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 void destroy_dev_tq(void *ctx, int pending);
59 static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
60 int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
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(cdevsw_gt_post_list);
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
82 dev_unlock_and_free(void)
84 struct cdev_priv_list cdp_free;
85 struct free_cdevsw csw_free;
86 struct cdev_priv *cdp;
89 mtx_assert(&devmtx, MA_OWNED);
92 * Make the local copy of the list heads while the dev_mtx is
93 * held. Free it later.
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);
102 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
103 TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
104 devfs_free(&cdp->cdp_c);
106 while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
107 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
113 dev_free_devlocked(struct cdev *cdev)
115 struct cdev_priv *cdp;
117 mtx_assert(&devmtx, MA_OWNED);
118 cdp = cdev2priv(cdev);
119 KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
120 ("destroy_dev() was not called after delist_dev(%p)", cdev));
121 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
125 cdevsw_free_devlocked(struct cdevsw *csw)
128 mtx_assert(&devmtx, MA_OWNED);
129 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
140 dev_ref(struct cdev *dev)
143 mtx_assert(&devmtx, MA_NOTOWNED);
150 dev_refl(struct cdev *dev)
153 mtx_assert(&devmtx, MA_OWNED);
158 dev_rel(struct cdev *dev)
162 mtx_assert(&devmtx, MA_NOTOWNED);
165 KASSERT(dev->si_refcount >= 0,
166 ("dev_rel(%s) gave negative count", devtoname(dev)));
168 if (dev->si_usecount == 0 &&
169 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
173 if (dev->si_devsw == NULL && dev->si_refcount == 0) {
174 LIST_REMOVE(dev, si_list);
183 dev_refthread(struct cdev *dev, int *ref)
186 struct cdev_priv *cdp;
188 mtx_assert(&devmtx, MA_NOTOWNED);
189 if ((dev->si_flags & SI_ETERNAL) != 0) {
191 return (dev->si_devsw);
196 cdp = cdev2priv(dev);
197 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
198 atomic_add_long(&dev->si_threadcount, 1);
208 devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
211 struct cdev_priv *cdp;
214 mtx_assert(&devmtx, MA_NOTOWNED);
215 if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
219 KASSERT((dev->si_flags & SI_ETERNAL) != 0,
220 ("Not eternal cdev"));
223 KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
235 cdp = cdev2priv(dev);
236 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
239 atomic_add_long(&dev->si_threadcount, 1);
250 dev_relthread(struct cdev *dev, int ref)
253 mtx_assert(&devmtx, MA_NOTOWNED);
256 KASSERT(dev->si_threadcount > 0,
257 ("%s threadcount is wrong", dev->si_name));
258 atomic_subtract_rel_long(&dev->si_threadcount, 1);
287 /* Define a dead_cdevsw for use when devices leave unexpectedly. */
289 #define dead_open (d_open_t *)enxio
290 #define dead_close (d_close_t *)enxio
291 #define dead_read (d_read_t *)enxio
292 #define dead_write (d_write_t *)enxio
293 #define dead_ioctl (d_ioctl_t *)enxio
294 #define dead_poll (d_poll_t *)enodev
295 #define dead_mmap (d_mmap_t *)enodev
298 dead_strategy(struct bio *bp)
301 biofinish(bp, NULL, ENXIO);
304 #define dead_dump (dumper_t *)enxio
305 #define dead_kqfilter (d_kqfilter_t *)enxio
306 #define dead_mmap_single (d_mmap_single_t *)enodev
308 static struct cdevsw dead_cdevsw = {
309 .d_version = D_VERSION,
311 .d_close = dead_close,
313 .d_write = dead_write,
314 .d_ioctl = dead_ioctl,
317 .d_strategy = dead_strategy,
320 .d_kqfilter = dead_kqfilter,
321 .d_mmap_single = dead_mmap_single
324 /* Default methods if driver does not specify method */
326 #define null_open (d_open_t *)nullop
327 #define null_close (d_close_t *)nullop
328 #define no_read (d_read_t *)enodev
329 #define no_write (d_write_t *)enodev
330 #define no_ioctl (d_ioctl_t *)enodev
331 #define no_mmap (d_mmap_t *)enodev
332 #define no_kqfilter (d_kqfilter_t *)enodev
333 #define no_mmap_single (d_mmap_single_t *)enodev
336 no_strategy(struct bio *bp)
