tools/power turbostat: Survive sparse die_id

Turbostat assumed that every package had a die_id = 0.
When this assumption was violated, it exited
when looking for the package uncore frequency:

turbostat: /sys/.../intel_uncore_frequency/package_01_die_00/current_freq_khz: open failed: No such file or directory
Signed-off-by: Len Brown <len.brown@intel.com>

tools/power/x86/turbostat/turbostat.c

@@ -2992,14 +2992,29 @@ int get_mp(int cpu, struct msr_counter *mp, unsigned long long *counterp)
 	return 0;
 }
 
-unsigned long long get_uncore_mhz(int package, int die)
+unsigned long long get_legacy_uncore_mhz(int package)
 {
 	char path[128];
+	int die;
+	static int warn_once;
 
-	sprintf(path, "/sys/devices/system/cpu/intel_uncore_frequency/package_%02d_die_%02d/current_freq_khz", package,
-		die);
+	/*
+	 * for this package, use the first die_id that exists
+	 */
+	for (die = 0; die <= topo.max_die_id; ++die) {
+
+		sprintf(path, "/sys/devices/system/cpu/intel_uncore_frequency/package_%02d_die_%02d/current_freq_khz",
+			package, die);
 
-	return (snapshot_sysfs_counter(path) / 1000);
+		if (access(path, R_OK) == 0)
+			return (snapshot_sysfs_counter(path) / 1000);
+	}
+	if (!warn_once) {
+		warnx("BUG: %s: No %s", __func__, path);
+		warn_once = 1;
+	}
+
+	return 0;
 }
 
 int get_epb(int cpu)
@@ -3631,9 +3646,8 @@ int get_counters(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 		p->pkg_temp_c = tj_max - ((msr >> 16) & 0x7F);
 	}
 
-	/* n.b. assume die0 uncore frequency applies to whole package */
 	if (DO_BIC(BIC_UNCORE_MHZ))
-		p->uncore_mhz = get_uncore_mhz(p->package_id, 0);
+		p->uncore_mhz = get_legacy_uncore_mhz(p->package_id);
 
 	if (DO_BIC(BIC_GFX_rc6))
 		p->gfx_rc6_ms = gfx_info[GFX_rc6].val_ull;
@@ -5300,22 +5314,22 @@ static void probe_intel_uncore_frequency_legacy(void)
 	int i, j;
 	char path[256];
 
-	if (access("/sys/devices/system/cpu/intel_uncore_frequency/package_00_die_00/current_freq_khz", R_OK))
-		return;
-
-	BIC_PRESENT(BIC_UNCORE_MHZ);
-
-	if (quiet)
-		return;
-
 	for (i = 0; i < topo.num_packages; ++i) {
-		for (j = 0; j < topo.num_die; ++j) {
+		for (j = 0; j <= topo.max_die_id; ++j) {
 			int k, l;
 			char path_base[128];
 
 			sprintf(path_base, "/sys/devices/system/cpu/intel_uncore_frequency/package_%02d_die_%02d", i,
 				j);
 
+			if (access(path_base, R_OK))
+				continue;
+
+			BIC_PRESENT(BIC_UNCORE_MHZ);
+
+			if (quiet)
+				return;
+
 			sprintf(path, "%s/min_freq_khz", path_base);
 			k = read_sysfs_int(path);
 			sprintf(path, "%s/max_freq_khz", path_base);
@@ -5480,7 +5494,6 @@ static void probe_graphics(void)
 	else if (!access("/sys/class/graphics/fb0/device/drm/card0/gt_cur_freq_mhz", R_OK))
 		gfx_info[GFX_MHz].path = "/sys/class/graphics/fb0/device/drm/card0/gt_cur_freq_mhz";
 
-
 	if (!access("/sys/class/drm/card0/gt_act_freq_mhz", R_OK))
 		gfx_info[GFX_ACTMHz].path = "/sys/class/drm/card0/gt_act_freq_mhz";
 	else if (!access("/sys/class/graphics/fb0/device/drm/card0/gt_act_freq_mhz", R_OK))