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 dev->si_threadcount--; 229 dev_unlock(); 230 } 231 232 int 233 nullop(void) 234 { 235 236 return (0); 237 } 238 239 int 240 eopnotsupp(void) 241 { 242 243 return (EOPNOTSUPP); 244 } 245 246 static int 247 enxio(void) 248 { 249 return (ENXIO); 250 } 251 252 static int 253 enodev(void) 254 { 255 return (ENODEV); 256 } 257 258 /* Define a dead_cdevsw for use when devices leave unexpectedly. */ 259 260 #define dead_open (d_open_t *)enxio 261 #define dead_close (d_close_t *)enxio 262 #define dead_read (d_read_t *)enxio 263 #define dead_write (d_write_t *)enxio 264 #define dead_ioctl (d_ioctl_t *)enxio 265 #define dead_poll (d_poll_t *)enodev 266 #define dead_mmap (d_mmap_t *)enodev 267 268 static void 269 dead_strategy(struct bio *bp) 270 { 271 272 biofinish(bp, NULL, ENXIO); 273 } 274 275 #define dead_dump (dumper_t *)enxio 276 #define dead_kqfilter (d_kqfilter_t *)enxio 277 278 static struct cdevsw dead_cdevsw = { 279 .d_version = D_VERSION, 280 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 281 .d_open = dead_open, 282 .d_close = dead_close, 283 .d_read = dead_read, 284 .d_write = dead_write, 285 .d_ioctl = dead_ioctl, 286 .d_poll = dead_poll, 287 .d_mmap = dead_mmap, 288 .d_strategy = dead_strategy, 289 .d_name = "dead", 290 .d_dump = dead_dump, 291 .d_kqfilter = dead_kqfilter 292 }; 293 294 /* Default methods if driver does not specify method */ 295 296 #define null_open (d_open_t *)nullop 297 #define null_close (d_close_t *)nullop 298 #define no_read (d_read_t *)enodev 299 #define no_write (d_write_t *)enodev 300 #define no_ioctl (d_ioctl_t *)enodev 301 #define no_mmap (d_mmap_t *)enodev 302 #define no_kqfilter (d_kqfilter_t *)enodev 303 304 static void 305 no_strategy(struct bio *bp) 306 { 307 308 biofinish(bp, NULL, ENODEV); 309 } 310 311 static int 312 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 313 { 314 /* 315 * Return true for read/write. If the user asked for something 316 * special, return POLLNVAL, so that clients have a way of 317 * determining reliably whether or not the extended 318 * functionality is present without hard-coding knowledge 319 * of specific filesystem implementations. 320 * Stay in sync with vop_nopoll(). 321 */ 322 if (events & ~POLLSTANDARD) 323 return (POLLNVAL); 324 325 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 326 } 327 328 #define no_dump (dumper_t *)enodev 329 330 static int 331 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 332 { 333 struct cdevsw *dsw; 334 int retval; 335 336 dsw = dev_refthread(dev); 337 if (dsw == NULL) 338 return (ENXIO); 339 mtx_lock(&Giant); 340 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td); 341 mtx_unlock(&Giant); 342 dev_relthread(dev); 343 return (retval); 344 } 345 346 static int 347 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp) 348 { 349 struct cdevsw *dsw; 350 int retval; 351 352 dsw = dev_refthread(dev); 353 if (dsw == NULL) 354 return (ENXIO); 355 mtx_lock(&Giant); 356 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp); 357 mtx_unlock(&Giant); 358 dev_relthread(dev); 359 return (retval); 360 } 361 362 static int 363 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 364 { 365 struct cdevsw *dsw; 366 int retval; 