Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_conf.c
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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/tty.h> 46 #include <sys/ucred.h> 47 #include <sys/taskqueue.h> 48 #include <machine/stdarg.h> 49 50 #include <fs/devfs/devfs_int.h> 51 #include <vm/vm.h> 52 53 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage"); 54 55 struct mtx devmtx; 56 static void destroy_devl(struct cdev *dev); 57 static int destroy_dev_sched_cbl(struct cdev *dev, 58 void (*cb)(void *), void *arg); 59 static struct cdev *make_dev_credv(int flags, 60 struct cdevsw *devsw, int minornr, 61 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, 62 va_list ap); 63 64 static struct cdev_priv_list cdevp_free_list = 65 TAILQ_HEAD_INITIALIZER(cdevp_free_list); 66 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list = 67 SLIST_HEAD_INITIALIZER(); 68 69 void 70 dev_lock(void) 71 { 72 73 mtx_lock(&devmtx); 74 } 75 76 /* 77 * Free all the memory collected while the cdev mutex was 78 * locked. Since devmtx is after the system map mutex, free() cannot 79 * be called immediately and is postponed until cdev mutex can be 80 * dropped. 81 */ 82 static void 83 dev_unlock_and_free(void) 84 { 85 struct cdev_priv_list cdp_free; 86 struct free_cdevsw csw_free; 87 struct cdev_priv *cdp; 88 struct cdevsw *csw; 89 90 mtx_assert(&devmtx, MA_OWNED); 91 92 /* 93 * Make the local copy of the list heads while the dev_mtx is 94 * held. Free it later. 95 */ 96 TAILQ_INIT(&cdp_free); 97 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list); 98 csw_free = cdevsw_gt_post_list; 99 SLIST_INIT(&cdevsw_gt_post_list); 100 101 mtx_unlock(&devmtx); 102 103 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) { 104 TAILQ_REMOVE(&cdp_free, cdp, cdp_list); 105 devfs_free(&cdp->cdp_c); 106 } 107 while ((csw = SLIST_FIRST(&csw_free)) != NULL) { 108 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list); 109 free(csw, M_DEVT); 110 } 111 } 112 113 static void 114 dev_free_devlocked(struct cdev *cdev) 115 { 116 struct cdev_priv *cdp; 117 118 mtx_assert(&devmtx, MA_OWNED); 119 cdp = cdev->si_priv; 120 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list); 121 } 122 123 static void 124 cdevsw_free_devlocked(struct cdevsw *csw) 125 { 126 127 mtx_assert(&devmtx, MA_OWNED); 128 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list); 129 } 130 131 void 132 dev_unlock(void) 133 { 134 135 mtx_unlock(&devmtx); 136 } 137 138 void 139 dev_ref(struct cdev *dev) 140 { 141 142 mtx_assert(&devmtx, MA_NOTOWNED); 143 mtx_lock(&devmtx); 144 dev->si_refcount++; 145 mtx_unlock(&devmtx); 146 } 147 148 void 149 dev_refl(struct cdev *dev) 150 { 151 152 mtx_assert(&devmtx, MA_OWNED); 153 dev->si_refcount++; 154 } 155 156 void 157 dev_rel(struct cdev *dev) 158 { 159 int flag = 0; 160 161 mtx_assert(&devmtx, MA_NOTOWNED); 162 dev_lock(); 163 dev->si_refcount--; 164 KASSERT(dev->si_refcount >= 0, 165 ("dev_rel(%s) gave negative count", devtoname(dev))); 166 #if 0 167 if (dev->si_usecount == 0 && 168 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED)) 169 ; 170 else 171 #endif 172 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 173 LIST_REMOVE(dev, si_list); 174 flag = 1; 175 } 176 dev_unlock(); 177 if (flag) 178 devfs_free(dev); 179 } 180 181 struct cdevsw * 182 dev_refthread(struct cdev *dev) 183 { 184 struct cdevsw *csw; 185 struct cdev_priv *cdp; 186 187 mtx_assert(&devmtx, MA_NOTOWNED); 188 dev_lock(); 189 csw = dev->si_devsw; 190 if (csw != NULL) { 191 cdp = dev->si_priv; 192 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) 