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 10 typedef struct page *new_page_t(struct page *page, unsigned long private); 11 typedef void free_page_t(struct page *page, unsigned long private); 12 13 struct 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: */ 23 extern const char *migrate_reason_names[MR_TYPES]; 24 25 #ifdef CONFIG_MIGRATION 26 27 extern void putback_movable_pages(struct list_head *l); 28 extern int migrate_page(struct address_space *mapping, 29 struct page *newpage, struct page *page, 30 enum migrate_mode mode); 31 extern 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); 34 extern struct page *alloc_migration_target(struct page *page, unsigned long private); 35 extern int isolate_movable_page(struct page *page, isolate_mode_t mode); 36 37 extern void migrate_page_states(struct page *newpage, struct page *page); 38 extern void migrate_page_copy(struct page *newpage, struct page *page); 39 extern int migrate_huge_page_move_mapping(struct address_space *mapping, 40 struct page *newpage, struct page *page); 41 extern int migrate_page_move_mapping(struct address_space *mapping, 42 struct page *newpage, struct page *page, int extra_count); 43 void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep, 44 spinlock_t *ptl); 45 void folio_migrate_flags(struct folio *newfolio, struct folio *folio); 46 void folio_migrate_copy(struct folio *newfolio, struct folio *folio); 47 int folio_migrate_mapping(struct address_space *mapping, 48 struct folio *newfolio, struct folio *folio, int extra_count); 49 50 #else 51 52 static inline void putback_movable_pages(struct list_head *l) {} 53 static inline int migrate_pages(struct list_head *l, new_page_t new, 54 free_page_t free, unsigned long private, enum migrate_mode mode, 55 int reason, unsigned int *ret_succeeded) 56 { return -ENOSYS; } 57 static inline struct page *alloc_migration_target(struct page *page, 58 unsigned long private) 59 { return NULL; } 60 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) 61 { return -EBUSY; } 62 63 static inline void migrate_page_states(struct page *newpage, struct page *page) 64 { 65 } 66 67 static inline void migrate_page_copy(struct page *newpage, 68 struct page *page) {} 69 70 static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 71 struct page *newpage, struct page *page) 72 { 73 return -ENOSYS; 74 } 75 76 #endif /* CONFIG_MIGRATION */ 77 78 #if defined(CONFIG_MIGRATION) && defined(CONFIG_NUMA) 79 extern void set_migration_target_nodes(void); 80 extern void migrate_on_reclaim_init(void); 81 extern bool numa_demotion_enabled; 82 extern int next_demotion_node(int node); 83 #else 84 static inline void set_migration_target_nodes(void) {} 85 static inline void migrate_on_reclaim_init(void) {} 86 static inline int next_demotion_node(int node) 87 { 88 return NUMA_NO_NODE; 89 } 90 #define numa_demotion_enabled false 91 #endif 92 93 #ifdef CONFIG_COMPACTION 94 extern int PageMovable(struct page *page); 95 extern void __SetPageMovable(struct page *page, struct address_space *mapping); 96 extern void __ClearPageMovable(struct page *page); 97 #else 98 static inline int PageMovable(struct page *page) { return 0; } 99 static inline void __SetPageMovable(struct page *page, 100 struct address_space *mapping) 101 { 102 } 103 static inline void __ClearPageMovable(struct page *page) 104 { 105 } 106 #endif 107 108 static inline bool folio_test_movable(struct folio *folio) 109 { 110 return PageMovable(&folio->page); 111 } 112 113 #ifdef CONFIG_NUMA_BALANCING 114 extern int migrate_misplaced_page(struct page *page, 115 struct vm_area_struct *vma, int node); 116 #else 117 static inline int migrate_misplaced_page(struct page *page, 118 struct vm_area_struct *vma, int node) 119 { 120 return -EAGAIN; /* can't migrate now */ 121 } 122 #endif /* CONFIG_NUMA_BALANCING */ 123 124 #ifdef CONFIG_MIGRATION 125 126 /* 127 * Watch out for PAE architecture, which has an unsigned long, and might not 128 * have enough bits to store all physical address and flags. So far we have 129 * enough room for all our flags. 130 */ 131 #define MIGRATE_PFN_VALID (1UL << 0) 132 #define MIGRATE_PFN_MIGRATE (1UL << 1) 133 #define MIGRATE_PFN_WRITE (1UL << 3) 134 #define MIGRATE_PFN_SHIFT 6 135 136 static inline struct page *migrate_pfn_to_page(unsigned long mpfn) 137 { 138 if (!(mpfn & MIGRATE_PFN_VALID)) 139 return NULL; 140 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT); 141 } 142 143 static inline unsigned long migrate_pfn(unsigned long pfn) 144 { 145 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID; 146 } 147 148 enum migrate_vma_direction { 149 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, 150 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, 151 }; 152 153 struct migrate_vma { 154 struct vm_area_struct *vma; 155 /* 156 * Both src and dst array must be big enough for 157 * (end - start) >> PAGE_SHIFT entries. 158 * 159 * The src array must not be modified by the caller after 160 * migrate_vma_setup(), and must not change the dst array after 161 * migrate_vma_pages() returns. 162 */ 163 unsigned long *dst; 164 unsigned long *src; 165 unsigned long cpages; 166 unsigned long npages; 167 unsigned long start; 168 unsigned long end; 169 170 /* 171 * Set to the owner value also stored in page->pgmap->owner for 172 * migrating out of device private memory. The flags also need to 173 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE. 174 * The caller should always set this field when using mmu notifier 175 * callbacks to avoid device MMU invalidations for device private 176 * pages that are not being migrated. 177 */ 178 void *pgmap_owner; 179 unsigned long flags; 180 }; 181 182 int migrate_vma_setup(struct migrate_vma *args); 183 void migrate_vma_pages(struct migrate_vma *migrate); 184 void migrate_vma_finalize(struct migrate_vma *migrate); 185 #endif /* CONFIG_MIGRATION */ 186 187 #endif /* _LINUX_MIGRATE_H */ 188