LXR linux/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
   7struct 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 */
  31struct 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 */
  59struct 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
  66int walk_page_range(struct mm_struct *mm, unsigned long start,
  67                unsigned long end, const struct mm_walk_ops *ops,
  68                void *private);
  69int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops,
  70                void *private);
  71int 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 */
  76