include/linux/pagewalk.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_PAGEWALK_H
   3 #define _LINUX_PAGEWALK_H
   4
   5 #include <linux/mm.h>
   6
   7 struct mm_walk;
   8
   9 /**
  10  * mm_walk_ops - callbacks for walk_page_range
  11  * @pud_entry:          if set, called for each non-empty PUD (2nd-level) entry
  12  *                      this handler should only handle pud_trans_huge() puds.
  13  *                      the pmd_entry or pte_entry callbacks will be used for
  14  *                      regular PUDs.
  15  * @pmd_entry:          if set, called for each non-empty PMD (3rd-level) entry
  16  *                      this handler is required to be able to handle
  17  *                      pmd_trans_huge() pmds.  They may simply choose to
  18  *                      split_huge_page() instead of handling it explicitly.
  19  * @pte_entry:          if set, called for each non-empty PTE (4th-level) entry
  20  * @pte_hole:           if set, called for each hole at all levels
  21  * @hugetlb_entry:      if set, called for each hugetlb entry
  22  * @test_walk:          caller specific callback function to determine whether
  23  *                      we walk over the current vma or not. Returning 0 means
  24  *                      "do page table walk over the current vma", returning
  25  *                      a negative value means "abort current page table walk
  26  *                      right now" and returning 1 means "skip the current vma"
  27  * @pre_vma:            if set, called before starting walk on a non-null vma.
  28  * @post_vma:           if set, called after a walk on a non-null vma, provided
  29  *                      that @pre_vma and the vma walk succeeded.
  30  */
  31 struct mm_walk_ops {
  32         int (*pud_entry)(pud_t *pud, unsigned long addr,
  33                          unsigned long next, struct mm_walk *walk);
  34         int (*pmd_entry)(pmd_t *pmd, unsigned long addr,
  35                          unsigned long next, struct mm_walk *walk);
  36         int (*pte_entry)(pte_t *pte, unsigned long addr,
  37                          unsigned long next, struct mm_walk *walk);
  38         int (*pte_hole)(unsigned long addr, unsigned long next,
  39                         struct mm_walk *walk);
  40         int (*hugetlb_entry)(pte_t *pte, unsigned long hmask,
  41                              unsigned long addr, unsigned long next,
  42                              struct mm_walk *walk);
  43         int (*test_walk)(unsigned long addr, unsigned long next,
  44                         struct mm_walk *walk);
  45         int (*pre_vma)(unsigned long start, unsigned long end,
  46                        struct mm_walk *walk);
  47         void (*post_vma)(struct mm_walk *walk);
  48 };
  49
  50 /**
  51  * mm_walk - walk_page_range data
  52  * @ops:        operation to call during the walk
  53  * @mm:         mm_struct representing the target process of page table walk
  54  * @vma:        vma currently walked (NULL if walking outside vmas)
  55  * @private:    private data for callbacks' usage
  56  *
  57  * (see the comment on walk_page_range() for more details)
  58  */
  59 struct mm_walk {
  60         const struct mm_walk_ops *ops;
  61         struct mm_struct *mm;
  62         struct vm_area_struct *vma;
  63         void *private;
  64 };
  65
  66 int walk_page_range(struct mm_struct *mm, unsigned long start,
  67                 unsigned long end, const struct mm_walk_ops *ops,
  68                 void *private);
  69 int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops,
  70                 void *private);
  71 int walk_page_mapping(struct address_space *mapping, pgoff_t first_index,
  72                       pgoff_t nr, const struct mm_walk_ops *ops,
  73                       void *private);
  74
  75 #endif /* _LINUX_PAGEWALK_H */