File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
new file mode 100644
index 0000000..b9d2f76
--- /dev/null
+++ b/drivers/firewire/net.c
@@ -0,0 +1,1726 @@
+/*
+ * IPv4 over IEEE 1394, per RFC 2734
+ * IPv6 over IEEE 1394, per RFC 3146
+ *
+ * Copyright (C) 2009 Jay Fenlason <fenlason@redhat.com>
+ *
+ * based on eth1394 by Ben Collins et al
+ */
+
+#include <linux/bug.h>
+#include <linux/compiler.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/ethtool.h>
+#include <linux/firewire.h>
+#include <linux/firewire-constants.h>
+#include <linux/highmem.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/jiffies.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <asm/unaligned.h>
+#include <net/arp.h>
+#include <net/firewire.h>
+
+/* rx limits */
+#define FWNET_MAX_FRAGMENTS		30 /* arbitrary, > TX queue depth */
+#define FWNET_ISO_PAGE_COUNT		(PAGE_SIZE < 16*1024 ? 4 : 2)
+
+/* tx limits */
+#define FWNET_MAX_QUEUED_DATAGRAMS	20 /* < 64 = number of tlabels */
+#define FWNET_MIN_QUEUED_DATAGRAMS	10 /* should keep AT DMA busy enough */
+#define FWNET_TX_QUEUE_LEN		FWNET_MAX_QUEUED_DATAGRAMS /* ? */
+
+#define IEEE1394_BROADCAST_CHANNEL	31
+#define IEEE1394_ALL_NODES		(0xffc0 | 0x003f)
+#define IEEE1394_MAX_PAYLOAD_S100	512
+#define FWNET_NO_FIFO_ADDR		(~0ULL)
+
+#define IANA_SPECIFIER_ID		0x00005eU
+#define RFC2734_SW_VERSION		0x000001U
+#define RFC3146_SW_VERSION		0x000002U
+
+#define IEEE1394_GASP_HDR_SIZE	8
+
+#define RFC2374_UNFRAG_HDR_SIZE	4
+#define RFC2374_FRAG_HDR_SIZE	8
+#define RFC2374_FRAG_OVERHEAD	4
+
+#define RFC2374_HDR_UNFRAG	0	/* unfragmented		*/
+#define RFC2374_HDR_FIRSTFRAG	1	/* first fragment	*/
+#define RFC2374_HDR_LASTFRAG	2	/* last fragment	*/
+#define RFC2374_HDR_INTFRAG	3	/* interior fragment	*/
+
+static bool fwnet_hwaddr_is_multicast(u8 *ha)
+{
+	return !!(*ha & 1);
+}
+
+/* IPv4 and IPv6 encapsulation header */
+struct rfc2734_header {
+	u32 w0;
+	u32 w1;
+};
+
+#define fwnet_get_hdr_lf(h)		(((h)->w0 & 0xc0000000) >> 30)
+#define fwnet_get_hdr_ether_type(h)	(((h)->w0 & 0x0000ffff))
+#define fwnet_get_hdr_dg_size(h)	((((h)->w0 & 0x0fff0000) >> 16) + 1)
+#define fwnet_get_hdr_fg_off(h)		(((h)->w0 & 0x00000fff))
+#define fwnet_get_hdr_dgl(h)		(((h)->w1 & 0xffff0000) >> 16)
+
+#define fwnet_set_hdr_lf(lf)		((lf) << 30)
+#define fwnet_set_hdr_ether_type(et)	(et)
+#define fwnet_set_hdr_dg_size(dgs)	(((dgs) - 1) << 16)
+#define fwnet_set_hdr_fg_off(fgo)	(fgo)
+
+#define fwnet_set_hdr_dgl(dgl)		((dgl) << 16)
+
+static inline void fwnet_make_uf_hdr(struct rfc2734_header *hdr,
+		unsigned ether_type)
+{
+	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_UNFRAG)
+		  | fwnet_set_hdr_ether_type(ether_type);
+}
+
+static inline void fwnet_make_ff_hdr(struct rfc2734_header *hdr,
+		unsigned ether_type, unsigned dg_size, unsigned dgl)
+{
+	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_FIRSTFRAG)
+		  | fwnet_set_hdr_dg_size(dg_size)
+		  | fwnet_set_hdr_ether_type(ether_type);
+	hdr->w1 = fwnet_set_hdr_dgl(dgl);
+}
+
+static inline void fwnet_make_sf_hdr(struct rfc2734_header *hdr,
+		unsigned lf, unsigned dg_size, unsigned fg_off, unsigned dgl)
+{
+	hdr->w0 = fwnet_set_hdr_lf(lf)
+		  | fwnet_set_hdr_dg_size(dg_size)
+		  | fwnet_set_hdr_fg_off(fg_off);
+	hdr->w1 = fwnet_set_hdr_dgl(dgl);
+}
+
+/* This list keeps track of what parts of the datagram have been filled in */
+struct fwnet_fragment_info {
+	struct list_head fi_link;
+	u16 offset;
+	u16 len;
+};
+
+struct fwnet_partial_datagram {
+	struct list_head pd_link;
+	struct list_head fi_list;
+	struct sk_buff *skb;
+	/* FIXME Why not use skb->data? */
+	char *pbuf;
+	u16 datagram_label;
+	u16 ether_type;
+	u16 datagram_size;
+};
+
+static DEFINE_MUTEX(fwnet_device_mutex);
+static LIST_HEAD(fwnet_device_list);
+
+struct fwnet_device {
+	struct list_head dev_link;
+	spinlock_t lock;
+	enum {
+		FWNET_BROADCAST_ERROR,
+		FWNET_BROADCAST_RUNNING,
+		FWNET_BROADCAST_STOPPED,
+	} broadcast_state;
+	struct fw_iso_context *broadcast_rcv_context;
+	struct fw_iso_buffer broadcast_rcv_buffer;
+	void **broadcast_rcv_buffer_ptrs;
+	unsigned broadcast_rcv_next_ptr;
+	unsigned num_broadcast_rcv_ptrs;
+	unsigned rcv_buffer_size;
+	/*
+	 * This value is the maximum unfragmented datagram size that can be
+	 * sent by the hardware.  It already has the GASP overhead and the
+	 * unfragmented datagram header overhead calculated into it.
+	 */
+	unsigned broadcast_xmt_max_payload;
+	u16 broadcast_xmt_datagramlabel;
+
+	/*
+	 * The CSR address that remote nodes must send datagrams to for us to
+	 * receive them.
+	 */
+	struct fw_address_handler handler;
+	u64 local_fifo;
+
+	/* Number of tx datagrams that have been queued but not yet acked */
+	int queued_datagrams;
+
+	int peer_count;
+	struct list_head peer_list;
+	struct fw_card *card;
+	struct net_device *netdev;
+};
+
+struct fwnet_peer {
+	struct list_head peer_link;
+	struct fwnet_device *dev;
+	u64 guid;
+
+	/* guarded by dev->lock */
+	struct list_head pd_list; /* received partial datagrams */
+	unsigned pdg_size;        /* pd_list size */
+
+	u16 datagram_label;       /* outgoing datagram label */
+	u16 max_payload;          /* includes RFC2374_FRAG_HDR_SIZE overhead */
+	int node_id;
+	int generation;
+	unsigned speed;
+};
+
+/* This is our task struct. It's used for the packet complete callback.  */
+struct fwnet_packet_task {
+	struct fw_transaction transaction;
+	struct rfc2734_header hdr;
+	struct sk_buff *skb;
+	struct fwnet_device *dev;
+
+	int outstanding_pkts;
+	u64 fifo_addr;
+	u16 dest_node;
+	u16 max_payload;
+	u8 generation;
+	u8 speed;
+	u8 enqueued;
+};
+
+/*
+ * Get fifo address embedded in hwaddr
+ */
+static __u64 fwnet_hwaddr_fifo(union fwnet_hwaddr *ha)
+{
+	return (u64)get_unaligned_be16(&ha->uc.fifo_hi) << 32
+	       | get_unaligned_be32(&ha->uc.fifo_lo);
+}
+
+/*
+ * saddr == NULL means use device source address.
