eth1394.c

Ieee1394驱动实现

		node_info->fifo =	fifo_addr;

		/* Now that we're done with the 1394 specific stuff, we'll
		 * need to alter some of the data.  Believe it or not, all
		 * that needs to be done is sender_IP_address needs to be
		 * moved, the destination hardware address get stuffed
		 * in and the hardware address length set to 8.
		 *
		 * IMPORTANT: The code below overwrites 1394 specific data
		 * needed above so keep the munging of the data for the
		 * higher level IP stack last. */

		arp->ar_hln = 8;
		arp_ptr += arp->ar_hln;		/* skip over sender unique id */
		*(u32 *)arp_ptr = arp1394->sip;	/* move sender IP addr */
		arp_ptr += arp->ar_pln;		/* skip over sender IP addr */

		if (arp->ar_op == htons(ARPOP_REQUEST))
			memset(arp_ptr, 0, sizeof(u64));
		else
			memcpy(arp_ptr, dev->dev_addr, sizeof(u64));
	}

	/* Now add the ethernet header. */
	if (dev->hard_header(skb, dev, ntohs(ether_type), &dest_hw, NULL,
			     skb->len) >= 0)
		ret = ether1394_type_trans(skb, dev);

	return ret;
}

static int fragment_overlap(struct list_head *frag_list, int offset, int len)
{
	struct fragment_info *fi;
	int end = offset + len;

	list_for_each_entry(fi, frag_list, list)
		if (offset < fi->offset + fi->len && end > fi->offset)
			return 1;

	return 0;
}

static struct list_head *find_partial_datagram(struct list_head *pdgl, int dgl)
{
	struct partial_datagram *pd;

	list_for_each_entry(pd, pdgl, list)
		if (pd->dgl == dgl)
			return &pd->list;

	return NULL;
}

/* Assumes that new fragment does not overlap any existing fragments */
static int new_fragment(struct list_head *frag_info, int offset, int len)
{
	struct list_head *lh;
	struct fragment_info *fi, *fi2, *new;

	list_for_each(lh, frag_info) {
		fi = list_entry(lh, struct fragment_info, list);
		if (fi->offset + fi->len == offset) {
			/* The new fragment can be tacked on to the end */
			fi->len += len;
			/* Did the new fragment plug a hole? */
			fi2 = list_entry(lh->next, struct fragment_info, list);
			if (fi->offset + fi->len == fi2->offset) {
				/* glue fragments together */
				fi->len += fi2->len;
				list_del(lh->next);
				kfree(fi2);
			}
			return 0;
		} else if (offset + len == fi->offset) {
			/* The new fragment can be tacked on to the beginning */
			fi->offset = offset;
			fi->len += len;
			/* Did the new fragment plug a hole? */
			fi2 = list_entry(lh->prev, struct fragment_info, list);
			if (fi2->offset + fi2->len == fi->offset) {
				/* glue fragments together */
				fi2->len += fi->len;
				list_del(lh);
				kfree(fi);
			}
			return 0;
		} else if (offset > fi->offset + fi->len) {
			break;
		} else if (offset + len < fi->offset) {
			lh = lh->prev;
			break;
		}
	}

	new = kmalloc(sizeof(*new), GFP_ATOMIC);
	if (!new)
		return -ENOMEM;

	new->offset = offset;
	new->len = len;

	list_add(&new->list, lh);
	return 0;
}

static int new_partial_datagram(struct net_device *dev, struct list_head *pdgl,
				int dgl, int dg_size, char *frag_buf,
				int frag_off, int frag_len)
{
	struct partial_datagram *new;

	new = kmalloc(sizeof(*new), GFP_ATOMIC);
	if (!new)
		return -ENOMEM;

	INIT_LIST_HEAD(&new->frag_info);

	if (new_fragment(&new->frag_info, frag_off, frag_len) < 0) {
		kfree(new);
		return -ENOMEM;
	}

	new->dgl = dgl;
	new->dg_size = dg_size;

	new->skb = dev_alloc_skb(dg_size + dev->hard_header_len + 15);
	if (!new->skb) {
		struct fragment_info *fi = list_entry(new->frag_info.next,
						      struct fragment_info,
						      list);
		kfree(fi);
		kfree(new);
		return -ENOMEM;
	}

	skb_reserve(new->skb, (dev->hard_header_len + 15) & ~15);
	new->pbuf = skb_put(new->skb, dg_size);
	memcpy(new->pbuf + frag_off, frag_buf, frag_len);

	list_add(&new->list, pdgl);
	return 0;
}

static int update_partial_datagram(struct list_head *pdgl, struct list_head *lh,
				   char *frag_buf, int frag_off, int frag_len)
{
	struct partial_datagram *pd =
			list_entry(lh, struct partial_datagram, list);

	if (new_fragment(&pd->frag_info, frag_off, frag_len) < 0)
		return -ENOMEM;

	memcpy(pd->pbuf + frag_off, frag_buf, frag_len);

