diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgtable.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/mm/pgtable_64.c | 32 |
2 files changed, 36 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 8d1c41d28318..ac07a30a7934 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -281,6 +281,10 @@ extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp); extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp); +#define __HAVE_ARCH_PMDP_HUGE_SPLIT_PREPARE +extern void pmdp_huge_split_prepare(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp); + #define pmd_move_must_withdraw pmd_move_must_withdraw struct spinlock; static inline int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl, diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c index 3124a20d0fab..cdf2123d46db 100644 --- a/arch/powerpc/mm/pgtable_64.c +++ b/arch/powerpc/mm/pgtable_64.c @@ -646,6 +646,28 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) return pgtable; } +void pmdp_huge_split_prepare(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp) +{ + VM_BUG_ON(address & ~HPAGE_PMD_MASK); + VM_BUG_ON(REGION_ID(address) != USER_REGION_ID); + + /* + * We can't mark the pmd none here, because that will cause a race + * against exit_mmap. We need to continue mark pmd TRANS HUGE, while + * we spilt, but at the same time we wan't rest of the ppc64 code + * not to insert hash pte on this, because we will be modifying + * the deposited pgtable in the caller of this function. Hence + * clear the _PAGE_USER so that we move the fault handling to + * higher level function and that will serialize against ptl. + * We need to flush existing hash pte entries here even though, + * the translation is still valid, because we will withdraw + * pgtable_t after this. + */ + pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_USER, 0); +} + + /* * set a new huge pmd. We should not be called for updating * an existing pmd entry. That should go via pmd_hugepage_update. @@ -663,10 +685,20 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr, return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd)); } +/* + * We use this to invalidate a pmdp entry before switching from a + * hugepte to regular pmd entry. + */ void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0); + + /* + * This ensures that generic code that rely on IRQ disabling + * to prevent a parallel THP split work as expected. + */ + kick_all_cpus_sync(); } /* |