+ * daddr == NULL means leave destination address (eg unresolved arp).
+ */
+static int fwnet_header_create(struct sk_buff *skb, struct net_device *net,
+			unsigned short type, const void *daddr,
+			const void *saddr, unsigned len)
+{
+	struct fwnet_header *h;
+
+	h = (struct fwnet_header *)skb_push(skb, sizeof(*h));
+	put_unaligned_be16(type, &h->h_proto);
+
+	if (net->flags & (IFF_LOOPBACK | IFF_NOARP)) {
+		memset(h->h_dest, 0, net->addr_len);
+
+		return net->hard_header_len;
+	}
+
+	if (daddr) {
+		memcpy(h->h_dest, daddr, net->addr_len);
+
+		return net->hard_header_len;
+	}
+
+	return -net->hard_header_len;
+}
+
+static int fwnet_header_cache(const struct neighbour *neigh,
+			      struct hh_cache *hh, __be16 type)
+{
+	struct net_device *net;
+	struct fwnet_header *h;
+
+	if (type == cpu_to_be16(ETH_P_802_3))
+		return -1;
+	net = neigh->dev;
+	h = (struct fwnet_header *)((u8 *)hh->hh_data + HH_DATA_OFF(sizeof(*h)));
+	h->h_proto = type;
+	memcpy(h->h_dest, neigh->ha, net->addr_len);
+	hh->hh_len = FWNET_HLEN;
+
+	return 0;
+}
+
+/* Called by Address Resolution module to notify changes in address. */
+static void fwnet_header_cache_update(struct hh_cache *hh,
+		const struct net_device *net, const unsigned char *haddr)
+{
+	memcpy((u8 *)hh->hh_data + HH_DATA_OFF(FWNET_HLEN), haddr, net->addr_len);
+}
+
+static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+{
+	memcpy(haddr, skb->dev->dev_addr, FWNET_ALEN);
+
+	return FWNET_ALEN;
+}
+
+static const struct header_ops fwnet_header_ops = {
+	.create         = fwnet_header_create,
+	.cache		= fwnet_header_cache,
+	.cache_update	= fwnet_header_cache_update,
+	.parse          = fwnet_header_parse,
+};
+
+/* FIXME: is this correct for all cases? */
+static bool fwnet_frag_overlap(struct fwnet_partial_datagram *pd,
+			       unsigned offset, unsigned len)
+{
+	struct fwnet_fragment_info *fi;
+	unsigned end = offset + len;
+
+	list_for_each_entry(fi, &pd->fi_list, fi_link)
+		if (offset < fi->offset + fi->len && end > fi->offset)
+			return true;
+
+	return false;
+}
+
+/* Assumes that new fragment does not overlap any existing fragments */
+static struct fwnet_fragment_info *fwnet_frag_new(
+	struct fwnet_partial_datagram *pd, unsigned offset, unsigned len)
+{
+	struct fwnet_fragment_info *fi, *fi2, *new;
+	struct list_head *list;
+
+	list = &pd->fi_list;
+	list_for_each_entry(fi, &pd->fi_list, fi_link) {
+		if (fi->offset + fi->len == offset) {
+			/* The new fragment can be tacked on to the end */
+			/* Did the new fragment plug a hole? */
+			fi2 = list_entry(fi->fi_link.next,
+					 struct fwnet_fragment_info, fi_link);
+			if (fi->offset + fi->len == fi2->offset) {
+				/* glue fragments together */
+				fi->len += len + fi2->len;
+				list_del(&fi2->fi_link);
+				kfree(fi2);
+			} else {
+				fi->len += len;
+			}
+
+			return fi;
+		}
+		if (offset + len == fi->offset) {
+			/* The new fragment can be tacked on to the beginning */
+			/* Did the new fragment plug a hole? */
+			fi2 = list_entry(fi->fi_link.prev,
+					 struct fwnet_fragment_info, fi_link);
+			if (fi2->offset + fi2->len == fi->offset) {
+				/* glue fragments together */
+				fi2->len += fi->len + len;
+				list_del(&fi->fi_link);
+				kfree(fi);
+
+				return fi2;
+			}
+			fi->offset = offset;
+			fi->len += len;
+
+			return fi;
+		}
+		if (offset > fi->offset + fi->len) {
+			list = &fi->fi_link;
+			break;
+		}
+		if (offset + len < fi->offset) {
+			list = fi->fi_link.prev;
+			break;
+		}
+	}
+
+	new = kmalloc(sizeof(*new), GFP_ATOMIC);
+	if (!new)
+		return NULL;
+
+	new->offset = offset;
+	new->len = len;
+	list_add(&new->fi_link, list);
+
+	return new;
+}
+
+static struct fwnet_partial_datagram *fwnet_pd_new(struct net_device *net,
+		struct fwnet_peer *peer, u16 datagram_label, unsigned dg_size,
+		void *frag_buf, unsigned frag_off, unsigned frag_len)
+{
+	struct fwnet_partial_datagram *new;
+	struct fwnet_fragment_info *fi;
+
+	new = kmalloc(sizeof(*new), GFP_ATOMIC);
+	if (!new)
+		goto fail;
+
+	INIT_LIST_HEAD(&new->fi_list);
+	fi = fwnet_frag_new(new, frag_off, frag_len);
+	if (fi == NULL)
+		goto fail_w_new;
+
+	new->datagram_label = datagram_label;
+	new->datagram_size = dg_size;
+	new->skb = dev_alloc_skb(dg_size + LL_RESERVED_SPACE(net));
+	if (new->skb == NULL)
+		goto fail_w_fi;
+
+	skb_reserve(new->skb, LL_RESERVED_SPACE(net));
+	new->pbuf = skb_put(new->skb, dg_size);
+	memcpy(new->pbuf + frag_off, frag_buf, frag_len);
+	list_add_tail(&new->pd_link, &peer->pd_list);
+
+	return new;
+
+fail_w_fi:
+	kfree(fi);
+fail_w_new:
+	kfree(new);
+fail:
+	return NULL;
+}
+
+static struct fwnet_partial_datagram *fwnet_pd_find(struct fwnet_peer *peer,
+						    u16 datagram_label)
+{
+	struct fwnet_partial_datagram *pd;
+
+	list_for_each_entry(pd, &peer->pd_list, pd_link)
+		if (pd->datagram_label == datagram_label)
+			return pd;
+
+	return NULL;
+}
+
+
+static void fwnet_pd_delete(struct fwnet_partial_datagram *old)
+{
+	struct fwnet_fragment_info *fi, *n;
+
+	list_for_each_entry_safe(fi, n, &old->fi_list, fi_link)
+		kfree(fi);
+
+	list_del(&old->pd_link);
+	dev_kfree_skb_any(old->skb);
+	kfree(old);
+}
+
+static bool fwnet_pd_update(struct fwnet_peer *peer,
+		struct fwnet_partial_datagram *pd, void *frag_buf,
+		unsigned frag_off, unsigned frag_len)
+{
+	if (fwnet_frag_new(pd, frag_off, frag_len) == NULL)
+		return false;
+
+	memcpy(pd->pbuf + frag_off, frag_buf, frag_len);
+
+	/*
+	 * Move list entry to beginning of list so that oldest partial
+	 * datagrams percolate to the end of the list
+	 */
