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/bio.h> 34 #include <sys/lock.h> 35 #include <sys/mutex.h> 36 #include <sys/module.h> 37 #include <sys/malloc.h> 38 #include <sys/conf.h> 39 #include <sys/vnode.h> 40 #include <sys/queue.h> 41 #include <sys/poll.h> 42 #include <sys/sx.h> 43 #include <sys/ctype.h> 44 #include <sys/tty.h> 45 #include <sys/ucred.h> 46 #include <sys/taskqueue.h> 47 #include <machine/stdarg.h> 48 49 #include <fs/devfs/devfs_int.h> 50 51 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage"); 52 53 struct mtx devmtx; 54 static void destroy_devl(struct cdev *dev); 55 static int destroy_dev_sched_cbl(struct cdev *dev, 56 void (*cb)(void *), void *arg); 57 static struct cdev *make_dev_credv(int flags, 58 struct cdevsw *devsw, int minornr, 59 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, 60 va_list ap); 61 62 static struct cdev_priv_list cdevp_free_list = 63 TAILQ_HEAD_INITIALIZER(cdevp_free_list); 64 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list = 65 SLIST_HEAD_INITIALIZER(); 66 67 void 68 dev_lock(void) 69 { 70 71 mtx_lock(&devmtx); 72 } 73 74 /* 75 * Free all the memory collected while the cdev mutex was 76 * locked. Since devmtx is after the system map mutex, free() cannot 77 * be called immediately and is postponed until cdev mutex can be 78 * dropped. 79 */ 80 static void 81 dev_unlock_and_free(void) 82 { 83 struct cdev_priv_list cdp_free; 84 struct free_cdevsw csw_free; 85 struct cdev_priv *cdp; 86 struct cdevsw *csw; 87 88 mtx_assert(&devmtx, MA_OWNED); 89 90 /* 91 * Make the local copy of the list heads while the dev_mtx is 92 * held. Free it later. 93 */ 94 TAILQ_INIT(&cdp_free); 95 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list); 96 csw_free = cdevsw_gt_post_list; 97 SLIST_INIT(&cdevsw_gt_post_list); 98 99 mtx_unlock(&devmtx); 100 101 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) { 102 TAILQ_REMOVE(&cdp_free, cdp, cdp_list); 103 devfs_free(&cdp->cdp_c); 104 } 105 while ((csw = SLIST_FIRST(&csw_free)) != NULL) { 106 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list); 107 free(csw, M_DEVT); 108 } 109 } 110 111 static void 112 dev_free_devlocked(struct cdev *cdev) 113 { 114 struct cdev_priv *cdp; 115 116 mtx_assert(&devmtx, MA_OWNED); 117 cdp = cdev->si_priv; 118 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list); 119 } 120 121 static void 122 cdevsw_free_devlocked(struct cdevsw *csw) 123 { 124 125 mtx_assert(&devmtx, MA_OWNED); 126 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list); 127 } 128 129 void 130 dev_unlock(void) 131 { 132 133 mtx_unlock(&devmtx); 134 } 135 136 void 137 dev_ref(struct cdev *dev) 138 { 139 140 mtx_assert(&devmtx, MA_NOTOWNED); 141 mtx_lock(&devmtx); 142 dev->si_refcount++; 143 mtx_unlock(&devmtx); 144 } 145 146 void 147 dev_refl(struct cdev *dev) 148 { 149 150 mtx_assert(&devmtx, MA_OWNED); 151 dev->si_refcount++; 152 } 153 154 void 155 dev_rel(struct cdev *dev) 156 { 157 int flag = 0; 158 159 mtx_assert(&devmtx, MA_NOTOWNED); 160 dev_lock(); 161 dev->si_refcount--; 162 KASSERT(dev->si_refcount >= 0, 163 ("dev_rel(%s) gave negative count", devtoname(dev))); 164 #if 0 165 if (dev->si_usecount == 0 && 166 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED)) 167 ; 168 else 169 #endif 170 if (dev->si_devsw == NULL && dev->si_refcount == 0) { 171 LIST_REMOVE(dev, si_list); 172 flag = 1; 173 } 174 dev_unlock(); 175 if (flag) 