367 368 dsw = dev_refthread(dev); 369 if (dsw == NULL) 370 return (ENXIO); 371 mtx_lock(&Giant); 372 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td); 373 mtx_unlock(&Giant); 374 dev_relthread(dev); 375 return (retval); 376 } 377 378 static void 379 giant_strategy(struct bio *bp) 380 { 381 struct cdevsw *dsw; 382 struct cdev *dev; 383 384 dev = bp->bio_dev; 385 dsw = dev_refthread(dev); 386 if (dsw == NULL) { 387 biofinish(bp, NULL, ENXIO); 388 return; 389 } 390 mtx_lock(&Giant); 391 dsw->d_gianttrick->d_strategy(bp); 392 mtx_unlock(&Giant); 393 dev_relthread(dev); 394 } 395 396 static int 397 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 398 { 399 struct cdevsw *dsw; 400 int retval; 401 402 dsw = dev_refthread(dev); 403 if (dsw == NULL) 404 return (ENXIO); 405 mtx_lock(&Giant); 406 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td); 407 mtx_unlock(&Giant); 408 dev_relthread(dev); 409 return (retval); 410 } 411 412 static int 413 giant_read(struct cdev *dev, struct uio *uio, int ioflag) 414 { 415 struct cdevsw *dsw; 416 int retval; 417 418 dsw = dev_refthread(dev); 419 if (dsw == NULL) 420 return (ENXIO); 421 mtx_lock(&Giant); 422 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag); 423 mtx_unlock(&Giant); 424 dev_relthread(dev); 425 return (retval); 426 } 427 428 static int 429 giant_write(struct cdev *dev, struct uio *uio, int ioflag) 430 { 431 struct cdevsw *dsw; 432 int retval; 433 434 dsw = dev_refthread(dev); 435 if (dsw == NULL) 436 return (ENXIO); 437 mtx_lock(&Giant); 438 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag); 439 mtx_unlock(&Giant); 440 dev_relthread(dev); 441 return (retval); 442 } 443 444 static int 445 giant_poll(struct cdev *dev, int events, struct thread *td) 446 { 447 struct cdevsw *dsw; 448 int retval; 449 450 dsw = dev_refthread(dev); 451 if (dsw == NULL) 452 return (ENXIO); 453 mtx_lock(&Giant); 454 retval = dsw->d_gianttrick->d_poll(dev, events, td); 455 mtx_unlock(&Giant); 456 dev_relthread(dev); 457 return (retval); 458 } 459 460 static int 461 giant_kqfilter(struct cdev *dev, struct knote *kn) 462 { 463 struct cdevsw *dsw; 464 int retval; 465 466 dsw = dev_refthread(dev); 467 if (dsw == NULL) 468 return (ENXIO); 469 mtx_lock(&Giant); 470 retval = dsw->d_gianttrick->d_kqfilter(dev, kn); 471 mtx_unlock(&Giant); 472 dev_relthread(dev); 473 return (retval); 474 } 475 476 static int 477 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot) 478 { 479 struct cdevsw *dsw; 480 int retval; 481 482 dsw = dev_refthread(dev); 483 if (dsw == NULL) 484 return (ENXIO); 485 mtx_lock(&Giant); 486 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot); 487 mtx_unlock(&Giant); 488 dev_relthread(dev); 489 return (retval); 490 } 491 492 493 /* 494 * struct cdev * and u_dev_t primitives 495 */ 496 497 int 498 minor(struct cdev *x) 499 { 500 if (x == NULL) 501 return NODEV; 502 return(x->si_drv0 & MAXMINOR); 503 } 504 505 int 506 dev2unit(struct cdev *x) 507 { 508 509 if (x == NULL) 510 return NODEV; 511 return (minor2unit(minor(x))); 512 } 513 514 u_int 515 minor2unit(u_int _minor) 516 { 517 518 KASSERT((_minor & ~MAXMINOR) == 0, ("Illegal minor %x", _minor)); 519 return ((_minor & 0xff) | ((_minor >> 8) & 0xffff00)); 520 } 521 522 int 523 