kern_conf.c revision 191116
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 191116 2009-04-15 20:15:36Z ed $"); 29 30#include <sys/param.h> 31#include <sys/kernel.h> 32#include <sys/systm.h> 33#include <sys/bus.h> 34#include <sys/bio.h> 35#include <sys/lock.h> 36#include <sys/mutex.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/sx.h> 44#include <sys/ctype.h> 45#include <sys/ucred.h> 46#include <sys/taskqueue.h> 47#include <machine/stdarg.h> 48 49#include <fs/devfs/devfs_int.h> 50 51static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage"); 52 53struct mtx devmtx; 54static void destroy_devl(struct cdev *dev); 55static int destroy_dev_sched_cbl(struct cdev *dev, 56 void (*cb)(void *), void *arg); 57static struct cdev *make_dev_credv(int flags, 58 struct cdevsw *devsw, int unit, 59 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, 60 va_list ap); 61 62static struct cdev_priv_list cdevp_free_list = 63 TAILQ_HEAD_INITIALIZER(cdevp_free_list); 64static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list = 65 SLIST_HEAD_INITIALIZER(); 66 67void 68dev_lock(void) 69{ 70 71 mtx_lock(&devmtx); 72} 73 74/* 75 * Free all the memory collected while the cdev mutex was 76 * locked. Since devmtx is after the system map mutex, free() cannot 77 * be called immediately and is postponed until cdev mutex can be 78 * dropped. 79 */ 80static void 81dev_unlock_and_free(void) 82{ 83 struct cdev_priv_list cdp_free; 84 struct free_cdevsw csw_free; 85 struct cdev_priv *cdp; 86 struct cdevsw *csw; 87 88 mtx_assert(&devmtx, MA_OWNED); 89 90 /* 91 * Make the local copy of the list heads while the dev_mtx is 92 * held. Free it later. 93 */ 94 TAILQ_INIT(&cdp_free); 95 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list); 96 csw_free = cdevsw_gt_post_list; 97 SLIST_INIT(&cdevsw_gt_post_list); 98 99 mtx_unlock(&devmtx); 100 101 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) { 102 TAILQ_REMOVE(&cdp_free, cdp, cdp_list); 103 devfs_free(&cdp->cdp_c); 104 } 105 while ((csw = SLIST_FIRST(&csw_free)) != NULL) { 106 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list); 107 free(csw, M_DEVT); 108 } 109} 110 111static void 112dev_free_devlocked(struct cdev *cdev) 113{ 114 struct cdev_priv *cdp; 115 116 mtx_assert(&devmtx, MA_OWNED); 117 cdp = cdev2priv(cdev); 118 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list); 119} 120 121static void 122cdevsw_free_devlocked(struct cdevsw *csw) 123{ 124 125 mtx_assert(&devmtx, MA_OWNED); 126 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list); 127} 128 129void 130dev_unlock(void) 131{ 132 133 mtx_unlock(&devmtx); 134} 135 136void 137dev_ref(struct cdev *dev) 138{ 139 140 mtx_assert(&devmtx, MA_NOTOWNED); 141 mtx_lock(&devmtx); 142 dev->si_refcount++; 143 mtx_unlock(&devmtx); 144} 145 146void 147dev_refl(struct cdev *dev) 148{ 149 150 mtx_assert(&devmtx, MA_OWNED); 151 dev->si_refcount++; 152} 153 154void 155dev_rel(struct cdev *dev) 156{ 157 int flag = 0; 158 159 mtx_assert(&devmtx, MA_NOTOWNED); 160 dev_lock(); 161 dev->si_refcount--; 162 KASSERT(dev->si_refcount >= 0, 163 ("dev_rel(%s) gave negative count", devtoname(dev))); 164#if 0 165 if (dev->si_usecount == 0 && 166 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED)) 167 ; 168 else 169#endif 170 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 