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/tty.h>
46 #include <sys/ucred.h>
47 #include <sys/taskqueue.h>
48 #include <machine/stdarg.h>
49
50 #include <fs/devfs/devfs_int.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 minornr,
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 = cdev->si_priv;
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 = dev->si_priv;
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 = (*devp)->si_priv;
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
280 static struct cdevsw dead_cdevsw = {
281 .d_version = D_VERSION,
282 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */
283 .d_open = dead_open,
284 .d_close = dead_close,
285 .d_read = dead_read,
286 .d_write = dead_write,
287 .d_ioctl = dead_ioctl,
288 .d_poll = dead_poll,
289 .d_mmap = dead_mmap,
290 .d_strategy = dead_strategy,
291 .d_name = "dead",
292 .d_dump = dead_dump,
293 .d_kqfilter = dead_kqfilter
294 };
295
296 /* Default methods if driver does not specify method */
297
298 #define null_open (d_open_t *)nullop
299 #define null_close (d_close_t *)nullop
300 #define no_read (d_read_t *)enodev
301 #define no_write (d_write_t *)enodev
302 #define no_ioctl (d_ioctl_t *)enodev
303 #define no_mmap (d_mmap_t *)enodev
304 #define no_kqfilter (d_kqfilter_t *)enodev
305
306 static void
307 no_strategy(struct bio *bp)
308 {
309
310 biofinish(bp, NULL, ENODEV);
311 }
312
313 static int
314 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
315 {
316 /*
317 * Return true for read/write. If the user asked for something
318 * special, return POLLNVAL, so that clients have a way of
319 * determining reliably whether or not the extended
320 * functionality is present without hard-coding knowledge
321 * of specific filesystem implementations.
322 * Stay in sync with vop_nopoll().
323 */
324 if (events & ~POLLSTANDARD)
325 return (POLLNVAL);
326
327 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
328 }
329
330 #define no_dump (dumper_t *)enodev
331
332 static int
333 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
334 {
335 struct cdevsw *dsw;
336 int retval;
337
338 dsw = dev_refthread(dev);
339 if (dsw == NULL)
340 return (ENXIO);
341 mtx_lock(&Giant);
342 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
343 mtx_unlock(&Giant);
344 dev_relthread(dev);
345 return (retval);
346 }
347
348 static int
349 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
350 {
351 struct cdevsw *dsw;
352 int retval;
353
354 dsw = dev_refthread(dev);
355 if (dsw == NULL)
356 return (ENXIO);
357 mtx_lock(&Giant);
358 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
359 mtx_unlock(&Giant);
360 dev_relthread(dev);
361 return (retval);
362 }
363
364 static int
365 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
366 {
367 struct cdevsw *dsw;
368 int retval;
369
370 dsw = dev_refthread(dev);
371 if (dsw == NULL)
372 return (ENXIO);
373 mtx_lock(&Giant);
374 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
375 mtx_unlock(&Giant);
376 dev_relthread(dev);
377 return (retval);
378 }
379
380 static void
381 giant_strategy(struct bio *bp)
382 {
383 struct cdevsw *dsw;
384 struct cdev *dev;
385
386 dev = bp->bio_dev;
387 dsw = dev_refthread(dev);
388 if (dsw == NULL) {
389 biofinish(bp, NULL, ENXIO);
390 return;
391 }
392 mtx_lock(&Giant);
393 dsw->d_gianttrick->d_strategy(bp);
394 mtx_unlock(&Giant);
395 dev_relthread(dev);
396 }
397
398 static int
