diff --git a/sys/compat/linsysfs/linsysfs.h b/sys/compat/linsysfs/linsysfs.h
new file mode 100644
--- /dev/null
+++ b/sys/compat/linsysfs/linsysfs.h
@@ -0,0 +1,51 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2006 IronPort Systems
+ * All rights reserved.
+ * Copyright (c) 2023 Dmitry Chagin <dchagin@FreeBSD.org>
+ *
+ * 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.
+ */
+
+#ifndef _COMPAT_LINSYSFS_LINSYSFS_H_
+#define _COMPAT_LINSYSFS_LINSYSFS_H_
+
+typedef struct pfs_node *linsysfs_bus_cb_t(device_t, device_t,
+		    struct pfs_node *, struct pfs_node *);
+
+void linsysfs_bus_drm(struct pfs_node *, struct pfs_node *, device_t);
+
+int linsysfs_fill_data(PFS_FILL_ARGS);
+char *linsysfs_full_pfs_path(const struct pfs_node *);
+
+struct pfs_node *linsysfs_create_dir(struct pfs_node *, const char *,
+		    pfs_attr_t, pfs_vis_t, pfs_destroy_t);
+struct pfs_node	*linsysfs_create_file(struct pfs_node *, const char *,
+		    pfs_fill_t, pfs_attr_t, pfs_vis_t,
+		    pfs_destroy_t, int, void *);
+struct pfs_node	*linsysfs_create_link(struct pfs_node *, const char *,
+		    pfs_fill_t, pfs_attr_t, pfs_vis_t,
+		    pfs_destroy_t, int, void *);
+struct pfs_node	*linsysfs_find_pcinode(device_t);
+
+#endif /* _COMPAT_LINSYSFS_LINSYSFS_H_ */
diff --git a/sys/compat/linsysfs/linsysfs.c b/sys/compat/linsysfs/linsysfs.c
--- a/sys/compat/linsysfs/linsysfs.c
+++ b/sys/compat/linsysfs/linsysfs.c
@@ -3,6 +3,7 @@
  *
  * Copyright (c) 2006 IronPort Systems
  * All rights reserved.
+ * Copyright (c) 2023 Dmitry Chagin <dchagin@FreeBSD.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -33,8 +34,10 @@
 #include <sys/systm.h>
 #include <sys/ctype.h>
 #include <sys/kernel.h>
+#include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mount.h>
+#include <sys/mutex.h>
 #include <sys/sbuf.h>
 #include <sys/smp.h>
 #include <sys/socket.h>
@@ -53,20 +56,102 @@
 #include <compat/linux/linux_util.h>
 #include <fs/pseudofs/pseudofs.h>
 
-struct scsi_host_queue {
-	TAILQ_ENTRY(scsi_host_queue) scsi_host_next;
-	char *path;
-	char *name;
+#include <compat/linsysfs/linsysfs.h>
+
+static MALLOC_DEFINE(M_LINSYSFS, "linsysfs", "linsysfs");
+
+struct pci_nodes_queue {
+	TAILQ_ENTRY(pci_nodes_queue) pci_nodes_next;
+	device_t dev;
+	struct pfs_node *node;;
 };
+TAILQ_HEAD(,pci_nodes_queue) pci_nodes_q;
 
-TAILQ_HEAD(,scsi_host_queue) scsi_host_q;
+/* Mutex for pci_nodes_queue. */
+static struct mtx pci_nodes_mtx;
+MTX_SYSINIT(pci_nodes_mtx, &pci_nodes_mtx, "linsysfs", MTX_DEF);
 