176 devfs_free(dev); 177 } 178 179 struct cdevsw * 180 dev_refthread(struct cdev *dev) 181 { 182 struct cdevsw *csw; 183 struct cdev_priv *cdp; 184 185 mtx_assert(&devmtx, MA_NOTOWNED); 186 dev_lock(); 187 csw = dev->si_devsw; 188 if (csw != NULL) { 189 cdp = dev->si_priv; 190 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) 191 dev->si_threadcount++; 192 else 193 csw = NULL; 194 } 195 dev_unlock(); 196 return (csw); 197 } 198 199 struct cdevsw * 200 devvn_refthread(struct vnode *vp, struct cdev **devp) 201 { 202 struct cdevsw *csw; 203 struct cdev_priv *cdp; 204 205 mtx_assert(&devmtx, MA_NOTOWNED); 206 csw = NULL; 207 dev_lock(); 208 *devp = vp->v_rdev; 209 if (*devp != NULL) { 210 cdp = (*devp)->si_priv; 211 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) { 212 csw = (*devp)->si_devsw; 213 if (csw != NULL) 214 (*devp)->si_threadcount++; 215 } 216 } 217 dev_unlock(); 218 return (csw); 219 } 220 221 void 222 dev_relthread(struct cdev *dev) 223 { 224 225 mtx_assert(&devmtx, MA_NOTOWNED); 226 dev_lock(); 227 dev->si_threadcount--; 228 dev_unlock(); 229 } 230 231 int 232 nullop(void) 233 { 234 235 return (0); 236 } 237 238 int 239 eopnotsupp(void) 240 { 241 242 return (EOPNOTSUPP); 243 } 244 245 static int 246 enxio(void) 247 { 248 return (ENXIO); 249 } 250 251 static int 252 enodev(void) 253 { 254 return (ENODEV); 255 } 256 257 /* Define a dead_cdevsw for use when devices leave unexpectedly. */ 258 259 #define dead_open (d_open_t *)enxio 260 #define dead_close (d_close_t *)enxio 261 #define dead_read (d_read_t *)enxio 262 #define dead_write (d_write_t *)enxio 263 #define dead_ioctl (d_ioctl_t *)enxio 264 #define dead_poll (d_poll_t *)enodev 265 #define dead_mmap (d_mmap_t *)enodev 266 267 static void 268 dead_strategy(struct bio *bp) 269 { 270 271 biofinish(bp, NULL, ENXIO); 272 } 273 274 #define dead_dump (dumper_t *)enxio 275 #define dead_kqfilter (d_kqfilter_t *)enxio 276 277 static struct cdevsw dead_cdevsw = { 278 .d_version = D_VERSION, 279 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */ 280 .d_open = dead_open, 281 .d_close = dead_close, 282 .d_read = dead_read, 283 .d_write = dead_write, 284 .d_ioctl = dead_ioctl, 285 .d_poll = dead_poll, 286 .d_mmap = dead_mmap, 287 .d_strategy = dead_strategy, 288 .d_name = "dead", 289 .d_dump = dead_dump, 290 .d_kqfilter = dead_kqfilter 291 }; 292 293 /* Default methods if driver does not specify method */ 294 295 #define null_open (d_open_t *)nullop 296 #define null_close (d_close_t *)nullop 297 #define no_read (d_read_t *)enodev 298 #define no_write (d_write_t *)enodev 299 #define no_ioctl (d_ioctl_t *)enodev 300 #define no_mmap (d_mmap_t *)enodev 301 #define no_kqfilter (d_kqfilter_t *)enodev 302 303 static void 304 no_strategy(struct bio *bp) 305 { 306 307 biofinish(bp, NULL, ENODEV); 308 } 309 310 static int 311 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused) 312 { 313 /* 314 * Return true for read/write. If the user asked for something 315 * special, return POLLNVAL, so that clients have a way of 316 * determining reliably whether or not the extended 317 * functionality is present without hard-coding knowledge 318 * of specific filesystem implementations. 319 * Stay in sync with vop_nopoll(). 