kern_conf.c revision 209105
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 209105 2010-06-12 13:21:25Z kib $"); 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#include <vm/vm.h> 51 52static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage"); 53 54struct mtx devmtx; 55static void destroy_devl(struct cdev *dev); 56static int destroy_dev_sched_cbl(struct cdev *dev, 57 void (*cb)(void *), void *arg); 58static struct cdev *make_dev_credv(int flags, 59 struct cdevsw *devsw, int unit, 60 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, 61 va_list ap); 62 63static struct cdev_priv_list cdevp_free_list = 64 TAILQ_HEAD_INITIALIZER(cdevp_free_list); 65static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list = 66 SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list); 67 68void 69dev_lock(void) 70{ 71 72 mtx_lock(&devmtx); 73} 74 75/* 76 * Free all the memory collected while the cdev mutex was 77 * locked. Since devmtx is after the system map mutex, free() cannot 78 * be called immediately and is postponed until cdev mutex can be 79 * dropped. 80 */ 81static void 82dev_unlock_and_free(void) 83{ 84 struct cdev_priv_list cdp_free; 85 struct free_cdevsw csw_free; 86 struct cdev_priv *cdp; 87 struct cdevsw *csw; 88 89 mtx_assert(&devmtx, MA_OWNED); 90 91 /* 92 * Make the local copy of the list heads while the dev_mtx is 93 * held. Free it later. 94 */ 95 TAILQ_INIT(&cdp_free); 96 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list); 97 csw_free = cdevsw_gt_post_list; 98 SLIST_INIT(&cdevsw_gt_post_list); 99 100 mtx_unlock(&devmtx); 101 102 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) { 103 TAILQ_REMOVE(&cdp_free, cdp, cdp_list); 104 devfs_free(&cdp->cdp_c); 105 } 106 while ((csw = SLIST_FIRST(&csw_free)) != NULL) { 107 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list); 108 free(csw, M_DEVT); 109 } 110} 111 112static void 113dev_free_devlocked(struct cdev *cdev) 114{ 115 struct cdev_priv *cdp; 116 117 mtx_assert(&devmtx, MA_OWNED); 118 cdp = cdev2priv(cdev); 119 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list); 120} 121 122static void 123cdevsw_free_devlocked(struct cdevsw *csw) 124{ 125 126 mtx_assert(&devmtx, MA_OWNED); 127 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list); 128} 129 130void 131dev_unlock(void) 132{ 133 134 mtx_unlock(&devmtx); 135} 136 137void 138dev_ref(struct cdev *dev) 139{ 140 141 mtx_assert(&devmtx, MA_NOTOWNED); 142 mtx_lock(&devmtx); 143 dev->si_refcount++; 144 mtx_unlock(&devmtx); 145} 146 147void 148dev_refl(struct cdev *dev) 149{ 150 151 mtx_assert(&devmtx, MA_OWNED); 152 dev->si_refcount++; 153} 154 155void 156dev_rel(struct cdev *dev) 157{ 158 int flag = 0; 159 160 mtx_assert(&devmtx, MA_NOTOWNED); 161 dev_lock(); 162 dev->si_refcount--; 163 KASSERT(dev->si_refcount >= 0, 164 ("dev_rel(%s) gave negative count", devtoname(dev))); 165#if 0 166 if (dev->si_usecount == 0 && 167 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED)) 168 ; 169 else 170#endif 171 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 172 LIST_REMOVE(dev, si_list); 173 flag = 1; 174 } 175 dev_unlock(); 176 if (flag) 177 devfs_free(dev); 178} 179 180struct cdevsw * 181dev_refthread(struct cdev *dev) 182{ 183 struct cdevsw *csw; 184 struct cdev_priv *cdp; 185 186 mtx_assert(&devmtx, MA_NOTOWNED); 187 dev_lock(); 188 csw = dev->si_devsw; 189 if (csw != NULL) { 190 cdp = cdev2priv(dev); 191 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) 192 dev->si_threadcount++; 193 else 194 csw = NULL; 195 } 196 dev_unlock(); 197 return (csw); 198} 199 200struct cdevsw * 201devvn_refthread(struct vnode *vp, struct cdev **devp) 202{ 203 struct cdevsw *csw; 204 struct cdev_priv *cdp; 205 206 mtx_assert(&devmtx, MA_NOTOWNED); 207 csw = NULL; 208 dev_lock(); 209 *devp = vp->v_rdev; 210 if (*devp != NULL) { 211 cdp = cdev2priv(*devp); 212 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) { 213 csw = (*devp)->si_devsw; 214 if (csw != NULL) 215 (*devp)->si_threadcount++; 216 } 217 } 218 dev_unlock(); 219 return (csw); 220} 221 222void 223dev_relthread(struct cdev *dev) 224{ 225 226 mtx_assert(&devmtx, MA_NOTOWNED); 227 dev_lock(); 228 KASSERT(dev->si_threadcount > 0, 229 ("%s threadcount is wrong", dev->si_name)); 230 dev->si_threadcount--; 231 dev_unlock(); 232} 233 234int 235nullop(void) 236{ 237 238 return (0); 239} 240 241int 242eopnotsupp(void) 243{ 244 245 return (EOPNOTSUPP); 246} 247 248static int 249enxio(void) 250{ 251 return (ENXIO); 252} 253 254static int 255enodev(void) 256{ 257 return (ENODEV); 258} 259 260/* Define a dead_cdevsw for use when devices leave unexpectedly. */ 261 262#define dead_open (d_open_t *)enxio 263#define dead_close (d_close_t *)enxio 264#define dead_read (d_read_t *)enxio 265#define dead_write (d_write_t *)enxio 266#define dead_ioctl (d_ioctl_t *)enxio 267#define dead_poll (d_poll_t *)enodev 268#define dead_mmap (d_mmap_t *)enodev 269 270static void 271dead_strategy(struct bio *bp) 272{ 273 274 biofinish(bp, NULL, ENXIO); 275} 276 277#define dead_dump (dumper_t *)enxio 278#define dead_kqfilter (d_kqfilter_t *)enxio 279#define dead_mmap_single (d_mmap_single_t *)enodev 280 281static struct cdevsw dead_cdevsw = { 282 .d_version = D_VERSION, 283 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 284 .d_open = dead_open, 285 .d_close = dead_close, 286 .d_read = dead_read, 287 .d_write = dead_write, 288 .d_ioctl = dead_ioctl, 289 .d_poll = dead_poll, 290 .d_mmap = dead_mmap, 291 .d_strategy = dead_strategy, 292 .d_name = "dead", 293 .d_dump = dead_dump, 294 .d_kqfilter = dead_kqfilter, 295 .d_mmap_single = dead_mmap_single 296}; 297 298/* Default methods if driver does not specify method */ 299 300#define null_open (d_open_t *)nullop 301#define null_close (d_close_t *)nullop 302#define no_read (d_read_t *)enodev 303#define no_write (d_write_t *)enodev 304#define no_ioctl (d_ioctl_t *)enodev 305#define no_mmap (d_mmap_t *)enodev 306#define no_kqfilter (d_kqfilter_t *)enodev 307#define no_mmap_single (d_mmap_single_t *)enodev 308 309static void 310no_strategy(struct bio *bp) 311{ 312 313 biofinish(bp, NULL, ENODEV); 314} 315 316static int 317no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 318{ 319 320 return (poll_no_poll(events)); 321} 322 323#define no_dump (dumper_t *)enodev 324 325static int 326giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 327{ 328 struct cdevsw *dsw; 329 int retval; 330 331 dsw = dev_refthread(dev); 332 if (dsw == NULL) 333 return (ENXIO); 334 mtx_lock(&Giant); 335 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td); 336 mtx_unlock(&Giant); 337 dev_relthread(dev); 338 return (retval); 339} 340 341static int 342giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp) 343{ 344 struct cdevsw *dsw; 345 int retval; 346 347 dsw = dev_refthread(dev); 348 if (dsw == NULL) 349 return (ENXIO); 350 mtx_lock(&Giant); 351 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp); 352 mtx_unlock(&Giant); 353 dev_relthread(dev); 354 return (retval); 355} 356 357static int 358giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 359{ 360 struct cdevsw *dsw; 361 int retval; 362 363 dsw = dev_refthread(dev); 364 if (dsw == NULL) 365 return (ENXIO); 366 mtx_lock(&Giant); 367 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td); 368 mtx_unlock(&Giant); 369 dev_relthread(dev); 370 return (retval); 371} 372 373static void 374giant_strategy(struct bio *bp) 375{ 376 struct cdevsw *dsw; 377 struct cdev *dev; 378 379 dev = bp->bio_dev; 380 dsw = dev_refthread(dev); 381 if (dsw == NULL) { 382 biofinish(bp, NULL, ENXIO); 383 return; 384 } 385 mtx_lock(&Giant); 386 dsw->d_gianttrick->d_strategy(bp); 387 mtx_unlock(&Giant); 388 dev_relthread(dev); 389} 390 391static int 392giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 393{ 394 struct cdevsw *dsw; 395 int retval; 396 397 dsw = dev_refthread(dev); 398 if (dsw == NULL) 399 return (ENXIO); 400 mtx_lock(&Giant); 401 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td); 402 mtx_unlock(&Giant); 403 dev_relthread(dev); 404 return (retval); 405} 406 407static int 408giant_read(struct cdev *dev, struct uio *uio, int ioflag) 409{ 410 struct cdevsw *dsw; 411 int retval; 412 413 dsw = dev_refthread(dev); 414 if (dsw == NULL) 415 return (ENXIO); 416 mtx_lock(&Giant); 417 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag); 418 mtx_unlock(&Giant); 419 dev_relthread(dev); 420 return (retval); 421} 422 423static int 424giant_write(struct cdev *dev, struct uio *uio, int ioflag) 425{ 426 struct cdevsw *dsw; 427 int retval; 428 429 dsw = dev_refthread(dev); 430 if (dsw == NULL) 431 return (ENXIO); 432 mtx_lock(&Giant); 433 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag); 434 mtx_unlock(&Giant); 435 dev_relthread(dev); 436 return (retval); 437} 438 439static int 440giant_poll(struct cdev *dev, int events, struct thread *td) 441{ 442 struct cdevsw *dsw; 443 int retval; 444 445 dsw = dev_refthread(dev); 446 if (dsw == NULL) 447 return (ENXIO); 448 mtx_lock(&Giant); 449 retval = dsw->d_gianttrick->d_poll(dev, events, td); 450 mtx_unlock(&Giant); 451 dev_relthread(dev); 452 return (retval); 453} 454 455static int 456giant_kqfilter(struct cdev *dev, struct knote *kn) 457{ 458 struct cdevsw *dsw; 459 int retval; 460 461 dsw = dev_refthread(dev); 462 if (dsw == NULL) 463 return (ENXIO); 464 mtx_lock(&Giant); 465 retval = dsw->d_gianttrick->d_kqfilter(dev, kn); 466 mtx_unlock(&Giant); 467 dev_relthread(dev); 468 return (retval); 469} 470 471static int 472giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot, 473 vm_memattr_t *memattr) 474{ 475 struct cdevsw *dsw; 476 int retval; 477 478 dsw = dev_refthread(dev); 479 if (dsw == NULL) 480 return (ENXIO); 481 mtx_lock(&Giant); 482 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot, 483 memattr); 484 mtx_unlock(&Giant); 485 dev_relthread(dev); 486 return (retval); 487} 488 489static int 490giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size, 491 vm_object_t *object, int nprot) 492{ 493 struct cdevsw *dsw; 494 int retval; 495 496 dsw = dev_refthread(dev); 497 if (dsw == NULL) 498 return (ENXIO); 499 mtx_lock(&Giant); 500 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object, 