unit2minor(int unit) 524 { 525 526 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); 527 return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 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 int 582 uminor(dev_t dev) 583 { 584 return (dev & MAXMINOR); 585 } 586 587 int 588 umajor(dev_t dev) 589 { 590 return ((dev & ~MAXMINOR) >> 8); 591 } 592 593 static void 594 fini_cdevsw(struct cdevsw *devsw) 595 { 596 struct cdevsw *gt; 597 598 if (devsw->d_gianttrick != NULL) { 599 gt = devsw->d_gianttrick; 600 memcpy(devsw, gt, sizeof *devsw); 601 cdevsw_free_devlocked(gt); 602 devsw->d_gianttrick = NULL; 603 } 604 devsw->d_flags &= ~D_INIT; 605 } 606 607 static void 608 prep_cdevsw(struct cdevsw *devsw) 609 { 610 struct cdevsw *dsw2; 611 612 mtx_assert(&devmtx, MA_OWNED); 613 if (devsw->d_flags & D_INIT) 614 return; 615 if (devsw->d_flags & D_NEEDGIANT) { 616 dev_unlock(); 617 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK); 618 dev_lock(); 619 } else 620 dsw2 = NULL; 621 if (devsw->d_flags & D_INIT) { 622 if (dsw2 != NULL) 623 cdevsw_free_devlocked(dsw2); 624 return; 625 } 626 627 if (devsw->d_version != D_VERSION_01) { 628 printf( 629 "WARNING: Device driver \"%s\" has wrong version %s\n", 630 devsw->d_name == NULL ? "???" : devsw->d_name, 631 "and is disabled. Recompile KLD module."); 632 devsw->d_open = dead_open; 633 devsw->d_close = dead_close; 634 devsw->d_read = dead_read; 635 devsw->d_write = dead_write; 636 devsw->d_ioctl = dead_ioctl; 637 devsw->d_poll = dead_poll; 638 devsw->d_mmap = dead_mmap; 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_TTY) { 645 if (devsw->d_ioctl == NULL) devsw->d_ioctl = ttyioctl; 646 if (devsw->d_read == NULL) devsw->d_read = ttyread; 647 if (devsw->d_write == NULL) devsw->d_write = ttywrite; 648 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = ttykqfilter; 649 if (devsw->d_poll == NULL) devsw->d_poll = ttypoll; 650 } 651 652 if (devsw->d_flags & D_NEEDGIANT) { 653 if (devsw->d_gianttrick == NULL) { 654 memcpy(dsw2, devsw, sizeof *dsw2); 655 devsw->d_gianttrick = dsw2; 656 dsw2 = NULL; 657 } 658 } 659 660 #define FIXUP(member, noop, giant) \ 661 do { \ 662 if (devsw->member == NULL) { \ 663 devsw->member = noop; \ 664 } else if (devsw->d_flags & D_NEEDGIANT) \ 665 devsw->member = giant; \ 666 } \ 667 while (0) 668 669 FIXUP(d_open, null_open, giant_open); 670 FIXUP(d_fdopen, NULL, giant_fdopen); 671 FIXUP(d_close, null_close, giant_close); 672 FIXUP(d_read, no_read, giant_read); 673 FIXUP(d_write, no_write, giant_write); 674 FIXUP(d_ioctl, no_ioctl, giant_ioctl); 675 FIXUP(d_poll, no_poll, giant_poll); 676 FIXUP(d_mmap, no_mmap, giant_mmap); 677 FIXUP(d_strategy, no_strategy, giant_strategy); 678 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter); 679 680 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 681 682 LIST_INIT(&devsw->d_devs); 683 684 devsw->d_flags |= D_INIT; 685 686 if (dsw2 != NULL) 687 cdevsw_free_devlocked(dsw2); 688 } 689 690 struct cdev * 691 make_dev_credv(int flags, struct cdevsw *devsw, int minornr, 692 struct ucred *cr, uid_t uid, 693 gid_t gid, int mode, const char *fmt, va_list ap) 694 { 695 struct cdev *dev; 696 int i; 697 698 KASSERT((minornr & ~MAXMINOR) == 0, 699 ("Invalid minor (0x%x) in make_dev", minornr)); 700 701 dev = devfs_alloc(); 702 dev_lock(); 703 prep_cdevsw(devsw); 704 dev = newdev(devsw, minornr, dev); 705 if (flags & MAKEDEV_REF) 706 dev_refl(dev); 707 if (dev->si_flags & SI_CHEAPCLONE && 708 dev->si_flags & SI_NAMED) { 709 /* 710 * This is allowed as it removes races and generally 711 * simplifies cloning devices. 