1 files changed, 108 insertions, 93 deletions

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 72120061b7d4..3ef77f52a4f0 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -10,6 +10,8 @@
 typedef struct page *new_page_t(struct page *page, unsigned long private);
 typedef void free_page_t(struct page *page, unsigned long private);
 
+struct migration_target_control;
+
 /*
  * Return values from addresss_space_operations.migratepage():
  * - negative errno on page migration failure;
@@ -17,89 +19,83 @@ typedef void free_page_t(struct page *page, unsigned long private);
  */
 #define MIGRATEPAGE_SUCCESS		0
 
-enum migrate_reason {
-	MR_COMPACTION,
-	MR_MEMORY_FAILURE,
-	MR_MEMORY_HOTPLUG,
-	MR_SYSCALL,		/* also applies to cpusets */
-	MR_MEMPOLICY_MBIND,
-	MR_NUMA_MISPLACED,
-	MR_CONTIG_RANGE,
-	MR_TYPES
+/**
+ * struct movable_operations - Driver page migration
+ * @isolate_page:
+ * The VM calls this function to prepare the page to be moved.  The page
+ * is locked and the driver should not unlock it.  The driver should
+ * return ``true`` if the page is movable and ``false`` if it is not
+ * currently movable.  After this function returns, the VM uses the
+ * page->lru field, so the driver must preserve any information which
+ * is usually stored here.
+ *
+ * @migrate_page:
+ * After isolation, the VM calls this function with the isolated
+ * @src page.  The driver should copy the contents of the
+ * @src page to the @dst page and set up the fields of @dst page.
+ * Both pages are locked.
+ * If page migration is successful, the driver should call
+ * __ClearPageMovable(@src) and return MIGRATEPAGE_SUCCESS.
+ * If the driver cannot migrate the page at the moment, it can return
+ * -EAGAIN.  The VM interprets this as a temporary migration failure and
+ * will retry it later.  Any other error value is a permanent migration
+ * failure and migration will not be retried.
+ * The driver shouldn't touch the @src->lru field while in the
+ * migrate_page() function.  It may write to @dst->lru.
+ *
+ * @putback_page:
+ * If migration fails on the isolated page, the VM informs the driver
+ * that the page is no longer a candidate for migration by calling
+ * this function.  The driver should put the isolated page back into
+ * its own data structure.
+ */
+struct movable_operations {
+	bool (*isolate_page)(struct page *, isolate_mode_t);
+	int (*migrate_page)(struct page *dst, struct page *src,
+			enum migrate_mode);
+	void (*putback_page)(struct page *);
 };
 
-/* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
+/* Defined in mm/debug.c: */
 extern const char *migrate_reason_names[MR_TYPES];
 
-static inline struct page *new_page_nodemask(struct page *page,
-				int preferred_nid, nodemask_t *nodemask)
-{
-	gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL;
-	unsigned int order = 0;
-	struct page *new_page = NULL;
-
-	if (PageHuge(page))
-		return alloc_huge_page_nodemask(page_hstate(compound_head(page)),
-				preferred_nid, nodemask);
-
-	if (PageTransHuge(page)) {
-		gfp_mask |= GFP_TRANSHUGE;
-		order = HPAGE_PMD_ORDER;
-	}
-
-	if (PageHighMem(page) || (zone_idx(page_zone(page)) == ZONE_MOVABLE))
-		gfp_mask |= __GFP_HIGHMEM;
-
-	new_page = __alloc_pages_nodemask(gfp_mask, order,
-				preferred_nid, nodemask);
-
-	if (new_page && PageTransHuge(new_page))
-		prep_transhuge_page(new_page);
-
-	return new_page;
-}
-
 #ifdef CONFIG_MIGRATION
 
 extern void putback_movable_pages(struct list_head *l);
-extern int migrate_page(struct address_space *mapping,
-			struct page *newpage, struct page *page,
-			enum migrate_mode mode);
+int migrate_folio_extra(struct address_space *mapping, struct folio *dst,
+		struct folio *src, enum migrate_mode mode, int extra_count);
+int migrate_folio(struct address_space *mapping, struct folio *dst,
+		struct folio *src, enum migrate_mode mode);
 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
-		unsigned long private, enum migrate_mode mode, int reason);
+		unsigned long private, enum migrate_mode mode, int reason,
+		unsigned int *ret_succeeded);
+extern struct page *alloc_migration_target(struct page *page, unsigned long private);
 extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
-extern void putback_movable_page(struct page *page);
-
-extern int migrate_prep(void);
-extern int migrate_prep_local(void);
-extern void migrate_page_states(struct page *newpage, struct page *page);
-extern void migrate_page_copy(struct page *newpage, struct page *page);
-extern int migrate_huge_page_move_mapping(struct address_space *mapping,
-				  struct page *newpage, struct page *page);
-extern int migrate_page_move_mapping(struct address_space *mapping,
-		struct page *newpage, struct page *page, int extra_count);
+
+int migrate_huge_page_move_mapping(struct address_space *mapping,
+		struct folio *dst, struct folio *src);
+void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep,
+				spinlock_t *ptl);
+void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
+void folio_migrate_copy(struct folio *newfolio, struct folio *folio);
+int folio_migrate_mapping(struct address_space *mapping,
+		struct folio *newfolio, struct folio *folio, int extra_count);
+
 #else
 
 static inline void putback_movable_pages(struct list_head *l) {}
 static inline int migrate_pages(struct list_head *l, new_page_t new,
 		free_page_t free, unsigned long private, enum migrate_mode mode,
-		int reason)
+		int reason, unsigned int *ret_succeeded)
 	{ return -ENOSYS; }
+static inline struct page *alloc_migration_target(struct page *page,
+		unsigned long private)
+	{ return NULL; }
 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
 	{ return -EBUSY; }
 
