194        void (*shutdown)(struct tty_port *port);
 195        void (*drop)(struct tty_port *port);
 196};
 197        
 198struct tty_port {
 199        struct tty_struct       *tty;           /* Back pointer */
 200        const struct tty_port_operations *ops;  /* Port operations */
 201        spinlock_t              lock;           /* Lock protecting tty field */
 202        int                     blocked_open;   /* Waiting to open */
 203        int                     count;          /* Usage count */
 204        wait_queue_head_t       open_wait;      /* Open waiters */
 205        wait_queue_head_t       close_wait;     /* Close waiters */
 206        wait_queue_head_t       delta_msr_wait; /* Modem status change */
 207        unsigned long           flags;          /* TTY flags ASY_*/
 208        struct mutex            mutex;          /* Locking */
 209        unsigned char           *xmit_buf;      /* Optional buffer */
 210        unsigned int            close_delay;    /* Close port delay */
 211        unsigned int            closing_wait;   /* Delay for output */
 212        int                     drain_delay;    /* Set to zero if no pure time
 213                                                   based drain is needed else
 214                                                   set to size of fifo */
 215};
 216
 217/*
 218 * Where all of the state associated with a tty is kept while the tty
 219 * is open.  Since the termios state should be kept even if the tty
 220 * has been closed --- for things like the baud rate, etc --- it is
 221 * not stored here, but rather a pointer to the real state is stored
 222 * here.  Possible the winsize structure should have the same
 223 * treatment, but (1) the default 80x24 is usually right and (2) it's
 224 * most often used by a windowing system, which will set the correct
 225 * size each time the window is created or resized anyway.
 226 *                                              - TYT, 9/14/92
 227 */
 228
 229struct tty_operations;
 230
 231struct tty_struct {
 232        int     magic;
 233        struct kref kref;
 234        struct tty_driver *driver;
 235        const struct tty_operations *ops;
 236        int index;
 237
 238        /* Protects ldisc changes: Lock tty not pty */
 239        struct mutex ldisc_mutex;
 240        struct tty_ldisc *ldisc;
 241
 242        struct mutex termios_mutex;
 243        spinlock_t ctrl_lock;
 244        /* Termios values are protected by the termios mutex */
 245        struct ktermios *termios, *termios_locked;
 246        struct termiox *termiox;        /* May be NULL for unsupported */
 247        char name[64];
 248        struct pid *pgrp;               /* Protected by ctrl lock */
 249        struct pid *session;
 250        unsigned long flags;
 251        int count;
 252        struct winsize winsize;         /* termios mutex */
 253        unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
 254        unsigned char low_latency:1, warned:1;
 255        unsigned char ctrl_status;      /* ctrl_lock */
 256        unsigned int receive_room;      /* Bytes free for queue */
 257
 258        struct tty_struct *link;
 259        struct fasync_struct *fasync;
 260        struct tty_bufhead buf;         /* Locked internally */
 261        int alt_speed;          /* For magic substitution of 38400 bps */
 262        wait_queue_head_t write_wait;
 263        wait_queue_head_t read_wait;
 264        struct work_struct hangup_work;
 265        void *disc_data;
 266        void *driver_data;
 267        struct list_head tty_files;
 268
 269#define N_TTY_BUF_SIZE 4096
 270
 271        /*
 272         * The following is data for the N_TTY line discipline.  For
 273         * historical reasons, this is included in the tty structure.
 274         * Mostly locked by the BKL.
 275         */
 276        unsigned int column;
 277        unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
 278        unsigned char closing:1;
 279        unsigned char echo_overrun:1;
 280        unsigned short minimum_to_wake;
 281        unsigned long overrun_time;
 282        int num_overrun;
 283        unsigned long process_char_map[256/(8*sizeof(unsigned long))];
 284        char *read_buf;
 285        int read_head;
 286        int read_tail;
 287        int read_cnt;
 288        unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
 289        unsigned char *echo_buf;
 290        unsigned int echo_pos;
 291        unsigned int echo_cnt;
 292        int canon_data;
 293        unsigned long canon_head;
 294        unsigned int canon_column;
 295        struct mutex atomic_read_lock;
 296        struct mutex atomic_write_lock;
 297        struct mutex output_lock;
 298        struct mutex echo_lock;
 299        unsigned char *write_buf;
 300        int write_cnt;
 301        spinlock_t read_lock;
 302        /* If the tty has a pending do_SAK, queue it here - akpm */
 303        struct work_struct SAK_work;
 304        struct tty_port *port;
 305};
 306
 307/* tty magic number */
 308#define TTY_MAGIC               0x5401
 309
 310/*
 311 * These bits are used in the flags field of the tty structure.
 312 *
 313 * So that interrupts won't be able to mess up the queues,
 314 * copy_to_cooked must be atomic with respect to itself, as must
 315 * tty->write.  Thus, you must use the inline functions set_bit() and
 316 * clear_bit() to make things atomic.