171 LIST_REMOVE(dev, si_list); 172 flag = 1; 173 } 174 dev_unlock(); 175 if (flag) 176 devfs_free(dev); 177} 178 179struct cdevsw * 180dev_refthread(struct cdev *dev) 181{ 182 struct cdevsw *csw; 183 struct cdev_priv *cdp; 184 185 mtx_assert(&devmtx, MA_NOTOWNED); 186 dev_lock(); 187 csw = dev->si_devsw; 188 if (csw != NULL) { 189 cdp = cdev2priv(dev); 190 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) 191 dev->si_threadcount++; 192 else 193 csw = NULL; 194 } 195 dev_unlock(); 196 return (csw); 197} 198 199struct cdevsw * 200devvn_refthread(struct vnode *vp, struct cdev **devp) 201{ 202 struct cdevsw *csw; 203 struct cdev_priv *cdp; 204 205 mtx_assert(&devmtx, MA_NOTOWNED); 206 csw = NULL; 207 dev_lock(); 208 *devp = vp->v_rdev; 209 if (*devp != NULL) { 210 cdp = cdev2priv(*devp); 211 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) { 212 csw = (*devp)->si_devsw; 213 if (csw != NULL) 214 (*devp)->si_threadcount++; 215 } 216 } 217 dev_unlock(); 218 return (csw); 219} 220 221void 222dev_relthread(struct cdev *dev) 223{ 224 225 mtx_assert(&devmtx, MA_NOTOWNED); 226 dev_lock(); 227 KASSERT(dev->si_threadcount > 0, 228 ("%s threadcount is wrong", dev->si_name)); 229 dev->si_threadcount--; 230 dev_unlock(); 231} 232 233int 234nullop(void) 235{ 236 237 return (0); 238} 239 240int 241eopnotsupp(void) 242{ 243 244 return (EOPNOTSUPP); 245} 246 247static int 248enxio(void) 249{ 250 return (ENXIO); 251} 252 253static int 254enodev(void) 255{ 256 return (ENODEV); 257} 258 259/* Define a dead_cdevsw for use when devices leave unexpectedly. */ 260 261#define dead_open (d_open_t *)enxio 262#define dead_close (d_close_t *)enxio 263#define dead_read (d_read_t *)enxio 264#define dead_write (d_write_t *)enxio 265#define dead_ioctl (d_ioctl_t *)enxio 266#define dead_poll (d_poll_t *)enodev 267#define dead_mmap (d_mmap_t *)enodev 268 269static void 270dead_strategy(struct bio *bp) 271{ 272 273 biofinish(bp, NULL, ENXIO); 274} 275 276#define dead_dump (dumper_t *)enxio 277#define dead_kqfilter (d_kqfilter_t *)enxio 278 279static struct cdevsw dead_cdevsw = { 280 .d_version = D_VERSION, 281 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 282 .d_open = dead_open, 283 .d_close = dead_close, 284 .d_read = dead_read, 285 .d_write = dead_write, 286 .d_ioctl = dead_ioctl, 287 .d_poll = dead_poll, 288 .d_mmap = dead_mmap, 289 .d_strategy = dead_strategy, 290 .d_name = "dead", 291 .d_dump = dead_dump, 292 .d_kqfilter = dead_kqfilter 293}; 294 295/* Default methods if driver does not specify method */ 296 297#define null_open (d_open_t *)nullop 298#define null_close (d_close_t *)nullop 299#define no_read (d_read_t *)enodev 300#define no_write (d_write_t *)enodev 301#define no_ioctl (d_ioctl_t *)enodev 302#define no_mmap (d_mmap_t *)enodev 303#define no_kqfilter (d_kqfilter_t *)enodev 304 305static void 306no_strategy(struct bio *bp) 307{ 308 309 biofinish(bp, NULL, ENODEV); 310} 311 312static int 313no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 314{ 315 316 return (poll_no_poll(events)); 317} 318 319#define no_dump (dumper_t *)enodev 320 321static int 322giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 323{ 324 struct cdevsw *dsw; 325 int retval; 326 327 dsw = dev_refthread(dev); 328 if (dsw == NULL) 329 return (ENXIO); 330 mtx_lock(&Giant); 331 