kern_conf.c revision 136014
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 136014 2004-10-01 06:33:39Z 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 vnode *vp) 102{ 103 struct cdev *dev; 104 int flag; 105 106 dev = vp->v_rdev; 107 mtx_assert(&devmtx, MA_NOTOWNED); 108 dev_lock(); 109 SLIST_REMOVE(&dev->si_hlist, vp, vnode, v_specnext); 110 dev->si_usecount -= vp->v_usecount; 111 vp->v_rdev = NULL; 112 dev->si_refcount--; 113 KASSERT(dev->si_refcount >= 0, 114 ("dev_rel(%s) gave negative count", devtoname(dev))); 115 flag = 0; 116 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 117 LIST_REMOVE(dev, si_list); 118 flag = 1; 119 } 120 dev_unlock(); 121 if (flag) 122 freedev(dev); 123 return; 124} 125 126struct cdevsw * 127dev_refthread(struct cdev *dev) 128{ 129 struct cdevsw *csw; 130 131 mtx_assert(&devmtx, MA_NOTOWNED); 132 dev_lock(); 133 csw = dev->si_devsw; 134 if (csw != NULL) 135 dev->si_threadcount++; 136 dev_unlock(); 137 return (csw); 138} 139 140void 141dev_relthread(struct cdev *dev) 142{ 143 144 mtx_assert(&devmtx, MA_NOTOWNED); 145 dev_lock(); 146 dev->si_threadcount--; 147 dev_unlock(); 148} 149 150int 151nullop(void) 152{ 153 154 return (0); 155} 156 157int 158eopnotsupp(void) 159{ 160 161 return (EOPNOTSUPP); 162} 163 164static int 165enxio(void) 166{ 167 return (ENXIO); 168} 169 170static int 171enodev(void) 172{ 173 return (ENODEV); 174} 175 176/* Define a dead_cdevsw for use when devices leave unexpectedly. */ 177 178#define dead_open (d_open_t *)enxio 179#define dead_close (d_close_t *)enxio 180#define dead_read (d_read_t *)enxio 181#define dead_write (d_write_t *)enxio 182#define dead_ioctl (d_ioctl_t *)enxio 183#define dead_poll (d_poll_t *)enodev 184#define dead_mmap (d_mmap_t *)enodev 185 186static void 187dead_strategy(struct bio *bp) 188{ 189 190 biofinish(bp, NULL, ENXIO); 191} 192 193#define dead_dump (dumper_t *)enxio 194#define dead_kqfilter (d_kqfilter_t *)enxio 195 196static struct cdevsw dead_cdevsw = { 197 .d_version = D_VERSION, 198 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 199 .d_open = dead_open, 200 .d_close = dead_close, 201 .d_read = dead_read, 202 .d_write = dead_write, 203 .d_ioctl = dead_ioctl, 204 .d_poll = dead_poll, 205 .d_mmap = dead_mmap, 206 .d_strategy = dead_strategy, 207 .d_name = "dead", 208 .d_maj = 255, 209 .d_dump = dead_dump, 210 .d_kqfilter = dead_kqfilter 211}; 212 213/* Default methods if driver does not specify method */ 214 215#define null_open (d_open_t *)nullop 216#define null_close (d_close_t *)nullop 217#define no_read (d_read_t *)enodev 218#define no_write (d_write_t *)enodev 219#define no_ioctl (d_ioctl_t *)enodev 220#define no_mmap (d_mmap_t *)enodev 221#define no_kqfilter (d_kqfilter_t *)enodev 222 223static void 224no_strategy(struct bio *bp) 225{ 226 227 biofinish(bp, NULL, ENODEV); 228} 229 230static int 231no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 232{ 233 /* 234 * Return true for read/write. If the user asked for something 235 * special, return POLLNVAL, so that clients have a way of 236 * determining reliably whether or not the extended 237 * functionality is present without hard-coding knowledge 238 * of specific filesystem implementations. 239 * Stay in sync with vop_nopoll(). 