339 biofinish(bp, NULL, ENODEV);
343 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
346 return (poll_no_poll(events));
349 #define no_dump (dumper_t *)enodev
352 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
357 dsw = dev_refthread(dev, &ref);
361 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
363 dev_relthread(dev, ref);
368 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
373 dsw = dev_refthread(dev, &ref);
377 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
379 dev_relthread(dev, ref);
384 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
389 dsw = dev_refthread(dev, &ref);
393 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
395 dev_relthread(dev, ref);
400 giant_strategy(struct bio *bp)
407 dsw = dev_refthread(dev, &ref);
409 biofinish(bp, NULL, ENXIO);
413 dsw->d_gianttrick->d_strategy(bp);
415 dev_relthread(dev, ref);
419 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
424 dsw = dev_refthread(dev, &ref);
428 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
430 dev_relthread(dev, ref);
435 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
440 dsw = dev_refthread(dev, &ref);
444 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
446 dev_relthread(dev, ref);
451 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
456 dsw = dev_refthread(dev, &ref);
460 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
462 dev_relthread(dev, ref);
467 giant_poll(struct cdev *dev, int events, struct thread *td)
472 dsw = dev_refthread(dev, &ref);
476 retval = dsw->d_gianttrick->d_poll(dev, events, td);
478 dev_relthread(dev, ref);
483 giant_kqfilter(struct cdev *dev, struct knote *kn)
488 dsw = dev_refthread(dev, &ref);
492 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
494 dev_relthread(dev, ref);
499 giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
500 vm_memattr_t *memattr)
505 dsw = dev_refthread(dev, &ref);
509 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
512 dev_relthread(dev, ref);
517 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
518 vm_object_t *object, int nprot)
523 dsw = dev_refthread(dev, &ref);
527 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
530 dev_relthread(dev, ref);
535 notify(struct cdev *dev, const char *ev, int flags)
537 static const char prefix[] = "cdev=";
543 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
544 namelen = strlen(dev->si_name);
545 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
548 memcpy(data, prefix, sizeof(prefix) - 1);
549 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
550 devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
555 notify_create(struct cdev *dev, int flags)
558 notify(dev, "CREATE", flags);
562 notify_destroy(struct cdev *dev)
565 notify(dev, "DESTROY", MAKEDEV_WAITOK);
569 newdev(struct cdevsw *csw, int unit, struct cdev *si)
573 mtx_assert(&devmtx, MA_OWNED);
574 if (csw->d_flags & D_NEEDMINOR) {
575 /* We may want to return an existing device */
576 LIST_FOREACH(si2, &csw->d_devs, si_list) {
577 if (dev2unit(si2) == unit) {
578 dev_free_devlocked(si);
585 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
590 fini_cdevsw(struct cdevsw *devsw)
594 if (devsw->d_gianttrick != NULL) {
595 gt = devsw->d_gianttrick;
596 memcpy(devsw, gt, sizeof *devsw);
597 cdevsw_free_devlocked(gt);
598 devsw->d_gianttrick = NULL;
600 devsw->d_flags &= ~D_INIT;
604 prep_cdevsw(struct cdevsw *devsw, int flags)
608 mtx_assert(&devmtx, MA_OWNED);
609 if (devsw->d_flags & D_INIT)
611 if (devsw->d_flags & D_NEEDGIANT) {
613 dsw2 = malloc(sizeof *dsw2, M_DEVT,
614 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
616 if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
620 if (devsw->d_flags & D_INIT) {
622 cdevsw_free_devlocked(dsw2);
626 if (devsw->d_version != D_VERSION_03) {
628 "WARNING: Device driver \"%s\" has wrong version %s\n",
629 devsw->d_name == NULL ? "???" : devsw->d_name,
630 "and is disabled. Recompile KLD module.");
631 devsw->d_open = dead_open;
632 devsw->d_close = dead_close;
633 devsw->d_read = dead_read;
634 devsw->d_write = dead_write;
635 devsw->d_ioctl = dead_ioctl;
