[PATCH V3 1/2] mm: move vma_is_anonymous check within pmd_move_must_withdraw

[Aneesh Kumar K.V]

Architectures like ppc64 want to use page table deposit/withraw
even with huge pmd dax entries. Allow arch to override the
vma_is_anonymous check by moving that to pmd_move_must_withdraw
function

Acked-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/pgtable.h |  3 ++-
 include/asm-generic/pgtable.h                | 12 ------------
 mm/huge_memory.c                             | 18 ++++++++++++++++--
 3 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h 
b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 9fd77f8794a0..700301bc5190 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1009,7 +1009,8 @@ static inline void pmdp_huge_split_prepare(struct 
vm_area_struct *vma,
 #define pmd_move_must_withdraw pmd_move_must_withdraw
 struct spinlock;
 static inline int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
-                                        struct spinlock *old_pmd_ptl)
+                                        struct spinlock *old_pmd_ptl,
+                                        struct vm_area_struct *vma)
 {
        if (radix_enabled())
                return false;
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index c4f8fd2fd384..324990273ad2 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -653,18 +653,6 @@ static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
 }
 #endif
 
-#ifndef pmd_move_must_withdraw
-static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,
-                                        spinlock_t *old_pmd_ptl)
-{
-       /*
-        * With split pmd lock we also need to move preallocated
-        * PTE page table if new_pmd is on different PMD page table.
-        */
-       return new_pmd_ptl != old_pmd_ptl;
-}
-#endif
-
 /*
  * This function is meant to be used by sites walking pagetables with
  * the mmap_sem hold in read mode to protect against MADV_DONTNEED and
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index cdcd25cb30fe..54f265ec902e 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1424,6 +1424,21 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct 
vm_area_struct *vma,
        return 1;
 }
 
+#ifndef pmd_move_must_withdraw
+static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,
+                                        spinlock_t *old_pmd_ptl,
+                                        struct vm_area_struct *vma)
+{
+       /*
+        * With split pmd lock we also need to move preallocated
+        * PTE page table if new_pmd is on different PMD page table.
+        *
+        * We also don't deposit and withdraw tables for file pages.
+        */
+       return (new_pmd_ptl != old_pmd_ptl) && vma_is_anonymous(vma);
+}
+#endif
+
 bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
                  unsigned long new_addr, unsigned long old_end,
                  pmd_t *old_pmd, pmd_t *new_pmd)
@@ -1458,8 +1473,7 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned 
long old_addr,
                pmd = pmdp_huge_get_and_clear(mm, old_addr, old_pmd);
                VM_BUG_ON(!pmd_none(*new_pmd));
 
-               if (pmd_move_must_withdraw(new_ptl, old_ptl) &&
-                               vma_is_anonymous(vma)) {
+               if (pmd_move_must_withdraw(new_ptl, old_ptl, vma)) {
                        pgtable_t pgtable;
                        pgtable = pgtable_trans_huge_withdraw(mm, old_pmd);
                        pgtable_trans_huge_deposit(mm, new_pmd, pgtable);
-- 
2.10.2