1 // SPDX-License-Identifier: GPL-2.0
2 #ifndef __TRACE_STAT_H
3 #define __TRACE_STAT_H
4 
5 #include <linux/seq_file.h>
6 
7 /*
8  * If you want to provide a stat file (one-shot statistics), fill
9  * an iterator with stat_start/stat_next and a stat_show callbacks.
10  * The others callbacks are optional.
11  */
12 struct tracer_stat {
13 	/* The name of your stat file */
14 	const char		*name;
15 	/* Iteration over statistic entries */
16 	void			*(*stat_start)(struct tracer_stat *trace);
17 	void			*(*stat_next)(void *prev, int idx);
18 	/* Compare two entries for stats sorting */
19 	int			(*stat_cmp)(void *p1, void *p2);
20 	/* Print a stat entry */
21 	int			(*stat_show)(struct seq_file *s, void *p);
22 	/* Release an entry */
23 	void			(*stat_release)(void *stat);
24 	/* Print the headers of your stat entries */
25 	int			(*stat_headers)(struct seq_file *s);
26 };
27 
28 /*
29  * Destroy or create a stat file
30  */
31 extern int register_stat_tracer(struct tracer_stat *trace);
32 extern void unregister_stat_tracer(struct tracer_stat *trace);
33 
34 #endif /* __TRACE_STAT_H */
35