320 */ 321 if (events & ~POLLSTANDARD) 322 return (POLLNVAL); 323 324 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 325 } 326 327 #define no_dump (dumper_t *)enodev 328 329 static int 330 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 331 { 332 struct cdevsw *dsw; 333 int retval; 334 335 dsw = dev_refthread(dev); 336 if (dsw == NULL) 337 return (ENXIO); 338 mtx_lock(&Giant); 339 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td); 340 mtx_unlock(&Giant); 341 dev_relthread(dev); 342 return (retval); 343 } 344 345 static int 346 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp) 347 { 348 struct cdevsw *dsw; 349 int retval; 350 351 dsw = dev_refthread(dev); 352 if (dsw == NULL) 353 return (ENXIO); 354 mtx_lock(&Giant); 355 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp); 356 mtx_unlock(&Giant); 357 dev_relthread(dev); 358 return (retval); 359 } 360 361 static int 362 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 363 { 364 struct cdevsw *dsw; 365 int retval; 366 367 dsw = dev_refthread(dev); 368 if (dsw == NULL) 369 return (ENXIO); 370 mtx_lock(&Giant); 371 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td); 372 mtx_unlock(&Giant); 373 dev_relthread(dev); 374 return (retval); 375 } 376 377 static void 378 giant_strategy(struct bio *bp) 379 { 380 struct cdevsw *dsw; 381 struct cdev *dev; 382 383 dev = bp->bio_dev; 384 dsw = dev_refthread(dev); 385 if (dsw == NULL) { 386 biofinish(bp, NULL, ENXIO); 387 return; 388 } 389 mtx_lock(&Giant); 390 dsw->d_gianttrick->d_strategy(bp); 391 mtx_unlock(&Giant); 392 dev_relthread(dev); 393 } 394 395 static int 396 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 397 { 398 struct cdevsw *dsw; 399 int retval; 400 401 dsw = dev_refthread(dev); 402 if (dsw == NULL) 403 return (ENXIO); 404 mtx_lock(&Giant); 405 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td); 406 mtx_unlock(&Giant); 407 dev_relthread(dev); 408 return (retval); 409 } 410 411 static int 412 giant_read(struct cdev *dev, struct uio *uio, int ioflag) 413 { 414 struct cdevsw *dsw; 415 int retval; 416 417 dsw = dev_refthread(dev); 418 if (dsw == NULL) 419 return (ENXIO); 420 mtx_lock(&Giant); 421 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag); 422 mtx_unlock(&Giant); 423 dev_relthread(dev); 424 return (retval); 425 } 426 427 static int 428 giant_write(struct cdev *dev, struct uio *uio, int ioflag) 429 { 430 struct cdevsw *dsw; 431 int retval; 432 433 dsw = dev_refthread(dev); 434 if (dsw == NULL) 435 return (ENXIO); 436 mtx_lock(&Giant); 437 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag); 438 mtx_unlock(&Giant); 439 dev_relthread(dev); 440 return (retval); 441 } 442 443 static int 444 giant_poll(struct cdev *dev, int events, struct thread *td) 445 { 446 struct cdevsw *dsw; 447 int retval; 448 449 dsw = dev_refthread(dev); 450 if (dsw == NULL) 451 return (ENXIO); 452 mtx_lock(&Giant); 453 retval = dsw->d_gianttrick->d_poll(dev, events, td); 454 mtx_unlock(&Giant); 455 dev_relthread(dev); 456 return (retval); 457 } 458 459 static int 460 giant_kqfilter(struct cdev *dev, struct knote *kn) 461 { 462 struct cdevsw *dsw; 463 int retval; 464 465 dsw = dev_refthread(dev); 466 if (dsw == NULL) 467 return (ENXIO); 468 mtx_lock(&Giant); 469 retval = dsw->d_gianttrick->d_kqfilter(dev, kn); 470 mtx_unlock(&Giant); 471 dev_relthread(dev); 472 return (retval); 473 } 474 475 static int 476 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot) 477 { 478 struct cdevsw *dsw; 479 int retval; 480 481 dsw = dev_refthread(dev); 482 if (dsw == NULL) 483 return (ENXIO); 484 