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  * Lock subclasses for tty locks
  19  *
  20  * TTY_LOCK_NORMAL is for normal ttys and master ptys.
  21  * TTY_LOCK_SLAVE is for slave ptys only.
  22  *
  23  * Lock subclasses are necessary for handling nested locking with pty pairs.
  24  * tty locks which use nested locking:
  25  *
  26  * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
  27  *                The stable lock order is master pty first, then slave pty.
  28  * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
  29  *                 Subclassing this lock enables the slave pty to hold its
  30  *                 termios_rwsem when claiming the master tty_buffer lock.
  31  * tty_buffer lock - slave ptys can claim nested buffer lock when handling
  32  *                   signal chars. The stable lock order is slave pty, then
  33  *                   master.
  34  */
  35
  36 enum {
  37         TTY_LOCK_NORMAL = 0,
  38         TTY_LOCK_SLAVE,
  39 };
  40
  41 /*
  42  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
  43  * hardcoded at present.)
  44  */
  45 #define NR_UNIX98_PTY_DEFAULT   4096      /* Default maximum for Unix98 ptys */
  46 #define NR_UNIX98_PTY_RESERVE   1024      /* Default reserve for main devpts */
  47 #define NR_UNIX98_PTY_MAX       (1 << MINORBITS) /* Absolute limit */
  48
  49 /*
  50  * This character is the same as _POSIX_VDISABLE: it cannot be used as
  51  * a c_cc[] character, but indicates that a particular special character
  52  * isn't in use (eg VINTR has no character etc)
  53  */
  54 #define __DISABLED_CHAR '\0'
  55
  56 struct tty_buffer {
  57         union {
  58                 struct tty_buffer *next;
  59                 struct llist_node free;
  60         };
  61         int used;
  62         int size;
  63         int commit;
  64         int read;
  65         int flags;
  66         /* Data points here */
  67         unsigned long data[0];
  68 };
  69
  70 /* Values for .flags field of tty_buffer */
  71 #define TTYB_NORMAL     1       /* buffer has no flags buffer */
  72
  73 static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
  74 {
  75         return ((unsigned char *)b->data) + ofs;
  76 }
  77
  78 static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
  79 {
  80         return (char *)char_buf_ptr(b, ofs) + b->size;
  81 }
  82
  83 struct tty_bufhead {
  84         struct tty_buffer *head;        /* Queue head */
  85         struct work_struct work;
  86         struct mutex       lock;
  87         atomic_t           priority;
  88         struct tty_buffer sentinel;
  89         struct llist_head free;         /* Free queue head */
  90         atomic_t           mem_used;    /* In-use buffers excluding free list */
  91         int                mem_limit;
  92         struct tty_buffer *tail;        /* Active buffer */
  93 };
  94 /*
  95  * When a break, frame error, or parity error happens, these codes are
  96  * stuffed into the flags buffer.
