[PATCH rfc -next 00/10] mm: convert to generic VMA lock-based page fault

[Kefeng Wang]

Add a generic VMA lock-based page fault handler in mm core, and convert
architectures to use it, which eliminate architectures's duplicated codes.

With it, we can avoid multiple changes in architectures's code if we 
add new feature or bugfix.

This fixes riscv missing change about commit 38b3aec8e8d2 "mm: drop per-VMA
lock when returning VM_FAULT_RETRY or VM_FAULT_COMPLETED", and in the end,
we enable this feature on ARM32/Loongarch too.

This is based on next-20230713, only built test(no loongarch compiler,
so except loongarch).

Kefeng Wang (10):
  mm: add a generic VMA lock-based page fault handler
  x86: mm: use try_vma_locked_page_fault()
  arm64: mm: use try_vma_locked_page_fault()
  s390: mm: use try_vma_locked_page_fault()
  powerpc: mm: use try_vma_locked_page_fault()
  riscv: mm: use try_vma_locked_page_fault()
  ARM: mm: try VMA lock-based page fault handling first
  loongarch: mm: cleanup __do_page_fault()
  loongarch: mm: add access_error() helper
  loongarch: mm: try VMA lock-based page fault handling first

 arch/arm/Kconfig          |  1 +
 arch/arm/mm/fault.c       | 15 ++++++-
 arch/arm64/mm/fault.c     | 28 +++---------
 arch/loongarch/Kconfig    |  1 +
 arch/loongarch/mm/fault.c | 92 ++++++++++++++++++++++++---------------
 arch/powerpc/mm/fault.c   | 54 ++++++++++-------------
 arch/riscv/mm/fault.c     | 38 +++++++---------
 arch/s390/mm/fault.c      | 23 +++-------
 arch/x86/mm/fault.c       | 39 +++++++----------
 include/linux/mm.h        | 28 ++++++++++++
 mm/memory.c               | 42 ++++++++++++++++++
 11 files changed, 206 insertions(+), 155 deletions(-)

-- 
2.27.0