memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap

memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap

For removing memmap region of sparse-vmemmap which is allocated bootmem,
memmap region of sparse-vmemmap needs to be registered by
get_page_bootmem().  So the patch searches pages of virtual mapping and
registers the pages by get_page_bootmem().

NOTE: register_page_bootmem_memmap() is not implemented for ia64,
      ppc, s390, and sparc.  So introduce CONFIG_HAVE_BOOTMEM_INFO_NODE
      and revert register_page_bootmem_info_node() when platform doesn't
      support it.

      It's implemented by adding a new Kconfig option named
      CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected
      by memory-hotplug feature fully supported archs(currently only on
      x86_64).

      Since we have 2 config options called MEMORY_HOTPLUG and
      MEMORY_HOTREMOVE used for memory hot-add and hot-remove separately,
      and codes in function register_page_bootmem_info_node() are only
      used for collecting infomation for hot-remove, so reside it under
      MEMORY_HOTREMOVE.

      Besides page_isolation.c selected by MEMORY_ISOLATION under
      MEMORY_HOTPLUG is also such case, move it too.

[[email protected]: put register_page_bootmem_memmap inside CONFIG_MEMORY_HOTPLUG_SPARSE]
[[email protected]: introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node()]
[[email protected]: remove the arch specific functions without any implementation]
[[email protected]: mm/Kconfig: move auto selects from MEMORY_HOTPLUG to MEMORY_HOTREMOVE as needed]
[[email protected]: fix defined but not used warning]
Signed-off-by: Wen Congyang <[email protected]>
Signed-off-by: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Tang Chen <[email protected]>
Reviewed-by: Wu Jianguo <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Jianguo Wu <[email protected]>
Cc: Kamezawa Hiroyuki <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Signed-off-by: Lin Feng <[email protected]>
Signed-off-by: David Rientjes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>