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 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
122 cdevsw_free_devlocked(struct cdevsw *csw)
125 mtx_assert(&devmtx, MA_OWNED);
126 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
137 dev_ref(struct cdev *dev)
140 mtx_assert(&devmtx, MA_NOTOWNED);
147 dev_refl(struct cdev *dev)
150 mtx_assert(&devmtx, MA_OWNED);
155 dev_rel(struct cdev *dev)
159 mtx_assert(&devmtx, MA_NOTOWNED);
162 KASSERT(dev->si_refcount >= 0,
163 ("dev_rel(%s) gave negative count", devtoname(dev)));
165 if (dev->si_usecount == 0 &&
166 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
170 if (dev->si_devsw == NULL && dev->si_refcount == 0) {
171 LIST_REMOVE(dev, si_list);
180 dev_refthread(struct cdev *dev, int *ref)
183 struct cdev_priv *cdp;
185 mtx_assert(&devmtx, MA_NOTOWNED);
186 if ((dev->si_flags & SI_ETERNAL) != 0) {
188 return (dev->si_devsw);
193 cdp = cdev2priv(dev);
194 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
195 dev->si_threadcount++;
205 devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
208 struct cdev_priv *cdp;
211 mtx_assert(&devmtx, MA_NOTOWNED);
212 if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
216 KASSERT((dev->si_flags & SI_ETERNAL) != 0,
217 ("Not eternal cdev"));
220 KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
232 cdp = cdev2priv(dev);
233 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
236 dev->si_threadcount++;
247 dev_relthread(struct cdev *dev, int ref)
250 mtx_assert(&devmtx, MA_NOTOWNED);
254 KASSERT(dev->si_threadcount > 0,
255 ("%s threadcount is wrong", dev->si_name));
256 dev->si_threadcount--;
286 /* Define a dead_cdevsw for use when devices leave unexpectedly. */
288 #define dead_open (d_open_t *)enxio
289 #define dead_close (d_close_t *)enxio
290 #define dead_read (d_read_t *)enxio
291 #define dead_write (d_write_t *)enxio
292 #define dead_ioctl (d_ioctl_t *)enxio
293 #define dead_poll (d_poll_t *)enodev
294 #define dead_mmap (d_mmap_t *)enodev
297 dead_strategy(struct bio *bp)
300 biofinish(bp, NULL, ENXIO);
303 #define dead_dump (dumper_t *)enxio
304 #define dead_kqfilter (d_kqfilter_t *)enxio
305 #define dead_mmap_single (d_mmap_single_t *)enodev
307 static struct cdevsw dead_cdevsw = {
308 .d_version = D_VERSION,
310 .d_close = dead_close,
312 .d_write = dead_write,
313 .d_ioctl = dead_ioctl,
316 .d_strategy = dead_strategy,
319 .d_kqfilter = dead_kqfilter,
320 .d_mmap_single = dead_mmap_single
323 /* Default methods if driver does not specify method */
325 #define null_open (d_open_t *)nullop
326 #define null_close (d_close_t *)nullop
327 #define no_read (d_read_t *)enodev
328 #define no_write (d_write_t *)enodev
329 #define no_ioctl (d_ioctl_t *)enodev
330 #define no_mmap (d_mmap_t *)enodev
331 #define no_kqfilter (d_kqfilter_t *)enodev
332 #define no_mmap_single (d_mmap_single_t *)enodev
335 no_strategy(struct bio *bp)
338 biofinish(bp, NULL, ENODEV);
342 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
345 return (poll_no_poll(events));
348 #define no_dump (dumper_t *)enodev
351 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
356 dsw = dev_refthread(dev, &ref);
360 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
362 dev_relthread(dev, ref);
367 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
372 dsw = dev_refthread(dev, &ref);
376 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
378 dev_relthread(dev, ref);
383 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
388 dsw = dev_refthread(dev, &ref);
392 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
394 dev_relthread(dev, ref);
399 giant_strategy(struct bio *bp)
