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
  23 enum transparent_hugepage_flag {
  24         TRANSPARENT_HUGEPAGE_FLAG,
  25         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
  26         TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
  27         TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
  28         TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
  29 #ifdef CONFIG_DEBUG_VM
  30         TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
  31 #endif
  32 };
  33
  34 enum page_check_address_pmd_flag {
  35         PAGE_CHECK_ADDRESS_PMD_FLAG,
  36         PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
  37         PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
  38 };
  39 extern pmd_t *page_check_address_pmd(struct page *page,
  40                                      struct mm_struct *mm,
  41                                      unsigned long address,
  42                                      enum page_check_address_pmd_flag flag);
  43
  44 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  45 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
  46 #define HPAGE_PMD_MASK HPAGE_MASK
  47 #define HPAGE_PMD_SIZE HPAGE_SIZE
  48
  49 #define transparent_hugepage_enabled(__vma)                             \
  50         (transparent_hugepage_flags & (1<<TRANSPARENT_HUGEPAGE_FLAG) || \
  51          (transparent_hugepage_flags &                                  \
  52           (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&                    \
  53           (__vma)->vm_flags & VM_HUGEPAGE))
  54 #define transparent_hugepage_defrag(__vma)                              \
  55         ((transparent_hugepage_flags &                                  \
  56           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||                     \
  57          (transparent_hugepage_flags &                                  \
  58           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&             \
  59           (__vma)->vm_flags & VM_HUGEPAGE))
  60 #ifdef CONFIG_DEBUG_VM
  61 #define transparent_hugepage_debug_cow()                                \
  62         (transparent_hugepage_flags &                                   \
  63          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
  64 #else /* CONFIG_DEBUG_VM */
  65 #define transparent_hugepage_debug_cow() 0
  66 #endif /* CONFIG_DEBUG_VM */
  67
  68 extern unsigned long transparent_hugepage_flags;
  69 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  70                           pmd_t *dst_pmd, pmd_t *src_pmd,
  71                           struct vm_area_struct *vma,
  72                           unsigned long addr, unsigned long end);
  73 extern int handle_pte_fault(struct mm_struct *mm,
  74                             struct vm_area_struct *vma, unsigned long address,
  75                             pte_t *pte, pmd_t *pmd, unsigned int flags);
  76 extern int split_huge_page(struct page *page);
  77 extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
  78 #define split_huge_page_pmd(__mm, __pmd)                                \
  79         do {                                                            \
  80                 pmd_t *____pmd = (__pmd);                               \
  81                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
  82                         __split_huge_page_pmd(__mm, ____pmd);           \
  83         }  while (0)
  84 #define wait_split_huge_page(__anon_vma, __pmd)                         \
  85         do {                                                            \
  86                 pmd_t *____pmd = (__pmd);                               \
  87                 spin_unlock_wait(&(__anon_vma)->root->lock);            \
  88                 /*                                                      \
  89                  * spin_unlock_wait() is just a loop in C and so the    \
  90                  * CPU can reorder anything around it.                  \
  91                  */                                                     \
  92                 smp_mb();                                               \
  93                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
  94                        pmd_trans_huge(*____pmd));                       \
  95         } while (0)
  96 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
  97 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
  98 #if HPAGE_PMD_ORDER > MAX_ORDER
  99 #error "hugepages can't be allocated by the buddy allocator"
 100 #endif
 101 extern int hugepage_madvise(unsigned long *vm_flags);
 102 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 103 #define HPAGE_PMD_SHIFT ({ BUG(); 0; })
 104 #define HPAGE_PMD_MASK ({ BUG(); 0; })
 105 #define HPAGE_PMD_SIZE ({ BUG(); 0; })
 106
 107 #define transparent_hugepage_enabled(__vma) 0
 108
 109 #define transparent_hugepage_flags 0UL
 110 static inline int split_huge_page(struct page *page)
 111 {
 112         return 0;
 113 }
 114 #define split_huge_page_pmd(__mm, __pmd)        \
 115         do { } while (0)
 116 #define wait_split_huge_page(__anon_vma, __pmd) \
 117         do { } while (0)
 118 static inline int hugepage_madvise(unsigned long *vm_flags)
 119 {
 120         BUG();
 121         return 0;
 122 }
 123 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 124
 125 #endif /* _LINUX_HUGE_MM_H */