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 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 struct cdev *make_dev_credv(int flags, 59 struct cdevsw *devsw, int minornr, 60 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, 61 va_list ap); 62 63 static struct cdev_priv_list cdevp_free_list = 64 TAILQ_HEAD_INITIALIZER(cdevp_free_list); 65 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list = 66 SLIST_HEAD_INITIALIZER(); 67 68 void 69 dev_lock(void) 70 { 71 72 mtx_lock(&devmtx); 73 } 74 75 /* 76 * Free all the memory collected while the cdev mutex was 77 * locked. Since devmtx is after the system map mutex, free() cannot 78 * be called immediately and is postponed until cdev mutex can be 79 * dropped. 80 */ 81 static void 82 dev_unlock_and_free(void) 83 { 84 struct cdev_priv_list cdp_free; 85 struct free_cdevsw csw_free; 86 struct cdev_priv *cdp; 87 struct cdevsw *csw; 88 89 mtx_assert(&devmtx, MA_OWNED); 90 91 /* 92 * Make the local copy of the list heads while the dev_mtx is 93 * held. Free it later. 94 */ 95 TAILQ_INIT(&cdp_free); 96 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list); 97 csw_free = cdevsw_gt_post_list; 98 SLIST_INIT(&cdevsw_gt_post_list); 99 100 mtx_unlock(&devmtx); 101 102 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) { 103 TAILQ_REMOVE(&cdp_free, cdp, cdp_list); 104 devfs_free(&cdp->cdp_c); 105 } 106 while ((csw = SLIST_FIRST(&csw_free)) != NULL) { 107 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list); 108 free(csw, M_DEVT); 109 } 110 } 111 112 static void 113 dev_free_devlocked(struct cdev *cdev) 114 { 115 struct cdev_priv *cdp; 116 117 mtx_assert(&devmtx, MA_OWNED); 118 cdp = cdev->si_priv; 119 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list); 120 } 121 122 static void 123 cdevsw_free_devlocked(struct cdevsw *csw) 124 { 125 126 mtx_assert(&devmtx, MA_OWNED); 127 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list); 128 } 129 130 void 131 dev_unlock(void) 132 { 133 134 mtx_unlock(&devmtx); 135 } 136 137 void 138 dev_ref(struct cdev *dev) 139 { 140 141 mtx_assert(&devmtx, MA_NOTOWNED); 142 mtx_lock(&devmtx); 143 dev->si_refcount++; 144 mtx_unlock(&devmtx); 145 } 146 147 void 148 dev_refl(struct cdev *dev) 149 { 150 151 mtx_assert(&devmtx, MA_OWNED); 152 dev->si_refcount++; 153 } 154 155 void 156 dev_rel(struct cdev *dev) 157 { 158 int flag = 0; 159 160 mtx_assert(&devmtx, MA_NOTOWNED); 161 dev_lock(); 162 dev->si_refcount--; 163 KASSERT(dev->si_refcount >= 0, 164 ("dev_rel(%s) gave negative count", devtoname(dev))); 165 #if 0 166 if (dev->si_usecount == 0 && 167 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED)) 168 ; 169 else 170 #endif 171 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 172 LIST_REMOVE(dev, si_list); 173 flag = 1; 174 } 175 dev_unlock(); 176 if (flag) 177 devfs_free(dev); 178 } 179 180 struct cdevsw * 181 dev_refthread(struct cdev *dev) 182 { 183 struct cdevsw *csw; 184 struct cdev_priv *cdp; 185 186 mtx_assert(&devmtx, MA_NOTOWNED); 187 dev_lock(); 188 csw = dev->si_devsw; 189 if (csw != NULL) { 190 cdp = dev->si_priv; 191 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) 192 dev->si_threadcount++; 193 else 194 csw = NULL; 195 } 196 dev_unlock(); 197 return (csw); 198 } 199 200 struct cdevsw * 201 devvn_refthread(struct vnode *vp, struct cdev **devp) 202 { 203 struct cdevsw *csw; 204 struct cdev_priv *cdp; 205 206 mtx_assert(&devmtx, MA_NOTOWNED); 