Re: [RFC PATCH 11/25] kvx: Add memory management

[Mike Rapoport <rppt@kernel.org>]

On Tue, Jan 03, 2023 at 05:43:45PM +0100, Yann Sionneau wrote:
> Add memory management support for kvx, including: cache and tlb
> management, page fault handling, ioremap/mmap and streaming dma support.
> 
> CC: Will Deacon <will@kernel.org>
> CC: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
> CC: Andrew Morton <akpm@linux-foundation.org>
> CC: Nick Piggin <npiggin@gmail.com>
> CC: Peter Zijlstra <peterz@infradead.org>
> CC: Paul Walmsley <paul.walmsley@sifive.com>
> CC: Palmer Dabbelt <palmer@dabbelt.com>
> CC: Albert Ou <aou@eecs.berkeley.edu>
> CC: linux-kernel@vger.kernel.org
> CC: linux-arch@vger.kernel.org
> CC: linux-mm@kvack.org
> CC: linux-riscv@lists.infradead.org
> Co-developed-by: Clement Leger <clement.leger@bootlin.com>
> Signed-off-by: Clement Leger <clement.leger@bootlin.com>
> Co-developed-by: Guillaume Thouvenin <gthouvenin@kalray.eu>
> Signed-off-by: Guillaume Thouvenin <gthouvenin@kalray.eu>
> Co-developed-by: Jean-Christophe Pince <jcpince@gmail.com>
> Signed-off-by: Jean-Christophe Pince <jcpince@gmail.com>
> Co-developed-by: Jules Maselbas <jmaselbas@kalray.eu>
> Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
> Co-developed-by: Julian Vetter <jvetter@kalray.eu>
> Signed-off-by: Julian Vetter <jvetter@kalray.eu>
> Co-developed-by: Julien Hascoet <jhascoet@kalray.eu>
> Signed-off-by: Julien Hascoet <jhascoet@kalray.eu>
> Co-developed-by: Louis Morhet <lmorhet@kalray.eu>
> Signed-off-by: Louis Morhet <lmorhet@kalray.eu>
> Co-developed-by: Marc Poulhiès <dkm@kataplop.net>
> Signed-off-by: Marc Poulhiès <dkm@kataplop.net>
> Co-developed-by: Marius Gligor <mgligor@kalray.eu>
> Signed-off-by: Marius Gligor <mgligor@kalray.eu>
> Co-developed-by: Vincent Chardon <vincent.chardon@elsys-design.com>
> Signed-off-by: Vincent Chardon <vincent.chardon@elsys-design.com>
> Co-developed-by: Yann Sionneau <ysionneau@kalray.eu>
> Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>
> ---
>  arch/kvx/include/asm/cache.h         |  46 +++
>  arch/kvx/include/asm/cacheflush.h    | 181 +++++++++
>  arch/kvx/include/asm/fixmap.h        |  47 +++
>  arch/kvx/include/asm/hugetlb.h       |  36 ++
>  arch/kvx/include/asm/l2_cache.h      |  75 ++++
>  arch/kvx/include/asm/l2_cache_defs.h |  64 ++++
>  arch/kvx/include/asm/mem_map.h       |  44 +++
>  arch/kvx/include/asm/mmu.h           | 296 +++++++++++++++
>  arch/kvx/include/asm/mmu_context.h   | 156 ++++++++
>  arch/kvx/include/asm/mmu_stats.h     |  38 ++
>  arch/kvx/include/asm/page.h          | 187 ++++++++++
>  arch/kvx/include/asm/page_size.h     |  29 ++
>  arch/kvx/include/asm/pgalloc.h       | 101 +++++
>  arch/kvx/include/asm/pgtable-bits.h  | 102 ++++++
>  arch/kvx/include/asm/pgtable.h       | 451 +++++++++++++++++++++++
>  arch/kvx/include/asm/rm_fw.h         |  16 +
>  arch/kvx/include/asm/sparsemem.h     |  15 +
>  arch/kvx/include/asm/symbols.h       |  16 +
>  arch/kvx/include/asm/tlb.h           |  24 ++
>  arch/kvx/include/asm/tlb_defs.h      | 131 +++++++
>  arch/kvx/include/asm/tlbflush.h      |  58 +++
>  arch/kvx/include/asm/vmalloc.h       |  10 +
>  arch/kvx/mm/cacheflush.c             | 154 ++++++++
>  arch/kvx/mm/dma-mapping.c            |  95 +++++
>  arch/kvx/mm/extable.c                |  24 ++
>  arch/kvx/mm/fault.c                  | 264 ++++++++++++++
>  arch/kvx/mm/hugetlbpage.c            | 317 ++++++++++++++++
>  arch/kvx/mm/init.c                   | 527 +++++++++++++++++++++++++++
>  arch/kvx/mm/kernel_rwx.c             | 228 ++++++++++++
>  arch/kvx/mm/mmap.c                   |  31 ++
>  arch/kvx/mm/mmu.c                    | 204 +++++++++++
>  arch/kvx/mm/mmu_stats.c              |  94 +++++
>  arch/kvx/mm/tlb.c                    | 433 ++++++++++++++++++++++
>  33 files changed, 4494 insertions(+)

Please strip functionality that's not essential for boot and the re-add it
after the very core code is merged. I'd say multiple page size, hugetlb and
strict RWX are not necessary to start with.

I'd also suggest to have separate patches for different parts, like cache
and tlb management, page tables and page fault fault handling, ioremap/mmap
and streaming dma support.

-- 
Sincerely yours,
Mike.