linux/include/linux/tty.h
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   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
  14
  15
  16/*
  17 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
  18 * hardcoded at present.)
  19 */
  20#define NR_UNIX98_PTY_DEFAULT   4096      /* Default maximum for Unix98 ptys */
  21#define NR_UNIX98_PTY_RESERVE   1024      /* Default reserve for main devpts */
  22#define NR_UNIX98_PTY_MAX       (1 << MINORBITS) /* Absolute limit */
  23
  24/*
  25 * This character is the same as _POSIX_VDISABLE: it cannot be used as
  26 * a c_cc[] character, but indicates that a particular special character
  27 * isn't in use (eg VINTR has no character etc)
  28 */
  29#define __DISABLED_CHAR '\0'
  30
  31struct tty_buffer {
  32        struct tty_buffer *next;
  33        char *char_buf_ptr;
  34        unsigned char *flag_buf_ptr;
  35        int used;
  36        int size;
  37        int commit;
  38        int read;
  39        /* Data points here */
  40        unsigned long data[0];
  41};
  42
  43/*
  44 * We default to dicing tty buffer allocations to this many characters
  45 * in order to avoid multiple page allocations. We know the size of
  46 * tty_buffer itself but it must also be taken into account that the
  47 * the buffer is 256 byte aligned. See tty_buffer_find for the allocation
  48 * logic this must match
  49 */
  50
  51#define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF)
  52
  53
  54struct tty_bufhead {
  55        struct work_struct work;
  56        spinlock_t lock;
  57        struct tty_buffer *head;        /* Queue head */
  58        struct tty_buffer *tail;        /* Active buffer */
  59        struct tty_buffer *free;        /* Free queue head */
  60        int memory_used;                /* Buffer space used excluding
  61                                                                free queue */
  62};
  63/*
  64 * When a break, frame error, or parity error happens, these codes are
  65 * stuffed into the flags buffer.
  66 */
  67#define TTY_NORMAL      0
  68#define TTY_BREAK       1
  69#define TTY_FRAME       2
  70#define TTY_PARITY      3
  71#define TTY_OVERRUN     4
  72
  73#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
  74#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
  75#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
  76#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
  77#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
  78#define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
  79#define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
  80#define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
  81#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
  82#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
  83#define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
  84#define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
  85#define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
  86#define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
  87#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
  88#define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
  89#define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
  90
  91#define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
  92#define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
