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/8.1/sys/kern/kern_conf.c 208344 2010-05-20 09:38:15Z kib $");
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 struct cdev *make_dev_credv(int flags,
59 struct cdevsw *devsw, int unit,
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(cdevsw_gt_post_list);
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 = cdev2priv(cdev);
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 = cdev2priv(dev);
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 = cdev2priv(*devp);
212 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
213 csw = (*devp)->si_devsw;
214 if (csw != NULL)
215 (*devp)->si_threadcount++;
216 }
217 }
218 dev_unlock();
219 return (csw);
220 }
221
222 void
223 dev_relthread(struct cdev *dev)
224 {
225
226 mtx_assert(&devmtx, MA_NOTOWNED);
227 dev_lock();
228 KASSERT(dev->si_threadcount > 0,
229 ("%s threadcount is wrong", dev->si_name));
230 dev->si_threadcount--;
231 dev_unlock();
232 }
233
234 int
235 nullop(void)
236 {
237
238 return (0);
239 }
240
241 int
242 eopnotsupp(void)
243 {
244
245 return (EOPNOTSUPP);
246 }
247
248 static int
249 enxio(void)
250 {
251 return (ENXIO);
252 }
253
254 static int
255 enodev(void)
256 {
257 return (ENODEV);
258 }
259
260 /* Define a dead_cdevsw for use when devices leave unexpectedly. */
261
262 #define dead_open (d_open_t *)enxio
263 #define dead_close (d_close_t *)enxio
264 #define dead_read (d_read_t *)enxio
265 #define dead_write (d_write_t *)enxio
266 #define dead_ioctl (d_ioctl_t *)enxio
267 #define dead_poll (d_poll_t *)enodev
268 #define dead_mmap (d_mmap_t *)enodev
269
270 static void
271 dead_strategy(struct bio *bp)
272 {
273
274 biofinish(bp, NULL, ENXIO);
275 }
276
277 #define dead_dump (dumper_t *)enxio
278 #define dead_kqfilter (d_kqfilter_t *)enxio
279 #define dead_mmap_single (d_mmap_single_t *)enodev
280
281 static struct cdevsw dead_cdevsw = {
282 .d_version = D_VERSION,
283 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */
284 .d_open = dead_open,
285 .d_close = dead_close,
286 .d_read = dead_read,
287 .d_write = dead_write,
288 .d_ioctl = dead_ioctl,
289 .d_poll = dead_poll,
290 .d_mmap = dead_mmap,
291 .d_strategy = dead_strategy,
292 .d_name = "dead",
293 .d_dump = dead_dump,
294 .d_kqfilter = dead_kqfilter,
295 .d_mmap_single = dead_mmap_single
296 };
297
298 /* Default methods if driver does not specify method */
299
300 #define null_open (d_open_t *)nullop
301 #define null_close (d_close_t *)nullop
302 #define no_read (d_read_t *)enodev
303 #define no_write (d_write_t *)enodev
304 #define no_ioctl (d_ioctl_t *)enodev
305 #define no_mmap (d_mmap2_t *)enodev
306 #define no_kqfilter (d_kqfilter_t *)enodev
307 #define no_mmap_single (d_mmap_single_t *)enodev
308
309 static void
310 no_strategy(struct bio *bp)
311 {
312
313 biofinish(bp, NULL, ENODEV);
314 }
315
316 static int
317 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
318 {
319
320 return (poll_no_poll(events));
321 }
322
323 #define no_dump (dumper_t *)enodev
324
325 static int
326 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
327 {
328 struct cdevsw *dsw;
329 int retval;
330
331 dsw = dev_refthread(dev);
332 if (dsw == NULL)
333 return (ENXIO);
334 mtx_lock(&Giant);
335 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
