FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_conf.c
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: releng/8.4/sys/kern/kern_conf.c 241323 2012-10-07 18:37:59Z jhb $");
29
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/bio.h>
35 #include <sys/lock.h>
36 #include <sys/mutex.h>
37 #include <sys/module.h>
38 #include <sys/malloc.h>
39 #include <sys/conf.h>
40 #include <sys/vnode.h>
41 #include <sys/queue.h>
42 #include <sys/poll.h>
43 #include <sys/sx.h>
44 #include <sys/ctype.h>
45 #include <sys/ucred.h>
46 #include <sys/taskqueue.h>
47 #include <machine/stdarg.h>
48
49 #include <fs/devfs/devfs_int.h>
50 #include <vm/vm.h>
51
52 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
53
54 struct mtx devmtx;
55 static void destroy_devl(struct cdev *dev);
56 static int destroy_dev_sched_cbl(struct cdev *dev,
57 void (*cb)(void *), void *arg);
58 static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
59 int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
60 va_list ap);
61
62 static struct cdev_priv_list cdevp_free_list =
63 TAILQ_HEAD_INITIALIZER(cdevp_free_list);
64 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
65 SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
66
67 void
68 dev_lock(void)
69 {
70
71 mtx_lock(&devmtx);
72 }
73
74 /*
75 * Free all the memory collected while the cdev mutex was
76 * locked. Since devmtx is after the system map mutex, free() cannot
77 * be called immediately and is postponed until cdev mutex can be
78 * dropped.
79 */
80 static void
81 dev_unlock_and_free(void)
82 {
83 struct cdev_priv_list cdp_free;
84 struct free_cdevsw csw_free;
85 struct cdev_priv *cdp;
86 struct cdevsw *csw;
87
88 mtx_assert(&devmtx, MA_OWNED);
89
90 /*
91 * Make the local copy of the list heads while the dev_mtx is
92 * held. Free it later.
93 */
94 TAILQ_INIT(&cdp_free);
95 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
96 csw_free = cdevsw_gt_post_list;
97 SLIST_INIT(&cdevsw_gt_post_list);
98
99 mtx_unlock(&devmtx);
100
101 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
102 TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
103 devfs_free(&cdp->cdp_c);
104 }
105 while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
106 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
107 free(csw, M_DEVT);
108 }
109 }
110
111 static void
112 dev_free_devlocked(struct cdev *cdev)
113 {
114 struct cdev_priv *cdp;
115
116 mtx_assert(&devmtx, MA_OWNED);
117 cdp = cdev2priv(cdev);
118 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
119 }
120
121 static void
122 cdevsw_free_devlocked(struct cdevsw *csw)
123 {
124
125 mtx_assert(&devmtx, MA_OWNED);
126 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
127 }
128
129 void
130 dev_unlock(void)
131 {
132
133 mtx_unlock(&devmtx);
134 }
135
136 void
137 dev_ref(struct cdev *dev)
138 {
139
140 mtx_assert(&devmtx, MA_NOTOWNED);
141 mtx_lock(&devmtx);
142 dev->si_refcount++;
143 mtx_unlock(&devmtx);
144 }
145
146 void
147 dev_refl(struct cdev *dev)
148 {
149
150 mtx_assert(&devmtx, MA_OWNED);
151 dev->si_refcount++;
152 }
153
154 void
155 dev_rel(struct cdev *dev)
156 {
157 int flag = 0;
158
159 mtx_assert(&devmtx, MA_NOTOWNED);
160 dev_lock();
161 dev->si_refcount--;
162 KASSERT(dev->si_refcount >= 0,
163 ("dev_rel(%s) gave negative count", devtoname(dev)));
164 #if 0
165 if (dev->si_usecount == 0 &&
166 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
167 ;
168 else
169 #endif
170 if (dev->si_devsw == NULL && dev->si_refcount == 0) {
171 LIST_REMOVE(dev, si_list);
172 flag = 1;
173 }
174 dev_unlock();
175 if (flag)
176 devfs_free(dev);
177 }
178
179 struct cdevsw *
180 dev_refthread(struct cdev *dev, int *ref)
181 {
182 struct cdevsw *csw;
183 struct cdev_priv *cdp;
184
185 mtx_assert(&devmtx, MA_NOTOWNED);
186 if ((dev->si_flags & SI_ETERNAL) != 0) {
187 *ref = 0;
188 return (dev->si_devsw);
189 }
190 dev_lock();
191 csw = dev->si_devsw;
192 if (csw != NULL) {
193 cdp = cdev2priv(dev);
194 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
