mm: remove special swap entry functions

[mirror_ubuntu-kernels.git] / include / linux / swapops.h

diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 708fbeb21dd397c8a3511d1368f389cc5124d280..c24c79812bc1dd4726118d2acfaf5a6856efa298 100644 (file)
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -128,16 +128,6 @@ static inline bool is_write_device_private_entry(swp_entry_t entry)
 {
        return unlikely(swp_type(entry) == SWP_DEVICE_WRITE);
 }
-
-static inline unsigned long device_private_entry_to_pfn(swp_entry_t entry)
-{
-       return swp_offset(entry);
-}
-
-static inline struct page *device_private_entry_to_page(swp_entry_t entry)
-{
-       return pfn_to_page(swp_offset(entry));
-}
 #else /* CONFIG_DEVICE_PRIVATE */
 static inline swp_entry_t make_device_private_entry(struct page *page, bool write)
 {
@@ -157,16 +147,6 @@ static inline bool is_write_device_private_entry(swp_entry_t entry)
 {
        return false;
 }
-
-static inline unsigned long device_private_entry_to_pfn(swp_entry_t entry)
-{
-       return 0;
-}
-
-static inline struct page *device_private_entry_to_page(swp_entry_t entry)
-{
-       return NULL;
-}
 #endif /* CONFIG_DEVICE_PRIVATE */
 
 #ifdef CONFIG_MIGRATION
@@ -189,22 +169,6 @@ static inline int is_write_migration_entry(swp_entry_t entry)
        return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE);
 }
 
-static inline unsigned long migration_entry_to_pfn(swp_entry_t entry)
-{
-       return swp_offset(entry);
-}
-
-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(compound_head(p)));
-       return p;
-}
-
 static inline void make_migration_entry_read(swp_entry_t *entry)
 {
        *entry = swp_entry(SWP_MIGRATION_READ, swp_offset(*entry));
@@ -224,16 +188,6 @@ static inline int is_migration_entry(swp_entry_t swp)
        return 0;
 }
 
-static inline unsigned long migration_entry_to_pfn(swp_entry_t entry)
-{
-       return 0;
-}
-
-static inline struct page *migration_entry_to_page(swp_entry_t entry)
-{
-       return NULL;
-}
-
 static inline void make_migration_entry_read(swp_entry_t *entryp) { }
 static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
                                        spinlock_t *ptl) { }
@@ -248,6 +202,29 @@ static inline int is_write_migration_entry(swp_entry_t entry)
 
 #endif
 
+static inline struct page *pfn_swap_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(is_migration_entry(entry) && !PageLocked(p));
+
+       return p;
+}
+
+/*
+ * A pfn swap entry is a special type of swap entry that always has a pfn stored
+ * in the swap offset. They are used to represent unaddressable device memory
+ * and to restrict access to a page undergoing migration.
+ */
+static inline bool is_pfn_swap_entry(swp_entry_t entry)
+{
+       return is_migration_entry(entry) || is_device_private_entry(entry);
+}
+
 struct page_vma_mapped_walk;
 
 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION