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 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
  55 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
  56
  57 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  58 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
  59 #define HPAGE_PMD_MASK HPAGE_MASK
  60 #define HPAGE_PMD_SIZE HPAGE_SIZE
  61
  62 #define transparent_hugepage_enabled(__vma)                             \
  63         ((transparent_hugepage_flags &                                  \
  64           (1<<TRANSPARENT_HUGEPAGE_FLAG) ||                             \
  65           (transparent_hugepage_flags &                                 \
  66            (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&                   \
  67            ((__vma)->vm_flags & VM_HUGEPAGE))) &&                       \
  68          !((__vma)->vm_flags & VM_NOHUGEPAGE) &&                        \
  69          !is_vma_temporary_stack(__vma))
  70 #define transparent_hugepage_defrag(__vma)                              \
  71         ((transparent_hugepage_flags &                                  \
  72           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||                     \
  73          (transparent_hugepage_flags &                                  \
  74           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&             \
  75           (__vma)->vm_flags & VM_HUGEPAGE))
  76 #ifdef CONFIG_DEBUG_VM
  77 #define transparent_hugepage_debug_cow()                                \
  78         (transparent_hugepage_flags &                                   \
  79          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
  80 #else /* CONFIG_DEBUG_VM */
  81 #define transparent_hugepage_debug_cow() 0
  82 #endif /* CONFIG_DEBUG_VM */
  83
  84 extern unsigned long transparent_hugepage_flags;
  85 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  86                           pmd_t *dst_pmd, pmd_t *src_pmd,
  87                           struct vm_area_struct *vma,
  88                           unsigned long addr, unsigned long end);
  89 extern int handle_pte_fault(struct mm_struct *mm,
  90                             struct vm_area_struct *vma, unsigned long address,
  91                             pte_t *pte, pmd_t *pmd, unsigned int flags);
  92 extern int split_huge_page(struct page *page);
  93 extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
  94 #define split_huge_page_pmd(__mm, __pmd)                                \
  95         do {                                                            \
  96                 pmd_t *____pmd = (__pmd);                               \
  97                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
  98                         __split_huge_page_pmd(__mm, ____pmd);           \
  99         }  while (0)
 100 #define wait_split_huge_page(__anon_vma, __pmd)                         \
 101         do {                                                            \
 102                 pmd_t *____pmd = (__pmd);                               \
 103                 anon_vma_lock(__anon_vma);                              \
 104                 anon_vma_unlock(__anon_vma);                            \
 105                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
 106                        pmd_trans_huge(*____pmd));                       \
 107         } while (0)
 108 #if HPAGE_PMD_ORDER > MAX_ORDER
 109 #error "hugepages can't be allocated by the buddy allocator"
 110 #endif
 111 extern int hugepage_madvise(struct vm_area_struct *vma,
 112                             unsigned long *vm_flags, int advice);
 113 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 114                                     unsigned long start,
 115                                     unsigned long end,
 116                                     long adjust_next);
 117 extern int __pmd_trans_huge_lock(pmd_t *pmd,
 118                                  struct vm_area_struct *vma);
 119 /* mmap_sem must be held on entry */
 120 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 121                                       struct vm_area_struct *vma)
 122 {
 123         VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
 124         if (pmd_trans_huge(*pmd))
 125                 return __pmd_trans_huge_lock(pmd, vma);
 126         else
 127                 return 0;
 128 }
 129 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 130                                          unsigned long start,
 131                                          unsigned long end,
 132                                          long adjust_next)
 133 {
 134         if (!vma->anon_vma || vma->vm_ops)
 135                 return;
 136         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 137 }
 138 static inline int hpage_nr_pages(struct page *page)
 139 {
 140         if (unlikely(PageTransHuge(page)))
 141                 return HPAGE_PMD_NR;
 142         return 1;
 143 }
 144 static inline struct page *compound_trans_head(struct page *page)
 145 {
 146         if (PageTail(page)) {
 147                 struct page *head;
 148                 head = page->first_page;
 149                 smp_rmb();
 150                 /*
 151                  * head may be a dangling pointer.
 152                  * __split_huge_page_refcount clears PageTail before
 153                  * overwriting first_page, so if PageTail is still
 154                  * there it means the head pointer isn't dangling.
 155                  */
 156                 if (PageTail(page))
 157                         return head;
 158         }
 159         return page;
 160 }
 161 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 162 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 163 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 164 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 165
 166 #define hpage_nr_pages(x) 1
 167
 168 #define transparent_hugepage_enabled(__vma) 0
 169
 170 #define transparent_hugepage_flags 0UL
 171 static inline int split_huge_page(struct page *page)
 172 {
 173         return 0;
 174 }
 175 #define split_huge_page_pmd(__mm, __pmd)        \
 176         do { } while (0)
 177 #define wait_split_huge_page(__anon_vma, __pmd) \
 178         do { } while (0)
 179 #define compound_trans_head(page) compound_head(page)
 180 static inline int hugepage_madvise(struct vm_area_struct *vma,
 181                                    unsigned long *vm_flags, int advice)
 182 {
 183         BUG();
 184         return 0;
 185 }
 186 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 187                                          unsigned long start,
 188                                          unsigned long end,
 189                                          long adjust_next)
 190 {
 191 }
 192 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 193                                       struct vm_area_struct *vma)
 194 {
 195         return 0;
 196 }
 197 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 198
 199 #endif /* _LINUX_HUGE_MM_H */