xref: /openbmc/linux/drivers/firewire/net.c (revision afb46f79)
1 /*
2  * IPv4 over IEEE 1394, per RFC 2734
3  * IPv6 over IEEE 1394, per RFC 3146
4  *
5  * Copyright (C) 2009 Jay Fenlason <fenlason@redhat.com>
6  *
7  * based on eth1394 by Ben Collins et al
8  */
9 
10 #include <linux/bug.h>
11 #include <linux/compiler.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/ethtool.h>
15 #include <linux/firewire.h>
16 #include <linux/firewire-constants.h>
17 #include <linux/highmem.h>
18 #include <linux/in.h>
19 #include <linux/ip.h>
20 #include <linux/jiffies.h>
21 #include <linux/mod_devicetable.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/mutex.h>
25 #include <linux/netdevice.h>
26 #include <linux/skbuff.h>
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 
30 #include <asm/unaligned.h>
31 #include <net/arp.h>
32 #include <net/firewire.h>
33 
34 /* rx limits */
35 #define FWNET_MAX_FRAGMENTS		30 /* arbitrary, > TX queue depth */
36 #define FWNET_ISO_PAGE_COUNT		(PAGE_SIZE < 16*1024 ? 4 : 2)
37 
38 /* tx limits */
39 #define FWNET_MAX_QUEUED_DATAGRAMS	20 /* < 64 = number of tlabels */
40 #define FWNET_MIN_QUEUED_DATAGRAMS	10 /* should keep AT DMA busy enough */
41 #define FWNET_TX_QUEUE_LEN		FWNET_MAX_QUEUED_DATAGRAMS /* ? */
42 
43 #define IEEE1394_BROADCAST_CHANNEL	31
44 #define IEEE1394_ALL_NODES		(0xffc0 | 0x003f)
45 #define IEEE1394_MAX_PAYLOAD_S100	512
46 #define FWNET_NO_FIFO_ADDR		(~0ULL)
47 
48 #define IANA_SPECIFIER_ID		0x00005eU
49 #define RFC2734_SW_VERSION		0x000001U
50 #define RFC3146_SW_VERSION		0x000002U
51 
52 #define IEEE1394_GASP_HDR_SIZE	8
53 
54 #define RFC2374_UNFRAG_HDR_SIZE	4
55 #define RFC2374_FRAG_HDR_SIZE	8
56 #define RFC2374_FRAG_OVERHEAD	4
57 
58 #define RFC2374_HDR_UNFRAG	0	/* unfragmented		*/
59 #define RFC2374_HDR_FIRSTFRAG	1	/* first fragment	*/
60 #define RFC2374_HDR_LASTFRAG	2	/* last fragment	*/
61 #define RFC2374_HDR_INTFRAG	3	/* interior fragment	*/
62 
63 static bool fwnet_hwaddr_is_multicast(u8 *ha)
64 {
65 	return !!(*ha & 1);
66 }
67 
68 /* IPv4 and IPv6 encapsulation header */
69 struct rfc2734_header {
70 	u32 w0;
71 	u32 w1;
72 };
73 
74 #define fwnet_get_hdr_lf(h)		(((h)->w0 & 0xc0000000) >> 30)
75 #define fwnet_get_hdr_ether_type(h)	(((h)->w0 & 0x0000ffff))
76 #define fwnet_get_hdr_dg_size(h)	(((h)->w0 & 0x0fff0000) >> 16)
77 #define fwnet_get_hdr_fg_off(h)		(((h)->w0 & 0x00000fff))
78 #define fwnet_get_hdr_dgl(h)		(((h)->w1 & 0xffff0000) >> 16)
79 
80 #define fwnet_set_hdr_lf(lf)		((lf)  << 30)
81 #define fwnet_set_hdr_ether_type(et)	(et)
82 #define fwnet_set_hdr_dg_size(dgs)	((dgs) << 16)
83 #define fwnet_set_hdr_fg_off(fgo)	(fgo)
84 
85 #define fwnet_set_hdr_dgl(dgl)		((dgl) << 16)
86 
87 static inline void fwnet_make_uf_hdr(struct rfc2734_header *hdr,
88 		unsigned ether_type)
89 {
90 	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_UNFRAG)
91 		  | fwnet_set_hdr_ether_type(ether_type);
92 }
93 
94 static inline void fwnet_make_ff_hdr(struct rfc2734_header *hdr,
95 		unsigned ether_type, unsigned dg_size, unsigned dgl)
96 {
97 	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_FIRSTFRAG)
98 		  | fwnet_set_hdr_dg_size(dg_size)
99 		  | fwnet_set_hdr_ether_type(ether_type);
100 	hdr->w1 = fwnet_set_hdr_dgl(dgl);