+	list_move_tail(&pd->pd_link, &peer->pd_list);
+
+	return true;
+}
+
+static bool fwnet_pd_is_complete(struct fwnet_partial_datagram *pd)
+{
+	struct fwnet_fragment_info *fi;
+
+	fi = list_entry(pd->fi_list.next, struct fwnet_fragment_info, fi_link);
+
+	return fi->len == pd->datagram_size;
+}
+
+/* caller must hold dev->lock */
+static struct fwnet_peer *fwnet_peer_find_by_guid(struct fwnet_device *dev,
+						  u64 guid)
+{
+	struct fwnet_peer *peer;
+
+	list_for_each_entry(peer, &dev->peer_list, peer_link)
+		if (peer->guid == guid)
+			return peer;
+
+	return NULL;
+}
+
+/* caller must hold dev->lock */
+static struct fwnet_peer *fwnet_peer_find_by_node_id(struct fwnet_device *dev,
+						int node_id, int generation)
+{
+	struct fwnet_peer *peer;
+
+	list_for_each_entry(peer, &dev->peer_list, peer_link)
+		if (peer->node_id    == node_id &&
+		    peer->generation == generation)
+			return peer;
+
+	return NULL;
+}
+
+/* See IEEE 1394-2008 table 6-4, table 8-8, table 16-18. */
+static unsigned fwnet_max_payload(unsigned max_rec, unsigned speed)
+{
+	max_rec = min(max_rec, speed + 8);
+	max_rec = clamp(max_rec, 8U, 11U); /* 512...4096 */
+
+	return (1 << (max_rec + 1)) - RFC2374_FRAG_HDR_SIZE;
+}
+
+
+static int fwnet_finish_incoming_packet(struct net_device *net,
+					struct sk_buff *skb, u16 source_node_id,
+					bool is_broadcast, u16 ether_type)
+{
+	struct fwnet_device *dev;
+	int status;
+	__be64 guid;
+
+	switch (ether_type) {
+	case ETH_P_ARP:
+	case ETH_P_IP:
+#if IS_ENABLED(CONFIG_IPV6)
+	case ETH_P_IPV6:
+#endif
+		break;
+	default:
+		goto err;
+	}
+
+	dev = netdev_priv(net);
+	/* Write metadata, and then pass to the receive level */
+	skb->dev = net;
+	skb->ip_summed = CHECKSUM_NONE;
+
+	/*
+	 * Parse the encapsulation header. This actually does the job of
+	 * converting to an ethernet-like pseudo frame header.
+	 */
+	guid = cpu_to_be64(dev->card->guid);
+	if (dev_hard_header(skb, net, ether_type,
+			   is_broadcast ? net->broadcast : net->dev_addr,
+			   NULL, skb->len) >= 0) {
+		struct fwnet_header *eth;
+		u16 *rawp;
+		__be16 protocol;
+
+		skb_reset_mac_header(skb);
+		skb_pull(skb, sizeof(*eth));
+		eth = (struct fwnet_header *)skb_mac_header(skb);
+		if (fwnet_hwaddr_is_multicast(eth->h_dest)) {
+			if (memcmp(eth->h_dest, net->broadcast,
+				   net->addr_len) == 0)
+				skb->pkt_type = PACKET_BROADCAST;
+#if 0
+			else
+				skb->pkt_type = PACKET_MULTICAST;
+#endif
+		} else {
+			if (memcmp(eth->h_dest, net->dev_addr, net->addr_len))
+				skb->pkt_type = PACKET_OTHERHOST;
+		}
+		if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN) {
+			protocol = eth->h_proto;
+		} else {
+			rawp = (u16 *)skb->data;
+			if (*rawp == 0xffff)
+				protocol = htons(ETH_P_802_3);
+			else
+				protocol = htons(ETH_P_802_2);
+		}
+		skb->protocol = protocol;
+	}
+	status = netif_rx(skb);
+	if (status == NET_RX_DROP) {
+		net->stats.rx_errors++;
+		net->stats.rx_dropped++;
+	} else {
+		net->stats.rx_packets++;
+		net->stats.rx_bytes += skb->len;
+	}
+
+	return 0;
+
+ err:
+	net->stats.rx_errors++;
+	net->stats.rx_dropped++;
+
+	dev_kfree_skb_any(skb);
+
+	return -ENOENT;
+}
+
+static int fwnet_incoming_packet(struct fwnet_device *dev, __be32 *buf, int len,
+				 int source_node_id, int generation,
+				 bool is_broadcast)
+{
+	struct sk_buff *skb;
+	struct net_device *net = dev->netdev;
+	struct rfc2734_header hdr;
+	unsigned lf;
+	unsigned long flags;
+	struct fwnet_peer *peer;
+	struct fwnet_partial_datagram *pd;
+	int fg_off;
+	int dg_size;
+	u16 datagram_label;
+	int retval;
+	u16 ether_type;
+
+	if (len <= RFC2374_UNFRAG_HDR_SIZE)
+		return 0;
+
+	hdr.w0 = be32_to_cpu(buf[0]);
+	lf = fwnet_get_hdr_lf(&hdr);
+	if (lf == RFC2374_HDR_UNFRAG) {
+		/*
+		 * 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.
+		 */
+		ether_type = fwnet_get_hdr_ether_type(&hdr);
+		buf++;
+		len -= RFC2374_UNFRAG_HDR_SIZE;
+
+		skb = dev_alloc_skb(len + LL_RESERVED_SPACE(net));
+		if (unlikely(!skb)) {
+			net->stats.rx_dropped++;
+
+			return -ENOMEM;
+		}
+		skb_reserve(skb, LL_RESERVED_SPACE(net));
+		memcpy(skb_put(skb, len), buf, len);
+
+		return fwnet_finish_incoming_packet(net, skb, source_node_id,
+						    is_broadcast, ether_type);
+	}
+
+	/* A datagram fragment has been received, now the fun begins. */
+
+	if (len <= RFC2374_FRAG_HDR_SIZE)
+		return 0;
+
+	hdr.w1 = ntohl(buf[1]);
+	buf += 2;
+	len -= RFC2374_FRAG_HDR_SIZE;
+	if (lf == RFC2374_HDR_FIRSTFRAG) {
+		ether_type = fwnet_get_hdr_ether_type(&hdr);
+		fg_off = 0;
+	} else {
+		ether_type = 0;
+		fg_off = fwnet_get_hdr_fg_off(&hdr);
+	}
+	datagram_label = fwnet_get_hdr_dgl(&hdr);
+	dg_size = fwnet_get_hdr_dg_size(&hdr);
+
+	if (fg_off + len > dg_size)
+		return 0;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	peer = fwnet_peer_find_by_node_id(dev, source_node_id, generation);
+	if (!peer) {
+		retval = -ENOENT;
+		goto fail;
+	}
+
+	pd = fwnet_pd_find(peer, datagram_label);
+	if (pd == NULL) {
+		while (peer->pdg_size >= FWNET_MAX_FRAGMENTS) {
+			/* remove the oldest */
+			fwnet_pd_delete(list_first_entry(&peer->pd_list,
+				struct fwnet_partial_datagram, pd_link));
+			peer->pdg_size--;
+		}
+		pd = fwnet_pd_new(net, peer, datagram_label,
+				  dg_size, buf, fg_off, len);
+		if (pd == NULL) {
+			retval = -ENOMEM;
+			goto fail;
+		}
+		peer->pdg_size++;
+	} else {
+		if (fwnet_frag_overlap(pd, fg_off, len) ||
+		    pd->datagram_size != dg_size) {
+			/*
+			 * Differing datagram sizes or overlapping fragments,
+			 * discard old datagram and start a new one.
