overlay: Search for right debugfs path

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

overlay/debugfs.c

@@ -25,15 +25,25 @@
 #include <sys/stat.h>
 #include <sys/mount.h>
 #include <errno.h>
+#include <stdio.h>
 
 #include "debugfs.h"
 
+char debugfs_path[128];
+
 int debugfs_init(void)
 {
+	const char *path = "/sys/kernel/debug";
 	struct stat st;
+	int n;
+
+	if (stat("/debug/dri", &st) == 0) {
+		path = "/debug/dri";
+		goto find_minor;
+	}
 
 	if (stat("/sys/kernel/debug/dri", &st) == 0)
-		return 0;
+		goto find_minor;
 
 	if (stat("/sys/kernel/debug", &st))
 		return errno;
@@ -41,5 +51,16 @@ int debugfs_init(void)
 	if (mount("debug", "/sys/kernel/debug", "debugfs", 0, 0))
 		return errno;
 
+find_minor:
+	for (n = 0; n < 16; n++) {
+		int len = sprintf(debugfs_path, "%s/dri/%d", path, n);
+		sprintf(debugfs_path + len, "/i915_error_state");
+		if (stat(debugfs_path, &st) == 0) {
+			debugfs_path[len] = '\0';
 			return 0;
 		}
+	}
+
+	debugfs_path[0] = '\0';
+	return ENOENT;
+}

overlay/debugfs.h

@@ -25,6 +25,7 @@
 #ifndef DEBUGFS_H
 #define DEBUGFS_H
 
+extern char debugfs_path[128];
 int debugfs_init(void);
 
 #endif /* DEBUGFS_H */

overlay/gem-objects.c

@@ -30,6 +30,7 @@
 #include <string.h>
 
 #include "gem-objects.h"
+#include "debugfs.h"
 
 /* /sys/kernel/debug/dri/0/i915_gem_objects:
  *	46 objects, 20107264 bytes
@@ -52,7 +53,8 @@ int gem_objects_init(struct gem_objects *obj)
 
 	memset(obj, 0, sizeof(*obj));
 
-	fd = open("/sys/kernel/debug/dri/0/i915_gem_objects", 0);
+	sprintf(buf, "%s/i915_gem_objects", debugfs_path);
+	fd = open(buf, 0);
 	if (fd < 0)
 		return errno;
 	len = read(fd, buf, sizeof(buf)-1);
@@ -97,7 +99,8 @@ int gem_objects_update(struct gem_objects *obj)
 	freed = obj->comm;
 	obj->comm = NULL;
 
-	fd = open("/sys/kernel/debug/dri/0/i915_gem_objects", 0);
+	sprintf(buf, "%s/i915_gem_objects", debugfs_path);
+	fd = open(buf, 0);
 	if (fd < 0) {
 		ret = errno;
 		goto done;

overlay/gpu-freq.c

@@ -29,6 +29,7 @@
 #include <stdio.h>
 
 #include "gpu-freq.h"
+#include "debugfs.h"
 
 int gpu_freq_init(struct gpu_freq *gf)
 {
@@ -37,7 +38,8 @@ int gpu_freq_init(struct gpu_freq *gf)
 
 	memset(gf, 0, sizeof(*gf));
 
-	fd = open("/sys/kernel/debug/dri/0/i915_cur_delayinfo", 0);
+	sprintf(buf, "%s/i915_cur_delayinfo", debugfs_path);
+	fd = open(buf, 0);
 	if (fd < 0)
 		return gf->error = errno;
 
@@ -83,7 +85,8 @@ int gpu_freq_update(struct gpu_freq *gf)
 	if (gf->error)
 		return gf->error;
 
-	fd = open("/sys/kernel/debug/dri/0/i915_cur_delayinfo", 0);
+	sprintf(buf, "%s/i915_cur_delayinfo", debugfs_path);
+	fd = open(buf, 0);
 	if (fd < 0)
 		return gf->error = errno;
 

overlay/gpu-perf.c

@@ -36,6 +36,7 @@
 #include <errno.h>
 
 #include "gpu-perf.h"
+#include "debugfs.h"
 
 #if defined(__i386__)
 #define rmb()           asm volatile("lock; addl $0,0(%%esp)" ::: "memory")
@@ -45,7 +46,6 @@
 #define rmb()           asm volatile("lfence" ::: "memory")
 #endif
 
-#define TRACING_EVENT_PATH "/sys/kernel/debug/tracing/events"
 #define N_PAGES 32
 
 struct sample_event {
@@ -85,7 +85,7 @@ static uint64_t tracepoint_id(const char *sys, const char *name)
 	char buf[1024];
 	int fd, n;
 
-	snprintf(buf, sizeof(buf), "%s/%s/%s/id", TRACING_EVENT_PATH, sys, name);
+	snprintf(buf, sizeof(buf), "%s/tracing/events/%s/%s/id", debugfs_path, sys, name);
 	fd = open(buf, 0);
 	if (fd < 0)
 		return 0;

overlay/power.c

@@ -31,6 +31,7 @@
 #include <errno.h>
 
 #include "power.h"
+#include "debugfs.h"
 
 /* XXX Is this exposed through RAPL? */
 
@@ -41,7 +42,8 @@ int power_init(struct power *power)
 
 	memset(power, 0, sizeof(*power));
 
-	fd = open("/sys/kernel/debug/dri/0/i915_energy_uJ", 0);
+	sprintf(buf, "%s/i915_energy_uJ", debugfs_path);
+	fd = open(buf, 0);
 	if (fd < 0)
 		return power->error = errno;
 
@@ -54,12 +56,13 @@ int power_init(struct power *power)
 	return 0;
 }
 
-static uint64_t file_to_u64(const char *path)
+static uint64_t file_to_u64(const char *name)
 {
 	char buf[4096];
 	int fd, len;
 
-	fd = open(path, 0);
+	sprintf(buf, "%s/i915_energy_uJ", name);
+	fd = open(buf, 0);
 	if (fd < 0)
 		return 0;
 
@@ -93,7 +96,7 @@ int power_update(struct power *power)
 	if (power->error)
 		return power->error;
 
-	s->energy = file_to_u64("/sys/kernel/debug/dri/0/i915_energy_uJ");
+	s->energy = file_to_u64("i915_energy_uJ");
 	s->timestamp = clock_ms_to_u64();
 	if (power->count == 1)
 		return EAGAIN;