195 dev->si_threadcount++;
196 else
197 csw = NULL;
198 }
199 dev_unlock();
200 *ref = 1;
201 return (csw);
202 }
203
204 struct cdevsw *
205 devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
206 {
207 struct cdevsw *csw;
208 struct cdev_priv *cdp;
209 struct cdev *dev;
210
211 mtx_assert(&devmtx, MA_NOTOWNED);
212 if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
213 dev = vp->v_rdev;
214 if (dev == NULL)
215 return (NULL);
216 KASSERT((dev->si_flags & SI_ETERNAL) != 0,
217 ("Not eternal cdev"));
218 *ref = 0;
219 csw = dev->si_devsw;
220 KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
221 *devp = dev;
222 return (csw);
223 }
224
225 csw = NULL;
226 dev_lock();
227 dev = vp->v_rdev;
228 if (dev == NULL) {
229 dev_unlock();
230 return (NULL);
231 }
232 cdp = cdev2priv(dev);
233 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
234 csw = dev->si_devsw;
235 if (csw != NULL)
236 dev->si_threadcount++;
237 }
238 dev_unlock();
239 if (csw != NULL) {
240 *devp = dev;
241 *ref = 1;
242 }
243 return (csw);
244 }
245
246 void
247 dev_relthread(struct cdev *dev, int ref)
248 {
249
250 mtx_assert(&devmtx, MA_NOTOWNED);
251 if (!ref)
252 return;
253 dev_lock();
254 KASSERT(dev->si_threadcount > 0,
255 ("%s threadcount is wrong", dev->si_name));
256 dev->si_threadcount--;
257 dev_unlock();
258 }
259
260 int
261 nullop(void)
262 {
263
264 return (0);
265 }
266
267 int
268 eopnotsupp(void)
269 {
270
271 return (EOPNOTSUPP);
272 }
273
274 static int
275 enxio(void)
276 {
277 return (ENXIO);
278 }
279
280 static int
281 enodev(void)
282 {
283 return (ENODEV);
284 }
285
286 /* Define a dead_cdevsw for use when devices leave unexpectedly. */
287
288 #define dead_open (d_open_t *)enxio
289 #define dead_close (d_close_t *)enxio
290 #define dead_read (d_read_t *)enxio
291 #define dead_write (d_write_t *)enxio
292 #define dead_ioctl (d_ioctl_t *)enxio
293 #define dead_poll (d_poll_t *)enodev
294 #define dead_mmap (d_mmap_t *)enodev
295
296 static void
297 dead_strategy(struct bio *bp)
298 {
299
300 biofinish(bp, NULL, ENXIO);
301 }
302
303 #define dead_dump (dumper_t *)enxio
304 #define dead_kqfilter (d_kqfilter_t *)enxio
305 #define dead_mmap_single (d_mmap_single_t *)enodev
306
307 static struct cdevsw dead_cdevsw = {
308 .d_version = D_VERSION,
309 .d_open = dead_open,
310 .d_close = dead_close,
311 .d_read = dead_read,
312 .d_write = dead_write,
313 .d_ioctl = dead_ioctl,
314 .d_poll = dead_poll,
315 .d_mmap = dead_mmap,
316 .d_strategy = dead_strategy,
317 .d_name = "dead",
318 .d_dump = dead_dump,
319 .d_kqfilter = dead_kqfilter,
320 .d_mmap_single = dead_mmap_single
321 };
322
323 /* Default methods if driver does not specify method */
324
325 #define null_open (d_open_t *)nullop
326 #define null_close (d_close_t *)nullop
327 #define no_read (d_read_t *)enodev
328 #define no_write (d_write_t *)enodev
329 #define no_ioctl (d_ioctl_t *)enodev
330 #define no_mmap (d_mmap2_t *)enodev
331 #define no_kqfilter (d_kqfilter_t *)enodev
332 #define no_mmap_single (d_mmap_single_t *)enodev
333
334 static void
335 no_strategy(struct bio *bp)
336 {
337
338 biofinish(bp, NULL, ENODEV);
339 }
340
341 static int
342 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
343 {
344
345 return (poll_no_poll(events));
346 }
347
348 #define no_dump (dumper_t *)enodev
349
350 static int
351 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
352 {
353 struct cdevsw *dsw;
354 int ref, retval;
355
356 dsw = dev_refthread(dev, &ref);
357 if (dsw == NULL)
358 return (ENXIO);
359 mtx_lock(&Giant);
360 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
361 mtx_unlock(&Giant);
362 dev_relthread(dev, ref);
363 return (retval);
364 }
365
366 static int
367 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
368 {
369 struct cdevsw *dsw;
370 int ref, retval;
371
372 dsw = dev_refthread(dev, &ref);
373 if (dsw == NULL)
374 return (ENXIO);
375 mtx_lock(&Giant);
376 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
377 mtx_unlock(&Giant);
