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         spinlock_t         flush_lock;
  65         atomic_t           priority;
  66         struct tty_buffer sentinel;
  67         struct llist_head free;         /* Free queue head */
  68         atomic_t           mem_used;    /* In-use buffers excluding free list */
  69         int                mem_limit;
  70         struct tty_buffer *tail;        /* Active buffer */
  71 };
  72 /*
  73  * When a break, frame error, or parity error happens, these codes are
  74  * stuffed into the flags buffer.
  75  */
  76 #define TTY_NORMAL      0
  77 #define TTY_BREAK       1
  78 #define TTY_FRAME       2
  79 #define TTY_PARITY      3
  80 #define TTY_OVERRUN     4
  81
  82 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
  83 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
  84 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
  85 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
  86 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
  87 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
  88 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
  89 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
  90 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
  91 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
  92 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
  93 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
  94 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
  95 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
  96 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
  97 #define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
  98 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
  99
 100 #define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
 101 #define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
 102 #define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
 103 #define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
 104
 105 #define I_IGNBRK(tty)   _I_FLAG((tty), IGNBRK)
 106 #define I_BRKINT(tty)   _I_FLAG((tty), BRKINT)
 107 #define I_IGNPAR(tty)   _I_FLAG((tty), IGNPAR)
 108 #define I_PARMRK(tty)   _I_FLAG((tty), PARMRK)
 109 #define I_INPCK(tty)    _I_FLAG((tty), INPCK)
 110 #define I_ISTRIP(tty)   _I_FLAG((tty), ISTRIP)
 111 #define I_INLCR(tty)    _I_FLAG((tty), INLCR)
 112 #define I_IGNCR(tty)    _I_FLAG((tty), IGNCR)
 113 #define I_ICRNL(tty)    _I_FLAG((tty), ICRNL)
 114 #define I_IUCLC(tty)    _I_FLAG((tty), IUCLC)
 115 #define I_IXON(tty)     _I_FLAG((tty), IXON)
 116 #define I_IXANY(tty)    _I_FLAG((tty), IXANY)
 117 #define I_IXOFF(tty)    _I_FLAG((tty), IXOFF)
 118 #define I_IMAXBEL(tty)  _I_FLAG((tty), IMAXBEL)
 119 #define I_IUTF8(tty)    _I_FLAG((tty), IUTF8)
 120
 121 #define O_OPOST(tty)    _O_FLAG((tty), OPOST)
 122 #define O_OLCUC(tty)    _O_FLAG((tty), OLCUC)
 123 #define O_ONLCR(tty)    _O_FLAG((tty), ONLCR)
 124 #define O_OCRNL(tty)    _O_FLAG((tty), OCRNL)
 125 #define O_ONOCR(tty)    _O_FLAG((tty), ONOCR)
 126 #define O_ONLRET(tty)   _O_FLAG((tty), ONLRET)
 127 #define O_OFILL(tty)    _O_FLAG((tty), OFILL)
 128 #define O_OFDEL(tty)    _O_FLAG((tty), OFDEL)
 129 #define O_NLDLY(tty)    _O_FLAG((tty), NLDLY)
 130 #define O_CRDLY(tty)    _O_FLAG((tty), CRDLY)
 131 #define O_TABDLY(tty)   _O_FLAG((tty), TABDLY)
 132 #define O_BSDLY(tty)    _O_FLAG((tty), BSDLY)
 133 #define O_VTDLY(tty)    _O_FLAG((tty), VTDLY)
 134 #define O_FFDLY(tty)    _O_FLAG((tty), FFDLY)
 135
 136 #define C_BAUD(tty)     _C_FLAG((tty), CBAUD)
 137 #define C_CSIZE(tty)    _C_FLAG((tty), CSIZE)
 138 #define C_CSTOPB(tty)   _C_FLAG((tty), CSTOPB)
 139 #define C_CREAD(tty)    _C_FLAG((tty), CREAD)
 140 #define C_PARENB(tty)   _C_FLAG((tty), PARENB)
