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/bio.h> 34 #include <sys/lock.h> 35 #include <sys/mutex.h> 36 #include <sys/sysctl.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/ctype.h> 44 #include <sys/tty.h> 45 #include <machine/stdarg.h> 46 47 static MALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage"); 48 49 /* Built at compile time from sys/conf/majors */ 50 extern unsigned char reserved_majors[256]; 51 52 /* 53 * This is the number of hash-buckets. Experiements with 'real-life' 54 * udev_t's show that a prime halfway between two powers of two works 55 * best. 56 */ 57 #define DEVT_HASH 83 58 59 /* The number of dev_t's we can create before malloc(9) kick in. */ 60 #define DEVT_STASH 50 61 62 static struct cdev devt_stash[DEVT_STASH]; 63 64 static LIST_HEAD(, cdev) dev_hash[DEVT_HASH]; 65 66 static LIST_HEAD(, cdev) dev_free; 67 68 static int free_devt; 69 SYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, ""); 70 71 static struct mtx devmtx; 72 static void freedev(dev_t dev); 73 74 static void 75 devlock(void) 76 { 77 if (!mtx_initialized(&devmtx)) 78 mtx_init(&devmtx, "dev_t", NULL, MTX_DEF); 79 mtx_lock(&devmtx); 80 } 81 82 static void 83 devunlock(void) 84 { 85 mtx_unlock(&devmtx); 86 } 87 88 void 89 dev_ref(dev_t dev) 90 { 91 devlock(); 92 dev->si_refcount++; 93 devunlock(); 94 } 95 96 void 97 dev_rel(dev_t dev) 98 { 99 devlock(); 100 dev->si_refcount--; 101 KASSERT(dev->si_refcount >= 0, 102 ("dev_rel(%s) gave negative count", devtoname(dev))); 103 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 104 LIST_REMOVE(dev, si_list); 105 freedev(dev); 106 } 107 devunlock(); 108 } 109 110 void 111 cdevsw_ref(struct cdevsw *csw) 112 { 113 devlock(); 114 csw->d_refcount++; 115 devunlock(); 116 } 117 118 void 119 cdevsw_rel(struct cdevsw *csw) 120 { 121 devlock(); 122 csw->d_refcount--; 123 KASSERT(csw->d_refcount >= 0, 124 ("cdevsw_vrel(%s) gave negative count", csw->d_name)); 125 devunlock(); 126 } 127 128 static dev_t makedev(int x, int y); 129 130 int 131 nullop(void) 132 { 133 134 return (0); 135 } 136 137 int 138 eopnotsupp(void) 139 { 140 141 return (EOPNOTSUPP); 142 } 143 144 static int 145 enxio(void) 146 { 147 return (ENXIO); 148 } 149 150 static int 151 enodev(void) 152 { 153 return (ENODEV); 154 } 155 156 /* Define a dead_cdevsw for use when devices leave unexpectedly. */ 157 158 #define dead_open (d_open_t *)enxio 159 #define dead_close (d_close_t *)enxio 160 #define dead_read (d_read_t *)enxio 161 #define dead_write (d_write_t *)enxio 162 #define dead_ioctl (d_ioctl_t *)enxio 163 #define dead_poll (d_poll_t *)enodev 164 #define dead_mmap (d_mmap_t *)enodev 165 166 static void 167 dead_strategy(struct bio *bp) 168 { 169 170 biofinish(bp, NULL, ENXIO); 171 } 172 173 #define dead_dump (dumper_t *)enxio 174 #define dead_kqfilter (d_kqfilter_t *)enxio 175 176 static struct cdevsw dead_cdevsw = { 177 .d_version = D_VERSION, 178 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 179 .d_open = dead_open, 180 .d_close = dead_close, 181 .d_read = dead_read, 182 .d_write = dead_write, 183 .d_ioctl = dead_ioctl, 184 .d_poll = dead_poll, 185 .d_mmap = dead_mmap, 186 .d_strategy = dead_strategy, 187 .d_name = "dead", 188 .d_maj = 255, 189 .d_dump = dead_dump, 190 .d_kqfilter = dead_kqfilter 191 }; 192 193 /* Default methods if driver does not specify method */ 194 195 #define null_open (d_open_t *)nullop 196 #define null_close (d_close_t *)nullop 197 #define no_read (d_read_t *)enodev 198 #define no_write (d_write_t *)enodev 199 #define no_ioctl (d_ioctl_t *)enodev 200 #define no_mmap (d_mmap_t *)enodev 201 202 static int 203 no_kqfilter(dev_t dev __unused, struct knote *kn __unused) 204 { 205 206 return (1); 207 } 208 209 static void 210 no_strategy(struct bio *bp) 211 { 212 213 biofinish(bp, NULL, ENODEV); 214 } 215 216 static int 217 no_poll(dev_t dev __unused, int events, struct thread *td __unused) 218 { 219 /* 220 * Return true for read/write. If the user asked for something 221 * special, return POLLNVAL, so that clients have a way of 222 * determining reliably whether or not the extended 223 * functionality is present without hard-coding knowledge 224 * of specific filesystem implementations. 225 * Stay in sync with vop_nopoll(). 226 */ 227 if (events & ~POLLSTANDARD) 228 return (POLLNVAL); 229 230 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 231 } 232 233 #define no_dump (dumper_t *)enodev 234 235 struct cdevsw * 236 devsw(dev_t dev) 237 { 238 if (dev->si_devsw != NULL) 239 return (dev->si_devsw); 240 return (&dead_cdevsw); 241 } 242 243 /* 244 * dev_t and u_dev_t primitives 245 */ 246 247 int 248 major(dev_t x) 249 { 250 if (x == NODEV) 251 return NOUDEV; 252 return((x->si_udev >> 8) & 0xff); 253 } 254 255 int 256 minor(dev_t x) 257 { 258 if (x == NODEV) 259 return NOUDEV; 260 return(x->si_udev & 0xffff00ff); 261 } 262 263 int 264 dev2unit(dev_t x) 265 { 266 int i; 267 268 if (x == NODEV) 269 return NOUDEV; 270 i = minor(x); 271 return ((i & 0xff) | (i >> 8)); 272 } 273 274 int 275 unit2minor(int unit) 276 { 277 278 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); 279 return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 280 } 281 282 static dev_t 283 allocdev(void) 284 { 285 static int stashed; 286 struct cdev *si; 287 288 if (LIST_FIRST(&dev_free)) { 289 si = LIST_FIRST(&dev_free); 290 LIST_REMOVE(si, si_hash); 291 } else if (stashed >= DEVT_STASH) { 292 MALLOC(si, struct cdev *, sizeof(*si), M_DEVT, 293 M_USE_RESERVE | M_ZERO | M_WAITOK); 294 } else { 295 si = devt_stash + stashed++; 296 bzero(si, sizeof *si); 297 si->si_flags |= SI_STASHED; 298 } 299 si->__si_namebuf[0] = '\0'; 300 si->si_name = si->__si_namebuf; 301 LIST_INIT(&si->si_children); 302 TAILQ_INIT(&si->si_snapshots); 303 return (si); 304 } 305 306 static dev_t 307 makedev(int x, int y) 308 { 309 struct cdev *si; 310 udev_t udev; 311 int hash; 312 313 if (x == umajor(NOUDEV) && y == uminor(NOUDEV)) 314 panic("makedev of NOUDEV"); 315 udev = (x << 8) | y; 316 hash = udev % DEVT_HASH; 317 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 318 if (si->si_udev == udev) 319 return (si); 320 } 321 si = allocdev(); 322 