  97  */
  98 #define TTY_NORMAL      0
  99 #define TTY_BREAK       1
 100 #define TTY_FRAME       2
 101 #define TTY_PARITY      3
 102 #define TTY_OVERRUN     4
 103
 104 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
 105 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
 106 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
 107 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
 108 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
 109 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
 110 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
 111 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
 112 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
 113 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
 114 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
 115 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
 116 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
 117 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
 118 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
 119 #define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
 120 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
 121
 122 #define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
 123 #define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
 124 #define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
 125 #define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
 126
 127 #define I_IGNBRK(tty)   _I_FLAG((tty), IGNBRK)
 128 #define I_BRKINT(tty)   _I_FLAG((tty), BRKINT)
 129 #define I_IGNPAR(tty)   _I_FLAG((tty), IGNPAR)
 130 #define I_PARMRK(tty)   _I_FLAG((tty), PARMRK)
 131 #define I_INPCK(tty)    _I_FLAG((tty), INPCK)
 132 #define I_ISTRIP(tty)   _I_FLAG((tty), ISTRIP)
 133 #define I_INLCR(tty)    _I_FLAG((tty), INLCR)
 134 #define I_IGNCR(tty)    _I_FLAG((tty), IGNCR)
 135 #define I_ICRNL(tty)    _I_FLAG((tty), ICRNL)
 136 #define I_IUCLC(tty)    _I_FLAG((tty), IUCLC)
 137 #define I_IXON(tty)     _I_FLAG((tty), IXON)
 138 #define I_IXANY(tty)    _I_FLAG((tty), IXANY)
 139 #define I_IXOFF(tty)    _I_FLAG((tty), IXOFF)
 140 #define I_IMAXBEL(tty)  _I_FLAG((tty), IMAXBEL)
 141 #define I_IUTF8(tty)    _I_FLAG((tty), IUTF8)
 142
 143 #define O_OPOST(tty)    _O_FLAG((tty), OPOST)
 144 #define O_OLCUC(tty)    _O_FLAG((tty), OLCUC)
 145 #define O_ONLCR(tty)    _O_FLAG((tty), ONLCR)
 146 #define O_OCRNL(tty)    _O_FLAG((tty), OCRNL)
 147 #define O_ONOCR(tty)    _O_FLAG((tty), ONOCR)
 148 #define O_ONLRET(tty)   _O_FLAG((tty), ONLRET)
 149 #define O_OFILL(tty)    _O_FLAG((tty), OFILL)
 150 #define O_OFDEL(tty)    _O_FLAG((tty), OFDEL)
 151 #define O_NLDLY(tty)    _O_FLAG((tty), NLDLY)
 152 #define O_CRDLY(tty)    _O_FLAG((tty), CRDLY)
 153 #define O_TABDLY(tty)   _O_FLAG((tty), TABDLY)
 154 #define O_BSDLY(tty)    _O_FLAG((tty), BSDLY)
 155 #define O_VTDLY(tty)    _O_FLAG((tty), VTDLY)
 156 #define O_FFDLY(tty)    _O_FLAG((tty), FFDLY)
 157
 158 #define C_BAUD(tty)     _C_FLAG((tty), CBAUD)
 159 #define C_CSIZE(tty)    _C_FLAG((tty), CSIZE)
 160 #define C_CSTOPB(tty)   _C_FLAG((tty), CSTOPB)
 161 #define C_CREAD(tty)    _C_FLAG((tty), CREAD)
 162 #define C_PARENB(tty)   _C_FLAG((tty), PARENB)
 163 #define C_PARODD(tty)   _C_FLAG((tty), PARODD)
 164 #define C_HUPCL(tty)    _C_FLAG((tty), HUPCL)
 165 #define C_CLOCAL(tty)   _C_FLAG((tty), CLOCAL)
 166 #define C_CIBAUD(tty)   _C_FLAG((tty), CIBAUD)
 167 #define C_CRTSCTS(tty)  _C_FLAG((tty), CRTSCTS)
 168 #define C_CMSPAR(tty)   _C_FLAG((tty), CMSPAR)
 169
 170 #define L_ISIG(tty)     _L_FLAG((tty), ISIG)
 171 #define L_ICANON(tty)   _L_FLAG((tty), ICANON)
 172 #define L_XCASE(tty)    _L_FLAG((tty), XCASE)
 173 #define L_ECHO(tty)     _L_FLAG((tty), ECHO)
 174 #define L_ECHOE(tty)    _L_FLAG((tty), ECHOE)
 175 #define L_ECHOK(tty)    _L_FLAG((tty), ECHOK)
 176 #define L_ECHONL(tty)   _L_FLAG((tty), ECHONL)
 177 #define L_NOFLSH(tty)   _L_FLAG((tty), NOFLSH)
 178 #define L_TOSTOP(tty)   _L_FLAG((tty), TOSTOP)
 179 #define L_ECHOCTL(tty)  _L_FLAG((tty), ECHOCTL)
 180 #define L_ECHOPRT(tty)  _L_FLAG((tty), ECHOPRT)
 181 #define L_ECHOKE(tty)   _L_FLAG((tty), ECHOKE)
 182 #define L_FLUSHO(tty)   _L_FLAG((tty), FLUSHO)
 183 #define L_PENDIN(tty)   _L_FLAG((tty), PENDIN)
 184 #define L_IEXTEN(tty)   _L_FLAG((tty), IEXTEN)
 185 #define L_EXTPROC(tty)  _L_FLAG((tty), EXTPROC)
 186
 187 struct device;
 188 struct signal_struct;
 189
 190 /*
 191  * Port level information. Each device keeps its own port level information
 192  * so provide a common structure for those ports wanting to use common support
 193  * routines.