-static int host_number = 0;
+/*
+ * Create pci device node.
+ */
+static struct pfs_node *
+linsysfs_create_pcidev_node(struct pfs_node *dir, struct pci_devinfo *dinfo,
+    pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy, int flags,
+    device_t dev)
+{
+	char device[PCI_MAXNAMELEN + 1];
+	struct pci_nodes_queue *nq;
+	struct pfs_node *node;
+
+	nq  = malloc(sizeof(*nq), M_LINSYSFS, M_WAITOK);
+
+	sprintf(device, "0000:%02x:%02x.%x",
+	    dinfo->cfg.bus,
+	    dinfo->cfg.slot,
+	    dinfo->cfg.func);
+	node = pfs_create_dir(dir, device, attr, vis, destroy, flags);
+	node->pn_data = dev;
+	nq->node = node;
+	nq->dev= dev;
+	mtx_lock(&pci_nodes_mtx);
+	TAILQ_INSERT_TAIL(&pci_nodes_q, nq, pci_nodes_next);
+	mtx_unlock(&pci_nodes_mtx);
+	return (node);
+}
 
-static int
-atoi(const char *str)
+/*
+ * Locate a node by dev.
+ */
+struct pfs_node *
+linsysfs_find_pcinode(device_t dev)
 {
-	return (int)strtol(str, (char **)NULL, 10);
+	struct pci_nodes_queue *nq, *nq_tmp;
+
+	mtx_lock(&pci_nodes_mtx);
+	TAILQ_FOREACH_SAFE(nq, &pci_nodes_q, pci_nodes_next, nq_tmp) {
+		if (nq->dev == dev) {
+			mtx_unlock(&pci_nodes_mtx);
+			return (nq->node);
+		}
+	}
+	mtx_unlock(&pci_nodes_mtx);
+	return (NULL);
+}
+
+struct pfs_node *
+linsysfs_create_dir(struct pfs_node *parent, const char *name,
+    pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy)
+{
+	struct pfs_node *node;
+
+	if (parent == NULL)
+		return (NULL);
+	node = pfs_create_dir(parent, name, attr, vis, destroy, 0);
+	return (node);
+}
+
+struct pfs_node	*
+linsysfs_create_file(struct pfs_node *parent, const char *name,
+    pfs_fill_t fill, pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy,
+    int flags, void *data)
+{
+	struct pfs_node *node;
+
+	node = pfs_create_file(parent, name, fill, attr, vis, destroy, flags);
+	node->pn_data = data;
+	return (node);
+}
+
+struct pfs_node	*
+linsysfs_create_link(struct pfs_node *parent, const char *name,
+    pfs_fill_t fill, pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy,
+    int flags, void *data)
+{
+	struct pfs_node *node;
+
+	node = pfs_create_link(parent, name, fill, attr, vis, destroy, flags);
+	node->pn_data = data;
+	return (node);
 }
 
 static int
@@ -215,22 +300,14 @@
 static int
 linsysfs_scsiname(PFS_FILL_ARGS)
 {
-	struct scsi_host_queue *scsi_host;
-	int index;
+	device_t dev = pn->pn_data;
+	char *name;
 
-	if (strncmp(pn->pn_parent->pn_name, "host", 4) == 0) {
-		index = atoi(&pn->pn_parent->pn_name[4]);
-	} else {
-		sbuf_printf(sb, "unknown\n");
-		return (0);
-	}
-	TAILQ_FOREACH(scsi_host, &scsi_host_q, scsi_host_next) {
-		if (index-- == 0) {
-			sbuf_printf(sb, "%s\n", scsi_host->name);
-			return (0);
-		}
-	}
-	sbuf_printf(sb, "unknown\n");
+	name = linux_driver_get_name_dev(dev);
+	if (name != NULL)
+		sbuf_printf(sb, "%s", name);
+	else
+		sbuf_printf(sb, "%s", device_get_nameunit(dev));
 	return (0);
 }
 
@@ -240,26 +317,16 @@
 static int
 linsysfs_link_scsi_host(PFS_FILL_ARGS)
 {
-	struct scsi_host_queue *scsi_host;
-	int index;
+	struct pfs_node *node = pn->pn_data;
+	char *path;
 