 141 #define C_PARODD(tty)   _C_FLAG((tty), PARODD)
 142 #define C_HUPCL(tty)    _C_FLAG((tty), HUPCL)
 143 #define C_CLOCAL(tty)   _C_FLAG((tty), CLOCAL)
 144 #define C_CIBAUD(tty)   _C_FLAG((tty), CIBAUD)
 145 #define C_CRTSCTS(tty)  _C_FLAG((tty), CRTSCTS)
 146 #define C_CMSPAR(tty)   _C_FLAG((tty), CMSPAR)
 147
 148 #define L_ISIG(tty)     _L_FLAG((tty), ISIG)
 149 #define L_ICANON(tty)   _L_FLAG((tty), ICANON)
 150 #define L_XCASE(tty)    _L_FLAG((tty), XCASE)
 151 #define L_ECHO(tty)     _L_FLAG((tty), ECHO)
 152 #define L_ECHOE(tty)    _L_FLAG((tty), ECHOE)
 153 #define L_ECHOK(tty)    _L_FLAG((tty), ECHOK)
 154 #define L_ECHONL(tty)   _L_FLAG((tty), ECHONL)
 155 #define L_NOFLSH(tty)   _L_FLAG((tty), NOFLSH)
 156 #define L_TOSTOP(tty)   _L_FLAG((tty), TOSTOP)
 157 #define L_ECHOCTL(tty)  _L_FLAG((tty), ECHOCTL)
 158 #define L_ECHOPRT(tty)  _L_FLAG((tty), ECHOPRT)
 159 #define L_ECHOKE(tty)   _L_FLAG((tty), ECHOKE)
 160 #define L_FLUSHO(tty)   _L_FLAG((tty), FLUSHO)
 161 #define L_PENDIN(tty)   _L_FLAG((tty), PENDIN)
 162 #define L_IEXTEN(tty)   _L_FLAG((tty), IEXTEN)
 163 #define L_EXTPROC(tty)  _L_FLAG((tty), EXTPROC)
 164
 165 struct device;
 166 struct signal_struct;
 167
 168 /*
 169  * Port level information. Each device keeps its own port level information
 170  * so provide a common structure for those ports wanting to use common support
 171  * routines.
 172  *
 173  * The tty port has a different lifetime to the tty so must be kept apart.
 174  * In addition be careful as tty -> port mappings are valid for the life
 175  * of the tty object but in many cases port -> tty mappings are valid only
 176  * until a hangup so don't use the wrong path.
 177  */
 178
 179 struct tty_port;
 180
 181 struct tty_port_operations {
 182         /* Return 1 if the carrier is raised */
 183         int (*carrier_raised)(struct tty_port *port);
 184         /* Control the DTR line */
 185         void (*dtr_rts)(struct tty_port *port, int raise);
 186         /* Called when the last close completes or a hangup finishes
 187            IFF the port was initialized. Do not use to free resources. Called
 188            under the port mutex to serialize against activate/shutdowns */
 189         void (*shutdown)(struct tty_port *port);
 190         /* Called under the port mutex from tty_port_open, serialized using
 191            the port mutex */
 192         /* FIXME: long term getting the tty argument *out* of this would be
 193            good for consoles */
 194         int (*activate)(struct tty_port *port, struct tty_struct *tty);
 195         /* Called on the final put of a port */
 196         void (*destruct)(struct tty_port *port);
 197 };
 198
 199 struct tty_port {
 200         struct tty_bufhead      buf;            /* Locked internally */
 201         struct tty_struct       *tty;           /* Back pointer */
 202         struct tty_struct       *itty;          /* internal back ptr */
 203         const struct tty_port_operations *ops;  /* Port operations */
 204         spinlock_t              lock;           /* Lock protecting tty field */
 205         int                     blocked_open;   /* Waiting to open */
 206         int                     count;          /* Usage count */
 207         wait_queue_head_t       open_wait;      /* Open waiters */
 208         wait_queue_head_t       close_wait;     /* Close waiters */
 209         wait_queue_head_t       delta_msr_wait; /* Modem status change */
 210         unsigned long           flags;          /* TTY flags ASY_*/
 211         unsigned char           console:1,      /* port is a console */
 212                                 low_latency:1;  /* optional: tune for latency */
 213         struct mutex            mutex;          /* Locking */
 214         struct mutex            buf_mutex;      /* Buffer alloc lock */
 215         unsigned char           *xmit_buf;      /* Optional buffer */
 216         unsigned int            close_delay;    /* Close port delay */
 217         unsigned int            closing_wait;   /* Delay for output */
 218         int                     drain_delay;    /* Set to zero if no pure time
 219                                                    based drain is needed else
 220                                                    set to size of fifo */
 221         struct kref             kref;           /* Ref counter */
 222 };
 223
 224 /*
 225  * Where all of the state associated with a tty is kept while the tty
 226  * is open.  Since the termios state should be kept even if the tty
 227  * has been closed --- for things like the baud rate, etc --- it is
 228  * not stored here, but rather a pointer to the real state is stored
 229  * here.  Possible the winsize structure should have the same
 230  * treatment, but (1) the default 80x24 is usually right and (2) it's
 231  * most often used by a windowing system, which will set the correct
 232  * size each time the window is created or resized anyway.
 233  *                                              - TYT, 9/14/92
 234  */
 235
 236 struct tty_operations;
 237
 238 struct tty_struct {
 239         int     magic;
 240         struct kref kref;
 241         struct device *dev;
 242         struct tty_driver *driver;
 243         const struct tty_operations *ops;
 244         int index;
 245
 246         /* Protects ldisc changes: Lock tty not pty */
 247         struct ld_semaphore ldisc_sem;
 248         struct tty_ldisc *ldisc;
 249
 250         struct mutex atomic_write_lock;
 251         struct mutex legacy_mutex;
 252         struct mutex throttle_mutex;
 253         struct rw_semaphore termios_rwsem;
 254         struct mutex winsize_mutex;
 255         spinlock_t ctrl_lock;
 256         /* Termios values are protected by the termios rwsem */
 257         struct ktermios termios, termios_locked;
 258         struct termiox *termiox;        /* May be NULL for unsupported */
 259         char name[64];
 260         struct pid *pgrp;               /* Protected by ctrl lock */
 261         struct pid *session;
 262         unsigned long flags;
 263         int count;
 264         struct winsize winsize;         /* winsize_mutex */
 265         unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
 266         unsigned char ctrl_status;      /* ctrl_lock */
 267         unsigned int receive_room;      /* Bytes free for queue */
 268         int flow_change;
 269
 270         struct tty_struct *link;
 271         struct fasync_struct *fasync;
 272         int alt_speed;          /* For magic substitution of 38400 bps */
 273         wait_queue_head_t write_wait;
 274         wait_queue_head_t read_wait;
 275         struct work_struct hangup_work;
 276         void *disc_data;
 277         void *driver_data;
 278         struct list_head tty_files;
 279
 280 #define N_TTY_BUF_SIZE 4096
 281
 282         unsigned char closing:1;
 283         unsigned char *write_buf;
 284         int write_cnt;
 285         /* If the tty has a pending do_SAK, queue it here - akpm */
 286         struct work_struct SAK_work;
 287         struct tty_port *port;
 288 };
 289
 290 /* Each of a tty's open files has private_data pointing to tty_file_private */
 291 struct tty_file_private {
 292         struct tty_struct *tty;
 293         struct file *file;
 294         struct list_head list;
 295 };
 296
 297 /* tty magic number */
 298 #define TTY_MAGIC               0x5401
 299
 300 /*
 301  * These bits are used in the flags field of the tty structure.
 302  *
 303  * So that interrupts won't be able to mess up the queues,
 304  * copy_to_cooked must be atomic with respect to itself, as must
 305  * tty->write.  Thus, you must use the inline functions set_bit() and
 306  * clear_bit() to make things atomic.
 307  */
 308 #define TTY_THROTTLED           0       /* Call unthrottle() at threshold min */
 309 #define TTY_IO_ERROR            1       /* Cause an I/O error (may be no ldisc too) */
 310 #define TTY_OTHER_CLOSED        2       /* Other side (if any) has closed */
 311 #define TTY_EXCLUSIVE           3       /* Exclusive open mode */
 312 #define TTY_DEBUG               4       /* Debugging */
 313 #define TTY_DO_WRITE_WAKEUP     5       /* Call write_wakeup after queuing new */
 314 #define TTY_CLOSING             7       /* ->close() in progress */
 315 #define TTY_LDISC_OPEN          11      /* Line discipline is open */
 316 #define TTY_PTY_LOCK            16      /* pty private */
 317 #define TTY_NO_WRITE_SPLIT      17      /* Preserve write boundaries to driver */
 318 #define TTY_HUPPED              18      /* Post driver->hangup() */
 319 #define TTY_HUPPING             21      /* ->hangup() in progress */
 320 #define TTY_LDISC_HALTED        22      /* Line discipline is halted */
 321
 322 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
 323
 324 /* Values for tty->flow_change */
 325 #define TTY_THROTTLE_SAFE 1
 326 #define TTY_UNTHROTTLE_SAFE 2
 327
 328 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
 329 {
 330         tty->flow_change = val;
 331 }
 332
 333 static inline void tty_set_flow_change(struct tty_struct *tty, int val)
 334 {
 335         tty->flow_change = val;
 336         smp_mb();
 337 }
 338
 339 #ifdef CONFIG_TTY
 340 extern void console_init(void);
 341 extern void tty_kref_put(struct tty_struct *tty);
 342 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
 343 extern void tty_vhangup_self(void);
 344 extern void disassociate_ctty(int priv);
 345 extern dev_t tty_devnum(struct tty_struct *tty);
 346 extern void proc_clear_tty(struct task_struct *p);
 347 extern struct tty_struct *get_current_tty(void);
 348 /* tty_io.c */
 349 extern int __init tty_init(void);
 350 #else
 351 static inline void console_init(void)
 352 { }
 353 static inline void tty_kref_put(struct tty_struct *tty)
 354 { }
 355 static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
 356 { return NULL; }
 357 static inline void tty_vhangup_self(void)
 358 { }
 359 static inline void disassociate_ctty(int priv)
 360 { }
 361 static inline dev_t tty_devnum(struct tty_struct *tty)
 362 { return 0; }
 363 static inline void proc_clear_tty(struct task_struct *p)
 364 { }
 365 static inline struct tty_struct *get_current_tty(void)
 366 { return NULL; }
 367 /* tty_io.c */
 368 static inline int __init tty_init(void)
 369 { return 0; }
 370 #endif
 371
 372 extern void tty_write_flush(struct tty_struct *);
 373
 374 extern struct ktermios tty_std_termios;
 375
 376 extern int vcs_init(void);
 377
 378 extern struct class *tty_class;
 379
 380 /**
 381  *      tty_kref_get            -       get a tty reference
 382  *      @tty: tty device
 383  *
 384  *      Return a new reference to a tty object. The caller must hold
 385  *      sufficient locks/counts to ensure that their existing reference cannot
 386  *      go away
 387  */
 388
 389 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
 390 {
