kern_conf.c revision 142724
1132451Sroberto/*- 2132451Sroberto * Copyright (c) 1999-2002 Poul-Henning Kamp 3132451Sroberto * All rights reserved. 4132451Sroberto * 5132451Sroberto * Redistribution and use in source and binary forms, with or without 6132451Sroberto * modification, are permitted provided that the following conditions 7132451Sroberto * are met: 8132451Sroberto * 1. Redistributions of source code must retain the above copyright 9132451Sroberto * notice, this list of conditions and the following disclaimer. 10132451Sroberto * 2. Redistributions in binary form must reproduce the above copyright 11132451Sroberto * notice, this list of conditions and the following disclaimer in the 12132451Sroberto * documentation and/or other materials provided with the distribution. 13132451Sroberto * 14132451Sroberto * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15132451Sroberto * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16132451Sroberto * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17132451Sroberto * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18132451Sroberto * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19132451Sroberto * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20132451Sroberto * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21132451Sroberto * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22132451Sroberto * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23132451Sroberto * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24132451Sroberto * SUCH DAMAGE. 25132451Sroberto */ 26132451Sroberto 27132451Sroberto#include <sys/cdefs.h> 28132451Sroberto__FBSDID("$FreeBSD: head/sys/kern/kern_conf.c 142724 2005-02-27 22:41:07Z phk $"); 29132451Sroberto 30132451Sroberto#include <sys/param.h> 31132451Sroberto#include <sys/kernel.h> 32132451Sroberto#include <sys/systm.h> 33132451Sroberto#include <sys/bio.h> 34132451Sroberto#include <sys/lock.h> 35132451Sroberto#include <sys/mutex.h> 36132451Sroberto#include <sys/sysctl.h> 37132451Sroberto#include <sys/module.h> 38132451Sroberto#include <sys/malloc.h> 39132451Sroberto#include <sys/conf.h> 40132451Sroberto#include <sys/vnode.h> 41132451Sroberto#include <sys/queue.h> 42132451Sroberto#include <sys/poll.h> 43132451Sroberto#include <sys/ctype.h> 44132451Sroberto#include <sys/tty.h> 45132451Sroberto#include <machine/stdarg.h> 46132451Sroberto 47132451Srobertostatic MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage"); 48132451Sroberto 49132451Sroberto/* Built at compile time from sys/conf/majors */ 50132451Srobertoextern unsigned char reserved_majors[256]; 51132451Sroberto 52132451Sroberto/* 53132451Sroberto * This is the number of hash-buckets. Experiments with 'real-life' 54132451Sroberto * dev_t's show that a prime halfway between two powers of two works 55132451Sroberto * best. 56132451Sroberto */ 57132451Sroberto#define DEVT_HASH 83 58132451Sroberto 59132451Srobertostatic LIST_HEAD(, cdev) dev_hash[DEVT_HASH]; 60132451Sroberto 61132451Srobertostatic struct mtx devmtx; 62132451Srobertostatic void freedev(struct cdev *dev); 63132451Srobertostatic struct cdev *newdev(int x, int y, struct cdev *); 64132451Srobertostatic void destroy_devl(struct cdev *dev); 65132451Sroberto 