mm/mremap: convert huge PUD move to separate helper

With TRANSPARENT_HUGEPAGE_PUD enabled the kernel can find huge PUD
entries.  Add a helper to move huge PUD entries on mremap().

This will be used by a later patch to optimize mremap of PUD_SIZE aligned
level 4 PTE mapped address

This also make sure we support mremap on huge PUD entries even with
CONFIG_HAVE_MOVE_PUD disabled.

[[email protected]: fix build failure with clang-10]
  Link: https://lore.kernel.org/lkml/YMuOSnJsL9qkxweY@archlinux-ax161
  Link: https://lkml.kernel.org/r/[email protected]

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Kalesh Singh <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions