[linux-2.6-block.git] / kernel / trace / trace_dynevent.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Common header file for generic dynamic events.
 */

#ifndef _TRACE_DYNEVENT_H
#define _TRACE_DYNEVENT_H

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/seq_file.h>

#include "trace.h"

struct dyn_event;

/**
 * struct dyn_event_operations - Methods for each type of dynamic events
 *
 * These methods must be set for each type, since there is no default method.
 * Before using this for dyn_event_init(), it must be registered by
 * dyn_event_register().
 *
 * @create: Parse and create event method. This is invoked when user passes
 *  a event definition to dynamic_events interface. This must not destruct
 *  the arguments and return -ECANCELED if given arguments doesn't match its
 *  command prefix.
 * @show: Showing method. This is invoked when user reads the event definitions
 *  via dynamic_events interface.
 * @is_busy: Check whether given event is busy so that it can not be deleted.
 *  Return true if it is busy, otherwides false.
 * @free: Delete the given event. Return 0 if success, otherwides error.
 * @match: Check whether given event and system name match this event.
 *  Return true if it matches, otherwides false.
 *
 * Except for @create, these methods are called under holding event_mutex.
 */
struct dyn_event_operations {
	struct list_head	list;
	int (*create)(int argc, const char *argv[]);
	int (*show)(struct seq_file *m, struct dyn_event *ev);
	bool (*is_busy)(struct dyn_event *ev);
	int (*free)(struct dyn_event *ev);
	bool (*match)(const char *system, const char *event,
			struct dyn_event *ev);
};

/* Register new dyn_event type -- must be called at first */
int dyn_event_register(struct dyn_event_operations *ops);

/**
 * struct dyn_event - Dynamic event list header
 *
 * The dyn_event structure encapsulates a list and a pointer to the operators
 * for making a global list of dynamic events.
 * User must includes this in each event structure, so that those events can
 * be added/removed via dynamic_events interface.
 */
struct dyn_event {
	struct list_head		list;
	struct dyn_event_operations	*ops;
};

extern struct list_head dyn_event_list;

static inline
int dyn_event_init(struct dyn_event *ev, struct dyn_event_operations *ops)
{
	if (!ev || !ops)
		return -EINVAL;

	INIT_LIST_HEAD(&ev->list);
	ev->ops = ops;
	return 0;
}

static inline int dyn_event_add(struct dyn_event *ev)
{
	lockdep_assert_held(&event_mutex);

	if (!ev || !ev->ops)
		return -EINVAL;

	list_add_tail(&ev->list, &dyn_event_list);
	return 0;
}

static inline void dyn_event_remove(struct dyn_event *ev)
{
	lockdep_assert_held(&event_mutex);
	list_del_init(&ev->list);
}

void *dyn_event_seq_start(struct seq_file *m, loff_t *pos);
void *dyn_event_seq_next(struct seq_file *m, void *v, loff_t *pos);
void dyn_event_seq_stop(struct seq_file *m, void *v);
int dyn_events_release_all(struct dyn_event_operations *type);
int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type);

/*
 * for_each_dyn_event	-	iterate over the dyn_event list
 * @pos:	the struct dyn_event * to use as a loop cursor
 *
 * This is just a basement of for_each macro. Wrap this for
 * each actual event structure with ops filtering.
 */
#define for_each_dyn_event(pos)	\
	list_for_each_entry(pos, &dyn_event_list, list)

/*
 * for_each_dyn_event	-	iterate over the dyn_event list safely
 * @pos:	the struct dyn_event * to use as a loop cursor
 * @n:		the struct dyn_event * to use as temporary storage
 */
#define for_each_dyn_event_safe(pos, n)	\
	list_for_each_entry_safe(pos, n, &dyn_event_list, list)

#endif
Commit	Line	Data
5448d44c MH	1	/* 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
	16	struct 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.
	32	* Return true if it is busy, otherwides false.
	33	* @free: Delete the given event. Return 0 if success, otherwides error.
	34	* @match: Check whether given event and system name match this event.
	35	* Return true if it matches, otherwides false.
	36	*
	37	* Except for @create, these methods are called under holding event_mutex.
	38	*/
	39	struct dyn_event_operations {
	40	struct list_head list;
	41	int (create)(int argc, const char argv[]);
	42	int (show)(struct seq_file m, struct dyn_event *ev);
	43	bool (is_busy)(struct dyn_event ev);
	44	int (free)(struct dyn_event ev);
	45	bool (match)(const char system, const char *event,
	46	struct dyn_event *ev);
	47	};
	48
	49	/* Register new dyn_event type -- must be called at first */
	50	int dyn_event_register(struct dyn_event_operations *ops);
	51
	52	/**
	53	* struct dyn_event - Dynamic event list header
	54	*
	55	* The dyn_event structure encapsulates a list and a pointer to the operators
	56	* for making a global list of dynamic events.
	57	* User must includes this in each event structure, so that those events can
	58	* be added/removed via dynamic_events interface.
	59	*/
	60	struct dyn_event {
	61	struct list_head list;
	62	struct dyn_event_operations *ops;
	63	};
	64
65	extern struct list_head dyn_event_list;
66
67	static inline
68	int dyn_event_init(struct dyn_event ev, struct dyn_event_operations ops)
69	{
70	if (!ev \|\| !ops)
71	return -EINVAL;
72
73	INIT_LIST_HEAD(&ev->list);
74	ev->ops = ops;
75	return 0;
76	}
77
78	static inline int dyn_event_add(struct dyn_event *ev)
79	{
80	lockdep_assert_held(&event_mutex);
81
82	if (!ev \|\| !ev->ops)
83	return -EINVAL;
84
85	list_add_tail(&ev->list, &dyn_event_list);
86	return 0;
87	}
88
89	static inline void dyn_event_remove(struct dyn_event *ev)
90	{
91	lockdep_assert_held(&event_mutex);
92	list_del_init(&ev->list);
93	}
94
95	void dyn_event_seq_start(struct seq_file m, loff_t *pos);
96	void dyn_event_seq_next(struct seq_file m, void v, loff_t pos);
97	void dyn_event_seq_stop(struct seq_file m, void v);
98	int dyn_events_release_all(struct dyn_event_operations *type);
99	int dyn_event_release(int argc, char *argv, struct dyn_event_operations type);
100
101	/*
102	* for_each_dyn_event - iterate over the dyn_event list
103	* @pos: the struct dyn_event * to use as a loop cursor
104	*
105	* This is just a basement of for_each macro. Wrap this for
106	* each actual event structure with ops filtering.
107	*/
108	#define for_each_dyn_event(pos) \
109	list_for_each_entry(pos, &dyn_event_list, list)
110
111	/*
112	* for_each_dyn_event - iterate over the dyn_event list safely
113	* @pos: the struct dyn_event * to use as a loop cursor
114	* @n: the struct dyn_event * to use as temporary storage
115	*/
116	#define for_each_dyn_event_safe(pos, n) \
117	list_for_each_entry_safe(pos, n, &dyn_event_list, list)
118
119	#endif