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
51static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
52
53struct mtx devmtx;
54static void destroy_devl(struct cdev *dev);
55static int destroy_dev_sched_cbl(struct cdev *dev,
56 void (*cb)(void *), void *arg);
57static struct cdev *make_dev_credv(int flags,
58 struct cdevsw *devsw, int minornr,
59 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
60 va_list ap);
61
62static struct cdev_priv_list cdevp_free_list =
63 TAILQ_HEAD_INITIALIZER(cdevp_free_list);
64static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
65 SLIST_HEAD_INITIALIZER();
66
67void
68dev_lock(void)
69{
70
71 mtx_lock(&devmtx);
72}
73
74/*
75 * Free all the memory collected while the cdev mutex was
76 * locked. Since devmtx is after the system map mutex, free() cannot
77 * be called immediately and is postponed until cdev mutex can be
78 * dropped.
79 */
80static void
81dev_unlock_and_free(void)
82{
83 struct cdev_priv_list cdp_free;
84 struct free_cdevsw csw_free;
85 struct cdev_priv *cdp;
86 struct cdevsw *csw;
87
88 mtx_assert(&devmtx, MA_OWNED);
89
90 /*
91 * Make the local copy of the list heads while the dev_mtx is
92 * held. Free it later.
93 */
94 TAILQ_INIT(&cdp_free);
95 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
96 csw_free = cdevsw_gt_post_list;
97 SLIST_INIT(&cdevsw_gt_post_list);
98
99 mtx_unlock(&devmtx);
100
101 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
102 TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
103 devfs_free(&cdp->cdp_c);
104 }
105 while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
106 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
107 free(csw, M_DEVT);
108 }
109}
110
111static void
112dev_free_devlocked(struct cdev *cdev)
113{
114 struct cdev_priv *cdp;
115
116 mtx_assert(&devmtx, MA_OWNED);
117 cdp = cdev2priv(cdev);
118 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
119}
120
121static void
122cdevsw_free_devlocked(struct cdevsw *csw)
123{
124
125 mtx_assert(&devmtx, MA_OWNED);
126 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
127}
128
129void
130dev_unlock(void)
131{
132
133 mtx_unlock(&devmtx);
134}
135
136void
137dev_ref(struct cdev *dev)
138{
139
140 mtx_assert(&devmtx, MA_NOTOWNED);
141 mtx_lock(&devmtx);
142 dev->si_refcount++;
143 mtx_unlock(&devmtx);
144}
145
146void
147dev_refl(struct cdev *dev)
148{
149
150 mtx_assert(&devmtx, MA_OWNED);
151 dev->si_refcount++;
152}
153
154void
155dev_rel(struct cdev *dev)
156{
157 int flag = 0;
158
159 mtx_assert(&devmtx, MA_NOTOWNED);
160 dev_lock();
161 dev->si_refcount--;
162 KASSERT(dev->si_refcount >= 0,
163 ("dev_rel(%s) gave negative count", devtoname(dev)));
164#if 0
165 if (dev->si_usecount == 0 &&
166 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
167 ;
168 else
169#endif
170 if (dev->si_devsw == NULL && dev->si_refcount == 0) {
171 LIST_REMOVE(dev, si_list);
172 flag = 1;
173 }
174 dev_unlock();
175 if (flag)
176 devfs_free(dev);
177}
178
179struct cdevsw *
180dev_refthread(struct cdev *dev)
181{
182 struct cdevsw *csw;
183 struct cdev_priv *cdp;
184
185 mtx_assert(&devmtx, MA_NOTOWNED);
186 dev_lock();
187 csw = dev->si_devsw;
188 if (csw != NULL) {
189 cdp = cdev2priv(dev);
190 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
191 dev->si_threadcount++;
192 else
193 csw = NULL;
194 }
195 dev_unlock();
196 return (csw);
197}
198
199struct cdevsw *
200devvn_refthread(struct vnode *vp, struct cdev **devp)
201{
202 struct cdevsw *csw;
203 struct cdev_priv *cdp;
204
205 mtx_assert(&devmtx, MA_NOTOWNED);
206 csw = NULL;
207 dev_lock();
208 *devp = vp->v_rdev;
209 if (*devp != NULL) {
210 cdp = cdev2priv(*devp);
211 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
212 csw = (*devp)->si_devsw;
213 if (csw != NULL)
214 (*devp)->si_threadcount++;
215 }
216 }
217 dev_unlock();
218 return (csw);
219}
220
221void
222dev_relthread(struct cdev *dev)
223{
224
225 mtx_assert(&devmtx, MA_NOTOWNED);
226 dev_lock();
227 KASSERT(dev->si_threadcount > 0,
228 ("%s threadcount is wrong", dev->si_name));
229 dev->si_threadcount--;
230 dev_unlock();
231}
232
233int
234nullop(void)
235{
236
237 return (0);
238}
239
240int
241eopnotsupp(void)
242{
243
244 return (EOPNOTSUPP);
245}
246
247static int
248enxio(void)
249{
250 return (ENXIO);
251}
252
253static int
254enodev(void)
255{
256 return (ENODEV);
257}
258
259/* Define a dead_cdevsw for use when devices leave unexpectedly. */
260
261#define dead_open (d_open_t *)enxio
262#define dead_close (d_close_t *)enxio
263#define dead_read (d_read_t *)enxio
264#define dead_write (d_write_t *)enxio
265#define dead_ioctl (d_ioctl_t *)enxio
266#define dead_poll (d_poll_t *)enodev
267#define dead_mmap (d_mmap_t *)enodev
268
269static void
270dead_strategy(struct bio *bp)
271{
272
273 biofinish(bp, NULL, ENXIO);
274}
275
276#define dead_dump (dumper_t *)enxio
277#define dead_kqfilter (d_kqfilter_t *)enxio
278
279static struct cdevsw dead_cdevsw = {
280 .d_version = D_VERSION,
281 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */
282 .d_open = dead_open,
283 .d_close = dead_close,
284 .d_read = dead_read,
285 .d_write = dead_write,
286 .d_ioctl = dead_ioctl,
287 .d_poll = dead_poll,
288 .d_mmap = dead_mmap,
289 .d_strategy = dead_strategy,
290 .d_name = "dead",
291 .d_dump = dead_dump,
292 .d_kqfilter = dead_kqfilter
293};
294
295/* Default methods if driver does not specify method */
296
297#define null_open (d_open_t *)nullop
298#define null_close (d_close_t *)nullop
299#define no_read (d_read_t *)enodev
300#define no_write (d_write_t *)enodev
301#define no_ioctl (d_ioctl_t *)enodev
302#define no_mmap (d_mmap_t *)enodev
303#define no_kqfilter (d_kqfilter_t *)enodev
304
305static void
306no_strategy(struct bio *bp)
307{
308
309 biofinish(bp, NULL, ENODEV);
310}
311
312static int
313no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
314{
315 /*
316 * Return true for read/write. If the user asked for something
317 * special, return POLLNVAL, so that clients have a way of
318 * determining reliably whether or not the extended
319 * functionality is present without hard-coding knowledge
320 * of specific filesystem implementations.
