mm: use inline helper functions instead of ugly macros

mm: use inline helper functions instead of ugly macros

Patch series "support batched checking of the young flag for MGLRU", v3.

This is a follow-up to the previous work [1], to support batched checking
of the young flag for MGLRU.

Similarly, batched checking of young flag for large folios can improve
performance during large-folio reclamation when MGLRU is enabled.  I
observed noticeable performance improvements (see patch 5) on an Arm64
machine that supports contiguous PTEs.  All mm-selftests are passed.

Patch 1 - 3: cleanup patches.
Patch 4: add a new generic batched PTE helper: test_and_clear_young_ptes().
Patch 5: support batched young flag checking for MGLRU.
Patch 6: implement the Arm64 arch-specific test_and_clear_young_ptes().

This patch (of 6):

People have already complained that these *_clear_young_notify() related
macros are very ugly, so let's use inline helpers to make them more
readable.

In addition, we cannot implement these inline helper functions in the
mmu_notifier.h file, because some arch-specific files will include the
mmu_notifier.h, which introduces header compilation dependencies and
causes build errors (e.g., arch/arm64/include/asm/tlbflush.h).  Moreover,
since these functions are only used in the mm, implementing these inline
helpers in the mm/internal.h header seems reasonable.

Link: https://lkml.kernel.org/r/cover.1772778858.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/ea14af84e7967ccebb25082c28a8669d6da8fe57.1772778858.git.baolin.wang@linux.alibaba.com
Link: https://lore.kernel.org/all/cover.1770645603.git.baolin.wang@linux.alibaba.com/
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Xu <weixugc@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>