20 files changed, 1308 insertions, 434 deletions

diff --git a/sys/dev/bhnd/bhnd.c b/sys/dev/bhnd/bhnd.c
index 104ca8ecb44a..f4c1ea29cf81 100644
--- a/sys/dev/bhnd/bhnd.c
+++ b/sys/dev/bhnd/bhnd.c
@@ -1,7 +1,11 @@
 /*-
  * Copyright (c) 2015-2016 Landon Fuller <landonf@FreeBSD.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -69,11 +73,9 @@ __FBSDID("$FreeBSD$");
 #include "bhnd.h"
 #include "bhndvar.h"
 
-MALLOC_DEFINE(M_BHND, "bhnd", "bhnd bus data structures");
+#include "bhnd_private.h"
 
-/* Bus pass at which all bus-required children must be available, and
- * attachment may be finalized. */
-#define	BHND_FINISH_ATTACH_PASS	BUS_PASS_DEFAULT
+MALLOC_DEFINE(M_BHND, "bhnd", "bhnd bus data structures");
 
 /**
  * bhnd_generic_probe_nomatch() reporting configuration.
@@ -92,23 +94,8 @@ static const struct bhnd_nomatch {
 	{ BHND_MFGID_INVALID,	BHND_COREID_INVALID,		false	}
 };
 
-
 static int			 bhnd_delete_children(struct bhnd_softc *sc);
 
-static int			 bhnd_finish_attach(struct bhnd_softc *sc);
-
-static device_t			 bhnd_find_chipc(struct bhnd_softc *sc);
-static struct chipc_caps	*bhnd_find_chipc_caps(struct bhnd_softc *sc);
-static device_t			 bhnd_find_platform_dev(struct bhnd_softc *sc,
-				     const char *classname);
-static device_t			 bhnd_find_pmu(struct bhnd_softc *sc);
-static device_t			 bhnd_find_nvram(struct bhnd_softc *sc);
-
-static int			 compare_ascending_probe_order(const void *lhs,
-				     const void *rhs);
-static int			 compare_descending_probe_order(const void *lhs,
-				     const void *rhs);
-
 /**
  * Default bhnd(4) bus driver implementation of DEVICE_ATTACH().
  *
@@ -119,8 +106,6 @@ int
 bhnd_generic_attach(device_t dev)
 {
 	struct bhnd_softc	*sc;
-	device_t		*devs;
-	int			 ndevs;
 	int			 error;
 
 	if (device_is_attached(dev))
@@ -129,29 +114,13 @@ bhnd_generic_attach(device_t dev)
 	sc = device_get_softc(dev);
 	sc->dev = dev;
 
-	if ((error = device_get_children(dev, &devs, &ndevs)))
-		return (error);
-
 	/* Probe and attach all children */
-	qsort(devs, ndevs, sizeof(*devs), compare_ascending_probe_order);
-	for (int i = 0; i < ndevs; i++) {
-		device_t child = devs[i];
-		device_probe_and_attach(child);
-	}
-
-	/* Try to finalize attachment */
-	if (bus_current_pass >= BHND_FINISH_ATTACH_PASS) {
-		if ((error = bhnd_finish_attach(sc)))
-			goto cleanup;
-	}
-
-cleanup:
-	free(devs, M_TEMP);
-
-	if (error)
+	if ((error = bhnd_bus_probe_children(dev))) {
 		bhnd_delete_children(sc);
+		return (error);
+	}
 
-	return (error);
+	return (0);
 }
 
 /**
@@ -164,11 +133,13 @@ bhnd_delete_children(struct bhnd_softc *sc)
 	int			 ndevs;
 	int			 error;
 
-	if ((error = device_get_children(sc->dev, &devs, &ndevs)))
+	/* Fetch children in detach order */
+	error = bhnd_bus_get_children(sc->dev, &devs, &ndevs,
+	    BHND_DEVICE_ORDER_DETACH);
+	if (error)
 		return (error);
 
-	/* Detach in the reverse of attach order */
-	qsort(devs, ndevs, sizeof(*devs), compare_descending_probe_order);
+	/* Perform detach */
 	for (int i = 0; i < ndevs; i++) {
 		device_t child = devs[i];
 
@@ -178,7 +149,7 @@ bhnd_delete_children(struct bhnd_softc *sc)
 	}
 
 cleanup:
-	free(devs, M_TEMP);
+	bhnd_bus_free_children(devs);
 	return (error);
 }
 
@@ -193,12 +164,17 @@ int
 bhnd_generic_detach(device_t dev)
 {
 	struct bhnd_softc	*sc;
+	int			 error;
 
 	if (!device_is_attached(dev))
 		return (EBUSY);
 
 	sc = device_get_softc(dev);
-	return (bhnd_delete_children(sc));
+
+	if ((error = bhnd_delete_children(sc)))
+		return (error);
+
+	return (0);
 }
 
 /**
@@ -218,11 +194,13 @@ bhnd_generic_shutdown(device_t dev)
 	if (!device_is_attached(dev))
 		return (EBUSY);
 
-	if ((error = device_get_children(dev, &devs, &ndevs)))
+	/* Fetch children in detach order */
+	error = bhnd_bus_get_children(dev, &devs, &ndevs,
+	    BHND_DEVICE_ORDER_DETACH);
+	if (error)
 		return (error);
 
-	/* Shutdown in the reverse of attach order */
-	qsort(devs, ndevs, sizeof(*devs), compare_descending_probe_order);
+	/* Perform shutdown */
 	for (int i = 0; i < ndevs; i++) {
 		device_t child = devs[i];
 
@@ -232,7 +210,7 @@ bhnd_generic_shutdown(device_t dev)
 	}
 
 cleanup:
-	free(devs, M_TEMP);
+	bhnd_bus_free_children(devs);
 	return (error);
 }
 
@@ -253,10 +231,13 @@ bhnd_generic_resume(device_t dev)
 	if (!device_is_attached(dev))
 		return (EBUSY);
 
-	if ((error = device_get_children(dev, &devs, &ndevs)))
+	/* Fetch children in attach order */
+	error = bhnd_bus_get_children(dev, &devs, &ndevs,
+	    BHND_DEVICE_ORDER_ATTACH);
+	if (error)
 		return (error);
 
-	qsort(devs, ndevs, sizeof(*devs), compare_ascending_probe_order);
+	/* Perform resume */
 	for (int i = 0; i < ndevs; i++) {
 		device_t child = devs[i];
 
@@ -266,7 +247,7 @@ bhnd_generic_resume(device_t dev)
 	}
 
 cleanup:
-	free(devs, M_TEMP);
+	bhnd_bus_free_children(devs);
 	return (error);
 }
 
@@ -289,11 +270,13 @@ bhnd_generic_suspend(device_t dev)
 	if (!device_is_attached(dev))
 		return (EBUSY);
 
-	if ((error = device_get_children(dev, &devs, &ndevs)))
+	/* Fetch children in detach order */
+	error = bhnd_bus_get_children(dev, &devs, &ndevs,
+	    BHND_DEVICE_ORDER_DETACH);
+	if (error)
 		return (error);
 
-	/* Suspend in the reverse of attach order */
-	qsort(devs, ndevs, sizeof(*devs), compare_descending_probe_order);
+	/* Perform suspend */
 	for (int i = 0; i < ndevs; i++) {
 		device_t child = devs[i];
 		error = BUS_SUSPEND_CHILD(device_get_parent(child), child);
@@ -310,259 +293,10 @@ bhnd_generic_suspend(device_t dev)
 	}
 
 cleanup:
-	free(devs, M_TEMP);
+	bhnd_bus_free_children(devs);
 	return (error);
 }
 
