sys/kern/tty_cons.c

   1 /*-
   2  * Copyright (c) 1988 University of Utah.
   3  * Copyright (c) 1991 The Regents of the University of California.
   4  * All rights reserved.
   5  *
   6  * This code is derived from software contributed to Berkeley by
   7  * the Systems Programming Group of the University of Utah Computer
   8  * Science Department.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      from: @(#)cons.c        7.2 (Berkeley) 5/9/91
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include "opt_ddb.h"
  41
  42 #include <sys/param.h>
  43 #include <sys/systm.h>
  44 #include <sys/lock.h>
  45 #include <sys/mutex.h>
  46 #include <sys/conf.h>
  47 #include <sys/cons.h>
  48 #include <sys/fcntl.h>
  49 #include <sys/kdb.h>
  50 #include <sys/kernel.h>
  51 #include <sys/malloc.h>
  52 #include <sys/msgbuf.h>
  53 #include <sys/namei.h>
  54 #include <sys/priv.h>
  55 #include <sys/proc.h>
  56 #include <sys/queue.h>
  57 #include <sys/reboot.h>
  58 #include <sys/sysctl.h>
  59 #include <sys/sbuf.h>
  60 #include <sys/tty.h>
  61 #include <sys/uio.h>
  62 #include <sys/vnode.h>
  63
  64 #include <ddb/ddb.h>
  65
  66 #include <machine/cpu.h>
  67 #include <machine/clock.h>
  68
  69 static MALLOC_DEFINE(M_TTYCONS, "tty console", "tty console handling");
  70
  71 static  d_open_t        cnopen;
  72 static  d_close_t       cnclose;
  73 static  d_read_t        cnread;
  74 static  d_write_t       cnwrite;
  75 static  d_ioctl_t       cnioctl;
  76 static  d_poll_t        cnpoll;
  77 static  d_kqfilter_t    cnkqfilter;
  78
  79 static struct cdevsw cn_cdevsw = {
  80         .d_version =    D_VERSION,
  81         .d_open =       cnopen,
  82         .d_close =      cnclose,
  83         .d_read =       cnread,
  84         .d_write =      cnwrite,
  85         .d_ioctl =      cnioctl,
  86         .d_poll =       cnpoll,
  87         .d_name =       "console",
  88         .d_flags =      D_TTY | D_NEEDGIANT,
  89         .d_kqfilter =   cnkqfilter,
  90 };
  91
  92 struct cn_device {
  93         STAILQ_ENTRY(cn_device) cnd_next;
  94         struct          vnode *cnd_vp;
  95         struct          consdev *cnd_cn;
  96 };
  97
  98 #define CNDEVPATHMAX    32
  99 #define CNDEVTAB_SIZE   4
 100 static struct cn_device cn_devtab[CNDEVTAB_SIZE];
 101 static STAILQ_HEAD(, cn_device) cn_devlist =
 102     STAILQ_HEAD_INITIALIZER(cn_devlist);
 103
 104 #define CND_INVALID(cnd, td)                                            \
 105         (cnd == NULL || cnd->cnd_vp == NULL ||                          \
 106             (cnd->cnd_vp->v_type == VBAD && !cn_devopen(cnd, td, 1)))
 107
 108 static dev_t    cn_udev_t;
 109 SYSCTL_OPAQUE(_machdep, OID_AUTO, consdev, CTLFLAG_RD,
 110         &cn_udev_t, sizeof cn_udev_t, "T,struct cdev *", "");
 111
 112 int     cons_avail_mask = 0;    /* Bit mask. Each registered low level console
 113                                  * which is currently unavailable for inpit
 114                                  * (i.e., if it is in graphics mode) will have
 115                                  * this bit cleared.
 116                                  */
 117 static int cn_mute;
 118 static int openflag;                    /* how /dev/console was opened */
 119 static int cn_is_open;
 120 static char *consbuf;                   /* buffer used by `consmsgbuf' */
 121 static struct callout conscallout;      /* callout for outputting to constty */
 122 struct msgbuf consmsgbuf;               /* message buffer for console tty */
 123 static u_char console_pausing;          /* pause after each line during probe */
 124 static char *console_pausestr=
 125 "<pause; press any key to proceed to next line or '.' to end pause mode>";
 126 struct tty *constty;                    /* pointer to console "window" tty */
 127 static struct mtx cnputs_mtx;           /* Mutex for cnputs(). */
 128 static int use_cnputs_mtx = 0;          /* != 0 if cnputs_mtx locking reqd. */
 129
 130 static void constty_timeout(void *arg);
 131
 132 static struct consdev cons_consdev;
 133 DATA_SET(cons_set, cons_consdev);
 134 SET_DECLARE(cons_set, struct consdev);
 135
 136 void
 137 cninit(void)
 138 {
 139         struct consdev *best_cn, *cn, **list;
 140
 141         /*
 142          * Check if we should mute the console (for security reasons perhaps)
 143          * It can be changes dynamically using sysctl kern.consmute
 144          * once we are up and going.
