[PATCH i-g-t 3/5] tests/intel/xe_oa: Return hwe from same gt from oa_unit_engine()

[Ashutosh Dixit <ashutosh.dixit@intel.com>]

For some tests (e.g. mmio trigger) a hwe (and exec_queue) is needed for
batch submissions, even when the OA unit does not have any attached
hwe's (e.g. OAM SAG). To enable such use cases, return a hwe from the same
gt when an OA unit has no attached engines.

Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
---
 tests/intel/xe_oa.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/tests/intel/xe_oa.c b/tests/intel/xe_oa.c
index 9302d1c83a..c8475720c5 100644
--- a/tests/intel/xe_oa.c
+++ b/tests/intel/xe_oa.c
@@ -486,7 +486,22 @@ static u64 oa_format_fields(u64 name)
 
 static const struct drm_xe_engine_class_instance *oa_unit_engine(const struct drm_xe_oa_unit *oau)
 {
-	return !oau ? NULL : oau->num_engines ? &oau->eci[random() % oau->num_engines] : NULL;
+	const struct drm_xe_engine_class_instance *hwe;
+
+	igt_assert(oau);
+
+	hwe = oau->num_engines ? &oau->eci[random() % oau->num_engines] : NULL;
+
+	/* If an OA unit has no hwe's, return a hwe from the same gt */
+	if (hwe || !(oau->capabilities & DRM_XE_OA_CAPS_OA_UNIT_GT_ID))
+		goto exit;
+
+	xe_for_each_engine(drm_fd, hwe)
+		if (hwe->gt_id == oau->gt_id)
+			break;
+	igt_assert(hwe);
+exit:
+	return hwe;
 }
 
 static int __first_and_num_oa_units(const struct drm_xe_oa_unit **oau)
-- 
2.48.1