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/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 51 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage"); 52 53 struct mtx devmtx; 54 static void destroy_devl(struct cdev *dev); 55 static int destroy_dev_sched_cbl(struct cdev *dev, 56 void (*cb)(void *), void *arg); 57 static struct cdev *make_dev_credv(int flags, 58 struct cdevsw *devsw, int minornr, 59 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, 60 va_list ap); 61 62 static struct cdev_priv_list cdevp_free_list = 63 TAILQ_HEAD_INITIALIZER(cdevp_free_list); 64 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list = 65 SLIST_HEAD_INITIALIZER(); 66 67 void 68 dev_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 */ 80 static void 81 dev_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 } 110 111 static void 112 dev_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 } 120 121 static void 122 cdevsw_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 } 128 129 void 130 dev_unlock(void) 131 { 132 133 mtx_unlock(&devmtx); 134 } 135 136 void 137 dev_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 } 145 146 void 147 dev_refl(struct cdev *dev) 148 { 149 150 mtx_assert(&devmtx, MA_OWNED); 151 dev->si_refcount++; 152 } 153 154 void 155 dev_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 } 178 179 struct cdevsw * 180 dev_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 } 198 199 struct cdevsw * 200 devvn_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 } 220 221 void 222 dev_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 } 232 233 int 234 nullop(void) 235 { 236 237 return (0); 238 } 239 240 int 241 eopnotsupp(void) 242 { 243 244 return (EOPNOTSUPP); 245 } 246 247 static int 248 enxio(void) 249 { 250 return (ENXIO); 251 } 252 253 static int 254 enodev(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 268 269 static void 270 dead_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 278 279 static 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 304 305 static void 306 no_strategy(struct bio *bp) 307 { 308 309 biofinish(bp, NULL, ENODEV); 310 } 311 312 static int 313 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 314 { 315 /* 316 * Return true for read/write. If the user asked for something 317 * special, return POLLNVAL, so that clients have a way of 318 * determining reliably whether or not the extended 319 * functionality is present without hard-coding knowledge 320 * of specific filesystem implementations. 321 * Stay in sync with vop_nopoll(). 322 */ 323 if (events & ~POLLSTANDARD) 324 return (POLLNVAL); 325 326 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 327 } 328 329 #define no_dump (dumper_t *)enodev 330 331 static int 332 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 333 { 334 struct cdevsw *dsw; 335 int retval; 336 337 dsw = dev_refthread(dev); 338 if (dsw == NULL) 339 return (ENXIO); 340 mtx_lock(&Giant); 341 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td); 342 mtx_unlock(&Giant); 343 dev_relthread(dev); 344 return (retval); 345 } 346 347 static int 348 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp) 349 { 350 struct cdevsw *dsw; 351 int retval; 352 353 dsw = dev_refthread(dev); 354 if (dsw == NULL) 355 return (ENXIO); 356 