207 csw = NULL; 208 dev_lock(); 209 *devp = vp->v_rdev; 210 if (*devp != NULL) { 211 cdp = (*devp)->si_priv; 212 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) { 213 csw = (*devp)->si_devsw; 214 if (csw != NULL) 215 (*devp)->si_threadcount++; 216 } 217 } 218 dev_unlock(); 219 return (csw); 220 } 221 222 void 223 dev_relthread(struct cdev *dev) 224 { 225 226 mtx_assert(&devmtx, MA_NOTOWNED); 227 dev_lock(); 228 KASSERT(dev->si_threadcount > 0, 229 ("%s threadcount is wrong", dev->si_name)); 230 dev->si_threadcount--; 231 dev_unlock(); 232 } 233 234 int 235 nullop(void) 236 { 237 238 return (0); 239 } 240 241 int 242 eopnotsupp(void) 243 { 244 245 return (EOPNOTSUPP); 246 } 247 248 static int 249 enxio(void) 250 { 251 return (ENXIO); 252 } 253 254 static int 255 enodev(void) 256 { 257 return (ENODEV); 258 } 259 260 /* Define a dead_cdevsw for use when devices leave unexpectedly. */ 261 262 #define dead_open (d_open_t *)enxio 263 #define dead_close (d_close_t *)enxio 264 #define dead_read (d_read_t *)enxio 265 #define dead_write (d_write_t *)enxio 266 #define dead_ioctl (d_ioctl_t *)enxio 267 #define dead_poll (d_poll_t *)enodev 268 #define dead_mmap (d_mmap_t *)enodev 269 270 static void 271 dead_strategy(struct bio *bp) 272 { 273 274 biofinish(bp, NULL, ENXIO); 275 } 276 277 #define dead_dump (dumper_t *)enxio 278 #define dead_kqfilter (d_kqfilter_t *)enxio 279 280 static struct cdevsw dead_cdevsw = { 281 .d_version = D_VERSION, 282 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 283 .d_open = dead_open, 284 .d_close = dead_close, 285 .d_read = dead_read, 286 .d_write = dead_write, 287 .d_ioctl = dead_ioctl, 288 .d_poll = dead_poll, 289 .d_mmap = dead_mmap, 290 .d_strategy = dead_strategy, 291 .d_name = "dead", 292 .d_dump = dead_dump, 293 .d_kqfilter = dead_kqfilter 294 }; 295 296 /* Default methods if driver does not specify method */ 297 298 #define null_open (d_open_t *)nullop 299 #define null_close (d_close_t *)nullop 300 #define no_read (d_read_t *)enodev 301 #define no_write (d_write_t *)enodev 302 #define no_ioctl (d_ioctl_t *)enodev 303 #define no_mmap (d_mmap_t *)enodev 304 #define no_kqfilter (d_kqfilter_t *)enodev 305 306 static void 307 no_strategy(struct bio *bp) 308 { 309 310 biofinish(bp, NULL, ENODEV); 311 } 312 313 static int 314 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 315 { 316 /* 317 * Return true for read/write. If the user asked for something 318 * special, return POLLNVAL, so that clients have a way of 319 * determining reliably whether or not the extended 320 * functionality is present without hard-coding knowledge 321 * of specific filesystem implementations. 322 * Stay in sync with vop_nopoll(). 323 */ 324 if (events & ~POLLSTANDARD) 325 return (POLLNVAL); 326 327 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 328 } 329 330 #define no_dump (dumper_t *)enodev 331 332 static int 333 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 334 { 335 struct cdevsw *dsw; 336 int retval; 337 338 dsw = dev_refthread(dev); 339 if (dsw == NULL) 340 return (ENXIO); 341 mtx_lock(&Giant); 342 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td); 343 mtx_unlock(&Giant); 344 dev_relthread(dev); 345 return (retval); 346 } 347 348 static int 349 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp) 350 { 351 struct cdevsw *dsw; 352 int retval; 353 354 dsw = dev_refthread(dev); 355 if (dsw == NULL) 356 return (ENXIO); 357 mtx_lock(&Giant); 358 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp); 359 mtx_unlock(&Giant); 360 dev_relthread(dev); 361 return (retval); 362 } 363 364 static int 365 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 366 { 367 struct cdevsw *dsw; 368 int retval; 369 370 dsw = dev_refthread(dev); 371 if (dsw == NULL) 372 return (ENXIO); 373 mtx_lock(&Giant); 374 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td); 375 mtx_unlock(&Giant); 376 dev_relthread(dev); 377 return (retval); 378 } 379 380 static void 381 giant_strategy(struct bio *bp) 382 { 383 struct cdevsw *dsw; 384 struct cdev *dev; 385 386 dev = bp->bio_dev; 387 dsw = dev_refthread(dev); 388 if (dsw == NULL) { 389 biofinish(bp, NULL, ENXIO); 390 return; 391 } 392 mtx_lock(&Giant); 393 dsw->d_gianttrick->d_strategy(bp); 394 mtx_unlock(&Giant); 395 dev_relthread(dev); 396 } 397 398 static int 399 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 400 { 401 struct cdevsw *dsw; 402 int retval; 403 404 dsw = dev_refthread(dev); 405 if (dsw == NULL) 406 return (ENXIO); 407 mtx_lock(&Giant); 408 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td); 409 mtx_unlock(&Giant); 410 dev_relthread(dev); 411 return (retval); 412 } 413 414 static int 415 giant_read(struct cdev *dev, struct uio *uio, int ioflag) 416 { 417 struct cdevsw *dsw; 418 int retval; 419 420 dsw = dev_refthread(dev); 421 if (dsw == NULL) 422 return (ENXIO); 423 mtx_lock(&Giant); 424 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag); 425 mtx_unlock(&Giant); 426 dev_relthread(dev); 427 return (retval); 428 } 429 430 static int 431 giant_write(struct cdev *dev, struct uio *uio, int ioflag) 432 { 433 struct cdevsw *dsw; 434 int retval; 435 436 dsw = dev_refthread(dev); 437 if (dsw == NULL) 438 return (ENXIO); 439 mtx_lock(&Giant); 440 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag); 441 mtx_unlock(&Giant); 442 dev_relthread(dev); 443 return (retval); 444 } 445 446 static int 447 giant_poll(struct cdev *dev, int events, struct thread *td) 448 { 449 struct cdevsw *dsw; 450 int retval; 451 452 dsw = dev_refthread(dev); 453 if (dsw == NULL) 454 return (ENXIO); 455 mtx_lock(&Giant); 456 retval = dsw->d_gianttrick->d_poll(dev, events, td); 457 mtx_unlock(&Giant); 458 dev_relthread(dev); 459 return (retval); 460 } 461 462 static int 463 giant_kqfilter(struct cdev *dev, struct knote *kn) 464 { 465 struct cdevsw *dsw; 466 int retval; 467 468 dsw = dev_refthread(dev); 469 if (dsw == NULL) 470 return (ENXIO); 471 mtx_lock(&Giant); 472 retval = dsw->d_gianttrick->d_kqfilter(dev, kn); 473 mtx_unlock(&Giant); 474 dev_relthread(dev); 475 return (retval); 476 } 477 478 static int 479 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot) 480 { 481 struct cdevsw *dsw; 482 int retval; 483 484 dsw = dev_refthread(dev); 485 if (dsw == NULL) 486 return (ENXIO); 487 mtx_lock(&Giant); 488 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot); 489 mtx_unlock(&Giant); 490 dev_relthread(dev); 491 return (retval); 492 } 493 494 495 /* 496 * struct cdev * and u_dev_t primitives 497 */ 498 499 int 500 minor(struct cdev *x) 501 { 502 if (x == NULL) 503 return NODEV; 504 return (x->si_drv0); 505 } 506 507 int 508 dev2unit(struct cdev *x) 509 { 510 511 if (x == NULL) 512 return NODEV; 513 return (x->si_drv0); 514 } 515 516 u_int 517 minor2unit(u_int _minor) 518 { 519 520 return (_minor); 521 } 522 523 int 524 unit2minor(int