406 dsw = dev_refthread(dev, &ref);
408 biofinish(bp, NULL, ENXIO);
412 dsw->d_gianttrick->d_strategy(bp);
414 dev_relthread(dev, ref);
418 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
423 dsw = dev_refthread(dev, &ref);
427 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
429 dev_relthread(dev, ref);
434 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
439 dsw = dev_refthread(dev, &ref);
443 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
445 dev_relthread(dev, ref);
450 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
455 dsw = dev_refthread(dev, &ref);
459 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
461 dev_relthread(dev, ref);
466 giant_poll(struct cdev *dev, int events, struct thread *td)
471 dsw = dev_refthread(dev, &ref);
475 retval = dsw->d_gianttrick->d_poll(dev, events, td);
477 dev_relthread(dev, ref);
482 giant_kqfilter(struct cdev *dev, struct knote *kn)
487 dsw = dev_refthread(dev, &ref);
491 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
493 dev_relthread(dev, ref);
498 giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
499 vm_memattr_t *memattr)
504 dsw = dev_refthread(dev, &ref);
508 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
511 dev_relthread(dev, ref);
516 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
517 vm_object_t *object, int nprot)
522 dsw = dev_refthread(dev, &ref);
526 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
529 dev_relthread(dev, ref);
534 notify(struct cdev *dev, const char *ev, int flags)
536 static const char prefix[] = "cdev=";
542 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
543 namelen = strlen(dev->si_name);
544 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
547 memcpy(data, prefix, sizeof(prefix) - 1);
548 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
549 devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
554 notify_create(struct cdev *dev, int flags)
557 notify(dev, "CREATE", flags);
561 notify_destroy(struct cdev *dev)
564 notify(dev, "DESTROY", MAKEDEV_WAITOK);
568 newdev(struct cdevsw *csw, int unit, struct cdev *si)
572 mtx_assert(&devmtx, MA_OWNED);
573 if (csw->d_flags & D_NEEDMINOR) {
574 /* We may want to return an existing device */
575 LIST_FOREACH(si2, &csw->d_devs, si_list) {
576 if (dev2unit(si2) == unit) {
577 dev_free_devlocked(si);
584 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
589 fini_cdevsw(struct cdevsw *devsw)
593 if (devsw->d_gianttrick != NULL) {
594 gt = devsw->d_gianttrick;
595 memcpy(devsw, gt, sizeof *devsw);
596 cdevsw_free_devlocked(gt);
597 devsw->d_gianttrick = NULL;
599 devsw->d_flags &= ~D_INIT;
603 prep_cdevsw(struct cdevsw *devsw, int flags)
607 mtx_assert(&devmtx, MA_OWNED);
608 if (devsw->d_flags & D_INIT)
610 if (devsw->d_flags & D_NEEDGIANT) {
612 dsw2 = malloc(sizeof *dsw2, M_DEVT,
613 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
615 if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
619 if (devsw->d_flags & D_INIT) {
621 cdevsw_free_devlocked(dsw2);
625 if (devsw->d_version != D_VERSION_03) {
627 "WARNING: Device driver \"%s\" has wrong version %s\n",
628 devsw->d_name == NULL ? "???" : devsw->d_name,
629 "and is disabled. Recompile KLD module.");
630 devsw->d_open = dead_open;
631 devsw->d_close = dead_close;
632 devsw->d_read = dead_read;
633 devsw->d_write = dead_write;
634 devsw->d_ioctl = dead_ioctl;
635 devsw->d_poll = dead_poll;
636 devsw->d_mmap = dead_mmap;
637 devsw->d_mmap_single = dead_mmap_single;
638 devsw->d_strategy = dead_strategy;
639 devsw->d_dump = dead_dump;
640 devsw->d_kqfilter = dead_kqfilter;
643 if (devsw->d_flags & D_NEEDGIANT) {
644 if (devsw->d_gianttrick == NULL) {
