1 /*- 2 * Copyright (c) 1999-2002 Poul-Henning Kamp 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/kernel.h> 32 #include <sys/systm.h> 33 #include <sys/bus.h> 34 #include <sys/bio.h> 35 #include <sys/lock.h> 36 #include <sys/mutex.h> 37 #include <sys/module.h> 38 #include <sys/malloc.h> 39 #include <sys/conf.h> 40 #include <sys/vnode.h> 41 #include <sys/queue.h> 42 #include <sys/poll.h> 43 #include <sys/sx.h> 44 #include <sys/ctype.h> 45 #include <sys/ucred.h> 46 #include <sys/taskqueue.h> 47 #include <machine/stdarg.h> 48 49 #include <fs/devfs/devfs_int.h> 50 51 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage"); 52 53 struct mtx devmtx; 54 static void destroy_devl(struct cdev *dev); 55 static int destroy_dev_sched_cbl(struct cdev *dev, 56 void (*cb)(void *), void *arg); 57 static struct cdev *make_dev_credv(int flags, 58 struct cdevsw *devsw, int unit, 59 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, 60 va_list ap); 61 62 static struct cdev_priv_list cdevp_free_list = 63 TAILQ_HEAD_INITIALIZER(cdevp_free_list); 64 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list = 65 SLIST_HEAD_INITIALIZER(); 66 67 void 68 dev_lock(void) 69 { 70 71 mtx_lock(&devmtx); 72 } 73 74 /* 75 * Free all the memory collected while the cdev mutex was 76 * locked. Since devmtx is after the system map mutex, free() cannot 77 * be called immediately and is postponed until cdev mutex can be 78 * dropped. 79 */ 80 static void 81 dev_unlock_and_free(void) 82 { 83 struct cdev_priv_list cdp_free; 84 struct free_cdevsw csw_free; 85 struct cdev_priv *cdp; 86 struct cdevsw *csw; 87 88 mtx_assert(&devmtx, MA_OWNED); 89 90 /* 91 * Make the local copy of the list heads while the dev_mtx is 92 * held. Free it later. 93 */ 94 TAILQ_INIT(&cdp_free); 95 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list); 96 csw_free = cdevsw_gt_post_list; 97 SLIST_INIT(&cdevsw_gt_post_list); 98 99 mtx_unlock(&devmtx); 100 101 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) { 102 TAILQ_REMOVE(&cdp_free, cdp, cdp_list); 103 devfs_free(&cdp->cdp_c); 104 } 105 while ((csw = SLIST_FIRST(&csw_free)) != NULL) { 106 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list); 107 free(csw, M_DEVT); 108 } 109 } 110 111 static void 112 dev_free_devlocked(struct cdev *cdev) 113 { 114 struct cdev_priv *cdp; 115 116 mtx_assert(&devmtx, MA_OWNED); 117 cdp = cdev2priv(cdev); 118 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list); 119 } 120 121 static void 122 cdevsw_free_devlocked(struct cdevsw *csw) 123 { 124 125 mtx_assert(&devmtx, MA_OWNED); 126 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list); 127 } 128 129 void 130 dev_unlock(void) 131 { 132 133 mtx_unlock(&devmtx); 134 } 135 136 void 137 dev_ref(struct cdev *dev) 138 { 139 140 mtx_assert(&devmtx, MA_NOTOWNED); 141 mtx_lock(&devmtx); 142 dev->si_refcount++; 143 mtx_unlock(&devmtx); 144 } 145 146 void 147 dev_refl(struct cdev *dev) 148 { 149 150 mtx_assert(&devmtx, MA_OWNED); 151 dev->si_refcount++; 152 } 153 154 void 155 dev_rel(struct cdev *dev) 156 { 157 int flag = 0; 158 159 mtx_assert(&devmtx, MA_NOTOWNED); 160 dev_lock(); 161 dev->si_refcount--; 162 KASSERT(dev->si_refcount >= 0, 163 ("dev_rel(%s) gave negative count", devtoname(dev))); 164 #if 0 165 if (dev->si_usecount == 0 && 166 