  93#define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
  94#define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
  95
  96#define I_IGNBRK(tty)   _I_FLAG((tty), IGNBRK)
  97#define I_BRKINT(tty)   _I_FLAG((tty), BRKINT)
  98#define I_IGNPAR(tty)   _I_FLAG((tty), IGNPAR)
  99#define I_PARMRK(tty)   _I_FLAG((tty), PARMRK)
 100#define I_INPCK(tty)    _I_FLAG((tty), INPCK)
 101#define I_ISTRIP(tty)   _I_FLAG((tty), ISTRIP)
 102#define I_INLCR(tty)    _I_FLAG((tty), INLCR)
 103#define I_IGNCR(tty)    _I_FLAG((tty), IGNCR)
 104#define I_ICRNL(tty)    _I_FLAG((tty), ICRNL)
 105#define I_IUCLC(tty)    _I_FLAG((tty), IUCLC)
 106#define I_IXON(tty)     _I_FLAG((tty), IXON)
 107#define I_IXANY(tty)    _I_FLAG((tty), IXANY)
 108#define I_IXOFF(tty)    _I_FLAG((tty), IXOFF)
 109#define I_IMAXBEL(tty)  _I_FLAG((tty), IMAXBEL)
 110#define I_IUTF8(tty)    _I_FLAG((tty), IUTF8)
 111
 112#define O_OPOST(tty)    _O_FLAG((tty), OPOST)
 113#define O_OLCUC(tty)    _O_FLAG((tty), OLCUC)
 114#define O_ONLCR(tty)    _O_FLAG((tty), ONLCR)
 115#define O_OCRNL(tty)    _O_FLAG((tty), OCRNL)
 116#define O_ONOCR(tty)    _O_FLAG((tty), ONOCR)
 117#define O_ONLRET(tty)   _O_FLAG((tty), ONLRET)
 118#define O_OFILL(tty)    _O_FLAG((tty), OFILL)
 119#define O_OFDEL(tty)    _O_FLAG((tty), OFDEL)
 120#define O_NLDLY(tty)    _O_FLAG((tty), NLDLY)
 121#define O_CRDLY(tty)    _O_FLAG((tty), CRDLY)
 122#define O_TABDLY(tty)   _O_FLAG((tty), TABDLY)
 123#define O_BSDLY(tty)    _O_FLAG((tty), BSDLY)
 124#define O_VTDLY(tty)    _O_FLAG((tty), VTDLY)
 125#define O_FFDLY(tty)    _O_FLAG((tty), FFDLY)
 126
 127#define C_BAUD(tty)     _C_FLAG((tty), CBAUD)
 128#define C_CSIZE(tty)    _C_FLAG((tty), CSIZE)
 129#define C_CSTOPB(tty)   _C_FLAG((tty), CSTOPB)
 130#define C_CREAD(tty)    _C_FLAG((tty), CREAD)
 131#define C_PARENB(tty)   _C_FLAG((tty), PARENB)
 132#define C_PARODD(tty)   _C_FLAG((tty), PARODD)
 133#define C_HUPCL(tty)    _C_FLAG((tty), HUPCL)
 134#define C_CLOCAL(tty)   _C_FLAG((tty), CLOCAL)
 135#define C_CIBAUD(tty)   _C_FLAG((tty), CIBAUD)
 136#define C_CRTSCTS(tty)  _C_FLAG((tty), CRTSCTS)
 137
 138#define L_ISIG(tty)     _L_FLAG((tty), ISIG)
 139#define L_ICANON(tty)   _L_FLAG((tty), ICANON)
 140#define L_XCASE(tty)    _L_FLAG((tty), XCASE)
 141#define L_ECHO(tty)     _L_FLAG((tty), ECHO)
 142#define L_ECHOE(tty)    _L_FLAG((tty), ECHOE)
 143#define L_ECHOK(tty)    _L_FLAG((tty), ECHOK)
 144#define L_ECHONL(tty)   _L_FLAG((tty), ECHONL)
 145#define L_NOFLSH(tty)   _L_FLAG((tty), NOFLSH)
 146#define L_TOSTOP(tty)   _L_FLAG((tty), TOSTOP)
 147#define L_ECHOCTL(tty)  _L_FLAG((tty), ECHOCTL)
 148#define L_ECHOPRT(tty)  _L_FLAG((tty), ECHOPRT)
 149#define L_ECHOKE(tty)   _L_FLAG((tty), ECHOKE)
 150#define L_FLUSHO(tty)   _L_FLAG((tty), FLUSHO)
 151#define L_PENDIN(tty)   _L_FLAG((tty), PENDIN)
 152#define L_IEXTEN(tty)   _L_FLAG((tty), IEXTEN)
 153#define L_EXTPROC(tty)  _L_FLAG((tty), EXTPROC)
 154
 155struct device;
 156struct signal_struct;
 157
 158/*
 159 * Port level information. Each device keeps its own port level information
 160 * so provide a common structure for those ports wanting to use common support
 161 * routines.
 162 *
 163 * The tty port has a different lifetime to the tty so must be kept apart.
 164 * In addition be careful as tty -> port mappings are valid for the life
 165 * of the tty object but in many cases port -> tty mappings are valid only
 166 * until a hangup so don't use the wrong path.
