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("$FreeBSD$");
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_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)
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, M_NOWAIT);
521 if (data == NULL)
522 return;
523 memcpy(data, prefix, sizeof(prefix) - 1);
524 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
525 devctl_notify("DEVFS", "CDEV", ev, data);
526 free(data, M_TEMP);
527 }
528
529 static void
530 notify_create(struct cdev *dev)
531 {
532
533 notify(dev, "CREATE");
534 }
535
536 static void
537 notify_destroy(struct cdev *dev)
538 {
539
540 notify(dev, "DESTROY");
541 }
542
543 static struct cdev *
544 newdev(struct cdevsw *csw, int unit, struct cdev *si)
545 {
546 struct cdev *si2;
547
548 mtx_assert(&devmtx, MA_OWNED);
549 if (csw->d_flags & D_NEEDMINOR) {
550 /* We may want to return an existing device */
551 LIST_FOREACH(si2, &csw->d_devs, si_list) {
552 if (dev2unit(si2) == unit) {
553 dev_free_devlocked(si);
554 return (si2);
555 }
556 }
557 }
558 si->si_drv0 = unit;
559 si->si_devsw = csw;
560 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
561 return (si);
562 }
563
564 static void
565 fini_cdevsw(struct cdevsw *devsw)
566 {
567 struct cdevsw *gt;
568
569 if (devsw->d_gianttrick != NULL) {
570 gt = devsw->d_gianttrick;
571 memcpy(devsw, gt, sizeof *devsw);
572 cdevsw_free_devlocked(gt);
573 devsw->d_gianttrick = NULL;
574 }
575 devsw->d_flags &= ~D_INIT;
576 }
577
578 static void
579 prep_cdevsw(struct cdevsw *devsw)
580 {
581 struct cdevsw *dsw2;
582
583 mtx_assert(&devmtx, MA_OWNED);
584 if (devsw->d_flags & D_INIT)
585 return;
586 if (devsw->d_flags & D_NEEDGIANT) {
587 dev_unlock();
588 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK);
589 dev_lock();
590 } else
591 dsw2 = NULL;
592 if (devsw->d_flags & D_INIT) {
593 if (dsw2 != NULL)
594 cdevsw_free_devlocked(dsw2);
595 return;
596 }
597
598 if (devsw->d_version != D_VERSION_01 &&
599 devsw->d_version != D_VERSION_02) {
600 printf(
601 "WARNING: Device driver \"%s\" has wrong version %s\n",
602 devsw->d_name == NULL ? "???" : devsw->d_name,
603 "and is disabled. Recompile KLD module.");
604 devsw->d_open = dead_open;
605 devsw->d_close = dead_close;
606 devsw->d_read = dead_read;
607 devsw->d_write = dead_write;
608 devsw->d_ioctl = dead_ioctl;
609 devsw->d_poll = dead_poll;
610 devsw->d_mmap = dead_mmap;
611 devsw->d_strategy = dead_strategy;
612 devsw->d_dump = dead_dump;
613 devsw->d_kqfilter = dead_kqfilter;
614 }
615 if (devsw->d_version == D_VERSION_01)
616 devsw->d_mmap_single = NULL;
617
618 if (devsw->d_flags & D_NEEDGIANT) {
619 if (devsw->d_gianttrick == NULL) {
620 memcpy(dsw2, devsw, sizeof *dsw2);
621 devsw->d_gianttrick = dsw2;
622 devsw->d_flags |= D_MMAP2;
623 dsw2 = NULL;
624 }
625 }
626
627 #define FIXUP(member, noop, giant) \
628 do { \
629 if (devsw->member == NULL) { \
