Index: linux-2.6-paulus/arch/powerpc/platforms/pseries/hotplug-memory.c
===================================================================
--- linux-2.6-paulus.orig/arch/powerpc/platforms/pseries/hotplug-memory.c	2008-08-25 13:08:27.000000000 -0500
+++ linux-2.6-paulus/arch/powerpc/platforms/pseries/hotplug-memory.c	2008-10-01 14:20:08.000000000 -0500
@@ -21,7 +21,7 @@
 	struct zone *zone;
 	int ret;
 
-	start_pfn = base >> PFN_SECTION_SHIFT;
+	start_pfn = base >> PAGE_SHIFT;
 	zone = page_zone(pfn_to_page(start_pfn));
 
 	/*