kern_conf.c revision 135704
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: head/sys/kern/kern_conf.c 135704 2004-09-24 05:54:32Z phk $"); 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 47static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage"); 48 49/* Built at compile time from sys/conf/majors */ 50extern 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 62static struct cdev devt_stash[DEVT_STASH]; 63 64static LIST_HEAD(, cdev) dev_hash[DEVT_HASH]; 65 66static LIST_HEAD(, cdev) dev_free; 67 68static int free_devt; 69SYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, ""); 70 71static struct mtx devmtx; 72static void freedev(struct cdev *dev); 73static struct cdev *newdev(int x, int y); 74 75 76void 77dev_lock(void) 78{ 79 if (!mtx_initialized(&devmtx)) 80 mtx_init(&devmtx, "cdev", NULL, MTX_DEF); 81 mtx_lock(&devmtx); 82} 83 84void 85dev_unlock(void) 86{ 87 88 mtx_unlock(&devmtx); 89} 90 91void 92dev_ref(struct cdev *dev) 93{ 94 95 dev_lock(); 96 dev->si_refcount++; 97 dev_unlock(); 98} 99 100void 101dev_rel(struct cdev *dev) 102{ 103 104 dev->si_refcount--; 105 KASSERT(dev->si_refcount >= 0, 106 ("dev_rel(%s) gave negative count", devtoname(dev))); 107 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 108 LIST_REMOVE(dev, si_list); 109 freedev(dev); 110 } 111} 112struct cdevsw * 113dev_refthread(struct cdev *dev) 114{ 115 struct cdevsw *csw; 116 117 mtx_assert(&devmtx, MA_NOTOWNED); 118 dev_lock(); 119 csw = dev->si_devsw; 120 if (csw != NULL) 121 dev->si_threadcount++; 122 dev_unlock(); 123 return (csw); 124} 125 126void 127dev_relthread(struct cdev *dev) 128{ 129 130 mtx_assert(&devmtx, MA_NOTOWNED); 131 dev_lock(); 132 dev->si_threadcount--; 133 dev_unlock(); 134} 135 136int 137nullop(void) 138{ 139 140 return (0); 141} 142 143int 144eopnotsupp(void) 145{ 146 147 return (EOPNOTSUPP); 148} 149 150static int 151enxio(void) 152{ 153 return (ENXIO); 154} 155 156static int 157enodev(void) 158{ 159 return (ENODEV); 160} 161 162/* Define a dead_cdevsw for use when devices leave unexpectedly. */ 163 164#define dead_open (d_open_t *)enxio 165#define dead_close (d_close_t *)enxio 166#define dead_read (d_read_t *)enxio 167#define dead_write (d_write_t *)enxio 168#define dead_ioctl (d_ioctl_t *)enxio 169#define dead_poll (d_poll_t *)enodev 170#define dead_mmap (d_mmap_t *)enodev 171 172static void 173dead_strategy(struct bio *bp) 174{ 175 176 biofinish(bp, NULL, ENXIO); 177} 178 179#define dead_dump (dumper_t *)enxio 180#define dead_kqfilter (d_kqfilter_t *)enxio 181 182static struct cdevsw dead_cdevsw = { 183 .d_version = D_VERSION, 184 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 185 .d_open = dead_open, 186 .d_close = dead_close, 187 .d_read = dead_read, 188 .d_write = dead_write, 189 .d_ioctl = dead_ioctl, 190 .d_poll = dead_poll, 191 .d_mmap = dead_mmap, 192 .d_strategy = dead_strategy, 193 .d_name = "dead", 194 .d_maj = 255, 195 .d_dump = dead_dump, 196 .d_kqfilter = dead_kqfilter 197}; 198 199/* Default methods if driver does not specify method */ 200 201#define null_open (d_open_t *)nullop 202#define null_close (d_close_t *)nullop 203#define no_read (d_read_t *)enodev 204#define no_write (d_write_t *)enodev 205#define no_ioctl (d_ioctl_t *)enodev 206#define no_mmap (d_mmap_t *)enodev 207#define no_kqfilter (d_kqfilter_t *)enodev 208 209static void 210no_strategy(struct bio *bp) 211{ 212 213 biofinish(bp, NULL, ENODEV); 214} 215 