101 }
102 
103 static inline void fwnet_make_sf_hdr(struct rfc2734_header *hdr,
104 		unsigned lf, unsigned dg_size, unsigned fg_off, unsigned dgl)
105 {
106 	hdr->w0 = fwnet_set_hdr_lf(lf)
107 		  | fwnet_set_hdr_dg_size(dg_size)
108 		  | fwnet_set_hdr_fg_off(fg_off);
109 	hdr->w1 = fwnet_set_hdr_dgl(dgl);
110 }
111 
112 /* This list keeps track of what parts of the datagram have been filled in */
113 struct fwnet_fragment_info {
114 	struct list_head fi_link;
115 	u16 offset;
116 	u16 len;
117 };
118 
119 struct fwnet_partial_datagram {
120 	struct list_head pd_link;
121 	struct list_head fi_list;
122 	struct sk_buff *skb;
123 	/* FIXME Why not use skb->data? */
124 	char *pbuf;
125 	u16 datagram_label;
126 	u16 ether_type;
127 	u16 datagram_size;
128 };
129 
130 static DEFINE_MUTEX(fwnet_device_mutex);
131 static LIST_HEAD(fwnet_device_list);
132 
133 struct fwnet_device {
134 	struct list_head dev_link;
135 	spinlock_t lock;
136 	enum {
137 		FWNET_BROADCAST_ERROR,
138 		FWNET_BROADCAST_RUNNING,
139 		FWNET_BROADCAST_STOPPED,
140 	} broadcast_state;
141 	struct fw_iso_context *broadcast_rcv_context;
142 	struct fw_iso_buffer broadcast_rcv_buffer;
143 	void **broadcast_rcv_buffer_ptrs;
144 	unsigned broadcast_rcv_next_ptr;
145 	unsigned num_broadcast_rcv_ptrs;
146 	unsigned rcv_buffer_size;
147 	/*
148 	 * This value is the maximum unfragmented datagram size that can be
149 	 * sent by the hardware.  It already has the GASP overhead and the
150 	 * unfragmented datagram header overhead calculated into it.
151 	 */
152 	unsigned broadcast_xmt_max_payload;
153 	u16 broadcast_xmt_datagramlabel;
154 
155 	/*
156 	 * The CSR address that remote nodes must send datagrams to for us to
157 	 * receive them.
158 	 */
159 	struct fw_address_handler handler;
160 	u64 local_fifo;
161 
162 	/* Number of tx datagrams that have been queued but not yet acked */
163 	int queued_datagrams;
164 
165 	int peer_count;
166 	struct list_head peer_list;
167 	struct fw_card *card;
168 	struct net_device *netdev;
169 };
170 
171 struct fwnet_peer {
172 	struct list_head peer_link;
173 	struct fwnet_device *dev;
174 	u64 guid;
175 
176 	/* guarded by dev->lock */
177 	struct list_head pd_list; /* received partial datagrams */
178 	unsigned pdg_size;        /* pd_list size */
179 
180 	u16 datagram_label;       /* outgoing datagram label */
181 	u16 max_payload;          /* includes RFC2374_FRAG_HDR_SIZE overhead */
182 	int node_id;
183 	int generation;
184 	unsigned speed;
185 };
186 
187 /* This is our task struct. It's used for the packet complete callback.  */
188 struct fwnet_packet_task {
189 	struct fw_transaction transaction;
190 	struct rfc2734_header hdr;
191 	struct sk_buff *skb;
192 	struct fwnet_device *dev;
193 
194 	int outstanding_pkts;
195 	u64 fifo_addr;
196 	u16 dest_node;
197 	u16 max_payload;
198 	u8 generation;
199 	u8 speed;
200 	u8 enqueued;
201 };
202 
203 /*
204  * Get fifo address embedded in hwaddr
205  */
206 static __u64 fwnet_hwaddr_fifo(union fwnet_hwaddr *ha)
207 {
208 	return (u64)get_unaligned_be16(&ha->uc.fifo_hi) << 32
209 	       | get_unaligned_be32(&ha->uc.fifo_lo);
210 }
211 
212 /*
213  * saddr == NULL means use device source address.