 194  *
 195  * The tty port has a different lifetime to the tty so must be kept apart.
 196  * In addition be careful as tty -> port mappings are valid for the life
 197  * of the tty object but in many cases port -> tty mappings are valid only
 198  * until a hangup so don't use the wrong path.
 199  */
 200
 201 struct tty_port;
 202
 203 struct tty_port_operations {
 204         /* Return 1 if the carrier is raised */
 205         int (*carrier_raised)(struct tty_port *port);
 206         /* Control the DTR line */
 207         void (*dtr_rts)(struct tty_port *port, int raise);
 208         /* Called when the last close completes or a hangup finishes
 209            IFF the port was initialized. Do not use to free resources. Called
 210            under the port mutex to serialize against activate/shutdowns */
 211         void (*shutdown)(struct tty_port *port);
 212         /* Called under the port mutex from tty_port_open, serialized using
 213            the port mutex */
 214         /* FIXME: long term getting the tty argument *out* of this would be
 215            good for consoles */
 216         int (*activate)(struct tty_port *port, struct tty_struct *tty);
 217         /* Called on the final put of a port */
 218         void (*destruct)(struct tty_port *port);
 219 };
 220
 221 struct tty_port_client_operations {
 222         int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t);
 223         void (*write_wakeup)(struct tty_port *port);
 224 };
 225
 226 struct tty_port {
 227         struct tty_bufhead      buf;            /* Locked internally */
 228         struct tty_struct       *tty;           /* Back pointer */
 229         struct tty_struct       *itty;          /* internal back ptr */
 230         const struct tty_port_operations *ops;  /* Port operations */
 231         const struct tty_port_client_operations *client_ops; /* Port client operations */
 232         spinlock_t              lock;           /* Lock protecting tty field */
 233         int                     blocked_open;   /* Waiting to open */
 234         int                     count;          /* Usage count */
 235         wait_queue_head_t       open_wait;      /* Open waiters */
 236         wait_queue_head_t       delta_msr_wait; /* Modem status change */
 237         unsigned long           flags;          /* User TTY flags ASYNC_ */
 238         unsigned long           iflags;         /* Internal flags TTY_PORT_ */
 239         unsigned char           console:1,      /* port is a console */
 240                                 low_latency:1;  /* optional: tune for latency */
 241         struct mutex            mutex;          /* Locking */
 242         struct mutex            buf_mutex;      /* Buffer alloc lock */
 243         unsigned char           *xmit_buf;      /* Optional buffer */
 244         unsigned int            close_delay;    /* Close port delay */
 245         unsigned int            closing_wait;   /* Delay for output */
 246         int                     drain_delay;    /* Set to zero if no pure time
 247                                                    based drain is needed else
 248                                                    set to size of fifo */
 249         struct kref             kref;           /* Ref counter */
 250         void                    *client_data;
 251 };
 252
 253 /* tty_port::iflags bits -- use atomic bit ops */
 254 #define TTY_PORT_INITIALIZED    0       /* device is initialized */
 255 #define TTY_PORT_SUSPENDED      1       /* device is suspended */
 256 #define TTY_PORT_ACTIVE         2       /* device is open */
 257
 258 /*
 259  * uart drivers: use the uart_port::status field and the UPSTAT_* defines
 260  * for s/w-based flow control steering and carrier detection status
 261  */
 262 #define TTY_PORT_CTS_FLOW       3       /* h/w flow control enabled */
 263 #define TTY_PORT_CHECK_CD       4       /* carrier detect enabled */
 264
 265 /*
 266  * Where all of the state associated with a tty is kept while the tty
 267  * is open.  Since the termios state should be kept even if the tty
 268  * has been closed --- for things like the baud rate, etc --- it is
 269  * not stored here, but rather a pointer to the real state is stored
 270  * here.  Possible the winsize structure should have the same
 271  * treatment, but (1) the default 80x24 is usually right and (2) it's
 272  * most often used by a windowing system, which will set the correct
 273  * size each time the window is created or resized anyway.