unit) 525 { 526 527 return (unit); 528 } 529 530 static void 531 notify(struct cdev *dev, const char *ev) 532 { 533 static const char prefix[] = "cdev="; 534 char *data; 535 int namelen; 536 537 if (cold) 538 return; 539 namelen = strlen(dev->si_name); 540 data = malloc(namelen + sizeof(prefix), M_TEMP, M_WAITOK); 541 memcpy(data, prefix, sizeof(prefix) - 1); 542 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1); 543 devctl_notify("DEVFS", "CDEV", ev, data); 544 free(data, M_TEMP); 545 } 546 547 static void 548 notify_create(struct cdev *dev) 549 { 550 551 notify(dev, "CREATE"); 552 } 553 554 static void 555 notify_destroy(struct cdev *dev) 556 { 557 558 notify(dev, "DESTROY"); 559 } 560 561 static struct cdev * 562 newdev(struct cdevsw *csw, int y, struct cdev *si) 563 { 564 struct cdev *si2; 565 dev_t udev; 566 567 mtx_assert(&devmtx, MA_OWNED); 568 udev = y; 569 LIST_FOREACH(si2, &csw->d_devs, si_list) { 570 if (si2->si_drv0 == udev) { 571 dev_free_devlocked(si); 572 return (si2); 573 } 574 } 575 si->si_drv0 = udev; 576 si->si_devsw = csw; 577 LIST_INSERT_HEAD(&csw->d_devs, si, si_list); 578 return (si); 579 } 580 581 #define UMINORMASK 0xffff00ffU 582 583 int 584 uminor(dev_t dev) 585 { 586 return (dev & UMINORMASK); 587 } 588 589 int 590 umajor(dev_t dev) 591 { 592 return ((dev & ~UMINORMASK) >> 8); 593 } 594 595 static void 596 fini_cdevsw(struct cdevsw *devsw) 597 { 598 struct cdevsw *gt; 599 600 if (devsw->d_gianttrick != NULL) { 601 gt = devsw->d_gianttrick; 602 memcpy(devsw, gt, sizeof *devsw); 603 cdevsw_free_devlocked(gt); 604 devsw->d_gianttrick = NULL; 605 } 606 devsw->d_flags &= ~D_INIT; 607 } 608 609 static void 610 prep_cdevsw(struct cdevsw *devsw) 611 { 612 struct cdevsw *dsw2; 613 614 mtx_assert(&devmtx, MA_OWNED); 615 if (devsw->d_flags & D_INIT) 616 return; 617 if (devsw->d_flags & D_NEEDGIANT) { 618 dev_unlock(); 619 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK); 620 dev_lock(); 621 } else 622 dsw2 = NULL; 623 if (devsw->d_flags & D_INIT) { 624 if (dsw2 != NULL) 625 cdevsw_free_devlocked(dsw2); 626 return; 627 } 628 629 if (devsw->d_version != D_VERSION_01) { 630 printf( 631 "WARNING: Device driver \"%s\" has wrong version %s\n", 632 devsw->d_name == NULL ? "???" : devsw->d_name, 633 "and is disabled. Recompile KLD module."); 634 devsw->d_open = dead_open; 635 devsw->d_close = dead_close; 636 devsw->d_read = dead_read; 637 devsw->d_write = dead_write; 638 devsw->d_ioctl = dead_ioctl; 639 devsw->d_poll = dead_poll; 640 devsw->d_mmap = dead_mmap; 641 devsw->d_strategy = dead_strategy; 642 devsw->d_dump = dead_dump; 643 devsw->d_kqfilter = dead_kqfilter; 644 } 645 646 if (devsw->d_flags & D_TTY) { 647 if (devsw->d_ioctl == NULL) devsw->d_ioctl = ttyioctl; 648 if (devsw->d_read == NULL) devsw->d_read = ttyread; 649 if (devsw->d_write == NULL) devsw->d_write = ttywrite; 650 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = ttykqfilter; 651 if (devsw->d_poll == NULL) devsw->d_poll = ttypoll; 652 } 653 654 if (devsw->d_flags & D_NEEDGIANT) { 655 if (devsw->d_gianttrick == NULL) { 656 memcpy(dsw2, devsw, sizeof *dsw2); 657 devsw->d_gianttrick = dsw2; 658 dsw2 = NULL; 659 } 660 } 661 662 #define FIXUP(member, noop, giant) \ 663 do { \ 664 if (devsw->member == NULL) { \ 665 devsw->member = noop; \ 666 } else if (devsw->d_flags & D_NEEDGIANT) \ 667 devsw->member = giant; \ 668 } \ 669 while (0) 670 671 FIXUP(d_open, null_open, giant_open); 