	/* Move list entry to beginnig of list so that oldest partial
	 * datagrams percolate to the end of the list */
	list_move(lh, pdgl);
	return 0;
}

static int is_datagram_complete(struct list_head *lh, int dg_size)
{
	struct partial_datagram *pd;
	struct fragment_info *fi;

	pd = list_entry(lh, struct partial_datagram, list);
	fi = list_entry(pd->frag_info.next, struct fragment_info, list);

	return (fi->len == dg_size);
}

/* Packet reception. We convert the IP1394 encapsulation header to an
 * ethernet header, and fill it with some of our other fields. This is
 * an incoming packet from the 1394 bus.  */
static int ether1394_data_handler(struct net_device *dev, int srcid, int destid,
				  char *buf, int len)
{
	struct sk_buff *skb;
	unsigned long flags;
	struct eth1394_priv *priv = netdev_priv(dev);
	union eth1394_hdr *hdr = (union eth1394_hdr *)buf;
	u16 ether_type = 0;  /* initialized to clear warning */
	int hdr_len;
	struct unit_directory *ud = priv->ud_list[NODEID_TO_NODE(srcid)];
	struct eth1394_node_info *node_info;

	if (!ud) {
		struct eth1394_node_ref *node;
		node = eth1394_find_node_nodeid(&priv->ip_node_list, srcid);
		if (unlikely(!node)) {
			HPSB_PRINT(KERN_ERR, "ether1394 rx: sender nodeid "
				   "lookup failure: " NODE_BUS_FMT,
				   NODE_BUS_ARGS(priv->host, srcid));
			priv->stats.rx_dropped++;
			return -1;
		}
		ud = node->ud;

		priv->ud_list[NODEID_TO_NODE(srcid)] = ud;
	}

	node_info = (struct eth1394_node_info *)ud->device.driver_data;

	/* First, did we receive a fragmented or unfragmented datagram? */
	hdr->words.word1 = ntohs(hdr->words.word1);

	hdr_len = hdr_type_len[hdr->common.lf];

	if (hdr->common.lf == ETH1394_HDR_LF_UF) {
		/* An unfragmented datagram has been received by the ieee1394
		 * bus. Build an skbuff around it so we can pass it to the
		 * high level network layer. */

		skb = dev_alloc_skb(len + dev->hard_header_len + 15);
		if (unlikely(!skb)) {
			ETH1394_PRINT_G(KERN_ERR, "Out of memory\n");
			priv->stats.rx_dropped++;
			return -1;
		}
		skb_reserve(skb, (dev->hard_header_len + 15) & ~15);
		memcpy(skb_put(skb, len - hdr_len), buf + hdr_len,
		       len - hdr_len);
		ether_type = hdr->uf.ether_type;
	} else {
		/* A datagram fragment has been received, now the fun begins. */

		struct list_head *pdgl, *lh;
		struct partial_datagram *pd;
		int fg_off;
		int fg_len = len - hdr_len;
		int dg_size;
		int dgl;
		int retval;
		struct pdg_list *pdg = &(node_info->pdg);

		hdr->words.word3 = ntohs(hdr->words.word3);
		/* The 4th header word is reserved so no need to do ntohs() */

		if (hdr->common.lf == ETH1394_HDR_LF_FF) {
			ether_type = hdr->ff.ether_type;
			dgl = hdr->ff.dgl;
			dg_size = hdr->ff.dg_size + 1;
			fg_off = 0;
		} else {
			hdr->words.word2 = ntohs(hdr->words.word2);
			dgl = hdr->sf.dgl;
			dg_size = hdr->sf.dg_size + 1;
			fg_off = hdr->sf.fg_off;
		}
		spin_lock_irqsave(&pdg->lock, flags);

		pdgl = &(pdg->list);
		lh = find_partial_datagram(pdgl, dgl);

		if (lh == NULL) {
			while (pdg->sz >= max_partial_datagrams) {
				/* remove the oldest */
				purge_partial_datagram(pdgl->prev);
				pdg->sz--;
			}

			retval = new_partial_datagram(dev, pdgl, dgl, dg_size,
						      buf + hdr_len, fg_off,
						      fg_len);
			if (retval < 0) {
				spin_unlock_irqrestore(&pdg->lock, flags);
				goto bad_proto;
			}
			pdg->sz++;
			lh = find_partial_datagram(pdgl, dgl);
		} else {
			struct partial_datagram *pd;

			pd = list_entry(lh, struct partial_datagram, list);

