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
80#endif /* CONFIG_MIGRATION */
81
82#ifdef CONFIG_COMPACTION
83extern int PageMovable(struct page *page);
84extern void __SetPageMovable(struct page *page, struct address_space *mapping);
85extern void __ClearPageMovable(struct page *page);
86#else
87static inline int PageMovable(struct page *page) { return 0; }
88static inline void __SetPageMovable(struct page *page,
89 struct address_space *mapping)
90{
91}
92static inline void __ClearPageMovable(struct page *page)
93{
94}
95#endif
96
97#ifdef CONFIG_NUMA_BALANCING
98extern bool pmd_trans_migrating(pmd_t pmd);
99extern int migrate_misplaced_page(struct page *page,
100 struct vm_area_struct *vma, int node);
101#else
102static inline bool pmd_trans_migrating(pmd_t pmd)
103{
104 return false;
105}
106static inline int migrate_misplaced_page(struct page *page,
107 struct vm_area_struct *vma, int node)
108{
109 return -EAGAIN; /* can't migrate now */
110}
111#endif /* CONFIG_NUMA_BALANCING */
112
113#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
114extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
115 struct vm_area_struct *vma,
116 pmd_t *pmd, pmd_t entry,
117 unsigned long address,
118 struct page *page, int node);
119#else
120static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
121 struct vm_area_struct *vma,
122 pmd_t *pmd, pmd_t entry,
123 unsigned long address,
124 struct page *page, int node)
125{
126 return -EAGAIN;
127}
128#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
129
130
131#ifdef CONFIG_MIGRATION
132
133/*
134 * Watch out for PAE architecture, which has an unsigned long, and might not
135 * have enough bits to store all physical address and flags. So far we have
136 * enough room for all our flags.
137 */
138#define MIGRATE_PFN_VALID (1UL << 0)
139#define MIGRATE_PFN_MIGRATE (1UL << 1)
140#define MIGRATE_PFN_LOCKED (1UL << 2)
141#define MIGRATE_PFN_WRITE (1UL << 3)
142#define MIGRATE_PFN_SHIFT 6
143
144static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
145{
146 if (!(mpfn & MIGRATE_PFN_VALID))
147 return NULL;
148 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
149}
150
151static inline unsigned long migrate_pfn(unsigned long pfn)
152{
153 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
154}
155
156enum migrate_vma_direction {
157 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
158 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
159};
160
161struct migrate_vma {
162 struct vm_area_struct *vma;
163 /*
164 * Both src and dst array must be big enough for
165 * (end - start) >> PAGE_SHIFT entries.
166 *
167 * The src array must not be modified by the caller after
168 * migrate_vma_setup(), and must not change the dst array after
169 * migrate_vma_pages() returns.
170 */
171 unsigned long *dst;
172 unsigned long *src;
173 unsigned long cpages;
174 unsigned long npages;
175 unsigned long start;
176 unsigned long end;
177
178 /*
179 * Set to the owner value also stored in page->pgmap->owner for
180 * migrating out of device private memory. The flags also need to
181 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
182 * The caller should always set this field when using mmu notifier
183 * callbacks to avoid device MMU invalidations for device private
184 * pages that are not being migrated.
185 */
186 void *pgmap_owner;
187 unsigned long flags;
188};
189
190int migrate_vma_setup(struct migrate_vma *args);
191void migrate_vma_pages(struct migrate_vma *migrate);
192void migrate_vma_finalize(struct migrate_vma *migrate);
193
194#endif /* CONFIG_MIGRATION */
195
196#endif /* _LINUX_MIGRATE_H */