mtx_lock(&Giant); 357 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp); 358 mtx_unlock(&Giant); 359 dev_relthread(dev); 360 return (retval); 361 } 362 363 static int 364 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 365 { 366 struct cdevsw *dsw; 367 int retval; 368 369 dsw = dev_refthread(dev); 370 if (dsw == NULL) 371 return (ENXIO); 372 mtx_lock(&Giant); 373 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td); 374 mtx_unlock(&Giant); 375 dev_relthread(dev); 376 return (retval); 377 } 378 379 static void 380 giant_strategy(struct bio *bp) 381 { 382 struct cdevsw *dsw; 383 struct cdev *dev; 384 385 dev = bp->bio_dev; 386 dsw = dev_refthread(dev); 387 if (dsw == NULL) { 388 biofinish(bp, NULL, ENXIO); 389 return; 390 } 391 mtx_lock(&Giant); 392 dsw->d_gianttrick->d_strategy(bp); 393 mtx_unlock(&Giant); 394 dev_relthread(dev); 395 } 396 397 static int 398 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 399 { 400 struct cdevsw *dsw; 401 int retval; 402 403 dsw = dev_refthread(dev); 404 if (dsw == NULL) 405 return (ENXIO); 406 mtx_lock(&Giant); 407 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td); 408 mtx_unlock(&Giant); 409 dev_relthread(dev); 410 return (retval); 411 } 412 413 static int 414 giant_read(struct cdev *dev, struct uio *uio, int ioflag) 415 { 416 struct cdevsw *dsw; 417 int retval; 418 419 dsw = dev_refthread(dev); 420 if (dsw == NULL) 421 return (ENXIO); 422 mtx_lock(&Giant); 423 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag); 424 mtx_unlock(&Giant); 425 dev_relthread(dev); 426 return (retval); 427 } 428 429 static int 430 giant_write(struct cdev *dev, struct uio *uio, int ioflag) 431 { 432 struct cdevsw *dsw; 433 int retval; 434 435 dsw = dev_refthread(dev); 436 if (dsw == NULL) 437 return (ENXIO); 438 mtx_lock(&Giant); 439 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag); 440 mtx_unlock(&Giant); 441 dev_relthread(dev); 442 return (retval); 443 } 444 445 static int 446 giant_poll(struct cdev *dev, int events, struct thread *td) 447 { 448 struct cdevsw *dsw; 449 int retval; 450 451 dsw = dev_refthread(dev); 452 if (dsw == NULL) 453 return (ENXIO); 454 mtx_lock(&Giant); 455 retval = dsw->d_gianttrick->d_poll(dev, events, td); 456 mtx_unlock(&Giant); 457 dev_relthread(dev); 458 return (retval); 459 } 460 461 static int 462 giant_kqfilter(struct cdev *dev, struct knote *kn) 463 { 464 struct cdevsw *dsw; 465 int retval; 466 467 dsw = dev_refthread(dev); 468 if (dsw == NULL) 469 return (ENXIO); 470 mtx_lock(&Giant); 471 retval = dsw->d_gianttrick->d_kqfilter(dev, kn); 472 mtx_unlock(&Giant); 473 dev_relthread(dev); 474 return (retval); 475 } 476 477 static int 478 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot) 479 { 480 struct cdevsw *dsw; 481 int retval; 482 483 dsw = dev_refthread(dev); 484 if (dsw == NULL) 485 return (ENXIO); 486 mtx_lock(&Giant); 487 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot); 488 mtx_unlock(&Giant); 489 dev_relthread(dev); 490 return (retval); 491 } 492 493 494 static void 495 notify(struct cdev *dev, const char *ev) 496 { 497 static const char prefix[] = "cdev="; 498 char *data; 499 int namelen; 500 501 if (cold) 502 return; 503 namelen = strlen(dev->si_name); 504 data = malloc(namelen + sizeof(prefix), M_TEMP, M_WAITOK); 505 