Merge branch 'master'

[powerpc.git] / include / asm-generic / pgtable.h

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index f86c1e5..7dca30a 100644 (file)
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -8,7 +8,7 @@
  *  - update the page tables
  *  - inform the TLB about the new one
  *
- * We hold the mm semaphore for reading and vma->vm_mm->page_table_lock.
+ * We hold the mm semaphore for reading, and the pte lock.
  *
  * Note: the old pte is known to not be writable, so we don't need to
  * worry about dirty bits etc getting lost.
@@ -158,6 +158,19 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
 #define lazy_mmu_prot_update(pte)      do { } while (0)
 #endif
 
+#ifndef __HAVE_ARCH_MULTIPLE_ZERO_PAGE
+#define move_pte(pte, prot, old_addr, new_addr)        (pte)
+#else
+#define move_pte(pte, prot, old_addr, new_addr)                                \
+({                                                                     \
+       pte_t newpte = (pte);                                           \
+       if (pte_present(pte) && pfn_valid(pte_pfn(pte)) &&              \
+                       pte_page(pte) == ZERO_PAGE(old_addr))           \
+               newpte = mk_pte(ZERO_PAGE(new_addr), (prot));           \
+       newpte;                                                         \
+})
+#endif
+
 /*
  * When walking page tables, get the address of the next boundary,
  * or the end address of the range if that comes earlier.  Although no