76 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			76 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef __LINUX_PAGE_EXT_H
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| #define __LINUX_PAGE_EXT_H
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| 
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| #include <linux/types.h>
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| #include <linux/stacktrace.h>
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| #include <linux/stackdepot.h>
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| 
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| struct pglist_data;
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| struct page_ext_operations {
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| 	size_t offset;
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| 	size_t size;
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| 	bool (*need)(void);
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| 	void (*init)(void);
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| };
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| 
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| #ifdef CONFIG_PAGE_EXTENSION
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| 
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| enum page_ext_flags {
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| 	PAGE_EXT_DEBUG_GUARD,
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| 	PAGE_EXT_OWNER,
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| #if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
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| 	PAGE_EXT_YOUNG,
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| 	PAGE_EXT_IDLE,
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| #endif
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| };
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| 
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| /*
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|  * Page Extension can be considered as an extended mem_map.
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|  * A page_ext page is associated with every page descriptor. The
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|  * page_ext helps us add more information about the page.
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|  * All page_ext are allocated at boot or memory hotplug event,
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|  * then the page_ext for pfn always exists.
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|  */
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| struct page_ext {
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| 	unsigned long flags;
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| };
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| 
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| extern void pgdat_page_ext_init(struct pglist_data *pgdat);
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| 
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| #ifdef CONFIG_SPARSEMEM
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| static inline void page_ext_init_flatmem(void)
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| {
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| }
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| extern void page_ext_init(void);
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| #else
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| extern void page_ext_init_flatmem(void);
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| static inline void page_ext_init(void)
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| {
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| }
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| #endif
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| 
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| struct page_ext *lookup_page_ext(const struct page *page);
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| 
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| #else /* !CONFIG_PAGE_EXTENSION */
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| struct page_ext;
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| 
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| static inline void pgdat_page_ext_init(struct pglist_data *pgdat)
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| {
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| }
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| 
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| static inline struct page_ext *lookup_page_ext(const struct page *page)
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| {
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| 	return NULL;
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| }
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| 
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| static inline void page_ext_init(void)
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| {
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| }
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| 
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| static inline void page_ext_init_flatmem(void)
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| {
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| }
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| #endif /* CONFIG_PAGE_EXTENSION */
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| #endif /* __LINUX_PAGE_EXT_H */
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