-static void
-bhnd_new_pass(device_t dev)
-{
-	struct bhnd_softc	*sc;
-	int			 error;
-
-	sc = device_get_softc(dev);
-
-	/* Attach any permissible children */ 
-	bus_generic_new_pass(dev);
-
-	/* Finalize attachment */
-	if (!sc->attach_done && bus_current_pass >= BHND_FINISH_ATTACH_PASS) {
-		if ((error = bhnd_finish_attach(sc))) {
-			panic("bhnd_finish_attach() failed: %d", error);
-		}
-	}
-}
-
-/*
- * Finish any pending bus attachment operations.
- *
- * When attached as a SoC bus (as opposed to a bridged WiFi device), our
- * platform devices may not be attached until later bus passes, necessitating
- * delayed initialization on our part.
- */
-static int
-bhnd_finish_attach(struct bhnd_softc *sc)
-{
-	struct chipc_caps	*ccaps;
-
-	GIANT_REQUIRED;	/* for newbus */
-
-	KASSERT(bus_current_pass >= BHND_FINISH_ATTACH_PASS,
-	    ("bhnd_finish_attach() called in pass %d", bus_current_pass));
-
-	KASSERT(!sc->attach_done, ("duplicate call to bhnd_finish_attach()"));
-
-	/* Locate chipc device */
-	if ((sc->chipc_dev = bhnd_find_chipc(sc)) == NULL) {
-		device_printf(sc->dev, "error: ChipCommon device not found\n");
-		return (ENXIO);
-	}
-
-	ccaps = BHND_CHIPC_GET_CAPS(sc->chipc_dev);
-
-	/* Look for NVRAM device */
-	if (ccaps->nvram_src != BHND_NVRAM_SRC_UNKNOWN) {
-		if ((sc->nvram_dev = bhnd_find_nvram(sc)) == NULL) {
-			device_printf(sc->dev,
-			    "warning: NVRAM %s device not found\n",
-			    bhnd_nvram_src_name(ccaps->nvram_src));
-		}
-	}
-
-	/* Look for a PMU  */
-	if (ccaps->pmu || ccaps->pwr_ctrl) {
-		if ((sc->pmu_dev = bhnd_find_pmu(sc)) == NULL) {
-			device_printf(sc->dev,
-			    "attach failed: supported PMU not found\n");
-			return (ENXIO);
-		}
-	}
-
-	/* Mark attach as completed */
-	sc->attach_done = true;
-
-	return (0);
-}
-
-/* Locate the ChipCommon core. */
-static device_t
-bhnd_find_chipc(struct bhnd_softc *sc)
-{
-	device_t chipc;
-
-        /* Make sure we're holding Giant for newbus */
-	GIANT_REQUIRED;
-
-	/* chipc_dev is initialized during attachment */
-	if (sc->attach_done) {
-		if ((chipc = sc->chipc_dev) == NULL)
-			return (NULL);
-
-		goto found;
-	}
-
-	/* Locate chipc core with a core unit of 0 */
-	chipc = bhnd_find_child(sc->dev, BHND_DEVCLASS_CC, 0);
-	if (chipc == NULL)
-		return (NULL);
-
-found:
-	if (device_get_state(chipc) < DS_ATTACHING) {
-		device_printf(sc->dev, "chipc found, but did not attach\n");
-		return (NULL);
-	}
-
-	return (chipc);
-}
-
-/* Locate the ChipCommon core and return the device capabilities  */
-static struct chipc_caps *
-bhnd_find_chipc_caps(struct bhnd_softc *sc)
-{
-	device_t chipc;
-
-	if ((chipc = bhnd_find_chipc(sc)) == NULL) {
-		device_printf(sc->dev, 
-		    "chipc unavailable; cannot fetch capabilities\n");
-		return (NULL);
-	}
-
-	return (BHND_CHIPC_GET_CAPS(chipc));
-}
-
-/**
- * Find an attached platform device on @p dev, searching first for cores
- * matching @p classname, and if not found, searching the children of the first
- * bhnd_chipc device on the bus.
- * 
- * @param sc Driver state.
- * @param chipc Attached ChipCommon device.
- * @param classname Device class to search for.
- * 
- * @retval device_t A matching device.
- * @retval NULL If no matching device is found.
- */
-static device_t
-bhnd_find_platform_dev(struct bhnd_softc *sc, const char *classname)
-{
-	device_t chipc, child;
-
-        /* Make sure we're holding Giant for newbus */
-	GIANT_REQUIRED;
-
-	/* Look for a directly-attached child */
-	child = device_find_child(sc->dev, classname, -1);
-	if (child != NULL)
-		goto found;
-
-	/* Look for the first matching ChipCommon child */
-	if ((chipc = bhnd_find_chipc(sc)) == NULL) {
-		device_printf(sc->dev, 
-		    "chipc unavailable; cannot locate %s\n", classname);
-		return (NULL);
-	}
-
-	child = device_find_child(chipc, classname, -1);
-	if (child != NULL)
-		goto found;
-
-	/* Look for a parent-attached device (e.g. nexus0 -> bhnd_nvram) */
-	child = device_find_child(device_get_parent(sc->dev), classname, -1);
-	if (child == NULL)
-		return (NULL);
-
-found:
-	if (device_get_state(child) < DS_ATTACHING)
-		return (NULL);
-
-	return (child);
-}
-
-/* Locate the PMU device, if any */
-static device_t
-bhnd_find_pmu(struct bhnd_softc *sc)
-{
-        /* Make sure we're holding Giant for newbus */
-	GIANT_REQUIRED;
-
-	/* pmu_dev is initialized during attachment */
-	if (sc->attach_done) {
-		if (sc->pmu_dev == NULL)
-			return (NULL);
-
-		if (device_get_state(sc->pmu_dev) < DS_ATTACHING)
-			return (NULL);
-
-		return (sc->pmu_dev);
-	}
-
-
-	return (bhnd_find_platform_dev(sc, "bhnd_pmu"));
-}
-
-/* Locate the NVRAM device, if any */
-static device_t
-bhnd_find_nvram(struct bhnd_softc *sc)
-{
-	struct chipc_caps *ccaps;
-
-        /* Make sure we're holding Giant for newbus */
-	GIANT_REQUIRED;
-
-
-	/* nvram_dev is initialized during attachment */
-	if (sc->attach_done) {
-		if (sc->nvram_dev == NULL)
-			return (NULL);
-
-		if (device_get_state(sc->nvram_dev) < DS_ATTACHING)
-			return (NULL);
-
-		return (sc->nvram_dev);
-	}
-
-	if ((ccaps = bhnd_find_chipc_caps(sc)) == NULL)
-		return (NULL);
-
-	if (ccaps->nvram_src == BHND_NVRAM_SRC_UNKNOWN)
-		return (NULL);
-
-	return (bhnd_find_platform_dev(sc, "bhnd_nvram"));
-}
-
-/*
- * Ascending comparison of bhnd device's probe order.
- */
-static int
-compare_ascending_probe_order(const void *lhs, const void *rhs)
-{
-	device_t	ldev, rdev;
-	int		lorder, rorder;
-
-	ldev = (*(const device_t *) lhs);
-	rdev = (*(const device_t *) rhs);
-
-	lorder = BHND_BUS_GET_PROBE_ORDER(device_get_parent(ldev), ldev);
-	rorder = BHND_BUS_GET_PROBE_ORDER(device_get_parent(rdev), rdev);
-
-	if (lorder < rorder) {
-		return (-1);
-	} else if (lorder > rorder) {
-		return (1);
-	} else {
-		return (0);
-	}
-}
-
-/*
- * Descending comparison of bhnd device's probe order.
- */
-static int
-compare_descending_probe_order(const void *lhs, const void *rhs)
-{
-	return (compare_ascending_probe_order(rhs, lhs));
-}
-
 /**
  * Default bhnd(4) bus driver implementation of BHND_BUS_GET_PROBE_ORDER().
  *
@@ -613,7 +347,7 @@ bhnd_generic_get_probe_order(device_t dev, device_t child)
 	case BHND_DEVCLASS_EROM:
 	case BHND_DEVCLASS_OTHER:
 	case BHND_DEVCLASS_INVALID:
-		if (bhnd_find_hostb_device(dev) == child)
+		if (bhnd_bus_find_hostb_device(dev) == child)
 			return (BHND_PROBE_ROOT + BHND_PROBE_ORDER_EARLY);
 
 		return (BHND_PROBE_DEFAULT);
@@ -630,7 +364,6 @@ bhnd_generic_alloc_pmu(device_t dev, device_t child)
 {
 	struct bhnd_softc		*sc;
 	struct bhnd_resource		*br;
-	struct chipc_caps		*ccaps;
 	struct bhnd_core_pmu_info	*pm;
 	struct resource_list		*rl;
 	struct resource_list_entry	*rle;
@@ -646,18 +379,6 @@ bhnd_generic_alloc_pmu(device_t dev, device_t child)
 	pm = bhnd_get_pmu_info(child);
 	pmu_regs = BHND_CLK_CTL_ST;
 
-	if ((ccaps = bhnd_find_chipc_caps(sc)) == NULL) {
-		device_printf(sc->dev, "alloc_pmu failed: chipc "
-		    "capabilities unavailable\n");
-		return (ENXIO);
-	}
-	
-	if ((pmu_dev = bhnd_find_pmu(sc)) == NULL) {
-		device_printf(sc->dev, 
-		    "pmu unavailable; cannot allocate request state\n");
-		return (ENXIO);
-	}
-
 	/* already allocated? */
 	if (pm != NULL) {
 		panic("duplicate PMU allocation for %s",
@@ -719,23 +440,34 @@ bhnd_generic_alloc_pmu(device_t dev, device_t child)
 	else
 		pmu_regs -= r_addr - rman_get_start(rle->res);
 
+	/* Retain PMU reference on behalf of our caller */
+	pmu_dev = bhnd_retain_provider(child, BHND_SERVICE_PMU);
+	if (pmu_dev == NULL) {
+		device_printf(sc->dev, 
+		    "pmu unavailable; cannot allocate request state\n");
+		return (ENXIO);
+	}
+
 	/* Allocate and initialize PMU info */
 	br = malloc(sizeof(struct bhnd_resource), M_BHND, M_NOWAIT);
-	if (br == NULL)
+	if (br == NULL) {
+		bhnd_release_provider(child, pmu_dev, BHND_SERVICE_PMU);
 		return (ENOMEM);
+	}
 
 	br->res = rle->res;
 	br->direct = ((rman_get_flags(rle->res) & RF_ACTIVE) != 0);
 
 	pm = malloc(sizeof(*pm), M_BHND, M_NOWAIT);
 	if (pm == NULL) {
+		bhnd_release_provider(child, pmu_dev, BHND_SERVICE_PMU);
 		free(br, M_BHND);
 		return (ENOMEM);
 	}
 	pm->pm_dev = child;
-	pm->pm_pmu = pmu_dev;
 	pm->pm_res = br;
 	pm->pm_regs = pmu_regs;
+	pm->pm_pmu = pmu_dev;
 
 	bhnd_set_pmu_info(child, pm);
 	return (0);
@@ -749,29 +481,24 @@ bhnd_generic_release_pmu(device_t dev, device_t child)
 {
 	struct bhnd_softc		*sc;
 	struct bhnd_core_pmu_info	*pm;
-	device_t			 pmu;
 	int				 error;
 
 	GIANT_REQUIRED;	/* for newbus */
 	
 	sc = device_get_softc(dev);
 
-	if ((pmu = bhnd_find_pmu(sc)) == NULL) {
-		device_printf(sc->dev, 
-		    "pmu unavailable; cannot release request state\n");
-		return (ENXIO);
-	}
-
 	/* dispatch release request */
 	pm = bhnd_get_pmu_info(child);
 	if (pm == NULL)
 		panic("pmu over-release for %s", device_get_nameunit(child));
 
-	if ((error = BHND_PMU_CORE_RELEASE(pmu, pm)))
+	if ((error = BHND_PMU_CORE_RELEASE(pm->pm_pmu, pm)))
 		return (error);
 
 	/* free PMU info */
 	bhnd_set_pmu_info(child, NULL);
+
+	bhnd_release_provider(pm->pm_dev, pm->pm_pmu, BHND_SERVICE_PMU);
 	free(pm->pm_res, M_BHND);
 	free(pm, M_BHND);
 
@@ -875,9 +602,9 @@ bhnd_generic_is_region_valid(device_t dev, device_t child,
 /**
  * Default bhnd(4) bus driver implementation of BHND_BUS_GET_NVRAM_VAR().
  * 
- * This implementation searches @p dev for a usable NVRAM child device.
+ * This implementation searches @p dev for a registered NVRAM child device.
  * 
- * If no usable child device is found on @p dev, the request is delegated to
+ * If no NVRAM device is registered with @p dev, the request is delegated to
  * the BHND_BUS_GET_NVRAM_VAR() method on the parent of @p dev.
  */
 int
@@ -886,12 +613,17 @@ bhnd_generic_get_nvram_var(device_t dev, device_t child, const char *name,
 {
 	struct bhnd_softc	*sc;
 	device_t		 nvram, parent;
+	int			 error;
 
 	sc = device_get_softc(dev);
 
 	/* If a NVRAM device is available, consult it first */
-	if ((nvram = bhnd_find_nvram(sc)) != NULL)
-		return BHND_NVRAM_GETVAR(nvram, name, buf, size, type);
+	nvram = bhnd_retain_provider(child, BHND_SERVICE_NVRAM);
+	if (nvram != NULL) {
+		error = BHND_NVRAM_GETVAR(nvram, name, buf, size, type);
+		bhnd_release_provider(child, nvram, BHND_SERVICE_NVRAM);
+		return (error);
+	}
 
 	/* Otherwise, try to delegate to parent */
 	if ((parent = device_get_parent(dev)) == NULL)
@@ -1046,15 +778,6 @@ bhnd_generic_child_deleted(device_t dev, device_t child)
 		panic("%s leaked device pmu state\n",
 		    device_get_nameunit(child));
 	}
-
-	/* Clean up platform device references */
-	if (sc->chipc_dev == child) {
-		sc->chipc_dev = NULL;
-	} else if (sc->nvram_dev == child) {
-		sc->nvram_dev = NULL;
-	} else if (sc->pmu_dev == child) {
-		sc->pmu_dev = NULL;
-	}
 }
 
 /**
@@ -1176,7 +899,6 @@ static device_method_t bhnd_methods[] = {
 	DEVMETHOD(device_resume,		bhnd_generic_resume),
 
 	/* Bus interface */
-	DEVMETHOD(bus_new_pass,			bhnd_new_pass),
 	DEVMETHOD(bus_child_deleted,		bhnd_generic_child_deleted),
 	DEVMETHOD(bus_probe_nomatch,		bhnd_generic_probe_nomatch),
 	DEVMETHOD(bus_print_child,		bhnd_generic_print_child),
diff --git a/sys/dev/bhnd/bhnd.h b/sys/dev/bhnd/bhnd.h
index 2532c9d07092..33e34344968a 100644
--- a/sys/dev/bhnd/bhnd.h
+++ b/sys/dev/bhnd/bhnd.h
@@ -1,7 +1,11 @@
 /*-
- * Copyright (c) 2015 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -32,8 +36,10 @@
 #ifndef _BHND_BHND_H_
 #define _BHND_BHND_H_
 
-#include <sys/types.h>
+#include <sys/param.h>
 #include <sys/bus.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
 
