include/linux/tty.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_TTY_H
   3 #define _LINUX_TTY_H
   4
   5 #include <linux/fs.h>
   6 #include <linux/major.h>
   7 #include <linux/termios.h>
   8 #include <linux/workqueue.h>
   9 #include <linux/tty_driver.h>
  10 #include <linux/tty_ldisc.h>
  11 #include <linux/mutex.h>
  12 #include <linux/tty_flags.h>
  13 #include <uapi/linux/tty.h>
  14 #include <linux/rwsem.h>
  15 #include <linux/llist.h>
  16
  17
  18 /*
  19  * Lock subclasses for tty locks
  20  *
  21  * TTY_LOCK_NORMAL is for normal ttys and master ptys.
  22  * TTY_LOCK_SLAVE is for slave ptys only.
  23  *
  24  * Lock subclasses are necessary for handling nested locking with pty pairs.
  25  * tty locks which use nested locking:
  26  *
  27  * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
  28  *                The stable lock order is master pty first, then slave pty.
  29  * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
  30  *                 Subclassing this lock enables the slave pty to hold its
  31  *                 termios_rwsem when claiming the master tty_buffer lock.
  32  * tty_buffer lock - slave ptys can claim nested buffer lock when handling
  33  *                   signal chars. The stable lock order is slave pty, then
  34  *                   master.
  35  */
  36
  37 enum {
  38         TTY_LOCK_NORMAL = 0,
  39         TTY_LOCK_SLAVE,
  40 };
  41
  42 /*
  43  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
  44  * hardcoded at present.)
  45  */
  46 #define NR_UNIX98_PTY_DEFAULT   4096      /* Default maximum for Unix98 ptys */
  47 #define NR_UNIX98_PTY_RESERVE   1024      /* Default reserve for main devpts */
  48 #define NR_UNIX98_PTY_MAX       (1 << MINORBITS) /* Absolute limit */
  49
  50 /*
  51  * This character is the same as _POSIX_VDISABLE: it cannot be used as
  52  * a c_cc[] character, but indicates that a particular special character
  53  * isn't in use (eg VINTR has no character etc)
  54  */
  55 #define __DISABLED_CHAR '\0'
  56
  57 struct tty_buffer {
  58         union {
  59                 struct tty_buffer *next;
  60                 struct llist_node free;
  61         };
  62         int used;
  63         int size;
  64         int commit;
  65         int read;
  66         int flags;
  67         /* Data points here */
  68         unsigned long data[0];
  69 };
  70
  71 /* Values for .flags field of tty_buffer */
  72 #define TTYB_NORMAL     1       /* buffer has no flags buffer */
  73
  74 static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
  75 {
  76         return ((unsigned char *)b->data) + ofs;
  77 }
  78
  79 static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
  80 {
  81         return (char *)char_buf_ptr(b, ofs) + b->size;
  82 }
  83
  84 struct tty_bufhead {
  85         struct tty_buffer *head;        /* Queue head */
  86         struct work_struct work;
  87         struct mutex       lock;
  88         atomic_t           priority;
  89         struct tty_buffer sentinel;
  90         struct llist_head free;         /* Free queue head */
  91         atomic_t           mem_used;    /* In-use buffers excluding free list */
  92         int                mem_limit;
  93         struct tty_buffer *tail;        /* Active buffer */
  94 };
  95 /*
  96  * When a break, frame error, or parity error happens, these codes are
  97  * stuffed into the flags buffer.