mtx_lock(&Giant); 485 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot); 486 mtx_unlock(&Giant); 487 dev_relthread(dev); 488 return (retval); 489 } 490 491 492 /* 493 * struct cdev * and u_dev_t primitives 494 */ 495 496 int 497 minor(struct cdev *x) 498 { 499 if (x == NULL) 500 return NODEV; 501 return(x->si_drv0 & MAXMINOR); 502 } 503 504 int 505 dev2unit(struct cdev *x) 506 { 507 508 if (x == NULL) 509 return NODEV; 510 return (minor2unit(minor(x))); 511 } 512 513 u_int 514 minor2unit(u_int _minor) 515 { 516 517 KASSERT((_minor & ~MAXMINOR) == 0, ("Illegal minor %x", _minor)); 518 return ((_minor & 0xff) | ((_minor >> 8) & 0xffff00)); 519 } 520 521 int 522 unit2minor(int unit) 523 { 524 525 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); 526 return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 527 } 528 529 static struct cdev * 530 newdev(struct cdevsw *csw, int y, struct cdev *si) 531 { 532 struct cdev *si2; 533 dev_t udev; 534 535 mtx_assert(&devmtx, MA_OWNED); 536 udev = y; 537 LIST_FOREACH(si2, &csw->d_devs, si_list) { 538 if (si2->si_drv0 == udev) { 539 dev_free_devlocked(si); 540 return (si2); 541 } 542 } 543 si->si_drv0 = udev; 544 si->si_devsw = csw; 545 LIST_INSERT_HEAD(&csw->d_devs, si, si_list); 546 return (si); 547 } 548 549 int 550 uminor(dev_t dev) 551 { 552 return (dev & MAXMINOR); 553 } 554 555 int 556 umajor(dev_t dev) 557 { 558 return ((dev & ~MAXMINOR) >> 8); 559 } 560 561 static void 562 fini_cdevsw(struct cdevsw *devsw) 563 { 564 struct cdevsw *gt; 565 566 if (devsw->d_gianttrick != NULL) { 567 gt = devsw->d_gianttrick; 568 memcpy(devsw, gt, sizeof *devsw); 569 cdevsw_free_devlocked(gt); 570 devsw->d_gianttrick = NULL; 571 } 572 devsw->d_flags &= ~D_INIT; 573 } 574 575 static void 576 prep_cdevsw(struct cdevsw *devsw) 577 { 578 struct cdevsw *dsw2; 579 580 mtx_assert(&devmtx, MA_OWNED); 581 if (devsw->d_flags & D_INIT) 582 return; 583 if (devsw->d_flags & D_NEEDGIANT) { 584 dev_unlock(); 585 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK); 586 dev_lock(); 587 } else 588 dsw2 = NULL; 589 if (devsw->d_flags & D_INIT) { 590 if (dsw2 != NULL) 591 cdevsw_free_devlocked(dsw2); 592 return; 593 } 594 595 if (devsw->d_version != D_VERSION_01) { 596 printf( 597 "WARNING: Device driver \"%s\" has wrong version %s\n", 598 devsw->d_name == NULL ? "???" : devsw->d_name, 599 "and is disabled. Recompile KLD module."); 600 devsw->d_open = dead_open; 601 devsw->d_close = dead_close; 602 devsw->d_read = dead_read; 603 devsw->d_write = dead_write; 604 devsw->d_ioctl = dead_ioctl; 605 devsw->d_poll = dead_poll; 606 devsw->d_mmap = dead_mmap; 607 devsw->d_strategy = dead_strategy; 608 devsw->d_dump = dead_dump; 609 devsw->d_kqfilter = dead_kqfilter; 610 } 611 612 if (devsw->d_flags & D_TTY) { 613 if (devsw->d_ioctl == NULL) devsw->d_ioctl = ttyioctl; 614 if (devsw->d_read == NULL) devsw->d_read = ttyread; 615 if (devsw->d_write == NULL) devsw->d_write = ttywrite; 616 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = ttykqfilter; 617 if (devsw->d_poll == NULL) devsw->d_poll = ttypoll; 618 } 619 620 if (devsw->d_flags & D_NEEDGIANT) { 621 if (devsw->d_gianttrick == NULL) { 622 memcpy(dsw2, devsw, sizeof *dsw2); 623 devsw->d_gianttrick = dsw2; 624 dsw2 = NULL; 625 } 626 } 627 628 #define FIXUP(member, noop, giant) \ 629 do { \ 630 if (devsw->member == NULL) { \ 631 devsw->member = noop; \ 632 } else if (devsw->d_flags & D_NEEDGIANT) \ 633 devsw->member = giant; \ 634 } \ 635 while (0) 636 637 FIXUP(d_open, null_open, giant_open); 638 FIXUP(d_fdopen, NULL, giant_fdopen); 639 FIXUP(d_close, null_close, giant_close); 640 FIXUP(d_read, no_read, giant_read); 641 FIXUP(d_write, no_write, giant_write); 642 FIXUP(d_ioctl, no_ioctl, giant_ioctl); 643 FIXUP(d_poll, no_poll, giant_poll); 644 FIXUP(d_mmap, no_mmap, giant_mmap); 645 FIXUP(d_strategy, no_strategy, giant_strategy); 646 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter); 647 648 if (devsw->d_dump == NULL) devsw->d_dump = no_dump; 649 650 LIST_INIT(&devsw->d_devs); 651 652 devsw->d_flags |= D_INIT; 653 654 if (dsw2 != NULL) 655 cdevsw_free_devlocked(dsw2); 656 } 657 658 struct cdev * 659 make_dev_credv(int flags, struct cdevsw *devsw, int minornr, 660 struct ucred *cr, uid_t uid, 661 gid_t gid, int mode, const char *fmt, va_list ap) 662 { 663 struct cdev *dev; 664 int i; 665 666 KASSERT((minornr & ~MAXMINOR) == 0, 667 ("Invalid minor (0x%x) in make_dev", minornr)); 668 669 dev = devfs_alloc(); 670 dev_lock(); 671 prep_cdevsw(devsw); 672 dev = newdev(devsw, minornr, dev); 673 if (flags & MAKEDEV_REF) 674 dev_refl(dev); 675 if (dev->si_flags & SI_CHEAPCLONE && 676 dev->si_flags & SI_NAMED) { 677 /* 678 * This is allowed as it removes races and generally 679 * simplifies cloning devices. 680 * XXX: still ?? 681 */ 682 dev_unlock_and_free(); 683 return (dev); 684 } 685 KASSERT(!(dev->si_flags & SI_NAMED), 686 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)", 687 devsw->d_name, minor(dev), devtoname(dev))); 688 689 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 690 if (i > (sizeof dev->__si_namebuf - 1)) { 691 printf("WARNING: Device name truncated! (%s)\n", 692 dev->__si_namebuf); 693 } 694 695 dev->si_flags |= SI_NAMED; 696 #ifdef MAC 697 if (cr != NULL) 698 dev->si_cred = crhold(cr); 699 else 700 #endif 701 dev->si_cred = NULL; 702 dev->si_uid = uid; 703 dev->si_gid = gid; 704 dev->si_mode = mode; 705 706 devfs_create(dev); 707 clean_unrhdrl(devfs_inos); 708 dev_unlock_and_free(); 709 return (dev); 710 } 711 712 struct cdev * 713 make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int mode, 714 const char *fmt, ...) 715 { 716 struct cdev *dev; 717 va_list ap; 718 719 va_start(ap, fmt); 720 dev = make_dev_credv(0, devsw, minornr, NULL, uid, gid, mode, fmt, ap); 721 va_end(ap); 722 return (dev); 723 } 724 725 struct cdev * 726 make_dev_cred(struct cdevsw *devsw, int minornr, struct ucred *cr, uid_t uid, 727 gid_t gid, int mode, const char *fmt, ...) 728 { 729 struct cdev *dev; 730 va_list ap; 731 732 va_start(ap, fmt); 733 dev = make_dev_credv(0, devsw, minornr, cr, uid, gid, mode, fmt, ap); 734 va_end(ap); 735 736 return (dev); 737 } 738 739 struct cdev * 740 make_dev_credf(int flags, struct cdevsw *devsw, int minornr, 741 struct ucred *cr, uid_t uid, 742 gid_t gid, int mode, const char *fmt, ...) 743 { 744 struct cdev *dev; 745 va_list ap; 746 747 va_start(ap, fmt); 748 dev = make_dev_credv(flags, devsw, minornr, cr, uid, gid, mode, 749 fmt, ap); 750 va_end(ap); 751 752 return (dev); 753 } 754 755 static void 756 dev_dependsl(struct cdev *pdev, struct cdev *cdev) 757 { 758 759 cdev->si_parent = pdev; 760 cdev->si_flags |= SI_CHILD; 761 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 762 } 763 764 765 void 766 dev_depends(struct cdev *pdev, struct cdev *cdev) 767 { 768 769 dev_lock(); 770 dev_dependsl(pdev, cdev); 771 dev_unlock(); 772 } 773 774 struct cdev * 775 make_dev_alias(struct cdev *pdev, const char *fmt, ...) 