 145          *
 146          */
 147         cn_mute = ((boothowto & (RB_MUTE
 148                         |RB_SINGLE
 149                         |RB_VERBOSE
 150                         |RB_ASKNAME)) == RB_MUTE);
 151
 152         /*
 153          * Find the first console with the highest priority.
 154          */
 155         best_cn = NULL;
 156         SET_FOREACH(list, cons_set) {
 157                 cn = *list;
 158                 cnremove(cn);
 159                 if (cn->cn_probe == NULL)
 160                         continue;
 161                 cn->cn_probe(cn);
 162                 if (cn->cn_pri == CN_DEAD)
 163                         continue;
 164                 if (best_cn == NULL || cn->cn_pri > best_cn->cn_pri)
 165                         best_cn = cn;
 166                 if (boothowto & RB_MULTIPLE) {
 167                         /*
 168                          * Initialize console, and attach to it.
 169                          */
 170                         cn->cn_init(cn);
 171                         cnadd(cn);
 172                 }
 173         }
 174         if (best_cn == NULL)
 175                 return;
 176         if ((boothowto & RB_MULTIPLE) == 0) {
 177                 best_cn->cn_init(best_cn);
 178                 cnadd(best_cn);
 179         }
 180         if (boothowto & RB_PAUSE)
 181                 console_pausing = 1;
 182         /*
 183          * Make the best console the preferred console.
 184          */
 185         cnselect(best_cn);
 186 }
 187
 188 void
 189 cninit_finish()
 190 {
 191         console_pausing = 0;
 192 }
 193
 194 /* add a new physical console to back the virtual console */
 195 int
 196 cnadd(struct consdev *cn)
 197 {
 198         struct cn_device *cnd;
 199         int i;
 200
 201         STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
 202                 if (cnd->cnd_cn == cn)
 203                         return (0);
 204         for (i = 0; i < CNDEVTAB_SIZE; i++) {
 205                 cnd = &cn_devtab[i];
 206                 if (cnd->cnd_cn == NULL)
 207                         break;
 208         }
 209         if (cnd->cnd_cn != NULL)
 210                 return (ENOMEM);
 211         cnd->cnd_cn = cn;
 212         if (cn->cn_name[0] == '\0') {
 213                 /* XXX: it is unclear if/where this print might output */
 214                 printf("WARNING: console at %p has no name\n", cn);
 215         }
 216         STAILQ_INSERT_TAIL(&cn_devlist, cnd, cnd_next);
 217
 218         /* Add device to the active mask. */
 219         cnavailable(cn, (cn->cn_flags & CN_FLAG_NOAVAIL) == 0);
 220
 221         return (0);
 222 }
 223
 224 void
 225 cnremove(struct consdev *cn)
 226 {
 227         struct cn_device *cnd;
 228         int i;
 229
 230         STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
 231                 if (cnd->cnd_cn != cn)
 232                         continue;
 233                 STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
 234                 if (cnd->cnd_vp != NULL)
 235                         vn_close(cnd->cnd_vp, openflag, NOCRED, NULL);
 236                 cnd->cnd_vp = NULL;
 237                 cnd->cnd_cn = NULL;
 238
 239                 /* Remove this device from available mask. */
 240                 for (i = 0; i < CNDEVTAB_SIZE; i++)
 241                         if (cnd == &cn_devtab[i]) {
 242                                 cons_avail_mask &= ~(1 << i);
 243                                 break;
 244                         }
 245 #if 0
 246                 /*
 247                  * XXX
 248                  * syscons gets really confused if console resources are
 249                  * freed after the system has initialized.