  98  */
  99 #define TTY_NORMAL      0
 100 #define TTY_BREAK       1
 101 #define TTY_FRAME       2
 102 #define TTY_PARITY      3
 103 #define TTY_OVERRUN     4
 104
 105 #define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
 106 #define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
 107 #define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
 108 #define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
 109 #define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
 110 #define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
 111 #define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
 112 #define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
 113 #define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
 114 #define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
 115 #define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
 116 #define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
 117 #define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
 118 #define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
 119 #define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
 120 #define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
 121 #define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
 122
 123 #define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
 124 #define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
 125 #define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
 126 #define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
 127
 128 #define I_IGNBRK(tty)   _I_FLAG((tty), IGNBRK)
 129 #define I_BRKINT(tty)   _I_FLAG((tty), BRKINT)
 130 #define I_IGNPAR(tty)   _I_FLAG((tty), IGNPAR)
 131 #define I_PARMRK(tty)   _I_FLAG((tty), PARMRK)
 132 #define I_INPCK(tty)    _I_FLAG((tty), INPCK)
 133 #define I_ISTRIP(tty)   _I_FLAG((tty), ISTRIP)
 134 #define I_INLCR(tty)    _I_FLAG((tty), INLCR)
 135 #define I_IGNCR(tty)    _I_FLAG((tty), IGNCR)
 136 #define I_ICRNL(tty)    _I_FLAG((tty), ICRNL)
 137 #define I_IUCLC(tty)    _I_FLAG((tty), IUCLC)
 138 #define I_IXON(tty)     _I_FLAG((tty), IXON)
 139 #define I_IXANY(tty)    _I_FLAG((tty), IXANY)
 140 #define I_IXOFF(tty)    _I_FLAG((tty), IXOFF)
 141 #define I_IMAXBEL(tty)  _I_FLAG((tty), IMAXBEL)
 142 #define I_IUTF8(tty)    _I_FLAG((tty), IUTF8)
 143
 144 #define O_OPOST(tty)    _O_FLAG((tty), OPOST)
 145 #define O_OLCUC(tty)    _O_FLAG((tty), OLCUC)
 146 #define O_ONLCR(tty)    _O_FLAG((tty), ONLCR)
 147 #define O_OCRNL(tty)    _O_FLAG((tty), OCRNL)
 148 #define O_ONOCR(tty)    _O_FLAG((tty), ONOCR)
 149 #define O_ONLRET(tty)   _O_FLAG((tty), ONLRET)
 150 #define O_OFILL(tty)    _O_FLAG((tty), OFILL)
 151 #define O_OFDEL(tty)    _O_FLAG((tty), OFDEL)
 152 #define O_NLDLY(tty)    _O_FLAG((tty), NLDLY)
 153 #define O_CRDLY(tty)    _O_FLAG((tty), CRDLY)
 154 #define O_TABDLY(tty)   _O_FLAG((tty), TABDLY)
 155 #define O_BSDLY(tty)    _O_FLAG((tty), BSDLY)
 156 #define O_VTDLY(tty)    _O_FLAG((tty), VTDLY)
 157 #define O_FFDLY(tty)    _O_FLAG((tty), FFDLY)
 158
 159 #define C_BAUD(tty)     _C_FLAG((tty), CBAUD)
 160 #define C_CSIZE(tty)    _C_FLAG((tty), CSIZE)
 161 #define C_CSTOPB(tty)   _C_FLAG((tty), CSTOPB)
 162 #define C_CREAD(tty)    _C_FLAG((tty), CREAD)
 163 #define C_PARENB(tty)   _C_FLAG((tty), PARENB)
 164 #define C_PARODD(tty)   _C_FLAG((tty), PARODD)
 165 #define C_HUPCL(tty)    _C_FLAG((tty), HUPCL)
 166 #define C_CLOCAL(tty)   _C_FLAG((tty), CLOCAL)
 167 #define C_CIBAUD(tty)   _C_FLAG((tty), CIBAUD)
 168 #define C_CRTSCTS(tty)  _C_FLAG((tty), CRTSCTS)
 169 #define C_CMSPAR(tty)   _C_FLAG((tty), CMSPAR)
 170
 171 #define L_ISIG(tty)     _L_FLAG((tty), ISIG)
 172 #define L_ICANON(tty)   _L_FLAG((tty), ICANON)
 173 #define L_XCASE(tty)    _L_FLAG((tty), XCASE)
 174 #define L_ECHO(tty)     _L_FLAG((tty), ECHO)
 175 #define L_ECHOE(tty)    _L_FLAG((tty), ECHOE)
 176 #define L_ECHOK(tty)    _L_FLAG((tty), ECHOK)
 177 #define L_ECHONL(tty)   _L_FLAG((tty), ECHONL)
 178 #define L_NOFLSH(tty)   _L_FLAG((tty), NOFLSH)
 179 #define L_TOSTOP(tty)   _L_FLAG((tty), TOSTOP)
 180 #define L_ECHOCTL(tty)  _L_FLAG((tty), ECHOCTL)
 181 #define L_ECHOPRT(tty)  _L_FLAG((tty), ECHOPRT)
 182 #define L_ECHOKE(tty)   _L_FLAG((tty), ECHOKE)
 183 #define L_FLUSHO(tty)   _L_FLAG((tty), FLUSHO)
 184 #define L_PENDIN(tty)   _L_FLAG((tty), PENDIN)
 185 #define L_IEXTEN(tty)   _L_FLAG((tty), IEXTEN)
 186 #define L_EXTPROC(tty)  _L_FLAG((tty), EXTPROC)
 187
 188 struct device;
 189 struct signal_struct;
 190
 191 /*
 192  * Port level information. Each device keeps its own port level information
 193  * so provide a common structure for those ports wanting to use common support
 194  * routines.
