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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
3e32cb2e JW |
2 | #ifndef _LINUX_PAGE_COUNTER_H |
3 | #define _LINUX_PAGE_COUNTER_H | |
4 | ||
5 | #include <linux/atomic.h> | |
6 | #include <linux/kernel.h> | |
7 | #include <asm/page.h> | |
8 | ||
9 | struct page_counter { | |
10 | atomic_long_t count; | |
11 | unsigned long limit; | |
12 | struct page_counter *parent; | |
13 | ||
14 | /* legacy */ | |
15 | unsigned long watermark; | |
16 | unsigned long failcnt; | |
17 | }; | |
18 | ||
19 | #if BITS_PER_LONG == 32 | |
20 | #define PAGE_COUNTER_MAX LONG_MAX | |
21 | #else | |
22 | #define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE) | |
23 | #endif | |
24 | ||
25 | static inline void page_counter_init(struct page_counter *counter, | |
26 | struct page_counter *parent) | |
27 | { | |
28 | atomic_long_set(&counter->count, 0); | |
29 | counter->limit = PAGE_COUNTER_MAX; | |
30 | counter->parent = parent; | |
31 | } | |
32 | ||
33 | static inline unsigned long page_counter_read(struct page_counter *counter) | |
34 | { | |
35 | return atomic_long_read(&counter->count); | |
36 | } | |
37 | ||
64f21993 | 38 | void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages); |
3e32cb2e | 39 | void page_counter_charge(struct page_counter *counter, unsigned long nr_pages); |
6071ca52 JW |
40 | bool page_counter_try_charge(struct page_counter *counter, |
41 | unsigned long nr_pages, | |
42 | struct page_counter **fail); | |
64f21993 | 43 | void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages); |
3e32cb2e | 44 | int page_counter_limit(struct page_counter *counter, unsigned long limit); |
650c5e56 JW |
45 | int page_counter_memparse(const char *buf, const char *max, |
46 | unsigned long *nr_pages); | |
3e32cb2e JW |
47 | |
48 | static inline void page_counter_reset_watermark(struct page_counter *counter) | |
49 | { | |
50 | counter->watermark = page_counter_read(counter); | |
51 | } | |
52 | ||
53 | #endif /* _LINUX_PAGE_COUNTER_H */ |