mm, memory_hotplug: move movable_node to the hotplug proper

movable_node_is_enabled is defined in memblock proper while it is
initialized from the memory hotplug proper.  This is quite messy and it
makes a dependency between the two so move movable_node along with the
helper functions to memory_hotplug.

To make it more entertaining the kernel parameter is ignored unless
CONFIG_HAVE_MEMBLOCK_NODE_MAP=y because we do not have the node
information for each memblock otherwise.  So let's warn when the option
is disabled.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Reza Arbab <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Kani Toshimitsu <[email protected]>
Cc: Chen Yucong <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

mm/memblock.c

@@ -54,7 +54,6 @@ struct memblock memblock __initdata_memblock = {
 };
 
 int memblock_debug __initdata_memblock;
-bool movable_node_enabled __initdata_memblock = false;
 static bool system_has_some_mirror __initdata_memblock = false;
 static int memblock_can_resize __initdata_memblock;
 static int memblock_memory_in_slab __initdata_memblock = 0;