336 mtx_unlock(&Giant);
337 dev_relthread(dev);
338 return (retval);
339 }
340
341 static int
342 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
343 {
344 struct cdevsw *dsw;
345 int retval;
346
347 dsw = dev_refthread(dev);
348 if (dsw == NULL)
349 return (ENXIO);
350 mtx_lock(&Giant);
351 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
352 mtx_unlock(&Giant);
353 dev_relthread(dev);
354 return (retval);
355 }
356
357 static int
358 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
359 {
360 struct cdevsw *dsw;
361 int retval;
362
363 dsw = dev_refthread(dev);
364 if (dsw == NULL)
365 return (ENXIO);
366 mtx_lock(&Giant);
367 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
368 mtx_unlock(&Giant);
369 dev_relthread(dev);
370 return (retval);
371 }
372
373 static void
374 giant_strategy(struct bio *bp)
375 {
376 struct cdevsw *dsw;
377 struct cdev *dev;
378
379 dev = bp->bio_dev;
380 dsw = dev_refthread(dev);
381 if (dsw == NULL) {
382 biofinish(bp, NULL, ENXIO);
383 return;
384 }
385 mtx_lock(&Giant);
386 dsw->d_gianttrick->d_strategy(bp);
387 mtx_unlock(&Giant);
388 dev_relthread(dev);
389 }
390
391 static int
392 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
393 {
394 struct cdevsw *dsw;
395 int retval;
396
397 dsw = dev_refthread(dev);
398 if (dsw == NULL)
399 return (ENXIO);
400 mtx_lock(&Giant);
401 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
402 mtx_unlock(&Giant);
403 dev_relthread(dev);
404 return (retval);
405 }
406
407 static int
408 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
409 {
410 struct cdevsw *dsw;
411 int retval;
412
413 dsw = dev_refthread(dev);
414 if (dsw == NULL)
415 return (ENXIO);
416 mtx_lock(&Giant);
417 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
418 mtx_unlock(&Giant);
419 dev_relthread(dev);
420 return (retval);
421 }
422
423 static int
424 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
425 {
426 struct cdevsw *dsw;
427 int retval;
428
429 dsw = dev_refthread(dev);
430 if (dsw == NULL)
431 return (ENXIO);
432 mtx_lock(&Giant);
433 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
434 mtx_unlock(&Giant);
435 dev_relthread(dev);
436 return (retval);
437 }
438
439 static int
440 giant_poll(struct cdev *dev, int events, struct thread *td)
441 {
442 struct cdevsw *dsw;
443 int retval;
444
445 dsw = dev_refthread(dev);
446 if (dsw == NULL)
447 return (ENXIO);
448 mtx_lock(&Giant);
449 retval = dsw->d_gianttrick->d_poll(dev, events, td);
450 mtx_unlock(&Giant);
451 dev_relthread(dev);
452 return (retval);
453 }
454
455 static int
456 giant_kqfilter(struct cdev *dev, struct knote *kn)
457 {
458 struct cdevsw *dsw;
459 int retval;
460
461 dsw = dev_refthread(dev);
462 if (dsw == NULL)
463 return (ENXIO);
464 mtx_lock(&Giant);
465 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
466 mtx_unlock(&Giant);
467 dev_relthread(dev);
468 return (retval);
469 }
470
471 static int
472 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot,
473 vm_memattr_t *memattr)
474 {
475 struct cdevsw *dsw;
476 int retval;
477
478 dsw = dev_refthread(dev);
479 if (dsw == NULL)
480 return (ENXIO);
481 mtx_lock(&Giant);
482 if (dsw->d_gianttrick->d_flags & D_MMAP2)
483 retval = dsw->d_gianttrick->d_mmap2(dev, offset, paddr, nprot,
484 memattr);
485 else
