[PATCH 24/45] req-selftest-cancel

[Chris Wilson]

---
 drivers/gpu/drm/i915/i915_gem_request.c | 113 ++++++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index f7b702282b33..8ae767d5bae9 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -1304,6 +1304,28 @@ static void mock_request_set_delay(struct drm_i915_gem_request *request,
 	mock->timer.expires = delay;
 }
 
+static void mock_request_flush(struct drm_i915_gem_request *request)
+{
+	struct mock_request *mock =
+		container_of(request, typeof(*mock), request);
+
+	GEM_BUG_ON(!request->global_seqno);
+	if (del_timer_sync(&mock->timer))
+		timer_request_complete((unsigned long)request);
+}
+
+static bool mock_request_cancel(struct drm_i915_gem_request *request)
+{
+	struct mock_request *mock =
+		container_of(request, typeof(*mock), request);
+
+	if (!del_timer_sync(&mock->timer))
+		return false;
+
+	i915_gem_request_unsubmit(request);
+	return true;
+}
+
 static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
 {
 	struct intel_ring *ring;
@@ -1435,6 +1457,12 @@ mock_context(struct drm_i915_private *i915,
 	return ctx;
 }
 
+static void mock_context_close(struct i915_gem_context *ctx)
+{
+	ctx->closed = true;
+	i915_gem_context_put(ctx);
+}
+
 static void mock_retire_work_handler(struct work_struct *work)
 {
 }
@@ -1606,11 +1634,96 @@ static int igt_fence_wait(void *ignore)
 	return err;
 }
 
+static int igt_request_rewind(void *ignore)
+{
+	struct drm_i915_private *i915;
+	struct drm_i915_gem_request *request, *vip;
+	struct i915_gem_context *ctx[2];
+	int err = -ENOMEM;
+
+	i915 = mock_device();
+	if (!i915)
+		goto out;
+
+	mutex_lock(&i915->drm.struct_mutex);
+	ctx[0] = mock_context(i915, "A");
+	request = i915_gem_request_alloc(i915->engine[RCS], ctx[0]);
+	if (!request) {
+		err = -ENOMEM;
+		mutex_unlock(&i915->drm.struct_mutex);
+		goto out_device;
+	}
+
+	err = -EINVAL;
+	if (dma_fence_is_signaled(&request->fence)) {
+		pr_err("fence signaled before submit!\n");
+		i915_add_request(request);
+		mutex_unlock(&i915->drm.struct_mutex);
+		goto out_device;
+	}
+
+	mock_request_set_delay(request, 2 * HZ);
+	i915_add_request(request);
+	mutex_unlock(&i915->drm.struct_mutex);
+
+	/* Fake preemption */
+	mutex_lock(&i915->drm.struct_mutex);
+	ctx[1] = mock_context(i915, "B");
+	vip = i915_gem_request_alloc(i915->engine[RCS], ctx[1]);
+	if (!vip) {
+		err = -ENOMEM;
+		mutex_unlock(&i915->drm.struct_mutex);
+		goto err;
+	}
+
+	/* Simulate preemption: unwind the current request, submit the
+	 * high priority (vip) request, then afterwards requeue the old
+	 * requests.
+	 */
+	if (!mock_request_cancel(request)) {
+		pr_err("failed to cancel request!\n");
+		i915_add_request(vip);
+		mutex_unlock(&i915->drm.struct_mutex);
+		goto err;
+	}
+
+	i915_add_request(vip);
+	mutex_unlock(&i915->drm.struct_mutex);
+
+	mock_request_set_delay(request, 2 * HZ);
+	mock_submit_request(request);
+
+	if (i915_wait_request(vip, 0, HZ) == -ETIME) {
+		pr_err("timed out waiting for high priority request, vip.seqno=%d, current seqno=%d\n",
+		       vip->global_seqno, intel_engine_get_seqno(i915->engine[RCS]));
+		goto err;
+	}
+
+	if (i915_gem_request_completed(request)) {
+		pr_err("low priority request already completed\n");
+		goto err;
+	}
+
+	/* Skip the delay, we're done. */
+	mock_request_flush(request);
+	err = 0;
+err:
+	mutex_lock(&i915->drm.struct_mutex);
+	mock_context_close(ctx[1]);
+	mock_context_close(ctx[0]);
+	mutex_unlock(&i915->drm.struct_mutex);
+out_device:
+	mock_device_free(i915);
+out:
+	return err;
+}
+
 int i915_gem_request_selftest(void)
 {
 	static const struct i915_subtest tests[] = {
 		SUBTEST(igt_add_request),
 		SUBTEST(igt_fence_wait),
+		SUBTEST(igt_request_rewind),
 	};
 
 	return i915_subtests(tests, NULL);
-- 
2.11.0