int rproc_add_virtio_dev()

in remoteproc_virtio.c [342:439]

• 64 lines of code
• 9 McCabe index (conditional complexity)

int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
{
	struct rproc *rproc = rvdev->rproc;
	struct device *dev = &rvdev->dev;
	struct virtio_device *vdev;
	struct rproc_mem_entry *mem;
	int ret;

	if (rproc->ops->kick == NULL) {
		ret = -EINVAL;
		dev_err(dev, ".kick method not defined for %s\n", rproc->name);
		goto out;
	}

	/* Try to find dedicated vdev buffer carveout */
	mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index);
	if (mem) {
		phys_addr_t pa;

		if (mem->of_resm_idx != -1) {
			struct device_node *np = rproc->dev.parent->of_node;

			/* Associate reserved memory to vdev device */
			ret = of_reserved_mem_device_init_by_idx(dev, np,
								 mem->of_resm_idx);
			if (ret) {
				dev_err(dev, "Can't associate reserved memory\n");
				goto out;
			}
		} else {
			if (mem->va) {
				dev_warn(dev, "vdev %d buffer already mapped\n",
					 rvdev->index);
				pa = rproc_va_to_pa(mem->va);
			} else {
				/* Use dma address as carveout no memmapped yet */
				pa = (phys_addr_t)mem->dma;
			}

			/* Associate vdev buffer memory pool to vdev subdev */
			ret = dma_declare_coherent_memory(dev, pa,
							   mem->da,
							   mem->len);
			if (ret < 0) {
				dev_err(dev, "Failed to associate buffer\n");
				goto out;
			}
		}
	} else {
		struct device_node *np = rproc->dev.parent->of_node;

		/*
		 * If we don't have dedicated buffer, just attempt to re-assign
		 * the reserved memory from our parent. A default memory-region
		 * at index 0 from the parent's memory-regions is assigned for
		 * the rvdev dev to allocate from. Failure is non-critical and
		 * the allocations will fall back to global pools, so don't
		 * check return value either.
		 */
		of_reserved_mem_device_init_by_idx(dev, np, 0);
	}

	/* Allocate virtio device */
	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
	if (!vdev) {
		ret = -ENOMEM;
		goto out;
	}
	vdev->id.device	= id,
	vdev->config = &rproc_virtio_config_ops,
	vdev->dev.parent = dev;
	vdev->dev.release = rproc_virtio_dev_release;

	/*
	 * We're indirectly making a non-temporary copy of the rproc pointer
	 * here, because drivers probed with this vdev will indirectly
	 * access the wrapping rproc.
	 *
	 * Therefore we must increment the rproc refcount here, and decrement
	 * it _only_ when the vdev is released.
	 */
	get_device(&rproc->dev);

	/* Reference the vdev and vring allocations */
	kref_get(&rvdev->refcount);

	ret = register_virtio_device(vdev);
	if (ret) {
		put_device(&vdev->dev);
		dev_err(dev, "failed to register vdev: %d\n", ret);
		goto out;
	}

	dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);

out:
	return ret;
}