drm/vc4: gem: Add a managed action to cleanup the job queue

The job queue needs to be cleaned up using vc4_gem_destroy, but it's
not used consistently (vc4_drv's bind calls it in its error path, but
doesn't in unbind), and we can make that automatic through a managed
action. Let's remove the requirement to call vc4_gem_destroy.

Fixes: d5b1a78a ("drm/vc4: Add support for drawing 3D frames.")
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201029190104.2181730-3-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_drv.c

@@ -285,11 +285,13 @@ static int vc4_drm_bind(struct device *dev)
 	if (ret)
 		goto dev_put;
 
-	vc4_gem_init(drm);
+	ret = vc4_gem_init(drm);
+	if (ret)
+		goto dev_put;
 
 	ret = component_bind_all(dev, drm);
 	if (ret)
-		goto gem_destroy;
+		goto dev_put;
 
 	ret = vc4_plane_create_additional_planes(drm);
 	if (ret)
@@ -314,8 +316,6 @@ static int vc4_drm_bind(struct device *dev)
 
 unbind_all:
 	component_unbind_all(dev, drm);
-gem_destroy:
-	vc4_gem_destroy(drm);
 dev_put:
 	drm_dev_put(drm);
 	return ret;

drivers/gpu/drm/vc4/vc4_drv.h

@@ -874,8 +874,7 @@ extern struct platform_driver vc4_dsi_driver;
 extern const struct dma_fence_ops vc4_fence_ops;
 
 /* vc4_gem.c */
-void vc4_gem_init(struct drm_device *dev);
-void vc4_gem_destroy(struct drm_device *dev);
+int vc4_gem_init(struct drm_device *dev);
 int vc4_submit_cl_ioctl(struct drm_device *dev, void *data,
 			struct drm_file *file_priv);
 int vc4_wait_seqno_ioctl(struct drm_device *dev, void *data,

drivers/gpu/drm/vc4/vc4_gem.c

@@ -1263,8 +1263,8 @@ vc4_submit_cl_ioctl(struct drm_device *dev, void *data,
 	return ret;
 }
 
-void
-vc4_gem_init(struct drm_device *dev)
+static void vc4_gem_destroy(struct drm_device *dev, void *unused);
+int vc4_gem_init(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 
@@ -1285,10 +1285,11 @@ vc4_gem_init(struct drm_device *dev)
 
 	INIT_LIST_HEAD(&vc4->purgeable.list);
 	mutex_init(&vc4->purgeable.lock);
+
+	return drmm_add_action_or_reset(dev, vc4_gem_destroy, NULL);
 }
 
-void
-vc4_gem_destroy(struct drm_device *dev)
+static void vc4_gem_destroy(struct drm_device *dev, void *unused)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);