+#ifdef CONFIG_MEMORY_HOTPLUG
+/*
+ * Finds the lowest memory reosurce exists within [res->start.res->end)
+ * the caller must specify res->start, res->end, res->flags.
+ * If found, returns 0, res is overwritten, if not found, returns -1.
+ */
+int find_next_system_ram(struct resource *res)
+{
+ resource_size_t start, end;
+ struct resource *p;
+
+ BUG_ON(!res);
+
+ start = res->start;
+ end = res->end;
+ BUG_ON(start >= end);
+
+ read_lock(&resource_lock);
+ for (p = iomem_resource.child; p ; p = p->sibling) {
+ /* system ram is just marked as IORESOURCE_MEM */
+ if (p->flags != res->flags)
+ continue;
+ if (p->start > end) {
+ p = NULL;
+ break;
+ }
+ if ((p->end >= start) && (p->start < end))
+ break;
+ }
+ read_unlock(&resource_lock);
+ if (!p)
+ return -1;
+ /* copy data */
+ if (res->start < p->start)
+ res->start = p->start;
+ if (res->end > p->end)
+ res->end = p->end;
+ return 0;
+}
+#endif
+