 195  *
 196  * The tty port has a different lifetime to the tty so must be kept apart.
 197  * In addition be careful as tty -> port mappings are valid for the life
 198  * of the tty object but in many cases port -> tty mappings are valid only
 199  * until a hangup so don't use the wrong path.
 200  */
 201
 202 struct tty_port;
 203
 204 struct tty_port_operations {
 205         /* Return 1 if the carrier is raised */
 206         int (*carrier_raised)(struct tty_port *port);
 207         /* Control the DTR line */
 208         void (*dtr_rts)(struct tty_port *port, int raise);
 209         /* Called when the last close completes or a hangup finishes
 210            IFF the port was initialized. Do not use to free resources. Called
 211            under the port mutex to serialize against activate/shutdowns */
 212         void (*shutdown)(struct tty_port *port);
 213         /* Called under the port mutex from tty_port_open, serialized using
 214            the port mutex */
 215         /* FIXME: long term getting the tty argument *out* of this would be
 216            good for consoles */
 217         int (*activate)(struct tty_port *port, struct tty_struct *tty);
 218         /* Called on the final put of a port */
 219         void (*destruct)(struct tty_port *port);
 220 };
 221
 222 struct tty_port_client_operations {
 223         int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t);
 224         void (*write_wakeup)(struct tty_port *port);
 225 };
 226
 227 struct tty_port {
 228         struct tty_bufhead      buf;            /* Locked internally */
 229         struct tty_struct       *tty;           /* Back pointer */
 230         struct tty_struct       *itty;          /* internal back ptr */
 231         const struct tty_port_operations *ops;  /* Port operations */
 232         const struct tty_port_client_operations *client_ops; /* Port client operations */
 233         spinlock_t              lock;           /* Lock protecting tty field */
 234         int                     blocked_open;   /* Waiting to open */
 235         int                     count;          /* Usage count */
 236         wait_queue_head_t       open_wait;      /* Open waiters */
 237         wait_queue_head_t       delta_msr_wait; /* Modem status change */
 238         unsigned long           flags;          /* User TTY flags ASYNC_ */
 239         unsigned long           iflags;         /* Internal flags TTY_PORT_ */
 240         unsigned char           console:1,      /* port is a console */
 241                                 low_latency:1;  /* optional: tune for latency */
 242         struct mutex            mutex;          /* Locking */
 243         struct mutex            buf_mutex;      /* Buffer alloc lock */
 244         unsigned char           *xmit_buf;      /* Optional buffer */
 245         unsigned int            close_delay;    /* Close port delay */
 246         unsigned int            closing_wait;   /* Delay for output */
 247         int                     drain_delay;    /* Set to zero if no pure time
 248                                                    based drain is needed else
 249                                                    set to size of fifo */
 250         struct kref             kref;           /* Ref counter */
 251         void                    *client_data;
 252 };
 253
 254 /* tty_port::iflags bits -- use atomic bit ops */
 255 #define TTY_PORT_INITIALIZED    0       /* device is initialized */
 256 #define TTY_PORT_SUSPENDED      1       /* device is suspended */
 257 #define TTY_PORT_ACTIVE         2       /* device is open */
 258
 259 /*
 260  * uart drivers: use the uart_port::status field and the UPSTAT_* defines
 261  * for s/w-based flow control steering and carrier detection status
 262  */
 263 #define TTY_PORT_CTS_FLOW       3       /* h/w flow control enabled */
 264 #define TTY_PORT_CHECK_CD       4       /* carrier detect enabled */
 265 #define TTY_PORT_KOPENED        5       /* device exclusively opened by
 266                                            kernel */
 267
 268 /*
 269  * Where all of the state associated with a tty is kept while the tty
 270  * is open.  Since the termios state should be kept even if the tty
 271  * has been closed --- for things like the baud rate, etc --- it is
 272  * not stored here, but rather a pointer to the real state is stored
 273  * here.  Possible the winsize structure should have the same
 274  * treatment, but (1) the default 80x24 is usually right and (2) it's
 275  * most often used by a windowing system, which will set the correct
 276  * size each time the window is created or resized anyway.