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 static int
493 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
494 vm_object_t *object, int nprot)
495 {
496 struct cdevsw *dsw;
497 int retval;
498
499 dsw = dev_refthread(dev);
500 if (dsw == NULL)
501 return (ENXIO);
502 mtx_lock(&Giant);
503 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
504 nprot);
505 mtx_unlock(&Giant);
506 dev_relthread(dev);
507 return (retval);
508 }
509
510 static void
511 notify(struct cdev *dev, const char *ev, int flags)
512 {
513 static const char prefix[] = "cdev=";
514 char *data;
515 int namelen;
516
517 if (cold)
518 return;
519 namelen = strlen(dev->si_name);
520 data = malloc(namelen + sizeof(prefix), M_TEMP,
521 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
522 if (data == NULL)
523 return;
524 memcpy(data, prefix, sizeof(prefix) - 1);
525 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
526 devctl_notify("DEVFS", "CDEV", ev, data);
527 free(data, M_TEMP);
528 }
529
530 static void
531 notify_create(struct cdev *dev, int flags)
532 {
533
534 notify(dev, "CREATE", flags);
535 }
536
537 static void
538 notify_destroy(struct cdev *dev)
539 {
540
541 notify(dev, "DESTROY", MAKEDEV_WAITOK);
542 }
543
544 static struct cdev *
545 newdev(struct cdevsw *csw, int unit, struct cdev *si)
546 {
547 struct cdev *si2;
548
549 mtx_assert(&devmtx, MA_OWNED);
550 if (csw->d_flags & D_NEEDMINOR) {
551 /* We may want to return an existing device */
552 LIST_FOREACH(si2, &csw->d_devs, si_list) {
553 if (dev2unit(si2) == unit) {
554 dev_free_devlocked(si);
555 return (si2);
556 }
557 }
558 }
559 si->si_drv0 = unit;
560 si->si_devsw = csw;
561 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
562 return (si);
563 }
564
565 static void
566 fini_cdevsw(struct cdevsw *devsw)
567 {
568 struct cdevsw *gt;
569
570 if (devsw->d_gianttrick != NULL) {
571 gt = devsw->d_gianttrick;
572 memcpy(devsw, gt, sizeof *devsw);
573 cdevsw_free_devlocked(gt);
574 devsw->d_gianttrick = NULL;
575 }
576 devsw->d_flags &= ~D_INIT;
577 }
578
579 static int
580 prep_cdevsw(struct cdevsw *devsw, int flags)
581 {
582 struct cdevsw *dsw2;
583
584 mtx_assert(&devmtx, MA_OWNED);
585 if (devsw->d_flags & D_INIT)
586 return (1);
587 if (devsw->d_flags & D_NEEDGIANT) {
588 dev_unlock();
589 dsw2 = malloc(sizeof *dsw2, M_DEVT,
590 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
591 dev_lock();
592 if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
593 return (0);
594 } else
595 dsw2 = NULL;
596 if (devsw->d_flags & D_INIT) {
597 if (dsw2 != NULL)
598 cdevsw_free_devlocked(dsw2);
599 return (1);
600 }
601
602 if (devsw->d_version != D_VERSION_01 &&
603 devsw->d_version != D_VERSION_02) {
604 printf(
605 "WARNING: Device driver \"%s\" has wrong version %s\n",
606 devsw->d_name == NULL ? "???" : devsw->d_name,
607 "and is disabled. Recompile KLD module.");
608 devsw->d_open = dead_open;
609 devsw->d_close = dead_close;
610 devsw->d_read = dead_read;
611 devsw->d_write = dead_write;
612 devsw->d_ioctl = dead_ioctl;
613 devsw->d_poll = dead_poll;
614 devsw->d_mmap = dead_mmap;
615 devsw->d_strategy = dead_strategy;
616 devsw->d_dump = dead_dump;
617 devsw->d_kqfilter = dead_kqfilter;
618 }
619 if (devsw->d_version == D_VERSION_01)
620 devsw->d_mmap_single = NULL;
621