501 nprot); 502 mtx_unlock(&Giant); 503 dev_relthread(dev); 504 return (retval); 505} 506 507static void 508notify(struct cdev *dev, const char *ev, int flags) 509{ 510 static const char prefix[] = "cdev="; 511 char *data; 512 int namelen, mflags; 513 514 if (cold) 515 return; 516 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK; 517 namelen = strlen(dev->si_name); 518 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags); 519 if (data == NULL) 520 return; 521 memcpy(data, prefix, sizeof(prefix) - 1); 522 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1); 523 devctl_notify_f("DEVFS", "CDEV", ev, data, mflags); 524 free(data, M_TEMP); 525} 526 527static void 528notify_create(struct cdev *dev, int flags) 529{ 530 531 notify(dev, "CREATE", flags); 532} 533 534static void 535notify_destroy(struct cdev *dev) 536{ 537 538 notify(dev, "DESTROY", MAKEDEV_WAITOK); 539} 540 541static struct cdev * 542newdev(struct cdevsw *csw, int unit, struct cdev *si) 543{ 544 struct cdev *si2; 545 546 mtx_assert(&devmtx, MA_OWNED); 547 if (csw->d_flags & D_NEEDMINOR) { 548 /* We may want to return an existing device */ 549 LIST_FOREACH(si2, &csw->d_devs, si_list) { 550 if (dev2unit(si2) == unit) { 551 dev_free_devlocked(si); 552 return (si2); 553 } 554 } 555 } 556 si->si_drv0 = unit; 557 si->si_devsw = csw; 558 LIST_INSERT_HEAD(&csw->d_devs, si, si_list); 559 return (si); 560} 561 562static void 563fini_cdevsw(struct cdevsw *devsw) 564{ 565 struct cdevsw *gt; 566 567 if (devsw->d_gianttrick != NULL) { 568 gt = devsw->d_gianttrick; 569 memcpy(devsw, gt, sizeof *devsw); 570 cdevsw_free_devlocked(gt); 571 devsw->d_gianttrick = NULL; 572 } 573 devsw->d_flags &= ~D_INIT; 574} 575 576static int 577prep_cdevsw(struct cdevsw *devsw, int flags) 578{ 579 struct cdevsw *dsw2; 580 581 mtx_assert(&devmtx, MA_OWNED); 582 if (devsw->d_flags & D_INIT) 583 return (1); 584 if (devsw->d_flags & D_NEEDGIANT) { 585 dev_unlock(); 586 dsw2 = malloc(sizeof *dsw2, M_DEVT, 587 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK); 588 dev_lock(); 589 if (dsw2 == NULL && !(devsw->d_flags & D_INIT)) 590 return (0); 591 } else 592 dsw2 = NULL; 593 if (devsw->d_flags & D_INIT) { 594 if (dsw2 != NULL) 595 cdevsw_free_devlocked(dsw2); 596 return (1); 597 } 598 599 if (devsw->d_version != D_VERSION_03) { 600 printf( 601 "WARNING: Device driver \"%s\" has wrong version %s\n", 602 devsw->d_name == NULL ? "???" : devsw->d_name, 603 "and is disabled. Recompile KLD module."); 604 devsw->d_open = dead_open; 605 devsw->d_close = dead_close; 606 devsw->d_read = dead_read; 607 devsw->d_write = dead_write; 608 devsw->d_ioctl = dead_ioctl; 609 devsw->d_poll = dead_poll; 610 devsw->d_mmap = dead_mmap; 611 devsw->d_mmap_single = dead_mmap_single; 612 devsw->d_strategy = dead_strategy; 613 devsw->d_dump = dead_dump; 614 devsw->d_kqfilter = dead_kqfilter; 615 } 616 617 if (devsw->d_flags & D_NEEDGIANT) { 618 if (devsw->d_gianttrick == NULL) { 619 memcpy(dsw2, devsw, sizeof *dsw2); 620 devsw->d_gianttrick = dsw2; 621 dsw2 = NULL; 622 } 623 } 624 625#define FIXUP(member, noop, giant) \ 626 do { \ 627 if (devsw->member == NULL) { \ 628 devsw->member = noop; \ 629 } else if (devsw->d_flags & D_NEEDGIANT) \ 630 devsw->member = giant; \ 631 } \ 632 while (0) 633 634 FIXUP(d_open, null_open, giant_open); 635 FIXUP(d_fdopen, NULL, giant_fdopen); 636 FIXUP(d_close, null_close, giant_close); 637 