1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_MIGRATE_H
3 #define _LINUX_MIGRATE_H
6 #include <linux/mempolicy.h>
7 #include <linux/migrate_mode.h>
8 #include <linux/hugetlb.h>
10 typedef struct page *new_page_t(struct page *page, unsigned long private);
11 typedef void free_page_t(struct page *page, unsigned long private);
13 struct migration_target_control;
16 * Return values from addresss_space_operations.migratepage():
17 * - negative errno on page migration failure;
18 * - zero on page migration success;
20 #define MIGRATEPAGE_SUCCESS 0
24 * - macro MIGRATE_REASON in include/trace/events/migrate.h
25 * - migrate_reason_names[MR_TYPES] in mm/debug.c
31 MR_SYSCALL, /* also applies to cpusets */
40 extern const char *migrate_reason_names[MR_TYPES];
42 #ifdef CONFIG_MIGRATION
44 extern void putback_movable_pages(struct list_head *l);
45 extern int migrate_page(struct address_space *mapping,
46 struct page *newpage, struct page *page,
47 enum migrate_mode mode);
48 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
49 unsigned long private, enum migrate_mode mode, int reason,
50 unsigned int *ret_succeeded);
51 extern struct page *alloc_migration_target(struct page *page, unsigned long private);
52 extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
54 extern void migrate_page_states(struct page *newpage, struct page *page);
55 extern void migrate_page_copy(struct page *newpage, struct page *page);
56 extern int migrate_huge_page_move_mapping(struct address_space *mapping,
57 struct page *newpage, struct page *page);
58 extern int migrate_page_move_mapping(struct address_space *mapping,
59 struct page *newpage, struct page *page, int extra_count);
60 void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
61 void folio_migrate_copy(struct folio *newfolio, struct folio *folio);
62 int folio_migrate_mapping(struct address_space *mapping,
63 struct folio *newfolio, struct folio *folio, int extra_count);
66 static inline void putback_movable_pages(struct list_head *l) {}
67 static inline int migrate_pages(struct list_head *l, new_page_t new,
68 free_page_t free, unsigned long private, enum migrate_mode mode,
69 int reason, unsigned int *ret_succeeded)
71 static inline struct page *alloc_migration_target(struct page *page,
72 unsigned long private)
74 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
77 static inline void migrate_page_states(struct page *newpage, struct page *page)
81 static inline void migrate_page_copy(struct page *newpage,
84 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
85 struct page *newpage, struct page *page)
89 #endif /* CONFIG_MIGRATION */
91 #ifdef CONFIG_COMPACTION
92 extern int PageMovable(struct page *page);
93 extern void __SetPageMovable(struct page *page, struct address_space *mapping);
94 extern void __ClearPageMovable(struct page *page);
96 static inline int PageMovable(struct page *page) { return 0; }
97 static inline void __SetPageMovable(struct page *page,
98 struct address_space *mapping)
101 static inline void __ClearPageMovable(struct page *page)
106 #ifdef CONFIG_NUMA_BALANCING
107 extern int migrate_misplaced_page(struct page *page,
108 struct vm_area_struct *vma, int node);
110 static inline int migrate_misplaced_page(struct page *page,
111 struct vm_area_struct *vma, int node)
113 return -EAGAIN; /* can't migrate now */
115 #endif /* CONFIG_NUMA_BALANCING */
117 #ifdef CONFIG_MIGRATION
120 * Watch out for PAE architecture, which has an unsigned long, and might not
121 * have enough bits to store all physical address and flags. So far we have
122 * enough room for all our flags.
124 #define MIGRATE_PFN_VALID (1UL << 0)
125 #define MIGRATE_PFN_MIGRATE (1UL << 1)
126 #define MIGRATE_PFN_LOCKED (1UL << 2)
127 #define MIGRATE_PFN_WRITE (1UL << 3)
128 #define MIGRATE_PFN_SHIFT 6
130 static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
132 if (!(mpfn & MIGRATE_PFN_VALID))
134 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
137 static inline unsigned long migrate_pfn(unsigned long pfn)
139 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
142 enum migrate_vma_direction {
143 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
144 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
148 struct vm_area_struct *vma;
150 * Both src and dst array must be big enough for
151 * (end - start) >> PAGE_SHIFT entries.
153 * The src array must not be modified by the caller after
154 * migrate_vma_setup(), and must not change the dst array after
155 * migrate_vma_pages() returns.
159 unsigned long cpages;
160 unsigned long npages;
165 * Set to the owner value also stored in page->pgmap->owner for
166 * migrating out of device private memory. The flags also need to
167 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
168 * The caller should always set this field when using mmu notifier
169 * callbacks to avoid device MMU invalidations for device private
170 * pages that are not being migrated.
176 int migrate_vma_setup(struct migrate_vma *args);
177 void migrate_vma_pages(struct migrate_vma *migrate);
178 void migrate_vma_finalize(struct migrate_vma *migrate);
179 int next_demotion_node(int node);
181 #else /* CONFIG_MIGRATION disabled: */
183 static inline int next_demotion_node(int node)
188 #endif /* CONFIG_MIGRATION */
190 #endif /* _LINUX_MIGRATE_H */