 #include <machine/bus.h>
 
@@ -289,6 +295,35 @@ struct bhnd_device {
 #define	BHND_DEVICE_IS_END(_d)	\
 	(BHND_MATCH_IS_ANY(&(_d)->core) && (_d)->desc == NULL)
 
+/**
+ * bhnd device sort order.
+ */
+typedef enum {
+	BHND_DEVICE_ORDER_ATTACH,	/**< sort by bhnd(4) device attach order;
+					     child devices should be probed/attached
+					     in this order */
+	BHND_DEVICE_ORDER_DETACH,	/**< sort by bhnd(4) device detach order;
+					     child devices should be detached, suspended,
+					     and shutdown in this order */
+} bhnd_device_order;
+
+/**
+ * A registry of bhnd service providers.
+ */
+struct bhnd_service_registry {
+	STAILQ_HEAD(,bhnd_service_entry)	entries;	/**< registered services */
+	struct mtx				lock;		/**< state lock */
+};
+
+/**
+ * bhnd service provider flags.
+ */
+enum {
+	BHND_SPF_INHERITED	= (1<<0),	/**< service provider reference was inherited from
+						     a parent bus, and should be deregistered when the
+						     last active reference is released */
+};
+
 const char			*bhnd_vendor_name(uint16_t vendor);
 const char			*bhnd_port_type_name(bhnd_port_type port_type);
 const char			*bhnd_nvram_src_name(bhnd_nvram_src nvram_src);
@@ -304,12 +339,23 @@ bhnd_devclass_t			 bhnd_core_class(const struct bhnd_core_info *ci);
 int				 bhnd_format_chip_id(char *buffer, size_t size,
 				     uint16_t chip_id);
 
-device_t			 bhnd_match_child(device_t dev,
+device_t			 bhnd_bus_match_child(device_t bus,
 				     const struct bhnd_core_match *desc);
 
-device_t			 bhnd_find_child(device_t dev,
+device_t			 bhnd_bus_find_child(device_t bus,
 				     bhnd_devclass_t class, int unit);
 
+int				 bhnd_bus_get_children(device_t bus,
+				     device_t **devlistp, int *devcountp,
+				     bhnd_device_order order);
+
+void				 bhnd_bus_free_children(device_t *devlist);
+
+int				 bhnd_bus_probe_children(device_t bus);
+
+int				 bhnd_sort_devices(device_t *devlist,
+				     size_t devcount, bhnd_device_order order);
+
 device_t			 bhnd_find_bridge_root(device_t dev,
 				     devclass_t bus_class);
 
@@ -410,6 +456,51 @@ int				 bhnd_nvram_getvar_array(device_t dev,
 				     const char *name, void *buf, size_t count,
 				     bhnd_nvram_type type);
 
+int				 bhnd_service_registry_init(
+				     struct bhnd_service_registry *bsr);
+int				 bhnd_service_registry_fini(
+				     struct bhnd_service_registry *bsr);
+int				 bhnd_service_registry_add(
+				     struct bhnd_service_registry *bsr,
+				     device_t provider,
+				     bhnd_service_t service,
+				     uint32_t flags);
+int				 bhnd_service_registry_remove(
+				     struct bhnd_service_registry *bsr,
+				     device_t provider,
+				     bhnd_service_t service);
+device_t			 bhnd_service_registry_retain(
+				     struct bhnd_service_registry *bsr,
+				     bhnd_service_t service);
+bool				 bhnd_service_registry_release(
+				     struct bhnd_service_registry *bsr,
+				     device_t provider,
+				     bhnd_service_t service);
+
+int				 bhnd_bus_generic_register_provider(
+				     device_t dev, device_t child,
+				     device_t provider, bhnd_service_t service);
+int				 bhnd_bus_generic_deregister_provider(
+				     device_t dev, device_t child,
+				     device_t provider, bhnd_service_t service);
+device_t			 bhnd_bus_generic_retain_provider(device_t dev,
+				     device_t child, bhnd_service_t service);
+void				 bhnd_bus_generic_release_provider(device_t dev,
+				     device_t child, device_t provider,
+				     bhnd_service_t service);
+
+int				 bhnd_bus_generic_sr_register_provider(
+				     device_t dev, device_t child,
+				     device_t provider, bhnd_service_t service);
+int				 bhnd_bus_generic_sr_deregister_provider(
+				     device_t dev, device_t child,
+				     device_t provider, bhnd_service_t service);
+device_t			 bhnd_bus_generic_sr_retain_provider(device_t dev,
+				     device_t child, bhnd_service_t service);
+void				 bhnd_bus_generic_sr_release_provider(device_t dev,
+				     device_t child, device_t provider,
+				     bhnd_service_t service);
+
 bool				 bhnd_bus_generic_is_hw_disabled(device_t dev,
 				     device_t child);
 bool				 bhnd_bus_generic_is_region_valid(device_t dev,
@@ -458,11 +549,85 @@ bhnd_driver_get_erom_class(driver_t *driver)
  * @param dev A bhnd bus device.
  */
 static inline device_t
-bhnd_find_hostb_device(device_t dev) {
+bhnd_bus_find_hostb_device(device_t dev) {
 	return (BHND_BUS_FIND_HOSTB_DEVICE(dev));
 }
 
 /**
+ * Register a provider for a given @p service.
+ *
+ * @param dev		The device to register as a service provider
+ *			with its parent bus.
+ * @param service	The service for which @p dev will be registered.
+ *
+ * @retval 0		success
+ * @retval EEXIST	if an entry for @p service already exists.
+ * @retval non-zero	if registering @p dev otherwise fails, a regular
+ *			unix error code will be returned.
+ */
+static inline int
+bhnd_register_provider(device_t dev, bhnd_service_t service)
+{
+	return (BHND_BUS_REGISTER_PROVIDER(device_get_parent(dev), dev, dev,
+	    service));
+}
+
+ /**
+ * Attempt to remove a service provider registration for @p dev.
+ *
+ * @param dev		The device to be deregistered as a service provider.
+ * @param service	The service for which @p dev will be deregistered, or
+ *			BHND_SERVICE_INVALID to remove all service registrations
+ *			for @p dev.
+ *
+ * @retval 0		success
+ * @retval EBUSY	if active references to @p dev exist; @see
+ *			bhnd_retain_provider() and bhnd_release_provider().
+ */
+static inline int
+bhnd_deregister_provider(device_t dev, bhnd_service_t service)
+{
+	return (BHND_BUS_DEREGISTER_PROVIDER(device_get_parent(dev), dev, dev,
+	    service));
+}
+
+/**
+ * Retain and return a reference to the registered @p service provider, if any.
+ *
+ * @param dev		The requesting device.
+ * @param service	The service for which a provider should be returned.
+ *
+ * On success, the caller assumes ownership the returned provider, and
+ * is responsible for releasing this reference via
+ * BHND_BUS_RELEASE_PROVIDER().
+ *
+ * @retval device_t	success
+ * @retval NULL		if no provider is registered for @p service. 
+ */
+static inline device_t
+bhnd_retain_provider(device_t dev, bhnd_service_t service)
+{
+	return (BHND_BUS_RETAIN_PROVIDER(device_get_parent(dev), dev,
+	    service));
+}
+
+/**
+ * Release a reference to a provider device previously returned by
+ * bhnd_retain_provider().
+ *
+ * @param dev The requesting device.
+ * @param provider The provider to be released.
+ * @param service The service for which @p provider was previously retained.
+ */
+static inline void
+bhnd_release_provider(device_t dev, device_t provider,
+    bhnd_service_t service)
+{
+	return (BHND_BUS_RELEASE_PROVIDER(device_get_parent(dev), dev,
+	    provider, service));
+}
+
+/**
  * Return true if the hardware components required by @p dev are known to be
  * unpopulated or otherwise unusable.
  *
diff --git a/sys/dev/bhnd/bhnd_bus_if.m b/sys/dev/bhnd/bhnd_bus_if.m
index 1b2bff6d4159..28b513959e6e 100644
--- a/sys/dev/bhnd/bhnd_bus_if.m
+++ b/sys/dev/bhnd/bhnd_bus_if.m
@@ -1,7 +1,11 @@
 #-
 # Copyright (c) 2015-2016 Landon Fuller <landonf@FreeBSD.org>
+# Copyright (c) 2017 The FreeBSD Foundation
 # All rights reserved.
 #
+# Portions of this software were developed by Landon Fuller
+# under sponsorship from the FreeBSD Foundation.
+#
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
@@ -221,6 +225,12 @@ CODE {
 		return (NULL);
 	}
 
+	static struct bhnd_service_registry *
+	bhnd_bus_null_get_service_registry(device_t dev)
+	{
+		panic("bhnd_bus_get_service_registry unimplemented");
+	}
+
 	static bool
 	bhnd_bus_null_is_hw_disabled(device_t dev, device_t child)
 	{
@@ -274,6 +284,100 @@ STATICMETHOD bhnd_erom_class_t * get_erom_class {
 } DEFAULT bhnd_bus_null_get_erom_class;
 
 /**
+ * Register a shared bus @p provider for a given @p service.
+ *
+ * @param dev		The parent of @p child.
+ * @param child		The requesting child device.
+ * @param provider	The service provider to register.
+ * @param service	The service for which @p provider will be registered.
+ *
+ * @retval 0		success
+ * @retval EEXIST	if an entry for @p service already exists.
+ * @retval non-zero	if registering @p provider otherwise fails, a regular
+ *			unix error code will be returned.
+ */
+METHOD int register_provider {
+	device_t dev;
+	device_t child;
+	device_t provider;
+	bhnd_service_t service;
+} DEFAULT bhnd_bus_generic_register_provider;
+
+ /**
+ * Attempt to remove the @p service provider registration for @p provider.
+ *
+ * @param dev		The parent of @p child.
+ * @param child		The requesting child device.
+ * @param provider	The service provider to be deregistered.
+ * @param service	The service for which @p provider will be deregistered,
+ *			or BHND_SERVICE_INVALID to remove all service
+ *			registrations for @p provider.
+ *
+ * @retval 0		success
+ * @retval EBUSY	if active references to @p provider exist; @see
+ *			BHND_BUS_RETAIN_PROVIDER() and
+ *			BHND_BUS_RELEASE_PROVIDER().
+ */
+METHOD int deregister_provider {
+	device_t dev;
+	device_t child;
+	device_t provider;
+	bhnd_service_t service;
+} DEFAULT bhnd_bus_generic_deregister_provider;
+
+/**
+ * Retain and return a reference to the registered @p service provider, if any.
+ *
+ * @param dev		The parent of @p child.
+ * @param child		The requesting child device.
+ * @param service	The service for which a provider should be returned.
+ *
+ * On success, the caller assumes ownership the returned provider, and
+ * is responsible for releasing this reference via
+ * BHND_BUS_RELEASE_PROVIDER().
+ *
+ * @retval device_t	success
+ * @retval NULL		if no provider is registered for @p service. 
+ */
+METHOD device_t retain_provider {
+	device_t dev;
+	device_t child;
+	bhnd_service_t service;
+} DEFAULT bhnd_bus_generic_retain_provider;
+
+ /**
+ * Release a reference to a service provider previously returned by
+ * BHND_BUS_RETAIN_PROVIDER().
+ *
+ * @param dev		The parent of @p child.
+ * @param child		The requesting child device.
+ * @param provider	The provider to be released.
+ * @param service	The service for which @p provider was previously
+ *			retained.
+ */
+METHOD void release_provider {
+	device_t dev;
+	device_t child;
+	device_t provider;
+	bhnd_service_t service;
+} DEFAULT bhnd_bus_generic_release_provider;
+
+/**
+ * Return a struct bhnd_service_registry.
+ *
+ * Used by drivers which use bhnd_bus_generic_sr_register_provider() etc.
+ * to implement service provider registration. It should return a service
+ * registry that may be used to resolve provider requests from @p child.
+ *
+ * @param dev		The parent of @p child.
+ * @param child		The requesting child device.
+ */
+METHOD struct bhnd_service_registry * get_service_registry {
+	device_t dev;
+	device_t child;
+} DEFAULT bhnd_bus_null_get_service_registry;
+
+/**
  * Return the active host bridge core for the bhnd bus, if any.
  *
  * @param dev The bhnd bus device.
diff --git a/sys/dev/bhnd/bhnd_private.h b/sys/dev/bhnd/bhnd_private.h
new file mode 100644
index 000000000000..9c2ed900fa15
--- /dev/null
+++ b/sys/dev/bhnd/bhnd_private.h
@@ -0,0 +1,57 @@
+/*-
+ * Copyright (c) 2017 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Landon Fuller under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _BHND_BHND_PRIVATE_H_
+#define _BHND_BHND_PRIVATE_H_
+
+#include <sys/param.h>
+#include <sys/queue.h>
+
+#include "bhnd_types.h"
+
+/*
+ * Private bhnd(4) driver definitions.
+ */
+
+/**
+ * A bhnd(4) service registry entry.
+ */
+struct bhnd_service_entry {
+	device_t	provider;	/**< service provider */
+	bhnd_service_t	service;	/**< service implemented */
+	uint32_t	flags;		/**< entry flags (see BHND_SPF_*) */
+	volatile u_int	refs;		/**< reference count; updated atomically
+					     with only a shared lock held */
+
+	STAILQ_ENTRY(bhnd_service_entry) link;
+};
+
+#endif /* _BHND_BHND_PRIVATE_H_ */
diff --git a/sys/dev/bhnd/bhnd_subr.c b/sys/dev/bhnd/bhnd_subr.c
index 716a8721ecec..992b887288fa 100644
--- a/sys/dev/bhnd/bhnd_subr.c
+++ b/sys/dev/bhnd/bhnd_subr.c
@@ -1,7 +1,11 @@
 /*-
- * Copyright (c) 2015 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -32,6 +36,7 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/bus.h>
+#include <sys/refcount.h>
 #include <sys/systm.h>
 
