| /* SPDX-License-Identifier: GPL-2.0 */ |
| #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 |
| |
| enum page_ext_flags { |
| PAGE_EXT_OWNER, |
| PAGE_EXT_OWNER_ALLOCATED, |
| #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 unsigned long page_ext_size; |
| 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); |
| static inline void page_ext_init_flatmem_late(void) |
| { |
| } |
| #else |
| extern void page_ext_init_flatmem(void); |
| extern void page_ext_init_flatmem_late(void); |
| static inline void page_ext_init(void) |
| { |
| } |
| #endif |
| |
| struct page_ext *lookup_page_ext(const struct page *page); |
| |
| static inline struct page_ext *page_ext_next(struct page_ext *curr) |
| { |
| void *next = curr; |
| next += page_ext_size; |
| return next; |
| } |
| |
| #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(const struct page *page) |
| { |
| return NULL; |
| } |
| |
| static inline void page_ext_init(void) |
| { |
| } |
| |
| static inline void page_ext_init_flatmem_late(void) |
| { |
| } |
| |
| static inline void page_ext_init_flatmem(void) |
| { |
| } |
| #endif /* CONFIG_PAGE_EXTENSION */ |
| #endif /* __LINUX_PAGE_EXT_H */ |