214  * daddr == NULL means leave destination address (eg unresolved arp).
215  */
216 static int fwnet_header_create(struct sk_buff *skb, struct net_device *net,
217 			unsigned short type, const void *daddr,
218 			const void *saddr, unsigned len)
219 {
220 	struct fwnet_header *h;
221 
222 	h = (struct fwnet_header *)skb_push(skb, sizeof(*h));
223 	put_unaligned_be16(type, &h->h_proto);
224 
225 	if (net->flags & (IFF_LOOPBACK | IFF_NOARP)) {
226 		memset(h->h_dest, 0, net->addr_len);
227 
228 		return net->hard_header_len;
229 	}
230 
231 	if (daddr) {
232 		memcpy(h->h_dest, daddr, net->addr_len);
233 
234 		return net->hard_header_len;
235 	}
236 
237 	return -net->hard_header_len;
238 }
239 
240 static int fwnet_header_rebuild(struct sk_buff *skb)
241 {
242 	struct fwnet_header *h = (struct fwnet_header *)skb->data;
243 
244 	if (get_unaligned_be16(&h->h_proto) == ETH_P_IP)
245 		return arp_find((unsigned char *)&h->h_dest, skb);
246 
247 	dev_notice(&skb->dev->dev, "unable to resolve type %04x addresses\n",
248 		   be16_to_cpu(h->h_proto));
249 	return 0;
250 }
251 
252 static int fwnet_header_cache(const struct neighbour *neigh,
253 			      struct hh_cache *hh, __be16 type)
254 {
255 	struct net_device *net;
256 	struct fwnet_header *h;
257 
258 	if (type == cpu_to_be16(ETH_P_802_3))
259 		return -1;
260 	net = neigh->dev;
261 	h = (struct fwnet_header *)((u8 *)hh->hh_data + HH_DATA_OFF(sizeof(*h)));
262 	h->h_proto = type;
263 	memcpy(h->h_dest, neigh->ha, net->addr_len);
264 	hh->hh_len = FWNET_HLEN;
265 
266 	return 0;
267 }
268 
269 /* Called by Address Resolution module to notify changes in address. */
270 static void fwnet_header_cache_update(struct hh_cache *hh,
271 		const struct net_device *net, const unsigned char *haddr)
272 {
273 	memcpy((u8 *)hh->hh_data + HH_DATA_OFF(FWNET_HLEN), haddr, net->addr_len);
274 }
275 
276 static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr)
277 {
278 	memcpy(haddr, skb->dev->dev_addr, FWNET_ALEN);
279 
280 	return FWNET_ALEN;
281 }
282 
283 static const struct header_ops fwnet_header_ops = {
284 	.create         = fwnet_header_create,
285 	.rebuild        = fwnet_header_rebuild,
286 	.cache		= fwnet_header_cache,
287 	.cache_update	= fwnet_header_cache_update,
288 	.parse          = fwnet_header_parse,
289 };
290 
291 /* FIXME: is this correct for all cases? */
292 static bool fwnet_frag_overlap(struct fwnet_partial_datagram *pd,
293 			       unsigned offset, unsigned len)
294 {
295 	struct fwnet_fragment_info *fi;
296 	unsigned end = offset + len;
297 
298 	list_for_each_entry(fi, &pd->fi_list, fi_link)
299 		if (offset < fi->offset + fi->len && end > fi->offset)
300 			return true;
301 
302 	return false;
303 }
304 
305 /* Assumes that new fragment does not overlap any existing fragments */
306 static struct fwnet_fragment_info *fwnet_frag_new(
307 	struct fwnet_partial_datagram *pd, unsigned offset, unsigned len)