645 memcpy(dsw2, devsw, sizeof *dsw2);
646 devsw->d_gianttrick = dsw2;
651 #define FIXUP(member, noop, giant) \
653 if (devsw->member == NULL) { \
654 devsw->member = noop; \
655 } else if (devsw->d_flags & D_NEEDGIANT) \
656 devsw->member = giant; \
660 FIXUP(d_open, null_open, giant_open);
661 FIXUP(d_fdopen, NULL, giant_fdopen);
662 FIXUP(d_close, null_close, giant_close);
663 FIXUP(d_read, no_read, giant_read);
664 FIXUP(d_write, no_write, giant_write);
665 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
666 FIXUP(d_poll, no_poll, giant_poll);
667 FIXUP(d_mmap, no_mmap, giant_mmap);
668 FIXUP(d_strategy, no_strategy, giant_strategy);
669 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
670 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
672 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
674 LIST_INIT(&devsw->d_devs);
676 devsw->d_flags |= D_INIT;
679 cdevsw_free_devlocked(dsw2);
684 prep_devname(struct cdev *dev, const char *fmt, va_list ap)
687 char *from, *q, *s, *to;
689 mtx_assert(&devmtx, MA_OWNED);
691 len = vsnrprintf(dev->__si_namebuf, sizeof(dev->__si_namebuf), 32,
693 if (len > sizeof(dev->__si_namebuf) - 1)
694 return (ENAMETOOLONG);
696 /* Strip leading slashes. */
697 for (from = dev->__si_namebuf; *from == '/'; from++)
700 for (to = dev->__si_namebuf; *from != '\0'; from++, to++) {
701 /* Treat multiple sequential slashes as single. */
702 while (from[0] == '/' && from[1] == '/')
704 /* Trailing slash is considered invalid. */
705 if (from[0] == '/' && from[1] == '\0')
711 if (dev->__si_namebuf[0] == '\0')
714 /* Disallow "." and ".." components. */
715 for (s = dev->__si_namebuf;;) {
716 for (q = s; *q != '/' && *q != '\0'; q++)
718 if (q - s == 1 && s[0] == '.')
720 if (q - s == 2 && s[0] == '.' && s[1] == '.')
727 if (devfs_dev_exists(dev->__si_namebuf) != 0)
734 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
735 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
738 struct cdev *dev, *dev_new;
741 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
742 ("make_dev_credv: both WAITOK and NOWAIT specified"));
743 dev_new = devfs_alloc(flags);
747 res = prep_cdevsw(devsw, flags);
753 dev = newdev(devsw, unit, dev_new);
754 if ((dev->si_flags & SI_NAMED) == 0) {
755 res = prep_devname(dev, fmt, ap);
757 if ((flags & MAKEDEV_CHECKNAME) == 0) {
759 "make_dev_credv: bad si_name (error=%d, si_name=%s)",
762 if (dev == dev_new) {
763 LIST_REMOVE(dev, si_list);
771 if (flags & MAKEDEV_REF)
773 if (flags & MAKEDEV_ETERNAL)
774 dev->si_flags |= SI_ETERNAL;
775 if (dev->si_flags & SI_CHEAPCLONE &&
776 dev->si_flags & SI_NAMED) {
778 * This is allowed as it removes races and generally
779 * simplifies cloning devices.
782 dev_unlock_and_free();
786 KASSERT(!(dev->si_flags & SI_NAMED),
787 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
788 devsw->d_name, dev2unit(dev), devtoname(dev)));
789 dev->si_flags |= SI_NAMED;
791 dev->si_cred = crhold(cr);
797 clean_unrhdrl(devfs_inos);
798 dev_unlock_and_free();
800 notify_create(dev, flags);
807 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
808 const char *fmt, ...)
815 res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
818 KASSERT(res == 0 && dev != NULL,
819 ("make_dev: failed make_dev_credv (error=%d)", res));
824 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
825 gid_t gid, int mode, const char *fmt, ...)
832 res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
835 KASSERT(res == 0 && dev != NULL,
836 ("make_dev_cred: failed make_dev_credv (error=%d)", res));
841 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
842 uid_t uid, gid_t gid, int mode, const char *fmt, ...)
