kern_conf.c: Import from FreeBSD.

1 files changed, 1520 insertions, 0 deletions

diff --git a/freebsd/sys/kern/kern_conf.c b/freebsd/sys/kern/kern_conf.c
new file mode 100644
index 00000000..a5bd68c0
--- /dev/null
+++ b/freebsd/sys/kern/kern_conf.c
@@ -0,0 +1,1520 @@
+#include <machine/rtems-bsd-kernel-space.h>
+
+/*-
+ * Copyright (c) 1999-2002 Poul-Henning Kamp
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/bsd/sys/param.h>
+#include <sys/kernel.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/bio.h>
+#include <rtems/bsd/sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/module.h>
+#include <sys/malloc.h>
+#include <sys/conf.h>
+#include <sys/vnode.h>
+#include <sys/queue.h>
+#include <sys/poll.h>
+#include <sys/sx.h>
+#include <sys/ctype.h>
+#include <sys/ucred.h>
+#include <sys/taskqueue.h>
+#include <machine/stdarg.h>
+
+#include <fs/devfs/devfs_int.h>
+#include <vm/vm.h>
+
+static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
+
+struct mtx devmtx;
+static void destroy_devl(struct cdev *dev);
+static int destroy_dev_sched_cbl(struct cdev *dev,
+    void (*cb)(void *), void *arg);
+static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
+    int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
+    va_list ap);
+
+static struct cdev_priv_list cdevp_free_list =
+    TAILQ_HEAD_INITIALIZER(cdevp_free_list);
+static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
+    SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
+
+void
+dev_lock(void)
+{
+
+	mtx_lock(&devmtx);
+}
+
+/*
+ * Free all the memory collected while the cdev mutex was
+ * locked. Since devmtx is after the system map mutex, free() cannot
+ * be called immediately and is postponed until cdev mutex can be
+ * dropped.
+ */
+static void
+dev_unlock_and_free(void)
+{
+	struct cdev_priv_list cdp_free;
+	struct free_cdevsw csw_free;
+	struct cdev_priv *cdp;
+	struct cdevsw *csw;
+
+	mtx_assert(&devmtx, MA_OWNED);
+
+	/*
+	 * Make the local copy of the list heads while the dev_mtx is
+	 * held. Free it later.
+	 */
+	TAILQ_INIT(&cdp_free);
+	TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
+	csw_free = cdevsw_gt_post_list;
+	SLIST_INIT(&cdevsw_gt_post_list);
+
+	mtx_unlock(&devmtx);
+
+	while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
+		TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
+		devfs_free(&cdp->cdp_c);
+	}
+	while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
+		SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
+		free(csw, M_DEVT);
+	}
+}
+
+static void
+dev_free_devlocked(struct cdev *cdev)
+{
+	struct cdev_priv *cdp;
+
+	mtx_assert(&devmtx, MA_OWNED);
+	cdp = cdev2priv(cdev);
+	KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
+	    ("destroy_dev() was not called after delist_dev(%p)", cdev));
+	TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
+}
+
+static void
+cdevsw_free_devlocked(struct cdevsw *csw)
+{
+
+	mtx_assert(&devmtx, MA_OWNED);
+	SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
+}
+
+void
+dev_unlock(void)
+{
+
+	mtx_unlock(&devmtx);
+}
+
+void
+dev_ref(struct cdev *dev)
+{
+
+	mtx_assert(&devmtx, MA_NOTOWNED);
+	mtx_lock(&devmtx);
+	dev->si_refcount++;
+	mtx_unlock(&devmtx);
+}
+
+void
+dev_refl(struct cdev *dev)
+{
+
+	mtx_assert(&devmtx, MA_OWNED);
+	dev->si_refcount++;
+}
+
+void
+dev_rel(struct cdev *dev)
+{
+	int flag = 0;
+
+	mtx_assert(&devmtx, MA_NOTOWNED);
+	dev_lock();
+	dev->si_refcount--;
+	KASSERT(dev->si_refcount >= 0,
+	    ("dev_rel(%s) gave negative count", devtoname(dev)));
+#if 0
+	if (dev->si_usecount == 0 &&
+	    (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
+		;
+	else 
+#endif
+	if (dev->si_devsw == NULL && dev->si_refcount == 0) {
+		LIST_REMOVE(dev, si_list);
+		flag = 1;
+	}
+	dev_unlock();
+	if (flag)
+		devfs_free(dev);
+}
+
+struct cdevsw *
+dev_refthread(struct cdev *dev, int *ref)
+{
+	struct cdevsw *csw;
+	struct cdev_priv *cdp;
+
+	mtx_assert(&devmtx, MA_NOTOWNED);
+	if ((dev->si_flags & SI_ETERNAL) != 0) {
+		*ref = 0;
+		return (dev->si_devsw);
