mm: remove x86-only restriction of movable_node

mm: remove x86-only restriction of movable_node

In commit c5320926e370 ("mem-hotplug: introduce movable_node boot
option"), the memblock allocation direction is changed to bottom-up and
then back to top-down like this:

1. memblock_set_bottom_up(true), called by cmdline_parse_movable_node().
2. memblock_set_bottom_up(false), called by x86's numa_init().

Even though (1) occurs in generic mm code, it is wrapped by #ifdef
CONFIG_MOVABLE_NODE, which depends on X86_64.

This means that when we extend CONFIG_MOVABLE_NODE to non-x86 arches,
things will be unbalanced.  (1) will happen for them, but (2) will not.

This toggle was added in the first place because x86 has a delay between
adding memblocks and marking them as hotpluggable.  Since other arches
do this marking either immediately or not at all, they do not require
the bottom-up toggle.

So, resolve things by moving (1) from cmdline_parse_movable_node() to
x86's setup_arch(), immediately after the movable_node parameter has
been parsed.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Reza Arbab <[email protected]>
Acked-by: Balbir Singh <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Bharata B Rao <[email protected]>
Cc: Frank Rowand <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nathan Fontenot <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Stewart Smith <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>