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