X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=include%2Fasm-generic%2Fpgtable.h;h=358e4d309ceb179776f2a7036dabce02cdfad1d2;hb=8c65b4a60450590e79a28e9717ceffa9e4debb3f;hp=f86c1e549466a0809c02fecc750cb5627ed08027;hpb=ef88b7dba2b47c70037a34a599d383462bb74bd3;p=linux-2.6

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index f86c1e5494..358e4d309c 100644
--- 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.
@@ -128,6 +128,7 @@ do {									\
 #endif
 
 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
+struct mm_struct;
 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
 {
 	pte_t old_pte = *ptep;
@@ -158,6 +159,19 @@ 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