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
  13/*
  14 * Return values from addresss_space_operations.migratepage():
  15 * - negative errno on page migration failure;
  16 * - zero on page migration success;
  17 */
  18#define MIGRATEPAGE_SUCCESS             0
  19
  20enum migrate_reason {
  21        MR_COMPACTION,
  22        MR_MEMORY_FAILURE,
  23        MR_MEMORY_HOTPLUG,
  24        MR_SYSCALL,             /* also applies to cpusets */
  25        MR_MEMPOLICY_MBIND,
  26        MR_NUMA_MISPLACED,
  27        MR_CONTIG_RANGE,
  28        MR_TYPES
  29};
  30
  31/* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
  32extern const char *migrate_reason_names[MR_TYPES];
  33
  34static inline struct page *new_page_nodemask(struct page *page,
  35                                int preferred_nid, nodemask_t *nodemask)
  36{
  37        gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL;
  38        unsigned int order = 0;
  39        struct page *new_page = NULL;
  40
  41        if (PageHuge(page))
  42                return alloc_huge_page_nodemask(page_hstate(compound_head(page)),
  43                                preferred_nid, nodemask);
  44
  45        if (PageTransHuge(page)) {
  46                gfp_mask |= GFP_TRANSHUGE;
  47                order = HPAGE_PMD_ORDER;
  48        }
  49
  50        if (PageHighMem(page) || (zone_idx(page_zone(page)) == ZONE_MOVABLE))
  51                gfp_mask |= __GFP_HIGHMEM;
  52
  53        new_page = __alloc_pages_nodemask(gfp_mask, order,
  54                                preferred_nid, nodemask);
  55
  56        if (new_page && PageTransHuge(new_page))
  57                prep_transhuge_page(new_page);
  58
  59        return new_page;
  60}
  61
  62#ifdef CONFIG_MIGRATION
  63
  64extern void putback_movable_pages(struct list_head *l);
  65extern int migrate_page(struct address_space *mapping,
  66                        struct page *newpage, struct page *page,
  67                        enum migrate_mode mode);
  68extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
  69                unsigned long private, enum migrate_mode mode, int reason);
  70extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
  71extern void putback_movable_page(struct page *page);
  72
  73extern int migrate_prep(void);
  74extern int migrate_prep_local(void);
  75extern void migrate_page_states(struct page *newpage, struct page *page);
  76extern void migrate_page_copy(struct page *newpage, struct page *page);
  77extern int migrate_huge_page_move_mapping(struct address_space *mapping,
  78                                  struct page *newpage, struct page *page);
  79extern int migrate_page_move_mapping(struct address_space *mapping,
  80                struct page *newpage, struct page *page, int extra_count);
  81#else
  82
  83static inline void putback_movable_pages(struct list_head *l) {}
  84static inline int migrate_pages(struct list_head *l, new_page_t new,
  85                free_page_t free, unsigned long private, enum migrate_mode mode,
  86                int reason)
  87        { return -ENOSYS; }
  88static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
  89        { return -EBUSY; }
  90
  91static inline int migrate_prep(void) { return -ENOSYS; }
  92static inline int migrate_prep_local(void) { return -ENOSYS; }
  93
  94static inline void migrate_page_states(struct page *newpage, struct page *page)
  95{
  96}
  97
  98static inline void migrate_page_copy(struct page *newpage,
  99                                     struct page *page) {}
 100
 101static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
 102                                  struct page *newpage, struct page *page)
 103{
 104        return -ENOSYS;
 105}
 106
 107#endif /* CONFIG_MIGRATION */
 108
 109#ifdef CONFIG_COMPACTION
 110extern int PageMovable(struct page *page);
 111extern void __SetPageMovable(struct page *page, struct address_space *mapping);
 112extern void __ClearPageMovable(struct page *page);
 113#else
 114static inline int PageMovable(struct page *page) { return 0; };
 115static inline void __SetPageMovable(struct page *page,
 116                                struct address_space *mapping)
 117{
 118}
 119static inline void __ClearPageMovable(struct page *page)
 120{
 121}
 122#endif
 123
 124#ifdef CONFIG_NUMA_BALANCING
 125extern bool pmd_trans_migrating(pmd_t pmd);
 126extern int migrate_misplaced_page(struct page *page,
 127                                  struct vm_area_struct *vma, int node);
 128#else
 129static inline bool pmd_trans_migrating(pmd_t pmd)
 130{
 131        return false;
 132}
 133static inline int migrate_misplaced_page(struct page *page,
 134                                         struct vm_area_struct *vma, int node)
 135{
 136        return -EAGAIN; /* can't migrate now */
 137}
 138#endif /* CONFIG_NUMA_BALANCING */
 139
 140#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 141extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 142                        struct vm_area_struct *vma,
 143                        pmd_t *pmd, pmd_t entry,
 144                        unsigned long address,
 145                        struct page *page, int node);
 146#else
 147static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 148                        struct vm_area_struct *vma,
 149                        pmd_t *pmd, pmd_t entry,
 150                        unsigned long address,
 151                        struct page *page, int node)
 152{
 153        return -EAGAIN;
 154}
 155#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
 156
 157
 158#ifdef CONFIG_MIGRATION
 159
 160/*
 161 * Watch out for PAE architecture, which has an unsigned long, and might not
 162 * have enough bits to store all physical address and flags. So far we have
 163 * enough room for all our flags.
 164 */
 165#define MIGRATE_PFN_VALID       (1UL << 0)
 166#define MIGRATE_PFN_MIGRATE     (1UL << 1)
 167#define MIGRATE_PFN_LOCKED      (1UL << 2)
 168#define MIGRATE_PFN_WRITE       (1UL << 3)
 169#define MIGRATE_PFN_SHIFT       6
 170
 171static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
 172{
 173        if (!(mpfn & MIGRATE_PFN_VALID))
 174                return NULL;
 175        return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
 176}
 177
 178static inline unsigned long migrate_pfn(unsigned long pfn)
 179{
 180        return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
 181}
 182
 183struct migrate_vma {
 184        struct vm_area_struct   *vma;
 185        /*
 186         * Both src and dst array must be big enough for
 187         * (end - start) >> PAGE_SHIFT entries.
 188         *
 189         * The src array must not be modified by the caller after
 190         * migrate_vma_setup(), and must not change the dst array after
 191         * migrate_vma_pages() returns.
 192         */
 193        unsigned long           *dst;
 194        unsigned long           *src;
 195        unsigned long           cpages;
 196        unsigned long           npages;
 197        unsigned long           start;
 198        unsigned long           end;
 199};
 200
 201int migrate_vma_setup(struct migrate_vma *args);
 202void migrate_vma_pages(struct migrate_vma *migrate);
 203void migrate_vma_finalize(struct migrate_vma *migrate);
 204
 205#endif /* CONFIG_MIGRATION */
 206
 207#endif /* _LINUX_MIGRATE_H */
 208