diff options
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgtable.h | 15 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s64/pgtable.c | 13 |
2 files changed, 24 insertions, 4 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 1a91762b455d..66a953046a49 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -1313,12 +1313,27 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, { pmd_t old_pmd; + /* + * Non-present PMDs can be migration entries or device-private THP + * entries. This can happen at 2 places: + * - When the address space is being unmapped zap_huge_pmd(), and we + * encounter non-present pmds. + * - migrate_vma_collect_huge_pmd() could calls this during migration + * of device-private pmd entries. + */ + if (!pmd_present(*pmdp)) { + old_pmd = READ_ONCE(*pmdp); + pmd_clear(pmdp); + goto out; + } + if (radix_enabled()) { old_pmd = radix__pmdp_huge_get_and_clear(mm, addr, pmdp); } else { old_pmd = hash__pmdp_huge_get_and_clear(mm, addr, pmdp); } +out: page_table_check_pmd_clear(mm, addr, old_pmd); return old_pmd; diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c index 4b09c04654a8..42c7906d0e43 100644 --- a/arch/powerpc/mm/book3s64/pgtable.c +++ b/arch/powerpc/mm/book3s64/pgtable.c @@ -209,16 +209,21 @@ pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp, int full) { pmd_t pmd; + bool was_present = pmd_present(*pmdp); + VM_BUG_ON(addr & ~HPAGE_PMD_MASK); - VM_BUG_ON((pmd_present(*pmdp) && !pmd_trans_huge(*pmdp)) || - !pmd_present(*pmdp)); + VM_BUG_ON(was_present && !pmd_trans_huge(*pmdp)); + /* + * Check pmdp_huge_get_and_clear() for non-present pmd case. + */ pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp); /* * if it not a fullmm flush, then we can possibly end up converting * this PMD pte entry to a regular level 0 PTE by a parallel page fault. - * Make sure we flush the tlb in this case. + * Make sure we flush the tlb in this case. TLB flush not needed for + * non-present case. */ - if (!full) + if (was_present && !full) flush_pmd_tlb_range(vma, addr, addr + HPAGE_PMD_SIZE); return pmd; } |