[PATCHv4 06/12] powerpc/mm: update pmdp_invalidate to return old pmd value

Kirill A. Shutemov
2017-12-13T10:57:50Z

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

It's required to avoid losing dirty and accessed bits.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 4 ++--
arch/powerpc/mm/pgtable-book3s64.c | 7 +++++--
2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 44697817ccc6..ee19d5bbee06 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1137,8 +1137,8 @@ static inline pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm,
}

#define __HAVE_ARCH_PMDP_INVALIDATE
-extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmdp);
+extern pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp);

#define __HAVE_ARCH_PMDP_HUGE_SPLIT_PREPARE
static inline void pmdp_huge_split_prepare(struct vm_area_struct *vma,
diff --git a/arch/powerpc/mm/pgtable-book3s64.c b/arch/powerpc/mm/pgtable-book3s64.c
index 3b65917785a5..422e80253a33 100644
--- a/arch/powerpc/mm/pgtable-book3s64.c
+++ b/arch/powerpc/mm/pgtable-book3s64.c
@@ -90,16 +90,19 @@ void serialize_against_pte_lookup(struct mm_struct *mm)
* 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_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
- pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0);
+ unsigned long old_pmd;
+
+ old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0);
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.
*/
serialize_against_pte_lookup(vma->vm_mm);
+ return __pmd(old_pmd);
}

static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
--
2.15.0

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