1 files changed, 101 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_pm.c b/drivers/gpu/drm/i915/gt/selftest_engine_pm.c
index cbf6b0735272..b08fc5390e8a 100644
--- a/drivers/gpu/drm/i915/gt/selftest_engine_pm.c
+++ b/drivers/gpu/drm/i915/gt/selftest_engine_pm.c
@@ -6,7 +6,107 @@
 
 #include "i915_selftest.h"
 #include "selftest_engine.h"
+#include "selftest_engine_heartbeat.h"
 #include "selftests/igt_atomic.h"
+#include "selftests/igt_flush_test.h"
+#include "selftests/igt_spinner.h"
+
+static int live_engine_busy_stats(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	struct igt_spinner spin;
+	int err = 0;
+
+	/*
+	 * Check that if an engine supports busy-stats, they tell the truth.
+	 */
+
+	if (igt_spinner_init(&spin, gt))
+		return -ENOMEM;
+
+	GEM_BUG_ON(intel_gt_pm_is_awake(gt));
+	for_each_engine(engine, gt, id) {
+		struct i915_request *rq;
+		ktime_t de, dt;
+		ktime_t t[2];
+
+		if (!intel_engine_supports_stats(engine))
+			continue;
+
+		if (!intel_engine_can_store_dword(engine))
+			continue;
+
+		if (intel_gt_pm_wait_for_idle(gt)) {
+			err = -EBUSY;
+			break;
+		}
+
+		st_engine_heartbeat_disable(engine);
+
+		ENGINE_TRACE(engine, "measuring idle time\n");
+		preempt_disable();
+		de = intel_engine_get_busy_time(engine, &t[0]);
+		udelay(100);
+		de = ktime_sub(intel_engine_get_busy_time(engine, &t[1]), de);
+		preempt_enable();
+		dt = ktime_sub(t[1], t[0]);
+		if (de < 0 || de > 10) {
+			pr_err("%s: reported %lldns [%d%%] busyness while sleeping [for %lldns]\n",
+			       engine->name,
+			       de, (int)div64_u64(100 * de, dt), dt);
+			GEM_TRACE_DUMP();
+			err = -EINVAL;
+			goto end;
+		}
+
+		/* 100% busy */
+		rq = igt_spinner_create_request(&spin,
+						engine->kernel_context,
+						MI_NOOP);
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			goto end;
+		}
+		i915_request_add(rq);
+
+		if (!igt_wait_for_spinner(&spin, rq)) {
+			intel_gt_set_wedged(engine->gt);
+			err = -ETIME;
+			goto end;
+		}
+
+		ENGINE_TRACE(engine, "measuring busy time\n");
+		preempt_disable();
+		de = intel_engine_get_busy_time(engine, &t[0]);
+		udelay(100);
+		de = ktime_sub(intel_engine_get_busy_time(engine, &t[1]), de);
+		preempt_enable();
+		dt = ktime_sub(t[1], t[0]);
+		if (100 * de < 95 * dt || 95 * de > 100 * dt) {
+			pr_err("%s: reported %lldns [%d%%] busyness while spinning [for %lldns]\n",
+			       engine->name,
+			       de, (int)div64_u64(100 * de, dt), dt);
+			GEM_TRACE_DUMP();
+			err = -EINVAL;
+			goto end;
+		}
+
+end:
+		st_engine_heartbeat_enable(engine);
+		igt_spinner_end(&spin);
+		if (igt_flush_test(gt->i915))
+			err = -EIO;
+		if (err)
+			break;
+	}
+
+	igt_spinner_fini(&spin);
+	if (igt_flush_test(gt->i915))
+		err = -EIO;
+	return err;
+}
 
 static int live_engine_pm(void *arg)
 {
@@ -77,6 +177,7 @@ static int live_engine_pm(void *arg)
 int live_engine_pm_selftests(struct intel_gt *gt)
 {
 	static const struct i915_subtest tests[] = {
+		SUBTEST(live_engine_busy_stats),
 		SUBTEST(live_engine_pm),
 	};