399 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
400 {
401 struct cdevsw *dsw;
402 int retval;
403
404 dsw = dev_refthread(dev);
405 if (dsw == NULL)
406 return (ENXIO);
407 mtx_lock(&Giant);
408 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
409 mtx_unlock(&Giant);
410 dev_relthread(dev);
411 return (retval);
412 }
413
414 static int
415 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
416 {
417 struct cdevsw *dsw;
418 int retval;
419
420 dsw = dev_refthread(dev);
421 if (dsw == NULL)
422 return (ENXIO);
423 mtx_lock(&Giant);
424 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
425 mtx_unlock(&Giant);
426 dev_relthread(dev);
427 return (retval);
428 }
429
430 static int
431 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
432 {
433 struct cdevsw *dsw;
434 int retval;
435
436 dsw = dev_refthread(dev);
437 if (dsw == NULL)
438 return (ENXIO);
439 mtx_lock(&Giant);
440 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
441 mtx_unlock(&Giant);
442 dev_relthread(dev);
443 return (retval);
444 }
445
446 static int
447 giant_poll(struct cdev *dev, int events, struct thread *td)
448 {
449 struct cdevsw *dsw;
450 int retval;
451
452 dsw = dev_refthread(dev);
453 if (dsw == NULL)
454 return (ENXIO);
455 mtx_lock(&Giant);
456 retval = dsw->d_gianttrick->d_poll(dev, events, td);
457 mtx_unlock(&Giant);
458 dev_relthread(dev);
459 return (retval);
460 }
461
462 static int
463 giant_kqfilter(struct cdev *dev, struct knote *kn)
464 {
465 struct cdevsw *dsw;
466 int retval;
467
468 dsw = dev_refthread(dev);
469 if (dsw == NULL)
470 return (ENXIO);
471 mtx_lock(&Giant);
472 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
473 mtx_unlock(&Giant);
474 dev_relthread(dev);
475 return (retval);
476 }
477
478 static int
479 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
480 {
481 struct cdevsw *dsw;
482 int retval;
483
484 dsw = dev_refthread(dev);
485 if (dsw == NULL)
486 return (ENXIO);
487 mtx_lock(&Giant);
488 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot);
489 mtx_unlock(&Giant);
490 dev_relthread(dev);
491 return (retval);
492 }
493
494
495 /*
496 * struct cdev * and u_dev_t primitives
497 */
498
499 int
500 minor(struct cdev *x)
501 {
502 if (x == NULL)
503 return NODEV;
504 return(x->si_drv0 & MAXMINOR);
505 }
506
507 int
508 dev2unit(struct cdev *x)
509 {
510
511 if (x == NULL)
512 return NODEV;
513 return (minor2unit(minor(x)));
514 }
515
516 u_int
517 minor2unit(u_int _minor)
518 {
519
520 KASSERT((_minor & ~MAXMINOR) == 0, ("Illegal minor %x", _minor));
521 return ((_minor & 0xff) | ((_minor >> 8) & 0xffff00));
522 }
523
524 int
525 unit2minor(int unit)
526 {
527
528 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit));
529 return ((unit & 0xff) | ((unit << 8) & ~0xffff));
530 }
531
532 static void
533 notify(struct cdev *dev, const char *ev)
534 {
535 static const char prefix[] = "cdev=";
536 char *data;
537 int namelen;
538
539 if (cold)
540 return;
541 namelen = strlen(dev->si_name);
542 data = malloc(namelen + sizeof(prefix), M_TEMP, M_WAITOK);
543 memcpy(data, prefix, sizeof(prefix) - 1);
544 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
545 devctl_notify("DEVFS", "CDEV", ev, data);
546 free(data, M_TEMP);
547 }
548
549 static void
550 notify_create(struct cdev *dev)
551 {
552
553 notify(dev, "CREATE");
554 }
555
556 static void
557 notify_destroy(struct cdev *dev)
558 {
559
560 notify(dev, "DESTROY");
561 }
562
563 static struct cdev *