+	}
+	dev_lock();
+	csw = dev->si_devsw;
+	if (csw != NULL) {
+		cdp = cdev2priv(dev);
+		if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
+			dev->si_threadcount++;
+		else
+			csw = NULL;
+	}
+	dev_unlock();
+	*ref = 1;
+	return (csw);
+}
+
+struct cdevsw *
+devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
+{
+	struct cdevsw *csw;
+	struct cdev_priv *cdp;
+	struct cdev *dev;
+
+	mtx_assert(&devmtx, MA_NOTOWNED);
+	if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
+		dev = vp->v_rdev;
+		if (dev == NULL)
+			return (NULL);
+		KASSERT((dev->si_flags & SI_ETERNAL) != 0,
+		    ("Not eternal cdev"));
+		*ref = 0;
+		csw = dev->si_devsw;
+		KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
+		*devp = dev;
+		return (csw);
+	}
+
+	csw = NULL;
+	dev_lock();
+	dev = vp->v_rdev;
+	if (dev == NULL) {
+		dev_unlock();
+		return (NULL);
+	}
+	cdp = cdev2priv(dev);
+	if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
+		csw = dev->si_devsw;
+		if (csw != NULL)
+			dev->si_threadcount++;
+	}
+	dev_unlock();
+	if (csw != NULL) {
+		*devp = dev;
+		*ref = 1;
+	}
+	return (csw);
+}
+
+void	
+dev_relthread(struct cdev *dev, int ref)
+{
+
+	mtx_assert(&devmtx, MA_NOTOWNED);
+	if (!ref)
+		return;
+	dev_lock();
+	KASSERT(dev->si_threadcount > 0,
+	    ("%s threadcount is wrong", dev->si_name));
+	dev->si_threadcount--;
+	dev_unlock();
+}
+
+int
+nullop(void)
+{
+
+	return (0);
+}
+
+int
+eopnotsupp(void)
+{
+
+	return (EOPNOTSUPP);
+}
+
+static int
+enxio(void)
+{
+	return (ENXIO);
+}
+
+static int
+enodev(void)
+{
+	return (ENODEV);
+}
+
+/* Define a dead_cdevsw for use when devices leave unexpectedly. */
+
+#define dead_open	(d_open_t *)enxio
+#define dead_close	(d_close_t *)enxio
+#define dead_read	(d_read_t *)enxio
+#define dead_write	(d_write_t *)enxio
+#define dead_ioctl	(d_ioctl_t *)enxio
+#define dead_poll	(d_poll_t *)enodev
+#define dead_mmap	(d_mmap_t *)enodev
+
+static void
+dead_strategy(struct bio *bp)
+{
+
+	biofinish(bp, NULL, ENXIO);
+}
+
+#define dead_dump	(dumper_t *)enxio
+#define dead_kqfilter	(d_kqfilter_t *)enxio
+#define dead_mmap_single (d_mmap_single_t *)enodev
+
+static struct cdevsw dead_cdevsw = {
+	.d_version =	D_VERSION,
+	.d_open =	dead_open,
+	.d_close =	dead_close,
+	.d_read =	dead_read,
+	.d_write =	dead_write,
+	.d_ioctl =	dead_ioctl,
+	.d_poll =	dead_poll,
+	.d_mmap =	dead_mmap,
+	.d_strategy =	dead_strategy,
+	.d_name =	"dead",
+	.d_dump =	dead_dump,
+	.d_kqfilter =	dead_kqfilter,
+	.d_mmap_single = dead_mmap_single
+};
+
+/* Default methods if driver does not specify method */
+
+#define null_open	(d_open_t *)nullop
+#define null_close	(d_close_t *)nullop
+#define no_read		(d_read_t *)enodev
+#define no_write	(d_write_t *)enodev
+#define no_ioctl	(d_ioctl_t *)enodev
+#define no_mmap		(d_mmap_t *)enodev
+#define no_kqfilter	(d_kqfilter_t *)enodev
+#define no_mmap_single	(d_mmap_single_t *)enodev
+
+static void
+no_strategy(struct bio *bp)
+{
+
+	biofinish(bp, NULL, ENODEV);
+}
+
+static int
+no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
+{
+
+	return (poll_no_poll(events));
+}
+
+#define no_dump		(dumper_t *)enodev
+
+static int
+giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+
+static int
+giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+
+static int
+giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+
+static void
+giant_strategy(struct bio *bp)
+{
+	struct cdevsw *dsw;
+	struct cdev *dev;
+	int ref;
+
+	dev = bp->bio_dev;
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL) {
+		biofinish(bp, NULL, ENXIO);
+		return;
+	}
+	mtx_lock(&Giant);
+	dsw->d_gianttrick->d_strategy(bp);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+}
+
+static int
+giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+  
+static int
+giant_read(struct cdev *dev, struct uio *uio, int ioflag)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+
+static int
+giant_write(struct cdev *dev, struct uio *uio, int ioflag)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+
+static int
