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 extern void migrate_on_reclaim_init(void); 52 #ifdef CONFIG_HOTPLUG_CPU 53 extern void set_migration_target_nodes(void); 54 #else 55 static inline void set_migration_target_nodes(void) {} 56 #endif 57 #else 58 59 static inline void set_migration_target_nodes(void) {} 60 61 static inline void putback_movable_pages(struct list_head *l) {} 62 static 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; } 66 static inline struct page *alloc_migration_target(struct page *page, 67 unsigned long private) 68 { return NULL; } 69 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) 70 { return -EBUSY; } 71 72 static inline void migrate_page_states(struct page *newpage, struct page *page) 73 { 74 } 75 76 static inline void migrate_page_copy(struct page *newpage, 77 struct page *page) {} 78 79 static 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 89 extern int PageMovable(struct page *page); 90 extern void __SetPageMovable(struct page *page, struct address_space *mapping); 91 extern void __ClearPageMovable(struct page *page); 92 #else 93 static inline int PageMovable(struct page *page) { return 0; } 94 static inline void __SetPageMovable(struct page *page, 95 struct address_space *mapping) 96 { 97 } 98 static inline void __ClearPageMovable(struct page *page) 99 { 100 } 101 #endif 102 103 #ifdef CONFIG_NUMA_BALANCING 104 extern int migrate_misplaced_page(struct page *page, 105 struct vm_area_struct *vma, int node); 106 #else 107 static 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 6 125 126 static 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 } 132 133 static inline unsigned long migrate_pfn(unsigned long pfn) 134 { 135 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID; 136 } 137 138 enum migrate_vma_direction { 139 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, 140 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, 141 }; 142 143 struct 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 }; 171 172 int migrate_vma_setup(struct migrate_vma *args); 173 void migrate_vma_pages(struct migrate_vma *migrate); 174 void migrate_vma_finalize(struct migrate_vma *migrate); 175 int next_demotion_node(int node); 176 177 #else /* CONFIG_MIGRATION disabled: */ 178 179 static 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