378 dev_relthread(dev, ref);
379 return (retval);
380 }
381
382 static int
383 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
384 {
385 struct cdevsw *dsw;
386 int ref, retval;
387
388 dsw = dev_refthread(dev, &ref);
389 if (dsw == NULL)
390 return (ENXIO);
391 mtx_lock(&Giant);
392 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
393 mtx_unlock(&Giant);
394 dev_relthread(dev, ref);
395 return (retval);
396 }
397
398 static void
399 giant_strategy(struct bio *bp)
400 {
401 struct cdevsw *dsw;
402 struct cdev *dev;
403 int ref;
404
405 dev = bp->bio_dev;
406 dsw = dev_refthread(dev, &ref);
407 if (dsw == NULL) {
408 biofinish(bp, NULL, ENXIO);
409 return;
410 }
411 mtx_lock(&Giant);
412 dsw->d_gianttrick->d_strategy(bp);
413 mtx_unlock(&Giant);
414 dev_relthread(dev, ref);
415 }
416
417 static int
418 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
419 {
420 struct cdevsw *dsw;
421 int ref, retval;
422
423 dsw = dev_refthread(dev, &ref);
424 if (dsw == NULL)
425 return (ENXIO);
426 mtx_lock(&Giant);
427 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
428 mtx_unlock(&Giant);
429 dev_relthread(dev, ref);
430 return (retval);
431 }
432
433 static int
434 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
435 {
436 struct cdevsw *dsw;
437 int ref, retval;
438
439 dsw = dev_refthread(dev, &ref);
440 if (dsw == NULL)
441 return (ENXIO);
442 mtx_lock(&Giant);
443 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
444 mtx_unlock(&Giant);
445 dev_relthread(dev, ref);
446 return (retval);
447 }
448
449 static int
450 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
451 {
452 struct cdevsw *dsw;
453 int ref, retval;
454
455 dsw = dev_refthread(dev, &ref);
456 if (dsw == NULL)
457 return (ENXIO);
458 mtx_lock(&Giant);
459 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
460 mtx_unlock(&Giant);
461 dev_relthread(dev, ref);
462 return (retval);
463 }
464
465 static int
466 giant_poll(struct cdev *dev, int events, struct thread *td)
467 {
468 struct cdevsw *dsw;
469 int ref, retval;
470
471 dsw = dev_refthread(dev, &ref);
472 if (dsw == NULL)
473 return (ENXIO);
474 mtx_lock(&Giant);
475 retval = dsw->d_gianttrick->d_poll(dev, events, td);
476 mtx_unlock(&Giant);
477 dev_relthread(dev, ref);
478 return (retval);
479 }
480
481 static int
482 giant_kqfilter(struct cdev *dev, struct knote *kn)
483 {
484 struct cdevsw *dsw;
485 int ref, retval;
486
487 dsw = dev_refthread(dev, &ref);
488 if (dsw == NULL)
489 return (ENXIO);
490 mtx_lock(&Giant);
491 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
492 mtx_unlock(&Giant);
493 dev_relthread(dev, ref);
494 return (retval);
495 }
496
497 static int
498 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot,
499 vm_memattr_t *memattr)
500 {
501 struct cdevsw *dsw;
502 int ref, retval;
503
504 dsw = dev_refthread(dev, &ref);
505 if (dsw == NULL)
506 return (ENXIO);
507 mtx_lock(&Giant);
508 if (dsw->d_gianttrick->d_flags & D_MMAP2)
509 retval = dsw->d_gianttrick->d_mmap2(dev, offset, paddr, nprot,
510 memattr);
511 else
512 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot);
513 mtx_unlock(&Giant);
514 dev_relthread(dev, ref);
515 return (retval);
516 }
517
518 static int
519 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
520 vm_object_t *object, int nprot)
521 {
522 struct cdevsw *dsw;
523 int ref, retval;
524
525 dsw = dev_refthread(dev, &ref);
526 if (dsw == NULL)
527 return (ENXIO);
528 mtx_lock(&Giant);
529 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
530 nprot);
531 mtx_unlock(&Giant);
532 dev_relthread(dev, ref);
533 return (retval);
534 }
535
536 static void
537 notify(struct cdev *dev, const char *ev, int flags)
538 {
539 static const char prefix[] = "cdev=";
540 char *data;
541 int namelen, mflags;
542
543 if (cold)
544 return;
545 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
546 namelen = strlen(dev->si_name);
547 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
548 if (data == NULL)
549 return;
550 memcpy(data, prefix, sizeof(prefix) - 1);