630 devsw->member = noop; \
631 } else if (devsw->d_flags & D_NEEDGIANT) \
632 devsw->member = giant; \
633 } \
634 while (0)
635
636 FIXUP(d_open, null_open, giant_open);
637 FIXUP(d_fdopen, NULL, giant_fdopen);
638 FIXUP(d_close, null_close, giant_close);
639 FIXUP(d_read, no_read, giant_read);
640 FIXUP(d_write, no_write, giant_write);
641 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
642 FIXUP(d_poll, no_poll, giant_poll);
643 FIXUP(d_mmap2, no_mmap, giant_mmap);
644 FIXUP(d_strategy, no_strategy, giant_strategy);
645 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
646 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
647
648 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
649
650 LIST_INIT(&devsw->d_devs);
651
652 devsw->d_flags |= D_INIT;
653
654 if (dsw2 != NULL)
655 cdevsw_free_devlocked(dsw2);
656 }
657
658 struct cdev *
659 make_dev_credv(int flags, struct cdevsw *devsw, int unit,
660 struct ucred *cr, uid_t uid,
661 gid_t gid, int mode, const char *fmt, va_list ap)
662 {
663 struct cdev *dev;
664 int i;
665
666 dev = devfs_alloc();
667 dev_lock();
668 prep_cdevsw(devsw);
669 dev = newdev(devsw, unit, dev);
670 if (flags & MAKEDEV_REF)
671 dev_refl(dev);
672 if (dev->si_flags & SI_CHEAPCLONE &&
673 dev->si_flags & SI_NAMED) {
674 /*
675 * This is allowed as it removes races and generally
676 * simplifies cloning devices.
677 * XXX: still ??
678 */
679 dev_unlock_and_free();
680 return (dev);
681 }
682 KASSERT(!(dev->si_flags & SI_NAMED),
683 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
684 devsw->d_name, dev2unit(dev), devtoname(dev)));
685
686 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
687 if (i > (sizeof dev->__si_namebuf - 1)) {
688 printf("WARNING: Device name truncated! (%s)\n",
689 dev->__si_namebuf);
690 }
691
692 dev->si_flags |= SI_NAMED;
693 if (cr != NULL)
694 dev->si_cred = crhold(cr);
695 else
696 dev->si_cred = NULL;
697 dev->si_uid = uid;
698 dev->si_gid = gid;
699 dev->si_mode = mode;
700
701 devfs_create(dev);
702 clean_unrhdrl(devfs_inos);
703 dev_unlock_and_free();
704
705 notify_create(dev);
706
707 return (dev);
708 }
709
710 struct cdev *
711 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
712 const char *fmt, ...)
713 {
714 struct cdev *dev;
715 va_list ap;
716
717 va_start(ap, fmt);
718 dev = make_dev_credv(0, devsw, unit, NULL, uid, gid, mode, fmt, ap);
719 va_end(ap);
720 return (dev);
721 }
722
723 struct cdev *
724 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
725 gid_t gid, int mode, const char *fmt, ...)
726 {
727 struct cdev *dev;
728 va_list ap;
729
730 va_start(ap, fmt);
731 dev = make_dev_credv(0, devsw, unit, cr, uid, gid, mode, fmt, ap);
732 va_end(ap);
733
734 return (dev);
735 }
736
737 struct cdev *
738 make_dev_credf(int flags, struct cdevsw *devsw, int unit,
739 struct ucred *cr, uid_t uid,
740 gid_t gid, int mode, const char *fmt, ...)