564 newdev(struct cdevsw *csw, int y, struct cdev *si)
565 {
566 struct cdev *si2;
567 dev_t udev;
568
569 mtx_assert(&devmtx, MA_OWNED);
570 udev = y;
571 LIST_FOREACH(si2, &csw->d_devs, si_list) {
572 if (si2->si_drv0 == udev) {
573 dev_free_devlocked(si);
574 return (si2);
575 }
576 }
577 si->si_drv0 = udev;
578 si->si_devsw = csw;
579 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
580 return (si);
581 }
582
583 int
584 uminor(dev_t dev)
585 {
586 return (dev & MAXMINOR);
587 }
588
589 int
590 umajor(dev_t dev)
591 {
592 return ((dev & ~MAXMINOR) >> 8);
593 }
594
595 static void
596 fini_cdevsw(struct cdevsw *devsw)
597 {
598 struct cdevsw *gt;
599
600 if (devsw->d_gianttrick != NULL) {
601 gt = devsw->d_gianttrick;
602 memcpy(devsw, gt, sizeof *devsw);
603 cdevsw_free_devlocked(gt);
604 devsw->d_gianttrick = NULL;
605 }
606 devsw->d_flags &= ~D_INIT;
607 }
608
609 static void
610 prep_cdevsw(struct cdevsw *devsw)
611 {
612 struct cdevsw *dsw2;
613
614 mtx_assert(&devmtx, MA_OWNED);
615 if (devsw->d_flags & D_INIT)
616 return;
617 if (devsw->d_flags & D_NEEDGIANT) {
618 dev_unlock();
619 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK);
620 dev_lock();
621 } else
622 dsw2 = NULL;
623 if (devsw->d_flags & D_INIT) {
624 if (dsw2 != NULL)
625 cdevsw_free_devlocked(dsw2);
626 return;
627 }
628
629 if (devsw->d_version != D_VERSION_01) {
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
646 if (devsw->d_flags & D_TTY) {
647 if (devsw->d_ioctl == NULL) devsw->d_ioctl = ttyioctl;
648 if (devsw->d_read == NULL) devsw->d_read = ttyread;
649 if (devsw->d_write == NULL) devsw->d_write = ttywrite;
650 if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = ttykqfilter;
651 if (devsw->d_poll == NULL) devsw->d_poll = ttypoll;
652 }
653
654 if (devsw->d_flags & D_NEEDGIANT) {
655 if (devsw->d_gianttrick == NULL) {
656 memcpy(dsw2, devsw, sizeof *dsw2);
657 devsw->d_gianttrick = dsw2;
658 dsw2 = NULL;
659 }
660 }
661
662 #define FIXUP(member, noop, giant) \
663 do { \
664 if (devsw->member == NULL) { \
665 devsw->member = noop; \
666 } else if (devsw->d_flags & D_NEEDGIANT) \
667 devsw->member = giant; \
668 } \
669 while (0)
670
671 FIXUP(d_open, null_open, giant_open);
672 FIXUP(d_fdopen, NULL, giant_fdopen);
673 FIXUP(d_close, null_close, giant_close);
674 FIXUP(d_read, no_read, giant_read);
675 FIXUP(d_write, no_write, giant_write);
676 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
677 FIXUP(d_poll, no_poll, giant_poll);
678 FIXUP(d_mmap, no_mmap, giant_mmap);
679 FIXUP(d_strategy, no_strategy, giant_strategy);
680 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
681
682 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
683
684 LIST_INIT(&devsw->d_devs);
685
686 devsw->d_flags |= D_INIT;
687
688 if (dsw2 != NULL)
689 cdevsw_free_devlocked(dsw2);
690 }
691
692 struct cdev *
693 make_dev_credv(int flags, struct cdevsw *devsw, int minornr,
694 struct ucred *cr, uid_t uid,
695 gid_t gid, int mode, const char *fmt, va_list ap)
696 {
697 struct cdev *dev;
698 int i;
699
700 KASSERT((minornr & ~MAXMINOR) == 0,
701 ("Invalid minor (0x%x) in make_dev", minornr));
702
703 dev = devfs_alloc();
704 dev_lock();
705 prep_cdevsw(devsw);
706 dev = newdev(devsw, minornr, dev);
707 if (flags & MAKEDEV_REF)
708 dev_refl(dev);
709 if (dev->si_flags & SI_CHEAPCLONE &&
710 dev->si_flags & SI_NAMED) {
711 /*
712 * This is allowed as it removes races and generally
713 * simplifies cloning devices.
