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_LONGTERM_PIN,
31 MR_TYPES
32 };
33
34 /* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
35 extern const char *migrate_reason_names[MR_TYPES];
36
37 #ifdef CONFIG_MIGRATION
38
39 extern void putback_movable_pages(struct list_head *l);
40 extern int migrate_page(struct address_space *mapping,
41 struct page *newpage, struct page *page,
42 enum migrate_mode mode);
43 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
44 unsigned long private, enum migrate_mode mode, int reason);
45 extern struct page *alloc_migration_target(struct page *page, unsigned long private);
46 extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
47
48 extern void migrate_page_states(struct page *newpage, struct page *page);
49 extern void migrate_page_copy(struct page *newpage, struct page *page);
50 extern int migrate_huge_page_move_mapping(struct address_space *mapping,
51 struct page *newpage, struct page *page);
52 extern int migrate_page_move_mapping(struct address_space *mapping,
53 struct page *newpage, struct page *page, int extra_count);
54 #else
55
putback_movable_pages(struct list_head * l)56 static inline void putback_movable_pages(struct list_head *l) {}
migrate_pages(struct list_head * l,new_page_t new,free_page_t free,unsigned long private,enum migrate_mode mode,int reason)57 static inline int migrate_pages(struct list_head *l, new_page_t new,
58 free_page_t free, unsigned long private, enum migrate_mode mode,
59 int reason)
60 { return -ENOSYS; }
alloc_migration_target(struct page * page,unsigned long private)61 static inline struct page *alloc_migration_target(struct page *page,
62 unsigned long private)
63 { return NULL; }
isolate_movable_page(struct page * page,isolate_mode_t mode)64 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
65 { return -EBUSY; }
66
migrate_page_states(struct page * newpage,struct page * page)67 static inline void migrate_page_states(struct page *newpage, struct page *page)
68 {
69 }
70
migrate_page_copy(struct page * newpage,struct page * page)71 static inline void migrate_page_copy(struct page *newpage,
72 struct page *page) {}
73
migrate_huge_page_move_mapping(struct address_space * mapping,struct page * newpage,struct page * page)74 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
75 struct page *newpage, struct page *page)
76 {
77 return -ENOSYS;
78 }
79
80 #endif /* CONFIG_MIGRATION */
81
82 #ifdef CONFIG_COMPACTION
83 extern int PageMovable(struct page *page);
84 extern void __SetPageMovable(struct page *page, struct address_space *mapping);
85 extern void __ClearPageMovable(struct page *page);
86 #else
PageMovable(struct page * page)87 static inline int PageMovable(struct page *page) { return 0; }
__SetPageMovable(struct page * page,struct address_space * mapping)88 static inline void __SetPageMovable(struct page *page,
89 struct address_space *mapping)
90 {
91 }
__ClearPageMovable(struct page * page)92 static inline void __ClearPageMovable(struct page *page)
93 {
94 }
95 #endif
96
97 #ifdef CONFIG_NUMA_BALANCING
98 extern bool pmd_trans_migrating(pmd_t pmd);
99 extern int migrate_misplaced_page(struct page *page,
100 struct vm_area_struct *vma, int node);
101 #else
pmd_trans_migrating(pmd_t pmd)102 static inline bool pmd_trans_migrating(pmd_t pmd)
103 {
104 return false;
105 }
migrate_misplaced_page(struct page * page,struct vm_area_struct * vma,int node)106 static inline int migrate_misplaced_page(struct page *page,
107 struct vm_area_struct *vma, int node)
108 {
109 return -EAGAIN; /* can't migrate now */
110 }
111 #endif /* CONFIG_NUMA_BALANCING */
112
113 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
114 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
115 struct vm_area_struct *vma,
116 pmd_t *pmd, pmd_t entry,
117 unsigned long address,
118 struct page *page, int node);
119 #else
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)120 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
121 struct vm_area_struct *vma,
122 pmd_t *pmd, pmd_t entry,
123 unsigned long address,
124 struct page *page, int node)
125 {
126 return -EAGAIN;
127 }
128 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
129
130
131 #ifdef CONFIG_MIGRATION
132
133 /*
134 * Watch out for PAE architecture, which has an unsigned long, and might not
135 * have enough bits to store all physical address and flags. So far we have
136 * enough room for all our flags.
137 */
138 #define MIGRATE_PFN_VALID (1UL << 0)
139 #define MIGRATE_PFN_MIGRATE (1UL << 1)
140 #define MIGRATE_PFN_LOCKED (1UL << 2)
141 #define MIGRATE_PFN_WRITE (1UL << 3)
142 #define MIGRATE_PFN_SHIFT 6
143
migrate_pfn_to_page(unsigned long mpfn)144 static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
145 {
146 if (!(mpfn & MIGRATE_PFN_VALID))
147 return NULL;
148 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
149 }
150
migrate_pfn(unsigned long pfn)151 static inline unsigned long migrate_pfn(unsigned long pfn)
152 {
153 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
154 }
155
156 enum migrate_vma_direction {
157 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
158 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
159 };
160
161 struct migrate_vma {
162 struct vm_area_struct *vma;
163 /*
164 * Both src and dst array must be big enough for
165 * (end - start) >> PAGE_SHIFT entries.
166 *
167 * The src array must not be modified by the caller after
168 * migrate_vma_setup(), and must not change the dst array after
169 * migrate_vma_pages() returns.
170 */
171 unsigned long *dst;
172 unsigned long *src;
173 unsigned long cpages;
174 unsigned long npages;
175 unsigned long start;
176 unsigned long end;
177
178 /*
179 * Set to the owner value also stored in page->pgmap->owner for
180 * migrating out of device private memory. The flags also need to
181 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
182 * The caller should always set this field when using mmu notifier
183 * callbacks to avoid device MMU invalidations for device private
184 * pages that are not being migrated.
185 */
186 void *pgmap_owner;
187 unsigned long flags;
188 };
189
190 int migrate_vma_setup(struct migrate_vma *args);
191 void migrate_vma_pages(struct migrate_vma *migrate);
192 void migrate_vma_finalize(struct migrate_vma *migrate);
193
194 #endif /* CONFIG_MIGRATION */
195
196 #endif /* _LINUX_MIGRATE_H */
197