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/8.0/sys/kern/kern_conf.c 193275 2009-06-01 21:32:52Z 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 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();
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_mmap_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 {
474 struct cdevsw *dsw;
475 int retval;
476
477 dsw = dev_refthread(dev);
478 if (dsw == NULL)
479 return (ENXIO);
480 mtx_lock(&Giant);
481 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot);
482 mtx_unlock(&Giant);
483 dev_relthread(dev);
484 return (retval);
485 }
486
487 static int
488 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
489 vm_object_t *object, int nprot)
490 {
491 struct cdevsw *dsw;
492 int retval;
493
494 dsw = dev_refthread(dev);
495 if (dsw == NULL)
496 return (ENXIO);
497 mtx_lock(&Giant);
498 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
499 nprot);
500 mtx_unlock(&Giant);
501 dev_relthread(dev);
502 return (retval);
503 }
504
505 static void
506 notify(struct cdev *dev, const char *ev)
507 {
508 static const char prefix[] = "cdev=";
509 char *data;
510 int namelen;
511
512 if (cold)
513 return;
514 namelen = strlen(dev->si_name);
515 data = malloc(namelen + sizeof(prefix), M_TEMP, M_NOWAIT);
516 if (data == NULL)
517 return;
518 memcpy(data, prefix, sizeof(prefix) - 1);
519 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
520 devctl_notify("DEVFS", "CDEV", ev, data);
521 free(data, M_TEMP);
522 }
523
524 static void
525 notify_create(struct cdev *dev)
526 {
527
528 notify(dev, "CREATE");
529 }
530
531 static void
532 notify_destroy(struct cdev *dev)
533 {
534
535 notify(dev, "DESTROY");
536 }
537
538 static struct cdev *
539 newdev(struct cdevsw *csw, int unit, struct cdev *si)
540 {
541 struct cdev *si2;
542
543 mtx_assert(&devmtx, MA_OWNED);
544 if (csw->d_flags & D_NEEDMINOR) {
545 /* We may want to return an existing device */
546 LIST_FOREACH(si2, &csw->d_devs, si_list) {
547 if (dev2unit(si2) == unit) {
548 dev_free_devlocked(si);
549 return (si2);
550 }
551 }
552 }
553 si->si_drv0 = unit;
554 si->si_devsw = csw;
555 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
556 return (si);
557 }
558
559 static void
560 fini_cdevsw(struct cdevsw *devsw)
561 {
562 struct cdevsw *gt;
563
564 if (devsw->d_gianttrick != NULL) {
565 gt = devsw->d_gianttrick;
566 memcpy(devsw, gt, sizeof *devsw);
567 cdevsw_free_devlocked(gt);
568 devsw->d_gianttrick = NULL;
569 }
570 devsw->d_flags &= ~D_INIT;
571 }
572
573 static void
574 prep_cdevsw(struct cdevsw *devsw)
575 {
576 struct cdevsw *dsw2;
577
578 mtx_assert(&devmtx, MA_OWNED);
579 if (devsw->d_flags & D_INIT)
580 return;
581 if (devsw->d_flags & D_NEEDGIANT) {
582 dev_unlock();
583 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK);
584 dev_lock();
585 } else
586 dsw2 = NULL;
587 if (devsw->d_flags & D_INIT) {
588 if (dsw2 != NULL)
589 cdevsw_free_devlocked(dsw2);
590 return;
591 }
592
593 if (devsw->d_version != D_VERSION_01 &&
594 devsw->d_version != D_VERSION_02) {
595 printf(
596 "WARNING: Device driver \"%s\" has wrong version %s\n",
597 devsw->d_name == NULL ? "???" : devsw->d_name,
598 "and is disabled. Recompile KLD module.");