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td); 332 mtx_unlock(&Giant); 333 dev_relthread(dev); 334 return (retval); 335} 336 337static int 338giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp) 339{ 340 struct cdevsw *dsw; 341 int retval; 342 343 dsw = dev_refthread(dev); 344 if (dsw == NULL) 345 return (ENXIO); 346 mtx_lock(&Giant); 347 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp); 348 mtx_unlock(&Giant); 349 dev_relthread(dev); 350 return (retval); 351} 352 353static int 354giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 355{ 356 struct cdevsw *dsw; 357 int retval; 358 359 dsw = dev_refthread(dev); 360 if (dsw == NULL) 361 return (ENXIO); 362 mtx_lock(&Giant); 363 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td); 364 mtx_unlock(&Giant); 365 dev_relthread(dev); 366 return (retval); 367} 368 369static void 370giant_strategy(struct bio *bp) 371{ 372 struct cdevsw *dsw; 373 struct cdev *dev; 374 375 dev = bp->bio_dev; 376 dsw = dev_refthread(dev); 377 if (dsw == NULL) { 378 biofinish(bp, NULL, ENXIO); 379 return; 380 } 381 mtx_lock(&Giant); 382 dsw->d_gianttrick->d_strategy(bp); 383 mtx_unlock(&Giant); 384 dev_relthread(dev); 385} 386 387static int 388giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 389{ 390 struct cdevsw *dsw; 391 int retval; 392 393 dsw = dev_refthread(dev); 394 if (dsw == NULL) 395 return (ENXIO); 396 mtx_lock(&Giant); 397 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td); 398 mtx_unlock(&Giant); 399 dev_relthread(dev); 400 return (retval); 401} 402 403static int 404giant_read(struct cdev *dev, struct uio *uio, int ioflag) 405{ 406 struct cdevsw *dsw; 407 int retval; 408 409 dsw = dev_refthread(dev); 410 if (dsw == NULL) 411 return (ENXIO); 412 mtx_lock(&Giant); 413 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag); 414 mtx_unlock(&Giant); 415 dev_relthread(dev); 416 return (retval); 417} 418 419static int 420giant_write(struct cdev *dev, struct uio *uio, int ioflag) 421{ 422 struct cdevsw *dsw; 423 int retval; 424 425 dsw = dev_refthread(dev); 426 if (dsw == NULL) 427 return (ENXIO); 428 mtx_lock(&Giant); 429 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag); 430 mtx_unlock(&Giant); 431 dev_relthread(dev); 432 return (retval); 433} 434 435static int 436giant_poll(struct cdev *dev, int events, struct thread *td) 437{ 438 struct cdevsw *dsw; 439 int retval; 440 441 dsw = dev_refthread(dev); 442 if (dsw == NULL) 443 return (ENXIO); 444 mtx_lock(&Giant); 445 retval = dsw->d_gianttrick->d_poll(dev, events, td); 446 mtx_unlock(&Giant); 447 dev_relthread(dev); 448 return (retval); 449} 450 451static int 452giant_kqfilter(struct cdev *dev, struct knote *kn) 453{ 454 struct cdevsw *dsw; 455 int retval; 456 457 dsw = dev_refthread(dev); 458 if (dsw == NULL) 459 return (ENXIO); 460 mtx_lock(&Giant); 461 retval = dsw->d_gianttrick->d_kqfilter(dev, kn); 462 mtx_unlock(&Giant); 463 dev_relthread(dev); 464 return (retval); 465} 466 467static int 468giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot) 469{ 470 struct cdevsw *dsw; 471 int retval; 472 473 dsw = dev_refthread(dev); 474 if (dsw == NULL) 475 return (ENXIO); 476 mtx_lock(&Giant); 477 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot); 478 mtx_unlock(&Giant); 479 dev_relthread(dev); 480 return (retval); 481} 482 483 484static void 485notify(struct