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED)) 167 ; 168 else 169 #endif 170 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 171 LIST_REMOVE(dev, si_list); 172 flag = 1; 173 } 174 dev_unlock(); 175 if (flag) 176 devfs_free(dev); 177 } 178 179 struct cdevsw * 180 dev_refthread(struct cdev *dev) 181 { 182 struct cdevsw *csw; 183 struct cdev_priv *cdp; 184 185 mtx_assert(&devmtx, MA_NOTOWNED); 186 dev_lock(); 187 csw = dev->si_devsw; 188 if (csw != NULL) { 189 cdp = cdev2priv(dev); 190 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) 191 dev->si_threadcount++; 192 else 193 csw = NULL; 194 } 195 dev_unlock(); 196 return (csw); 197 } 198 199 struct cdevsw * 200 devvn_refthread(struct vnode *vp, struct cdev **devp) 201 { 202 struct cdevsw *csw; 203 struct cdev_priv *cdp; 204 205 mtx_assert(&devmtx, MA_NOTOWNED); 206 csw = NULL; 207 dev_lock(); 208 *devp = vp->v_rdev; 209 if (*devp != NULL) { 210 cdp = cdev2priv(*devp); 211 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) { 212 csw = (*devp)->si_devsw; 213 if (csw != NULL) 214 (*devp)->si_threadcount++; 215 } 216 } 217 dev_unlock(); 218 return (csw); 219 } 220 221 void 222 dev_relthread(struct cdev *dev) 223 { 224 225 mtx_assert(&devmtx, MA_NOTOWNED); 226 dev_lock(); 227 KASSERT(dev->si_threadcount > 0, 228 ("%s threadcount is wrong", dev->si_name)); 229 dev->si_threadcount--; 230 dev_unlock(); 231 } 232 233 int 234 nullop(void) 235 { 236 237 return (0); 238 } 239 240 int 241 eopnotsupp(void) 242 { 243 244 return (EOPNOTSUPP); 245 } 246 247 static int 248 enxio(void) 249 { 250 return (ENXIO); 251 } 252 253 static int 254 enodev(void) 255 { 256 return (ENODEV); 257 } 258 259 /* Define a dead_cdevsw for use when devices leave unexpectedly. */ 260 261 #define dead_open (d_open_t *)enxio 262 #define dead_close (d_close_t *)enxio 263 #define dead_read (d_read_t *)enxio 264 #define dead_write (d_write_t *)enxio 265 #define dead_ioctl (d_ioctl_t *)enxio 266 #define dead_poll (d_poll_t *)enodev 267 #define dead_mmap (d_mmap_t *)enodev 268 269 static void 270 dead_strategy(struct bio *bp) 271 { 272 273 biofinish(bp, NULL, ENXIO); 274 } 275 276 #define dead_dump (dumper_t *)enxio 277 #define dead_kqfilter (d_kqfilter_t *)enxio 278 279 static struct cdevsw dead_cdevsw = { 280 .d_version = D_VERSION, 281 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 282 .d_open = dead_open, 283 .d_close = dead_close, 284 .d_read = dead_read, 285 .d_write = dead_write, 286 .d_ioctl = dead_ioctl, 287 .d_poll = dead_poll, 288 .d_mmap = dead_mmap, 289 .d_strategy = dead_strategy, 290 .d_name = "dead", 291 .d_dump = dead_dump, 292 .d_kqfilter = dead_kqfilter 293 }; 294 295 /* Default methods if driver does not specify method */ 296 297 #define null_open (d_open_t *)nullop 298 #define null_close (d_close_t *)nullop 299 #define no_read (d_read_t *)enodev 300 #define no_write (d_write_t *)enodev 301 #define no_ioctl (d_ioctl_t *)enodev 302 #define no_mmap (d_mmap_t *)enodev 303 #define no_kqfilter (d_kqfilter_t *)enodev 304 305 static void 306 no_strategy(struct bio *bp) 307 { 308 309 biofinish(bp, NULL, ENODEV); 310 } 311 312 static int 313 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 314 { 315 316 return (poll_no_poll(events)); 317 } 318 319 #define no_dump (dumper_t *)enodev 320 321 static int 322 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 