+giant_poll(struct cdev *dev, int events, struct thread *td)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_poll(dev, events, td);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+
+static int
+giant_kqfilter(struct cdev *dev, struct knote *kn)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+
+static int
+giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
+    vm_memattr_t *memattr)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
+	    memattr);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+
+static int
+giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
+    vm_object_t *object, int nprot)
+{
+	struct cdevsw *dsw;
+	int ref, retval;
+
+	dsw = dev_refthread(dev, &ref);
+	if (dsw == NULL)
+		return (ENXIO);
+	mtx_lock(&Giant);
+	retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
+	    nprot);
+	mtx_unlock(&Giant);
+	dev_relthread(dev, ref);
+	return (retval);
+}
+
+static void
+notify(struct cdev *dev, const char *ev, int flags)
+{
+	static const char prefix[] = "cdev=";
+	char *data;
+	int namelen, mflags;
+
+	if (cold)
+		return;
+	mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
+	namelen = strlen(dev->si_name);
+	data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
+	if (data == NULL)
+		return;
+	memcpy(data, prefix, sizeof(prefix) - 1);
+	memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
+	devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
+	free(data, M_TEMP);
+}
+
+static void
+notify_create(struct cdev *dev, int flags)
+{
+
+	notify(dev, "CREATE", flags);
+}
+
+static void
+notify_destroy(struct cdev *dev)
+{
+
+	notify(dev, "DESTROY", MAKEDEV_WAITOK);
+}
+
+static struct cdev *
+newdev(struct cdevsw *csw, int unit, struct cdev *si)
+{
+	struct cdev *si2;
+
+	mtx_assert(&devmtx, MA_OWNED);
+	if (csw->d_flags & D_NEEDMINOR) {
+		/* We may want to return an existing device */
+		LIST_FOREACH(si2, &csw->d_devs, si_list) {
+			if (dev2unit(si2) == unit) {
+				dev_free_devlocked(si);
+				return (si2);
+			}
+		}
+	}
+	si->si_drv0 = unit;
+	si->si_devsw = csw;
+	LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
+	return (si);
+}
+
+static void
+fini_cdevsw(struct cdevsw *devsw)
+{
+	struct cdevsw *gt;
+
+	if (devsw->d_gianttrick != NULL) {
+		gt = devsw->d_gianttrick;
+		memcpy(devsw, gt, sizeof *devsw);
+		cdevsw_free_devlocked(gt);
+		devsw->d_gianttrick = NULL;
+	}
+	devsw->d_flags &= ~D_INIT;
+}
+
+static int
+prep_cdevsw(struct cdevsw *devsw, int flags)
+{
+	struct cdevsw *dsw2;
+
+	mtx_assert(&devmtx, MA_OWNED);
+	if (devsw->d_flags & D_INIT)
+		return (0);
+	if (devsw->d_flags & D_NEEDGIANT) {
+		dev_unlock();
+		dsw2 = malloc(sizeof *dsw2, M_DEVT,
+		     (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
+		dev_lock();
+		if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
+			return (ENOMEM);
+	} else
+		dsw2 = NULL;
+	if (devsw->d_flags & D_INIT) {
+		if (dsw2 != NULL)
+			cdevsw_free_devlocked(dsw2);
+		return (0);
+	}
+
+	if (devsw->d_version != D_VERSION_03) {
+		printf(
+		    "WARNING: Device driver \"%s\" has wrong version %s\n",
+		    devsw->d_name == NULL ? "???" : devsw->d_name,
+		    "and is disabled.  Recompile KLD module.");
+		devsw->d_open = dead_open;
+		devsw->d_close = dead_close;
+		devsw->d_read = dead_read;
+		devsw->d_write = dead_write;
+		devsw->d_ioctl = dead_ioctl;
+		devsw->d_poll = dead_poll;
+		devsw->d_mmap = dead_mmap;
+		devsw->d_mmap_single = dead_mmap_single;
+		devsw->d_strategy = dead_strategy;
+		devsw->d_dump = dead_dump;
+		devsw->d_kqfilter = dead_kqfilter;
+	}
+	
+	if (devsw->d_flags & D_NEEDGIANT) {
+		if (devsw->d_gianttrick == NULL) {
+			memcpy(dsw2, devsw, sizeof *dsw2);
+			devsw->d_gianttrick = dsw2;
+			dsw2 = NULL;
+		}
+	}
+
+#define FIXUP(member, noop, giant) 				\
+	do {							\
+		if (devsw->member == NULL) {			\
+			devsw->member = noop;			\
+		} else if (devsw->d_flags & D_NEEDGIANT)	\
+			devsw->member = giant;			\
+		}						\
+	while (0)
+
+	FIXUP(d_open,		null_open,	giant_open);
+	FIXUP(d_fdopen,		NULL,		giant_fdopen);