 250                  */
 251                 if (cn->cn_term != NULL)
 252                         cn->cn_term(cn);
 253 #endif
 254                 return;
 255         }
 256 }
 257
 258 void
 259 cnselect(struct consdev *cn)
 260 {
 261         struct cn_device *cnd;
 262
 263         STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
 264                 if (cnd->cnd_cn != cn)
 265                         continue;
 266                 if (cnd == STAILQ_FIRST(&cn_devlist))
 267                         return;
 268                 STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next);
 269                 STAILQ_INSERT_HEAD(&cn_devlist, cnd, cnd_next);
 270                 return;
 271         }
 272 }
 273
 274 void
 275 cnavailable(struct consdev *cn, int available)
 276 {
 277         int i;
 278
 279         for (i = 0; i < CNDEVTAB_SIZE; i++) {
 280                 if (cn_devtab[i].cnd_cn == cn)
 281                         break;
 282         }
 283         if (available) {
 284                 if (i < CNDEVTAB_SIZE)
 285                         cons_avail_mask |= (1 << i);
 286                 cn->cn_flags &= ~CN_FLAG_NOAVAIL;
 287         } else {
 288                 if (i < CNDEVTAB_SIZE)
 289                         cons_avail_mask &= ~(1 << i);
 290                 cn->cn_flags |= CN_FLAG_NOAVAIL;
 291         }
 292 }
 293
 294 int
 295 cnunavailable(void)
 296 {
 297
 298         return (cons_avail_mask == 0);
 299 }
 300
 301 /*
 302  * sysctl_kern_console() provides output parseable in conscontrol(1).
 303  */
 304 static int
 305 sysctl_kern_console(SYSCTL_HANDLER_ARGS)
 306 {
 307         struct cn_device *cnd;
 308         struct consdev *cp, **list;
 309         char *p;
 310         int delete, error;
 311         struct sbuf *sb;
 312
 313         sb = sbuf_new(NULL, NULL, CNDEVPATHMAX * 2, SBUF_AUTOEXTEND);
 314         if (sb == NULL)
 315                 return (ENOMEM);
 316         sbuf_clear(sb);
 317         STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
 318                 sbuf_printf(sb, "%s,", cnd->cnd_cn->cn_name);
 319         sbuf_printf(sb, "/");
 320         SET_FOREACH(list, cons_set) {
 321                 cp = *list;
 322                 if (cp->cn_name[0] != '\0')
 323                         sbuf_printf(sb, "%s,", cp->cn_name);
 324         }
 325         sbuf_finish(sb);
 326         error = sysctl_handle_string(oidp, sbuf_data(sb), sbuf_len(sb), req);
 327         if (error == 0 && req->newptr != NULL) {
 328                 p = sbuf_data(sb);
 329                 error = ENXIO;
 330                 delete = 0;
 331                 if (*p == '-') {
 332                         delete = 1;
 333                         p++;
 334                 }
 335                 SET_FOREACH(list, cons_set) {
 336                         cp = *list;
 337                         if (strcmp(p, cp->cn_name) != 0)
 338                                 continue;
 339                         if (delete) {
 340                                 cnremove(cp);
 341                                 error = 0;
 342                         } else {
 343                                 error = cnadd(cp);
 344                                 if (error == 0)
 345                                         cnselect(cp);
 346                         }
 347                         break;
 348                 }
 349         }
 350         sbuf_delete(sb);
 351         return (error);
 352 }
 353
 354 SYSCTL_PROC(_kern, OID_AUTO, console, CTLTYPE_STRING|CTLFLAG_RW,
 355         0, 0, sysctl_kern_console, "A", "Console device control");
 356
 357 /*
 358  * User has changed the state of the console muting.
 359  * This may require us to open or close the device in question.