216static int 217no_poll(struct cdev *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 235struct cdevsw * 236devsw(struct cdev *dev) 237{ 238 if (dev->si_devsw != NULL) 239 return (dev->si_devsw); 240 return (&dead_cdevsw); 241} 242 243/* 244 * struct cdev * and u_dev_t primitives 245 */ 246 247int 248major(struct cdev *x) 249{ 250 if (x == NULL) 251 return NODEV; 252 return((x->si_udev >> 8) & 0xff); 253} 254 255int 256minor(struct cdev *x) 257{ 258 if (x == NULL) 259 return NODEV; 260 return(x->si_udev & 0xffff00ff); 261} 262 263int 264dev2unit(struct cdev *x) 265{ 266 int i; 267 268 if (x == NULL) 269 return NODEV; 270 i = minor(x); 271 return ((i & 0xff) | (i >> 8)); 272} 273 274int 275unit2minor(int unit) 276{ 277 278 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); 279 return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 280} 281 282static struct cdev * 283allocdev(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 return (si); 303} 304 305static struct cdev * 306newdev(int x, int y) 307{ 308 struct cdev *si; 309 dev_t udev; 310 int hash; 311 312 if (x == umajor(NODEV) && y == uminor(NODEV)) 313 panic("newdev of NODEV"); 314 udev = (x << 8) | y; 315 hash = udev % DEVT_HASH; 316 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 317 if (si->si_udev == udev) 318 return (si); 319 } 320 si = allocdev(); 321 si->si_udev = udev; 322 LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 323 return (si); 324} 325 326static void 327freedev(struct cdev *dev) 328{ 329 330 if (dev->si_flags & SI_STASHED) { 331 bzero(dev, sizeof(*dev)); 332 dev->si_flags |= SI_STASHED; 333 LIST_INSERT_HEAD(&dev_free, dev, si_hash); 334 } else { 335 FREE(dev, M_DEVT); 336 } 337} 338 339dev_t 340dev2udev(struct cdev *x) 341{ 342 if (x == NULL) 343 return (NODEV); 344 return (x->si_udev); 345} 346 347struct cdev * 348findcdev(dev_t udev) 349{ 350 struct cdev *si; 351 int hash; 352 353 if (udev == NODEV) 354 return (NULL); 355 hash = udev % DEVT_HASH; 356 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 357 if (si->si_udev == udev) 358 return (si); 359 } 360 return (NULL); 361} 362 363int 364uminor(dev_t dev) 365{ 366 return (dev & 0xffff00ff); 367} 368 369int 370umajor(dev_t dev) 371{ 372 return ((dev & 0xff00) >> 8); 373} 374 375static void 376find_major(struct cdevsw *devsw) 377{ 378 int i; 379 380 for (i = NUMCDEVSW - 1; i > 0; i--) 381 if (reserved_majors[i] != i) 382 break; 383 KASSERT(i > 0, ("Out of major numbers (%s)", devsw->d_name)); 384 devsw->d_maj = i; 385 reserved_majors[i] = i; 386 devsw->d_flags |= D_ALLOCMAJ; 387} 388 389static void 390fini_cdevsw(struct cdevsw *devsw) 391{ 392 if (devsw->d_flags & D_ALLOCMAJ) { 393 reserved_majors[devsw->d_maj] = 0; 394 devsw->d_maj = MAJOR_AUTO; 395 devsw->d_flags &= ~D_ALLOCMAJ; 396 } else if (devsw->d_maj == 0) 397 devsw->d_maj = 256; 398 devsw->d_flags &= ~D_INIT; 399} 400 401static void 402prep_cdevsw(struct cdevsw *devsw) 403{ 404 405 dev_lock(); 406 407 if (devsw->d_version != D_VERSION_00) { 408 printf( 409 "WARNING: Device driver \"%s\" has wrong version %s\n", 410 devsw->d_name, "and is disabled. Recompile KLD module."); 411 devsw->d_open = dead_open; 412 devsw->d_close = dead_close; 413 devsw->d_read = dead_read; 414 devsw->d_write = dead_write; 415 devsw->d_ioctl = dead_ioctl; 416 devsw->d_poll = dead_poll; 417 devsw->d_mmap = dead_mmap; 418 devsw->d_strategy = dead_strategy; 419 devsw->d_dump = dead_dump; 