193 dev->si_threadcount++; 194 else 195 csw = NULL; 196 } 197 dev_unlock(); 198 return (csw); 199 } 200 201 struct cdevsw * 202 devvn_refthread(struct vnode *vp, struct cdev **devp) 203 { 204 struct cdevsw *csw; 205 struct cdev_priv *cdp; 206 207 mtx_assert(&devmtx, MA_NOTOWNED); 208 csw = NULL; 209 dev_lock(); 210 *devp = vp->v_rdev; 211 if (*devp != NULL) { 212 cdp = (*devp)->si_priv; 213 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) { 214 csw = (*devp)->si_devsw; 215 if (csw != NULL) 216 (*devp)->si_threadcount++; 217 } 218 } 219 dev_unlock(); 220 return (csw); 221 } 222 223 void 224 dev_relthread(struct cdev *dev) 225 { 226 227 mtx_assert(&devmtx, MA_NOTOWNED); 228 dev_lock(); 229 KASSERT(dev->si_threadcount > 0, 230 ("%s threadcount is wrong", dev->si_name)); 231 dev->si_threadcount--; 232 dev_unlock(); 233 } 234 235 int 236 nullop(void) 237 { 238 239 return (0); 240 } 241 242 int 243 eopnotsupp(void) 244 { 245 246 return (EOPNOTSUPP); 247 } 248 249 static int 250 enxio(void) 251 { 252 return (ENXIO); 253 } 254 255 static int 256 enodev(void) 257 { 258 return (ENODEV); 259 } 260 261 /* Define a dead_cdevsw for use when devices leave unexpectedly. */ 262 263 #define dead_open (d_open_t *)enxio 264 #define dead_close (d_close_t *)enxio 265 #define dead_read (d_read_t *)enxio 266 #define dead_write (d_write_t *)enxio 267 #define dead_ioctl (d_ioctl_t *)enxio 268 #define dead_poll (d_poll_t *)enodev 269 #define dead_mmap (d_mmap_t *)enodev 270 271 static void 272 dead_strategy(struct bio *bp) 273 { 274 275 biofinish(bp, NULL, ENXIO); 276 } 277 278 #define dead_dump (dumper_t *)enxio 279 #define dead_kqfilter (d_kqfilter_t *)enxio 280 #define dead_mmap_single (d_mmap_single_t *)enodev 281 282 static struct cdevsw dead_cdevsw = { 283 .d_version = D_VERSION, 284 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 285 .d_open = dead_open, 286 .d_close = dead_close, 287 .d_read = dead_read, 288 .d_write = dead_write, 289 .d_ioctl = dead_ioctl, 290 .d_poll = dead_poll, 291 .d_mmap = dead_mmap, 292 .d_strategy = dead_strategy, 293 .d_name = "dead", 294 .d_dump = dead_dump, 295 .d_kqfilter = dead_kqfilter, 296 .d_mmap_single = dead_mmap_single 297 }; 298 299 /* Default methods if driver does not specify method */ 300 301 #define null_open (d_open_t *)nullop 302 #define null_close (d_close_t *)nullop 303 #define no_read (d_read_t *)enodev 304 #define no_write (d_write_t *)enodev 305 #define no_ioctl (d_ioctl_t *)enodev 306 #define no_mmap (d_mmap2_t *)enodev 307 #define no_kqfilter (d_kqfilter_t *)enodev 308 #define no_mmap_single (d_mmap_single_t *)enodev 309 310 static void 311 no_strategy(struct bio *bp) 312 { 313 314 biofinish(bp, NULL, ENODEV); 315 } 316 317 static int 318 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 319 { 320 321 return (poll_no_poll(events)); 322 } 323 324 #define no_dump (dumper_t *)enodev 325 326 static int 327 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 328 { 329 struct cdevsw *dsw; 330 int retval; 331 332 dsw = dev_refthread(dev); 333 if (dsw == NULL) 334 return (ENXIO); 335 mtx_lock(&Giant); 336 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td); 337 mtx_unlock(&Giant); 338 dev_relthread(dev); 339 return (retval); 340 } 341 342 static int 343 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp) 344 { 345 struct cdevsw *dsw; 346 int retval; 347 348 dsw = dev_refthread(dev); 349 if (dsw == NULL) 350 return (ENXIO); 351 mtx_lock(&Giant); 352 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp); 353 mtx_unlock(&Giant); 354 dev_relthread(dev); 355 return (retval); 356 } 357 