tools/power turbostat: Harden probe_intel_uncore_frequency()

If sysfs directory "intel_uncore_frequency/cluster00/" exists,
then use uncore cluster code (now its own routine).

The previous check for
"intel_uncore_frequency/package_00_die_00/current_freq_khz",
could be unreliable in the face of sparse die id's.

Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 98256468e24806acfc0daee374d0cf9877e92131..ca33fb057d1fd41321577ead35784ad9021fcdc4 100644 (file)
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -5294,16 +5294,13 @@ static void dump_sysfs_file(char *path)
        fprintf(outf, "%s: %s", strrchr(path, '/') + 1, cpuidle_buf);
 }
 
-static void probe_intel_uncore_frequency(void)
+static void probe_intel_uncore_frequency_legacy(void)
 {
        int i, j;
        char path[256];
 
-       if (!genuine_intel)
-               return;
-
        if (access("/sys/devices/system/cpu/intel_uncore_frequency/package_00_die_00/current_freq_khz", R_OK))
-               goto probe_cluster;
+               return;
 
        BIC_PRESENT(BIC_UNCORE_MHZ);
 
@@ -5335,9 +5332,13 @@ static void probe_intel_uncore_frequency(void)
                        fprintf(outf, " %d MHz\n", k / 1000);
                }
        }
-       return;
+}
+
+static void probe_intel_uncore_frequency_cluster(void)
+{
+       int i;
+       char path[256];
 
-probe_cluster:
        if (access("/sys/devices/system/cpu/intel_uncore_frequency/uncore00/current_freq_khz", R_OK))
                return;
 
@@ -5351,6 +5352,7 @@ probe_cluster:
 
                sprintf(path_base, "/sys/devices/system/cpu/intel_uncore_frequency/uncore%02d", i);
 
+               /* uncore## start at 00 and skip no numbers, so stop upon first missing */
                if (access(path_base, R_OK))
                        break;
 
@@ -5382,6 +5384,17 @@ probe_cluster:
        }
 }
 
+static void probe_intel_uncore_frequency(void)
+{
+       if (!genuine_intel)
+               return;
+
+       if (access("/sys/devices/system/cpu/intel_uncore_frequency/uncore00", R_OK) == 0)
+               probe_intel_uncore_frequency_cluster();
+       else
+               probe_intel_uncore_frequency_legacy();
+}
+
 static void probe_graphics(void)
 {
        /* Xe graphics sysfs knobs */