321 * Stay in sync with vop_nopoll().
322 */
323 if (events & ~POLLSTANDARD)
324 return (POLLNVAL);
325
326 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
327}
328
329#define no_dump (dumper_t *)enodev
330
331static int
332giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
333{
334 struct cdevsw *dsw;
335 int retval;
336
337 dsw = dev_refthread(dev);
338 if (dsw == NULL)
339 return (ENXIO);
340 mtx_lock(&Giant);
341 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
342 mtx_unlock(&Giant);
343 dev_relthread(dev);
344 return (retval);
345}
346
347static int
348giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
349{
350 struct cdevsw *dsw;
351 int retval;
352
353 dsw = dev_refthread(dev);
354 if (dsw == NULL)
355 return (ENXIO);
356 mtx_lock(&Giant);
357 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
358 mtx_unlock(&Giant);
359 dev_relthread(dev);
360 return (retval);
361}
362
363static int
364giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
365{
366 struct cdevsw *dsw;
367 int retval;
368
369 dsw = dev_refthread(dev);
370 if (dsw == NULL)
371 return (ENXIO);
372 mtx_lock(&Giant);
373 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
374 mtx_unlock(&Giant);
375 dev_relthread(dev);
376 return (retval);
377}
378
379static void
380giant_strategy(struct bio *bp)
381{
382 struct cdevsw *dsw;
383 struct cdev *dev;
384
385 dev = bp->bio_dev;
386 dsw = dev_refthread(dev);
387 if (dsw == NULL) {
388 biofinish(bp, NULL, ENXIO);
389 return;
390 }
391 mtx_lock(&Giant);
392 dsw->d_gianttrick->d_strategy(bp);
393 mtx_unlock(&Giant);
394 dev_relthread(dev);
395}
396
397static int
398giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
399{
400 struct cdevsw *dsw;
401 int retval;
402
403 dsw = dev_refthread(dev);
404 if (dsw == NULL)
405 return (ENXIO);
406 mtx_lock(&Giant);
407 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
408 mtx_unlock(&Giant);
409 dev_relthread(dev);
410 return (retval);
411}
412
413static int
414giant_read(struct cdev *dev, struct uio *uio, int ioflag)
415{
416 struct cdevsw *dsw;
417 int retval;
418
419 dsw = dev_refthread(dev);
420 if (dsw == NULL)
421 return (ENXIO);
422 mtx_lock(&Giant);
423 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
424 mtx_unlock(&Giant);
425 dev_relthread(dev);
426 return (retval);
427}
428
429static int
430giant_write(struct cdev *dev, struct uio *uio, int ioflag)
431{
432 struct cdevsw *dsw;
433 int retval;
434
435 dsw = dev_refthread(dev);
436 if (dsw == NULL)
437 return (ENXIO);
438 mtx_lock(&Giant);
439 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
440 mtx_unlock(&Giant);
441 dev_relthread(dev);
442 return (retval);
443}
444
445static int
446giant_poll(struct cdev *dev, int events, struct thread *td)
447{
448 struct cdevsw *dsw;
449 int retval;
450
451 dsw = dev_refthread(dev);
452 if (dsw == NULL)
453 return (ENXIO);
454 mtx_lock(&Giant);
455 retval = dsw->d_gianttrick->d_poll(dev, events, td);
456 mtx_unlock(&Giant);
457 dev_relthread(dev);
458 return (retval);
459}
460
461static int
462giant_kqfilter(struct cdev *dev, struct knote *kn)
463{
464 struct cdevsw *dsw;
465 int retval;
466
467 dsw = dev_refthread(dev);
468 if (dsw == NULL)
469 return (ENXIO);
470 mtx_lock(&Giant);
471 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
472 mtx_unlock(&Giant);
473 dev_relthread(dev);
474 return (retval);
475}
476
477static int
478giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
479{
480 struct cdevsw *dsw;
481 int retval;
482
483 dsw = dev_refthread(dev);
484 if (dsw == NULL)
485 return (ENXIO);
486 mtx_lock(&Giant);
487 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot);
488 mtx_unlock(&Giant);
489 dev_relthread(dev);
490 return (retval);
491}
492
493
494static void
495notify(struct cdev *dev, const char *ev)
496{
497 static const char prefix[] = "cdev=";
498 char *data;
499 int namelen;
500
501 if (cold)
502 return;
503 namelen = strlen(dev->si_name);
504 data = malloc(namelen + sizeof(prefix), M_TEMP, M_WAITOK);
505 memcpy(data, prefix, sizeof(prefix) - 1);
506 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
507 devctl_notify("DEVFS", "CDEV", ev, data);
508 free(data, M_TEMP);
509}
510
511static void
512notify_create(struct cdev *dev)
513{
514
515 notify(dev, "CREATE");
516}
517
518static void
519notify_destroy(struct cdev *dev)
520{
521
522 notify(dev, "DESTROY");
523}
524
525static struct cdev *
526newdev(struct cdevsw *csw, int y, struct cdev *si)
527{
528 struct cdev *si2;
529 dev_t udev;
530
531 mtx_assert(&devmtx, MA_OWNED);
532 udev = y;
533 if (csw->d_flags & D_NEEDMINOR) {
534 /* We may want to return an existing device */
535 LIST_FOREACH(si2, &csw->d_devs, si_list) {