551 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
552 devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
553 free(data, M_TEMP);
554 }
555
556 static void
557 notify_create(struct cdev *dev, int flags)
558 {
559
560 notify(dev, "CREATE", flags);
561 }
562
563 static void
564 notify_destroy(struct cdev *dev)
565 {
566
567 notify(dev, "DESTROY", MAKEDEV_WAITOK);
568 }
569
570 static struct cdev *
571 newdev(struct cdevsw *csw, int unit, struct cdev *si)
572 {
573 struct cdev *si2;
574
575 mtx_assert(&devmtx, MA_OWNED);
576 if (csw->d_flags & D_NEEDMINOR) {
577 /* We may want to return an existing device */
578 LIST_FOREACH(si2, &csw->d_devs, si_list) {
579 if (dev2unit(si2) == unit) {
580 dev_free_devlocked(si);
581 return (si2);
582 }
583 }
584 }
585 si->si_drv0 = unit;
586 si->si_devsw = csw;
587 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
588 return (si);
589 }
590
591 static void
592 fini_cdevsw(struct cdevsw *devsw)
593 {
594 struct cdevsw *gt;
595
596 if (devsw->d_gianttrick != NULL) {
597 gt = devsw->d_gianttrick;
598 memcpy(devsw, gt, sizeof *devsw);
599 cdevsw_free_devlocked(gt);
600 devsw->d_gianttrick = NULL;
601 }
602 devsw->d_flags &= ~D_INIT;
603 }
604
605 static int
606 prep_cdevsw(struct cdevsw *devsw, int flags)
607 {
608 struct cdevsw *dsw2;
609
610 mtx_assert(&devmtx, MA_OWNED);
611 if (devsw->d_flags & D_INIT)
612 return (0);
613 if (devsw->d_flags & D_NEEDGIANT) {
614 dev_unlock();
615 dsw2 = malloc(sizeof *dsw2, M_DEVT,
616 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
617 dev_lock();
618 if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
619 return (ENOMEM);
620 } else
621 dsw2 = NULL;
622 if (devsw->d_flags & D_INIT) {
623 if (dsw2 != NULL)
624 cdevsw_free_devlocked(dsw2);
625 return (0);
626 }
627
628 if (devsw->d_version != D_VERSION_01 &&
629 devsw->d_version != D_VERSION_02) {
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 if (devsw->d_version == D_VERSION_01)
646 devsw->d_mmap_single = NULL;
647
648 if (devsw->d_flags & D_NEEDGIANT) {
649 if (devsw->d_gianttrick == NULL) {
650 memcpy(dsw2, devsw, sizeof *dsw2);
651 devsw->d_gianttrick = dsw2;
652 devsw->d_flags |= D_MMAP2;
653 dsw2 = NULL;
654 }
655 }
656
657 #define FIXUP(member, noop, giant) \
658 do { \
659 if (devsw->member == NULL) { \
660 devsw->member = noop; \
661 } else if (devsw->d_flags & D_NEEDGIANT) \
662 devsw->member = giant; \
663 } \
664 while (0)
665
666 FIXUP(d_open, null_open, giant_open);
667 FIXUP(d_fdopen, NULL, giant_fdopen);
668 FIXUP(d_close, null_close, giant_close);
669 FIXUP(d_read, no_read, giant_read);
670 FIXUP(d_write, no_write, giant_write);
671 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
672 FIXUP(d_poll, no_poll, giant_poll);
673 FIXUP(d_mmap2, no_mmap, giant_mmap);
674 FIXUP(d_strategy, no_strategy, giant_strategy);
675 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
676 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
677
678 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
679
680 LIST_INIT(&devsw->d_devs);
681
682 devsw->d_flags |= D_INIT;
683
684 if (dsw2 != NULL)
685 cdevsw_free_devlocked(dsw2);
686 return (0);
687 }
688
689 static int
690 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
691 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
692 va_list ap)
693 {
694 struct cdev *dev;
695 int i, res;
696
697 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
698 ("make_dev_credv: both WAITOK and NOWAIT specified"));
699 dev = devfs_alloc(flags);
700 if (dev == NULL)
701 return (ENOMEM);
702 dev_lock();
703 res = prep_cdevsw(devsw, flags);
704 if (res != 0) {
705 dev_unlock();
706 devfs_free(dev);
707 return (res);
708 }
709 dev = newdev(devsw, unit, dev);
710 if (flags & MAKEDEV_REF)
711 dev_refl(dev);
712 if (flags & MAKEDEV_ETERNAL)
713 dev->si_flags |= SI_ETERNAL;
714 if (dev->si_flags & SI_CHEAPCLONE &&
715 dev->si_flags & SI_NAMED) {
716 /*
717 * This is allowed as it removes races and generally
718 * simplifies cloning devices.
