xref: /OK3568_Linux_fs/kernel/include/linux/page_ext.h (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef __LINUX_PAGE_EXT_H
3*4882a593Smuzhiyun #define __LINUX_PAGE_EXT_H
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun #include <linux/types.h>
6*4882a593Smuzhiyun #include <linux/stacktrace.h>
7*4882a593Smuzhiyun #include <linux/stackdepot.h>
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun struct pglist_data;
10*4882a593Smuzhiyun struct page_ext_operations {
11*4882a593Smuzhiyun 	size_t offset;
12*4882a593Smuzhiyun 	size_t size;
13*4882a593Smuzhiyun 	bool (*need)(void);
14*4882a593Smuzhiyun 	void (*init)(void);
15*4882a593Smuzhiyun };
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun #ifdef CONFIG_PAGE_EXTENSION
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun enum page_ext_flags {
20*4882a593Smuzhiyun 	PAGE_EXT_OWNER,
21*4882a593Smuzhiyun 	PAGE_EXT_OWNER_ALLOCATED,
22*4882a593Smuzhiyun #if defined(CONFIG_PAGE_PINNER)
23*4882a593Smuzhiyun 	/* page refcount was increased by GUP or follow_page(FOLL_GET) */
24*4882a593Smuzhiyun 	PAGE_EXT_GET,
25*4882a593Smuzhiyun 	/* page migration failed */
26*4882a593Smuzhiyun 	PAGE_EXT_PINNER_MIGRATION_FAILED,
27*4882a593Smuzhiyun #endif
28*4882a593Smuzhiyun #if defined(CONFIG_PAGE_IDLE_FLAG) && !defined(CONFIG_64BIT)
29*4882a593Smuzhiyun 	PAGE_EXT_YOUNG,
30*4882a593Smuzhiyun 	PAGE_EXT_IDLE,
31*4882a593Smuzhiyun #endif
32*4882a593Smuzhiyun };
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun /*
35*4882a593Smuzhiyun  * Page Extension can be considered as an extended mem_map.
36*4882a593Smuzhiyun  * A page_ext page is associated with every page descriptor. The
37*4882a593Smuzhiyun  * page_ext helps us add more information about the page.
38*4882a593Smuzhiyun  * All page_ext are allocated at boot or memory hotplug event,
39*4882a593Smuzhiyun  * then the page_ext for pfn always exists.
40*4882a593Smuzhiyun  */
41*4882a593Smuzhiyun struct page_ext {
42*4882a593Smuzhiyun 	unsigned long flags;
43*4882a593Smuzhiyun };
44*4882a593Smuzhiyun 
45*4882a593Smuzhiyun extern unsigned long page_ext_size;
46*4882a593Smuzhiyun extern void pgdat_page_ext_init(struct pglist_data *pgdat);
47*4882a593Smuzhiyun 
48*4882a593Smuzhiyun #ifdef CONFIG_SPARSEMEM
page_ext_init_flatmem(void)49*4882a593Smuzhiyun static inline void page_ext_init_flatmem(void)
50*4882a593Smuzhiyun {
51*4882a593Smuzhiyun }
52*4882a593Smuzhiyun extern void page_ext_init(void);
page_ext_init_flatmem_late(void)53*4882a593Smuzhiyun static inline void page_ext_init_flatmem_late(void)
54*4882a593Smuzhiyun {
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun #else
57*4882a593Smuzhiyun extern void page_ext_init_flatmem(void);
58*4882a593Smuzhiyun extern void page_ext_init_flatmem_late(void);
page_ext_init(void)59*4882a593Smuzhiyun static inline void page_ext_init(void)
60*4882a593Smuzhiyun {
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun #endif
63*4882a593Smuzhiyun struct page_ext *lookup_page_ext(const struct page *page);
64*4882a593Smuzhiyun extern struct page_ext *page_ext_get(struct page *page);
65*4882a593Smuzhiyun extern void page_ext_put(struct page_ext *page_ext);
66*4882a593Smuzhiyun 
page_ext_next(struct page_ext * curr)67*4882a593Smuzhiyun static inline struct page_ext *page_ext_next(struct page_ext *curr)
68*4882a593Smuzhiyun {
69*4882a593Smuzhiyun 	void *next = curr;
70*4882a593Smuzhiyun 	next += page_ext_size;
71*4882a593Smuzhiyun 	return next;
72*4882a593Smuzhiyun }
73*4882a593Smuzhiyun 
74*4882a593Smuzhiyun #else /* !CONFIG_PAGE_EXTENSION */
75*4882a593Smuzhiyun struct page_ext;
76*4882a593Smuzhiyun 
pgdat_page_ext_init(struct pglist_data * pgdat)77*4882a593Smuzhiyun static inline void pgdat_page_ext_init(struct pglist_data *pgdat)
78*4882a593Smuzhiyun {
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun 
page_ext_init(void)81*4882a593Smuzhiyun static inline void page_ext_init(void)
82*4882a593Smuzhiyun {
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun 
page_ext_init_flatmem_late(void)85*4882a593Smuzhiyun static inline void page_ext_init_flatmem_late(void)
86*4882a593Smuzhiyun {
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun 
page_ext_init_flatmem(void)89*4882a593Smuzhiyun static inline void page_ext_init_flatmem(void)
90*4882a593Smuzhiyun {
91*4882a593Smuzhiyun }
92*4882a593Smuzhiyun 
page_ext_get(struct page * page)93*4882a593Smuzhiyun static inline struct page_ext *page_ext_get(struct page *page)
94*4882a593Smuzhiyun {
95*4882a593Smuzhiyun 	return NULL;
96*4882a593Smuzhiyun }
97*4882a593Smuzhiyun 
page_ext_put(struct page_ext * page_ext)98*4882a593Smuzhiyun static inline void page_ext_put(struct page_ext *page_ext)
99*4882a593Smuzhiyun {
100*4882a593Smuzhiyun }
101*4882a593Smuzhiyun #endif /* CONFIG_PAGE_EXTENSION */
102*4882a593Smuzhiyun #endif /* __LINUX_PAGE_EXT_H */
103