-	if (strncmp(pn->pn_parent->pn_name, "host", 4) == 0) {
-		index = atoi(&pn->pn_parent->pn_name[4]);
-	} else {
-		sbuf_printf(sb, "unknown\n");
-		return (0);
-	}
-	TAILQ_FOREACH(scsi_host, &scsi_host_q, scsi_host_next) {
-		if (index-- == 0) {
-			sbuf_printf(sb, "../../../devices%s", scsi_host->path);
-			return(0);
-		}
-	}
-	sbuf_printf(sb, "unknown\n");
+	path = linsysfs_full_pfs_path(node);
+	sbuf_printf(sb, "../../../%s", path);
+	free(path, M_TEMP);
 	return (0);
 }
 
-static int
+int
 linsysfs_fill_data(PFS_FILL_ARGS)
 {
 	sbuf_printf(sb, "%s", (char *)pn->pn_data);
@@ -346,25 +413,8 @@
 	return (0);
 }
 
-/*
- * Filler function for drm uevent file
- */
-static int
-linsysfs_fill_uevent_drm(PFS_FILL_ARGS)
-{
-	device_t dev;
-	int unit;
-
-	dev = (device_t)pn->pn_data;
-	unit = device_get_unit(dev);
-	sbuf_printf(sb,
-	    "MAJOR=226\nMINOR=%d\nDEVNAME=dri/card%d\nDEVTYPE=dri_minor\n",
-	    unit, unit);
-	return (0);
-}
-
-static char *
-get_full_pfs_path(struct pfs_node *cur)
+char *
+linsysfs_full_pfs_path(const struct pfs_node *cur)
 {
 	char *temp, *path;
 