712 * XXX: still ?? 713 */ 714 dev_unlock_and_free(); 715 return (dev); 716 } 717 KASSERT(!(dev->si_flags & SI_NAMED), 718 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)", 719 devsw->d_name, minor(dev), devtoname(dev))); 720 721 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 722 if (i > (sizeof dev->__si_namebuf - 1)) { 723 printf("WARNING: Device name truncated! (%s)\n", 724 dev->__si_namebuf); 725 } 726 727 dev->si_flags |= SI_NAMED; 728 #ifdef MAC 729 if (cr != NULL) 730 dev->si_cred = crhold(cr); 731 else 732 #endif 733 dev->si_cred = NULL; 734 dev->si_uid = uid; 735 dev->si_gid = gid; 736 dev->si_mode = mode; 737 738 devfs_create(dev); 739 clean_unrhdrl(devfs_inos); 740 dev_unlock_and_free(); 741 742 notify_create(dev); 743 744 return (dev); 745 } 746 747 struct cdev * 748 make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int mode, 749 const char *fmt, ...) 750 { 751 struct cdev *dev; 752 va_list ap; 753 754 va_start(ap, fmt); 755 dev = make_dev_credv(0, devsw, minornr, NULL, uid, gid, mode, fmt, ap); 756 va_end(ap); 757 return (dev); 758 } 759 760 struct cdev * 761 make_dev_cred(struct cdevsw *devsw, int minornr, struct ucred *cr, uid_t uid, 762 gid_t gid, int mode, const char *fmt, ...) 763 { 764 struct cdev *dev; 765 va_list ap; 766 767 va_start(ap, fmt); 768 dev = make_dev_credv(0, devsw, minornr, cr, uid, gid, mode, fmt, ap); 769 va_end(ap); 770 771 return (dev); 772 } 773 774 struct cdev * 775 make_dev_credf(int flags, struct cdevsw *devsw, int minornr, 776 struct ucred *cr, uid_t uid, 777 gid_t gid, int mode, const char *fmt, ...) 778 { 779 struct cdev *dev; 780 va_list ap; 781 782 va_start(ap, fmt); 783 dev = make_dev_credv(flags, devsw, minornr, cr, uid, gid, mode, 784 fmt, ap); 785 va_end(ap); 786 787 return (dev); 788 } 789 790 static void 791 dev_dependsl(struct cdev *pdev, struct cdev *cdev) 792 { 793 794 cdev->si_parent = pdev; 795 cdev->si_flags |= SI_CHILD; 796 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 797 } 798 799 800 void 801 dev_depends(struct cdev *pdev, struct cdev *cdev) 802 { 803 804 dev_lock(); 805 dev_dependsl(pdev, cdev); 806 dev_unlock(); 807 } 808 809 struct cdev * 810 make_dev_alias(struct cdev *pdev, const char *fmt, ...) 811 { 812 struct cdev *dev; 813 va_list ap; 814 int i; 815 816 dev = devfs_alloc(); 817 dev_lock(); 818 dev->si_flags |= SI_ALIAS; 819 dev->si_flags |= SI_NAMED; 820 va_start(ap, fmt); 821 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 822 if (i > (sizeof dev->__si_namebuf - 1)) { 823 printf("WARNING: Device name truncated! (%s)\n", 824 dev->__si_namebuf); 825 } 826 va_end(ap); 827 828 devfs_create(dev); 829 clean_unrhdrl(devfs_inos); 830 dev_unlock(); 831 dev_depends(pdev, dev); 832 833 notify_create(dev); 834 835 return (dev); 836 } 837 838 static void 839 destroy_devl(struct cdev *dev) 840 { 841 struct cdevsw *csw; 842 struct cdev_privdata *p, *p1; 843 844 