static int ntb_async_rx_submit()

in ntb_transport.c [1520:1586]

• 52 lines of code
• 7 McCabe index (conditional complexity)

static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
{
	struct dma_async_tx_descriptor *txd;
	struct ntb_transport_qp *qp = entry->qp;
	struct dma_chan *chan = qp->rx_dma_chan;
	struct dma_device *device;
	size_t pay_off, buff_off, len;
	struct dmaengine_unmap_data *unmap;
	dma_cookie_t cookie;
	void *buf = entry->buf;

	len = entry->len;
	device = chan->device;
	pay_off = (size_t)offset & ~PAGE_MASK;
	buff_off = (size_t)buf & ~PAGE_MASK;

	if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
		goto err;

	unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
	if (!unmap)
		goto err;

	unmap->len = len;
	unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
				      pay_off, len, DMA_TO_DEVICE);
	if (dma_mapping_error(device->dev, unmap->addr[0]))
		goto err_get_unmap;

	unmap->to_cnt = 1;

	unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
				      buff_off, len, DMA_FROM_DEVICE);
	if (dma_mapping_error(device->dev, unmap->addr[1]))
		goto err_get_unmap;

	unmap->from_cnt = 1;

	txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
					     unmap->addr[0], len,
					     DMA_PREP_INTERRUPT);
	if (!txd)
		goto err_get_unmap;

	txd->callback_result = ntb_rx_copy_callback;
	txd->callback_param = entry;
	dma_set_unmap(txd, unmap);

	cookie = dmaengine_submit(txd);
	if (dma_submit_error(cookie))
		goto err_set_unmap;

	dmaengine_unmap_put(unmap);

	qp->last_cookie = cookie;

	qp->rx_async++;

	return 0;

err_set_unmap:
	dmaengine_unmap_put(unmap);
err_get_unmap:
	dmaengine_unmap_put(unmap);
err:
	return -ENXIO;
}