perf intel-pt: Add support for recording the max non-turbo ratio

Previously the maximum non-turbo ratio was calculated from TSC assuming
a 100 MHz multiplier which is correct for current hardware supporting
Intel PT.  However more recent kernels also now export the value, so use
that in preference to the calculated value.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: http://lkml.kernel.org/r/1474641528-18776-11-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/x86/util/intel-pt.c

@@ -302,6 +302,7 @@ static int intel_pt_info_fill(struct auxtrace_record *itr,
 	bool cap_user_time_zero = false, per_cpu_mmaps;
 	u64 tsc_bit, mtc_bit, mtc_freq_bits, cyc_bit, noretcomp_bit;
 	u32 tsc_ctc_ratio_n, tsc_ctc_ratio_d;
+	unsigned long max_non_turbo_ratio;
 	int err;
 
 	if (priv_size != INTEL_PT_AUXTRACE_PRIV_SIZE)
@@ -317,6 +318,10 @@ static int intel_pt_info_fill(struct auxtrace_record *itr,
 
 	intel_pt_tsc_ctc_ratio(&tsc_ctc_ratio_n, &tsc_ctc_ratio_d);
 
+	if (perf_pmu__scan_file(intel_pt_pmu, "max_nonturbo_ratio",
+				"%lu", &max_non_turbo_ratio) != 1)
+		max_non_turbo_ratio = 0;
+
 	if (!session->evlist->nr_mmaps)
 		return -EINVAL;
 
@@ -351,6 +356,7 @@ static int intel_pt_info_fill(struct auxtrace_record *itr,
 	auxtrace_info->priv[INTEL_PT_TSC_CTC_N] = tsc_ctc_ratio_n;
 	auxtrace_info->priv[INTEL_PT_TSC_CTC_D] = tsc_ctc_ratio_d;
 	auxtrace_info->priv[INTEL_PT_CYC_BIT] = cyc_bit;
+	auxtrace_info->priv[INTEL_PT_MAX_NONTURBO_RATIO] = max_non_turbo_ratio;
 
 	return 0;
 }

tools/perf/util/intel-pt.c

@@ -2023,6 +2023,7 @@ static const char * const intel_pt_info_fmts[] = {
 	[INTEL_PT_TSC_CTC_N]		= "  TSC:CTC numerator   %"PRIu64"\n",
 	[INTEL_PT_TSC_CTC_D]		= "  TSC:CTC denominator %"PRIu64"\n",
 	[INTEL_PT_CYC_BIT]		= "  CYC bit             %#"PRIx64"\n",
+	[INTEL_PT_MAX_NONTURBO_RATIO]	= "  Max non-turbo ratio %"PRIu64"\n",
 };
 
 static void intel_pt_print_info(u64 *arr, int start, int finish)
@@ -2087,6 +2088,15 @@ int intel_pt_process_auxtrace_info(union perf_event *event,
 				    INTEL_PT_CYC_BIT);
 	}
 
+	if (auxtrace_info->header.size >= sizeof(struct auxtrace_info_event) +
+				(sizeof(u64) * INTEL_PT_MAX_NONTURBO_RATIO)) {
+		pt->max_non_turbo_ratio =
+			auxtrace_info->priv[INTEL_PT_MAX_NONTURBO_RATIO];
+		intel_pt_print_info(&auxtrace_info->priv[0],
+				    INTEL_PT_MAX_NONTURBO_RATIO,
+				    INTEL_PT_MAX_NONTURBO_RATIO);
+	}
+
 	pt->timeless_decoding = intel_pt_timeless_decoding(pt);
 	pt->have_tsc = intel_pt_have_tsc(pt);
 	pt->sampling_mode = false;
@@ -2156,7 +2166,9 @@ int intel_pt_process_auxtrace_info(union perf_event *event,
 	if (pt->tc.time_mult) {
 		u64 tsc_freq = intel_pt_ns_to_ticks(pt, 1000000000);
 
-		pt->max_non_turbo_ratio = (tsc_freq + 50000000) / 100000000;
+		if (!pt->max_non_turbo_ratio)
+			pt->max_non_turbo_ratio =
+					(tsc_freq + 50000000) / 100000000;
 		intel_pt_log("TSC frequency %"PRIu64"\n", tsc_freq);
 		intel_pt_log("Maximum non-turbo ratio %u\n",
 			     pt->max_non_turbo_ratio);

tools/perf/util/intel-pt.h

@@ -34,6 +34,7 @@ enum {
 	INTEL_PT_TSC_CTC_N,
 	INTEL_PT_TSC_CTC_D,
 	INTEL_PT_CYC_BIT,
+	INTEL_PT_MAX_NONTURBO_RATIO,
 	INTEL_PT_AUXTRACE_PRIV_MAX,
 };