memcpy(data, prefix, sizeof(prefix) - 1); 506 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1); 507 devctl_notify("DEVFS", "CDEV", ev, data); 508 free(data, M_TEMP); 509 } 510 511 static void 512 notify_create(struct cdev *dev) 513 { 514 515 notify(dev, "CREATE"); 516 } 517 518 static void 519 notify_destroy(struct cdev *dev) 520 { 521 522 notify(dev, "DESTROY"); 523 } 524 525 static struct cdev * 526 newdev(struct cdevsw *csw, int y, struct cdev *si) 527 { 528 struct cdev *si2; 529 dev_t udev; 530 531 mtx_assert(&devmtx, MA_OWNED); 532 udev = y; 533 if (csw->d_flags & D_NEEDMINOR) { 534 /* We may want to return an existing device */ 535 LIST_FOREACH(si2, &csw->d_devs, si_list) { 536 if (si2->si_drv0 == udev) { 537 dev_free_devlocked(si); 538 return (si2); 539 } 540 } 541 } 542 si->si_drv0 = udev; 543 si->si_devsw = csw; 544 LIST_INSERT_HEAD(&csw->d_devs, si, si_list); 545 return (si); 546 } 547 548 #define UMINORMASK 0xffff00ffU 549 550 int 551 uminor(dev_t dev) 552 { 553 return (dev & UMINORMASK); 554 } 555 556 int 557 umajor(dev_t dev) 558 { 559 return ((dev & ~UMINORMASK) >> 8); 560 } 561 562 static void 563 fini_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 } 575 576 static void 577 prep_cdevsw(struct cdevsw *devsw) 578 { 579 struct cdevsw *dsw2; 580 581 mtx_assert(&devmtx, MA_OWNED); 582 if (devsw->d_flags & D_INIT) 583 return; 584 if (devsw->d_flags & D_NEEDGIANT) { 585 dev_unlock(); 586 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK); 587 dev_lock(); 588 } else 589 dsw2 = NULL; 590 if (devsw->d_flags & D_INIT) { 591 if (dsw2 != NULL) 592 cdevsw_free_devlocked(dsw2); 593 return; 594 } 595 596 if (devsw->d_version != D_VERSION_01) { 597 printf( 598 "WARNING: Device driver \"%s\" has wrong version %s\n", 599 devsw->d_name == NULL ? "???" : devsw->d_name, 600 "and is disabled. Recompile KLD module."); 601 devsw->d_open = dead_open; 602 devsw->d_close = dead_close; 603 devsw->d_read = dead_read; 604 devsw->d_write = dead_write; 605 devsw->d_ioctl = dead_ioctl; 606 devsw->d_poll = dead_poll; 607 devsw->d_mmap = dead_mmap; 608 devsw->d_strategy = dead_strategy; 609 devsw->d_dump = dead_dump; 610 devsw->d_kqfilter = dead_kqfilter; 611 } 612 613 if (devsw->d_flags & D_NEEDGIANT) { 614 if (devsw->d_gianttrick == NULL) { 615 memcpy(dsw2, devsw, sizeof *dsw2); 616 devsw->d_gianttrick = dsw2; 617 dsw2 = NULL; 618 } 619 } 620 621 #define FIXUP(member, noop, giant) \ 622 do { \ 623 if (devsw->member == NULL) { \ 624 devsw->member = noop; \ 625 } else if (devsw->d_flags & D_NEEDGIANT) \ 626 devsw->member = giant; \ 627 } \ 628 while (0) 629 630 FIXUP(d_open, null_open, giant_open); 631 FIXUP(d_fdopen, NULL, giant_fdopen); 632 FIXUP(d_close, null_close, giant_close); 633 FIXUP(d_read, no_read, giant_read); 634 FIXUP(d_write, no_write, giant_write); 635 FIXUP(d_ioctl, no_ioctl, giant_ioctl); 636 FIXUP(d_poll, no_poll, giant_poll); 637 FIXUP(d_mmap, no_mmap, giant_mmap); 638 FIXUP(d_strategy, no_strategy, giant_strategy); 639 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter); 640 641 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 642 643 LIST_INIT(&devsw->d_devs); 644 645 devsw->d_flags |= D_INIT; 646 647 if (dsw2 != NULL) 648 cdevsw_free_devlocked(dsw2); 649 } 650 651 struct cdev * 652 make_dev_credv(int flags, struct cdevsw *devsw, int minornr, 653 struct ucred *cr, uid_t uid, 654 gid_t gid, int mode, const char *fmt, va_list ap) 655 { 656 struct cdev *dev; 657 int i; 658 659 dev = devfs_alloc(); 660 dev_lock(); 661 prep_cdevsw(devsw); 662 dev = newdev(devsw, minornr, dev); 663 if (flags & MAKEDEV_REF) 664 dev_refl(dev); 665 if (dev->si_flags & SI_CHEAPCLONE && 666 dev->si_flags & SI_NAMED) { 667 /* 668 * This is allowed as it removes races and generally 669 * simplifies cloning devices. 