240 */ 241 if (events & ~POLLSTANDARD) 242 return (POLLNVAL); 243 244 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 245} 246 247#define no_dump (dumper_t *)enodev 248 249/* 250 * struct cdev * and u_dev_t primitives 251 */ 252 253int 254major(struct cdev *x) 255{ 256 if (x == NULL) 257 return NODEV; 258 return((x->si_udev >> 8) & 0xff); 259} 260 261int 262minor(struct cdev *x) 263{ 264 if (x == NULL) 265 return NODEV; 266 return(x->si_udev & 0xffff00ff); 267} 268 269int 270dev2unit(struct cdev *x) 271{ 272 int i; 273 274 if (x == NULL) 275 return NODEV; 276 i = minor(x); 277 return ((i & 0xff) | (i >> 8)); 278} 279 280int 281unit2minor(int unit) 282{ 283 284 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); 285 return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 286} 287 288static struct cdev * 289allocdev(void) 290{ 291 static int stashed; 292 struct cdev *si; 293 294 if (LIST_FIRST(&dev_free)) { 295 si = LIST_FIRST(&dev_free); 296 LIST_REMOVE(si, si_hash); 297 } else if (stashed >= DEVT_STASH) { 298 MALLOC(si, struct cdev *, sizeof(*si), M_DEVT, 299 M_USE_RESERVE | M_ZERO | M_WAITOK); 300 } else { 301 si = devt_stash + stashed++; 302 bzero(si, sizeof *si); 303 si->si_flags |= SI_STASHED; 304 } 305 si->__si_namebuf[0] = '\0'; 306 si->si_name = si->__si_namebuf; 307 LIST_INIT(&si->si_children); 308 return (si); 309} 310 311static struct cdev * 312newdev(int x, int y) 313{ 314 struct cdev *si; 315 dev_t udev; 316 int hash; 317 318 if (x == umajor(NODEV) && y == uminor(NODEV)) 319 panic("newdev of NODEV"); 320 udev = (x << 8) | y; 321 hash = udev % DEVT_HASH; 322 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 323 if (si->si_udev == udev) 324 return (si); 325 } 326 si = allocdev(); 327 si->si_udev = udev; 328 LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 329 return (si); 330} 331 332static void 333freedev(struct cdev *dev) 334{ 335 336 if (dev->si_flags & SI_STASHED) { 337 bzero(dev, sizeof(*dev)); 338 dev->si_flags |= SI_STASHED; 339 LIST_INSERT_HEAD(&dev_free, dev, si_hash); 340 } else { 341 FREE(dev, M_DEVT); 342 } 343} 344 345dev_t 346dev2udev(struct cdev *x) 347{ 348 if (x == NULL) 349 return (NODEV); 350 return (x->si_udev); 351} 352 353struct cdev * 354findcdev(dev_t udev) 355{ 356 struct cdev *si; 357 int hash; 358 359 if (udev == NODEV) 360 return (NULL); 361 hash = udev % DEVT_HASH; 362 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 363 if (si->si_udev == udev) 364 return (si); 365 } 366 return (NULL); 367} 368 369int 370uminor(dev_t dev) 371{ 372 return (dev & 0xffff00ff); 373} 374 375int 376umajor(dev_t dev) 377{ 378 return ((dev & 0xff00) >> 8); 379} 380 381static void 382find_major(struct cdevsw *devsw) 383{ 384 int i; 385 386 for (i = NUMCDEVSW - 1; i > 0; i--) 387 if (reserved_majors[i] != i) 388 break; 389 KASSERT(i > 0, ("Out of major numbers (%s)", devsw->d_name)); 390 devsw->d_maj = i; 391 reserved_majors[i] = i; 392 devsw->d_flags |= D_ALLOCMAJ; 393} 394 395static void 396fini_cdevsw(struct cdevsw *devsw) 397{ 398 if (devsw->d_flags & D_ALLOCMAJ) { 399 reserved_majors[devsw->d_maj] = 0; 400 devsw->d_maj = MAJOR_AUTO; 401 devsw->d_flags &= ~D_ALLOCMAJ; 402 } else if (devsw->d_maj == 0) 403 devsw->d_maj = 256; 404 devsw->d_flags &= ~D_INIT; 405} 406 407static void 408prep_cdevsw(struct cdevsw *devsw) 409{ 410 411 dev_lock(); 412 413 if (devsw->d_version != D_VERSION_00) { 414 printf( 415 "WARNING: Device driver \"%s\" has wrong version %s\n", 416 devsw->d_name, "and is disabled. Recompile KLD module."); 417 devsw->d_open = dead_open; 418 devsw->d_close = dead_close; 419 devsw->d_read = dead_read; 420 devsw->d_write = dead_write; 421 devsw->d_ioctl = dead_ioctl; 422 devsw->d_poll = dead_poll; 423 devsw->d_mmap = dead_mmap; 424 devsw->d_strategy = dead_strategy; 425 devsw->d_dump = dead_dump; 426 devsw->d_kqfilter = dead_kqfilter; 427 } 428 429 if (devsw->d_flags & D_TTY) { 430 if (devsw->d_ioctl == NULL) devsw->d_ioctl = ttyioctl; 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 dev_unlock(); 467} 468 469struct cdev * 470make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int perms, const char *fmt, ...) 