323 { 324 struct cdevsw *dsw; 325 int retval; 326 327 dsw = dev_refthread(dev); 328 if (dsw == NULL) 329 return (ENXIO); 330 mtx_lock(&Giant); 331 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td); 332 mtx_unlock(&Giant); 333 dev_relthread(dev); 334 return (retval); 335 } 336 337 static int 338 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp) 339 { 340 struct cdevsw *dsw; 341 int retval; 342 343 dsw = dev_refthread(dev); 344 if (dsw == NULL) 345 return (ENXIO); 346 mtx_lock(&Giant); 347 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp); 348 mtx_unlock(&Giant); 349 dev_relthread(dev); 350 return (retval); 351 } 352 353 static int 354 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 355 { 356 struct cdevsw *dsw; 357 int retval; 358 359 dsw = dev_refthread(dev); 360 if (dsw == NULL) 361 return (ENXIO); 362 mtx_lock(&Giant); 363 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td); 364 mtx_unlock(&Giant); 365 dev_relthread(dev); 366 return (retval); 367 } 368 369 static void 370 giant_strategy(struct bio *bp) 371 { 372 struct cdevsw *dsw; 373 struct cdev *dev; 374 375 dev = bp->bio_dev; 376 dsw = dev_refthread(dev); 377 if (dsw == NULL) { 378 biofinish(bp, NULL, ENXIO); 379 return; 380 } 381 mtx_lock(&Giant); 382 dsw->d_gianttrick->d_strategy(bp); 383 mtx_unlock(&Giant); 384 dev_relthread(dev); 385 } 386 387 static int 388 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 389 { 390 struct cdevsw *dsw; 391 int retval; 392 393 dsw = dev_refthread(dev); 394 if (dsw == NULL) 395 return (ENXIO); 396 mtx_lock(&Giant); 397 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td); 398 mtx_unlock(&Giant); 399 dev_relthread(dev); 400 return (retval); 401 } 402 403 static int 404 giant_read(struct cdev *dev, struct uio *uio, int ioflag) 405 { 406 struct cdevsw *dsw; 407 int retval; 408 409 dsw = dev_refthread(dev); 410 if (dsw == NULL) 411 return (ENXIO); 412 mtx_lock(&Giant); 413 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag); 414 mtx_unlock(&Giant); 415 dev_relthread(dev); 416 return (retval); 417 } 418 419 static int 420 giant_write(struct cdev *dev, struct uio *uio, int ioflag) 421 { 422 struct cdevsw *dsw; 423 int retval; 424 425 dsw = dev_refthread(dev); 426 if (dsw == NULL) 427 return (ENXIO); 428 mtx_lock(&Giant); 429 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag); 430 mtx_unlock(&Giant); 431 dev_relthread(dev); 432 return (retval); 433 } 434 435 static int 436 giant_poll(struct cdev *dev, int events, struct thread *td) 437 { 438 struct cdevsw *dsw; 439 int retval; 440 441 dsw = dev_refthread(dev); 442 if (dsw == NULL) 443 return (ENXIO); 444 mtx_lock(&Giant); 445 retval = dsw->d_gianttrick->d_poll(dev, events, td); 446 mtx_unlock(&Giant); 447 dev_relthread(dev); 448 return (retval); 449 } 450 451 static int 452 giant_kqfilter(struct cdev *dev, struct knote *kn) 453 { 454 struct cdevsw *dsw; 455 int retval; 456 457 dsw = dev_refthread(dev); 458 if (dsw == NULL) 459 return (ENXIO); 460 mtx_lock(&Giant); 461 retval = dsw->d_gianttrick->d_kqfilter(dev, kn); 462 mtx_unlock(&Giant); 463 dev_relthread(dev); 464 return (retval); 465 } 466 467 static int 468 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot) 469 { 470 struct cdevsw *dsw; 471 int retval; 472 473 dsw = dev_refthread(dev); 