 274  *                                              - TYT, 9/14/92
 275  */
 276
 277 struct tty_operations;
 278
 279 struct tty_struct {
 280         int     magic;
 281         struct kref kref;
 282         struct device *dev;
 283         struct tty_driver *driver;
 284         const struct tty_operations *ops;
 285         int index;
 286
 287         /* Protects ldisc changes: Lock tty not pty */
 288         struct ld_semaphore ldisc_sem;
 289         struct tty_ldisc *ldisc;
 290
 291         struct mutex atomic_write_lock;
 292         struct mutex legacy_mutex;
 293         struct mutex throttle_mutex;
 294         struct rw_semaphore termios_rwsem;
 295         struct mutex winsize_mutex;
 296         spinlock_t ctrl_lock;
 297         spinlock_t flow_lock;
 298         /* Termios values are protected by the termios rwsem */
 299         struct ktermios termios, termios_locked;
 300         struct termiox *termiox;        /* May be NULL for unsupported */
 301         char name[64];
 302         struct pid *pgrp;               /* Protected by ctrl lock */
 303         struct pid *session;
 304         unsigned long flags;
 305         int count;
 306         struct winsize winsize;         /* winsize_mutex */
 307         unsigned long stopped:1,        /* flow_lock */
 308                       flow_stopped:1,
 309                       unused:BITS_PER_LONG - 2;
 310         int hw_stopped;
 311         unsigned long ctrl_status:8,    /* ctrl_lock */
 312                       packet:1,
 313                       unused_ctrl:BITS_PER_LONG - 9;
 314         unsigned int receive_room;      /* Bytes free for queue */
 315         int flow_change;
 316
 317         struct tty_struct *link;
 318         struct fasync_struct *fasync;
 319         int alt_speed;          /* For magic substitution of 38400 bps */
 320         wait_queue_head_t write_wait;
 321         wait_queue_head_t read_wait;
 322         struct work_struct hangup_work;
 323         void *disc_data;
 324         void *driver_data;
 325         spinlock_t files_lock;          /* protects tty_files list */
 326         struct list_head tty_files;
 327
 328 #define N_TTY_BUF_SIZE 4096
 329
 330         int closing;
 331         unsigned char *write_buf;
 332         int write_cnt;
 333         /* If the tty has a pending do_SAK, queue it here - akpm */
 334         struct work_struct SAK_work;
 335         struct tty_port *port;
 336 };
 337
 338 /* Each of a tty's open files has private_data pointing to tty_file_private */
 339 struct tty_file_private {
 340         struct tty_struct *tty;
 341         struct file *file;
 342         struct list_head list;
 343 };
 344
 345 /* tty magic number */
 346 #define TTY_MAGIC               0x5401
 347
 348 /*
 349  * These bits are used in the flags field of the tty structure.
 350  *
 351  * So that interrupts won't be able to mess up the queues,
 352  * copy_to_cooked must be atomic with respect to itself, as must
 353  * tty->write.  Thus, you must use the inline functions set_bit() and
 354  * clear_bit() to make things atomic.
