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 PMD_SHIFT
  64 #define HPAGE_PMD_SIZE  ((1UL) << HPAGE_PMD_SHIFT)
  65 #define HPAGE_PMD_MASK  (~(HPAGE_PMD_SIZE - 1))
  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 split_huge_page_to_list(struct page *page, struct list_head *list);
 100 static inline int split_huge_page(struct page *page)
 101 {
 102         return split_huge_page_to_list(page, NULL);
 103 }
 104 extern void __split_huge_page_pmd(struct vm_area_struct *vma,
 105                 unsigned long address, pmd_t *pmd);
 106 #define split_huge_page_pmd(__vma, __address, __pmd)                    \
 107         do {                                                            \
 108                 pmd_t *____pmd = (__pmd);                               \
 109                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
 110                         __split_huge_page_pmd(__vma, __address,         \
 111                                         ____pmd);                       \
 112         }  while (0)
 113 #define wait_split_huge_page(__anon_vma, __pmd)                         \
 114         do {                                                            \
 115                 pmd_t *____pmd = (__pmd);                               \
 116                 anon_vma_lock_write(__anon_vma);                        \
 117                 anon_vma_unlock_write(__anon_vma);                      \
 118                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
 119                        pmd_trans_huge(*____pmd));                       \
 120         } while (0)
 121 extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
 122                 pmd_t *pmd);
 123 #if HPAGE_PMD_ORDER >= MAX_ORDER
 124 #error "hugepages can't be allocated by the buddy allocator"
 125 #endif
 126 extern int hugepage_madvise(struct vm_area_struct *vma,
 127                             unsigned long *vm_flags, int advice);
 128 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 129                                     unsigned long start,
 130                                     unsigned long end,
 131                                     long adjust_next);
 132 extern int __pmd_trans_huge_lock(pmd_t *pmd,
 133                                  struct vm_area_struct *vma);
 134 /* mmap_sem must be held on entry */
 135 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 136                                       struct vm_area_struct *vma)
 137 {
 138         VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
 139         if (pmd_trans_huge(*pmd))
 140                 return __pmd_trans_huge_lock(pmd, vma);
 141         else
 142                 return 0;
 143 }
 144 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 145                                          unsigned long start,
 146                                          unsigned long end,
 147                                          long adjust_next)
 148 {
 149         if (!vma->anon_vma || vma->vm_ops)
 150                 return;
 151         __vma_adjust_trans_huge(vma, start, end, adjust_next);
 152 }
 153 static inline int hpage_nr_pages(struct page *page)
 154 {
 155         if (unlikely(PageTransHuge(page)))
 156                 return HPAGE_PMD_NR;
 157         return 1;
 158 }
 159 static inline struct page *compound_trans_head(struct page *page)
 160 {
 161         if (PageTail(page)) {
 162                 struct page *head;
 163                 head = page->first_page;
 164                 smp_rmb();
 165                 /*
 166                  * head may be a dangling pointer.
 167                  * __split_huge_page_refcount clears PageTail before
 168                  * overwriting first_page, so if PageTail is still
 169                  * there it means the head pointer isn't dangling.
 170                  */
 171                 if (PageTail(page))
 172                         return head;
 173         }
 174         return page;
 175 }
 176
 177 extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
 178                                 unsigned long addr, pmd_t pmd, pmd_t *pmdp);
 179
 180 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 181 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 182 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 183 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 184
 185 #define hpage_nr_pages(x) 1
 186
 187 #define transparent_hugepage_enabled(__vma) 0
 188
 189 #define transparent_hugepage_flags 0UL
 190 static inline int
 191 split_huge_page_to_list(struct page *page, struct list_head *list)
 192 {
 193         return 0;
 194 }
 195 static inline int split_huge_page(struct page *page)
 196 {
 197         return 0;
 198 }
 199 #define split_huge_page_pmd(__vma, __address, __pmd)    \
 200         do { } while (0)
 201 #define wait_split_huge_page(__anon_vma, __pmd) \
 202         do { } while (0)
 203 #define split_huge_page_pmd_mm(__mm, __address, __pmd)  \
 204         do { } while (0)
 205 #define compound_trans_head(page) compound_head(page)
 206 static inline int hugepage_madvise(struct vm_area_struct *vma,
 207                                    unsigned long *vm_flags, int advice)
 208 {
 209         BUG();
 210         return 0;
 211 }
 212 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 213                                          unsigned long start,
 214                                          unsigned long end,
 215                                          long adjust_next)
 216 {
 217 }
 218 static inline int pmd_trans_huge_lock(pmd_t *pmd,
 219                                       struct vm_area_struct *vma)
 220 {
 221         return 0;
 222 }
 223
 224 static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
 225                                         unsigned long addr, pmd_t pmd, pmd_t *pmdp)
 226 {
 227         return 0;
 228 }
 229
 230 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 231
 232 #endif /* _LINUX_HUGE_MM_H */