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 #include <vm/vm.h> 51 52 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage"); 53 54 struct mtx devmtx; 55 static void destroy_devl(struct cdev *dev); 56 static int destroy_dev_sched_cbl(struct cdev *dev, 57 void (*cb)(void *), void *arg); 58 static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, 59 int unit, 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(cdevsw_gt_post_list); 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, int *ref) 181 { 182 struct cdevsw *csw; 183 struct cdev_priv *cdp; 184 185 mtx_assert(&devmtx, MA_NOTOWNED); 186 if ((dev->si_flags & SI_ETERNAL) != 0) { 187 *ref = 0; 188 return (dev->si_devsw); 189 } 190 dev_lock(); 191 csw = dev->si_devsw; 192 if (csw != NULL) { 193 cdp = cdev2priv(dev); 194 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) 195 dev->si_threadcount++; 196 else 197 csw = NULL; 198 } 199 dev_unlock(); 200 *ref = 1; 201 return (csw); 202 } 203 204 struct cdevsw * 205 devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref) 206 { 207 struct cdevsw *csw; 208 struct cdev_priv *cdp; 209 struct cdev *dev; 210 211 mtx_assert(&devmtx, MA_NOTOWNED); 212 if ((vp->v_vflag & VV_ETERNALDEV) != 0) { 213 dev = vp->v_rdev; 214 if (dev == NULL) 215 return (NULL); 216 KASSERT((dev->si_flags & SI_ETERNAL) != 0, 217 ("Not eternal cdev")); 218 *ref = 0; 219 csw = dev->si_devsw; 220 KASSERT(csw != NULL, ("Eternal cdev is destroyed")); 221 *devp = dev; 222 return (csw); 223 } 224 225 csw = NULL; 226 dev_lock(); 227 dev = vp->v_rdev; 228 if (dev == NULL) { 229 dev_unlock(); 230 return (NULL); 231 } 232 cdp = cdev2priv(dev); 233 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) { 234 csw = dev->si_devsw; 235 if (csw != NULL) 236 dev->si_threadcount++; 237 } 238 dev_unlock(); 239 if (csw != NULL) { 240 *devp = dev; 241 *ref = 1; 242 } 243 return (csw); 244 } 245 246 void 247 dev_relthread(struct cdev *dev, int ref) 248 { 249 250 mtx_assert(&devmtx, MA_NOTOWNED); 251 if (!ref) 252 return; 253 dev_lock(); 254 KASSERT(dev->si_threadcount > 0, 255 ("%s threadcount is wrong", dev->si_name)); 256 dev->si_threadcount--; 257 dev_unlock(); 258 } 259 260 int 261 nullop(void) 262 { 263 264 return (0); 265 } 266 267 int 268 eopnotsupp(void) 269 { 270 271 return (EOPNOTSUPP); 272 } 273 274 static int 275 enxio(void) 276 { 277 return (ENXIO); 278 } 279 280 static int 281 enodev(void) 282 { 283 return (ENODEV); 284 } 285 286 /* Define a dead_cdevsw for use when devices leave unexpectedly. */ 287 288 #define dead_open (d_open_t *)enxio 289 #define dead_close (d_close_t *)enxio 290 #define dead_read (d_read_t *)enxio 291 #define dead_write (d_write_t *)enxio 292 #define dead_ioctl (d_ioctl_t *)enxio 293 #define dead_poll (d_poll_t *)enodev 294 #define dead_mmap (d_mmap_t *)enodev 295 296 static void 297 dead_strategy(struct bio *bp) 298 { 299 300 biofinish(bp, NULL, ENXIO); 301 } 302 303 #define dead_dump (dumper_t *)enxio 304 #define dead_kqfilter (d_kqfilter_t *)enxio 305 #define dead_mmap_single (d_mmap_single_t *)enodev 306 307 static struct cdevsw dead_cdevsw = { 308 .d_version = D_VERSION, 309 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 310 .d_open = dead_open, 311 .d_close = dead_close, 312 .d_read = dead_read, 313 .d_write = dead_write, 314 .d_ioctl = dead_ioctl, 315 .d_poll = dead_poll, 316 .d_mmap = dead_mmap, 317 .d_strategy = dead_strategy, 318 .d_name = "dead", 319 .d_dump = dead_dump, 320 .d_kqfilter = dead_kqfilter, 321 .d_mmap_single = dead_mmap_single 322 }; 323 324 /* Default methods if driver does not specify method */ 325 326 #define null_open (d_open_t *)nullop 327 #define null_close (d_close_t *)nullop 328 #define no_read (d_read_t *)enodev 329 #define no_write (d_write_t *)enodev 330 #define no_ioctl (d_ioctl_t *)enodev 331 #define no_mmap (d_mmap_t *)enodev 332 #define no_kqfilter (d_kqfilter_t *)enodev 333 #define no_mmap_single (d_mmap_single_t *)enodev 334 335 static void 336 no_strategy(struct bio *bp) 337 { 338 339 biofinish(bp, NULL, ENODEV); 340 } 341 342 static int 343 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 344 { 345 346 return (poll_no_poll(events)); 347 } 348 349 #define no_dump (dumper_t *)enodev 350 351 static int 352 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 353 { 354 struct cdevsw *dsw; 355 int ref, retval; 356 357 dsw = dev_refthread(dev, &ref); 358 if (dsw == NULL) 359 return (ENXIO); 360 mtx_lock(&Giant); 361 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td); 362 mtx_unlock(&Giant); 363 dev_relthread(dev, ref); 364 return (retval); 365 } 366 367 static int 368 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp) 369 { 370 struct cdevsw *dsw; 371 int ref, retval; 372 373 dsw = dev_refthread(dev, &ref); 374 if (dsw == NULL) 375 return (ENXIO); 376 mtx_lock(&Giant); 377 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp); 378 mtx_unlock(&Giant); 379 dev_relthread(dev, ref); 380 return (retval); 381 } 382 383 static int 384 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 385 { 386 struct cdevsw *dsw; 387 int ref, retval; 388 389 dsw = dev_refthread(dev, &ref); 390 if (dsw == NULL) 391 return (ENXIO); 392 mtx_lock(&Giant); 393 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td); 394 mtx_unlock(&Giant); 395 dev_relthread(dev, ref); 396 return (retval); 397 } 398 399 static void 400 giant_strategy(struct bio *bp) 401 { 402 struct cdevsw *dsw; 403 struct cdev *dev; 404 int ref; 405 406 dev = bp->bio_dev; 407 dsw = dev_refthread(dev, &ref); 408 if (dsw == NULL) { 409 biofinish(bp, NULL, ENXIO); 410 return; 411 } 412 mtx_lock(&Giant); 413 dsw->d_gianttrick->d_strategy(bp); 414 mtx_unlock(&Giant); 415 dev_relthread(dev, ref); 416 } 417 418 static int 419 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 420 { 421 struct cdevsw *dsw; 422 int ref, retval; 423 424 dsw = dev_refthread(dev, &ref); 425 if (dsw == NULL) 426 return (ENXIO); 427 mtx_lock(&Giant); 428 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td); 429 mtx_unlock(&Giant); 430 dev_relthread(dev, ref); 431 return (retval); 432 } 433 434 static int 435 giant_read(struct cdev *dev, struct uio *uio, int ioflag) 436 { 437 struct cdevsw *dsw; 438 int ref, retval; 439 440 dsw = dev_refthread(dev, &ref); 441 if (dsw == NULL) 442 return (ENXIO); 443 mtx_lock(&Giant); 444 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag); 445 mtx_unlock(&Giant); 446 dev_relthread(dev, ref); 447 return (retval); 448 } 449 450 static int 451 giant_write(struct cdev *dev, struct uio *uio, int ioflag) 452 { 453 struct cdevsw *dsw; 454 int ref, retval; 455 456 dsw = dev_refthread(dev, &ref); 457 if (dsw == NULL) 458 return (ENXIO); 459 mtx_lock(&Giant); 460 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag); 461 mtx_unlock(&Giant); 462 dev_relthread(dev, ref); 463 return (retval); 464 } 465 466 static int 467 giant_poll(struct cdev *dev, int events, struct thread *td) 468 { 469 struct cdevsw *dsw; 470 int ref, retval; 471 472 dsw = dev_refthread(dev, &ref); 473 if (dsw == NULL) 474 return (ENXIO); 475 mtx_lock(&Giant); 476 retval = dsw->d_gianttrick->d_poll(dev, events, td); 477 mtx_unlock(&Giant); 478 dev_relthread(dev, ref); 479 return (retval); 480 } 481 482 static int 483 giant_kqfilter(struct cdev *dev, struct knote *kn) 484 { 485 struct cdevsw *dsw; 486 int ref, retval; 487 488 dsw = dev_refthread(dev, &ref); 489 if (dsw == NULL) 490 return (ENXIO); 491 mtx_lock(&Giant); 492 retval = dsw->d_gianttrick->d_kqfilter(dev, kn); 493 mtx_unlock(&Giant); 494 dev_relthread(dev, ref); 495 return (retval); 496 } 497 498 static int 499 giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot, 500 vm_memattr_t *memattr) 501 { 502 struct cdevsw *dsw; 503 int ref, retval; 504 505 dsw = dev_refthread(dev, &ref); 506 if (dsw == NULL) 507 return (ENXIO); 508 mtx_lock(&Giant); 509 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot, 510 memattr); 511 mtx_unlock(&Giant); 512 dev_relthread(dev, ref); 513 return (retval); 514 } 515 516 static int 517 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size, 518 vm_object_t *object, int nprot) 519 { 520 struct cdevsw *dsw; 521 int ref, retval; 522 523 dsw = dev_refthread(dev, &ref); 524 if (dsw == NULL) 525 return (ENXIO); 526 mtx_lock(&Giant); 527 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object, 528 nprot); 529 mtx_unlock(&Giant); 530 dev_relthread(dev, ref); 531 return (retval); 532 } 533 534 static void 535 notify(struct cdev *dev, const char *ev, int flags) 536 { 537 static const char prefix[] = "cdev="; 538 char *data; 539 int namelen, mflags; 540 541 if (cold) 542 return; 543 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK; 544 namelen = strlen(dev->si_name); 545 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags); 546 if (data == NULL) 547 return; 548 memcpy(data, prefix, sizeof(prefix) - 1); 549 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1); 550 devctl_notify_f("DEVFS", "CDEV", ev, data, mflags); 551 free(data, M_TEMP); 552 } 553 554 static void 555 notify_create(struct cdev *dev, int flags) 556 { 557 558 notify(dev, "CREATE", flags); 559 } 560 561 static void 562 notify_destroy(struct cdev *dev) 563 { 564 565 notify(dev, "DESTROY", MAKEDEV_WAITOK); 566 } 567 568 static struct cdev * 569 newdev(struct cdevsw *csw, int unit, struct cdev *si) 570 { 571 struct cdev *si2; 572 573 mtx_assert(&devmtx, MA_OWNED); 574 if (csw->d_flags & D_NEEDMINOR) { 575 /* We may want to return an existing device */ 576 LIST_FOREACH(si2, &csw->d_devs, si_list) { 577 if (dev2unit(si2) == unit) { 578 dev_free_devlocked(si); 579 return (si2); 580 } 581 } 582 } 583 si->si_drv0 = unit; 584 si->si_devsw = csw; 585 LIST_INSERT_HEAD(&csw->d_devs, si, si_list); 586 return (si); 587 } 588 589 static void 590 fini_cdevsw(struct cdevsw *devsw) 591 { 592 struct cdevsw *gt; 593 594 if (devsw->d_gianttrick != NULL) { 595 gt = devsw->d_gianttrick; 596 memcpy(devsw, gt, sizeof *devsw); 597 cdevsw_free_devlocked(gt); 598 devsw->d_gianttrick = NULL; 599 } 600 devsw->d_flags &= ~D_INIT; 601 } 602 603 static int 604 prep_cdevsw(struct cdevsw *devsw, int flags) 605 { 606 struct cdevsw *dsw2; 607 608 mtx_assert(&devmtx, MA_OWNED); 609 if (devsw->d_flags & D_INIT) 610 return (0); 611 if (devsw->d_flags & D_NEEDGIANT) { 612 dev_unlock(); 613 dsw2 = malloc(sizeof *dsw2, M_DEVT, 614 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK); 615 dev_lock(); 616 if (dsw2 == NULL && !