static int viommu_probe()

in virtio-iommu.c [1063:1182]

• 93 lines of code
• 15 McCabe index (conditional complexity)

static int viommu_probe(struct virtio_device *vdev)
{
	struct device *parent_dev = vdev->dev.parent;
	struct viommu_dev *viommu = NULL;
	struct device *dev = &vdev->dev;
	u64 input_start = 0;
	u64 input_end = -1UL;
	int ret;

	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||
	    !virtio_has_feature(vdev, VIRTIO_IOMMU_F_MAP_UNMAP))
		return -ENODEV;

	viommu = devm_kzalloc(dev, sizeof(*viommu), GFP_KERNEL);
	if (!viommu)
		return -ENOMEM;

	spin_lock_init(&viommu->request_lock);
	ida_init(&viommu->domain_ids);
	viommu->dev = dev;
	viommu->vdev = vdev;
	INIT_LIST_HEAD(&viommu->requests);

	ret = viommu_init_vqs(viommu);
	if (ret)
		return ret;

	virtio_cread_le(vdev, struct virtio_iommu_config, page_size_mask,
			&viommu->pgsize_bitmap);

	if (!viommu->pgsize_bitmap) {
		ret = -EINVAL;
		goto err_free_vqs;
	}

	viommu->map_flags = VIRTIO_IOMMU_MAP_F_READ | VIRTIO_IOMMU_MAP_F_WRITE;
	viommu->last_domain = ~0U;

	/* Optional features */
	virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE,
				struct virtio_iommu_config, input_range.start,
				&input_start);

	virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE,
				struct virtio_iommu_config, input_range.end,
				&input_end);

	virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE,
				struct virtio_iommu_config, domain_range.start,
				&viommu->first_domain);

	virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE,
				struct virtio_iommu_config, domain_range.end,
				&viommu->last_domain);

	virtio_cread_le_feature(vdev, VIRTIO_IOMMU_F_PROBE,
				struct virtio_iommu_config, probe_size,
				&viommu->probe_size);

	viommu->geometry = (struct iommu_domain_geometry) {
		.aperture_start	= input_start,
		.aperture_end	= input_end,
		.force_aperture	= true,
	};

	if (virtio_has_feature(vdev, VIRTIO_IOMMU_F_MMIO))
		viommu->map_flags |= VIRTIO_IOMMU_MAP_F_MMIO;

	viommu_ops.pgsize_bitmap = viommu->pgsize_bitmap;

	virtio_device_ready(vdev);

	/* Populate the event queue with buffers */
	ret = viommu_fill_evtq(viommu);
	if (ret)
		goto err_free_vqs;

	ret = iommu_device_sysfs_add(&viommu->iommu, dev, NULL, "%s",
				     virtio_bus_name(vdev));
	if (ret)
		goto err_free_vqs;

	iommu_device_register(&viommu->iommu, &viommu_ops, parent_dev);

#ifdef CONFIG_PCI
	if (pci_bus_type.iommu_ops != &viommu_ops) {
		ret = bus_set_iommu(&pci_bus_type, &viommu_ops);
		if (ret)
			goto err_unregister;
	}
#endif
#ifdef CONFIG_ARM_AMBA
	if (amba_bustype.iommu_ops != &viommu_ops) {
		ret = bus_set_iommu(&amba_bustype, &viommu_ops);
		if (ret)
			goto err_unregister;
	}
#endif
	if (platform_bus_type.iommu_ops != &viommu_ops) {
		ret = bus_set_iommu(&platform_bus_type, &viommu_ops);
		if (ret)
			goto err_unregister;
	}

	vdev->priv = viommu;

	dev_info(dev, "input address: %u bits\n",
		 order_base_2(viommu->geometry.aperture_end));
	dev_info(dev, "page mask: %#llx\n", viommu->pgsize_bitmap);

	return 0;

err_unregister:
	iommu_device_sysfs_remove(&viommu->iommu);
	iommu_device_unregister(&viommu->iommu);
err_free_vqs:
	vdev->config->del_vqs(vdev);

	return ret;
}