719 * XXX: still ??
720 */
721 dev_unlock_and_free();
722 *dres = dev;
723 return (0);
724 }
725 KASSERT(!(dev->si_flags & SI_NAMED),
726 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
727 devsw->d_name, dev2unit(dev), devtoname(dev)));
728
729 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
730 if (i > (sizeof dev->__si_namebuf - 1)) {
731 printf("WARNING: Device name truncated! (%s)\n",
732 dev->__si_namebuf);
733 }
734
735 dev->si_flags |= SI_NAMED;
736 if (cr != NULL)
737 dev->si_cred = crhold(cr);
738 dev->si_uid = uid;
739 dev->si_gid = gid;
740 dev->si_mode = mode;
741
742 devfs_create(dev);
743 clean_unrhdrl(devfs_inos);
744 dev_unlock_and_free();
745
746 notify_create(dev, flags);
747
748 *dres = dev;
749 return (0);
750 }
751
752 struct cdev *
753 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
754 const char *fmt, ...)
755 {
756 struct cdev *dev;
757 va_list ap;
758 int res;
759
760 va_start(ap, fmt);
761 res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
762 ap);
763 va_end(ap);
764 KASSERT(res == 0 && dev != NULL, ("make_dev: failed make_dev_credv"));
765 return (dev);
766 }
767
768 struct cdev *
769 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
770 gid_t gid, int mode, const char *fmt, ...)
771 {
772 struct cdev *dev;
773 va_list ap;
774 int res;
775
776 va_start(ap, fmt);
777 res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
778 va_end(ap);
779
780 KASSERT(res == 0 && dev != NULL,
781 ("make_dev_cred: failed make_dev_credv"));
782 return (dev);
783 }
784
785 struct cdev *
786 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
787 uid_t uid, gid_t gid, int mode, const char *fmt, ...)
788 {
789 struct cdev *dev;
790 va_list ap;
791 int res;
792
793 va_start(ap, fmt);
794 res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
795 fmt, ap);
796 va_end(ap);
797
798 KASSERT((flags & MAKEDEV_NOWAIT) != 0 || res == 0,
799 ("make_dev_credf: failed make_dev_credv"));
800 return (res == 0 ? dev : NULL);
801 }
802
803 int
804 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
805 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
806 {
807 va_list ap;
808 int res;
809
810 va_start(ap, fmt);
811 res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
812 fmt, ap);
813 va_end(ap);
814
815 KASSERT((flags & MAKEDEV_NOWAIT) != 0 || res == 0,
816 ("make_dev_p: failed make_dev_credv"));
817 return (res);
818 }
819
820 static void
821 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
822 {
823
824 cdev->si_parent = pdev;
825 cdev->si_flags |= SI_CHILD;
826 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
827 }
828
829
830 void
831 dev_depends(struct cdev *pdev, struct cdev *cdev)
832 {
833
834 dev_lock();
835 dev_dependsl(pdev, cdev);
836 dev_unlock();
837 }
838
839 struct cdev *
840 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
841 {
842 struct cdev *dev;
843 va_list ap;
844 int i;
845
846 KASSERT(pdev != NULL, ("NULL pdev"));
847 dev = devfs_alloc(MAKEDEV_WAITOK);
848 dev_lock();
849 dev->si_flags |= SI_ALIAS;
850 dev->si_flags |= SI_NAMED;
851 va_start(ap, fmt);
852 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
853 if (i > (sizeof dev->__si_namebuf - 1)) {
854 printf("WARNING: Device name truncated! (%s)\n",
855 dev->__si_namebuf);
856 }
857 va_end(ap);
858
859 devfs_create(dev);
860 dev_dependsl(pdev, dev);
861 clean_unrhdrl(devfs_inos);
862 dev_unlock();
863
864 notify_create(dev, MAKEDEV_WAITOK);
865
866 return (dev);
867 }
868
869 static void
870 destroy_devl(struct cdev *dev)
871 {
872 struct cdevsw *csw;
873 struct cdev_privdata *p;
874
875 mtx_assert(&devmtx, MA_OWNED);
876 KASSERT(dev->si_flags & SI_NAMED,
