Index: head/sys/dev/bhnd/bcma/bcma.c
===================================================================
--- head/sys/dev/bhnd/bcma/bcma.c
+++ head/sys/dev/bhnd/bcma/bcma.c
@@ -181,14 +181,6 @@
 	}
 }
 
-static void
-bcma_child_deleted(device_t dev, device_t child)
-{
-	struct bcma_devinfo *dinfo = device_get_ivars(child);
-	if (dinfo != NULL)
-		bcma_free_dinfo(dev, dinfo);
-}
-
 static struct resource_list *
 bcma_get_resource_list(device_t dev, device_t child)
 {
@@ -415,6 +407,19 @@
 	return (ENOENT);
 }
 
+static struct bhnd_devinfo *
+bcma_alloc_bhnd_dinfo(device_t dev)
+{
+	struct bcma_devinfo *dinfo = bcma_alloc_dinfo(dev);
+	return ((struct bhnd_devinfo *)dinfo);
+}
+
+static void
+bcma_free_bhnd_dinfo(device_t dev, struct bhnd_devinfo *dinfo)
+{
+	bcma_free_dinfo(dev, (struct bcma_devinfo *)dinfo);
+}
+
 /**
  * Scan a device enumeration ROM table, adding all valid discovered cores to
  * the bus.
@@ -431,8 +436,7 @@
 	struct bcma_devinfo	*dinfo;
 	device_t		 child;
 	int			 error;
-	
-	dinfo = NULL;
+
 	corecfg = NULL;
 
 	/* Initialize our reader */
@@ -450,26 +454,20 @@
 			goto failed;
 		}
 
-		/* Allocate per-device bus info */
-		dinfo = bcma_alloc_dinfo(bus, corecfg);
-		if (dinfo == NULL) {
-			error = ENXIO;
-			goto failed;
-		}
-
-		/* The dinfo instance now owns the corecfg value */
-		corecfg = NULL;
-
 		/* Add the child device */
-		child = device_add_child(bus, NULL, -1);
+		child = BUS_ADD_CHILD(bus, 0, NULL, -1);
 		if (child == NULL) {
 			error = ENXIO;
 			goto failed;
 		}
 
-		/* The child device now owns the dinfo pointer */
-		device_set_ivars(child, dinfo);
-		dinfo = NULL;
+		/* Initialize device ivars */
+		dinfo = device_get_ivars(child);
+		if ((error = bcma_init_dinfo(bus, dinfo, corecfg)))
+			goto failed;
+
+		/* The dinfo instance now owns the corecfg value */
+		corecfg = NULL;
 
 		/* If pins are floating or the hardware is otherwise
 		 * unpopulated, the device shouldn't be used. */
@@ -482,9 +480,6 @@
 		return (0);
 	
 failed:
-	if (dinfo != NULL)
-		bcma_free_dinfo(bus, dinfo);
-
 	if (corecfg != NULL)
 		bcma_free_corecfg(corecfg);
 
@@ -499,13 +494,14 @@
 	DEVMETHOD(device_detach,		bcma_detach),
 	
 	/* Bus interface */
-	DEVMETHOD(bus_child_deleted,		bcma_child_deleted),
 	DEVMETHOD(bus_read_ivar,		bcma_read_ivar),
 	DEVMETHOD(bus_write_ivar,		bcma_write_ivar),
 	DEVMETHOD(bus_get_resource_list,	bcma_get_resource_list),
 
 	/* BHND interface */
 	DEVMETHOD(bhnd_bus_find_hostb_device,	bcma_find_hostb_device),
+	DEVMETHOD(bhnd_bus_alloc_devinfo,	bcma_alloc_bhnd_dinfo),
+	DEVMETHOD(bhnd_bus_free_devinfo,	bcma_free_bhnd_dinfo),
 	DEVMETHOD(bhnd_bus_reset_core,		bcma_reset_core),
 	DEVMETHOD(bhnd_bus_suspend_core,	bcma_suspend_core),
 	DEVMETHOD(bhnd_bus_get_port_count,	bcma_get_port_count),
Index: head/sys/dev/bhnd/bcma/bcma_subr.c
===================================================================
--- head/sys/dev/bhnd/bcma/bcma_subr.c
+++ head/sys/dev/bhnd/bcma/bcma_subr.c
@@ -186,28 +186,54 @@
 	}
 }
 