599 devsw->d_open = dead_open;
600 devsw->d_close = dead_close;
601 devsw->d_read = dead_read;
602 devsw->d_write = dead_write;
603 devsw->d_ioctl = dead_ioctl;
604 devsw->d_poll = dead_poll;
605 devsw->d_mmap = dead_mmap;
606 devsw->d_strategy = dead_strategy;
607 devsw->d_dump = dead_dump;
608 devsw->d_kqfilter = dead_kqfilter;
609 }
610 if (devsw->d_version == D_VERSION_01)
611 devsw->d_mmap_single = NULL;
612
613 if (devsw->d_flags & D_NEEDGIANT) {
614 if (devsw->d_gianttrick == NULL) {
615 memcpy(dsw2, devsw, sizeof *dsw2);
616 devsw->d_gianttrick = dsw2;
617 dsw2 = NULL;
618 }
619 }
620
621 #define FIXUP(member, noop, giant) \
622 do { \
623 if (devsw->member == NULL) { \
624 devsw->member = noop; \
625 } else if (devsw->d_flags & D_NEEDGIANT) \
626 devsw->member = giant; \
627 } \
628 while (0)
629
630 FIXUP(d_open, null_open, giant_open);
631 FIXUP(d_fdopen, NULL, giant_fdopen);
632 FIXUP(d_close, null_close, giant_close);
633 FIXUP(d_read, no_read, giant_read);
634 FIXUP(d_write, no_write, giant_write);
635 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
636 FIXUP(d_poll, no_poll, giant_poll);
637 FIXUP(d_mmap, no_mmap, giant_mmap);
638 FIXUP(d_strategy, no_strategy, giant_strategy);
639 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
640 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
641
642 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
643
644 LIST_INIT(&devsw->d_devs);
645
646 devsw->d_flags |= D_INIT;
647
648 if (dsw2 != NULL)
649 cdevsw_free_devlocked(dsw2);
650 }
651
652 struct cdev *
653 make_dev_credv(int flags, struct cdevsw *devsw, int unit,
654 struct ucred *cr, uid_t uid,
655 gid_t gid, int mode, const char *fmt, va_list ap)
656 {
657 struct cdev *dev;
658 int i;
659
660 dev = devfs_alloc();
661 dev_lock();
662 prep_cdevsw(devsw);
663 dev = newdev(devsw, unit, dev);
664 if (flags & MAKEDEV_REF)
665 dev_refl(dev);
666 if (dev->si_flags & SI_CHEAPCLONE &&
667 dev->si_flags & SI_NAMED) {
668 /*
669 * This is allowed as it removes races and generally
670 * simplifies cloning devices.
671 * XXX: still ??
672 */
673 dev_unlock_and_free();
674 return (dev);
675 }
676 KASSERT(!(dev->si_flags & SI_NAMED),
677 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
678 devsw->d_name, dev2unit(dev), devtoname(dev)));
679
680 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
681 if (i > (sizeof dev->__si_namebuf - 1)) {
682 printf("WARNING: Device name truncated! (%s)\n",
683 dev->__si_namebuf);
684 }
685
686 dev->si_flags |= SI_NAMED;
687 if (cr != NULL)
688 dev->si_cred = crhold(cr);
689 else
690 dev->si_cred = NULL;
691 dev->si_uid = uid;
692 dev->si_gid = gid;
693 dev->si_mode = mode;
694
695 devfs_create(dev);
696 clean_unrhdrl(devfs_inos);
697 dev_unlock_and_free();
698
699 notify_create(dev);
700
701 return (dev);
702 }
703
704 struct cdev *
705 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
706 const char *fmt, ...)
707 {
708 struct cdev *dev;
709 va_list ap;
710
711 va_start(ap, fmt);
712 dev = make_dev_credv(0, devsw, unit, NULL, uid, gid, mode, fmt, ap);
713 va_end(ap);
714 return (dev);
715 }
716
717 struct cdev *
718 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
719 gid_t gid, int mode, const char *fmt, ...)
