1 #ifndef __LINUX_PAGE_EXT_H
2 #define __LINUX_PAGE_EXT_H
4 #include <linux/types.h>
5 #include <linux/stacktrace.h>
6 #include <linux/stackdepot.h>
9 struct page_ext_operations {
16 #ifdef CONFIG_PAGE_EXTENSION
19 * page_ext->flags bits:
21 * PAGE_EXT_DEBUG_POISON is set for poisoned pages. This is used to
22 * implement generic debug pagealloc feature. The pages are filled with
23 * poison patterns and set this flag after free_pages(). The poisoned
24 * pages are verified whether the patterns are not corrupted and clear
25 * the flag before alloc_pages().
29 PAGE_EXT_DEBUG_POISON, /* Page is poisoned */
32 #if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
39 * Page Extension can be considered as an extended mem_map.
40 * A page_ext page is associated with every page descriptor. The
41 * page_ext helps us add more information about the page.
42 * All page_ext are allocated at boot or memory hotplug event,
43 * then the page_ext for pfn always exists.
49 extern void pgdat_page_ext_init(struct pglist_data *pgdat);
51 #ifdef CONFIG_SPARSEMEM
52 static inline void page_ext_init_flatmem(void)
55 extern void page_ext_init(void);
57 extern void page_ext_init_flatmem(void);
58 static inline void page_ext_init(void)
63 struct page_ext *lookup_page_ext(struct page *page);
65 #else /* !CONFIG_PAGE_EXTENSION */
68 static inline void pgdat_page_ext_init(struct pglist_data *pgdat)
72 static inline struct page_ext *lookup_page_ext(struct page *page)
77 static inline void page_ext_init(void)
81 static inline void page_ext_init_flatmem(void)
84 #endif /* CONFIG_PAGE_EXTENSION */
85 #endif /* __LINUX_PAGE_EXT_H */