perf tools: Add time conversion event

Intel PT uses the time members from the perf_event_mmap_page to convert
between TSC and perf time.

Due to a lack of foresight when Intel PT was implemented, those time
members were recorded in the (implementation dependent) AUXTRACE_INFO
event, the structure of which is generally inaccessible outside of the
Intel PT decoder.  However now the conversion between TSC and perf time
is needed when processing a jitdump file when Intel PT has been used for
tracing.

So add a user event to record the time members.  'perf record' will
synthesize the event if the information is available.  And session
processing will put a copy of the event on the session so that tools
like 'perf inject' can easily access it.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1457426324-30158-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/tools/perf/arch/x86/util/tsc.c b/tools/perf/arch/x86/util/tsc.c
index fd2868490d00..70ff7c14bea6 100644
--- a/tools/perf/arch/x86/util/tsc.c
+++ b/tools/perf/arch/x86/util/tsc.c
@@ -46,3 +46,34 @@ u64 rdtsc(void)
 
 	return low | ((u64)high) << 32;
 }
+
+int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc,
+				struct perf_tool *tool,
+				perf_event__handler_t process,
+				struct machine *machine)
+{
+	union perf_event event = {
+		.time_conv = {
+			.header = {
+				.type = PERF_RECORD_TIME_CONV,
+				.size = sizeof(struct time_conv_event),
+			},
+		},
+	};
+	struct perf_tsc_conversion tc;
+	int err;
+
+	err = perf_read_tsc_conversion(pc, &tc);
+	if (err == -EOPNOTSUPP)
+		return 0;
+	if (err)
+		return err;
+
+	pr_debug2("Synthesizing TSC conversion information\n");
+
+	event.time_conv.time_mult  = tc.time_mult;
+	event.time_conv.time_shift = tc.time_shift;
+	event.time_conv.time_zero  = tc.time_zero;
+
+	return process(tool, &event, NULL, machine);
+}