/* 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