622 if (devsw->d_flags & D_NEEDGIANT) {
623 if (devsw->d_gianttrick == NULL) {
624 memcpy(dsw2, devsw, sizeof *dsw2);
625 devsw->d_gianttrick = dsw2;
626 devsw->d_flags |= D_MMAP2;
627 dsw2 = NULL;
628 }
629 }
630
631 #define FIXUP(member, noop, giant) \
632 do { \
633 if (devsw->member == NULL) { \
634 devsw->member = noop; \
635 } else if (devsw->d_flags & D_NEEDGIANT) \
636 devsw->member = giant; \
637 } \
638 while (0)
639
640 FIXUP(d_open, null_open, giant_open);
641 FIXUP(d_fdopen, NULL, giant_fdopen);
642 FIXUP(d_close, null_close, giant_close);
643 FIXUP(d_read, no_read, giant_read);
644 FIXUP(d_write, no_write, giant_write);
645 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
646 FIXUP(d_poll, no_poll, giant_poll);
647 FIXUP(d_mmap2, no_mmap, giant_mmap);
648 FIXUP(d_strategy, no_strategy, giant_strategy);
649 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
650 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
651
652 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
653
654 LIST_INIT(&devsw->d_devs);
655
656 devsw->d_flags |= D_INIT;
657
658 if (dsw2 != NULL)
659 cdevsw_free_devlocked(dsw2);
660 return (1);
661 }
662
663 static struct cdev *
664 make_dev_credv(int flags, struct cdevsw *devsw, int unit,
665 struct ucred *cr, uid_t uid,
666 gid_t gid, int mode, const char *fmt, va_list ap)
667 {
668 struct cdev *dev;
669 int i;
670
671 dev = devfs_alloc(flags);
672 if (dev == NULL)
673 return (NULL);
674 dev_lock();
675 if (!prep_cdevsw(devsw, flags)) {
676 dev_unlock();
677 devfs_free(dev);
678 return (NULL);
679 }
680 dev = newdev(devsw, unit, dev);
681 if (flags & MAKEDEV_REF)
682 dev_refl(dev);
683 if (dev->si_flags & SI_CHEAPCLONE &&
684 dev->si_flags & SI_NAMED) {
685 /*
686 * This is allowed as it removes races and generally
687 * simplifies cloning devices.
688 * XXX: still ??
689 */
690 dev_unlock_and_free();
691 return (dev);
692 }
693 KASSERT(!(dev->si_flags & SI_NAMED),
694 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
695 devsw->d_name, dev2unit(dev), devtoname(dev)));
696
697 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
698 if (i > (sizeof dev->__si_namebuf - 1)) {
699 printf("WARNING: Device name truncated! (%s)\n",
700 dev->__si_namebuf);
701 }
702
703 dev->si_flags |= SI_NAMED;
704 if (cr != NULL)
705 dev->si_cred = crhold(cr);
706 dev->si_uid = uid;
707 dev->si_gid = gid;
708 dev->si_mode = mode;
709
710 devfs_create(dev);
711 clean_unrhdrl(devfs_inos);
712 dev_unlock_and_free();
713
714 notify_create(dev, flags);
715
716 return (dev);
717 }
718
719 struct cdev *
720 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
721 const char *fmt, ...)
722 {
723 struct cdev *dev;
724 va_list ap;
725
726 va_start(ap, fmt);
727 dev = make_dev_credv(0, devsw, unit, NULL, uid, gid, mode, fmt, ap);
728 va_end(ap);
729 return (dev);
730 }
731
732 struct cdev *
733 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
734 gid_t gid, int mode, const char *fmt, ...)
735 {
736 struct cdev *dev;
737 va_list ap;
738
739 va_start(ap, fmt);
740 dev = make_dev_credv(0, devsw, unit, cr, uid, gid, mode, fmt, ap);
741 va_end(ap);
742
743 return (dev);
744 }
745
746 struct cdev *
747 make_dev_credf(int flags, struct cdevsw *devsw, int unit,
748 struct ucred *cr, uid_t uid,
749 gid_t gid, int mode, const char *fmt, ...)
