diff options
Diffstat (limited to 'arch/arm64/mm/contpte.c')
| -rw-r--r-- | arch/arm64/mm/contpte.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c index 6d7f40667fa2..bedb58524535 100644 --- a/arch/arm64/mm/contpte.c +++ b/arch/arm64/mm/contpte.c @@ -26,6 +26,26 @@ static inline pte_t *contpte_align_down(pte_t *ptep) return PTR_ALIGN_DOWN(ptep, sizeof(*ptep) * CONT_PTES); } +static void contpte_try_unfold_partial(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, unsigned int nr) +{ + /* + * Unfold any partially covered contpte block at the beginning and end + * of the range. + */ + + if (ptep != contpte_align_down(ptep) || nr < CONT_PTES) + contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep)); + + if (ptep + nr != contpte_align_down(ptep + nr)) { + unsigned long last_addr = addr + PAGE_SIZE * (nr - 1); + pte_t *last_ptep = ptep + nr - 1; + + contpte_try_unfold(mm, last_addr, last_ptep, + __ptep_get(last_ptep)); + } +} + static void contpte_convert(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) { @@ -238,6 +258,24 @@ int contpte_ptep_clear_flush_young(struct vm_area_struct *vma, } EXPORT_SYMBOL(contpte_ptep_clear_flush_young); +void contpte_wrprotect_ptes(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, unsigned int nr) +{ + /* + * If wrprotecting an entire contig range, we can avoid unfolding. Just + * set wrprotect and wait for the later mmu_gather flush to invalidate + * the tlb. Until the flush, the page may or may not be wrprotected. + * After the flush, it is guaranteed wrprotected. If it's a partial + * range though, we must unfold, because we can't have a case where + * CONT_PTE is set but wrprotect applies to a subset of the PTEs; this + * would cause it to continue to be unpredictable after the flush. + */ + + contpte_try_unfold_partial(mm, addr, ptep, nr); + __wrprotect_ptes(mm, addr, ptep, nr); +} +EXPORT_SYMBOL(contpte_wrprotect_ptes); + int contpte_ptep_set_access_flags(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, pte_t entry, int dirty) |