mangoapp: show Adreno GPU and CPU stats

Valve's mangoapp reads an Adreno GPU's load, clock and temperatures from the
paths of its own hardware, and the CPU temperature from thermal zones named as
mainline kernels name them. Every Adreno under Android keeps the GPU values in
KGSL's sysfs, readable by the app, and Android kernels name the CPU sensors
cpuss-N / cpu-N-M; the session binds each where mangoapp looks. Thermal zones
are found by sensor name, since their numbering differs per device, and
anything that cannot be found is left alone.

app/src/main/java/com/droiddeck/launcher/runtime/LinuxRuntime.java

@@ -193,6 +193,8 @@ public final class LinuxRuntime {
             }
         }
         bindGpuNode(context, cmd);
+        bindAdrenoStats(cmd);
+        bindCpuTemps(cmd, root);
         if (extraBinds != null) {
             for (String spec : extraBinds) bind(cmd, spec);
         }
@@ -244,6 +246,72 @@ public final class LinuxRuntime {
         bind(cmd, KGSL_DEVICE + ":/dev/dri/" + node);
     }
 
+    /**
+     * Valve's mangoapp (Deck mode's performance overlay) reads an Adreno GPU's load, clock and
+     * temperatures from where they are on Valve's own hardware; every Adreno under Android keeps
+     * them in KGSL's sysfs, readable by the app. Only the GPU temperature has no KGSL file on older
+     * kernels, and thermal zones are numbered per device, so a zone is found by its sensor's name,
+     * which differs between Snapdragon generations. A value that cannot be found is left alone.
+     */
+    private static void bindAdrenoStats(List<String> cmd) {
+        String kgsl = "/sys/class/kgsl/kgsl-3d0/";
+        String gpuTemp = new File(kgsl + "temp").canRead() ? kgsl + "temp"
+                : thermalZone("gpuss-0", "gpuss-0-usr", "gpu0-usr", "gpu-usr", "gpu");
+        String[][] stats = {
+                {kgsl + "gpu_busy_percentage", "/sys/kernel/debug/dri/0/perf_now"},
+                {kgsl + "devfreq/cur_freq", "/sys/devices/platform/soc@0/3d00000.gpu/devfreq/3d00000.gpu/cur_freq"},
+                {gpuTemp, "/sys/class/thermal/thermal_zone28/temp"},
+                {gpuTemp, "/sys/class/thermal/thermal_zone26/temp"},
+                {thermalZone("ddr", "ddr-usr", "ddr-thermal"), "/sys/class/thermal/thermal_zone22/temp"},
+        };
+        for (String[] stat : stats) {
+            if (stat[0] != null && new File(stat[0]).canRead()) bind(cmd, stat[0] + ":" + stat[1]);
+        }
+    }
+
+    /**
+     * mangoapp's CPU temperature is the mean of the thermal zones named cpuN-thermal or
+     * cpuN-top-thermal, as mainline kernels name them; Android kernels name the same sensors
+     * cpuss-0, cpu-1-0 and the like, so those zones are shown under the mainline name.
+     */
+    private static void bindCpuTemps(List<String> cmd, File root) {
+        File name = new File(root, "etc/bannerlator/cpu-thermal-type");
+        try {
+            if (!name.isFile()) Files.write(name.toPath(), "cpu0-thermal\n".getBytes(StandardCharsets.US_ASCII));
+        } catch (IOException e) {
+            return;
+        }
+        for (java.util.Map.Entry<String, File> zone : thermalZones().entrySet()) {
+            String type = zone.getKey();
+            if (type.startsWith("cpu") && !type.matches("cpu\\d-(top-)?thermal")) {
+                bind(cmd, name.getPath() + ":" + new File(zone.getValue(), "type").getPath());
+            }
+        }
+    }
+
+    /** The temp file of the first thermal zone whose sensor has one of these names, in that order. */
+    private static String thermalZone(String... types) {
+        java.util.Map<String, File> zones = thermalZones();
+        for (String type : types) {
+            if (zones.containsKey(type)) return new File(zones.get(type), "temp").getPath();
+        }
+        return null;
+    }
+
+    /** The device's thermal zones by their sensor's name. */
+    private static java.util.Map<String, File> thermalZones() {
+        java.util.Map<String, File> byType = new java.util.HashMap<>();
+        File[] zones = new File("/sys/class/thermal").listFiles((dir, n) -> n.startsWith("thermal_zone"));
+        if (zones == null) return byType;
+        for (File zone : zones) {
+            try (java.io.BufferedReader r = new java.io.BufferedReader(new java.io.FileReader(new File(zone, "type")))) {
+                byType.putIfAbsent(String.valueOf(r.readLine()).trim(), zone);
+            } catch (IOException ignored) {
+            }
+        }
+        return byType;
+    }
+
     private static void bind(List<String> cmd, String spec) {
         cmd.add("-b");
         cmd.add(spec);