blob: d6f72dcb7269a35fc99c9a890fb35c2b7e16617e [file] [log] [blame]
Masami Hiramatsu5448d442018-11-05 18:02:08 +09001/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Common header file for generic dynamic events.
4 */
5
6#ifndef _TRACE_DYNEVENT_H
7#define _TRACE_DYNEVENT_H
8
9#include <linux/kernel.h>
10#include <linux/list.h>
11#include <linux/mutex.h>
12#include <linux/seq_file.h>
13
14#include "trace.h"
15
16struct dyn_event;
17
18/**
19 * struct dyn_event_operations - Methods for each type of dynamic events
20 *
21 * These methods must be set for each type, since there is no default method.
22 * Before using this for dyn_event_init(), it must be registered by
23 * dyn_event_register().
24 *
25 * @create: Parse and create event method. This is invoked when user passes
26 * a event definition to dynamic_events interface. This must not destruct
27 * the arguments and return -ECANCELED if given arguments doesn't match its
28 * command prefix.
29 * @show: Showing method. This is invoked when user reads the event definitions
30 * via dynamic_events interface.
31 * @is_busy: Check whether given event is busy so that it can not be deleted.
Qiujun Huang2b5894c2020-10-29 23:05:54 +080032 * Return true if it is busy, otherwise false.
33 * @free: Delete the given event. Return 0 if success, otherwise error.
Masami Hiramatsu30199132019-06-20 00:07:39 +090034 * @match: Check whether given event and system name match this event. The argc
Qiujun Huang2b5894c2020-10-29 23:05:54 +080035 * and argv is used for exact match. Return true if it matches, otherwise
Masami Hiramatsu30199132019-06-20 00:07:39 +090036 * false.
Masami Hiramatsu5448d442018-11-05 18:02:08 +090037 *
38 * Except for @create, these methods are called under holding event_mutex.
39 */
40struct dyn_event_operations {
41 struct list_head list;
42 int (*create)(int argc, const char *argv[]);
43 int (*show)(struct seq_file *m, struct dyn_event *ev);
44 bool (*is_busy)(struct dyn_event *ev);
45 int (*free)(struct dyn_event *ev);
46 bool (*match)(const char *system, const char *event,
Masami Hiramatsu30199132019-06-20 00:07:39 +090047 int argc, const char **argv, struct dyn_event *ev);
Masami Hiramatsu5448d442018-11-05 18:02:08 +090048};
49
50/* Register new dyn_event type -- must be called at first */
51int dyn_event_register(struct dyn_event_operations *ops);
52
53/**
54 * struct dyn_event - Dynamic event list header
55 *
56 * The dyn_event structure encapsulates a list and a pointer to the operators
57 * for making a global list of dynamic events.
58 * User must includes this in each event structure, so that those events can
59 * be added/removed via dynamic_events interface.
60 */
61struct dyn_event {
62 struct list_head list;
63 struct dyn_event_operations *ops;
64};
65
66extern struct list_head dyn_event_list;
67
68static inline
69int dyn_event_init(struct dyn_event *ev, struct dyn_event_operations *ops)
70{
71 if (!ev || !ops)
72 return -EINVAL;
73
74 INIT_LIST_HEAD(&ev->list);
75 ev->ops = ops;
76 return 0;
77}
78
79static inline int dyn_event_add(struct dyn_event *ev)
80{
81 lockdep_assert_held(&event_mutex);
82
83 if (!ev || !ev->ops)
84 return -EINVAL;
85
86 list_add_tail(&ev->list, &dyn_event_list);
87 return 0;
88}
89
90static inline void dyn_event_remove(struct dyn_event *ev)
91{
92 lockdep_assert_held(&event_mutex);
93 list_del_init(&ev->list);
94}
95
96void *dyn_event_seq_start(struct seq_file *m, loff_t *pos);
97void *dyn_event_seq_next(struct seq_file *m, void *v, loff_t *pos);
98void dyn_event_seq_stop(struct seq_file *m, void *v);
99int dyn_events_release_all(struct dyn_event_operations *type);
100int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type);
101
102/*
103 * for_each_dyn_event - iterate over the dyn_event list
104 * @pos: the struct dyn_event * to use as a loop cursor
105 *
106 * This is just a basement of for_each macro. Wrap this for
107 * each actual event structure with ops filtering.
108 */
109#define for_each_dyn_event(pos) \
110 list_for_each_entry(pos, &dyn_event_list, list)
111
112/*
113 * for_each_dyn_event - iterate over the dyn_event list safely
114 * @pos: the struct dyn_event * to use as a loop cursor
115 * @n: the struct dyn_event * to use as temporary storage
116 */
117#define for_each_dyn_event_safe(pos, n) \
118 list_for_each_entry_safe(pos, n, &dyn_event_list, list)
119
Tom Zanussi86c54262020-01-29 12:59:24 -0600120extern void dynevent_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen,
121 enum dynevent_type type,
122 dynevent_create_fn_t run_command);
123
124typedef int (*dynevent_check_arg_fn_t)(void *data);
125
126struct dynevent_arg {
127 const char *str;
128 char separator; /* e.g. ';', ',', or nothing */
Tom Zanussi86c54262020-01-29 12:59:24 -0600129};
130
131extern void dynevent_arg_init(struct dynevent_arg *arg,
Tom Zanussi86c54262020-01-29 12:59:24 -0600132 char separator);
133extern int dynevent_arg_add(struct dynevent_cmd *cmd,
Tom Zanussi74403b62020-01-31 15:55:32 -0600134 struct dynevent_arg *arg,
135 dynevent_check_arg_fn_t check_arg);
Tom Zanussi86c54262020-01-29 12:59:24 -0600136
137struct dynevent_arg_pair {
138 const char *lhs;
139 const char *rhs;
140 char operator; /* e.g. '=' or nothing */
141 char separator; /* e.g. ';', ',', or nothing */
Tom Zanussi86c54262020-01-29 12:59:24 -0600142};
143
144extern void dynevent_arg_pair_init(struct dynevent_arg_pair *arg_pair,
Tom Zanussi86c54262020-01-29 12:59:24 -0600145 char operator, char separator);
Tom Zanussi74403b62020-01-31 15:55:32 -0600146
Tom Zanussi86c54262020-01-29 12:59:24 -0600147extern int dynevent_arg_pair_add(struct dynevent_cmd *cmd,
Tom Zanussi74403b62020-01-31 15:55:32 -0600148 struct dynevent_arg_pair *arg_pair,
149 dynevent_check_arg_fn_t check_arg);
Tom Zanussi86c54262020-01-29 12:59:24 -0600150extern int dynevent_str_add(struct dynevent_cmd *cmd, const char *str);
151
Masami Hiramatsu5448d442018-11-05 18:02:08 +0900152#endif