 391         if (tty)
 392                 kref_get(&tty->kref);
 393         return tty;
 394 }
 395
 396 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
 397                               const char *routine);
 398 extern char *tty_name(struct tty_struct *tty, char *buf);
 399 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 400 extern int tty_check_change(struct tty_struct *tty);
 401 extern void stop_tty(struct tty_struct *tty);
 402 extern void start_tty(struct tty_struct *tty);
 403 extern int tty_register_driver(struct tty_driver *driver);
 404 extern int tty_unregister_driver(struct tty_driver *driver);
 405 extern struct device *tty_register_device(struct tty_driver *driver,
 406                                           unsigned index, struct device *dev);
 407 extern struct device *tty_register_device_attr(struct tty_driver *driver,
 408                                 unsigned index, struct device *device,
 409                                 void *drvdata,
 410                                 const struct attribute_group **attr_grp);
 411 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 412 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
 413                              int buflen);
 414 extern void tty_write_message(struct tty_struct *tty, char *msg);
 415 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
 416 extern int tty_chars_in_buffer(struct tty_struct *tty);
 417 extern int tty_write_room(struct tty_struct *tty);
 418 extern void tty_driver_flush_buffer(struct tty_struct *tty);
 419 extern void tty_throttle(struct tty_struct *tty);
 420 extern void tty_unthrottle(struct tty_struct *tty);
 421 extern int tty_throttle_safe(struct tty_struct *tty);
 422 extern int tty_unthrottle_safe(struct tty_struct *tty);
 423 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 424 extern void tty_driver_remove_tty(struct tty_driver *driver,
 425                                   struct tty_struct *tty);
 426 extern void tty_free_termios(struct tty_struct *tty);
 427 extern int is_current_pgrp_orphaned(void);
 428 extern int is_ignored(int sig);
 429 extern int tty_signal(int sig, struct tty_struct *tty);
 430 extern void tty_hangup(struct tty_struct *tty);
 431 extern void tty_vhangup(struct tty_struct *tty);
 432 extern void tty_unhangup(struct file *filp);
 433 extern int tty_hung_up_p(struct file *filp);
 434 extern void do_SAK(struct tty_struct *tty);
 435 extern void __do_SAK(struct tty_struct *tty);
 436 extern void no_tty(void);
 437 extern void tty_flush_to_ldisc(struct tty_struct *tty);
 438 extern void tty_buffer_free_all(struct tty_port *port);
 439 extern void tty_buffer_flush(struct tty_struct *tty);
 440 extern void tty_buffer_init(struct tty_port *port);
 441 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
 442 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 443 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
 444                                                 speed_t ibaud, speed_t obaud);
 445 extern void tty_encode_baud_rate(struct tty_struct *tty,
 446                                                 speed_t ibaud, speed_t obaud);
 447
 448 /**
 449  *      tty_get_baud_rate       -       get tty bit rates
 450  *      @tty: tty to query
 451  *
 452  *      Returns the baud rate as an integer for this terminal. The
 453  *      termios lock must be held by the caller and the terminal bit
 454  *      flags may be updated.