si->si_udev = udev; 323 LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 324 return (si); 325 } 326 327 static void 328 freedev(dev_t dev) 329 { 330 331 if (dev->si_flags & SI_STASHED) { 332 bzero(dev, sizeof(*dev)); 333 dev->si_flags |= SI_STASHED; 334 LIST_INSERT_HEAD(&dev_free, dev, si_hash); 335 } else { 336 FREE(dev, M_DEVT); 337 } 338 } 339 340 udev_t 341 dev2udev(dev_t x) 342 { 343 if (x == NODEV) 344 return (NOUDEV); 345 return (x->si_udev); 346 } 347 348 dev_t 349 udev2dev(udev_t udev) 350 { 351 struct cdev *si; 352 int hash; 353 354 if (udev == NOUDEV) 355 return (NODEV); 356 hash = udev % DEVT_HASH; 357 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 358 if (si->si_udev == udev) 359 return (si); 360 } 361 return (NODEV); 362 } 363 364 int 365 uminor(udev_t dev) 366 { 367 return (dev & 0xffff00ff); 368 } 369 370 int 371 umajor(udev_t dev) 372 { 373 return ((dev & 0xff00) >> 8); 374 } 375 376 udev_t 377 makeudev(int x, int y) 378 { 379 return ((x << 8) | y); 380 } 381 382 static void 383 find_major(struct cdevsw *devsw) 384 { 385 int i; 386 387 for (i = NUMCDEVSW - 1; i > 0; i--) 388 if (reserved_majors[i] != i) 389 break; 390 KASSERT(i > 0, ("Out of major numbers (%s)", devsw->d_name)); 391 devsw->d_maj = i; 392 reserved_majors[i] = i; 393 devsw->d_flags |= D_ALLOCMAJ; 394 } 395 396 static void 397 fini_cdevsw(struct cdevsw *devsw) 398 { 399 if (devsw->d_flags & D_ALLOCMAJ) { 400 reserved_majors[devsw->d_maj] = 0; 401 devsw->d_maj = MAJOR_AUTO; 402 devsw->d_flags &= ~D_ALLOCMAJ; 403 } else if (devsw->d_maj == 0) 404 devsw->d_maj = 256; 405 devsw->d_flags &= ~D_INIT; 406 } 407 408 static void 409 prep_cdevsw(struct cdevsw *devsw) 410 { 411 412 devlock(); 413 414 if (devsw->d_version != D_VERSION_00) { 415 printf( 416 "WARNING: Device driver \"%s\" has wrong version %s\n", 417 devsw->d_name, "and is disabled. Recompile KLD module."); 418 devsw->d_open = dead_open; 419 devsw->d_close = dead_close; 420 devsw->d_read = dead_read; 421 devsw->d_write = dead_write; 422 devsw->d_ioctl = dead_ioctl; 423 devsw->d_poll = dead_poll; 424 devsw->d_mmap = dead_mmap; 425 devsw->d_strategy = dead_strategy; 426 devsw->d_dump = dead_dump; 427 devsw->d_kqfilter = dead_kqfilter; 428 } 429 430 if (devsw->d_flags & D_TTY) { 431 if (devsw->d_read == NULL) devsw->d_read = ttyread; 432 if (devsw->d_write == NULL) devsw->d_write = ttywrite; 433 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = ttykqfilter; 434 if (devsw->d_poll == NULL) devsw->d_poll = ttypoll; 435 } 436 437 if (devsw->d_open == NULL) devsw->d_open = null_open; 438 if (devsw->d_close == NULL) devsw->d_close = null_close; 439 if (devsw->d_read == NULL) devsw->d_read = no_read; 440 if (devsw->d_write == NULL) devsw->d_write = no_write; 441 if (devsw->d_ioctl == NULL) devsw->d_ioctl = no_ioctl; 442 if (devsw->d_poll == NULL) devsw->d_poll = no_poll; 443 if (devsw->d_mmap == NULL) devsw->d_mmap = no_mmap; 444 if (devsw->d_strategy == NULL) devsw->d_strategy = no_strategy; 445 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 446 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = no_kqfilter; 