358 static int 359 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 360 { 361 struct cdevsw *dsw; 362 int retval; 363 364 dsw = dev_refthread(dev); 365 if (dsw == NULL) 366 return (ENXIO); 367 mtx_lock(&Giant); 368 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td); 369 mtx_unlock(&Giant); 370 dev_relthread(dev); 371 return (retval); 372 } 373 374 static void 375 giant_strategy(struct bio *bp) 376 { 377 struct cdevsw *dsw; 378 struct cdev *dev; 379 380 dev = bp->bio_dev; 381 dsw = dev_refthread(dev); 382 if (dsw == NULL) { 383 biofinish(bp, NULL, ENXIO); 384 return; 385 } 386 mtx_lock(&Giant); 387 dsw->d_gianttrick->d_strategy(bp); 388 mtx_unlock(&Giant); 389 dev_relthread(dev); 390 } 391 392 static int 393 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 394 { 395 struct cdevsw *dsw; 396 int retval; 397 398 dsw = dev_refthread(dev); 399 if (dsw == NULL) 400 return (ENXIO); 401 mtx_lock(&Giant); 402 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td); 403 mtx_unlock(&Giant); 404 dev_relthread(dev); 405 return (retval); 406 } 407 408 static int 409 giant_read(struct cdev *dev, struct uio *uio, int ioflag) 410 { 411 struct cdevsw *dsw; 412 int retval; 413 414 dsw = dev_refthread(dev); 415 if (dsw == NULL) 416 return (ENXIO); 417 mtx_lock(&Giant); 418 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag); 419 mtx_unlock(&Giant); 420 dev_relthread(dev); 421 return (retval); 422 } 423 424 static int 425 giant_write(struct cdev *dev, struct uio *uio, int ioflag) 426 { 427 struct cdevsw *dsw; 428 int retval; 429 430 dsw = dev_refthread(dev); 431 if (dsw == NULL) 432 return (ENXIO); 433 mtx_lock(&Giant); 434 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag); 435 mtx_unlock(&Giant); 436 dev_relthread(dev); 437 return (retval); 438 } 439 440 static int 441 giant_poll(struct cdev *dev, int events, struct thread *td) 442 { 443 struct cdevsw *dsw; 444 int retval; 445 446 dsw = dev_refthread(dev); 447 if (dsw == NULL) 448 return (ENXIO); 449 mtx_lock(&Giant); 450 retval = dsw->d_gianttrick->d_poll(dev, events, td); 451 mtx_unlock(&Giant); 452 dev_relthread(dev); 453 return (retval); 454 } 455 456 static int 457 giant_kqfilter(struct cdev *dev, struct knote *kn) 458 { 459 struct cdevsw *dsw; 460 int retval; 461 462 dsw = dev_refthread(dev); 463 if (dsw == NULL) 464 return (ENXIO); 465 mtx_lock(&Giant); 466 retval = dsw->d_gianttrick->d_kqfilter(dev, kn); 467 mtx_unlock(&Giant); 468 dev_relthread(dev); 469 return (retval); 470 } 471 472 static int 473 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot, 474 vm_memattr_t *memattr) 475 { 476 struct cdevsw *dsw; 477 int retval; 478 479 dsw = dev_refthread(dev); 480 if (dsw == NULL) 481 return (ENXIO); 482 mtx_lock(&Giant); 483 if (dsw->d_gianttrick->d_flags & D_MMAP2) 484 retval = dsw->d_gianttrick->d_mmap2(dev, offset, paddr, nprot, 485 memattr); 486 else 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 static int 494 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size, 495 vm_object_t *object, int nprot) 496 { 497 struct cdevsw *dsw; 498 int retval; 499 500 dsw = dev_refthread(dev); 501 if (dsw == NULL) 502 return (ENXIO); 503 mtx_lock(&Giant); 504 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object, 505 nprot); 506 mtx_unlock(&Giant); 507 dev_relthread(dev); 508 return (retval); 509 } 510 511 /* 512 * struct cdev * and u_dev_t primitives 513 */ 514 515 int 516 minor(struct cdev *x) 517 { 518 if (x == NULL) 519 return NODEV; 520 return(x->si_drv0 & MAXMINOR); 521 } 522 523 int 524 dev2unit(struct cdev *x) 525 { 526 527 if (x == NULL) 528 return