intel-gpu-overlay: Consolidate perf PMU access to library

Various tool modules implement their owm PMU open wrapper which
can be replaced by calling the library one.

v2:
 * Remove extra newline. (Chris Wilson)
 * Commit msg.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 32 insertions, 0 deletions

diff --git a/lib/igt_perf.c b/lib/igt_perf.c
index 45cccff0..961a858a 100644
--- a/lib/igt_perf.c
+++ b/lib/igt_perf.c
@@ -2,6 +2,8 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <string.h>
+#include <errno.h>
 
 #include "igt_perf.h"
 
@@ -24,3 +26,33 @@ uint64_t i915_type_id(void)
 	return strtoull(buf, 0, 0);
 }
 
+static int _perf_open(int config, int group, int format)
+{
+	struct perf_event_attr attr;
+
+	memset(&attr, 0, sizeof (attr));
+
+	attr.type = i915_type_id();
+	if (attr.type == 0)
+		return -ENOENT;
+
+	attr.config = config;
+
+	if (group >= 0)
+		format &= ~PERF_FORMAT_GROUP;
+
+	attr.read_format = format;
+
+	return perf_event_open(&attr, -1, 0, group, 0);
+}
+
+int perf_i915_open(int config)
+{
+	return _perf_open(config, -1, PERF_FORMAT_TOTAL_TIME_ENABLED);
+}
+
+int perf_i915_open_group(int config, int group)
+{
+	return _perf_open(config, group,
+			  PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_GROUP);
+}