+
 /**
- * Allocate and initialize new device info structure, assuming ownership
- * of the provided core configuration.
+ * Allocate and return a new empty device info structure.
  * 
  * @param bus The requesting bus device.
- * @param corecfg Device core configuration.
+ * 
+ * @retval NULL if allocation failed.
  */
 struct bcma_devinfo *
-bcma_alloc_dinfo(device_t bus, struct bcma_corecfg *corecfg)
+bcma_alloc_dinfo(device_t bus)
 {
 	struct bcma_devinfo *dinfo;
 	
-	dinfo = malloc(sizeof(struct bcma_devinfo), M_BHND, M_NOWAIT);
+	dinfo = malloc(sizeof(struct bcma_devinfo), M_BHND, M_NOWAIT|M_ZERO);
 	if (dinfo == NULL)
-		return NULL;
+		return (NULL);
 
-	dinfo->corecfg = corecfg;
+	dinfo->corecfg = NULL;
 	dinfo->res_agent = NULL;
 	dinfo->rid_agent = -1;
 
 	resource_list_init(&dinfo->resources);
 
+	return (dinfo);
+}
+
+/**
+ * Initialize a device info structure previously allocated via
+ * bcma_alloc_dinfo, assuming ownership of the provided core
+ * configuration.
+ * 
+ * @param bus The requesting bus device.
+ * @param dinfo The device info instance.
+ * @param corecfg Device core configuration; ownership of this value
+ * will be assumed by @p dinfo.
+ * 
+ * @retval 0 success
+ * @retval non-zero initialization failed.
+ */
+int
+bcma_init_dinfo(device_t bus, struct bcma_devinfo *dinfo,
+    struct bcma_corecfg *corecfg)
+{
+	KASSERT(dinfo->corecfg == NULL, ("dinfo previously initialized"));
+
+	/* Save core configuration value */
+	dinfo->corecfg = corecfg;
+
 	/* The device ports must always be initialized first to ensure that
 	 * rid 0 maps to the first device port */
 	bcma_dinfo_init_resource_info(bus, dinfo, &corecfg->dev_ports);
@@ -215,7 +241,7 @@
 	bcma_dinfo_init_resource_info(bus, dinfo, &corecfg->bridge_ports);
 	bcma_dinfo_init_resource_info(bus, dinfo, &corecfg->wrapper_ports);
 
-	return dinfo;
+	return (0);
 }
 
 /**
@@ -227,9 +253,11 @@
 void
 bcma_free_dinfo(device_t bus, struct bcma_devinfo *dinfo)
 {
-	bcma_free_corecfg(dinfo->corecfg);
 	resource_list_free(&dinfo->resources);
 
+	if (dinfo->corecfg != NULL)
+		bcma_free_corecfg(dinfo->corecfg);
+
 	/* Release agent resource, if any */
 	if (dinfo->res_agent != NULL) {
 		bhnd_release_resource(bus, SYS_RES_MEMORY, dinfo->rid_agent,
Index: head/sys/dev/bhnd/bcma/bcmavar.h
===================================================================
--- head/sys/dev/bhnd/bcma/bcmavar.h
+++ head/sys/dev/bhnd/bcma/bcmavar.h
@@ -69,7 +69,9 @@
 struct bcma_sport_list	*bcma_corecfg_get_port_list(struct bcma_corecfg *cfg,
 			     bhnd_port_type type);
 
-struct bcma_devinfo	*bcma_alloc_dinfo(device_t bus,
+struct bcma_devinfo	*bcma_alloc_dinfo(device_t bus);
+int			 bcma_init_dinfo(device_t bus,
+			     struct bcma_devinfo *dinfo,
 			     struct bcma_corecfg *corecfg);
 void			 bcma_free_dinfo(device_t bus,
 			     struct bcma_devinfo *dinfo);
@@ -132,7 +134,9 @@
  * BCMA per-device info
  */
 struct bcma_devinfo {
-	struct resource_list	resources;	/**< Slave port memory regions. */
+	struct bhnd_devinfo	 bhnd_dinfo;	/**< superclass device info. */
+
+	struct resource_list	 resources;	/**< Slave port memory regions. */
 	struct bcma_corecfg	*corecfg;	/**< IP core/block config */
 
 	struct bhnd_resource	*res_agent;	/**< Agent (wrapper) resource, or NULL. Not
@@ -147,4 +151,4 @@
 	device_t		hostb_dev;	/**< host bridge core, or NULL */
 };
 
