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 pgtable_t get_pmd_huge_pte(struct mm_struct *mm);
  19 extern struct page *follow_trans_huge_pmd(struct mm_struct *mm,
  20                                           unsigned long addr,
  21                                           pmd_t *pmd,
  22                                           unsigned int flags);
  23 extern int zap_huge_pmd(struct mmu_gather *tlb,
  24                         struct vm_area_struct *vma,
  25                         pmd_t *pmd);
  26 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  27                         unsigned long addr, unsigned long end,
  28                         unsigned char *vec);
  29 extern int move_huge_pmd(struct vm_area_struct *vma,
  30                          struct vm_area_struct *new_vma,
  31                          unsigned long old_addr,
  32                          unsigned long new_addr, unsigned long old_end,
  33                          pmd_t *old_pmd, pmd_t *new_pmd);
  34 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  35                         unsigned long addr, pgprot_t newprot);
  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 #ifdef CONFIG_DEBUG_VM
  44         TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
  45 #endif
  46 };
  47
  48 enum page_check_address_pmd_flag {
  49         PAGE_CHECK_ADDRESS_PMD_FLAG,
  50         PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
  51         PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
  52 };
  53 extern pmd_t *page_check_address_pmd(struct page *page,
  54                                      struct mm_struct *mm,
  55                                      unsigned long address,
  56                                      enum page_check_address_pmd_flag flag);
  57
  58 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  59 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
  60 #define HPAGE_PMD_MASK HPAGE_MASK
  61 #define HPAGE_PMD_SIZE HPAGE_SIZE
  62
  63 #define transparent_hugepage_enabled(__vma)                             \
  64         ((transparent_hugepage_flags &                                  \
  65           (1<<TRANSPARENT_HUGEPAGE_FLAG) ||                             \
  66           (transparent_hugepage_flags &                                 \
  67            (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&                   \
  68            ((__vma)->vm_flags & VM_HUGEPAGE))) &&                       \
  69          !((__vma)->vm_flags & VM_NOHUGEPAGE) &&                        \
  70          !is_vma_temporary_stack(__vma))
  71 #define transparent_hugepage_defrag(__vma)                              \
  72         ((transparent_hugepage_flags &                                  \
  73           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||                     \
  74          (transparent_hugepage_flags &                                  \
  75           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&             \
  76           (__vma)->vm_flags & VM_HUGEPAGE))
  77 #ifdef CONFIG_DEBUG_VM
  78 #define transparent_hugepage_debug_cow()                                \
  79         (transparent_hugepage_flags &                                   \
  80          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
  81 #else /* CONFIG_DEBUG_VM */
  82 #define transparent_hugepage_debug_cow() 0
  83 #endif /* CONFIG_DEBUG_VM */
  84
  85 extern unsigned long transparent_hugepage_flags;
  86 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  87                           pmd_t *dst_pmd, pmd_t *src_pmd,
  88                           struct vm_area_struct *vma,
  89                           unsigned long addr, unsigned long end);
  90 extern int handle_pte_fault(struct mm_struct *mm,
  91                             struct vm_area_struct *vma, unsigned long address,
  92                             pte_t *pte, pmd_t *pmd, unsigned int flags);
  93 extern int split_huge_page(struct page *page);
  94 extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
  95 #define split_huge_page_pmd(__mm, __pmd)                                \
  96         do {                                                            \
  97                 pmd_t *____pmd = (__pmd);                               \
  98                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
  99                         __split_huge_page_pmd(__mm, ____pmd);           \
 100         }  while (0)
 101 #define wait_split_huge_page(__anon_vma, __pmd)                         \
 102         do {                                                            \
 103                 pmd_t *____pmd = (__pmd);                               \
 104                 anon_vma_lock(__anon_vma);                              \
 105                 anon_vma_unlock(__anon_vma);                            \
 106                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
 107                        pmd_trans_huge(*____pmd));                       \
 108         } while (0)
 109 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
 110 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
 111 #if HPAGE_PMD_ORDER > MAX_ORDER
 112 #error "hugepages can't be allocated by the buddy allocator"
 113 #endif
 114 extern int hugepage_madvise(struct vm_area_struct *vma,
 115                             unsigned long *vm_flags, int advice);
 116 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 117                                     unsigned long start,
 118                                     unsigned long end,
 119                                     long adjust_next);
 120 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 121                                          unsigned long start,
 122                                          unsigned long end,
 123                                          long adjust_next)
 124 {
 125         if (!vma->anon_vma || vma->vm_ops)
 126                 return;
 127         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 128 }
 129 static inline int hpage_nr_pages(struct page *page)
 130 {
 131         if (unlikely(PageTransHuge(page)))
 132                 return HPAGE_PMD_NR;
 133         return 1;
 134 }
 135 static inline struct page *compound_trans_head(struct page *page)
 136 {
 137         if (PageTail(page)) {
 138                 struct page *head;
 139                 head = page->first_page;
 140                 smp_rmb();
 141                 /*
 142                  * head may be a dangling pointer.
 143                  * __split_huge_page_refcount clears PageTail before
 144                  * overwriting first_page, so if PageTail is still
 145                  * there it means the head pointer isn't dangling.
 146                  */
 147                 if (PageTail(page))
 148                         return head;
 149         }
 150         return page;
 151 }
 152 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 153 #define HPAGE_PMD_SHIFT ({ BUG(); 0; })
 154 #define HPAGE_PMD_MASK ({ BUG(); 0; })
 155 #define HPAGE_PMD_SIZE ({ BUG(); 0; })
 156
 157 #define hpage_nr_pages(x) 1
 158
 159 #define transparent_hugepage_enabled(__vma) 0
 160
 161 #define transparent_hugepage_flags 0UL
 162 static inline int split_huge_page(struct page *page)
 163 {
 164         return 0;
 165 }
 166 #define split_huge_page_pmd(__mm, __pmd)        \
 167         do { } while (0)
 168 #define wait_split_huge_page(__anon_vma, __pmd) \
 169         do { } while (0)
 170 #define compound_trans_head(page) compound_head(page)
 171 static inline int hugepage_madvise(struct vm_area_struct *vma,
 172                                    unsigned long *vm_flags, int advice)
 173 {
 174         BUG();
 175         return 0;
 176 }
 177 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 178                                          unsigned long start,
 179                                          unsigned long end,
 180                                          long adjust_next)
 181 {
 182 }
 183 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 184
 185 #endif /* _LINUX_HUGE_MM_H */