 #include <machine/bus.h>
@@ -51,6 +56,14 @@ __FBSDID("$FreeBSD$");
 
 #include "bhndreg.h"
 #include "bhndvar.h"
+#include "bhnd_private.h"
+
+static void	bhnd_service_registry_free_entry(
+		    struct bhnd_service_entry *entry);
+
+static int	compare_ascending_probe_order(const void *lhs, const void *rhs);
+static int	compare_descending_probe_order(const void *lhs,
+		    const void *rhs);
 
 /* BHND core device description table. */
 static const struct bhnd_core_desc {
@@ -331,9 +344,9 @@ bhnd_get_core_info(device_t dev) {
 }
 
 /**
- * Find a @p class child device with @p unit on @p dev.
+ * Find a @p class child device with @p unit on @p bus.
  * 
- * @param parent The bhnd-compatible bus to be searched.
+ * @param bus The bhnd-compatible bus to be searched.
  * @param class The device class to match on.
  * @param unit The core unit number; specify -1 to return the first match
  * regardless of unit number.
@@ -342,7 +355,7 @@ bhnd_get_core_info(device_t dev) {
  * @retval NULL if no matching child device is found.
  */
 device_t
-bhnd_find_child(device_t dev, bhnd_devclass_t class, int unit)
+bhnd_bus_find_child(device_t bus, bhnd_devclass_t class, int unit)
 {
 	struct bhnd_core_match md = {
 		BHND_MATCH_CORE_CLASS(class),
@@ -352,27 +365,27 @@ bhnd_find_child(device_t dev, bhnd_devclass_t class, int unit)
 	if (unit == -1)
 		md.m.match.core_unit = 0;
 
-	return bhnd_match_child(dev, &md);
+	return bhnd_bus_match_child(bus, &md);
 }
 
 /**
- * Find the first child device on @p dev that matches @p desc.
+ * Find the first child device on @p bus that matches @p desc.
  * 
- * @param parent The bhnd-compatible bus to be searched.
+ * @param bus The bhnd-compatible bus to be searched.
  * @param desc A match descriptor.
  * 
  * @retval device_t if a matching child device is found.
  * @retval NULL if no matching child device is found.
  */
 device_t
-bhnd_match_child(device_t dev, const struct bhnd_core_match *desc)
+bhnd_bus_match_child(device_t bus, const struct bhnd_core_match *desc)
 {
 	device_t	*devlistp;
 	device_t	 match;
 	int		 devcnt;
 	int		 error;
 
-	error = device_get_children(dev, &devlistp, &devcnt);
+	error = device_get_children(bus, &devlistp, &devcnt);
 	if (error != 0)
 		return (NULL);
 
@@ -392,6 +405,146 @@ done:
 }
 
 /**
+ * Retrieve an ordered list of all device instances currently connected to
+ * @p bus, returning a pointer to the array in @p devlistp and the count
+ * in @p ndevs.
+ * 
+ * The memory allocated for the table must be freed via
+ * bhnd_bus_free_children().
+ * 
+ * @param	bus		The bhnd-compatible bus to be queried.
+ * @param[out]	devlist		The array of devices.
+ * @param[out]	devcount	The number of devices in @p devlistp
+ * @param	order		The order in which devices will be returned
+ *				in @p devlist.
+ * 
+ * @retval 0		success
+ * @retval non-zero	if an error occurs, a regular unix error code will
+ *			be returned.
+ */
+int
+bhnd_bus_get_children(device_t bus, device_t **devlist, int *devcount,
+    bhnd_device_order order)
+{
+	int error;
+
+	/* Fetch device array */
+	if ((error = device_get_children(bus, devlist, devcount)))
+		return (error);
+
+	/* Perform requested sorting */
+	if ((error = bhnd_sort_devices(*devlist, *devcount, order))) {
+		bhnd_bus_free_children(*devlist);
+		return (error);
+	}
+
+	return (0);
+}
+
+/**
+ * Free any memory allocated in a previous call to bhnd_bus_get_children().
+ *
+ * @param devlist The device array returned by bhnd_bus_get_children().
+ */
+void
+bhnd_bus_free_children(device_t *devlist)
+{
+	free(devlist, M_TEMP);
+}
+
+/**
+ * Perform in-place sorting of an array of bhnd device instances.
+ * 
+ * @param devlist	An array of bhnd devices.
+ * @param devcount	The number of devices in @p devs.
+ * @param order		The sort order to be used.
+ */
+int
+bhnd_sort_devices(device_t *devlist, size_t devcount, bhnd_device_order order)
+{
+	int (*compare)(const void *, const void *);
+
+	switch (order) {
+	case BHND_DEVICE_ORDER_ATTACH:
+		compare = compare_ascending_probe_order;
+		break;
+	case BHND_DEVICE_ORDER_DETACH:
+		compare = compare_descending_probe_order;
+		break;
+	default:
+		printf("unknown sort order: %d\n", order);
+		return (EINVAL);
+	}
+
+	qsort(devlist, devcount, sizeof(*devlist), compare);
+	return (0);
+}
+
+/*
+ * Ascending comparison of bhnd device's probe order.
+ */
+static int
+compare_ascending_probe_order(const void *lhs, const void *rhs)
+{
+	device_t	ldev, rdev;
+	int		lorder, rorder;
+
+	ldev = (*(const device_t *) lhs);
+	rdev = (*(const device_t *) rhs);
+
+	lorder = BHND_BUS_GET_PROBE_ORDER(device_get_parent(ldev), ldev);
+	rorder = BHND_BUS_GET_PROBE_ORDER(device_get_parent(rdev), rdev);
+
+	if (lorder < rorder) {
+		return (-1);
+	} else if (lorder > rorder) {
+		return (1);
+	} else {
+		return (0);
+	}
+}
+
+/*
+ * Descending comparison of bhnd device's probe order.
+ */
+static int
+compare_descending_probe_order(const void *lhs, const void *rhs)
+{
+	return (compare_ascending_probe_order(rhs, lhs));
+}
+
+/**
+ * Call device_probe_and_attach() for each of the bhnd bus device's
+ * children, in bhnd attach order.
+ * 
+ * @param bus The bhnd-compatible bus for which all children should be probed
+ * and attached.
+ */
+int
+bhnd_bus_probe_children(device_t bus)
+{
+	device_t	*devs;
+	int		 ndevs;
+	int		 error;
+
+	/* Fetch children in attach order */
+	error = bhnd_bus_get_children(bus, &devs, &ndevs,
+	    BHND_DEVICE_ORDER_ATTACH);
+	if (error)
+		return (error);
+
+	/* Probe and attach all children */
+	for (int i = 0; i < ndevs; i++) {
+		device_t child = devs[i];
+		device_probe_and_attach(child);
+	}
+
+	bhnd_bus_free_children(devs);
+
+	return (0);
+}
+
+/**
  * Walk up the bhnd device hierarchy to locate the root device
  * to which the bhndb bridge is attached.
  * 
@@ -727,7 +880,7 @@ bhnd_device_lookup(device_t dev, const struct bhnd_device *table,
 	uint32_t			 dflags;
 
 	parent = device_get_parent(dev);
-	hostb = bhnd_find_hostb_device(parent);
+	hostb = bhnd_bus_find_hostb_device(parent);
 	attach_type = bhnd_get_attach_type(dev);
 
 	for (entry = table; !BHND_DEVICE_IS_END(entry); entry =
@@ -1345,6 +1498,277 @@ bhnd_nvram_getvar_array(device_t dev, const char *name, void *buf, size_t size,
 }
 
