intel_gpu_top: detect power-related files automatically

This allows to detect the acpi battery and debugfs i915_emon_status files
location automatically.

Note that this does not handles different possible locations for debugfs
yet.

Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>

1 files changed, 70 insertions, 51 deletions

diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c
index 8c771f3..14f333e 100644
--- a/tools/intel_gpu_top.c
+++ b/tools/intel_gpu_top.c
@@ -130,15 +130,14 @@ struct proc_cpudata
 
 struct powerdata
 {
+	char *battery_file;
+	char *battery_file_ext;
 	float watts;
 	float watts_chipset;
 	float watts_gfx;
 };
 
 
-#define BATTERY                     "BAT1"
-#define DEBUGFS                     "/sys/kernel/debug/dri/0/"
-
 static void
 get_cpu_stat(struct cpudata *cpu)
 {
@@ -162,6 +161,40 @@ get_cpu_stat(struct cpudata *cpu)
 
 }
 
+static void
+power_stat_init(struct powerdata *power)
+{
+#ifdef __linux__
+	int i, ret;
+	power->battery_file = (char *)malloc(FILENAME_MAX);
+	for (i=0, ret=-1; i < 16; i++) {
+		/* Discover battery */
+		snprintf(power->battery_file, FILENAME_MAX, "/proc/acpi/battery/BAT%d/state", i);
+		if ((ret = access(power->battery_file, R_OK)) == 0)
+			break;
+	}
+	if (ret < 0) {
+		free(power->battery_file);
+		power->battery_file = NULL;
+	}
+
+
+	power->battery_file_ext = (char *)malloc(FILENAME_MAX);
+	for (i=0, ret=-1; i < 16; i++) {
+		snprintf(power->battery_file_ext, FILENAME_MAX, "/sys/kernel/debug/dri/%d/i915_emon_status", i);
+		if ((ret = access(power->battery_file_ext, R_OK)) == 0)
+			break;
+	}
+	if (ret < 0) {
+		free(power->battery_file_ext);
+		power->battery_file_ext = NULL;
+	}
+#else
+#warning Non-Linux OS detected, POWER initialization not done.
+#endif
+
+}
+
 /* Reading from /sys/kernel/debug/dri/0/i915_emon_status can cause a division by zero within kernel, at least as of 3.2-rc1.
  *
  * So disabling it for now.
@@ -171,22 +204,9 @@ get_cpu_stat(struct cpudata *cpu)
  */
 
 #define USE_I915_EMON_STATUS 0
-static char*
-get_battery_file(char *battery)
-{
-#ifdef __linux__
-	/* The format is /proc/acpi/battery/BAT?/state */
-	char *temp = (char *)malloc(sizeof(char) * (35 * strlen(battery)));
-	sprintf(temp, "/proc/acpi/battery/%s/state", battery);
-	return temp;
-#else
-#warning Non-Linux OS detected, skipping battery detection
-	return NULL;
-#endif
-}
 
-	static void
-get_power_stat(struct powerdata *power, const char *battery_file, char *debugfs, float elapsed_time)
+static void
+get_power_stat(struct powerdata *power, float elapsed_time)
 {
 #ifdef __linux__
 	FILE *file;
@@ -196,39 +216,39 @@ get_power_stat(struct powerdata *power, const char *battery_file, char *debugfs,
 	/* Reset values */
 	power->watts = power->watts_chipset = power->watts_gfx = -1;
 
-	file = fopen(battery_file, "r");
-	if (!file) {
-		/* Unable to read battery information */
-		return;
-	}
-	/* Reading ACPI-adquired power
-	 * Sample /proc/acpi/battery/BAT?/state file format:
-	 * present:                 yes
-	 * capacity state:          ok
-	 * charging state:          discharging
-	 * present rate:            1746 mA
-	 * remaining capacity:      5301 mAh
-	 * present voltage:         11788 mV
-	 */
-	fgets(line, 255, file);
-	fgets(line, 255, file);
-	fgets(line, 255, file);
-	fgets(line, 255, file);
-	sscanf(line, "present rate:\t%lu mAh\n", &rate);
-	fgets(line, 255, file);
-	fgets(line, 255, file);
-	sscanf(line, "present voltage:\t%lu mV\n", &voltage);
-	fclose(file);
+	if (power->battery_file) {
+		file = fopen(power->battery_file, "r");
+		if (!file) {
+			/* Unable to read battery information */
+			return;
+		}
+		/* Reading ACPI-adquired power
+		 * Sample /proc/acpi/battery/BAT?/state file format:
+		 * present:                 yes
+		 * capacity state:          ok
+		 * charging state:          discharging
+		 * present rate:            1746 mA
+		 * remaining capacity:      5301 mAh
+		 * present voltage:         11788 mV
+		 */
+		fgets(line, 255, file);
+		fgets(line, 255, file);
+		fgets(line, 255, file);
+		fgets(line, 255, file);
+		sscanf(line, "present rate:\t%lu mAh\n", &rate);
+		fgets(line, 255, file);
+		fgets(line, 255, file);
+		sscanf(line, "present voltage:\t%lu mV\n", &voltage);
+		fclose(file);
 
-	power->watts = (float) (rate * voltage) / 1000000;
-	power->watts *= elapsed_time;
+		power->watts = (float) (rate * voltage) / 1000000;
+		power->watts *= elapsed_time;
+	}
 
 	/* Going deeper and reading GPU power */
-	if (debugfs && USE_I915_EMON_STATUS) {
-		char debugfs_entry[128];
+	if (power->battery_file_ext && USE_I915_EMON_STATUS) {
 		long tmp;
-		sprintf(debugfs_entry, "%s%s", debugfs, "i915_emon_status");
-		file = fopen(debugfs_entry, "r");
+		file = fopen(power->battery_file_ext, "r");
 		if (!file) {
 			/* Unable to read debugfs file */
 			return;
@@ -247,6 +267,7 @@ get_power_stat(struct powerdata *power, const char *battery_file, char *debugfs,
 		fgets(line, 255, file);
 		sscanf(line, "GFX power: %lu\n", &tmp);
 		power->watts_gfx = (float) tmp / 1000;
+		fclose(file);
 	}
 #else
 	/* We are not on Linux, give a warning on compile */
@@ -592,8 +613,6 @@ int main(int argc, char **argv)
 
 	struct cpudata oldcpu, cpu;
 	struct powerdata power;
-	char *battery = BATTERY, *battery_file = NULL;
-	char *debugfs = DEBUGFS;
 #ifdef __linux__
 	int do_perf=0;
 	char *perf_output=NULL;
@@ -730,7 +749,7 @@ int main(int argc, char **argv)
 
 		/* Calculate initial stats */
 		/* Battery */
-		battery_file = get_battery_file(battery);
+		power_stat_init(&power);
 		/* CPU */
 		get_cpu_stat(&oldcpu);
 
@@ -831,7 +850,7 @@ int main(int argc, char **argv)
 		get_cpu_stat(&cpu);
 
 		/* Power */
-		get_power_stat(&power, battery_file, debugfs, time_diff);
+		get_power_stat(&power, time_diff);
 
 		if (interactive) {
 			printf("%s", clear_screen);