670 * XXX: still ?? 671 */ 672 dev_unlock_and_free(); 673 return (dev); 674 } 675 KASSERT(!(dev->si_flags & SI_NAMED), 676 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)", 677 devsw->d_name, minor(dev), devtoname(dev))); 678 679 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 680 if (i > (sizeof dev->__si_namebuf - 1)) { 681 printf("WARNING: Device name truncated! (%s)\n", 682 dev->__si_namebuf); 683 } 684 685 dev->si_flags |= SI_NAMED; 686 if (cr != NULL) 687 dev->si_cred = crhold(cr); 688 else 689 dev->si_cred = NULL; 690 dev->si_uid = uid; 691 dev->si_gid = gid; 692 dev->si_mode = mode; 693 694 devfs_create(dev); 695 clean_unrhdrl(devfs_inos); 696 dev_unlock_and_free(); 697 698 notify_create(dev); 699 700 return (dev); 701 } 702 703 struct cdev * 704 make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int mode, 705 const char *fmt, ...) 706 { 707 struct cdev *dev; 708 va_list ap; 709 710 va_start(ap, fmt); 711 dev = make_dev_credv(0, devsw, minornr, NULL, uid, gid, mode, fmt, ap); 712 va_end(ap); 713 return (dev); 714 } 715 716 struct cdev * 717 make_dev_cred(struct cdevsw *devsw, int minornr, struct ucred *cr, uid_t uid, 718 gid_t gid, int mode, const char *fmt, ...) 719 { 720 struct cdev *dev; 721 va_list ap; 722 723 va_start(ap, fmt); 724 dev = make_dev_credv(0, devsw, minornr, cr, uid, gid, mode, fmt, ap); 725 va_end(ap); 726 727 return (dev); 728 } 729 730 struct cdev * 731 make_dev_credf(int flags, struct cdevsw *devsw, int minornr, 732 struct ucred *cr, uid_t uid, 733 gid_t gid, int mode, const char *fmt, ...) 734 { 735 struct cdev *dev; 736 va_list ap; 737 738 va_start(ap, fmt); 739 dev = make_dev_credv(flags, devsw, minornr, cr, uid, gid, mode, 740 fmt, ap); 741 va_end(ap); 742 743 return (dev); 744 } 745 746 static void 747 dev_dependsl(struct cdev *pdev, struct cdev *cdev) 748 { 749 750 cdev->si_parent = pdev; 751 cdev->si_flags |= SI_CHILD; 752 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 753 } 754 755 756 void 757 dev_depends(struct cdev *pdev, struct cdev *cdev) 758 { 759 760 dev_lock(); 761 dev_dependsl(pdev, cdev); 762 dev_unlock(); 763 } 764 765 struct cdev * 766 make_dev_alias(struct cdev *pdev, const char *fmt, ...) 767 { 768 struct cdev *dev; 769 va_list ap; 770 int i; 771 772 KASSERT(pdev != NULL, ("NULL pdev")); 773 dev = devfs_alloc(); 774 dev_lock(); 775 dev->si_flags |= SI_ALIAS; 776 dev->si_flags |= SI_NAMED; 777 va_start(ap, fmt); 778 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 779 if (i > (sizeof dev->__si_namebuf - 1)) { 780 printf("WARNING: Device name truncated! (%s)\n", 781 dev->__si_namebuf); 782 } 783 va_end(ap); 784 785 devfs_create(dev); 786 dev_dependsl(pdev, dev); 787 clean_unrhdrl(devfs_inos); 788 dev_unlock(); 789 790 notify_create(dev); 791 792 return (dev); 793 } 794 795 static void 796 destroy_devl(struct