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From:   Naresh Kamboju <naresh.kamboju@linaro.org>
Date:   Fri, 27 May 2022 14:39:01 +0530
Message-ID: <CA+G9fYuND9eW5qBEvcfjPuW=wobQq5bu5Bzr3QOX3YUT-Qsviw@mail.gmail.com>
Subject: Re: [PATCH] arm64/hugetlb: Fix building errors in huge_ptep_clear_flush()
To:     Baolin Wang <baolin.wang@linux.alibaba.com>
Cc:     torvalds@linux-foundation.org, catalin.marinas@arm.com,
        will@kernel.org, akpm@linux-foundation.org,
        anshuman.khandual@arm.com, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
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On Fri, 27 May 2022 at 10:21, Baolin Wang <baolin.wang@linux.alibaba.com> w=
rote:
>
> Fix below building errors which was caused by commit ae07562909f3
> ("mm: change huge_ptep_clear_flush() to return the original pte")
> interacting with commit fb396bb459c1 ("arm64/hugetlb: Drop TLB flush
> from get_clear_flush()").
>
> Due to the new get_clear_contig() has dropped TLB flush, we should
> add an explicit TLB flush in huge_ptep_clear_flush() to keep original
> semantics when changing to use new get_clear_contig().
>
> "
> arch/arm64/mm/hugetlbpage.c: In function =E2=80=98huge_ptep_clear_flush=
=E2=80=99:
> arch/arm64/mm/hugetlbpage.c:515:9: error: implicit declaration of
> function =E2=80=98get_clear_flush=E2=80=99; did you mean =E2=80=98ptep_cl=
ear_flush=E2=80=99?
> [-Werror=3Dimplicit-function-declaration]
>   515 |  return get_clear_flush(vma->vm_mm, addr, ptep, pgsize, ncontig);
>       |         ^~~~~~~~~~~~~~~
>       |         ptep_clear_flush
> "
>

This patch tested on arm, arm64, i386 and x86 with gcc-11 and clang-14.

> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
> Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Anshuman Khandual <anshuman.khandual@arm.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>

Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>

> ---
>  arch/arm64/mm/hugetlbpage.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 0f0c17dfeb9c..e2a5ec9fdc0d 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -507,12 +507,15 @@ pte_t huge_ptep_clear_flush(struct vm_area_struct *=
vma,
>  {
>         size_t pgsize;
>         int ncontig;
> +       pte_t orig_pte;
>
>         if (!pte_cont(READ_ONCE(*ptep)))
>                 return ptep_clear_flush(vma, addr, ptep);
>
>         ncontig =3D find_num_contig(vma->vm_mm, addr, ptep, &pgsize);
> -       return get_clear_flush(vma->vm_mm, addr, ptep, pgsize, ncontig);
> +       orig_pte =3D get_clear_contig(vma->vm_mm, addr, ptep, pgsize, nco=
ntig);
> +       flush_tlb_range(vma, addr, addr + pgsize * ncontig);
> +       return orig_pte;
>  }
>
>  static int __init hugetlbpage_init(void)
> --
> 2.27.0
>


--
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https://lkft.linaro.org