+			 */
+			fwnet_pd_delete(pd);
+			pd = fwnet_pd_new(net, peer, datagram_label,
+					  dg_size, buf, fg_off, len);
+			if (pd == NULL) {
+				peer->pdg_size--;
+				retval = -ENOMEM;
+				goto fail;
+			}
+		} else {
+			if (!fwnet_pd_update(peer, pd, buf, fg_off, len)) {
+				/*
+				 * Couldn't save off fragment anyway
+				 * so might as well obliterate the
+				 * datagram now.
+				 */
+				fwnet_pd_delete(pd);
+				peer->pdg_size--;
+				retval = -ENOMEM;
+				goto fail;
+			}
+		}
+	} /* new datagram or add to existing one */
+
+	if (lf == RFC2374_HDR_FIRSTFRAG)
+		pd->ether_type = ether_type;
+
+	if (fwnet_pd_is_complete(pd)) {
+		ether_type = pd->ether_type;
+		peer->pdg_size--;
+		skb = skb_get(pd->skb);
+		fwnet_pd_delete(pd);
+
+		spin_unlock_irqrestore(&dev->lock, flags);
+
+		return fwnet_finish_incoming_packet(net, skb, source_node_id,
+						    false, ether_type);
+	}
+	/*
+	 * Datagram is not complete, we're done for the
+	 * moment.
+	 */
+	retval = 0;
+ fail:
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	return retval;
+}
+
+static void fwnet_receive_packet(struct fw_card *card, struct fw_request *r,
+		int tcode, int destination, int source, int generation,
+		unsigned long long offset, void *payload, size_t length,
+		void *callback_data)
+{
+	struct fwnet_device *dev = callback_data;
+	int rcode;
+
+	if (destination == IEEE1394_ALL_NODES) {
+		kfree(r);
+
+		return;
+	}
+
+	if (offset != dev->handler.offset)
+		rcode = RCODE_ADDRESS_ERROR;
+	else if (tcode != TCODE_WRITE_BLOCK_REQUEST)
+		rcode = RCODE_TYPE_ERROR;
+	else if (fwnet_incoming_packet(dev, payload, length,
+				       source, generation, false) != 0) {
+		dev_err(&dev->netdev->dev, "incoming packet failure\n");
+		rcode = RCODE_CONFLICT_ERROR;
+	} else
+		rcode = RCODE_COMPLETE;
+
+	fw_send_response(card, r, rcode);
+}
+
+static int gasp_source_id(__be32 *p)
+{
+	return be32_to_cpu(p[0]) >> 16;
+}
+
+static u32 gasp_specifier_id(__be32 *p)
+{
+	return (be32_to_cpu(p[0]) & 0xffff) << 8 |
+	       (be32_to_cpu(p[1]) & 0xff000000) >> 24;
+}
+
+static u32 gasp_version(__be32 *p)
+{
+	return be32_to_cpu(p[1]) & 0xffffff;
+}
+
+static void fwnet_receive_broadcast(struct fw_iso_context *context,
+		u32 cycle, size_t header_length, void *header, void *data)
+{
+	struct fwnet_device *dev;
+	struct fw_iso_packet packet;
+	__be16 *hdr_ptr;
+	__be32 *buf_ptr;
+	int retval;
+	u32 length;
+	unsigned long offset;
+	unsigned long flags;
+
+	dev = data;
+	hdr_ptr = header;
+	length = be16_to_cpup(hdr_ptr);
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	offset = dev->rcv_buffer_size * dev->broadcast_rcv_next_ptr;
+	buf_ptr = dev->broadcast_rcv_buffer_ptrs[dev->broadcast_rcv_next_ptr++];
+	if (dev->broadcast_rcv_next_ptr == dev->num_broadcast_rcv_ptrs)
+		dev->broadcast_rcv_next_ptr = 0;
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	if (length > IEEE1394_GASP_HDR_SIZE &&
+	    gasp_specifier_id(buf_ptr) == IANA_SPECIFIER_ID &&
+	    (gasp_version(buf_ptr) == RFC2734_SW_VERSION
+#if IS_ENABLED(CONFIG_IPV6)
+	     || gasp_version(buf_ptr) == RFC3146_SW_VERSION
+#endif
+	    ))
+		fwnet_incoming_packet(dev, buf_ptr + 2,
+				      length - IEEE1394_GASP_HDR_SIZE,
+				      gasp_source_id(buf_ptr),
+				      context->card->generation, true);
+
+	packet.payload_length = dev->rcv_buffer_size;
+	packet.interrupt = 1;
+	packet.skip = 0;
+	packet.tag = 3;
+	packet.sy = 0;
+	packet.header_length = IEEE1394_GASP_HDR_SIZE;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	retval = fw_iso_context_queue(dev->broadcast_rcv_context, &packet,
+				      &dev->broadcast_rcv_buffer, offset);
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	if (retval >= 0)
+		fw_iso_context_queue_flush(dev->broadcast_rcv_context);
+	else
+		dev_err(&dev->netdev->dev, "requeue failed\n");
+}
+
+static struct kmem_cache *fwnet_packet_task_cache;
+
+static void fwnet_free_ptask(struct fwnet_packet_task *ptask)
+{
+	dev_kfree_skb_any(ptask->skb);
+	kmem_cache_free(fwnet_packet_task_cache, ptask);
+}
+
+/* Caller must hold dev->lock. */
+static void dec_queued_datagrams(struct fwnet_device *dev)
+{
+	if (--dev->queued_datagrams == FWNET_MIN_QUEUED_DATAGRAMS)
+		netif_wake_queue(dev->netdev);
+}
+
+static int fwnet_send_packet(struct fwnet_packet_task *ptask);
+
+static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
+{
+	struct fwnet_device *dev = ptask->dev;
+	struct sk_buff *skb = ptask->skb;
+	unsigned long flags;
+	bool free;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	ptask->outstanding_pkts--;
+
+	/* Check whether we or the networking TX soft-IRQ is last user. */
+	free = (ptask->outstanding_pkts == 0 && ptask->enqueued);
+	if (free)
+		dec_queued_datagrams(dev);
+
+	if (ptask->outstanding_pkts == 0) {
+		dev->netdev->stats.tx_packets++;
+		dev->netdev->stats.tx_bytes += skb->len;
+	}
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	if (ptask->outstanding_pkts > 0) {
+		u16 dg_size;
+		u16 fg_off;
+		u16 datagram_label;
+		u16 lf;
+
+		/* Update the ptask to point to the next fragment and send it */
+		lf = fwnet_get_hdr_lf(&ptask->hdr);
+		switch (lf) {
+		case RFC2374_HDR_LASTFRAG:
+		case RFC2374_HDR_UNFRAG:
+		default:
+			dev_err(&dev->netdev->dev,
+				"outstanding packet %x lf %x, header %x,%x\n",
+				ptask->outstanding_pkts, lf, ptask->hdr.w0,
+				ptask->hdr.w1);
+			BUG();
+