66132451Srobertovoid 67132451Srobertodev_lock(void) 68132451Sroberto{ 69132451Sroberto if (!mtx_initialized(&devmtx)) 70132451Sroberto mtx_init(&devmtx, "cdev", NULL, MTX_DEF); 71 mtx_lock(&devmtx); 72} 73 74void 75dev_unlock(void) 76{ 77 78 mtx_unlock(&devmtx); 79} 80 81void 82dev_ref(struct cdev *dev) 83{ 84 85 mtx_assert(&devmtx, MA_OWNED); 86 dev->si_refcount++; 87} 88 89void 90dev_rel(struct cdev *dev) 91{ 92 int flag = 0; 93 94 mtx_assert(&devmtx, MA_NOTOWNED); 95 dev_lock(); 96 dev->si_refcount--; 97 KASSERT(dev->si_refcount >= 0, 98 ("dev_rel(%s) gave negative count", devtoname(dev))); 99 if (dev->si_usecount == 0 && 100 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED)) 101 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 102 LIST_REMOVE(dev, si_list); 103 flag = 1; 104 } 105 dev_unlock(); 106 if (flag) 107 freedev(dev); 108} 109 110struct cdevsw * 111dev_refthread(struct cdev *dev) 112{ 113 struct cdevsw *csw; 114 115 mtx_assert(&devmtx, MA_NOTOWNED); 116 dev_lock(); 117 csw = dev->si_devsw; 118 if (csw != NULL) 119 dev->si_threadcount++; 120 dev_unlock(); 121 return (csw); 122} 123 124void 125dev_relthread(struct cdev *dev) 126{ 127 128 mtx_assert(&devmtx, MA_NOTOWNED); 129 dev_lock(); 130 dev->si_threadcount--; 131 dev_unlock(); 132} 133 134int 135nullop(void) 136{ 137 138 return (0); 139} 140 141int 142eopnotsupp(void) 143{ 144 145 return (EOPNOTSUPP); 146} 147 148static int 149enxio(void) 150{ 151 return (ENXIO); 152} 153 154static int 155enodev(void) 156{ 157 return (ENODEV); 158} 159 160/* Define a dead_cdevsw for use when devices leave unexpectedly. */ 161 162#define dead_open (d_open_t *)enxio 163#define dead_close (d_close_t *)enxio 164#define dead_read (d_read_t *)enxio 165#define dead_write (d_write_t *)enxio 166#define dead_ioctl (d_ioctl_t *)enxio 167#define dead_poll (d_poll_t *)enodev 168#define dead_mmap (d_mmap_t *)enodev 169 170static void 171dead_strategy(struct bio *bp) 172{ 173 174 biofinish(bp, NULL, ENXIO); 175} 176 177#define dead_dump (dumper_t *)enxio 178#define dead_kqfilter (d_kqfilter_t *)enxio 179 180static struct cdevsw dead_cdevsw = { 181 .d_version = D_VERSION, 182 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 183 .d_open = dead_open, 184 .d_close = dead_close, 185 .d_read = dead_read, 186 .d_write = dead_write, 187 .d_ioctl = dead_ioctl, 188 .d_poll = dead_poll, 189 .d_mmap = dead_mmap, 190 .d_strategy = dead_strategy, 191 .d_name = "dead", 192 .d_maj = 255, 193 .d_dump = dead_dump, 194 .d_kqfilter = dead_kqfilter 195}; 196 197/* Default methods if driver does not specify method */ 198 199#define null_open (d_open_t *)nullop 200#define null_close (d_close_t *)nullop 201#define no_read (d_read_t *)enodev 202#define no_write (d_write_t *)enodev 203#define no_ioctl (d_ioctl_t *)enodev 204#define no_mmap (d_mmap_t *)enodev 205#define no_kqfilter (d_kqfilter_t *)enodev 206 207static void 208no_strategy(struct bio *bp) 209{ 210 211 biofinish(bp, NULL, ENODEV); 212} 213 214static int 215no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 216{ 217 /* 218 * Return true for read/write. If the user asked for something 219 * special, return POLLNVAL, so that clients have a way of 220 * determining reliably whether or not the extended 221 * functionality is present without hard-coding knowledge 222 * of specific filesystem implementations. 