@@ -383,183 +433,6 @@
 	return (path);
 }
 
-/*
- * Filler function for symlink from drm char device to PCI device
- */
-static int
-linsysfs_fill_vgapci(PFS_FILL_ARGS)
-{
-	char *path;
-
-	path = get_full_pfs_path((struct pfs_node*)pn->pn_data);
-	sbuf_printf(sb, "../../../%s", path);
-	free(path, M_TEMP);
-	return (0);
-}
-
-#undef PCI_DEV
-#define PCI_DEV "pci"
-#define DRMN_DEV "drmn"
-static int
-linsysfs_run_bus(device_t dev, struct pfs_node *dir, struct pfs_node *scsi,
-    struct pfs_node *chardev, struct pfs_node *drm, char *path, char *prefix)
-{
-	struct scsi_host_queue *scsi_host;
-	struct pfs_node *sub_dir, *cur_file;
-	int i, nchildren, error;
-	device_t *children, parent;
-	devclass_t devclass;
-	const char *name = NULL;
-	struct pci_devinfo *dinfo;
-	char *device, *host, *new_path, *devname;
-
-	new_path = path;
-	devname = malloc(16, M_TEMP, M_WAITOK);
-
-	parent = device_get_parent(dev);
-	if (parent) {
-		devclass = device_get_devclass(parent);
-		if (devclass != NULL)
-			name = devclass_get_name(devclass);
-		if (name && strcmp(name, PCI_DEV) == 0) {
-			dinfo = device_get_ivars(dev);
-			if (dinfo) {
-				device = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
-				new_path = malloc(MAXPATHLEN, M_TEMP,
-				    M_WAITOK);
-				new_path[0] = '\000';
-				strcpy(new_path, path);
-				host = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
-				device[0] = '\000';
-				sprintf(device, "%s:%02x:%02x.%x",
-				    prefix,
-				    dinfo->cfg.bus,
-				    dinfo->cfg.slot,
-				    dinfo->cfg.func);
-				strcat(new_path, "/");
-				strcat(new_path, device);
-				dir = pfs_create_dir(dir, device,
-				    NULL, NULL, NULL, 0);
-				cur_file = pfs_create_file(dir, "vendor",
-				    &linsysfs_fill_vendor, NULL, NULL, NULL,
-				    PFS_RD);
-				cur_file->pn_data = (void*)dev;
-				cur_file = pfs_create_file(dir, "device",
-				    &linsysfs_fill_device, NULL, NULL, NULL,
-				    PFS_RD);
-				cur_file->pn_data = (void*)dev;
-				cur_file = pfs_create_file(dir,
-				    "subsystem_vendor",
-				    &linsysfs_fill_subvendor, NULL, NULL, NULL,
-				    PFS_RD);
-				cur_file->pn_data = (void*)dev;
-				cur_file = pfs_create_file(dir,
-				    "subsystem_device",
-				    &linsysfs_fill_subdevice, NULL, NULL, NULL,
-				    PFS_RD);
-				cur_file->pn_data = (void*)dev;
-				cur_file = pfs_create_file(dir, "revision",
-				    &linsysfs_fill_revid, NULL, NULL, NULL,
-				    PFS_RD);
-				cur_file->pn_data = (void*)dev;
-				cur_file = pfs_create_file(dir, "config",
-				    &linsysfs_fill_config, NULL, NULL, NULL,
-				    PFS_RD);
-				cur_file->pn_data = (void*)dev;
-				cur_file = pfs_create_file(dir, "uevent",
-				    &linsysfs_fill_uevent_pci, NULL, NULL,
-				    NULL, PFS_RD);
-				cur_file->pn_data = (void*)dev;
-				cur_file = pfs_create_link(dir, "subsystem",
