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                         int prot_numa);
  36
  37 enum transparent_hugepage_flag {
  38         TRANSPARENT_HUGEPAGE_FLAG,
  39         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
  40         TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
  41         TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
  42         TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
  43         TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
  44 #ifdef CONFIG_DEBUG_VM
  45         TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
  46 #endif
  47 };
  48
  49 enum page_check_address_pmd_flag {
  50         PAGE_CHECK_ADDRESS_PMD_FLAG,
  51         PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
  52         PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
  53 };
  54 extern pmd_t *page_check_address_pmd(struct page *page,
  55                                      struct mm_struct *mm,
  56                                      unsigned long address,
  57                                      enum page_check_address_pmd_flag flag);
  58
  59 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
  60 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
  61
  62 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  63 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
  64 #define HPAGE_PMD_MASK HPAGE_MASK
  65 #define HPAGE_PMD_SIZE HPAGE_SIZE
  66
  67 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
  68
  69 #define transparent_hugepage_enabled(__vma)                             \
  70         ((transparent_hugepage_flags &                                  \
  71           (1<<TRANSPARENT_HUGEPAGE_FLAG) ||                             \
  72           (transparent_hugepage_flags &                                 \
  73            (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&                   \
  74            ((__vma)->vm_flags & VM_HUGEPAGE))) &&                       \
  75          !((__vma)->vm_flags & VM_NOHUGEPAGE) &&                        \
  76          !is_vma_temporary_stack(__vma))
  77 #define transparent_hugepage_defrag(__vma)                              \
  78         ((transparent_hugepage_flags &                                  \
  79           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||                     \
  80          (transparent_hugepage_flags &                                  \
  81           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&             \
  82           (__vma)->vm_flags & VM_HUGEPAGE))
  83 #define transparent_hugepage_use_zero_page()                            \
  84         (transparent_hugepage_flags &                                   \
  85          (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
  86 #ifdef CONFIG_DEBUG_VM
  87 #define transparent_hugepage_debug_cow()                                \
  88         (transparent_hugepage_flags &                                   \
  89          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
  90 #else /* CONFIG_DEBUG_VM */
  91 #define transparent_hugepage_debug_cow() 0
  92 #endif /* CONFIG_DEBUG_VM */
  93
  94 extern unsigned long transparent_hugepage_flags;
  95 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  96                           pmd_t *dst_pmd, pmd_t *src_pmd,
  97                           struct vm_area_struct *vma,
  98                           unsigned long addr, unsigned long end);
  99 extern int handle_pte_fault(struct mm_struct *mm,
 100                             struct vm_area_struct *vma, unsigned long address,
 101                             pte_t *pte, pmd_t *pmd, unsigned int flags);
 102 extern int split_huge_page(struct page *page);
 103 extern void __split_huge_page_pmd(struct vm_area_struct *vma,
 104                 unsigned long address, pmd_t *pmd);
 105 #define split_huge_page_pmd(__vma, __address, __pmd)                    \
 106         do {                                                            \
 107                 pmd_t *____pmd = (__pmd);                               \
 108                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
 109                         __split_huge_page_pmd(__vma, __address,         \
 110                                         ____pmd);                       \
 111         }  while (0)
 112 #define wait_split_huge_page(__anon_vma, __pmd)                         \
 113         do {                                                            \
 114                 pmd_t *____pmd = (__pmd);                               \
 115                 anon_vma_lock_write(__anon_vma);                        \
 116                 anon_vma_unlock_write(__anon_vma);                      \
 117                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
 118                        pmd_trans_huge(*____pmd));                       \
 119         } while (0)
 120 extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
 121                 pmd_t *pmd);
 122 #if HPAGE_PMD_ORDER > MAX_ORDER
 123 #error "hugepages can't be allocated by the buddy allocator"
 124 #endif
 125 extern int hugepage_madvise(struct vm_area_struct *vma,
 126                             unsigned long *vm_flags, int advice);
 127 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 128                                     unsigned long start,
 129                                     unsigned long end,
 130                                     long adjust_next);
 131 extern int __pmd_trans_huge_lock(pmd_t *pmd,
 132                                  struct vm_area_struct *vma);
 133 /* mmap_sem must be held on entry */
 134 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 135                                       struct vm_area_struct *vma)
 136 {
 137         VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
 138         if (pmd_trans_huge(*pmd))
 139                 return __pmd_trans_huge_lock(pmd, vma);
 140         else
 141                 return 0;
 142 }
 143 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 144                                          unsigned long start,
 145                                          unsigned long end,
 146                                          long adjust_next)
 147 {
 148         if (!vma->anon_vma || vma->vm_ops)
 149                 return;
 150         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 151 }
 152 static inline int hpage_nr_pages(struct page *page)
 153 {
 154         if (unlikely(PageTransHuge(page)))
 155                 return HPAGE_PMD_NR;
 156         return 1;
 157 }
 158 static inline struct page *compound_trans_head(struct page *page)
 159 {
 160         if (PageTail(page)) {
 161                 struct page *head;
 162                 head = page->first_page;
 163                 smp_rmb();
 164                 /*
 165                  * head may be a dangling pointer.
 166                  * __split_huge_page_refcount clears PageTail before
 167                  * overwriting first_page, so if PageTail is still
 168                  * there it means the head pointer isn't dangling.
 169                  */
 170                 if (PageTail(page))
 171                         return head;
 172         }
 173         return page;
 174 }
 175
 176 extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
 177                                 unsigned long addr, pmd_t pmd, pmd_t *pmdp);
 178
 179 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 180 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 181 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 182 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 183
 184 #define hpage_nr_pages(x) 1
 185
 186 #define transparent_hugepage_enabled(__vma) 0
 187
 188 #define transparent_hugepage_flags 0UL
 189 static inline int split_huge_page(struct page *page)
 190 {
 191         return 0;
 192 }
 193 #define split_huge_page_pmd(__vma, __address, __pmd)    \
 194         do { } while (0)
 195 #define wait_split_huge_page(__anon_vma, __pmd) \
 196         do { } while (0)
 197 #define split_huge_page_pmd_mm(__mm, __address, __pmd)  \
 198         do { } while (0)
 199 #define compound_trans_head(page) compound_head(page)
 200 static inline int hugepage_madvise(struct vm_area_struct *vma,
 201                                    unsigned long *vm_flags, int advice)
 202 {
 203         BUG();
 204         return 0;
 205 }
 206 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 207                                          unsigned long start,
 208                                          unsigned long end,
 209                                          long adjust_next)
 210 {
 211 }
 212 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 213                                       struct vm_area_struct *vma)
 214 {
 215         return 0;
 216 }
 217
 218 static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
 219                                         unsigned long addr, pmd_t pmd, pmd_t *pmdp)
 220 {
 221         return 0;
 222 }
 223
 224 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 225
 226 #endif /* _LINUX_HUGE_MM_H */