741 {
742 struct cdev *dev;
743 va_list ap;
744
745 va_start(ap, fmt);
746 dev = make_dev_credv(flags, devsw, unit, cr, uid, gid, mode,
747 fmt, ap);
748 va_end(ap);
749
750 return (dev);
751 }
752
753 static void
754 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
755 {
756
757 cdev->si_parent = pdev;
758 cdev->si_flags |= SI_CHILD;
759 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
760 }
761
762
763 void
764 dev_depends(struct cdev *pdev, struct cdev *cdev)
765 {
766
767 dev_lock();
768 dev_dependsl(pdev, cdev);
769 dev_unlock();
770 }
771
772 struct cdev *
773 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
774 {
775 struct cdev *dev;
776 va_list ap;
777 int i;
778
779 KASSERT(pdev != NULL, ("NULL pdev"));
780 dev = devfs_alloc();
781 dev_lock();
782 dev->si_flags |= SI_ALIAS;
783 dev->si_flags |= SI_NAMED;
784 va_start(ap, fmt);
785 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
786 if (i > (sizeof dev->__si_namebuf - 1)) {
787 printf("WARNING: Device name truncated! (%s)\n",
788 dev->__si_namebuf);
789 }
790 va_end(ap);
791
792 devfs_create(dev);
793 dev_dependsl(pdev, dev);
794 clean_unrhdrl(devfs_inos);
795 dev_unlock();
796
797 notify_create(dev);
798
799 return (dev);
800 }
801
802 static void
803 destroy_devl(struct cdev *dev)
804 {
805 struct cdevsw *csw;
806 struct cdev_privdata *p, *p1;
807
808 mtx_assert(&devmtx, MA_OWNED);
809 KASSERT(dev->si_flags & SI_NAMED,
810 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
811
812 devfs_destroy(dev);
813
814 /* Remove name marking */
815 dev->si_flags &= ~SI_NAMED;
816
817 /* If we are a child, remove us from the parents list */
818 if (dev->si_flags & SI_CHILD) {
819 LIST_REMOVE(dev, si_siblings);
820 dev->si_flags &= ~SI_CHILD;
821 }
822
823 /* Kill our children */
824 while (!LIST_EMPTY(&dev->si_children))
825 destroy_devl(LIST_FIRST(&dev->si_children));
826
827 /* Remove from clone list */
828 if (dev->si_flags & SI_CLONELIST) {
829 LIST_REMOVE(dev, si_clone);
830 dev->si_flags &= ~SI_CLONELIST;
831 }
832
833 dev->si_refcount++; /* Avoid race with dev_rel() */
834 csw = dev->si_devsw;
835 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
836 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
837 csw->d_purge(dev);
838 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
839 if (dev->si_threadcount)
840 printf("Still %lu threads in %s\n",
841 dev->si_threadcount, devtoname(dev));
842 }
843 while (dev->si_threadcount != 0) {
844 /* Use unique dummy wait ident */
845 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
846 }
847
848 dev_unlock();
849 notify_destroy(dev);
850 mtx_lock(&cdevpriv_mtx);
851 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) {
852 devfs_destroy_cdevpriv(p);
853 mtx_lock(&cdevpriv_mtx);
854 }
855 mtx_unlock(&cdevpriv_mtx);
856 dev_lock();
857
858 dev->si_drv1 = 0;
859 dev->si_drv2 = 0;
860 bzero(&dev->__si_u, sizeof(dev->__si_u));
861
862 if (!(dev->si_flags & SI_ALIAS)) {
863 /* Remove from cdevsw list */
864 LIST_REMOVE(dev, si_list);
865
866 /* If cdevsw has no more struct cdev *'s, clean it */
867 if (LIST_EMPTY(&csw->d_devs)) {
868 fini_cdevsw(csw);
869 wakeup(&csw->d_devs);
870 }
871 }
872 dev->si_flags &= ~SI_ALIAS;
873 dev->si_refcount--; /* Avoid race with dev_rel() */
874
875 if (dev->si_refcount > 0) {
876 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
877 } else {
878 dev_free_devlocked(dev);
879 }
880 }
881
882 void
883 destroy_dev(struct cdev *dev)
884 {
885
886 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
887 dev_lock();
888 destroy_devl(dev);
889 dev_unlock_and_free();
890 }
891
892 const char *
893 devtoname(struct cdev *dev)
894 {
895
896 return (dev->si_name);
897 }
898
899 int
900 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
901 {
902 int u, i;
903
904 i = strlen(stem);
905 if (bcmp(stem, name, i) != 0)
906 return (0);
907 if (!isdigit(name[i]))
908 return (0);
909 u = 0;
910 if (name[i] == '' && isdigit(name[i+1]))
911 return (0);
912 while (isdigit(name[i])) {
913 u *= 10;
914 u += name[i++] - '';
915 }
916 if (u > 0xffffff)
917 return (0);
918 *unit = u;
919 if (namep)
920 *namep = &name[i];
921 if (name[i])
922 return (2);
923 return (1);
924 }
925
926 /*
927 * Helper functions for cloning device drivers.