 355  */
 356 #define TTY_THROTTLED           0       /* Call unthrottle() at threshold min */
 357 #define TTY_IO_ERROR            1       /* Cause an I/O error (may be no ldisc too) */
 358 #define TTY_OTHER_CLOSED        2       /* Other side (if any) has closed */
 359 #define TTY_EXCLUSIVE           3       /* Exclusive open mode */
 360 #define TTY_DO_WRITE_WAKEUP     5       /* Call write_wakeup after queuing new */
 361 #define TTY_LDISC_OPEN          11      /* Line discipline is open */
 362 #define TTY_PTY_LOCK            16      /* pty private */
 363 #define TTY_NO_WRITE_SPLIT      17      /* Preserve write boundaries to driver */
 364 #define TTY_HUPPED              18      /* Post driver->hangup() */
 365 #define TTY_LDISC_HALTED        22      /* Line discipline is halted */
 366
 367 /* Values for tty->flow_change */
 368 #define TTY_THROTTLE_SAFE 1
 369 #define TTY_UNTHROTTLE_SAFE 2
 370
 371 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
 372 {
 373         tty->flow_change = val;
 374 }
 375
 376 static inline void tty_set_flow_change(struct tty_struct *tty, int val)
 377 {
 378         tty->flow_change = val;
 379         smp_mb();
 380 }
 381
 382 static inline bool tty_io_error(struct tty_struct *tty)
 383 {
 384         return test_bit(TTY_IO_ERROR, &tty->flags);
 385 }
 386
 387 static inline bool tty_throttled(struct tty_struct *tty)
 388 {
 389         return test_bit(TTY_THROTTLED, &tty->flags);
 390 }
 391
 392 #ifdef CONFIG_TTY
 393 extern void console_init(void);
 394 extern void tty_kref_put(struct tty_struct *tty);
 395 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
 396 extern void tty_vhangup_self(void);
 397 extern void disassociate_ctty(int priv);
 398 extern dev_t tty_devnum(struct tty_struct *tty);
 399 extern void proc_clear_tty(struct task_struct *p);
 400 extern struct tty_struct *get_current_tty(void);
 401 /* tty_io.c */
 402 extern int __init tty_init(void);
 403 extern const char *tty_name(const struct tty_struct *tty);
 404 #else
 405 static inline void console_init(void)
 406 { }
 407 static inline void tty_kref_put(struct tty_struct *tty)
 408 { }
 409 static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
 410 { return NULL; }
 411 static inline void tty_vhangup_self(void)
 412 { }
 413 static inline void disassociate_ctty(int priv)
 414 { }
 415 static inline dev_t tty_devnum(struct tty_struct *tty)
 416 { return 0; }
 417 static inline void proc_clear_tty(struct task_struct *p)
 418 { }
 419 static inline struct tty_struct *get_current_tty(void)
 420 { return NULL; }
 421 /* tty_io.c */
 422 static inline int __init tty_init(void)
 423 { return 0; }
 424 static inline const char *tty_name(const struct tty_struct *tty)
 425 { return "(none)"; }
 426 #endif
 427
 428 extern struct ktermios tty_std_termios;
 429
 430 extern int vcs_init(void);
 431
 432 extern struct class *tty_class;
 433
 434 /**
 435  *      tty_kref_get            -       get a tty reference
 436  *      @tty: tty device
 437  *
 438  *      Return a new reference to a tty object. The caller must hold
 439  *      sufficient locks/counts to ensure that their existing reference cannot
 440  *      go away
 441  */
 442
 443 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
 444 {
 445         if (tty)
 446                 kref_get(&tty->kref);
 447         return tty;
 448 }
 449
 450 extern const char *tty_driver_name(const struct tty_struct *tty);
 451 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 452 extern int __tty_check_change(struct tty_struct *tty, int sig);
 453 extern int tty_check_change(struct tty_struct *tty);
 454 extern void __stop_tty(struct tty_struct *tty);
 455 extern void stop_tty(struct tty_struct *tty);
 456 extern void __start_tty(struct tty_struct *tty);
 457 extern void start_tty(struct tty_struct *tty);
 458 extern int tty_register_driver(struct tty_driver *driver);
 459 extern int tty_unregister_driver(struct tty_driver *driver);
 460 extern struct device *tty_register_device(struct tty_driver *driver,
 461                                           unsigned index, struct device *dev);