+	FIXUP(d_close,		null_close,	giant_close);
+	FIXUP(d_read,		no_read,	giant_read);
+	FIXUP(d_write,		no_write,	giant_write);
+	FIXUP(d_ioctl,		no_ioctl,	giant_ioctl);
+	FIXUP(d_poll,		no_poll,	giant_poll);
+	FIXUP(d_mmap,		no_mmap,	giant_mmap);
+	FIXUP(d_strategy,	no_strategy,	giant_strategy);
+	FIXUP(d_kqfilter,	no_kqfilter,	giant_kqfilter);
+	FIXUP(d_mmap_single,	no_mmap_single,	giant_mmap_single);
+
+	if (devsw->d_dump == NULL)	devsw->d_dump = no_dump;
+
+	LIST_INIT(&devsw->d_devs);
+
+	devsw->d_flags |= D_INIT;
+
+	if (dsw2 != NULL)
+		cdevsw_free_devlocked(dsw2);
+	return (0);
+}
+
+static int
+prep_devname(struct cdev *dev, const char *fmt, va_list ap)
+{
+	int len;
+	char *from, *q, *s, *to;
+
+	mtx_assert(&devmtx, MA_OWNED);
+
+	len = vsnrprintf(dev->__si_namebuf, sizeof(dev->__si_namebuf), 32,
+	    fmt, ap);
+	if (len > sizeof(dev->__si_namebuf) - 1)
+		return (ENAMETOOLONG);
+
+	/* Strip leading slashes. */
+	for (from = dev->__si_namebuf; *from == '/'; from++)
+		;
+
+	for (to = dev->__si_namebuf; *from != '\0'; from++, to++) {
+		/* Treat multiple sequential slashes as single. */
+		while (from[0] == '/' && from[1] == '/')
+			from++;
+		/* Trailing slash is considered invalid. */
+		if (from[0] == '/' && from[1] == '\0')
+			return (EINVAL);
+		*to = *from;
+	}
+	*to = '\0';
+
+	if (dev->__si_namebuf[0] == '\0')
+		return (EINVAL);
+
+	/* Disallow "." and ".." components. */
+	for (s = dev->__si_namebuf;;) {
+		for (q = s; *q != '/' && *q != '\0'; q++)
+			;
+		if (q - s == 1 && s[0] == '.')
+			return (EINVAL);
+		if (q - s == 2 && s[0] == '.' && s[1] == '.')
+			return (EINVAL);
+		if (*q != '/')
+			break;
+		s = q + 1;
+	}
+
+	if (devfs_dev_exists(dev->__si_namebuf) != 0)
+		return (EEXIST);
+
+	return (0);
+}
+
+static int
+make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
+    struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
+    va_list ap)
+{
+	struct cdev *dev, *dev_new;
+	int res;
+
+	KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
+	    ("make_dev_credv: both WAITOK and NOWAIT specified"));
+	dev_new = devfs_alloc(flags);
+	if (dev_new == NULL)
+		return (ENOMEM);
+	dev_lock();
+	res = prep_cdevsw(devsw, flags);
+	if (res != 0) {
+		dev_unlock();
+		devfs_free(dev_new);
+		return (res);
+	}
+	dev = newdev(devsw, unit, dev_new);
+	if ((dev->si_flags & SI_NAMED) == 0) {
+		res = prep_devname(dev, fmt, ap);
+		if (res != 0) {
+			if ((flags & MAKEDEV_CHECKNAME) == 0) {
+				panic(
+			"make_dev_credv: bad si_name (error=%d, si_name=%s)",
+				    res, dev->si_name);
+			}
+			if (dev == dev_new) {
+				LIST_REMOVE(dev, si_list);
+				dev_unlock();
+				devfs_free(dev);
+			} else
+				dev_unlock();
+			return (res);
+		}
+	}
+	if (flags & MAKEDEV_REF)
+		dev_refl(dev);
+	if (flags & MAKEDEV_ETERNAL)
+		dev->si_flags |= SI_ETERNAL;
+	if (dev->si_flags & SI_CHEAPCLONE &&
+	    dev->si_flags & SI_NAMED) {
+		/*
+		 * This is allowed as it removes races and generally
+		 * simplifies cloning devices.
+		 * XXX: still ??
+		 */
+		dev_unlock_and_free();
+		*dres = dev;
+		return (0);
+	}
+	KASSERT(!(dev->si_flags & SI_NAMED),
+	    ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
+	    devsw->d_name, dev2unit(dev), devtoname(dev)));
+	dev->si_flags |= SI_NAMED;
+	if (cr != NULL)
+		dev->si_cred = crhold(cr);
+	dev->si_uid = uid;
+	dev->si_gid = gid;
+	dev->si_mode = mode;
+
+	devfs_create(dev);
+	clean_unrhdrl(devfs_inos);
+	dev_unlock_and_free();
+
+	notify_create(dev, flags);
+
+	*dres = dev;
+	return (0);
+}
+
+struct cdev *
+make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
+    const char *fmt, ...)
+{
+	struct cdev *dev;
+	va_list ap;
+	int res;
+
+	va_start(ap, fmt);
+	res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
+	    ap);
+	va_end(ap);
+	KASSERT(res == 0 && dev != NULL,
+	    ("make_dev: failed make_dev_credv (error=%d)", res));
+	return (dev);
+}
+
+struct cdev *
+make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
+    gid_t gid, int mode, const char *fmt, ...)
