1 #ifndef _LINUX_HUGE_MM_H 2 #define _LINUX_HUGE_MM_H 3 4 extern int do_huge_pmd_anonymous_page(struct mm_struct *mm, 5 struct vm_area_struct *vma, 6 unsigned long address, pmd_t *pmd, 7 unsigned int flags); 8 extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, 9 pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr, 10 struct vm_area_struct *vma); 11 extern void huge_pmd_set_accessed(struct mm_struct *mm, 12 struct vm_area_struct *vma, 13 unsigned long address, pmd_t *pmd, 14 pmd_t orig_pmd, int dirty); 15 extern int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, 16 unsigned long address, pmd_t *pmd, 17 pmd_t orig_pmd); 18 extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, 19 unsigned long addr, 20 pmd_t *pmd, 21 unsigned int flags); 22 extern int zap_huge_pmd(struct mmu_gather *tlb, 23 struct vm_area_struct *vma, 24 pmd_t *pmd, unsigned long addr); 25 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, 26 unsigned long addr, unsigned long end, 27 unsigned char *vec); 28 extern int move_huge_pmd(struct vm_area_struct *vma, 29 struct vm_area_struct *new_vma, 30 unsigned long old_addr, 31 unsigned long new_addr, unsigned long old_end, 32 pmd_t *old_pmd, pmd_t *new_pmd); 33 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, 34 unsigned long addr, pgprot_t newprot, 35 int prot_numa); 36 37 enum transparent_hugepage_flag { 38 TRANSPARENT_HUGEPAGE_FLAG, 39 TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, 40 TRANSPARENT_HUGEPAGE_DEFRAG_FLAG, 41 TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, 42 TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG, 43 TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG, 44 #ifdef CONFIG_DEBUG_VM 45 TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG, 46 #endif 47 }; 48 49 enum page_check_address_pmd_flag { 50 PAGE_CHECK_ADDRESS_PMD_FLAG, 51 PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG, 52 PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG, 53 }; 54 extern pmd_t *page_check_address_pmd(struct page *page, 55 struct mm_struct *mm, 56 unsigned long address, 57 enum page_check_address_pmd_flag flag, 58 spinlock_t **ptl); 59 60 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT) 61 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER) 62 63 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 64 #define HPAGE_PMD_SHIFT PMD_SHIFT 65 #define HPAGE_PMD_SIZE ((1UL) << HPAGE_PMD_SHIFT) 66 #define HPAGE_PMD_MASK (~(HPAGE_PMD_SIZE - 1)) 67 68 extern bool is_vma_temporary_stack(struct vm_area_struct *vma); 69 70 #define transparent_hugepage_enabled(__vma) \ 71 ((transparent_hugepage_flags & \ 72 (1<<TRANSPARENT_HUGEPAGE_FLAG) || \ 73 (transparent_hugepage_flags & \ 74 (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) && \ 75 ((__vma)->vm_flags & VM_HUGEPAGE))) && \ 76 !((__vma)->vm_flags & VM_NOHUGEPAGE) && \ 77 !is_vma_temporary_stack(__vma)) 78 #define transparent_hugepage_defrag(__vma) \ 79 ((transparent_hugepage_flags & \ 80 (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) || \ 81 (transparent_hugepage_flags & \ 82 (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) && \ 83 (__vma)->vm_flags & VM_HUGEPAGE)) 84 #define transparent_hugepage_use_zero_page() \ 85 (transparent_hugepage_flags & \ 86 (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG)) 87 #ifdef CONFIG_DEBUG_VM 88 #define transparent_hugepage_debug_cow() \ 89 (transparent_hugepage_flags & \ 90 (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG)) 91 #else /* CONFIG_DEBUG_VM */ 92 #define transparent_hugepage_debug_cow() 0 93 #endif /* CONFIG_DEBUG_VM */ 94 95 extern unsigned long transparent_hugepage_flags; 96 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, 97 pmd_t *dst_pmd, pmd_t *src_pmd, 98 struct vm_area_struct *vma, 99 unsigned long addr, unsigned long end); 100 extern int split_huge_page_to_list(struct page *page, struct list_head *list); 101 static inline int split_huge_page(struct page *page) 102 { 103 return split_huge_page_to_list(page, NULL); 104 } 105 extern void __split_huge_page_pmd(struct vm_area_struct *vma, 106 unsigned long address, pmd_t *pmd); 107 #define split_huge_page_pmd(__vma, __address, __pmd) \ 108 do { \ 109 pmd_t *____pmd = (__pmd); \ 110 if (unlikely(pmd_trans_huge(*____pmd))) \ 111 __split_huge_page_pmd(__vma, __address, \ 112 ____pmd); \ 113 } while (0) 114 #define wait_split_huge_page(__anon_vma, __pmd) \ 115 do { \ 116 pmd_t *____pmd = (__pmd); \ 117 anon_vma_lock_write(__anon_vma); \ 118 anon_vma_unlock_write(__anon_vma); \ 119 BUG_ON(pmd_trans_splitting(*____pmd) || \ 120 