Commit | Line | Data |
---|---|---|
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 | /** |
91ab1a41 | 10 | * struct 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. | |
e2f8f44b REB |
18 | * @pte_entry: if set, called for each PTE (lowest-level) entry, |
19 | * including empty ones | |
b7a16c7a | 20 | * @pte_hole: if set, called for each hole at all levels, |
e2f8f44b REB |
21 | * depth is -1 if not known, 0:PGD, 1:P4D, 2:PUD, 3:PMD. |
22 | * Any folded depths (where PTRS_PER_P?D is equal to 1) | |
23 | * are skipped. | |
dd361e50 PX |
24 | * @hugetlb_entry: if set, called for each hugetlb entry. This hook |
25 | * function is called with the vma lock held, in order to | |
26 | * protect against a concurrent freeing of the pte_t* or | |
27 | * the ptl. In some cases, the hook function needs to drop | |
28 | * and retake the vma lock in order to avoid deadlocks | |
29 | * while calling other functions. In such cases the hook | |
30 | * function must either refrain from accessing the pte or | |
31 | * ptl after dropping the vma lock, or else revalidate | |
32 | * those items after re-acquiring the vma lock and before | |
33 | * accessing them. | |
7b86ac33 CH |
34 | * @test_walk: caller specific callback function to determine whether |
35 | * we walk over the current vma or not. Returning 0 means | |
36 | * "do page table walk over the current vma", returning | |
37 | * a negative value means "abort current page table walk | |
38 | * right now" and returning 1 means "skip the current vma" | |
c31783ee DH |
39 | * Note that this callback is not called when the caller |
40 | * passes in a single VMA as for walk_page_vma(). | |
ecaad8ac TH |
41 | * @pre_vma: if set, called before starting walk on a non-null vma. |
42 | * @post_vma: if set, called after a walk on a non-null vma, provided | |
43 | * that @pre_vma and the vma walk succeeded. | |
3afc4236 SP |
44 | * |
45 | * p?d_entry callbacks are called even if those levels are folded on a | |
46 | * particular architecture/configuration. | |
a520110e | 47 | */ |
7b86ac33 | 48 | struct mm_walk_ops { |
3afc4236 SP |
49 | int (*pgd_entry)(pgd_t *pgd, unsigned long addr, |
50 | unsigned long next, struct mm_walk *walk); | |
51 | int (*p4d_entry)(p4d_t *p4d, unsigned long addr, | |
52 | unsigned long next, struct mm_walk *walk); | |
a520110e CH |
53 | int (*pud_entry)(pud_t *pud, unsigned long addr, |
54 | unsigned long next, struct mm_walk *walk); | |
55 | int (*pmd_entry)(pmd_t *pmd, unsigned long addr, | |
56 | unsigned long next, struct mm_walk *walk); | |
57 | int (*pte_entry)(pte_t *pte, unsigned long addr, | |
58 | unsigned long next, struct mm_walk *walk); | |
59 | int (*pte_hole)(unsigned long addr, unsigned long next, | |
b7a16c7a | 60 | int depth, struct mm_walk *walk); |
a520110e CH |
61 | int (*hugetlb_entry)(pte_t *pte, unsigned long hmask, |
62 | unsigned long addr, unsigned long next, | |
63 | struct mm_walk *walk); | |
64 | int (*test_walk)(unsigned long addr, unsigned long next, | |
65 | struct mm_walk *walk); | |
ecaad8ac TH |
66 | int (*pre_vma)(unsigned long start, unsigned long end, |
67 | struct mm_walk *walk); | |
68 | void (*post_vma)(struct mm_walk *walk); | |
7b86ac33 CH |
69 | }; |
70 | ||
3afc4236 SP |
71 | /* |
72 | * Action for pud_entry / pmd_entry callbacks. | |
73 | * ACTION_SUBTREE is the default | |
74 | */ | |
75 | enum page_walk_action { | |
76 | /* Descend to next level, splitting huge pages if needed and possible */ | |
77 | ACTION_SUBTREE = 0, | |
78 | /* Continue to next entry at this level (ignoring any subtree) */ | |
79 | ACTION_CONTINUE = 1, | |
80 | /* Call again for this entry */ | |
81 | ACTION_AGAIN = 2 | |
82 | }; | |
83 | ||
7b86ac33 | 84 | /** |
91ab1a41 | 85 | * struct mm_walk - walk_page_range data |
7b86ac33 CH |
86 | * @ops: operation to call during the walk |
87 | * @mm: mm_struct representing the target process of page table walk | |
e47690d7 | 88 | * @pgd: pointer to PGD; only valid with no_vma (otherwise set to NULL) |
7b86ac33 | 89 | * @vma: vma currently walked (NULL if walking outside vmas) |
3afc4236 | 90 | * @action: next action to perform (see enum page_walk_action) |
488ae6a2 | 91 | * @no_vma: walk ignoring vmas (vma will always be NULL) |
7b86ac33 CH |
92 | * @private: private data for callbacks' usage |
93 | * | |
94 | * (see the comment on walk_page_range() for more details) | |
95 | */ | |
96 | struct mm_walk { | |
97 | const struct mm_walk_ops *ops; | |
a520110e | 98 | struct mm_struct *mm; |
e47690d7 | 99 | pgd_t *pgd; |
a520110e | 100 | struct vm_area_struct *vma; |
3afc4236 | 101 | enum page_walk_action action; |
488ae6a2 | 102 | bool no_vma; |
a520110e CH |
103 | void *private; |
104 | }; | |
105 | ||
7b86ac33 CH |
106 | int walk_page_range(struct mm_struct *mm, unsigned long start, |
107 | unsigned long end, const struct mm_walk_ops *ops, | |
108 | void *private); | |
488ae6a2 SP |
109 | int walk_page_range_novma(struct mm_struct *mm, unsigned long start, |
110 | unsigned long end, const struct mm_walk_ops *ops, | |
e47690d7 | 111 | pgd_t *pgd, |
488ae6a2 | 112 | void *private); |
e07cda5f DH |
113 | int walk_page_range_vma(struct vm_area_struct *vma, unsigned long start, |
114 | unsigned long end, const struct mm_walk_ops *ops, | |
115 | void *private); | |
7b86ac33 CH |
116 | int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, |
117 | void *private); | |
ecaad8ac TH |
118 | int walk_page_mapping(struct address_space *mapping, pgoff_t first_index, |
119 | pgoff_t nr, const struct mm_walk_ops *ops, | |
120 | void *private); | |
a520110e CH |
121 | |
122 | #endif /* _LINUX_PAGEWALK_H */ |