223 * Stay in sync with vop_nopoll(). 224 */ 225 if (events & ~POLLSTANDARD) 226 return (POLLNVAL); 227 228 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 229} 230 231#define no_dump (dumper_t *)enodev 232 233/* 234 * struct cdev * and u_dev_t primitives 235 */ 236 237int 238major(struct cdev *x) 239{ 240 if (x == NULL) 241 return NODEV; 242 return((x->si_udev >> 8) & 0xff); 243} 244 245int 246minor(struct cdev *x) 247{ 248 if (x == NULL) 249 return NODEV; 250 return(x->si_udev & MAXMINOR); 251} 252 253int 254dev2unit(struct cdev *x) 255{ 256 257 if (x == NULL) 258 return NODEV; 259 return (minor2unit(minor(x))); 260} 261 262int 263minor2unit(int _minor) 264{ 265 266 KASSERT((_minor & ~MAXMINOR) == 0, ("Illegal minor %x", _minor)); 267 return ((_minor & 0xff) | (_minor >> 8)); 268} 269 270int 271unit2minor(int unit) 272{ 273 274 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); 275 return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 276} 277 278static struct cdev * 279allocdev(void) 280{ 281 struct cdev *si; 282 283 si = malloc(sizeof *si, M_DEVT, M_USE_RESERVE | M_ZERO | M_WAITOK); 284 si->si_name = si->__si_namebuf; 285 LIST_INIT(&si->si_children); 286 LIST_INIT(&si->si_alist); 287 return (si); 288} 289 290static struct cdev * 291newdev(int x, int y, struct cdev *si) 292{ 293 struct cdev *si2; 294 dev_t udev; 295 int hash; 296 297 mtx_assert(&devmtx, MA_OWNED); 298 if (x == umajor(NODEV) && y == uminor(NODEV)) 299 panic("newdev of NODEV"); 300 udev = (x << 8) | y; 301 hash = udev % DEVT_HASH; 302 LIST_FOREACH(si2, &dev_hash[hash], si_hash) { 303 if (si2->si_udev == udev) { 304 freedev(si); 305 return (si2); 306 } 307 } 308 si->si_udev = udev; 309 LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 310 return (si); 311} 312 313static void 314freedev(struct cdev *dev) 315{ 316 317 free(dev, M_DEVT); 318} 319 320dev_t 321dev2udev(struct cdev *x) 322{ 323 if (x == NULL) 324 return (NODEV); 325 return (x->si_udev); 326} 327 328struct cdev * 329findcdev(dev_t udev) 330{ 331 struct cdev *si; 332 int hash; 333 334 mtx_assert(&devmtx, MA_NOTOWNED); 335 if (udev == NODEV) 336 return (NULL); 337 dev_lock(); 338 hash = udev % DEVT_HASH; 339 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 340 if (si->si_udev == udev) 341 break; 342 } 343 dev_unlock(); 344 return (si); 345} 346 347int 348uminor(dev_t dev) 349{ 350 return (dev & MAXMINOR); 351} 352 353int 354umajor(dev_t dev) 355{ 356 return ((dev & ~MAXMINOR) >> 8); 357} 358 359static void 360find_major(struct cdevsw *devsw) 361{ 362 int i; 363 364 for (i = NUMCDEVSW - 1; i > 0; i--) 365 if (reserved_majors[i] != i) 366 break; 367 KASSERT(i > 0, ("Out of major numbers (%s)", devsw->d_name)); 368 devsw->d_maj = i; 369 reserved_majors[i] = i; 370 devsw->d_flags |= D_ALLOCMAJ; 371} 372 373static void 374fini_cdevsw(struct cdevsw *devsw) 375{ 376 if (devsw->d_flags & D_ALLOCMAJ) { 377 reserved_majors[devsw->d_maj] = 0; 378 devsw->d_maj = MAJOR_AUTO; 379 devsw->d_flags &= ~D_ALLOCMAJ; 380 } 381 devsw->d_flags &= ~D_INIT; 382} 383 384static void 385prep_cdevsw(struct cdevsw *devsw) 386{ 387 388 dev_lock(); 389 390 if (devsw->d_version != D_VERSION_00) { 391 printf( 392 "WARNING: Device driver \"%s\" has wrong version %s\n", 393 devsw->d_name, "and is disabled. Recompile KLD module."); 394 devsw->d_open = dead_open; 395 devsw->d_close = dead_close; 396 devsw->d_read = dead_read; 397 devsw->d_write = dead_write; 398 devsw->d_ioctl = dead_ioctl; 399 devsw->d_poll = dead_poll; 400 devsw->d_mmap = dead_mmap; 401 devsw->d_strategy = dead_strategy; 402 devsw->d_dump = dead_dump; 403 devsw->d_kqfilter = dead_kqfilter; 404 } 405 406 if (devsw->d_flags & D_TTY) { 407 if (devsw->d_ioctl == NULL) devsw->d_ioctl = ttyioctl; 408 if (devsw->d_read == NULL) devsw->d_read = ttyread; 409 if (devsw->d_write == NULL) devsw->d_write = ttywrite; 410 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = ttykqfilter; 411 if (devsw->d_poll == NULL) devsw->d_poll = ttypoll; 412 } 413 414 if (devsw->d_open == NULL) devsw->d_open = null_open; 415 if (devsw->d_close == NULL) devsw->d_close = null_close; 416 if (devsw->d_read == NULL) devsw->d_read = no_read; 417 if (devsw->d_write == NULL) devsw->d_write = no_write; 418 if (devsw->d_ioctl == NULL) devsw->d_ioctl = no_ioctl; 419 if (devsw->d_poll == NULL) devsw->d_poll = no_poll; 420 if (devsw->d_mmap == NULL) devsw->d_mmap = no_mmap; 421 if (devsw->d_strategy == NULL) devsw->d_strategy = no_strategy; 422 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 423 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = no_kqfilter; 424 425 LIST_INIT(&devsw->d_devs); 426 427 devsw->d_flags |= D_INIT; 428 429 if (devsw->d_maj != MAJOR_AUTO) { 430 printf("NOTICE: Ignoring d_maj hint from driver \"%s\", %s", 431 devsw->d_name, "driver should be updated/fixed\n"); 432 devsw->d_maj = MAJOR_AUTO; 433 } 434 find_major(devsw); 435 dev_unlock(); 436} 437 438struct cdev * 439make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int perms, const char *fmt, ...) 440{ 441 struct cdev *dev; 442 va_list ap; 443 int i; 444 445 KASSERT((minornr & ~MAXMINOR) == 0, 446 ("Invalid minor (0x%x) in make_dev", minornr)); 447 448 if (!(devsw->d_flags & D_INIT)) 449 prep_cdevsw(devsw); 450 dev = allocdev(); 451 dev_lock(); 452 dev = newdev(devsw->d_maj, minornr, dev); 453 if (dev->si_flags & SI_CHEAPCLONE && 454 dev->si_flags & SI_NAMED && 455 dev->si_devsw == devsw) { 456 /* 457 * This is allowed as it removes races and generally 458 * simplifies cloning devices. 459 * XXX: still ?? 460 */ 461 dev_unlock(); 462 return (dev); 463 } 464 KASSERT(!(dev->si_flags & SI_NAMED), 465 ("make_dev() by driver %s on pre-existing device (maj=%d, min=%d, name=%s)", 466 devsw->d_name, major(dev), minor(dev), devtoname(dev))); 467 468 va_start(ap, fmt); 469 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 470 if (i > (sizeof dev->__si_namebuf - 1)) { 471 printf("WARNING: Device name truncated! (%s)\n", 472 dev->__si_namebuf); 473 } 474 va_end(ap); 475 476 dev->si_devsw = devsw; 477 dev->si_uid = uid; 478 dev->si_gid = gid; 479 dev->si_mode = perms; 480 dev->si_flags |= SI_NAMED; 481 482 LIST_INSERT_HEAD(&devsw->d_devs, dev, si_list); 483 devfs_create(dev); 484 dev_unlock(); 485 return (dev); 486} 487 488int 489dev_named(struct cdev *pdev, const char *name) 490{ 491 struct cdev *cdev; 492 493 if (strcmp(devtoname(pdev), name) == 0) 494 return (1); 495 LIST_FOREACH(cdev, &pdev->si_children, si_siblings) 496 if (strcmp(devtoname(cdev), name) == 0) 497 return (1); 498 return (0); 499} 500 501void 502dev_depends(struct cdev *pdev, struct cdev *cdev) 503{ 504 505 dev_lock(); 506 cdev->si_parent = pdev; 507 cdev->si_flags |= SI_CHILD; 508 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 509 dev_unlock(); 510} 511 512struct cdev * 513make_dev_alias(struct cdev *pdev, const char *fmt, ...) 