[PATCH i-g-t 3/3] tests/intel/xe_pmu: Add idle engine activity test

[Riana Tauro <riana.tauro@intel.com>]

Add a test to validate engine is idle by reading PMU counters
(engine-active-ticks, engine-total-ticks) when idle

Signed-off-by: Riana Tauro <riana.tauro@intel.com>
---
 tests/intel/xe_pmu.c | 35 +++++++++++++++++++++++++++--------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/tests/intel/xe_pmu.c b/tests/intel/xe_pmu.c
index cbb825755..b47be23ac 100644
--- a/tests/intel/xe_pmu.c
+++ b/tests/intel/xe_pmu.c
@@ -21,6 +21,9 @@
 #define SLEEP_DURATION 2 /* in seconds */
 const double tolerance = 0.1;
 
+/* flag masks */
+#define TEST_BUSY	BIT(0)
+
 #define assert_within_epsilon(x, ref, tolerance) \
 	igt_assert_f((double)(x) <= (1.0 + (tolerance)) * (double)(ref) && \
 		     (double)(x) >= (1.0 - (tolerance)) * (double)(ref), \
@@ -79,11 +82,13 @@ static uint64_t get_event_config(int xe, unsigned int gt, struct drm_xe_engine_c
 }
 
 /**
+ * SUBTEST: engine-activity-idle
+ * Description: Test to validate engine activity shows no load when idle
+ *
  * SUBTEST: engine-activity
- * Description: Test to validate engine activity stats by running a workload and
- *              reading the active ticks and total ticks PMU counters
+ * Description: Test to validate engine activity stats by running full load
  */
-static void engine_activity(int fd, struct drm_xe_engine_class_instance *eci)
+static void engine_activity(int fd, struct drm_xe_engine_class_instance *eci, unsigned int flags)
 {
 	uint64_t config, busy_ticks, total_ticks, before[2], after[2];
 	struct xe_cork *cork = NULL;
@@ -97,14 +102,18 @@ static void engine_activity(int fd, struct drm_xe_engine_class_instance *eci)
 	pmu_fd[1] = open_group(fd, config, pmu_fd[0]);
 
 	vm = xe_vm_create(fd, 0, 0);
-	cork = xe_cork_create_opts(fd, eci, vm, 1, 1);
-	xe_cork_sync_start(fd, cork);
+
+	if (flags & TEST_BUSY) {
+		cork = xe_cork_create_opts(fd, eci, vm, 1, 1);
+		xe_cork_sync_start(fd, cork);
+	}
 
 	pmu_read_multi(pmu_fd[0], 2, before);
 	usleep(SLEEP_DURATION * USEC_PER_SEC);
 	pmu_read_multi(pmu_fd[0], 2, after);
 
-	xe_cork_sync_end(fd, cork);
+	if (flags & TEST_BUSY)
+		xe_cork_sync_end(fd, cork);
 
 	busy_ticks = after[0] - before[0];
 	total_ticks = after[1] - before[1];
@@ -122,7 +131,10 @@ static void engine_activity(int fd, struct drm_xe_engine_class_instance *eci)
 	close(pmu_fd[0]);
 	close(pmu_fd[1]);
 
-	assert_within_epsilon(busy_ticks, total_ticks, tolerance);
+	if (flags & TEST_BUSY)
+		assert_within_epsilon(busy_ticks, total_ticks, tolerance);
+	else
+		igt_assert(!busy_ticks);
 }
 
 igt_main
@@ -134,12 +146,19 @@ igt_main
 		fd = drm_open_driver(DRIVER_XE);
 	}
 
+	igt_describe("Validate there is no engine activity when idle");
+	igt_subtest_with_dynamic("engine-activity-idle")
+		xe_for_each_engine(fd, hwe)
+			igt_dynamic_f("engine-%s%d", xe_engine_class_string(hwe->engine_class),
+				      hwe->engine_instance)
+				engine_activity(fd, hwe, 0);
+
 	igt_describe("Validate engine activity with workload running by reading pmu counters");
 	igt_subtest_with_dynamic("engine-activity")
 		xe_for_each_engine(fd, hwe)
 			igt_dynamic_f("engine-%s%d", xe_engine_class_string(hwe->engine_class),
 				      hwe->engine_instance)
-				engine_activity(fd, hwe);
+				engine_activity(fd, hwe, TEST_BUSY);
 
 	igt_fixture {
 		close(fd);
-- 
2.47.1