776 { 777 struct cdev *dev; 778 va_list ap; 779 int i; 780 781 dev = devfs_alloc(); 782 dev_lock(); 783 dev->si_flags |= SI_ALIAS; 784 dev->si_flags |= SI_NAMED; 785 va_start(ap, fmt); 786 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 787 if (i > (sizeof dev->__si_namebuf - 1)) { 788 printf("WARNING: Device name truncated! (%s)\n", 789 dev->__si_namebuf); 790 } 791 va_end(ap); 792 793 devfs_create(dev); 794 clean_unrhdrl(devfs_inos); 795 dev_unlock(); 796 dev_depends(pdev, dev); 797 return (dev); 798 } 799 800 static void 801 destroy_devl(struct cdev *dev) 802 { 803 struct cdevsw *csw; 804 805 mtx_assert(&devmtx, MA_OWNED); 806 KASSERT(dev->si_flags & SI_NAMED, 807 ("WARNING: Driver mistake: destroy_dev on %d\n", minor(dev))); 808 809 devfs_destroy(dev); 810 811 /* Remove name marking */ 812 dev->si_flags &= ~SI_NAMED; 813 814 /* If we are a child, remove us from the parents list */ 815 if (dev->si_flags & SI_CHILD) { 816 LIST_REMOVE(dev, si_siblings); 817 dev->si_flags &= ~SI_CHILD; 818 } 819 820 /* Kill our children */ 821 while (!LIST_EMPTY(&dev->si_children)) 822 destroy_devl(LIST_FIRST(&dev->si_children)); 823 824 /* Remove from clone list */ 825 if (dev->si_flags & SI_CLONELIST) { 826 LIST_REMOVE(dev, si_clone); 827 dev->si_flags &= ~SI_CLONELIST; 828 } 829 830 dev->si_refcount++; /* Avoid race with dev_rel() */ 831 csw = dev->si_devsw; 832 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */ 833 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) { 834 csw->d_purge(dev); 835 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10); 836 if (dev->si_threadcount) 837 printf("Still %lu threads in %s\n", 838 dev->si_threadcount, devtoname(dev)); 839 } 840 while (dev->si_threadcount != 0) { 841 /* Use unique dummy wait ident */ 842 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10); 843 } 844 845 dev->si_drv1 = 0; 846 dev->si_drv2 = 0; 847 bzero(&dev->__si_u, sizeof(dev->__si_u)); 848 849 if (!(dev->si_flags & SI_ALIAS)) { 850 /* Remove from cdevsw list */ 851 LIST_REMOVE(dev, si_list); 852 853 /* If cdevsw has no more struct cdev *'s, clean it */ 854 if (LIST_EMPTY(&csw->d_devs)) { 855 fini_cdevsw(csw); 856 wakeup(&csw->d_devs); 857 } 858 } 859 dev->si_flags &= ~SI_ALIAS; 860 dev->si_refcount--; /* Avoid race with dev_rel() */ 861 862 if (dev->si_refcount > 0) { 863 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list); 864 } else { 865 dev_free_devlocked(dev); 866 } 867 } 868 869 void 870 destroy_dev(struct cdev *dev) 871 { 872 873 dev_lock(); 874 destroy_devl(dev); 875 dev_unlock_and_free(); 876 } 877 878 const char * 879 devtoname(struct cdev *dev) 880 { 881 char *p; 882 struct cdevsw *csw; 883 int mynor; 884 885 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 886 p = dev->si_name; 887 csw = dev_refthread(dev); 888 if (csw != NULL) { 889 sprintf(p, "(%s)", csw->d_name); 890 dev_relthread(dev); 891 } 892 p += strlen(p); 893 mynor = minor(dev); 894 if (mynor < 0 || mynor > 255) 895 sprintf(p, "/%#x", (u_int)mynor); 896 else 897 sprintf(p, "/%d", mynor); 898 } 899 return (dev->si_name); 900 } 901 902 int 903 dev_stdclone(char *name, char **namep, const char *stem, int *unit) 904 { 905 int u, i; 906 907 i = strlen(stem); 908 if (bcmp(stem, name, i) != 0) 909 return (0); 910 if (!isdigit(name[i])) 911 return (0); 912 u = 0; 913 if (name[i] == '0' && isdigit(name[i+1])) 914 return (0); 915 while (isdigit(name[i])) { 916 u *= 10; 917 u += name[i++] - '0'; 918 } 919 if (u > 0xffffff) 920 return (0); 921 *unit = u; 922 if (namep) 923 *namep = &name[i]; 924 if (name[i]) 925 return (2); 926 return (1); 927 } 928 929 /* 930 * Helper functions for cloning device drivers. 