+{
+	struct cdev *dev;
+	va_list ap;
+	int res;
+
+	va_start(ap, fmt);
+	res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
+	va_end(ap);
+
+	KASSERT(res == 0 && dev != NULL,
+	    ("make_dev_cred: failed make_dev_credv (error=%d)", res));
+	return (dev);
+}
+
+struct cdev *
+make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
+    uid_t uid, gid_t gid, int mode, const char *fmt, ...)
+{
+	struct cdev *dev;
+	va_list ap;
+	int res;
+
+	va_start(ap, fmt);
+	res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
+	    fmt, ap);
+	va_end(ap);
+
+	KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
+	    ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
+	    ("make_dev_credf: failed make_dev_credv (error=%d)", res));
+	return (res == 0 ? dev : NULL);
+}
+
+int
+make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
+    struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
+{
+	va_list ap;
+	int res;
+
+	va_start(ap, fmt);
+	res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
+	    fmt, ap);
+	va_end(ap);
+
+	KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
+	    ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
+	    ("make_dev_p: failed make_dev_credv (error=%d)", res));
+	return (res);
+}
+
+static void
+dev_dependsl(struct cdev *pdev, struct cdev *cdev)
+{
+
+	cdev->si_parent = pdev;
+	cdev->si_flags |= SI_CHILD;
+	LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
+}
+
+
+void
+dev_depends(struct cdev *pdev, struct cdev *cdev)
+{
+
+	dev_lock();
+	dev_dependsl(pdev, cdev);
+	dev_unlock();
+}
+
+static int
+make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
+    const char *fmt, va_list ap)
+{
+	struct cdev *dev;
+	int error;
+
+	KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
+	KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
+	    ("make_dev_alias_v: both WAITOK and NOWAIT specified"));
+	KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
+	    MAKEDEV_CHECKNAME)) == 0,
+	    ("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
+
+	dev = devfs_alloc(flags);
+	if (dev == NULL)
+		return (ENOMEM);
+	dev_lock();
+	dev->si_flags |= SI_ALIAS;
+	error = prep_devname(dev, fmt, ap);
+	if (error != 0) {
+		if ((flags & MAKEDEV_CHECKNAME) == 0) {
+			panic("make_dev_alias_v: bad si_name "
+			    "(error=%d, si_name=%s)", error, dev->si_name);
+		}
+		dev_unlock();
+		devfs_free(dev);
+		return (error);
+	}
+	dev->si_flags |= SI_NAMED;
+	devfs_create(dev);
+	dev_dependsl(pdev, dev);
+	clean_unrhdrl(devfs_inos);
+	dev_unlock();
+
+	notify_create(dev, flags);
+	*cdev = dev;
+
+	return (0);
+}
+
+struct cdev *
+make_dev_alias(struct cdev *pdev, const char *fmt, ...)
+{
+	struct cdev *dev;
+	va_list ap;
+	int res;
+
+	va_start(ap, fmt);
+	res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
+	va_end(ap);
+
+	KASSERT(res == 0 && dev != NULL,
+	    ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
+	return (dev);
+}
+
+int
+make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
+    const char *fmt, ...)
+{
+	va_list ap;
+	int res;
+
+	va_start(ap, fmt);
+	res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
+	va_end(ap);
+	return (res);
+}
+
+int
+make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev, 
+    struct cdev *old_alias, const char *physpath)
+{
+	char *devfspath;
+	int physpath_len;
+	int max_parentpath_len;
+	int parentpath_len;
+	int devfspathbuf_len;
+	int mflags;
+	int ret;
+
+	*cdev = NULL;
+	devfspath = NULL;
+	physpath_len = strlen(physpath);
+	ret = EINVAL;
+	if (physpath_len == 0)
+		goto out;
+
+	if (strncmp("id1,", physpath, 4) == 0) {
+		physpath += 4;
+		physpath_len -= 4;
+		if (physpath_len == 0)
+			goto out;
+	}
+
+	max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
+	parentpath_len = strlen(pdev->si_name);
+	if (max_parentpath_len < parentpath_len) {
+		if (bootverbose)
+			printf("WARNING: Unable to alias %s "
+			    "to %s/%s - path too long\n",
+			    pdev->si_name, physpath, pdev->si_name);
+		ret = ENAMETOOLONG;
+		goto out;
+	}
+
+	mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
+	devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
+	devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
+	if (devfspath == NULL) {
+		ret = ENOMEM;
+		goto out;
+	}
+
+	sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
+	if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
+		/* Retain the existing alias. */
+		*cdev = old_alias;
+		old_alias = NULL;
+		ret = 0;
+	} else {
+		ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
+	}
+out:
+	if (old_alias != NULL)	
+		destroy_dev(old_alias);
+	if (devfspath != NULL)
+		free(devfspath, M_DEVBUF);
+	return (ret);
+}
+
+static void
+destroy_devl(struct cdev *dev)
+{
+	struct cdevsw *csw;
+	struct cdev_privdata *p;
+	struct cdev_priv *cdp;
+
+	mtx_assert(&devmtx, MA_OWNED);
+	KASSERT(dev->si_flags & SI_NAMED,
+	    ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
+	KASSERT((dev->si_flags & SI_ETERNAL) == 0,
+	    ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
+	     dev2unit(dev)));
+
+	cdp = cdev2priv(dev);
+	if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
+		/*
+		 * Avoid race with dev_rel(), e.g. from the populate
+		 * loop.  If CDP_UNREF_DTR flag is set, the reference
+		 * to be dropped at the end of destroy_devl() was
+		 * already taken by delist_dev_locked().