750 {
751 struct cdev *dev;
752 va_list ap;
753
754 va_start(ap, fmt);
755 dev = make_dev_credv(flags, devsw, unit, cr, uid, gid, mode,
756 fmt, ap);
757 va_end(ap);
758
759 return (dev);
760 }
761
762 static void
763 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
764 {
765
766 cdev->si_parent = pdev;
767 cdev->si_flags |= SI_CHILD;
768 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
769 }
770
771
772 void
773 dev_depends(struct cdev *pdev, struct cdev *cdev)
774 {
775
776 dev_lock();
777 dev_dependsl(pdev, cdev);
778 dev_unlock();
779 }
780
781 struct cdev *
782 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
783 {
784 struct cdev *dev;
785 va_list ap;
786 int i;
787
788 KASSERT(pdev != NULL, ("NULL pdev"));
789 dev = devfs_alloc(MAKEDEV_WAITOK);
790 dev_lock();
791 dev->si_flags |= SI_ALIAS;
792 dev->si_flags |= SI_NAMED;
793 va_start(ap, fmt);
794 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
795 if (i > (sizeof dev->__si_namebuf - 1)) {
796 printf("WARNING: Device name truncated! (%s)\n",
797 dev->__si_namebuf);
798 }
799 va_end(ap);
800
801 devfs_create(dev);
802 dev_dependsl(pdev, dev);
803 clean_unrhdrl(devfs_inos);
804 dev_unlock();
805
806 notify_create(dev, MAKEDEV_WAITOK);
807
808 return (dev);
809 }
810
811 static void
812 destroy_devl(struct cdev *dev)
813 {
814 struct cdevsw *csw;
815 struct cdev_privdata *p, *p1;
816
817 mtx_assert(&devmtx, MA_OWNED);
818 KASSERT(dev->si_flags & SI_NAMED,
819 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
820
821 devfs_destroy(dev);
822
823 /* Remove name marking */
824 dev->si_flags &= ~SI_NAMED;
825
826 /* If we are a child, remove us from the parents list */
827 if (dev->si_flags & SI_CHILD) {
828 LIST_REMOVE(dev, si_siblings);
829 dev->si_flags &= ~SI_CHILD;
830 }
831
832 /* Kill our children */
833 while (!LIST_EMPTY(&dev->si_children))
834 destroy_devl(LIST_FIRST(&dev->si_children));
835
836 /* Remove from clone list */
837 if (dev->si_flags & SI_CLONELIST) {
838 LIST_REMOVE(dev, si_clone);
839 dev->si_flags &= ~SI_CLONELIST;
840 }
841
842 dev->si_refcount++; /* Avoid race with dev_rel() */
843 csw = dev->si_devsw;
844 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
845 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
846 csw->d_purge(dev);
847 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
848 if (dev->si_threadcount)
849 printf("Still %lu threads in %s\n",
850 dev->si_threadcount, devtoname(dev));
851 }
852 while (dev->si_threadcount != 0) {
853 /* Use unique dummy wait ident */
854 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
855 }
856
857 dev_unlock();
858 notify_destroy(dev);
859 mtx_lock(&cdevpriv_mtx);
860 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) {
861 devfs_destroy_cdevpriv(p);
862 mtx_lock(&cdevpriv_mtx);
863 }
864 mtx_unlock(&cdevpriv_mtx);
865 dev_lock();
866
867 dev->si_drv1 = 0;
868 dev->si_drv2 = 0;
869 bzero(&dev->__si_u, sizeof(dev->__si_u));
870
871 if (!(dev->si_flags & SI_ALIAS)) {
872 /* Remove from cdevsw list */
873 LIST_REMOVE(dev, si_list);
874
875 /* If cdevsw has no more struct cdev *'s, clean it */
876 if (LIST_EMPTY(&csw->d_devs)) {
877 fini_cdevsw(csw);
878 wakeup(&csw->d_devs);
879 }
880 }
881 dev->si_flags &= ~SI_ALIAS;
882 dev->si_refcount--; /* Avoid race with dev_rel() */
883
884 if (dev->si_refcount > 0) {
885 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
886 } else {
887 dev_free_devlocked(dev);
888 }
889 }
890
891 void
892 destroy_dev(struct cdev *dev)
893 {
894
895 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
896 dev_lock();
897 destroy_devl(dev);
898 dev_unlock_and_free();
899 }
900
901 const char *
902 devtoname(struct cdev *dev)
903 {
904
905 return (dev->si_name);
906 }
907
908 int
909 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
910 {
911 int u, i;
912
913 i = strlen(stem);
914 if (bcmp(stem, name, i) != 0)
915 return (0);
916 if (!isdigit(name[i]))
917 return (0);
918 u = 0;
919 if (name[i] == '' && isdigit(name[i+1]))
920 return (0);
921 while (isdigit(name[i])) {
922 u *= 10;
923 u += name[i++] - '';
924 }
925 if (u > 0xffffff)
926 return (0);
927 *unit = u;
928 if (namep)
929 *namep = &name[i];
930 if (name[i])
931 return (2);
932 return (1);
933 }
934
935 /*
936 * Helper functions for cloning device drivers.
