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 void huge_pmd_set_accessed(struct mm_struct *mm,
  12                                   struct vm_area_struct *vma,
  13                                   unsigned long address, pmd_t *pmd,
  14                                   pmd_t orig_pmd, int dirty);
  15 extern int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
  16                                unsigned long address, pmd_t *pmd,
  17                                pmd_t orig_pmd);
  18 extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
  19                                           unsigned long addr,
  20                                           pmd_t *pmd,
  21                                           unsigned int flags);
  22 extern int zap_huge_pmd(struct mmu_gather *tlb,
  23                         struct vm_area_struct *vma,
  24                         pmd_t *pmd, unsigned long addr);
  25 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  26                         unsigned long addr, unsigned long end,
  27                         unsigned char *vec);
  28 extern int move_huge_pmd(struct vm_area_struct *vma,
  29                          struct vm_area_struct *new_vma,
  30                          unsigned long old_addr,
  31                          unsigned long new_addr, unsigned long old_end,
  32                          pmd_t *old_pmd, pmd_t *new_pmd);
  33 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  34                         unsigned long addr, pgprot_t newprot);
  35
  36 enum transparent_hugepage_flag {
  37         TRANSPARENT_HUGEPAGE_FLAG,
  38         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
  39         TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
  40         TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
  41         TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
  42         TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
  43 #ifdef CONFIG_DEBUG_VM
  44         TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
  45 #endif
  46 };
  47
  48 enum page_check_address_pmd_flag {
  49         PAGE_CHECK_ADDRESS_PMD_FLAG,
  50         PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
  51         PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
  52 };
  53 extern pmd_t *page_check_address_pmd(struct page *page,
  54                                      struct mm_struct *mm,
  55                                      unsigned long address,
  56                                      enum page_check_address_pmd_flag flag);
  57
  58 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
  59 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
  60
  61 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  62 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
  63 #define HPAGE_PMD_MASK HPAGE_MASK
  64 #define HPAGE_PMD_SIZE HPAGE_SIZE
  65
  66 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
  67
  68 #define transparent_hugepage_enabled(__vma)                             \
  69         ((transparent_hugepage_flags &                                  \
  70           (1<<TRANSPARENT_HUGEPAGE_FLAG) ||                             \
  71           (transparent_hugepage_flags &                                 \
  72            (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&                   \
  73            ((__vma)->vm_flags & VM_HUGEPAGE))) &&                       \
  74          !((__vma)->vm_flags & VM_NOHUGEPAGE) &&                        \
  75          !is_vma_temporary_stack(__vma))
  76 #define transparent_hugepage_defrag(__vma)                              \
  77         ((transparent_hugepage_flags &                                  \
  78           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||                     \
  79          (transparent_hugepage_flags &                                  \
  80           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&             \
  81           (__vma)->vm_flags & VM_HUGEPAGE))
  82 #define transparent_hugepage_use_zero_page()                            \
  83         (transparent_hugepage_flags &                                   \
  84          (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
  85 #ifdef CONFIG_DEBUG_VM
  86 #define transparent_hugepage_debug_cow()                                \
  87         (transparent_hugepage_flags &                                   \
  88          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
  89 #else /* CONFIG_DEBUG_VM */
  90 #define transparent_hugepage_debug_cow() 0
  91 #endif /* CONFIG_DEBUG_VM */
  92
  93 extern unsigned long transparent_hugepage_flags;
  94 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  95                           pmd_t *dst_pmd, pmd_t *src_pmd,
  96                           struct vm_area_struct *vma,
  97                           unsigned long addr, unsigned long end);
  98 extern int handle_pte_fault(struct mm_struct *mm,
  99                             struct vm_area_struct *vma, unsigned long address,
 100                             pte_t *pte, pmd_t *pmd, unsigned int flags);
