Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_conf.c
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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: releng/5.4/sys/kern/kern_conf.c 145335 2005-04-20 19:11:07Z cvs2svn $"); 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, "cdev", "cdev 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. Experiments with 'real-life' 54 * dev_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 struct cdev *'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(struct cdev *dev); 73 static struct cdev *newdev(int x, int y); 74 75 76 static void 77 devlock(void) 78 { 79 if (!mtx_initialized(&devmtx)) 80 mtx_init(&devmtx, "cdev", NULL, MTX_DEF); 81 mtx_lock(&devmtx); 82 } 83 84 static void 85 devunlock(void) 86 { 87 mtx_unlock(&devmtx); 88 } 89 90 void 91 dev_ref(struct cdev *dev) 92 { 93 devlock(); 94 dev->si_refcount++; 95 devunlock(); 96 } 97 98 void 99 dev_rel(struct cdev *dev) 100 { 101 devlock(); 102 dev->si_refcount--; 103 KASSERT(dev->si_refcount >= 0, 104 ("dev_rel(%s) gave negative count", devtoname(dev))); 105 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 106 LIST_REMOVE(dev, si_list); 107 freedev(dev); 108 } 109 devunlock(); 110 } 111 112 void 113 cdevsw_ref(struct cdevsw *csw) 114 { 115 devlock(); 116 csw->d_refcount++; 117 devunlock(); 118 } 119 120 void 121 cdevsw_rel(struct cdevsw *csw) 122 { 123 devlock(); 124 csw->d_refcount--; 125 KASSERT(csw->d_refcount >= 0, 126 ("cdevsw_vrel(%s) gave negative count", csw->d_name)); 127 devunlock(); 128 } 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 #define no_kqfilter (d_kqfilter_t *)enodev 202 203 static void 204 no_strategy(struct bio *bp) 205 { 206 207 biofinish(bp, NULL, ENODEV); 208 } 209 210 static int 211 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 212 { 213 /* 214 * Return true for read/write. If the user asked for something 215 * special, return POLLNVAL, so that clients have a way of 216 * determining reliably whether or not the extended 217 * functionality is present without hard-coding knowledge 218 * of specific filesystem implementations. 219 * Stay in sync with vop_nopoll(). 220 */ 221 if (events & ~POLLSTANDARD) 222 return (POLLNVAL); 223 224 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 225 } 226 227 #define no_dump (dumper_t *)enodev 228 229 struct cdevsw * 230 devsw(struct cdev *dev) 231 { 232 if (dev->si_devsw != NULL) 233 return (dev->si_devsw); 234 return (&dead_cdevsw); 235 } 236 237 /* 238 * struct cdev * and u_dev_t primitives 239 */ 240 241 int 242 major(struct cdev *x) 243 { 244 if (x == NULL) 245 return NODEV; 246 return((x->si_udev >> 8) & 0xff); 247 } 248 249 int 250 minor(struct cdev *x) 251 { 252 if (x == NULL) 253 return NODEV; 254 return(x->si_udev & 0xffff00ff); 255 } 256 257 int 258 dev2unit(struct cdev *x) 259 { 260 int i; 261 262 if (x == NULL) 263 return NODEV; 264 i = minor(x); 265 return ((i & 0xff) | (i >> 8)); 266 } 267 268 int 269 unit2minor(int unit) 270 { 271 272 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); 273 return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 274 } 275 276 static struct cdev * 277 allocdev(void) 278 { 279 static int stashed; 280 struct cdev *si; 281 282 if (LIST_FIRST(&dev_free)) { 283 si = LIST_FIRST(&dev_free); 284 LIST_REMOVE(si, si_hash); 