2 * Copyright (c) 1999-2002 Poul-Henning Kamp
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
36 #include <sys/mutex.h>
37 #include <sys/module.h>
38 #include <sys/malloc.h>
40 #include <sys/vnode.h>
41 #include <sys/queue.h>
44 #include <sys/ctype.h>
45 #include <sys/ucred.h>
46 #include <sys/taskqueue.h>
47 #include <machine/stdarg.h>
49 #include <fs/devfs/devfs_int.h>
52 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
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 int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
59 int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
62 static struct cdev_priv_list cdevp_free_list =
63 TAILQ_HEAD_INITIALIZER(cdevp_free_list);
64 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
65 SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
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
81 dev_unlock_and_free(void)
83 struct cdev_priv_list cdp_free;
84 struct free_cdevsw csw_free;
85 struct cdev_priv *cdp;
88 mtx_assert(&devmtx, MA_OWNED);
91 * Make the local copy of the list heads while the dev_mtx is
92 * held. Free it later.
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);
101 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
102 TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
103 devfs_free(&cdp->cdp_c);
105 while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
106 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
112 dev_free_devlocked(struct cdev *cdev)
114 struct cdev_priv *cdp;
116 mtx_assert(&devmtx, MA_OWNED);
117 cdp = cdev2priv(cdev);
118 KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
119 ("destroy_dev() was not called after delist_dev(%p)", cdev));
120 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
124 cdevsw_free_devlocked(struct cdevsw *csw)
127 mtx_assert(&devmtx, MA_OWNED);
128 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
139 dev_ref(struct cdev *dev)
142 mtx_assert(&devmtx, MA_NOTOWNED);
149 dev_refl(struct cdev *dev)
152 mtx_assert(&devmtx, MA_OWNED);
157 dev_rel(struct cdev *dev)
161 mtx_assert(&devmtx, MA_NOTOWNED);
164 KASSERT(dev->si_refcount >= 0,
165 ("dev_rel(%s) gave negative count", devtoname(dev)));
167 if (dev->si_usecount == 0 &&
168 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
172 if (dev->si_devsw == NULL && dev->si_refcount == 0) {
173 LIST_REMOVE(dev, si_list);
182 dev_refthread(struct cdev *dev, int *ref)
185 struct cdev_priv *cdp;
187 mtx_assert(&devmtx, MA_NOTOWNED);
188 if ((dev->si_flags & SI_ETERNAL) != 0) {
190 return (dev->si_devsw);
195 cdp = cdev2priv(dev);
196 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
197 dev->si_threadcount++;
207 devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
210 struct cdev_priv *cdp;
213 mtx_assert(&devmtx, MA_NOTOWNED);
214 if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
218 KASSERT((dev->si_flags & SI_ETERNAL) != 0,
219 ("Not eternal cdev"));
222 KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
234 cdp = cdev2priv(dev);
235 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
238 dev->si_threadcount++;
249 dev_relthread(struct cdev *dev, int ref)
252 mtx_assert(&devmtx, MA_NOTOWNED);
256 KASSERT(dev->si_threadcount > 0,
257 ("%s threadcount is wrong", dev->si_name));
258 dev->si_threadcount--;
288 /* Define a dead_cdevsw for use when devices leave unexpectedly. */
290 #define dead_open (d_open_t *)enxio
291 #define dead_close (d_close_t *)enxio
292 #define dead_read (d_read_t *)enxio
293 #define dead_write (d_write_t *)enxio
294 #define dead_ioctl (d_ioctl_t *)enxio
295 #define dead_poll (d_poll_t *)enodev
296 #define dead_mmap (d_mmap_t *)enodev
299 dead_strategy(struct bio *bp)
302 biofinish(bp, NULL, ENXIO);
305 #define dead_dump (dumper_t *)enxio
306 #define dead_kqfilter (d_kqfilter_t *)enxio
307 #define dead_mmap_single (d_mmap_single_t *)enodev
309 static struct cdevsw dead_cdevsw = {
310 .d_version = D_VERSION,
312 .d_close = dead_close,
314 .d_write = dead_write,
315 .d_ioctl = dead_ioctl,
318 .d_strategy = dead_strategy,
321 .d_kqfilter = dead_kqfilter,
322 .d_mmap_single = dead_mmap_single
325 /* Default methods if driver does not specify method */
327 #define null_open (d_open_t *)nullop
