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a520110e CH |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_PAGEWALK_H | |
3 | #define _LINUX_PAGEWALK_H | |
4 | ||
5 | #include <linux/mm.h> | |
6 | ||
7b86ac33 CH |
7 | struct mm_walk; |
8 | ||
a520110e | 9 | /** |
7b86ac33 | 10 | * mm_walk_ops - callbacks for walk_page_range |
3afc4236 SP |
11 | * @pgd_entry: if set, called for each non-empty PGD (top-level) entry |
12 | * @p4d_entry: if set, called for each non-empty P4D entry | |
13 | * @pud_entry: if set, called for each non-empty PUD entry | |
14 | * @pmd_entry: if set, called for each non-empty PMD entry | |
7b86ac33 CH |
15 | * this handler is required to be able to handle |
16 | * pmd_trans_huge() pmds. They may simply choose to | |
17 | * split_huge_page() instead of handling it explicitly. | |
3afc4236 SP |
18 | * @pte_entry: if set, called for each non-empty PTE (lowest-level) |
19 | * entry | |
b7a16c7a SP |
20 | * @pte_hole: if set, called for each hole at all levels, |
21 | * depth is -1 if not known, 0:PGD, 1:P4D, 2:PUD, 3:PMD | |
22 | * 4:PTE. Any folded depths (where PTRS_PER_P?D is equal | |
23 | * to 1) are skipped. | |
7b86ac33 CH |
24 | * @hugetlb_entry: if set, called for each hugetlb entry |
25 | * @test_walk: caller specific callback function to determine whether | |
26 | * we walk over the current vma or not. Returning 0 means | |
27 | * "do page table walk over the current vma", returning | |
28 | * a negative value means "abort current page table walk | |
29 | * right now" and returning 1 means "skip the current vma" | |
ecaad8ac TH |
30 | * @pre_vma: if set, called before starting walk on a non-null vma. |
31 | * @post_vma: if set, called after a walk on a non-null vma, provided | |
32 | * that @pre_vma and the vma walk succeeded. | |
3afc4236 SP |
33 | * |
34 | * p?d_entry callbacks are called even if those levels are folded on a | |
35 | * particular architecture/configuration. | |
a520110e | 36 | */ |
7b86ac33 | 37 | struct mm_walk_ops { |
3afc4236 SP |
38 | int (*pgd_entry)(pgd_t *pgd, unsigned long addr, |
39 | unsigned long next, struct mm_walk *walk); | |
40 | int (*p4d_entry)(p4d_t *p4d, unsigned long addr, | |
41 | unsigned long next, struct mm_walk *walk); | |
a520110e CH |
42 | int (*pud_entry)(pud_t *pud, unsigned long addr, |
43 | unsigned long next, struct mm_walk *walk); | |
44 | int (*pmd_entry)(pmd_t *pmd, unsigned long addr, | |
45 | unsigned long next, struct mm_walk *walk); | |
46 | int (*pte_entry)(pte_t *pte, unsigned long addr, | |
47 | unsigned long next, struct mm_walk *walk); | |
48 | int (*pte_hole)(unsigned long addr, unsigned long next, | |
b7a16c7a | 49 | int depth, struct mm_walk *walk); |
a520110e CH |
50 | int (*hugetlb_entry)(pte_t *pte, unsigned long hmask, |
51 | unsigned long addr, unsigned long next, | |
52 | struct mm_walk *walk); | |
53 | int (*test_walk)(unsigned long addr, unsigned long next, | |
54 | struct mm_walk *walk); | |
ecaad8ac TH |
55 | int (*pre_vma)(unsigned long start, unsigned long end, |
56 | struct mm_walk *walk); | |
57 | void (*post_vma)(struct mm_walk *walk); | |
7b86ac33 CH |
58 | }; |
59 | ||
3afc4236 SP |
60 | /* |
61 | * Action for pud_entry / pmd_entry callbacks. | |
62 | * ACTION_SUBTREE is the default | |
63 | */ | |
64 | enum page_walk_action { | |
65 | /* Descend to next level, splitting huge pages if needed and possible */ | |
66 | ACTION_SUBTREE = 0, | |
67 | /* Continue to next entry at this level (ignoring any subtree) */ | |
68 | ACTION_CONTINUE = 1, | |
69 | /* Call again for this entry */ | |
70 | ACTION_AGAIN = 2 | |
71 | }; | |
72 | ||
7b86ac33 CH |
73 | /** |
74 | * mm_walk - walk_page_range data | |
75 | * @ops: operation to call during the walk | |
76 | * @mm: mm_struct representing the target process of page table walk | |
e47690d7 | 77 | * @pgd: pointer to PGD; only valid with no_vma (otherwise set to NULL) |
7b86ac33 | 78 | * @vma: vma currently walked (NULL if walking outside vmas) |
3afc4236 | 79 | * @action: next action to perform (see enum page_walk_action) |
488ae6a2 | 80 | * @no_vma: walk ignoring vmas (vma will always be NULL) |
7b86ac33 CH |
81 | * @private: private data for callbacks' usage |
82 | * | |
83 | * (see the comment on walk_page_range() for more details) | |
84 | */ | |
85 | struct mm_walk { | |
86 | const struct mm_walk_ops *ops; | |
a520110e | 87 | struct mm_struct *mm; |
e47690d7 | 88 | pgd_t *pgd; |
a520110e | 89 | struct vm_area_struct *vma; |
3afc4236 | 90 | enum page_walk_action action; |
488ae6a2 | 91 | bool no_vma; |
a520110e CH |
92 | void *private; |
93 | }; | |
94 | ||
7b86ac33 CH |
95 | int walk_page_range(struct mm_struct *mm, unsigned long start, |
96 | unsigned long end, const struct mm_walk_ops *ops, | |
97 | void *private); | |
488ae6a2 SP |
98 | int walk_page_range_novma(struct mm_struct *mm, unsigned long start, |
99 | unsigned long end, const struct mm_walk_ops *ops, | |
e47690d7 | 100 | pgd_t *pgd, |
488ae6a2 | 101 | void *private); |
7b86ac33 CH |
102 | int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, |
103 | void *private); | |
ecaad8ac TH |
104 | int walk_page_mapping(struct address_space *mapping, pgoff_t first_index, |
105 | pgoff_t nr, const struct mm_walk_ops *ops, | |
106 | void *private); | |
a520110e CH |
107 | |
108 | #endif /* _LINUX_PAGEWALK_H */ |