Re: [PATCH v2 00/19] ARC mm updates: support 3/4 levels and asm-generic/pgalloc

From: Mike Rapoport
Date: Sun Aug 15 2021 - 05:27:43 EST


On Thu, Aug 12, 2021 at 04:37:34PM -0700, Vineet Gupta wrote:
> Hi,
>
> Big pile of ARC mm changes to prepare for 3 or 4 levels of paging (from
> current 2) needed for new hardware page walked MMUv6 (in aRCv3 ISA based
> cores).
>
> Most of these changes are incremental cleanups to make way for 14/18 and
> 15/18 which actually imeplement the new levels (in existing ARCv2 port)
> and worth a critical eye.
>
> CC'ing some of you guys dealing with page tables for a while :-)
> to spot any obvious gotchas.

There are a couple of small nits here and there, but overall

Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>

> Thx,
> -Vineet
>
> Changes since v1 [1]
> - Switched ARC to asm-generic/pgalloc.h (so struct page based pgtable_t) [Mike Rapoport]
> - Dropped {pud,pmd}_alloc_one/{pud,pmd}_free provided by asm-generic/pgalloc.h [Mike Rapoport]
> - Negative diffstat now due to above
> - Added BUILD_BUG_ON() to arch/arc/mm/init.c for sanity of table sizes
> - Consolidated 2 patches related to ARC_USE_SCRATCH_REG [Mike Rapoport]
> - Reworked how mmu is re-enabled in entry code [Jose Abreu]
>
> [1] http://lists.infradead.org/pipermail/linux-snps-arc/2021-August/005326.html
>
> Vineet Gupta (19):
> ARC: mm: use SCRATCH_DATA0 register for caching pgdir in ARCv2 only
> ARC: mm: remove tlb paranoid code
> ARC: mm: move mmu/cache externs out to setup.h
> ARC: mm: Fixes to allow STRICT_MM_TYPECHECKS
> ARC: mm: Enable STRICT_MM_TYPECHECKS
> ARC: ioremap: use more commonly used PAGE_KERNEL based uncached flag
> ARC: mm: pmd_populate* to use the canonical set_pmd (and drop pmd_set)
> ARC: mm: switch pgtable_t back to struct page *
> ARC: mm: switch to asm-generic/pgalloc.h
> ARC: mm: non-functional code cleanup ahead of 3 levels
> ARC: mm: move MMU specific bits out of ASID allocator
> ARC: mm: move MMU specific bits out of entry code ...
> ARC: mm: disintegrate mmu.h (arcv2 bits out)
> ARC: mm: disintegrate pgtable.h into levels and flags
> ARC: mm: hack to allow 2 level build with 4 level code
> ARC: mm: support 3 levels of page tables
> ARC: mm: support 4 levels of page tables
> ARC: mm: vmalloc sync from kernel to user table to update PMD ...
> ARC: mm: introduce _PAGE_TABLE to explicitly link pgd,pud,pmd entries
>
> arch/arc/Kconfig | 7 +-
> arch/arc/include/asm/cache.h | 4 -
> arch/arc/include/asm/entry-compact.h | 8 -
> arch/arc/include/asm/mmu-arcv2.h | 103 +++++++
> arch/arc/include/asm/mmu.h | 73 +----
> arch/arc/include/asm/mmu_context.h | 28 +-
> arch/arc/include/asm/page.h | 74 +++--
> arch/arc/include/asm/pgalloc.h | 81 ++----
> arch/arc/include/asm/pgtable-bits-arcv2.h | 151 +++++++++++
> arch/arc/include/asm/pgtable-levels.h | 179 ++++++++++++
> arch/arc/include/asm/pgtable.h | 315 +---------------------
> arch/arc/include/asm/processor.h | 2 +-
> arch/arc/include/asm/setup.h | 12 +-
> arch/arc/kernel/entry-arcv2.S | 1 +
> arch/arc/kernel/entry.S | 7 +-
> arch/arc/mm/fault.c | 20 +-
> arch/arc/mm/init.c | 5 +
> arch/arc/mm/ioremap.c | 3 +-
> arch/arc/mm/tlb.c | 68 +----
> arch/arc/mm/tlbex.S | 78 ++----
> 20 files changed, 591 insertions(+), 628 deletions(-)
> create mode 100644 arch/arc/include/asm/mmu-arcv2.h
> create mode 100644 arch/arc/include/asm/pgtable-bits-arcv2.h
> create mode 100644 arch/arc/include/asm/pgtable-levels.h
>
> --
> 2.25.1
>

--
Sincerely yours,
Mike.