849 res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
853 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
854 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
855 ("make_dev_credf: failed make_dev_credv (error=%d)", res));
856 return (res == 0 ? dev : NULL);
860 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
861 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
867 res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
871 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
872 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
873 ("make_dev_p: failed make_dev_credv (error=%d)", res));
878 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
881 cdev->si_parent = pdev;
882 cdev->si_flags |= SI_CHILD;
883 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
888 dev_depends(struct cdev *pdev, struct cdev *cdev)
892 dev_dependsl(pdev, cdev);
897 make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
898 const char *fmt, va_list ap)
903 KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
904 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
905 ("make_dev_alias_v: both WAITOK and NOWAIT specified"));
906 KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
907 MAKEDEV_CHECKNAME)) == 0,
908 ("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
910 dev = devfs_alloc(flags);
914 dev->si_flags |= SI_ALIAS;
915 error = prep_devname(dev, fmt, ap);
917 if ((flags & MAKEDEV_CHECKNAME) == 0) {
918 panic("make_dev_alias_v: bad si_name "
919 "(error=%d, si_name=%s)", error, dev->si_name);
925 dev->si_flags |= SI_NAMED;
927 dev_dependsl(pdev, dev);
928 clean_unrhdrl(devfs_inos);
931 notify_create(dev, flags);
938 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
945 res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
948 KASSERT(res == 0 && dev != NULL,
949 ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
954 make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
955 const char *fmt, ...)
961 res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
967 make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
968 struct cdev *old_alias, const char *physpath)
972 int max_parentpath_len;
974 int devfspathbuf_len;
980 physpath_len = strlen(physpath);
982 if (physpath_len == 0)
985 if (strncmp("id1,", physpath, 4) == 0) {
988 if (physpath_len == 0)
992 max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
993 parentpath_len = strlen(pdev->si_name);
994 if (max_parentpath_len < parentpath_len) {
996 printf("WARNING: Unable to alias %s "
997 "to %s/%s - path too long\n",
998 pdev->si_name, physpath, pdev->si_name);
1003 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
1004 devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
1005 devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
1006 if (devfspath == NULL) {
1011 sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
1012 if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
1013 /* Retain the existing alias. */
1018 ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
1021 if (old_alias != NULL)
1022 destroy_dev(old_alias);
1023 if (devfspath != NULL)
1024 free(devfspath, M_DEVBUF);
1029 destroy_devl(struct cdev *dev)
1032 struct cdev_privdata *p;
1034 mtx_assert(&devmtx, MA_OWNED);
1035 KASSERT(dev->si_flags & SI_NAMED,
1036 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
1037 KASSERT((dev->si_flags & SI_ETERNAL) == 0,
1038 ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
1043 /* Remove name marking */
1044 dev->si_flags &= ~SI_NAMED;
1046 dev->si_refcount++; /* Avoid race with dev_rel() */
1048 /* If we are a child, remove us from the parents list */
1049 if (dev->si_flags & SI_CHILD) {
1050 LIST_REMOVE(dev, si_siblings);
1051 dev->si_flags &= ~SI_CHILD;
1054 /* Kill our children */
1055 while (!LIST_EMPTY(&dev->si_children))
1056 destroy_devl(LIST_FIRST(&dev->si_children));
1058 /* Remove from clone list */
1059 if (dev->si_flags & SI_CLONELIST) {
1060 LIST_REMOVE(dev, si_clone);
1061 dev->si_flags &= ~SI_CLONELIST;
1064 csw = dev->si_devsw;
1065 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
1066 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
1068 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
1069 if (dev->si_threadcount)
1070 printf("Still %lu threads in %s\n",
1071 dev->si_threadcount, devtoname(dev));
1073 while (dev->si_threadcount != 0) {
1074 /* Use unique dummy wait ident */
1075 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
1079 notify_destroy(dev);
1080 mtx_lock(&cdevpriv_mtx);
1081 while ((p = LIST_FIRST(&cdev2priv(dev)->cdp_fdpriv)) != NULL) {
1082 devfs_destroy_cdevpriv(p);
1083 mtx_lock(&cdevpriv_mtx);
1085 mtx_unlock(&cdevpriv_mtx);
1090 bzero(&dev->__si_u, sizeof(dev->__si_u));
1092 if (!(dev->si_flags & SI_ALIAS)) {
1093 /* Remove from cdevsw list */
1094 LIST_REMOVE(dev, si_list);
1096 /* If cdevsw has no more struct cdev *'s, clean it */
1097 if (LIST_EMPTY(&csw->d_devs)) {
1099 wakeup(&csw->d_devs);
1102 dev->si_flags &= ~SI_ALIAS;
1103 dev->si_refcount--; /* Avoid race with dev_rel() */
1105 if (dev->si_refcount > 0) {
1106 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
1108 dev_free_devlocked(dev);
1113 destroy_dev(struct cdev *dev)
1116 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1119 dev_unlock_and_free();
1123 devtoname(struct cdev *dev)
1126 return (dev->si_name);
1130 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1135 if (bcmp(stem, name, i) != 0)
1137 if (!isdigit(name[i]))
1140 if (name[i] == '0' && isdigit(name[i+1]))
1142 while (isdigit(name[i])) {
1144 u += name[i++] - '0';
1157 * Helper functions for cloning device drivers.