-#endif /* _BCMA_BCMAVAR_H_ */
\ No newline at end of file
+#endif /* _BCMA_BCMAVAR_H_ */
Index: head/sys/dev/bhnd/bhnd.c
===================================================================
--- head/sys/dev/bhnd/bhnd.c
+++ head/sys/dev/bhnd/bhnd.c
@@ -493,6 +493,54 @@
 }
 
 /**
+ * Default bhnd(4) bus driver implementation of BUS_ADD_CHILD().
+ * 
+ * This implementation manages internal bhnd(4) state, and must be called
+ * by subclassing drivers.
+ */
+device_t
+bhnd_generic_add_child(device_t dev, u_int order, const char *name, int unit)
+{
+	struct bhnd_devinfo	*dinfo;
+	device_t		 child;
+
+	child = device_add_child_ordered(dev, order, name, unit);
+	if (child == NULL)
+		return (NULL);
+
+	if ((dinfo = BHND_BUS_ALLOC_DEVINFO(dev)) == NULL) {
+		device_delete_child(dev, child);
+		return (NULL);
+	}
+
+	device_set_ivars(child, dinfo);
+
+	/* Inform concrete bus driver. */
+	BHND_BUS_CHILD_ADDED(dev, child);
+
+	return (child);
+}
+
+/**
+ * Default bhnd(4) bus driver implementation of BUS_CHILD_DELETED().
+ * 
+ * This implementation manages internal bhnd(4) state, and must be called
+ * by subclassing drivers.
+ */
+void
+bhnd_generic_child_deleted(device_t dev, device_t child)
+{
+	struct bhnd_softc	*sc;
+	struct bhnd_devinfo	*dinfo;
+
+	sc = device_get_softc(dev);
+
+	/* Free device info */
+	if ((dinfo = device_get_ivars(child)) != NULL)
+		BHND_BUS_FREE_DEVINFO(dev, dinfo);
+}
+
+/**
  * Helper function for implementing BUS_SUSPEND_CHILD().
  *
  * TODO: Power management
@@ -611,6 +659,8 @@
 	DEVMETHOD(device_resume,		bhnd_generic_resume),
 
 	/* Bus interface */
+	DEVMETHOD(bus_add_child,		bhnd_generic_add_child),
+	DEVMETHOD(bus_child_deleted,		bhnd_generic_child_deleted),
 	DEVMETHOD(bus_probe_nomatch,		bhnd_generic_probe_nomatch),
 	DEVMETHOD(bus_print_child,		bhnd_generic_print_child),
 	DEVMETHOD(bus_child_pnpinfo_str,	bhnd_child_pnpinfo_str),
Index: head/sys/dev/bhnd/bhnd_bus_if.m
===================================================================
--- head/sys/dev/bhnd/bhnd_bus_if.m
+++ head/sys/dev/bhnd/bhnd_bus_if.m
@@ -41,6 +41,7 @@
 	struct bhnd_board_info;
 	struct bhnd_core_info;
 	struct bhnd_chipid;
+	struct bhnd_devinfo;
 	struct bhnd_resource;
 }
 
@@ -67,6 +68,11 @@
 	{
 		panic("bhnd_bus_read_boardinfo unimplemented");
 	}
+	
+	static void
+	bhnd_bus_null_child_added(device_t dev, device_t child)
+	{
+	}
 
 	static device_t
 	bhnd_bus_null_find_hostb_device(device_t dev)
@@ -228,6 +234,46 @@
 } DEFAULT bhnd_bus_null_read_board_info;
 
 /**
+ * Allocate and zero-initialize a buffer suitably sized and aligned for a
+ * bhnd_devinfo structure.
+ *
+ * @param dev The bhnd bus device.
+ *
+ * @retval non-NULL	success
+ * @retval NULL		allocation failed
+ */
+METHOD struct bhnd_devinfo * alloc_devinfo {
+	device_t dev;
+};
+
+/**
+ * Release memory previously allocated for @p devinfo.
+ *
+ * @param dev The bhnd bus device.
+ * @param dinfo A devinfo buffer previously allocated via
+ * BHND_BUS_ALLOC_DEVINFO().
+ */
+METHOD void free_devinfo {
+	device_t dev;
+	struct bhnd_devinfo *dinfo;
+};
+
+/**
+ * Notify a bhnd bus that a child was added.
+ *
+ * Called at the end of BUS_ADD_CHILD() to allow the concrete bhnd(4)
+ * driver instance to initialize any additional driver-specific state for the
+ * child.
+ *
+ * @param dev The bhnd bus whose child is being added.
+ * @param child The child added to @p dev.
+ */
+METHOD void child_added {
+	device_t dev;
+	device_t child;
+} DEFAULT bhnd_bus_null_child_added;
+
+/**
  * Reset the device's hardware core.
  *
  * @param dev The parent of @p child.
Index: head/sys/dev/bhnd/bhndvar.h
===================================================================
--- head/sys/dev/bhnd/bhndvar.h
+++ head/sys/dev/bhnd/bhndvar.h
@@ -46,6 +46,13 @@
 DECLARE_CLASS(bhnd_driver);
 
