[PATCH] x86_64: Make pfn_valid work early in boot

It needs num_physpages, so initialize it early. It's later overwritten
again.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/kernel/setup.c

@@ -614,6 +614,7 @@ void __init setup_arch(char **cmdline_p)
 	 * we are rounding upwards:
 	 */
 	end_pfn = e820_end_of_ram();
+	num_physpages = end_pfn;		/* for pfn_valid */
 
 	check_efer();