420 devsw->d_kqfilter = dead_kqfilter; 421 } 422 423 if (devsw->d_flags & D_TTY) { 424 if (devsw->d_ioctl == NULL) devsw->d_ioctl = ttyioctl; 425 if (devsw->d_read == NULL) devsw->d_read = ttyread; 426 if (devsw->d_write == NULL) devsw->d_write = ttywrite; 427 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = ttykqfilter; 428 if (devsw->d_poll == NULL) devsw->d_poll = ttypoll; 429 } 430 431 if (devsw->d_open == NULL) devsw->d_open = null_open; 432 if (devsw->d_close == NULL) devsw->d_close = null_close; 433 if (devsw->d_read == NULL) devsw->d_read = no_read; 434 if (devsw->d_write == NULL) devsw->d_write = no_write; 435 if (devsw->d_ioctl == NULL) devsw->d_ioctl = no_ioctl; 436 if (devsw->d_poll == NULL) devsw->d_poll = no_poll; 437 if (devsw->d_mmap == NULL) devsw->d_mmap = no_mmap; 438 if (devsw->d_strategy == NULL) devsw->d_strategy = no_strategy; 439 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 440 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = no_kqfilter; 441 442 LIST_INIT(&devsw->d_devs); 443 444 devsw->d_flags |= D_INIT; 445 446 if (devsw->d_maj == MAJOR_AUTO) { 447 find_major(devsw); 448 } else { 449 if (devsw->d_maj == 256) /* XXX: tty_cons.c is magic */ 450 devsw->d_maj = 0; 451 KASSERT(devsw->d_maj >= 0 && devsw->d_maj < 256, 452 ("Invalid major (%d) in make_dev", devsw->d_maj)); 453 if (reserved_majors[devsw->d_maj] != devsw->d_maj) { 454 printf("WARNING: driver \"%s\" used %s %d\n", 455 devsw->d_name, "unreserved major device number", 456 devsw->d_maj); 457 reserved_majors[devsw->d_maj] = devsw->d_maj; 458 } 459 } 460 dev_unlock(); 461} 462 463struct cdev * 464make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int perms, const char *fmt, ...) 465{ 466 struct cdev *dev; 467 va_list ap; 468 int i; 469 470 KASSERT((minornr & ~0xffff00ff) == 0, 471 ("Invalid minor (0x%x) in make_dev", minornr)); 472 473 if (!(devsw->d_flags & D_INIT)) 474 prep_cdevsw(devsw); 475 dev = newdev(devsw->d_maj, minornr); 476 if (dev->si_flags & SI_CHEAPCLONE && 477 dev->si_flags & SI_NAMED && 478 dev->si_devsw == devsw) { 479 /* 480 * This is allowed as it removes races and generally 481 * simplifies cloning devices. 482 * XXX: still ?? 483 */ 484 return (dev); 485 } 486 dev_lock(); 487 KASSERT(!(dev->si_flags & SI_NAMED), 488 ("make_dev() by driver %s on pre-existing device (maj=%d, min=%d, name=%s)", 489 devsw->d_name, major(dev), minor(dev), devtoname(dev))); 490 491 va_start(ap, fmt); 492 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 493 if (i > (sizeof dev->__si_namebuf - 1)) { 494 printf("WARNING: Device name truncated! (%s)\n", 495 dev->__si_namebuf); 496 } 497 va_end(ap); 498 dev->si_devsw = devsw; 499 dev->si_uid = uid; 500 dev->si_gid = gid; 501 dev->si_mode = perms; 502 dev->si_flags |= SI_NAMED; 503 504 LIST_INSERT_HEAD(&devsw->d_devs, dev, si_list); 505 devfs_create(dev); 506 dev_unlock(); 507 return (dev); 508} 509 510int 511dev_named(struct cdev *pdev, const char *name) 512{ 513 struct cdev *cdev; 514 515 if (strcmp(devtoname(pdev), name) == 0) 516 return (1); 517 LIST_FOREACH(cdev, &pdev->si_children, si_siblings) 518 if (strcmp(devtoname(cdev), name) == 0) 519 return (1); 520 return (0); 521} 522 523void 524dev_depends(struct cdev *pdev, struct cdev *cdev) 525{ 526 527 dev_lock(); 528 cdev->si_parent = pdev; 529 cdev->si_flags |= SI_CHILD; 530 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 531 dev_unlock(); 532} 533 534struct cdev * 535make_dev_alias(struct cdev *pdev, const char *fmt, ...) 