-				    &linsysfs_fill_data, NULL, NULL, NULL, 0);
-				/* libdrm just checks that the link ends in "/pci" */
-				cur_file->pn_data = "/sys/bus/pci";
-
-				if (dinfo->cfg.baseclass == PCIC_STORAGE) {
-					/* DJA only make this if needed */
-					sprintf(host, "host%d", host_number++);
-					strcat(new_path, "/");
-					strcat(new_path, host);
-					pfs_create_dir(dir, host,
-					    NULL, NULL, NULL, 0);
-					scsi_host = malloc(sizeof(
-					    struct scsi_host_queue),
-					    M_DEVBUF, M_NOWAIT);
-					scsi_host->path = malloc(
-					    strlen(new_path) + 1,
-					    M_DEVBUF, M_NOWAIT);
-					scsi_host->path[0] = '\000';
-					bcopy(new_path, scsi_host->path,
-					    strlen(new_path) + 1);
-					scsi_host->name = "unknown";
-
-					sub_dir = pfs_create_dir(scsi, host,
-					    NULL, NULL, NULL, 0);
-					pfs_create_link(sub_dir, "device",
-					    &linsysfs_link_scsi_host,
-					    NULL, NULL, NULL, 0);
-					pfs_create_file(sub_dir, "proc_name",
-					    &linsysfs_scsiname,
-					    NULL, NULL, NULL, PFS_RD);
-					scsi_host->name
-					    = linux_driver_get_name_dev(dev);
-					TAILQ_INSERT_TAIL(&scsi_host_q,
-					    scsi_host, scsi_host_next);
-				}
-				free(device, M_TEMP);
-				free(host, M_TEMP);
-			}
-		}
-
-		devclass = device_get_devclass(dev);
-		if (devclass != NULL)
-			name = devclass_get_name(devclass);
-		else
-			name = NULL;
-		if (name != NULL && strcmp(name, DRMN_DEV) == 0 &&
-		    device_get_unit(dev) >= 0) {
-			dinfo = device_get_ivars(parent);
-			if (dinfo != NULL && dinfo->cfg.baseclass == PCIC_DISPLAY) {
-				pfs_create_dir(dir, "drm", NULL, NULL, NULL, 0);
-				sprintf(devname, "226:%d",
-				    device_get_unit(dev));
-				sub_dir = pfs_create_dir(chardev,
-				    devname, NULL, NULL, NULL, 0);
-				cur_file = pfs_create_link(sub_dir,
-				    "device", &linsysfs_fill_vgapci, NULL,
-				    NULL, NULL, PFS_RD);
-				cur_file->pn_data = (void*)dir;
-				cur_file = pfs_create_file(sub_dir,
-				    "uevent", &linsysfs_fill_uevent_drm, NULL,
-				    NULL, NULL, PFS_RD);
-				cur_file->pn_data = (void*)dev;
-				sprintf(devname, "card%d",
-				    device_get_unit(dev));
-				sub_dir = pfs_create_dir(drm,
-				    devname, NULL, NULL, NULL, 0);
-				cur_file = pfs_create_link(sub_dir,
-				    "device", &linsysfs_fill_vgapci, NULL,
-				    NULL, NULL, PFS_RD);
-				cur_file->pn_data = (void*)dir;
-			}
-		}
-	}
-
-	error = device_get_children(dev, &children, &nchildren);
-	if (error == 0) {
-		for (i = 0; i < nchildren; i++)
-			if (children[i])
-				linsysfs_run_bus(children[i], dir, scsi,
-				    chardev, drm, new_path, prefix);
-		free(children, M_TEMP);
-	}
-	if (new_path != path)
-		free(new_path, M_TEMP);
-	free(devname, M_TEMP);
-
-	return (1);
-}
-
 /*
  * Filler function for sys/devices/system/cpu/{online,possible,present}
  */
@@ -609,6 +482,143 @@
 	free(name, M_TEMP);
 }
 
