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