+		 */
+		dev_refl(dev);
+
+		devfs_destroy(dev);
+	}
+
+	/* Remove name marking */
+	dev->si_flags &= ~SI_NAMED;
+
+	/* If we are a child, remove us from the parents list */
+	if (dev->si_flags & SI_CHILD) {
+		LIST_REMOVE(dev, si_siblings);
+		dev->si_flags &= ~SI_CHILD;
+	}
+
+	/* Kill our children */
+	while (!LIST_EMPTY(&dev->si_children))
+		destroy_devl(LIST_FIRST(&dev->si_children));
+
+	/* Remove from clone list */
+	if (dev->si_flags & SI_CLONELIST) {
+		LIST_REMOVE(dev, si_clone);
+		dev->si_flags &= ~SI_CLONELIST;
+	}
+
+	csw = dev->si_devsw;
+	dev->si_devsw = NULL;	/* already NULL for SI_ALIAS */
+	while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
+		csw->d_purge(dev);
+		msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
+		if (dev->si_threadcount)
+			printf("Still %lu threads in %s\n",
+			    dev->si_threadcount, devtoname(dev));
+	}
+	while (dev->si_threadcount != 0) {
+		/* Use unique dummy wait ident */
+		msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
+	}
+
+	dev_unlock();
+	if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
+		/* avoid out of order notify events */
+		notify_destroy(dev);
+	}
+	mtx_lock(&cdevpriv_mtx);
+	while ((p = LIST_FIRST(&cdp->cdp_fdpriv)) != NULL) {
+		devfs_destroy_cdevpriv(p);
+		mtx_lock(&cdevpriv_mtx);
+	}
+	mtx_unlock(&cdevpriv_mtx);
+	dev_lock();
+
+	dev->si_drv1 = 0;
+	dev->si_drv2 = 0;
+	bzero(&dev->__si_u, sizeof(dev->__si_u));
+
+	if (!(dev->si_flags & SI_ALIAS)) {
+		/* Remove from cdevsw list */
+		LIST_REMOVE(dev, si_list);
+
+		/* If cdevsw has no more struct cdev *'s, clean it */
+		if (LIST_EMPTY(&csw->d_devs)) {
+			fini_cdevsw(csw);
+			wakeup(&csw->d_devs);
+		}
+	}
+	dev->si_flags &= ~SI_ALIAS;
+	cdp->cdp_flags &= ~CDP_UNREF_DTR;
+	dev->si_refcount--;
+
+	if (dev->si_refcount > 0)
+		LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
+	else
+		dev_free_devlocked(dev);
+}
+
+static void
+delist_dev_locked(struct cdev *dev)
+{
+	struct cdev_priv *cdp;
+	struct cdev *child;
+
+	mtx_assert(&devmtx, MA_OWNED);
+	cdp = cdev2priv(dev);
+	if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
+		return;
+	cdp->cdp_flags |= CDP_UNREF_DTR;
+	dev_refl(dev);
+	devfs_destroy(dev);
+	LIST_FOREACH(child, &dev->si_children, si_siblings)
+		delist_dev_locked(child);
+	dev_unlock();	
+	/* ensure the destroy event is queued in order */
+	notify_destroy(dev);
+	dev_lock();
+}
+
+/*
+ * This function will delist a character device and its children from
+ * the directory listing and create a destroy event without waiting
+ * for all character device references to go away. At some later point
+ * destroy_dev() must be called to complete the character device
+ * destruction. After calling this function the character device name
+ * can instantly be re-used.
+ */
+void
+delist_dev(struct cdev *dev)
+{
+
+	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "delist_dev");
+	dev_lock();
+	delist_dev_locked(dev);
+	dev_unlock();
+}
+
+void
+destroy_dev(struct cdev *dev)
+{
+
+	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
+	dev_lock();
+	destroy_devl(dev);
+	dev_unlock_and_free();
+}
+
+const char *
+devtoname(struct cdev *dev)
+{
+
+	return (dev->si_name);
+}
+
+int
+dev_stdclone(char *name, char **namep, const char *stem, int *unit)
+{
+	int u, i;
+
+	i = strlen(stem);
+	if (bcmp(stem, name, i) != 0)
+		return (0);
+	if (!isdigit(name[i]))
+		return (0);
+	u = 0;
+	if (name[i] == '0' && isdigit(name[i+1]))
+		return (0);
+	while (isdigit(name[i])) {
+		u *= 10;
+		u += name[i++] - '0';
+	}
+	if (u > 0xffffff)
+		return (0);
+	*unit = u;
+	if (namep)
+		*namep = &name[i];
+	if (name[i]) 
+		return (2);
+	return (1);
+}
+
+/*
+ * Helper functions for cloning device drivers.