pmd_trans_huge(*____pmd)); \ 121 } while (0) 122 extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address, 123 pmd_t *pmd); 124 #if HPAGE_PMD_ORDER >= MAX_ORDER 125 #error "hugepages can't be allocated by the buddy allocator" 126 #endif 127 extern int hugepage_madvise(struct vm_area_struct *vma, 128 unsigned long *vm_flags, int advice); 129 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma, 130 unsigned long start, 131 unsigned long end, 132 long adjust_next); 133 extern int __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, 134 spinlock_t **ptl); 135 /* mmap_sem must be held on entry */ 136 static inline int pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, 137 spinlock_t **ptl) 138 { 139 VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem)); 140 if (pmd_trans_huge(*pmd)) 141 return __pmd_trans_huge_lock(pmd, vma, ptl); 142 else 143 return 0; 144 } 145 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma, 146 unsigned long start, 147 unsigned long end, 148 long adjust_next) 149 { 150 if (!vma->anon_vma || vma->vm_ops) 151 return; 152 __vma_adjust_trans_huge(vma, start, end, adjust_next); 153 } 154 static inline int hpage_nr_pages(struct page *page) 155 { 156 if (unlikely(PageTransHuge(page))) 157 return HPAGE_PMD_NR; 158 return 1; 159 } 160 /* 161 * compound_trans_head() should be used instead of compound_head(), 162 * whenever the "page" passed as parameter could be the tail of a 163 * transparent hugepage that could be undergoing a 164 * __split_huge_page_refcount(). The page structure layout often 165 * changes across releases and it makes extensive use of unions. So if 166 * the page structure layout will change in a way that 167 * page->first_page gets clobbered by __split_huge_page_refcount, the 168 * implementation making use of smp_rmb() will be required. 169 * 170 * Currently we define compound_trans_head as compound_head, because 171 * page->private is in the same union with page->first_page, and 172 * page->private isn't clobbered. However this also means we're 173 * currently leaving dirt into the page->private field of anonymous 174 * pages resulting from a THP split, instead of setting page->private 175 * to zero like for every other page that has PG_private not set. But 176 * anonymous pages don't use page->private so this is not a problem. 177 */ 178 #if 0 179 /* This will be needed if page->private will be clobbered in split_huge_page */ 180 static inline struct page *compound_trans_head(struct page *page) 181 { 182 if (PageTail(page)) { 183 struct page *head; 184 head = page->first_page; 185 smp_rmb(); 186 /* 187 * head may be a dangling pointer. 188 * __split_huge_page_refcount clears PageTail before 189 * overwriting first_page, so if PageTail is still 190 * there it means the head pointer isn't dangling. 191 */ 192 if (PageTail(page)) 193 return head; 194 } 195 return page; 196 } 197 #else 198 #define compound_trans_head(page) compound_head(page) 199 #endif 200 201 extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, 202 unsigned long addr, pmd_t pmd, pmd_t *pmdp); 203 204 #else /* CONFIG_TRANSPARENT_HUGEPAGE */ 205 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; }) 206 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; }) 207 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; }) 208 209 #define hpage_nr_pages(x) 1 210 211 #define transparent_hugepage_enabled(__vma) 0 212 213 #define transparent_hugepage_flags 0UL 214 static inline int 215 split_huge_page_to_list(struct page *page, struct list_head *list) 216 { 217 return 0; 218 } 219 static inline int split_huge_page(struct page *page) 220 { 221 return 0; 222 } 223 #define split_huge_page_pmd(__vma, __address, __pmd) \ 224 do { } while (0) 225 #define wait_split_huge_page(__anon_vma, __pmd) \ 226 do { } while (0) 227 #define split_huge_page_pmd_mm(__mm, __address, __pmd) \ 228 do { } while (0) 229 #define compound_trans_head(page) compound_head(page) 230 static inline int hugepage_madvise(struct vm_area_struct *vma, 231 unsigned long *vm_flags, int advice) 232 { 233 BUG(); 234 return 0; 235 } 236 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma, 237 unsigned long start, 238 unsigned long end, 239 long adjust_next) 240 { 241 } 242 static inline int pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, 243 spinlock_t **ptl) 244 { 245 return 0; 246 } 247 248 static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, 249 unsigned long addr, pmd_t pmd, pmd_t *pmdp) 250 { 251 return 0; 252 } 253 254 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 255 256 #endif /* _LINUX_HUGE_MM_H */ 257