(devsw->d_flags & D_INIT)) 617 return (ENOMEM); 618 } else 619 dsw2 = NULL; 620 if (devsw->d_flags & D_INIT) { 621 if (dsw2 != NULL) 622 cdevsw_free_devlocked(dsw2); 623 return (0); 624 } 625 626 if (devsw->d_version != D_VERSION_03) { 627 printf( 628 "WARNING: Device driver \"%s\" has wrong version %s\n", 629 devsw->d_name == NULL ? "???" : devsw->d_name, 630 "and is disabled. Recompile KLD module."); 631 devsw->d_open = dead_open; 632 devsw->d_close = dead_close; 633 devsw->d_read = dead_read; 634 devsw->d_write = dead_write; 635 devsw->d_ioctl = dead_ioctl; 636 devsw->d_poll = dead_poll; 637 devsw->d_mmap = dead_mmap; 638 devsw->d_mmap_single = dead_mmap_single; 639 devsw->d_strategy = dead_strategy; 640 devsw->d_dump = dead_dump; 641 devsw->d_kqfilter = dead_kqfilter; 642 } 643 644 if (devsw->d_flags & D_NEEDGIANT) { 645 if (devsw->d_gianttrick == NULL) { 646 memcpy(dsw2, devsw, sizeof *dsw2); 647 devsw->d_gianttrick = dsw2; 648 dsw2 = NULL; 649 } 650 } 651 652 #define FIXUP(member, noop, giant) \ 653 do { \ 654 if (devsw->member == NULL) { \ 655 devsw->member = noop; \ 656 } else if (devsw->d_flags & D_NEEDGIANT) \ 657 devsw->member = giant; \ 658 } \ 659 while (0) 660 661 FIXUP(d_open, null_open, giant_open); 662 FIXUP(d_fdopen, NULL, giant_fdopen); 663 FIXUP(d_close, null_close, giant_close); 664 FIXUP(d_read, no_read, giant_read); 665 FIXUP(d_write, no_write, giant_write); 666 FIXUP(d_ioctl, no_ioctl, giant_ioctl); 667 FIXUP(d_poll, no_poll, giant_poll); 668 FIXUP(d_mmap, no_mmap, giant_mmap); 669 FIXUP(d_strategy, no_strategy, giant_strategy); 670 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter); 671 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single); 672 673 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 674 675 LIST_INIT(&devsw->d_devs); 676 677 devsw->d_flags |= D_INIT; 678 679 if (dsw2 != NULL) 680 cdevsw_free_devlocked(dsw2); 681 return (0); 682 } 683 684 static int 685 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit, 686 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, 687 va_list ap) 688 { 689 struct cdev *dev; 690 int i, res; 691 692 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0, 693 ("make_dev_credv: both WAITOK and NOWAIT specified")); 694 dev = devfs_alloc(flags); 695 if (dev == NULL) 696 return (ENOMEM); 697 dev_lock(); 698 res = prep_cdevsw(devsw, flags); 699 if (res != 0) { 700 dev_unlock(); 701 devfs_free(dev); 702 return (res); 703 } 704 dev = newdev(devsw, unit, dev); 705 if (flags & MAKEDEV_REF) 706 dev_refl(dev); 707 if (flags & MAKEDEV_ETERNAL) 708 dev->si_flags |= SI_ETERNAL; 709 if (dev->si_flags & SI_CHEAPCLONE && 710 dev->si_flags & SI_NAMED) { 711 /* 712 * This is allowed as it removes races and generally 713 * simplifies cloning devices. 714 * XXX: still ?? 715 */ 716 dev_unlock_and_free(); 717 *dres = dev; 718 return (0); 719 } 720 KASSERT(!(dev->si_flags & SI_NAMED), 721 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)", 722 devsw->d_name, dev2unit(dev), devtoname(dev))); 723 724 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 725 if (i > (sizeof dev->__si_namebuf - 1)) { 726 printf("WARNING: Device name truncated! (%s)\n", 727 dev->__si_namebuf); 728 } 729 730 dev->si_flags |= SI_NAMED; 731 if (cr != NULL) 732 dev->si_cred = crhold(cr); 733 dev->si_uid = uid; 734 dev->si_gid = gid; 735 dev->si_mode = mode; 736 737 devfs_create(dev); 738 clean_unrhdrl(devfs_inos); 739 dev_unlock_and_free(); 740 741 notify_create(dev, flags); 742 743 *dres = dev; 744 return (0); 745 } 746 747 struct cdev * 748 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode, 749 const char *fmt, ...) 