"Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> writes:
> Architectures like ppc64 require to do a conditional tlb flush based on the old
> and new value of pte. Follow the regular pte change protection sequence for
> hugetlb too. This allows the architectures to override the update sequence.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
> ---
> include/linux/hugetlb.h | 20 ++++++++++++++++++++
> mm/hugetlb.c | 8 +++++---
> 2 files changed, 25 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 087fd5f48c91..39e78b80375c 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -543,6 +543,26 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr
> set_huge_pte_at(mm, addr, ptep, pte);
> }
> #endif
> +
> +#ifndef huge_ptep_modify_prot_start
> +#define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
> +static inline pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
> + unsigned long addr, pte_t *ptep)
> +{
> + return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
> +}
> +#endif
> +
> +#ifndef huge_ptep_modify_prot_commit
> +#define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
> +static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> + unsigned long addr, pte_t *ptep,
> + pte_t old_pte, pte_t pte)
> +{
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> +}
> +#endif
> +
> #else /* CONFIG_HUGETLB_PAGE */
> struct hstate {};
> #define alloc_huge_page(v, a, r) NULL
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index df2e7dd5ff17..f824d2200ca9 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -4387,10 +4387,12 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
> continue;
> }
> if (!huge_pte_none(pte)) {
> - pte = huge_ptep_get_and_clear(mm, address, ptep);
> - pte = pte_mkhuge(huge_pte_modify(pte, newprot));
> + pte_t old_pte;
> +
> + old_pte = huge_ptep_modify_prot_start(vma, address, ptep);
> + pte = pte_mkhuge(huge_pte_modify(old_pte, newprot));
> pte = arch_make_huge_pte(pte, vma, NULL, 0);
> - set_huge_pte_at(mm, address, ptep, pte);
> + huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte);
> pages++;
> }
> spin_unlock(ptl);
Looks like a faithful conversion.
Reviewed-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
cheers