+ *
+ * The objective here is to make it unnecessary for the device drivers to
+ * use rman or similar to manage their unit number space.  Due to the way
+ * we do "on-demand" devices, using rman or other "private" methods 
+ * will be very tricky to lock down properly once we lock down this file.
+ *
+ * Instead we give the drivers these routines which puts the struct cdev *'s
+ * that are to be managed on their own list, and gives the driver the ability
+ * to ask for the first free unit number or a given specified unit number.
+ *
+ * In addition these routines support paired devices (pty, nmdm and similar)
+ * by respecting a number of "flag" bits in the minor number.
+ *
+ */
+
+struct clonedevs {
+	LIST_HEAD(,cdev)	head;
+};
+
+void
+clone_setup(struct clonedevs **cdp)
+{
+
+	*cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
+	LIST_INIT(&(*cdp)->head);
+}
+
+int
+clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
+    struct cdev **dp, int extra)
+{
+	struct clonedevs *cd;
+	struct cdev *dev, *ndev, *dl, *de;
+	int unit, low, u;
+
+	KASSERT(*cdp != NULL,
+	    ("clone_setup() not called in driver \"%s\"", csw->d_name));
+	KASSERT(!(extra & CLONE_UNITMASK),
+	    ("Illegal extra bits (0x%x) in clone_create", extra));
+	KASSERT(*up <= CLONE_UNITMASK,
+	    ("Too high unit (0x%x) in clone_create", *up));
+	KASSERT(csw->d_flags & D_NEEDMINOR,
+	    ("clone_create() on cdevsw without minor numbers"));
+
+
+	/*
+	 * Search the list for a lot of things in one go:
+	 *   A preexisting match is returned immediately.
+	 *   The lowest free unit number if we are passed -1, and the place
+	 *	 in the list where we should insert that new element.
+	 *   The place to insert a specified unit number, if applicable
+	 *       the end of the list.
+	 */
+	unit = *up;
+	ndev = devfs_alloc(MAKEDEV_WAITOK);
+	dev_lock();
+	prep_cdevsw(csw, MAKEDEV_WAITOK);
+	low = extra;
+	de = dl = NULL;
+	cd = *cdp;
+	LIST_FOREACH(dev, &cd->head, si_clone) {
+		KASSERT(dev->si_flags & SI_CLONELIST,
+		    ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
+		u = dev2unit(dev);
+		if (u == (unit | extra)) {
+			*dp = dev;
+			dev_unlock();
+			devfs_free(ndev);
+			return (0);
+		}
+		if (unit == -1 && u == low) {
+			low++;
+			de = dev;
+			continue;
+		} else if (u < (unit | extra)) {
+			de = dev;
+			continue;
+		} else if (u > (unit | extra)) {
+			dl = dev;
+			break;
+		}
+	}
+	if (unit == -1)
+		unit = low & CLONE_UNITMASK;
+	dev = newdev(csw, unit | extra, ndev);
+	if (dev->si_flags & SI_CLONELIST) {
+		printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
+		printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
+		LIST_FOREACH(dev, &cd->head, si_clone) {
+			printf("\t%p %s\n", dev, dev->si_name);
+		}
+		panic("foo");
+	}
+	KASSERT(!(dev->si_flags & SI_CLONELIST),
+	    ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
+	if (dl != NULL)
+		LIST_INSERT_BEFORE(dl, dev, si_clone);
+	else if (de != NULL)
+		LIST_INSERT_AFTER(de, dev, si_clone);
+	else
+		LIST_INSERT_HEAD(&cd->head, dev, si_clone);
+	dev->si_flags |= SI_CLONELIST;
+	*up = unit;
+	dev_unlock_and_free();
+	return (1);
+}
+
+/*
+ * Kill everything still on the list.  The driver should already have
+ * disposed of any softc hung of the struct cdev *'s at this time.
