fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / include / linux / swapops.h

diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 0cfc704..ec639aa 100644 (file)
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -4,7 +4,7 @@
  * the low-order bits.
  *
  * We arrange the `type' and `offset' fields so that `type' is at the five
- * high-order bits of the smp_entry_t and `offset' is right-aligned in the
+ * high-order bits of the swp_entry_t and `offset' is right-aligned in the
  * remaining bits.
  *
  * swp_entry_t's are *never* stored anywhere in their arch-dependent format.
@@ -30,8 +30,7 @@ static inline swp_entry_t swp_entry(unsigned long type, pgoff_t offset)
  */
 static inline unsigned swp_type(swp_entry_t entry)
 {
-       return (entry.val >> SWP_TYPE_SHIFT(entry)) &
-                       ((1 << MAX_SWAPFILES_SHIFT) - 1);
+       return (entry.val >> SWP_TYPE_SHIFT(entry));
 }
 
 /*
@@ -68,3 +67,56 @@ static inline pte_t swp_entry_to_pte(swp_entry_t entry)
        BUG_ON(pte_file(__swp_entry_to_pte(arch_entry)));
        return __swp_entry_to_pte(arch_entry);
 }
+
+#ifdef CONFIG_MIGRATION
+static inline swp_entry_t make_migration_entry(struct page *page, int write)
+{
+       BUG_ON(!PageLocked(page));
+       return swp_entry(write ? SWP_MIGRATION_WRITE : SWP_MIGRATION_READ,
+                       page_to_pfn(page));
+}
+
+static inline int is_migration_entry(swp_entry_t entry)
+{
+       return unlikely(swp_type(entry) == SWP_MIGRATION_READ ||
+                       swp_type(entry) == SWP_MIGRATION_WRITE);
+}
+
+static inline int is_write_migration_entry(swp_entry_t entry)
+{
+       return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE);
+}
+
+static inline struct page *migration_entry_to_page(swp_entry_t entry)
+{
+       struct page *p = pfn_to_page(swp_offset(entry));
+       /*
+        * Any use of migration entries may only occur while the
+        * corresponding page is locked
+        */
+       BUG_ON(!PageLocked(p));
+       return p;
+}
+
+static inline void make_migration_entry_read(swp_entry_t *entry)
+{
+       *entry = swp_entry(SWP_MIGRATION_READ, swp_offset(*entry));
+}
+
+extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
+                                       unsigned long address);
+#else
+
+#define make_migration_entry(page, write) swp_entry(0, 0)
+#define is_migration_entry(swp) 0
+#define migration_entry_to_page(swp) NULL
+static inline void make_migration_entry_read(swp_entry_t *entryp) { }
+static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
+                                        unsigned long address) { }
+static inline int is_write_migration_entry(swp_entry_t entry)
+{
+       return 0;
+}
+
+#endif
+