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