328 #define null_close (d_close_t *)nullop
329 #define no_read (d_read_t *)enodev
330 #define no_write (d_write_t *)enodev
331 #define no_ioctl (d_ioctl_t *)enodev
332 #define no_mmap (d_mmap_t *)enodev
333 #define no_kqfilter (d_kqfilter_t *)enodev
334 #define no_mmap_single (d_mmap_single_t *)enodev
337 no_strategy(struct bio *bp)
340 biofinish(bp, NULL, ENODEV);
344 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
347 return (poll_no_poll(events));
350 #define no_dump (dumper_t *)enodev
353 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
358 dsw = dev_refthread(dev, &ref);
362 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
364 dev_relthread(dev, ref);
369 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
374 dsw = dev_refthread(dev, &ref);
378 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
380 dev_relthread(dev, ref);
385 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
390 dsw = dev_refthread(dev, &ref);
394 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
396 dev_relthread(dev, ref);
401 giant_strategy(struct bio *bp)
408 dsw = dev_refthread(dev, &ref);
410 biofinish(bp, NULL, ENXIO);
414 dsw->d_gianttrick->d_strategy(bp);
416 dev_relthread(dev, ref);
420 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
425 dsw = dev_refthread(dev, &ref);
429 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
431 dev_relthread(dev, ref);
436 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
441 dsw = dev_refthread(dev, &ref);
445 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
447 dev_relthread(dev, ref);
452 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
457 dsw = dev_refthread(dev, &ref);
461 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
463 dev_relthread(dev, ref);
468 giant_poll(struct cdev *dev, int events, struct thread *td)
473 dsw = dev_refthread(dev, &ref);
477 retval = dsw->d_gianttrick->d_poll(dev, events, td);
479 dev_relthread(dev, ref);
484 giant_kqfilter(struct cdev *dev, struct knote *kn)
489 dsw = dev_refthread(dev, &ref);
493 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
495 dev_relthread(dev, ref);
500 giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
501 vm_memattr_t *memattr)
506 dsw = dev_refthread(dev, &ref);
510 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
513 dev_relthread(dev, ref);
518 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
519 vm_object_t *object, int nprot)
524 dsw = dev_refthread(dev, &ref);
528 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
531 dev_relthread(dev, ref);
536 notify(struct cdev *dev, const char *ev, int flags)
538 static const char prefix[] = "cdev=";
544 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
545 namelen = strlen(dev->si_name);
546 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
549 memcpy(data, prefix, sizeof(prefix) - 1);
550 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
551 devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
556 notify_create(struct cdev *dev, int flags)
559 notify(dev, "CREATE", flags);
563 notify_destroy(struct cdev *dev)
566 notify(dev, "DESTROY", MAKEDEV_WAITOK);
570 newdev(struct cdevsw *csw, int unit, struct cdev *si)
574 mtx_assert(&devmtx, MA_OWNED);
575 if (csw->d_flags & D_NEEDMINOR) {
576 /* We may want to return an existing device */
577 LIST_FOREACH(si2, &csw->d_devs, si_list) {
578 if (dev2unit(si2) == unit) {
579 dev_free_devlocked(si);
586 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
591 fini_cdevsw(struct cdevsw *devsw)
595 if (devsw->d_gianttrick != NULL) {
596 gt = devsw->d_gianttrick;
597 memcpy(devsw, gt, sizeof *devsw);
598 cdevsw_free_devlocked(gt);
599 devsw->d_gianttrick = NULL;
601 devsw->d_flags &= ~D_INIT;
605 prep_cdevsw(struct cdevsw *devsw, int flags)
609 mtx_assert(&devmtx, MA_OWNED);
610 if (devsw->d_flags & D_INIT)
612 if (devsw->d_flags & D_NEEDGIANT) {
614 dsw2 = malloc(sizeof *dsw2, M_DEVT,
615 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
617 if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
621 if (devsw->d_flags & D_INIT) {
623 cdevsw_free_devlocked(dsw2);
627 if (devsw->d_version != D_VERSION_03) {
629 "WARNING: Device driver \"%s\" has wrong version %s\n",
