Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _LINUX_MIGRATE_H
3 : #define _LINUX_MIGRATE_H
4 :
5 : #include <linux/mm.h>
6 : #include <linux/mempolicy.h>
7 : #include <linux/migrate_mode.h>
8 : #include <linux/hugetlb.h>
9 :
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);
12 :
13 : struct migration_target_control;
14 :
15 : /*
16 : * Return values from addresss_space_operations.migratepage():
17 : * - negative errno on page migration failure;
18 : * - zero on page migration success;
19 : */
20 : #define MIGRATEPAGE_SUCCESS 0
21 :
22 : enum migrate_reason {
23 : MR_COMPACTION,
24 : MR_MEMORY_FAILURE,
25 : MR_MEMORY_HOTPLUG,
26 : MR_SYSCALL, /* also applies to cpusets */
27 : MR_MEMPOLICY_MBIND,
28 : MR_NUMA_MISPLACED,
29 : MR_CONTIG_RANGE,
30 : MR_TYPES
31 : };
32 :
33 : /* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
34 : extern const char *migrate_reason_names[MR_TYPES];
35 :
36 : #ifdef CONFIG_MIGRATION
37 :
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);
47 :
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);
56 : #else
57 :
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)
62 : { return -ENOSYS; }
63 : static inline struct page *alloc_migration_target(struct page *page,
64 : unsigned long private)
65 : { return NULL; }
66 : static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
67 : { return -EBUSY; }
68 :
69 : static inline int migrate_prep(void) { return -ENOSYS; }
70 : static inline int migrate_prep_local(void) { return -ENOSYS; }
71 :
72 : static inline void migrate_page_states(struct page *newpage, struct page *page)
73 : {
74 : }
75 :
76 : static inline void migrate_page_copy(struct page *newpage,
77 : struct page *page) {}
78 :
79 : static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
80 : struct page *newpage, struct page *page)
81 : {
82 : return -ENOSYS;
83 : }
84 :
85 : #endif /* CONFIG_MIGRATION */
86 :
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);
91 : #else
92 : static inline int PageMovable(struct page *page) { return 0; }
93 : static inline void __SetPageMovable(struct page *page,
94 : struct address_space *mapping)
95 : {
96 : }
97 : static inline void __ClearPageMovable(struct page *page)
98 : {
99 : }
100 : #endif
101 :
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);
106 : #else
107 0 : static inline bool pmd_trans_migrating(pmd_t pmd)
108 : {
109 0 : return false;
110 : }
111 : static inline int migrate_misplaced_page(struct page *page,
112 : struct vm_area_struct *vma, int node)
113 : {
114 : return -EAGAIN; /* can't migrate now */
115 : }
116 : #endif /* CONFIG_NUMA_BALANCING */
117 :
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);
124 : #else
125 0 : 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)
130 : {
131 0 : return -EAGAIN;
132 : }
133 : #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
134 :
135 :
136 : #ifdef CONFIG_MIGRATION
137 :
138 : /*
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.
142 : */
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
148 :
149 : static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
150 : {
151 : if (!(mpfn & MIGRATE_PFN_VALID))
152 : return NULL;
153 : return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
154 : }
155 :
156 : static inline unsigned long migrate_pfn(unsigned long pfn)
157 : {
158 : return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
159 : }
160 :
161 : enum migrate_vma_direction {
162 : MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
163 : MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
164 : };
165 :
166 : struct migrate_vma {
167 : struct vm_area_struct *vma;
168 : /*
169 : * Both src and dst array must be big enough for
170 : * (end - start) >> PAGE_SHIFT entries.
171 : *
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.
175 : */
176 : unsigned long *dst;
177 : unsigned long *src;
178 : unsigned long cpages;
179 : unsigned long npages;
180 : unsigned long start;
181 : unsigned long end;
182 :
183 : /*
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.
190 : */
191 : void *pgmap_owner;
192 : unsigned long flags;
193 : };
194 :
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);
198 :
199 : #endif /* CONFIG_MIGRATION */
200 :
201 : #endif /* _LINUX_MIGRATE_H */
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