931 * 932 * The objective here is to make it unnecessary for the device drivers to 933 * use rman or similar to manage their unit number space. Due to the way 934 * we do "on-demand" devices, using rman or other "private" methods 935 * will be very tricky to lock down properly once we lock down this file. 936 * 937 * Instead we give the drivers these routines which puts the struct cdev *'s 938 * that are to be managed on their own list, and gives the driver the ability 939 * to ask for the first free unit number or a given specified unit number. 940 * 941 * In addition these routines support paired devices (pty, nmdm and similar) 942 * by respecting a number of "flag" bits in the minor number. 943 * 944 */ 945 946 struct clonedevs { 947 LIST_HEAD(,cdev) head; 948 }; 949 950 void 951 clone_setup(struct clonedevs **cdp) 952 { 953 954 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO); 955 LIST_INIT(&(*cdp)->head); 956 } 957 958 int 959 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra) 960 { 961 struct clonedevs *cd; 962 struct cdev *dev, *ndev, *dl, *de; 963 int unit, low, u; 964 965 KASSERT(*cdp != NULL, 966 ("clone_setup() not called in driver \"%s\"", csw->d_name)); 967 KASSERT(!(extra & CLONE_UNITMASK), 968 ("Illegal extra bits (0x%x) in clone_create", extra)); 969 KASSERT(*up <= CLONE_UNITMASK, 970 ("Too high unit (0x%x) in clone_create", *up)); 971 972 973 /* 974 * Search the list for a lot of things in one go: 975 * A preexisting match is returned immediately. 976 * The lowest free unit number if we are passed -1, and the place 977 * in the list where we should insert that new element. 978 * The place to insert a specified unit number, if applicable 979 * the end of the list. 980 */ 981 unit = *up; 982 ndev = devfs_alloc(); 983 dev_lock(); 984 prep_cdevsw(csw); 985 low = extra; 986 de = dl = NULL; 987 cd = *cdp; 988 LIST_FOREACH(dev, &cd->head, si_clone) { 989 KASSERT(dev->si_flags & SI_CLONELIST, 990 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 991 u = dev2unit(dev); 992 if (u == (unit | extra)) { 993 *dp = dev; 994 dev_unlock(); 995 devfs_free(ndev); 996 return (0); 997 } 998 if (unit == -1 && u == low) { 999 low++; 1000 de = dev; 1001 continue; 1002 } else if (u < (unit | extra)) { 1003 de = dev; 1004 continue; 1005 } else if (u > (unit | extra)) { 1006 dl = dev; 1007 break; 1008 } 1009 } 1010 if (unit == -1) 1011 unit = low & CLONE_UNITMASK; 1012 dev = newdev(csw, unit2minor(unit | extra), ndev); 1013 if (dev->si_flags & SI_CLONELIST) { 1014 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name); 1015 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra); 1016 LIST_FOREACH(dev, &cd->head, si_clone) { 1017 printf("\t%p %s\n", dev, dev->si_name); 1018 } 1019 panic("foo"); 1020 } 1021 KASSERT(!