 462 extern struct device *tty_register_device_attr(struct tty_driver *driver,
 463                                 unsigned index, struct device *device,
 464                                 void *drvdata,
 465                                 const struct attribute_group **attr_grp);
 466 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 467 extern void tty_write_message(struct tty_struct *tty, char *msg);
 468 extern int tty_send_xchar(struct tty_struct *tty, char ch);
 469 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
 470 extern int tty_chars_in_buffer(struct tty_struct *tty);
 471 extern int tty_write_room(struct tty_struct *tty);
 472 extern void tty_driver_flush_buffer(struct tty_struct *tty);
 473 extern void tty_throttle(struct tty_struct *tty);
 474 extern void tty_unthrottle(struct tty_struct *tty);
 475 extern int tty_throttle_safe(struct tty_struct *tty);
 476 extern int tty_unthrottle_safe(struct tty_struct *tty);
 477 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 478 extern int is_current_pgrp_orphaned(void);
 479 extern void tty_hangup(struct tty_struct *tty);
 480 extern void tty_vhangup(struct tty_struct *tty);
 481 extern int tty_hung_up_p(struct file *filp);
 482 extern void do_SAK(struct tty_struct *tty);
 483 extern void __do_SAK(struct tty_struct *tty);
 484 extern void no_tty(void);
 485 extern void tty_buffer_free_all(struct tty_port *port);
 486 extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
 487 extern void tty_buffer_init(struct tty_port *port);
 488 extern void tty_buffer_set_lock_subclass(struct tty_port *port);
 489 extern bool tty_buffer_restart_work(struct tty_port *port);
 490 extern bool tty_buffer_cancel_work(struct tty_port *port);
 491 extern void tty_buffer_flush_work(struct tty_port *port);
 492 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
 493 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 494 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
 495                                                 speed_t ibaud, speed_t obaud);
 496 extern void tty_encode_baud_rate(struct tty_struct *tty,
 497                                                 speed_t ibaud, speed_t obaud);
 498
 499 /**
 500  *      tty_get_baud_rate       -       get tty bit rates
 501  *      @tty: tty to query
 502  *
 503  *      Returns the baud rate as an integer for this terminal. The
 504  *      termios lock must be held by the caller and the terminal bit
 505  *      flags may be updated.
 506  *
 507  *      Locking: none
 508  */
 509 static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
 510 {
 511         return tty_termios_baud_rate(&tty->termios);
 512 }
 513
 514 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 515 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
 516 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 517
 518 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 519 extern void tty_ldisc_deref(struct tty_ldisc *);
 520 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
 521 extern void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
 522 extern int tty_ldisc_reinit(struct tty_struct *tty, int disc);
 523 extern const struct file_operations tty_ldiscs_proc_fops;
 524
 525 extern void tty_wakeup(struct tty_struct *tty);
 526 extern void tty_ldisc_flush(struct tty_struct *tty);
 527
 528 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 529 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 530                         unsigned int cmd, unsigned long arg);
 531 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
 532 extern void tty_default_fops(struct file_operations *fops);
 533 extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
 534 extern int tty_alloc_file(struct file *file);
 535 extern void tty_add_file(struct tty_struct *tty, struct file *file);
 536 extern void tty_free_file(struct file *file);
 537 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
 538 extern void tty_release_struct(struct tty_struct *tty, int idx);
 539 extern int tty_release(struct inode *inode, struct file *filp);
 540 extern void tty_init_termios(struct tty_struct *tty);
