Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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#if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
22 PAGE_EXT_YOUNG,
23 PAGE_EXT_IDLE,
24#endif
25};
26
27/*
28 * Page Extension can be considered as an extended mem_map.
29 * A page_ext page is associated with every page descriptor. The
30 * page_ext helps us add more information about the page.
31 * All page_ext are allocated at boot or memory hotplug event,
32 * then the page_ext for pfn always exists.
33 */
34struct page_ext {
35 unsigned long flags;
36};
37
38extern void pgdat_page_ext_init(struct pglist_data *pgdat);
39
40#ifdef CONFIG_SPARSEMEM
41static inline void page_ext_init_flatmem(void)
42{
43}
44extern void page_ext_init(void);
45#else
46extern void page_ext_init_flatmem(void);
47static inline void page_ext_init(void)
48{
49}
50#endif
51
52struct page_ext *lookup_page_ext(const struct page *page);
53
54#else /* !CONFIG_PAGE_EXTENSION */
55struct page_ext;
56
57static inline void pgdat_page_ext_init(struct pglist_data *pgdat)
58{
59}
60
61static inline struct page_ext *lookup_page_ext(const struct page *page)
62{
63 return NULL;
64}
65
66static inline void page_ext_init(void)
67{
68}
69
70static inline void page_ext_init_flatmem(void)
71{
72}
73#endif /* CONFIG_PAGE_EXTENSION */
74#endif /* __LINUX_PAGE_EXT_H */