 /**
+ * bhnd per-device info.  Must be first member of all subclass
+ * devinfo structures.
+ */
+struct bhnd_devinfo {
+};
+
+/**
  * bhnd driver instance state. Must be first member of all subclass
  * softc structures.
  */
@@ -66,6 +73,10 @@
 void			 bhnd_generic_probe_nomatch(device_t dev,
 			     device_t child);
 
+device_t		 bhnd_generic_add_child(device_t dev, u_int order,
+			     const char *name, int unit);
+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,
Index: head/sys/dev/bhnd/siba/siba.c
===================================================================
--- head/sys/dev/bhnd/siba/siba.c
+++ head/sys/dev/bhnd/siba/siba.c
@@ -206,14 +206,6 @@
 	}
 }
 
-static void
-siba_child_deleted(device_t dev, device_t child)
-{
-	struct siba_devinfo *dinfo = device_get_ivars(child);
-	if (dinfo != NULL)
-		siba_free_dinfo(dev, dinfo);
-}
-
 static struct resource_list *
 siba_get_resource_list(device_t dev, device_t child)
 {
@@ -436,6 +428,19 @@
 	return (0);
 }
 
+static struct bhnd_devinfo *
+siba_alloc_bhnd_dinfo(device_t dev)
+{
+	struct siba_devinfo *dinfo = siba_alloc_dinfo(dev);
+	return ((struct bhnd_devinfo *)dinfo);
+}
+
+static void
+siba_free_bhnd_dinfo(device_t dev, struct bhnd_devinfo *dinfo)
+{
+	siba_free_dinfo(dev, (struct siba_devinfo *)dinfo);
+}
+
 /**
  * Scan the core table and add all valid discovered cores to
  * the bus.
@@ -556,6 +561,13 @@
 			goto cleanup;
 		}
 
+		/* Add the child device */
+		child = BUS_ADD_CHILD(dev, 0, NULL, -1);
+		if (child == NULL) {
+			error = ENXIO;
+			goto cleanup;
+		}
+		
 		/* Read the core info */
 		idhigh = bus_read_4(r, SB0_REG_ABS(SIBA_CFG0_IDHIGH));
 		idlow = bus_read_4(r, SB0_REG_ABS(SIBA_CFG0_IDLOW));
@@ -570,27 +582,18 @@
 				cores[i].unit++;
 		}
 
-		/* Allocate per-device bus info */
-		dinfo = siba_alloc_dinfo(dev, &cid);
-		if (dinfo == NULL) {
+		/* Initialize per-device bus info */
+		if ((dinfo = device_get_ivars(child)) == NULL) {
 			error = ENXIO;
 			goto cleanup;
 		}
 
-		/* Register the core's address space(s). */
-		if ((error = siba_register_addrspaces(dev, dinfo, r)))
+		if ((error = siba_init_dinfo(dev, dinfo, &cid)))
 			goto cleanup;
 
-		/* Add the child device */
-		child = device_add_child(dev, NULL, -1);
-		if (child == NULL) {
-			error = ENXIO;
+		/* Register the core's address space(s). */
+		if ((error = siba_register_addrspaces(dev, dinfo, r)))
 			goto cleanup;
-		}
-
-		/* The child device now owns the dinfo pointer */
-		device_set_ivars(child, dinfo);
-		dinfo = NULL;
 
 		/* If pins are floating or the hardware is otherwise
 		 * unpopulated, the device shouldn't be used. */
@@ -606,9 +609,6 @@
 	if (cores != NULL)
 		free(cores, M_BHND);
 
-	if (dinfo != NULL)
-		siba_free_dinfo(dev, dinfo);
-
 	if (r != NULL)
 		bus_release_resource(dev, SYS_RES_MEMORY, rid, r);
 