714 * XXX: still ??
715 */
716 dev_unlock_and_free();
717 return (dev);
718 }
719 KASSERT(!(dev->si_flags & SI_NAMED),
720 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
721 devsw->d_name, minor(dev), devtoname(dev)));
722
723 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
724 if (i > (sizeof dev->__si_namebuf - 1)) {
725 printf("WARNING: Device name truncated! (%s)\n",
726 dev->__si_namebuf);
727 }
728
729 dev->si_flags |= SI_NAMED;
730 #ifdef MAC
731 if (cr != NULL)
732 dev->si_cred = crhold(cr);
733 else
734 #endif
735 dev->si_cred = NULL;
736 dev->si_uid = uid;
737 dev->si_gid = gid;
738 dev->si_mode = mode;
739
740 devfs_create(dev);
741 clean_unrhdrl(devfs_inos);
742 dev_unlock_and_free();
743
744 notify_create(dev);
745
746 return (dev);
747 }
748
749 struct cdev *
750 make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int mode,
751 const char *fmt, ...)
752 {
753 struct cdev *dev;
754 va_list ap;
755
756 va_start(ap, fmt);
757 dev = make_dev_credv(0, devsw, minornr, NULL, uid, gid, mode, fmt, ap);
758 va_end(ap);
759 return (dev);
760 }
761
762 struct cdev *
763 make_dev_cred(struct cdevsw *devsw, int minornr, struct ucred *cr, uid_t uid,
764 gid_t gid, int mode, const char *fmt, ...)
765 {
766 struct cdev *dev;
767 va_list ap;
768
769 va_start(ap, fmt);
770 dev = make_dev_credv(0, devsw, minornr, cr, uid, gid, mode, fmt, ap);
771 va_end(ap);
772
773 return (dev);
774 }
775
776 struct cdev *
777 make_dev_credf(int flags, struct cdevsw *devsw, int minornr,
778 struct ucred *cr, uid_t uid,
779 gid_t gid, int mode, const char *fmt, ...)
780 {
781 struct cdev *dev;
782 va_list ap;
783
784 va_start(ap, fmt);
785 dev = make_dev_credv(flags, devsw, minornr, cr, uid, gid, mode,
786 fmt, ap);
787 va_end(ap);
788
789 return (dev);
790 }
791
792 static void
793 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
794 {
795
796 cdev->si_parent = pdev;
797 cdev->si_flags |= SI_CHILD;
798 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
799 }
800
801
802 void
803 dev_depends(struct cdev *pdev, struct cdev *cdev)
804 {
805
806 dev_lock();
807 dev_dependsl(pdev, cdev);
808 dev_unlock();
809 }
810
811 struct cdev *
812 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
813 {
814 struct cdev *dev;
815 va_list ap;
816 int i;
817
818 KASSERT(pdev != NULL, ("NULL pdev"));
819 dev = devfs_alloc();
820 dev_lock();
821 dev->si_flags |= SI_ALIAS;
822 dev->si_flags |= SI_NAMED;
823 va_start(ap, fmt);
824 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
825 if (i > (sizeof dev->__si_namebuf - 1)) {
826 printf("WARNING: Device name truncated! (%s)\n",
827 dev->__si_namebuf);
828 }
829 va_end(ap);
830
831 devfs_create(dev);
832 dev_dependsl(pdev, dev);
833 clean_unrhdrl(devfs_inos);
834 dev_unlock();
835
836 notify_create(dev);
837
838 return (dev);
839 }
840
841 static void
842 destroy_devl(struct cdev *dev)
843 {
844 struct cdevsw *csw;
845 struct cdev_privdata *p, *p1;
846
847 mtx_assert(&devmtx, MA_OWNED);
848 KASSERT(dev->si_flags & SI_NAMED,
849 ("WARNING: Driver mistake: destroy_dev on %d\n", minor(dev)));
850
851 devfs_destroy(dev);
852