937 *
938 * The objective here is to make it unnecessary for the device drivers to
939 * use rman or similar to manage their unit number space. Due to the way
940 * we do "on-demand" devices, using rman or other "private" methods
941 * will be very tricky to lock down properly once we lock down this file.
942 *
943 * Instead we give the drivers these routines which puts the struct cdev *'s
944 * that are to be managed on their own list, and gives the driver the ability
945 * to ask for the first free unit number or a given specified unit number.
946 *
947 * In addition these routines support paired devices (pty, nmdm and similar)
948 * by respecting a number of "flag" bits in the minor number.
949 *
950 */
951
952 struct clonedevs {
953 LIST_HEAD(,cdev) head;
954 };
955
956 void
957 clone_setup(struct clonedevs **cdp)
958 {
959
960 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
961 LIST_INIT(&(*cdp)->head);
962 }
963
964 int
965 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
966 struct cdev **dp, int extra)
967 {
968 struct clonedevs *cd;
969 struct cdev *dev, *ndev, *dl, *de;
970 int unit, low, u;
971
972 KASSERT(*cdp != NULL,
973 ("clone_setup() not called in driver \"%s\"", csw->d_name));
974 KASSERT(!(extra & CLONE_UNITMASK),
975 ("Illegal extra bits (0x%x) in clone_create", extra));
976 KASSERT(*up <= CLONE_UNITMASK,
977 ("Too high unit (0x%x) in clone_create", *up));
978 KASSERT(csw->d_flags & D_NEEDMINOR,
979 ("clone_create() on cdevsw without minor numbers"));
980
981
982 /*
983 * Search the list for a lot of things in one go:
984 * A preexisting match is returned immediately.
985 * The lowest free unit number if we are passed -1, and the place
986 * in the list where we should insert that new element.
987 * The place to insert a specified unit number, if applicable
988 * the end of the list.
989 */
990 unit = *up;
991 ndev = devfs_alloc(MAKEDEV_WAITOK);
992 dev_lock();
993 prep_cdevsw(csw, MAKEDEV_WAITOK);
994 low = extra;
995 de = dl = NULL;
996 cd = *cdp;
997 LIST_FOREACH(dev, &cd->head, si_clone) {
998 KASSERT(dev->si_flags & SI_CLONELIST,
999 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1000 u = dev2unit(dev);
1001 if (u == (unit | extra)) {
1002 *dp = dev;
1003 dev_unlock();
1004 devfs_free(ndev);
1005 return (0);
1006 }
1007 if (unit == -1 && u == low) {
1008 low++;
1009 de = dev;
1010 continue;
1011 } else if (u < (unit | extra)) {
1012 de = dev;
1013 continue;
1014 } else if (u > (unit | extra)) {
1015 dl = dev;
1016 break;
1017 }
1018 }
1019 if (unit == -1)
1020 unit = low & CLONE_UNITMASK;
1021 dev = newdev(csw, unit | extra, ndev);
1022 if (dev->si_flags & SI_CLONELIST) {
1023 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1024 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1025 LIST_FOREACH(dev, &cd->head, si_clone) {
1026 printf("\t%p %s\n", dev, dev->si_name);
1027 }
1028 panic("foo");
1029 }
1030 KASSERT(!(dev->si_flags & SI_CLONELIST),
1031 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1032 if (dl != NULL)
1033 LIST_INSERT_BEFORE(dl, dev, si_clone);
1034 else if (de != NULL)
1035 LIST_INSERT_AFTER(de, dev, si_clone);
1036 else
1037 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1038 dev->si_flags |= SI_CLONELIST;
1039 *up = unit;
1040 dev_unlock_and_free();
1041 return (1);
1042 }
1043
1044 /*
1045 * Kill everything still on the list. The driver should already have
1046 * disposed of any softc hung of the struct cdev *'s at this time.