 541 extern int tty_standard_install(struct tty_driver *driver,
 542                 struct tty_struct *tty);
 543
 544 extern struct mutex tty_mutex;
 545
 546 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 547
 548 extern void tty_port_init(struct tty_port *port);
 549 extern void tty_port_link_device(struct tty_port *port,
 550                 struct tty_driver *driver, unsigned index);
 551 extern struct device *tty_port_register_device(struct tty_port *port,
 552                 struct tty_driver *driver, unsigned index,
 553                 struct device *device);
 554 extern struct device *tty_port_register_device_attr(struct tty_port *port,
 555                 struct tty_driver *driver, unsigned index,
 556                 struct device *device, void *drvdata,
 557                 const struct attribute_group **attr_grp);
 558 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 559 extern void tty_port_free_xmit_buf(struct tty_port *port);
 560 extern void tty_port_destroy(struct tty_port *port);
 561 extern void tty_port_put(struct tty_port *port);
 562
 563 static inline struct tty_port *tty_port_get(struct tty_port *port)
 564 {
 565         if (port && kref_get_unless_zero(&port->kref))
 566                 return port;
 567         return NULL;
 568 }
 569
 570 /* If the cts flow control is enabled, return true. */
 571 static inline bool tty_port_cts_enabled(struct tty_port *port)
 572 {
 573         return test_bit(TTY_PORT_CTS_FLOW, &port->iflags);
 574 }
 575
 576 static inline void tty_port_set_cts_flow(struct tty_port *port, bool val)
 577 {
 578         if (val)
 579                 set_bit(TTY_PORT_CTS_FLOW, &port->iflags);
 580         else
 581                 clear_bit(TTY_PORT_CTS_FLOW, &port->iflags);
 582 }
 583
 584 static inline bool tty_port_active(struct tty_port *port)
 585 {
 586         return test_bit(TTY_PORT_ACTIVE, &port->iflags);
 587 }
 588
 589 static inline void tty_port_set_active(struct tty_port *port, bool val)
 590 {
 591         if (val)
 592                 set_bit(TTY_PORT_ACTIVE, &port->iflags);
 593         else
 594                 clear_bit(TTY_PORT_ACTIVE, &port->iflags);
 595 }
 596
 597 static inline bool tty_port_check_carrier(struct tty_port *port)
 598 {
 599         return test_bit(TTY_PORT_CHECK_CD, &port->iflags);
 600 }
 601
 602 static inline void tty_port_set_check_carrier(struct tty_port *port, bool val)
 603 {
 604         if (val)
 605                 set_bit(TTY_PORT_CHECK_CD, &port->iflags);
 606         else
 607                 clear_bit(TTY_PORT_CHECK_CD, &port->iflags);
 608 }
 609
 610 static inline bool tty_port_suspended(struct tty_port *port)
 611 {
 612         return test_bit(TTY_PORT_SUSPENDED, &port->iflags);
 613 }
 614
 615 static inline void tty_port_set_suspended(struct tty_port *port, bool val)
 616 {
 617         if (val)
 618                 set_bit(TTY_PORT_SUSPENDED, &port->iflags);
 619         else
 620                 clear_bit(TTY_PORT_SUSPENDED, &port->iflags);
 621 }
 622
 623 static inline bool tty_port_initialized(struct tty_port *port)
 624 {
 625         return test_bit(TTY_PORT_INITIALIZED, &port->iflags);
 626 }
 627
 628 static inline void tty_port_set_initialized(struct tty_port *port, bool val)
 629 {
 630         if (val)
 631                 set_bit(TTY_PORT_INITIALIZED, &port->iflags);
 632         else
 633                 clear_bit(TTY_PORT_INITIALIZED, &port->iflags);
 634 }
 635
 636 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
 637 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 638 extern int tty_port_carrier_raised(struct tty_port *port);
 639 extern void tty_port_raise_dtr_rts(struct tty_port *port);
 640 extern void tty_port_lower_dtr_rts(struct tty_port *port);
 641 extern void tty_port_hangup(struct tty_port *port);
 642 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
 643 extern void tty_port_tty_wakeup(struct tty_port *port);
 644 extern int tty_port_block_til_ready(struct tty_port *port,
 645                                 struct tty_struct *tty, struct file *filp);
 646 extern int tty_port_close_start(struct tty_port *port,