750 { 751 struct cdev *dev; 752 va_list ap; 753 int res; 754 755 va_start(ap, fmt); 756 res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt, 757 ap); 758 va_end(ap); 759 KASSERT(res == 0 && dev != NULL, ("make_dev: failed make_dev_credv")); 760 return (dev); 761 } 762 763 struct cdev * 764 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid, 765 gid_t gid, int mode, const char *fmt, ...) 766 { 767 struct cdev *dev; 768 va_list ap; 769 int res; 770 771 va_start(ap, fmt); 772 res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap); 773 va_end(ap); 774 775 KASSERT(res == 0 && dev != NULL, 776 ("make_dev_cred: failed make_dev_credv")); 777 return (dev); 778 } 779 780 struct cdev * 781 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr, 782 uid_t uid, gid_t gid, int mode, const char *fmt, ...) 783 { 784 struct cdev *dev; 785 va_list ap; 786 int res; 787 788 va_start(ap, fmt); 789 res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode, 790 fmt, ap); 791 va_end(ap); 792 793 KASSERT((flags & MAKEDEV_NOWAIT) != 0 || res == 0, 794 ("make_dev_credf: failed make_dev_credv")); 795 return (res == 0 ? dev : NULL); 796 } 797 798 int 799 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw, 800 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...) 801 { 802 va_list ap; 803 int res; 804 805 va_start(ap, fmt); 806 res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode, 807 fmt, ap); 808 va_end(ap); 809 810 KASSERT((flags & MAKEDEV_NOWAIT) != 0 || res == 0, 811 ("make_dev_p: failed make_dev_credv")); 812 return (res); 813 } 814 815 static void 816 dev_dependsl(struct cdev *pdev, struct cdev *cdev) 817 { 818 819 cdev->si_parent = pdev; 820 cdev->si_flags |= SI_CHILD; 821 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 822 } 823 824 825 void 826 dev_depends(struct cdev *pdev, struct cdev *cdev) 827 { 828 829 dev_lock(); 830 dev_dependsl(pdev, cdev); 831 dev_unlock(); 832 } 833 834 struct cdev * 835 make_dev_alias(struct cdev *pdev, const char *fmt, ...) 836 { 837 struct cdev *dev; 838 va_list ap; 839 int i; 840 841 KASSERT(pdev != NULL, ("NULL pdev")); 842 dev = devfs_alloc(MAKEDEV_WAITOK); 843 dev_lock(); 844 dev->si_flags |= SI_ALIAS; 845 dev->si_flags |= SI_NAMED; 846 va_start(ap, fmt); 847 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 848 if (i > (sizeof dev->__si_namebuf - 1)) { 849 printf("WARNING: Device name truncated! (%s)\n", 850 dev->__si_namebuf); 851 } 852 va_end(ap); 853 854 devfs_create(dev); 855 dev_dependsl(pdev, dev); 856 clean_unrhdrl(devfs_inos); 857 dev_unlock(); 858 859 notify_create(dev, MAKEDEV_WAITOK); 860 861 return (dev); 862 } 863 864 static void 865 destroy_devl(struct cdev *dev) 866 { 867 struct cdevsw *csw; 868 struct cdev_privdata *p, *p1; 869 870 mtx_assert(&devmtx, MA_OWNED); 871 KASSERT(dev->si_flags & SI_NAMED, 872 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev))); 873 KASSERT((dev->si_flags & SI_ETERNAL) == 0, 874 ("WARNING: Driver mistake: destroy_dev on eternal %d\n", 875 dev2unit(dev))); 876 877 devfs_destroy(dev); 878 879 /* Remove name marking */ 880 dev->si_flags &= ~SI_NAMED; 881 882 /* If we are a child, remove us from the parents list */ 883 if (dev->si_flags & SI_CHILD) { 884 LIST_REMOVE(dev, si_siblings); 885 dev->si_flags &= ~SI_CHILD; 886 } 887 888 /* Kill our children */ 889 while (!LIST_EMPTY(&dev->si_children)) 890 destroy_devl(LIST_FIRST(&dev->si_children)); 891 892 /* Remove from clone list */ 893 if (dev->si_flags & SI_CLONELIST) { 894 LIST_REMOVE(dev, si_clone); 895 dev->si_flags &= ~SI_CLONELIST; 896 } 897 898 dev->si_refcount++; /* Avoid race with dev_rel() */ 899 csw = dev->si_devsw; 900 