static void solos_bh()

in solos-pci.c [757:895]

• 109 lines of code
• 24 McCabe index (conditional complexity)

static void solos_bh(unsigned long card_arg)
{
	struct solos_card *card = (void *)card_arg;
	uint32_t card_flags;
	uint32_t rx_done = 0;
	int port;

	/*
	 * Since fpga_tx() is going to need to read the flags under its lock,
	 * it can return them to us so that we don't have to hit PCI MMIO
	 * again for the same information
	 */
	card_flags = fpga_tx(card);

	for (port = 0; port < card->nr_ports; port++) {
		if (card_flags & (0x10 << port)) {
			struct pkt_hdr _hdr, *header;
			struct sk_buff *skb;
			struct atm_vcc *vcc;
			int size;

			if (card->using_dma) {
				skb = card->rx_skb[port];
				card->rx_skb[port] = NULL;

				dma_unmap_single(&card->dev->dev, SKB_CB(skb)->dma_addr,
						 RX_DMA_SIZE, DMA_FROM_DEVICE);

				header = (void *)skb->data;
				size = le16_to_cpu(header->size);
				skb_put(skb, size + sizeof(*header));
				skb_pull(skb, sizeof(*header));
			} else {
				header = &_hdr;

				rx_done |= 0x10 << port;

				memcpy_fromio(header, RX_BUF(card, port), sizeof(*header));

				size = le16_to_cpu(header->size);
				if (size > (card->buffer_size - sizeof(*header))){
					dev_warn(&card->dev->dev, "Invalid buffer size\n");
					continue;
				}

				/* Use netdev_alloc_skb() because it adds NET_SKB_PAD of
				 * headroom, and ensures we can route packets back out an
				 * Ethernet interface (for example) without having to
				 * reallocate. Adding NET_IP_ALIGN also ensures that both
				 * PPPoATM and PPPoEoBR2684 packets end up aligned. */
				skb = netdev_alloc_skb_ip_align(NULL, size + 1);
				if (!skb) {
					if (net_ratelimit())
						dev_warn(&card->dev->dev, "Failed to allocate sk_buff for RX\n");
					continue;
				}

				memcpy_fromio(skb_put(skb, size),
					      RX_BUF(card, port) + sizeof(*header),
					      size);
			}
			if (atmdebug) {
				dev_info(&card->dev->dev, "Received: port %d\n", port);
				dev_info(&card->dev->dev, "size: %d VPI: %d VCI: %d\n",
					 size, le16_to_cpu(header->vpi),
					 le16_to_cpu(header->vci));
				print_buffer(skb);
			}

			switch (le16_to_cpu(header->type)) {
			case PKT_DATA:
				vcc = find_vcc(card->atmdev[port], le16_to_cpu(header->vpi),
					       le16_to_cpu(header->vci));
				if (!vcc) {
					if (net_ratelimit())
						dev_warn(&card->dev->dev, "Received packet for unknown VPI.VCI %d.%d on port %d\n",
							 le16_to_cpu(header->vpi), le16_to_cpu(header->vci),
							 port);
					dev_kfree_skb_any(skb);
					break;
				}
				atm_charge(vcc, skb->truesize);
				vcc->push(vcc, skb);
				atomic_inc(&vcc->stats->rx);
				break;

			case PKT_STATUS:
				if (process_status(card, port, skb) &&
				    net_ratelimit()) {
					dev_warn(&card->dev->dev, "Bad status packet of %d bytes on port %d:\n", skb->len, port);
					print_buffer(skb);
				}
				dev_kfree_skb_any(skb);
				break;

			case PKT_COMMAND:
			default: /* FIXME: Not really, surely? */
				if (process_command(card, port, skb))
					break;
				spin_lock(&card->cli_queue_lock);
				if (skb_queue_len(&card->cli_queue[port]) > 10) {
					if (net_ratelimit())
						dev_warn(&card->dev->dev, "Dropping console response on port %d\n",
							 port);
					dev_kfree_skb_any(skb);
				} else
					skb_queue_tail(&card->cli_queue[port], skb);
				spin_unlock(&card->cli_queue_lock);
				break;
			}
		}
		/* Allocate RX skbs for any ports which need them */
		if (card->using_dma && card->atmdev[port] &&
		    !card->rx_skb[port]) {
			/* Unlike the MMIO case (qv) we can't add NET_IP_ALIGN
			 * here; the FPGA can only DMA to addresses which are
			 * aligned to 4 bytes. */
			struct sk_buff *skb = dev_alloc_skb(RX_DMA_SIZE);
			if (skb) {
				SKB_CB(skb)->dma_addr =
					dma_map_single(&card->dev->dev, skb->data,
						       RX_DMA_SIZE, DMA_FROM_DEVICE);
				iowrite32(SKB_CB(skb)->dma_addr,
					  card->config_regs + RX_DMA_ADDR(port));
				card->rx_skb[port] = skb;
			} else {
				if (net_ratelimit())
					dev_warn(&card->dev->dev, "Failed to allocate RX skb");

				/* We'll have to try again later */
				tasklet_schedule(&card->tlet);
			}
		}
	}
	if (rx_done)
		iowrite32(rx_done, card->config_regs + FLAGS_ADDR);

	return;
}