[PATCH 00/12] Make riscv use THP contpte support for arm64

Alexandre Ghiti alexghiti at rivosinc.com
Wed May 8 12:19:19 PDT 2024


This allows riscv to support napot (riscv equivalent to contpte) THPs by
moving arm64 contpte support into mm, the previous series [1] only merging
riscv and arm64 implementations of hugetlbfs contpte.

riscv contpte specification allows for different contpte sizes, although
only 64KB is supported for now. So in this patchset is implemented the
support of multiple contpte sizes, which introduces a few arch specific
helpers to determine what sizes are supported. Even though only one size
is supported on riscv, the implementation of the multi size support is to
show what it will look like when we support other sizes, and make sure
it does not regress arm64.

I tested arm64 using the cow kselftest and a kernel build with 4KB base
page size and 64KB contpte. riscv was tested with the same tests on *all*
contpte sizes that fit in the last page table level (support for PMD sizes
is not present here). Both arch were only tested on qemu.

Alexandre Ghiti (12):
  mm, arm64: Rename ARM64_CONTPTE to THP_CONTPTE
  mm, riscv, arm64: Use common ptep_get() function
  mm, riscv, arm64: Use common set_ptes() function
  mm, riscv, arm64: Use common ptep_get_lockless() function
  mm, riscv, arm64: Use common set_pte() function
  mm, riscv, arm64: Use common pte_clear() function
  mm, riscv, arm64: Use common ptep_get_and_clear() function
  mm, riscv, arm64: Use common ptep_test_and_clear_young() function
  mm, riscv, arm64: Use common ptep_clear_flush_young() function
  mm, riscv, arm64: Use common ptep_set_access_flags() function
  mm, riscv, arm64: Use common ptep_set_wrprotect()/wrprotect_ptes()
    functions
  mm, riscv, arm64: Use common
    get_and_clear_full_ptes()/clear_full_ptes() functions

 arch/arm64/Kconfig               |   9 -
 arch/arm64/include/asm/pgtable.h | 318 +++++---------
 arch/arm64/mm/Makefile           |   1 -
 arch/arm64/mm/contpte.c          | 408 ------------------
 arch/arm64/mm/hugetlbpage.c      |   6 +-
 arch/arm64/mm/mmu.c              |   2 +-
 arch/riscv/include/asm/kfence.h  |   4 +-
 arch/riscv/include/asm/pgtable.h | 206 +++++++++-
 arch/riscv/kernel/efi.c          |   4 +-
 arch/riscv/kernel/hibernate.c    |   2 +-
 arch/riscv/kvm/mmu.c             |  26 +-
 arch/riscv/mm/fault.c            |   2 +-
 arch/riscv/mm/init.c             |   4 +-
 arch/riscv/mm/kasan_init.c       |  16 +-
 arch/riscv/mm/pageattr.c         |   8 +-
 arch/riscv/mm/pgtable.c          |   6 +-
 include/linux/contpte.h          |  37 ++
 mm/Kconfig                       |   9 +
 mm/contpte.c                     | 685 ++++++++++++++++++++++++++++++-
 19 files changed, 1056 insertions(+), 697 deletions(-)
 delete mode 100644 arch/arm64/mm/contpte.c
 create mode 100644 include/linux/contpte.h

-- 
2.39.2




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