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 901 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 902 csw->d_purge(dev); 903 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 904 if (dev->si_threadcount) 905 printf("Still %lu threads in %s\n", 906 dev->si_threadcount, devtoname(dev)); 907 } 908 while (dev->si_threadcount != 0) { 909 /* Use unique dummy wait ident */ 910 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); 911 } 912 913 dev_unlock(); 914 notify_destroy(dev); 915 mtx_lock(&cdevpriv_mtx); 916 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) { 917 devfs_destroy_cdevpriv(p); 918 mtx_lock(&cdevpriv_mtx); 919 } 920 mtx_unlock(&cdevpriv_mtx); 921 dev_lock(); 922 923 dev->si_drv1 = 0; 924 dev->si_drv2 = 0; 925 bzero(&dev->__si_u, sizeof(dev->__si_u)); 926 927 if (!(dev->si_flags & SI_ALIAS)) { 928 /* Remove from cdevsw list */ 929 LIST_REMOVE(dev, si_list); 930 931 /* If cdevsw has no more struct cdev *'s, clean it */ 932 if (LIST_EMPTY(&csw->d_devs)) { 933 fini_cdevsw(csw); 934 wakeup(&csw->d_devs); 935 } 936 } 937 dev->si_flags &= ~SI_ALIAS; 938 dev->si_refcount--; /* Avoid race with dev_rel() */ 939 940 if (dev->si_refcount > 0) { 941 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 942 } else { 943 dev_free_devlocked(dev); 944 } 945 } 946 947 void 948 destroy_dev(struct cdev *dev) 949 { 950 951 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev"); 952 dev_lock(); 953 destroy_devl(dev); 954 dev_unlock_and_free(); 955 } 956 957 const char * 958 devtoname(struct cdev *dev) 959 { 960 961 return (dev->si_name); 962 } 963 964 int 965 dev_stdclone(char *name, char **namep, const char *stem, int *unit) 966 { 967 int u, i; 968 969 i = strlen(stem); 970 if (bcmp(stem, name, i) != 0) 971 return (0); 972 if (!isdigit(name[i])) 973 return (0); 974 u = 0; 975 if (name[i] == '0' && isdigit(name[i+1])) 976 return (0); 977 while (isdigit(name[i])) { 978 u *= 10; 979 u += name[i++] - '0'; 980 } 981 if (u > 0xffffff) 982 return (0); 983 *unit = u; 984 if (namep) 985 *namep = &name[i]; 986 if (name[i]) 987 return (2); 988 return (1); 989 } 990 991 /* 992 * Helper functions for cloning device drivers. 993 * 994 * The objective here is to make it unnecessary for the device drivers to 995 * use rman or similar to manage their unit number space. Due to the way 996 * we do "on-demand" devices, using rman or other "private" methods 997 * will be very tricky to lock down properly once we lock down this file. 998 * 999 * Instead we give the drivers these routines which puts the struct cdev *'s 1000 * that are to be managed on their own list, and gives the driver the ability 1001 * to ask for the first free unit number or a given specified unit number. 1002 * 1003 * In addition these routines support paired devices (pty, nmdm and similar) 1004 * by respecting a number of "flag" bits in the minor number. 1005 * 1006 */ 1007 1008 struct clonedevs { 1009 LIST_HEAD(,cdev) head; 1010 }; 1011 1012 void 1013 clone_setup(struct clonedevs **cdp) 1014 { 1015 1016 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 1017 LIST_INIT(&(*cdp)->head); 1018 } 1019 1020 int 1021 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, 1022 struct cdev **dp, int extra) 1023 { 1024 struct clonedevs *cd; 1025 struct cdev *dev, *ndev, *dl, *de; 1026 int unit, low, u; 1027 1028 KASSERT(*cdp != NULL, 1029 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 1030 KASSERT(!