 277  *                                              - TYT, 9/14/92
 278  */
 279
 280 struct tty_operations;
 281
 282 struct tty_struct {
 283         int     magic;
 284         struct kref kref;
 285         struct device *dev;
 286         struct tty_driver *driver;
 287         const struct tty_operations *ops;
 288         int index;
 289
 290         /* Protects ldisc changes: Lock tty not pty */
 291         struct ld_semaphore ldisc_sem;
 292         struct tty_ldisc *ldisc;
 293
 294         struct mutex atomic_write_lock;
 295         struct mutex legacy_mutex;
 296         struct mutex throttle_mutex;
 297         struct rw_semaphore termios_rwsem;
 298         struct mutex winsize_mutex;
 299         spinlock_t ctrl_lock;
 300         spinlock_t flow_lock;
 301         /* Termios values are protected by the termios rwsem */
 302         struct ktermios termios, termios_locked;
 303         struct termiox *termiox;        /* May be NULL for unsupported */
 304         char name[64];
 305         struct pid *pgrp;               /* Protected by ctrl lock */
 306         struct pid *session;
 307         unsigned long flags;
 308         int count;
 309         struct winsize winsize;         /* winsize_mutex */
 310         unsigned long stopped:1,        /* flow_lock */
 311                       flow_stopped:1,
 312                       unused:BITS_PER_LONG - 2;
 313         int hw_stopped;
 314         unsigned long ctrl_status:8,    /* ctrl_lock */
 315                       packet:1,
 316                       unused_ctrl:BITS_PER_LONG - 9;
 317         unsigned int receive_room;      /* Bytes free for queue */
 318         int flow_change;
 319
 320         struct tty_struct *link;
 321         struct fasync_struct *fasync;
 322         wait_queue_head_t write_wait;
 323         wait_queue_head_t read_wait;
 324         struct work_struct hangup_work;
 325         void *disc_data;
 326         void *driver_data;
 327         spinlock_t files_lock;          /* protects tty_files list */
 328         struct list_head tty_files;
 329
 330 #define N_TTY_BUF_SIZE 4096
 331
 332         int closing;
 333         unsigned char *write_buf;
 334         int write_cnt;
 335         /* If the tty has a pending do_SAK, queue it here - akpm */
 336         struct work_struct SAK_work;
 337         struct tty_port *port;
 338 } __randomize_layout;
 339
 340 /* Each of a tty's open files has private_data pointing to tty_file_private */
 341 struct tty_file_private {
 342         struct tty_struct *tty;
 343         struct file *file;
 344         struct list_head list;
 345 };
 346
 347 /* tty magic number */
 348 #define TTY_MAGIC               0x5401
 349
 350 /*
 351  * These bits are used in the flags field of the tty structure.
 352  *
 353  * So that interrupts won't be able to mess up the queues,
 354  * copy_to_cooked must be atomic with respect to itself, as must
 355  * tty->write.  Thus, you must use the inline functions set_bit() and
 356  * clear_bit() to make things atomic.