NODEV; 529 return (minor2unit(minor(x))); 530 } 531 532 u_int 533 minor2unit(u_int _minor) 534 { 535 536 KASSERT((_minor & ~MAXMINOR) == 0, ("Illegal minor %x", _minor)); 537 return ((_minor & 0xff) | ((_minor >> 8) & 0xffff00)); 538 } 539 540 int 541 unit2minor(int unit) 542 { 543 544 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); 545 return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 546 } 547 548 static void 549 notify(struct cdev *dev, const char *ev) 550 { 551 static const char prefix[] = "cdev="; 552 char *data; 553 int namelen; 554 555 if (cold) 556 return; 557 namelen = strlen(dev->si_name); 558 data = malloc(namelen + sizeof(prefix), M_TEMP, M_WAITOK); 559 memcpy(data, prefix, sizeof(prefix) - 1); 560 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1); 561 devctl_notify("DEVFS", "CDEV", ev, data); 562 free(data, M_TEMP); 563 } 564 565 static void 566 notify_create(struct cdev *dev) 567 { 568 569 notify(dev, "CREATE"); 570 } 571 572 static void 573 notify_destroy(struct cdev *dev) 574 { 575 576 notify(dev, "DESTROY"); 577 } 578 579 static struct cdev * 580 newdev(struct cdevsw *csw, int y, struct cdev *si) 581 { 582 struct cdev *si2; 583 dev_t udev; 584 585 mtx_assert(&devmtx, MA_OWNED); 586 udev = y; 587 LIST_FOREACH(si2, &csw->d_devs, si_list) { 588 if (si2->si_drv0 == udev) { 589 dev_free_devlocked(si); 590 return (si2); 591 } 592 } 593 si->si_drv0 = udev; 594 si->si_devsw = csw; 595 LIST_INSERT_HEAD(&csw->d_devs, si, si_list); 596 return (si); 597 } 598 599 int 600 uminor(dev_t dev) 601 { 602 return (dev & MAXMINOR); 603 } 604 605 int 606 umajor(dev_t dev) 607 { 608 return ((dev & ~MAXMINOR) >> 8); 609 } 610 611 static void 612 fini_cdevsw(struct cdevsw *devsw) 613 { 614 struct cdevsw *gt; 615 616 if (devsw->d_gianttrick != NULL) { 617 gt = devsw->d_gianttrick; 618 memcpy(devsw, gt, sizeof *devsw); 619 cdevsw_free_devlocked(gt); 620 devsw->d_gianttrick = NULL; 621 } 622 devsw->d_flags &= ~D_INIT; 623 } 624 625 static void 626 prep_cdevsw(struct cdevsw *devsw) 627 { 628 struct cdevsw *dsw2; 629 630 mtx_assert(&devmtx, MA_OWNED); 631 if (devsw->d_flags & D_INIT) 632 return; 633 if (devsw->d_flags & D_NEEDGIANT) { 634 dev_unlock(); 635 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK); 636 dev_lock(); 637 } else 638 dsw2 = NULL; 639 if (devsw->d_flags & D_INIT) { 640 if (dsw2 != NULL) 641 cdevsw_free_devlocked(dsw2); 642 return; 643 } 644 645 if (devsw->d_version != D_VERSION_01 && 646 devsw->d_version != D_VERSION_02) { 647 printf( 648 "WARNING: Device driver \"%s\" has wrong version %s\n", 649 devsw->d_name == NULL ? "???" : devsw->d_name, 650 "and is disabled. Recompile KLD module."); 651 devsw->d_open = dead_open; 652 devsw->d_close = dead_close; 653 devsw->d_read = dead_read; 654 devsw->d_write = dead_write; 655 devsw->d_ioctl = dead_ioctl; 656 devsw->d_poll = dead_poll; 657 devsw->d_mmap = dead_mmap; 658 devsw->d_strategy = dead_strategy; 659 devsw->d_dump = dead_dump; 660 devsw->d_kqfilter = dead_kqfilter; 661 } 662 if (devsw->d_version == D_VERSION_01) 663 devsw->d_mmap_single = NULL; 664 665 if (devsw->d_flags & D_TTY) { 666 if (devsw->d_ioctl == NULL) devsw->d_ioctl = ttyioctl; 667 if (devsw->d_read == NULL) devsw->d_read = ttyread; 668 if (devsw->d_write == NULL) devsw->d_write = ttywrite; 669 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = ttykqfilter; 670 if (devsw->d_poll == NULL) devsw->d_poll = ttypoll; 671 } 672 673 if (devsw->d_flags & D_NEEDGIANT) { 674 if (devsw->d_gianttrick == NULL) { 675 memcpy(dsw2, devsw, sizeof *dsw2); 676 devsw->d_gianttrick = dsw2; 677 devsw->d_flags |= D_MMAP2; 678 dsw2 = NULL; 679 } 680 } 681 682 #define FIXUP(member, noop, giant) \ 683 do { \ 684 if (devsw->member == NULL) { \ 685 devsw->member = noop; \ 686 } else if (devsw->d_flags & D_NEEDGIANT) \ 687 devsw->member = giant; \ 688 } \ 689 while (0) 690 691 FIXUP(d_open, null_open, giant_open); 692 FIXUP(d_fdopen, NULL, giant_fdopen); 693 FIXUP(d_close, null_close, giant_close); 694 FIXUP(d_read, no_read, giant_read); 695 FIXUP(d_write, no_write, giant_write); 696 FIXUP(d_ioctl, no_ioctl, giant_ioctl); 697 FIXUP(d_poll, no_poll, giant_poll); 698 FIXUP(d_mmap2, no_mmap, giant_mmap); 699 FIXUP(d_strategy, no_strategy, giant_strategy); 700 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter); 701 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single); 702 703 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 704 705 LIST_INIT(&devsw->d_devs); 706 707 devsw->d_flags |= D_INIT; 708 709 if (dsw2 != NULL) 710 cdevsw_free_devlocked(dsw2); 711 } 712 713 struct cdev * 714 make_dev_credv(int flags, struct cdevsw *devsw, int minornr, 715 struct ucred *cr, uid_t uid, 716 gid_t gid, int mode, const char *fmt, va_list ap) 717 { 718 struct cdev *dev; 719 int i; 720 721 KASSERT((minornr & ~MAXMINOR) == 0, 722 ("Invalid minor (0x%x) in make_dev", minornr)); 723 724 dev = devfs_alloc(); 725 dev_lock(); 726 prep_cdevsw(devsw); 727 dev = newdev(devsw, minornr, dev); 728 if (flags & MAKEDEV_REF) 729 dev_refl(dev); 730 if (dev->si_flags & SI_CHEAPCLONE && 731 dev->si_flags & SI_NAMED) { 732 /* 733 * This is allowed as it removes races and generally 734 * simplifies cloning devices. 735 * XXX: still ?? 736 */ 737 dev_unlock_and_free(); 738 return (dev); 739 } 740 KASSERT(!(dev->si_flags & SI_NAMED), 741 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)", 742 devsw->d_name, minor(dev), devtoname(dev))); 743 744 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 745 if (i > (sizeof dev->__si_namebuf - 1)) { 746 printf("WARNING: Device name truncated! (%s)\n", 747 dev->__si_namebuf); 748 } 749 750 dev->si_flags |= SI_NAMED; 751 #ifdef MAC 752 if (cr != NULL) 753 dev->si_cred = crhold(cr); 754 else 755 #endif 756 dev->si_cred = NULL; 757 dev->si_uid = uid; 758 dev->si_gid = gid; 759 dev->si_mode = mode; 760 761 devfs_create(dev); 762 clean_unrhdrl(devfs_inos); 763 dev_unlock_and_free(); 764 765 notify_create(dev); 766 767 return (dev); 768 } 769 770 struct cdev * 771 make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int mode, 772 const char *fmt, ...) 773 { 774 struct cdev *dev; 775 va_list ap; 776 777 va_start(ap, fmt); 778 dev = make_dev_credv(0, devsw, minornr, NULL, uid, gid, mode, fmt, ap); 779 va_end(ap); 780 return (dev); 781 } 782 783 struct cdev * 784 make_dev_cred(struct cdevsw *devsw, int minornr, struct ucred *cr, uid_t uid, 785 gid_t gid, int mode, const char *fmt, ...) 786 { 787 struct cdev *dev; 788 va_list ap; 789 790 va_start(ap, fmt); 791 dev = make_dev_credv(0, devsw, minornr, cr, uid, gid, mode, fmt, ap); 792 va_end(ap); 793 794 return (dev); 795 } 796 797 struct cdev * 798 make_dev_credf(int flags, struct cdevsw *devsw, int minornr, 799 struct ucred *cr, uid_t uid, 800 gid_t gid, int mode, const char *fmt, ...) 801 { 802 struct cdev *dev; 803 va_list ap; 804 805 va_start(ap, fmt); 806 dev = make_dev_credv(flags, devsw, minornr, cr, uid, gid, mode, 807 fmt, ap); 808 va_end(ap); 809 810 return (dev); 811 } 812 813 static void 814 dev_dependsl(struct cdev *pdev, struct cdev *cdev) 815 { 816 817 cdev->si_parent = pdev; 818 cdev->si_flags |= SI_CHILD; 819 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 820 } 821 822 823 void 824 dev_depends(struct cdev *pdev, struct cdev *cdev) 825 { 826 827 dev_lock(); 828 dev_dependsl(pdev, cdev); 829 dev_unlock(); 830 } 831 832 struct cdev * 833 make_dev_alias(struct cdev *pdev, const char *fmt, ...) 