			if (fragment_overlap(&pd->frag_info, fg_off, fg_len)) {
				/* Overlapping fragments, obliterate old
				 * datagram and start new one. */
				purge_partial_datagram(lh);
				retval = new_partial_datagram(dev, pdgl, dgl,
							      dg_size,
							      buf + hdr_len,
							      fg_off, fg_len);
				if (retval < 0) {
					pdg->sz--;
					spin_unlock_irqrestore(&pdg->lock, flags);
					goto bad_proto;
				}
			} else {
				retval = update_partial_datagram(pdgl, lh,
								 buf + hdr_len,
								 fg_off, fg_len);
				if (retval < 0) {
					/* Couldn't save off fragment anyway
					 * so might as well obliterate the
					 * datagram now. */
					purge_partial_datagram(lh);
					pdg->sz--;
					spin_unlock_irqrestore(&pdg->lock, flags);
					goto bad_proto;
				}
			} /* fragment overlap */
		} /* new datagram or add to existing one */

		pd = list_entry(lh, struct partial_datagram, list);

		if (hdr->common.lf == ETH1394_HDR_LF_FF)
			pd->ether_type = ether_type;

		if (is_datagram_complete(lh, dg_size)) {
			ether_type = pd->ether_type;
			pdg->sz--;
			skb = skb_get(pd->skb);
			purge_partial_datagram(lh);
			spin_unlock_irqrestore(&pdg->lock, flags);
		} else {
			/* Datagram is not complete, we're done for the
			 * moment. */
			spin_unlock_irqrestore(&pdg->lock, flags);
			return 0;
		}
	} /* unframgented datagram or fragmented one */

	/* Write metadata, and then pass to the receive level */
	skb->dev = dev;
	skb->ip_summed = CHECKSUM_UNNECESSARY;	/* don't check it */

	/* Parse the encapsulation header. This actually does the job of
	 * converting to an ethernet frame header, aswell as arp
	 * conversion if needed. ARP conversion is easier in this
	 * direction, since we are using ethernet as our backend.  */
	skb->protocol = ether1394_parse_encap(skb, dev, srcid, destid,
					      ether_type);

	spin_lock_irqsave(&priv->lock, flags);

	if (!skb->protocol) {
		priv->stats.rx_errors++;
		priv->stats.rx_dropped++;
		dev_kfree_skb_any(skb);
		goto bad_proto;
	}

	if (netif_rx(skb) == NET_RX_DROP) {
		priv->stats.rx_errors++;
		priv->stats.rx_dropped++;
		goto bad_proto;
	}

	/* Statistics */
	priv->stats.rx_packets++;
	priv->stats.rx_bytes += skb->len;

bad_proto:
	if (netif_queue_stopped(dev))
		netif_wake_queue(dev);
	spin_unlock_irqrestore(&priv->lock, flags);

	dev->last_rx = jiffies;

	return 0;
}

static int ether1394_write(struct hpsb_host *host, int srcid, int destid,
			   quadlet_t *data, u64 addr, size_t len, u16 flags)
{
	struct eth1394_host_info *hi;

	hi = hpsb_get_hostinfo(&eth1394_highlevel, host);
	if (unlikely(!hi)) {
		ETH1394_PRINT_G(KERN_ERR, "No net device at fw-host%d\n",
				host->id);
		return RCODE_ADDRESS_ERROR;
	}

	if (ether1394_data_handler(hi->dev, srcid, destid, (char*)data, len))
		return RCODE_ADDRESS_ERROR;
	else
		return RCODE_COMPLETE;
}

static void ether1394_iso(struct hpsb_iso *iso)
{
	quadlet_t *data;
	char *buf;
	struct eth1394_host_info *hi;
	struct net_device *dev;
	struct eth1394_priv *priv;
	unsigned int len;
	u32 specifier_id;
	u16 source_id;
	int i;
	int nready;

	hi = hpsb_get_hostinfo(&eth1394_highlevel, iso->host);
	if (unlikely(!hi)) {
		ETH1394_PRINT_G(KERN_ERR, "No net device at fw-host%d\n",
				iso->host->id);
		return;
	}

	dev = hi->dev;

	nready = hpsb_iso_n_ready(iso);
	for (i = 0; i < nready; i++) {
		struct hpsb_iso_packet_info *info =
			&iso->infos[(iso->first_packet + i) % iso->buf_packets];
		data = (quadlet_t *)(iso->data_buf.kvirt + info->offset);

		/* skip over GASP header */
		buf = (char *)data + 8;
		len = info->len - 8;

		specifier_id = (be32_to_cpu(data[0]) & 0xffff) << 8 |
			       (be32_to_cpu(data[1]) & 0xff000000) >> 24;
		source_id = be32_to_cpu(data[0]) >> 16;

		priv = netdev_priv(dev);

		if (info->channel != (iso->host->csr.broadcast_channel & 0x3f)
		    || specifier_id != ETHER1394_GASP_SPECIFIER_ID) {
			/* This packet is not for us */
			continue;
		}
		ether1394_data_handler(dev, source_id, LOCAL_BUS | ALL_NODES,
				       buf, len);
	}

	hpsb_iso_recv_release_packets(iso, i);

	dev->last_rx = jiffies;
}

/******************************************
 * Datagram transmission code
 ******************************************/

/* Convert a standard ARP packet to 1394 ARP. The first 8 bytes (the entire