536 if (si2->si_drv0 == udev) {
537 dev_free_devlocked(si);
538 return (si2);
539 }
540 }
541 }
542 si->si_drv0 = udev;
543 si->si_devsw = csw;
544 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
545 return (si);
546}
547
548#define UMINORMASK 0xffff00ffU
549
550int
551uminor(dev_t dev)
552{
553 return (dev & UMINORMASK);
554}
555
556int
557umajor(dev_t dev)
558{
559 return ((dev & ~UMINORMASK) >> 8);
560}
561
562static void
563fini_cdevsw(struct cdevsw *devsw)
564{
565 struct cdevsw *gt;
566
567 if (devsw->d_gianttrick != NULL) {
568 gt = devsw->d_gianttrick;
569 memcpy(devsw, gt, sizeof *devsw);
570 cdevsw_free_devlocked(gt);
571 devsw->d_gianttrick = NULL;
572 }
573 devsw->d_flags &= ~D_INIT;
574}
575
576static void
577prep_cdevsw(struct cdevsw *devsw)
578{
579 struct cdevsw *dsw2;
580
581 mtx_assert(&devmtx, MA_OWNED);
582 if (devsw->d_flags & D_INIT)
583 return;
584 if (devsw->d_flags & D_NEEDGIANT) {
585 dev_unlock();
586 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK);
587 dev_lock();
588 } else
589 dsw2 = NULL;
590 if (devsw->d_flags & D_INIT) {
591 if (dsw2 != NULL)
592 cdevsw_free_devlocked(dsw2);
593 return;
594 }
595
596 if (devsw->d_version != D_VERSION_01) {
597 printf(
598 "WARNING: Device driver \"%s\" has wrong version %s\n",
599 devsw->d_name == NULL ? "???" : devsw->d_name,
600 "and is disabled. Recompile KLD module.");
601 devsw->d_open = dead_open;
602 devsw->d_close = dead_close;
603 devsw->d_read = dead_read;
604 devsw->d_write = dead_write;
605 devsw->d_ioctl = dead_ioctl;
606 devsw->d_poll = dead_poll;
607 devsw->d_mmap = dead_mmap;
608 devsw->d_strategy = dead_strategy;
609 devsw->d_dump = dead_dump;
610 devsw->d_kqfilter = dead_kqfilter;
611 }
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
641 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
642
643 LIST_INIT(&devsw->d_devs);
644
645 devsw->d_flags |= D_INIT;
646
647 if (dsw2 != NULL)
648 cdevsw_free_devlocked(dsw2);
649}
650
651struct cdev *
652make_dev_credv(int flags, struct cdevsw *devsw, int minornr,
653 struct ucred *cr, uid_t uid,
654 gid_t gid, int mode, const char *fmt, va_list ap)
655{
656 struct cdev *dev;
657 int i;
658
659 dev = devfs_alloc();
660 dev_lock();
661 prep_cdevsw(devsw);
662 dev = newdev(devsw, minornr, dev);
663 if (flags & MAKEDEV_REF)
664 dev_refl(dev);
665 if (dev->si_flags & SI_CHEAPCLONE &&
666 dev->si_flags & SI_NAMED) {
667 /*
668 * This is allowed as it removes races and generally
669 * simplifies cloning devices.
670 * XXX: still ??
671 */
672 dev_unlock_and_free();
673 return (dev);
674 }
675 KASSERT(!(dev->si_flags & SI_NAMED),
676 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
677 devsw->d_name, minor(dev), devtoname(dev)));
678
679 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
680 if (i > (sizeof dev->__si_namebuf - 1)) {
681 printf("WARNING: Device name truncated! (%s)\n",
682 dev->__si_namebuf);
683 }
684
685 dev->si_flags |= SI_NAMED;
686 if (cr != NULL)
687 dev->si_cred = crhold(cr);
688 else
689 dev->si_cred = NULL;
690 dev->si_uid = uid;
691 dev->si_gid = gid;
692 dev->si_mode = mode;
693
694 devfs_create(dev);
695 clean_unrhdrl(devfs_inos);
696 dev_unlock_and_free();
697
698 notify_create(dev);
699
700 return (dev);
701}
702
703struct cdev *
704make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int mode,
705 const char *fmt, ...)
706{
707 struct cdev *dev;
708 va_list ap;
709
710 va_start(ap, fmt);
711 dev = make_dev_credv(0, devsw, minornr, NULL, uid, gid, mode, fmt, ap);
712 va_end(ap);
713 return (dev);
714}
715
716struct cdev *
717make_dev_cred(struct cdevsw *devsw, int minornr, struct ucred *cr, uid_t uid,
718 gid_t gid, int mode, const char *fmt, ...)
719{
720 struct cdev *dev;
721 va_list ap;
722
723 va_start(ap, fmt);
724 dev = make_dev_credv(0, devsw, minornr, cr, uid, gid, mode, fmt, ap);
725 va_end(ap);
726
727 return (dev);
728}
729
730struct cdev *
731make_dev_credf(int flags, struct cdevsw *devsw, int minornr,
732 struct ucred *cr, uid_t uid,
733 gid_t gid, int mode, const char *fmt, ...)
734{
735 struct cdev *dev;
736 va_list ap;
737
738 va_start(ap, fmt);
739 dev = make_dev_credv(flags, devsw, minornr, cr, uid, gid, mode,
740 fmt, ap);
741 va_end(ap);
742
743 return (dev);
744}
745
746static void
747dev_dependsl(struct cdev *pdev, struct cdev *cdev)
748{
749
750 cdev->si_parent = pdev;
751 cdev->si_flags |= SI_CHILD;
752 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
753}
754
755
756void
757dev_depends(struct cdev *pdev, struct cdev *cdev)
758{
759
760 dev_lock();
761 dev_dependsl(pdev, cdev);
762 dev_unlock();
763}
764
765struct cdev *
766make_dev_alias(struct cdev *pdev, const char *fmt, ...)