1159 * The objective here is to make it unnecessary for the device drivers to
1160 * use rman or similar to manage their unit number space. Due to the way
1161 * we do "on-demand" devices, using rman or other "private" methods
1162 * will be very tricky to lock down properly once we lock down this file.
1164 * Instead we give the drivers these routines which puts the struct cdev *'s
1165 * that are to be managed on their own list, and gives the driver the ability
1166 * to ask for the first free unit number or a given specified unit number.
1168 * In addition these routines support paired devices (pty, nmdm and similar)
1169 * by respecting a number of "flag" bits in the minor number.
1174 LIST_HEAD(,cdev) head;
1178 clone_setup(struct clonedevs **cdp)
1181 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1182 LIST_INIT(&(*cdp)->head);
1186 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1187 struct cdev **dp, int extra)
1189 struct clonedevs *cd;
1190 struct cdev *dev, *ndev, *dl, *de;
1193 KASSERT(*cdp != NULL,
1194 ("clone_setup() not called in driver \"%s\"", csw->d_name));
1195 KASSERT(!(extra & CLONE_UNITMASK),
1196 ("Illegal extra bits (0x%x) in clone_create", extra));
1197 KASSERT(*up <= CLONE_UNITMASK,
1198 ("Too high unit (0x%x) in clone_create", *up));
1199 KASSERT(csw->d_flags & D_NEEDMINOR,
1200 ("clone_create() on cdevsw without minor numbers"));
1204 * Search the list for a lot of things in one go:
1205 * A preexisting match is returned immediately.
1206 * The lowest free unit number if we are passed -1, and the place
1207 * in the list where we should insert that new element.
1208 * The place to insert a specified unit number, if applicable
1209 * the end of the list.
1212 ndev = devfs_alloc(MAKEDEV_WAITOK);
1214 prep_cdevsw(csw, MAKEDEV_WAITOK);
1218 LIST_FOREACH(dev, &cd->head, si_clone) {
1219 KASSERT(dev->si_flags & SI_CLONELIST,
1220 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1222 if (u == (unit | extra)) {
1228 if (unit == -1 && u == low) {
1232 } else if (u < (unit | extra)) {
1235 } else if (u > (unit | extra)) {
1241 unit = low & CLONE_UNITMASK;
1242 dev = newdev(csw, unit | extra, ndev);
1243 if (dev->si_flags & SI_CLONELIST) {
1244 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1245 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1246 LIST_FOREACH(dev, &cd->head, si_clone) {
1247 printf("\t%p %s\n", dev, dev->si_name);
1251 KASSERT(!(dev->si_flags & SI_CLONELIST),
1252 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1254 LIST_INSERT_BEFORE(dl, dev, si_clone);
1255 else if (de != NULL)
1256 LIST_INSERT_AFTER(de, dev, si_clone);
1258 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1259 dev->si_flags |= SI_CLONELIST;
1261 dev_unlock_and_free();
1266 * Kill everything still on the list. The driver should already have
1267 * disposed of any softc hung of the struct cdev *'s at this time.