853 /* Remove name marking */
854 dev->si_flags &= ~SI_NAMED;
855
856 /* If we are a child, remove us from the parents list */
857 if (dev->si_flags & SI_CHILD) {
858 LIST_REMOVE(dev, si_siblings);
859 dev->si_flags &= ~SI_CHILD;
860 }
861
862 /* Kill our children */
863 while (!LIST_EMPTY(&dev->si_children))
864 destroy_devl(LIST_FIRST(&dev->si_children));
865
866 /* Remove from clone list */
867 if (dev->si_flags & SI_CLONELIST) {
868 LIST_REMOVE(dev, si_clone);
869 dev->si_flags &= ~SI_CLONELIST;
870 }
871
872 dev->si_refcount++; /* Avoid race with dev_rel() */
873 csw = dev->si_devsw;
874 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
875 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
876 csw->d_purge(dev);
877 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
878 if (dev->si_threadcount)
879 printf("Still %lu threads in %s\n",
880 dev->si_threadcount, devtoname(dev));
881 }
882 while (dev->si_threadcount != 0) {
883 /* Use unique dummy wait ident */
884 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
885 }
886
887 dev_unlock();
888 notify_destroy(dev);
889 mtx_lock(&cdevpriv_mtx);
890 LIST_FOREACH_SAFE(p, &dev->si_priv->cdp_fdpriv, cdpd_list, p1) {
891 devfs_destroy_cdevpriv(p);
892 mtx_lock(&cdevpriv_mtx);
893 }
894 mtx_unlock(&cdevpriv_mtx);
895 dev_lock();
896
897 dev->si_drv1 = 0;
898 dev->si_drv2 = 0;
899 bzero(&dev->__si_u, sizeof(dev->__si_u));
900
901 if (!(dev->si_flags & SI_ALIAS)) {
902 /* Remove from cdevsw list */
903 LIST_REMOVE(dev, si_list);
904
905 /* If cdevsw has no more struct cdev *'s, clean it */
906 if (LIST_EMPTY(&csw->d_devs)) {
907 fini_cdevsw(csw);
908 wakeup(&csw->d_devs);
909 }
910 }
911 dev->si_flags &= ~SI_ALIAS;
912 dev->si_refcount--; /* Avoid race with dev_rel() */
913
914 if (dev->si_refcount > 0) {
915 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
916 } else {
917 dev_free_devlocked(dev);
918 }
919 }
920
921 void
922 destroy_dev(struct cdev *dev)
923 {
924
925 dev_lock();
926 destroy_devl(dev);
927 dev_unlock_and_free();
928 }
929
930 const char *
931 devtoname(struct cdev *dev)
932 {
933 char *p;
934 struct cdevsw *csw;
935 int mynor;
936
937 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') {
938 p = dev->si_name;
939 csw = dev_refthread(dev);
940 if (csw != NULL) {
941 sprintf(p, "(%s)", csw->d_name);
942 dev_relthread(dev);
943 }
944 p += strlen(p);
945 mynor = minor(dev);
946 if (mynor < 0 || mynor > 255)
947 sprintf(p, "/%#x", (u_int)mynor);
948 else
949 sprintf(p, "/%d", mynor);
950 }
951 return (dev->si_name);
952 }
953
954 int
955 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
956 {
957 int u, i;
958
959 i = strlen(stem);
960 if (bcmp(stem, name, i) != 0)
961 return (0);
962 if (!isdigit(name[i]))
963 return (0);
964 u = 0;
965 if (name[i] == '' && isdigit(name[i+1]))
966 return (0);
967 while (isdigit(name[i])) {
968 u *= 10;
969 u += name[i++] - '';
970 }
971 if (u > 0xffffff)
972 return (0);
973 *unit = u;
974 if (namep)
975 *namep = &name[i];
976 if (name[i])
977 return (2);
978 return (1);
979 }
980
981 /*
982 * Helper functions for cloning device drivers.