cdev *dev) 797 { 798 struct cdevsw *csw; 799 struct cdev_privdata *p, *p1; 800 801 mtx_assert(&devmtx, MA_OWNED); 802 KASSERT(dev->si_flags & SI_NAMED, 803 ("WARNING: Driver mistake: destroy_dev on %d\n", minor(dev))); 804 805 devfs_destroy(dev); 806 807 /* Remove name marking */ 808 dev->si_flags &= ~SI_NAMED; 809 810 /* If we are a child, remove us from the parents list */ 811 if (dev->si_flags & SI_CHILD) { 812 LIST_REMOVE(dev, si_siblings); 813 dev->si_flags &= ~SI_CHILD; 814 } 815 816 /* Kill our children */ 817 while (!LIST_EMPTY(&dev->si_children)) 818 destroy_devl(LIST_FIRST(&dev->si_children)); 819 820 /* Remove from clone list */ 821 if (dev->si_flags & SI_CLONELIST) { 822 LIST_REMOVE(dev, si_clone); 823 dev->si_flags &= ~SI_CLONELIST; 824 } 825 826 dev->si_refcount++; /* Avoid race with dev_rel() */ 827 csw = dev->si_devsw; 828 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 829 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 830 csw->d_purge(dev); 831 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 832 if (dev->si_threadcount) 833 printf("Still %lu threads in %s\n", 834 dev->si_threadcount, devtoname(dev)); 835 } 836 while (dev->si_threadcount != 0) { 837 /* Use unique dummy wait ident */ 838 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); 839 } 840 841 dev_unlock(); 842 notify_destroy(dev); 843 mtx_lock(&cdevpriv_mtx); 844 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) { 845 devfs_destroy_cdevpriv(p); 846 mtx_lock(&cdevpriv_mtx); 847 } 848 mtx_unlock(&cdevpriv_mtx); 849 dev_lock(); 850 851 dev->si_drv1 = 0; 852 dev->si_drv2 = 0; 853 bzero(&dev->__si_u, sizeof(dev->__si_u)); 854 855 if (!(dev->si_flags & SI_ALIAS)) { 856 /* Remove from cdevsw list */ 857 LIST_REMOVE(dev, si_list); 858 859 /* If cdevsw has no more struct cdev *'s, clean it */ 860 if (LIST_EMPTY(&csw->d_devs)) { 861 fini_cdevsw(csw); 862 wakeup(&csw->d_devs); 863 } 864 } 865 dev->si_flags &= ~SI_ALIAS; 866 dev->si_refcount--; /* Avoid race with dev_rel() */ 867 868 if (dev->si_refcount > 0) { 869 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 870 } else { 871 dev_free_devlocked(dev); 872 } 873 } 874 875 void 876 destroy_dev(struct cdev *dev) 877 { 878 879 dev_lock(); 880 destroy_devl(dev); 881 dev_unlock_and_free(); 882 } 883 884 const char * 885 devtoname(struct cdev *dev) 886 { 887 char *p; 888 struct cdevsw *csw; 889 int mynor; 890 891 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 892 p = dev->si_name; 893 csw = dev_refthread(dev); 894 if (csw != NULL) { 895 sprintf(p, "(%s)", csw->d_name); 896 dev_relthread(dev); 897 } 898 p += strlen(p); 899 mynor = minor(dev); 900 if (mynor < 0 || mynor > 255) 901 sprintf(p, "/%#x", (u_int)mynor); 902 else 903 sprintf(p, "/%d", mynor); 904 } 905 return (dev->si_name); 906 } 907 908 int 909 dev_stdclone(char *name, char **namep, const char *stem, int *unit) 910 { 911 int u, i; 912 913 i = strlen(stem); 914 if (bcmp(stem, name, i) != 0) 915 return (0); 916 if (!isdigit(name[i])) 917 return (0); 918 u = 0; 919 if (name[i] == '0' && isdigit(name[i+1])) 920 return (0); 921 while (isdigit(name[i])) { 922 u *= 10; 923 u += name[i++] - '0'; 924 } 925 if (u > 0xffffff) 926 return (0); 927 *unit = u; 928 if (namep) 929 *namep = &name[i]; 930 if (name[i]) 931 return (2); 932 return (1); 933 } 934 935 /* 936 * Helper functions for cloning device drivers. 