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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
eefa864b JK |
2 | #ifndef __LINUX_PAGE_EXT_H |
3 | #define __LINUX_PAGE_EXT_H | |
4 | ||
48c96a36 JK |
5 | #include <linux/types.h> |
6 | #include <linux/stacktrace.h> | |
f2ca0b55 | 7 | #include <linux/stackdepot.h> |
48c96a36 | 8 | |
eefa864b | 9 | struct pglist_data; |
6189eb82 PT |
10 | |
11 | /** | |
12 | * struct page_ext_operations - per page_ext client operations | |
13 | * @offset: Offset to the client's data within page_ext. Offset is returned to | |
14 | * the client by page_ext_init. | |
15 | * @size: The size of the client data within page_ext. | |
16 | * @need: Function that returns true if client requires page_ext. | |
17 | * @init: (optional) Called to initialize client once page_exts are allocated. | |
18 | * @need_shared_flags: True when client is using shared page_ext->flags | |
19 | * field. | |
20 | * | |
21 | * Each Page Extension client must define page_ext_operations in | |
22 | * page_ext_ops array. | |
23 | */ | |
eefa864b | 24 | struct page_ext_operations { |
980ac167 JK |
25 | size_t offset; |
26 | size_t size; | |
eefa864b JK |
27 | bool (*need)(void); |
28 | void (*init)(void); | |
6189eb82 | 29 | bool need_shared_flags; |
eefa864b JK |
30 | }; |
31 | ||
32 | #ifdef CONFIG_PAGE_EXTENSION | |
33 | ||
6189eb82 PT |
34 | /* |
35 | * The page_ext_flags users must set need_shared_flags to true. | |
36 | */ | |
e30825f1 | 37 | enum page_ext_flags { |
48c96a36 | 38 | PAGE_EXT_OWNER, |
fdf3bf80 | 39 | PAGE_EXT_OWNER_ALLOCATED, |
1c676e0d | 40 | #if defined(CONFIG_PAGE_IDLE_FLAG) && !defined(CONFIG_64BIT) |
33c3fc71 VD |
41 | PAGE_EXT_YOUNG, |
42 | PAGE_EXT_IDLE, | |
43 | #endif | |
e30825f1 JK |
44 | }; |
45 | ||
eefa864b JK |
46 | /* |
47 | * Page Extension can be considered as an extended mem_map. | |
48 | * A page_ext page is associated with every page descriptor. The | |
49 | * page_ext helps us add more information about the page. | |
50 | * All page_ext are allocated at boot or memory hotplug event, | |
51 | * then the page_ext for pfn always exists. | |
52 | */ | |
53 | struct page_ext { | |
54 | unsigned long flags; | |
55 | }; | |
56 | ||
c4f20f14 | 57 | extern bool early_page_ext; |
5556cfe8 | 58 | extern unsigned long page_ext_size; |
eefa864b JK |
59 | extern void pgdat_page_ext_init(struct pglist_data *pgdat); |
60 | ||
c4f20f14 LZ |
61 | static inline bool early_page_ext_enabled(void) |
62 | { | |
63 | return early_page_ext; | |
64 | } | |
65 | ||
eefa864b JK |
66 | #ifdef CONFIG_SPARSEMEM |
67 | static inline void page_ext_init_flatmem(void) | |
68 | { | |
69 | } | |
70 | extern void page_ext_init(void); | |
7fb7ab6d ZH |
71 | static inline void page_ext_init_flatmem_late(void) |
72 | { | |
73 | } | |
eefa864b JK |
74 | #else |
75 | extern void page_ext_init_flatmem(void); | |
7fb7ab6d | 76 | extern void page_ext_init_flatmem_late(void); |
eefa864b JK |
77 | static inline void page_ext_init(void) |
78 | { | |
79 | } | |
80 | #endif | |
81 | ||
b1d5488a CTK |
82 | extern struct page_ext *page_ext_get(struct page *page); |
83 | extern void page_ext_put(struct page_ext *page_ext); | |
eefa864b | 84 | |
5556cfe8 VB |
85 | static inline struct page_ext *page_ext_next(struct page_ext *curr) |
86 | { | |
87 | void *next = curr; | |
88 | next += page_ext_size; | |
89 | return next; | |
90 | } | |
91 | ||
eefa864b JK |
92 | #else /* !CONFIG_PAGE_EXTENSION */ |
93 | struct page_ext; | |
94 | ||
c4f20f14 LZ |
95 | static inline bool early_page_ext_enabled(void) |
96 | { | |
97 | return false; | |
98 | } | |
99 | ||
eefa864b JK |
100 | static inline void pgdat_page_ext_init(struct pglist_data *pgdat) |
101 | { | |
102 | } | |
103 | ||
eefa864b JK |
104 | static inline void page_ext_init(void) |
105 | { | |
106 | } | |
107 | ||
7fb7ab6d ZH |
108 | static inline void page_ext_init_flatmem_late(void) |
109 | { | |
110 | } | |
111 | ||
eefa864b JK |
112 | static inline void page_ext_init_flatmem(void) |
113 | { | |
114 | } | |
b1d5488a CTK |
115 | |
116 | static inline struct page_ext *page_ext_get(struct page *page) | |
117 | { | |
118 | return NULL; | |
119 | } | |
120 | ||
121 | static inline void page_ext_put(struct page_ext *page_ext) | |
122 | { | |
123 | } | |
eefa864b JK |
124 | #endif /* CONFIG_PAGE_EXTENSION */ |
125 | #endif /* __LINUX_PAGE_EXT_H */ |