[PATCH 2/3] virtgpu: add virtio_gpu_fence_cleanup()

[Manos Pitsidianakis <manos.pitsidianakis@linaro.org>]

When virtio_gpu_remove() is called, there might be in-flight command
objects in the virtqueues that the VIRTIO device hasn't processed. These
commands might use fences, which end up being leaked, as reported by
/sys/kernel/debug/kmemleak.

This commit adds a cleanup function that lowers the reference count of
all in-flight fences, resulting in their de-allocation.

Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
---
 drivers/gpu/drm/virtio/virtgpu_drv.h   |  1 +
 drivers/gpu/drm/virtio/virtgpu_fence.c | 12 ++++++++++++
 drivers/gpu/drm/virtio/virtgpu_kms.c   |  1 +
 3 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index b3d367be6f204dbc98bf1c6e5c43a37ac8c0d8b3..c94b5edb2aec42fe5cd6416e243cf40e4e2b060f 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -465,6 +465,7 @@ void virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
 			  struct virtio_gpu_fence *fence);
 void virtio_gpu_fence_event_process(struct virtio_gpu_device *vdev,
 				    u64 fence_id);
+void virtio_gpu_fence_cleanup(struct virtio_gpu_device *vdev);
 
 /* virtgpu_object.c */
 void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo);
diff --git a/drivers/gpu/drm/virtio/virtgpu_fence.c b/drivers/gpu/drm/virtio/virtgpu_fence.c
index 44c1d8ef3c4d07881e2c4c92cc67f6aba7a5df4f..3e536d190c0464f4db8955605bbf0aa4aa3612bd 100644
--- a/drivers/gpu/drm/virtio/virtgpu_fence.c
+++ b/drivers/gpu/drm/virtio/virtgpu_fence.c
@@ -157,3 +157,15 @@ void virtio_gpu_fence_event_process(struct virtio_gpu_device *vgdev,
 	}
 	spin_unlock_irqrestore(&drv->lock, irq_flags);
 }
+
+void virtio_gpu_fence_cleanup(struct virtio_gpu_device *vgdev)
+{
+	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
+	struct virtio_gpu_fence *curr, *tmp;
+
+	list_for_each_entry_safe(curr, tmp, &drv->fences, node) {
+		dma_fence_signal_locked(&curr->f);
+		list_del(&curr->node);
+		dma_fence_put(&curr->f);
+	}
+}
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
index da70d9248072b64786a5d48b71bccaa80b8aae8f..7b3c4d314f8eee692e2842a7056d6dc64936fc2f 100644
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -286,6 +286,7 @@ void virtio_gpu_deinit(struct drm_device *dev)
 	flush_work(&vgdev->cursorq.dequeue_work);
 	flush_work(&vgdev->config_changed_work);
 	virtio_reset_device(vgdev->vdev);
+	virtio_gpu_fence_cleanup(vgdev);
 	virtio_gpu_queue_cleanup(vgdev);
 	vgdev->vdev->config->del_vqs(vgdev->vdev);
 }

-- 
2.47.2