983 *
984 * The objective here is to make it unnecessary for the device drivers to
985 * use rman or similar to manage their unit number space. Due to the way
986 * we do "on-demand" devices, using rman or other "private" methods
987 * will be very tricky to lock down properly once we lock down this file.
988 *
989 * Instead we give the drivers these routines which puts the struct cdev *'s
990 * that are to be managed on their own list, and gives the driver the ability
991 * to ask for the first free unit number or a given specified unit number.
992 *
993 * In addition these routines support paired devices (pty, nmdm and similar)
994 * by respecting a number of "flag" bits in the minor number.
995 *
996 */
997
998 struct clonedevs {
999 LIST_HEAD(,cdev) head;
1000 };
1001
1002 void
1003 clone_setup(struct clonedevs **cdp)
1004 {
1005
1006 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1007 LIST_INIT(&(*cdp)->head);
1008 }
1009
1010 int
1011 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra)
1012 {
1013 struct clonedevs *cd;
1014 struct cdev *dev, *ndev, *dl, *de;
1015 int unit, low, u;
1016
1017 KASSERT(*cdp != NULL,
1018 ("clone_setup() not called in driver \"%s\"", csw->d_name));
1019 KASSERT(!(extra & CLONE_UNITMASK),
1020 ("Illegal extra bits (0x%x) in clone_create", extra));
1021 KASSERT(*up <= CLONE_UNITMASK,
1022 ("Too high unit (0x%x) in clone_create", *up));
1023
1024
1025 /*
1026 * Search the list for a lot of things in one go:
1027 * A preexisting match is returned immediately.
1028 * The lowest free unit number if we are passed -1, and the place
1029 * in the list where we should insert that new element.
1030 * The place to insert a specified unit number, if applicable
1031 * the end of the list.
1032 */
1033 unit = *up;
1034 ndev = devfs_alloc();
1035 dev_lock();
1036 prep_cdevsw(csw);
1037 low = extra;
1038 de = dl = NULL;
1039 cd = *cdp;
1040 LIST_FOREACH(dev, &cd->head, si_clone) {
1041 KASSERT(dev->si_flags & SI_CLONELIST,
1042 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1043 u = dev2unit(dev);
1044 if (u == (unit | extra)) {
1045 *dp = dev;
1046 dev_unlock();
1047 devfs_free(ndev);
1048 return (0);
1049 }
1050 if (unit == -1 && u == low) {
1051 low++;
1052 de = dev;
1053 continue;
1054 } else if (u < (unit | extra)) {
1055 de = dev;
1056 continue;
1057 } else if (u > (unit | extra)) {
1058 dl = dev;
1059 break;
1060 }
1061 }
1062 if (unit == -1)
1063 unit = low & CLONE_UNITMASK;
1064 dev = newdev(csw, unit2minor(unit | extra), ndev);
1065 if (dev->si_flags & SI_CLONELIST) {
1066 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1067 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1068 LIST_FOREACH(dev, &cd->head, si_clone) {
1069 printf("\t%p %s\n", dev, dev->si_name);
1070 }
1071 panic("foo");
1072 }
1073 KASSERT(!(dev->si_flags & SI_CLONELIST),
1074 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1075 if (dl != NULL)
1076 LIST_INSERT_BEFORE(dl, dev, si_clone);
1077 else if (de != NULL)
1078 LIST_INSERT_AFTER(de, dev, si_clone);
1079 else
1080 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1081 dev->si_flags |= SI_CLONELIST;
1082 *up = unit;
1083 dev_unlock_and_free();
1084 return (1);
1085 }
1086
1087 /*
1088 * Kill everything still on the list. The driver should already have
1089 * disposed of any softc hung of the struct cdev *'s at this time.