474 if (dsw == NULL) 475 return (ENXIO); 476 mtx_lock(&Giant); 477 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot); 478 mtx_unlock(&Giant); 479 dev_relthread(dev); 480 return (retval); 481 } 482 483 484 static void 485 notify(struct cdev *dev, const char *ev) 486 { 487 static const char prefix[] = "cdev="; 488 char *data; 489 int namelen; 490 491 if (cold) 492 return; 493 namelen = strlen(dev->si_name); 494 data = malloc(namelen + sizeof(prefix), M_TEMP, M_NOWAIT); 495 if (data == NULL) 496 return; 497 memcpy(data, prefix, sizeof(prefix) - 1); 498 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1); 499 devctl_notify("DEVFS", "CDEV", ev, data); 500 free(data, M_TEMP); 501 } 502 503 static void 504 notify_create(struct cdev *dev) 505 { 506 507 notify(dev, "CREATE"); 508 } 509 510 static void 511 notify_destroy(struct cdev *dev) 512 { 513 514 notify(dev, "DESTROY"); 515 } 516 517 static struct cdev * 518 newdev(struct cdevsw *csw, int unit, struct cdev *si) 519 { 520 struct cdev *si2; 521 522 mtx_assert(&devmtx, MA_OWNED); 523 if (csw->d_flags & D_NEEDMINOR) { 524 /* We may want to return an existing device */ 525 LIST_FOREACH(si2, &csw->d_devs, si_list) { 526 if (dev2unit(si2) == unit) { 527 dev_free_devlocked(si); 528 return (si2); 529 } 530 } 531 } 532 si->si_drv0 = unit; 533 si->si_devsw = csw; 534 LIST_INSERT_HEAD(&csw->d_devs, si, si_list); 535 return (si); 536 } 537 538 static void 539 fini_cdevsw(struct cdevsw *devsw) 540 { 541 struct cdevsw *gt; 542 543 if (devsw->d_gianttrick != NULL) { 544 gt = devsw->d_gianttrick; 545 memcpy(devsw, gt, sizeof *devsw); 546 cdevsw_free_devlocked(gt); 547 devsw->d_gianttrick = NULL; 548 } 549 devsw->d_flags &= ~D_INIT; 550 } 551 552 static void 553 prep_cdevsw(struct cdevsw *devsw) 554 { 555 struct cdevsw *dsw2; 556 557 mtx_assert(&devmtx, MA_OWNED); 558 if (devsw->d_flags & D_INIT) 559 return; 560 if (devsw->d_flags & D_NEEDGIANT) { 561 dev_unlock(); 562 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK); 563 dev_lock(); 564 } else 565 dsw2 = NULL; 566 if (devsw->d_flags & D_INIT) { 567 if (dsw2 != NULL) 568 cdevsw_free_devlocked(dsw2); 569 return; 570 } 571 572 if (devsw->d_version != D_VERSION_01) { 573 printf( 574 "WARNING: Device driver \"%s\" has wrong version %s\n", 575 devsw->d_name == NULL ? "???" : devsw->d_name, 576 "and is disabled. Recompile KLD module."); 577 devsw->d_open = dead_open; 578 devsw->d_close = dead_close; 579 devsw->d_read = dead_read; 580 devsw->d_write = dead_write; 581 devsw->d_ioctl = dead_ioctl; 582 devsw->d_poll = dead_poll; 583 devsw->d_mmap = dead_mmap; 584 devsw->d_strategy = dead_strategy; 585 devsw->d_dump = dead_dump; 586 devsw->d_kqfilter = dead_kqfilter; 587 } 588 589 if (devsw->d_flags & D_NEEDGIANT) { 590 if (devsw->d_gianttrick == NULL) { 591 memcpy(dsw2, devsw, sizeof *dsw2); 592 devsw->d_gianttrick = dsw2; 593 dsw2 = NULL; 594 } 595 } 596 597 #define FIXUP(member, noop, giant) \ 598 do { \ 599 if (devsw->member == NULL) { \ 600 devsw->member = noop; \ 601 } else if (devsw->d_flags & D_NEEDGIANT) \ 602 devsw->member = giant; \ 603 } \ 604 while (0) 605 606 FIXUP(d_open, null_open, giant_open); 607 FIXUP(d_fdopen, NULL, giant_fdopen); 608 FIXUP(d_close, null_close, giant_close); 609 FIXUP(d_read, no_read, giant_read); 610 FIXUP(d_write, no_write, giant_write); 