928 *
929 * The objective here is to make it unnecessary for the device drivers to
930 * use rman or similar to manage their unit number space. Due to the way
931 * we do "on-demand" devices, using rman or other "private" methods
932 * will be very tricky to lock down properly once we lock down this file.
933 *
934 * Instead we give the drivers these routines which puts the struct cdev *'s
935 * that are to be managed on their own list, and gives the driver the ability
936 * to ask for the first free unit number or a given specified unit number.
937 *
938 * In addition these routines support paired devices (pty, nmdm and similar)
939 * by respecting a number of "flag" bits in the minor number.
940 *
941 */
942
943 struct clonedevs {
944 LIST_HEAD(,cdev) head;
945 };
946
947 void
948 clone_setup(struct clonedevs **cdp)
949 {
950
951 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
952 LIST_INIT(&(*cdp)->head);
953 }
954
955 int
956 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra)
957 {
958 struct clonedevs *cd;
959 struct cdev *dev, *ndev, *dl, *de;
960 int unit, low, u;
961
962 KASSERT(*cdp != NULL,
963 ("clone_setup() not called in driver \"%s\"", csw->d_name));
964 KASSERT(!(extra & CLONE_UNITMASK),
965 ("Illegal extra bits (0x%x) in clone_create", extra));
966 KASSERT(*up <= CLONE_UNITMASK,
967 ("Too high unit (0x%x) in clone_create", *up));
968 KASSERT(csw->d_flags & D_NEEDMINOR,
969 ("clone_create() on cdevsw without minor numbers"));
970
971
972 /*
973 * Search the list for a lot of things in one go:
974 * A preexisting match is returned immediately.
975 * The lowest free unit number if we are passed -1, and the place
976 * in the list where we should insert that new element.
977 * The place to insert a specified unit number, if applicable
978 * the end of the list.
979 */
980 unit = *up;
981 ndev = devfs_alloc();
982 dev_lock();
983 prep_cdevsw(csw);
984 low = extra;
985 de = dl = NULL;
986 cd = *cdp;
987 LIST_FOREACH(dev, &cd->head, si_clone) {
988 KASSERT(dev->si_flags & SI_CLONELIST,
989 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
990 u = dev2unit(dev);
991 if (u == (unit | extra)) {
992 *dp = dev;
993 dev_unlock();
994 devfs_free(ndev);
995 return (0);
996 }
997 if (unit == -1 && u == low) {
998 low++;
999 de = dev;
1000 continue;
1001 } else if (u < (unit | extra)) {
1002 de = dev;
1003 continue;
1004 } else if (u > (unit | extra)) {
1005 dl = dev;
1006 break;
1007 }
1008 }
1009 if (unit == -1)
1010 unit = low & CLONE_UNITMASK;
1011 dev = newdev(csw, unit | extra, ndev);
1012 if (dev->si_flags & SI_CLONELIST) {
1013 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1014 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1015 LIST_FOREACH(dev, &cd->head, si_clone) {
1016 printf("\t%p %s\n", dev, dev->si_name);
1017 }
1018 panic("foo");
1019 }
1020 KASSERT(!(dev->si_flags & SI_CLONELIST),
1021 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1022 if (dl != NULL)
1023 LIST_INSERT_BEFORE(dl, dev, si_clone);
1024 else if (de != NULL)
1025 LIST_INSERT_AFTER(de, dev, si_clone);
1026 else
1027 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1028 dev->si_flags |= SI_CLONELIST;
1029 *up = unit;
1030 dev_unlock_and_free();
1031 return (1);
1032 }
1033
1034 /*
1035 * Kill everything still on the list. The driver should already have
1036 * disposed of any softc hung of the struct cdev *'s at this time.
