include/linux/huge_mm.h

   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
  36 enum transparent_hugepage_flag {
  37         TRANSPARENT_HUGEPAGE_FLAG,
  38         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
  39         TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
  40         TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
  41         TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
  42 #ifdef CONFIG_DEBUG_VM
  43         TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
  44 #endif
  45 };
  46
  47 enum page_check_address_pmd_flag {
  48         PAGE_CHECK_ADDRESS_PMD_FLAG,
  49         PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
  50         PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
  51 };
  52 extern pmd_t *page_check_address_pmd(struct page *page,
  53                                      struct mm_struct *mm,
  54                                      unsigned long address,
  55                                      enum page_check_address_pmd_flag flag);
  56
  57 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
  58 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
  59
  60 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  61 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
  62 #define HPAGE_PMD_MASK HPAGE_MASK
  63 #define HPAGE_PMD_SIZE HPAGE_SIZE
  64
  65 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
  66
  67 #define transparent_hugepage_enabled(__vma)                             \
  68         ((transparent_hugepage_flags &                                  \
  69           (1<<TRANSPARENT_HUGEPAGE_FLAG) ||                             \
  70           (transparent_hugepage_flags &                                 \
  71            (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&                   \
  72            ((__vma)->vm_flags & VM_HUGEPAGE))) &&                       \
  73          !((__vma)->vm_flags & VM_NOHUGEPAGE) &&                        \
  74          !is_vma_temporary_stack(__vma))
  75 #define transparent_hugepage_defrag(__vma)                              \
  76         ((transparent_hugepage_flags &                                  \
  77           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||                     \
  78          (transparent_hugepage_flags &                                  \
  79           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&             \
  80           (__vma)->vm_flags & VM_HUGEPAGE))
  81 #ifdef CONFIG_DEBUG_VM
  82 #define transparent_hugepage_debug_cow()                                \
  83         (transparent_hugepage_flags &                                   \
  84          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
  85 #else /* CONFIG_DEBUG_VM */
  86 #define transparent_hugepage_debug_cow() 0
  87 #endif /* CONFIG_DEBUG_VM */
  88
  89 extern unsigned long transparent_hugepage_flags;
  90 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  91                           pmd_t *dst_pmd, pmd_t *src_pmd,
  92                           struct vm_area_struct *vma,
  93                           unsigned long addr, unsigned long end);
  94 extern int handle_pte_fault(struct mm_struct *mm,
  95                             struct vm_area_struct *vma, unsigned long address,
  96                             pte_t *pte, pmd_t *pmd, unsigned int flags);
  97 extern int split_huge_page(struct page *page);
  98 extern void __split_huge_page_pmd(struct vm_area_struct *vma,
  99                 unsigned long address, pmd_t *pmd);
 100 #define split_huge_page_pmd(__vma, __address, __pmd)                    \
 101         do {                                                            \
 102                 pmd_t *____pmd = (__pmd);                               \
 103                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
 104                         __split_huge_page_pmd(__vma, __address,         \
 105                                         ____pmd);                       \
 106         }  while (0)
 107 #define wait_split_huge_page(__anon_vma, __pmd)                         \
 108         do {                                                            \
 109                 pmd_t *____pmd = (__pmd);                               \
 110                 anon_vma_lock(__anon_vma);                              \
 111                 anon_vma_unlock(__anon_vma);                            \
 112                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
 113                        pmd_trans_huge(*____pmd));                       \
 114         } while (0)
 115 extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
 116                 pmd_t *pmd);
 117 #if HPAGE_PMD_ORDER > MAX_ORDER
 118 #error "hugepages can't be allocated by the buddy allocator"
 119 #endif
 120 extern int hugepage_madvise(struct vm_area_struct *vma,
 121                             unsigned long *vm_flags, int advice);
 122 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 123                                     unsigned long start,
 124                                     unsigned long end,
 125                                     long adjust_next);
 126 extern int __pmd_trans_huge_lock(pmd_t *pmd,
 127                                  struct vm_area_struct *vma);
 128 /* mmap_sem must be held on entry */
 129 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 130                                       struct vm_area_struct *vma)
 131 {
 132         VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
 133         if (pmd_trans_huge(*pmd))
 134                 return __pmd_trans_huge_lock(pmd, vma);
 135         else
 136                 return 0;
 137 }
 138 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 139                                          unsigned long start,
 140                                          unsigned long end,
 141                                          long adjust_next)
 142 {
 143         if (!vma->anon_vma || vma->vm_ops)
 144                 return;
 145         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 146 }
 147 static inline int hpage_nr_pages(struct page *page)
 148 {
 149         if (unlikely(PageTransHuge(page)))
 150                 return HPAGE_PMD_NR;
 151         return 1;
 152 }
 153 static inline struct page *compound_trans_head(struct page *page)
 154 {
 155         if (PageTail(page)) {
 156                 struct page *head;
 157                 head = page->first_page;
 158                 smp_rmb();
 159                 /*
 160                  * head may be a dangling pointer.
 161                  * __split_huge_page_refcount clears PageTail before
 162                  * overwriting first_page, so if PageTail is still
 163                  * there it means the head pointer isn't dangling.
 164                  */
 165                 if (PageTail(page))
 166                         return head;
 167         }
 168         return page;
 169 }
 170 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 171 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 172 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 173 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 174
 175 #define hpage_nr_pages(x) 1
 176
 177 #define transparent_hugepage_enabled(__vma) 0
 178
 179 #define transparent_hugepage_flags 0UL
 180 static inline int split_huge_page(struct page *page)
 181 {
 182         return 0;
 183 }
 184 #define split_huge_page_pmd(__vma, __address, __pmd)    \
 185         do { } while (0)
 186 #define wait_split_huge_page(__anon_vma, __pmd) \
 187         do { } while (0)
 188 #define split_huge_page_pmd_mm(__mm, __address, __pmd)  \
 189         do { } while (0)
 190 #define compound_trans_head(page) compound_head(page)
 191 static inline int hugepage_madvise(struct vm_area_struct *vma,
 192                                    unsigned long *vm_flags, int advice)
 193 {
 194         BUG();
 195         return 0;
 196 }
 197 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 198                                          unsigned long start,
 199                                          unsigned long end,
 200                                          long adjust_next)
 201 {
 202 }
 203 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 204                                       struct vm_area_struct *vma)
 205 {
 206         return 0;
 207 }
 208 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 209
 210 #endif /* _LINUX_HUGE_MM_H */