285 } else if (stashed >= DEVT_STASH) { 286 MALLOC(si, struct cdev *, sizeof(*si), M_DEVT, 287 M_USE_RESERVE | M_ZERO | M_WAITOK); 288 } else { 289 si = devt_stash + stashed++; 290 bzero(si, sizeof *si); 291 si->si_flags |= SI_STASHED; 292 } 293 si->__si_namebuf[0] = '\0'; 294 si->si_name = si->__si_namebuf; 295 LIST_INIT(&si->si_children); 296 TAILQ_INIT(&si->si_snapshots); 297 return (si); 298 } 299 300 static struct cdev * 301 newdev(int x, int y) 302 { 303 struct cdev *si; 304 dev_t udev; 305 int hash; 306 307 if (x == umajor(NODEV) && y == uminor(NODEV)) 308 panic("newdev of NODEV"); 309 udev = (x << 8) | y; 310 hash = udev % DEVT_HASH; 311 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 312 if (si->si_udev == udev) 313 return (si); 314 } 315 si = allocdev(); 316 si->si_udev = udev; 317 LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 318 return (si); 319 } 320 321 static void 322 freedev(struct cdev *dev) 323 { 324 325 if (dev->si_flags & SI_STASHED) { 326 bzero(dev, sizeof(*dev)); 327 dev->si_flags |= SI_STASHED; 328 LIST_INSERT_HEAD(&dev_free, dev, si_hash); 329 } else { 330 FREE(dev, M_DEVT); 331 } 332 } 333 334 dev_t 335 dev2udev(struct cdev *x) 336 { 337 if (x == NULL) 338 return (NODEV); 339 return (x->si_udev); 340 } 341 342 struct cdev * 343 findcdev(dev_t udev) 344 { 345 struct cdev *si; 346 int hash; 347 348 if (udev == NODEV) 349 return (NULL); 350 hash = udev % DEVT_HASH; 351 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 352 if (si->si_udev == udev) 353 return (si); 354 } 355 return (NULL); 356 } 357 358 int 359 uminor(dev_t dev) 360 { 361 return (dev & 0xffff00ff); 362 } 363 364 int 365 umajor(dev_t dev) 366 { 367 return ((dev & 0xff00) >> 8); 368 } 369 370 static void 371 find_major(struct cdevsw *devsw) 372 { 373 int i; 374 375 for (i = NUMCDEVSW - 1; i > 0; i--) 376 if (reserved_majors[i] != i) 377 break; 378 KASSERT(i > 0, ("Out of major numbers (%s)", devsw->d_name)); 379 devsw->d_maj = i; 380 reserved_majors[i] = i; 381 devsw->d_flags |= D_ALLOCMAJ; 382 } 383 384 static void 385 fini_cdevsw(struct cdevsw *devsw) 386 { 387 if (devsw->d_flags & D_ALLOCMAJ) { 388 reserved_majors[devsw->d_maj] = 0; 389 devsw->d_maj = MAJOR_AUTO; 390 devsw->d_flags &= ~D_ALLOCMAJ; 391 } else if (devsw->d_maj == 0) 392 devsw->d_maj = 256; 393 devsw->d_flags &= ~D_INIT; 394 } 395 396 static void 397 prep_cdevsw(struct cdevsw *devsw) 398 { 399 400 devlock(); 401 402 if (devsw->d_version != D_VERSION_00) { 403 printf( 404 "WARNING: Device driver \"%s\" has wrong version %s\n", 405 devsw->d_name, "and is disabled. Recompile KLD module."); 406 devsw->d_open = dead_open; 407 devsw->d_close = dead_close; 408 devsw->d_read = dead_read; 409 devsw->d_write = dead_write; 410 devsw->d_ioctl = dead_ioctl; 411 devsw->d_poll = dead_poll; 412 devsw->d_mmap = dead_mmap; 413 devsw->d_strategy = dead_strategy; 414 devsw->d_dump = dead_dump; 415 devsw->d_kqfilter = dead_kqfilter; 416 } 417 418 if (devsw->d_flags & D_TTY) { 419 if (devsw->d_ioctl == NULL) devsw->d_ioctl = ttyioctl; 420 if (devsw->d_read == NULL) devsw->d_read = ttyread; 421 if (devsw->d_write == NULL) devsw->d_write = ttywrite; 422 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = ttykqfilter; 423 if (devsw->d_poll == NULL) devsw->d_poll = ttypoll; 424 } 425 426 if (devsw->d_open == NULL) devsw->d_open = null_open; 427 if (devsw->d_close == NULL) devsw->d_close = null_close; 428 if (devsw->d_read == NULL) devsw->d_read = no_read; 429 if (devsw->d_write == NULL) devsw->d_write = no_write; 430 if (devsw->d_ioctl == NULL) devsw->d_ioctl = no_ioctl; 431 if (devsw->d_poll == NULL) devsw->d_poll = no_poll; 432 if (devsw->d_mmap == NULL) devsw->d_mmap = no_mmap; 433 if (devsw->d_strategy == NULL) devsw->d_strategy = no_strategy; 434 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 435 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = no_kqfilter; 436 437 LIST_INIT(&devsw->d_devs); 438 439 devsw->d_flags |= D_INIT; 440 441 if (devsw->d_maj == MAJOR_AUTO) { 442 find_major(devsw); 443 } else { 444 if (devsw->d_maj == 256) /* XXX: tty_cons.c is magic */ 445 devsw->d_maj = 0; 446 KASSERT(devsw->d_maj >= 0 && devsw->d_maj < 256, 447 ("Invalid major (%d) in make_dev", devsw->d_maj)); 448 if (reserved_majors[devsw->d_maj] != devsw->d_maj) { 449 printf("WARNING: driver \"%s\" used %s %d\n", 450 devsw->d_name, "unreserved major device number", 451 devsw->d_maj); 452 reserved_majors[devsw->d_maj] = devsw->d_maj; 453 } 454 } 455 devunlock(); 456 } 457 458 struct cdev * 459 make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int perms, const char *fmt, ...) 460 { 461 struct cdev *dev; 462 va_list ap; 463 int i; 464 465 KASSERT((minornr & ~0xffff00ff) == 0, 466 ("Invalid minor (0x%x) in make_dev", minornr)); 467 468 if (!(devsw->d_flags & D_INIT)) 469 prep_cdevsw(devsw); 470 dev = newdev(devsw->d_maj, minornr); 471 if (dev->si_flags & SI_CHEAPCLONE && 472 dev->si_flags & SI_NAMED && 473 dev->si_devsw == devsw) { 474 /* 475 * This is allowed as it removes races and generally 476 * simplifies cloning devices. 477 * XXX: still ?? 478 */ 479 return (dev); 480 } 481 devlock(); 482 KASSERT(!(dev->si_flags & SI_NAMED), 483 ("make_dev() by driver %s on pre-existing device (maj=%d, min=%d, name=%s)", 484 devsw->d_name, major(dev), minor(dev), devtoname(dev))); 485 486 va_start(ap, fmt); 487 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 488 if (i > (sizeof dev->__si_namebuf - 1)) { 489 printf("WARNING: Device name truncated! (%s)", 490 dev->__si_namebuf); 491 } 492 va_end(ap); 493 dev->si_devsw = devsw; 494 dev->si_uid = uid; 495 dev->si_gid = gid; 496 dev->si_mode = perms; 497 dev->si_flags |= SI_NAMED; 498 499 LIST_INSERT_HEAD(&devsw->d_devs, dev, si_list); 500 devfs_create(dev); 501 devunlock(); 502 return (dev); 503 } 504 505 int 506 dev_named(struct cdev *pdev, const char *name) 507 { 508 struct cdev *cdev; 509 510 if (strcmp(devtoname(pdev), name) == 0) 511 return (1); 512 LIST_FOREACH(cdev, &pdev->si_children, si_siblings) 513 if (strcmp(devtoname(cdev), name) == 0) 514 return (1); 515 return (0); 516 } 517 518 void 519 dev_depends(struct cdev *pdev, struct cdev *cdev) 520 { 521 522 devlock(); 523 cdev->si_parent = pdev; 524 cdev->si_flags |= SI_CHILD; 525 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 526 devunlock(); 527 } 528 529 struct cdev * 530 make_dev_alias(struct cdev *pdev, const char *fmt, ...) 