+unsigned long __init early_calculate_totalpages(void)
+{
+ int i;
+ unsigned long totalpages = 0;
+
+ for (i = 0; i < nr_nodemap_entries; i++)
+ totalpages += early_node_map[i].end_pfn -
+ early_node_map[i].start_pfn;
+
+ return totalpages;
+}
+
+/*
+ * Find the PFN the Movable zone begins in each node. Kernel memory
+ * is spread evenly between nodes as long as the nodes have enough
+ * memory. When they don't, some nodes will have more kernelcore than
+ * others
+ */
+void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
+{
+ int i, nid;
+ unsigned long usable_startpfn;
+ unsigned long kernelcore_node, kernelcore_remaining;
+ int usable_nodes = num_online_nodes();
+
+ /*
+ * If movablecore was specified, calculate what size of
+ * kernelcore that corresponds so that memory usable for
+ * any allocation type is evenly spread. If both kernelcore
+ * and movablecore are specified, then the value of kernelcore
+ * will be used for required_kernelcore if it's greater than
+ * what movablecore would have allowed.
+ */
+ if (required_movablecore) {
+ unsigned long totalpages = early_calculate_totalpages();
+ unsigned long corepages;
+
+ /*
+ * Round-up so that ZONE_MOVABLE is at least as large as what
+ * was requested by the user
+ */
+ required_movablecore =
+ roundup(required_movablecore, MAX_ORDER_NR_PAGES);
+ corepages = totalpages - required_movablecore;
+
+ required_kernelcore = max(required_kernelcore, corepages);
+ }
+
+ /* If kernelcore was not specified, there is no ZONE_MOVABLE */
+ if (!required_kernelcore)
+ return;
+
+ /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
+ find_usable_zone_for_movable();
+ usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
+
+restart:
+ /* Spread kernelcore memory as evenly as possible throughout nodes */
+ kernelcore_node = required_kernelcore / usable_nodes;
+ for_each_online_node(nid) {
+ /*
+ * Recalculate kernelcore_node if the division per node
+ * now exceeds what is necessary to satisfy the requested
+ * amount of memory for the kernel
+ */
+ if (required_kernelcore < kernelcore_node)
+ kernelcore_node = required_kernelcore / usable_nodes;
+
+ /*
+ * As the map is walked, we track how much memory is usable
+ * by the kernel using kernelcore_remaining. When it is
+ * 0, the rest of the node is usable by ZONE_MOVABLE
+ */
+ kernelcore_remaining = kernelcore_node;
+
+ /* Go through each range of PFNs within this node */
+ for_each_active_range_index_in_nid(i, nid) {
+ unsigned long start_pfn, end_pfn;
+ unsigned long size_pages;
+
+ start_pfn = max(early_node_map[i].start_pfn,
+ zone_movable_pfn[nid]);
+ end_pfn = early_node_map[i].end_pfn;
+ if (start_pfn >= end_pfn)
+ continue;
+
+ /* Account for what is only usable for kernelcore */
+ if (start_pfn < usable_startpfn) {
+ unsigned long kernel_pages;
+ kernel_pages = min(end_pfn, usable_startpfn)
+ - start_pfn;
+
+ kernelcore_remaining -= min(kernel_pages,
+ kernelcore_remaining);
+ required_kernelcore -= min(kernel_pages,
+ required_kernelcore);
+
+ /* Continue if range is now fully accounted */
+ if (end_pfn <= usable_startpfn) {
+
+ /*
+ * Push zone_movable_pfn to the end so
+ * that if we have to rebalance
+ * kernelcore across nodes, we will
+ * not double account here
+ */
+ zone_movable_pfn[nid] = end_pfn;
+ continue;
+ }
+ start_pfn = usable_startpfn;
+ }
+
+ /*
+ * The usable PFN range for ZONE_MOVABLE is from
+ * start_pfn->end_pfn. Calculate size_pages as the
+ * number of pages used as kernelcore
+ */
+ size_pages = end_pfn - start_pfn;
+ if (size_pages > kernelcore_remaining)
+ size_pages = kernelcore_remaining;
+ zone_movable_pfn[nid] = start_pfn + size_pages;
+
+ /*
+ * Some kernelcore has been met, update counts and
+ * break if the kernelcore for this node has been
+ * satisified
+ */
+ required_kernelcore -= min(required_kernelcore,
+ size_pages);
+ kernelcore_remaining -= size_pages;
+ if (!kernelcore_remaining)
+ break;
+ }
+ }
+
+ /*
+ * If there is still required_kernelcore, we do another pass with one
+ * less node in the count. This will push zone_movable_pfn[nid] further
+ * along on the nodes that still have memory until kernelcore is
+ * satisified
+ */
+ usable_nodes--;
+ if (usable_nodes && required_kernelcore > usable_nodes)
+ goto restart;
+
+ /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
+ for (nid = 0; nid < MAX_NUMNODES; nid++)
+ zone_movable_pfn[nid] =
+ roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
+}
+