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