 357  */
 358 #define TTY_THROTTLED           0       /* Call unthrottle() at threshold min */
 359 #define TTY_IO_ERROR            1       /* Cause an I/O error (may be no ldisc too) */
 360 #define TTY_OTHER_CLOSED        2       /* Other side (if any) has closed */
 361 #define TTY_EXCLUSIVE           3       /* Exclusive open mode */
 362 #define TTY_DO_WRITE_WAKEUP     5       /* Call write_wakeup after queuing new */
 363 #define TTY_LDISC_OPEN          11      /* Line discipline is open */
 364 #define TTY_PTY_LOCK            16      /* pty private */
 365 #define TTY_NO_WRITE_SPLIT      17      /* Preserve write boundaries to driver */
 366 #define TTY_HUPPED              18      /* Post driver->hangup() */
 367 #define TTY_HUPPING             19      /* Hangup in progress */
 368 #define TTY_LDISC_CHANGING      20      /* Change pending - non-block IO */
 369 #define TTY_LDISC_HALTED        22      /* Line discipline is halted */
 370
 371 /* Values for tty->flow_change */
 372 #define TTY_THROTTLE_SAFE 1
 373 #define TTY_UNTHROTTLE_SAFE 2
 374
 375 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
 376 {
 377         tty->flow_change = val;
 378 }
 379
 380 static inline void tty_set_flow_change(struct tty_struct *tty, int val)
 381 {
 382         tty->flow_change = val;
 383         smp_mb();
 384 }
 385
 386 static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
 387 {
 388         return file->f_flags & O_NONBLOCK ||
 389                 test_bit(TTY_LDISC_CHANGING, &tty->flags);
 390 }
 391
 392 static inline bool tty_io_error(struct tty_struct *tty)
 393 {
 394         return test_bit(TTY_IO_ERROR, &tty->flags);
 395 }
 396
 397 static inline bool tty_throttled(struct tty_struct *tty)
 398 {
 399         return test_bit(TTY_THROTTLED, &tty->flags);
 400 }
 401
 402 #ifdef CONFIG_TTY
 403 extern void tty_kref_put(struct tty_struct *tty);
 404 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
 405 extern void tty_vhangup_self(void);
 406 extern void disassociate_ctty(int priv);
 407 extern dev_t tty_devnum(struct tty_struct *tty);
 408 extern void proc_clear_tty(struct task_struct *p);
 409 extern struct tty_struct *get_current_tty(void);
 410 /* tty_io.c */
 411 extern int __init tty_init(void);
 412 extern const char *tty_name(const struct tty_struct *tty);
 413 extern struct tty_struct *tty_kopen(dev_t device);
 414 extern void tty_kclose(struct tty_struct *tty);
 415 extern int tty_dev_name_to_number(const char *name, dev_t *number);
 416 extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
 417 extern void tty_ldisc_unlock(struct tty_struct *tty);
 418 #else
 419 static inline void tty_kref_put(struct tty_struct *tty)
 420 { }
 421 static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
 422 { return NULL; }
 423 static inline void tty_vhangup_self(void)
 424 { }
 425 static inline void disassociate_ctty(int priv)
 426 { }
 427 static inline dev_t tty_devnum(struct tty_struct *tty)
 428 { return 0; }
 429 static inline void proc_clear_tty(struct task_struct *p)
 430 { }
 431 static inline struct tty_struct *get_current_tty(void)
 432 { return NULL; }
 433 /* tty_io.c */
 434 static inline int __init tty_init(void)
 435 { return 0; }
 436 static inline const char *tty_name(const struct tty_struct *tty)
 437 { return "(none)"; }
 438 static inline struct tty_struct *tty_kopen(dev_t device)
 439 { return ERR_PTR(-ENODEV); }
 440 static inline void tty_kclose(struct tty_struct *tty)
 441 { }
 442 static inline int tty_dev_name_to_number(const char *name, dev_t *number)
 443 { return -ENOTSUPP; }
 444 #endif
 445
 446 extern struct ktermios tty_std_termios;
 447
 448 extern int vcs_init(void);
 449
 450 extern struct class *tty_class;
 451
 452 /**
 453  *      tty_kref_get            -       get a tty reference
 454  *      @tty: tty device
 455  *
 456  *      Return a new reference to a tty object. The caller must hold
 457  *      sufficient locks/counts to ensure that their existing reference cannot
 458  *      go away
 459  */
 460
 461 static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
 462 {
 463         if (tty)
 464                 kref_get(&tty->kref);
 465         return tty;
 466 }
 467
 468 extern const char *tty_driver_name(const struct tty_struct *tty);
 469 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 470 extern int __tty_check_change(struct tty_struct *tty, int sig);
 471 extern int tty_check_change(struct tty_struct *tty);
 472 extern void __stop_tty(struct tty_struct *tty);
 473 extern void stop_tty(struct tty_struct *tty);
 474 extern void __start_tty(struct tty_struct *tty);
 475 extern void start_tty(struct tty_struct *tty);
 476 extern int tty_register_driver(struct tty_driver *driver);
