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1 | #ifndef __LINUX_PAGE_EXT_H |
2 | #define __LINUX_PAGE_EXT_H | |
3 | ||
48c96a36 JK |
4 | #include <linux/types.h> |
5 | #include <linux/stacktrace.h> | |
6 | ||
eefa864b JK |
7 | struct pglist_data; |
8 | struct page_ext_operations { | |
9 | bool (*need)(void); | |
10 | void (*init)(void); | |
11 | }; | |
12 | ||
13 | #ifdef CONFIG_PAGE_EXTENSION | |
14 | ||
e30825f1 JK |
15 | /* |
16 | * page_ext->flags bits: | |
17 | * | |
18 | * PAGE_EXT_DEBUG_POISON is set for poisoned pages. This is used to | |
19 | * implement generic debug pagealloc feature. The pages are filled with | |
20 | * poison patterns and set this flag after free_pages(). The poisoned | |
21 | * pages are verified whether the patterns are not corrupted and clear | |
22 | * the flag before alloc_pages(). | |
23 | */ | |
24 | ||
25 | enum page_ext_flags { | |
26 | PAGE_EXT_DEBUG_POISON, /* Page is poisoned */ | |
27 | PAGE_EXT_DEBUG_GUARD, | |
48c96a36 | 28 | PAGE_EXT_OWNER, |
e30825f1 JK |
29 | }; |
30 | ||
eefa864b JK |
31 | /* |
32 | * Page Extension can be considered as an extended mem_map. | |
33 | * A page_ext page is associated with every page descriptor. The | |
34 | * page_ext helps us add more information about the page. | |
35 | * All page_ext are allocated at boot or memory hotplug event, | |
36 | * then the page_ext for pfn always exists. | |
37 | */ | |
38 | struct page_ext { | |
39 | unsigned long flags; | |
48c96a36 JK |
40 | #ifdef CONFIG_PAGE_OWNER |
41 | unsigned int order; | |
42 | gfp_t gfp_mask; | |
94f759d6 | 43 | unsigned int nr_entries; |
48c96a36 JK |
44 | unsigned long trace_entries[8]; |
45 | #endif | |
eefa864b JK |
46 | }; |
47 | ||
48 | extern void pgdat_page_ext_init(struct pglist_data *pgdat); | |
49 | ||
50 | #ifdef CONFIG_SPARSEMEM | |
51 | static inline void page_ext_init_flatmem(void) | |
52 | { | |
53 | } | |
54 | extern void page_ext_init(void); | |
55 | #else | |
56 | extern void page_ext_init_flatmem(void); | |
57 | static inline void page_ext_init(void) | |
58 | { | |
59 | } | |
60 | #endif | |
61 | ||
62 | struct page_ext *lookup_page_ext(struct page *page); | |
63 | ||
64 | #else /* !CONFIG_PAGE_EXTENSION */ | |
65 | struct page_ext; | |
66 | ||
67 | static inline void pgdat_page_ext_init(struct pglist_data *pgdat) | |
68 | { | |
69 | } | |
70 | ||
71 | static inline struct page_ext *lookup_page_ext(struct page *page) | |
72 | { | |
73 | return NULL; | |
74 | } | |
75 | ||
76 | static inline void page_ext_init(void) | |
77 | { | |
78 | } | |
79 | ||
80 | static inline void page_ext_init_flatmem(void) | |
81 | { | |
82 | } | |
83 | #endif /* CONFIG_PAGE_EXTENSION */ | |
84 | #endif /* __LINUX_PAGE_EXT_H */ |