+		case RFC2374_HDR_FIRSTFRAG:
+			/* Set frag type here for future interior fragments */
+			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
+			fg_off = ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
+			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
+			break;
+
+		case RFC2374_HDR_INTFRAG:
+			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
+			fg_off = fwnet_get_hdr_fg_off(&ptask->hdr)
+				  + ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
+			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
+			break;
+		}
+
+		if (ptask->dest_node == IEEE1394_ALL_NODES) {
+			skb_pull(skb,
+				 ptask->max_payload + IEEE1394_GASP_HDR_SIZE);
+		} else {
+			skb_pull(skb, ptask->max_payload);
+		}
+		if (ptask->outstanding_pkts > 1) {
+			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_INTFRAG,
+					  dg_size, fg_off, datagram_label);
+		} else {
+			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_LASTFRAG,
+					  dg_size, fg_off, datagram_label);
+			ptask->max_payload = skb->len + RFC2374_FRAG_HDR_SIZE;
+		}
+		fwnet_send_packet(ptask);
+	}
+
+	if (free)
+		fwnet_free_ptask(ptask);
+}
+
+static void fwnet_transmit_packet_failed(struct fwnet_packet_task *ptask)
+{
+	struct fwnet_device *dev = ptask->dev;
+	unsigned long flags;
+	bool free;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* One fragment failed; don't try to send remaining fragments. */
+	ptask->outstanding_pkts = 0;
+
+	/* Check whether we or the networking TX soft-IRQ is last user. */
+	free = ptask->enqueued;
+	if (free)
+		dec_queued_datagrams(dev);
+
+	dev->netdev->stats.tx_dropped++;
+	dev->netdev->stats.tx_errors++;
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	if (free)
+		fwnet_free_ptask(ptask);
+}
+
+static void fwnet_write_complete(struct fw_card *card, int rcode,
+				 void *payload, size_t length, void *data)
+{
+	struct fwnet_packet_task *ptask = data;
+	static unsigned long j;
+	static int last_rcode, errors_skipped;
+
+	if (rcode == RCODE_COMPLETE) {
+		fwnet_transmit_packet_done(ptask);
+	} else {
+		if (printk_timed_ratelimit(&j,  1000) || rcode != last_rcode) {
+			dev_err(&ptask->dev->netdev->dev,
+				"fwnet_write_complete failed: %x (skipped %d)\n",
+				rcode, errors_skipped);
+
+			errors_skipped = 0;
+			last_rcode = rcode;
+		} else {
+			errors_skipped++;
+		}
+		fwnet_transmit_packet_failed(ptask);
+	}
+}
+
+static int fwnet_send_packet(struct fwnet_packet_task *ptask)
+{
+	struct fwnet_device *dev;
+	unsigned tx_len;
+	struct rfc2734_header *bufhdr;
+	unsigned long flags;
+	bool free;
+
+	dev = ptask->dev;
+	tx_len = ptask->max_payload;
+	switch (fwnet_get_hdr_lf(&ptask->hdr)) {
+	case RFC2374_HDR_UNFRAG:
+		bufhdr = (struct rfc2734_header *)
+				skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
+		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
+		break;
+
+	case RFC2374_HDR_FIRSTFRAG:
+	case RFC2374_HDR_INTFRAG:
+	case RFC2374_HDR_LASTFRAG:
+		bufhdr = (struct rfc2734_header *)
+				skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
+		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
+		put_unaligned_be32(ptask->hdr.w1, &bufhdr->w1);
+		break;
+
+	default:
+		BUG();
+	}
+	if (ptask->dest_node == IEEE1394_ALL_NODES) {
+		u8 *p;
+		int generation;
+		int node_id;
+		unsigned int sw_version;
+
+		/* ptask->generation may not have been set yet */
+		generation = dev->card->generation;
+		smp_rmb();
+		node_id = dev->card->node_id;
+
+		switch (ptask->skb->protocol) {
+		default:
+			sw_version = RFC2734_SW_VERSION;
+			break;
+#if IS_ENABLED(CONFIG_IPV6)
+		case htons(ETH_P_IPV6):
+			sw_version = RFC3146_SW_VERSION;
+#endif
+		}
+
+		p = skb_push(ptask->skb, IEEE1394_GASP_HDR_SIZE);
+		put_unaligned_be32(node_id << 16 | IANA_SPECIFIER_ID >> 8, p);
+		put_unaligned_be32((IANA_SPECIFIER_ID & 0xff) << 24
+						| sw_version, &p[4]);
+
+		/* We should not transmit if broadcast_channel.valid == 0. */
+		fw_send_request(dev->card, &ptask->transaction,
+				TCODE_STREAM_DATA,
+				fw_stream_packet_destination_id(3,
+						IEEE1394_BROADCAST_CHANNEL, 0),
+				generation, SCODE_100, 0ULL, ptask->skb->data,
+				tx_len + 8, fwnet_write_complete, ptask);
+
+		spin_lock_irqsave(&dev->lock, flags);
+
+		/* If the AT tasklet already ran, we may be last user. */
+		free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
+		if (!free)
+			ptask->enqueued = true;
+		else
+			dec_queued_datagrams(dev);
+
+		spin_unlock_irqrestore(&dev->lock, flags);
+
+		goto out;
+	}
+
+	fw_send_request(dev->card, &ptask->transaction,
+			TCODE_WRITE_BLOCK_REQUEST, ptask->dest_node,
+			ptask->generation, ptask->speed, ptask->fifo_addr,
+			ptask->skb->data, tx_len, fwnet_write_complete, ptask);
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* If the AT tasklet already ran, we may be last user. */
+	free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
+	if (!free)
+		ptask->enqueued = true;
+	else
+		dec_queued_datagrams(dev);
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	dev->netdev->trans_start = jiffies;
+ out:
+	if (free)
+		fwnet_free_ptask(ptask);
+
+	return 0;
+}
+
+static void fwnet_fifo_stop(struct fwnet_device *dev)
+{
+	if (dev->local_fifo == FWNET_NO_FIFO_ADDR)
+		return;
+
+	fw_core_remove_address_handler(&dev->handler);
+	dev->local_fifo = FWNET_NO_FIFO_ADDR;
+}
+
+static int fwnet_fifo_start(struct fwnet_device *dev)
+{