FIXUP(d_read, no_read, giant_read); 638 FIXUP(d_write, no_write, giant_write); 639 FIXUP(d_ioctl, no_ioctl, giant_ioctl); 640 FIXUP(d_poll, no_poll, giant_poll); 641 FIXUP(d_mmap, no_mmap, giant_mmap); 642 FIXUP(d_strategy, no_strategy, giant_strategy); 643 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter); 644 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single); 645 646 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 647 648 LIST_INIT(&devsw->d_devs); 649 650 devsw->d_flags |= D_INIT; 651 652 if (dsw2 != NULL) 653 cdevsw_free_devlocked(dsw2); 654 return (1); 655} 656 657static struct cdev * 658make_dev_credv(int flags, struct cdevsw *devsw, int unit, 659 struct ucred *cr, uid_t uid, 660 gid_t gid, int mode, const char *fmt, va_list ap) 661{ 662 struct cdev *dev; 663 int i; 664 665 dev = devfs_alloc(flags); 666 if (dev == NULL) 667 return (NULL); 668 dev_lock(); 669 if (!prep_cdevsw(devsw, flags)) { 670 dev_unlock(); 671 devfs_free(dev); 672 return (NULL); 673 } 674 dev = newdev(devsw, unit, dev); 675 if (flags & MAKEDEV_REF) 676 dev_refl(dev); 677 if (dev->si_flags & SI_CHEAPCLONE && 678 dev->si_flags & SI_NAMED) { 679 /* 680 * This is allowed as it removes races and generally 681 * simplifies cloning devices. 682 * XXX: still ?? 683 */ 684 dev_unlock_and_free(); 685 return (dev); 686 } 687 KASSERT(!(dev->si_flags & SI_NAMED), 688 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)", 689 devsw->d_name, dev2unit(dev), devtoname(dev))); 690 691 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 692 if (i > (sizeof dev->__si_namebuf - 1)) { 693 printf("WARNING: Device name truncated! (%s)\n", 694 dev->__si_namebuf); 695 } 696 697 dev->si_flags |= SI_NAMED; 698 if (cr != NULL) 699 dev->si_cred = crhold(cr); 700 dev->si_uid = uid; 701 dev->si_gid = gid; 702 dev->si_mode = mode; 703 704 devfs_create(dev); 705 clean_unrhdrl(devfs_inos); 706 dev_unlock_and_free(); 707 708 notify_create(dev, flags); 709 710 return (dev); 711} 712 713struct cdev * 714make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode, 715 const char *fmt, ...) 716{ 717 struct cdev *dev; 718 va_list ap; 719 720 va_start(ap, fmt); 721 dev = make_dev_credv(0, devsw, unit, NULL, uid, gid, mode, fmt, ap); 722 va_end(ap); 723 return (dev); 724} 725 726struct cdev * 727make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid, 728 gid_t gid, int mode, const char *fmt, ...) 729{ 730 struct cdev *dev; 731 va_list ap; 732 733 va_start(ap, fmt); 734 dev = make_dev_credv(0, devsw, unit, cr, uid, gid, mode, fmt, ap); 735 va_end(ap); 736 737 return (dev); 738} 739 740struct cdev * 741make_dev_credf(int flags, struct cdevsw *devsw, int unit, 742 struct ucred *cr, uid_t uid, 743 gid_t gid, int mode, const char *fmt, ...) 744{ 745 struct cdev *dev; 746 va_list ap; 747 748 va_start(ap, fmt); 749 dev = make_dev_credv(flags, devsw, unit, cr, uid, gid, mode, 750 fmt, ap); 751 va_end(ap); 752 753 return (dev); 754} 755 756static void 757dev_dependsl(struct cdev *pdev, struct cdev *cdev) 758{ 759 760 cdev->si_parent = pdev; 761 cdev->si_flags |= SI_CHILD; 762 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 763} 764 765 766void 767dev_depends(struct cdev *pdev, struct cdev *cdev) 768{ 769 770 dev_lock(); 771 dev_dependsl(pdev, cdev); 772 dev_unlock(); 773} 774 775struct cdev * 776make_dev_alias(struct cdev *pdev, const char *fmt, ...) 