877 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
878 KASSERT((dev->si_flags & SI_ETERNAL) == 0,
879 ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
880 dev2unit(dev)));
881
882 devfs_destroy(dev);
883
884 /* Remove name marking */
885 dev->si_flags &= ~SI_NAMED;
886
887 dev->si_refcount++; /* Avoid race with dev_rel() */
888
889 /* If we are a child, remove us from the parents list */
890 if (dev->si_flags & SI_CHILD) {
891 LIST_REMOVE(dev, si_siblings);
892 dev->si_flags &= ~SI_CHILD;
893 }
894
895 /* Kill our children */
896 while (!LIST_EMPTY(&dev->si_children))
897 destroy_devl(LIST_FIRST(&dev->si_children));
898
899 /* Remove from clone list */
900 if (dev->si_flags & SI_CLONELIST) {
901 LIST_REMOVE(dev, si_clone);
902 dev->si_flags &= ~SI_CLONELIST;
903 }
904
905 csw = dev->si_devsw;
906 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
907 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
908 csw->d_purge(dev);
909 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
910 if (dev->si_threadcount)
911 printf("Still %lu threads in %s\n",
912 dev->si_threadcount, devtoname(dev));
913 }
914 while (dev->si_threadcount != 0) {
915 /* Use unique dummy wait ident */
916 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
917 }
918
919 dev_unlock();
920 notify_destroy(dev);
921 mtx_lock(&cdevpriv_mtx);
922 while ((p = LIST_FIRST(&cdev2priv(dev)->cdp_fdpriv)) != NULL) {
923 devfs_destroy_cdevpriv(p);
924 mtx_lock(&cdevpriv_mtx);
925 }
926 mtx_unlock(&cdevpriv_mtx);
927 dev_lock();
928
929 dev->si_drv1 = 0;
930 dev->si_drv2 = 0;
931 bzero(&dev->__si_u, sizeof(dev->__si_u));
932
933 if (!(dev->si_flags & SI_ALIAS)) {
934 /* Remove from cdevsw list */
935 LIST_REMOVE(dev, si_list);
936
937 /* If cdevsw has no more struct cdev *'s, clean it */
938 if (LIST_EMPTY(&csw->d_devs)) {
939 fini_cdevsw(csw);
940 wakeup(&csw->d_devs);
941 }
942 }
943 dev->si_flags &= ~SI_ALIAS;
944 dev->si_refcount--; /* Avoid race with dev_rel() */
945
946 if (dev->si_refcount > 0) {
947 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
948 } else {
949 dev_free_devlocked(dev);
950 }
951 }
952
953 void
954 destroy_dev(struct cdev *dev)
955 {
956
957 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
958 dev_lock();
959 destroy_devl(dev);
960 dev_unlock_and_free();
961 }
962
963 const char *
964 devtoname(struct cdev *dev)
965 {
966
967 return (dev->si_name);
968 }
969
970 int
971 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
972 {
973 int u, i;
974
975 i = strlen(stem);
976 if (bcmp(stem, name, i) != 0)
977 return (0);
978 if (!isdigit(name[i]))
979 return (0);
980 u = 0;
981 if (name[i] == '' && isdigit(name[i+1]))
982 return (0);
983 while (isdigit(name[i])) {
984 u *= 10;
985 u += name[i++] - '';
986 }
987 if (u > 0xffffff)
988 return (0);
989 *unit = u;
990 if (namep)
991 *namep = &name[i];
992 if (name[i])
993 return (2);
994 return (1);
995 }
996
997 /*
998 * Helper functions for cloning device drivers.
999 *
1000 * The objective here is to make it unnecessary for the device drivers to
1001 * use rman or similar to manage their unit number space. Due to the way
1002 * we do "on-demand" devices, using rman or other "private" methods
1003 * will be very tricky to lock down properly once we lock down this file.
1004 *
1005 * Instead we give the drivers these routines which puts the struct cdev *'s
1006 * that are to be managed on their own list, and gives the driver the ability
1007 * to ask for the first free unit number or a given specified unit number.
1008 *
1009 * In addition these routines support paired devices (pty, nmdm and similar)
1010 * by respecting a number of "flag" bits in the minor number.
