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