672 FIXUP(d_fdopen, NULL, giant_fdopen); 673 FIXUP(d_close, null_close, giant_close); 674 FIXUP(d_read, no_read, giant_read); 675 FIXUP(d_write, no_write, giant_write); 676 FIXUP(d_ioctl, no_ioctl, giant_ioctl); 677 FIXUP(d_poll, no_poll, giant_poll); 678 FIXUP(d_mmap, no_mmap, giant_mmap); 679 FIXUP(d_strategy, no_strategy, giant_strategy); 680 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter); 681 682 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 683 684 LIST_INIT(&devsw->d_devs); 685 686 devsw->d_flags |= D_INIT; 687 688 if (dsw2 != NULL) 689 cdevsw_free_devlocked(dsw2); 690 } 691 692 struct cdev * 693 make_dev_credv(int flags, struct cdevsw *devsw, int minornr, 694 struct ucred *cr, uid_t uid, 695 gid_t gid, int mode, const char *fmt, va_list ap) 696 { 697 struct cdev *dev; 698 int i; 699 700 dev = devfs_alloc(); 701 dev_lock(); 702 prep_cdevsw(devsw); 703 dev = newdev(devsw, minornr, dev); 704 if (flags & MAKEDEV_REF) 705 dev_refl(dev); 706 if (dev->si_flags & SI_CHEAPCLONE && 707 dev->si_flags & SI_NAMED) { 708 /* 709 * This is allowed as it removes races and generally 710 * simplifies cloning devices. 711 * XXX: still ?? 712 */ 713 dev_unlock_and_free(); 714 return (dev); 715 } 716 KASSERT(!(dev->si_flags & SI_NAMED), 717 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)", 718 devsw->d_name, minor(dev), devtoname(dev))); 719 720 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 721 if (i > (sizeof dev->__si_namebuf - 1)) { 722 printf("WARNING: Device name truncated! (%s)\n", 723 dev->__si_namebuf); 724 } 725 726 dev->si_flags |= SI_NAMED; 727 #ifdef MAC 728 if (cr != NULL) 729 dev->si_cred = crhold(cr); 730 else 731 #endif 732 dev->si_cred = NULL; 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); 742 743 return (dev); 744 } 745 746 struct cdev * 747 make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int mode, 748 const char *fmt, ...) 749 { 750 struct cdev *dev; 751 va_list ap; 752 753 va_start(ap, fmt); 754 dev = make_dev_credv(0, devsw, minornr, NULL, uid, gid, mode, fmt, ap); 755 va_end(ap); 756 return (dev); 757 } 758 759 struct cdev * 760 make_dev_cred(struct cdevsw *devsw, int minornr, struct ucred *cr, uid_t uid, 761 gid_t gid, int mode, const char *fmt, ...) 762 { 763 struct cdev *dev; 764 va_list ap; 765 766 va_start(ap, fmt); 767 dev = make_dev_credv(0, devsw, minornr, cr, uid, gid, mode, fmt, ap); 768 va_end(ap); 769 770 return (dev); 771 } 772 773 struct cdev * 774 make_dev_credf(int flags, struct cdevsw *devsw, int minornr, 775 struct ucred *cr, uid_t uid, 776 gid_t gid, int mode, const char *fmt, ...) 777 { 778 struct cdev *dev; 779 va_list ap; 780 781 va_start(ap, fmt); 782 dev = make_dev_credv(flags, devsw, minornr, cr, uid, gid, mode, 783 fmt, ap); 784 va_end(ap); 785 786 return (dev); 787 } 788 789 static void 790 dev_dependsl(struct cdev *pdev, struct cdev *cdev) 791 { 792 793 cdev->si_parent = pdev; 794 cdev->si_flags |= SI_CHILD; 795 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 796 } 797 798 799 void 800 dev_depends(struct cdev *pdev, struct cdev *cdev) 801 { 802 803 dev_lock(); 804 dev_dependsl(pdev, cdev); 805 dev_unlock(); 806 } 807 808 struct cdev * 809 make_dev_alias(struct cdev *pdev, const char *fmt, ...) 