611 FIXUP(d_ioctl, no_ioctl, giant_ioctl); 612 FIXUP(d_poll, no_poll, giant_poll); 613 FIXUP(d_mmap, no_mmap, giant_mmap); 614 FIXUP(d_strategy, no_strategy, giant_strategy); 615 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter); 616 617 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 618 619 LIST_INIT(&devsw->d_devs); 620 621 devsw->d_flags |= D_INIT; 622 623 if (dsw2 != NULL) 624 cdevsw_free_devlocked(dsw2); 625 } 626 627 struct cdev * 628 make_dev_credv(int flags, struct cdevsw *devsw, int unit, 629 struct ucred *cr, uid_t uid, 630 gid_t gid, int mode, const char *fmt, va_list ap) 631 { 632 struct cdev *dev; 633 int i; 634 635 dev = devfs_alloc(); 636 dev_lock(); 637 prep_cdevsw(devsw); 638 dev = newdev(devsw, unit, dev); 639 if (flags & MAKEDEV_REF) 640 dev_refl(dev); 641 if (dev->si_flags & SI_CHEAPCLONE && 642 dev->si_flags & SI_NAMED) { 643 /* 644 * This is allowed as it removes races and generally 645 * simplifies cloning devices. 646 * XXX: still ?? 647 */ 648 dev_unlock_and_free(); 649 return (dev); 650 } 651 KASSERT(!(dev->si_flags & SI_NAMED), 652 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)", 653 devsw->d_name, dev2unit(dev), devtoname(dev))); 654 655 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 656 if (i > (sizeof dev->__si_namebuf - 1)) { 657 printf("WARNING: Device name truncated! (%s)\n", 658 dev->__si_namebuf); 659 } 660 661 dev->si_flags |= SI_NAMED; 662 if (cr != NULL) 663 dev->si_cred = crhold(cr); 664 else 665 dev->si_cred = NULL; 666 dev->si_uid = uid; 667 dev->si_gid = gid; 668 dev->si_mode = mode; 669 670 devfs_create(dev); 671 clean_unrhdrl(devfs_inos); 672 dev_unlock_and_free(); 673 674 notify_create(dev); 675 676 return (dev); 677 } 678 679 struct cdev * 680 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode, 681 const char *fmt, ...) 682 { 683 struct cdev *dev; 684 va_list ap; 685 686 va_start(ap, fmt); 687 dev = make_dev_credv(0, devsw, unit, NULL, uid, gid, mode, fmt, ap); 688 va_end(ap); 689 return (dev); 690 } 691 692 struct cdev * 693 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid, 694 gid_t gid, int mode, const char *fmt, ...) 695 { 696 struct cdev *dev; 697 va_list ap; 698 699 va_start(ap, fmt); 700 dev = make_dev_credv(0, devsw, unit, cr, uid, gid, mode, fmt, ap); 701 va_end(ap); 702 703 return (dev); 704 } 705 706 struct cdev * 707 make_dev_credf(int flags, struct cdevsw *devsw, int unit, 708 struct ucred *cr, uid_t uid, 709 gid_t gid, int mode, const char *fmt, ...) 710 { 711 struct cdev *dev; 712 va_list ap; 713 714 va_start(ap, fmt); 715 dev = make_dev_credv(flags, devsw, unit, cr, uid, gid, mode, 716 fmt, ap); 717 va_end(ap); 718 719 return (dev); 720 } 721 722 static void 723 dev_dependsl(struct cdev *pdev, struct cdev *cdev) 724 { 725 726 cdev->si_parent = pdev; 727 cdev->si_flags |= SI_CHILD; 728 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 729 } 730 731 732 void 733 dev_depends(struct cdev *pdev, struct cdev *cdev) 734 { 735 736 dev_lock(); 737 dev_dependsl(pdev, cdev); 738 dev_unlock(); 739 } 740 741 struct cdev * 742 make_dev_alias(struct cdev *pdev, const char *fmt, ...) 