+#undef PCI_DEV
+#define PCI_DEV "pci"
+#define DRMN_DEV "drmn"
+/*
+ * Filler callback for sys/devices/pci0000:00.
+ */
+static struct pfs_node *
+linsysfs_pcibus_cb(device_t parent, device_t dev, struct pfs_node *pci,
+    struct pfs_node *dir)
+{
+	struct pci_devinfo *dinfo;
+	const char *classname;
+	devclass_t dc;
+
+	dinfo = NULL;
+	classname = NULL;
+	dc = device_get_devclass(parent);
+	if (dc != NULL)
+		classname = devclass_get_name(dc);
+	if (strcmp(classname, PCI_DEV) == 0)
+		dinfo = device_get_ivars(dev);
+
+	/* PCI tree. */
+	if (dinfo != NULL) {
+		pci = linsysfs_create_pcidev_node(pci, dinfo,
+		    NULL, NULL, NULL, 0, dev);
+		linsysfs_create_file(pci, "vendor",
+		    &linsysfs_fill_vendor, NULL, NULL, NULL, PFS_RD, dev);
+		linsysfs_create_file(pci, "device",
+		    &linsysfs_fill_device, NULL, NULL, NULL, PFS_RD, dev);
+		linsysfs_create_file(pci, "subsystem_vendor",
+		    &linsysfs_fill_subvendor, NULL, NULL, NULL, PFS_RD, dev);
+		linsysfs_create_file(pci, "subsystem_device",
+		    &linsysfs_fill_subdevice, NULL, NULL, NULL, PFS_RD, dev);
+		linsysfs_create_file(pci, "revision",
+		    &linsysfs_fill_revid, NULL, NULL, NULL, PFS_RD, dev);
+		linsysfs_create_file(pci, "config",
+		    &linsysfs_fill_config, NULL, NULL, NULL, PFS_RD, dev);
+		linsysfs_create_file(pci, "uevent",
+		    &linsysfs_fill_uevent_pci, NULL, NULL, NULL, PFS_RD, dev);
+		linsysfs_create_link(pci, "subsystem",
+		    &linsysfs_fill_data, NULL, NULL, NULL, 0, "/sys/bus/pci");
+		/* TODO: libdrm just checks that the link ends in "/pci" */
+	}
+	/* vgapci/drmn childrens. */
+	if (strcmp(classname, DRMN_DEV) == 0)
+		linsysfs_bus_drm(pci, dir, dev);
+	return (pci);
+}
+
+/*
+ * Filler callback for scsi in sys/devices/pci0000:00.
+ */
+static struct pfs_node *
+linsysfs_scsi_cb(device_t parent, device_t dev, struct pfs_node *pci,
+    struct pfs_node *scsi)
+{
+	char host[PCI_MAXNAMELEN + 1];
+	struct pci_devinfo *dinfo;
+	const char *classname;
+	struct pfs_node *pdir, *sdir;
+	devclass_t dc;
+
+	dinfo = NULL;
+	classname = NULL;
+	dc = device_get_devclass(parent);
+	if (dc != NULL)
+		classname = devclass_get_name(dc);
+	if (strcmp(classname, PCI_DEV) == 0)
+		dinfo = device_get_ivars(dev);
+
+	if (dinfo != NULL &&
+	    dinfo->cfg.baseclass == PCIC_STORAGE) {
+		/* DJA only make this if needed */
+		pdir = linsysfs_find_pcinode(dev);
+		KASSERT(pdir != NULL, ("Inconsistent dev %p node", dev));
+		if (pdir == NULL)
+			return (pci);
+		host[0] = '\000';
+		snprintf(host, sizeof(host), "host%d",
+		    device_get_unit(dev));
+		sdir = linsysfs_create_dir(scsi, host, NULL, NULL, NULL);
+		pdir = linsysfs_create_dir(pdir, host, NULL, NULL, NULL);
+		linsysfs_create_link(sdir, "device",
+		    &linsysfs_link_scsi_host, NULL, NULL, NULL, PFS_RD, pdir);
+		linsysfs_create_file(sdir, "proc_name",
+		    &linsysfs_scsiname, NULL, NULL, NULL, PFS_RD, dev);
+	}
+	return (pci);
+}
+
+/*
+ * Traverse the device tree.
+ */
+static int
+linsysfs_bus_foreach(device_t dev, linsysfs_bus_cb_t cb,
+    struct pfs_node *pci, struct pfs_node *dir)
+{
+	device_t *ch, parent;
+	int n, count, error;
+
+	parent = device_get_parent(dev);
+	if (parent != NULL)
+		pci = (*cb)(parent, dev, pci, dir);
+	error = device_get_children(dev, &ch, &count);
+	if (error != 0)
+		return (error);
+	for (n = 0; n < count; n++) {
+		error = linsysfs_bus_foreach(ch[n], cb, pci, dir);
+		if (error != 0)
+			break;
+	}
+	free(ch, M_TEMP);
+	return (error);
+}
+
+/*
+ * Scan device tree starting from root.
+ */
+static int
+linsysfs_bus_scan(const char *root, linsysfs_bus_cb_t cb,
+    struct pfs_node *pci, struct pfs_node *dir)
+{
+	devclass_t dc;
+	device_t dev;
+	int error;
+
+	bus_topo_lock();
+	dc = devclass_find(root);
+	KASSERT(dc != NULL, ("Invalid %s class", root));
+	dev = devclass_get_device(dc, 0);
+	KASSERT(dev != NULL, ("Scan of %s failed", root));
+	error = linsysfs_bus_foreach(dev, cb, pci, dir);
+	bus_topo_unlock();
+	return (error);
+}
+
 /*
  * Constructor
  */
@@ -618,17 +628,14 @@
 	struct pfs_node *root;
 	struct pfs_node *class;
 	struct pfs_node *dir, *sys, *cpu;
-	struct pfs_node *drm;
 	struct pfs_node *pci;
 	struct pfs_node *scsi;
 	struct pfs_node *net;
 	struct pfs_node *devdir, *chardev;
 	struct pfs_node *kernel;
-	devclass_t devclass;
-	device_t dev;
-
-	TAILQ_INIT(&scsi_host_q);
+	int error;
 