1090 */
1091 void
1092 clone_cleanup(struct clonedevs **cdp)
1093 {
1094 struct cdev *dev;
1095 struct cdev_priv *cp;
1096 struct clonedevs *cd;
1097
1098 cd = *cdp;
1099 if (cd == NULL)
1100 return;
1101 dev_lock();
1102 while (!LIST_EMPTY(&cd->head)) {
1103 dev = LIST_FIRST(&cd->head);
1104 LIST_REMOVE(dev, si_clone);
1105 KASSERT(dev->si_flags & SI_CLONELIST,
1106 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1107 dev->si_flags &= ~SI_CLONELIST;
1108 cp = dev->si_priv;
1109 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1110 cp->cdp_flags |= CDP_SCHED_DTR;
1111 KASSERT(dev->si_flags & SI_NAMED,
1112 ("Driver has goofed in cloning underways udev %x", dev->si_drv0));
1113 destroy_devl(dev);
1114 }
1115 }
1116 dev_unlock_and_free();
1117 free(cd, M_DEVBUF);
1118 *cdp = NULL;
1119 }
1120
1121 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1122 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1123 static struct task dev_dtr_task;
1124
1125 static void
1126 destroy_dev_tq(void *ctx, int pending)
1127 {
1128 struct cdev_priv *cp;
1129 struct cdev *dev;
1130 void (*cb)(void *);
1131 void *cb_arg;
1132
1133 dev_lock();
1134 while (!TAILQ_EMPTY(&dev_ddtr)) {
1135 cp = TAILQ_FIRST(&dev_ddtr);
1136 dev = &cp->cdp_c;
1137 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1138 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1139 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1140 cb = cp->cdp_dtr_cb;
1141 cb_arg = cp->cdp_dtr_cb_arg;
1142 destroy_devl(dev);
1143 dev_unlock_and_free();
1144 dev_rel(dev);
1145 if (cb != NULL)
1146 cb(cb_arg);
1147 dev_lock();
1148 }
1149 dev_unlock();
1150 }
1151
1152 /*
1153 * devmtx shall be locked on entry. devmtx will be unlocked after
1154 * function return.
1155 */
1156 static int
1157 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1158 {
1159 struct cdev_priv *cp;
1160
1161 mtx_assert(&devmtx, MA_OWNED);
1162 cp = dev->si_priv;
1163 if (cp->cdp_flags & CDP_SCHED_DTR) {
1164 dev_unlock();
1165 return (0);
1166 }
1167 dev_refl(dev);
1168 cp->cdp_flags |= CDP_SCHED_DTR;
1169 cp->cdp_dtr_cb = cb;
1170 cp->cdp_dtr_cb_arg = arg;
1171 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1172 dev_unlock();
1173 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1174 return (1);
1175 }
1176
1177 int
1178 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1179 {
1180 dev_lock();
1181 return (destroy_dev_sched_cbl(dev, cb, arg));
1182 }
1183
1184 int
1185 destroy_dev_sched(struct cdev *dev)
1186 {
1187 return (destroy_dev_sched_cb(dev, NULL, NULL));
1188 }
1189
1190 void
1191 destroy_dev_drain(struct cdevsw *csw)
1192 {
1193
1194 dev_lock();
1195 while (!LIST_EMPTY(&csw->d_devs)) {
1196 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1197 }
1198 dev_unlock();
1199 }
1200
1201 void
1202 drain_dev_clone_events(void)
1203 {
1204
1205 sx_xlock(&clone_drain_lock);
1206 sx_xunlock(&clone_drain_lock);
1207 }
1208
1209 static void
1210 devdtr_init(void *dummy __unused)
1211 {
1212
1213 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
1214 }
1215
1216 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
Cache object: 75e4770856d39085fe7f0404e8162c20
|