743 { 744 struct cdev *dev; 745 va_list ap; 746 int i; 747 748 KASSERT(pdev != NULL, ("NULL pdev")); 749 dev = devfs_alloc(); 750 dev_lock(); 751 dev->si_flags |= SI_ALIAS; 752 dev->si_flags |= SI_NAMED; 753 va_start(ap, fmt); 754 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 755 if (i > (sizeof dev->__si_namebuf - 1)) { 756 printf("WARNING: Device name truncated! (%s)\n", 757 dev->__si_namebuf); 758 } 759 va_end(ap); 760 761 devfs_create(dev); 762 dev_dependsl(pdev, dev); 763 clean_unrhdrl(devfs_inos); 764 dev_unlock(); 765 766 notify_create(dev); 767 768 return (dev); 769 } 770 771 static void 772 destroy_devl(struct cdev *dev) 773 { 774 struct cdevsw *csw; 775 struct cdev_privdata *p, *p1; 776 777 mtx_assert(&devmtx, MA_OWNED); 778 KASSERT(dev->si_flags & SI_NAMED, 779 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev))); 780 781 devfs_destroy(dev); 782 783 /* Remove name marking */ 784 dev->si_flags &= ~SI_NAMED; 785 786 /* If we are a child, remove us from the parents list */ 787 if (dev->si_flags & SI_CHILD) { 788 LIST_REMOVE(dev, si_siblings); 789 dev->si_flags &= ~SI_CHILD; 790 } 791 792 /* Kill our children */ 793 while (!LIST_EMPTY(&dev->si_children)) 794 destroy_devl(LIST_FIRST(&dev->si_children)); 795 796 /* Remove from clone list */ 797 if (dev->si_flags & SI_CLONELIST) { 798 LIST_REMOVE(dev, si_clone); 799 dev->si_flags &= ~SI_CLONELIST; 800 } 801 802 dev->si_refcount++; /* Avoid race with dev_rel() */ 803 csw = dev->si_devsw; 804 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 805 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 806 csw->d_purge(dev); 807 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 808 if (dev->si_threadcount) 809 printf("Still %lu threads in %s\n", 810 dev->si_threadcount, devtoname(dev)); 811 } 812 while (dev->si_threadcount != 0) { 813 /* Use unique dummy wait ident */ 814 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); 815 } 816 817 dev_unlock(); 818 notify_destroy(dev); 819 mtx_lock(&cdevpriv_mtx); 820 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) { 821 devfs_destroy_cdevpriv(p); 822 mtx_lock(&cdevpriv_mtx); 823 } 824 mtx_unlock(&cdevpriv_mtx); 825 dev_lock(); 826 827 dev->si_drv1 = 0; 828 dev->si_drv2 = 0; 829 bzero(&dev->__si_u, sizeof(dev->__si_u)); 830 831 if (!(dev->si_flags & SI_ALIAS)) { 832 /* Remove from cdevsw list */ 833 LIST_REMOVE(dev, si_list); 834 835 /* If cdevsw has no more struct cdev *'s, clean it */ 836 if (LIST_EMPTY(&csw->d_devs)) { 837 fini_cdevsw(csw); 838 wakeup(&csw->d_devs); 839 } 840 } 841 dev->si_flags &= ~SI_ALIAS; 842 dev->si_refcount--; /* Avoid race with dev_rel() */ 843 844 if (dev->si_refcount > 0) { 845 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 846 } else { 847 dev_free_devlocked(dev); 848 } 849 } 850 851 void 852 destroy_dev(struct cdev *dev) 853 { 854 855 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev"); 856 dev_lock(); 857 destroy_devl(dev); 858 dev_unlock_and_free(); 859 } 860 861 const char * 862 devtoname(struct cdev *dev) 863 { 864 865 return (dev->si_name); 866 } 867 868 int 869 dev_stdclone(char *name, char **namep, const char *stem, int *unit) 870 { 871 int u, i; 872 873 i = strlen(stem); 874 if (bcmp(stem, name, i) != 0) 875 return (0); 876 if (!isdigit(name[i])) 877 return (0); 878 u = 0; 879 if (name[i] == '0' && isdigit(name[i+1])) 880 return (0); 881 while (isdigit(name[i])) { 882 u *= 10; 883 u += name[i++] - '0'; 884 } 885 if (u > 0xffffff) 886 return (0); 887 *unit = u; 888 if (namep) 889 *namep = &name[i]; 890 if (name[i]) 891 return (2); 892 return (1); 893 } 894 895 /* 896 * Helper functions for cloning device drivers. 