 167 */
 168
 169struct tty_port;
 170
 171struct tty_port_operations {
 172        /* Return 1 if the carrier is raised */
 173        int (*carrier_raised)(struct tty_port *port);
 174        /* Control the DTR line */
 175        void (*dtr_rts)(struct tty_port *port, int raise);
 176        /* Called when the last close completes or a hangup finishes
 177           IFF the port was initialized. Do not use to free resources. Called
 178           under the port mutex to serialize against activate/shutdowns */
 179        void (*shutdown)(struct tty_port *port);
 180        void (*drop)(struct tty_port *port);
 181        /* Called under the port mutex from tty_port_open, serialized using
 182           the port mutex */
 183        /* FIXME: long term getting the tty argument *out* of this would be
 184           good for consoles */
 185        int (*activate)(struct tty_port *port, struct tty_struct *tty);
 186        /* Called on the final put of a port */
 187        void (*destruct)(struct tty_port *port);
 188};
 189        
 190struct tty_port {
 191        struct tty_struct       *tty;           /* Back pointer */
 192        const struct tty_port_operations *ops;  /* Port operations */
 193        spinlock_t              lock;           /* Lock protecting tty field */
 194        int                     blocked_open;   /* Waiting to open */
 195        int                     count;          /* Usage count */
 196        wait_queue_head_t       open_wait;      /* Open waiters */
 197        wait_queue_head_t       close_wait;     /* Close waiters */
 198        wait_queue_head_t       delta_msr_wait; /* Modem status change */
 199        unsigned long           flags;          /* TTY flags ASY_*/
 200        unsigned char           console:1;      /* port is a console */
 201        struct mutex            mutex;          /* Locking */
 202        struct mutex            buf_mutex;      /* Buffer alloc lock */
 203        unsigned char           *xmit_buf;      /* Optional buffer */
 204        unsigned int            close_delay;    /* Close port delay */
 205        unsigned int            closing_wait;   /* Delay for output */
 206        int                     drain_delay;    /* Set to zero if no pure time
 207                                                   based drain is needed else
 208                                                   set to size of fifo */
 209        struct kref             kref;           /* Ref counter */
 210};
 211
 212/*
 213 * Where all of the state associated with a tty is kept while the tty
 214 * is open.  Since the termios state should be kept even if the tty
 215 * has been closed --- for things like the baud rate, etc --- it is
 216 * not stored here, but rather a pointer to the real state is stored
 217 * here.  Possible the winsize structure should have the same
 218 * treatment, but (1) the default 80x24 is usually right and (2) it's
 219 * most often used by a windowing system, which will set the correct
 220 * size each time the window is created or resized anyway.
 221 *                                              - TYT, 9/14/92
 222 */
 223
 224struct tty_operations;
 225
 226struct tty_struct {
 227        int     magic;
 228        struct kref kref;
 229        struct device *dev;
 230        struct tty_driver *driver;
 231        const struct tty_operations *ops;
 232        int index;
 233
 234        /* Protects ldisc changes: Lock tty not pty */
 235        struct mutex ldisc_mutex;
 236        struct tty_ldisc *ldisc;
 237
 238        struct mutex legacy_mutex;
 239        struct mutex termios_mutex;
 240        spinlock_t ctrl_lock;
 241        /* Termios values are protected by the termios mutex */
 242        struct ktermios termios, termios_locked;
 243        struct termiox *termiox;        /* May be NULL for unsupported */
 244        char name[64];
 245        struct pid *pgrp;               /* Protected by ctrl lock */
 246        struct pid *session;
 247        unsigned long flags;
 248        int count;
 249        struct winsize winsize;         /* termios mutex */
 250        unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
 251        unsigned char low_latency:1, warned:1;
 252        unsigned char ctrl_status;      /* ctrl_lock */
 253        unsigned int receive_room;      /* Bytes free for queue */
 254
 255        struct tty_struct *link;
 256        struct fasync_struct *fasync;
 257        struct tty_bufhead buf;         /* Locked internally */
 258        int alt_speed;          /* For magic substitution of 38400 bps */
 259        wait_queue_head_t write_wait;
 260        wait_queue_head_t read_wait;
 261        struct work_struct hangup_work;
 262        void *disc_data;
 263        void *driver_data;
 264        struct list_head tty_files;
 265
 266#define N_TTY_BUF_SIZE 4096
 267
 268        /*
 269         * The following is data for the N_TTY line discipline.  For
 270         * historical reasons, this is included in the tty structure.