937 * 938 * The objective here is to make it unnecessary for the device drivers to 939 * use rman or similar to manage their unit number space. Due to the way 940 * we do "on-demand" devices, using rman or other "private" methods 941 * will be very tricky to lock down properly once we lock down this file. 942 * 943 * Instead we give the drivers these routines which puts the struct cdev *'s 944 * that are to be managed on their own list, and gives the driver the ability 945 * to ask for the first free unit number or a given specified unit number. 946 * 947 * In addition these routines support paired devices (pty, nmdm and similar) 948 * by respecting a number of "flag" bits in the minor number. 949 * 950 */ 951 952 struct clonedevs { 953 LIST_HEAD(,cdev) head; 954 }; 955 956 void 957 clone_setup(struct clonedevs **cdp) 958 { 959 960 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 961 LIST_INIT(&(*cdp)->head); 962 } 963 964 int 965 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra) 966 { 967 struct clonedevs *cd; 968 struct cdev *dev, *ndev, *dl, *de; 969 int unit, low, u; 970 971 KASSERT(*cdp != NULL, 972 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 973 KASSERT(!(extra & CLONE_UNITMASK), 974 ("Illegal extra bits (0x%x) in clone_create", extra)); 975 KASSERT(*up <= CLONE_UNITMASK, 976 ("Too high unit (0x%x) in clone_create", *up)); 977 KASSERT(csw->d_flags & D_NEEDMINOR, 978 ("clone_create() on cdevsw without minor numbers")); 979 980 981 /* 982 * Search the list for a lot of things in one go: 983 * A preexisting match is returned immediately. 984 * The lowest free unit number if we are passed -1, and the place 985 * in the list where we should insert that new element. 986 * The place to insert a specified unit number, if applicable 987 * the end of the list. 988 */ 989 unit = *up; 990 ndev = devfs_alloc(); 991 dev_lock(); 992 prep_cdevsw(csw); 993 low = extra; 994 de = dl = NULL; 995 cd = *cdp; 996 LIST_FOREACH(dev, &cd->head, si_clone) { 997 KASSERT(dev->si_flags & SI_CLONELIST, 998 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 999 u = dev2unit(dev); 1000 if (u == (unit | extra)) { 1001 *dp = dev; 1002 dev_unlock(); 1003 devfs_free(ndev); 1004 return (0); 1005 } 1006 if (unit == -1 && u == low) { 1007 low++; 1008 de = dev; 1009 continue; 1010 } else if (u < (unit | extra)) { 1011 de = dev; 1012 continue; 1013 } else if (u > (unit | extra)) { 1014 dl = dev; 1015 break; 1016 } 1017 } 1018 if (unit == -1) 1019 unit = low & CLONE_UNITMASK; 1020 dev = newdev(csw, unit2minor(unit | extra), ndev); 1021 if (dev->si_flags & SI_CLONELIST) { 1022 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 1023 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra); 1024 LIST_FOREACH(dev, &cd->head, si_clone) { 1025 printf("\t%p %s\n", dev, dev->si_name); 1026 } 1027 panic("foo"); 1028 } 1029 KASSERT(!