(extra & CLONE_UNITMASK), 1031 ("Illegal extra bits (0x%x) in clone_create", extra)); 1032 KASSERT(*up <= CLONE_UNITMASK, 1033 ("Too high unit (0x%x) in clone_create", *up)); 1034 KASSERT(csw->d_flags & D_NEEDMINOR, 1035 ("clone_create() on cdevsw without minor numbers")); 1036 1037 1038 /* 1039 * Search the list for a lot of things in one go: 1040 * A preexisting match is returned immediately. 1041 * The lowest free unit number if we are passed -1, and the place 1042 * in the list where we should insert that new element. 1043 * The place to insert a specified unit number, if applicable 1044 * the end of the list. 1045 */ 1046 unit = *up; 1047 ndev = devfs_alloc(MAKEDEV_WAITOK); 1048 dev_lock(); 1049 prep_cdevsw(csw, MAKEDEV_WAITOK); 1050 low = extra; 1051 de = dl = NULL; 1052 cd = *cdp; 1053 LIST_FOREACH(dev, &cd->head, si_clone) { 1054 KASSERT(dev->si_flags & SI_CLONELIST, 1055 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1056 u = dev2unit(dev); 1057 if (u == (unit | extra)) { 1058 *dp = dev; 1059 dev_unlock(); 1060 devfs_free(ndev); 1061 return (0); 1062 } 1063 if (unit == -1 && u == low) { 1064 low++; 1065 de = dev; 1066 continue; 1067 } else if (u < (unit | extra)) { 1068 de = dev; 1069 continue; 1070 } else if (u > (unit | extra)) { 1071 dl = dev; 1072 break; 1073 } 1074 } 1075 if (unit == -1) 1076 unit = low & CLONE_UNITMASK; 1077 dev = newdev(csw, unit | extra, ndev); 1078 if (dev->si_flags & SI_CLONELIST) { 1079 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 1080 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra); 1081 LIST_FOREACH(dev, &cd->head, si_clone) { 1082 printf("\t%p %s\n", dev, dev->si_name); 1083 } 1084 panic("foo"); 1085 } 1086 KASSERT(!(dev->si_flags & SI_CLONELIST), 1087 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 1088 if (dl != NULL) 1089 LIST_INSERT_BEFORE(dl, dev, si_clone); 1090 else if (de != NULL) 1091 LIST_INSERT_AFTER(de, dev, si_clone); 1092 else 1093 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 1094 dev->si_flags |= SI_CLONELIST; 1095 *up = unit; 1096 dev_unlock_and_free(); 1097 return (1); 1098 } 1099 1100 /* 1101 * Kill everything still on the list. The driver should already have 1102 * disposed of any softc hung of the struct cdev *'s at this time. 1103 */ 1104 void 1105 clone_cleanup(struct clonedevs **cdp) 1106 { 1107 struct cdev *dev; 1108 struct cdev_priv *cp; 1109 struct clonedevs *cd; 1110 1111 cd = *cdp; 1112 if (cd == NULL) 1113 return; 1114 dev_lock(); 1115 while (!LIST_EMPTY(&cd->head)) { 1116 dev = LIST_FIRST(&cd->head); 1117 LIST_REMOVE(dev, si_clone); 1118 KASSERT(dev->si_flags & SI_CLONELIST, 1119 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1120 dev->si_flags &= ~SI_CLONELIST; 1121 cp = cdev2priv(dev); 1122 if (!(cp->cdp_flags & CDP_SCHED_DTR)) { 1123 cp->cdp_flags |= CDP_SCHED_DTR; 1124 KASSERT(dev->si_flags & SI_NAMED, 1125 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev))); 1126 destroy_devl(dev); 1127 } 1128 } 1129 dev_unlock_and_free(); 1130 free(cd, M_DEVBUF); 1131 *cdp = NULL; 1132 } 1133 1134 static TAILQ_HEAD(, cdev_priv) dev_ddtr = 1135 TAILQ_HEAD_INITIALIZER(dev_ddtr); 1136 static struct task dev_dtr_task; 1137 1138 static void 1139 destroy_dev_tq(void *ctx, int pending) 1140 { 1141 struct cdev_priv *cp; 1142 struct cdev *dev; 1143 void (*cb)(void *); 1144 void *cb_arg; 1145 1146 dev_lock(); 1147 while (!TAILQ_EMPTY(&dev_ddtr)) { 1148 cp = TAILQ_FIRST(&dev_ddtr); 1149 dev = &cp->cdp_c; 1150 KASSERT(cp->cdp_flags & CDP_SCHED_DTR, 1151 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp)); 1152 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list); 1153 cb = cp->cdp_dtr_cb; 1154 cb_arg = cp->cdp_dtr_cb_arg; 1155 destroy_devl(dev); 1156 dev_unlock_and_free(); 1157 dev_rel(dev); 1158 if (cb != NULL) 1159 cb(cb_arg); 1160 dev_lock(); 1161 } 1162 dev_unlock(); 1163 } 1164 1165 /* 1166 * devmtx shall be locked on entry. devmtx will be unlocked after 1167 * function return. 