767{
768 struct cdev *dev;
769 va_list ap;
770 int i;
771
772 KASSERT(pdev != NULL, ("NULL pdev"));
773 dev = devfs_alloc();
774 dev_lock();
775 dev->si_flags |= SI_ALIAS;
776 dev->si_flags |= SI_NAMED;
777 va_start(ap, fmt);
778 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
779 if (i > (sizeof dev->__si_namebuf - 1)) {
780 printf("WARNING: Device name truncated! (%s)\n",
781 dev->__si_namebuf);
782 }
783 va_end(ap);
784
785 devfs_create(dev);
786 dev_dependsl(pdev, dev);
787 clean_unrhdrl(devfs_inos);
788 dev_unlock();
789
790 notify_create(dev);
791
792 return (dev);
793}
794
795static void
796destroy_devl(struct cdev *dev)
797{
798 struct cdevsw *csw;
799 struct cdev_privdata *p, *p1;
800
801 mtx_assert(&devmtx, MA_OWNED);
802 KASSERT(dev->si_flags & SI_NAMED,
803 ("WARNING: Driver mistake: destroy_dev on %d\n", minor(dev)));
804
805 devfs_destroy(dev);
806
807 /* Remove name marking */
808 dev->si_flags &= ~SI_NAMED;
809
810 /* If we are a child, remove us from the parents list */
811 if (dev->si_flags & SI_CHILD) {
812 LIST_REMOVE(dev, si_siblings);
813 dev->si_flags &= ~SI_CHILD;
814 }
815
816 /* Kill our children */
817 while (!LIST_EMPTY(&dev->si_children))
818 destroy_devl(LIST_FIRST(&dev->si_children));
819
820 /* Remove from clone list */
821 if (dev->si_flags & SI_CLONELIST) {
822 LIST_REMOVE(dev, si_clone);
823 dev->si_flags &= ~SI_CLONELIST;
824 }
825
826 dev->si_refcount++; /* Avoid race with dev_rel() */
827 csw = dev->si_devsw;
828 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
829 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
830 csw->d_purge(dev);
831 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
832 if (dev->si_threadcount)
833 printf("Still %lu threads in %s\n",
834 dev->si_threadcount, devtoname(dev));
835 }
836 while (dev->si_threadcount != 0) {
837 /* Use unique dummy wait ident */
838 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
839 }
840
841 dev_unlock();
842 notify_destroy(dev);
843 mtx_lock(&cdevpriv_mtx);
844 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) {
845 devfs_destroy_cdevpriv(p);
846 mtx_lock(&cdevpriv_mtx);
847 }
848 mtx_unlock(&cdevpriv_mtx);
849 dev_lock();
850
851 dev->si_drv1 = 0;
852 dev->si_drv2 = 0;
853 bzero(&dev->__si_u, sizeof(dev->__si_u));
854
855 if (!(dev->si_flags & SI_ALIAS)) {
856 /* Remove from cdevsw list */
857 LIST_REMOVE(dev, si_list);
858
859 /* If cdevsw has no more struct cdev *'s, clean it */
860 if (LIST_EMPTY(&csw->d_devs)) {
861 fini_cdevsw(csw);
862 wakeup(&csw->d_devs);
863 }
864 }
865 dev->si_flags &= ~SI_ALIAS;
866 dev->si_refcount--; /* Avoid race with dev_rel() */
867
868 if (dev->si_refcount > 0) {
869 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
870 } else {
871 dev_free_devlocked(dev);
872 }
873}
874
875void
876destroy_dev(struct cdev *dev)
877{
878
879 dev_lock();
880 destroy_devl(dev);
881 dev_unlock_and_free();
882}
883
884const char *
885devtoname(struct cdev *dev)
886{
887 char *p;
888 struct cdevsw *csw;
889 int mynor;
890
891 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') {
892 p = dev->si_name;
893 csw = dev_refthread(dev);
894 if (csw != NULL) {
895 sprintf(p, "(%s)", csw->d_name);
896 dev_relthread(dev);
897 }
898 p += strlen(p);
899 mynor = minor(dev);
900 if (mynor < 0 || mynor > 255)
901 sprintf(p, "/%#x", (u_int)mynor);
902 else
903 sprintf(p, "/%d", mynor);
904 }
905 return (dev->si_name);
906}
907
908int
909dev_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] == '0' && isdigit(name[i+1]))
920 return (0);
921 while (isdigit(name[i])) {
922 u *= 10;
923 u += name[i++] - '0';
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
952struct clonedevs {
953 LIST_HEAD(,cdev) head;
954};
955
956void
957clone_setup(struct clonedevs **cdp)
958{
959
960 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
961 LIST_INIT(&(*cdp)->head);
962}
963
964int
965clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra)
966{
967 struct clonedevs *cd;
968 struct cdev *dev, *ndev, *dl, *de;
969 int unit, low, u;
970
971 KASSERT(*cdp != NULL,
972 ("clone_setup() not called in driver \"%s\"", csw->d_name));
973 KASSERT(!(extra & CLONE_UNITMASK),
974 ("Illegal extra bits (0x%x) in clone_create", extra));
975 KASSERT(*up <= CLONE_UNITMASK,
976 ("Too high unit (0x%x) in clone_create", *up));
977 KASSERT(csw->d_flags & D_NEEDMINOR,
978 ("clone_create() on cdevsw without minor numbers"));
979
980
981 /*
982 * Search the list for a lot of things in one go:
983 * A preexisting match is returned immediately.
984 * The lowest free unit number if we are passed -1, and the place
985 * in the list where we should insert that new element.
986 * The place to insert a specified unit number, if applicable
987 * the end of the list.
988 */
989 unit = *up;
990 ndev = devfs_alloc();
991 dev_lock();
992 prep_cdevsw(csw);
993 low = extra;
994 de = dl = NULL;
995 cd = *cdp;
996 LIST_FOREACH(dev, &cd->head, si_clone) {
997 KASSERT(dev->si_flags & SI_CLONELIST,
998 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
999 u = dev2unit(dev);
1000 if (u == (unit | extra)) {
1001 *dp = dev;
1002 dev_unlock();
1003 devfs_free(ndev);
1004 return (0);
1005 }
1006 if (unit == -1 && u == low) {
1007 low++;
1008 de = dev;
1009 continue;
1010 } else if (u < (unit | extra)) {
1011 de = dev;
1012 continue;
1013 } else if (u > (unit | extra)) {
1014 dl = dev;
1015 break;
1016 }
1017 }
1018 if (unit == -1)
1019 unit = low & CLONE_UNITMASK;
| 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
51static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
52
53struct mtx devmtx;
54static void destroy_devl(struct cdev *dev);
55static int destroy_dev_sched_cbl(struct cdev *dev,
56 void (*cb)(void *), void *arg);
57static struct cdev *make_dev_credv(int flags,
58 struct cdevsw *devsw, int minornr,
59 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
60 va_list ap);
61
62static struct cdev_priv_list cdevp_free_list =
63 TAILQ_HEAD_INITIALIZER(cdevp_free_list);
64static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
65 SLIST_HEAD_INITIALIZER();
66
67void
68dev_lock(void)
69{
70
71 mtx_lock(&devmtx);
72}
73
74/*
75 * Free all the memory collected while the cdev mutex was
76 * locked. Since devmtx is after the system map mutex, free() cannot
77 * be called immediately and is postponed until cdev mutex can be
78 * dropped.
