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
22enum 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 */
35extern const char *migrate_reason_names[MR_TYPES];
36
37#ifdef CONFIG_MIGRATION
38
39extern void putback_movable_pages(struct list_head *l);
40extern int migrate_page(struct address_space *mapping,
41 struct page *newpage, struct page *page,
42 enum migrate_mode mode);
43extern 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);
45extern struct page *alloc_migration_target(struct page *page, unsigned long private);
46extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
47
48extern void migrate_page_states(struct page *newpage, struct page *page);
49extern void migrate_page_copy(struct page *newpage, struct page *page);
50extern int migrate_huge_page_move_mapping(struct address_space *mapping,
51 struct page *newpage, struct page *page);
52extern int migrate_page_move_mapping(struct address_space *mapping,
53 struct page *newpage, struct page *page, int extra_count);
54extern void copy_huge_page(struct page *dst, struct page *src);
55#else
56
57static inline void putback_movable_pages(struct list_head *l) {}
58static inline int migrate_pages(struct list_head *l, new_page_t new,
59 free_page_t free, unsigned long private, enum migrate_mode mode,
60 int reason)
61 { return -ENOSYS; }
62static inline struct page *alloc_migration_target(struct page *page,
63 unsigned long private)
64 { return NULL; }
65static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
66 { return -EBUSY; }
67
68static inline void migrate_page_states(struct page *newpage, struct page *page)
69{
70}
71
72static inline void migrate_page_copy(struct page *newpage,
73 struct page *page) {}
74
75static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
76 struct page *newpage, struct page *page)
77{
78 return -ENOSYS;
79}
80
81static inline void copy_huge_page(struct page *dst, struct page *src)
82{
83}
84#endif /* CONFIG_MIGRATION */
85
86#ifdef CONFIG_COMPACTION
87extern int PageMovable(struct page *page);
88extern void __SetPageMovable(struct page *page, struct address_space *mapping);
89extern void __ClearPageMovable(struct page *page);
90#else
91static inline int PageMovable(struct page *page) { return 0; }
92static inline void __SetPageMovable(struct page *page,
93 struct address_space *mapping)
94{
95}
96static inline void __ClearPageMovable(struct page *page)
97{
98}
99#endif
100
101#ifdef CONFIG_NUMA_BALANCING
102extern int migrate_misplaced_page(struct page *page,
103 struct vm_area_struct *vma, int node);
104#else
105static inline int migrate_misplaced_page(struct page *page,
106 struct vm_area_struct *vma, int node)
107{
108 return -EAGAIN; /* can't migrate now */
109}
110#endif /* CONFIG_NUMA_BALANCING */
111
112#ifdef CONFIG_MIGRATION
113
114/*
115 * Watch out for PAE architecture, which has an unsigned long, and might not
116 * have enough bits to store all physical address and flags. So far we have
117 * enough room for all our flags.
118 */
119#define MIGRATE_PFN_VALID (1UL << 0)
120#define MIGRATE_PFN_MIGRATE (1UL << 1)
121#define MIGRATE_PFN_LOCKED (1UL << 2)
122#define MIGRATE_PFN_WRITE (1UL << 3)
123#define MIGRATE_PFN_SHIFT 6
124
125static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
126{
127 if (!(mpfn & MIGRATE_PFN_VALID))
128 return NULL;
129 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
130}
131
132static inline unsigned long migrate_pfn(unsigned long pfn)
133{
134 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
135}
136
137enum migrate_vma_direction {
138 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
139 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
140};
141
142struct migrate_vma {
143 struct vm_area_struct *vma;
144 /*
145 * Both src and dst array must be big enough for
146 * (end - start) >> PAGE_SHIFT entries.
147 *
148 * The src array must not be modified by the caller after
149 * migrate_vma_setup(), and must not change the dst array after
150 * migrate_vma_pages() returns.
151 */
152 unsigned long *dst;
153 unsigned long *src;
154 unsigned long cpages;
155 unsigned long npages;
156 unsigned long start;
157 unsigned long end;
158
159 /*
160 * Set to the owner value also stored in page->pgmap->owner for
161 * migrating out of device private memory. The flags also need to
162 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
163 * The caller should always set this field when using mmu notifier
164 * callbacks to avoid device MMU invalidations for device private
165 * pages that are not being migrated.
166 */
167 void *pgmap_owner;
168 unsigned long flags;
169};
170
171int migrate_vma_setup(struct migrate_vma *args);
172void migrate_vma_pages(struct migrate_vma *migrate);
173void migrate_vma_finalize(struct migrate_vma *migrate);
174
175#endif /* CONFIG_MIGRATION */
176
177#endif /* _LINUX_MIGRATE_H */