drm/i915: Individual request cancellation

Currently, we cancel outstanding requests within a context when the
context is closed. We may also want to cancel individual requests using
the same graceful preemption mechanism.

v2 (Tvrtko):
 * Cancel waiters carefully considering no timeline lock and RCU.
 * Fixed selftests.

v3 (Tvrtko):
 * Remove error propagation to waiters for now.

v4 (Tvrtko):
 * Rebase for extracted i915_request_active_engine. (Matt)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
[danvet: Resolve conflict because intel_engine_flush_scheduler is
still called intel_engine_flush_submission]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-3-tvrtko.ursulin@linux.intel.com

1 files changed, 201 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
index 9a9e92a775c8..ee8e753d98ce 100644
--- a/drivers/gpu/drm/i915/selftests/i915_request.c
+++ b/drivers/gpu/drm/i915/selftests/i915_request.c
@@ -609,6 +609,206 @@ static int live_nop_request(void *arg)
 	return err;
 }
 
+static int __cancel_inactive(struct intel_engine_cs *engine)
+{
+	struct intel_context *ce;
+	struct igt_spinner spin;
+	struct i915_request *rq;
+	int err = 0;
+
+	if (igt_spinner_init(&spin, engine->gt))
+		return -ENOMEM;
+
+	ce = intel_context_create(engine);
+	if (IS_ERR(ce)) {
+		err = PTR_ERR(ce);
+		goto out_spin;
+	}
+
+	rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto out_ce;
+	}
+
+	pr_debug("%s: Cancelling inactive request\n", engine->name);
+	i915_request_cancel(rq, -EINTR);
+	i915_request_get(rq);
+	i915_request_add(rq);
+
+	if (i915_request_wait(rq, 0, HZ / 5) < 0) {
+		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+		pr_err("%s: Failed to cancel inactive request\n", engine->name);
+		intel_engine_dump(engine, &p, "%s\n", engine->name);
+		err = -ETIME;
+		goto out_rq;
+	}
+
+	if (rq->fence.error != -EINTR) {
+		pr_err("%s: fence not cancelled (%u)\n",
+		       engine->name, rq->fence.error);
+		err = -EINVAL;
+	}
+
+out_rq:
+	i915_request_put(rq);
+out_ce:
+	intel_context_put(ce);
+out_spin:
+	igt_spinner_fini(&spin);
+	if (err)
+		pr_err("%s: %s error %d\n", __func__, engine->name, err);
+	return err;
+}
+
+static int __cancel_active(struct intel_engine_cs *engine)
+{
+	struct intel_context *ce;
+	struct igt_spinner spin;
+	struct i915_request *rq;
+	int err = 0;
+
+	if (igt_spinner_init(&spin, engine->gt))
+		return -ENOMEM;
+
+	ce = intel_context_create(engine);
+	if (IS_ERR(ce)) {
+		err = PTR_ERR(ce);
+		goto out_spin;
+	}
+
+	rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto out_ce;
+	}
+
+	pr_debug("%s: Cancelling active request\n", engine->name);
+	i915_request_get(rq);
+	i915_request_add(rq);
+	if (!igt_wait_for_spinner(&spin, rq)) {
+		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+		pr_err("Failed to start spinner on %s\n", engine->name);
+		intel_engine_dump(engine, &p, "%s\n", engine->name);
+		err = -ETIME;
+		goto out_rq;
+	}
+	i915_request_cancel(rq, -EINTR);
+
+	if (i915_request_wait(rq, 0, HZ / 5) < 0) {
+		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+		pr_err("%s: Failed to cancel active request\n", engine->name);
+		intel_engine_dump(engine, &p, "%s\n", engine->name);
+		err = -ETIME;
+		goto out_rq;
+	}
+
+	if (rq->fence.error != -EINTR) {
+		pr_err("%s: fence not cancelled (%u)\n",
+		       engine->name, rq->fence.error);
+		err = -EINVAL;
+	}
+
+out_rq:
+	i915_request_put(rq);
+out_ce:
+	intel_context_put(ce);
+out_spin:
+	igt_spinner_fini(&spin);
+	if (err)
+		pr_err("%s: %s error %d\n", __func__, engine->name, err);
+	return err;
+}
+
+static int __cancel_completed(struct intel_engine_cs *engine)
+{
+	struct intel_context *ce;
+	struct igt_spinner spin;
+	struct i915_request *rq;
+	int err = 0;
+
+	if (igt_spinner_init(&spin, engine->gt))
+		return -ENOMEM;
+
+	ce = intel_context_create(engine);
+	if (IS_ERR(ce)) {
+		err = PTR_ERR(ce);
+		goto out_spin;
+	}
+
+	rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto out_ce;
+	}
+	igt_spinner_end(&spin);
+	i915_request_get(rq);
+	i915_request_add(rq);
+
+	if (i915_request_wait(rq, 0, HZ / 5) < 0) {
+		err = -ETIME;
+		goto out_rq;
+	}
+
+	pr_debug("%s: Cancelling completed request\n", engine->name);
+	i915_request_cancel(rq, -EINTR);
+	if (rq->fence.error) {
+		pr_err("%s: fence not cancelled (%u)\n",
+		       engine->name, rq->fence.error);
+		err = -EINVAL;
+	}
+
+out_rq:
+	i915_request_put(rq);
+out_ce:
+	intel_context_put(ce);
+out_spin:
+	igt_spinner_fini(&spin);
+	if (err)
+		pr_err("%s: %s error %d\n", __func__, engine->name, err);
+	return err;
+}
+
+static int live_cancel_request(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct intel_engine_cs *engine;
+
+	/*
+	 * Check cancellation of requests. We expect to be able to immediately
+	 * cancel active requests, even if they are currently on the GPU.
+	 */
+
+	for_each_uabi_engine(engine, i915) {
+		struct igt_live_test t;
+		int err, err2;
+
+		if (!intel_engine_has_preemption(engine))
+			continue;
+
+		err = igt_live_test_begin(&t, i915, __func__, engine->name);
+		if (err)
+			return err;
+
+		err = __cancel_inactive(engine);
+		if (err == 0)
+			err = __cancel_active(engine);
+		if (err == 0)
+			err = __cancel_completed(engine);
+
+		err2 = igt_live_test_end(&t);
+		if (err)
+			return err;
+		if (err2)
+			return err2;
+	}
+
+	return 0;
+}
+
 static struct i915_vma *empty_batch(struct drm_i915_private *i915)
 {
 	struct drm_i915_gem_object *obj;
@@ -1486,6 +1686,7 @@ int i915_request_live_selftests(struct drm_i915_private *i915)
 		SUBTEST(live_sequential_engines),
 		SUBTEST(live_parallel_engines),
 		SUBTEST(live_empty_request),
+		SUBTEST(live_cancel_request),
 		SUBTEST(live_breadcrumbs_smoketest),
 	};