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Date:   Thu, 30 Jan 2020 09:40:51 -0800 (PST)
From:   Palmer Dabbelt <palmerdabbelt@google.com>
Subject:     Re: [PATCH] riscv: Use flush_icache_mm for flush_icache_user_range
CC:     linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org,
        guoren@linux.alibaba.com, Andrew Waterman <andrew@sifive.com>,
        palmer@sifive.com
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On Fri, 24 Jan 2020 16:18:10 GMT (+0000), guoren@linux.alibaba.com wrote:
> The only call path is:
>
> __access_remote_vm -> copy_to_user_page -> flush_icache_user_range
>
> Seems it's ok to use flush_icache_mm instead of flush_icache_all and
> it could reduce flush_icache_all called on other harts.
>
> I think the patch is the fixup for the commit 08f051eda33b.
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Cc: Andrew Waterman <andrew@sifive.com>
> Cc: Palmer Dabbelt <palmer@sifive.com>
> ---
>  arch/riscv/include/asm/cacheflush.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h
> index b69aecbb36d3..26589623fd57 100644
> --- a/arch/riscv/include/asm/cacheflush.h
> +++ b/arch/riscv/include/asm/cacheflush.h
> @@ -85,7 +85,7 @@ static inline void flush_dcache_page(struct page *page)
>   * so instead we just flush the whole thing.
>   */
>  #define flush_icache_range(start, end) flush_icache_all()
> -#define flush_icache_user_range(vma, pg, addr, len) flush_icache_all()
> +#define flush_icache_user_range(vma, pg, addr, len) flush_icache_mm(vma->vm_mm, 0)
>
>  void dma_wbinv_range(unsigned long start, unsigned long end);
>  void dma_wb_range(unsigned long start, unsigned long end);

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>

I've added this to for-next with some minor modifications as
4d99abce8ce80e866020ffa5b2bd790269235f37.  It missed the PR I'm sending
now-ish, but I'll include it as part of the next one even if it's during an
early RC.

Thanks!