1037 */
1038 void
1039 clone_cleanup(struct clonedevs **cdp)
1040 {
1041 struct cdev *dev;
1042 struct cdev_priv *cp;
1043 struct clonedevs *cd;
1044
1045 cd = *cdp;
1046 if (cd == NULL)
1047 return;
1048 dev_lock();
1049 while (!LIST_EMPTY(&cd->head)) {
1050 dev = LIST_FIRST(&cd->head);
1051 LIST_REMOVE(dev, si_clone);
1052 KASSERT(dev->si_flags & SI_CLONELIST,
1053 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1054 dev->si_flags &= ~SI_CLONELIST;
1055 cp = cdev2priv(dev);
1056 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1057 cp->cdp_flags |= CDP_SCHED_DTR;
1058 KASSERT(dev->si_flags & SI_NAMED,
1059 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1060 destroy_devl(dev);
1061 }
1062 }
1063 dev_unlock_and_free();
1064 free(cd, M_DEVBUF);
1065 *cdp = NULL;
1066 }
1067
1068 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1069 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1070 static struct task dev_dtr_task;
1071
1072 static void
1073 destroy_dev_tq(void *ctx, int pending)
1074 {
1075 struct cdev_priv *cp;
1076 struct cdev *dev;
1077 void (*cb)(void *);
1078 void *cb_arg;
1079
1080 dev_lock();
1081 while (!TAILQ_EMPTY(&dev_ddtr)) {
1082 cp = TAILQ_FIRST(&dev_ddtr);
1083 dev = &cp->cdp_c;
1084 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1085 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1086 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1087 cb = cp->cdp_dtr_cb;
1088 cb_arg = cp->cdp_dtr_cb_arg;
1089 destroy_devl(dev);
1090 dev_unlock_and_free();
1091 dev_rel(dev);
1092 if (cb != NULL)
1093 cb(cb_arg);
1094 dev_lock();
1095 }
1096 dev_unlock();
1097 }
1098
1099 /*
1100 * devmtx shall be locked on entry. devmtx will be unlocked after
1101 * function return.
1102 */
1103 static int
1104 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1105 {
1106 struct cdev_priv *cp;
1107
1108 mtx_assert(&devmtx, MA_OWNED);
1109 cp = cdev2priv(dev);
1110 if (cp->cdp_flags & CDP_SCHED_DTR) {
1111 dev_unlock();
1112 return (0);
1113 }
1114 dev_refl(dev);
1115 cp->cdp_flags |= CDP_SCHED_DTR;
1116 cp->cdp_dtr_cb = cb;
1117 cp->cdp_dtr_cb_arg = arg;
1118 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1119 dev_unlock();
1120 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1121 return (1);
1122 }
1123
1124 int
1125 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1126 {
1127 dev_lock();
1128 return (destroy_dev_sched_cbl(dev, cb, arg));
1129 }
1130
1131 int
1132 destroy_dev_sched(struct cdev *dev)
1133 {
1134 return (destroy_dev_sched_cb(dev, NULL, NULL));
1135 }
1136
1137 void
1138 destroy_dev_drain(struct cdevsw *csw)
1139 {
1140
1141 dev_lock();
1142 while (!LIST_EMPTY(&csw->d_devs)) {
1143 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1144 }
1145 dev_unlock();
1146 }
1147
1148 void
1149 drain_dev_clone_events(void)
1150 {
1151
1152 sx_xlock(&clone_drain_lock);
1153 sx_xunlock(&clone_drain_lock);
1154 }
1155
1156 static void
1157 devdtr_init(void *dummy __unused)
1158 {
1159
1160 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
1161 }
1162
1163 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
Cache object: 7bfe97b623cee732de973c59fc179aa8
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