Linux kernel mirror (for testing)
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linux
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
10typedef struct page *new_page_t(struct page *page, unsigned long private);
11typedef void free_page_t(struct page *page, unsigned long private);
12
13struct 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/* Defined in mm/debug.c: */
23extern const char *migrate_reason_names[MR_TYPES];
24
25#ifdef CONFIG_MIGRATION
26
27extern void putback_movable_pages(struct list_head *l);
28extern int migrate_page(struct address_space *mapping,
29 struct page *newpage, struct page *page,
30 enum migrate_mode mode);
31extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
32 unsigned long private, enum migrate_mode mode, int reason,
33 unsigned int *ret_succeeded);
34extern struct page *alloc_migration_target(struct page *page, unsigned long private);
35extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
36
37extern void migrate_page_states(struct page *newpage, struct page *page);
38extern void migrate_page_copy(struct page *newpage, struct page *page);
39extern int migrate_huge_page_move_mapping(struct address_space *mapping,
40 struct page *newpage, struct page *page);
41extern int migrate_page_move_mapping(struct address_space *mapping,
42 struct page *newpage, struct page *page, int extra_count);
43void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep,
44 spinlock_t *ptl);
45void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
46void folio_migrate_copy(struct folio *newfolio, struct folio *folio);
47int folio_migrate_mapping(struct address_space *mapping,
48 struct folio *newfolio, struct folio *folio, int extra_count);
49
50extern bool numa_demotion_enabled;
51#else
52
53static inline void putback_movable_pages(struct list_head *l) {}
54static inline int migrate_pages(struct list_head *l, new_page_t new,
55 free_page_t free, unsigned long private, enum migrate_mode mode,
56 int reason, unsigned int *ret_succeeded)
57 { return -ENOSYS; }
58static inline struct page *alloc_migration_target(struct page *page,
59 unsigned long private)
60 { return NULL; }
61static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
62 { return -EBUSY; }
63
64static inline void migrate_page_states(struct page *newpage, struct page *page)
65{
66}
67
68static inline void migrate_page_copy(struct page *newpage,
69 struct page *page) {}
70
71static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
72 struct page *newpage, struct page *page)
73{
74 return -ENOSYS;
75}
76
77#define numa_demotion_enabled false
78#endif /* CONFIG_MIGRATION */
79
80#ifdef CONFIG_COMPACTION
81extern int PageMovable(struct page *page);
82extern void __SetPageMovable(struct page *page, struct address_space *mapping);
83extern void __ClearPageMovable(struct page *page);
84#else
85static inline int PageMovable(struct page *page) { return 0; }
86static inline void __SetPageMovable(struct page *page,
87 struct address_space *mapping)
88{
89}
90static inline void __ClearPageMovable(struct page *page)
91{
92}
93#endif
94
95#ifdef CONFIG_NUMA_BALANCING
96extern int migrate_misplaced_page(struct page *page,
97 struct vm_area_struct *vma, int node);
98#else
99static inline int migrate_misplaced_page(struct page *page,
100 struct vm_area_struct *vma, int node)
101{
102 return -EAGAIN; /* can't migrate now */
103}
104#endif /* CONFIG_NUMA_BALANCING */
105
106#ifdef CONFIG_MIGRATION
107
108/*
109 * Watch out for PAE architecture, which has an unsigned long, and might not
110 * have enough bits to store all physical address and flags. So far we have
111 * enough room for all our flags.
112 */
113#define MIGRATE_PFN_VALID (1UL << 0)
114#define MIGRATE_PFN_MIGRATE (1UL << 1)
115#define MIGRATE_PFN_WRITE (1UL << 3)
116#define MIGRATE_PFN_SHIFT 6
117
118static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
119{
120 if (!(mpfn & MIGRATE_PFN_VALID))
121 return NULL;
122 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
123}
124
125static inline unsigned long migrate_pfn(unsigned long pfn)
126{
127 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
128}
129
130enum migrate_vma_direction {
131 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
132 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
133};
134
135struct migrate_vma {
136 struct vm_area_struct *vma;
137 /*
138 * Both src and dst array must be big enough for
139 * (end - start) >> PAGE_SHIFT entries.
140 *
141 * The src array must not be modified by the caller after
142 * migrate_vma_setup(), and must not change the dst array after
143 * migrate_vma_pages() returns.
144 */
145 unsigned long *dst;
146 unsigned long *src;
147 unsigned long cpages;
148 unsigned long npages;
149 unsigned long start;
150 unsigned long end;
151
152 /*
153 * Set to the owner value also stored in page->pgmap->owner for
154 * migrating out of device private memory. The flags also need to
155 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
156 * The caller should always set this field when using mmu notifier
157 * callbacks to avoid device MMU invalidations for device private
158 * pages that are not being migrated.
159 */
160 void *pgmap_owner;
161 unsigned long flags;
162};
163
164int migrate_vma_setup(struct migrate_vma *args);
165void migrate_vma_pages(struct migrate_vma *migrate);
166void migrate_vma_finalize(struct migrate_vma *migrate);
167int next_demotion_node(int node);
168
169#else /* CONFIG_MIGRATION disabled: */
170
171static inline int next_demotion_node(int node)
172{
173 return NUMA_NO_NODE;
174}
175
176#endif /* CONFIG_MIGRATION */
177
178#endif /* _LINUX_MIGRATE_H */