 455  *
 456  *      Locking: none
 457  */
 458 static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
 459 {
 460         return tty_termios_baud_rate(&tty->termios);
 461 }
 462
 463 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 464 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
 465 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 466
 467 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 468 extern void tty_ldisc_deref(struct tty_ldisc *);
 469 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
 470 extern void tty_ldisc_hangup(struct tty_struct *tty);
 471 extern const struct file_operations tty_ldiscs_proc_fops;
 472
 473 extern void tty_wakeup(struct tty_struct *tty);
 474 extern void tty_ldisc_flush(struct tty_struct *tty);
 475
 476 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 477 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 478                         unsigned int cmd, unsigned long arg);
 479 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
 480 extern void tty_default_fops(struct file_operations *fops);
 481 extern struct tty_struct *alloc_tty_struct(void);
 482 extern int tty_alloc_file(struct file *file);
 483 extern void tty_add_file(struct tty_struct *tty, struct file *file);
 484 extern void tty_free_file(struct file *file);
 485 extern void free_tty_struct(struct tty_struct *tty);
 486 extern void initialize_tty_struct(struct tty_struct *tty,
 487                 struct tty_driver *driver, int idx);
 488 extern void deinitialize_tty_struct(struct tty_struct *tty);
 489 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
 490 extern int tty_release(struct inode *inode, struct file *filp);
 491 extern int tty_init_termios(struct tty_struct *tty);
 492 extern int tty_standard_install(struct tty_driver *driver,
 493                 struct tty_struct *tty);
 494
 495 extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
 496 extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
 497
 498 extern struct mutex tty_mutex;
 499 extern spinlock_t tty_files_lock;
 500
 501 extern void tty_write_unlock(struct tty_struct *tty);
 502 extern int tty_write_lock(struct tty_struct *tty, int ndelay);
 503 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 504
 505 extern void tty_port_init(struct tty_port *port);
 506 extern void tty_port_link_device(struct tty_port *port,
 507                 struct tty_driver *driver, unsigned index);
 508 extern struct device *tty_port_register_device(struct tty_port *port,
 509                 struct tty_driver *driver, unsigned index,
 510                 struct device *device);
 511 extern struct device *tty_port_register_device_attr(struct tty_port *port,
 512                 struct tty_driver *driver, unsigned index,
 513                 struct device *device, void *drvdata,
 514                 const struct attribute_group **attr_grp);
 515 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 516 extern void tty_port_free_xmit_buf(struct tty_port *port);
 517 extern void tty_port_destroy(struct tty_port *port);
 518 extern void tty_port_put(struct tty_port *port);
 519
 520 static inline struct tty_port *tty_port_get(struct tty_port *port)
 521 {
 522         if (port && kref_get_unless_zero(&port->kref))
 523                 return port;
 524         return NULL;
 525 }
 526
 527 /* If the cts flow control is enabled, return true. */
 528 static inline bool tty_port_cts_enabled(struct tty_port *port)
 529 {
 530         return port->flags & ASYNC_CTS_FLOW;
 531 }
 532
 533 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
 534 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 535 extern int tty_port_carrier_raised(struct tty_port *port);
 536 extern void tty_port_raise_dtr_rts(struct tty_port *port);
 537 extern void tty_port_lower_dtr_rts(struct tty_port *port);
 538 extern void tty_port_hangup(struct tty_port *port);
 539 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
 540 extern void tty_port_tty_wakeup(struct tty_port *port);
 541 extern int tty_port_block_til_ready(struct tty_port *port,
 542                                 struct tty_struct *tty, struct file *filp);
 543 extern int tty_port_close_start(struct tty_port *port,
 544                                 struct tty_struct *tty, struct file *filp);
 545 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
 546 extern void tty_port_close(struct tty_port *port,
 547                                 struct tty_struct *tty, struct file *filp);
 548 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
 549                                 struct tty_struct *tty);
 550 extern int tty_port_open(struct tty_port *port,
 551                                 struct tty_struct *tty, struct file *filp);
 552 static inline int tty_port_users(struct tty_port *port)
 553 {
 554         return port->count + port->blocked_open;
 555 }
 556
 557 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 558 extern int tty_unregister_ldisc(int disc);
 559 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
 560 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 561 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
 562 extern void tty_ldisc_init(struct tty_struct *tty);
 563 extern void tty_ldisc_deinit(struct tty_struct *tty);