79 */
80static void
81dev_unlock_and_free(void)
82{
83 struct cdev_priv_list cdp_free;
84 struct free_cdevsw csw_free;
85 struct cdev_priv *cdp;
86 struct cdevsw *csw;
87
88 mtx_assert(&devmtx, MA_OWNED);
89
90 /*
91 * Make the local copy of the list heads while the dev_mtx is
92 * held. Free it later.
93 */
94 TAILQ_INIT(&cdp_free);
95 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
96 csw_free = cdevsw_gt_post_list;
97 SLIST_INIT(&cdevsw_gt_post_list);
98
99 mtx_unlock(&devmtx);
100
101 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
102 TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
103 devfs_free(&cdp->cdp_c);
104 }
105 while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
106 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
107 free(csw, M_DEVT);
108 }
109}
110
111static void
112dev_free_devlocked(struct cdev *cdev)
113{
114 struct cdev_priv *cdp;
115
116 mtx_assert(&devmtx, MA_OWNED);
117 cdp = cdev2priv(cdev);
118 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
119}
120
121static void
122cdevsw_free_devlocked(struct cdevsw *csw)
123{
124
125 mtx_assert(&devmtx, MA_OWNED);
126 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
127}
128
129void
130dev_unlock(void)
131{
132
133 mtx_unlock(&devmtx);
134}
135
136void
137dev_ref(struct cdev *dev)
138{
139
140 mtx_assert(&devmtx, MA_NOTOWNED);
141 mtx_lock(&devmtx);
142 dev->si_refcount++;
143 mtx_unlock(&devmtx);
144}
145
146void
147dev_refl(struct cdev *dev)
148{
149
150 mtx_assert(&devmtx, MA_OWNED);
151 dev->si_refcount++;
152}
153
154void
155dev_rel(struct cdev *dev)
156{
157 int flag = 0;
158
159 mtx_assert(&devmtx, MA_NOTOWNED);
160 dev_lock();
161 dev->si_refcount--;
162 KASSERT(dev->si_refcount >= 0,
163 ("dev_rel(%s) gave negative count", devtoname(dev)));
164#if 0
165 if (dev->si_usecount == 0 &&
166 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
167 ;
168 else
169#endif
170 if (dev->si_devsw == NULL && dev->si_refcount == 0) {
171 LIST_REMOVE(dev, si_list);
172 flag = 1;
173 }
174 dev_unlock();
175 if (flag)
176 devfs_free(dev);
177}
178
179struct cdevsw *
180dev_refthread(struct cdev *dev)
181{
182 struct cdevsw *csw;
183 struct cdev_priv *cdp;
184
185 mtx_assert(&devmtx, MA_NOTOWNED);
186 dev_lock();
187 csw = dev->si_devsw;
188 if (csw != NULL) {
189 cdp = cdev2priv(dev);
190 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
191 dev->si_threadcount++;
192 else
193 csw = NULL;
194 }
195 dev_unlock();
196 return (csw);
197}
198
199struct cdevsw *
200devvn_refthread(struct vnode *vp, struct cdev **devp)
201{
202 struct cdevsw *csw;
203 struct cdev_priv *cdp;
204
205 mtx_assert(&devmtx, MA_NOTOWNED);
206 csw = NULL;
207 dev_lock();
208 *devp = vp->v_rdev;
209 if (*devp != NULL) {
210 cdp = cdev2priv(*devp);
211 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
212 csw = (*devp)->si_devsw;
213 if (csw != NULL)
214 (*devp)->si_threadcount++;
215 }
216 }
217 dev_unlock();
218 return (csw);
219}
220
221void
222dev_relthread(struct cdev *dev)
223{
224
225 mtx_assert(&devmtx, MA_NOTOWNED);
226 dev_lock();
227 KASSERT(dev->si_threadcount > 0,
228 ("%s threadcount is wrong", dev->si_name));
229 dev->si_threadcount--;
230 dev_unlock();
231}
232
233int
234nullop(void)
235{
236
237 return (0);
238}
239
240int
241eopnotsupp(void)
242{
243
244 return (EOPNOTSUPP);
245}
246
247static int
248enxio(void)
249{
250 return (ENXIO);
251}
252
253static int
254enodev(void)
255{
256 return (ENODEV);
257}
258
259/* Define a dead_cdevsw for use when devices leave unexpectedly. */
260
261#define dead_open (d_open_t *)enxio
262#define dead_close (d_close_t *)enxio
263#define dead_read (d_read_t *)enxio
264#define dead_write (d_write_t *)enxio
265#define dead_ioctl (d_ioctl_t *)enxio
266#define dead_poll (d_poll_t *)enodev
267#define dead_mmap (d_mmap_t *)enodev
268
269static void
270dead_strategy(struct bio *bp)
271{
272
273 biofinish(bp, NULL, ENXIO);
274}
275
276#define dead_dump (dumper_t *)enxio
277#define dead_kqfilter (d_kqfilter_t *)enxio
278
279static struct cdevsw dead_cdevsw = {
280 .d_version = D_VERSION,
281 .d_flags = D_NEEDGIANT, /* XXX: does dead_strategy need this ? */
282 .d_open = dead_open,
283 .d_close = dead_close,
284 .d_read = dead_read,
285 .d_write = dead_write,
286 .d_ioctl = dead_ioctl,
287 .d_poll = dead_poll,
288 .d_mmap = dead_mmap,
289 .d_strategy = dead_strategy,
290 .d_name = "dead",
291 .d_dump = dead_dump,
292 .d_kqfilter = dead_kqfilter
293};
294
295/* Default methods if driver does not specify method */
296
297#define null_open (d_open_t *)nullop
298#define null_close (d_close_t *)nullop
299#define no_read (d_read_t *)enodev
300#define no_write (d_write_t *)enodev
301#define no_ioctl (d_ioctl_t *)enodev
302#define no_mmap (d_mmap_t *)enodev
303#define no_kqfilter (d_kqfilter_t *)enodev
304
305static void
306no_strategy(struct bio *bp)
307{
308
309 biofinish(bp, NULL, ENODEV);
310}
311
312static int
313no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
314{
315 /*
316 * Return true for read/write. If the user asked for something
317 * special, return POLLNVAL, so that clients have a way of
318 * determining reliably whether or not the extended
319 * functionality is present without hard-coding knowledge
320 * of specific filesystem implementations.