mtx_assert(&devmtx, MA_OWNED); 845 KASSERT(dev->si_flags & SI_NAMED, 846 ("WARNING: Driver mistake: destroy_dev on %d\n", minor(dev))); 847 848 devfs_destroy(dev); 849 850 /* Remove name marking */ 851 dev->si_flags &= ~SI_NAMED; 852 853 /* If we are a child, remove us from the parents list */ 854 if (dev->si_flags & SI_CHILD) { 855 LIST_REMOVE(dev, si_siblings); 856 dev->si_flags &= ~SI_CHILD; 857 } 858 859 /* Kill our children */ 860 while (!LIST_EMPTY(&dev->si_children)) 861 destroy_devl(LIST_FIRST(&dev->si_children)); 862 863 /* Remove from clone list */ 864 if (dev->si_flags & SI_CLONELIST) { 865 LIST_REMOVE(dev, si_clone); 866 dev->si_flags &= ~SI_CLONELIST; 867 } 868 869 dev->si_refcount++; /* Avoid race with dev_rel() */ 870 csw = dev->si_devsw; 871 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 872 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 873 csw->d_purge(dev); 874 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 875 if (dev->si_threadcount) 876 printf("Still %lu threads in %s\n", 877 dev->si_threadcount, devtoname(dev)); 878 } 879 while (dev->si_threadcount != 0) { 880 /* Use unique dummy wait ident */ 881 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); 882 } 883 884 dev_unlock(); 885 notify_destroy(dev); 886 mtx_lock(&cdevpriv_mtx); 887 LIST_FOREACH_SAFE(p, &dev->si_priv->cdp_fdpriv, cdpd_list, p1) { 888 devfs_destroy_cdevpriv(p); 889 mtx_lock(&cdevpriv_mtx); 890 } 891 mtx_unlock(&cdevpriv_mtx); 892 dev_lock(); 893 894 dev->si_drv1 = 0; 895 dev->si_drv2 = 0; 896 bzero(&dev->__si_u, sizeof(dev->__si_u)); 897 898 if (!(dev->si_flags & SI_ALIAS)) { 899 /* Remove from cdevsw list */ 900 LIST_REMOVE(dev, si_list); 901 902 /* If cdevsw has no more struct cdev *'s, clean it */ 903 if (LIST_EMPTY(&csw->d_devs)) { 904 fini_cdevsw(csw); 905 wakeup(&csw->d_devs); 906 } 907 } 908 dev->si_flags &= ~SI_ALIAS; 909 dev->si_refcount--; /* Avoid race with dev_rel() */ 910 911 if (dev->si_refcount > 0) { 912 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 913 } else { 914 dev_free_devlocked(dev); 915 } 916 } 917 918 void 919 destroy_dev(struct cdev *dev) 920 { 921 922 dev_lock(); 923 destroy_devl(dev); 924 dev_unlock_and_free(); 925 } 926 927 const char * 928 devtoname(struct cdev *dev) 929 { 930 char *p; 931 struct cdevsw *csw; 932 int mynor; 933 934 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 935 p = dev->si_name; 936 csw = dev_refthread(dev); 937 if (csw != NULL) { 938 sprintf(p, "(%s)", csw->d_name); 939 dev_relthread(dev); 940 } 941 p += strlen(p); 942 mynor = minor(dev); 943 if (mynor < 0 || mynor > 255) 944 sprintf(p, "/%#x", (u_int)mynor); 945 else 946 sprintf(p, "/%d", mynor); 947 } 948 return (dev->si_name); 949 } 950 951 int 952 dev_stdclone(char *name, char **namep, const char *stem, int *unit) 953 { 954 int u, i; 955 956 i = strlen(stem); 957 if (bcmp(stem, name, i) != 0) 958 return (0); 959 if (!isdigit(name[i])) 960 return (0); 961 u = 0; 962 if (name[i] == '0' && isdigit(name[i+1])) 963 return (0); 964 while (isdigit(name[i])) { 965 u *= 10; 966 u += name[i++] - '0'; 967 } 968 if (u > 0xffffff) 969 return (0); 970 *unit = u; 971 if (namep) 972 *namep = &name[i]; 973 if (name[i]) 974 return (2); 975 return (1); 976 } 977 978 /* 979 * Helper functions for cloning device drivers. 