 360  */
 361 static int
 362 sysctl_kern_consmute(SYSCTL_HANDLER_ARGS)
 363 {
 364         int error;
 365         int ocn_mute;
 366
 367         ocn_mute = cn_mute;
 368         error = sysctl_handle_int(oidp, &cn_mute, 0, req);
 369         if (error != 0 || req->newptr == NULL)
 370                 return (error);
 371         if (ocn_mute && !cn_mute && cn_is_open)
 372                 error = cnopen(NULL, openflag, 0, curthread);
 373         else if (!ocn_mute && cn_mute && cn_is_open) {
 374                 error = cnclose(NULL, openflag, 0, curthread);
 375                 cn_is_open = 1;         /* XXX hack */
 376         }
 377         return (error);
 378 }
 379
 380 SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
 381         0, sizeof(cn_mute), sysctl_kern_consmute, "I", "");
 382
 383 static int
 384 cn_devopen(struct cn_device *cnd, struct thread *td, int forceopen)
 385 {
 386         char path[CNDEVPATHMAX];
 387         struct nameidata nd;
 388         struct vnode *vp;
 389         struct cdev *dev;
 390         struct cdevsw *csw;
 391         int error;
 392
 393         if ((vp = cnd->cnd_vp) != NULL) {
 394                 if (!forceopen && vp->v_type != VBAD) {
 395                         dev = vp->v_rdev;
 396                         csw = dev_refthread(dev);
 397                         if (csw == NULL)
 398                                 return (ENXIO);
 399                         error = (*csw->d_open)(dev, openflag, 0, td);
 400                         dev_relthread(dev);
 401                         return (error);
 402                 }
 403                 cnd->cnd_vp = NULL;
 404                 vn_close(vp, openflag, td->td_ucred, td);
 405         }
 406         snprintf(path, sizeof(path), "/dev/%s", cnd->cnd_cn->cn_name);
 407         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, td);
 408         error = vn_open(&nd, &openflag, 0, NULL);
 409         if (error == 0) {
 410                 NDFREE(&nd, NDF_ONLY_PNBUF);
 411                 VOP_UNLOCK(nd.ni_vp, 0);
 412                 if (nd.ni_vp->v_type == VCHR)
 413                         cnd->cnd_vp = nd.ni_vp;
 414                 else
 415                         vn_close(nd.ni_vp, openflag, td->td_ucred, td);
 416         }
 417         return (cnd->cnd_vp != NULL);
 418 }
 419
 420 static int
 421 cnopen(struct cdev *dev, int flag, int mode, struct thread *td)
 422 {
 423         struct cn_device *cnd;
 424
 425         openflag = flag | FWRITE;       /* XXX */
 426         cn_is_open = 1;                 /* console is logically open */
 427         if (cn_mute)
 428                 return (0);
 429         STAILQ_FOREACH(cnd, &cn_devlist, cnd_next)
 430                 cn_devopen(cnd, td, 0);
 431         return (0);
 432 }
 433
 434 static int
 435 cnclose(struct cdev *dev, int flag, int mode, struct thread *td)
 436 {
 437         struct cn_device *cnd;
 438         struct vnode *vp;
 439
 440         STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
 441                 if ((vp = cnd->cnd_vp) == NULL)
 442                         continue;
 443                 cnd->cnd_vp = NULL;
 444                 vn_close(vp, openflag, td->td_ucred, td);
 445         }
 446         cn_is_open = 0;
 447         return (0);
 448 }
 449
 450 static int
 451 cnread(struct cdev *dev, struct uio *uio, int flag)
 452 {
 453         struct cn_device *cnd;
 454         struct cdevsw *csw;
 455         int error;
 456
 457         cnd = STAILQ_FIRST(&cn_devlist);
 458         if (cn_mute || CND_INVALID(cnd, curthread))
 459                 return (0);
 460         dev = cnd->cnd_vp->v_rdev;
 461         csw = dev_refthread(dev);
 462         if (csw == NULL)
 463                 return (ENXIO);
 464         error = (csw->d_read)(dev, uio, flag);
 465         dev_relthread(dev);
 466         return (error);
 467 }
 468
 469 static int
 470 cnwrite(struct cdev *dev, struct uio *uio, int flag)
 471 {
 472         struct cn_device *cnd;
 473         struct cdevsw *csw;
 474         int error;
 475
 476         cnd = STAILQ_FIRST(&cn_devlist);
 477         if (cn_mute || CND_INVALID(cnd, curthread))
 478                 goto done;
 479         if (constty)
 480                 dev = constty->t_dev;
 481         else
 482                 dev = cnd->cnd_vp->v_rdev;
 483         if (dev != NULL) {
 484                 log_console(uio);
 485                 csw = dev_refthread(dev);
 486                 if (csw == NULL)
 487                         return (ENXIO);
 488                 error = (csw->d_write)(dev, uio, flag);
 489                 dev_relthread(dev);
 490                 return (error);
 491         }
 492 done:
 493         uio->uio_resid = 0; /* dump the data */
 494         return (0);
 495 }
 496
 497 static int
 498 cnioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
 499 {
 500         struct cn_device *cnd;
 501         struct cdevsw *csw;
 502         int error;
 503
 504         cnd = STAILQ_FIRST(&cn_devlist);
 505         if (cn_mute || CND_INVALID(cnd, td))
 506                 return (0);
 507         /*
 508          * Superuser can always use this to wrest control of console
 509          * output from the "virtual" console.