-static inline int migrate_prep(void) { return -ENOSYS; }
-static inline int migrate_prep_local(void) { return -ENOSYS; }
-
-static inline void migrate_page_states(struct page *newpage, struct page *page)
-{
-}
-
-static inline void migrate_page_copy(struct page *newpage,
-				     struct page *page) {}
-
 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
-				  struct page *newpage, struct page *page)
+				  struct folio *dst, struct folio *src)
 {
 	return -ENOSYS;
 }
@@ -107,13 +103,13 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
 #endif /* CONFIG_MIGRATION */
 
 #ifdef CONFIG_COMPACTION
-extern int PageMovable(struct page *page);
-extern void __SetPageMovable(struct page *page, struct address_space *mapping);
-extern void __ClearPageMovable(struct page *page);
+bool PageMovable(struct page *page);
+void __SetPageMovable(struct page *page, const struct movable_operations *ops);
+void __ClearPageMovable(struct page *page);
 #else
-static inline int PageMovable(struct page *page) { return 0; };
+static inline bool PageMovable(struct page *page) { return false; }
 static inline void __SetPageMovable(struct page *page,
-				struct address_space *mapping)
+		const struct movable_operations *ops)
 {
 }
 static inline void __ClearPageMovable(struct page *page)
@@ -121,15 +117,24 @@ static inline void __ClearPageMovable(struct page *page)
 }
 #endif
 
+static inline bool folio_test_movable(struct folio *folio)
+{
+	return PageMovable(&folio->page);
+}
+
+static inline
+const struct movable_operations *page_movable_ops(struct page *page)
+{
+	VM_BUG_ON(!__PageMovable(page));
+
+	return (const struct movable_operations *)
+		((unsigned long)page->mapping - PAGE_MAPPING_MOVABLE);
+}
+
 #ifdef CONFIG_NUMA_BALANCING
-extern bool pmd_trans_migrating(pmd_t pmd);
 extern int migrate_misplaced_page(struct page *page,
 				  struct vm_area_struct *vma, int node);
 #else
-static inline bool pmd_trans_migrating(pmd_t pmd)
-{
-	return false;
-}
 static inline int migrate_misplaced_page(struct page *page,
 					 struct vm_area_struct *vma, int node)
 {
@@ -137,24 +142,6 @@ static inline int migrate_misplaced_page(struct page *page,
 }
 #endif /* CONFIG_NUMA_BALANCING */
 
-#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
-extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
-			struct vm_area_struct *vma,
-			pmd_t *pmd, pmd_t entry,
-			unsigned long address,
-			struct page *page, int node);
-#else
-static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
-			struct vm_area_struct *vma,
-			pmd_t *pmd, pmd_t entry,
-			unsigned long address,
-			struct page *page, int node)
-{
-	return -EAGAIN;
-}
-#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
-
-
 #ifdef CONFIG_MIGRATION
 
 /*
@@ -164,7 +151,6 @@ static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
  */
 #define MIGRATE_PFN_VALID	(1UL << 0)
 #define MIGRATE_PFN_MIGRATE	(1UL << 1)
-#define MIGRATE_PFN_LOCKED	(1UL << 2)
 #define MIGRATE_PFN_WRITE	(1UL << 3)
 #define MIGRATE_PFN_SHIFT	6
 
@@ -180,6 +166,12 @@ static inline unsigned long migrate_pfn(unsigned long pfn)
 	return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
 }
 
+enum migrate_vma_direction {
+	MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
+	MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
+	MIGRATE_VMA_SELECT_DEVICE_COHERENT = 1 << 2,
+};
+
 struct migrate_vma {
 	struct vm_area_struct	*vma;
 	/*
@@ -196,11 +188,34 @@ struct migrate_vma {
 	unsigned long		npages;
 	unsigned long		start;
 	unsigned long		end;
+
+	/*
+	 * Set to the owner value also stored in page->pgmap->owner for
+	 * migrating out of device private memory. The flags also need to
+	 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
+	 * The caller should always set this field when using mmu notifier
+	 * callbacks to avoid device MMU invalidations for device private
+	 * pages that are not being migrated.
+	 */
+	void			*pgmap_owner;
+	unsigned long		flags;
+
+	/*
+	 * Set to vmf->page if this is being called to migrate a page as part of
+	 * a migrate_to_ram() callback.
+	 */
+	struct page		*fault_page;
 };
 
 int migrate_vma_setup(struct migrate_vma *args);
 void migrate_vma_pages(struct migrate_vma *migrate);
 void migrate_vma_finalize(struct migrate_vma *migrate);
+int migrate_device_range(unsigned long *src_pfns, unsigned long start,
+			unsigned long npages);
+void migrate_device_pages(unsigned long *src_pfns, unsigned long *dst_pfns,
+			unsigned long npages);
+void migrate_device_finalize(unsigned long *src_pfns,
+			unsigned long *dst_pfns, unsigned long npages);
 
 #endif /* CONFIG_MIGRATION */