471{ 472 struct cdev *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 = newdev(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 dev_lock(); 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)\n", 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 dev_unlock(); 513 return (dev); 514} 515 516int 517dev_named(struct cdev *pdev, const char *name) 518{ 519 struct cdev *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 529void 530dev_depends(struct cdev *pdev, struct cdev *cdev) 531{ 532 533 dev_lock(); 534 cdev->si_parent = pdev; 535 cdev->si_flags |= SI_CHILD; 536 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 537 dev_unlock(); 538} 539 540struct cdev * 541make_dev_alias(struct cdev *pdev, const char *fmt, ...) 542{ 543 struct cdev *dev; 544 va_list ap; 545 int i; 546 547 dev = allocdev(); 548 dev_lock(); 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)\n", 555 dev->__si_namebuf); 556 } 557 va_end(ap); 558 559 devfs_create(dev); 560 dev_unlock(); 561 dev_depends(pdev, dev); 562 return (dev); 563} 564 565static void 566idestroy_dev(struct cdev *dev) 567{ 568 struct cdevsw *csw; 569 570 KASSERT(dev->si_flags & SI_NAMED, 571 ("WARNING: Driver mistake: destroy_dev on %d/%d\n", 572 major(dev), minor(dev))); 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 csw = dev->si_devsw; 596 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 597 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 598 printf("Purging %lu threads from %s\n", 599 dev->si_threadcount, devtoname(dev)); 600 csw->d_purge(dev); 601 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 602 } 603 if (csw != NULL && csw->d_purge != NULL) 604 printf("All threads purged from %s\n", devtoname(dev)); 605 606 dev->si_drv1 = 0; 607 dev->si_drv2 = 0; 608 bzero(&dev->__si_u, sizeof(dev->__si_u)); 609 610 if (!(dev->si_flags & SI_ALIAS)) { 611 /* Remove from cdevsw list */ 612 LIST_REMOVE(dev, si_list); 613 614 /* If cdevsw has no struct cdev *'s, clean it */ 615 if (LIST_EMPTY(&csw->d_devs)) 616 fini_cdevsw(csw); 617 618 LIST_REMOVE(dev, si_hash); 619 } 620 dev->si_flags &= ~SI_ALIAS; 621 622 if (dev->si_refcount > 0) { 623 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 624 } else { 625 freedev(dev); 626 } 627} 628 629void 630destroy_dev(struct cdev *dev) 631{ 632 633 dev_lock(); 634 idestroy_dev(dev); 635 dev_unlock(); 636} 637 638const char * 639devtoname(struct cdev *dev) 640{ 641 char *p; 642 struct cdevsw *csw; 643 int mynor; 644 645 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 646 p = dev->si_name; 647 sprintf(p, "#%d", major(dev)); 648 p += strlen(p); 649 csw = dev_refthread(dev); 650 if (csw != NULL) { 651 sprintf(p, "(%s)", csw->d_name); 652 dev_relthread(dev); 653 } 654 p += strlen(p); 655 mynor = minor(dev); 656 if (mynor < 0 || mynor > 255) 657 sprintf(p, "/%#x", (u_int)mynor); 658 else 659 sprintf(p, "/%d", mynor); 660 } 661 return (dev->si_name); 662} 663 664int 665dev_stdclone(char *name, char **namep, const char *stem, int *unit) 666{ 667 int u, i; 668 669 i = strlen(stem); 670 if (bcmp(stem, name, i) != 0) 671 return (0); 672 if (!isdigit(name[i])) 673 return (0); 674 u = 0; 675 if (name[i] == '0' && isdigit(name[i+1])) 676 return (0); 677 while (isdigit(name[i])) { 678 u *= 10; 679 u += name[i++] - '0'; 680 } 681 if (u > 0xffffff) 682 return (0); 683 *unit = u; 684 if (namep) 685 *namep = &name[i]; 686 if (name[i]) 687 return (2); 688 return (1); 689} 690 691/* 692 * Helper functions for cloning device drivers. 