720 {
721 struct cdev *dev;
722 va_list ap;
723
724 va_start(ap, fmt);
725 dev = make_dev_credv(0, devsw, unit, cr, uid, gid, mode, fmt, ap);
726 va_end(ap);
727
728 return (dev);
729 }
730
731 struct cdev *
732 make_dev_credf(int flags, struct cdevsw *devsw, int unit,
733 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(flags, devsw, unit, cr, uid, gid, mode,
741 fmt, ap);
742 va_end(ap);
743
744 return (dev);
745 }
746
747 static void
748 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
749 {
750
751 cdev->si_parent = pdev;
752 cdev->si_flags |= SI_CHILD;
753 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
754 }
755
756
757 void
758 dev_depends(struct cdev *pdev, struct cdev *cdev)
759 {
760
761 dev_lock();
762 dev_dependsl(pdev, cdev);
763 dev_unlock();
764 }
765
766 struct cdev *
767 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
768 {
769 struct cdev *dev;
770 va_list ap;
771 int i;
772
773 KASSERT(pdev != NULL, ("NULL pdev"));
774 dev = devfs_alloc();
775 dev_lock();
776 dev->si_flags |= SI_ALIAS;
777 dev->si_flags |= SI_NAMED;
778 va_start(ap, fmt);
779 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
780 if (i > (sizeof dev->__si_namebuf - 1)) {
781 printf("WARNING: Device name truncated! (%s)\n",
782 dev->__si_namebuf);
783 }
784 va_end(ap);
785
786 devfs_create(dev);
787 dev_dependsl(pdev, dev);
788 clean_unrhdrl(devfs_inos);
789 dev_unlock();
790
791 notify_create(dev);
792
793 return (dev);
794 }
795
796 static void
797 destroy_devl(struct cdev *dev)
798 {
799 struct cdevsw *csw;
800 struct cdev_privdata *p, *p1;
801
802 mtx_assert(&devmtx, MA_OWNED);
803 KASSERT(dev->si_flags & SI_NAMED,
804 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
805
806 devfs_destroy(dev);
807
808 /* Remove name marking */
809 dev->si_flags &= ~SI_NAMED;
810
811 /* If we are a child, remove us from the parents list */
812 if (dev->si_flags & SI_CHILD) {
813 LIST_REMOVE(dev, si_siblings);
814 dev->si_flags &= ~SI_CHILD;
815 }
816
817 /* Kill our children */
818 while (!LIST_EMPTY(&dev->si_children))
819 destroy_devl(LIST_FIRST(&dev->si_children));
820
821 /* Remove from clone list */
822 if (dev->si_flags & SI_CLONELIST) {
823 LIST_REMOVE(dev, si_clone);
824 dev->si_flags &= ~SI_CLONELIST;
825 }
826
827 dev->si_refcount++; /* Avoid race with dev_rel() */
828 csw = dev->si_devsw;
829 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
830 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
831 csw->d_purge(dev);
832 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
833 if (dev->si_threadcount)
834 printf("Still %lu threads in %s\n",
835 dev->si_threadcount, devtoname(dev));
836 }
837 while (dev->si_threadcount != 0) {
838 /* Use unique dummy wait ident */
839 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
840 }
841
842 dev_unlock();
843 notify_destroy(dev);
844 mtx_lock(&cdevpriv_mtx);
845 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) {
846 devfs_destroy_cdevpriv(p);
847 mtx_lock(&cdevpriv_mtx);
848 }
849 mtx_unlock(&cdevpriv_mtx);
850 dev_lock();
851
852 dev->si_drv1 = 0;
853 dev->si_drv2 = 0;
854 bzero(&dev->__si_u, sizeof(dev->__si_u));
855
856 if (!(dev->si_flags & SI_ALIAS)) {
857 /* Remove from cdevsw list */
858 LIST_REMOVE(dev, si_list);
859
860 /* If cdevsw has no more struct cdev *'s, clean it */
861 if (LIST_EMPTY(&csw->d_devs)) {
862 fini_cdevsw(csw);
863 wakeup(&csw->d_devs);
864 }
865 }
866 dev->si_flags &= ~SI_ALIAS;
867 dev->si_refcount--; /* Avoid race with dev_rel() */
868
869 if (dev->si_refcount > 0) {
870 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
871 } else {
872 dev_free_devlocked(dev);
873 }
874 }
875
876 void
877 destroy_dev(struct cdev *dev)
878 {
879
880 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
881 dev_lock();
882 destroy_devl(dev);
883 dev_unlock_and_free();
884 }
885
886 const char *
887 devtoname(struct cdev *dev)
888 {
889
890 return (dev->si_name);
891 }
892
893 int
894 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
895 {
896 int u, i;
897
898 i = strlen(stem);
899 if (bcmp(stem, name, i) != 0)
900 return (0);
901 if (!isdigit(name[i]))
902 return (0);
903 u = 0;
904 if (name[i] == '' && isdigit(name[i+1]))
905 return (0);
906 while (isdigit(name[i])) {
907 u *= 10;
908 u += name[i++] - '';
909 }
910 if (u > 0xffffff)
911 return (0);
912 *unit = u;
913 if (namep)
914 *namep = &name[i];
915 if (name[i])
916 return (2);
917 return (1);
918 }
919
920 /*
921 * Helper functions for cloning device drivers.
