From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> Subject: mm/hugetlb: add prot_modify_start/commit sequence for hugetlb update 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. Link: http://lkml.kernel.org/r/20190116085035.29729-5-aneesh.kumar@xxxxxxxxxxxxx Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Reviewed-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/hugetlb.h | 20 ++++++++++++++++++++ mm/hugetlb.c | 8 +++++--- 2 files changed, 25 insertions(+), 3 deletions(-) --- a/include/linux/hugetlb.h~mm-hugetlb-add-prot_modify_start-commit-sequence-for-hugetlb-update +++ a/include/linux/hugetlb.h @@ -580,6 +580,26 @@ static inline void set_huge_swap_pte_at( 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 --- a/mm/hugetlb.c~mm-hugetlb-add-prot_modify_start-commit-sequence-for-hugetlb-update +++ a/mm/hugetlb.c @@ -4399,10 +4399,12 @@ unsigned long hugetlb_change_protection( 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); _