834 { 835 struct cdev *dev; 836 va_list ap; 837 int i; 838 839 KASSERT(pdev != NULL, ("NULL pdev")); 840 dev = devfs_alloc(); 841 dev_lock(); 842 dev->si_flags |= SI_ALIAS; 843 dev->si_flags |= SI_NAMED; 844 va_start(ap, fmt); 845 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 846 if (i > (sizeof dev->__si_namebuf - 1)) { 847 printf("WARNING: Device name truncated! (%s)\n", 848 dev->__si_namebuf); 849 } 850 va_end(ap); 851 852 devfs_create(dev); 853 dev_dependsl(pdev, dev); 854 clean_unrhdrl(devfs_inos); 855 dev_unlock(); 856 857 notify_create(dev); 858 859 return (dev); 860 } 861 862 static void 863 destroy_devl(struct cdev *dev) 864 { 865 struct cdevsw *csw; 866 struct cdev_privdata *p; 867 868 mtx_assert(&devmtx, MA_OWNED); 869 KASSERT(dev->si_flags & SI_NAMED, 870 ("WARNING: Driver mistake: destroy_dev on %d\n", minor(dev))); 871 872 devfs_destroy(dev); 873 874 /* Remove name marking */ 875 dev->si_flags &= ~SI_NAMED; 876 877 dev->si_refcount++; /* Avoid race with dev_rel() */ 878 879 /* If we are a child, remove us from the parents list */ 880 if (dev->si_flags & SI_CHILD) { 881 LIST_REMOVE(dev, si_siblings); 882 dev->si_flags &= ~SI_CHILD; 883 } 884 885 /* Kill our children */ 886 while (!LIST_EMPTY(&dev->si_children)) 887 destroy_devl(LIST_FIRST(&dev->si_children)); 888 889 /* Remove from clone list */ 890 if (dev->si_flags & SI_CLONELIST) { 891 LIST_REMOVE(dev, si_clone); 892 dev->si_flags &= ~SI_CLONELIST; 893 } 894 895 csw = dev->si_devsw; 896 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 897 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 898 csw->d_purge(dev); 899 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 900 if (dev->si_threadcount) 901 printf("Still %lu threads in %s\n", 902 dev->si_threadcount, devtoname(dev)); 903 } 904 while (dev->si_threadcount != 0) { 905 /* Use unique dummy wait ident */ 906 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); 907 } 908 909 dev_unlock(); 910 notify_destroy(dev); 911 mtx_lock(&cdevpriv_mtx); 912 while ((p = LIST_FIRST(&dev->si_priv->cdp_fdpriv)) != NULL) { 913 devfs_destroy_cdevpriv(p); 914 mtx_lock(&cdevpriv_mtx); 915 } 916 mtx_unlock(&cdevpriv_mtx); 917 dev_lock(); 918 919 dev->si_drv1 = 0; 920 dev->si_drv2 = 0; 921 bzero(&dev->__si_u, sizeof(dev->__si_u)); 922 923 if (!(dev->si_flags & SI_ALIAS)) { 924 /* Remove from cdevsw list */ 925 LIST_REMOVE(dev, si_list); 926 927 /* If cdevsw has no more struct cdev *'s, clean it */ 928 if (LIST_EMPTY(&csw->d_devs)) { 929 fini_cdevsw(csw); 930 wakeup(&csw->d_devs); 931 } 932 } 933 dev->si_flags &= ~SI_ALIAS; 934 dev->si_refcount--; /* Avoid race with dev_rel() */ 935 936 if (dev->si_refcount > 0) { 937 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 938 } else { 939 dev_free_devlocked(dev); 940 } 941 } 942 943 void 944 destroy_dev(struct cdev *dev) 945 { 946 947 dev_lock(); 948 destroy_devl(dev); 949 dev_unlock_and_free(); 950 } 951 952 const char * 953 devtoname(struct cdev *dev) 954 { 955 char *p; 956 struct cdevsw *csw; 957 int mynor; 958 959 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 960 p = dev->si_name; 961 csw = dev_refthread(dev); 962 if (csw != NULL) { 963 sprintf(p, "(%s)", csw->d_name); 964 dev_relthread(dev); 965 } 966 p += strlen(p); 967 mynor = minor(dev); 968 if (mynor < 0 || mynor > 255) 969 sprintf(p, "/%#x", (u_int)mynor); 970 else 