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From:   Anup Patel <anup@brainfault.org>
Date:   Mon, 24 May 2021 13:33:08 +0530
Message-ID: <CAAhSdy3ORUGqyL-9oMQCKYCXnG8M=xrZ8q+AiWg8s+v6zsk=_A@mail.gmail.com>
Subject: Re: [PATCH 1/3] riscv: Fixup _PAGE_GLOBAL in _PAGE_KERNEL
To:     Guo Ren <guoren@kernel.org>
Cc:     Anup Patel <anup.patel@wdc.com>,
        Palmer Dabbelt <palmerdabbelt@google.com>,
        Arnd Bergmann <arnd@arndb.de>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        "linux-kernel@vger.kernel.org List" <linux-kernel@vger.kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        linux-sunxi@lists.linux.dev, Guo Ren <guoren@linux.alibaba.com>
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On Mon, May 24, 2021 at 12:22 PM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> 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@linux.alibaba.com>
> Cc: Anup Patel <anup.patel@wdc.com>
> Cc: Palmer Dabbelt <palmerdabbelt@google.com>

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@brainfault.org>

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
>