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 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 putback_movable_pages(struct list_head * l)56 static inline void putback_movable_pages(struct list_head *l) {} migrate_pages(struct list_head * l,new_page_t new,free_page_t free,unsigned long private,enum migrate_mode mode,int reason)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; } alloc_migration_target(struct page * page,unsigned long private)61 static inline struct page *alloc_migration_target(struct page *page, 62 unsigned long private) 63 { return NULL; } isolate_movable_page(struct page * page,isolate_mode_t mode)64 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) 65 { return -EBUSY; } 66 migrate_page_states(struct page * newpage,struct page * page)67 static inline void migrate_page_states(struct page *newpage, struct page *page) 68 { 69 } 70 migrate_page_copy(struct page * newpage,struct page * page)71 static inline void migrate_page_copy(struct page *newpage, 72 struct page *page) {} 73 migrate_huge_page_move_mapping(struct address_space * mapping,struct page * newpage,struct page * page)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 80 #endif /* CONFIG_MIGRATION */ 81 82 #ifdef CONFIG_COMPACTION 83 extern int PageMovable(struct page *page); 84 extern void __SetPageMovable(struct page *page, struct address_space *mapping); 85 extern void __ClearPageMovable(struct page *page); 86 #else PageMovable(struct page * page)87 static inline int PageMovable(struct page *page) { return 0; }; __SetPageMovable(struct page * page,struct address_space * mapping)88 static inline void __SetPageMovable(struct page *page, 89 struct address_space *mapping) 90 { 91 } __ClearPageMovable(struct page * page)92 static inline void __ClearPageMovable(struct page *page) 93 { 94 } 95 #endif 96 97 #ifdef CONFIG_NUMA_BALANCING 98 extern bool pmd_trans_migrating(pmd_t pmd); 99 extern int migrate_misplaced_page(struct page *page, 100 struct vm_fault *vmf, int node); 101 #else pmd_trans_migrating(pmd_t pmd)102 static inline bool pmd_trans_migrating(pmd_t pmd) 103 { 104 return false; 105 } migrate_misplaced_page(struct page * page,struct vm_fault * vmf,int node)106 static inline int migrate_misplaced_page(struct page *page, 107 struct vm_fault *vmf, int node) 108 { 109 return -EAGAIN; /* can't migrate now */ 110 } 111 #endif /* CONFIG_NUMA_BALANCING */ 112 113 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 114 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm, 115 struct vm_area_struct *vma, 116 pmd_t *pmd, pmd_t entry, 117 unsigned long address, 118 struct page *page, int node); 119 #else migrate_misplaced_transhuge_page(struct mm_struct * mm,struct vm_area_struct * vma,pmd_t * pmd,pmd_t entry,unsigned long address,struct page * page,int node)120 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm, 121 struct vm_area_struct *vma, 122 pmd_t *pmd, pmd_t entry, 123 unsigned long address, 124 struct page *page, int node) 125 { 126 return -EAGAIN; 127 } 128 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/ 129 130 131 #ifdef CONFIG_MIGRATION 132 133 /* 134 * Watch out for PAE architecture, which has an unsigned long, and might not 135 * have enough bits to store all physical address and flags. So far we have 136 * enough room for all our flags. 137 */ 138 #define MIGRATE_PFN_VALID (1UL << 0) 139 #define MIGRATE_PFN_MIGRATE (1UL << 1) 140 #define MIGRATE_PFN_LOCKED (1UL << 2) 141 #define MIGRATE_PFN_WRITE (1UL << 3) 142 #define MIGRATE_PFN_SHIFT 6 143 migrate_pfn_to_page(unsigned long mpfn)144 static inline struct page *migrate_pfn_to_page(unsigned long mpfn) 145 { 146 if (!(mpfn & MIGRATE_PFN_VALID)) 147 return NULL; 148 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT); 149 } 150 migrate_pfn(unsigned long pfn)151 static inline unsigned long migrate_pfn(unsigned long pfn) 152 { 153 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID; 154 } 155 156 enum migrate_vma_direction { 157 MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, 158 MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, 159 }; 160 161 struct migrate_vma { 162 struct vm_area_struct *vma; 163 /* 164 * Both src and dst array must be big enough for 165 * (end - start) >> PAGE_SHIFT entries. 166 * 167 * The src array must not be modified by the caller after 168 * migrate_vma_setup(), and must not change the dst array after 169 * migrate_vma_pages() returns. 170 */ 171 unsigned long *dst; 172 unsigned long *src; 173 unsigned long cpages; 174 unsigned long npages; 175 unsigned long start; 176 unsigned long end; 177 178 /* 179 * Set to the owner value also stored in page->pgmap->owner for 180 * migrating out of device private memory. The flags also need to 181 * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE. 182 * The caller should always set this field when using mmu notifier 183 * callbacks to avoid device MMU invalidations for device private 184 * pages that are not being migrated. 185 */ 186 void *pgmap_owner; 187 unsigned long flags; 188 }; 189 190 int migrate_vma_setup(struct migrate_vma *args); 191 void migrate_vma_pages(struct migrate_vma *migrate); 192 void migrate_vma_finalize(struct migrate_vma *migrate); 193 194 #endif /* CONFIG_MIGRATION */ 195 196 #endif /* _LINUX_MIGRATE_H */ 197