 317 */
 318#define TTY_THROTTLED           0       /* Call unthrottle() at threshold min */
 319#define TTY_IO_ERROR            1       /* Cause an I/O error (may be no ldisc too) */
 320#define TTY_OTHER_CLOSED        2       /* Other side (if any) has closed */
 321#define TTY_EXCLUSIVE           3       /* Exclusive open mode */
 322#define TTY_DEBUG               4       /* Debugging */
 323#define TTY_DO_WRITE_WAKEUP     5       /* Call write_wakeup after queuing new */
 324#define TTY_PUSH                6       /* n_tty private */
 325#define TTY_CLOSING             7       /* ->close() in progress */
 326#define TTY_LDISC               9       /* Line discipline attached */
 327#define TTY_LDISC_CHANGING      10      /* Line discipline changing */
 328#define TTY_LDISC_OPEN          11      /* Line discipline is open */
 329#define TTY_HW_COOK_OUT         14      /* Hardware can do output cooking */
 330#define TTY_HW_COOK_IN          15      /* Hardware can do input cooking */
 331#define TTY_PTY_LOCK            16      /* pty private */
 332#define TTY_NO_WRITE_SPLIT      17      /* Preserve write boundaries to driver */
 333#define TTY_HUPPED              18      /* Post driver->hangup() */
 334#define TTY_FLUSHING            19      /* Flushing to ldisc in progress */
 335#define TTY_FLUSHPENDING        20      /* Queued buffer flush pending */
 336
 337#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
 338
 339extern void tty_write_flush(struct tty_struct *);
 340
 341extern struct ktermios tty_std_termios;
 342
 343extern int kmsg_redirect;
 344
 345extern void console_init(void);
 346extern int vcs_init(void);
 347
 348extern struct class *tty_class;
 349
 350/**
 351 *      tty_kref_get            -       get a tty reference
 352 *      @tty: tty device
 353 *
 354 *      Return a new reference to a tty object. The caller must hold
 355 *      sufficient locks/counts to ensure that their existing reference cannot
 356 *      go away
 357 */
 358
 359static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
 360{
 361        if (tty)
 362                kref_get(&tty->kref);
 363        return tty;
 364}
 365extern void tty_kref_put(struct tty_struct *tty);
 366
 367extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
 368                              const char *routine);
 369extern char *tty_name(struct tty_struct *tty, char *buf);
 370extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 371extern int tty_check_change(struct tty_struct *tty);
 372extern void stop_tty(struct tty_struct *tty);
 373extern void start_tty(struct tty_struct *tty);
 374extern int tty_register_driver(struct tty_driver *driver);
 375extern int tty_unregister_driver(struct tty_driver *driver);
 376extern struct device *tty_register_device(struct tty_driver *driver,
 377                                          unsigned index, struct device *dev);
 378extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 379extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
 380                             int buflen);
 381extern void tty_write_message(struct tty_struct *tty, char *msg);
 382extern int tty_put_char(struct tty_struct *tty, unsigned char c);
 383extern int tty_chars_in_buffer(struct tty_struct *tty);
 384extern int tty_write_room(struct tty_struct *tty);
 385extern void tty_driver_flush_buffer(struct tty_struct *tty);
 386extern void tty_throttle(struct tty_struct *tty);
 387extern void tty_unthrottle(struct tty_struct *tty);
 388extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 389extern void tty_shutdown(struct tty_struct *tty);
 390extern void tty_free_termios(struct tty_struct *tty);
 391extern int is_current_pgrp_orphaned(void);
 392extern struct pid *tty_get_pgrp(struct tty_struct *tty);
 393extern int is_ignored(int sig);
 394extern int tty_signal(int sig, struct tty_struct *tty);
 395extern void tty_hangup(struct tty_struct *tty);
 396extern void tty_vhangup(struct tty_struct *tty);
 397extern void tty_vhangup_self(void);
 398extern void tty_unhangup(struct file *filp);
 399extern int tty_hung_up_p(struct file *filp);
 400extern void do_SAK(struct tty_struct *tty);
 401extern void __do_SAK(struct tty_struct *tty);
 402extern void disassociate_ctty(int priv);
 403extern void no_tty(void);
 404extern void tty_flip_buffer_push(struct tty_struct *tty);
 405extern void tty_flush_to_ldisc(struct tty_struct *tty);
 406extern void tty_buffer_free_all(struct tty_struct *tty);
 407extern void tty_buffer_flush(struct tty_struct *tty);
 408extern void tty_buffer_init(struct tty_struct *tty);
 409extern speed_t tty_get_baud_rate(struct tty_struct *tty);
 410extern speed_t tty_termios_baud_rate(struct ktermios *termios);
 411extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 412extern void tty_termios_encode_baud_rate(struct ktermios *termios,
 413                                                speed_t ibaud, speed_t obaud);
 414extern void tty_encode_baud_rate(struct tty_struct *tty,
 415                                                speed_t ibaud, speed_t obaud);
 416extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 417extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
 418