536{ 537 struct cdev *dev; 538 va_list ap; 539 int i; 540 541 dev = allocdev(); 542 dev_lock(); 543 dev->si_flags |= SI_ALIAS; 544 dev->si_flags |= SI_NAMED; 545 va_start(ap, fmt); 546 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 547 if (i > (sizeof dev->__si_namebuf - 1)) { 548 printf("WARNING: Device name truncated! (%s)\n", 549 dev->__si_namebuf); 550 } 551 va_end(ap); 552 553 devfs_create(dev); 554 dev_unlock(); 555 dev_depends(pdev, dev); 556 return (dev); 557} 558 559static void 560idestroy_dev(struct cdev *dev) 561{ 562 if (!(dev->si_flags & SI_NAMED)) { 563 printf( "WARNING: Driver mistake: destroy_dev on %d/%d\n", 564 major(dev), minor(dev)); 565 panic("don't do that"); 566 } 567 568 devfs_destroy(dev); 569 570 /* Remove name marking */ 571 dev->si_flags &= ~SI_NAMED; 572 573 /* If we are a child, remove us from the parents list */ 574 if (dev->si_flags & SI_CHILD) { 575 LIST_REMOVE(dev, si_siblings); 576 dev->si_flags &= ~SI_CHILD; 577 } 578 579 /* Kill our children */ 580 while (!LIST_EMPTY(&dev->si_children)) 581 idestroy_dev(LIST_FIRST(&dev->si_children)); 582 583 /* Remove from clone list */ 584 if (dev->si_flags & SI_CLONELIST) { 585 LIST_REMOVE(dev, si_clone); 586 dev->si_flags &= ~SI_CLONELIST; 587 } 588 589 if (!(dev->si_flags & SI_ALIAS)) { 590 /* Remove from cdevsw list */ 591 LIST_REMOVE(dev, si_list); 592 593 /* If cdevsw has no struct cdev *'s, clean it */ 594 if (LIST_EMPTY(&dev->si_devsw->d_devs)) 595 fini_cdevsw(dev->si_devsw); 596 597 LIST_REMOVE(dev, si_hash); 598 } 599 dev->si_drv1 = 0; 600 dev->si_drv2 = 0; 601 dev->si_devsw = NULL; 602 bzero(&dev->__si_u, sizeof(dev->__si_u)); 603 dev->si_flags &= ~SI_ALIAS; 604 if (dev->si_refcount > 0) { 605 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 606 } else { 607 freedev(dev); 608 } 609} 610 611void 612destroy_dev(struct cdev *dev) 613{ 614 615 dev_lock(); 616 idestroy_dev(dev); 617 dev_unlock(); 618} 619 620const char * 621devtoname(struct cdev *dev) 622{ 623 char *p; 624 int mynor; 625 626 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 627 p = dev->si_name; 628 if (devsw(dev)) 629 sprintf(p, "#%s/", devsw(dev)->d_name); 630 else 631 sprintf(p, "#%d/", major(dev)); 632 p += strlen(p); 633 mynor = minor(dev); 634 if (mynor < 0 || mynor > 255) 635 sprintf(p, "%#x", (u_int)mynor); 636 else 637 sprintf(p, "%d", mynor); 638 } 639 return (dev->si_name); 640} 641 642int 643dev_stdclone(char *name, char **namep, const char *stem, int *unit) 644{ 645 int u, i; 646 647 i = strlen(stem); 648 if (bcmp(stem, name, i) != 0) 649 return (0); 650 if (!isdigit(name[i])) 651 return (0); 652 u = 0; 653 if (name[i] == '0' && isdigit(name[i+1])) 654 return (0); 655 while (isdigit(name[i])) { 656 u *= 10; 657 u += name[i++] - '0'; 658 } 659 if (u > 0xffffff) 660 return (0); 661 *unit = u; 662 if (namep) 663 *namep = &name[i]; 664 if (name[i]) 665 return (2); 666 return (1); 667} 668 669/* 670 * Helper functions for cloning device drivers. 671 * 672 * The objective here is to make it unnecessary for the device drivers to 673 * use rman or similar to manage their unit number space. Due to the way 674 * we do "on-demand" devices, using rman or other "private" methods 675 * will be very tricky to lock down properly once we lock down this file. 676 * 677 * Instead we give the drivers these routines which puts the struct cdev *'s 678 * that are to be managed on their own list, and gives the driver the ability 679 * to ask for the first free unit number or a given specified unit number. 