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 /* 14 * Return values from addresss_space_operations.migratepage(): 15 * - negative errno on page migration failure; 16 * - zero on page migration success; 17 */ 18 #define MIGRATEPAGE_SUCCESS 0 19 20 enum migrate_reason { 21 MR_COMPACTION, 22 MR_MEMORY_FAILURE, 23 MR_MEMORY_HOTPLUG, 24 MR_SYSCALL, /* also applies to cpusets */ 25 MR_MEMPOLICY_MBIND, 26 MR_NUMA_MISPLACED, 27 MR_CONTIG_RANGE, 28 MR_TYPES 29 }; 30 31 /* In mm/debug.c; also keep sync with include/trace/events/migrate.h */ 32 extern const char *migrate_reason_names[MR_TYPES]; 33 34 static inline struct page *new_page_nodemask(struct page *page, 35 int preferred_nid, nodemask_t *nodemask) 36 { 37 gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL; 38 unsigned int order = 0; 39 struct page *new_page = NULL; 40 41 if (PageHuge(page)) 42 return alloc_huge_page_nodemask(page_hstate(compound_head(page)), 43 preferred_nid, nodemask); 44 45 if (PageTransHuge(page)) { 46 gfp_mask |= GFP_TRANSHUGE; 47 order = HPAGE_PMD_ORDER; 48 } 49 50 if (PageHighMem(page) || (zone_idx(page_zone(page)) == ZONE_MOVABLE)) 51 gfp_mask |= __GFP_HIGHMEM; 52 53 new_page = __alloc_pages_nodemask(gfp_mask, order, 54 preferred_nid, nodemask); 55 56 if (new_page && PageTransHuge(new_page)) 57 prep_transhuge_page(new_page); 58 59 return new_page; 60 } 61 62 #ifdef CONFIG_MIGRATION 63 64 extern void putback_movable_pages(struct list_head *l); 65 extern int migrate_page(struct address_space *mapping, 66 struct page *newpage, struct page *page, 67 enum migrate_mode mode); 68 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, 69 unsigned long private, enum migrate_mode mode, int reason); 70 extern int isolate_movable_page(struct page *page, isolate_mode_t mode); 71 extern void putback_movable_page(struct page *page); 72 73 extern int migrate_prep(void); 74 extern int migrate_prep_local(void); 75 extern void migrate_page_states(struct page *newpage, struct page *page); 76 extern void migrate_page_copy(struct page *newpage, struct page *page); 77 extern int migrate_huge_page_move_mapping(struct address_space *mapping, 78 struct page *newpage, struct page *page); 79 extern int migrate_page_move_mapping(struct address_space *mapping, 80 struct page *newpage, struct page *page, int extra_count); 81 #else 82 83 static inline void putback_movable_pages(struct list_head *l) {} 84 static inline int migrate_pages(struct list_head *l, new_page_t new, 85 free_page_t free, unsigned long private, enum migrate_mode mode, 86 int reason) 87 { return -ENOSYS; } 88 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) 89 { return -EBUSY; } 90 91 static inline int migrate_prep(void) { return -ENOSYS; } 92 static inline int migrate_prep_local(void) { return -ENOSYS; } 93 94 static inline void migrate_page_states(struct page *newpage, struct page *page) 95 { 96 } 97 98 static inline void migrate_page_copy(struct page *newpage, 99 struct page *page) {} 100 101 static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 102 struct page *newpage, struct page *page) 103 { 104 return -ENOSYS; 105 } 106 107 #endif /* CONFIG_MIGRATION */ 108 109 #ifdef CONFIG_COMPACTION 110 extern int PageMovable(struct page *page); 111 extern void __SetPageMovable(struct page *page, struct address_space *mapping); 112 extern void __ClearPageMovable(struct page *page); 113 #else 114 static inline int PageMovable(struct page *page) { return 0; }; 115 static inline void __SetPageMovable(struct page *page, 116 struct address_space *mapping) 117 { 118 } 119 static inline void __ClearPageMovable(struct page *page) 120 { 121 } 122 #endif 123 124 #ifdef CONFIG_NUMA_BALANCING 125 extern bool pmd_trans_migrating(pmd_t pmd); 126 extern int migrate_misplaced_page(struct page *page, 127 struct vm_area_struct *vma, int node); 128 #else 129 static inline bool pmd_trans_migrating(pmd_t pmd) 130 { 131 return false; 132 } 133 static inline int migrate_misplaced_page(struct page *page, 134 struct vm_area_struct *vma, int node) 135 { 136 return -EAGAIN; /* can't migrate now */ 137 } 138 #endif /* CONFIG_NUMA_BALANCING */ 139 140 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 141 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm, 142 struct vm_area_struct *vma, 143 pmd_t *pmd, pmd_t entry, 144 unsigned long address, 145 struct page *page, int node); 146 #else 147 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm, 148 struct vm_area_struct *vma, 149 pmd_t *pmd, pmd_t entry, 150 unsigned long address, 151 struct page *page, int node) 152 { 153 return -EAGAIN; 154 } 155 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/ 156 157 158 #ifdef CONFIG_MIGRATION 159 160 /* 161 * Watch out for PAE architecture, which has an unsigned long, and might not 162 * have enough bits to store all physical address and flags. So far we have 163 * enough room for all our flags. 164 */ 165 #define MIGRATE_PFN_VALID (1UL << 0) 166 #define MIGRATE_PFN_MIGRATE (1UL << 1) 167 #define MIGRATE_PFN_LOCKED (1UL << 2) 168 #define MIGRATE_PFN_WRITE (1UL << 3) 169 #define MIGRATE_PFN_SHIFT 6 170 171 static inline struct page *migrate_pfn_to_page(unsigned long mpfn) 172 { 173 if (!(mpfn & MIGRATE_PFN_VALID)) 174 return NULL; 175 return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT); 176 } 177 178 static inline unsigned long migrate_pfn(unsigned long pfn) 179 { 180 return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID; 181 } 182 183 struct migrate_vma { 184 struct vm_area_struct *vma; 185 /* 186 * Both src and dst array must be big enough for 187 * (end - start) >> PAGE_SHIFT entries. 188 * 189 * The src array must not be modified by the caller after 190 * migrate_vma_setup(), and must not change the dst array after 191 * migrate_vma_pages() returns. 192 */ 193 unsigned long *dst; 194 unsigned long *src; 195 unsigned long cpages; 196 unsigned long npages; 197 unsigned long start; 198 unsigned long end; 199 }; 200 201 int migrate_vma_setup(struct migrate_vma *args); 202 void migrate_vma_pages(struct migrate_vma *migrate); 203 void migrate_vma_finalize(struct migrate_vma *migrate); 204 205 #endif /* CONFIG_MIGRATION */ 206 207 #endif /* _LINUX_MIGRATE_H */ 208