971 sprintf(p, "/%d", mynor); 972 } 973 return (dev->si_name); 974 } 975 976 int 977 dev_stdclone(char *name, char **namep, const char *stem, int *unit) 978 { 979 int u, i; 980 981 i = strlen(stem); 982 if (bcmp(stem, name, i) != 0) 983 return (0); 984 if (!isdigit(name[i])) 985 return (0); 986 u = 0; 987 if (name[i] == '' && isdigit(name[i+1])) 988 return (0); 989 while (isdigit(name[i])) { 990 u *= 10; 991 u += name[i++] - ''; 992 } 993 if (u > 0xffffff) 994 return (0); 995 *unit = u; 996 if (namep) 997 *namep = &name[i]; 998 if (name[i]) 999 return (2); 1000 return (1); 1001 } 1002 1003 /* 1004 * Helper functions for cloning device drivers. 1005 * 1006 * The objective here is to make it unnecessary for the device drivers to 1007 * use rman or similar to manage their unit number space. Due to the way 1008 * we do "on-demand" devices, using rman or other "private" methods 1009 * will be very tricky to lock down properly once we lock down this file. 1010 * 1011 * Instead we give the drivers these routines which puts the struct cdev *'s 1012 * that are to be managed on their own list, and gives the driver the ability 1013 * to ask for the first free unit number or a given specified unit number. 1014 * 1015 * In addition these routines support paired devices (pty, nmdm and similar) 1016 * by respecting a number of "flag" bits in the minor number. 1017 * 1018 */ 1019 1020 struct clonedevs { 1021 LIST_HEAD(,cdev) head; 1022 }; 1023 1024 void 1025 clone_setup(struct clonedevs **cdp) 1026 { 1027 1028 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 1029 LIST_INIT(&(*cdp)->head); 1030 } 1031 1032 int 1033 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra) 1034 { 1035 struct clonedevs *cd; 1036 struct cdev *dev, *ndev, *dl, *de; 1037 int unit, low, u; 1038 1039 KASSERT(*cdp != NULL, 1040 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 1041 KASSERT(!(extra & CLONE_UNITMASK), 1042 ("Illegal extra bits (0x%x) in clone_create", extra)); 1043 KASSERT(*up <= CLONE_UNITMASK, 1044 ("Too high unit (0x%x) in clone_create", *up)); 1045 1046 1047 /* 1048 * Search the list for a lot of things in one go: 1049 * A preexisting match is returned immediately. 1050 * The lowest free unit number if we are passed -1, and the place 1051 * in the list where we should insert that new element. 1052 * The place to insert a specified unit number, if applicable 1053 * the end of the list. 1054 */ 1055 unit = *up; 1056 ndev = devfs_alloc(); 1057 dev_lock(); 1058 prep_cdevsw(csw); 1059 low = extra; 1060 de = dl = NULL; 1061 cd = *cdp; 1062 LIST_FOREACH(dev, &cd->head, si_clone) { 1063 KASSERT(dev->si_flags & SI_CLONELIST, 1064 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1065 u = dev2unit(dev); 1066 if (u == (unit | extra)) { 1067 *dp = dev; 1068 dev_unlock(); 1069 devfs_free(ndev); 1070 return (0); 1071 } 1072 if (unit == -1 && u == low) { 1073 low++; 1074 de = dev; 1075 continue; 1076 } else if (u < (unit | extra)) { 1077 de = dev; 1078 continue; 1079 } else if (u > (unit | extra)) { 1080 dl = dev; 1081 break; 1082 } 1083 } 1084 if (unit == -1) 1085 unit = low & CLONE_UNITMASK; 1086 dev = newdev(csw, unit2minor(unit | extra), ndev); 1087 if (dev->si_flags & SI_CLONELIST) { 1088 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 1089 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra); 1090 LIST_FOREACH(dev, &cd->head, si_clone) { 1091 printf("\t%p %s\n", dev, dev->si_name); 1092 } 1093 panic("foo"); 1094 } 1095 KASSERT(!