514{ 515 struct cdev *dev; 516 va_list ap; 517 int i; 518 519 dev = allocdev(); 520 dev_lock(); 521 dev->si_flags |= SI_ALIAS; 522 dev->si_flags |= SI_NAMED; 523 va_start(ap, fmt); 524 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 525 if (i > (sizeof dev->__si_namebuf - 1)) { 526 printf("WARNING: Device name truncated! (%s)\n", 527 dev->__si_namebuf); 528 } 529 va_end(ap); 530 531 devfs_create(dev); 532 dev_unlock(); 533 dev_depends(pdev, dev); 534 return (dev); 535} 536 537static void 538destroy_devl(struct cdev *dev) 539{ 540 struct cdevsw *csw; 541 542 mtx_assert(&devmtx, MA_OWNED); 543 KASSERT(dev->si_flags & SI_NAMED, 544 ("WARNING: Driver mistake: destroy_dev on %d/%d\n", 545 major(dev), minor(dev))); 546 547 devfs_destroy(dev); 548 549 /* Remove name marking */ 550 dev->si_flags &= ~SI_NAMED; 551 552 /* If we are a child, remove us from the parents list */ 553 if (dev->si_flags & SI_CHILD) { 554 LIST_REMOVE(dev, si_siblings); 555 dev->si_flags &= ~SI_CHILD; 556 } 557 558 /* Kill our children */ 559 while (!LIST_EMPTY(&dev->si_children)) 560 destroy_devl(LIST_FIRST(&dev->si_children)); 561 562 /* Remove from clone list */ 563 if (dev->si_flags & SI_CLONELIST) { 564 LIST_REMOVE(dev, si_clone); 565 dev->si_flags &= ~SI_CLONELIST; 566 } 567 568 csw = dev->si_devsw; 569 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 570 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 571 printf("Purging %lu threads from %s\n", 572 dev->si_threadcount, devtoname(dev)); 573 csw->d_purge(dev); 574 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 575 } 576 if (csw != NULL && csw->d_purge != NULL) 577 printf("All threads purged from %s\n", devtoname(dev)); 578 579 dev->si_drv1 = 0; 580 dev->si_drv2 = 0; 581 bzero(&dev->__si_u, sizeof(dev->__si_u)); 582 583 if (!(dev->si_flags & SI_ALIAS)) { 584 /* Remove from cdevsw list */ 585 LIST_REMOVE(dev, si_list); 586 587 /* If cdevsw has no struct cdev *'s, clean it */ 588 if (LIST_EMPTY(&csw->d_devs)) 589 fini_cdevsw(csw); 590 591 LIST_REMOVE(dev, si_hash); 592 } 593 dev->si_flags &= ~SI_ALIAS; 594 595 if (dev->si_refcount > 0) { 596 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 597 } else { 598 freedev(dev); 599 } 600} 601 602void 603destroy_dev(struct cdev *dev) 604{ 605 606 dev_lock(); 607 destroy_devl(dev); 608 dev_unlock(); 609} 610 611const char * 612devtoname(struct cdev *dev) 613{ 614 char *p; 615 struct cdevsw *csw; 616 int mynor; 617 618 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 619 p = dev->si_name; 620 sprintf(p, "#%d", major(dev)); 621 p += strlen(p); 622 csw = dev_refthread(dev); 623 if (csw != NULL) { 624 sprintf(p, "(%s)", csw->d_name); 625 dev_relthread(dev); 626 } 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 637int 