mm, hwpoison: enable 1GB hugepage support (v3)

Here is v3 of "enabling memory error handling on 1GB hugepage" patchset.

I applied feedbacks for v2, thank you very much.  Overall design of the
patchset is unchanged. Please see individual patches for details about
changes.

Patch dependency:

- "mm/memory-failure: disable unpoison once hw error happens"
  (actually the conflict is not logical one, but adding MF_SIMULATED to
   mf_flags conflicts with patch 6/9.)

Previous versions:

- v1: https://lore.kernel.org/linux-mm/20220602050631.771414-1-...
- v2: https://lore.kernel.org/linux-mm/20220623235153.2623702-1...

Thanks,
Naoya Horiguchi
---
Summary:

Naoya Horiguchi (9):
      mm/hugetlb: check gigantic_page_runtime_supported() in return_unused_surplus_pages()
      mm/hugetlb: separate path for hwpoison entry in copy_hugetlb_page_range()
      mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry
      mm, hwpoison, hugetlb: support saving mechanism of raw error pages
      mm, hwpoison: make unpoison aware of raw error info in hwpoisoned hugepage
      mm, hwpoison: set PG_hwpoison for busy hugetlb pages
      mm, hwpoison: make __page_handle_poison returns int
      mm, hwpoison: skip raw hwpoison page in freeing 1GB hugepage
      mm, hwpoison: enable memory error handling on 1GB hugepage

 arch/x86/mm/hugetlbpage.c |   8 ++-
 include/linux/hugetlb.h   |  18 +++++-
 include/linux/mm.h        |   2 +-
 include/linux/swapops.h   |   9 +++
 include/ras/ras_event.h   |   1 -
 mm/hugetlb.c              |  99 ++++++++++++++++++++++---------
 mm/memory-failure.c       | 148 ++++++++++++++++++++++++++++++++++++----------
 7 files changed, 224 insertions(+), 61 deletions(-)