 101 extern int split_huge_page(struct page *page);
 102 extern void __split_huge_page_pmd(struct vm_area_struct *vma,
 103                 unsigned long address, pmd_t *pmd);
 104 #define split_huge_page_pmd(__vma, __address, __pmd)                    \
 105         do {                                                            \
 106                 pmd_t *____pmd = (__pmd);                               \
 107                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
 108                         __split_huge_page_pmd(__vma, __address,         \
 109                                         ____pmd);                       \
 110         }  while (0)
 111 #define wait_split_huge_page(__anon_vma, __pmd)                         \
 112         do {                                                            \
 113                 pmd_t *____pmd = (__pmd);                               \
 114                 anon_vma_lock(__anon_vma);                              \
 115                 anon_vma_unlock(__anon_vma);                            \
 116                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
 117                        pmd_trans_huge(*____pmd));                       \
 118         } while (0)
 119 extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
 120                 pmd_t *pmd);
 121 #if HPAGE_PMD_ORDER > MAX_ORDER
 122 #error "hugepages can't be allocated by the buddy allocator"
 123 #endif
 124 extern int hugepage_madvise(struct vm_area_struct *vma,
 125                             unsigned long *vm_flags, int advice);
 126 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 127                                     unsigned long start,
 128                                     unsigned long end,
 129                                     long adjust_next);
 130 extern int __pmd_trans_huge_lock(pmd_t *pmd,
 131                                  struct vm_area_struct *vma);
 132 /* mmap_sem must be held on entry */
 133 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 134                                       struct vm_area_struct *vma)
 135 {
 136         VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
 137         if (pmd_trans_huge(*pmd))
 138                 return __pmd_trans_huge_lock(pmd, vma);
 139         else
 140                 return 0;
 141 }
 142 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 143                                          unsigned long start,
 144                                          unsigned long end,
 145                                          long adjust_next)
 146 {
 147         if (!vma->anon_vma || vma->vm_ops)
 148                 return;
 149         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 150 }
 151 static inline int hpage_nr_pages(struct page *page)
 152 {
 153         if (unlikely(PageTransHuge(page)))
 154                 return HPAGE_PMD_NR;
 155         return 1;
 156 }
 157 static inline struct page *compound_trans_head(struct page *page)
 158 {
 159         if (PageTail(page)) {
 160                 struct page *head;
 161                 head = page->first_page;
 162                 smp_rmb();
 163                 /*
 164                  * head may be a dangling pointer.
 165                  * __split_huge_page_refcount clears PageTail before
 166                  * overwriting first_page, so if PageTail is still
 167                  * there it means the head pointer isn't dangling.
 168                  */
 169                 if (PageTail(page))
 170                         return head;
 171         }
 172         return page;
 173 }
 174 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 175 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 176 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 177 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 178
 179 #define hpage_nr_pages(x) 1
 180
 181 #define transparent_hugepage_enabled(__vma) 0
 182
 183 #define transparent_hugepage_flags 0UL
 184 static inline int split_huge_page(struct page *page)
 185 {
 186         return 0;
 187 }
 188 #define split_huge_page_pmd(__vma, __address, __pmd)    \
 189         do { } while (0)
 190 #define wait_split_huge_page(__anon_vma, __pmd) \
 191         do { } while (0)
 192 #define split_huge_page_pmd_mm(__mm, __address, __pmd)  \
 193         do { } while (0)
 194 #define compound_trans_head(page) compound_head(page)
 195 static inline int hugepage_madvise(struct vm_area_struct *vma,
 196                                    unsigned long *vm_flags, int advice)
 197 {
 198         BUG();
 199         return 0;
 200 }
 201 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 202                                          unsigned long start,
 203                                          unsigned long end,
 204                                          long adjust_next)
 205 {
 206 }
 207 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 208                                       struct vm_area_struct *vma)
 209 {
 210         return 0;
 211 }
 212 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 213
 214 #endif /* _LINUX_HUGE_MM_H */