777{ 778 struct cdev *dev; 779 va_list ap; 780 int i; 781 782 KASSERT(pdev != NULL, ("NULL pdev")); 783 dev = devfs_alloc(MAKEDEV_WAITOK); 784 dev_lock(); 785 dev->si_flags |= SI_ALIAS; 786 dev->si_flags |= SI_NAMED; 787 va_start(ap, fmt); 788 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 789 if (i > (sizeof dev->__si_namebuf - 1)) { 790 printf("WARNING: Device name truncated! (%s)\n", 791 dev->__si_namebuf); 792 } 793 va_end(ap); 794 795 devfs_create(dev); 796 dev_dependsl(pdev, dev); 797 clean_unrhdrl(devfs_inos); 798 dev_unlock(); 799 800 notify_create(dev, MAKEDEV_WAITOK); 801 802 return (dev); 803} 804 805static void 806destroy_devl(struct cdev *dev) 807{ 808 struct cdevsw *csw; 809 struct cdev_privdata *p, *p1; 810 811 mtx_assert(&devmtx, MA_OWNED); 812 KASSERT(dev->si_flags & SI_NAMED, 813 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev))); 814 815 devfs_destroy(dev); 816 817 /* Remove name marking */ 818 dev->si_flags &= ~SI_NAMED; 819 820 /* If we are a child, remove us from the parents list */ 821 if (dev->si_flags & SI_CHILD) { 822 LIST_REMOVE(dev, si_siblings); 823 dev->si_flags &= ~SI_CHILD; 824 } 825 826 /* Kill our children */ 827 while (!LIST_EMPTY(&dev->si_children)) 828 destroy_devl(LIST_FIRST(&dev->si_children)); 829 830 /* Remove from clone list */ 831 if (dev->si_flags & SI_CLONELIST) { 832 LIST_REMOVE(dev, si_clone); 833 dev->si_flags &= ~SI_CLONELIST; 834 } 835 836 dev->si_refcount++; /* Avoid race with dev_rel() */ 837 csw = dev->si_devsw; 838 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 839 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 840 csw->d_purge(dev); 841 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 842 if (dev->si_threadcount) 843 printf("Still %lu threads in %s\n", 844 dev->si_threadcount, devtoname(dev)); 845 } 846 while (dev->si_threadcount != 0) { 847 /* Use unique dummy wait ident */ 848 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); 849 } 850 851 dev_unlock(); 852 notify_destroy(dev); 853 mtx_lock(&cdevpriv_mtx); 854 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) { 855 devfs_destroy_cdevpriv(p); 856 mtx_lock(&cdevpriv_mtx); 857 } 858 mtx_unlock(&cdevpriv_mtx); 859 dev_lock(); 860 861 dev->si_drv1 = 0; 862 dev->si_drv2 = 0; 863 bzero(&dev->__si_u, sizeof(dev->__si_u)); 864 865 if (!(dev->si_flags & SI_ALIAS)) { 866 /* Remove from cdevsw list */ 867 LIST_REMOVE(dev, si_list); 868 869 /* If cdevsw has no more struct cdev *'s, clean it */ 870 if (LIST_EMPTY(&csw->d_devs)) { 871 fini_cdevsw(csw); 872 wakeup(&csw->d_devs); 873 } 874 } 875 dev->si_flags &= ~SI_ALIAS; 876 dev->si_refcount--; /* Avoid race with dev_rel() */ 877 878 if (dev->si_refcount > 0) { 879 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 880 } else { 881 dev_free_devlocked(dev); 882 } 883} 884 885void 886destroy_dev(struct cdev *dev) 887{ 888 889 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev"); 890 dev_lock(); 891 destroy_devl(dev); 892 dev_unlock_and_free(); 893} 894 895const char * 896devtoname(struct cdev *dev) 897{ 898 899 return (dev->si_name); 900} 901 902int 903dev_stdclone(char *name, char **namep, const char *stem, int *unit) 904{ 905 int u, i; 906 907 i = strlen(stem); 908 if (bcmp(stem, name, i) != 0) 909 return (0); 910 if (!isdigit(name[i])) 911 return (0); 912 u = 0; 913 if (name[i] == '0' && isdigit(name[i+1])) 914 return (0); 915 while (isdigit(name[i])) { 916 u *= 10; 917 u += name[i++] - '0'; 918 } 919 if (u > 0xffffff) 920 return (0); 921 *unit = u; 922 if (namep) 923 *namep = &name[i]; 924 if (name[i]) 925 return (2); 926 return (1); 927} 928 929/* 930 * Helper functions for cloning device drivers. 