693 * 694 * The objective here is to make it unnecessary for the device drivers to 695 * use rman or similar to manage their unit number space. Due to the way 696 * we do "on-demand" devices, using rman or other "private" methods 697 * will be very tricky to lock down properly once we lock down this file. 698 * 699 * Instead we give the drivers these routines which puts the struct cdev *'s 700 * that are to be managed on their own list, and gives the driver the ability 701 * to ask for the first free unit number or a given specified unit number. 702 * 703 * In addition these routines support paired devices (pty, nmdm and similar) 704 * by respecting a number of "flag" bits in the minor number. 705 * 706 */ 707 708struct clonedevs { 709 LIST_HEAD(,cdev) head; 710}; 711 712void 713clone_setup(struct clonedevs **cdp) 714{ 715 716 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 717 LIST_INIT(&(*cdp)->head); 718} 719 720int 721clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, u_int extra) 722{ 723 struct clonedevs *cd; 724 struct cdev *dev, *dl, *de; 725 int unit, low, u; 726 727 KASSERT(*cdp != NULL, 728 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 729 KASSERT(!(extra & CLONE_UNITMASK), 730 ("Illegal extra bits (0x%x) in clone_create", extra)); 731 KASSERT(*up <= CLONE_UNITMASK, 732 ("Too high unit (0x%x) in clone_create", *up)); 733 734 if (csw->d_maj == MAJOR_AUTO) 735 find_major(csw); 736 737 /* 738 * Search the list for a lot of things in one go: 739 * A preexisting match is returned immediately. 740 * The lowest free unit number if we are passed -1, and the place 741 * in the list where we should insert that new element. 742 * The place to insert a specified unit number, if applicable 743 * the end of the list. 744 */ 745 unit = *up; 746 low = extra; 747 de = dl = NULL; 748 cd = *cdp; 749 LIST_FOREACH(dev, &cd->head, si_clone) { 750 u = dev2unit(dev); 751 if (u == (unit | extra)) { 752 *dp = dev; 753 return (0); 754 } 755 if (unit == -1 && u == low) { 756 low++; 757 de = dev; 758 continue; 759 } 760 if (u > (unit | extra)) { 761 dl = dev; 762 break; 763 } 764 de = dev; 765 } 766 if (unit == -1) 767 unit = low & CLONE_UNITMASK; 768 dev = newdev(csw->d_maj, unit2minor(unit | extra)); 769 KASSERT(!(dev->si_flags & SI_CLONELIST), 770 ("Dev %p should not be on clonelist", dev)); 771 if (dl != NULL) 772 LIST_INSERT_BEFORE(dl, dev, si_clone); 773 else if (de != NULL) 774 LIST_INSERT_AFTER(de, dev, si_clone); 775 else 776 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 777 dev->si_flags |= SI_CLONELIST; 778 *up = unit; 779 return (1); 780} 781 782/* 783 * Kill everything still on the list. The driver should already have 784 * disposed of any softc hung of the struct cdev *'s at this time. 785 */ 786void 787clone_cleanup(struct clonedevs **cdp) 788{ 789 struct cdev *dev, *tdev; 790 struct clonedevs *cd; 791 792 cd = *cdp; 793 if (cd == NULL) 794 return; 795 LIST_FOREACH_SAFE(dev, &cd->head, si_clone, tdev) { 796 KASSERT(dev->si_flags & SI_NAMED, 797 ("Driver has goofed in cloning underways udev %x", dev->si_udev)); 798 destroy_dev(dev); 799 } 800 free(cd, M_DEVBUF); 801 *cdp = NULL; 802} 803 804/* 805 * Helper sysctl for devname(3). We're given a struct cdev * and return 806 * the name, if any, registered by the device driver. 807 */ 808static int 809sysctl_devname(SYSCTL_HANDLER_ARGS) 810{ 811 int error; 812 dev_t ud; 813 struct cdev *dev; 814 815 error = SYSCTL_IN(req, &ud, sizeof (ud)); 816 if (error) 817 return (error); 818 if (ud == NODEV) 819 return(EINVAL); 820 dev = findcdev(ud); 821 if (dev == NULL) 822 error = ENOENT; 823 else 824 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1); 825 return (error); 826} 827 828SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY, 829 NULL, 0, sysctl_devname, "", "devname(3) handler"); 830