+	TAILQ_INIT(&pci_nodes_q);
 	root = pi->pi_root;
 
 	/* /sys/bus/... */
@@ -637,7 +644,7 @@
 	/* /sys/class/... */
 	class = pfs_create_dir(root, "class", NULL, NULL, NULL, 0);
 	scsi = pfs_create_dir(class, "scsi_host", NULL, NULL, NULL, 0);
-	drm = pfs_create_dir(class, "drm", NULL, NULL, NULL, 0);
+	pfs_create_dir(class, "drm", NULL, NULL, NULL, 0);
 	pfs_create_dir(class, "power_supply", NULL, NULL, NULL, 0);
 
 	/* /sys/class/net/.. */
@@ -651,14 +658,6 @@
 	dir = pfs_create_dir(root, "devices", NULL, NULL, NULL, 0);
 	pci = pfs_create_dir(dir, "pci0000:00", NULL, NULL, NULL, 0);
 
-	devclass = devclass_find("root");
-	if (devclass == NULL) {
-		return (0);
-	}
-
-	dev = devclass_get_device(devclass, 0);
-	linsysfs_run_bus(dev, pci, scsi, chardev, drm, "/pci0000:00", "0000");
-
 	/* /sys/devices/system */
 	sys = pfs_create_dir(dir, "system", NULL, NULL, NULL, 0);
 
@@ -683,7 +682,12 @@
 	/* /sys/subsystem/... */
 	dir = pfs_create_dir(root, "subsystem", NULL, NULL, NULL, 0);
 
-	return (0);
+	/* /sys/devices/pci0000:00 */
+	error = linsysfs_bus_scan("root", linsysfs_pcibus_cb, pci, chardev);
+	if (error == 0)
+		error = linsysfs_bus_scan("root", linsysfs_scsi_cb, pci, scsi);
+
+	return (error);
 }
 
 /*
@@ -692,14 +696,14 @@
 static int
 linsysfs_uninit(PFS_INIT_ARGS)
 {
-	struct scsi_host_queue *scsi_host, *scsi_host_tmp;
+	struct pci_nodes_queue *nq, *nq_tmp;
 
-	TAILQ_FOREACH_SAFE(scsi_host, &scsi_host_q, scsi_host_next,
-	    scsi_host_tmp) {
-		TAILQ_REMOVE(&scsi_host_q, scsi_host, scsi_host_next);
-		free(scsi_host->path, M_TEMP);
-		free(scsi_host, M_TEMP);
+	mtx_lock(&pci_nodes_mtx);
+	TAILQ_FOREACH_SAFE(nq, &pci_nodes_q, pci_nodes_next, nq_tmp) {
+		TAILQ_REMOVE(&pci_nodes_q, nq, pci_nodes_next);
+		free(nq, M_LINSYSFS);
 	}
+	mtx_unlock(&pci_nodes_mtx);
 