922 *
923 * The objective here is to make it unnecessary for the device drivers to
924 * use rman or similar to manage their unit number space. Due to the way
925 * we do "on-demand" devices, using rman or other "private" methods
926 * will be very tricky to lock down properly once we lock down this file.
927 *
928 * Instead we give the drivers these routines which puts the struct cdev *'s
929 * that are to be managed on their own list, and gives the driver the ability
930 * to ask for the first free unit number or a given specified unit number.
931 *
932 * In addition these routines support paired devices (pty, nmdm and similar)
933 * by respecting a number of "flag" bits in the minor number.
934 *
935 */
936
937 struct clonedevs {
938 LIST_HEAD(,cdev) head;
939 };
940
941 void
942 clone_setup(struct clonedevs **cdp)
943 {
944
945 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
946 LIST_INIT(&(*cdp)->head);
947 }
948
949 int
950 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra)
951 {
952 struct clonedevs *cd;
953 struct cdev *dev, *ndev, *dl, *de;
954 int unit, low, u;
955
956 KASSERT(*cdp != NULL,
957 ("clone_setup() not called in driver \"%s\"", csw->d_name));
958 KASSERT(!(extra & CLONE_UNITMASK),
959 ("Illegal extra bits (0x%x) in clone_create", extra));
960 KASSERT(*up <= CLONE_UNITMASK,
961 ("Too high unit (0x%x) in clone_create", *up));
962 KASSERT(csw->d_flags & D_NEEDMINOR,
963 ("clone_create() on cdevsw without minor numbers"));
964
965
966 /*
967 * Search the list for a lot of things in one go:
968 * A preexisting match is returned immediately.
969 * The lowest free unit number if we are passed -1, and the place
970 * in the list where we should insert that new element.
971 * The place to insert a specified unit number, if applicable
972 * the end of the list.
973 */
974 unit = *up;
975 ndev = devfs_alloc();
976 dev_lock();
977 prep_cdevsw(csw);
978 low = extra;
979 de = dl = NULL;
980 cd = *cdp;
981 LIST_FOREACH(dev, &cd->head, si_clone) {
982 KASSERT(dev->si_flags & SI_CLONELIST,
983 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
984 u = dev2unit(dev);
985 if (u == (unit | extra)) {
986 *dp = dev;
987 dev_unlock();
988 devfs_free(ndev);
989 return (0);
990 }
991 if (unit == -1 && u == low) {
992 low++;
993 de = dev;
994 continue;
995 } else if (u < (unit | extra)) {
996 de = dev;
997 continue;
998 } else if (u > (unit | extra)) {
999 dl = dev;
1000 break;
1001 }
1002 }
1003 if (unit == -1)
1004 unit = low & CLONE_UNITMASK;
1005 dev = newdev(csw, unit | extra, ndev);
1006 if (dev->si_flags & SI_CLONELIST) {
1007 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1008 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1009 LIST_FOREACH(dev, &cd->head, si_clone) {
1010 printf("\t%p %s\n", dev, dev->si_name);
1011 }
1012 panic("foo");
1013 }
1014 KASSERT(!(dev->si_flags & SI_CLONELIST),
1015 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1016 if (dl != NULL)
1017 LIST_INSERT_BEFORE(dl, dev, si_clone);
1018 else if (de != NULL)
1019 LIST_INSERT_AFTER(de, dev, si_clone);
1020 else
1021 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1022 dev->si_flags |= SI_CLONELIST;
1023 *up = unit;
1024 dev_unlock_and_free();
1025 return (1);
1026 }
1027
1028 /*
1029 * Kill everything still on the list. The driver should already have
1030 * disposed of any softc hung of the struct cdev *'s at this time.