931 * 932 * The objective here is to make it unnecessary for the device drivers to 933 * use rman or similar to manage their unit number space. Due to the way 934 * we do "on-demand" devices, using rman or other "private" methods 935 * will be very tricky to lock down properly once we lock down this file. 936 * 937 * Instead we give the drivers these routines which puts the struct cdev *'s 938 * that are to be managed on their own list, and gives the driver the ability 939 * to ask for the first free unit number or a given specified unit number. 940 * 941 * In addition these routines support paired devices (pty, nmdm and similar) 942 * by respecting a number of "flag" bits in the minor number. 943 * 944 */ 945 946struct clonedevs { 947 LIST_HEAD(,cdev) head; 948}; 949 950void 951clone_setup(struct clonedevs **cdp) 952{ 953 954 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 955 LIST_INIT(&(*cdp)->head); 956} 957 958int 959clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, 960 struct cdev **dp, int extra) 961{ 962 struct clonedevs *cd; 963 struct cdev *dev, *ndev, *dl, *de; 964 int unit, low, u; 965 966 KASSERT(*cdp != NULL, 967 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 968 KASSERT(!(extra & CLONE_UNITMASK), 969 ("Illegal extra bits (0x%x) in clone_create", extra)); 970 KASSERT(*up <= CLONE_UNITMASK, 971 ("Too high unit (0x%x) in clone_create", *up)); 972 KASSERT(csw->d_flags & D_NEEDMINOR, 973 ("clone_create() on cdevsw without minor numbers")); 974 975 976 /* 977 * Search the list for a lot of things in one go: 978 * A preexisting match is returned immediately. 979 * The lowest free unit number if we are passed -1, and the place 980 * in the list where we should insert that new element. 981 * The place to insert a specified unit number, if applicable 982 * the end of the list. 983 */ 984 unit = *up; 985 ndev = devfs_alloc(MAKEDEV_WAITOK); 986 dev_lock(); 987 prep_cdevsw(csw, MAKEDEV_WAITOK); 988 low = extra; 989 de = dl = NULL; 990 cd = *cdp; 991 LIST_FOREACH(dev, &cd->head, si_clone) { 992 KASSERT(dev->si_flags & SI_CLONELIST, 993 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 994 u = dev2unit(dev); 995 if (u == (unit | extra)) { 996 *dp = dev; 997 dev_unlock(); 998 devfs_free(ndev); 999 return (0); 1000 } 1001 if (unit == -1 && u == low) { 1002 low++; 1003 de = dev; 1004 continue; 1005 } else if (u < (unit | extra)) { 1006 de = dev; 1007 continue; 1008 } else if (u > (unit | extra)) { 1009 dl = dev; 1010 break; 1011 } 1012 } 1013 if (unit == -1) 1014 unit = low & CLONE_UNITMASK; 1015 dev = newdev(csw, unit | extra, ndev); 1016 if (dev->si_flags & SI_CLONELIST) { 1017 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 1018 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra); 1019 LIST_FOREACH(dev, &cd->head, si_clone) { 1020 printf("\t%p %s\n", dev, dev->si_name); 1021 } 1022 panic("foo"); 1023 } 1024 KASSERT(!