 	return (0);
 }
diff --git a/sys/compat/linsysfs/linsysfs_drm.c b/sys/compat/linsysfs/linsysfs_drm.c
new file mode 100644
--- /dev/null
+++ b/sys/compat/linsysfs/linsysfs_drm.c
@@ -0,0 +1,146 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2023 Dmitry Chagin <dchagin@FreeBSD.org>
+ *
+ * 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 <sys/param.h>
+#include <sys/sbuf.h>
+
+#include <dev/pci/pcivar.h>
+
+#include <fs/pseudofs/pseudofs.h>
+
+#include <compat/linsysfs/linsysfs.h>
+#include <linux/device.h>
+
+/*
+ * Filler function for drm uevent file.
+ */
+static int
+linsysfs_drm_fill_uevent(PFS_FILL_ARGS)
+{
+	device_t bsddev = pn->pn_data;
+	struct device *dev;
+
+	/*
+	 * XXX. bsddev can die, drm-kmod will delete it on unregister path.
+	 */
+	dev = device_get_softc(bsddev);
+	if (dev == NULL)
+		return (-1);
+	return (sbuf_printf(sb,
+	    "MAJOR=%d\nMINOR=%d\nDEVNAME=dri/%s\nDEVTYPE=drm_minor\n",
+	    MAJOR(dev->devt), MINOR(dev->devt), dev_name(dev)));
+}
+
+/*
+ * Filler function for drm dev file.
+ */
+static int
+linsysfs_drm_fill_dev(PFS_FILL_ARGS)
+{
+	device_t bsddev = pn->pn_data;
+	struct device *dev;
+
+	/*
+	 * XXX. bsddev can die, drm-kmod will delete it on unregister path.
+	 */
+	dev = device_get_softc(bsddev);
+	if (dev == NULL)
+		return (-1);
+	return (sbuf_printf(sb, "%d:%d", MAJOR(dev->devt), MINOR(dev->devt)));
+}
+
+/*
+ * Filler function for symlink from drm/device to PCI device.
+ */
+static int
+linsysfs_drm_fill_vgapci(PFS_FILL_ARGS)
+{
+	struct pfs_node *node = pn->pn_data;
+	char *path;
+
+	path = linsysfs_full_pfs_path(node);
+	sbuf_printf(sb, "../../../../../%s", path);
+	free(path, M_TEMP);
+	return (0);
+}
+
+/*
+ * Filler function for symlink from dev/char to drm device.
+ */
+static int
+linsysfs_drm_fill_charlink(PFS_FILL_ARGS)
+{
+	struct pfs_node *node = pn->pn_data;
+	char *path;
+
+	path = linsysfs_full_pfs_path(node);
+	sbuf_printf(sb, "../../%s", path);
+	free(path, M_TEMP);
+	return (0);
+}
+
+/*
+ * Filler function for drm childrens.
+ */
+#define DRM_DEV "drm"
+void
+linsysfs_bus_drm(struct pfs_node *devdir, struct pfs_node *chardir,
+    device_t bsddev)
+{
+	const char *classname;
+	struct pfs_node *dir;
+	struct device *dev;
+	char charlink[16];	/* Major:Minor */
+
+	classname = devclass_get_name(device_get_devclass(bsddev));
+
+	if (strcmp(classname, DRM_DEV) == 0  &&
+	    (dev = device_get_softc(bsddev)) != NULL) {
+		dir = pfs_find_node(devdir, DRM_DEV);
+		if (dir == NULL)
+			dir = linsysfs_create_dir(devdir, DRM_DEV,
+			    NULL, NULL, NULL);
+		dir = linsysfs_create_dir(dir, dev_name(dev), NULL, NULL, NULL);
+		linsysfs_create_file(dir, "uevent",
+		    &linsysfs_drm_fill_uevent, NULL, NULL, NULL, PFS_RD, bsddev);
+		linsysfs_create_link(dir, "device",
+		    &linsysfs_drm_fill_vgapci, NULL, NULL, NULL, PFS_RD, devdir);
+		linsysfs_create_link(dir, "subsystem",
+		    &linsysfs_fill_data, NULL, NULL, NULL, PFS_RD,
+		    "/sys/class/drm");
+		snprintf(charlink, sizeof(charlink), "%d:%d",
+		    MAJOR(dev->devt), MINOR(dev->devt));
+		linsysfs_create_link(chardir, charlink,
+		    &linsysfs_drm_fill_charlink, NULL, NULL, NULL, PFS_RD, dir);
+		linsysfs_create_file(dir, "dev",
+		    &linsysfs_drm_fill_dev, NULL, NULL, NULL, PFS_RD, bsddev);
+		linsysfs_create_dir(dir, "power", NULL, NULL, NULL);
+	}
+}
diff --git a/sys/modules/linsysfs/Makefile b/sys/modules/linsysfs/Makefile
--- a/sys/modules/linsysfs/Makefile
+++ b/sys/modules/linsysfs/Makefile
@@ -5,7 +5,9 @@
 KMOD=	linsysfs
 SRCS=	vnode_if.h \
 	device_if.h bus_if.h  pci_if.h \
-	linsysfs.c
+	linsysfs.c linsysfs_drm.c
+
+CFLAGS+= ${LINUXKPI_INCLUDES}
 
 .if !defined(KERNBUILDDIR)
 .warning Building Linuxulator outside of a kernel does not make sense