897 * 898 * The objective here is to make it unnecessary for the device drivers to 899 * use rman or similar to manage their unit number space. Due to the way 900 * we do "on-demand" devices, using rman or other "private" methods 901 * will be very tricky to lock down properly once we lock down this file. 902 * 903 * Instead we give the drivers these routines which puts the struct cdev *'s 904 * that are to be managed on their own list, and gives the driver the ability 905 * to ask for the first free unit number or a given specified unit number. 906 * 907 * In addition these routines support paired devices (pty, nmdm and similar) 908 * by respecting a number of "flag" bits in the minor number. 909 * 910 */ 911 912 struct clonedevs { 913 LIST_HEAD(,cdev) head; 914 }; 915 916 void 917 clone_setup(struct clonedevs **cdp) 918 { 919 920 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 921 LIST_INIT(&(*cdp)->head); 922 } 923 924 int 925 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra) 926 { 927 struct clonedevs *cd; 928 struct cdev *dev, *ndev, *dl, *de; 929 int unit, low, u; 930 931 KASSERT(*cdp != NULL, 932 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 933 KASSERT(!(extra & CLONE_UNITMASK), 934 ("Illegal extra bits (0x%x) in clone_create", extra)); 935 KASSERT(*up <= CLONE_UNITMASK, 936 ("Too high unit (0x%x) in clone_create", *up)); 937 KASSERT(csw->d_flags & D_NEEDMINOR, 938 ("clone_create() on cdevsw without minor numbers")); 939 940 941 /* 942 * Search the list for a lot of things in one go: 943 * A preexisting match is returned immediately. 944 * The lowest free unit number if we are passed -1, and the place 945 * in the list where we should insert that new element. 946 * The place to insert a specified unit number, if applicable 947 * the end of the list. 948 */ 949 unit = *up; 950 ndev = devfs_alloc(); 951 dev_lock(); 952 prep_cdevsw(csw); 953 low = extra; 954 de = dl = NULL; 955 cd = *cdp; 956 LIST_FOREACH(dev, &cd->head, si_clone) { 957 KASSERT(dev->si_flags & SI_CLONELIST, 958 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 959 u = dev2unit(dev); 960 if (u == (unit | extra)) { 961 *dp = dev; 962 dev_unlock(); 963 devfs_free(ndev); 964 return (0); 965 } 966 if (unit == -1 && u == low) { 967 low++; 968 de = dev; 969 continue; 970 } else if (u < (unit | extra)) { 971 de = dev; 972 continue; 973 } else if (u > (unit | extra)) { 974 dl = dev; 975 break; 976 } 977 } 978 if (unit == -1) 979 unit = low & CLONE_UNITMASK; 980 dev = newdev(csw, unit | extra, ndev); 981 if (dev->si_flags & SI_CLONELIST) { 982 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 983 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra); 984 LIST_FOREACH(dev, &cd->head, si_clone) { 985 printf("\t%p %s\n", dev, dev->si_name); 986 } 987 panic("foo"); 988 } 989 KASSERT(!