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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, |
33c3fc71 VD |
29 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT) |
30 | PAGE_EXT_YOUNG, | |
31 | PAGE_EXT_IDLE, | |
32 | #endif | |
e30825f1 JK |
33 | }; |
34 | ||
eefa864b JK |
35 | /* |
36 | * Page Extension can be considered as an extended mem_map. | |
37 | * A page_ext page is associated with every page descriptor. The | |
38 | * page_ext helps us add more information about the page. | |
39 | * All page_ext are allocated at boot or memory hotplug event, | |
40 | * then the page_ext for pfn always exists. | |
41 | */ | |
42 | struct page_ext { | |
43 | unsigned long flags; | |
48c96a36 JK |
44 | #ifdef CONFIG_PAGE_OWNER |
45 | unsigned int order; | |
46 | gfp_t gfp_mask; | |
94f759d6 | 47 | unsigned int nr_entries; |
7cd12b4a | 48 | int last_migrate_reason; |
48c96a36 JK |
49 | unsigned long trace_entries[8]; |
50 | #endif | |
eefa864b JK |
51 | }; |
52 | ||
53 | extern void pgdat_page_ext_init(struct pglist_data *pgdat); | |
54 | ||
55 | #ifdef CONFIG_SPARSEMEM | |
56 | static inline void page_ext_init_flatmem(void) | |
57 | { | |
58 | } | |
59 | extern void page_ext_init(void); | |
60 | #else | |
61 | extern void page_ext_init_flatmem(void); | |
62 | static inline void page_ext_init(void) | |
63 | { | |
64 | } | |
65 | #endif | |
66 | ||
67 | struct page_ext *lookup_page_ext(struct page *page); | |
68 | ||
69 | #else /* !CONFIG_PAGE_EXTENSION */ | |
70 | struct page_ext; | |
71 | ||
72 | static inline void pgdat_page_ext_init(struct pglist_data *pgdat) | |
73 | { | |
74 | } | |
75 | ||
76 | static inline struct page_ext *lookup_page_ext(struct page *page) | |
77 | { | |
78 | return NULL; | |
79 | } | |
80 | ||
81 | static inline void page_ext_init(void) | |
82 | { | |
83 | } | |
84 | ||
85 | static inline void page_ext_init_flatmem(void) | |
86 | { | |
87 | } | |
88 | #endif /* CONFIG_PAGE_EXTENSION */ | |
89 | #endif /* __LINUX_PAGE_EXT_H */ |