 /**
+ * Initialize a service provider registry.
+ * 
+ * @param bsr		The service registry to initialize.
+ * 
+ * @retval 0            success
+ * @retval non-zero     if an error occurs initializing the service registry,
+ *                      a regular unix error code will be returned.
+
+ */
+int
+bhnd_service_registry_init(struct bhnd_service_registry *bsr)
+{
+	STAILQ_INIT(&bsr->entries);
+	mtx_init(&bsr->lock, "bhnd_service_registry lock", NULL, MTX_DEF);
+
+	return (0);
+}
+
+/**
+ * Release all resources held by @p bsr.
+ * 
+ * @param bsr		A service registry instance previously successfully
+ *			initialized via bhnd_service_registry_init().
+ *
+ * @retval 0		success
+ * @retval EBUSY	if active references to service providers registered
+ *			with @p bsr exist.
+ */
+int
+bhnd_service_registry_fini(struct bhnd_service_registry *bsr)
+{
+	struct bhnd_service_entry *entry, *enext;
+
+	/* Remove everthing we can */
+	mtx_lock(&bsr->lock);
+	STAILQ_FOREACH_SAFE(entry, &bsr->entries, link, enext) {
+		if (entry->refs > 0)
+			continue;
+
+		STAILQ_REMOVE(&bsr->entries, entry, bhnd_service_entry, link);
+		free(entry, M_BHND);
+	}
+
+	if (!STAILQ_EMPTY(&bsr->entries)) {
+		mtx_unlock(&bsr->lock);
+		return (EBUSY);
+	}
+	mtx_unlock(&bsr->lock);
+
+	mtx_destroy(&bsr->lock);
+	return (0);
+}
+
+/**
+ * Register a @p provider for the given @p service.
+ *
+ * @param bsr		Service registry to be modified.
+ * @param provider	Service provider to register.
+ * @param service	Service for which @p provider will be registered.
+ * @param flags		Service provider flags (see BHND_SPF_*).
+ *
+ * @retval 0		success
+ * @retval EEXIST	if an entry for @p service already exists.
+ * @retval EINVAL	if @p service is BHND_SERVICE_ANY.
+ * @retval non-zero	if registering @p provider otherwise fails, a regular
+ *			unix error code will be returned.
+ */
+int
+bhnd_service_registry_add(struct bhnd_service_registry *bsr, device_t provider,
+    bhnd_service_t service, uint32_t flags)
+{
+	struct bhnd_service_entry *entry;
+
+	if (service == BHND_SERVICE_ANY)
+		return (EINVAL);
+
+	mtx_lock(&bsr->lock);
+
+	/* Is a service provider already registered? */
+	STAILQ_FOREACH(entry, &bsr->entries, link) {
+		if (entry->service == service) {
+			mtx_unlock(&bsr->lock);
+			return (EEXIST);
+		}
+	}
+
+	/* Initialize and insert our new entry */
+	entry = malloc(sizeof(*entry), M_BHND, M_NOWAIT);
+	if (entry == NULL) {
+		mtx_unlock(&bsr->lock);
+		return (ENOMEM);
+	}
+
+	entry->provider = provider;
+	entry->service = service;
+	entry->flags = flags;
+	refcount_init(&entry->refs, 0);
+
+	STAILQ_INSERT_HEAD(&bsr->entries, entry, link);
+
+	mtx_unlock(&bsr->lock);
+	return (0);
+}
+
+/**
+ * Free an unreferenced registry entry.
+ * 
+ * @param entry	The entry to be deallocated.
+ */
+static void
+bhnd_service_registry_free_entry(struct bhnd_service_entry *entry)
+{
+	KASSERT(entry->refs == 0, ("provider has active references"));
+	free(entry, M_BHND);
+}
+
+/**
+ * Attempt to remove the @p service provider registration for @p provider.
+ *
+ * @param bsr		The service registry to be modified.
+ * @param provider	The service provider to be deregistered.
+ * @param service	The service for which @p provider will be deregistered,
+ *			or BHND_SERVICE_ANY to remove all service
+ *			registrations for @p provider.
+ *
+ * @retval 0		success
+ * @retval EBUSY	if active references to @p provider exist; @see
+ *			bhnd_service_registry_retain() and
+ *			bhnd_service_registry_release().
+ */
+int
+bhnd_service_registry_remove(struct bhnd_service_registry *bsr,
+    device_t provider, bhnd_service_t service)
+{
+	struct bhnd_service_entry *entry, *enext;
+
+	mtx_lock(&bsr->lock);
+
+#define	BHND_PROV_MATCH(_e)	\
+	((_e)->provider == provider &&	\
+	 (service == BHND_SERVICE_ANY || (_e)->service == service))
+
+	/* Validate matching provider entries before making any
+	 * modifications */
+	STAILQ_FOREACH(entry, &bsr->entries, link) {
+		/* Skip non-matching entries */
+		if (!BHND_PROV_MATCH(entry))
+			continue;
+
+		/* Entry is in use? */
+		if (entry->refs > 0) {
+			mtx_unlock(&bsr->lock);
+			return (EBUSY);
+		}
+	}
+
+	/* We can now safely remove matching entries */
+	STAILQ_FOREACH_SAFE(entry, &bsr->entries, link, enext) {
+		/* Skip non-matching entries */
+		if (!BHND_PROV_MATCH(entry))
+			continue;
+
+		/* Remove from list */
+		STAILQ_REMOVE(&bsr->entries, entry, bhnd_service_entry, link);
+
+		/* Free provider entry */
+		bhnd_service_registry_free_entry(entry);
+	}
+#undef	BHND_PROV_MATCH
+
+	mtx_unlock(&bsr->lock);
+	return (0);
+}
+
+/**
+ * Retain and return a reference to a registered @p service provider, if any.
+ *
+ * @param bsr		The service registry to be queried.
+ * @param service	The service for which a provider should be returned.
+ *
+ * On success, the caller assumes ownership the returned provider, and
+ * is responsible for releasing this reference via
+ * bhnd_service_registry_release().
+ *
+ * @retval device_t	success
+ * @retval NULL		if no provider is registered for @p service.
+ */
+device_t
+bhnd_service_registry_retain(struct bhnd_service_registry *bsr,
+    bhnd_service_t service)
+{
+	struct bhnd_service_entry *entry;
+
+	mtx_lock(&bsr->lock);
+	STAILQ_FOREACH(entry, &bsr->entries, link) {
+		if (entry->service != service)
+			continue;
+
+		/* With a live refcount, entry is gauranteed to remain alive
+		 * after we release our lock */
+		refcount_acquire(&entry->refs);
+
+		mtx_unlock(&bsr->lock);
+		return (entry->provider);
+	}
+	mtx_unlock(&bsr->lock);
+
+	/* Not found */
+	return (NULL);
+}
+
+/**
+ * Release a reference to a service provider previously returned by
+ * bhnd_service_registry_retain().
+ * 
+ * If this is the last reference to an inherited service provider registration
+ * (@see BHND_SPF_INHERITED), the registration will also be removed, and
+ * true will be returned.
+ *
+ * @param bsr		The service registry from which @p provider
+ *			was returned.
+ * @param provider	The provider to be released.
+ * @param service	The service for which @p provider was previously
+ *			retained.
+ * @retval true		The inherited service provider registration was removed;
+ *			the caller should release its own reference to the
+ *			provider.
+ * @retval false	The service provider was not inherited, or active
+ *			references to the provider remain.
+ */
+bool
+bhnd_service_registry_release(struct bhnd_service_registry *bsr,
+    device_t provider, bhnd_service_t service)
+{
+	struct bhnd_service_entry *entry;
+
+	/* Exclusive lock, as we need to prevent any new references to the
+	 * entry from being taken if it's to be removed */
+	mtx_lock(&bsr->lock);
+	STAILQ_FOREACH(entry, &bsr->entries, link) {
+		bool removed;
+
+		if (entry->provider != provider)
+			continue;
+
+		if (entry->service != service)
+			continue;
+
+		if (refcount_release(&entry->refs) &&
+		    (entry->flags & BHND_SPF_INHERITED))
+		{
+			/* If an inherited entry is no longer actively
+			 * referenced, remove the local registration and inform
+			 * the caller. */
+			STAILQ_REMOVE(&bsr->entries, entry, bhnd_service_entry,
+			    link);
+			bhnd_service_registry_free_entry(entry);
+			removed = true;
+		} else {
+			removed = false;
+		}
+
+		mtx_unlock(&bsr->lock);
+		return (removed);
+	}
+
+	/* Caller owns a reference, but no such provider is registered? */
+	panic("invalid service provider reference");
+}
+
+/**
  * Using the bhnd(4) bus-level core information and a custom core name,
  * populate @p dev's device description.
  * 
@@ -1428,6 +1852,222 @@ bhnd_set_default_bus_desc(device_t dev, const struct bhnd_chipid *chip_id)
 }
 
 /**
+ * Helper function for implementing BHND_BUS_REGISTER_PROVIDER().
+ * 
+ * This implementation delegates the request to the BHND_BUS_REGISTER_PROVIDER()
+ * method on the parent of @p dev. If no parent exists, the implementation
+ * will return an error. 
+ */
+int
+bhnd_bus_generic_register_provider(device_t dev, device_t child,
+    device_t provider, bhnd_service_t service)
+{
+	device_t parent = device_get_parent(dev);
+
+	if (parent != NULL) {
+		return (BHND_BUS_REGISTER_PROVIDER(parent, child,
+		    provider, service));
+	}
+
+	return (ENXIO);
+}
+
+/**
+ * Helper function for implementing BHND_BUS_DEREGISTER_PROVIDER().
+ * 
+ * This implementation delegates the request to the
+ * BHND_BUS_DEREGISTER_PROVIDER() method on the parent of @p dev. If no parent
+ * exists, the implementation will panic.
+ */
+int
+bhnd_bus_generic_deregister_provider(device_t dev, device_t child,
+    device_t provider, bhnd_service_t service)
+{
+	device_t parent = device_get_parent(dev);
+
+	if (parent != NULL) {
+		return (BHND_BUS_DEREGISTER_PROVIDER(parent, child,
+		    provider, service));
+	}
+
+	panic("missing BHND_BUS_DEREGISTER_PROVIDER()");
+}
+
+/**
+ * Helper function for implementing BHND_BUS_RETAIN_PROVIDER().
+ * 
+ * This implementation delegates the request to the
+ * BHND_BUS_DEREGISTER_PROVIDER() method on the parent of @p dev. If no parent
+ * exists, the implementation will return NULL.
+ */
+device_t
+bhnd_bus_generic_retain_provider(device_t dev, device_t child,
+    bhnd_service_t service)
+{
+	device_t parent = device_get_parent(dev);
+
+	if (parent != NULL) {
+		return (BHND_BUS_RETAIN_PROVIDER(parent, child,
+		    service));
+	}
+
+	return (NULL);
+}
+
+/**
+ * Helper function for implementing BHND_BUS_RELEASE_PROVIDER().
+ * 
+ * This implementation delegates the request to the
+ * BHND_BUS_DEREGISTER_PROVIDER() method on the parent of @p dev. If no parent
+ * exists, the implementation will panic.
+ */
+void
+bhnd_bus_generic_release_provider(device_t dev, device_t child,
+    device_t provider, bhnd_service_t service)
+{
+	device_t parent = device_get_parent(dev);
+
+	if (parent != NULL) {
+		return (BHND_BUS_RELEASE_PROVIDER(parent, child,
+		    provider, service));
+	}
+
+	panic("missing BHND_BUS_RELEASE_PROVIDER()");
+}
+
+/**
+ * Helper function for implementing BHND_BUS_REGISTER_PROVIDER().
+ * 
+ * This implementation uses the bhnd_service_registry_add() function to
+ * do most of the work. It calls BHND_BUS_GET_SERVICE_REGISTRY() to find
+ * a suitable service registry to edit.
+ */
+int
+bhnd_bus_generic_sr_register_provider(device_t dev, device_t child,
+    device_t provider, bhnd_service_t service)
+{
+	struct bhnd_service_registry *bsr;
+
+	bsr = BHND_BUS_GET_SERVICE_REGISTRY(dev, child);
+
+	KASSERT(bsr != NULL, ("NULL service registry"));
+
+	return (bhnd_service_registry_add(bsr, provider, service, 0));
+}
+
+/**
+ * Helper function for implementing BHND_BUS_DEREGISTER_PROVIDER().
+ * 
+ * This implementation uses the bhnd_service_registry_remove() function to
+ * do most of the work. It calls BHND_BUS_GET_SERVICE_REGISTRY() to find
+ * a suitable service registry to edit.
+ */
+int
+bhnd_bus_generic_sr_deregister_provider(device_t dev, device_t child,
+    device_t provider, bhnd_service_t service)
+{
+	struct bhnd_service_registry *bsr;
+
+	bsr = BHND_BUS_GET_SERVICE_REGISTRY(dev, child);
+
+	KASSERT(bsr != NULL, ("NULL service registry"));
+
+	return (bhnd_service_registry_remove(bsr, provider, service));
+}
+
+/**
+ * Helper function for implementing BHND_BUS_RETAIN_PROVIDER().
+ * 
+ * This implementation uses the bhnd_service_registry_retain() function to
+ * do most of the work. It calls BHND_BUS_GET_SERVICE_REGISTRY() to find
+ * a suitable service registry.
+ * 
+ * If a local provider for the service is not available, and a parent device is
+ * available, this implementation will attempt to fetch and locally register
+ * a service provider reference from the parent of @p dev.
+ */
+device_t
+bhnd_bus_generic_sr_retain_provider(device_t dev, device_t child,
+    bhnd_service_t service)
+{
+	struct bhnd_service_registry	*bsr;
+	device_t			 parent, provider;
+	int				 error;
+
+	bsr = BHND_BUS_GET_SERVICE_REGISTRY(dev, child);
+	KASSERT(bsr != NULL, ("NULL service registry"));
+
+	/*
+	 * Attempt to fetch a service provider reference from either the local
+	 * service registry, or if not found, from our parent.
+	 * 
+	 * If we fetch a provider from our parent, we register the provider
+	 * with the local service registry to prevent conflicting local
+	 * registrations from being added.
+	 */
+	while (1) {
+		/* Check the local service registry first */
+		provider = bhnd_service_registry_retain(bsr, service);
+		if (provider != NULL)
+			return (provider);
+
+		/* Otherwise, try to delegate to our parent (if any) */
+		if ((parent = device_get_parent(dev)) == NULL)
+			return (NULL);
+
+		provider = BHND_BUS_RETAIN_PROVIDER(parent, dev, service);
+		if (provider == NULL)
+			return (NULL);
+
+		/* Register the inherited service registration with the local
+		 * registry */
+		error = bhnd_service_registry_add(bsr, provider, service,
+		    BHND_SPF_INHERITED);
+		if (error) {
+			BHND_BUS_RELEASE_PROVIDER(parent, dev, provider,
+			    service);
+			if (error == EEXIST) {
+				/* A valid service provider was registered
+				 * concurrently; retry fetching from the local
+				 * registry */
+				continue;
+			}
+
+			device_printf(dev, "failed to register service "
+			    "provider: %d\n", error);
+			return (NULL);
+		}
+	}
+}
+
+/**
+ * Helper function for implementing BHND_BUS_RELEASE_PROVIDER().
+ * 
+ * This implementation uses the bhnd_service_registry_release() function to
+ * do most of the work. It calls BHND_BUS_GET_SERVICE_REGISTRY() to find
+ * a suitable service registry.
+ */
+void
+bhnd_bus_generic_sr_release_provider(device_t dev, device_t child,
+    device_t provider, bhnd_service_t service)
+{
+	struct bhnd_service_registry	*bsr;
+
+	bsr = BHND_BUS_GET_SERVICE_REGISTRY(dev, child);
+	KASSERT(bsr != NULL, ("NULL service registry"));
+
+	/* Release the provider reference; if the refcount hits zero on an
+	 * inherited reference, true will be returned, and we need to drop
+	 * our own bus reference to the provider */
+	if (!bhnd_service_registry_release(bsr, provider, service))
+		return;
+
+	/* Drop our reference to the borrowed provider */
+	BHND_BUS_RELEASE_PROVIDER(device_get_parent(dev), dev, provider,
+	    service);
+}
+
+/**
  * Helper function for implementing BHND_BUS_IS_HW_DISABLED().
  * 
  * If a parent device is available, this implementation delegates the
diff --git a/sys/dev/bhnd/bhnd_types.h b/sys/dev/bhnd/bhnd_types.h
index ffdbf1a47489..d819afedbecb 100644
--- a/sys/dev/bhnd/bhnd_types.h
+++ b/sys/dev/bhnd/bhnd_types.h
@@ -1,7 +1,11 @@
 /*-
- * Copyright (c) 2015 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -65,6 +69,14 @@ typedef enum {
 	BHND_DEVCLASS_INVALID		/**< no/invalid class */
 } bhnd_devclass_t;
 
