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 enum migrate_reason { 23 MR_COMPACTION, 24 MR_MEMORY_FAILURE, 25 MR_MEMORY_HOTPLUG, 26 MR_SYSCALL, /* also applies to cpusets */ 27 MR_MEMPOLICY_MBIND, 28 MR_NUMA_MISPLACED, 29 MR_CONTIG_RANGE, 30 MR_LONGTERM_PIN, 31 MR_DEMOTION, 32 MR_TYPES 33 }; 34 35 /* In mm/debug.c; also keep sync with include/trace/events/migrate.h */ 36 extern const char *migrate_reason_names[MR_TYPES]; 37 38 #ifdef CONFIG_MIGRATION 39 40 extern void putback_movable_pages(struct list_head *l); 41 extern int migrate_page(struct address_space *mapping, 42 struct page *newpage, struct page *page, 43 enum migrate_mode mode); 44 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, 45 unsigned long private, enum migrate_mode mode, int reason, 46 unsigned int *ret_succeeded); 47 extern struct page *alloc_migration_target(struct page *page, unsigned long private); 48 extern int isolate_movable_page(struct page *page, isolate_mode_t mode); 49 50 extern void migrate_page_states(struct page *newpage, struct page *page); 51 extern void migrate_page_copy(struct page *newpage, struct page *page); 52 extern int migrate_huge_page_move_mapping(struct address_space *mapping, 53 struct page *newpage, struct page *page); 54 extern int migrate_page_move_mapping(struct address_space *mapping, 55 struct page *newpage, struct page *page, int extra_count); 56 #else 57 58 static inline void putback_movable_pages(struct list_head *l) {} 59 static inline int migrate_pages(struct list_head *l, new_page_t new, 60 free_page_t free, unsigned long private, enum migrate_mode mode, 61 int reason, unsigned int *ret_succeeded) 62 { return -ENOSYS; } 63 static inline struct page *alloc_migration_target(struct page *page, 64 unsigned long private) 65 { return NULL; } 66 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) 67 { return -EBUSY; } 68 69 static inline void migrate_page_states(struct page *newpage, struct page *page) 70 { 71 } 72 73 static inline void migrate_page_copy(struct page *newpage, 74 struct page *page) {} 75 76 static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 77 struct page *newpage, struct page *page) 78 { 79 return -ENOSYS; 80 } 81 #endif /* CONFIG_MIGRATION */ 82 83 #ifdef CONFIG_COMPACTION 84 extern int PageMovable(struct page *page); 85 extern void __SetPageMovable(struct page *page, struct address_space *mapping); 86 extern void __ClearPageMovable(struct page *page); 87 #else 88 static inline int PageMovable(struct page *page) { return 0; } 89 static inline void __SetPageMovable(struct page *page, 90 struct address_space *mapping) 91 { 92 } 93 static inline void __ClearPageMovable(struct page *page) 94 { 95 } 96 #endif 97 98 #ifdef CONFIG_NUMA_BALANCING 99 extern int migrate_misplaced_page(struct page *page, 100 struct vm_area_struct *vma, int node); 101 #else 102 static inline int migrate_misplaced_page(struct page *page, 103 struct vm_area_struct *vma, int node) 104 { 105 return -EAGAIN; /* can't migrate now */ 106 } 107 #endif /* CONFIG_NUMA_BALANCING */ 108 109 #ifdef CONFIG_MIGRATION 110 111 /* 112 * Watch out for PAE architecture, which has an unsigned long, and might not 113 * have enough bits to store all physical address and flags. So far we have 114 * enough room for all our flags. 115 */ 116 #define MIGRATE_PFN_VALID (1UL << 0) 117 #define MIGRATE_PFN_MIGRATE (1UL << 1) 118 #define MIGRATE_PFN_LOCKED (1UL << 2) 119 #define MIGRATE_PFN_WRITE (1UL << 3) 120 #define MIGRATE_PFN_SHIFT 6 121 122 static inline struct page *migrate_pfn_to_page(unsigned long mpfn) 123 { 124 if (!(mpfn & MIGRATE_PFN_VALID)) 125 return NULL; 126 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT); 127 } 128 129 static inline unsigned long migrate_pfn(unsigned long pfn) 130 { 131 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID; 132 } 133 134 enum migrate_vma_direction { 135 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, 136 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, 137 }; 138 139 struct migrate_vma { 140 struct vm_area_struct *vma; 141 /* 142 * Both src and dst array must be big enough for 143 * (end - start) >> PAGE_SHIFT entries. 144 * 145 * The src array must not be modified by the caller after 146 * migrate_vma_setup(), and must not change the dst array after 147 * migrate_vma_pages() returns. 148 */ 149 unsigned long *dst; 150 unsigned long *src; 151 unsigned long cpages; 152 unsigned long npages; 153 unsigned long start; 154 unsigned long end; 155 156 /* 157 * Set to the owner value also stored in page->pgmap->owner for 158 * migrating out of device private memory. The flags also need to 159 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE. 160 * The caller should always set this field when using mmu notifier 161 * callbacks to avoid device MMU invalidations for device private 162 * pages that are not being migrated. 163 */ 164 void *pgmap_owner; 165 unsigned long flags; 166 }; 167 168 int migrate_vma_setup(struct migrate_vma *args); 169 void migrate_vma_pages(struct migrate_vma *migrate); 170 void migrate_vma_finalize(struct migrate_vma *migrate); 171 int next_demotion_node(int node); 172 173 #else /* CONFIG_MIGRATION disabled: */ 174 175 static inline int next_demotion_node(int node) 176 { 177 return NUMA_NO_NODE; 178 } 179 180 #endif /* CONFIG_MIGRATION */ 181 182 #endif /* _LINUX_MIGRATE_H */ 183