#ifndef __LINUX_PAGE_EXT_H #define __LINUX_PAGE_EXT_H #include <linux/types.h> #include <linux/stacktrace.h> #include <linux/stackdepot.h> struct pglist_data; struct page_ext_operations { size_t offset; size_t size; bool (*need)(void); void (*init)(void); }; #ifdef CONFIG_PAGE_EXTENSION /* * page_ext->flags bits: * * PAGE_EXT_DEBUG_POISON is set for poisoned pages. This is used to * implement generic debug pagealloc feature. The pages are filled with * poison patterns and set this flag after free_pages(). The poisoned * pages are verified whether the patterns are not corrupted and clear * the flag before alloc_pages(). */ enum page_ext_flags { PAGE_EXT_DEBUG_POISON, /* Page is poisoned */ PAGE_EXT_DEBUG_GUARD, PAGE_EXT_OWNER, #if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT) PAGE_EXT_YOUNG, PAGE_EXT_IDLE, #endif }; /* * Page Extension can be considered as an extended mem_map. * A page_ext page is associated with every page descriptor. The * page_ext helps us add more information about the page. * All page_ext are allocated at boot or memory hotplug event, * then the page_ext for pfn always exists. */ struct page_ext { unsigned long flags; }; extern void pgdat_page_ext_init(struct pglist_data *pgdat); #ifdef CONFIG_SPARSEMEM static inline void page_ext_init_flatmem(void) { } extern void page_ext_init(void); #else extern void page_ext_init_flatmem(void); static inline void page_ext_init(void) { } #endif struct page_ext *lookup_page_ext(struct page *page); #else /* !CONFIG_PAGE_EXTENSION */ struct page_ext; static inline void pgdat_page_ext_init(struct pglist_data *pgdat) { } static inline struct page_ext *lookup_page_ext(struct page *page) { return NULL; } static inline void page_ext_init(void) { } static inline void page_ext_init_flatmem(void) { } #endif /* CONFIG_PAGE_EXTENSION */ #endif /* __LINUX_PAGE_EXT_H */