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
26 MR_SYSCALL, /* also applies to cpusets */
35 /* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
36 extern const char *migrate_reason_names[MR_TYPES];
38 #ifdef CONFIG_MIGRATION
40 extern void putback_movable_pages(struct list_head *l);
41 extern int migrate_page(struct address_space *mapping,
42 struct page *newpage, struct page *page,
43 enum migrate_mode mode);
44 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
45 unsigned long private, enum migrate_mode mode, int reason,
46 unsigned int *ret_succeeded);
47 extern struct page *alloc_migration_target(struct page *page, unsigned long private);
48 extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
50 extern void migrate_page_states(struct page *newpage, struct page *page);
51 extern void migrate_page_copy(struct page *newpage, struct page *page);
52 extern int migrate_huge_page_move_mapping(struct address_space *mapping,
53 struct page *newpage, struct page *page);
54 extern int migrate_page_move_mapping(struct address_space *mapping,
55 struct page *newpage, struct page *page, int extra_count);
58 static inline void putback_movable_pages(struct list_head *l) {}
59 static inline int migrate_pages(struct list_head *l, new_page_t new,
60 free_page_t free, unsigned long private, enum migrate_mode mode,
61 int reason, unsigned int *ret_succeeded)
63 static inline struct page *alloc_migration_target(struct page *page,
64 unsigned long private)
66 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
69 static inline void migrate_page_states(struct page *newpage, struct page *page)
73 static inline void migrate_page_copy(struct page *newpage,
76 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
77 struct page *newpage, struct page *page)
81 #endif /* CONFIG_MIGRATION */
83 #ifdef CONFIG_COMPACTION
84 extern int PageMovable(struct page *page);
85 extern void __SetPageMovable(struct page *page, struct address_space *mapping);
86 extern void __ClearPageMovable(struct page *page);
88 static inline int PageMovable(struct page *page) { return 0; }
89 static inline void __SetPageMovable(struct page *page,
90 struct address_space *mapping)
93 static inline void __ClearPageMovable(struct page *page)
98 #ifdef CONFIG_NUMA_BALANCING
99 extern int migrate_misplaced_page(struct page *page,
100 struct vm_area_struct *vma, int node);
102 static inline int migrate_misplaced_page(struct page *page,
103 struct vm_area_struct *vma, int node)
105 return -EAGAIN; /* can't migrate now */
107 #endif /* CONFIG_NUMA_BALANCING */
109 #ifdef CONFIG_MIGRATION
112 * Watch out for PAE architecture, which has an unsigned long, and might not
113 * have enough bits to store all physical address and flags. So far we have
114 * enough room for all our flags.
116 #define MIGRATE_PFN_VALID (1UL << 0)
117 #define MIGRATE_PFN_MIGRATE (1UL << 1)
118 #define MIGRATE_PFN_LOCKED (1UL << 2)
119 #define MIGRATE_PFN_WRITE (1UL << 3)
120 #define MIGRATE_PFN_SHIFT 6
122 static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
124 if (!(mpfn & MIGRATE_PFN_VALID))
126 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
129 static inline unsigned long migrate_pfn(unsigned long pfn)
131 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
134 enum migrate_vma_direction {
135 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
136 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
140 struct vm_area_struct *vma;
142 * Both src and dst array must be big enough for
143 * (end - start) >> PAGE_SHIFT entries.
145 * The src array must not be modified by the caller after
146 * migrate_vma_setup(), and must not change the dst array after
147 * migrate_vma_pages() returns.
151 unsigned long cpages;
152 unsigned long npages;
157 * Set to the owner value also stored in page->pgmap->owner for
158 * migrating out of device private memory. The flags also need to
159 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
160 * The caller should always set this field when using mmu notifier
161 * callbacks to avoid device MMU invalidations for device private
162 * pages that are not being migrated.
168 int migrate_vma_setup(struct migrate_vma *args);
169 void migrate_vma_pages(struct migrate_vma *migrate);
170 void migrate_vma_finalize(struct migrate_vma *migrate);
171 int next_demotion_node(int node);
173 #else /* CONFIG_MIGRATION disabled: */
175 static inline int next_demotion_node(int node)
180 #endif /* CONFIG_MIGRATION */
182 #endif /* _LINUX_MIGRATE_H */