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