drm/i915/selftests: Pin the mock kernel context

The driver assumes that the kernel context is pinned and always
available for use from any process or atomic context. Make it so for
selftesting as well!
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180523142346.27953-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/selftests/mock_engine.c

@@ -212,8 +212,13 @@ struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,
 	if (!engine->base.buffer)
 		goto err_breadcrumbs;
 
+	if (IS_ERR(intel_context_pin(i915->kernel_context, &engine->base)))
+		goto err_ring;
+
 	return &engine->base;
 
+err_ring:
+	mock_ring_free(engine->base.buffer);
 err_breadcrumbs:
 	intel_engine_fini_breadcrumbs(&engine->base);
 	i915_timeline_fini(&engine->base.timeline);
@@ -254,6 +259,8 @@ void mock_engine_free(struct intel_engine_cs *engine)
 	if (ce)
 		intel_context_unpin(ce);
 
+	__intel_context_unpin(engine->i915->kernel_context, engine);
+
 	mock_ring_free(engine->buffer);
 
 	intel_engine_fini_breadcrumbs(engine);

drivers/gpu/drm/i915/selftests/mock_gem_device.c

@@ -136,8 +136,6 @@ static struct dev_pm_domain pm_domain = {
 struct drm_i915_private *mock_gem_device(void)
 {
 	struct drm_i915_private *i915;
-	struct intel_engine_cs *engine;
-	enum intel_engine_id id;
 	struct pci_dev *pdev;
 	int err;
 
@@ -233,13 +231,13 @@ struct drm_i915_private *mock_gem_device(void)
 	mock_init_ggtt(i915);
 
 	mkwrite_device_info(i915)->ring_mask = BIT(0);
-	i915->engine[RCS] = mock_engine(i915, "mock", RCS);
-	if (!i915->engine[RCS])
-		goto err_unlock;
-
 	i915->kernel_context = mock_context(i915, NULL);
 	if (!i915->kernel_context)
-		goto err_engine;
+		goto err_unlock;
+
+	i915->engine[RCS] = mock_engine(i915, "mock", RCS);
+	if (!i915->engine[RCS])
+		goto err_context;
 
 	mutex_unlock(&i915->drm.struct_mutex);
 
@@ -247,9 +245,8 @@ struct drm_i915_private *mock_gem_device(void)
 
 	return i915;
 
-err_engine:
-	for_each_engine(engine, i915, id)
-		mock_engine_free(engine);
+err_context:
+	i915_gem_contexts_fini(i915);
 err_unlock:
 	mutex_unlock(&i915->drm.struct_mutex);
 	kmem_cache_destroy(i915->priorities);