perf header: Recognize version number for perf data file

Keep the recognized data file version within 'struct perf_header'.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1374083403-14591-8-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index e6387dc..307c9ae 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -34,6 +34,11 @@
 	HEADER_FEAT_BITS	= 256,
 };
 
+enum perf_header_version {
+	PERF_HEADER_VERSION_1,
+	PERF_HEADER_VERSION_2,
+};
+
 struct perf_file_section {
 	u64 offset;
 	u64 size;
@@ -85,12 +90,13 @@
 };
 
 struct perf_header {
-	bool			needs_swap;
-	u64			data_offset;
-	u64			data_size;
-	u64			feat_offset;
+	enum perf_header_version	version;
+	bool				needs_swap;
+	u64				data_offset;
+	u64				data_size;
+	u64				feat_offset;
 	DECLARE_BITMAP(adds_features, HEADER_FEAT_BITS);
-	struct perf_session_env env;
+	struct perf_session_env 	env;
 };
 
 struct perf_evlist;