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 struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
  15                                           unsigned long addr,
  16                                           pmd_t *pmd,
  17                                           unsigned int flags);
  18 extern int zap_huge_pmd(struct mmu_gather *tlb,
  19                         struct vm_area_struct *vma,
  20                         pmd_t *pmd, unsigned long addr);
  21 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  22                         unsigned long addr, unsigned long end,
  23                         unsigned char *vec);
  24 extern int move_huge_pmd(struct vm_area_struct *vma,
  25                          struct vm_area_struct *new_vma,
  26                          unsigned long old_addr,
  27                          unsigned long new_addr, unsigned long old_end,
  28                          pmd_t *old_pmd, pmd_t *new_pmd);
  29 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  30                         unsigned long addr, pgprot_t newprot);
  31
  32 enum transparent_hugepage_flag {
  33         TRANSPARENT_HUGEPAGE_FLAG,
  34         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
  35         TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
  36         TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
  37         TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
  38 #ifdef CONFIG_DEBUG_VM
  39         TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
  40 #endif
  41 };
  42
  43 enum page_check_address_pmd_flag {
  44         PAGE_CHECK_ADDRESS_PMD_FLAG,
  45         PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
  46         PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
  47 };
  48 extern pmd_t *page_check_address_pmd(struct page *page,
  49                                      struct mm_struct *mm,
  50                                      unsigned long address,
  51                                      enum page_check_address_pmd_flag flag);
  52
  53 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
  54 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
  55
  56 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  57 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
  58 #define HPAGE_PMD_MASK HPAGE_MASK
  59 #define HPAGE_PMD_SIZE HPAGE_SIZE
  60
  61 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
  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 #if HPAGE_PMD_ORDER > MAX_ORDER
 110 #error "hugepages can't be allocated by the buddy allocator"
 111 #endif
 112 extern int hugepage_madvise(struct vm_area_struct *vma,
 113                             unsigned long *vm_flags, int advice);
 114 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 115                                     unsigned long start,
 116                                     unsigned long end,
 117                                     long adjust_next);
 118 extern int __pmd_trans_huge_lock(pmd_t *pmd,
 119                                  struct vm_area_struct *vma);
 120 /* mmap_sem must be held on entry */
 121 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 122                                       struct vm_area_struct *vma)
 123 {
 124         VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
 125         if (pmd_trans_huge(*pmd))
 126                 return __pmd_trans_huge_lock(pmd, vma);
 127         else
 128                 return 0;
 129 }
 130 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 131                                          unsigned long start,
 132                                          unsigned long end,
 133                                          long adjust_next)
 134 {
 135         if (!vma->anon_vma || vma->vm_ops)
 136                 return;
 137         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 138 }
 139 static inline int hpage_nr_pages(struct page *page)
 140 {
 141         if (unlikely(PageTransHuge(page)))
 142                 return HPAGE_PMD_NR;
 143         return 1;
 144 }
 145 static inline struct page *compound_trans_head(struct page *page)
 146 {
 147         if (PageTail(page)) {
 148                 struct page *head;
 149                 head = page->first_page;
 150                 smp_rmb();
 151                 /*
 152                  * head may be a dangling pointer.
 153                  * __split_huge_page_refcount clears PageTail before
 154                  * overwriting first_page, so if PageTail is still
 155                  * there it means the head pointer isn't dangling.
 156                  */
 157                 if (PageTail(page))
 158                         return head;
 159         }
 160         return page;
 161 }
 162 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 163 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 164 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 165 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 166
 167 #define hpage_nr_pages(x) 1
 168
 169 #define transparent_hugepage_enabled(__vma) 0
 170
 171 #define transparent_hugepage_flags 0UL
 172 static inline int split_huge_page(struct page *page)
 173 {
 174         return 0;
 175 }
 176 #define split_huge_page_pmd(__mm, __pmd)        \
 177         do { } while (0)
 178 #define wait_split_huge_page(__anon_vma, __pmd) \
 179         do { } while (0)
 180 #define compound_trans_head(page) compound_head(page)
 181 static inline int hugepage_madvise(struct vm_area_struct *vma,
 182                                    unsigned long *vm_flags, int advice)
 183 {
 184         BUG();
 185         return 0;
 186 }
 187 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 188                                          unsigned long start,
 189                                          unsigned long end,
 190                                          long adjust_next)
 191 {
 192 }
 193 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 194                                       struct vm_area_struct *vma)
 195 {
 196         return 0;
 197 }
 198 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 199
 200 #endif /* _LINUX_HUGE_MM_H */