cdev *dev, const char *ev) 486{ 487 static const char prefix[] = "cdev="; 488 char *data; 489 int namelen; 490 491 if (cold) 492 return; 493 namelen = strlen(dev->si_name); 494 data = malloc(namelen + sizeof(prefix), M_TEMP, M_WAITOK); 495 memcpy(data, prefix, sizeof(prefix) - 1); 496 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1); 497 devctl_notify("DEVFS", "CDEV", ev, data); 498 free(data, M_TEMP); 499} 500 501static void 502notify_create(struct cdev *dev) 503{ 504 505 notify(dev, "CREATE"); 506} 507 508static void 509notify_destroy(struct cdev *dev) 510{ 511 512 notify(dev, "DESTROY"); 513} 514 515static struct cdev * 516newdev(struct cdevsw *csw, int unit, struct cdev *si) 517{ 518 struct cdev *si2; 519 520 mtx_assert(&devmtx, MA_OWNED); 521 if (csw->d_flags & D_NEEDMINOR) { 522 /* We may want to return an existing device */ 523 LIST_FOREACH(si2, &csw->d_devs, si_list) { 524 if (dev2unit(si2) == unit) { 525 dev_free_devlocked(si); 526 return (si2); 527 } 528 } 529 } 530 si->si_drv0 = unit; 531 si->si_devsw = csw; 532 LIST_INSERT_HEAD(&csw->d_devs, si, si_list); 533 return (si); 534} 535 536static void 537fini_cdevsw(struct cdevsw *devsw) 538{ 539 struct cdevsw *gt; 540 541 if (devsw->d_gianttrick != NULL) { 542 gt = devsw->d_gianttrick; 543 memcpy(devsw, gt, sizeof *devsw); 544 cdevsw_free_devlocked(gt); 545 devsw->d_gianttrick = NULL; 546 } 547 devsw->d_flags &= ~D_INIT; 548} 549 550static void 551prep_cdevsw(struct cdevsw *devsw) 552{ 553 struct cdevsw *dsw2; 554 555 mtx_assert(&devmtx, MA_OWNED); 556 if (devsw->d_flags & D_INIT) 557 return; 558 if (devsw->d_flags & D_NEEDGIANT) { 559 dev_unlock(); 560 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK); 561 dev_lock(); 562 } else 563 dsw2 = NULL; 564 if (devsw->d_flags & D_INIT) { 565 if (dsw2 != NULL) 566 cdevsw_free_devlocked(dsw2); 567 return; 568 } 569 570 if (devsw->d_version != D_VERSION_01) { 571 printf( 572 "WARNING: Device driver \"%s\" has wrong version %s\n", 573 devsw->d_name == NULL ? "???" : devsw->d_name, 574 "and is disabled. Recompile KLD module."); 575 devsw->d_open = dead_open; 576 devsw->d_close = dead_close; 577 devsw->d_read = dead_read; 578 devsw->d_write = dead_write; 579 devsw->d_ioctl = dead_ioctl; 580 devsw->d_poll = dead_poll; 581 devsw->d_mmap = dead_mmap; 582 devsw->d_strategy = dead_strategy; 583 devsw->d_dump = dead_dump; 584 devsw->d_kqfilter = dead_kqfilter; 585 } 586 587 if (devsw->d_flags & D_NEEDGIANT) { 588 if (devsw->d_gianttrick == NULL) { 589 memcpy(dsw2, devsw, sizeof *dsw2); 590 devsw->d_gianttrick = dsw2; 591 dsw2 = NULL; 592 } 593 } 594 595#define FIXUP(member, noop, giant) \ 596 do { \ 597 if (devsw->member == NULL) { \ 598 devsw->member = noop; \ 599 } else if (devsw->d_flags & D_NEEDGIANT) \ 600 devsw->member = giant; \ 601 } \ 602 while (0) 603 604 FIXUP(d_open, null_open, giant_open); 605 FIXUP(d_fdopen, NULL, giant_fdopen); 606 FIXUP(d_close, null_close, giant_close); 607 FIXUP(d_read, no_read, giant_read); 608 FIXUP(d_write, no_write, giant_write); 609 FIXUP(d_ioctl, no_ioctl, giant_ioctl); 610 FIXUP(d_poll, no_poll, giant_poll); 611 FIXUP(d_mmap, no_mmap, giant_mmap); 612 FIXUP(d_strategy, no_strategy, giant_strategy); 613 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter); 614 615 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 