(dev->si_flags & SI_CLONELIST), 1022 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name)); 1023 if (dl != NULL) 1024 LIST_INSERT_BEFORE(dl, dev, si_clone); 1025 else if (de != NULL) 1026 LIST_INSERT_AFTER(de, dev, si_clone); 1027 else 1028 LIST_INSERT_HEAD(&cd->head, dev, si_clone); 1029 dev->si_flags |= SI_CLONELIST; 1030 *up = unit; 1031 dev_unlock_and_free(); 1032 return (1); 1033 } 1034 1035 /* 1036 * Kill everything still on the list. The driver should already have 1037 * disposed of any softc hung of the struct cdev *'s at this time. 1038 */ 1039 void 1040 clone_cleanup(struct clonedevs **cdp) 1041 { 1042 struct cdev *dev; 1043 struct cdev_priv *cp; 1044 struct clonedevs *cd; 1045 1046 cd = *cdp; 1047 if (cd == NULL) 1048 return; 1049 dev_lock(); 1050 while (!LIST_EMPTY(&cd->head)) { 1051 dev = LIST_FIRST(&cd->head); 1052 LIST_REMOVE(dev, si_clone); 1053 KASSERT(dev->si_flags & SI_CLONELIST, 1054 ("Dev %p(%s) should be on clonelist", dev, dev->si_name)); 1055 dev->si_flags &= ~SI_CLONELIST; 1056 cp = dev->si_priv; 1057 if (!(cp->cdp_flags & CDP_SCHED_DTR)) { 1058 cp->cdp_flags |= CDP_SCHED_DTR; 1059 KASSERT(dev->si_flags & SI_NAMED, 1060 ("Driver has goofed in cloning underways udev %x", dev->si_drv0)); 1061 destroy_devl(dev); 1062 } 1063 } 1064 dev_unlock_and_free(); 1065 free(cd, M_DEVBUF); 1066 *cdp = NULL; 1067 } 1068 1069 static TAILQ_HEAD(, cdev_priv) dev_ddtr = 1070 TAILQ_HEAD_INITIALIZER(dev_ddtr); 1071 static struct task dev_dtr_task; 1072 1073 static void 1074 destroy_dev_tq(void *ctx, int pending) 1075 { 1076 struct cdev_priv *cp; 1077 struct cdev *dev; 1078 void (*cb)(void *); 1079 void *cb_arg; 1080 1081 dev_lock(); 1082 while (!TAILQ_EMPTY(&dev_ddtr)) { 1083 cp = TAILQ_FIRST(&dev_ddtr); 1084 dev = &cp->cdp_c; 1085 KASSERT(cp->cdp_flags & CDP_SCHED_DTR, 1086 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp)); 1087 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list); 1088 cb = cp->cdp_dtr_cb; 1089 cb_arg = cp->cdp_dtr_cb_arg; 1090 destroy_devl(dev); 1091 dev_unlock_and_free(); 1092 dev_rel(dev); 1093 if (cb != NULL) 1094 cb(cb_arg); 1095 dev_lock(); 1096 } 1097 dev_unlock(); 1098 } 1099 1100 /* 1101 * devmtx shall be locked on entry. devmtx will be unlocked after 1102 * function return. 1103 */ 1104 static int 1105 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg) 1106 { 1107 struct cdev_priv *cp; 1108 1109 mtx_assert(&devmtx, MA_OWNED); 1110 cp = dev->si_priv; 1111 if (cp->cdp_flags & CDP_SCHED_DTR) { 1112 dev_unlock(); 1113 return (0); 1114 } 1115 dev_refl(dev); 1116 cp->cdp_flags |= CDP_SCHED_DTR; 1117 cp->cdp_dtr_cb = cb; 1118 cp->cdp_dtr_cb_arg = arg; 1119 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list); 1120 dev_unlock(); 1121 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task); 1122 return (1); 1123 } 1124 1125 int 1126 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg) 1127 { 1128 dev_lock(); 1129 return (destroy_dev_sched_cbl(dev, cb, arg)); 1130 } 1131 1132 int 1133 destroy_dev_sched(struct cdev *dev) 1134 { 1135 return (destroy_dev_sched_cb(dev, NULL, NULL)); 1136 } 1137 1138 void 1139 destroy_dev_drain(struct cdevsw *csw) 1140 { 1141 1142 dev_lock(); 1143 while (!LIST_EMPTY(&csw->d_devs)) { 1144 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10); 1145 } 1146 dev_unlock(); 1147 } 1148 1149 void 1150 drain_dev_clone_events(void) 1151 { 1152 1153 sx_xlock(&clone_drain_lock); 1154 sx_xunlock(&clone_drain_lock); 1155 } 1156 1157 static void 1158 devdtr_init(void *dummy __unused) 1159 { 1160 1161 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL); 1162 } 1163 1164 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL); 1165