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_TYPES 31 }; 32 33 /* In mm/debug.c; also keep sync with include/trace/events/migrate.h */ 34 extern const char *migrate_reason_names[MR_TYPES]; 35 36 #ifdef CONFIG_MIGRATION 37 38 extern void putback_movable_pages(struct list_head *l); 39 extern int migrate_page(struct address_space *mapping, 40 struct page *newpage, struct page *page, 41 enum migrate_mode mode); 42 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, 43 unsigned long private, enum migrate_mode mode, int reason); 44 extern struct page *alloc_migration_target(struct page *page, unsigned long private); 45 extern int isolate_movable_page(struct page *page, isolate_mode_t mode); 46 extern void putback_movable_page(struct page *page); 47 48 extern int migrate_prep(void); 49 extern int migrate_prep_local(void); 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) 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 int migrate_prep(void) { return -ENOSYS; } 70 static inline int migrate_prep_local(void) { return -ENOSYS; } 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 #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 bool pmd_trans_migrating(pmd_t pmd); 104 extern int migrate_misplaced_page(struct page *page, 105 struct vm_area_struct *vma, int node); 106 #else 107 static inline bool pmd_trans_migrating(pmd_t pmd) 108 { 109 return false; 110 } 111 static inline int migrate_misplaced_page(struct page *page, 112 struct vm_area_struct *vma, int node) 113 { 114 return -EAGAIN; /* can't migrate now */ 115 } 116 #endif /* CONFIG_NUMA_BALANCING */ 117 118 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 119 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm, 120 struct vm_area_struct *vma, 121 pmd_t *pmd, pmd_t entry, 122 unsigned long address, 123 struct page *page, int node); 124 #else 125 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm, 126 struct vm_area_struct *vma, 127 pmd_t *pmd, pmd_t entry, 128 unsigned long address, 129 struct page *page, int node) 130 { 131 return -EAGAIN; 132 } 133 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/ 134 135 136 #ifdef CONFIG_MIGRATION 137 138 /* 139 * Watch out for PAE architecture, which has an unsigned long, and might not 140 * have enough bits to store all physical address and flags. So far we have 141 * enough room for all our flags. 142 */ 143 #define MIGRATE_PFN_VALID (1UL << 0) 144 #define MIGRATE_PFN_MIGRATE (1UL << 1) 145 #define MIGRATE_PFN_LOCKED (1UL << 2) 146 #define MIGRATE_PFN_WRITE (1UL << 3) 147 #define MIGRATE_PFN_SHIFT 6 148 149 static inline struct page *migrate_pfn_to_page(unsigned long mpfn) 150 { 151 if (!(mpfn & MIGRATE_PFN_VALID)) 152 return NULL; 153 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT); 154 } 155 156 static inline unsigned long migrate_pfn(unsigned long pfn) 157 { 158 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID; 159 } 160 161 enum migrate_vma_direction { 162 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, 163 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, 164 }; 165 166 struct migrate_vma { 167 struct vm_area_struct *vma; 168 /* 169 * Both src and dst array must be big enough for 170 * (end - start) >> PAGE_SHIFT entries. 171 * 172 * The src array must not be modified by the caller after 173 * migrate_vma_setup(), and must not change the dst array after 174 * migrate_vma_pages() returns. 175 */ 176 unsigned long *dst; 177 unsigned long *src; 178 unsigned long cpages; 179 unsigned long npages; 180 unsigned long start; 181 unsigned long end; 182 183 /* 184 * Set to the owner value also stored in page->pgmap->owner for 185 * migrating out of device private memory. The flags also need to 186 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE. 187 * The caller should always set this field when using mmu notifier 188 * callbacks to avoid device MMU invalidations for device private 189 * pages that are not being migrated. 190 */ 191 void *pgmap_owner; 192 unsigned long flags; 193 }; 194 195 int migrate_vma_setup(struct migrate_vma *args); 196 void migrate_vma_pages(struct migrate_vma *migrate); 197 void migrate_vma_finalize(struct migrate_vma *migrate); 198 199 #endif /* CONFIG_MIGRATION */ 200 201 #endif /* _LINUX_MIGRATE_H */ 202