616 617 LIST_INIT(&devsw->d_devs); 618 619 devsw->d_flags |= D_INIT; 620 621 if (dsw2 != NULL) 622 cdevsw_free_devlocked(dsw2); 623} 624 625struct cdev * 626make_dev_credv(int flags, struct cdevsw *devsw, int unit, 627 struct ucred *cr, uid_t uid, 628 gid_t gid, int mode, const char *fmt, va_list ap) 629{ 630 struct cdev *dev; 631 int i; 632 633 dev = devfs_alloc(); 634 dev_lock(); 635 prep_cdevsw(devsw); 636 dev = newdev(devsw, unit, dev); 637 if (flags & MAKEDEV_REF) 638 dev_refl(dev); 639 if (dev->si_flags & SI_CHEAPCLONE && 640 dev->si_flags & SI_NAMED) { 641 /* 642 * This is allowed as it removes races and generally 643 * simplifies cloning devices. 644 * XXX: still ?? 645 */ 646 dev_unlock_and_free(); 647 return (dev); 648 } 649 KASSERT(!(dev->si_flags & SI_NAMED), 650 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)", 651 devsw->d_name, dev2unit(dev), devtoname(dev))); 652 653 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 654 if (i > (sizeof dev->__si_namebuf - 1)) { 655 printf("WARNING: Device name truncated! (%s)\n", 656 dev->__si_namebuf); 657 } 658 659 dev->si_flags |= SI_NAMED; 660 if (cr != NULL) 661 dev->si_cred = crhold(cr); 662 else 663 dev->si_cred = NULL; 664 dev->si_uid = uid; 665 dev->si_gid = gid; 666 dev->si_mode = mode; 667 668 devfs_create(dev); 669 clean_unrhdrl(devfs_inos); 670 dev_unlock_and_free(); 671 672 notify_create(dev); 673 674 return (dev); 675} 676 677struct cdev * 678make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode, 679 const char *fmt, ...) 680{ 681 struct cdev *dev; 682 va_list ap; 683 684 va_start(ap, fmt); 685 dev = make_dev_credv(0, devsw, unit, NULL, uid, gid, mode, fmt, ap); 686 va_end(ap); 687 return (dev); 688} 689 690struct cdev * 691make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid, 692 gid_t gid, int mode, const char *fmt, ...) 693{ 694 struct cdev *dev; 695 va_list ap; 696 697 va_start(ap, fmt); 698 dev = make_dev_credv(0, devsw, unit, cr, uid, gid, mode, fmt, ap); 699 va_end(ap); 700 701 return (dev); 702} 703 704struct cdev * 705make_dev_credf(int flags, struct cdevsw *devsw, int unit, 706 struct ucred *cr, uid_t uid, 707 gid_t gid, int mode, const char *fmt, ...) 708{ 709 struct cdev *dev; 710 va_list ap; 711 712 va_start(ap, fmt); 713 dev = make_dev_credv(flags, devsw, unit, cr, uid, gid, mode, 714 fmt, ap); 715 va_end(ap); 716 717 return (dev); 718} 719 720static void 721dev_dependsl(struct cdev *pdev, struct cdev *cdev) 722{ 723 724 cdev->si_parent = pdev; 725 cdev->si_flags |= SI_CHILD; 726 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 727} 728 729 730void 731dev_depends(struct cdev *pdev, struct cdev *cdev) 732{ 733 734 dev_lock(); 735 dev_dependsl(pdev, cdev); 736 dev_unlock(); 737} 738 739struct cdev * 740make_dev_alias(struct cdev *pdev, const char *fmt, ...) 741{ 742 struct cdev *dev; 743 va_list ap; 744 int i; 745 746 KASSERT(pdev != NULL, ("NULL pdev")); 747 dev = devfs_alloc(); 748 dev_lock(); 749 dev->si_flags |= SI_ALIAS; 750 dev->si_flags |= SI_NAMED; 751 va_start(ap, fmt); 752 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 753 if (i > (sizeof dev->__si_namebuf - 1)) { 754 printf("WARNING: Device name truncated! (%s)\n", 755 dev->__si_namebuf); 756 } 757 va_end(ap); 758 759 devfs_create(dev); 760 dev_dependsl(pdev, dev); 761 clean_unrhdrl(devfs_inos); 762 