(dev->si_flags & SI_CLONELIST), 1030 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 1031 if (dl != NULL) 1032 LIST_INSERT_BEFORE(dl, dev, si_clone); 1033 else if (de != NULL) 1034 LIST_INSERT_AFTER(de, dev, si_clone); 1035 else 1036 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 1037 dev->si_flags |= SI_CLONELIST; 1038 *up = unit; 1039 dev_unlock_and_free(); 1040 return (1); 1041 } 1042 1043 /* 1044 * Kill everything still on the list. The driver should already have 1045 * disposed of any softc hung of the struct cdev *'s at this time. 1046 */ 1047 void 1048 clone_cleanup(struct clonedevs **cdp) 1049 { 1050 struct cdev *dev; 1051 struct cdev_priv *cp; 1052 struct clonedevs *cd; 1053 1054 cd = *cdp; 1055 if (cd == NULL) 1056 return; 1057 dev_lock(); 1058 while (!LIST_EMPTY(&cd->head)) { 1059 dev = LIST_FIRST(&cd->head); 1060 LIST_REMOVE(dev, si_clone); 1061 KASSERT(dev->si_flags & SI_CLONELIST, 1062 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1063 dev->si_flags &= ~SI_CLONELIST; 1064 cp = cdev2priv(dev); 1065 if (!(cp->cdp_flags & CDP_SCHED_DTR)) { 1066 cp->cdp_flags |= CDP_SCHED_DTR; 1067 KASSERT(dev->si_flags & SI_NAMED, 1068 ("Driver has goofed in cloning underways udev %x", dev->si_drv0)); 1069 destroy_devl(dev); 1070 } 1071 } 1072 dev_unlock_and_free(); 1073 free(cd, M_DEVBUF); 1074 *cdp = NULL; 1075 } 1076 1077 static TAILQ_HEAD(, cdev_priv) dev_ddtr = 1078 TAILQ_HEAD_INITIALIZER(dev_ddtr); 1079 static struct task dev_dtr_task; 1080 1081 static void 1082 destroy_dev_tq(void *ctx, int pending) 1083 { 1084 struct cdev_priv *cp; 1085 struct cdev *dev; 1086 void (*cb)(void *); 1087 void *cb_arg; 1088 1089 dev_lock(); 1090 while (!TAILQ_EMPTY(&dev_ddtr)) { 1091 cp = TAILQ_FIRST(&dev_ddtr); 1092 dev = &cp->cdp_c; 1093 KASSERT(cp->cdp_flags & CDP_SCHED_DTR, 1094 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp)); 1095 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list); 1096 cb = cp->cdp_dtr_cb; 1097 cb_arg = cp->cdp_dtr_cb_arg; 1098 destroy_devl(dev); 1099 dev_unlock_and_free(); 1100 dev_rel(dev); 1101 if (cb != NULL) 1102 cb(cb_arg); 1103 dev_lock(); 1104 } 1105 dev_unlock(); 1106 } 1107 1108 /* 1109 * devmtx shall be locked on entry. devmtx will be unlocked after 1110 * function return. 1111 */ 1112 static int 1113 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg) 1114 { 1115 struct cdev_priv *cp; 1116 1117 mtx_assert(&devmtx, MA_OWNED); 1118 cp = cdev2priv(dev); 1119 if (cp->cdp_flags & CDP_SCHED_DTR) { 1120 dev_unlock(); 1121 return (0); 1122 } 1123 dev_refl(dev); 1124 cp->cdp_flags |= CDP_SCHED_DTR; 1125 cp->cdp_dtr_cb = cb; 1126 cp->cdp_dtr_cb_arg = arg; 1127 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list); 1128 dev_unlock(); 1129 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task); 1130 return (1); 1131 } 1132 1133 int 1134 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg) 1135 { 1136 dev_lock(); 1137 return (destroy_dev_sched_cbl(dev, cb, arg)); 1138 } 1139 1140 int 1141 destroy_dev_sched(struct cdev *dev) 1142 { 1143 return (destroy_dev_sched_cb(dev, NULL, NULL)); 1144 } 1145 1146 void 1147 destroy_dev_drain(struct cdevsw *csw) 1148 { 1149 1150 dev_lock(); 1151 while (!LIST_EMPTY(&csw->d_devs)) { 1152 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10); 1153 } 1154 dev_unlock(); 1155 } 1156 1157 void 1158 drain_dev_clone_events(void) 1159 { 1160 1161 sx_xlock(&clone_drain_lock); 1162 sx_xunlock(&clone_drain_lock); 1163 } 1164 1165 static void 1166 devdtr_init(void *dummy __unused) 1167 { 1168 1169 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL); 1170 } 1171 1172 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL); 1173