+/** bhnd(4) platform services. */
+typedef enum {
+	BHND_SERVICE_CHIPC,		/**< chipcommon service; implements the bhnd_chipc interface */
+	BHND_SERVICE_PMU,		/**< pmu service; implements the bhnd_pmu interface */
+	BHND_SERVICE_NVRAM,		/**< nvram service; implements the bhnd_nvram interface */
+
+	BHND_SERVICE_ANY = 1000,	/**< match on any service type */
+} bhnd_service_t;
 
 /**
  * bhnd(4) port types.
diff --git a/sys/dev/bhnd/bhndb/bhnd_bhndb.c b/sys/dev/bhnd/bhndb/bhnd_bhndb.c
index 12efb04c33a4..fdd45ef39819 100644
--- a/sys/dev/bhnd/bhndb/bhnd_bhndb.c
+++ b/sys/dev/bhnd/bhndb/bhnd_bhndb.c
@@ -1,7 +1,11 @@
 /*-
  * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -90,7 +94,7 @@ bhnd_bhndb_find_hostb_device(device_t dev)
 
 	/* Find the corresponding bus device */
 	md = bhnd_core_get_match_desc(&core);
-	return (bhnd_match_child(dev, &md));
+	return (bhnd_bus_match_child(dev, &md));
 }
 
 static int
diff --git a/sys/dev/bhnd/bhndb/bhndb.c b/sys/dev/bhnd/bhndb/bhndb.c
index c5b08276caf1..0178e063fa1a 100644
--- a/sys/dev/bhnd/bhndb/bhndb.c
+++ b/sys/dev/bhnd/bhndb/bhndb.c
@@ -1,7 +1,11 @@
 /*-
- * Copyright (c) 2015 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -522,14 +526,16 @@ bhndb_attach(device_t dev, bhnd_devclass_t bridge_devclass)
 	sc->parent_dev = device_get_parent(dev);
 	sc->bridge_class = bridge_devclass;
 
+	if ((error = bhnd_service_registry_init(&sc->services)))
+		return (error);
+
 	BHNDB_LOCK_INIT(sc);
 	
 	/* Populate generic resource allocation state. */
 	cfg = BHNDB_BUS_GET_GENERIC_HWCFG(sc->parent_dev, sc->dev);
 	sc->bus_res = bhndb_alloc_resources(dev, sc->parent_dev, cfg);
-	if (sc->bus_res == NULL) {
-		return (ENXIO);
-	}
+	if (sc->bus_res == NULL)
+		goto failed;
 
 	/* Allocate our host resources */
 	if ((error = bhndb_alloc_host_resources(sc->bus_res)))
@@ -573,6 +579,8 @@ failed:
 	if (sc->bus_res != NULL)
 		bhndb_free_resources(sc->bus_res);
 
+	bhnd_service_registry_fini(&sc->services);
+
 	return (error);
 }
 
@@ -911,11 +919,15 @@ bhndb_generic_detach(device_t dev)
 	int			 error;
 
 	sc = device_get_softc(dev);
-	
+
 	/* Detach children */
 	if ((error = bus_generic_detach(dev)))
 		return (error);
 
+	/* Clean up our service registry */
+	if ((error = bhnd_service_registry_fini(&sc->services)))
+		return (error);
+
 	/* Clean up our driver state. */
 	bhndb_free_resources(sc->bus_res);
 	
@@ -1212,6 +1224,17 @@ bhndb_get_hostb_core(device_t dev, device_t child, struct bhnd_core_info *core)
 }
 
 /**
+ * Default bhndb(4) implementation of BHND_BUS_GET_SERVICE_REGISTRY().
+ */
+static struct bhnd_service_registry *
+bhndb_get_service_registry(device_t dev, device_t child)
+{
+	struct bhndb_softc *sc = device_get_softc(dev);
+
+	return (&sc->services);
+}
+
+/**
  * Default bhndb(4) implementation of BUS_ALLOC_RESOURCE().
  */
 static struct resource *
@@ -2146,6 +2169,13 @@ static device_method_t bhndb_methods[] = {
 	DEVMETHOD(bhnd_bus_activate_resource,	bhndb_activate_bhnd_resource),
 	DEVMETHOD(bhnd_bus_deactivate_resource,	bhndb_deactivate_bhnd_resource),
 	DEVMETHOD(bhnd_bus_get_nvram_var,	bhnd_bus_generic_get_nvram_var),
+
+	DEVMETHOD(bhnd_bus_get_service_registry,bhndb_get_service_registry),
+	DEVMETHOD(bhnd_bus_register_provider,	bhnd_bus_generic_sr_register_provider),
+	DEVMETHOD(bhnd_bus_deregister_provider,	bhnd_bus_generic_sr_deregister_provider),
+	DEVMETHOD(bhnd_bus_retain_provider,	bhnd_bus_generic_sr_retain_provider),
+	DEVMETHOD(bhnd_bus_release_provider,	bhnd_bus_generic_sr_release_provider),
+	
 	DEVMETHOD(bhnd_bus_read_1,		bhndb_bus_read_1),
 	DEVMETHOD(bhnd_bus_read_2,		bhndb_bus_read_2),
 	DEVMETHOD(bhnd_bus_read_4,		bhndb_bus_read_4),
diff --git a/sys/dev/bhnd/bhndb/bhndbvar.h b/sys/dev/bhnd/bhndb/bhndbvar.h
index 2ce502d14342..f7018f49e11a 100644
--- a/sys/dev/bhnd/bhndb/bhndbvar.h
+++ b/sys/dev/bhnd/bhndb/bhndbvar.h
@@ -1,7 +1,11 @@
 /*-
- * Copyright (c) 2015 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -96,6 +100,8 @@ struct bhndb_softc {
 	device_t			 parent_dev;	/**< parent device */
 	device_t			 bus_dev;	/**< child bhnd(4) bus */
 
+	struct bhnd_service_registry	 services;	/**< local service registry */
+
 	struct mtx			 sc_mtx;	/**< resource lock. */
 	struct bhndb_resources		*bus_res;	/**< bus resource state */
 };
diff --git a/sys/dev/bhnd/bhndvar.h b/sys/dev/bhnd/bhndvar.h
index 2602302a1861..6bbbb796ebba 100644
--- a/sys/dev/bhnd/bhndvar.h
+++ b/sys/dev/bhnd/bhndvar.h
@@ -1,7 +1,11 @@
 /*-
  * Copyright (c) 2015-2016 Landon Fuller <landonf@FreeBSD.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -34,7 +38,10 @@
 
 #include <sys/param.h>
 #include <sys/bus.h>
+#include <sys/lock.h>
 #include <sys/malloc.h>
+#include <sys/queue.h>
+#include <sys/sx.h>
 
 #include "bhnd.h"
 
@@ -45,57 +52,51 @@
 MALLOC_DECLARE(M_BHND);
 DECLARE_CLASS(bhnd_driver);
 
-int			 bhnd_generic_attach(device_t dev);
-int			 bhnd_generic_detach(device_t dev);
-int			 bhnd_generic_shutdown(device_t dev);
-int			 bhnd_generic_resume(device_t dev);
-int			 bhnd_generic_suspend(device_t dev);
+int				 bhnd_generic_attach(device_t dev);
+int				 bhnd_generic_detach(device_t dev);
+int				 bhnd_generic_shutdown(device_t dev);
+int				 bhnd_generic_resume(device_t dev);
+int				 bhnd_generic_suspend(device_t dev);
 
-int			 bhnd_generic_get_probe_order(device_t dev,
-			     device_t child);
+int				 bhnd_generic_get_probe_order(device_t dev,
+				     device_t child);
 