 271         * Mostly locked by the BKL.
 272         */
 273        unsigned int column;
 274        unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
 275        unsigned char closing:1;
 276        unsigned char echo_overrun:1;
 277        unsigned short minimum_to_wake;
 278        unsigned long overrun_time;
 279        int num_overrun;
 280        unsigned long process_char_map[256/(8*sizeof(unsigned long))];
 281        char *read_buf;
 282        int read_head;
 283        int read_tail;
 284        int read_cnt;
 285        unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
 286        unsigned char *echo_buf;
 287        unsigned int echo_pos;
 288        unsigned int echo_cnt;
 289        int canon_data;
 290        unsigned long canon_head;
 291        unsigned int canon_column;
 292        struct mutex atomic_read_lock;
 293        struct mutex atomic_write_lock;
 294        struct mutex output_lock;
 295        struct mutex echo_lock;
 296        unsigned char *write_buf;
 297        int write_cnt;
 298        spinlock_t read_lock;
 299        /* If the tty has a pending do_SAK, queue it here - akpm */
 300        struct work_struct SAK_work;
 301        struct tty_port *port;
 302};
 303
 304/* Each of a tty's open files has private_data pointing to tty_file_private */
 305struct tty_file_private {
 306        struct tty_struct *tty;
 307        struct file *file;
 308        struct list_head list;
 309};
 310
 311/* tty magic number */
 312#define TTY_MAGIC               0x5401
 313
 314/*
 315 * These bits are used in the flags field of the tty structure.
 316 *
 317 * So that interrupts won't be able to mess up the queues,
 318 * copy_to_cooked must be atomic with respect to itself, as must
 319 * tty->write.  Thus, you must use the inline functions set_bit() and
 320 * clear_bit() to make things atomic.
 321 */
 322#define TTY_THROTTLED           0       /* Call unthrottle() at threshold min */
 323#define TTY_IO_ERROR            1       /* Cause an I/O error (may be no ldisc too) */
 324#define TTY_OTHER_CLOSED        2       /* Other side (if any) has closed */
 325#define TTY_EXCLUSIVE           3       /* Exclusive open mode */
 326#define TTY_DEBUG               4       /* Debugging */
 327#define TTY_DO_WRITE_WAKEUP     5       /* Call write_wakeup after queuing new */
 328#define TTY_PUSH                6       /* n_tty private */
 329#define TTY_CLOSING             7       /* ->close() in progress */
 330#define TTY_LDISC               9       /* Line discipline attached */
 331#define TTY_LDISC_CHANGING      10      /* Line discipline changing */
 332#define TTY_LDISC_OPEN          11      /* Line discipline is open */
 333#define TTY_HW_COOK_OUT         14      /* Hardware can do output cooking */
 334#define TTY_HW_COOK_IN          15      /* Hardware can do input cooking */
 335#define TTY_PTY_LOCK            16      /* pty private */
 336#define TTY_NO_WRITE_SPLIT      17      /* Preserve write boundaries to driver */
 337#define TTY_HUPPED              18      /* Post driver->hangup() */
 338#define TTY_FLUSHING            19      /* Flushing to ldisc in progress */
 339#define TTY_FLUSHPENDING        20      /* Queued buffer flush pending */
 340#define TTY_HUPPING             21      /* ->hangup() in progress */
 341
 342#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
 343
 344extern void tty_write_flush(struct tty_struct *);
 345
 346extern struct ktermios tty_std_termios;
 347
 348extern void console_init(void);
 349extern int vcs_init(void);
 350
 351extern struct class *tty_class;
 352
 353/**
 354 *      tty_kref_get            -       get a tty reference
 355 *      @tty: tty device
 356 *
 357 *      Return a new reference to a tty object. The caller must hold
 358 *      sufficient locks/counts to ensure that their existing reference cannot
 359 *      go away
 360 */
 361
 362static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
 363{
 364        if (tty)
 365                kref_get(&tty->kref);
 366        return tty;
 367}
 368extern void tty_kref_put(struct tty_struct *tty);
 369
 370extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
 371                              const char *routine);
 372extern char *tty_name(struct tty_struct *tty, char *buf);
 373extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 374extern int tty_check_change(struct tty_struct *tty);
 375extern void stop_tty(struct tty_struct *tty);
 376extern void start_tty(struct tty_struct *tty);
 377extern int tty_register_driver(struct tty_driver *driver);