636 devsw->d_poll = dead_poll;
637 devsw->d_mmap = dead_mmap;
638 devsw->d_mmap_single = dead_mmap_single;
639 devsw->d_strategy = dead_strategy;
640 devsw->d_dump = dead_dump;
641 devsw->d_kqfilter = dead_kqfilter;
644 if (devsw->d_flags & D_NEEDGIANT) {
645 if (devsw->d_gianttrick == NULL) {
646 memcpy(dsw2, devsw, sizeof *dsw2);
647 devsw->d_gianttrick = dsw2;
652 #define FIXUP(member, noop, giant) \
654 if (devsw->member == NULL) { \
655 devsw->member = noop; \
656 } else if (devsw->d_flags & D_NEEDGIANT) \
657 devsw->member = giant; \
661 FIXUP(d_open, null_open, giant_open);
662 FIXUP(d_fdopen, NULL, giant_fdopen);
663 FIXUP(d_close, null_close, giant_close);
664 FIXUP(d_read, no_read, giant_read);
665 FIXUP(d_write, no_write, giant_write);
666 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
667 FIXUP(d_poll, no_poll, giant_poll);
668 FIXUP(d_mmap, no_mmap, giant_mmap);
669 FIXUP(d_strategy, no_strategy, giant_strategy);
670 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
671 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
673 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
675 LIST_INIT(&devsw->d_devs);
677 devsw->d_flags |= D_INIT;
680 cdevsw_free_devlocked(dsw2);
685 prep_devname(struct cdev *dev, const char *fmt, va_list ap)
688 char *from, *q, *s, *to;
690 mtx_assert(&devmtx, MA_OWNED);
692 len = vsnrprintf(dev->si_name, sizeof(dev->si_name), 32, fmt, ap);
693 if (len > sizeof(dev->si_name) - 1)
694 return (ENAMETOOLONG);
696 /* Strip leading slashes. */
697 for (from = dev->si_name; *from == '/'; from++)
700 for (to = dev->si_name; *from != '\0'; from++, to++) {
702 * Spaces and double quotation marks cause
703 * problems for the devctl(4) protocol.
704 * Reject names containing those characters.
706 if (isspace(*from) || *from == '"')
708 /* Treat multiple sequential slashes as single. */
709 while (from[0] == '/' && from[1] == '/')
711 /* Trailing slash is considered invalid. */
712 if (from[0] == '/' && from[1] == '\0')
718 if (dev->si_name[0] == '\0')
721 /* Disallow "." and ".." components. */
722 for (s = dev->si_name;;) {
723 for (q = s; *q != '/' && *q != '\0'; q++)
725 if (q - s == 1 && s[0] == '.')
727 if (q - s == 2 && s[0] == '.' && s[1] == '.')
734 if (devfs_dev_exists(dev->si_name) != 0)
741 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
742 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
745 struct cdev *dev, *dev_new;
748 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
749 ("make_dev_credv: both WAITOK and NOWAIT specified"));
750 dev_new = devfs_alloc(flags);
754 res = prep_cdevsw(devsw, flags);
760 dev = newdev(devsw, unit, dev_new);
761 if ((dev->si_flags & SI_NAMED) == 0) {
762 res = prep_devname(dev, fmt, ap);
764 if ((flags & MAKEDEV_CHECKNAME) == 0) {
766 "make_dev_credv: bad si_name (error=%d, si_name=%s)",
769 if (dev == dev_new) {
770 LIST_REMOVE(dev, si_list);
778 if (flags & MAKEDEV_REF)
780 if (flags & MAKEDEV_ETERNAL)
781 dev->si_flags |= SI_ETERNAL;
782 if (dev->si_flags & SI_CHEAPCLONE &&
783 dev->si_flags & SI_NAMED) {
785 * This is allowed as it removes races and generally
786 * simplifies cloning devices.
789 dev_unlock_and_free();
793 KASSERT(!(dev->si_flags & SI_NAMED),
794 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
795 devsw->d_name, dev2unit(dev), devtoname(dev)));
796 dev->si_flags |= SI_NAMED;
798 dev->si_cred = crhold(cr);
804 clean_unrhdrl(devfs_inos);
805 dev_unlock_and_free();
807 notify_create(dev, flags);
814 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
815 const char *fmt, ...)
822 res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
825 KASSERT(res == 0 && dev != NULL,
826 ("make_dev: failed make_dev_credv (error=%d)", res));
831 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
832 gid_t gid, int mode, const char *fmt, ...)
839 res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
842 KASSERT(res == 0 && dev != NULL,
843 ("make_dev_cred: failed make_dev_credv (error=%d)", res));
848 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
849 uid_t uid, gid_t gid, int mode, const char *fmt, ...)