447 448 LIST_INIT(&devsw->d_devs); 449 450 devsw->d_flags |= D_INIT; 451 452 if (devsw->d_maj == MAJOR_AUTO) { 453 find_major(devsw); 454 } else { 455 if (devsw->d_maj == 256) /* XXX: tty_cons.c is magic */ 456 devsw->d_maj = 0; 457 KASSERT(devsw->d_maj >= 0 && devsw->d_maj < 256, 458 ("Invalid major (%d) in make_dev", devsw->d_maj)); 459 if (reserved_majors[devsw->d_maj] != devsw->d_maj) { 460 printf("WARNING: driver \"%s\" used %s %d\n", 461 devsw->d_name, "unreserved major device number", 462 devsw->d_maj); 463 reserved_majors[devsw->d_maj] = devsw->d_maj; 464 } 465 } 466 devunlock(); 467 } 468 469 dev_t 470 make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int perms, const char *fmt, ...) 471 { 472 dev_t dev; 473 va_list ap; 474 int i; 475 476 KASSERT((minornr & ~0xffff00ff) == 0, 477 ("Invalid minor (0x%x) in make_dev", minornr)); 478 479 if (!(devsw->d_flags & D_INIT)) 480 prep_cdevsw(devsw); 481 dev = makedev(devsw->d_maj, minornr); 482 if (dev->si_flags & SI_CHEAPCLONE && 483 dev->si_flags & SI_NAMED && 484 dev->si_devsw == devsw) { 485 /* 486 * This is allowed as it removes races and generally 487 * simplifies cloning devices. 488 * XXX: still ?? 489 */ 490 return (dev); 491 } 492 devlock(); 493 KASSERT(!(dev->si_flags & SI_NAMED), 494 ("make_dev() by driver %s on pre-existing device (maj=%d, min=%d, name=%s)", 495 devsw->d_name, major(dev), minor(dev), devtoname(dev))); 496 497 va_start(ap, fmt); 498 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 499 if (i > (sizeof dev->__si_namebuf - 1)) { 500 printf("WARNING: Device name truncated! (%s)", 501 dev->__si_namebuf); 502 } 503 va_end(ap); 504 dev->si_devsw = devsw; 505 dev->si_uid = uid; 506 dev->si_gid = gid; 507 dev->si_mode = perms; 508 dev->si_flags |= SI_NAMED; 509 510 LIST_INSERT_HEAD(&devsw->d_devs, dev, si_list); 511 devfs_create(dev); 512 devunlock(); 513 return (dev); 514 } 515 516 int 517 dev_named(dev_t pdev, const char *name) 518 { 519 dev_t cdev; 520 521 if (strcmp(devtoname(pdev), name) == 0) 522 return (1); 523 LIST_FOREACH(cdev, &pdev->si_children, si_siblings) 524 if (strcmp(devtoname(cdev), name) == 0) 525 return (1); 526 return (0); 527 } 528 529 void 530 dev_depends(dev_t pdev, dev_t cdev) 531 { 532 533 devlock(); 534 cdev->si_parent = pdev; 535 cdev->si_flags |= SI_CHILD; 536 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 537 devunlock(); 538 } 539 540 dev_t 541 make_dev_alias(dev_t pdev, const char *fmt, ...) 542 { 543 dev_t dev; 544 va_list ap; 545 int i; 546 547 dev = allocdev(); 548 devlock(); 549 dev->si_flags |= SI_ALIAS; 550 dev->si_flags |= SI_NAMED; 551 va_start(ap, fmt); 552 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 553 if (i > (sizeof dev->__si_namebuf - 1)) { 554 printf("WARNING: Device name truncated! (%s)", 555 dev->__si_namebuf); 556 } 557 va_end(ap); 558 559 devfs_create(dev); 560 devunlock(); 561 dev_depends(pdev, dev); 562 return (dev); 563 } 564 565 static void 566 idestroy_dev(dev_t dev) 567 { 568 if (!