]> git.karo-electronics.de Git - karo-tx-linux.git/blob - include/linux/page_counter.h
Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[karo-tx-linux.git] / include / linux / page_counter.h
1 #ifndef _LINUX_PAGE_COUNTER_H
2 #define _LINUX_PAGE_COUNTER_H
3
4 #include <linux/atomic.h>
5 #include <linux/kernel.h>
6 #include <asm/page.h>
7
8 struct page_counter {
9         atomic_long_t count;
10         unsigned long limit;
11         struct page_counter *parent;
12
13         /* legacy */
14         unsigned long watermark;
15         unsigned long failcnt;
16 };
17
18 #if BITS_PER_LONG == 32
19 #define PAGE_COUNTER_MAX LONG_MAX
20 #else
21 #define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
22 #endif
23
24 static inline void page_counter_init(struct page_counter *counter,
25                                      struct page_counter *parent)
26 {
27         atomic_long_set(&counter->count, 0);
28         counter->limit = PAGE_COUNTER_MAX;
29         counter->parent = parent;
30 }
31
32 static inline unsigned long page_counter_read(struct page_counter *counter)
33 {
34         return atomic_long_read(&counter->count);
35 }
36
37 void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
38 void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
39 bool page_counter_try_charge(struct page_counter *counter,
40                              unsigned long nr_pages,
41                              struct page_counter **fail);
42 void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
43 int page_counter_limit(struct page_counter *counter, unsigned long limit);
44 int page_counter_memparse(const char *buf, const char *max,
45                           unsigned long *nr_pages);
46
47 static inline void page_counter_reset_watermark(struct page_counter *counter)
48 {
49         counter->watermark = page_counter_read(counter);
50 }
51
52 #endif /* _LINUX_PAGE_COUNTER_H */