memory-hotplug: ia64: suitable memory should go to ZONE_MOVABLE

This patch introduces zone_for_memory() to arch_add_memory() on ia64 to
ensure new, higher memory added into ZONE_MOVABLE if movable zone has
already setup.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Mel Gorman" <mgorman@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/ia64/mm/init.c

@@ -631,7 +631,8 @@ int arch_add_memory(int nid, u64 start, u64 size)
 
 	pgdat = NODE_DATA(nid);
 
-	zone = pgdat->node_zones + ZONE_NORMAL;
+	zone = pgdat->node_zones +
+		zone_for_memory(nid, start, size, ZONE_NORMAL);
 	ret = __add_pages(nid, zone, start_pfn, nr_pages);
 
 	if (ret)