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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * include/linux/pagevec.h | |
4 | * | |
5 | * In many places it is efficient to batch an operation up against multiple | |
6 | * pages. A pagevec is a multipage container which is used for that. | |
7 | */ | |
8 | ||
78854014 DH |
9 | #ifndef _LINUX_PAGEVEC_H |
10 | #define _LINUX_PAGEVEC_H | |
11 | ||
10bbd235 MW |
12 | #include <linux/xarray.h> |
13 | ||
146500e9 MW |
14 | /* 15 pointers + header align the pagevec structure to a power of two */ |
15 | #define PAGEVEC_SIZE 15 | |
1da177e4 LT |
16 | |
17 | struct page; | |
10331795 | 18 | struct folio; |
1da177e4 LT |
19 | struct address_space; |
20 | ||
10331795 | 21 | /* Layout must match folio_batch */ |
1da177e4 | 22 | struct pagevec { |
146500e9 | 23 | unsigned char nr; |
7f0b5fb9 | 24 | bool percpu_pvec_drained; |
1da177e4 LT |
25 | struct page *pages[PAGEVEC_SIZE]; |
26 | }; | |
27 | ||
28 | void __pagevec_release(struct pagevec *pvec); | |
1da177e4 | 29 | |
86679820 | 30 | static inline void pagevec_init(struct pagevec *pvec) |
1da177e4 LT |
31 | { |
32 | pvec->nr = 0; | |
7f0b5fb9 | 33 | pvec->percpu_pvec_drained = false; |
1da177e4 LT |
34 | } |
35 | ||
36 | static inline void pagevec_reinit(struct pagevec *pvec) | |
37 | { | |
38 | pvec->nr = 0; | |
39 | } | |
40 | ||
41 | static inline unsigned pagevec_count(struct pagevec *pvec) | |
42 | { | |
43 | return pvec->nr; | |
44 | } | |
45 | ||
46 | static inline unsigned pagevec_space(struct pagevec *pvec) | |
47 | { | |
48 | return PAGEVEC_SIZE - pvec->nr; | |
49 | } | |
50 | ||
51 | /* | |
52 | * Add a page to a pagevec. Returns the number of slots still available. | |
53 | */ | |
54 | static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page) | |
55 | { | |
56 | pvec->pages[pvec->nr++] = page; | |
57 | return pagevec_space(pvec); | |
58 | } | |
59 | ||
1da177e4 LT |
60 | static inline void pagevec_release(struct pagevec *pvec) |
61 | { | |
62 | if (pagevec_count(pvec)) | |
63 | __pagevec_release(pvec); | |
64 | } | |
65 | ||
10331795 MWO |
66 | /** |
67 | * struct folio_batch - A collection of folios. | |
68 | * | |
69 | * The folio_batch is used to amortise the cost of retrieving and | |
70 | * operating on a set of folios. The order of folios in the batch may be | |
71 | * significant (eg delete_from_page_cache_batch()). Some users of the | |
72 | * folio_batch store "exceptional" entries in it which can be removed | |
73 | * by calling folio_batch_remove_exceptionals(). | |
74 | */ | |
75 | struct folio_batch { | |
76 | unsigned char nr; | |
77 | bool percpu_pvec_drained; | |
78 | struct folio *folios[PAGEVEC_SIZE]; | |
79 | }; | |
80 | ||
81 | /* Layout must match pagevec */ | |
82 | static_assert(sizeof(struct pagevec) == sizeof(struct folio_batch)); | |
83 | static_assert(offsetof(struct pagevec, pages) == | |
84 | offsetof(struct folio_batch, folios)); | |
85 | ||
86 | /** | |
87 | * folio_batch_init() - Initialise a batch of folios | |
88 | * @fbatch: The folio batch. | |
89 | * | |
90 | * A freshly initialised folio_batch contains zero folios. | |
91 | */ | |
92 | static inline void folio_batch_init(struct folio_batch *fbatch) | |
93 | { | |
94 | fbatch->nr = 0; | |
6840f909 | 95 | fbatch->percpu_pvec_drained = false; |
10331795 MWO |
96 | } |
97 | ||
81156128 LS |
98 | static inline void folio_batch_reinit(struct folio_batch *fbatch) |
99 | { | |
100 | fbatch->nr = 0; | |
101 | } | |
102 | ||
10331795 MWO |
103 | static inline unsigned int folio_batch_count(struct folio_batch *fbatch) |
104 | { | |
105 | return fbatch->nr; | |
106 | } | |
107 | ||
108 | static inline unsigned int fbatch_space(struct folio_batch *fbatch) | |
109 | { | |
110 | return PAGEVEC_SIZE - fbatch->nr; | |
111 | } | |
112 | ||
113 | /** | |
114 | * folio_batch_add() - Add a folio to a batch. | |
115 | * @fbatch: The folio batch. | |
116 | * @folio: The folio to add. | |
117 | * | |
118 | * The folio is added to the end of the batch. | |
119 | * The batch must have previously been initialised using folio_batch_init(). | |
120 | * | |
121 | * Return: The number of slots still available. | |
122 | */ | |
123 | static inline unsigned folio_batch_add(struct folio_batch *fbatch, | |
124 | struct folio *folio) | |
125 | { | |
126 | fbatch->folios[fbatch->nr++] = folio; | |
127 | return fbatch_space(fbatch); | |
128 | } | |
129 | ||
130 | static inline void folio_batch_release(struct folio_batch *fbatch) | |
131 | { | |
132 | pagevec_release((struct pagevec *)fbatch); | |
133 | } | |
134 | ||
1613fac9 | 135 | void folio_batch_remove_exceptionals(struct folio_batch *fbatch); |
78854014 | 136 | #endif /* _LINUX_PAGEVEC_H */ |