 378extern int tty_unregister_driver(struct tty_driver *driver);
 379extern struct device *tty_register_device(struct tty_driver *driver,
 380                                          unsigned index, struct device *dev);
 381extern struct device *tty_register_device_attr(struct tty_driver *driver,
 382                                unsigned index, struct device *device,
 383                                void *drvdata,
 384                                const struct attribute_group **attr_grp);
 385extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 386extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
 387                             int buflen);
 388extern void tty_write_message(struct tty_struct *tty, char *msg);
 389extern int tty_put_char(struct tty_struct *tty, unsigned char c);
 390extern int tty_chars_in_buffer(struct tty_struct *tty);
 391extern int tty_write_room(struct tty_struct *tty);
 392extern void tty_driver_flush_buffer(struct tty_struct *tty);
 393extern void tty_throttle(struct tty_struct *tty);
 394extern void tty_unthrottle(struct tty_struct *tty);
 395extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 396extern void tty_driver_remove_tty(struct tty_driver *driver,
 397                                  struct tty_struct *tty);
 398extern void tty_free_termios(struct tty_struct *tty);
 399extern int is_current_pgrp_orphaned(void);
 400extern struct pid *tty_get_pgrp(struct tty_struct *tty);
 401extern int is_ignored(int sig);
 402extern int tty_signal(int sig, struct tty_struct *tty);
 403extern void tty_hangup(struct tty_struct *tty);
 404extern void tty_vhangup(struct tty_struct *tty);
 405extern void tty_vhangup_locked(struct tty_struct *tty);
 406extern void tty_vhangup_self(void);
 407extern void tty_unhangup(struct file *filp);
 408extern int tty_hung_up_p(struct file *filp);
 409extern void do_SAK(struct tty_struct *tty);
 410extern void __do_SAK(struct tty_struct *tty);
 411extern void disassociate_ctty(int priv);
 412extern void no_tty(void);
 413extern void tty_flip_buffer_push(struct tty_struct *tty);
 414extern void tty_flush_to_ldisc(struct tty_struct *tty);
 415extern void tty_buffer_free_all(struct tty_struct *tty);
 416extern void tty_buffer_flush(struct tty_struct *tty);
 417extern void tty_buffer_init(struct tty_struct *tty);
 418extern speed_t tty_get_baud_rate(struct tty_struct *tty);
 419extern speed_t tty_termios_baud_rate(struct ktermios *termios);
 420extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 421extern void tty_termios_encode_baud_rate(struct ktermios *termios,
 422                                                speed_t ibaud, speed_t obaud);
 423extern void tty_encode_baud_rate(struct tty_struct *tty,
 424                                                speed_t ibaud, speed_t obaud);
 425extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 426extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
 427extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 428
 429extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 430extern void tty_ldisc_deref(struct tty_ldisc *);
 431extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
 432extern void tty_ldisc_hangup(struct tty_struct *tty);
 433extern const struct file_operations tty_ldiscs_proc_fops;
 434
 435extern void tty_wakeup(struct tty_struct *tty);
 436extern void tty_ldisc_flush(struct tty_struct *tty);
 437
 438extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 439extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 440                        unsigned int cmd, unsigned long arg);
 441extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
 442extern dev_t tty_devnum(struct tty_struct *tty);
 443extern void proc_clear_tty(struct task_struct *p);
 444extern struct tty_struct *get_current_tty(void);
 445extern void tty_default_fops(struct file_operations *fops);
 446extern struct tty_struct *alloc_tty_struct(void);
 447extern int tty_alloc_file(struct file *file);
 448extern void tty_add_file(struct tty_struct *tty, struct file *file);
 449extern void tty_free_file(struct file *file);
 450extern void free_tty_struct(struct tty_struct *tty);
 451extern void initialize_tty_struct(struct tty_struct *tty,
 452                struct tty_driver *driver, int idx);
 453extern void deinitialize_tty_struct(struct tty_struct *tty);
 454extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
 455extern int tty_release(struct inode *inode, struct file *filp);
 456extern int tty_init_termios(struct tty_struct *tty);
 457extern int tty_standard_install(struct tty_driver *driver,