 510          */
 511         if (cmd == TIOCCONS && constty) {
 512                 error = priv_check(td, PRIV_TTY_CONSOLE);
 513                 if (error)
 514                         return (error);
 515                 constty = NULL;
 516                 return (0);
 517         }
 518         dev = cnd->cnd_vp->v_rdev;
 519         if (dev == NULL)
 520                 return (0);     /* XXX : ENOTTY ? */
 521         csw = dev_refthread(dev);
 522         if (csw == NULL)
 523                 return (ENXIO);
 524         error = (csw->d_ioctl)(dev, cmd, data, flag, td);
 525         dev_relthread(dev);
 526         return (error);
 527 }
 528
 529 /*
 530  * XXX
 531  * poll/kqfilter do not appear to be correct
 532  */
 533 static int
 534 cnpoll(struct cdev *dev, int events, struct thread *td)
 535 {
 536         struct cn_device *cnd;
 537         struct cdevsw *csw;
 538         int error;
 539
 540         cnd = STAILQ_FIRST(&cn_devlist);
 541         if (cn_mute || CND_INVALID(cnd, td))
 542                 return (0);
 543         dev = cnd->cnd_vp->v_rdev;
 544         if (dev == NULL)
 545                 return (0);
 546         csw = dev_refthread(dev);
 547         if (csw == NULL)
 548                 return (ENXIO);
 549         error = (csw->d_poll)(dev, events, td);
 550         dev_relthread(dev);
 551         return (error);
 552 }
 553
 554 static int
 555 cnkqfilter(struct cdev *dev, struct knote *kn)
 556 {
 557         struct cn_device *cnd;
 558         struct cdevsw *csw;
 559         int error;
 560
 561         cnd = STAILQ_FIRST(&cn_devlist);
 562         if (cn_mute || CND_INVALID(cnd, curthread))
 563                 return (EINVAL);
 564         dev = cnd->cnd_vp->v_rdev;
 565         if (dev == NULL)
 566                 return (ENXIO);
 567         csw = dev_refthread(dev);
 568         if (csw == NULL)
 569                 return (ENXIO);
 570         error = (csw->d_kqfilter)(dev, kn);
 571         dev_relthread(dev);
 572         return (error);
 573 }
 574
 575 /*
 576  * Low level console routines.
 577  */
 578 int
 579 cngetc(void)
 580 {
 581         int c;
 582
 583         if (cn_mute)
 584                 return (-1);
 585         while ((c = cncheckc()) == -1)
 586                 ;
 587         if (c == '\r')
 588                 c = '\n';               /* console input is always ICRNL */
 589         return (c);
 590 }
 591
 592 int
 593 cncheckc(void)
 594 {
 595         struct cn_device *cnd;
 596         struct consdev *cn;
 597         int c;
 598
 599         if (cn_mute)
 600                 return (-1);
 601         STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
 602                 cn = cnd->cnd_cn;
 603                 if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
 604                         if (cn->cn_checkc != NULL)
 605                                 c = cn->cn_checkc(cn);
 606                         else
 607                                 c = cn->cn_getc(cn);
 608                         if (c != -1) {
 609                                 return (c);
 610                         }
 611                 }
 612         }
 613         return (-1);
 614 }
 615
 616 void
 617 cnputc(int c)
 618 {
 619         struct cn_device *cnd;
 620         struct consdev *cn;
 621         char *cp;
 622
 623         if (cn_mute || c == '\0')
 624                 return;
 625         STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) {
 626                 cn = cnd->cnd_cn;
 627                 if (!kdb_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) {
 628                         if (c == '\n')
 629                                 cn->cn_putc(cn, '\r');
 630                         cn->cn_putc(cn, c);
 631                 }
 632         }
 633         if (console_pausing && c == '\n' && !kdb_active) {
 634                 for (cp = console_pausestr; *cp != '\0'; cp++)
 635                         cnputc(*cp);
 636                 if (cngetc() == '.')