856 res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
860 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
861 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
862 ("make_dev_credf: failed make_dev_credv (error=%d)", res));
863 return (res == 0 ? dev : NULL);
867 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
868 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
874 res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
878 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
879 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
880 ("make_dev_p: failed make_dev_credv (error=%d)", res));
885 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
888 cdev->si_parent = pdev;
889 cdev->si_flags |= SI_CHILD;
890 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
895 dev_depends(struct cdev *pdev, struct cdev *cdev)
899 dev_dependsl(pdev, cdev);
904 make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
905 const char *fmt, va_list ap)
910 KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
911 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
912 ("make_dev_alias_v: both WAITOK and NOWAIT specified"));
913 KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
914 MAKEDEV_CHECKNAME)) == 0,
915 ("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
917 dev = devfs_alloc(flags);
921 dev->si_flags |= SI_ALIAS;
922 error = prep_devname(dev, fmt, ap);
924 if ((flags & MAKEDEV_CHECKNAME) == 0) {
925 panic("make_dev_alias_v: bad si_name "
926 "(error=%d, si_name=%s)", error, dev->si_name);
932 dev->si_flags |= SI_NAMED;
934 dev_dependsl(pdev, dev);
935 clean_unrhdrl(devfs_inos);
938 notify_create(dev, flags);
945 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
952 res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
955 KASSERT(res == 0 && dev != NULL,
956 ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
961 make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
962 const char *fmt, ...)
968 res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
974 make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
975 struct cdev *old_alias, const char *physpath)
979 int max_parentpath_len;
981 int devfspathbuf_len;
987 physpath_len = strlen(physpath);
989 if (physpath_len == 0)
992 if (strncmp("id1,", physpath, 4) == 0) {
995 if (physpath_len == 0)
999 max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
1000 parentpath_len = strlen(pdev->si_name);
1001 if (max_parentpath_len < parentpath_len) {
1003 printf("WARNING: Unable to alias %s "
1004 "to %s/%s - path too long\n",
1005 pdev->si_name, physpath, pdev->si_name);
1010 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
1011 devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
1012 devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
1013 if (devfspath == NULL) {
1018 sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
1019 if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
1020 /* Retain the existing alias. */
1025 ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
1028 if (old_alias != NULL)
1029 destroy_dev(old_alias);
1030 if (devfspath != NULL)
1031 free(devfspath, M_DEVBUF);
1036 destroy_devl(struct cdev *dev)
1039 struct cdev_privdata *p;
1040 struct cdev_priv *cdp;
1042 mtx_assert(&devmtx, MA_OWNED);
1043 KASSERT(dev->si_flags & SI_NAMED,
1044 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
1045 KASSERT((dev->si_flags & SI_ETERNAL) == 0,
1046 ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
1049 cdp = cdev2priv(dev);
1050 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1052 * Avoid race with dev_rel(), e.g. from the populate
1053 * loop. If CDP_UNREF_DTR flag is set, the reference
1054 * to be dropped at the end of destroy_devl() was
1055 * already taken by delist_dev_locked().
1062 /* Remove name marking */
1063 dev->si_flags &= ~SI_NAMED;
1065 /* If we are a child, remove us from the parents list */
1066 if (dev->si_flags & SI_CHILD) {
1067 LIST_REMOVE(dev, si_siblings);
1068 dev->si_flags &= ~SI_CHILD;
1071 /* Kill our children */
1072 while (!LIST_EMPTY(&dev->si_children))
1073 destroy_devl(LIST_FIRST(&dev->si_children));
1075 /* Remove from clone list */
1076 if (dev->si_flags & SI_CLONELIST) {
1077 LIST_REMOVE(dev, si_clone);
1078 dev->si_flags &= ~SI_CLONELIST;
1081 csw = dev->si_devsw;
1082 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
1083 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
1085 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
1086 if (dev->si_threadcount)
1087 printf("Still %lu threads in %s\n",
1088 dev->si_threadcount, devtoname(dev));
1090 while (dev->si_threadcount != 0) {
1091 /* Use unique dummy wait ident */
1092 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
1096 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1097 /* avoid out of order notify events */
1098 notify_destroy(dev);
1100 mtx_lock(&cdevpriv_mtx);
1101 while ((p = LIST_FIRST(&cdp->cdp_fdpriv)) != NULL) {
1102 devfs_destroy_cdevpriv(p);
1103 mtx_lock(&cdevpriv_mtx);
1105 mtx_unlock(&cdevpriv_mtx);
1110 bzero(&dev->__si_u, sizeof(dev->__si_u));
1112 if (!(dev->si_flags & SI_ALIAS)) {
1113 /* Remove from cdevsw list */
1114 LIST_REMOVE(dev, si_list);
1116 /* If cdevsw has no more struct cdev *'s, clean it */
1117 if (LIST_EMPTY(&csw->d_devs)) {
1119 wakeup(&csw->d_devs);
1122 dev->si_flags &= ~SI_ALIAS;
1123 cdp->cdp_flags &= ~CDP_UNREF_DTR;
1126 if (dev->si_refcount > 0)
1127 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
1129 dev_free_devlocked(dev);
1133 delist_dev_locked(struct cdev *dev)
1135 struct cdev_priv *cdp;
1138 mtx_assert(&devmtx, MA_OWNED);
1139 cdp = cdev2priv(dev);
1140 if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
1142 cdp->cdp_flags |= CDP_UNREF_DTR;
1145 LIST_FOREACH(child, &dev->si_children, si_siblings)
1146 delist_dev_locked(child);
1148 /* ensure the destroy event is queued in order */
1149 notify_destroy(dev);
1154 * This function will delist a character device and its children from
1155 * the directory listing and create a destroy event without waiting
1156 * for all character device references to go away. At some later point
1157 * destroy_dev() must be called to complete the character device
1158 * destruction. After calling this function the character device name
1159 * can instantly be re-used.