308 {
309 	struct fwnet_fragment_info *fi, *fi2, *new;
310 	struct list_head *list;
311 
312 	list = &pd->fi_list;
313 	list_for_each_entry(fi, &pd->fi_list, fi_link) {
314 		if (fi->offset + fi->len == offset) {
315 			/* The new fragment can be tacked on to the end */
316 			/* Did the new fragment plug a hole? */
317 			fi2 = list_entry(fi->fi_link.next,
318 					 struct fwnet_fragment_info, fi_link);
319 			if (fi->offset + fi->len == fi2->offset) {
320 				/* glue fragments together */
321 				fi->len += len + fi2->len;
322 				list_del(&fi2->fi_link);
323 				kfree(fi2);
324 			} else {
325 				fi->len += len;
326 			}
327 
328 			return fi;
329 		}
330 		if (offset + len == fi->offset) {
331 			/* The new fragment can be tacked on to the beginning */
332 			/* Did the new fragment plug a hole? */
333 			fi2 = list_entry(fi->fi_link.prev,
334 					 struct fwnet_fragment_info, fi_link);
335 			if (fi2->offset + fi2->len == fi->offset) {
336 				/* glue fragments together */
337 				fi2->len += fi->len + len;
338 				list_del(&fi->fi_link);
339 				kfree(fi);
340 
341 				return fi2;
342 			}
343 			fi->offset = offset;
344 			fi->len += len;
345 
346 			return fi;
347 		}
348 		if (offset > fi->offset + fi->len) {
349 			list = &fi->fi_link;
350 			break;
351 		}
352 		if (offset + len < fi->offset) {
353 			list = fi->fi_link.prev;
354 			break;
355 		}
356 	}
357 
358 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
359 	if (!new)
360 		return NULL;
361 
362 	new->offset = offset;
363 	new->len = len;
364 	list_add(&new->fi_link, list);
365 
366 	return new;
367 }
368 
369 static struct fwnet_partial_datagram *fwnet_pd_new(struct net_device *net,
370 		struct fwnet_peer *peer, u16 datagram_label, unsigned dg_size,
371 		void *frag_buf, unsigned frag_off, unsigned frag_len)
372 {
373 	struct fwnet_partial_datagram *new;
374 	struct fwnet_fragment_info *fi;
375 
376 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
377 	if (!new)
378 		goto fail;
379 
380 	INIT_LIST_HEAD(&new->fi_list);
381 	fi = fwnet_frag_new(new, frag_off, frag_len);
382 	if (fi == NULL)
383 		goto fail_w_new;
384 
385 	new->datagram_label = datagram_label;
386 	new->datagram_size = dg_size;
387 	new->skb = dev_alloc_skb(dg_size + LL_RESERVED_SPACE(net));
388 	if (new->skb == NULL)
389 		goto fail_w_fi;
390 
391 	skb_reserve(new->skb, LL_RESERVED_SPACE(net));
392 	new->pbuf = skb_put(new->skb, dg_size);
393 	memcpy(new->pbuf + frag_off, frag_buf, frag_len);
394 	list_add_tail(&new->pd_link, &peer->pd_list);
395 
396 	return new;
397 
398 fail_w_fi:
399 	kfree(fi);
400 fail_w_new:
401 	kfree(new);
402 fail:
403 	return NULL;
404 }
405 
406 static struct fwnet_partial_datagram *fwnet_pd_find(struct fwnet_peer *peer,
407 						    u16 datagram_label)
408 {
409 	struct fwnet_partial_datagram *pd;
410 
411 	list_for_each_entry(pd, &peer->pd_list, pd_link)
