mm,hwpoison: refactor get_any_page

mm,hwpoison: refactor get_any_page

Patch series "HWPoison: Refactor get page interface", v2.

This patch (of 3):

When we want to grab a refcount via get_any_page, we call __get_any_page
that calls get_hwpoison_page to get the actual refcount.

get_any_page() is only there because we have a sort of retry mechanism in
case the page we met is unknown to us or if we raced with an allocation.

Also __get_any_page() prints some messages about the page type in case the
page was a free page or the page type was unknown, but if anything, we
only need to print a message in case the pagetype was unknown, as that is
reporting an error down the chain.

Let us merge get_any_page() and __get_any_page(), and let the message be
printed in soft_offline_page.  While we are it, we can also remove the
'pfn' parameter as it is no longer used.

Link: https://lkml.kernel.org/r/20201204102558.31607-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20201204102558.31607-2-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Vlastimil Babka <Vbabka@suse.cz>
Cc: Qian Cai <qcai@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>