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