x86: introduce initmem_init for 64 bit

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-x86/page_64.h b/include/asm-x86/page_64.h
index 6ea7285..ac37643 100644
--- a/include/asm-x86/page_64.h
+++ b/include/asm-x86/page_64.h
@@ -83,6 +83,7 @@
 extern unsigned long init_memory_mapping(unsigned long start,
 					 unsigned long end);
 
+extern void initmem_init(unsigned long start_pfn, unsigned long end_pfn);
 #endif	/* !__ASSEMBLY__ */
 
 #ifdef CONFIG_FLATMEM