+	int retval;
+
+	if (dev->local_fifo != FWNET_NO_FIFO_ADDR)
+		return 0;
+
+	dev->handler.length = 4096;
+	dev->handler.address_callback = fwnet_receive_packet;
+	dev->handler.callback_data = dev;
+
+	retval = fw_core_add_address_handler(&dev->handler,
+					     &fw_high_memory_region);
+	if (retval < 0)
+		return retval;
+
+	dev->local_fifo = dev->handler.offset;
+
+	return 0;
+}
+
+static void __fwnet_broadcast_stop(struct fwnet_device *dev)
+{
+	unsigned u;
+
+	if (dev->broadcast_state != FWNET_BROADCAST_ERROR) {
+		for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++)
+			kunmap(dev->broadcast_rcv_buffer.pages[u]);
+		fw_iso_buffer_destroy(&dev->broadcast_rcv_buffer, dev->card);
+	}
+	if (dev->broadcast_rcv_context) {
+		fw_iso_context_destroy(dev->broadcast_rcv_context);
+		dev->broadcast_rcv_context = NULL;
+	}
+	kfree(dev->broadcast_rcv_buffer_ptrs);
+	dev->broadcast_rcv_buffer_ptrs = NULL;
+	dev->broadcast_state = FWNET_BROADCAST_ERROR;
+}
+
+static void fwnet_broadcast_stop(struct fwnet_device *dev)
+{
+	if (dev->broadcast_state == FWNET_BROADCAST_ERROR)
+		return;
+	fw_iso_context_stop(dev->broadcast_rcv_context);
+	__fwnet_broadcast_stop(dev);
+}
+
+static int fwnet_broadcast_start(struct fwnet_device *dev)
+{
+	struct fw_iso_context *context;
+	int retval;
+	unsigned num_packets;
+	unsigned max_receive;
+	struct fw_iso_packet packet;
+	unsigned long offset;
+	void **ptrptr;
+	unsigned u;
+
+	if (dev->broadcast_state != FWNET_BROADCAST_ERROR)
+		return 0;
+
+	max_receive = 1U << (dev->card->max_receive + 1);
+	num_packets = (FWNET_ISO_PAGE_COUNT * PAGE_SIZE) / max_receive;
+
+	ptrptr = kmalloc(sizeof(void *) * num_packets, GFP_KERNEL);
+	if (!ptrptr) {
+		retval = -ENOMEM;
+		goto failed;
+	}
+	dev->broadcast_rcv_buffer_ptrs = ptrptr;
+
+	context = fw_iso_context_create(dev->card, FW_ISO_CONTEXT_RECEIVE,
+					IEEE1394_BROADCAST_CHANNEL,
+					dev->card->link_speed, 8,
+					fwnet_receive_broadcast, dev);
+	if (IS_ERR(context)) {
+		retval = PTR_ERR(context);
+		goto failed;
+	}
+
+	retval = fw_iso_buffer_init(&dev->broadcast_rcv_buffer, dev->card,
+				    FWNET_ISO_PAGE_COUNT, DMA_FROM_DEVICE);
+	if (retval < 0)
+		goto failed;
+
+	dev->broadcast_state = FWNET_BROADCAST_STOPPED;
+
+	for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++) {
+		void *ptr;
+		unsigned v;
+
+		ptr = kmap(dev->broadcast_rcv_buffer.pages[u]);
+		for (v = 0; v < num_packets / FWNET_ISO_PAGE_COUNT; v++)
+			*ptrptr++ = (void *) ((char *)ptr + v * max_receive);
+	}
+	dev->broadcast_rcv_context = context;
+
+	packet.payload_length = max_receive;
+	packet.interrupt = 1;
+	packet.skip = 0;
+	packet.tag = 3;
+	packet.sy = 0;
+	packet.header_length = IEEE1394_GASP_HDR_SIZE;
+	offset = 0;
+
+	for (u = 0; u < num_packets; u++) {
+		retval = fw_iso_context_queue(context, &packet,
+				&dev->broadcast_rcv_buffer, offset);
+		if (retval < 0)
+			goto failed;
+
+		offset += max_receive;
+	}
+	dev->num_broadcast_rcv_ptrs = num_packets;
+	dev->rcv_buffer_size = max_receive;
+	dev->broadcast_rcv_next_ptr = 0U;
+	retval = fw_iso_context_start(context, -1, 0,
+			FW_ISO_CONTEXT_MATCH_ALL_TAGS); /* ??? sync */
+	if (retval < 0)
+		goto failed;
+
+	/* FIXME: adjust it according to the min. speed of all known peers? */
+	dev->broadcast_xmt_max_payload = IEEE1394_MAX_PAYLOAD_S100
+			- IEEE1394_GASP_HDR_SIZE - RFC2374_UNFRAG_HDR_SIZE;
+	dev->broadcast_state = FWNET_BROADCAST_RUNNING;
+
+	return 0;
+
+ failed:
+	__fwnet_broadcast_stop(dev);
+	return retval;
+}
+
+static void set_carrier_state(struct fwnet_device *dev)
+{
+	if (dev->peer_count > 1)
+		netif_carrier_on(dev->netdev);
+	else
+		netif_carrier_off(dev->netdev);
+}
+
+/* ifup */
+static int fwnet_open(struct net_device *net)
+{
+	struct fwnet_device *dev = netdev_priv(net);
+	int ret;
+
+	ret = fwnet_broadcast_start(dev);
+	if (ret)
+		return ret;
+
+	netif_start_queue(net);
+
+	spin_lock_irq(&dev->lock);
+	set_carrier_state(dev);
+	spin_unlock_irq(&dev->lock);
+
+	return 0;
+}
+
+/* ifdown */
+static int fwnet_stop(struct net_device *net)
+{
+	struct fwnet_device *dev = netdev_priv(net);
+
+	netif_stop_queue(net);
+	fwnet_broadcast_stop(dev);
+
+	return 0;
+}
+
+static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
+{
+	struct fwnet_header hdr_buf;
+	struct fwnet_device *dev = netdev_priv(net);
+	__be16 proto;
+	u16 dest_node;
+	unsigned max_payload;
+	u16 dg_size;
+	u16 *datagram_label_ptr;
+	struct fwnet_packet_task *ptask;
+	struct fwnet_peer *peer;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* Can this happen? */
+	if (netif_queue_stopped(dev->netdev)) {
+		spin_unlock_irqrestore(&dev->lock, flags);
+
+		return NETDEV_TX_BUSY;
+	}
+
+	ptask = kmem_cache_alloc(fwnet_packet_task_cache, GFP_ATOMIC);
+	if (ptask == NULL)
+		goto fail;
+
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		goto fail;
+
+	/*
+	 * Make a copy of the driver-specific header.
+	 * We might need to rebuild the header on tx failure.
+	 */
+	memcpy(&hdr_buf, skb->data, sizeof(hdr_buf));
+	proto = hdr_buf.h_proto;
+
+	switch (proto) {
+	case htons(ETH_P_ARP):
+	case htons(ETH_P_IP):
+#if IS_ENABLED(CONFIG_IPV6)
+	case htons(ETH_P_IPV6):
+#endif
+		break;
+	default:
+		goto fail;
+	}
+
+	skb_pull(skb, sizeof(hdr_buf));
+	dg_size = skb->len;
+
+	/*
+	 * Set the transmission type for the packet.  ARP packets and IP
+	 * broadcast packets are sent via GASP.