 458                struct tty_struct *tty);
 459
 460extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
 461extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
 462
 463extern struct mutex tty_mutex;
 464extern spinlock_t tty_files_lock;
 465
 466extern void tty_write_unlock(struct tty_struct *tty);
 467extern int tty_write_lock(struct tty_struct *tty, int ndelay);
 468#define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 469
 470extern void tty_port_init(struct tty_port *port);
 471extern void tty_port_link_device(struct tty_port *port,
 472                struct tty_driver *driver, unsigned index);
 473extern struct device *tty_port_register_device(struct tty_port *port,
 474                struct tty_driver *driver, unsigned index,
 475                struct device *device);
 476extern struct device *tty_port_register_device_attr(struct tty_port *port,
 477                struct tty_driver *driver, unsigned index,
 478                struct device *device, void *drvdata,
 479                const struct attribute_group **attr_grp);
 480extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 481extern void tty_port_free_xmit_buf(struct tty_port *port);
 482extern void tty_port_put(struct tty_port *port);
 483
 484static inline struct tty_port *tty_port_get(struct tty_port *port)
 485{
 486        if (port)
 487                kref_get(&port->kref);
 488        return port;
 489}
 490
 491/* If the cts flow control is enabled, return true. */
 492static inline bool tty_port_cts_enabled(struct tty_port *port)
 493{
 494        return port->flags & ASYNC_CTS_FLOW;
 495}
 496
 497extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
 498extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 499extern int tty_port_carrier_raised(struct tty_port *port);
 500extern void tty_port_raise_dtr_rts(struct tty_port *port);
 501extern void tty_port_lower_dtr_rts(struct tty_port *port);
 502extern void tty_port_hangup(struct tty_port *port);
 503extern int tty_port_block_til_ready(struct tty_port *port,
 504                                struct tty_struct *tty, struct file *filp);
 505extern int tty_port_close_start(struct tty_port *port,
 506                                struct tty_struct *tty, struct file *filp);
 507extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
 508extern void tty_port_close(struct tty_port *port,
 509                                struct tty_struct *tty, struct file *filp);
 510extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
 511                                struct tty_struct *tty);
 512extern int tty_port_open(struct tty_port *port,
 513                                struct tty_struct *tty, struct file *filp);
 514static inline int tty_port_users(struct tty_port *port)
 515{
 516        return port->count + port->blocked_open;
 517}
 518
 519extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 520extern int tty_unregister_ldisc(int disc);
 521extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
 522extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 523extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
 524extern void tty_ldisc_init(struct tty_struct *tty);
 525extern void tty_ldisc_deinit(struct tty_struct *tty);
 526extern void tty_ldisc_begin(void);
 527/* This last one is just for the tty layer internals and shouldn't be used elsewhere */
 528extern void tty_ldisc_enable(struct tty_struct *tty);
 529
 530
 531/* n_tty.c */
 532extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 533extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 534
 535/* tty_audit.c */
 536#ifdef CONFIG_AUDIT
 537extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
 538                               size_t size);
 539extern void tty_audit_exit(void);
 540extern void tty_audit_fork(struct signal_struct *sig);
 541extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
 542extern void tty_audit_push(struct tty_struct *tty);
 543extern int tty_audit_push_task(struct task_struct *tsk,
 544                               kuid_t loginuid, u32 sessionid);
 545#else
 546static inline void tty_audit_add_data(struct tty_struct *tty,
 547                                      unsigned char *data, size_t size)
 548{
 549}
 550static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 551{
 552}
 553static inline void tty_audit_exit(void)
 554{
 555}
 556static inline void tty_audit_fork(struct signal_struct *sig)
 557{
 558}
 559static inline void tty_audit_push(struct tty_struct *tty)
 560{
 561}
