diff options
Diffstat (limited to 'arch/arm64/mm/hugetlbpage.c')
| -rw-r--r-- | arch/arm64/mm/hugetlbpage.c | 38 |
1 files changed, 34 insertions, 4 deletions
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index f85be2f8b140..f58ea503ad01 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -323,11 +323,40 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, return get_clear_flush(mm, addr, ptep, pgsize, ncontig); } +/* + * huge_ptep_set_access_flags will update access flags (dirty, accesssed) + * and write permission. + * + * For a contiguous huge pte range we need to check whether or not write + * permission has to change only on the first pte in the set. Then for + * all the contiguous ptes we need to check whether or not there is a + * discrepancy between dirty or young. + */ +static int __cont_access_flags_changed(pte_t *ptep, pte_t pte, int ncontig) +{ + int i; + + if (pte_write(pte) != pte_write(huge_ptep_get(ptep))) + return 1; + + for (i = 0; i < ncontig; i++) { + pte_t orig_pte = huge_ptep_get(ptep + i); + + if (pte_dirty(pte) != pte_dirty(orig_pte)) + return 1; + + if (pte_young(pte) != pte_young(orig_pte)) + return 1; + } + + return 0; +} + int huge_ptep_set_access_flags(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, pte_t pte, int dirty) { - int ncontig, i, changed = 0; + int ncontig, i; size_t pgsize = 0; unsigned long pfn = pte_pfn(pte), dpfn; pgprot_t hugeprot; @@ -339,9 +368,10 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma, ncontig = find_num_contig(vma->vm_mm, addr, ptep, &pgsize); dpfn = pgsize >> PAGE_SHIFT; + if (!__cont_access_flags_changed(ptep, pte, ncontig)) + return 0; + orig_pte = get_clear_flush(vma->vm_mm, addr, ptep, pgsize, ncontig); - if (!pte_same(orig_pte, pte)) - changed = 1; /* Make sure we don't lose the dirty or young state */ if (pte_dirty(orig_pte)) @@ -354,7 +384,7 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma, for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn) set_pte_at(vma->vm_mm, addr, ptep, pfn_pte(pfn, hugeprot)); - return changed; + return 1; } void huge_ptep_set_wrprotect(struct mm_struct *mm, |