+ /*
+ * Don't allow to offline memory blocks that contain holes.
+ * Consequently, memory blocks with holes can never get onlined
+ * via the hotplug path - online_pages() - as hotplugged memory has
+ * no holes. This way, we e.g., don't have to worry about marking
+ * memory holes PG_reserved, don't need pfn_valid() checks, and can
+ * avoid using walk_system_ram_range() later.
+ */
+ walk_system_ram_range(start_pfn, end_pfn - start_pfn, &nr_pages,
+ count_system_ram_pages_cb);
+ if (nr_pages != end_pfn - start_pfn) {
+ ret = -EINVAL;
+ reason = "memory holes";
+ goto failed_removal;
+ }
+