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 move_huge_pmd(struct vm_area_struct *vma,
  26                          struct vm_area_struct *new_vma,
  27                          unsigned long old_addr,
  28                          unsigned long new_addr, unsigned long old_end,
  29                          pmd_t *old_pmd, pmd_t *new_pmd);
  30 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  31                         unsigned long addr, pgprot_t newprot);
  32
  33 enum transparent_hugepage_flag {
  34         TRANSPARENT_HUGEPAGE_FLAG,
  35         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
  36         TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
  37         TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
  38         TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
  39 #ifdef CONFIG_DEBUG_VM
  40         TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
  41 #endif
  42 };
  43
  44 enum page_check_address_pmd_flag {
  45         PAGE_CHECK_ADDRESS_PMD_FLAG,
  46         PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
  47         PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
  48 };
  49 extern pmd_t *page_check_address_pmd(struct page *page,
  50                                      struct mm_struct *mm,
  51                                      unsigned long address,
  52                                      enum page_check_address_pmd_flag flag);
  53
  54 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  55 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
  56 #define HPAGE_PMD_MASK HPAGE_MASK
  57 #define HPAGE_PMD_SIZE HPAGE_SIZE
  58
  59 #define transparent_hugepage_enabled(__vma)                             \
  60         ((transparent_hugepage_flags &                                  \
  61           (1<<TRANSPARENT_HUGEPAGE_FLAG) ||                             \
  62           (transparent_hugepage_flags &                                 \
  63            (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&                   \
  64            ((__vma)->vm_flags & VM_HUGEPAGE))) &&                       \
  65          !((__vma)->vm_flags & VM_NOHUGEPAGE) &&                        \
  66          !is_vma_temporary_stack(__vma))
  67 #define transparent_hugepage_defrag(__vma)                              \
  68         ((transparent_hugepage_flags &                                  \
  69           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||                     \
  70          (transparent_hugepage_flags &                                  \
  71           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&             \
  72           (__vma)->vm_flags & VM_HUGEPAGE))
  73 #ifdef CONFIG_DEBUG_VM
  74 #define transparent_hugepage_debug_cow()                                \
  75         (transparent_hugepage_flags &                                   \
  76          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
  77 #else /* CONFIG_DEBUG_VM */
  78 #define transparent_hugepage_debug_cow() 0
  79 #endif /* CONFIG_DEBUG_VM */
  80
  81 extern unsigned long transparent_hugepage_flags;
  82 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  83                           pmd_t *dst_pmd, pmd_t *src_pmd,
  84                           struct vm_area_struct *vma,
  85                           unsigned long addr, unsigned long end);
  86 extern int handle_pte_fault(struct mm_struct *mm,
  87                             struct vm_area_struct *vma, unsigned long address,
  88                             pte_t *pte, pmd_t *pmd, unsigned int flags);
  89 extern int split_huge_page(struct page *page);
  90 extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
  91 #define split_huge_page_pmd(__mm, __pmd)                                \
  92         do {                                                            \
  93                 pmd_t *____pmd = (__pmd);                               \
  94                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
  95                         __split_huge_page_pmd(__mm, ____pmd);           \
  96         }  while (0)
  97 #define wait_split_huge_page(__anon_vma, __pmd)                         \
  98         do {                                                            \
  99                 pmd_t *____pmd = (__pmd);                               \
 100                 anon_vma_lock(__anon_vma);                              \
 101                 anon_vma_unlock(__anon_vma);                            \
 102                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
 103                        pmd_trans_huge(*____pmd));                       \
 104         } while (0)
 105 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
 106 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
 107 #if HPAGE_PMD_ORDER > MAX_ORDER
 108 #error "hugepages can't be allocated by the buddy allocator"
 109 #endif
 110 extern int hugepage_madvise(struct vm_area_struct *vma,
 111                             unsigned long *vm_flags, int advice);
 112 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 113                                     unsigned long start,
 114                                     unsigned long end,
 115                                     long adjust_next);
 116 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 117                                          unsigned long start,
 118                                          unsigned long end,
 119                                          long adjust_next)
 120 {
 121         if (!vma->anon_vma || vma->vm_ops)
 122                 return;
 123         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 124 }
 125 static inline int hpage_nr_pages(struct page *page)
 126 {
 127         if (unlikely(PageTransHuge(page)))
 128                 return HPAGE_PMD_NR;
 129         return 1;
 130 }
 131 static inline struct page *compound_trans_head(struct page *page)
 132 {
 133         if (PageTail(page)) {
 134                 struct page *head;
 135                 head = page->first_page;
 136                 smp_rmb();
 137                 /*
 138                  * head may be a dangling pointer.
 139                  * __split_huge_page_refcount clears PageTail before
 140                  * overwriting first_page, so if PageTail is still
 141                  * there it means the head pointer isn't dangling.
 142                  */
 143                 if (PageTail(page))
 144                         return head;
 145         }
 146         return page;
 147 }
 148 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 149 #define HPAGE_PMD_SHIFT ({ BUG(); 0; })
 150 #define HPAGE_PMD_MASK ({ BUG(); 0; })
 151 #define HPAGE_PMD_SIZE ({ BUG(); 0; })
 152
 153 #define hpage_nr_pages(x) 1
 154
 155 #define transparent_hugepage_enabled(__vma) 0
 156
 157 #define transparent_hugepage_flags 0UL
 158 static inline int split_huge_page(struct page *page)
 159 {
 160         return 0;
 161 }
 162 #define split_huge_page_pmd(__mm, __pmd)        \
 163         do { } while (0)
 164 #define wait_split_huge_page(__anon_vma, __pmd) \
 165         do { } while (0)
 166 #define compound_trans_head(page) compound_head(page)
 167 static inline int hugepage_madvise(struct vm_area_struct *vma,
 168                                    unsigned long *vm_flags, int advice)
 169 {
 170         BUG();
 171         return 0;
 172 }
 173 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 174                                          unsigned long start,
 175                                          unsigned long end,
 176                                          long adjust_next)
 177 {
 178 }
 179 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 180
 181 #endif /* _LINUX_HUGE_MM_H */