630 devsw->d_name == NULL ? "???" : devsw->d_name,
631 "and is disabled. Recompile KLD module.");
632 devsw->d_open = dead_open;
633 devsw->d_close = dead_close;
634 devsw->d_read = dead_read;
635 devsw->d_write = dead_write;
636 devsw->d_ioctl = dead_ioctl;
637 devsw->d_poll = dead_poll;
638 devsw->d_mmap = dead_mmap;
639 devsw->d_mmap_single = dead_mmap_single;
640 devsw->d_strategy = dead_strategy;
641 devsw->d_dump = dead_dump;
642 devsw->d_kqfilter = dead_kqfilter;
645 if (devsw->d_flags & D_NEEDGIANT) {
646 if (devsw->d_gianttrick == NULL) {
647 memcpy(dsw2, devsw, sizeof *dsw2);
648 devsw->d_gianttrick = dsw2;
653 #define FIXUP(member, noop, giant) \
655 if (devsw->member == NULL) { \
656 devsw->member = noop; \
657 } else if (devsw->d_flags & D_NEEDGIANT) \
658 devsw->member = giant; \
662 FIXUP(d_open, null_open, giant_open);
663 FIXUP(d_fdopen, NULL, giant_fdopen);
664 FIXUP(d_close, null_close, giant_close);
665 FIXUP(d_read, no_read, giant_read);
666 FIXUP(d_write, no_write, giant_write);
667 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
668 FIXUP(d_poll, no_poll, giant_poll);
669 FIXUP(d_mmap, no_mmap, giant_mmap);
670 FIXUP(d_strategy, no_strategy, giant_strategy);
671 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
672 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
674 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
676 LIST_INIT(&devsw->d_devs);
678 devsw->d_flags |= D_INIT;
681 cdevsw_free_devlocked(dsw2);
686 prep_devname(struct cdev *dev, const char *fmt, va_list ap)
689 char *from, *q, *s, *to;
691 mtx_assert(&devmtx, MA_OWNED);
693 len = vsnrprintf(dev->__si_namebuf, sizeof(dev->__si_namebuf), 32,
695 if (len > sizeof(dev->__si_namebuf) - 1)
696 return (ENAMETOOLONG);
698 /* Strip leading slashes. */
699 for (from = dev->__si_namebuf; *from == '/'; from++)
702 for (to = dev->__si_namebuf; *from != '\0'; from++, to++) {
703 /* Treat multiple sequential slashes as single. */
704 while (from[0] == '/' && from[1] == '/')
706 /* Trailing slash is considered invalid. */
707 if (from[0] == '/' && from[1] == '\0')
713 if (dev->__si_namebuf[0] == '\0')
716 /* Disallow "." and ".." components. */
717 for (s = dev->__si_namebuf;;) {
718 for (q = s; *q != '/' && *q != '\0'; q++)
720 if (q - s == 1 && s[0] == '.')
722 if (q - s == 2 && s[0] == '.' && s[1] == '.')
729 if (devfs_dev_exists(dev->__si_namebuf) != 0)
736 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
737 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
740 struct cdev *dev, *dev_new;
743 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
744 ("make_dev_credv: both WAITOK and NOWAIT specified"));
745 dev_new = devfs_alloc(flags);
749 res = prep_cdevsw(devsw, flags);
755 dev = newdev(devsw, unit, dev_new);
756 if ((dev->si_flags & SI_NAMED) == 0) {
757 res = prep_devname(dev, fmt, ap);
759 if ((flags & MAKEDEV_CHECKNAME) == 0) {
761 "make_dev_credv: bad si_name (error=%d, si_name=%s)",
764 if (dev == dev_new) {
765 LIST_REMOVE(dev, si_list);
773 if (flags & MAKEDEV_REF)
775 if (flags & MAKEDEV_ETERNAL)
776 dev->si_flags |= SI_ETERNAL;
777 if (dev->si_flags & SI_CHEAPCLONE &&
778 dev->si_flags & SI_NAMED) {
780 * This is allowed as it removes races and generally
781 * simplifies cloning devices.
784 dev_unlock_and_free();
788 KASSERT(!(dev->si_flags & SI_NAMED),
789 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
790 devsw->d_name, dev2unit(dev), devtoname(dev)));
791 dev->si_flags |= SI_NAMED;
793 dev->si_cred = crhold(cr);
799 clean_unrhdrl(devfs_inos);
800 dev_unlock_and_free();
802 notify_create(dev, flags);
809 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
810 const char *fmt, ...)
817 res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
820 KASSERT(res == 0 && dev != NULL,
821 ("make_dev: failed make_dev_credv (error=%d)", res));
826 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
827 gid_t gid, int mode, const char *fmt, ...)
834 res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
837 KASSERT(res == 0 && dev != NULL,
838 ("make_dev_cred: failed make_dev_credv (error=%d)", res));
843 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
844 uid_t uid, gid_t gid, int mode, const char *fmt, ...)