412 		if (pd->datagram_label == datagram_label)
413 			return pd;
414 
415 	return NULL;
416 }
417 
418 
419 static void fwnet_pd_delete(struct fwnet_partial_datagram *old)
420 {
421 	struct fwnet_fragment_info *fi, *n;
422 
423 	list_for_each_entry_safe(fi, n, &old->fi_list, fi_link)
424 		kfree(fi);
425 
426 	list_del(&old->pd_link);
427 	dev_kfree_skb_any(old->skb);
428 	kfree(old);
429 }
430 
431 static bool fwnet_pd_update(struct fwnet_peer *peer,
432 		struct fwnet_partial_datagram *pd, void *frag_buf,
433 		unsigned frag_off, unsigned frag_len)
434 {
435 	if (fwnet_frag_new(pd, frag_off, frag_len) == NULL)
436 		return false;
437 
438 	memcpy(pd->pbuf + frag_off, frag_buf, frag_len);
439 
440 	/*
441 	 * Move list entry to beginning of list so that oldest partial
442 	 * datagrams percolate to the end of the list
443 	 */
444 	list_move_tail(&pd->pd_link, &peer->pd_list);
445 
446 	return true;
447 }
448 
449 static bool fwnet_pd_is_complete(struct fwnet_partial_datagram *pd)
450 {
451 	struct fwnet_fragment_info *fi;
452 
453 	fi = list_entry(pd->fi_list.next, struct fwnet_fragment_info, fi_link);
454 
455 	return fi->len == pd->datagram_size;
456 }
457 
458 /* caller must hold dev->lock */
459 static struct fwnet_peer *fwnet_peer_find_by_guid(struct fwnet_device *dev,
460 						  u64 guid)
461 {
462 	struct fwnet_peer *peer;
463 
464 	list_for_each_entry(peer, &dev->peer_list, peer_link)
465 		if (peer->guid == guid)
466 			return peer;
467 
468 	return NULL;
469 }
470 
471 /* caller must hold dev->lock */
472 static struct fwnet_peer *fwnet_peer_find_by_node_id(struct fwnet_device *dev,
473 						int node_id, int generation)
474 {
475 	struct fwnet_peer *peer;
476 
477 	list_for_each_entry(peer, &dev->peer_list, peer_link)
478 		if (peer->node_id    == node_id &&
479 		    peer->generation == generation)
480 			return peer;
481 
482 	return NULL;
483 }
484 
485 /* See IEEE 1394-2008 table 6-4, table 8-8, table 16-18. */
486 static unsigned fwnet_max_payload(unsigned max_rec, unsigned speed)
487 {
488 	max_rec = min(max_rec, speed + 8);
489 	max_rec = clamp(max_rec, 8U, 11U); /* 512...4096 */
490 
491 	return (1 << (max_rec + 1)) - RFC2374_FRAG_HDR_SIZE;
492 }
493 
494 
495 static int fwnet_finish_incoming_packet(struct net_device *net,
496 					struct sk_buff *skb, u16 source_node_id,
497 					bool is_broadcast, u16 ether_type)
498 {
499 	struct fwnet_device *dev;
500 	int status;
501 	__be64 guid;
502 
503 	switch (ether_type) {
504 	case ETH_P_ARP:
505 	case ETH_P_IP:
506 #if IS_ENABLED(CONFIG_IPV6)
507 	case ETH_P_IPV6:
508 #endif
509 		break;
510 	default:
511 		goto err;
512 	}
513 
514 	dev = netdev_priv(net);
515 	/* Write metadata, and then pass to the receive level */
516 	skb->dev = net;
517 	skb->ip_summed = CHECKSUM_NONE;
518 
519 	/*
520 	 * Parse the encapsulation header. This actually does the job of
521 	 * converting to an ethernet-like pseudo frame header.