(dev->si_flags & SI_CLONELIST), 1025 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 1026 if (dl != NULL) 1027 LIST_INSERT_BEFORE(dl, dev, si_clone); 1028 else if (de != NULL) 1029 LIST_INSERT_AFTER(de, dev, si_clone); 1030 else 1031 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 1032 dev->si_flags |= SI_CLONELIST; 1033 *up = unit; 1034 dev_unlock_and_free(); 1035 return (1); 1036} 1037 1038/* 1039 * Kill everything still on the list. The driver should already have 1040 * disposed of any softc hung of the struct cdev *'s at this time. 1041 */ 1042void 1043clone_cleanup(struct clonedevs **cdp) 1044{ 1045 struct cdev *dev; 1046 struct cdev_priv *cp; 1047 struct clonedevs *cd; 1048 1049 cd = *cdp; 1050 if (cd == NULL) 1051 return; 1052 dev_lock(); 1053 while (!LIST_EMPTY(&cd->head)) { 1054 dev = LIST_FIRST(&cd->head); 1055 LIST_REMOVE(dev, si_clone); 1056 KASSERT(dev->si_flags & SI_CLONELIST, 1057 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1058 dev->si_flags &= ~SI_CLONELIST; 1059 cp = cdev2priv(dev); 1060 if (!(cp->cdp_flags & CDP_SCHED_DTR)) { 1061 cp->cdp_flags |= CDP_SCHED_DTR; 1062 KASSERT(dev->si_flags & SI_NAMED, 1063 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev))); 1064 destroy_devl(dev); 1065 } 1066 } 1067 dev_unlock_and_free(); 1068 free(cd, M_DEVBUF); 1069 *cdp = NULL; 1070} 1071 1072static TAILQ_HEAD(, cdev_priv) dev_ddtr = 1073 TAILQ_HEAD_INITIALIZER(dev_ddtr); 1074static struct task dev_dtr_task; 1075 1076static void 1077destroy_dev_tq(void *ctx, int pending) 1078{ 1079 struct cdev_priv *cp; 1080 struct cdev *dev; 1081 void (*cb)(void *); 1082 void *cb_arg; 1083 1084 dev_lock(); 1085 while (!TAILQ_EMPTY(&dev_ddtr)) { 1086 cp = TAILQ_FIRST(&dev_ddtr); 1087 dev = &cp->cdp_c; 1088 KASSERT(cp->cdp_flags & CDP_SCHED_DTR, 1089 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp)); 1090 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list); 1091 cb = cp->cdp_dtr_cb; 1092 cb_arg = cp->cdp_dtr_cb_arg; 1093 destroy_devl(dev); 1094 dev_unlock_and_free(); 1095 dev_rel(dev); 1096 if (cb != NULL) 1097 cb(cb_arg); 1098 dev_lock(); 1099 } 1100 dev_unlock(); 1101} 1102 1103/* 1104 * devmtx shall be locked on entry. devmtx will be unlocked after 1105 * function return. 1106 */ 1107static int 1108destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg) 1109{ 1110 struct cdev_priv *cp; 1111 1112 mtx_assert(&devmtx, MA_OWNED); 1113 cp = cdev2priv(dev); 1114 if (cp->cdp_flags & CDP_SCHED_DTR) { 1115 dev_unlock(); 1116 return (0); 1117 } 1118 dev_refl(dev); 1119 cp->cdp_flags |= CDP_SCHED_DTR; 1120 cp->cdp_dtr_cb = cb; 1121 cp->cdp_dtr_cb_arg = arg; 1122 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list); 1123 dev_unlock(); 1124 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task); 1125 return (1); 1126} 1127 1128int 1129destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg) 1130{ 1131 1132 dev_lock(); 1133 return (destroy_dev_sched_cbl(dev, cb, arg)); 1134} 1135 1136int 1137destroy_dev_sched(struct cdev *dev) 1138{ 1139 1140 return (destroy_dev_sched_cb(dev, NULL, NULL)); 1141} 1142 1143void 1144destroy_dev_drain(struct cdevsw *csw) 1145{ 1146 1147 dev_lock(); 1148 while (!LIST_EMPTY(&csw->d_devs)) { 1149 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10); 1150 } 1151 dev_unlock(); 1152} 1153 1154void 1155drain_dev_clone_events(void) 1156{ 1157 1158 sx_xlock(&clone_drain_lock); 1159 sx_xunlock(&clone_drain_lock); 1160} 1161 1162static void 1163devdtr_init(void *dummy __unused) 1164{ 1165 1166 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL); 1167} 1168 1169SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL); 1170