@@ -624,13 +624,14 @@
 	DEVMETHOD(device_suspend,		siba_suspend),
 	
 	/* Bus interface */
-	DEVMETHOD(bus_child_deleted,		siba_child_deleted),
 	DEVMETHOD(bus_read_ivar,		siba_read_ivar),
 	DEVMETHOD(bus_write_ivar,		siba_write_ivar),
 	DEVMETHOD(bus_get_resource_list,	siba_get_resource_list),
 
 	/* BHND interface */
 	DEVMETHOD(bhnd_bus_find_hostb_device,	siba_find_hostb_device),
+	DEVMETHOD(bhnd_bus_alloc_devinfo,	siba_alloc_bhnd_dinfo),
+	DEVMETHOD(bhnd_bus_free_devinfo,	siba_free_bhnd_dinfo),
 	DEVMETHOD(bhnd_bus_reset_core,		siba_reset_core),
 	DEVMETHOD(bhnd_bus_suspend_core,	siba_suspend_core),
 	DEVMETHOD(bhnd_bus_get_port_count,	siba_get_port_count),
Index: head/sys/dev/bhnd/siba/siba_subr.c
===================================================================
--- head/sys/dev/bhnd/siba/siba_subr.c
+++ head/sys/dev/bhnd/siba/siba_subr.c
@@ -106,23 +106,21 @@
 }
 
 /**
- * Allocate and initialize new device info structure, copying the
- * provided core id.
+ * Allocate and return a new empty device info structure.
  * 
- * @param dev The requesting bus device.
- * @param core Device core info.
+ * @param bus The requesting bus device.
+ * 
+ * @retval NULL if allocation failed.
  */
 struct siba_devinfo *
-siba_alloc_dinfo(device_t bus, const struct siba_core_id *core_id)
+siba_alloc_dinfo(device_t bus)
 {
 	struct siba_devinfo *dinfo;
 	
-	dinfo = malloc(sizeof(struct siba_devinfo), M_BHND, M_NOWAIT);
+	dinfo = malloc(sizeof(struct siba_devinfo), M_BHND, M_NOWAIT|M_ZERO);
 	if (dinfo == NULL)
 		return NULL;
 
-	dinfo->core_id = *core_id;
-
 	for (u_int i = 0; i < nitems(dinfo->cfg); i++) {
 		dinfo->cfg[i] = NULL;
 		dinfo->cfg_rid[i] = -1;
@@ -134,6 +132,25 @@
 }
 
 /**
+ * Initialize a device info structure previously allocated via
+ * siba_alloc_dinfo, copying the provided core id.
+ * 
+ * @param dev The requesting bus device.
+ * @param dinfo The device info instance.
+ * @param core Device core info.
+ * 
+ * @retval 0 success
+ * @retval non-zero initialization failed.
+ */
+int
+siba_init_dinfo(device_t dev, struct siba_devinfo *dinfo,
+    const struct siba_core_id *core_id)
+{
+	dinfo->core_id = *core_id;
+	return (0);
+}
+
+/**
  * Map an addrspace index to its corresponding bhnd(4) port number.
  * 
  * @param addrspace Address space index.
Index: head/sys/dev/bhnd/siba/sibavar.h
===================================================================
--- head/sys/dev/bhnd/siba/sibavar.h
+++ head/sys/dev/bhnd/siba/sibavar.h
@@ -63,7 +63,9 @@
 int			 siba_add_children(device_t bus,
 			     const struct bhnd_chipid *chipid);
 
-struct siba_devinfo	*siba_alloc_dinfo(device_t dev,
+struct siba_devinfo	*siba_alloc_dinfo(device_t dev);
+int			 siba_init_dinfo(device_t dev,
+			     struct siba_devinfo *dinfo,
 			     const struct siba_core_id *core_id);
 void			 siba_free_dinfo(device_t dev,
 			     struct siba_devinfo *dinfo);
@@ -136,6 +138,8 @@
  * siba(4) per-device info
  */
 struct siba_devinfo {
+	struct bhnd_devinfo	 bhnd_dinfo;	/**< superclass device info. */
+
 	struct resource_list	 resources;	/**< per-core memory regions. */
 	struct siba_core_id	 core_id;	/**< core identification info */
 	struct siba_addrspace	 addrspace[SIBA_MAX_ADDRSPACE];	/**< memory map descriptors */