321 * Stay in sync with vop_nopoll().
322 */
323 if (events & ~POLLSTANDARD)
324 return (POLLNVAL);
325
326 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
327}
328
329#define no_dump (dumper_t *)enodev
330
331static int
332giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
333{
334 struct cdevsw *dsw;
335 int retval;
336
337 dsw = dev_refthread(dev);
338 if (dsw == NULL)
339 return (ENXIO);
340 mtx_lock(&Giant);
341 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
342 mtx_unlock(&Giant);
343 dev_relthread(dev);
344 return (retval);
345}
346
347static int
348giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
349{
350 struct cdevsw *dsw;
351 int retval;
352
353 dsw = dev_refthread(dev);
354 if (dsw == NULL)
355 return (ENXIO);
356 mtx_lock(&Giant);
357 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
358 mtx_unlock(&Giant);
359 dev_relthread(dev);
360 return (retval);
361}
362
363static int
364giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
365{
366 struct cdevsw *dsw;
367 int retval;
368
369 dsw = dev_refthread(dev);
370 if (dsw == NULL)
371 return (ENXIO);
372 mtx_lock(&Giant);
373 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
374 mtx_unlock(&Giant);
375 dev_relthread(dev);
376 return (retval);
377}
378
379static void
380giant_strategy(struct bio *bp)
381{
382 struct cdevsw *dsw;
383 struct cdev *dev;
384
385 dev = bp->bio_dev;
386 dsw = dev_refthread(dev);
387 if (dsw == NULL) {
388 biofinish(bp, NULL, ENXIO);
389 return;
390 }
391 mtx_lock(&Giant);
392 dsw->d_gianttrick->d_strategy(bp);
393 mtx_unlock(&Giant);
394 dev_relthread(dev);
395}
396
397static int
398giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
399{
400 struct cdevsw *dsw;
401 int retval;
402
403 dsw = dev_refthread(dev);
404 if (dsw == NULL)
405 return (ENXIO);
406 mtx_lock(&Giant);
407 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
408 mtx_unlock(&Giant);
409 dev_relthread(dev);
410 return (retval);
411}
412
413static int
414giant_read(struct cdev *dev, struct uio *uio, int ioflag)
415{
416 struct cdevsw *dsw;
417 int retval;
418
419 dsw = dev_refthread(dev);
420 if (dsw == NULL)
421 return (ENXIO);
422 mtx_lock(&Giant);
423 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
424 mtx_unlock(&Giant);
425 dev_relthread(dev);
426 return (retval);
427}
428
429static int
430giant_write(struct cdev *dev, struct uio *uio, int ioflag)
431{
432 struct cdevsw *dsw;
433 int retval;
434
435 dsw = dev_refthread(dev);
436 if (dsw == NULL)
437 return (ENXIO);
438 mtx_lock(&Giant);
439 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
440 mtx_unlock(&Giant);
441 dev_relthread(dev);
442 return (retval);
443}
444
445static int
446giant_poll(struct cdev *dev, int events, struct thread *td)
447{
448 struct cdevsw *dsw;
449 int retval;
450
451 dsw = dev_refthread(dev);
452 if (dsw == NULL)
453 return (ENXIO);
454 mtx_lock(&Giant);
455 retval = dsw->d_gianttrick->d_poll(dev, events, td);
456 mtx_unlock(&Giant);
457 dev_relthread(dev);
458 return (retval);
459}
460
461static int
462giant_kqfilter(struct cdev *dev, struct knote *kn)
463{
464 struct cdevsw *dsw;
465 int retval;
466
467 dsw = dev_refthread(dev);
468 if (dsw == NULL)
469 return (ENXIO);
470 mtx_lock(&Giant);
471 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
472 mtx_unlock(&Giant);
473 dev_relthread(dev);
474 return (retval);
475}
476
477static int
478giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
479{
480 struct cdevsw *dsw;
481 int retval;
482
483 dsw = dev_refthread(dev);
484 if (dsw == NULL)
485 return (ENXIO);
486 mtx_lock(&Giant);
487 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot);
488 mtx_unlock(&Giant);
489 dev_relthread(dev);
490 return (retval);
491}
492
493
494static void
495notify(struct cdev *dev, const char *ev)
496{
497 static const char prefix[] = "cdev=";
498 char *data;
499 int namelen;
500
501 if (cold)
502 return;
503 namelen = strlen(dev->si_name);
504 data = malloc(namelen + sizeof(prefix), M_TEMP, M_WAITOK);
505 memcpy(data, prefix, sizeof(prefix) - 1);
506 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
507 devctl_notify("DEVFS", "CDEV", ev, data);
508 free(data, M_TEMP);
509}
510
511static void
512notify_create(struct cdev *dev)
513{
514
515 notify(dev, "CREATE");
516}
517
518static void
519notify_destroy(struct cdev *dev)
520{
521
522 notify(dev, "DESTROY");
523}
524
525static struct cdev *
526newdev(struct cdevsw *csw, int y, struct cdev *si)
527{
528 struct cdev *si2;
529 dev_t udev;
530
531 mtx_assert(&devmtx, MA_OWNED);
532 udev = y;
533 if (csw->d_flags & D_NEEDMINOR) {
534 /* We may want to return an existing device */
535 LIST_FOREACH(si2, &csw->d_devs, si_list) {
