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 extern bool numa_demotion_enabled; 51 #else 52 53 static inline void putback_movable_pages(struct list_head *l) {} 54 static 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; } 58 static inline struct page *alloc_migration_target(struct page *page, 59 unsigned long private) 60 { return NULL; } 61 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) 62 { return -EBUSY; } 63 64 static inline void migrate_page_states(struct page *newpage, struct page *page) 65 { 66 } 67 68 static inline void migrate_page_copy(struct page *newpage, 69 struct page *page) {} 70 71 static 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 81 extern int PageMovable(struct page *page); 82 extern void __SetPageMovable(struct page *page, struct address_space *mapping); 83 extern void __ClearPageMovable(struct page *page); 84 #else 85 static inline int PageMovable(struct page *page) { return 0; } 86 static inline void __SetPageMovable(struct page *page, 87 struct address_space *mapping) 88 { 89 } 90 static inline void __ClearPageMovable(struct page *page) 91 { 92 } 93 #endif 94 95 #ifdef CONFIG_NUMA_BALANCING 96 extern int migrate_misplaced_page(struct page *page, 97 struct vm_area_struct *vma, int node); 98 #else 99 static 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 6 117 118 static 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 } 124 125 static inline unsigned long migrate_pfn(unsigned long pfn) 126 { 127 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID; 128 } 129 130 enum migrate_vma_direction { 131 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, 132 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, 133 }; 134 135 struct 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 }; 163 164 int migrate_vma_setup(struct migrate_vma *args); 165 void migrate_vma_pages(struct migrate_vma *migrate); 166 void migrate_vma_finalize(struct migrate_vma *migrate); 167 int next_demotion_node(int node); 168 169 #else /* CONFIG_MIGRATION disabled: */ 170 171 static 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