522 	 */
523 	guid = cpu_to_be64(dev->card->guid);
524 	if (dev_hard_header(skb, net, ether_type,
525 			   is_broadcast ? net->broadcast : net->dev_addr,
526 			   NULL, skb->len) >= 0) {
527 		struct fwnet_header *eth;
528 		u16 *rawp;
529 		__be16 protocol;
530 
531 		skb_reset_mac_header(skb);
532 		skb_pull(skb, sizeof(*eth));
533 		eth = (struct fwnet_header *)skb_mac_header(skb);
534 		if (fwnet_hwaddr_is_multicast(eth->h_dest)) {
535 			if (memcmp(eth->h_dest, net->broadcast,
536 				   net->addr_len) == 0)
537 				skb->pkt_type = PACKET_BROADCAST;
538 #if 0
539 			else
540 				skb->pkt_type = PACKET_MULTICAST;
541 #endif
542 		} else {
543 			if (memcmp(eth->h_dest, net->dev_addr, net->addr_len))
544 				skb->pkt_type = PACKET_OTHERHOST;
545 		}
546 		if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN) {
547 			protocol = eth->h_proto;
548 		} else {
549 			rawp = (u16 *)skb->data;
550 			if (*rawp == 0xffff)
551 				protocol = htons(ETH_P_802_3);
552 			else
553 				protocol = htons(ETH_P_802_2);
554 		}
555 		skb->protocol = protocol;
556 	}
557 	status = netif_rx(skb);
558 	if (status == NET_RX_DROP) {
559 		net->stats.rx_errors++;
560 		net->stats.rx_dropped++;
561 	} else {
562 		net->stats.rx_packets++;
563 		net->stats.rx_bytes += skb->len;
564 	}
565 
566 	return 0;
567 
568  err:
569 	net->stats.rx_errors++;
570 	net->stats.rx_dropped++;
571 
572 	dev_kfree_skb_any(skb);
573 
574 	return -ENOENT;
575 }
576 
577 static int fwnet_incoming_packet(struct fwnet_device *dev, __be32 *buf, int len,
578 				 int source_node_id, int generation,
579 				 bool is_broadcast)
580 {
581 	struct sk_buff *skb;
582 	struct net_device *net = dev->netdev;
583 	struct rfc2734_header hdr;
584 	unsigned lf;
585 	unsigned long flags;
586 	struct fwnet_peer *peer;
587 	struct fwnet_partial_datagram *pd;
588 	int fg_off;
589 	int dg_size;
590 	u16 datagram_label;
591 	int retval;
592 	u16 ether_type;
593 
594 	hdr.w0 = be32_to_cpu(buf[0]);
595 	lf = fwnet_get_hdr_lf(&hdr);
596 	if (lf == RFC2374_HDR_UNFRAG) {
597 		/*
598 		 * An unfragmented datagram has been received by the ieee1394
599 		 * bus. Build an skbuff around it so we can pass it to the
600 		 * high level network layer.