(dev->si_flags & SI_CLONELIST), 990 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 991 if (dl != NULL) 992 LIST_INSERT_BEFORE(dl, dev, si_clone); 993 else if (de != NULL) 994 LIST_INSERT_AFTER(de, dev, si_clone); 995 else 996 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 997 dev->si_flags |= SI_CLONELIST; 998 *up = unit; 999 dev_unlock_and_free(); 1000 return (1); 1001 } 1002 1003 /* 1004 * Kill everything still on the list. The driver should already have 1005 * disposed of any softc hung of the struct cdev *'s at this time. 1006 */ 1007 void 1008 clone_cleanup(struct clonedevs **cdp) 1009 { 1010 struct cdev *dev; 1011 struct cdev_priv *cp; 1012 struct clonedevs *cd; 1013 1014 cd = *cdp; 1015 if (cd == NULL) 1016 return; 1017 dev_lock(); 1018 while (!LIST_EMPTY(&cd->head)) { 1019 dev = LIST_FIRST(&cd->head); 1020 LIST_REMOVE(dev, si_clone); 1021 KASSERT(dev->si_flags & SI_CLONELIST, 1022 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1023 dev->si_flags &= ~SI_CLONELIST; 1024 cp = cdev2priv(dev); 1025 if (!(cp->cdp_flags & CDP_SCHED_DTR)) { 1026 cp->cdp_flags |= CDP_SCHED_DTR; 1027 KASSERT(dev->si_flags & SI_NAMED, 1028 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev))); 1029 destroy_devl(dev); 1030 } 1031 } 1032 dev_unlock_and_free(); 1033 free(cd, M_DEVBUF); 1034 *cdp = NULL; 1035 } 1036 1037 static TAILQ_HEAD(, cdev_priv) dev_ddtr = 1038 TAILQ_HEAD_INITIALIZER(dev_ddtr); 1039 static struct task dev_dtr_task; 1040 1041 static void 1042 destroy_dev_tq(void *ctx, int pending) 1043 { 1044 struct cdev_priv *cp; 1045 struct cdev *dev; 1046 void (*cb)(void *); 1047 void *cb_arg; 1048 1049 dev_lock(); 1050 while (!TAILQ_EMPTY(&dev_ddtr)) { 1051 cp = TAILQ_FIRST(&dev_ddtr); 1052 dev = &cp->cdp_c; 1053 KASSERT(cp->cdp_flags & CDP_SCHED_DTR, 1054 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp)); 1055 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list); 1056 cb = cp->cdp_dtr_cb; 1057 cb_arg = cp->cdp_dtr_cb_arg; 1058 destroy_devl(dev); 1059 dev_unlock_and_free(); 1060 dev_rel(dev); 1061 if (cb != NULL) 1062 cb(cb_arg); 1063 dev_lock(); 1064 } 1065 dev_unlock(); 1066 } 1067 1068 /* 1069 * devmtx shall be locked on entry. devmtx will be unlocked after 1070 * function return. 1071 */ 1072 static int 1073 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg) 1074 { 1075 struct cdev_priv *cp; 1076 1077 mtx_assert(&devmtx, MA_OWNED); 1078 cp = cdev2priv(dev); 1079 if (cp->cdp_flags & CDP_SCHED_DTR) { 1080 dev_unlock(); 1081 return (0); 1082 } 1083 dev_refl(dev); 1084 cp->cdp_flags |= CDP_SCHED_DTR; 1085 cp->cdp_dtr_cb = cb; 1086 cp->cdp_dtr_cb_arg = arg; 1087 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list); 1088 dev_unlock(); 1089 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task); 1090 return (1); 1091 } 1092 1093 int 1094 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg) 1095 { 1096 dev_lock(); 1097 return (destroy_dev_sched_cbl(dev, cb, arg)); 1098 } 1099 1100 int 1101 destroy_dev_sched(struct cdev *dev) 1102 { 1103 return (destroy_dev_sched_cb(dev, NULL, NULL)); 1104 } 1105 1106 void 1107 destroy_dev_drain(struct cdevsw *csw) 1108 { 1109 1110 dev_lock(); 1111 while (!LIST_EMPTY(&csw->d_devs)) { 1112 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10); 1113 } 1114 dev_unlock(); 1115 } 1116 1117 void 1118 drain_dev_clone_events(void) 1119 { 1120 1121 sx_xlock(&clone_drain_lock); 1122 sx_xunlock(&clone_drain_lock); 1123 } 1124 1125 static void 1126 devdtr_init(void *dummy __unused) 1127 { 1128 1129 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL); 1130 } 1131 1132 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL); 1133