static void vdpasim_net_work()

in vdpa_sim/vdpa_sim_net.c [33:104]

• 56 lines of code
• 13 McCabe index (conditional complexity)

static void vdpasim_net_work(struct work_struct *work)
{
	struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
	struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
	struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
	ssize_t read, write;
	size_t total_write;
	int pkts = 0;
	int err;

	spin_lock(&vdpasim->lock);

	if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
		goto out;

	if (!txq->ready || !rxq->ready)
		goto out;

	while (true) {
		total_write = 0;
		err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
					   &txq->head, GFP_ATOMIC);
		if (err <= 0)
			break;

		err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
					   &rxq->head, GFP_ATOMIC);
		if (err <= 0) {
			vringh_complete_iotlb(&txq->vring, txq->head, 0);
			break;
		}

		while (true) {
			read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
						     vdpasim->buffer,
						     PAGE_SIZE);
			if (read <= 0)
				break;

			write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
						      vdpasim->buffer, read);
			if (write <= 0)
				break;

			total_write += write;
		}

		/* Make sure data is wrote before advancing index */
		smp_wmb();

		vringh_complete_iotlb(&txq->vring, txq->head, 0);
		vringh_complete_iotlb(&rxq->vring, rxq->head, total_write);

		/* Make sure used is visible before rasing the interrupt. */
		smp_wmb();

		local_bh_disable();
		if (vringh_need_notify_iotlb(&txq->vring) > 0)
			vringh_notify(&txq->vring);
		if (vringh_need_notify_iotlb(&rxq->vring) > 0)
			vringh_notify(&rxq->vring);
		local_bh_enable();

		if (++pkts > 4) {
			schedule_work(&vdpasim->work);
			goto out;
		}
	}

out:
	spin_unlock(&vdpasim->lock);
}