dev_unlock(); 763 764 notify_create(dev); 765 766 return (dev); 767} 768 769static void 770destroy_devl(struct cdev *dev) 771{ 772 struct cdevsw *csw; 773 struct cdev_privdata *p, *p1; 774 775 mtx_assert(&devmtx, MA_OWNED); 776 KASSERT(dev->si_flags & SI_NAMED, 777 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev))); 778 779 devfs_destroy(dev); 780 781 /* Remove name marking */ 782 dev->si_flags &= ~SI_NAMED; 783 784 /* If we are a child, remove us from the parents list */ 785 if (dev->si_flags & SI_CHILD) { 786 LIST_REMOVE(dev, si_siblings); 787 dev->si_flags &= ~SI_CHILD; 788 } 789 790 /* Kill our children */ 791 while (!LIST_EMPTY(&dev->si_children)) 792 destroy_devl(LIST_FIRST(&dev->si_children)); 793 794 /* Remove from clone list */ 795 if (dev->si_flags & SI_CLONELIST) { 796 LIST_REMOVE(dev, si_clone); 797 dev->si_flags &= ~SI_CLONELIST; 798 } 799 800 dev->si_refcount++; /* Avoid race with dev_rel() */ 801 csw = dev->si_devsw; 802 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 803 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 804 csw->d_purge(dev); 805 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 806 if (dev->si_threadcount) 807 printf("Still %lu threads in %s\n", 808 dev->si_threadcount, devtoname(dev)); 809 } 810 while (dev->si_threadcount != 0) { 811 /* Use unique dummy wait ident */ 812 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); 813 } 814 815 dev_unlock(); 816 notify_destroy(dev); 817 mtx_lock(&cdevpriv_mtx); 818 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) { 819 devfs_destroy_cdevpriv(p); 820 mtx_lock(&cdevpriv_mtx); 821 } 822 mtx_unlock(&cdevpriv_mtx); 823 dev_lock(); 824 825 dev->si_drv1 = 0; 826 dev->si_drv2 = 0; 827 bzero(&dev->__si_u, sizeof(dev->__si_u)); 828 829 if (!(dev->si_flags & SI_ALIAS)) { 830 /* Remove from cdevsw list */ 831 LIST_REMOVE(dev, si_list); 832 833 /* If cdevsw has no more struct cdev *'s, clean it */ 834 if (LIST_EMPTY(&csw->d_devs)) { 835 fini_cdevsw(csw); 836 wakeup(&csw->d_devs); 837 } 838 } 839 dev->si_flags &= ~SI_ALIAS; 840 dev->si_refcount--; /* Avoid race with dev_rel() */ 841 842 if (dev->si_refcount > 0) { 843 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 844 } else { 845 dev_free_devlocked(dev); 846 } 847} 848 849void 850destroy_dev(struct cdev *dev) 851{ 852 853 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev"); 854 dev_lock(); 855 destroy_devl(dev); 856 dev_unlock_and_free(); 857} 858 859const char * 860devtoname(struct cdev *dev) 861{ 862 char *p; 863 struct cdevsw *csw; 864 int mynor; 865 866 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 867 p = dev->si_name; 868 csw = dev_refthread(dev); 869 if (csw != NULL) { 870 sprintf(p, "(%s)", csw->d_name); 871 dev_relthread(dev); 872 } 873 p += strlen(p); 874 mynor = dev2unit(dev); 875 if (mynor < 0 || mynor > 255) 876 sprintf(p, "/%#x", (u_int)mynor); 877 else 878 sprintf(p, "/%d", mynor); 879 } 880 return (dev->si_name); 881} 882 883int 884dev_stdclone(char *name, char **namep, const char *stem, int *unit) 885{ 886 int u, i; 887 888 i = strlen(stem); 889 if (bcmp(stem, name, i) != 0) 890 return (0); 891 if (!isdigit(name[i])) 892 return (0); 893 u = 0; 894 if (name[i] == '0' && isdigit(name[i+1])) 895 return (0); 896 while (isdigit(name[i])) { 897 u *= 10; 898 u += name[i++] - '0'; 899 } 900 if (u > 0xffffff) 901 return (0); 902 *unit = u; 903 if (namep) 904 *namep = &name[i]; 905 if (name[i]) 906 return (2); 907 return (1); 908} 909 910/* 911 * Helper functions for cloning device drivers. 