 564 extern void tty_ldisc_begin(void);
 565
 566 static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 567                                         char *f, int count)
 568 {
 569         if (ld->ops->receive_buf2)
 570                 count = ld->ops->receive_buf2(ld->tty, p, f, count);
 571         else {
 572                 count = min_t(int, count, ld->tty->receive_room);
 573                 if (count)
 574                         ld->ops->receive_buf(ld->tty, p, f, count);
 575         }
 576         return count;
 577 }
 578
 579
 580 /* n_tty.c */
 581 extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 582 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 583
 584 /* tty_audit.c */
 585 #ifdef CONFIG_AUDIT
 586 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
 587                                size_t size, unsigned icanon);
 588 extern void tty_audit_exit(void);
 589 extern void tty_audit_fork(struct signal_struct *sig);
 590 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
 591 extern void tty_audit_push(struct tty_struct *tty);
 592 extern int tty_audit_push_current(void);
 593 #else
 594 static inline void tty_audit_add_data(struct tty_struct *tty,
 595                 unsigned char *data, size_t size, unsigned icanon)
 596 {
 597 }
 598 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 599 {
 600 }
 601 static inline void tty_audit_exit(void)
 602 {
 603 }
 604 static inline void tty_audit_fork(struct signal_struct *sig)
 605 {
 606 }
 607 static inline void tty_audit_push(struct tty_struct *tty)
 608 {
 609 }
 610 static inline int tty_audit_push_current(void)
 611 {
 612         return 0;
 613 }
 614 #endif
 615
 616 /* tty_ioctl.c */
 617 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 618                        unsigned int cmd, unsigned long arg);
 619 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
 620                        unsigned int cmd, unsigned long arg);
 621
 622 /* serial.c */
 623
 624 extern void serial_console_init(void);
 625
 626 /* pcxx.c */
 627
 628 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
 629
 630 /* vt.c */
 631
 632 extern int vt_ioctl(struct tty_struct *tty,
 633                     unsigned int cmd, unsigned long arg);
 634
 635 extern long vt_compat_ioctl(struct tty_struct *tty,
 636                      unsigned int cmd, unsigned long arg);
 637
 638 /* tty_mutex.c */
 639 /* functions for preparation of BKL removal */
 640 extern void __lockfunc tty_lock(struct tty_struct *tty);
 641 extern void __lockfunc tty_unlock(struct tty_struct *tty);
 642 extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
 643                                 struct tty_struct *tty2);
 644 extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
 645                                 struct tty_struct *tty2);
 646
 647 /*
 648  * this shall be called only from where BTM is held (like close)
 649  *
 650  * We need this to ensure nobody waits for us to finish while we are waiting.
 651  * Without this we were encountering system stalls.
 652  *
 653  * This should be indeed removed with BTM removal later.
 654  *
 655  * Locking: BTM required. Nobody is allowed to hold port->mutex.
 656  */
 657 static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
 658                 long timeout)
 659 {
 660         tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
 661         tty_wait_until_sent(tty, timeout);
 662         tty_lock(tty);
 663 }
 664
 665 /*
 666  * wait_event_interruptible_tty -- wait for a condition with the tty lock held
 667  *
 668  * The condition we are waiting for might take a long time to
 669  * become true, or might depend on another thread taking the
 670  * BTM. In either case, we need to drop the BTM to guarantee
 671  * forward progress. This is a leftover from the conversion
 672  * from the BKL and should eventually get removed as the BTM
 673  * falls out of use.
 674  *
 675  * Do not use in new code.
 676  */
 677 #define wait_event_interruptible_tty(tty, wq, condition)                \
 678 ({                                                                      \
 679         int __ret = 0;                                                  \
 680         if (!(condition))                                               \
 681                 __ret = __wait_event_interruptible_tty(tty, wq,         \
 682                                                        condition);      \
 683         __ret;                                                          \
 684 })
 685
 686 #define __wait_event_interruptible_tty(tty, wq, condition)              \
 687         ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0,          \
 688                         tty_unlock(tty);                                \
 689                         schedule();                                     \
 690                         tty_lock(tty))
 691
 692 #ifdef CONFIG_PROC_FS
 693 extern void proc_tty_register_driver(struct tty_driver *);
 694 extern void proc_tty_unregister_driver(struct tty_driver *);
 695 #else
 696 static inline void proc_tty_register_driver(struct tty_driver *d) {}
 697 static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
 698 #endif
 699
 700 #endif