ftrace: change trace.c to use registered events

Impact: rework trace.c to use new event register API

Almost every ftrace event has to implement its output display in
trace.c through a different function. Some events did not handle
all the formats (trace, latency-trace, raw, hex, binary), and
this method does not scale well.

This patch converts the format functions to use the event API to
find the event and and print its format. Currently, we have
a print function for trace, latency_trace, raw, hex and binary.
A trace_nop_print is available if the event wants to avoid output
on a particular format.

Perhaps other tracers could use this in the future (like mmiotrace and
function_graph).

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 16 insertions, 0 deletions

diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index 1fcc76e1378e..ecab4ea4a4fd 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -36,8 +36,24 @@ struct trace_event *ftrace_find_event(int type);
 int register_ftrace_event(struct trace_event *event);
 int unregister_ftrace_event(struct trace_event *event);
 
+int
+trace_nop_print(struct trace_seq *s, struct trace_entry *entry, int flags);
+
 #define MAX_MEMHEX_BYTES        8
 #define HEX_CHARS               (MAX_MEMHEX_BYTES*2 + 1)
 
+#define SEQ_PUT_FIELD_RET(s, x)                         \
+do {                                                    \
+        if (!trace_seq_putmem(s, &(x), sizeof(x)))      \
+                return 0;                               \
+} while (0)
+
+#define SEQ_PUT_HEX_FIELD_RET(s, x)                     \
+do {                                                    \
+        BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES);     \
+        if (!trace_seq_putmem_hex(s, &(x), sizeof(x)))  \
+                return 0;                               \
+} while (0)
+
 #endif