980 * 981 * The objective here is to make it unnecessary for the device drivers to 982 * use rman or similar to manage their unit number space. Due to the way 983 * we do "on-demand" devices, using rman or other "private" methods 984 * will be very tricky to lock down properly once we lock down this file. 985 * 986 * Instead we give the drivers these routines which puts the struct cdev *'s 987 * that are to be managed on their own list, and gives the driver the ability 988 * to ask for the first free unit number or a given specified unit number. 989 * 990 * In addition these routines support paired devices (pty, nmdm and similar) 991 * by respecting a number of "flag" bits in the minor number. 992 * 993 */ 994 995 struct clonedevs { 996 LIST_HEAD(,cdev) head; 997 }; 998 999 void 1000 clone_setup(struct clonedevs **cdp) 1001 { 1002 1003 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 1004 LIST_INIT(&(*cdp)->head); 1005 } 1006 1007 int 1008 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra) 1009 { 1010 struct clonedevs *cd; 1011 struct cdev *dev, *ndev, *dl, *de; 1012 int unit, low, u; 1013 1014 KASSERT(*cdp != NULL, 1015 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 1016 KASSERT(!(extra & CLONE_UNITMASK), 1017 ("Illegal extra bits (0x%x) in clone_create", extra)); 1018 KASSERT(*up <= CLONE_UNITMASK, 1019 ("Too high unit (0x%x) in clone_create", *up)); 1020 1021 1022 /* 1023 * Search the list for a lot of things in one go: 1024 * A preexisting match is returned immediately. 1025 * The lowest free unit number if we are passed -1, and the place 1026 * in the list where we should insert that new element. 1027 * The place to insert a specified unit number, if applicable 1028 * the end of the list. 1029 */ 1030 unit = *up; 1031 ndev = devfs_alloc(); 1032 dev_lock(); 1033 prep_cdevsw(csw); 1034 low = extra; 1035 de = dl = NULL; 1036 cd = *cdp; 1037 LIST_FOREACH(dev, &cd->head, si_clone) { 1038 KASSERT(dev->si_flags & SI_CLONELIST, 1039 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1040 u = dev2unit(dev); 1041 if (u == (unit | extra)) { 1042 *dp = dev; 1043 dev_unlock(); 1044 devfs_free(ndev); 1045 return (0); 1046 } 1047 if (unit == -1 && u == low) { 1048 low++; 1049 de = dev; 1050 continue; 1051 } else if (u < (unit | extra)) { 1052 de = dev; 1053 continue; 1054 } else if (u > (unit | extra)) { 1055 dl = dev; 1056 break; 1057 } 1058 } 1059 if (unit == -1) 1060 unit = low & CLONE_UNITMASK; 1061 dev = newdev(csw, unit2minor(unit | extra), ndev); 1062 if (dev->si_flags & SI_CLONELIST) { 1063 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 1064 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra); 1065 LIST_FOREACH(dev, &cd->head, si_clone) { 1066 printf("\t%p %s\n", dev, dev->si_name); 1067 } 1068 panic("foo"); 1069 } 1070 KASSERT(!