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/* Defined in mm/debug.c: */
  23extern const char *migrate_reason_names[MR_TYPES];
  24
  25#ifdef CONFIG_MIGRATION
  26
  27extern void putback_movable_pages(struct list_head *l);
  28extern int migrate_page(struct address_space *mapping,
  29                        struct page *newpage, struct page *page,
  30                        enum migrate_mode mode);
  31extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
  32                unsigned long private, enum migrate_mode mode, int reason,
  33                unsigned int *ret_succeeded);
  34extern struct page *alloc_migration_target(struct page *page, unsigned long private);
  35extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
  36
  37extern void migrate_page_states(struct page *newpage, struct page *page);
  38extern void migrate_page_copy(struct page *newpage, struct page *page);
  39extern int migrate_huge_page_move_mapping(struct address_space *mapping,
  40                                  struct page *newpage, struct page *page);
  41extern int migrate_page_move_mapping(struct address_space *mapping,
  42                struct page *newpage, struct page *page, int extra_count);
  43void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep,
  44                                spinlock_t *ptl);
  45void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
  46void folio_migrate_copy(struct folio *newfolio, struct folio *folio);
  47int folio_migrate_mapping(struct address_space *mapping,
  48                struct folio *newfolio, struct folio *folio, int extra_count);
  49
  50extern bool numa_demotion_enabled;
  51#else
  52
  53static inline void putback_movable_pages(struct list_head *l) {}
  54static inline int migrate_pages(struct list_head *l, new_page_t new,
  55                free_page_t free, unsigned long private, enum migrate_mode mode,
  56                int reason, unsigned int *ret_succeeded)
  57        { return -ENOSYS; }
  58static inline struct page *alloc_migration_target(struct page *page,
  59                unsigned long private)
  60        { return NULL; }
  61static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
  62        { return -EBUSY; }
  63
  64static inline void migrate_page_states(struct page *newpage, struct page *page)
  65{
  66}
  67
  68static inline void migrate_page_copy(struct page *newpage,
  69                                     struct page *page) {}
  70
  71static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
  72                                  struct page *newpage, struct page *page)
  73{
  74        return -ENOSYS;
  75}
  76
  77#define numa_demotion_enabled   false
  78#endif /* CONFIG_MIGRATION */
  79
  80#ifdef CONFIG_COMPACTION
  81extern int PageMovable(struct page *page);
  82extern void __SetPageMovable(struct page *page, struct address_space *mapping);
  83extern void __ClearPageMovable(struct page *page);
  84#else
  85static inline int PageMovable(struct page *page) { return 0; }
  86static inline void __SetPageMovable(struct page *page,
  87                                struct address_space *mapping)
  88{
  89}
  90static inline void __ClearPageMovable(struct page *page)
  91{
  92}
  93#endif
  94
  95#ifdef CONFIG_NUMA_BALANCING
  96extern int migrate_misplaced_page(struct page *page,
  97                                  struct vm_area_struct *vma, int node);
  98#else
  99static inline int migrate_misplaced_page(struct page *page,
 100                                         struct vm_area_struct *vma, int node)
 101{
 102        return -EAGAIN; /* can't migrate now */
 103}
 104#endif /* CONFIG_NUMA_BALANCING */
 105
 106#ifdef CONFIG_MIGRATION
 107
 108/*
 109 * Watch out for PAE architecture, which has an unsigned long, and might not
 110 * have enough bits to store all physical address and flags. So far we have
 111 * enough room for all our flags.
 112 */
 113#define MIGRATE_PFN_VALID       (1UL << 0)
 114#define MIGRATE_PFN_MIGRATE     (1UL << 1)
 115#define MIGRATE_PFN_WRITE       (1UL << 3)
 116#define MIGRATE_PFN_SHIFT       6
 117
 118static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
 119{
 120        if (!(mpfn & MIGRATE_PFN_VALID))
 121                return NULL;
 122        return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
 123}
 124
 125static inline unsigned long migrate_pfn(unsigned long pfn)
 126{
 127        return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
 128}
 129
 130enum migrate_vma_direction {
 131        MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
 132        MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
 133};
 134
 135struct migrate_vma {
 136        struct vm_area_struct   *vma;
 137        /*
 138         * Both src and dst array must be big enough for
 139         * (end - start) >> PAGE_SHIFT entries.
 140         *
 141         * The src array must not be modified by the caller after
 142         * migrate_vma_setup(), and must not change the dst array after
 143         * migrate_vma_pages() returns.
 144         */
 145        unsigned long           *dst;
 146        unsigned long           *src;
 147        unsigned long           cpages;
 148        unsigned long           npages;
 149        unsigned long           start;
 150        unsigned long           end;
 151
 152        /*
 153         * Set to the owner value also stored in page->pgmap->owner for
 154         * migrating out of device private memory. The flags also need to
 155         * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
 156         * The caller should always set this field when using mmu notifier
 157         * callbacks to avoid device MMU invalidations for device private
 158         * pages that are not being migrated.
 159         */
 160        void                    *pgmap_owner;
 161        unsigned long           flags;
 162};
 163
 164int migrate_vma_setup(struct migrate_vma *args);
 165void migrate_vma_pages(struct migrate_vma *migrate);
 166void migrate_vma_finalize(struct migrate_vma *migrate);
 167int next_demotion_node(int node);
 168
 169#else /* CONFIG_MIGRATION disabled: */
 170
 171static inline int next_demotion_node(int node)
 172{
 173        return NUMA_NO_NODE;
 174}
 175
 176#endif /* CONFIG_MIGRATION */
 177
 178#endif /* _LINUX_MIGRATE_H */
 179