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 /* 23 * Keep sync with: 24 * - macro MIGRATE_REASON in include/trace/events/migrate.h 25 * - migrate_reason_names[MR_TYPES] in mm/debug.c 26 */ 27 enum migrate_reason { 28 MR_COMPACTION, 29 MR_MEMORY_FAILURE, 30 MR_MEMORY_HOTPLUG, 31 MR_SYSCALL, /* also applies to cpusets */ 32 MR_MEMPOLICY_MBIND, 33 MR_NUMA_MISPLACED, 34 MR_CONTIG_RANGE, 35 MR_LONGTERM_PIN, 36 MR_DEMOTION, 37 MR_TYPES 38 }; 39 40 extern const char *migrate_reason_names[MR_TYPES]; 41 42 #ifdef CONFIG_MIGRATION 43 44 extern void putback_movable_pages(struct list_head *l); 45 extern int migrate_page(struct address_space *mapping, 46 struct page *newpage, struct page *page, 47 enum migrate_mode mode); 48 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, 49 unsigned long private, enum migrate_mode mode, int reason, 50 unsigned int *ret_succeeded); 51 extern struct page *alloc_migration_target(struct page *page, unsigned long private); 52 extern int isolate_movable_page(struct page *page, isolate_mode_t mode); 53 54 extern void migrate_page_states(struct page *newpage, struct page *page); 55 extern void migrate_page_copy(struct page *newpage, struct page *page); 56 extern int migrate_huge_page_move_mapping(struct address_space *mapping, 57 struct page *newpage, struct page *page); 58 extern int migrate_page_move_mapping(struct address_space *mapping, 59 struct page *newpage, struct page *page, int extra_count); 60 #else 61 62 static inline void putback_movable_pages(struct list_head *l) {} 63 static inline int migrate_pages(struct list_head *l, new_page_t new, 64 free_page_t free, unsigned long private, enum migrate_mode mode, 65 int reason, unsigned int *ret_succeeded) 66 { return -ENOSYS; } 67 static inline struct page *alloc_migration_target(struct page *page, 68 unsigned long private) 69 { return NULL; } 70 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) 71 { return -EBUSY; } 72 73 static inline void migrate_page_states(struct page *newpage, struct page *page) 74 { 75 } 76 77 static inline void migrate_page_copy(struct page *newpage, 78 struct page *page) {} 79 80 static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 81 struct page *newpage, struct page *page) 82 { 83 return -ENOSYS; 84 } 85 #endif /* CONFIG_MIGRATION */ 86 87 #ifdef CONFIG_COMPACTION 88 extern int PageMovable(struct page *page); 89 extern void __SetPageMovable(struct page *page, struct address_space *mapping); 90 extern void __ClearPageMovable(struct page *page); 91 #else 92 static inline int PageMovable(struct page *page) { return 0; } 93 static inline void __SetPageMovable(struct page *page, 94 struct address_space *mapping) 95 { 96 } 97 static inline void __ClearPageMovable(struct page *page) 98 { 99 } 100 #endif 101 102 #ifdef CONFIG_NUMA_BALANCING 103 extern int migrate_misplaced_page(struct page *page, 104 struct vm_area_struct *vma, int node); 105 #else 106 static inline int migrate_misplaced_page(struct page *page, 107 struct vm_area_struct *vma, int node) 108 { 109 return -EAGAIN; /* can't migrate now */ 110 } 111 #endif /* CONFIG_NUMA_BALANCING */ 112 113 #ifdef CONFIG_MIGRATION 114 115 /* 116 * Watch out for PAE architecture, which has an unsigned long, and might not 117 * have enough bits to store all physical address and flags. So far we have 118 * enough room for all our flags. 119 */ 120 #define MIGRATE_PFN_VALID (1UL << 0) 121 #define MIGRATE_PFN_MIGRATE (1UL << 1) 122 #define MIGRATE_PFN_LOCKED (1UL << 2) 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