LXR linux/include/linux/migrate.h

   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
  22/*
  23 * Keep sync with:
  24 * - macro MIGRATE_REASON in include/trace/events/migrate.h
  25 * - migrate_reason_names[MR_TYPES] in mm/debug.c
  26 */
  27enum migrate_reason {
  28        MR_COMPACTION,
  29        MR_MEMORY_FAILURE,
  30        MR_MEMORY_HOTPLUG,
  31        MR_SYSCALL,             /* also applies to cpusets */
  32        MR_MEMPOLICY_MBIND,
  33        MR_NUMA_MISPLACED,
  34        MR_CONTIG_RANGE,
  35        MR_LONGTERM_PIN,
  36        MR_DEMOTION,
  37        MR_TYPES
  38};
  39
  40extern const char *migrate_reason_names[MR_TYPES];
  41
  42#ifdef CONFIG_MIGRATION
  43
  44extern void putback_movable_pages(struct list_head *l);
  45extern int migrate_page(struct address_space *mapping,
  46                        struct page *newpage, struct page *page,
  47                        enum migrate_mode mode);
  48extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
  49                unsigned long private, enum migrate_mode mode, int reason,
  50                unsigned int *ret_succeeded);
  51extern struct page *alloc_migration_target(struct page *page, unsigned long private);
  52extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
  53
  54extern void migrate_page_states(struct page *newpage, struct page *page);
  55extern void migrate_page_copy(struct page *newpage, struct page *page);
  56extern int migrate_huge_page_move_mapping(struct address_space *mapping,
  57                                  struct page *newpage, struct page *page);
  58extern int migrate_page_move_mapping(struct address_space *mapping,
  59                struct page *newpage, struct page *page, int extra_count);
  60#else
  61
  62static inline void putback_movable_pages(struct list_head *l) {}
  63static inline int migrate_pages(struct list_head *l, new_page_t new,
  64                free_page_t free, unsigned long private, enum migrate_mode mode,
  65                int reason, unsigned int *ret_succeeded)
  66        { return -ENOSYS; }
  67static inline struct page *alloc_migration_target(struct page *page,
  68                unsigned long private)
  69        { return NULL; }
  70static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
  71        { return -EBUSY; }
  72
  73static inline void migrate_page_states(struct page *newpage, struct page *page)
  74{
  75}
  76
  77static inline void migrate_page_copy(struct page *newpage,
  78                                     struct page *page) {}
  79
  80static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
  81                                  struct page *newpage, struct page *page)
  82{
  83        return -ENOSYS;
  84}
  85#endif /* CONFIG_MIGRATION */
  86
  87#ifdef CONFIG_COMPACTION
  88extern int PageMovable(struct page *page);
  89extern void __SetPageMovable(struct page *page, struct address_space *mapping);
  90extern void __ClearPageMovable(struct page *page);
  91#else
  92static inline int PageMovable(struct page *page) { return 0; }
  93static inline void __SetPageMovable(struct page *page,
  94                                struct address_space *mapping)
  95{
  96}
  97static inline void __ClearPageMovable(struct page *page)
  98{
  99}
 100#endif
 101
 102#ifdef CONFIG_NUMA_BALANCING
 103extern int migrate_misplaced_page(struct page *page,
 104                                  struct vm_area_struct *vma, int node);
 105#else
 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#ifdef CONFIG_MIGRATION
 114
 115/*
 116 * Watch out for PAE architecture, which has an unsigned long, and might not
 117 * have enough bits to store all physical address and flags. So far we have
 118 * enough room for all our flags.
 119 */
 120#define MIGRATE_PFN_VALID       (1UL << 0)
 121#define MIGRATE_PFN_MIGRATE     (1UL << 1)
 122#define MIGRATE_PFN_LOCKED      (1UL << 2)
 123#define MIGRATE_PFN_WRITE       (1UL << 3)
 124#define MIGRATE_PFN_SHIFT       6
 125
 126static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
 127{
 128        if (!(mpfn & MIGRATE_PFN_VALID))
 129                return NULL;
 130        return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
 131}
 132
 133static inline unsigned long migrate_pfn(unsigned long pfn)
 134{
 135        return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
 136}
 137
 138enum migrate_vma_direction {
 139        MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
 140        MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
 141};
 142
 143struct migrate_vma {
 144        struct vm_area_struct   *vma;
 145        /*
 146         * Both src and dst array must be big enough for
 147         * (end - start) >> PAGE_SHIFT entries.
 148         *
 149         * The src array must not be modified by the caller after
 150         * migrate_vma_setup(), and must not change the dst array after
 151         * migrate_vma_pages() returns.
 152         */
 153        unsigned long           *dst;
 154        unsigned long           *src;
 155        unsigned long           cpages;
 156        unsigned long           npages;
 157        unsigned long           start;
 158        unsigned long           end;
 159
 160        /*
 161         * Set to the owner value also stored in page->pgmap->owner for
 162         * migrating out of device private memory. The flags also need to
 163         * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
 164         * The caller should always set this field when using mmu notifier
 165         * callbacks to avoid device MMU invalidations for device private
 166         * pages that are not being migrated.
 167         */
 168        void                    *pgmap_owner;
 169        unsigned long           flags;
 170};
 171
 172int migrate_vma_setup(struct migrate_vma *args);
 173void migrate_vma_pages(struct migrate_vma *migrate);
 174void migrate_vma_finalize(struct migrate_vma *migrate);
 175int next_demotion_node(int node);
 176
 177#else /* CONFIG_MIGRATION disabled: */
 178
 179static inline int next_demotion_node(int node)
 180{
 181        return NUMA_NO_NODE;
 182}
 183
 184#endif /* CONFIG_MIGRATION */
 185
 186#endif /* _LINUX_MIGRATE_H */
 187