1168 */ 1169 static int 1170 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg) 1171 { 1172 struct cdev_priv *cp; 1173 1174 mtx_assert(&devmtx, MA_OWNED); 1175 cp = cdev2priv(dev); 1176 if (cp->cdp_flags & CDP_SCHED_DTR) { 1177 dev_unlock(); 1178 return (0); 1179 } 1180 dev_refl(dev); 1181 cp->cdp_flags |= CDP_SCHED_DTR; 1182 cp->cdp_dtr_cb = cb; 1183 cp->cdp_dtr_cb_arg = arg; 1184 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list); 1185 dev_unlock(); 1186 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task); 1187 return (1); 1188 } 1189 1190 int 1191 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg) 1192 { 1193 1194 dev_lock(); 1195 return (destroy_dev_sched_cbl(dev, cb, arg)); 1196 } 1197 1198 int 1199 destroy_dev_sched(struct cdev *dev) 1200 { 1201 1202 return (destroy_dev_sched_cb(dev, NULL, NULL)); 1203 } 1204 1205 void 1206 destroy_dev_drain(struct cdevsw *csw) 1207 { 1208 1209 dev_lock(); 1210 while (!LIST_EMPTY(&csw->d_devs)) { 1211 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10); 1212 } 1213 dev_unlock(); 1214 } 1215 1216 void 1217 drain_dev_clone_events(void) 1218 { 1219 1220 sx_xlock(&clone_drain_lock); 1221 sx_xunlock(&clone_drain_lock); 1222 } 1223 1224 static void 1225 devdtr_init(void *dummy __unused) 1226 { 1227 1228 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL); 1229 } 1230 1231 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL); 1232 1233 #include "opt_ddb.h" 1234 #ifdef DDB 1235 #include <sys/kernel.h> 1236 1237 #include <ddb/ddb.h> 1238 1239 DB_SHOW_COMMAND(cdev, db_show_cdev) 1240 { 1241 struct cdev_priv *cdp; 1242 struct cdev *dev; 1243 u_int flags; 1244 char buf[512]; 1245 1246 if (!have_addr) { 1247 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) { 1248 dev = &cdp->cdp_c; 1249 db_printf("%s %p\n", dev->si_name, dev); 1250 if (db_pager_quit) 1251 break; 1252 } 1253 return; 1254 } 1255 1256 dev = (struct cdev *)addr; 1257 cdp = cdev2priv(dev); 1258 db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n", 1259 dev->si_name, dev->si_refcount, dev->si_usecount, 1260 dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first); 1261 db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n", 1262 dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2); 1263 flags = dev->si_flags; 1264 #define SI_FLAG(flag) do { \ 1265 if (flags & (flag)) { \ 1266 if (buf[0] != '\0') \ 1267 strlcat(buf, ", ", sizeof(buf)); \ 1268 strlcat(buf, (#flag) + 3, sizeof(buf)); \ 1269 flags &= ~(flag); \ 1270 } \ 1271 } while (0) 1272 buf[0] = '\0'; 1273 SI_FLAG(SI_ETERNAL); 1274 SI_FLAG(SI_ALIAS); 1275 SI_FLAG(SI_NAMED); 1276 SI_FLAG(SI_CHEAPCLONE); 1277 SI_FLAG(SI_CHILD); 1278 SI_FLAG(SI_DEVOPEN); 1279 SI_FLAG(SI_CONSOPEN); 1280 SI_FLAG(SI_DUMPDEV); 1281 SI_FLAG(SI_CANDELETE); 1282 SI_FLAG(SI_CLONELIST); 1283 db_printf("si_flags %s\n", buf); 1284 1285 flags = cdp->cdp_flags; 1286 #define CDP_FLAG(flag) do { \ 1287 if (flags & (flag)) { \ 1288 if (buf[0] != '\0') \ 1289 strlcat(buf, ", ", sizeof(buf)); \ 1290 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 1291 flags &= ~(flag); \ 1292 } \ 1293 } while (0) 1294 buf[0] = '\0'; 1295 CDP_FLAG(CDP_ACTIVE); 1296 CDP_FLAG(CDP_SCHED_DTR); 1297 db_printf("cdp_flags %s\n", buf); 1298 } 1299 #endif 1300