912 * 913 * The objective here is to make it unnecessary for the device drivers to 914 * use rman or similar to manage their unit number space. Due to the way 915 * we do "on-demand" devices, using rman or other "private" methods 916 * will be very tricky to lock down properly once we lock down this file. 917 * 918 * Instead we give the drivers these routines which puts the struct cdev *'s 919 * that are to be managed on their own list, and gives the driver the ability 920 * to ask for the first free unit number or a given specified unit number. 921 * 922 * In addition these routines support paired devices (pty, nmdm and similar) 923 * by respecting a number of "flag" bits in the minor number. 924 * 925 */ 926 927struct clonedevs { 928 LIST_HEAD(,cdev) head; 929}; 930 931void 932clone_setup(struct clonedevs **cdp) 933{ 934 935 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 936 LIST_INIT(&(*cdp)->head); 937} 938 939int 940clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra) 941{ 942 struct clonedevs *cd; 943 struct cdev *dev, *ndev, *dl, *de; 944 int unit, low, u; 945 946 KASSERT(*cdp != NULL, 947 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 948 KASSERT(!(extra & CLONE_UNITMASK), 949 ("Illegal extra bits (0x%x) in clone_create", extra)); 950 KASSERT(*up <= CLONE_UNITMASK, 951 ("Too high unit (0x%x) in clone_create", *up)); 952 KASSERT(csw->d_flags & D_NEEDMINOR, 953 ("clone_create() on cdevsw without minor numbers")); 954 955 956 /* 957 * Search the list for a lot of things in one go: 958 * A preexisting match is returned immediately. 959 * The lowest free unit number if we are passed -1, and the place 960 * in the list where we should insert that new element. 961 * The place to insert a specified unit number, if applicable 962 * the end of the list. 963 */ 964 unit = *up; 965 ndev = devfs_alloc(); 966 dev_lock(); 967 prep_cdevsw(csw); 968 low = extra; 969 de = dl = NULL; 970 cd = *cdp; 971 LIST_FOREACH(dev, &cd->head, si_clone) { 972 KASSERT(dev->si_flags & SI_CLONELIST, 973 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 974 u = dev2unit(dev); 975 if (u == (unit | extra)) { 976 *dp = dev; 977 dev_unlock(); 978 devfs_free(ndev); 979 return (0); 980 } 981 if (unit == -1 && u == low) { 982 low++; 983 de = dev; 984 continue; 985 } else if (u < (unit | extra)) { 986 de = dev; 987 continue; 988 } else if (u > (unit | extra)) { 989 dl = dev; 990 break; 991 } 992 } 993 if (unit == -1) 994 unit = low & CLONE_UNITMASK; 995 dev = newdev(csw, unit | extra, ndev); 996 if (dev->si_flags & SI_CLONELIST) { 997 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 998 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra); 999 LIST_FOREACH(dev, &cd->head, si_clone) { 1000 printf("\t%p %s\n", dev, dev->si_name); 1001 } 1002 panic("foo"); 1003 } 1004 KASSERT(!