firewire net: Use LL_RESERVED_SPACE(), HH_DATA_OFF().

index df6a1ca..2b27bff 100644
@@ -270,7 +270,7 @@ static int fwnet_header_cache(const struct neighbour *neigh,
 	if (type == cpu_to_be16(ETH_P_802_3))
 		return -1;
 	net = neigh->dev;
-	h = (struct fwnet_header *)((u8 *)hh->hh_data + 16 - sizeof(*h));
+	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;

@@ -282,7 +282,7 @@ static int fwnet_header_cache(const struct neighbour *neigh,
 static void fwnet_header_cache_update(struct hh_cache *hh,
 		const struct net_device *net, const unsigned char *haddr)
 {
-	memcpy((u8 *)hh->hh_data + 16 - FWNET_HLEN, haddr, net->addr_len);
+	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)

@@ -398,11 +398,11 @@ static struct fwnet_partial_datagram *fwnet_pd_new(struct net_device *net,
 
 	new->datagram_label = datagram_label;
 	new->datagram_size = dg_size;
-	new->skb = dev_alloc_skb(dg_size + net->hard_header_len + 15);
+	new->skb = dev_alloc_skb(dg_size + LL_RESERVED_SPACE(net));
 	if (new->skb == NULL)
 		goto fail_w_fi;
 
-	skb_reserve(new->skb, (net->hard_header_len + 15) & ~15);
+	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);

@@ -690,14 +690,14 @@ static int fwnet_incoming_packet(struct fwnet_device *dev, __be32 *buf, int len,
 		buf++;
 		len -= RFC2374_UNFRAG_HDR_SIZE;
 
-		skb = dev_alloc_skb(len + net->hard_header_len + 15);
+		skb = dev_alloc_skb(len + LL_RESERVED_SPACE(net));
 		if (unlikely(!skb)) {
 			dev_err(&net->dev, "out of memory\n");
 			net->stats.rx_dropped++;
 
 			return -ENOMEM;
 		}
-		skb_reserve(skb, (net->hard_header_len + 15) & ~15);
+		skb_reserve(skb, LL_RESERVED_SPACE(net));
 		memcpy(skb_put(skb, len), buf, len);
 
 		return fwnet_finish_incoming_packet(net, skb, source_node_id,