+	 */
+	if (fwnet_hwaddr_is_multicast(hdr_buf.h_dest)) {
+		max_payload        = dev->broadcast_xmt_max_payload;
+		datagram_label_ptr = &dev->broadcast_xmt_datagramlabel;
+
+		ptask->fifo_addr   = FWNET_NO_FIFO_ADDR;
+		ptask->generation  = 0;
+		ptask->dest_node   = IEEE1394_ALL_NODES;
+		ptask->speed       = SCODE_100;
+	} else {
+		union fwnet_hwaddr *ha = (union fwnet_hwaddr *)hdr_buf.h_dest;
+		__be64 guid = get_unaligned(&ha->uc.uniq_id);
+		u8 generation;
+
+		peer = fwnet_peer_find_by_guid(dev, be64_to_cpu(guid));
+		if (!peer)
+			goto fail;
+
+		generation         = peer->generation;
+		dest_node          = peer->node_id;
+		max_payload        = peer->max_payload;
+		datagram_label_ptr = &peer->datagram_label;
+
+		ptask->fifo_addr   = fwnet_hwaddr_fifo(ha);
+		ptask->generation  = generation;
+		ptask->dest_node   = dest_node;
+		ptask->speed       = peer->speed;
+	}
+
+	ptask->hdr.w0 = 0;
+	ptask->hdr.w1 = 0;
+	ptask->skb = skb;
+	ptask->dev = dev;
+
+	/* Does it all fit in one packet? */
+	if (dg_size <= max_payload) {
+		fwnet_make_uf_hdr(&ptask->hdr, ntohs(proto));
+		ptask->outstanding_pkts = 1;
+		max_payload = dg_size + RFC2374_UNFRAG_HDR_SIZE;
+	} else {
+		u16 datagram_label;
+
+		max_payload -= RFC2374_FRAG_OVERHEAD;
+		datagram_label = (*datagram_label_ptr)++;
+		fwnet_make_ff_hdr(&ptask->hdr, ntohs(proto), dg_size,
+				  datagram_label);
+		ptask->outstanding_pkts = DIV_ROUND_UP(dg_size, max_payload);
+		max_payload += RFC2374_FRAG_HDR_SIZE;
+	}
+
+	if (++dev->queued_datagrams == FWNET_MAX_QUEUED_DATAGRAMS)
+		netif_stop_queue(dev->netdev);
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	ptask->max_payload = max_payload;
+	ptask->enqueued    = 0;
+
+	fwnet_send_packet(ptask);
+
+	return NETDEV_TX_OK;
+
+ fail:
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	if (ptask)
+		kmem_cache_free(fwnet_packet_task_cache, ptask);
+
+	if (skb != NULL)
+		dev_kfree_skb(skb);
+
+	net->stats.tx_dropped++;
+	net->stats.tx_errors++;
+
+	/*
+	 * FIXME: According to a patch from 2003-02-26, "returning non-zero
+	 * causes serious problems" here, allegedly.  Before that patch,
+	 * -ERRNO was returned which is not appropriate under Linux 2.6.
+	 * Perhaps more needs to be done?  Stop the queue in serious
+	 * conditions and restart it elsewhere?
+	 */
+	return NETDEV_TX_OK;
+}
+
+static int fwnet_change_mtu(struct net_device *net, int new_mtu)
+{
+	if (new_mtu < 68)
+		return -EINVAL;
+
+	net->mtu = new_mtu;
+	return 0;
+}
+
+static const struct ethtool_ops fwnet_ethtool_ops = {
+	.get_link	= ethtool_op_get_link,
+};
+
+static const struct net_device_ops fwnet_netdev_ops = {
+	.ndo_open       = fwnet_open,
+	.ndo_stop	= fwnet_stop,
+	.ndo_start_xmit = fwnet_tx,
+	.ndo_change_mtu = fwnet_change_mtu,
+};
+
+static void fwnet_init_dev(struct net_device *net)
+{
+	net->header_ops		= &fwnet_header_ops;
+	net->netdev_ops		= &fwnet_netdev_ops;
+	net->watchdog_timeo	= 2 * HZ;
+	net->flags		= IFF_BROADCAST | IFF_MULTICAST;
+	net->features		= NETIF_F_HIGHDMA;
+	net->addr_len		= FWNET_ALEN;
+	net->hard_header_len	= FWNET_HLEN;
+	net->type		= ARPHRD_IEEE1394;
+	net->tx_queue_len	= FWNET_TX_QUEUE_LEN;
+	net->ethtool_ops	= &fwnet_ethtool_ops;
+}
+
+/* caller must hold fwnet_device_mutex */
+static struct fwnet_device *fwnet_dev_find(struct fw_card *card)
+{
+	struct fwnet_device *dev;
+
+	list_for_each_entry(dev, &fwnet_device_list, dev_link)
+		if (dev->card == card)
+			return dev;
+
+	return NULL;
+}
+
+static int fwnet_add_peer(struct fwnet_device *dev,
+			  struct fw_unit *unit, struct fw_device *device)
+{
+	struct fwnet_peer *peer;
+
+	peer = kmalloc(sizeof(*peer), GFP_KERNEL);
+	if (!peer)
+		return -ENOMEM;
+
+	dev_set_drvdata(&unit->device, peer);
+
+	peer->dev = dev;
+	peer->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
+	INIT_LIST_HEAD(&peer->pd_list);
+	peer->pdg_size = 0;
+	peer->datagram_label = 0;
+	peer->speed = device->max_speed;
+	peer->max_payload = fwnet_max_payload(device->max_rec, peer->speed);
+
+	peer->generation = device->generation;
+	smp_rmb();
+	peer->node_id = device->node_id;
+
+	spin_lock_irq(&dev->lock);
+	list_add_tail(&peer->peer_link, &dev->peer_list);
+	dev->peer_count++;
+	set_carrier_state(dev);
+	spin_unlock_irq(&dev->lock);
+
+	return 0;
+}
+
+static int fwnet_probe(struct fw_unit *unit,
+		       const struct ieee1394_device_id *id)
+{
+	struct fw_device *device = fw_parent_device(unit);
+	struct fw_card *card = device->card;
+	struct net_device *net;
+	bool allocated_netdev = false;
+	struct fwnet_device *dev;
+	unsigned max_mtu;
+	int ret;
+	union fwnet_hwaddr *ha;
+
+	mutex_lock(&fwnet_device_mutex);
+
+	dev = fwnet_dev_find(card);
+	if (dev) {
+		net = dev->netdev;
+		goto have_dev;
+	}
+
+	net = alloc_netdev(sizeof(*dev), "firewire%d", NET_NAME_UNKNOWN,
+			   fwnet_init_dev);
+	if (net == NULL) {
+		mutex_unlock(&fwnet_device_mutex);
+		return -ENOMEM;
+	}
+
+	allocated_netdev = true;
+	SET_NETDEV_DEV(net, card->device);
+	dev = netdev_priv(net);
+
+	spin_lock_init(&dev->lock);
+	dev->broadcast_state = FWNET_BROADCAST_ERROR;
+	dev->broadcast_rcv_context = NULL;
+	dev->broadcast_xmt_max_payload = 0;
+	dev->broadcast_xmt_datagramlabel = 0;
+	dev->local_fifo = FWNET_NO_FIFO_ADDR;
+	dev->queued_datagrams = 0;
+	INIT_LIST_HEAD(&dev->peer_list);
+	dev->card = card;
+	dev->netdev = net;
+
+	ret = fwnet_fifo_start(dev);
+	if (ret < 0)
+		goto out;
+	dev->local_fifo = dev->handler.offset;
+
+	/*
+	 * Use the RFC 2734 default 1500 octets or the maximum payload
+	 * as initial MTU
+	 */
+	max_mtu = (1 << (card->max_receive + 1))
+		  - sizeof(struct rfc2734_header) - IEEE1394_GASP_HDR_SIZE;
+	net->mtu = min(1500U, max_mtu);
+
+	/* Set our hardware address while we're at it */
+	ha = (union fwnet_hwaddr *)net->dev_addr;
