i386: use pte_update_defer in ptep_test_and_clear_{dirty,young}

If you actually clear the bit, you need to:

+         pte_update_defer(vma->vm_mm, addr, ptep);

The reason is, when updating PTEs, the hypervisor must be notified.  Using
atomic operations to do this is fine for all hypervisors I am aware of.
However, for hypervisors which shadow page tables, if these PTE
modifications are not trapped, you need a post-modification call to fulfill
the update of the shadow page table.

Acked-by: Zachary Amsden <zach@vmware.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 18 insertions, 20 deletions

diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h
index 995e8b34efd0..e16359f81a40 100644
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -297,22 +297,24 @@ do {									\
 } while (0)
 
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
-static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma,
-                                            unsigned long addr, pte_t *ptep)
-{
-        if (!pte_dirty(*ptep))
-                return 0;
-        return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte_low);
-}
+#define ptep_test_and_clear_dirty(vma, addr, ptep) ({                   \
+        int ret = 0;                                                    \
+        if (pte_dirty(*ptep))                                           \
+                ret = test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte_low); \
+        if (ret)                                                        \
+                pte_update_defer(vma->vm_mm, addr, ptep);               \
+        ret;                                                            \
+})
 
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
-static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
-                                            unsigned long addr, pte_t *ptep)
-{
-        if (!pte_young(*ptep))
-                return 0;
-        return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte_low);
-}
+#define ptep_test_and_clear_young(vma, addr, ptep) ({                   \
+        int ret = 0;                                                    \
+        if (pte_young(*ptep))                                           \
+                ret = test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte_low); \
+        if (ret)                                                        \
+                pte_update_defer(vma->vm_mm, addr, ptep);               \
+        ret;                                                            \
+})
 
 /*
  * Rules for using ptep_establish: the pte MUST be a user pte, and
@@ -330,10 +332,8 @@ do {									\
 ({                                                                      \
         int __dirty;                                                    \
         __dirty = ptep_test_and_clear_dirty((vma), (address), (ptep));  \
-        if (__dirty) {                                                  \
-                pte_update_defer((vma)->vm_mm, (address), (ptep));      \
+        if (__dirty)                                                    \
                 flush_tlb_page(vma, address);                           \
-        }                                                               \
         __dirty;                                                        \
 })
 
@@ -342,10 +342,8 @@ do {									\
 ({                                                                      \
         int __young;                                                    \
         __young = ptep_test_and_clear_young((vma), (address), (ptep));  \
-        if (__young) {                                                  \
-                pte_update_defer((vma)->vm_mm, (address), (ptep));      \
+        if (__young)                                                    \
                 flush_tlb_page(vma, address);                           \
-        }                                                               \
         __young;                                                        \
 })