[PATCH 52/73] drm/i915/selftests: Exercise relative timeline modes

[Chris Wilson]

A quick test to verify that the backend accepts each type of timeline
and can use them to track and control request emission.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/selftest_timeline.c | 105 ++++++++++++++++++++
 1 file changed, 105 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/selftest_timeline.c b/drivers/gpu/drm/i915/gt/selftest_timeline.c
index e44bfceef413..a0a6a5ba09d2 100644
--- a/drivers/gpu/drm/i915/gt/selftest_timeline.c
+++ b/drivers/gpu/drm/i915/gt/selftest_timeline.c
@@ -1365,9 +1365,114 @@ static int live_hwsp_recycle(void *arg)
 	return err;
 }
 
+static int live_hwsp_relative(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+
+	/*
+	 * Check backend support for different timeline modes.
+	 */
+
+	for_each_engine(engine, gt, id) {
+		enum intel_timeline_mode mode;
+
+		if (!intel_engine_has_scheduler(engine))
+			continue;
+
+		for (mode = INTEL_TIMELINE_ABSOLUTE;
+		     mode <= INTEL_TIMELINE_RELATIVE_ENGINE;
+		     mode++) {
+			struct intel_timeline *tl;
+			struct i915_request *rq;
+			struct intel_context *ce;
+			const char *msg;
+			int err;
+
+			if (mode == INTEL_TIMELINE_RELATIVE_CONTEXT &&
+			    !HAS_EXECLISTS(gt->i915))
+				continue;
+
+			ce = intel_context_create(engine);
+			if (IS_ERR(ce))
+				return PTR_ERR(ce);
+
+			err = intel_context_alloc_state(ce);
+			if (err) {
+				intel_context_put(ce);
+				return err;
+			}
+
+			switch (mode) {
+			case INTEL_TIMELINE_ABSOLUTE:
+				tl = intel_timeline_create(gt);
+				msg = "local";
+				break;
+
+			case INTEL_TIMELINE_RELATIVE_CONTEXT:
+				tl = __intel_timeline_create(gt,
+							     ce->state,
+							     INTEL_TIMELINE_RELATIVE_CONTEXT |
+							     0x400);
+				msg = "ppHWSP";
+				break;
+
+			case INTEL_TIMELINE_RELATIVE_ENGINE:
+				tl = __intel_timeline_create(gt,
+							     engine->status_page.vma,
+							     0x400);
+				msg = "HWSP";
+				break;
+			default:
+				continue;
+			}
+			if (IS_ERR(tl)) {
+				intel_context_put(ce);
+				return PTR_ERR(tl);
+			}
+
+			pr_info("Testing %s timeline on %s\n",
+				msg, engine->name);
+
+			intel_timeline_put(ce->timeline);
+			ce->timeline = tl;
+
+			err = intel_timeline_pin(tl, NULL);
+			if (err) {
+				intel_context_put(ce);
+				return err;
+			}
+			tl->seqno = 0xc0000000;
+			WRITE_ONCE(*(u32 *)tl->hwsp_seqno, tl->seqno);
+			intel_timeline_unpin(tl);
+
+			rq = intel_context_create_request(ce);
+			intel_context_put(ce);
+			if (IS_ERR(rq))
+				return PTR_ERR(rq);
+
+			GEM_BUG_ON(rcu_access_pointer(rq->timeline) != tl);
+
+			i915_request_get(rq);
+			i915_request_add(rq);
+
+			if (i915_request_wait(rq, 0, HZ / 5) < 0) {
+				i915_request_put(rq);
+				return -EIO;
+			}
+
+			i915_request_put(rq);
+		}
+	}
+
+	return 0;
+}
+
 int intel_timeline_live_selftests(struct drm_i915_private *i915)
 {
 	static const struct i915_subtest tests[] = {
+		SUBTEST(live_hwsp_relative),
 		SUBTEST(live_hwsp_recycle),
 		SUBTEST(live_hwsp_engine),
 		SUBTEST(live_hwsp_alternate),
-- 
2.20.1