851 res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
855 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
856 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
857 ("make_dev_credf: failed make_dev_credv (error=%d)", res));
858 return (res == 0 ? dev : NULL);
862 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
863 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
869 res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
873 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
874 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
875 ("make_dev_p: failed make_dev_credv (error=%d)", res));
880 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
883 cdev->si_parent = pdev;
884 cdev->si_flags |= SI_CHILD;
885 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
890 dev_depends(struct cdev *pdev, struct cdev *cdev)
894 dev_dependsl(pdev, cdev);
899 make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
900 const char *fmt, va_list ap)
905 KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
906 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
907 ("make_dev_alias_v: both WAITOK and NOWAIT specified"));
908 KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
909 MAKEDEV_CHECKNAME)) == 0,
910 ("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
912 dev = devfs_alloc(flags);
916 dev->si_flags |= SI_ALIAS;
917 error = prep_devname(dev, fmt, ap);
919 if ((flags & MAKEDEV_CHECKNAME) == 0) {
920 panic("make_dev_alias_v: bad si_name "
921 "(error=%d, si_name=%s)", error, dev->si_name);
927 dev->si_flags |= SI_NAMED;
929 dev_dependsl(pdev, dev);
930 clean_unrhdrl(devfs_inos);
933 notify_create(dev, flags);
940 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
947 res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
950 KASSERT(res == 0 && dev != NULL,
951 ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
956 make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
957 const char *fmt, ...)
963 res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
969 make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
970 struct cdev *old_alias, const char *physpath)
974 int max_parentpath_len;
976 int devfspathbuf_len;
982 physpath_len = strlen(physpath);
984 if (physpath_len == 0)
987 if (strncmp("id1,", physpath, 4) == 0) {
990 if (physpath_len == 0)
994 max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
995 parentpath_len = strlen(pdev->si_name);
996 if (max_parentpath_len < parentpath_len) {
998 printf("WARNING: Unable to alias %s "
999 "to %s/%s - path too long\n",
1000 pdev->si_name, physpath, pdev->si_name);
1005 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
1006 devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
1007 devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
1008 if (devfspath == NULL) {
1013 sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
1014 if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
1015 /* Retain the existing alias. */
1020 ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
1023 if (old_alias != NULL)
1024 destroy_dev(old_alias);
1025 if (devfspath != NULL)
1026 free(devfspath, M_DEVBUF);
1031 destroy_devl(struct cdev *dev)
1034 struct cdev_privdata *p;
1035 struct cdev_priv *cdp;
1037 mtx_assert(&devmtx, MA_OWNED);
1038 KASSERT(dev->si_flags & SI_NAMED,
1039 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
1040 KASSERT((dev->si_flags & SI_ETERNAL) == 0,
1041 ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
1044 cdp = cdev2priv(dev);
1045 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1047 * Avoid race with dev_rel(), e.g. from the populate
1048 * loop. If CDP_UNREF_DTR flag is set, the reference
1049 * to be dropped at the end of destroy_devl() was
1050 * already taken by delist_dev_locked().
1057 /* Remove name marking */
1058 dev->si_flags &= ~SI_NAMED;
1060 /* If we are a child, remove us from the parents list */
1061 if (dev->si_flags & SI_CHILD) {
1062 LIST_REMOVE(dev, si_siblings);
1063 dev->si_flags &= ~SI_CHILD;
1066 /* Kill our children */
1067 while (!LIST_EMPTY(&dev->si_children))
1068 destroy_devl(LIST_FIRST(&dev->si_children));
1070 /* Remove from clone list */
1071 if (dev->si_flags & SI_CLONELIST) {
1072 LIST_REMOVE(dev, si_clone);
1073 dev->si_flags &= ~SI_CLONELIST;
1076 csw = dev->si_devsw;
1077 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
1078 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
1080 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
1081 if (dev->si_threadcount)
1082 printf("Still %lu threads in %s\n",
1083 dev->si_threadcount, devtoname(dev));
1085 while (dev->si_threadcount != 0) {
1086 /* Use unique dummy wait ident */
1087 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
1091 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1092 /* avoid out of order notify events */
1093 notify_destroy(dev);
1095 mtx_lock(&cdevpriv_mtx);
1096 while ((p = LIST_FIRST(&cdp->cdp_fdpriv)) != NULL) {
1097 devfs_destroy_cdevpriv(p);
1098 mtx_lock(&cdevpriv_mtx);
1100 mtx_unlock(&cdevpriv_mtx);
1105 bzero(&dev->__si_u, sizeof(dev->__si_u));
1107 if (!(dev->si_flags & SI_ALIAS)) {
1108 /* Remove from cdevsw list */
1109 LIST_REMOVE(dev, si_list);
1111 /* If cdevsw has no more struct cdev *'s, clean it */
1112 if (LIST_EMPTY(&csw->d_devs)) {
1114 wakeup(&csw->d_devs);
1117 dev->si_flags &= ~SI_ALIAS;
1118 cdp->cdp_flags &= ~CDP_UNREF_DTR;
1121 if (dev->si_refcount > 0)
1122 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
1124 dev_free_devlocked(dev);
1128 delist_dev_locked(struct cdev *dev)
1130 struct cdev_priv *cdp;
1133 mtx_assert(&devmtx, MA_OWNED);
1134 cdp = cdev2priv(dev);
1135 if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
1137 cdp->cdp_flags |= CDP_UNREF_DTR;
1140 LIST_FOREACH(child, &dev->si_children, si_siblings)
1141 delist_dev_locked(child);
1143 /* ensure the destroy event is queued in order */
1144 notify_destroy(dev);
1149 * This function will delist a character device and its children from
1150 * the directory listing and create a destroy event without waiting
1151 * for all character device references to go away. At some later point
1152 * destroy_dev() must be called to complete the character device
1153 * destruction. After calling this function the character device name
1154 * can instantly be re-used.
