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