638dev_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] == '0' && isdigit(name[i+1])) 649 return (0); 650 while (isdigit(name[i])) { 651 u *= 10; 652 u += name[i++] - '0'; 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 681struct clonedevs { 682 LIST_HEAD(,cdev) head; 683}; 684 685void 686clone_setup(struct clonedevs **cdp) 687{ 688 689 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 690 LIST_INIT(&(*cdp)->head); 691} 692 693int 694clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, u_int extra) 695{ 696 struct clonedevs *cd; 697 struct cdev *dev, *ndev, *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 ndev = allocdev(); 720 dev_lock(); 721 low = extra; 722 de = dl = NULL; 723 cd = *cdp; 724 LIST_FOREACH(dev, &cd->head, si_clone) { 725 KASSERT(dev->si_flags & SI_CLONELIST, 726 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 727 u = dev2unit(dev); 728 if (u == (unit | extra)) { 729 *dp = dev; 730 freedev(ndev); 731 dev_unlock(); 732 return (0); 733 } 734 if (unit == -1 && u == low) { 735 low++; 736 de = dev; 737 continue; 738 } 739 if (u > (unit | extra)) { 740 dl = dev; 741 break; 742 } 743 } 744 if (unit == -1) 745 unit = low & CLONE_UNITMASK; 746 dev = newdev(csw->d_maj, unit2minor(unit | extra), ndev); 747 if (dev->si_flags & SI_CLONELIST) { 748 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 749 printf("unit=%d\n", unit); 750 LIST_FOREACH(dev, &cd->head, si_clone) { 751 printf("\t%p %s\n", dev, dev->si_name); 752 } 753 panic("foo"); 754 } 755 KASSERT(!(dev->si_flags & SI_CLONELIST), 756 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 757 if (dl != NULL) 758 LIST_INSERT_BEFORE(dl, dev, si_clone); 759 else if (de != NULL) 760 LIST_INSERT_AFTER(de, dev, si_clone); 761 else 762 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 763 dev->si_flags |= SI_CLONELIST; 764 *up = unit; 765 dev_unlock(); 766 return (1); 767} 768 769/* 770 * Kill everything still on the list. The driver should already have 771 * disposed of any softc hung of the struct cdev *'s at this time. 772 */ 773void 774clone_cleanup(struct clonedevs **cdp) 775{ 776 struct cdev *dev, *tdev; 777 struct clonedevs *cd; 778 779 cd = *cdp; 780 if (cd == NULL) 781 return; 782 dev_lock(); 783 LIST_FOREACH_SAFE(dev, &cd->head, si_clone, tdev) { 784 KASSERT(dev->si_flags & SI_CLONELIST, 785 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 786 KASSERT(dev->si_flags & SI_NAMED, 787 ("Driver has goofed in cloning underways udev %x", dev->si_udev)); 788 destroy_devl(dev); 789 } 790 dev_unlock(); 791 free(cd, M_DEVBUF); 792 *cdp = NULL; 793} 794 795/* 796 * Helper sysctl for devname(3). We're given a struct cdev * and return 797 * the name, if any, registered by the device driver. 798 */ 799static int 800sysctl_devname(SYSCTL_HANDLER_ARGS) 801{ 802 int error; 803 dev_t ud; 804 struct cdev *dev; 805 806 error = SYSCTL_IN(req, &ud, sizeof (ud)); 807 if (error) 808 return (error); 809 if (ud == NODEV) 810 return(EINVAL); 811 dev = findcdev(ud); 812 if (dev == NULL) 813 error = ENOENT; 814 else 815 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1); 816 return (error); 817} 818 819SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY, 820 NULL, 0, sysctl_devname, "", "devname(3) handler"); 821