1162 delist_dev(struct cdev *dev)
1165 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "delist_dev");
1167 delist_dev_locked(dev);
1172 destroy_dev(struct cdev *dev)
1175 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1178 dev_unlock_and_free();
1182 devtoname(struct cdev *dev)
1185 return (dev->si_name);
1189 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1194 if (bcmp(stem, name, i) != 0)
1196 if (!isdigit(name[i]))
1199 if (name[i] == '0' && isdigit(name[i+1]))
1201 while (isdigit(name[i])) {
1203 u += name[i++] - '0';
1216 * Helper functions for cloning device drivers.
1218 * The objective here is to make it unnecessary for the device drivers to
1219 * use rman or similar to manage their unit number space. Due to the way
1220 * we do "on-demand" devices, using rman or other "private" methods
1221 * will be very tricky to lock down properly once we lock down this file.
1223 * Instead we give the drivers these routines which puts the struct cdev *'s
1224 * that are to be managed on their own list, and gives the driver the ability
1225 * to ask for the first free unit number or a given specified unit number.
1227 * In addition these routines support paired devices (pty, nmdm and similar)
1228 * by respecting a number of "flag" bits in the minor number.
1233 LIST_HEAD(,cdev) head;
1237 clone_setup(struct clonedevs **cdp)
1240 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1241 LIST_INIT(&(*cdp)->head);
1245 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1246 struct cdev **dp, int extra)
1248 struct clonedevs *cd;
1249 struct cdev *dev, *ndev, *dl, *de;
1252 KASSERT(*cdp != NULL,
1253 ("clone_setup() not called in driver \"%s\"", csw->d_name));
1254 KASSERT(!(extra & CLONE_UNITMASK),
1255 ("Illegal extra bits (0x%x) in clone_create", extra));
1256 KASSERT(*up <= CLONE_UNITMASK,
1257 ("Too high unit (0x%x) in clone_create", *up));
1258 KASSERT(csw->d_flags & D_NEEDMINOR,
1259 ("clone_create() on cdevsw without minor numbers"));
1263 * Search the list for a lot of things in one go:
1264 * A preexisting match is returned immediately.
1265 * The lowest free unit number if we are passed -1, and the place
1266 * in the list where we should insert that new element.
1267 * The place to insert a specified unit number, if applicable
1268 * the end of the list.
1271 ndev = devfs_alloc(MAKEDEV_WAITOK);
1273 prep_cdevsw(csw, MAKEDEV_WAITOK);
1277 LIST_FOREACH(dev, &cd->head, si_clone) {
1278 KASSERT(dev->si_flags & SI_CLONELIST,
1279 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1281 if (u == (unit | extra)) {
1287 if (unit == -1 && u == low) {
1291 } else if (u < (unit | extra)) {
1294 } else if (u > (unit | extra)) {
1300 unit = low & CLONE_UNITMASK;
1301 dev = newdev(csw, unit | extra, ndev);
1302 if (dev->si_flags & SI_CLONELIST) {
1303 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1304 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1305 LIST_FOREACH(dev, &cd->head, si_clone) {
1306 printf("\t%p %s\n", dev, dev->si_name);
1310 KASSERT(!(dev->si_flags & SI_CLONELIST),
1311 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1313 LIST_INSERT_BEFORE(dl, dev, si_clone);
1314 else if (de != NULL)
1315 LIST_INSERT_AFTER(de, dev, si_clone);
1317 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1318 dev->si_flags |= SI_CLONELIST;
1320 dev_unlock_and_free();
1325 * Kill everything still on the list. The driver should already have
1326 * disposed of any softc hung of the struct cdev *'s at this time.
