+/*
+ * Page buddy system uses "index >> (i+1)", where "index" is
+ * at most "size-1".
+ *
+ * The extra "+3" is to round down to byte size (8 bits per byte
+ * assumption). Thus we get "(size-1) >> (i+4)" as the last byte
+ * we can access.
+ *
+ * The "+1" is because we want to round the byte allocation up
+ * rather than down. So we should have had a "+7" before we shifted
+ * down by three. Also, we have to add one as we actually _use_ the
+ * last bit (it's [0,n] inclusive, not [0,n[).
+ *
+ * So we actually had +7+1 before we shift down by 3. But
+ * (n+8) >> 3 == (n >> 3) + 1 (modulo overflows, which we do not have).
+ *
+ * Finally, we LONG_ALIGN because all bitmap operations are on longs.
+ */
+unsigned long pages_to_bitmap_size(unsigned long order, unsigned long nr_pages)
+{
+ unsigned long bitmap_size;
+
+ bitmap_size = (nr_pages-1) >> (order+4);
+ bitmap_size = LONG_ALIGN(bitmap_size+1);
+
+ return bitmap_size;
+}
+
+void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, unsigned long size)
+{
+ int order;
+ for (order = 0; ; order++) {
+ unsigned long bitmap_size;
+
+ INIT_LIST_HEAD(&zone->free_area[order].free_list);
+ if (order == MAX_ORDER-1) {
+ zone->free_area[order].map = NULL;
+ break;
+ }
+
+ bitmap_size = pages_to_bitmap_size(order, size);
+ zone->free_area[order].map =
+ (unsigned long *) alloc_bootmem_node(pgdat, bitmap_size);
+ }
+}
+