810 { 811 struct cdev *dev; 812 va_list ap; 813 int i; 814 815 dev = devfs_alloc(); 816 dev_lock(); 817 dev->si_flags |= SI_ALIAS; 818 dev->si_flags |= SI_NAMED; 819 va_start(ap, fmt); 820 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 821 if (i > (sizeof dev->__si_namebuf - 1)) { 822 printf("WARNING: Device name truncated! (%s)\n", 823 dev->__si_namebuf); 824 } 825 va_end(ap); 826 827 devfs_create(dev); 828 clean_unrhdrl(devfs_inos); 829 dev_unlock(); 830 dev_depends(pdev, dev); 831 832 notify_create(dev); 833 834 return (dev); 835 } 836 837 static void 838 destroy_devl(struct cdev *dev) 839 { 840 struct cdevsw *csw; 841 struct cdev_privdata *p, *p1; 842 843 mtx_assert(&devmtx, MA_OWNED); 844 KASSERT(dev->si_flags & SI_NAMED, 845 ("WARNING: Driver mistake: destroy_dev on %d\n", minor(dev))); 846 847 devfs_destroy(dev); 848 849 /* Remove name marking */ 850 dev->si_flags &= ~SI_NAMED; 851 852 /* If we are a child, remove us from the parents list */ 853 if (dev->si_flags & SI_CHILD) { 854 LIST_REMOVE(dev, si_siblings); 855 dev->si_flags &= ~SI_CHILD; 856 } 857 858 /* Kill our children */ 859 while (!LIST_EMPTY(&dev->si_children)) 860 destroy_devl(LIST_FIRST(&dev->si_children)); 861 862 /* Remove from clone list */ 863 if (dev->si_flags & SI_CLONELIST) { 864 LIST_REMOVE(dev, si_clone); 865 dev->si_flags &= ~SI_CLONELIST; 866 } 867 868 dev->si_refcount++; /* Avoid race with dev_rel() */ 869 csw = dev->si_devsw; 870 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 871 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 872 csw->d_purge(dev); 873 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 874 if (dev->si_threadcount) 875 printf("Still %lu threads in %s\n", 876 dev->si_threadcount, devtoname(dev)); 877 } 878 while (dev->si_threadcount != 0) { 879 /* Use unique dummy wait ident */ 880 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); 881 } 882 883 dev_unlock(); 884 notify_destroy(dev); 885 mtx_lock(&cdevpriv_mtx); 886 LIST_FOREACH_SAFE(p, &dev->si_priv->cdp_fdpriv, cdpd_list, p1) { 887 devfs_destroy_cdevpriv(p); 888 mtx_lock(&cdevpriv_mtx); 889 } 890 mtx_unlock(&cdevpriv_mtx); 891 dev_lock(); 892 893 dev->si_drv1 = 0; 894 dev->si_drv2 = 0; 895 bzero(&dev->__si_u, sizeof(dev->__si_u)); 896 897 if (!(dev->si_flags & SI_ALIAS)) { 898 /* Remove from cdevsw list */ 899 LIST_REMOVE(dev, si_list); 900 901 /* If cdevsw has no more struct cdev *'s, clean it */ 902 if (LIST_EMPTY(&csw->d_devs)) { 903 fini_cdevsw(csw); 904 wakeup(&csw->d_devs); 905 } 906 } 907 dev->si_flags &= ~SI_ALIAS; 908 dev->si_refcount--; /* Avoid race with dev_rel() */ 909 910 if (dev->si_refcount > 0) { 911 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 912 } else { 913 dev_free_devlocked(dev); 914 } 915 } 916 917 void 918 destroy_dev(struct cdev *dev) 919 { 920 921 dev_lock(); 922 destroy_devl(dev); 923 dev_unlock_and_free(); 924 } 925 926 const char * 927 devtoname(struct cdev *dev) 928 { 929 char *p; 930 struct cdevsw *csw; 931 int mynor; 932 933 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 934 p = dev->si_name; 935 csw = dev_refthread(dev); 936 if (csw != NULL) { 937 sprintf(p, "(%s)", csw->d_name); 938 dev_relthread(dev); 939 } 940 p += strlen(p); 941 mynor = minor(dev); 942 if (mynor < 0 || mynor > 255) 943 sprintf(p, "/%#x", (u_int)mynor); 944 else 945 sprintf(p, "/%d", mynor); 946 } 947 return (dev->si_name); 948 } 949 950 int 951 dev_stdclone(char *name, char **namep, const char *stem, int *unit) 952 { 953 int u, i; 954 955 i = strlen(stem); 956 if (bcmp(stem, name, i) != 0) 957 return (0); 958 if (!isdigit(name[i])) 959 return (0); 960 u = 0; 961 if (name[i] == '0' && isdigit(name[i+1])) 962 return (0); 963 while (isdigit(name[i])) { 964 u *= 10; 965 u += name[i++] - '0'; 966 } 967 if (u > 0xffffff) 968 return (0); 969 *unit = u; 970 if (namep) 971 *namep = &name[i]; 972 if (name[i]) 973 return (2); 974 return (1); 975 } 976 977 /* 978 * Helper functions for cloning device drivers. 