1329 clone_cleanup(struct clonedevs **cdp)
1332 struct cdev_priv *cp;
1333 struct clonedevs *cd;
1339 while (!LIST_EMPTY(&cd->head)) {
1340 dev = LIST_FIRST(&cd->head);
1341 LIST_REMOVE(dev, si_clone);
1342 KASSERT(dev->si_flags & SI_CLONELIST,
1343 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1344 dev->si_flags &= ~SI_CLONELIST;
1345 cp = cdev2priv(dev);
1346 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1347 cp->cdp_flags |= CDP_SCHED_DTR;
1348 KASSERT(dev->si_flags & SI_NAMED,
1349 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1353 dev_unlock_and_free();
1358 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1359 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1360 static struct task dev_dtr_task = TASK_INITIALIZER(0, destroy_dev_tq, NULL);
1363 destroy_dev_tq(void *ctx, int pending)
1365 struct cdev_priv *cp;
1371 while (!TAILQ_EMPTY(&dev_ddtr)) {
1372 cp = TAILQ_FIRST(&dev_ddtr);
1374 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1375 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1376 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1377 cb = cp->cdp_dtr_cb;
1378 cb_arg = cp->cdp_dtr_cb_arg;
1380 dev_unlock_and_free();
1390 * devmtx shall be locked on entry. devmtx will be unlocked after
1394 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1396 struct cdev_priv *cp;
1398 mtx_assert(&devmtx, MA_OWNED);
1399 cp = cdev2priv(dev);
1400 if (cp->cdp_flags & CDP_SCHED_DTR) {
1405 cp->cdp_flags |= CDP_SCHED_DTR;
1406 cp->cdp_dtr_cb = cb;
1407 cp->cdp_dtr_cb_arg = arg;
1408 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1410 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1415 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1419 return (destroy_dev_sched_cbl(dev, cb, arg));
1423 destroy_dev_sched(struct cdev *dev)
1426 return (destroy_dev_sched_cb(dev, NULL, NULL));
1430 destroy_dev_drain(struct cdevsw *csw)
1434 while (!LIST_EMPTY(&csw->d_devs)) {
1435 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1441 drain_dev_clone_events(void)
1444 sx_xlock(&clone_drain_lock);
1445 sx_xunlock(&clone_drain_lock);
1448 #include "opt_ddb.h"
1450 #include <sys/kernel.h>
1452 #include <ddb/ddb.h>
1454 DB_SHOW_COMMAND(cdev, db_show_cdev)
1456 struct cdev_priv *cdp;
1462 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1464 db_printf("%s %p\n", dev->si_name, dev);
1471 dev = (struct cdev *)addr;
1472 cdp = cdev2priv(dev);
1473 db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1474 dev->si_name, dev->si_refcount, dev->si_usecount,
1475 dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1476 db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1477 dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1478 flags = dev->si_flags;
1479 #define SI_FLAG(flag) do { \
1480 if (flags & (flag)) { \
1481 if (buf[0] != '\0') \
1482 strlcat(buf, ", ", sizeof(buf)); \
1483 strlcat(buf, (#flag) + 3, sizeof(buf)); \
1488 SI_FLAG(SI_ETERNAL);
1491 SI_FLAG(SI_CHEAPCLONE);
1493 SI_FLAG(SI_DUMPDEV);
1494 SI_FLAG(SI_CLONELIST);
1495 db_printf("si_flags %s\n", buf);
1497 flags = cdp->cdp_flags;
1498 #define CDP_FLAG(flag) do { \
1499 if (flags & (flag)) { \
1500 if (buf[0] != '\0') \
1501 strlcat(buf, ", ", sizeof(buf)); \
1502 strlcat(buf, (#flag) + 4, sizeof(buf)); \
1507 CDP_FLAG(CDP_ACTIVE);
1508 CDP_FLAG(CDP_SCHED_DTR);
1509 db_printf("cdp_flags %s\n", buf);