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

[Vineet Gupta <vgupta@kernel.org>]

On 8/15/21 2:26 AM, Mike Rapoport wrote:
> 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

I've fixed the last remaining things locally and won't repost, unless 
you want me to.

>
> Acked-by: Mike Rapoport <rppt@linux.ibm.com>

Thx for spending time to review this Mike. Much appreciated.


-Vineet

>
>> 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
>>