tracing: Ftrace dynamic ftrace_event_call support

Add dynamic ftrace_event_call support to ftrace. Trace engines can add
new ftrace_event_call to ftrace on the fly. Each operator function of
the call takes an ftrace_event_call data structure as an argument,
because these functions may be shared among several ftrace_event_calls.

Changes from v13:
 - Define remove_subsystem_dir() always (revirt a2ca5e03), because
   trace_remove_event_call() uses it.
 - Modify syscall tracer because of ftrace_event_call change.

[fweisbec@gmail.com: Fixed conflict against latest tracing/core]

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203453.31965.71901.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 360a77a..f2bd7a8 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -434,7 +434,7 @@
  *	event_trace_printk(_RET_IP_, "<call>: " <fmt>);
  * }
  *
- * static int ftrace_reg_event_<call>(void)
+ * static int ftrace_reg_event_<call>(struct ftrace_event_call *unused)
  * {
  *	int ret;
  *
@@ -445,7 +445,7 @@
  *	return ret;
  * }
  *
- * static void ftrace_unreg_event_<call>(void)
+ * static void ftrace_unreg_event_<call>(struct ftrace_event_call *unused)
  * {
  *	unregister_trace_<call>(ftrace_event_<call>);
  * }
@@ -478,7 +478,7 @@
  *	trace_current_buffer_unlock_commit(event, irq_flags, pc);
  * }
  *
- * static int ftrace_raw_reg_event_<call>(void)
+ * static int ftrace_raw_reg_event_<call>(struct ftrace_event_call *unused)
  * {
  *	int ret;
  *
@@ -489,7 +489,7 @@
  *	return ret;
  * }
  *
- * static void ftrace_unreg_event_<call>(void)
+ * static void ftrace_unreg_event_<call>(struct ftrace_event_call *unused)
  * {
  *	unregister_trace_<call>(ftrace_raw_event_<call>);
  * }
@@ -498,7 +498,7 @@
  *	.trace			= ftrace_raw_output_<call>, <-- stage 2
  * };
  *
- * static int ftrace_raw_init_event_<call>(void)
+ * static int ftrace_raw_init_event_<call>(struct ftrace_event_call *unused)
  * {
  *	int id;
  *
@@ -592,7 +592,7 @@
 		trace_nowake_buffer_unlock_commit(event, irq_flags, pc); \
 }									\
 									\
-static int ftrace_raw_reg_event_##call(void *ptr)			\
+static int ftrace_raw_reg_event_##call(struct ftrace_event_call *unused)\
 {									\
 	int ret;							\
 									\
@@ -603,7 +603,7 @@
 	return ret;							\
 }									\
 									\
-static void ftrace_raw_unreg_event_##call(void *ptr)			\
+static void ftrace_raw_unreg_event_##call(struct ftrace_event_call *unused)\
 {									\
 	unregister_trace_##call(ftrace_raw_event_##call);		\
 }									\
@@ -612,7 +612,7 @@
 	.trace			= ftrace_raw_output_##call,		\
 };									\
 									\
-static int ftrace_raw_init_event_##call(void)				\
+static int ftrace_raw_init_event_##call(struct ftrace_event_call *unused)\
 {									\
 	int id;								\
 									\