[mirror_ubuntu-bionic-kernel.git] / include / linux / page_counter.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_PAGE_COUNTER_H
#define _LINUX_PAGE_COUNTER_H

#include <linux/atomic.h>
#include <linux/kernel.h>
#include <asm/page.h>

struct page_counter {
	atomic_long_t count;
	unsigned long limit;
	struct page_counter *parent;

	/* legacy */
	unsigned long watermark;
	unsigned long failcnt;
};

#if BITS_PER_LONG == 32
#define PAGE_COUNTER_MAX LONG_MAX
#else
#define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
#endif

static inline void page_counter_init(struct page_counter *counter,
				     struct page_counter *parent)
{
	atomic_long_set(&counter->count, 0);
	counter->limit = PAGE_COUNTER_MAX;
	counter->parent = parent;
}

static inline unsigned long page_counter_read(struct page_counter *counter)
{
	return atomic_long_read(&counter->count);
}

void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
bool page_counter_try_charge(struct page_counter *counter,
			     unsigned long nr_pages,
			     struct page_counter **fail);
void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
int page_counter_limit(struct page_counter *counter, unsigned long limit);
int page_counter_memparse(const char *buf, const char *max,
			  unsigned long *nr_pages);

static inline void page_counter_reset_watermark(struct page_counter *counter)
{
	counter->watermark = page_counter_read(counter);
}

#endif /* _LINUX_PAGE_COUNTER_H */
Commit	Line	Data
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,
650c5e56 JW	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 */