1047 */
1048 void
1049 clone_cleanup(struct clonedevs **cdp)
1050 {
1051 struct cdev *dev;
1052 struct cdev_priv *cp;
1053 struct clonedevs *cd;
1054
1055 cd = *cdp;
1056 if (cd == NULL)
1057 return;
1058 dev_lock();
1059 while (!LIST_EMPTY(&cd->head)) {
1060 dev = LIST_FIRST(&cd->head);
1061 LIST_REMOVE(dev, si_clone);
1062 KASSERT(dev->si_flags & SI_CLONELIST,
1063 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1064 dev->si_flags &= ~SI_CLONELIST;
1065 cp = cdev2priv(dev);
1066 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1067 cp->cdp_flags |= CDP_SCHED_DTR;
1068 KASSERT(dev->si_flags & SI_NAMED,
1069 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1070 destroy_devl(dev);
1071 }
1072 }
1073 dev_unlock_and_free();
1074 free(cd, M_DEVBUF);
1075 *cdp = NULL;
1076 }
1077
1078 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1079 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1080 static struct task dev_dtr_task;
1081
1082 static void
1083 destroy_dev_tq(void *ctx, int pending)
1084 {
1085 struct cdev_priv *cp;
1086 struct cdev *dev;
1087 void (*cb)(void *);
1088 void *cb_arg;
1089
1090 dev_lock();
1091 while (!TAILQ_EMPTY(&dev_ddtr)) {
1092 cp = TAILQ_FIRST(&dev_ddtr);
1093 dev = &cp->cdp_c;
1094 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1095 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1096 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1097 cb = cp->cdp_dtr_cb;
1098 cb_arg = cp->cdp_dtr_cb_arg;
1099 destroy_devl(dev);
1100 dev_unlock_and_free();
1101 dev_rel(dev);
1102 if (cb != NULL)
1103 cb(cb_arg);
1104 dev_lock();
1105 }
1106 dev_unlock();
1107 }
1108
1109 /*
1110 * devmtx shall be locked on entry. devmtx will be unlocked after
1111 * function return.
1112 */
1113 static int
1114 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1115 {
1116 struct cdev_priv *cp;
1117
1118 mtx_assert(&devmtx, MA_OWNED);
1119 cp = cdev2priv(dev);
1120 if (cp->cdp_flags & CDP_SCHED_DTR) {
1121 dev_unlock();
1122 return (0);
1123 }
1124 dev_refl(dev);
1125 cp->cdp_flags |= CDP_SCHED_DTR;
1126 cp->cdp_dtr_cb = cb;
1127 cp->cdp_dtr_cb_arg = arg;
1128 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1129 dev_unlock();
1130 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1131 return (1);
1132 }
1133
1134 int
1135 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1136 {
1137
1138 dev_lock();
1139 return (destroy_dev_sched_cbl(dev, cb, arg));
1140 }
1141
1142 int
1143 destroy_dev_sched(struct cdev *dev)
1144 {
1145
1146 return (destroy_dev_sched_cb(dev, NULL, NULL));
1147 }
1148
1149 void
1150 destroy_dev_drain(struct cdevsw *csw)
1151 {
1152
1153 dev_lock();
1154 while (!LIST_EMPTY(&csw->d_devs)) {
1155 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1156 }
1157 dev_unlock();
1158 }
1159
1160 void
1161 drain_dev_clone_events(void)
1162 {
1163
1164 sx_xlock(&clone_drain_lock);
1165 sx_xunlock(&clone_drain_lock);
1166 }
1167
1168 static void
1169 devdtr_init(void *dummy __unused)
1170 {
1171
1172 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
1173 }
1174
1175 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
Cache object: 0554206b94e05e5f0b8f19fcb0a8827c
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