 562static inline int tty_audit_push_task(struct task_struct *tsk,
 563                                      kuid_t loginuid, u32 sessionid)
 564{
 565        return 0;
 566}
 567#endif
 568
 569/* tty_io.c */
 570extern int __init tty_init(void);
 571
 572/* tty_ioctl.c */
 573extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
 574                       unsigned int cmd, unsigned long arg);
 575extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
 576                       unsigned int cmd, unsigned long arg);
 577
 578/* serial.c */
 579
 580extern void serial_console_init(void);
 581
 582/* pcxx.c */
 583
 584extern int pcxe_open(struct tty_struct *tty, struct file *filp);
 585
 586/* vt.c */
 587
 588extern int vt_ioctl(struct tty_struct *tty,
 589                    unsigned int cmd, unsigned long arg);
 590
 591extern long vt_compat_ioctl(struct tty_struct *tty,
 592                     unsigned int cmd, unsigned long arg);
 593
 594/* tty_mutex.c */
 595/* functions for preparation of BKL removal */
 596extern void __lockfunc tty_lock(struct tty_struct *tty);
 597extern void __lockfunc tty_unlock(struct tty_struct *tty);
 598extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
 599                                struct tty_struct *tty2);
 600extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
 601                                struct tty_struct *tty2);
 602
 603/*
 604 * this shall be called only from where BTM is held (like close)
 605 *
 606 * We need this to ensure nobody waits for us to finish while we are waiting.
 607 * Without this we were encountering system stalls.
 608 *
 609 * This should be indeed removed with BTM removal later.
 610 *
 611 * Locking: BTM required. Nobody is allowed to hold port->mutex.
 612 */
 613static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
 614                long timeout)
 615{
 616        tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
 617        tty_wait_until_sent(tty, timeout);
 618        tty_lock(tty);
 619}
 620
 621/*
 622 * wait_event_interruptible_tty -- wait for a condition with the tty lock held
 623 *
 624 * The condition we are waiting for might take a long time to
 625 * become true, or might depend on another thread taking the
 626 * BTM. In either case, we need to drop the BTM to guarantee
 627 * forward progress. This is a leftover from the conversion
 628 * from the BKL and should eventually get removed as the BTM
 629 * falls out of use.
 630 *
 631 * Do not use in new code.
 632 */
 633#define wait_event_interruptible_tty(tty, wq, condition)                \
 634({                                                                      \
 635        int __ret = 0;                                                  \
 636        if (!(condition)) {                                             \
 637                __wait_event_interruptible_tty(tty, wq, condition, __ret);      \
 638        }                                                               \
 639        __ret;                                                          \
 640})
 641
 642#define __wait_event_interruptible_tty(tty, wq, condition, ret)         \
 643do {                                                                    \
 644        DEFINE_WAIT(__wait);                                            \
 645                                                                        \
 646        for (;;) {                                                      \
 647                prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE);      \
 648                if (condition)                                          \
 649                        break;                                          \
 650                if (!signal_pending(current)) {                         \
 651                        tty_unlock(tty);                                        \
 652                        schedule();                                     \
 653                        tty_lock(tty);                                  \
 654                        continue;                                       \
 655                }                                                       \
 656                ret = -ERESTARTSYS;                                     \
 657                break;                                                  \
 658        }                                                               \
 659        finish_wait(&wq, &__wait);                                      \
 660} while (0)
 661
 662
 663#endif
 664
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