(dev->si_flags & SI_NAMED)) { 569 printf( "WARNING: Driver mistake: destroy_dev on %d/%d\n", 570 major(dev), minor(dev)); 571 panic("don't do that"); 572 } 573 574 devfs_destroy(dev); 575 576 /* Remove name marking */ 577 dev->si_flags &= ~SI_NAMED; 578 579 /* If we are a child, remove us from the parents list */ 580 if (dev->si_flags & SI_CHILD) { 581 LIST_REMOVE(dev, si_siblings); 582 dev->si_flags &= ~SI_CHILD; 583 } 584 585 /* Kill our children */ 586 while (!LIST_EMPTY(&dev->si_children)) 587 idestroy_dev(LIST_FIRST(&dev->si_children)); 588 589 /* Remove from clone list */ 590 if (dev->si_flags & SI_CLONELIST) { 591 LIST_REMOVE(dev, si_clone); 592 dev->si_flags &= ~SI_CLONELIST; 593 } 594 595 if (!(dev->si_flags & SI_ALIAS)) { 596 /* Remove from cdevsw list */ 597 LIST_REMOVE(dev, si_list); 598 599 /* If cdevsw has no dev_t's, clean it */ 600 if (LIST_EMPTY(&dev->si_devsw->d_devs)) 601 fini_cdevsw(dev->si_devsw); 602 603 LIST_REMOVE(dev, si_hash); 604 } 605 dev->si_drv1 = 0; 606 dev->si_drv2 = 0; 607 dev->si_devsw = NULL; 608 bzero(&dev->__si_u, sizeof(dev->__si_u)); 609 dev->si_flags &= ~SI_ALIAS; 610 if (dev->si_refcount > 0) { 611 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 612 } else { 613 freedev(dev); 614 } 615 } 616 617 void 618 destroy_dev(dev_t dev) 619 { 620 621 devlock(); 622 idestroy_dev(dev); 623 devunlock(); 624 } 625 626 const char * 627 devtoname(dev_t dev) 628 { 629 char *p; 630 int mynor; 631 632 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 633 p = dev->si_name; 634 if (devsw(dev)) 635 sprintf(p, "#%s/", devsw(dev)->d_name); 636 else 637 sprintf(p, "#%d/", major(dev)); 638 p += strlen(p); 639 mynor = minor(dev); 640 if (mynor < 0 || mynor > 255) 641 sprintf(p, "%#x", (u_int)mynor); 642 else 643 sprintf(p, "%d", mynor); 644 } 645 return (dev->si_name); 646 } 647 648 int 649 dev_stdclone(char *name, char **namep, const char *stem, int *unit) 650 { 651 int u, i; 652 653 i = strlen(stem); 654 if (bcmp(stem, name, i) != 0) 655 return (0); 656 if (!isdigit(name[i])) 657 return (0); 658 u = 0; 659 if (name[i] == '0' && isdigit(name[i+1])) 660 return (0); 661 while (isdigit(name[i])) { 662 u *= 10; 663 u += name[i++] - '0'; 664 } 665 if (u > 0xffffff) 666 return (0); 667 *unit = u; 668 if (namep) 669 *namep = &name[i]; 670 if (name[i]) 671 return (2); 672 return (1); 673 } 674 675 /* 676 * Helper functions for cloning device drivers. 677 * 678 * The objective here is to make it unnecessary for the device drivers to 679 * use rman or similar to manage their unit number space. Due to the way 680 * we do "on-demand" devices, using rman or other "private" methods 681 * will be very tricky to lock down properly once we lock down this file. 682 * 683 * Instead we give the drivers these routines which puts the dev_t's that 684 * are to be managed on their own list, and gives the driver the ability 685 * to ask for the first free unit number or a given specified unit number. 686 * 687 * In addition these routines support paired devices (pty, nmdm and similar) 688 * by respecting a number of "flag" bits in the minor number. 