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