Re: [PATCH 1/3] riscv: Fixup _PAGE_GLOBAL in _PAGE_KERNEL

[Anup Patel]

On Mon, May 24, 2021 at 12:22 PM <guoren@xxxxxxxxxx> wrote:
>
> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
>
> Kernel virtual address translation should avoid care asid or it'll
> cause more TLB-miss and TLB-refill. Because the current asid in satp
> belongs to the current process, but the target kernel va TLB entry's
> asid still belongs to the previous process.
>
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> Cc: Anup Patel <anup.patel@xxxxxxx>
> Cc: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>

First of all thanks for doing this series, I had similar changes in mind
as follow-up to the ASID allocator.

I went through all three patches and at least I don't see any
obvious issue but I think we should try testing it more on a few
existing platforms.

Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>

Regards,
Anup

> ---
>  arch/riscv/include/asm/pgtable.h | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 78f2323..017da15 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -135,6 +135,7 @@
>                                 | _PAGE_PRESENT \
>                                 | _PAGE_ACCESSED \
>                                 | _PAGE_DIRTY \
> +                               | _PAGE_GLOBAL \
>                                 | _PAGE_CACHE)
>
>  #define PAGE_KERNEL            __pgprot(_PAGE_KERNEL)
> --
> 2.7.4
>