Index: head/sys/kern/bus_if.m
===================================================================
--- head/sys/kern/bus_if.m
+++ head/sys/kern/bus_if.m
@@ -418,6 +418,35 @@
 };
 
 /**
+ * @brief Map an interrupt
+ *
+ * This method is used to get an interrupt mapping data according to provided
+ * hints. The hints could be modified afterwards, but only if mapping data was
+ * allocated. This method is intended to be called before BUS_ALLOC_RESOURCE().
+ *
+ * @param _dev		the parent device of @p _child
+ * @param _child	the device which is requesting an allocation
+ * @param _rid		a pointer to the resource identifier
+ * @param _start	a pointer to the hint at the start of the resource
+ *			range - pass @c 0 for any start address
+ * @param _end		a pointer to the hint at the end of the resource
+ *			range - pass @c ~0 for any end address
+ * @param _count	a pointer to the hint at the size of resource
+ *			range required - pass @c 1 for any size
+ * @param _imd		a pointer to the interrupt mapping data which was
+ *			allocated
+ */
+METHOD int map_intr {
+	device_t	_dev;
+	device_t	_child;
+	int		*_rid;
+	rman_res_t	*_start;
+	rman_res_t	*_end;
+	rman_res_t	*_count;
+	struct intr_map_data **_imd;
+} DEFAULT bus_generic_map_intr;
+
+/**
  * @brief Install an interrupt handler
  *
  * This method is used to associate an interrupt handler function with
Index: head/sys/kern/subr_bus.c
===================================================================
--- head/sys/kern/subr_bus.c
+++ head/sys/kern/subr_bus.c
@@ -3951,6 +3951,23 @@
 }
 
 /**
+ * @brief Helper function for implementing BUS_MAP_INTR().
+ *
+ * This simple implementation of BUS_MAP_INTR() simply calls the
+ * BUS_MAP_INTR() method of the parent of @p dev.
+ */
+int
+bus_generic_map_intr(device_t dev, device_t child, int *rid, rman_res_t *start,
+    rman_res_t *end, rman_res_t *count, struct intr_map_data **imd)
+{
+	/* Propagate up the bus hierarchy until someone handles it. */
+	if (dev->parent)
+		return (BUS_MAP_INTR(dev->parent, child, rid, start, end, count,
+		    imd));
+	return (EINVAL);
+}
+
+/**
  * @brief Helper function for implementing BUS_SETUP_INTR().
  *
  * This simple implementation of BUS_SETUP_INTR() simply calls the
@@ -4405,6 +4422,41 @@
 		}
 }
 
+#ifdef INTRNG
+/**
+ * @internal
+ *
+ * This can be converted to bus method later. (XXX)
+ */
+static struct intr_map_data *
+bus_extend_resource(device_t dev, int type, int *rid, rman_res_t *start,
+    rman_res_t *end, rman_res_t *count)
+{
+	struct intr_map_data *imd;
+	struct resource_list *rl;
+	int rv;
+
+	if (dev->parent == NULL)
+		return (NULL);
+	if (type != SYS_RES_IRQ)
+		return (NULL);
+
+	if (!RMAN_IS_DEFAULT_RANGE(*start, *end))
+		return (NULL);
+	rl = BUS_GET_RESOURCE_LIST(dev->parent, dev);
+	if (rl != NULL) {
+		if (resource_list_find(rl, type, *rid) != NULL)
+			return (NULL);
+	}
+	rv = BUS_MAP_INTR(dev->parent, dev, rid, start, end, count, &imd);
+	if (rv != 0)
+		return (NULL);
+	if (rl != NULL)
+		resource_list_add(rl, type, *rid, *start, *end, *count);
+	return (imd);
+}
+#endif
+
 /**
  * @brief Wrapper function for BUS_ALLOC_RESOURCE().
  *
@@ -4412,13 +4464,31 @@
  * parent of @p dev.
  */
 struct resource *
-bus_alloc_resource(device_t dev, int type, int *rid, rman_res_t start, rman_res_t end,
-    rman_res_t count, u_int flags)
+bus_alloc_resource(device_t dev, int type, int *rid, rman_res_t start,
+    rman_res_t end, rman_res_t count, u_int flags)
 {
+	struct resource *res;
+#ifdef INTRNG
+	struct intr_map_data *imd;
+#endif
+
 	if (dev->parent == NULL)
 		return (NULL);
-	return (BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
-	    count, flags));
+
+#ifdef INTRNG
+	imd = bus_extend_resource(dev, type, rid, &start, &end, &count);
+#endif
+	res = BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
+	    count, flags);
+#ifdef INTRNG
+	if (imd != NULL) {
+		if (res != NULL && rman_get_virtual(res) == NULL)
+			rman_set_virtual(res, imd);
+		else
+			imd->destruct(imd);
+	}
+#endif
+	return (res);
 }
 