 477 extern int tty_unregister_driver(struct tty_driver *driver);
 478 extern struct device *tty_register_device(struct tty_driver *driver,
 479                                           unsigned index, struct device *dev);
 480 extern struct device *tty_register_device_attr(struct tty_driver *driver,
 481                                 unsigned index, struct device *device,
 482                                 void *drvdata,
 483                                 const struct attribute_group **attr_grp);
 484 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 485 extern void tty_write_message(struct tty_struct *tty, char *msg);
 486 extern int tty_send_xchar(struct tty_struct *tty, char ch);
 487 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
 488 extern int tty_chars_in_buffer(struct tty_struct *tty);
 489 extern int tty_write_room(struct tty_struct *tty);
 490 extern void tty_driver_flush_buffer(struct tty_struct *tty);
 491 extern void tty_throttle(struct tty_struct *tty);
 492 extern void tty_unthrottle(struct tty_struct *tty);
 493 extern int tty_throttle_safe(struct tty_struct *tty);
 494 extern int tty_unthrottle_safe(struct tty_struct *tty);
 495 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 496 extern int is_current_pgrp_orphaned(void);
 497 extern void tty_hangup(struct tty_struct *tty);
 498 extern void tty_vhangup(struct tty_struct *tty);
 499 extern void tty_vhangup_session(struct tty_struct *tty);
 500 extern int tty_hung_up_p(struct file *filp);
 501 extern void do_SAK(struct tty_struct *tty);
 502 extern void __do_SAK(struct tty_struct *tty);
 503 extern void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
 504 extern int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
 505 extern void session_clear_tty(struct pid *session);
 506 extern void no_tty(void);
 507 extern void tty_buffer_free_all(struct tty_port *port);
 508 extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
 509 extern void tty_buffer_init(struct tty_port *port);
 510 extern void tty_buffer_set_lock_subclass(struct tty_port *port);
 511 extern bool tty_buffer_restart_work(struct tty_port *port);
 512 extern bool tty_buffer_cancel_work(struct tty_port *port);
 513 extern void tty_buffer_flush_work(struct tty_port *port);
 514 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
 515 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 516 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
 517                                                 speed_t ibaud, speed_t obaud);
 518 extern void tty_encode_baud_rate(struct tty_struct *tty,
 519                                                 speed_t ibaud, speed_t obaud);
 520
 521 /**
 522  *      tty_get_baud_rate       -       get tty bit rates
 523  *      @tty: tty to query
 524  *
 525  *      Returns the baud rate as an integer for this terminal. The
 526  *      termios lock must be held by the caller and the terminal bit
 527  *      flags may be updated.
 528  *
 529  *      Locking: none
 530  */
 531 static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
 532 {
 533         return tty_termios_baud_rate(&tty->termios);
 534 }
 535
 536 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 537 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
 538 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 539
 540 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 541 extern void tty_ldisc_deref(struct tty_ldisc *);
 542 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
 543 extern void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
 544 extern int tty_ldisc_reinit(struct tty_struct *tty, int disc);
 545 extern const struct file_operations tty_ldiscs_proc_fops;
 546
 547 extern void tty_wakeup(struct tty_struct *tty);
 548 extern void tty_ldisc_flush(struct tty_struct *tty);
 549
 550 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 551 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 552                         unsigned int cmd, unsigned long arg);
 553 extern long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
 554                               struct file *file, unsigned int cmd, unsigned long arg);
 555 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
 556 extern void tty_default_fops(struct file_operations *fops);
 557 extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
 558 extern int tty_alloc_file(struct file *file);
 559 extern void tty_add_file(struct tty_struct *tty, struct file *file);
 560 extern void tty_free_file(struct file *file);
 561 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
 562 extern void tty_release_struct(struct tty_struct *tty, int idx);
 563 extern int tty_release(struct inode *inode, struct file *filp);