 419extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 420extern void tty_ldisc_deref(struct tty_ldisc *);
 421extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
 422extern void tty_ldisc_hangup(struct tty_struct *tty);
 423extern const struct file_operations tty_ldiscs_proc_fops;
 424
 425extern void tty_wakeup(struct tty_struct *tty);
 426extern void tty_ldisc_flush(struct tty_struct *tty);
 427
 428extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 429extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 430                        unsigned int cmd, unsigned long arg);
 431extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
 432extern dev_t tty_devnum(struct tty_struct *tty);
 433extern void proc_clear_tty(struct task_struct *p);
 434extern struct tty_struct *get_current_tty(void);
 435extern void tty_default_fops(struct file_operations *fops);
 436extern struct tty_struct *alloc_tty_struct(void);
 437extern void free_tty_struct(struct tty_struct *tty);
 438extern void initialize_tty_struct(struct tty_struct *tty,
 439                struct tty_driver *driver, int idx);
 440extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
 441                                                                int first_ok);
 442extern void tty_release_dev(struct file *filp);
 443extern int tty_init_termios(struct tty_struct *tty);
 444
 445extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
 446extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
 447
 448extern struct mutex tty_mutex;
 449
 450extern void tty_write_unlock(struct tty_struct *tty);
 451extern int tty_write_lock(struct tty_struct *tty, int ndelay);
 452#define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 453
 454extern void tty_port_init(struct tty_port *port);
 455extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 456extern void tty_port_free_xmit_buf(struct tty_port *port);
 457extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
 458extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 459extern int tty_port_carrier_raised(struct tty_port *port);
 460extern void tty_port_raise_dtr_rts(struct tty_port *port);
 461extern void tty_port_lower_dtr_rts(struct tty_port *port);
 462extern void tty_port_hangup(struct tty_port *port);
 463extern int tty_port_block_til_ready(struct tty_port *port,
 464                                struct tty_struct *tty, struct file *filp);
 465extern int tty_port_close_start(struct tty_port *port,
 466                                struct tty_struct *tty, struct file *filp);
 467extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
 468extern void tty_port_close(struct tty_port *port,
 469                                struct tty_struct *tty, struct file *filp);
 470extern inline int tty_port_users(struct tty_port *port)
 471{
 472        return port->count + port->blocked_open;
 473}
 474
 475extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 476extern int tty_unregister_ldisc(int disc);
 477extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
 478extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 479extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
 480extern void tty_ldisc_init(struct tty_struct *tty);
 481extern void tty_ldisc_begin(void);
 482/* This last one is just for the tty layer internals and shouldn't be used elsewhere */
 483extern void tty_ldisc_enable(struct tty_struct *tty);
 484
 485
 486/* n_tty.c */
 487extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 488
 489/* tty_audit.c */
 490#ifdef CONFIG_AUDIT
 491extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
 492                               size_t size);
 493extern void tty_audit_exit(void);
 494extern void tty_audit_fork(struct signal_struct *sig);
 495extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
 496extern void tty_audit_push(struct tty_struct *tty);
 497extern void tty_audit_push_task(struct task_struct *tsk,
 498                                        uid_t loginuid, u32 sessionid);
 499#else
 500static inline void tty_audit_add_data(struct tty_struct *tty,
 501                                      unsigned char *data, size_t size)
 502{
 503}
 504static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 505{
 506}
 507static inline void tty_audit_exit(void)
 508{
 509}
 510static inline void tty_audit_fork(struct signal_struct *sig)
 511{
 512}
 513static inline void tty_audit_push(struct tty_struct *tty)
 514{
 515}
 516static inline void tty_audit_push_task(struct task_struct *tsk,
 517                                        uid_t loginuid, u32 sessionid)
 518{
 519}
 520#endif
 521
 522/* tty_ioctl.c */
 523extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 524                       unsigned int cmd, unsigned long arg);
 525
 526/* serial.c */
 527
 528extern void serial_console_init(void);
 529
 530/* pcxx.c */
 531
 532extern int pcxe_open(struct tty_struct *tty, struct file *filp);
 533
 534/* vt.c */
 535
 536extern int vt_ioctl(struct tty_struct *tty, struct file *file,
 537                    unsigned int cmd, unsigned long arg);
 538
 539extern long vt_compat_ioctl(struct tty_struct *tty, struct file * file,
 540                     unsigned int cmd, unsigned long arg);
 541
 542#endif /* __KERNEL__ */
 543#endif
 544