 /**
@@ -4503,9 +4573,23 @@
 int
 bus_release_resource(device_t dev, int type, int rid, struct resource *r)
 {
+	int rv;
+#ifdef INTRNG
+	struct intr_map_data *imd;
+#endif
+
 	if (dev->parent == NULL)
 		return (EINVAL);
-	return (BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r));
+
+#ifdef INTRNG
+	imd = (type == SYS_RES_IRQ) ? rman_get_virtual(r) : NULL;
+#endif
+	rv = BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r);
+#ifdef INTRNG
+	if (imd != NULL)
+		imd->destruct(imd);
+#endif
+	return (rv);
 }
 
 /**
Index: head/sys/kern/subr_intr.c
===================================================================
--- head/sys/kern/subr_intr.c
+++ head/sys/kern/subr_intr.c
@@ -560,7 +560,6 @@
 	mtx_unlock(&isrc_table_lock);
 
 	ddata->idd_data = (struct intr_map_data *)((uintptr_t)ddata + size);
-	ddata->idd_data->size = extsize;
 	return (ddata);
 }
 
Index: head/sys/sys/bus.h
===================================================================
--- head/sys/sys/bus.h
+++ head/sys/sys/bus.h
@@ -272,6 +272,17 @@
 	INTR_POLARITY_LOW = 2
 };
 
+enum intr_map_data_type {
+	INTR_MAP_DATA_ACPI,
+	INTR_MAP_DATA_FDT,
+	INTR_MAP_DATA_GPIO,
+};
+
+struct intr_map_data {
+	enum intr_map_data_type	type;
+	void (*destruct)(struct intr_map_data *);
+};
+
 /**
  * CPU sets supported by bus_get_cpus().  Note that not all sets may be
  * supported for a given device.  If a request is not supported by a
@@ -448,6 +459,9 @@
 				     int type, int rid, struct resource *r);
 int	bus_generic_resume(device_t dev);
 int	bus_generic_resume_child(device_t dev, device_t child);
+int	bus_generic_map_intr(device_t dev, device_t child, int *rid,
+			      rman_res_t *start, rman_res_t *end,
+			      rman_res_t *count, struct intr_map_data **imd);
 int	bus_generic_setup_intr(device_t dev, device_t child,
 			       struct resource *irq, int flags,
 			       driver_filter_t *filter, driver_intr_t *intr, 
Index: head/sys/sys/intr.h
===================================================================
--- head/sys/sys/intr.h
+++ head/sys/sys/intr.h
@@ -34,17 +34,6 @@
 
 #define	INTR_IRQ_INVALID	0xFFFFFFFF
 
-enum intr_map_data_type {
-	INTR_MAP_DATA_ACPI,
-	INTR_MAP_DATA_FDT,
-	INTR_MAP_DATA_GPIO,
-};
-
-struct intr_map_data {
-	enum intr_map_data_type	type;
-	size_t			size;
-};
-
 #ifdef DEV_ACPI
 struct intr_map_data_acpi {
 	struct intr_map_data	hdr;