531 { 532 struct cdev *dev; 533 va_list ap; 534 int i; 535 536 dev = allocdev(); 537 devlock(); 538 dev->si_flags |= SI_ALIAS; 539 dev->si_flags |= SI_NAMED; 540 va_start(ap, fmt); 541 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 542 if (i > (sizeof dev->__si_namebuf - 1)) { 543 printf("WARNING: Device name truncated! (%s)", 544 dev->__si_namebuf); 545 } 546 va_end(ap); 547 548 devfs_create(dev); 549 devunlock(); 550 dev_depends(pdev, dev); 551 return (dev); 552 } 553 554 static void 555 idestroy_dev(struct cdev *dev) 556 { 557 if (!(dev->si_flags & SI_NAMED)) { 558 printf( "WARNING: Driver mistake: destroy_dev on %d/%d\n", 559 major(dev), minor(dev)); 560 panic("don't do that"); 561 } 562 563 devfs_destroy(dev); 564 565 /* Remove name marking */ 566 dev->si_flags &= ~SI_NAMED; 567 568 /* If we are a child, remove us from the parents list */ 569 if (dev->si_flags & SI_CHILD) { 570 LIST_REMOVE(dev, si_siblings); 571 dev->si_flags &= ~SI_CHILD; 572 } 573 574 /* Kill our children */ 575 while (!LIST_EMPTY(&dev->si_children)) 576 idestroy_dev(LIST_FIRST(&dev->si_children)); 577 578 /* Remove from clone list */ 579 if (dev->si_flags & SI_CLONELIST) { 580 LIST_REMOVE(dev, si_clone); 581 dev->si_flags &= ~SI_CLONELIST; 582 } 583 584 if (!(dev->si_flags & SI_ALIAS)) { 585 /* Remove from cdevsw list */ 586 LIST_REMOVE(dev, si_list); 587 588 /* If cdevsw has no struct cdev *'s, clean it */ 589 if (LIST_EMPTY(&dev->si_devsw->d_devs)) 590 fini_cdevsw(dev->si_devsw); 591 592 LIST_REMOVE(dev, si_hash); 593 } 594 dev->si_drv1 = 0; 595 dev->si_drv2 = 0; 596 dev->si_devsw = NULL; 597 bzero(&dev->__si_u, sizeof(dev->__si_u)); 598 dev->si_flags &= ~SI_ALIAS; 599 if (dev->si_refcount > 0) { 600 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 601 } else { 602 freedev(dev); 603 } 604 } 605 606 void 607 destroy_dev(struct cdev *dev) 608 { 609 610 devlock(); 611 idestroy_dev(dev); 612 devunlock(); 613 } 614 615 const char * 616 devtoname(struct cdev *dev) 617 { 618 char *p; 619 int mynor; 620 621 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 622 p = dev->si_name; 623 if (devsw(dev)) 624 sprintf(p, "#%s/", devsw(dev)->d_name); 625 else 626 sprintf(p, "#%d/", major(dev)); 627 p += strlen(p); 628 mynor = minor(dev); 629 if (mynor < 0 || mynor > 255) 630 sprintf(p, "%#x", (u_int)mynor); 631 else 632 sprintf(p, "%d", mynor); 633 } 634 return (dev->si_name); 635 } 636 637 int 638 dev_stdclone(char *name, char **namep, const char *stem, int *unit) 639 { 640 int u, i; 641 642 i = strlen(stem); 643 if (bcmp(stem, name, i) != 0) 644 return (0); 645 if (!isdigit(name[i])) 646 return (0); 647 u = 0; 648 if (name[i] == '' && isdigit(name[i+1])) 649 return (0); 650 while (isdigit(name[i])) { 651 u *= 10; 652 u += name[i++] - ''; 653 } 654 if (u > 0xffffff) 655 return (0); 656 *unit = u; 657 if (namep) 658 *namep = &name[i]; 659 if (name[i]) 660 return (2); 661 return (1); 662 } 663 664 /* 665 * Helper functions for cloning device drivers. 666 * 667 * The objective here is to make it unnecessary for the device drivers to 668 * use rman or similar to manage their unit number space. Due to the way 669 * we do "on-demand" devices, using rman or other "private" methods 670 * will be very tricky to lock down properly once we lock down this file. 671 * 672 * Instead we give the drivers these routines which puts the struct cdev *'s 673 * that are to be managed on their own list, and gives the driver the ability 674 * to ask for the first free unit number or a given specified unit number. 