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 */
33 /* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
34 extern const char *migrate_reason_names[MR_TYPES];
36 #ifdef CONFIG_MIGRATION
38 extern void putback_movable_pages(struct list_head *l);
39 extern int migrate_page(struct address_space *mapping,
40 struct page *newpage, struct page *page,
41 enum migrate_mode mode);
42 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
43 unsigned long private, enum migrate_mode mode, int reason);
44 extern struct page *alloc_migration_target(struct page *page, unsigned long private);
45 extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
46 extern void putback_movable_page(struct page *page);
48 extern void migrate_prep(void);
49 extern void migrate_prep_local(void);
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,
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 int migrate_prep(void) { return -ENOSYS; }
70 static inline int migrate_prep_local(void) { return -ENOSYS; }
72 static inline void migrate_page_states(struct page *newpage, struct page *page)
76 static inline void migrate_page_copy(struct page *newpage,
79 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
80 struct page *newpage, struct page *page)
85 #endif /* CONFIG_MIGRATION */
87 #ifdef CONFIG_COMPACTION
88 extern int PageMovable(struct page *page);
89 extern void __SetPageMovable(struct page *page, struct address_space *mapping);
90 extern void __ClearPageMovable(struct page *page);
92 static inline int PageMovable(struct page *page) { return 0; };
93 static inline void __SetPageMovable(struct page *page,
94 struct address_space *mapping)
97 static inline void __ClearPageMovable(struct page *page)
102 #ifdef CONFIG_NUMA_BALANCING
103 extern bool pmd_trans_migrating(pmd_t pmd);
104 extern int migrate_misplaced_page(struct page *page,
105 struct vm_area_struct *vma, int node);
107 static inline bool pmd_trans_migrating(pmd_t pmd)
111 static inline int migrate_misplaced_page(struct page *page,
112 struct vm_area_struct *vma, int node)
114 return -EAGAIN; /* can't migrate now */
116 #endif /* CONFIG_NUMA_BALANCING */
118 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
119 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
120 struct vm_area_struct *vma,
121 pmd_t *pmd, pmd_t entry,
122 unsigned long address,
123 struct page *page, int node);
125 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
126 struct vm_area_struct *vma,
127 pmd_t *pmd, pmd_t entry,
128 unsigned long address,
129 struct page *page, int node)
133 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
136 #ifdef CONFIG_MIGRATION
139 * Watch out for PAE architecture, which has an unsigned long, and might not
140 * have enough bits to store all physical address and flags. So far we have
141 * enough room for all our flags.
143 #define MIGRATE_PFN_VALID (1UL << 0)
144 #define MIGRATE_PFN_MIGRATE (1UL << 1)
145 #define MIGRATE_PFN_LOCKED (1UL << 2)
146 #define MIGRATE_PFN_WRITE (1UL << 3)
147 #define MIGRATE_PFN_SHIFT 6
149 static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
151 if (!(mpfn & MIGRATE_PFN_VALID))
153 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
156 static inline unsigned long migrate_pfn(unsigned long pfn)
158 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
161 enum migrate_vma_direction {
162 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
163 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
167 struct vm_area_struct *vma;
169 * Both src and dst array must be big enough for
170 * (end - start) >> PAGE_SHIFT entries.
172 * The src array must not be modified by the caller after
173 * migrate_vma_setup(), and must not change the dst array after
174 * migrate_vma_pages() returns.
178 unsigned long cpages;
179 unsigned long npages;
184 * Set to the owner value also stored in page->pgmap->owner for
185 * migrating out of device private memory. The flags also need to
186 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
187 * The caller should always set this field when using mmu notifier
188 * callbacks to avoid device MMU invalidations for device private
189 * pages that are not being migrated.
195 int migrate_vma_setup(struct migrate_vma *args);
196 void migrate_vma_pages(struct migrate_vma *migrate);
197 void migrate_vma_finalize(struct migrate_vma *migrate);
199 #endif /* CONFIG_MIGRATION */
201 #endif /* _LINUX_MIGRATE_H */