689 * 690 */ 691 692 struct clonedevs { 693 LIST_HEAD(,cdev) head; 694 }; 695 696 void 697 clone_setup(struct clonedevs **cdp) 698 { 699 700 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 701 LIST_INIT(&(*cdp)->head); 702 } 703 704 int 705 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, dev_t *dp, u_int extra) 706 { 707 struct clonedevs *cd; 708 dev_t dev, dl, de; 709 int unit, low, u; 710 711 KASSERT(*cdp != NULL, 712 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 713 KASSERT(!(extra & CLONE_UNITMASK), 714 ("Illegal extra bits (0x%x) in clone_create", extra)); 715 KASSERT(*up <= CLONE_UNITMASK, 716 ("Too high unit (0x%x) in clone_create", *up)); 717 718 if (csw->d_maj == MAJOR_AUTO) 719 find_major(csw); 720 721 /* 722 * Search the list for a lot of things in one go: 723 * A preexisting match is returned immediately. 724 * The lowest free unit number if we are passed -1, and the place 725 * in the list where we should insert that new element. 726 * The place to insert a specified unit number, if applicable 727 * the end of the list. 728 */ 729 unit = *up; 730 low = extra; 731 de = dl = NULL; 732 cd = *cdp; 733 LIST_FOREACH(dev, &cd->head, si_clone) { 734 u = dev2unit(dev); 735 if (u == (unit | extra)) { 736 *dp = dev; 737 return (0); 738 } 739 if (unit == -1 && u == low) { 740 low++; 741 de = dev; 742 continue; 743 } 744 if (u > (unit | extra)) { 745 dl = dev; 746 break; 747 } 748 de = dev; 749 } 750 if (unit == -1) 751 unit = low & CLONE_UNITMASK; 752 dev = makedev(csw->d_maj, unit2minor(unit | extra)); 753 KASSERT(!(dev->si_flags & SI_CLONELIST), 754 ("Dev %p should not be on clonelist", dev)); 755 if (dl != NULL) 756 LIST_INSERT_BEFORE(dl, dev, si_clone); 757 else if (de != NULL) 758 LIST_INSERT_AFTER(de, dev, si_clone); 759 else 760 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 761 dev->si_flags |= SI_CLONELIST; 762 *up = unit; 763 return (1); 764 } 765 766 /* 767 * Kill everything still on the list. The driver should already have 768 * disposed of any softc hung of the dev_t's at this time. 769 */ 770 void 771 clone_cleanup(struct clonedevs **cdp) 772 { 773 dev_t dev, tdev; 774 struct clonedevs *cd; 775 776 cd = *cdp; 777 if (cd == NULL) 778 return; 779 LIST_FOREACH_SAFE(dev, &cd->head, si_clone, tdev) { 780 KASSERT(dev->si_flags & SI_NAMED, 781 ("Driver has goofed in cloning underways udev %x", dev->si_udev)); 782 destroy_dev(dev); 783 } 784 free(cd, M_DEVBUF); 785 *cdp = NULL; 786 } 787 788 /* 789 * Helper sysctl for devname(3). We're given a {u}dev_t and return 790 * the name, if any, registered by the device driver. 791 */ 792 static int 793 sysctl_devname(SYSCTL_HANDLER_ARGS) 794 { 795 int error; 796 udev_t ud; 797 dev_t dev; 798 799 error = SYSCTL_IN(req, &ud, sizeof (ud)); 800 if (error) 801 return (error); 802 if (ud == NOUDEV) 803 return(EINVAL); 804 dev = udev2dev(ud); 805 if (dev == NODEV) 806 error = ENOENT; 807 else 808 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1); 809 return (error); 810 } 811 812 SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY, 813 NULL, 0, sysctl_devname, "", "devname(3) handler"); 814