979 * 980 * The objective here is to make it unnecessary for the device drivers to 981 * use rman or similar to manage their unit number space. Due to the way 982 * we do "on-demand" devices, using rman or other "private" methods 983 * will be very tricky to lock down properly once we lock down this file. 984 * 985 * Instead we give the drivers these routines which puts the struct cdev *'s 986 * that are to be managed on their own list, and gives the driver the ability 987 * to ask for the first free unit number or a given specified unit number. 988 * 989 * In addition these routines support paired devices (pty, nmdm and similar) 990 * by respecting a number of "flag" bits in the minor number. 991 * 992 */ 993 994 struct clonedevs { 995 LIST_HEAD(,cdev) head; 996 }; 997 998 void 999 clone_setup(struct clonedevs **cdp) 1000 { 1001 1002 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 1003 LIST_INIT(&(*cdp)->head); 1004 } 1005 1006 int 1007 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra) 1008 { 1009 struct clonedevs *cd; 1010 struct cdev *dev, *ndev, *dl, *de; 1011 int unit, low, u; 1012 1013 KASSERT(*cdp != NULL, 1014 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 1015 KASSERT(!(extra & CLONE_UNITMASK), 1016 ("Illegal extra bits (0x%x) in clone_create", extra)); 1017 KASSERT(*up <= CLONE_UNITMASK, 1018 ("Too high unit (0x%x) in clone_create", *up)); 1019 1020 1021 /* 1022 * Search the list for a lot of things in one go: 1023 * A preexisting match is returned immediately. 1024 * The lowest free unit number if we are passed -1, and the place 1025 * in the list where we should insert that new element. 1026 * The place to insert a specified unit number, if applicable 1027 * the end of the list. 1028 */ 1029 unit = *up; 1030 ndev = devfs_alloc(); 1031 dev_lock(); 1032 prep_cdevsw(csw); 1033 low = extra; 1034 de = dl = NULL; 1035 cd = *cdp; 1036 LIST_FOREACH(dev, &cd->head, si_clone) { 1037 KASSERT(dev->si_flags & SI_CLONELIST, 1038 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1039 u = dev2unit(dev); 1040 if (u == (unit | extra)) { 1041 *dp = dev; 1042 dev_unlock(); 1043 devfs_free(ndev); 1044 return (0); 1045 } 1046 if (unit == -1 && u == low) { 1047 low++; 1048 de = dev; 1049 continue; 1050 } else if (u < (unit | extra)) { 1051 de = dev; 1052 continue; 1053 } else if (u > (unit | extra)) { 1054 dl = dev; 1055 break; 1056 } 1057 } 1058 if (unit == -1) 1059 unit = low & CLONE_UNITMASK; 1060 dev = newdev(csw, unit2minor(unit | extra), ndev); 1061 if (dev->si_flags & SI_CLONELIST) { 1062 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 1063 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra); 1064 LIST_FOREACH(dev, &cd->head, si_clone) { 1065 printf("\t%p %s\n", dev, dev->si_name); 1066 } 1067 panic("foo"); 1068 } 1069 KASSERT(!