1157 delist_dev(struct cdev *dev)
1160 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "delist_dev");
1162 delist_dev_locked(dev);
1167 destroy_dev(struct cdev *dev)
1170 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1173 dev_unlock_and_free();
1177 devtoname(struct cdev *dev)
1180 return (dev->si_name);
1184 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1189 if (bcmp(stem, name, i) != 0)
1191 if (!isdigit(name[i]))
1194 if (name[i] == '0' && isdigit(name[i+1]))
1196 while (isdigit(name[i])) {
1198 u += name[i++] - '0';
1211 * Helper functions for cloning device drivers.
1213 * The objective here is to make it unnecessary for the device drivers to
1214 * use rman or similar to manage their unit number space. Due to the way
1215 * we do "on-demand" devices, using rman or other "private" methods
1216 * will be very tricky to lock down properly once we lock down this file.
1218 * Instead we give the drivers these routines which puts the struct cdev *'s
1219 * that are to be managed on their own list, and gives the driver the ability
1220 * to ask for the first free unit number or a given specified unit number.
1222 * In addition these routines support paired devices (pty, nmdm and similar)
1223 * by respecting a number of "flag" bits in the minor number.
1228 LIST_HEAD(,cdev) head;
1232 clone_setup(struct clonedevs **cdp)
1235 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1236 LIST_INIT(&(*cdp)->head);
1240 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1241 struct cdev **dp, int extra)
1243 struct clonedevs *cd;
1244 struct cdev *dev, *ndev, *dl, *de;
1247 KASSERT(*cdp != NULL,
1248 ("clone_setup() not called in driver \"%s\"", csw->d_name));
1249 KASSERT(!(extra & CLONE_UNITMASK),
1250 ("Illegal extra bits (0x%x) in clone_create", extra));
1251 KASSERT(*up <= CLONE_UNITMASK,
1252 ("Too high unit (0x%x) in clone_create", *up));
1253 KASSERT(csw->d_flags & D_NEEDMINOR,
1254 ("clone_create() on cdevsw without minor numbers"));
1258 * Search the list for a lot of things in one go:
1259 * A preexisting match is returned immediately.
1260 * The lowest free unit number if we are passed -1, and the place
1261 * in the list where we should insert that new element.
1262 * The place to insert a specified unit number, if applicable
1263 * the end of the list.
1266 ndev = devfs_alloc(MAKEDEV_WAITOK);
1268 prep_cdevsw(csw, MAKEDEV_WAITOK);
1272 LIST_FOREACH(dev, &cd->head, si_clone) {
1273 KASSERT(dev->si_flags & SI_CLONELIST,
1274 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1276 if (u == (unit | extra)) {
1282 if (unit == -1 && u == low) {
1286 } else if (u < (unit | extra)) {
1289 } else if (u > (unit | extra)) {
1295 unit = low & CLONE_UNITMASK;
1296 dev = newdev(csw, unit | extra, ndev);
1297 if (dev->si_flags & SI_CLONELIST) {
1298 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1299 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1300 LIST_FOREACH(dev, &cd->head, si_clone) {
1301 printf("\t%p %s\n", dev, dev->si_name);
1305 KASSERT(!(dev->si_flags & SI_CLONELIST),
1306 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1308 LIST_INSERT_BEFORE(dl, dev, si_clone);
1309 else if (de != NULL)
1310 LIST_INSERT_AFTER(de, dev, si_clone);
1312 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1313 dev->si_flags |= SI_CLONELIST;
1315 dev_unlock_and_free();
1320 * Kill everything still on the list. The driver should already have
1321 * disposed of any softc hung of the struct cdev *'s at this time.