680 * 681 * In addition these routines support paired devices (pty, nmdm and similar) 682 * by respecting a number of "flag" bits in the minor number. 683 * 684 */ 685 686struct clonedevs { 687 LIST_HEAD(,cdev) head; 688}; 689 690void 691clone_setup(struct clonedevs **cdp) 692{ 693 694 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 695 LIST_INIT(&(*cdp)->head); 696} 697 698int 699clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, u_int extra) 700{ 701 struct clonedevs *cd; 702 struct cdev *dev, *dl, *de; 703 int unit, low, u; 704 705 KASSERT(*cdp != NULL, 706 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 707 KASSERT(!(extra & CLONE_UNITMASK), 708 ("Illegal extra bits (0x%x) in clone_create", extra)); 709 KASSERT(*up <= CLONE_UNITMASK, 710 ("Too high unit (0x%x) in clone_create", *up)); 711 712 if (csw->d_maj == MAJOR_AUTO) 713 find_major(csw); 714 715 /* 716 * Search the list for a lot of things in one go: 717 * A preexisting match is returned immediately. 718 * The lowest free unit number if we are passed -1, and the place 719 * in the list where we should insert that new element. 720 * The place to insert a specified unit number, if applicable 721 * the end of the list. 722 */ 723 unit = *up; 724 low = extra; 725 de = dl = NULL; 726 cd = *cdp; 727 LIST_FOREACH(dev, &cd->head, si_clone) { 728 u = dev2unit(dev); 729 if (u == (unit | extra)) { 730 *dp = dev; 731 return (0); 732 } 733 if (unit == -1 && u == low) { 734 low++; 735 de = dev; 736 continue; 737 } 738 if (u > (unit | extra)) { 739 dl = dev; 740 break; 741 } 742 de = dev; 743 } 744 if (unit == -1) 745 unit = low & CLONE_UNITMASK; 746 dev = newdev(csw->d_maj, unit2minor(unit | extra)); 747 KASSERT(!(dev->si_flags & SI_CLONELIST), 748 ("Dev %p should not be on clonelist", dev)); 749 if (dl != NULL) 750 LIST_INSERT_BEFORE(dl, dev, si_clone); 751 else if (de != NULL) 752 LIST_INSERT_AFTER(de, dev, si_clone); 753 else 754 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 755 dev->si_flags |= SI_CLONELIST; 756 *up = unit; 757 return (1); 758} 759 760/* 761 * Kill everything still on the list. The driver should already have 762 * disposed of any softc hung of the struct cdev *'s at this time. 763 */ 764void 765clone_cleanup(struct clonedevs **cdp) 766{ 767 struct cdev *dev, *tdev; 768 struct clonedevs *cd; 769 770 cd = *cdp; 771 if (cd == NULL) 772 return; 773 LIST_FOREACH_SAFE(dev, &cd->head, si_clone, tdev) { 774 KASSERT(dev->si_flags & SI_NAMED, 775 ("Driver has goofed in cloning underways udev %x", dev->si_udev)); 776 destroy_dev(dev); 777 } 778 free(cd, M_DEVBUF); 779 *cdp = NULL; 780} 781 782/* 783 * Helper sysctl for devname(3). We're given a struct cdev * and return 784 * the name, if any, registered by the device driver. 785 */ 786static int 787sysctl_devname(SYSCTL_HANDLER_ARGS) 788{ 789 int error; 790 dev_t ud; 791 struct cdev *dev; 792 793 error = SYSCTL_IN(req, &ud, sizeof (ud)); 794 if (error) 795 return (error); 796 if (ud == NODEV) 797 return(EINVAL); 798 dev = findcdev(ud); 799 if (dev == NULL) 800 error = ENOENT; 801 else 802 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1); 803 return (error); 804} 805 806SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY, 807 NULL, 0, sysctl_devname, "", "devname(3) handler"); 808