[RFC 3/7] drm/virtio: Add helpers to initialize and free the imported object

[Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx>]

The imported object can be considered a guest blob resource;
therefore, we use create_blob cmd while creating it. These helpers
are used in the next patch which does the actual import.

Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx>
---
 drivers/gpu/drm/virtio/virtgpu_prime.c | 69 ++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c
index 2a90df39c5de..1e87dbc9a897 100644
--- a/drivers/gpu/drm/virtio/virtgpu_prime.c
+++ b/drivers/gpu/drm/virtio/virtgpu_prime.c
@@ -186,6 +186,75 @@ long virtgpu_dma_buf_import_sgt(struct virtio_gpu_mem_entry **ents,
 	return 0;
 }
 
+static void virtgpu_dma_buf_free_obj(struct drm_gem_object *obj)
+{
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
+	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
+	struct dma_buf_attachment *attach = obj->import_attach;
+
+	if (bo->created) {
+		virtio_gpu_cmd_unref_resource(vgdev, bo);
+		virtio_gpu_notify(vgdev);
+	}
+
+	if (attach) {
+		dma_buf_detach(attach->dmabuf, attach);
+		dma_buf_put(attach->dmabuf);
+	}
+
+	drm_gem_object_release(&bo->base.base);
+	kfree(bo);
+}
+
+static int virtgpu_dma_buf_init_obj(struct drm_device *dev,
+				    struct virtio_gpu_object *bo,
+				    struct dma_buf_attachment *attach)
+{
+	struct virtio_gpu_device *vgdev = dev->dev_private;
+	struct virtio_gpu_object_params params = { 0 };
+	struct dma_resv *resv = attach->dmabuf->resv;
+	struct virtio_gpu_mem_entry *ents = NULL;
+	unsigned int nents;
+	int ret;
+
+	ret = virtio_gpu_resource_id_get(vgdev, &bo->hw_res_handle);
+	if (ret) {
+		virtgpu_dma_buf_free_obj(&bo->base.base);
+		return ret;
+	}
+
+	dma_resv_lock(resv, NULL);
+
+	ret = dma_buf_pin(attach);
+	if (ret)
+		goto err_pin;
+
+	ret = virtgpu_dma_buf_import_sgt(&ents, &nents, bo, attach);
+	if (ret)
+		goto err_import;
+
+	bo->guest_blob = true;
+	params.blob = true;
+	params.blob_mem = VIRTGPU_BLOB_MEM_GUEST;
+	params.blob_flags = VIRTGPU_BLOB_FLAG_USE_SHAREABLE;
+	params.size = attach->dmabuf->size;
+
+	virtio_gpu_cmd_resource_create_blob(vgdev, bo, &params,
+					    ents, nents);
+	dma_buf_unpin(attach);
+	dma_resv_unlock(resv);
+
+	return 0;
+
+err_import:
+	dma_buf_unpin(attach);
+err_pin:
+	dma_resv_unlock(resv);
+	ida_free(&vgdev->resource_ida, bo->hw_res_handle - 1);
+	virtgpu_dma_buf_free_obj(&bo->base.base);
+	return ret;
+}
+
 struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev,
 						struct dma_buf *buf)
 {
-- 
2.43.0