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 int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
  12                                unsigned long address, pmd_t *pmd,
  13                                pmd_t orig_pmd);
  14 extern pgtable_t get_pmd_huge_pte(struct mm_struct *mm);
  15 extern struct page *follow_trans_huge_pmd(struct mm_struct *mm,
  16                                           unsigned long addr,
  17                                           pmd_t *pmd,
  18                                           unsigned int flags);
  19 extern int zap_huge_pmd(struct mmu_gather *tlb,
  20                         struct vm_area_struct *vma,
  21                         pmd_t *pmd);
  22 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  23                         unsigned long addr, unsigned long end,
  24                         unsigned char *vec);
  25 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  26                         unsigned long addr, pgprot_t newprot);
  27
  28 enum transparent_hugepage_flag {
  29         TRANSPARENT_HUGEPAGE_FLAG,
  30         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
  31         TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
  32         TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
  33         TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
  34 #ifdef CONFIG_DEBUG_VM
  35         TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
  36 #endif
  37 };
  38
  39 enum page_check_address_pmd_flag {
  40         PAGE_CHECK_ADDRESS_PMD_FLAG,
  41         PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
  42         PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
  43 };
  44 extern pmd_t *page_check_address_pmd(struct page *page,
  45                                      struct mm_struct *mm,
  46                                      unsigned long address,
  47                                      enum page_check_address_pmd_flag flag);
  48
  49 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  50 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
  51 #define HPAGE_PMD_MASK HPAGE_MASK
  52 #define HPAGE_PMD_SIZE HPAGE_SIZE
  53
  54 #define transparent_hugepage_enabled(__vma)                             \
  55         ((transparent_hugepage_flags &                                  \
  56           (1<<TRANSPARENT_HUGEPAGE_FLAG) ||                             \
  57           (transparent_hugepage_flags &                                 \
  58            (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&                   \
  59            ((__vma)->vm_flags & VM_HUGEPAGE))) &&                       \
  60          !((__vma)->vm_flags & VM_NOHUGEPAGE) &&                        \
  61          !is_vma_temporary_stack(__vma))
  62 #define transparent_hugepage_defrag(__vma)                              \
  63         ((transparent_hugepage_flags &                                  \
  64           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||                     \
  65          (transparent_hugepage_flags &                                  \
  66           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&             \
  67           (__vma)->vm_flags & VM_HUGEPAGE))
  68 #ifdef CONFIG_DEBUG_VM
  69 #define transparent_hugepage_debug_cow()                                \
  70         (transparent_hugepage_flags &                                   \
  71          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
  72 #else /* CONFIG_DEBUG_VM */
  73 #define transparent_hugepage_debug_cow() 0
  74 #endif /* CONFIG_DEBUG_VM */
  75
  76 extern unsigned long transparent_hugepage_flags;
  77 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  78                           pmd_t *dst_pmd, pmd_t *src_pmd,
  79                           struct vm_area_struct *vma,
  80                           unsigned long addr, unsigned long end);
  81 extern int handle_pte_fault(struct mm_struct *mm,
  82                             struct vm_area_struct *vma, unsigned long address,
  83                             pte_t *pte, pmd_t *pmd, unsigned int flags);
  84 extern int split_huge_page(struct page *page);
  85 extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
  86 #define split_huge_page_pmd(__mm, __pmd)                                \
  87         do {                                                            \
  88                 pmd_t *____pmd = (__pmd);                               \
  89                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
  90                         __split_huge_page_pmd(__mm, ____pmd);           \
  91         }  while (0)
  92 #define wait_split_huge_page(__anon_vma, __pmd)                         \
  93         do {                                                            \
  94                 pmd_t *____pmd = (__pmd);                               \
  95                 anon_vma_lock(__anon_vma);                              \
  96                 anon_vma_unlock(__anon_vma);                            \
  97                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
  98                        pmd_trans_huge(*____pmd));                       \
  99         } while (0)
 100 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
 101 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
 102 #if HPAGE_PMD_ORDER > MAX_ORDER
 103 #error "hugepages can't be allocated by the buddy allocator"
 104 #endif
 105 extern int hugepage_madvise(struct vm_area_struct *vma,
 106                             unsigned long *vm_flags, int advice);
 107 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 108                                     unsigned long start,
 109                                     unsigned long end,
 110                                     long adjust_next);
 111 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 112                                          unsigned long start,
 113                                          unsigned long end,
 114                                          long adjust_next)
 115 {
 116         if (!vma->anon_vma || vma->vm_ops)
 117                 return;
 118         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 119 }
 120 static inline int hpage_nr_pages(struct page *page)
 121 {
 122         if (unlikely(PageTransHuge(page)))
 123                 return HPAGE_PMD_NR;
 124         return 1;
 125 }
 126 static inline struct page *compound_trans_head(struct page *page)
 127 {
 128         if (PageTail(page)) {
 129                 struct page *head;
 130                 head = page->first_page;
 131                 smp_rmb();
 132                 /*
 133                  * head may be a dangling pointer.
 134                  * __split_huge_page_refcount clears PageTail before
 135                  * overwriting first_page, so if PageTail is still
 136                  * there it means the head pointer isn't dangling.
 137                  */
 138                 if (PageTail(page))
 139                         return head;
 140         }
 141         return page;
 142 }
 143 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 144 #define HPAGE_PMD_SHIFT ({ BUG(); 0; })
 145 #define HPAGE_PMD_MASK ({ BUG(); 0; })
 146 #define HPAGE_PMD_SIZE ({ BUG(); 0; })
 147
 148 #define hpage_nr_pages(x) 1
 149
 150 #define transparent_hugepage_enabled(__vma) 0
 151
 152 #define transparent_hugepage_flags 0UL
 153 static inline int split_huge_page(struct page *page)
 154 {
 155         return 0;
 156 }
 157 #define split_huge_page_pmd(__mm, __pmd)        \
 158         do { } while (0)
 159 #define wait_split_huge_page(__anon_vma, __pmd) \
 160         do { } while (0)
 161 #define compound_trans_head(page) compound_head(page)
 162 static inline int hugepage_madvise(struct vm_area_struct *vma,
 163                                    unsigned long *vm_flags, int advice)
 164 {
 165         BUG();
 166         return 0;
 167 }
 168 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 169                                          unsigned long start,
 170                                          unsigned long end,
 171                                          long adjust_next)
 172 {
 173 }
 174 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 175
 176 #endif /* _LINUX_HUGE_MM_H */