[PATCH] unify pfn_to_page: x86_64 pfn_to_page

x86_64 can use generic funcs.
For DISCONTIGMEM, CONFIG_OUT_OF_LINE_PFN_TO_PAGE is selected.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 1cb4aa2..4310b4a 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -334,6 +334,10 @@
 	def_bool y
 	depends on NUMA
 
+config OUT_OF_LINE_PFN_TO_PAGE
+	def_bool y
+	depends on DISCONTIGMEM
+
 config NR_CPUS
 	int "Maximum number of CPUs (2-256)"
 	range 2 255