Hi Petko,
On Sun, Jul 23, 2023 at 3:48 PM Petko Manolov
<petko.manolov@xxxxxxxxxxxx> wrote:
>
> From: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
>
> huge_ptep_get must be reimplemented in order to go through all the PTEs
> of a NAPOT region: this is needed because the HW can update the A/D bits
> of any of the PTE that constitutes the NAPOT region.
>
> Fixes: 82a1a1f3bfb6 ("riscv: mm: support Svnapot in hugetlb page")
> Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
> Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
> Link: https://lore.kernel.org/r/20230428120120.21620-2-alexghiti@xxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
> Signed-off-by: Petko Manolov <petko.manolov@xxxxxxxxxxxx>
> ---
> arch/riscv/include/asm/hugetlb.h | 3 +++
> arch/riscv/mm/hugetlbpage.c | 24 ++++++++++++++++++++++++
> 2 files changed, 27 insertions(+)
>
> diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
> index fe6f23006641..ce1ebda1a49a 100644
> --- a/arch/riscv/include/asm/hugetlb.h
> +++ b/arch/riscv/include/asm/hugetlb.h
> @@ -36,6 +36,9 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> unsigned long addr, pte_t *ptep,
> pte_t pte, int dirty);
>
> +#define __HAVE_ARCH_HUGE_PTEP_GET
> +pte_t huge_ptep_get(pte_t *ptep);
> +
> pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags);
> #define arch_make_huge_pte arch_make_huge_pte
>
> diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
> index 238d00bdac14..e0ef56dc57b9 100644
> --- a/arch/riscv/mm/hugetlbpage.c
> +++ b/arch/riscv/mm/hugetlbpage.c
> @@ -3,6 +3,30 @@
> #include <linux/err.h>
>
> #ifdef CONFIG_RISCV_ISA_SVNAPOT
> +pte_t huge_ptep_get(pte_t *ptep)
> +{
> + unsigned long pte_num;
> + int i;
> + pte_t orig_pte = ptep_get(ptep);
> +
> + if (!pte_present(orig_pte) || !pte_napot(orig_pte))
> + return orig_pte;
> +
> + pte_num = napot_pte_num(napot_cont_order(orig_pte));
> +
> + for (i = 0; i < pte_num; i++, ptep++) {
> + pte_t pte = ptep_get(ptep);
> +
> + if (pte_dirty(pte))
> + orig_pte = pte_mkdirty(orig_pte);
> +
> + if (pte_young(pte))
> + orig_pte = pte_mkyoung(orig_pte);
> + }
> +
> + return orig_pte;
> +}
> +
> pte_t *huge_pte_alloc(struct mm_struct *mm,
> struct vm_area_struct *vma,
> unsigned long addr,
> --
> 2.39.2
>
Not sure I understand why you propose this patch to stable since
svnapot support was introduced in 6.4 and this fix (and another one)
was merged in 6.4 too. Am I missing something?
Thanks,
Alex