1324 clone_cleanup(struct clonedevs **cdp)
1327 struct cdev_priv *cp;
1328 struct clonedevs *cd;
1334 while (!LIST_EMPTY(&cd->head)) {
1335 dev = LIST_FIRST(&cd->head);
1336 LIST_REMOVE(dev, si_clone);
1337 KASSERT(dev->si_flags & SI_CLONELIST,
1338 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1339 dev->si_flags &= ~SI_CLONELIST;
1340 cp = cdev2priv(dev);
1341 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1342 cp->cdp_flags |= CDP_SCHED_DTR;
1343 KASSERT(dev->si_flags & SI_NAMED,
1344 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1348 dev_unlock_and_free();
1353 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1354 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1355 static struct task dev_dtr_task;
1358 destroy_dev_tq(void *ctx, int pending)
1360 struct cdev_priv *cp;
1366 while (!TAILQ_EMPTY(&dev_ddtr)) {
1367 cp = TAILQ_FIRST(&dev_ddtr);
1369 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1370 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1371 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1372 cb = cp->cdp_dtr_cb;
1373 cb_arg = cp->cdp_dtr_cb_arg;
1375 dev_unlock_and_free();
1385 * devmtx shall be locked on entry. devmtx will be unlocked after
1389 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1391 struct cdev_priv *cp;
1393 mtx_assert(&devmtx, MA_OWNED);
1394 cp = cdev2priv(dev);
1395 if (cp->cdp_flags & CDP_SCHED_DTR) {
1400 cp->cdp_flags |= CDP_SCHED_DTR;
1401 cp->cdp_dtr_cb = cb;
1402 cp->cdp_dtr_cb_arg = arg;
1403 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1405 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1410 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1414 return (destroy_dev_sched_cbl(dev, cb, arg));
1418 destroy_dev_sched(struct cdev *dev)
1421 return (destroy_dev_sched_cb(dev, NULL, NULL));
1425 destroy_dev_drain(struct cdevsw *csw)
1429 while (!LIST_EMPTY(&csw->d_devs)) {
1430 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1436 drain_dev_clone_events(void)
1439 sx_xlock(&clone_drain_lock);
1440 sx_xunlock(&clone_drain_lock);
1444 devdtr_init(void *dummy __unused)
1447 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
1450 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
1452 #include "opt_ddb.h"
1454 #include <sys/kernel.h>
1456 #include <ddb/ddb.h>
1458 DB_SHOW_COMMAND(cdev, db_show_cdev)
1460 struct cdev_priv *cdp;
1466 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1468 db_printf("%s %p\n", dev->si_name, dev);
1475 dev = (struct cdev *)addr;
1476 cdp = cdev2priv(dev);
1477 db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1478 dev->si_name, dev->si_refcount, dev->si_usecount,
1479 dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1480 db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1481 dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1482 flags = dev->si_flags;
1483 #define SI_FLAG(flag) do { \
1484 if (flags & (flag)) { \
1485 if (buf[0] != '\0') \
1486 strlcat(buf, ", ", sizeof(buf)); \
1487 strlcat(buf, (#flag) + 3, sizeof(buf)); \
1492 SI_FLAG(SI_ETERNAL);
1495 SI_FLAG(SI_CHEAPCLONE);
1497 SI_FLAG(SI_DEVOPEN);
1498 SI_FLAG(SI_CONSOPEN);
1499 SI_FLAG(SI_DUMPDEV);
1500 SI_FLAG(SI_CANDELETE);
1501 SI_FLAG(SI_CLONELIST);
1502 db_printf("si_flags %s\n", buf);
1504 flags = cdp->cdp_flags;
1505 #define CDP_FLAG(flag) do { \
1506 if (flags & (flag)) { \
1507 if (buf[0] != '\0') \
1508 strlcat(buf, ", ", sizeof(buf)); \
1509 strlcat(buf, (#flag) + 4, sizeof(buf)); \
1514 CDP_FLAG(CDP_ACTIVE);
1515 CDP_FLAG(CDP_SCHED_DTR);
1516 db_printf("cdp_flags %s\n", buf);