1 files changed, 152 insertions, 0 deletions
diff --git a/kernel/trace/trace_dynevent.h b/kernel/trace/trace_dynevent.h
new file mode 100644
index 000000000..d6857a254
--- /dev/null
+++ b/kernel/trace/trace_dynevent.h
@@ -0,0 +1,152 @@
+/* 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. The argc
+ *  and argv is used for exact match. 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,
+		      int argc, const char **argv, 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)
+
+extern void dynevent_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen,
+			      enum dynevent_type type,
+			      dynevent_create_fn_t run_command);
+
+typedef int (*dynevent_check_arg_fn_t)(void *data);
+
+struct dynevent_arg {
+	const char		*str;
+	char			separator; /* e.g. ';', ',', or nothing */
+};
+
+extern void dynevent_arg_init(struct dynevent_arg *arg,
+			      char separator);
+extern int dynevent_arg_add(struct dynevent_cmd *cmd,
+			    struct dynevent_arg *arg,
+			    dynevent_check_arg_fn_t check_arg);
+
+struct dynevent_arg_pair {
+	const char		*lhs;
+	const char		*rhs;
+	char			operator; /* e.g. '=' or nothing */
+	char			separator; /* e.g. ';', ',', or nothing */
+};
+
+extern void dynevent_arg_pair_init(struct dynevent_arg_pair *arg_pair,
+				   char operator, char separator);
+
+extern int dynevent_arg_pair_add(struct dynevent_cmd *cmd,
+				 struct dynevent_arg_pair *arg_pair,
+				 dynevent_check_arg_fn_t check_arg);
+extern int dynevent_str_add(struct dynevent_cmd *cmd, const char *str);
+
+#endif