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, 53 insertions, 0 deletions

diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 6c00feb3bac7..c15222a01073 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -14,7 +14,9 @@
 #include <linux/hash.h>
 #include <linux/fs.h>
 #include <asm/local.h>
+
 #include "trace.h"
+#include "trace_output.h"
 
 #ifdef CONFIG_BRANCH_TRACER
 
@@ -142,6 +144,49 @@ static void branch_trace_reset(struct trace_array *tr)
         stop_branch_trace(tr);
 }
 
+static int
+trace_print_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct print_entry *field;
+
+        trace_assign_type(field, entry);
+
+        if (seq_print_ip_sym(s, field->ip, flags))
+                goto partial;
+
+        if (trace_seq_printf(s, ": %s", field->buf))
+                goto partial;
+
+ partial:
+        return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static int
+trace_branch_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct trace_branch *field;
+
+        trace_assign_type(field, entry);
+
+        if (trace_seq_printf(s, "[%s] %s:%s:%d\n",
+                             field->correct ? "  ok  " : " MISS ",
+                             field->func,
+                             field->file,
+                             field->line))
+                return TRACE_TYPE_PARTIAL_LINE;
+
+        return 0;
+}
+
+static struct trace_event trace_branch_event = {
+        .type           = TRACE_BRANCH,
+        .trace          = trace_branch_print,
+        .latency_trace  = trace_branch_print,
+        .raw            = trace_nop_print,
+        .hex            = trace_nop_print,
+        .binary         = trace_nop_print,
+};
+
 struct tracer branch_trace __read_mostly =
 {
         .name           = "branch",
@@ -154,6 +199,14 @@ struct tracer branch_trace __read_mostly =
 
 __init static int init_branch_trace(void)
 {
+        int ret;
+
+        ret = register_ftrace_event(&trace_branch_event);
+        if (!ret) {
+                printk(KERN_WARNING "Warning: could not register branch events\n");
+                return 1;
+        }
+
         return register_tracer(&branch_trace);
 }