1270 clone_cleanup(struct clonedevs **cdp)
1273 struct cdev_priv *cp;
1274 struct clonedevs *cd;
1280 while (!LIST_EMPTY(&cd->head)) {
1281 dev = LIST_FIRST(&cd->head);
1282 LIST_REMOVE(dev, si_clone);
1283 KASSERT(dev->si_flags & SI_CLONELIST,
1284 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1285 dev->si_flags &= ~SI_CLONELIST;
1286 cp = cdev2priv(dev);
1287 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1288 cp->cdp_flags |= CDP_SCHED_DTR;
1289 KASSERT(dev->si_flags & SI_NAMED,
1290 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1294 dev_unlock_and_free();
1299 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1300 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1301 static struct task dev_dtr_task;
1304 destroy_dev_tq(void *ctx, int pending)
1306 struct cdev_priv *cp;
1312 while (!TAILQ_EMPTY(&dev_ddtr)) {
1313 cp = TAILQ_FIRST(&dev_ddtr);
1315 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1316 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1317 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1318 cb = cp->cdp_dtr_cb;
1319 cb_arg = cp->cdp_dtr_cb_arg;
1321 dev_unlock_and_free();
1331 * devmtx shall be locked on entry. devmtx will be unlocked after
1335 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1337 struct cdev_priv *cp;
1339 mtx_assert(&devmtx, MA_OWNED);
1340 cp = cdev2priv(dev);
1341 if (cp->cdp_flags & CDP_SCHED_DTR) {
1346 cp->cdp_flags |= CDP_SCHED_DTR;
1347 cp->cdp_dtr_cb = cb;
1348 cp->cdp_dtr_cb_arg = arg;
1349 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1351 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1356 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1360 return (destroy_dev_sched_cbl(dev, cb, arg));
1364 destroy_dev_sched(struct cdev *dev)
1367 return (destroy_dev_sched_cb(dev, NULL, NULL));
1371 destroy_dev_drain(struct cdevsw *csw)
1375 while (!LIST_EMPTY(&csw->d_devs)) {
1376 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1382 drain_dev_clone_events(void)
1385 sx_xlock(&clone_drain_lock);
1386 sx_xunlock(&clone_drain_lock);
1390 devdtr_init(void *dummy __unused)
1393 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
1396 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
1398 #include "opt_ddb.h"
1400 #include <sys/kernel.h>
1402 #include <ddb/ddb.h>
1404 DB_SHOW_COMMAND(cdev, db_show_cdev)
1406 struct cdev_priv *cdp;
1412 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1414 db_printf("%s %p\n", dev->si_name, dev);
1421 dev = (struct cdev *)addr;
1422 cdp = cdev2priv(dev);
1423 db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1424 dev->si_name, dev->si_refcount, dev->si_usecount,
1425 dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1426 db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1427 dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1428 flags = dev->si_flags;
1429 #define SI_FLAG(flag) do { \
1430 if (flags & (flag)) { \
1431 if (buf[0] != '\0') \
1432 strlcat(buf, ", ", sizeof(buf)); \
1433 strlcat(buf, (#flag) + 3, sizeof(buf)); \
1438 SI_FLAG(SI_ETERNAL);
1441 SI_FLAG(SI_CHEAPCLONE);
1443 SI_FLAG(SI_DEVOPEN);
1444 SI_FLAG(SI_CONSOPEN);
1445 SI_FLAG(SI_DUMPDEV);
1446 SI_FLAG(SI_CANDELETE);
1447 SI_FLAG(SI_CLONELIST);
1448 db_printf("si_flags %s\n", buf);
1450 flags = cdp->cdp_flags;
1451 #define CDP_FLAG(flag) do { \
1452 if (flags & (flag)) { \
1453 if (buf[0] != '\0') \
1454 strlcat(buf, ", ", sizeof(buf)); \
1455 strlcat(buf, (#flag) + 4, sizeof(buf)); \
1460 CDP_FLAG(CDP_ACTIVE);
1461 CDP_FLAG(CDP_SCHED_DTR);
1462 db_printf("cdp_flags %s\n", buf);