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;
  51extern void migrate_on_reclaim_init(void);
  52#ifdef CONFIG_HOTPLUG_CPU
  53extern void set_migration_target_nodes(void);
  54#else
  55static inline void set_migration_target_nodes(void) {}
  56#endif
  57#else
  58
  59static inline void set_migration_target_nodes(void) {}
  60
  61static inline void putback_movable_pages(struct list_head *l) {}
  62static inline int migrate_pages(struct list_head *l, new_page_t new,
  63                free_page_t free, unsigned long private, enum migrate_mode mode,
  64                int reason, unsigned int *ret_succeeded)
  65        { return -ENOSYS; }
  66static inline struct page *alloc_migration_target(struct page *page,
  67                unsigned long private)
  68        { return NULL; }
  69static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
  70        { return -EBUSY; }
  71
  72static inline void migrate_page_states(struct page *newpage, struct page *page)
  73{
  74}
  75
  76static inline void migrate_page_copy(struct page *newpage,
  77                                     struct page *page) {}
  78
  79static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
  80                                  struct page *newpage, struct page *page)
  81{
  82        return -ENOSYS;
  83}
  84
  85#define numa_demotion_enabled   false
  86#endif /* CONFIG_MIGRATION */
  87
  88#ifdef CONFIG_COMPACTION
  89extern int PageMovable(struct page *page);
  90extern void __SetPageMovable(struct page *page, struct address_space *mapping);
  91extern void __ClearPageMovable(struct page *page);
  92#else
  93static inline int PageMovable(struct page *page) { return 0; }
  94static inline void __SetPageMovable(struct page *page,
  95                                struct address_space *mapping)
  96{
  97}
  98static inline void __ClearPageMovable(struct page *page)
  99{
 100}
 101#endif
 102
 103#ifdef CONFIG_NUMA_BALANCING
 104extern int migrate_misplaced_page(struct page *page,
 105                                  struct vm_area_struct *vma, int node);
 106#else
 107static inline int migrate_misplaced_page(struct page *page,
 108                                         struct vm_area_struct *vma, int node)
 109{
 110        return -EAGAIN; /* can't migrate now */
 111}
 112#endif /* CONFIG_NUMA_BALANCING */
 113
 114#ifdef CONFIG_MIGRATION
 115
 116/*
 117 * Watch out for PAE architecture, which has an unsigned long, and might not
 118 * have enough bits to store all physical address and flags. So far we have
 119 * enough room for all our flags.
 120 */
 121#define MIGRATE_PFN_VALID       (1UL << 0)
 122#define MIGRATE_PFN_MIGRATE     (1UL << 1)
 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