+struct mdesc_handle;
+
+/* Machine description operations are to be surrounded by grab and
+ * release calls. The mdesc_handle returned from the grab is
+ * the first argument to all of the operational calls that work
+ * on mdescs.
+ */
+extern struct mdesc_handle *mdesc_grab(void);
+extern void mdesc_release(struct mdesc_handle *);
+
+#define MDESC_NODE_NULL (~(u64)0)
+
+extern u64 mdesc_node_by_name(struct mdesc_handle *handle,
+ u64 from_node, const char *name);
+#define mdesc_for_each_node_by_name(__hdl, __node, __name) \
+ for (__node = mdesc_node_by_name(__hdl, MDESC_NODE_NULL, __name); \
+ (__node) != MDESC_NODE_NULL; \
+ __node = mdesc_node_by_name(__hdl, __node, __name))
+
+/* Access to property values returned from mdesc_get_property() are
+ * only valid inside of a mdesc_grab()/mdesc_release() sequence.
+ * Once mdesc_release() is called, the memory backed up by these
+ * pointers may reference freed up memory.
+ *
+ * Therefore callers must make copies of any property values
+ * they need.
+ *
+ * These same rules apply to mdesc_node_name().
+ */
+extern const void *mdesc_get_property(struct mdesc_handle *handle,
+ u64 node, const char *name, int *lenp);
+extern const char *mdesc_node_name(struct mdesc_handle *hp, u64 node);
+
+/* MD arc iteration, the standard sequence is:
+ *
+ * unsigned long arc;
+ * mdesc_for_each_arc(arc, handle, node, MDESC_ARC_TYPE_{FWD,BACK}) {
+ * unsigned long target = mdesc_arc_target(handle, arc);
+ * ...
+ * }
+ */