return entry.val & SWP_OFFSET_MASK(entry);
}
+#ifdef CONFIG_MMU
+/* check whether a pte points to a swap entry */
+static inline int is_swap_pte(pte_t pte)
+{
+ return !pte_none(pte) && !pte_present(pte) && !pte_file(pte);
+}
+#endif
+
/*
* Convert the arch-dependent pte representation of a swp_entry_t into an
* arch-independent swp_entry_t.
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)
+static inline int is_migration_entry(swp_entry_t swp)
+{
+ return 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
+