536 if (si2->si_drv0 == udev) {
537 dev_free_devlocked(si);
538 return (si2);
539 }
540 }
541 }
542 si->si_drv0 = udev;
543 si->si_devsw = csw;
544 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
545 return (si);
546}
547
548#define UMINORMASK 0xffff00ffU
549
550int
551uminor(dev_t dev)
552{
553 return (dev & UMINORMASK);
554}
555
556int
557umajor(dev_t dev)
558{
559 return ((dev & ~UMINORMASK) >> 8);
560}
561
562static void
563fini_cdevsw(struct cdevsw *devsw)
564{
565 struct cdevsw *gt;
566
567 if (devsw->d_gianttrick != NULL) {
568 gt = devsw->d_gianttrick;
569 memcpy(devsw, gt, sizeof *devsw);
570 cdevsw_free_devlocked(gt);
571 devsw->d_gianttrick = NULL;
572 }
573 devsw->d_flags &= ~D_INIT;
574}
575
576static void
577prep_cdevsw(struct cdevsw *devsw)
578{
579 struct cdevsw *dsw2;
580
581 mtx_assert(&devmtx, MA_OWNED);
582 if (devsw->d_flags & D_INIT)
583 return;
584 if (devsw->d_flags & D_NEEDGIANT) {
585 dev_unlock();
586 dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK);
587 dev_lock();
588 } else
589 dsw2 = NULL;
590 if (devsw->d_flags & D_INIT) {
591 if (dsw2 != NULL)
592 cdevsw_free_devlocked(dsw2);
593 return;
594 }
595
596 if (devsw->d_version != D_VERSION_01) {
597 printf(
598 "WARNING: Device driver \"%s\" has wrong version %s\n",
599 devsw->d_name == NULL ? "???" : devsw->d_name,
600 "and is disabled. Recompile KLD module.");
601 devsw->d_open = dead_open;
602 devsw->d_close = dead_close;
603 devsw->d_read = dead_read;
604 devsw->d_write = dead_write;
605 devsw->d_ioctl = dead_ioctl;
606 devsw->d_poll = dead_poll;
607 devsw->d_mmap = dead_mmap;
608 devsw->d_strategy = dead_strategy;
609 devsw->d_dump = dead_dump;
610 devsw->d_kqfilter = dead_kqfilter;
611 }
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
641 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
642
643 LIST_INIT(&devsw->d_devs);
644
645 devsw->d_flags |= D_INIT;
646
647 if (dsw2 != NULL)
648 cdevsw_free_devlocked(dsw2);
649}
650
651struct cdev *
652make_dev_credv(int flags, struct cdevsw *devsw, int minornr,
653 struct ucred *cr, uid_t uid,
654 gid_t gid, int mode, const char *fmt, va_list ap)
655{
656 struct cdev *dev;
657 int i;
658
659 dev = devfs_alloc();
660 dev_lock();
661 prep_cdevsw(devsw);
662 dev = newdev(devsw, minornr, dev);
663 if (flags & MAKEDEV_REF)
664 dev_refl(dev);
665 if (dev->si_flags & SI_CHEAPCLONE &&
666 dev->si_flags & SI_NAMED) {
667 /*
668 * This is allowed as it removes races and generally
669 * simplifies cloning devices.
670 * XXX: still ??
671 */
672 dev_unlock_and_free();
673 return (dev);
674 }
675 KASSERT(!(dev->si_flags & SI_NAMED),
676 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
677 devsw->d_name, minor(dev), devtoname(dev)));
678
679 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
680 if (i > (sizeof dev->__si_namebuf - 1)) {
681 printf("WARNING: Device name truncated! (%s)\n",
682 dev->__si_namebuf);
683 }
684
685 dev->si_flags |= SI_NAMED;
686 if (cr != NULL)
687 dev->si_cred = crhold(cr);
688 else
689 dev->si_cred = NULL;
690 dev->si_uid = uid;
691 dev->si_gid = gid;
692 dev->si_mode = mode;
693
694 devfs_create(dev);
695 clean_unrhdrl(devfs_inos);
696 dev_unlock_and_free();
697
698 notify_create(dev);
699
700 return (dev);
701}
702
703struct cdev *
704make_dev(struct cdevsw *devsw, int minornr, uid_t uid, gid_t gid, int mode,
705 const char *fmt, ...)
706{
707 struct cdev *dev;
708 va_list ap;
709
710 va_start(ap, fmt);
711 dev = make_dev_credv(0, devsw, minornr, NULL, uid, gid, mode, fmt, ap);
712 va_end(ap);
713 return (dev);
714}
715
716struct cdev *
717make_dev_cred(struct cdevsw *devsw, int minornr, struct ucred *cr, uid_t uid,
718 gid_t gid, int mode, const char *fmt, ...)
719{
720 struct cdev *dev;
721 va_list ap;
722
723 va_start(ap, fmt);
724 dev = make_dev_credv(0, devsw, minornr, cr, uid, gid, mode, fmt, ap);
725 va_end(ap);
726
727 return (dev);
728}
729
730struct cdev *
731make_dev_credf(int flags, struct cdevsw *devsw, int minornr,
732 struct ucred *cr, uid_t uid,
733 gid_t gid, int mode, const char *fmt, ...)
734{
735 struct cdev *dev;
736 va_list ap;
737
738 va_start(ap, fmt);
739 dev = make_dev_credv(flags, devsw, minornr, cr, uid, gid, mode,
740 fmt, ap);
741 va_end(ap);
742
743 return (dev);
744}
745
746static void
747dev_dependsl(struct cdev *pdev, struct cdev *cdev)
748{
749
750 cdev->si_parent = pdev;
751 cdev->si_flags |= SI_CHILD;
752 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
753}
754
755
756void
757dev_depends(struct cdev *pdev, struct cdev *cdev)
758{
759
760 dev_lock();
761 dev_dependsl(pdev, cdev);
762 dev_unlock();
763}
764
765struct cdev *
766make_dev_alias(struct cdev *pdev, const char *fmt, ...)