(dev->si_flags & SI_CLONELIST), 1071 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 1072 if (dl != NULL) 1073 LIST_INSERT_BEFORE(dl, dev, si_clone); 1074 else if (de != NULL) 1075 LIST_INSERT_AFTER(de, dev, si_clone); 1076 else 1077 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 1078 dev->si_flags |= SI_CLONELIST; 1079 *up = unit; 1080 dev_unlock_and_free(); 1081 return (1); 1082 } 1083 1084 /* 1085 * Kill everything still on the list. The driver should already have 1086 * disposed of any softc hung of the struct cdev *'s at this time. 1087 */ 1088 void 1089 clone_cleanup(struct clonedevs **cdp) 1090 { 1091 struct cdev *dev; 1092 struct cdev_priv *cp; 1093 struct clonedevs *cd; 1094 1095 cd = *cdp; 1096 if (cd == NULL) 1097 return; 1098 dev_lock(); 1099 while (!LIST_EMPTY(&cd->head)) { 1100 dev = LIST_FIRST(&cd->head); 1101 LIST_REMOVE(dev, si_clone); 1102 KASSERT(dev->si_flags & SI_CLONELIST, 1103 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1104 dev->si_flags &= ~SI_CLONELIST; 1105 cp = dev->si_priv; 1106 if (!(cp->cdp_flags & CDP_SCHED_DTR)) { 1107 cp->cdp_flags |= CDP_SCHED_DTR; 1108 KASSERT(dev->si_flags & SI_NAMED, 1109 ("Driver has goofed in cloning underways udev %x", dev->si_drv0)); 1110 destroy_devl(dev); 1111 } 1112 } 1113 dev_unlock_and_free(); 1114 free(cd, M_DEVBUF); 1115 *cdp = NULL; 1116 } 1117 1118 static TAILQ_HEAD(, cdev_priv) dev_ddtr = 1119 TAILQ_HEAD_INITIALIZER(dev_ddtr); 1120 static struct task dev_dtr_task; 1121 1122 static void 1123 destroy_dev_tq(void *ctx, int pending) 1124 { 1125 struct cdev_priv *cp; 1126 struct cdev *dev; 1127 void (*cb)(void *); 1128 void *cb_arg; 1129 1130 dev_lock(); 1131 while (!TAILQ_EMPTY(&dev_ddtr)) { 1132 cp = TAILQ_FIRST(&dev_ddtr); 1133 dev = &cp->cdp_c; 1134 KASSERT(cp->cdp_flags & CDP_SCHED_DTR, 1135 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp)); 1136 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list); 1137 cb = cp->cdp_dtr_cb; 1138 cb_arg = cp->cdp_dtr_cb_arg; 1139 destroy_devl(dev); 1140 dev_unlock_and_free(); 1141 dev_rel(dev); 1142 if (cb != NULL) 1143 cb(cb_arg); 1144 dev_lock(); 1145 } 1146 dev_unlock(); 1147 } 1148 1149 /* 1150 * devmtx shall be locked on entry. devmtx will be unlocked after 1151 * function return. 1152 */ 1153 static int 1154 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg) 1155 { 1156 struct cdev_priv *cp; 1157 1158 mtx_assert(&devmtx, MA_OWNED); 1159 cp = dev->si_priv; 1160 if (cp->cdp_flags & CDP_SCHED_DTR) { 1161 dev_unlock(); 1162 return (0); 1163 } 1164 dev_refl(dev); 1165 cp->cdp_flags |= CDP_SCHED_DTR; 1166 cp->cdp_dtr_cb = cb; 1167 cp->cdp_dtr_cb_arg = arg; 1168 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list); 1169 dev_unlock(); 1170 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task); 1171 return (1); 1172 } 1173 1174 int 1175 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg) 1176 { 1177 dev_lock(); 1178 return (destroy_dev_sched_cbl(dev, cb, arg)); 1179 } 1180 1181 int 1182 destroy_dev_sched(struct cdev *dev) 1183 { 1184 return (destroy_dev_sched_cb(dev, NULL, NULL)); 1185 } 1186 1187 void 1188 destroy_dev_drain(struct cdevsw *csw) 1189 { 1190 1191 dev_lock(); 1192 while (!LIST_EMPTY(&csw->d_devs)) { 1193 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10); 1194 } 1195 dev_unlock(); 1196 } 1197 1198 void 1199 drain_dev_clone_events(void) 1200 { 1201 1202 sx_xlock(&clone_drain_lock); 1203 sx_xunlock(&clone_drain_lock); 1204 } 1205 1206 static void 1207 devdtr_init(void *dummy __unused) 1208 { 1209 1210 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL); 1211 } 1212 1213 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL); 1214