(dev->si_flags & SI_CLONELIST), 1005 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 1006 if (dl != NULL) 1007 LIST_INSERT_BEFORE(dl, dev, si_clone); 1008 else if (de != NULL) 1009 LIST_INSERT_AFTER(de, dev, si_clone); 1010 else 1011 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 1012 dev->si_flags |= SI_CLONELIST; 1013 *up = unit; 1014 dev_unlock_and_free(); 1015 return (1); 1016} 1017 1018/* 1019 * Kill everything still on the list. The driver should already have 1020 * disposed of any softc hung of the struct cdev *'s at this time. 1021 */ 1022void 1023clone_cleanup(struct clonedevs **cdp) 1024{ 1025 struct cdev *dev; 1026 struct cdev_priv *cp; 1027 struct clonedevs *cd; 1028 1029 cd = *cdp; 1030 if (cd == NULL) 1031 return; 1032 dev_lock(); 1033 while (!LIST_EMPTY(&cd->head)) { 1034 dev = LIST_FIRST(&cd->head); 1035 LIST_REMOVE(dev, si_clone); 1036 KASSERT(dev->si_flags & SI_CLONELIST, 1037 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1038 dev->si_flags &= ~SI_CLONELIST; 1039 cp = cdev2priv(dev); 1040 if (!(cp->cdp_flags & CDP_SCHED_DTR)) { 1041 cp->cdp_flags |= CDP_SCHED_DTR; 1042 KASSERT(dev->si_flags & SI_NAMED, 1043 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev))); 1044 destroy_devl(dev); 1045 } 1046 } 1047 dev_unlock_and_free(); 1048 free(cd, M_DEVBUF); 1049 *cdp = NULL; 1050} 1051 1052static TAILQ_HEAD(, cdev_priv) dev_ddtr = 1053 TAILQ_HEAD_INITIALIZER(dev_ddtr); 1054static struct task dev_dtr_task; 1055 1056static void 1057destroy_dev_tq(void *ctx, int pending) 1058{ 1059 struct cdev_priv *cp; 1060 struct cdev *dev; 1061 void (*cb)(void *); 1062 void *cb_arg; 1063 1064 dev_lock(); 1065 while (!TAILQ_EMPTY(&dev_ddtr)) { 1066 cp = TAILQ_FIRST(&dev_ddtr); 1067 dev = &cp->cdp_c; 1068 KASSERT(cp->cdp_flags & CDP_SCHED_DTR, 1069 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp)); 1070 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list); 1071 cb = cp->cdp_dtr_cb; 1072 cb_arg = cp->cdp_dtr_cb_arg; 1073 destroy_devl(dev); 1074 dev_unlock_and_free(); 1075 dev_rel(dev); 1076 if (cb != NULL) 1077 cb(cb_arg); 1078 dev_lock(); 1079 } 1080 dev_unlock(); 1081} 1082 1083/* 1084 * devmtx shall be locked on entry. devmtx will be unlocked after 1085 * function return. 1086 */ 1087static int 1088destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg) 1089{ 1090 struct cdev_priv *cp; 1091 1092 mtx_assert(&devmtx, MA_OWNED); 1093 cp = cdev2priv(dev); 1094 if (cp->cdp_flags & CDP_SCHED_DTR) { 1095 dev_unlock(); 1096 return (0); 1097 } 1098 dev_refl(dev); 1099 cp->cdp_flags |= CDP_SCHED_DTR; 1100 cp->cdp_dtr_cb = cb; 1101 cp->cdp_dtr_cb_arg = arg; 1102 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list); 1103 dev_unlock(); 1104 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task); 1105 return (1); 1106} 1107 1108int 1109destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg) 1110{ 1111 dev_lock(); 1112 return (destroy_dev_sched_cbl(dev, cb, arg)); 1113} 1114 1115int 1116destroy_dev_sched(struct cdev *dev) 1117{ 1118 return (destroy_dev_sched_cb(dev, NULL, NULL)); 1119} 1120 1121void 1122destroy_dev_drain(struct cdevsw *csw) 1123{ 1124 1125 dev_lock(); 1126 while (!LIST_EMPTY(&csw->d_devs)) { 1127 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10); 1128 } 1129 dev_unlock(); 1130} 1131 1132void 1133drain_dev_clone_events(void) 1134{ 1135 1136 sx_xlock(&clone_drain_lock); 1137 sx_xunlock(&clone_drain_lock); 1138} 1139 1140static void 1141devdtr_init(void *dummy __unused) 1142{ 1143 1144 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL); 1145} 1146 1147SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL); 1148