 564 extern void tty_init_termios(struct tty_struct *tty);
 565 extern void tty_save_termios(struct tty_struct *tty);
 566 extern int tty_standard_install(struct tty_driver *driver,
 567                 struct tty_struct *tty);
 568
 569 extern struct mutex tty_mutex;
 570
 571 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 572
 573 extern void tty_port_init(struct tty_port *port);
 574 extern void tty_port_link_device(struct tty_port *port,
 575                 struct tty_driver *driver, unsigned index);
 576 extern struct device *tty_port_register_device(struct tty_port *port,
 577                 struct tty_driver *driver, unsigned index,
 578                 struct device *device);
 579 extern struct device *tty_port_register_device_attr(struct tty_port *port,
 580                 struct tty_driver *driver, unsigned index,
 581                 struct device *device, void *drvdata,
 582                 const struct attribute_group **attr_grp);
 583 extern struct device *tty_port_register_device_serdev(struct tty_port *port,
 584                 struct tty_driver *driver, unsigned index,
 585                 struct device *device);
 586 extern struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
 587                 struct tty_driver *driver, unsigned index,
 588                 struct device *device, void *drvdata,
 589                 const struct attribute_group **attr_grp);
 590 extern void tty_port_unregister_device(struct tty_port *port,
 591                 struct tty_driver *driver, unsigned index);
 592 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 593 extern void tty_port_free_xmit_buf(struct tty_port *port);
 594 extern void tty_port_destroy(struct tty_port *port);
 595 extern void tty_port_put(struct tty_port *port);
 596
 597 static inline struct tty_port *tty_port_get(struct tty_port *port)
 598 {
 599         if (port && kref_get_unless_zero(&port->kref))
 600                 return port;
 601         return NULL;
 602 }
 603
 604 /* If the cts flow control is enabled, return true. */
 605 static inline bool tty_port_cts_enabled(struct tty_port *port)
 606 {
 607         return test_bit(TTY_PORT_CTS_FLOW, &port->iflags);
 608 }
 609
 610 static inline void tty_port_set_cts_flow(struct tty_port *port, bool val)
 611 {
 612         if (val)
 613                 set_bit(TTY_PORT_CTS_FLOW, &port->iflags);
 614         else
 615                 clear_bit(TTY_PORT_CTS_FLOW, &port->iflags);
 616 }
 617
 618 static inline bool tty_port_active(struct tty_port *port)
 619 {
 620         return test_bit(TTY_PORT_ACTIVE, &port->iflags);
 621 }
 622
 623 static inline void tty_port_set_active(struct tty_port *port, bool val)
 624 {
 625         if (val)
 626                 set_bit(TTY_PORT_ACTIVE, &port->iflags);
 627         else
 628                 clear_bit(TTY_PORT_ACTIVE, &port->iflags);
 629 }
 630
 631 static inline bool tty_port_check_carrier(struct tty_port *port)
 632 {
 633         return test_bit(TTY_PORT_CHECK_CD, &port->iflags);
 634 }
 635
 636 static inline void tty_port_set_check_carrier(struct tty_port *port, bool val)
 637 {
 638         if (val)
 639                 set_bit(TTY_PORT_CHECK_CD, &port->iflags);
 640         else
 641                 clear_bit(TTY_PORT_CHECK_CD, &port->iflags);
 642 }
 643
 644 static inline bool tty_port_suspended(struct tty_port *port)
 645 {
 646         return test_bit(TTY_PORT_SUSPENDED, &port->iflags);
 647 }
 648
 649 static inline void tty_port_set_suspended(struct tty_port *port, bool val)
 650 {
 651         if (val)
 652                 set_bit(TTY_PORT_SUSPENDED, &port->iflags);
 653         else
 654                 clear_bit(TTY_PORT_SUSPENDED, &port->iflags);
 655 }
 656
 657 static inline bool tty_port_initialized(struct tty_port *port)
 658 {
 659         return test_bit(TTY_PORT_INITIALIZED, &port->iflags);
 660 }
 661
 662 static inline void tty_port_set_initialized(struct tty_port *port, bool val)
 663 {
 664         if (val)
 665                 set_bit(TTY_PORT_INITIALIZED, &port->iflags);
 666         else
 667                 clear_bit(TTY_PORT_INITIALIZED, &port->iflags);
 668 }
 669
 670 static inline bool tty_port_kopened(struct tty_port *port)
 671 {
 672         return test_bit(TTY_PORT_KOPENED, &port->iflags);
 673 }
 674
 675 static inline void tty_port_set_kopened(struct tty_port *port, bool val)
 676 {
 677         if (val)
 678                 set_bit(TTY_PORT_KOPENED, &port->iflags);
 679         else
 680                 clear_bit(TTY_PORT_KOPENED, &port->iflags);
 681 }
 682
 683 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
 684 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 685 extern int tty_port_carrier_raised(struct tty_port *port);