+ */
+void
+clone_cleanup(struct clonedevs **cdp)
+{
+	struct cdev *dev;
+	struct cdev_priv *cp;
+	struct clonedevs *cd;
+	
+	cd = *cdp;
+	if (cd == NULL)
+		return;
+	dev_lock();
+	while (!LIST_EMPTY(&cd->head)) {
+		dev = LIST_FIRST(&cd->head);
+		LIST_REMOVE(dev, si_clone);
+		KASSERT(dev->si_flags & SI_CLONELIST,
+		    ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
+		dev->si_flags &= ~SI_CLONELIST;
+		cp = cdev2priv(dev);
+		if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
+			cp->cdp_flags |= CDP_SCHED_DTR;
+			KASSERT(dev->si_flags & SI_NAMED,
+				("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
+			destroy_devl(dev);
+		}
+	}
+	dev_unlock_and_free();
+	free(cd, M_DEVBUF);
+	*cdp = NULL;
+}
+
+static TAILQ_HEAD(, cdev_priv) dev_ddtr =
+	TAILQ_HEAD_INITIALIZER(dev_ddtr);
+static struct task dev_dtr_task;
+
+static void
+destroy_dev_tq(void *ctx, int pending)
+{
+	struct cdev_priv *cp;
+	struct cdev *dev;
+	void (*cb)(void *);
+	void *cb_arg;
+
+	dev_lock();
+	while (!TAILQ_EMPTY(&dev_ddtr)) {
+		cp = TAILQ_FIRST(&dev_ddtr);
+		dev = &cp->cdp_c;
+		KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
+		    ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
+		TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
+		cb = cp->cdp_dtr_cb;
+		cb_arg = cp->cdp_dtr_cb_arg;
+		destroy_devl(dev);
+		dev_unlock_and_free();
+		dev_rel(dev);
+		if (cb != NULL)
+			cb(cb_arg);
+		dev_lock();
+	}
+	dev_unlock();
+}
+
+/*
+ * devmtx shall be locked on entry. devmtx will be unlocked after
+ * function return.
+ */
+static int
+destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
+{
+	struct cdev_priv *cp;
+
+	mtx_assert(&devmtx, MA_OWNED);
+	cp = cdev2priv(dev);
+	if (cp->cdp_flags & CDP_SCHED_DTR) {
+		dev_unlock();
+		return (0);
+	}
+	dev_refl(dev);
+	cp->cdp_flags |= CDP_SCHED_DTR;
+	cp->cdp_dtr_cb = cb;
+	cp->cdp_dtr_cb_arg = arg;
+	TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
+	dev_unlock();
+	taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
+	return (1);
+}
+
+int
+destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
+{
+
+	dev_lock();
+	return (destroy_dev_sched_cbl(dev, cb, arg));
+}
+
+int
+destroy_dev_sched(struct cdev *dev)
+{
+
+	return (destroy_dev_sched_cb(dev, NULL, NULL));
+}
+
+void
+destroy_dev_drain(struct cdevsw *csw)
+{
+
+	dev_lock();
+	while (!LIST_EMPTY(&csw->d_devs)) {
+		msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
+	}
+	dev_unlock();
+}
+
+void
+drain_dev_clone_events(void)
+{
+
+	sx_xlock(&clone_drain_lock);
+	sx_xunlock(&clone_drain_lock);
+}
+
+static void
+devdtr_init(void *dummy __unused)
+{
+
+	TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
+}
+
+SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
+
+#include <rtems/bsd/local/opt_ddb.h>
+#ifdef DDB
+#include <sys/kernel.h>
+
+#include <ddb/ddb.h>
+
+DB_SHOW_COMMAND(cdev, db_show_cdev)
+{
+	struct cdev_priv *cdp;
+	struct cdev *dev;
+	u_int flags;
+	char buf[512];
+
+	if (!have_addr) {
+		TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
+			dev = &cdp->cdp_c;
+			db_printf("%s %p\n", dev->si_name, dev);
+			if (db_pager_quit)
+				break;
+		}
+		return;
+	}
+
+	dev = (struct cdev *)addr;
+	cdp = cdev2priv(dev);
+	db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
+	    dev->si_name, dev->si_refcount, dev->si_usecount,
+	    dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
+	db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
+	    dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
+	flags = dev->si_flags;
+#define	SI_FLAG(flag)	do {						\
+	if (flags & (flag)) {						\
+		if (buf[0] != '\0')					\
+			strlcat(buf, ", ", sizeof(buf));		\
+		strlcat(buf, (#flag) + 3, sizeof(buf));			\
+		flags &= ~(flag);					\
+	}								\
+} while (0)
+	buf[0] = '\0';
+	SI_FLAG(SI_ETERNAL);
+	SI_FLAG(SI_ALIAS);
+	SI_FLAG(SI_NAMED);
+	SI_FLAG(SI_CHEAPCLONE);
+	SI_FLAG(SI_CHILD);
+	SI_FLAG(SI_DEVOPEN);
+	SI_FLAG(SI_CONSOPEN);
+	SI_FLAG(SI_DUMPDEV);
+	SI_FLAG(SI_CANDELETE);
+	SI_FLAG(SI_CLONELIST);
+	db_printf("si_flags %s\n", buf);
+
+	flags = cdp->cdp_flags;
+#define	CDP_FLAG(flag)	do {						\
+	if (flags & (flag)) {						\
+		if (buf[0] != '\0')					\
+			strlcat(buf, ", ", sizeof(buf));		\
+		strlcat(buf, (#flag) + 4, sizeof(buf));			\
+		flags &= ~(flag);					\
+	}								\
+} while (0)
+	buf[0] = '\0';
+	CDP_FLAG(CDP_ACTIVE);
+	CDP_FLAG(CDP_SCHED_DTR);
+	db_printf("cdp_flags %s\n", buf);
+}
+#endif