+	put_unaligned_be64(card->guid, &ha->uc.uniq_id);
+	ha->uc.max_rec = dev->card->max_receive;
+	ha->uc.sspd = dev->card->link_speed;
+	put_unaligned_be16(dev->local_fifo >> 32, &ha->uc.fifo_hi);
+	put_unaligned_be32(dev->local_fifo & 0xffffffff, &ha->uc.fifo_lo);
+
+	memset(net->broadcast, -1, net->addr_len);
+
+	ret = register_netdev(net);
+	if (ret)
+		goto out;
+
+	list_add_tail(&dev->dev_link, &fwnet_device_list);
+	dev_notice(&net->dev, "IP over IEEE 1394 on card %s\n",
+		   dev_name(card->device));
+ have_dev:
+	ret = fwnet_add_peer(dev, unit, device);
+	if (ret && allocated_netdev) {
+		unregister_netdev(net);
+		list_del(&dev->dev_link);
+ out:
+		fwnet_fifo_stop(dev);
+		free_netdev(net);
+	}
+
+	mutex_unlock(&fwnet_device_mutex);
+
+	return ret;
+}
+
+/*
+ * FIXME abort partially sent fragmented datagrams,
+ * discard partially received fragmented datagrams
+ */
+static void fwnet_update(struct fw_unit *unit)
+{
+	struct fw_device *device = fw_parent_device(unit);
+	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
+	int generation;
+
+	generation = device->generation;
+
+	spin_lock_irq(&peer->dev->lock);
+	peer->node_id    = device->node_id;
+	peer->generation = generation;
+	spin_unlock_irq(&peer->dev->lock);
+}
+
+static void fwnet_remove_peer(struct fwnet_peer *peer, struct fwnet_device *dev)
+{
+	struct fwnet_partial_datagram *pd, *pd_next;
+
+	spin_lock_irq(&dev->lock);
+	list_del(&peer->peer_link);
+	dev->peer_count--;
+	set_carrier_state(dev);
+	spin_unlock_irq(&dev->lock);
+
+	list_for_each_entry_safe(pd, pd_next, &peer->pd_list, pd_link)
+		fwnet_pd_delete(pd);
+
+	kfree(peer);
+}
+
+static void fwnet_remove(struct fw_unit *unit)
+{
+	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
+	struct fwnet_device *dev = peer->dev;
+	struct net_device *net;
+	int i;
+
+	mutex_lock(&fwnet_device_mutex);
+
+	net = dev->netdev;
+
+	fwnet_remove_peer(peer, dev);
+
+	if (list_empty(&dev->peer_list)) {
+		unregister_netdev(net);
+
+		fwnet_fifo_stop(dev);
+
+		for (i = 0; dev->queued_datagrams && i < 5; i++)
+			ssleep(1);
+		WARN_ON(dev->queued_datagrams);
+		list_del(&dev->dev_link);
+
+		free_netdev(net);
+	}
+
+	mutex_unlock(&fwnet_device_mutex);
+}
+
+static const struct ieee1394_device_id fwnet_id_table[] = {
+	{
+		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
+				IEEE1394_MATCH_VERSION,
+		.specifier_id = IANA_SPECIFIER_ID,
+		.version      = RFC2734_SW_VERSION,
+	},
+#if IS_ENABLED(CONFIG_IPV6)
+	{
+		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
+				IEEE1394_MATCH_VERSION,
+		.specifier_id = IANA_SPECIFIER_ID,
+		.version      = RFC3146_SW_VERSION,
+	},
+#endif
+	{ }
+};
+
+static struct fw_driver fwnet_driver = {
+	.driver = {
+		.owner  = THIS_MODULE,
+		.name   = KBUILD_MODNAME,
+		.bus    = &fw_bus_type,
+	},
+	.probe    = fwnet_probe,
+	.update   = fwnet_update,
+	.remove   = fwnet_remove,
+	.id_table = fwnet_id_table,
+};
+
+static const u32 rfc2374_unit_directory_data[] = {
+	0x00040000,	/* directory_length		*/
+	0x1200005e,	/* unit_specifier_id: IANA	*/
+	0x81000003,	/* textual descriptor offset	*/
+	0x13000001,	/* unit_sw_version: RFC 2734	*/
+	0x81000005,	/* textual descriptor offset	*/
+	0x00030000,	/* descriptor_length		*/
+	0x00000000,	/* text				*/
+	0x00000000,	/* minimal ASCII, en		*/
+	0x49414e41,	/* I A N A			*/
+	0x00030000,	/* descriptor_length		*/
+	0x00000000,	/* text				*/
+	0x00000000,	/* minimal ASCII, en		*/
+	0x49507634,	/* I P v 4			*/
+};
+
+static struct fw_descriptor rfc2374_unit_directory = {
+	.length = ARRAY_SIZE(rfc2374_unit_directory_data),
+	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
+	.data   = rfc2374_unit_directory_data
+};
+
+#if IS_ENABLED(CONFIG_IPV6)
+static const u32 rfc3146_unit_directory_data[] = {
+	0x00040000,	/* directory_length		*/
+	0x1200005e,	/* unit_specifier_id: IANA	*/
+	0x81000003,	/* textual descriptor offset	*/
+	0x13000002,	/* unit_sw_version: RFC 3146	*/
+	0x81000005,	/* textual descriptor offset	*/
+	0x00030000,	/* descriptor_length		*/
+	0x00000000,	/* text				*/
+	0x00000000,	/* minimal ASCII, en		*/
+	0x49414e41,	/* I A N A			*/
+	0x00030000,	/* descriptor_length		*/
+	0x00000000,	/* text				*/
+	0x00000000,	/* minimal ASCII, en		*/
+	0x49507636,	/* I P v 6			*/
+};
+
+static struct fw_descriptor rfc3146_unit_directory = {
+	.length = ARRAY_SIZE(rfc3146_unit_directory_data),
+	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
+	.data   = rfc3146_unit_directory_data
+};
+#endif
+
+static int __init fwnet_init(void)
+{
+	int err;
+
+	err = fw_core_add_descriptor(&rfc2374_unit_directory);
+	if (err)
+		return err;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	err = fw_core_add_descriptor(&rfc3146_unit_directory);
+	if (err)
+		goto out;
+#endif
+
+	fwnet_packet_task_cache = kmem_cache_create("packet_task",
+			sizeof(struct fwnet_packet_task), 0, 0, NULL);
+	if (!fwnet_packet_task_cache) {
+		err = -ENOMEM;
+		goto out2;
+	}
+
+	err = driver_register(&fwnet_driver.driver);
+	if (!err)
+		return 0;
+
+	kmem_cache_destroy(fwnet_packet_task_cache);
+out2:
+#if IS_ENABLED(CONFIG_IPV6)
+	fw_core_remove_descriptor(&rfc3146_unit_directory);
+out:
+#endif
+	fw_core_remove_descriptor(&rfc2374_unit_directory);
+
+	return err;
+}
+module_init(fwnet_init);
+
+static void __exit fwnet_cleanup(void)
+{
+	driver_unregister(&fwnet_driver.driver);
+	kmem_cache_destroy(fwnet_packet_task_cache);
+#if IS_ENABLED(CONFIG_IPV6)
+	fw_core_remove_descriptor(&rfc3146_unit_directory);
+#endif
+	fw_core_remove_descriptor(&rfc2374_unit_directory);
+}
+module_exit(fwnet_cleanup);
+
+MODULE_AUTHOR("Jay Fenlason <fenlason@redhat.com>");
+MODULE_DESCRIPTION("IP over IEEE1394 as per RFC 2734/3146");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(ieee1394, fwnet_id_table);