-int			 bhnd_generic_alloc_pmu(device_t dev,
-			     device_t child);
-int			 bhnd_generic_release_pmu(device_t dev,
-			     device_t child);
-int			 bhnd_generic_request_clock(device_t dev,
-			     device_t child, bhnd_clock clock);
-int			 bhnd_generic_enable_clocks(device_t dev,
-			     device_t child, uint32_t clocks);
-int			 bhnd_generic_request_ext_rsrc(device_t dev,
-			     device_t child, u_int rsrc);
-int			 bhnd_generic_release_ext_rsrc(device_t dev,
-			     device_t child, u_int rsrc);
+int				 bhnd_generic_alloc_pmu(device_t dev,
+				     device_t child);
+int				 bhnd_generic_release_pmu(device_t dev,
+				     device_t child);
+int				 bhnd_generic_request_clock(device_t dev,
+				     device_t child, bhnd_clock clock);
+int				 bhnd_generic_enable_clocks(device_t dev,
+				     device_t child, uint32_t clocks);
+int				 bhnd_generic_request_ext_rsrc(device_t dev,
+				     device_t child, u_int rsrc);
+int				 bhnd_generic_release_ext_rsrc(device_t dev,
+				     device_t child, u_int rsrc);
 
-int			 bhnd_generic_print_child(device_t dev,
-			     device_t child);
-void			 bhnd_generic_probe_nomatch(device_t dev,
-			     device_t child);
+int				 bhnd_generic_print_child(device_t dev,
+				     device_t child);
+void				 bhnd_generic_probe_nomatch(device_t dev,
+				     device_t child);
 
-void			 bhnd_generic_child_deleted(device_t dev,
-			     device_t child);
-int			 bhnd_generic_suspend_child(device_t dev,
-			     device_t child);
-int			 bhnd_generic_resume_child(device_t dev,
-			     device_t child);
+void				 bhnd_generic_child_deleted(device_t dev,
+				     device_t child);
+int				 bhnd_generic_suspend_child(device_t dev,
+				     device_t child);
+int				 bhnd_generic_resume_child(device_t dev,
+				     device_t child);
 
-int			 bhnd_generic_get_nvram_var(device_t dev,
-			     device_t child, const char *name, void *buf,
-			     size_t *size, bhnd_nvram_type type);
+int				 bhnd_generic_get_nvram_var(device_t dev,
+				     device_t child, const char *name,
+				     void *buf, size_t *size,
+				     bhnd_nvram_type type);
 
 /**
  * bhnd driver instance state. Must be first member of all subclass
  * softc structures.
  */
 struct bhnd_softc {
-	device_t	dev;			/**< bus device */
-
-	bool		attach_done;		/**< true if initialization of 
-						  *  all platform devices has
-						  *  been completed */
-	device_t	chipc_dev;		/**< bhnd_chipc device */ 
-	device_t	nvram_dev;		/**< bhnd_nvram device, if any */
-	device_t	pmu_dev;		/**< bhnd_pmu device, if any */
+	device_t dev;	/**< bus device */
 };
 
 #endif /* _BHND_BHNDVAR_H_ */
diff --git a/sys/dev/bhnd/cores/chipc/chipc.c b/sys/dev/bhnd/cores/chipc/chipc.c
index 0d1f893a8a6a..31a5a2d3780c 100644
--- a/sys/dev/bhnd/cores/chipc/chipc.c
+++ b/sys/dev/bhnd/cores/chipc/chipc.c
@@ -1,8 +1,12 @@
 /*-
  * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
  * Copyright (c) 2016 Michael Zhilin <mizhka@gmail.com>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * This software was developed by Landon Fuller under sponsorship from
+ * the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -211,6 +215,10 @@ chipc_attach(device_t dev)
 	if ((error = bus_generic_attach(dev)))
 		goto failed;
 
+	/* Register ourselves with the bus */
+	if ((error = bhnd_register_provider(dev, BHND_SERVICE_CHIPC)))
+		goto failed;
+
 	return (0);
 	
 failed:
@@ -234,6 +242,9 @@ chipc_detach(device_t dev)
 
 	sc = device_get_softc(dev);
 
+	if ((error = bhnd_deregister_provider(dev, BHND_SERVICE_ANY)))
+		return (error);
+
 	if ((error = bus_generic_detach(dev)))
 		return (error);
 
@@ -1087,7 +1098,7 @@ chipc_should_enable_muxed_sprom(struct chipc_softc *sc)
 	mtx_lock(&Giant);	/* for newbus */
 
 	parent = device_get_parent(sc->dev);
-	hostb = bhnd_find_hostb_device(parent);
+	hostb = bhnd_bus_find_hostb_device(parent);
 
 	if ((error = device_get_children(parent, &devs, &devcount))) {
 		mtx_unlock(&Giant);
diff --git a/sys/dev/bhnd/cores/chipc/pwrctl/bhnd_pwrctl.c b/sys/dev/bhnd/cores/chipc/pwrctl/bhnd_pwrctl.c
index d2bf54c8ce35..90155418ed7f 100644
--- a/sys/dev/bhnd/cores/chipc/pwrctl/bhnd_pwrctl.c
+++ b/sys/dev/bhnd/cores/chipc/pwrctl/bhnd_pwrctl.c
@@ -1,7 +1,11 @@
 /*-
  * Copyright (c) 2016 Landon Fuller <landonf@FreeBSD.org>
- * Copyright (c) 2010, Broadcom Corporation.
+ * Copyright (c) 2010 Broadcom Corporation.
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
+ *
+ * This software was developed by Landon Fuller under sponsorship from
+ * the FreeBSD Foundation.
  * 
  * This file is derived from the siutils.c source distributed with the
  * Asus RT-N16 firmware source code release.
@@ -116,6 +120,7 @@ bhnd_pwrctl_attach(device_t dev)
 	struct chipc_softc		*chipc_sc;
 	bhnd_devclass_t			 hostb_class;
 	device_t			 hostb_dev;
+	device_t			 bus;
 	int				 error;
 
 	sc = device_get_softc(dev);
@@ -128,10 +133,12 @@ bhnd_pwrctl_attach(device_t dev)
 	sc->quirks = bhnd_device_quirks(sc->chipc_dev, pwrctl_devices,
 	    sizeof(pwrctl_devices[0]));
 
+	bus = device_get_parent(sc->chipc_dev);
+
 	/* On devices that lack a slow clock source, HT must always be
 	 * enabled. */
 	hostb_class = BHND_DEVCLASS_INVALID;
-	hostb_dev = bhnd_find_hostb_device(device_get_parent(sc->chipc_dev));
+	hostb_dev = bhnd_bus_find_hostb_device(device_get_parent(sc->chipc_dev));
 	if (hostb_dev != NULL)
 		hostb_class = bhnd_get_class(hostb_dev);
 
@@ -177,6 +184,13 @@ bhnd_pwrctl_attach(device_t dev)
 
 	PWRCTL_UNLOCK(sc);
 
+	/* Register as the bus PMU provider */
+	if ((error = bhnd_register_provider(dev, BHND_SERVICE_PMU))) {
+		device_printf(sc->dev, "failed to register PMU with bus : %d\n",
+		    error);
+		goto cleanup;
+	}
+
 	return (0);
 
 cleanup:
@@ -193,9 +207,16 @@ bhnd_pwrctl_detach(device_t dev)
 
 	sc = device_get_softc(dev);
 
+	if ((error = bhnd_deregister_provider(dev, BHND_SERVICE_ANY)))
+		return (error);
+
+	PWRCTL_LOCK(sc);
+
 	if ((error = bhnd_pwrctl_setclk(sc, BHND_CLOCK_DYN)))
 		return (error);
 
+	PWRCTL_UNLOCK(sc);
+
 	STAILQ_FOREACH_SAFE(clkres, &sc->clkres_list, cr_link, crnext)
 		free(clkres, M_DEVBUF);
 
diff --git a/sys/dev/bhnd/cores/pci/bhnd_pci_hostb.c b/sys/dev/bhnd/cores/pci/bhnd_pci_hostb.c
index ec2b5b2b9e9a..5d5657a1cf26 100644
--- a/sys/dev/bhnd/cores/pci/bhnd_pci_hostb.c
+++ b/sys/dev/bhnd/cores/pci/bhnd_pci_hostb.c
@@ -1,7 +1,11 @@
 /*-
- * Copyright (c) 2015 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -561,7 +565,7 @@ bhnd_pci_wars_hwup(struct bhnd_pcihb_softc *sc, bhnd_pci_war_state state)
 		bus_size_t	reg;
 		
 		bhnd = device_get_parent(sc->dev);
-		chipc = bhnd_find_child(bhnd, BHND_DEVCLASS_CC, 0);
+		chipc = bhnd_bus_find_child(bhnd, BHND_DEVCLASS_CC, 0);
 		KASSERT(chipc != NULL, ("missing chipcommon device"));
 
 		/* Write SerDes PLL disable flag to the ChipCommon core */
diff --git a/sys/dev/bhnd/cores/pmu/bhnd_pmu.c b/sys/dev/bhnd/cores/pmu/bhnd_pmu.c
index 6d7e907da4cb..254fa309dd39 100644
--- a/sys/dev/bhnd/cores/pmu/bhnd_pmu.c
+++ b/sys/dev/bhnd/cores/pmu/bhnd_pmu.c
@@ -1,7 +1,11 @@
 /*-
  * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -128,7 +132,7 @@ bhnd_pmu_attach(device_t dev, struct bhnd_resource *res)
 	/* Fetch capability flags */
 	sc->caps = bhnd_bus_read_4(sc->res, BHND_PMU_CAP);
 
-	/* Find the bus-attached core */
+	/* Find the bus and bus-attached core */
 	bhnd_class = devclass_find("bhnd");
 	core = sc->dev;
 	while ((bus = device_get_parent(core)) != NULL) {
@@ -153,7 +157,7 @@ bhnd_pmu_attach(device_t dev, struct bhnd_resource *res)
 	}
 
 	/* Locate ChipCommon device */
-	sc->chipc_dev = bhnd_find_child(bus, BHND_DEVCLASS_CC, 0);
+	sc->chipc_dev = bhnd_bus_find_child(bus, BHND_DEVCLASS_CC, 0);
 	if (sc->chipc_dev == NULL) {
 		device_printf(sc->dev, "chipcommon device not found\n");
 		return (ENXIO);
@@ -186,6 +190,13 @@ bhnd_pmu_attach(device_t dev, struct bhnd_resource *res)
 		goto failed;
 	}
 
+	/* Register ourselves with the bus */
+	if ((error = bhnd_register_provider(dev, BHND_SERVICE_PMU))) {
+		device_printf(sc->dev, "failed to register PMU with bus : %d\n",
+		    error);
+		goto failed;
+	}
+
 	/* Set up sysctl nodes */
 	ctx = device_get_sysctl_ctx(dev);
 	tree = device_get_sysctl_tree(dev);
@@ -217,9 +228,13 @@ int
 bhnd_pmu_detach(device_t dev)
 {
 	struct bhnd_pmu_softc	*sc;
+	int			 error;
 
 	sc = device_get_softc(dev);
 
+	if ((error = bhnd_deregister_provider(dev, BHND_SERVICE_ANY)))
+		return (error);
+
 	BPMU_LOCK_DESTROY(sc);
 	bhnd_pmu_query_fini(&sc->query);
 
diff --git a/sys/dev/bhnd/nvram/bhnd_sprom.c b/sys/dev/bhnd/nvram/bhnd_sprom.c
index d830af9785d1..0eb17b4b1e88 100644
--- a/sys/dev/bhnd/nvram/bhnd_sprom.c
+++ b/sys/dev/bhnd/nvram/bhnd_sprom.c
@@ -1,7 +1,11 @@
 /*-
  * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -99,8 +103,10 @@ bhnd_sprom_attach(device_t dev, bus_size_t offset)
 
 	sc = device_get_softc(dev);
 	sc->dev = dev;
+	sc->store = NULL;
 
 	io = NULL;
+	r = NULL;
 
