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, unsigned long addr);
  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 extern int __pmd_trans_huge_lock(pmd_t *pmd,
 117                                  struct vm_area_struct *vma);
 118 /* mmap_sem must be held on entry */
 119 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 120                                       struct vm_area_struct *vma)
 121 {
 122         VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
 123         if (pmd_trans_huge(*pmd))
 124                 return __pmd_trans_huge_lock(pmd, vma);
 125         else
 126                 return 0;
 127 }
 128 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 129                                          unsigned long start,
 130                                          unsigned long end,
 131                                          long adjust_next)
 132 {
 133         if (!vma->anon_vma || vma->vm_ops)
 134                 return;
 135         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 136 }
 137 static inline int hpage_nr_pages(struct page *page)
 138 {
 139         if (unlikely(PageTransHuge(page)))
 140                 return HPAGE_PMD_NR;
 141         return 1;
 142 }
 143 static inline struct page *compound_trans_head(struct page *page)
 144 {
 145         if (PageTail(page)) {
 146                 struct page *head;
 147                 head = page->first_page;
 148                 smp_rmb();
 149                 /*
 150                  * head may be a dangling pointer.
 151                  * __split_huge_page_refcount clears PageTail before
 152                  * overwriting first_page, so if PageTail is still
 153                  * there it means the head pointer isn't dangling.
 154                  */
 155                 if (PageTail(page))
 156                         return head;
 157         }
 158         return page;
 159 }
 160 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 161 #define HPAGE_PMD_SHIFT ({ BUG(); 0; })
 162 #define HPAGE_PMD_MASK ({ BUG(); 0; })
 163 #define HPAGE_PMD_SIZE ({ BUG(); 0; })
 164
 165 #define hpage_nr_pages(x) 1
 166
 167 #define transparent_hugepage_enabled(__vma) 0
 168
 169 #define transparent_hugepage_flags 0UL
 170 static inline int split_huge_page(struct page *page)
 171 {
 172         return 0;
 173 }
 174 #define split_huge_page_pmd(__mm, __pmd)        \
 175         do { } while (0)
 176 #define wait_split_huge_page(__anon_vma, __pmd) \
 177         do { } while (0)
 178 #define compound_trans_head(page) compound_head(page)
 179 static inline int hugepage_madvise(struct vm_area_struct *vma,
 180                                    unsigned long *vm_flags, int advice)
 181 {
 182         BUG();
 183         return 0;
 184 }
 185 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 186                                          unsigned long start,
 187                                          unsigned long end,
 188                                          long adjust_next)
 189 {
 190 }
 191 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 192                                       struct vm_area_struct *vma)
 193 {
 194         return 0;
 195 }
 196 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 197
 198 #endif /* _LINUX_HUGE_MM_H */