675 * 676 * In addition these routines support paired devices (pty, nmdm and similar) 677 * by respecting a number of "flag" bits in the minor number. 678 * 679 */ 680 681 struct clonedevs { 682 LIST_HEAD(,cdev) head; 683 }; 684 685 void 686 clone_setup(struct clonedevs **cdp) 687 { 688 689 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 690 LIST_INIT(&(*cdp)->head); 691 } 692 693 int 694 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, u_int extra) 695 { 696 struct clonedevs *cd; 697 struct cdev *dev, *dl, *de; 698 int unit, low, u; 699 700 KASSERT(*cdp != NULL, 701 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 702 KASSERT(!(extra & CLONE_UNITMASK), 703 ("Illegal extra bits (0x%x) in clone_create", extra)); 704 KASSERT(*up <= CLONE_UNITMASK, 705 ("Too high unit (0x%x) in clone_create", *up)); 706 707 if (csw->d_maj == MAJOR_AUTO) 708 find_major(csw); 709 710 /* 711 * Search the list for a lot of things in one go: 712 * A preexisting match is returned immediately. 713 * The lowest free unit number if we are passed -1, and the place 714 * in the list where we should insert that new element. 715 * The place to insert a specified unit number, if applicable 716 * the end of the list. 717 */ 718 unit = *up; 719 low = extra; 720 de = dl = NULL; 721 cd = *cdp; 722 LIST_FOREACH(dev, &cd->head, si_clone) { 723 u = dev2unit(dev); 724 if (u == (unit | extra)) { 725 *dp = dev; 726 return (0); 727 } 728 if (unit == -1 && u == low) { 729 low++; 730 de = dev; 731 continue; 732 } 733 if (u > (unit | extra)) { 734 dl = dev; 735 break; 736 } 737 de = dev; 738 } 739 if (unit == -1) 740 unit = low & CLONE_UNITMASK; 741 dev = newdev(csw->d_maj, unit2minor(unit | extra)); 742 KASSERT(!(dev->si_flags & SI_CLONELIST), 743 ("Dev %p should not be on clonelist", dev)); 744 if (dl != NULL) 745 LIST_INSERT_BEFORE(dl, dev, si_clone); 746 else if (de != NULL) 747 LIST_INSERT_AFTER(de, dev, si_clone); 748 else 749 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 750 dev->si_flags |= SI_CLONELIST; 751 *up = unit; 752 return (1); 753 } 754 755 /* 756 * Kill everything still on the list. The driver should already have 757 * disposed of any softc hung of the struct cdev *'s at this time. 758 */ 759 void 760 clone_cleanup(struct clonedevs **cdp) 761 { 762 struct cdev *dev, *tdev; 763 struct clonedevs *cd; 764 765 cd = *cdp; 766 if (cd == NULL) 767 return; 768 LIST_FOREACH_SAFE(dev, &cd->head, si_clone, tdev) { 769 KASSERT(dev->si_flags & SI_NAMED, 770 ("Driver has goofed in cloning underways udev %x", dev->si_udev)); 771 destroy_dev(dev); 772 } 773 free(cd, M_DEVBUF); 774 *cdp = NULL; 775 } 776 777 /* 778 * Helper sysctl for devname(3). We're given a struct cdev * and return 779 * the name, if any, registered by the device driver. 780 */ 781 static int 782 sysctl_devname(SYSCTL_HANDLER_ARGS) 783 { 784 int error; 785 dev_t ud; 786 struct cdev *dev; 787 788 error = SYSCTL_IN(req, &ud, sizeof (ud)); 789 if (error) 790 return (error); 791 if (ud == NODEV) 792 return(EINVAL); 793 dev = findcdev(ud); 794 if (dev == NULL) 795 error = ENOENT; 796 else 797 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1); 798 return (error); 799 } 800 801 SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY, 802 NULL, 0, sysctl_devname, "", "devname(3) handler");
Cache object: f655ff29153f4ef704a0e251406357c5
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