(dev->si_flags & SI_CLONELIST), 1070 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 1071 if (dl != NULL) 1072 LIST_INSERT_BEFORE(dl, dev, si_clone); 1073 else if (de != NULL) 1074 LIST_INSERT_AFTER(de, dev, si_clone); 1075 else 1076 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 1077 dev->si_flags |= SI_CLONELIST; 1078 *up = unit; 1079 dev_unlock_and_free(); 1080 return (1); 1081 } 1082 1083 /* 1084 * Kill everything still on the list. The driver should already have 1085 * disposed of any softc hung of the struct cdev *'s at this time. 1086 */ 1087 void 1088 clone_cleanup(struct clonedevs **cdp) 1089 { 1090 struct cdev *dev; 1091 struct cdev_priv *cp; 1092 struct clonedevs *cd; 1093 1094 cd = *cdp; 1095 if (cd == NULL) 1096 return; 1097 dev_lock(); 1098 while (!LIST_EMPTY(&cd->head)) { 1099 dev = LIST_FIRST(&cd->head); 1100 LIST_REMOVE(dev, si_clone); 1101 KASSERT(dev->si_flags & SI_CLONELIST, 1102 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1103 dev->si_flags &= ~SI_CLONELIST; 1104 cp = dev->si_priv; 1105 if (!(cp->cdp_flags & CDP_SCHED_DTR)) { 1106 cp->cdp_flags |= CDP_SCHED_DTR; 1107 KASSERT(dev->si_flags & SI_NAMED, 1108 ("Driver has goofed in cloning underways udev %x", dev->si_drv0)); 1109 destroy_devl(dev); 1110 } 1111 } 1112 dev_unlock_and_free(); 1113 free(cd, M_DEVBUF); 1114 *cdp = NULL; 1115 } 1116 1117 static TAILQ_HEAD(, cdev_priv) dev_ddtr = 1118 TAILQ_HEAD_INITIALIZER(dev_ddtr); 1119 static struct task dev_dtr_task; 1120 1121 static void 1122 destroy_dev_tq(void *ctx, int pending) 1123 { 1124 struct cdev_priv *cp; 1125 struct cdev *dev; 1126 void (*cb)(void *); 1127 void *cb_arg; 1128 1129 dev_lock(); 1130 while (!TAILQ_EMPTY(&dev_ddtr)) { 1131 cp = TAILQ_FIRST(&dev_ddtr); 1132 dev = &cp->cdp_c; 1133 KASSERT(cp->cdp_flags & CDP_SCHED_DTR, 1134 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp)); 1135 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list); 1136 cb = cp->cdp_dtr_cb; 1137 cb_arg = cp->cdp_dtr_cb_arg; 1138 destroy_devl(dev); 1139 dev_unlock_and_free(); 1140 dev_rel(dev); 1141 if (cb != NULL) 1142 cb(cb_arg); 1143 dev_lock(); 1144 } 1145 dev_unlock(); 1146 } 1147 1148 /* 1149 * devmtx shall be locked on entry. devmtx will be unlocked after 1150 * function return. 1151 */ 1152 static int 1153 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg) 1154 { 1155 struct cdev_priv *cp; 1156 1157 mtx_assert(&devmtx, MA_OWNED); 1158 cp = dev->si_priv; 1159 if (cp->cdp_flags & CDP_SCHED_DTR) { 1160 dev_unlock(); 1161 return (0); 1162 } 1163 dev_refl(dev); 1164 cp->cdp_flags |= CDP_SCHED_DTR; 1165 cp->cdp_dtr_cb = cb; 1166 cp->cdp_dtr_cb_arg = arg; 1167 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list); 1168 dev_unlock(); 1169 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task); 1170 return (1); 1171 } 1172 1173 int 1174 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg) 1175 { 1176 dev_lock(); 1177 return (destroy_dev_sched_cbl(dev, cb, arg)); 1178 } 1179 1180 int 1181 destroy_dev_sched(struct cdev *dev) 1182 { 1183 return (destroy_dev_sched_cb(dev, NULL, NULL)); 1184 } 1185 1186 void 1187 destroy_dev_drain(struct cdevsw *csw) 1188 { 1189 1190 dev_lock(); 1191 while (!LIST_EMPTY(&csw->d_devs)) { 1192 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10); 1193 } 1194 dev_unlock(); 1195 } 1196 1197 void 1198 drain_dev_clone_events(void) 1199 { 1200 1201 sx_xlock(&clone_drain_lock); 1202 sx_xunlock(&clone_drain_lock); 1203 } 1204 1205 static void 1206 devdtr_init(void *dummy __unused) 1207 { 1208 1209 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL); 1210 } 1211 1212 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL); 1213