 647                                 struct tty_struct *tty, struct file *filp);
 648 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
 649 extern void tty_port_close(struct tty_port *port,
 650                                 struct tty_struct *tty, struct file *filp);
 651 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
 652                                 struct tty_struct *tty);
 653 extern int tty_port_open(struct tty_port *port,
 654                                 struct tty_struct *tty, struct file *filp);
 655 static inline int tty_port_users(struct tty_port *port)
 656 {
 657         return port->count + port->blocked_open;
 658 }
 659
 660 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 661 extern int tty_unregister_ldisc(int disc);
 662 extern int tty_set_ldisc(struct tty_struct *tty, int disc);
 663 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 664 extern void tty_ldisc_release(struct tty_struct *tty);
 665 extern void tty_ldisc_init(struct tty_struct *tty);
 666 extern void tty_ldisc_deinit(struct tty_struct *tty);
 667 extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
 668                                  char *f, int count);
 669
 670 /* n_tty.c */
 671 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 672 extern void __init n_tty_init(void);
 673
 674 /* tty_audit.c */
 675 #ifdef CONFIG_AUDIT
 676 extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
 677                                size_t size);
 678 extern void tty_audit_exit(void);
 679 extern void tty_audit_fork(struct signal_struct *sig);
 680 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
 681 extern int tty_audit_push(void);
 682 #else
 683 static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
 684                                       size_t size)
 685 {
 686 }
 687 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 688 {
 689 }
 690 static inline void tty_audit_exit(void)
 691 {
 692 }
 693 static inline void tty_audit_fork(struct signal_struct *sig)
 694 {
 695 }
 696 static inline int tty_audit_push(void)
 697 {
 698         return 0;
 699 }
 700 #endif
 701
 702 /* tty_ioctl.c */
 703 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 704                        unsigned int cmd, unsigned long arg);
 705 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
 706                        unsigned int cmd, unsigned long arg);
 707
 708 /* vt.c */
 709
 710 extern int vt_ioctl(struct tty_struct *tty,
 711                     unsigned int cmd, unsigned long arg);
 712
 713 extern long vt_compat_ioctl(struct tty_struct *tty,
 714                      unsigned int cmd, unsigned long arg);
 715
 716 /* tty_mutex.c */
 717 /* functions for preparation of BKL removal */
 718 extern void tty_lock(struct tty_struct *tty);
 719 extern int  tty_lock_interruptible(struct tty_struct *tty);
 720 extern void tty_unlock(struct tty_struct *tty);
 721 extern void tty_lock_slave(struct tty_struct *tty);
 722 extern void tty_unlock_slave(struct tty_struct *tty);
 723 extern void tty_set_lock_subclass(struct tty_struct *tty);
 724
 725 #ifdef CONFIG_PROC_FS
 726 extern void proc_tty_register_driver(struct tty_driver *);
 727 extern void proc_tty_unregister_driver(struct tty_driver *);
 728 #else
 729 static inline void proc_tty_register_driver(struct tty_driver *d) {}
 730 static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
 731 #endif
 732
 733 #define tty_msg(fn, tty, f, ...) \
 734         fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
 735
 736 #define tty_debug(tty, f, ...)  tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
 737 #define tty_info(tty, f, ...)   tty_msg(pr_info, tty, f, ##__VA_ARGS__)
 738 #define tty_notice(tty, f, ...) tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
 739 #define tty_warn(tty, f, ...)   tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
 740 #define tty_err(tty, f, ...)    tty_msg(pr_err, tty, f, ##__VA_ARGS__)
 741
 742 #define tty_info_ratelimited(tty, f, ...) \
 743                 tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
 744
 745 #endif