 686 extern void tty_port_raise_dtr_rts(struct tty_port *port);
 687 extern void tty_port_lower_dtr_rts(struct tty_port *port);
 688 extern void tty_port_hangup(struct tty_port *port);
 689 extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
 690 extern void tty_port_tty_wakeup(struct tty_port *port);
 691 extern int tty_port_block_til_ready(struct tty_port *port,
 692                                 struct tty_struct *tty, struct file *filp);
 693 extern int tty_port_close_start(struct tty_port *port,
 694                                 struct tty_struct *tty, struct file *filp);
 695 extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
 696 extern void tty_port_close(struct tty_port *port,
 697                                 struct tty_struct *tty, struct file *filp);
 698 extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
 699                                 struct tty_struct *tty);
 700 extern int tty_port_open(struct tty_port *port,
 701                                 struct tty_struct *tty, struct file *filp);
 702 static inline int tty_port_users(struct tty_port *port)
 703 {
 704         return port->count + port->blocked_open;
 705 }
 706
 707 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 708 extern int tty_unregister_ldisc(int disc);
 709 extern int tty_set_ldisc(struct tty_struct *tty, int disc);
 710 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 711 extern void tty_ldisc_release(struct tty_struct *tty);
 712 extern int __must_check tty_ldisc_init(struct tty_struct *tty);
 713 extern void tty_ldisc_deinit(struct tty_struct *tty);
 714 extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
 715                                  char *f, int count);
 716
 717 /* n_tty.c */
 718 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 719 #ifdef CONFIG_TTY
 720 extern void __init n_tty_init(void);
 721 #else
 722 static inline void n_tty_init(void) { }
 723 #endif
 724
 725 /* tty_audit.c */
 726 #ifdef CONFIG_AUDIT
 727 extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
 728                                size_t size);
 729 extern void tty_audit_exit(void);
 730 extern void tty_audit_fork(struct signal_struct *sig);
 731 extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
 732 extern int tty_audit_push(void);
 733 #else
 734 static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
 735                                       size_t size)
 736 {
 737 }
 738 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 739 {
 740 }
 741 static inline void tty_audit_exit(void)
 742 {
 743 }
 744 static inline void tty_audit_fork(struct signal_struct *sig)
 745 {
 746 }
 747 static inline int tty_audit_push(void)
 748 {
 749         return 0;
 750 }
 751 #endif
 752
 753 /* tty_ioctl.c */
 754 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 755                        unsigned int cmd, unsigned long arg);
 756 extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
 757                        unsigned int cmd, unsigned long arg);
 758
 759 /* vt.c */
 760
 761 extern int vt_ioctl(struct tty_struct *tty,
 762                     unsigned int cmd, unsigned long arg);
 763
 764 extern long vt_compat_ioctl(struct tty_struct *tty,
 765                      unsigned int cmd, unsigned long arg);
 766
 767 /* tty_mutex.c */
 768 /* functions for preparation of BKL removal */
 769 extern void tty_lock(struct tty_struct *tty);
 770 extern int  tty_lock_interruptible(struct tty_struct *tty);
 771 extern void tty_unlock(struct tty_struct *tty);
 772 extern void tty_lock_slave(struct tty_struct *tty);
 773 extern void tty_unlock_slave(struct tty_struct *tty);
 774 extern void tty_set_lock_subclass(struct tty_struct *tty);
 775
 776 #ifdef CONFIG_PROC_FS
 777 extern void proc_tty_register_driver(struct tty_driver *);
 778 extern void proc_tty_unregister_driver(struct tty_driver *);
 779 #else
 780 static inline void proc_tty_register_driver(struct tty_driver *d) {}
 781 static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
 782 #endif
 783
 784 #define tty_msg(fn, tty, f, ...) \
 785         fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
 786
 787 #define tty_debug(tty, f, ...)  tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
 788 #define tty_info(tty, f, ...)   tty_msg(pr_info, tty, f, ##__VA_ARGS__)
 789 #define tty_notice(tty, f, ...) tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
 790 #define tty_warn(tty, f, ...)   tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
 791 #define tty_err(tty, f, ...)    tty_msg(pr_err, tty, f, ##__VA_ARGS__)
 792
 793 #define tty_info_ratelimited(tty, f, ...) \
 794                 tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
 795
 796 #endif