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