1011 *
1012 */
1013
1014 struct clonedevs {
1015 LIST_HEAD(,cdev) head;
1016 };
1017
1018 void
1019 clone_setup(struct clonedevs **cdp)
1020 {
1021
1022 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1023 LIST_INIT(&(*cdp)->head);
1024 }
1025
1026 int
1027 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1028 struct cdev **dp, int extra)
1029 {
1030 struct clonedevs *cd;
1031 struct cdev *dev, *ndev, *dl, *de;
1032 int unit, low, u;
1033
1034 KASSERT(*cdp != NULL,
1035 ("clone_setup() not called in driver \"%s\"", csw->d_name));
1036 KASSERT(!(extra & CLONE_UNITMASK),
1037 ("Illegal extra bits (0x%x) in clone_create", extra));
1038 KASSERT(*up <= CLONE_UNITMASK,
1039 ("Too high unit (0x%x) in clone_create", *up));
1040 KASSERT(csw->d_flags & D_NEEDMINOR,
1041 ("clone_create() on cdevsw without minor numbers"));
1042
1043
1044 /*
1045 * Search the list for a lot of things in one go:
1046 * A preexisting match is returned immediately.
1047 * The lowest free unit number if we are passed -1, and the place
1048 * in the list where we should insert that new element.
1049 * The place to insert a specified unit number, if applicable
1050 * the end of the list.
1051 */
1052 unit = *up;
1053 ndev = devfs_alloc(MAKEDEV_WAITOK);
1054 dev_lock();
1055 prep_cdevsw(csw, MAKEDEV_WAITOK);
1056 low = extra;
1057 de = dl = NULL;
1058 cd = *cdp;
1059 LIST_FOREACH(dev, &cd->head, si_clone) {
1060 KASSERT(dev->si_flags & SI_CLONELIST,
1061 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1062 u = dev2unit(dev);
1063 if (u == (unit | extra)) {
1064 *dp = dev;
1065 dev_unlock();
1066 devfs_free(ndev);
1067 return (0);
1068 }
1069 if (unit == -1 && u == low) {
1070 low++;
1071 de = dev;
1072 continue;
1073 } else if (u < (unit | extra)) {
1074 de = dev;
1075 continue;
1076 } else if (u > (unit | extra)) {
1077 dl = dev;
1078 break;
1079 }
1080 }
1081 if (unit == -1)
1082 unit = low & CLONE_UNITMASK;
1083 dev = newdev(csw, unit | extra, ndev);
1084 if (dev->si_flags & SI_CLONELIST) {
1085 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1086 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1087 LIST_FOREACH(dev, &cd->head, si_clone) {
1088 printf("\t%p %s\n", dev, dev->si_name);
1089 }
1090 panic("foo");
1091 }
1092 KASSERT(!(dev->si_flags & SI_CLONELIST),
1093 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1094 if (dl != NULL)
1095 LIST_INSERT_BEFORE(dl, dev, si_clone);
1096 else if (de != NULL)
1097 LIST_INSERT_AFTER(de, dev, si_clone);
1098 else
1099 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1100 dev->si_flags |= SI_CLONELIST;
1101 *up = unit;
1102 dev_unlock_and_free();
1103 return (1);
1104 }
1105
1106 /*
1107 * Kill everything still on the list. The driver should already have
1108 * disposed of any softc hung of the struct cdev *'s at this time.
1109 */
1110 void
1111 clone_cleanup(struct clonedevs **cdp)
1112 {
1113 struct cdev *dev;
1114 struct cdev_priv *cp;
1115 struct clonedevs *cd;
1116
1117 cd = *cdp;
1118 if (cd == NULL)
1119 return;
1120 dev_lock();
1121 while (!LIST_EMPTY(&cd->head)) {
1122 dev = LIST_FIRST(&cd->head);
1123 LIST_REMOVE(dev, si_clone);
1124 KASSERT(dev->si_flags & SI_CLONELIST,
1125 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1126 dev->si_flags &= ~SI_CLONELIST;
1127 cp = cdev2priv(dev);
1128 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1129 cp->cdp_flags |= CDP_SCHED_DTR;
1130 KASSERT(dev->si_flags & SI_NAMED,
1131 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1132 destroy_devl(dev);
1133 }
1134 }
1135 dev_unlock_and_free();
1136 free(cd, M_DEVBUF);
1137 *cdp = NULL;
1138 }
1139
1140 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1141 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1142 static struct task dev_dtr_task;
1143
1144 static void
1145 destroy_dev_tq(void *ctx, int pending)
1146 {
1147 struct cdev_priv *cp;
1148 struct cdev *dev;
1149 void (*cb)(void *);
1150 void *cb_arg;
1151
1152 dev_lock();
1153 while (!TAILQ_EMPTY(&dev_ddtr)) {
1154 cp = TAILQ_FIRST(&dev_ddtr);
1155 dev = &cp->cdp_c;
1156 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1157 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1158 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1159 cb = cp->cdp_dtr_cb;
1160 cb_arg = cp->cdp_dtr_cb_arg;
1161 destroy_devl(dev);
1162 dev_unlock_and_free();
1163 dev_rel(dev);
1164 if (cb != NULL)
1165 cb(cb_arg);
1166 dev_lock();
1167 }
1168 dev_unlock();
1169 }
1170
1171 /*
1172 * devmtx shall be locked on entry. devmtx will be unlocked after
1173 * function return.
