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 44 extern bool numa_demotion_enabled; 45 #else 46 47 static inline void putback_movable_pages(struct list_head *l) {} 48 static inline int migrate_pages(struct list_head *l, new_page_t new, 49 free_page_t free, unsigned long private, enum migrate_mode mode, 50 int reason, unsigned int *ret_succeeded) 51 { return -ENOSYS; } 52 static inline struct page *alloc_migration_target(struct page *page, 53 unsigned long private) 54 { return NULL; } 55 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) 56 { return -EBUSY; } 57 58 static inline void migrate_page_states(struct page *newpage, struct page *page) 59 { 60 } 61 62 static inline void migrate_page_copy(struct page *newpage, 63 struct page *page) {} 64 65 static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 66 struct page *newpage, struct page *page) 67 { 68 return -ENOSYS; 69 } 70 71 #define numa_demotion_enabled false 72 #endif /* CONFIG_MIGRATION */ 73 74 #ifdef CONFIG_COMPACTION 75 extern int PageMovable(struct page *page); 76 extern void __SetPageMovable(struct page *page, struct address_space *mapping); 77 extern void __ClearPageMovable(struct page *page); 78 #else 79 static inline int PageMovable(struct page *page) { return 0; } 80 static inline void __SetPageMovable(struct page *page, 81 struct address_space *mapping) 82 { 83 } 84 static inline void __ClearPageMovable(struct page *page) 85 { 86 } 87 #endif 88 89 #ifdef CONFIG_NUMA_BALANCING 90 extern int migrate_misplaced_page(struct page *page, 91 struct vm_area_struct *vma, int node); 92 #else 93 static inline int migrate_misplaced_page(struct page *page, 94 struct vm_area_struct *vma, int node) 95 { 96 return -EAGAIN; /* can't migrate now */ 97 } 98 #endif /* CONFIG_NUMA_BALANCING */ 99 100 #ifdef CONFIG_MIGRATION 101 102 /* 103 * Watch out for PAE architecture, which has an unsigned long, and might not 104 * have enough bits to store all physical address and flags. So far we have 105 * enough room for all our flags. 106 */ 107 #define MIGRATE_PFN_VALID (1UL << 0) 108 #define MIGRATE_PFN_MIGRATE (1UL << 1) 109 #define MIGRATE_PFN_LOCKED (1UL << 2) 110 #define MIGRATE_PFN_WRITE (1UL << 3) 111 #define MIGRATE_PFN_SHIFT 6 112 113 static inline struct page *migrate_pfn_to_page(unsigned long mpfn) 114 { 115 if (!(mpfn & MIGRATE_PFN_VALID)) 116 return NULL; 117 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT); 118 } 119 120 static inline unsigned long migrate_pfn(unsigned long pfn) 121 { 122 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID; 123 } 124 125 enum migrate_vma_direction { 126 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, 127 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, 128 }; 129 130 struct migrate_vma { 131 struct vm_area_struct *vma; 132 /* 133 * Both src and dst array must be big enough for 134 * (end - start) >> PAGE_SHIFT entries. 135 * 136 * The src array must not be modified by the caller after 137 * migrate_vma_setup(), and must not change the dst array after 138 * migrate_vma_pages() returns. 139 */ 140 unsigned long *dst; 141 unsigned long *src; 142 unsigned long cpages; 143 unsigned long npages; 144 unsigned long start; 145 unsigned long end; 146 147 /* 148 * Set to the owner value also stored in page->pgmap->owner for 149 * migrating out of device private memory. The flags also need to 150 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE. 151 * The caller should always set this field when using mmu notifier 152 * callbacks to avoid device MMU invalidations for device private 153 * pages that are not being migrated. 154 */ 155 void *pgmap_owner; 156 unsigned long flags; 157 }; 158 159 int migrate_vma_setup(struct migrate_vma *args); 160 void migrate_vma_pages(struct migrate_vma *migrate); 161 void migrate_vma_finalize(struct migrate_vma *migrate); 162 int next_demotion_node(int node); 163 164 #else /* CONFIG_MIGRATION disabled: */ 165 166 static inline int next_demotion_node(int node) 167 { 168 return NUMA_NO_NODE; 169 } 170 171 #endif /* CONFIG_MIGRATION */ 172 173 #endif /* _LINUX_MIGRATE_H */ 174