1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef DM_STATS_H
 3#define DM_STATS_H
 4
 5#include <linux/types.h>
 6#include <linux/mutex.h>
 7#include <linux/list.h>
 8
 9int dm_statistics_init(void);
10void dm_statistics_exit(void);
11
12struct dm_stats {
13	struct mutex mutex;
14	struct list_head list;	/* list of struct dm_stat */
15	struct dm_stats_last_position __percpu *last;
16	sector_t last_sector;
17	unsigned last_rw;
18};
19
20struct dm_stats_aux {
21	bool merged;
22	unsigned long long duration_ns;
23};
24
25void dm_stats_init(struct dm_stats *st);
26void dm_stats_cleanup(struct dm_stats *st);
27
28struct mapped_device;
29
30int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
31		     char *result, unsigned maxlen);
32
33void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
34			 sector_t bi_sector, unsigned bi_sectors, bool end,
35			 unsigned long duration_jiffies,
36			 struct dm_stats_aux *aux);
37
38static inline bool dm_stats_used(struct dm_stats *st)
39{
40	return !list_empty(&st->list);
41}
42
43#endif