767{
768 struct cdev *dev;
769 va_list ap;
770 int i;
771
772 KASSERT(pdev != NULL, ("NULL pdev"));
773 dev = devfs_alloc();
774 dev_lock();
775 dev->si_flags |= SI_ALIAS;
776 dev->si_flags |= SI_NAMED;
777 va_start(ap, fmt);
778 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
779 if (i > (sizeof dev->__si_namebuf - 1)) {
780 printf("WARNING: Device name truncated! (%s)\n",
781 dev->__si_namebuf);
782 }
783 va_end(ap);
784
785 devfs_create(dev);
786 dev_dependsl(pdev, dev);
787 clean_unrhdrl(devfs_inos);
788 dev_unlock();
789
790 notify_create(dev);
791
792 return (dev);
793}
794
795static void
796destroy_devl(struct cdev *dev)
797{
798 struct cdevsw *csw;
799 struct cdev_privdata *p, *p1;
800
801 mtx_assert(&devmtx, MA_OWNED);
802 KASSERT(dev->si_flags & SI_NAMED,
803 ("WARNING: Driver mistake: destroy_dev on %d\n", minor(dev)));
804
805 devfs_destroy(dev);
806
807 /* Remove name marking */
808 dev->si_flags &= ~SI_NAMED;
809
810 /* If we are a child, remove us from the parents list */
811 if (dev->si_flags & SI_CHILD) {
812 LIST_REMOVE(dev, si_siblings);
813 dev->si_flags &= ~SI_CHILD;
814 }
815
816 /* Kill our children */
817 while (!LIST_EMPTY(&dev->si_children))
818 destroy_devl(LIST_FIRST(&dev->si_children));
819
820 /* Remove from clone list */
821 if (dev->si_flags & SI_CLONELIST) {
822 LIST_REMOVE(dev, si_clone);
823 dev->si_flags &= ~SI_CLONELIST;
824 }
825
826 dev->si_refcount++; /* Avoid race with dev_rel() */
827 csw = dev->si_devsw;
828 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
829 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
830 csw->d_purge(dev);
831 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
832 if (dev->si_threadcount)
833 printf("Still %lu threads in %s\n",
834 dev->si_threadcount, devtoname(dev));
835 }
836 while (dev->si_threadcount != 0) {
837 /* Use unique dummy wait ident */
838 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
839 }
840
841 dev_unlock();
842 notify_destroy(dev);
843 mtx_lock(&cdevpriv_mtx);
844 LIST_FOREACH_SAFE(p, &cdev2priv(dev)->cdp_fdpriv, cdpd_list, p1) {
845 devfs_destroy_cdevpriv(p);
846 mtx_lock(&cdevpriv_mtx);
847 }
848 mtx_unlock(&cdevpriv_mtx);
849 dev_lock();
850
851 dev->si_drv1 = 0;
852 dev->si_drv2 = 0;
853 bzero(&dev->__si_u, sizeof(dev->__si_u));
854
855 if (!(dev->si_flags & SI_ALIAS)) {
856 /* Remove from cdevsw list */
857 LIST_REMOVE(dev, si_list);
858
859 /* If cdevsw has no more struct cdev *'s, clean it */
860 if (LIST_EMPTY(&csw->d_devs)) {
861 fini_cdevsw(csw);
862 wakeup(&csw->d_devs);
863 }
864 }
865 dev->si_flags &= ~SI_ALIAS;
866 dev->si_refcount--; /* Avoid race with dev_rel() */
867
868 if (dev->si_refcount > 0) {
869 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
870 } else {
871 dev_free_devlocked(dev);
872 }
873}
874
875void
876destroy_dev(struct cdev *dev)
877{
878
879 dev_lock();
880 destroy_devl(dev);
881 dev_unlock_and_free();
882}
883
884const char *
885devtoname(struct cdev *dev)
886{
887 char *p;
888 struct cdevsw *csw;
889 int mynor;
890
891 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') {
892 p = dev->si_name;
893 csw = dev_refthread(dev);
894 if (csw != NULL) {
895 sprintf(p, "(%s)", csw->d_name);
896 dev_relthread(dev);
897 }
898 p += strlen(p);
899 mynor = minor(dev);
900 if (mynor < 0 || mynor > 255)
901 sprintf(p, "/%#x", (u_int)mynor);
902 else
903 sprintf(p, "/%d", mynor);
904 }
905 return (dev->si_name);
906}
907
908int
909dev_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] == '0' && isdigit(name[i+1]))
920 return (0);
921 while (isdigit(name[i])) {
922 u *= 10;
923 u += name[i++] - '0';
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
952struct clonedevs {
953 LIST_HEAD(,cdev) head;
954};
955
956void
957clone_setup(struct clonedevs **cdp)
958{
959
960 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
961 LIST_INIT(&(*cdp)->head);
962}
963
964int
965clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, struct cdev **dp, int extra)
966{
967 struct clonedevs *cd;
968 struct cdev *dev, *ndev, *dl, *de;
969 int unit, low, u;
970
971 KASSERT(*cdp != NULL,
972 ("clone_setup() not called in driver \"%s\"", csw->d_name));
973 KASSERT(!(extra & CLONE_UNITMASK),
974 ("Illegal extra bits (0x%x) in clone_create", extra));
975 KASSERT(*up <= CLONE_UNITMASK,
976 ("Too high unit (0x%x) in clone_create", *up));
977 KASSERT(csw->d_flags & D_NEEDMINOR,
978 ("clone_create() on cdevsw without minor numbers"));
979
980
981 /*
982 * Search the list for a lot of things in one go:
983 * A preexisting match is returned immediately.
984 * The lowest free unit number if we are passed -1, and the place
985 * in the list where we should insert that new element.
986 * The place to insert a specified unit number, if applicable
987 * the end of the list.
988 */
989 unit = *up;
990 ndev = devfs_alloc();
991 dev_lock();
992 prep_cdevsw(csw);
993 low = extra;
994 de = dl = NULL;
995 cd = *cdp;
996 LIST_FOREACH(dev, &cd->head, si_clone) {
997 KASSERT(dev->si_flags & SI_CLONELIST,
998 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
999 u = dev2unit(dev);
1000 if (u == (unit | extra)) {
1001 *dp = dev;
1002 dev_unlock();
1003 devfs_free(ndev);
1004 return (0);
1005 }
1006 if (unit == -1 && u == low) {
1007 low++;
1008 de = dev;
1009 continue;
1010 } else if (u < (unit | extra)) {
1011 de = dev;
1012 continue;
1013 } else if (u > (unit | extra)) {
1014 dl = dev;
1015 break;
1016 }
1017 }
1018 if (unit == -1)
1019 unit = low & CLONE_UNITMASK;
|