Prepare for removing num_physpages and simplify mem_init().
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>