1#ifndef _LINUX_MIGRATE_H
2#define _LINUX_MIGRATE_H
3
4#include <linux/mm.h>
5#include <linux/mempolicy.h>
6#include <linux/migrate_mode.h>
7
8typedef struct page *new_page_t(struct page *page, unsigned long private,
9				int **reason);
10typedef void free_page_t(struct page *page, unsigned long private);
11
12/*
13 * Return values from addresss_space_operations.migratepage():
14 * - negative errno on page migration failure;
15 * - zero on page migration success;
16 */
17#define MIGRATEPAGE_SUCCESS		0
18
19enum migrate_reason {
20	MR_COMPACTION,
21	MR_MEMORY_FAILURE,
22	MR_MEMORY_HOTPLUG,
23	MR_SYSCALL,		/* also applies to cpusets */
24	MR_MEMPOLICY_MBIND,
25	MR_NUMA_MISPLACED,
26	MR_CMA
27};
28
29#ifdef CONFIG_MIGRATION
30
31extern void putback_movable_pages(struct list_head *l);
32extern int migrate_page(struct address_space *,
33			struct page *, struct page *, enum migrate_mode);
34extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
35		unsigned long private, enum migrate_mode mode, int reason);
36
37extern int migrate_prep(void);
38extern int migrate_prep_local(void);
39extern void migrate_page_copy(struct page *newpage, struct page *page);
40extern int migrate_huge_page_move_mapping(struct address_space *mapping,
41				  struct page *newpage, struct page *page);
42extern int migrate_page_move_mapping(struct address_space *mapping,
43		struct page *newpage, struct page *page,
44		struct buffer_head *head, enum migrate_mode mode,
45		int extra_count);
46#else
47
48static inline void putback_movable_pages(struct list_head *l) {}
49static inline int migrate_pages(struct list_head *l, new_page_t new,
50		free_page_t free, unsigned long private, enum migrate_mode mode,
51		int reason)
52	{ return -ENOSYS; }
53
54static inline int migrate_prep(void) { return -ENOSYS; }
55static inline int migrate_prep_local(void) { return -ENOSYS; }
56
57static inline void migrate_page_copy(struct page *newpage,
58				     struct page *page) {}
59
60static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
61				  struct page *newpage, struct page *page)
62{
63	return -ENOSYS;
64}
65
66#endif /* CONFIG_MIGRATION */
67
68#ifdef CONFIG_NUMA_BALANCING
69extern bool pmd_trans_migrating(pmd_t pmd);
70extern int migrate_misplaced_page(struct page *page,
71				  struct vm_area_struct *vma, int node);
72#else
73static inline bool pmd_trans_migrating(pmd_t pmd)
74{
75	return false;
76}
77static inline int migrate_misplaced_page(struct page *page,
78					 struct vm_area_struct *vma, int node)
79{
80	return -EAGAIN; /* can't migrate now */
81}
82#endif /* CONFIG_NUMA_BALANCING */
83
84#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
85extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
86			struct vm_area_struct *vma,
87			pmd_t *pmd, pmd_t entry,
88			unsigned long address,
89			struct page *page, int node);
90#else
91static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
92			struct vm_area_struct *vma,
93			pmd_t *pmd, pmd_t entry,
94			unsigned long address,
95			struct page *page, int node)
96{
97	return -EAGAIN;
98}
99#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
100
101#endif /* _LINUX_MIGRATE_H */
102