ftrace: Add FTRACE_ENTRY_REG macro to allow event registration

Adding FTRACE_ENTRY_REG macro so particular ftrace entries
could specify registration function and thus become accesible
via perf.

This will be used in upcomming patch for function trace.

Link: http://lkml.kernel.org/r/1329317514-8131-5-git-send-email-jolsa@redhat.com

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

2 files changed, 20 insertions, 2 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 55c6ea00f28a..638476af8d7b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -68,6 +68,10 @@ enum trace_type {
 #undef FTRACE_ENTRY_DUP
 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
 
+#undef FTRACE_ENTRY_REG
+#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, regfn) \
+        FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
+
 #include "trace_entries.h"
 
 /*
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index bbeec31e0ae3..f74de861cde9 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -18,6 +18,14 @@
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM    ftrace
 
+/*
+ * The FTRACE_ENTRY_REG macro allows ftrace entry to define register
+ * function and thus become accesible via perf.
+ */
+#undef FTRACE_ENTRY_REG
+#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, regfn) \
+        FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
+
 /* not needed for this file */
 #undef __field_struct
 #define __field_struct(type, item)
@@ -152,13 +160,14 @@ ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
 #undef F_printk
 #define F_printk(fmt, args...) #fmt ", "  __stringify(args)
 
-#undef FTRACE_ENTRY
-#define FTRACE_ENTRY(call, struct_name, etype, tstruct, print)          \
+#undef FTRACE_ENTRY_REG
+#define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, regfn)\
                                                                         \
 struct ftrace_event_class event_class_ftrace_##call = {                 \
         .system                 = __stringify(TRACE_SYSTEM),            \
         .define_fields          = ftrace_define_fields_##call,          \
         .fields                 = LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
+        .reg                    = regfn,                                \
 };                                                                      \
                                                                         \
 struct ftrace_event_call __used event_##call = {                        \
@@ -170,4 +179,9 @@ struct ftrace_event_call __used event_##call = {			\
 struct ftrace_event_call __used                                         \
 __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call;
 
+#undef FTRACE_ENTRY
+#define FTRACE_ENTRY(call, struct_name, etype, tstruct, print)          \
+        FTRACE_ENTRY_REG(call, struct_name, etype,                      \
+                         PARAMS(tstruct), PARAMS(print), NULL)
+
 #include "trace_entries.h"