1031 */
1032 void
1033 clone_cleanup(struct clonedevs **cdp)
1034 {
1035 struct cdev *dev;
1036 struct cdev_priv *cp;
1037 struct clonedevs *cd;
1038
1039 cd = *cdp;
1040 if (cd == NULL)
1041 return;
1042 dev_lock();
1043 while (!LIST_EMPTY(&cd->head)) {
1044 dev = LIST_FIRST(&cd->head);
1045 LIST_REMOVE(dev, si_clone);
1046 KASSERT(dev->si_flags & SI_CLONELIST,
1047 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1048 dev->si_flags &= ~SI_CLONELIST;
1049 cp = cdev2priv(dev);
1050 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1051 cp->cdp_flags |= CDP_SCHED_DTR;
1052 KASSERT(dev->si_flags & SI_NAMED,
1053 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1054 destroy_devl(dev);
1055 }
1056 }
1057 dev_unlock_and_free();
1058 free(cd, M_DEVBUF);
1059 *cdp = NULL;
1060 }
1061
1062 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1063 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1064 static struct task dev_dtr_task;
1065
1066 static void
1067 destroy_dev_tq(void *ctx, int pending)
1068 {
1069 struct cdev_priv *cp;
1070 struct cdev *dev;
1071 void (*cb)(void *);
1072 void *cb_arg;
1073
1074 dev_lock();
1075 while (!TAILQ_EMPTY(&dev_ddtr)) {
1076 cp = TAILQ_FIRST(&dev_ddtr);
1077 dev = &cp->cdp_c;
1078 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1079 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1080 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1081 cb = cp->cdp_dtr_cb;
1082 cb_arg = cp->cdp_dtr_cb_arg;
1083 destroy_devl(dev);
1084 dev_unlock_and_free();
1085 dev_rel(dev);
1086 if (cb != NULL)
1087 cb(cb_arg);
1088 dev_lock();
1089 }
1090 dev_unlock();
1091 }
1092
1093 /*
1094 * devmtx shall be locked on entry. devmtx will be unlocked after
1095 * function return.
1096 */
1097 static int
1098 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1099 {
1100 struct cdev_priv *cp;
1101
1102 mtx_assert(&devmtx, MA_OWNED);
1103 cp = cdev2priv(dev);
1104 if (cp->cdp_flags & CDP_SCHED_DTR) {
1105 dev_unlock();
1106 return (0);
1107 }
1108 dev_refl(dev);
1109 cp->cdp_flags |= CDP_SCHED_DTR;
1110 cp->cdp_dtr_cb = cb;
1111 cp->cdp_dtr_cb_arg = arg;
1112 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1113 dev_unlock();
1114 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1115 return (1);
1116 }
1117
1118 int
1119 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1120 {
1121 dev_lock();
1122 return (destroy_dev_sched_cbl(dev, cb, arg));
1123 }
1124
1125 int
1126 destroy_dev_sched(struct cdev *dev)
1127 {
1128 return (destroy_dev_sched_cb(dev, NULL, NULL));
1129 }
1130
1131 void
1132 destroy_dev_drain(struct cdevsw *csw)
1133 {
1134
1135 dev_lock();
1136 while (!LIST_EMPTY(&csw->d_devs)) {
1137 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1138 }
1139 dev_unlock();
1140 }
1141
1142 void
1143 drain_dev_clone_events(void)
1144 {
1145
1146 sx_xlock(&clone_drain_lock);
1147 sx_xunlock(&clone_drain_lock);
1148 }
1149
1150 static void
1151 devdtr_init(void *dummy __unused)
1152 {
1153
1154 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
1155 }
1156
1157 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
Cache object: 5b3bcee785bac9485fc10c9993ae2800
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