1174 */
1175 static int
1176 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1177 {
1178 struct cdev_priv *cp;
1179
1180 mtx_assert(&devmtx, MA_OWNED);
1181 cp = cdev2priv(dev);
1182 if (cp->cdp_flags & CDP_SCHED_DTR) {
1183 dev_unlock();
1184 return (0);
1185 }
1186 dev_refl(dev);
1187 cp->cdp_flags |= CDP_SCHED_DTR;
1188 cp->cdp_dtr_cb = cb;
1189 cp->cdp_dtr_cb_arg = arg;
1190 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1191 dev_unlock();
1192 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1193 return (1);
1194 }
1195
1196 int
1197 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1198 {
1199
1200 dev_lock();
1201 return (destroy_dev_sched_cbl(dev, cb, arg));
1202 }
1203
1204 int
1205 destroy_dev_sched(struct cdev *dev)
1206 {
1207
1208 return (destroy_dev_sched_cb(dev, NULL, NULL));
1209 }
1210
1211 void
1212 destroy_dev_drain(struct cdevsw *csw)
1213 {
1214
1215 dev_lock();
1216 while (!LIST_EMPTY(&csw->d_devs)) {
1217 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1218 }
1219 dev_unlock();
1220 }
1221
1222 void
1223 drain_dev_clone_events(void)
1224 {
1225
1226 sx_xlock(&clone_drain_lock);
1227 sx_xunlock(&clone_drain_lock);
1228 }
1229
1230 static void
1231 devdtr_init(void *dummy __unused)
1232 {
1233
1234 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
1235 }
1236
1237 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
1238
1239 #include "opt_ddb.h"
1240 #ifdef DDB
1241 #include <sys/kernel.h>
1242
1243 #include <ddb/ddb.h>
1244
1245 DB_SHOW_COMMAND(cdev, db_show_cdev)
1246 {
1247 struct cdev_priv *cdp;
1248 struct cdev *dev;
1249 u_int flags;
1250 char buf[512];
1251
1252 if (!have_addr) {
1253 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1254 dev = &cdp->cdp_c;
1255 db_printf("%s %p\n", dev->si_name, dev);
1256 if (db_pager_quit)
1257 break;
1258 }
1259 return;
1260 }
1261
1262 dev = (struct cdev *)addr;
1263 cdp = cdev2priv(dev);
1264 db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1265 dev->si_name, dev->si_refcount, dev->si_usecount,
1266 dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1267 db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1268 dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1269 flags = dev->si_flags;
1270 #define SI_FLAG(flag) do { \
1271 if (flags & (flag)) { \
1272 if (buf[0] != '\0') \
1273 strlcat(buf, ", ", sizeof(buf)); \
1274 strlcat(buf, (#flag) + 3, sizeof(buf)); \
1275 flags &= ~(flag); \
1276 } \
1277 } while (0)
1278 buf[0] = '\0';
1279 SI_FLAG(SI_ETERNAL);
1280 SI_FLAG(SI_ALIAS);
1281 SI_FLAG(SI_NAMED);
1282 SI_FLAG(SI_CHEAPCLONE);
1283 SI_FLAG(SI_CHILD);
1284 SI_FLAG(SI_DEVOPEN);
1285 SI_FLAG(SI_CONSOPEN);
1286 SI_FLAG(SI_DUMPDEV);
1287 SI_FLAG(SI_CANDELETE);
1288 SI_FLAG(SI_CLONELIST);
1289 db_printf("si_flags %s\n", buf);
1290
1291 flags = cdp->cdp_flags;
1292 #define CDP_FLAG(flag) do { \
1293 if (flags & (flag)) { \
1294 if (buf[0] != '\0') \
1295 strlcat(buf, ", ", sizeof(buf)); \
1296 strlcat(buf, (#flag) + 4, sizeof(buf)); \
1297 flags &= ~(flag); \
1298 } \
1299 } while (0)
1300 buf[0] = '\0';
1301 CDP_FLAG(CDP_ACTIVE);
1302 CDP_FLAG(CDP_SCHED_DTR);
1303 db_printf("cdp_flags %s\n", buf);
1304 }
1305 #endif
Cache object: 3069892c047852bf9d4079f13d026aa8
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