 	/* Allocate SPROM resource */
 	rid = 0;
@@ -138,6 +144,16 @@ bhnd_sprom_attach(device_t dev, bus_size_t offset)
 	bhnd_nvram_io_free(io);
 	bhnd_release_resource(dev, SYS_RES_MEMORY, rid, r);
 
+	io = NULL;
+	r = NULL;
+
+	/* Register ourselves with the bus */
+	if ((error = bhnd_register_provider(dev, BHND_SERVICE_NVRAM))) {
+		device_printf(dev, "failed to register NVRAM provider: %d\n",
+		    error);
+		goto failed;
+	}
+
 	return (0);
 
 failed:
@@ -145,7 +161,11 @@ failed:
 	if (io != NULL)
 		bhnd_nvram_io_free(io);
 
-	bhnd_release_resource(dev, SYS_RES_MEMORY, rid, r);
+	if (r != NULL)
+		bhnd_release_resource(dev, SYS_RES_MEMORY, rid, r);
+
+	if (sc->store != NULL)
+		bhnd_nvram_store_free(sc->store);
 
 	return (error);
 }
@@ -175,9 +195,13 @@ int
 bhnd_sprom_detach(device_t dev)
 {
 	struct bhnd_sprom_softc	*sc;
+	int			 error;
 	
 	sc = device_get_softc(dev);
 
+	if ((error = bhnd_deregister_provider(dev, BHND_SERVICE_ANY)))
+		return (error);
+
 	bhnd_nvram_store_free(sc->store);
 
 	return (0);
diff --git a/sys/dev/bhnd/siba/siba_bhndb.c b/sys/dev/bhnd/siba/siba_bhndb.c
index cfc1180ad930..13082edc2347 100644
--- a/sys/dev/bhnd/siba/siba_bhndb.c
+++ b/sys/dev/bhnd/siba/siba_bhndb.c
@@ -1,7 +1,11 @@
 /*-
- * Copyright (c) 2015 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -222,14 +226,14 @@ siba_bhndb_wars_pcie_clear_d11_timeout(struct siba_softc *sc)
 	uint32_t		 imcfg;
 
 	/* Only applies when bridged by PCIe */
-	if ((hostb_dev = bhnd_find_hostb_device(sc->dev)) == NULL)
+	if ((hostb_dev = bhnd_bus_find_hostb_device(sc->dev)) == NULL)
 		return (ENXIO);
 
 	if (bhnd_get_class(hostb_dev) != BHND_DEVCLASS_PCIE)
 		return (0);
 
 	/* Only applies if there's a D11 core */
-	d11 = bhnd_match_child(sc->dev, &(struct bhnd_core_match) {
+	d11 = bhnd_bus_match_child(sc->dev, &(struct bhnd_core_match) {
 		BHND_MATCH_CORE(BHND_MFGID_BCM, BHND_COREID_D11),
 		BHND_MATCH_CORE_UNIT(0)
 	});
@@ -259,7 +263,7 @@ siba_bhndb_wars_hwup(struct siba_softc *sc)
 	uint32_t		 quirks;
 	int			 error;
 
-	if ((hostb_dev = bhnd_find_hostb_device(sc->dev)) == NULL)
+	if ((hostb_dev = bhnd_bus_find_hostb_device(sc->dev)) == NULL)
 		return (ENXIO);
 
 	quirks = bhnd_device_quirks(hostb_dev, bridge_devs,
diff --git a/sys/mips/broadcom/bcm_machdep.c b/sys/mips/broadcom/bcm_machdep.c
index eef277c07bfd..f0b9ba732178 100644
--- a/sys/mips/broadcom/bcm_machdep.c
+++ b/sys/mips/broadcom/bcm_machdep.c
@@ -2,9 +2,12 @@
  * Copyright (c) 2007 Bruce M. Simpson.
  * Copyright (c) 2016 Michael Zhilin <mizhka@gmail.com>
  * Copyright (c) 2016 Landon Fuller <landonf@FreeBSD.org>
- *
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -393,6 +396,12 @@ bcm_init_platform_data(struct bcm_platform *bp)
 		}
 	}
 
+	/* Initialize our platform service registry */
+	if ((error = bhnd_service_registry_init(&bp->services))) {
+		BCM_ERR("error initializing service registry: %d\n", error);
+		return (error);
+	}
+
 	bcm_platform_data_avail = true;
 	return (0);
 }
diff --git a/sys/mips/broadcom/bcm_machdep.h b/sys/mips/broadcom/bcm_machdep.h
index a20f40754c69..64ac40e69c46 100644
--- a/sys/mips/broadcom/bcm_machdep.h
+++ b/sys/mips/broadcom/bcm_machdep.h
@@ -1,7 +1,11 @@
 /*-
  * Copyright (c) 2016 Landon Fuller <landonf@FreeBSD.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -45,33 +49,35 @@
 extern const struct bhnd_pmu_io	bcm_pmu_soc_io;
 
 struct bcm_platform {
-	struct bhnd_chipid	 cid;		/**< chip id */
-	struct bhnd_core_info	 cc_id;		/**< chipc core info */
-	uintptr_t		 cc_addr;	/**< chipc core phys address */
-	uint32_t		 cc_caps;	/**< chipc capabilities */
-	uint32_t		 cc_caps_ext;	/**< chipc extended capabilies */
+	struct bhnd_chipid		 cid;		/**< chip id */
+	struct bhnd_core_info		 cc_id;		/**< chipc core info */
+	uintptr_t			 cc_addr;	/**< chipc core phys address */
+	uint32_t			 cc_caps;	/**< chipc capabilities */
+	uint32_t			 cc_caps_ext;	/**< chipc extended capabilies */
 
 	/* On non-AOB devices, the PMU register block is mapped to chipc;
 	 * the pmu_id and pmu_addr values will be copied from cc_id
 	 * and cc_addr. */
-	struct bhnd_core_info	 pmu_id;		/**< PMU core info */
-	uintptr_t		 pmu_addr;	/**< PMU core phys address, or
+	struct bhnd_core_info		 pmu_id;		/**< PMU core info */
+	uintptr_t			 pmu_addr;	/**< PMU core phys address, or
 						     0x0 if no PMU */
 
-	struct bhnd_pmu_query	 pmu;		/**< PMU query instance */
+	struct bhnd_pmu_query		 pmu;		/**< PMU query instance */
 
-	bhnd_erom_class_t	*erom_impl;	/**< erom parser class */
-	struct kobj_ops		 erom_ops;	/**< compiled kobj opcache */
+	bhnd_erom_class_t		*erom_impl;	/**< erom parser class */
+	struct kobj_ops			 erom_ops;	/**< compiled kobj opcache */
 	union {
 		bhnd_erom_static_t	 data;
 		bhnd_erom_t		 obj;
 	} erom;
 
-	struct bhnd_nvram_io	*nvram_io;	/**< NVRAM I/O context, or NULL if unavailable */
-	bhnd_nvram_data_class	*nvram_cls;	/**< NVRAM data class, or NULL if unavailable */
+	struct bhnd_nvram_io		*nvram_io;	/**< NVRAM I/O context, or NULL if unavailable */
+	bhnd_nvram_data_class		*nvram_cls;	/**< NVRAM data class, or NULL if unavailable */
+
+	struct bhnd_service_registry	 services;	/**< platform service providers */
 
 #ifdef CFE
-	int			cfe_console;	/**< Console handle, or -1 */
+	int				 cfe_console;	/**< Console handle, or -1 */
 #endif
 };
 
diff --git a/sys/mips/broadcom/bcm_nvram_cfe.c b/sys/mips/broadcom/bcm_nvram_cfe.c
index 7132a45ae38c..a237e9832534 100644
--- a/sys/mips/broadcom/bcm_nvram_cfe.c
+++ b/sys/mips/broadcom/bcm_nvram_cfe.c
@@ -1,7 +1,11 @@
 /*-
  * Copyright (c) 2016 Landon Fuller <landonf@FreeBSD.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -120,6 +124,13 @@ bhnd_nvram_cfe_attach(device_t dev)
 	if (error)
 		return (error);
 
+	error = bhnd_service_registry_add(&bp->services, dev,
+	    BHND_SERVICE_NVRAM, 0);
+	if (error) {
+		bhnd_nvram_store_free(sc->store);
+		return (error);
+	}
+
 	return (error);
 }
 
@@ -138,10 +149,18 @@ bhnd_nvram_cfe_suspend(device_t dev)
 static int
 bhnd_nvram_cfe_detach(device_t dev)
 {
-	struct bhnd_nvram_cfe_softc *sc;
+	struct bcm_platform		*bp;
+	struct bhnd_nvram_cfe_softc	*sc;
+	int				 error;
 
+	bp = bcm_get_platform();
 	sc = device_get_softc(dev);
 
+	error = bhnd_service_registry_remove(&bp->services, dev,
+	    BHND_SERVICE_ANY);
+	if (error)
+		return (error);
+
 	bhnd_nvram_store_free(sc->store);
 
 	return (0);
diff --git a/sys/mips/broadcom/bhnd_nexus.c b/sys/mips/broadcom/bhnd_nexus.c
index f2a4d117b62e..72996f9ee010 100644
--- a/sys/mips/broadcom/bhnd_nexus.c
+++ b/sys/mips/broadcom/bhnd_nexus.c
@@ -1,7 +1,11 @@
 /*-
  * Copyright (c) 2015-2016 Landon Fuller <landon@freebsd.org>
+ * Copyright (c) 2017 The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed by Landon Fuller
+ * under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -54,6 +58,17 @@ __FBSDID("$FreeBSD$");
 
 #include "bhnd_nexusvar.h"
 
+
+/**
+ * Default bhnd_nexus implementation of BHND_BUS_GET_SERVICE_REGISTRY().
+ */
+static struct bhnd_service_registry *
+bhnd_nexus_get_service_registry(device_t dev, device_t child)
+{
+	struct bcm_platform *bp = bcm_get_platform();
+	return (&bp->services);
+}
+
 /**
  * Default bhnd_nexus implementation of BHND_BUS_ACTIVATE_RESOURCE().
  */
@@ -160,6 +175,11 @@ bhnd_nexus_assign_intr(device_t dev, device_t child, int rid)
 
 static device_method_t bhnd_nexus_methods[] = {
 	/* bhnd interface */
+	DEVMETHOD(bhnd_bus_get_service_registry,bhnd_nexus_get_service_registry),
+	DEVMETHOD(bhnd_bus_register_provider,	bhnd_bus_generic_sr_register_provider),
+	DEVMETHOD(bhnd_bus_deregister_provider,	bhnd_bus_generic_sr_deregister_provider),
+	DEVMETHOD(bhnd_bus_retain_provider,	bhnd_bus_generic_sr_retain_provider),
+	DEVMETHOD(bhnd_bus_release_provider,	bhnd_bus_generic_sr_release_provider),
 	DEVMETHOD(bhnd_bus_activate_resource,	bhnd_nexus_activate_resource),
 	DEVMETHOD(bhnd_bus_deactivate_resource, bhnd_nexus_deactivate_resource),
 	DEVMETHOD(bhnd_bus_is_hw_disabled,	bhnd_nexus_is_hw_disabled),