(dev->si_flags & SI_CLONELIST), 1096 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 1097 if (dl != NULL) 1098 LIST_INSERT_BEFORE(dl, dev, si_clone); 1099 else if (de != NULL) 1100 LIST_INSERT_AFTER(de, dev, si_clone); 1101 else 1102 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 1103 dev->si_flags |= SI_CLONELIST; 1104 *up = unit; 1105 dev_unlock_and_free(); 1106 return (1); 1107 } 1108 1109 /* 1110 * Kill everything still on the list. The driver should already have 1111 * disposed of any softc hung of the struct cdev *'s at this time. 1112 */ 1113 void 1114 clone_cleanup(struct clonedevs **cdp) 1115 { 1116 struct cdev *dev; 1117 struct cdev_priv *cp; 1118 struct clonedevs *cd; 1119 1120 cd = *cdp; 1121 if (cd == NULL) 1122 return; 1123 dev_lock(); 1124 while (!LIST_EMPTY(&cd->head)) { 1125 dev = LIST_FIRST(&cd->head); 1126 LIST_REMOVE(dev, si_clone); 1127 KASSERT(dev->si_flags & SI_CLONELIST, 1128 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1129 dev->si_flags &= ~SI_CLONELIST; 1130 cp = dev->si_priv; 1131 if (!(cp->cdp_flags & CDP_SCHED_DTR)) { 1132 cp->cdp_flags |= CDP_SCHED_DTR; 1133 KASSERT(dev->si_flags & SI_NAMED, 1134 ("Driver has goofed in cloning underways udev %x", dev->si_drv0)); 1135 destroy_devl(dev); 1136 } 1137 } 1138 dev_unlock_and_free(); 1139 free(cd, M_DEVBUF); 1140 *cdp = NULL; 1141 } 1142 1143 static TAILQ_HEAD(, cdev_priv) dev_ddtr = 1144 TAILQ_HEAD_INITIALIZER(dev_ddtr); 1145 static struct task dev_dtr_task; 1146 1147 static void 1148 destroy_dev_tq(void *ctx, int pending) 1149 { 1150 struct cdev_priv *cp; 1151 struct cdev *dev; 1152 void (*cb)(void *); 1153 void *cb_arg; 1154 1155 dev_lock(); 1156 while (!TAILQ_EMPTY(&dev_ddtr)) { 1157 cp = TAILQ_FIRST(&dev_ddtr); 1158 dev = &cp->cdp_c; 1159 KASSERT(cp->cdp_flags & CDP_SCHED_DTR, 1160 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp)); 1161 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list); 1162 cb = cp->cdp_dtr_cb; 1163 cb_arg = cp->cdp_dtr_cb_arg; 1164 destroy_devl(dev); 1165 dev_unlock_and_free(); 1166 dev_rel(dev); 1167 if (cb != NULL) 1168 cb(cb_arg); 1169 dev_lock(); 1170 } 1171 dev_unlock(); 1172 } 1173 1174 /* 1175 * devmtx shall be locked on entry. devmtx will be unlocked after 1176 * function return. 1177 */ 1178 static int 1179 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg) 1180 { 1181 struct cdev_priv *cp; 1182 1183 mtx_assert(&devmtx, MA_OWNED); 1184 cp = dev->si_priv; 1185 if (cp->cdp_flags & CDP_SCHED_DTR) { 1186 dev_unlock(); 1187 return (0); 1188 } 1189 dev_refl(dev); 1190 cp->cdp_flags |= CDP_SCHED_DTR; 1191 cp->cdp_dtr_cb = cb; 1192 cp->cdp_dtr_cb_arg = arg; 1193 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list); 1194 dev_unlock(); 1195 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task); 1196 return (1); 1197 } 1198 1199 int 1200 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg) 1201 { 1202 dev_lock(); 1203 return (destroy_dev_sched_cbl(dev, cb, arg)); 1204 } 1205 1206 int 1207 destroy_dev_sched(struct cdev *dev) 1208 { 1209 return (destroy_dev_sched_cb(dev, NULL, NULL)); 1210 } 1211 1212 void 1213 destroy_dev_drain(struct cdevsw *csw) 1214 { 1215 1216 dev_lock(); 1217 while (!LIST_EMPTY(&csw->d_devs)) { 1218 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10); 1219 } 1220 dev_unlock(); 1221 } 1222 1223 void 1224 drain_dev_clone_events(void) 1225 { 1226 1227 sx_xlock(&clone_drain_lock); 1228 sx_xunlock(&clone_drain_lock); 1229 } 1230 1231 static void 1232 devdtr_init(void *dummy __unused) 1233 { 1234 1235 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL); 1236 } 1237 1238 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
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