 637                         console_pausing = 0;
 638                 cnputc('\r');
 639                 for (cp = console_pausestr; *cp != '\0'; cp++)
 640                         cnputc(' ');
 641                 cnputc('\r');
 642         }
 643 }
 644
 645 void
 646 cnputs(char *p)
 647 {
 648         int c;
 649         int unlock_reqd = 0;
 650
 651         if (use_cnputs_mtx) {
 652                 mtx_lock_spin(&cnputs_mtx);
 653                 unlock_reqd = 1;
 654         }
 655
 656         while ((c = *p++) != '\0')
 657                 cnputc(c);
 658
 659         if (unlock_reqd)
 660                 mtx_unlock_spin(&cnputs_mtx);
 661 }
 662
 663 static int consmsgbuf_size = 8192;
 664 SYSCTL_INT(_kern, OID_AUTO, consmsgbuf_size, CTLFLAG_RW, &consmsgbuf_size, 0,
 665     "");
 666
 667 /*
 668  * Redirect console output to a tty.
 669  */
 670 void
 671 constty_set(struct tty *tp)
 672 {
 673         int size;
 674
 675         KASSERT(tp != NULL, ("constty_set: NULL tp"));
 676         if (consbuf == NULL) {
 677                 size = consmsgbuf_size;
 678                 consbuf = malloc(size, M_TTYCONS, M_WAITOK);
 679                 msgbuf_init(&consmsgbuf, consbuf, size);
 680                 callout_init(&conscallout, 0);
 681         }
 682         constty = tp;
 683         constty_timeout(NULL);
 684 }
 685
 686 /*
 687  * Disable console redirection to a tty.
 688  */
 689 void
 690 constty_clear(void)
 691 {
 692         int c;
 693
 694         constty = NULL;
 695         if (consbuf == NULL)
 696                 return;
 697         callout_stop(&conscallout);
 698         while ((c = msgbuf_getchar(&consmsgbuf)) != -1)
 699                 cnputc(c);
 700         free(consbuf, M_TTYCONS);
 701         consbuf = NULL;
 702 }
 703
 704 /* Times per second to check for pending console tty messages. */
 705 static int constty_wakeups_per_second = 5;
 706 SYSCTL_INT(_kern, OID_AUTO, constty_wakeups_per_second, CTLFLAG_RW,
 707     &constty_wakeups_per_second, 0, "");
 708
 709 static void
 710 constty_timeout(void *arg)
 711 {
 712         int c;
 713
 714         if (constty != NULL) {
 715                 tty_lock(constty);
 716                 while ((c = msgbuf_getchar(&consmsgbuf)) != -1) {
 717                         if (tty_putchar(constty, c) < 0) {
 718                                 tty_unlock(constty);
 719                                 constty = NULL;
 720                                 break;
 721                         }
 722                 }
 723
 724                 if (constty != NULL)
 725                         tty_unlock(constty);
 726         }
 727         if (constty != NULL) {
 728                 callout_reset(&conscallout, hz / constty_wakeups_per_second,
 729                     constty_timeout, NULL);
 730         } else {
 731                 /* Deallocate the constty buffer memory. */
 732                 constty_clear();
 733         }
 734 }
 735
 736 static void
 737 cn_drvinit(void *unused)
 738 {
 739
 740         make_dev(&cn_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "console");
 741
 742         mtx_init(&cnputs_mtx, "cnputs_mtx", NULL, MTX_SPIN | MTX_NOWITNESS);
 743         use_cnputs_mtx = 1;
 744 }
 745
 746 SYSINIT(cndev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, cn_drvinit, NULL);
 747
 748 /*
 749  * Sysbeep(), if we have hardware for it
 750  */
 751
 752 #ifdef HAS_TIMER_SPKR
 753
 754 static int beeping;
 755
 756 static void
 757 sysbeepstop(void *chan)
 758 {
 759
 760         timer_spkr_release();
 761         beeping = 0;
 762 }
 763
 764 int
 765 sysbeep(int pitch, int period)
 766 {
 767
 768         if (timer_spkr_acquire()) {
 769                 if (!beeping) {
 770                         /* Something else owns it. */
 771                         return (EBUSY);
 772                 }
 773         }
 774         timer_spkr_setfreq(pitch);
 775         if (!beeping) {
 776                 beeping = period;
 777                 timeout(sysbeepstop, (void *)NULL, period);
 778         }
 779         return (0);
 780 }
 781
 782 #else
 783
 784 /*
 785  * No hardware, no sound
 786  */
 787
 788 int
 789 sysbeep(int pitch __unused, int period __unused)
 790 {
 791
 792         return (ENODEV);
 793 }
 794
 795 #endif
 796