diff options
| -rw-r--r-- | arch/powerpc/mm/book3s64/hash_pgtable.c | 11 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s64/pgtable.c | 8 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s64/radix_pgtable.c | 19 |
3 files changed, 7 insertions, 31 deletions
diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c index 64733b9cb20a..64ca375278dc 100644 --- a/arch/powerpc/mm/book3s64/hash_pgtable.c +++ b/arch/powerpc/mm/book3s64/hash_pgtable.c @@ -363,17 +363,6 @@ pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm, * hash fault look at them. */ memset(pgtable, 0, PTE_FRAG_SIZE); - /* - * Serialize against find_current_mm_pte variants which does lock-less - * lookup in page tables with local interrupts disabled. For huge pages - * it casts pmd_t to pte_t. Since format of pte_t is different from - * pmd_t we want to prevent transit from pmd pointing to page table - * to pmd pointing to huge page (and back) while interrupts are disabled. - * We clear pmd to possibly replace it with page table pointer in - * different code paths. So make sure we wait for the parallel - * find_curren_mm_pte to finish. - */ - serialize_against_pte_lookup(mm); return old_pmd; } diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c index e0bb69c616e4..127325ead505 100644 --- a/arch/powerpc/mm/book3s64/pgtable.c +++ b/arch/powerpc/mm/book3s64/pgtable.c @@ -109,14 +109,6 @@ pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID); flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); - /* - * This ensures that generic code that rely on IRQ disabling - * to prevent a parallel THP split work as expected. - * - * Marking the entry with _PAGE_INVALID && ~_PAGE_PRESENT requires - * a special case check in pmd_access_permitted. - */ - serialize_against_pte_lookup(vma->vm_mm); return __pmd(old_pmd); } diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c index 8f9edf07063a..dfb9fe92aea8 100644 --- a/arch/powerpc/mm/book3s64/radix_pgtable.c +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c @@ -962,7 +962,13 @@ pmd_t radix__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long addre pmd = *pmdp; pmd_clear(pmdp); - /*FIXME!! Verify whether we need this kick below */ + /* + * pmdp collapse_flush need to ensure that there are no parallel gup + * walk after this call. This is needed so that we can have stable + * page ref count when collapsing a page. We don't allow a collapse page + * if we have gup taken on the page. We can ensure that by sending IPI + * because gup walk happens with IRQ disabled. + */ serialize_against_pte_lookup(vma->vm_mm); radix__flush_tlb_collapsed_pmd(vma->vm_mm, address); @@ -1023,17 +1029,6 @@ pmd_t radix__pmdp_huge_get_and_clear(struct mm_struct *mm, old = radix__pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0); old_pmd = __pmd(old); - /* - * Serialize against find_current_mm_pte which does lock-less - * lookup in page tables with local interrupts disabled. For huge pages - * it casts pmd_t to pte_t. Since format of pte_t is different from - * pmd_t we want to prevent transit from pmd pointing to page table - * to pmd pointing to huge page (and back) while interrupts are disabled. - * We clear pmd to possibly replace it with page table pointer in - * different code paths. So make sure we wait for the parallel - * find_current_mm_pte to finish. - */ - serialize_against_pte_lookup(mm); return old_pmd; } |