601 		 */
602 		ether_type = fwnet_get_hdr_ether_type(&hdr);
603 		buf++;
604 		len -= RFC2374_UNFRAG_HDR_SIZE;
605 
606 		skb = dev_alloc_skb(len + LL_RESERVED_SPACE(net));
607 		if (unlikely(!skb)) {
608 			net->stats.rx_dropped++;
609 
610 			return -ENOMEM;
611 		}
612 		skb_reserve(skb, LL_RESERVED_SPACE(net));
613 		memcpy(skb_put(skb, len), buf, len);
614 
615 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
616 						    is_broadcast, ether_type);
617 	}
618 	/* A datagram fragment has been received, now the fun begins. */
619 	hdr.w1 = ntohl(buf[1]);
620 	buf += 2;
621 	len -= RFC2374_FRAG_HDR_SIZE;
622 	if (lf == RFC2374_HDR_FIRSTFRAG) {
623 		ether_type = fwnet_get_hdr_ether_type(&hdr);
624 		fg_off = 0;
625 	} else {
626 		ether_type = 0;
627 		fg_off = fwnet_get_hdr_fg_off(&hdr);
628 	}
629 	datagram_label = fwnet_get_hdr_dgl(&hdr);
630 	dg_size = fwnet_get_hdr_dg_size(&hdr); /* ??? + 1 */
631 
632 	spin_lock_irqsave(&dev->lock, flags);
633 
634 	peer = fwnet_peer_find_by_node_id(dev, source_node_id, generation);
635 	if (!peer) {
636 		retval = -ENOENT;
637 		goto fail;
638 	}
639 
640 	pd = fwnet_pd_find(peer, datagram_label);
641 	if (pd == NULL) {
642 		while (peer->pdg_size >= FWNET_MAX_FRAGMENTS) {
643 			/* remove the oldest */
644 			fwnet_pd_delete(list_first_entry(&peer->pd_list,
645 				struct fwnet_partial_datagram, pd_link));
646 			peer->pdg_size--;
647 		}
648 		pd = fwnet_pd_new(net, peer, datagram_label,
649 				  dg_size, buf, fg_off, len);
650 		if (pd == NULL) {
651 			retval = -ENOMEM;
652 			goto fail;
653 		}
654 		peer->pdg_size++;
655 	} else {
656 		if (fwnet_frag_overlap(pd, fg_off, len) ||
657 		    pd->datagram_size != dg_size) {
658 			/*
659 			 * Differing datagram sizes or overlapping fragments,
660 			 * discard old datagram and start a new one.
661 			 */
662 			fwnet_pd_delete(pd);
663 			pd = fwnet_pd_new(net, peer, datagram_label,
664 					  dg_size, buf, fg_off, len);
665 			if (pd == NULL) {
666 				peer->pdg_size--;
667 				retval = -ENOMEM;
668 				goto fail;
669 			}
670 		} else {
671 			if (!fwnet_pd_update(peer, pd, buf, fg_off, len)) {
672 				/*
673 				 * Couldn't save off fragment anyway
674 				 * so might as well obliterate the
675 				 * datagram now.
676 				 */
677 				fwnet_pd_delete(pd);
678 				peer->pdg_size--;
679 				retval = -ENOMEM;
680 				goto fail;
681 			}
682 		}
683 	} /* new datagram or add to existing one */
684 
685 	if (lf == RFC2374_HDR_FIRSTFRAG)
686 		pd->ether_type = ether_type;
687 
688 	if (fwnet_pd_is_complete(pd)) {
689 		ether_type = pd->ether_type;
690 		peer->pdg_size--;
691 		skb = skb_get(pd->skb);
692 		fwnet_pd_delete(pd);
693 
694 		spin_unlock_irqrestore(&dev->lock, flags);
695 
696 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
697 						    false, ether_type);
698 	}
699 	/*
700 	 * Datagram is not complete, we're done for the
701 	 * moment.
702 	 */
703 	retval = 0;
704  fail:
705 	spin_unlock_irqrestore(&dev->lock, flags);
706 
707 	return retval;
708 }
709 
710 static void fwnet_receive_packet(struct fw_card *card, struct fw_request *r,
711 		int tcode, int destination, int source, int generation,
712 		unsigned long long offset, void *payload, size_t length,
713 		void *callback_data)
714 {
715 	struct fwnet_device *dev = callback_data;
716 	int rcode;
717 
718 	if (destination == IEEE1394_ALL_NODES) {
719 		kfree(r);
720 
721 		return;
722 	}
723 
724 	if (offset != dev->handler.offset)
725 		rcode = RCODE_ADDRESS_ERROR;
726 	else if (tcode != TCODE_WRITE_BLOCK_REQUEST)
727 		rcode = RCODE_TYPE_ERROR;
728 	else if (fwnet_incoming_packet(dev, payload, length,
729 				       source, generation, false) != 0) {
730 		dev_err(&dev->netdev->dev, "incoming packet failure\n");
731 		rcode = RCODE_CONFLICT_ERROR;
732 	} else
733 		rcode = RCODE_COMPLETE;
734 
735 	fw_send_response(card, r, rcode);
736 }
737 
738 static void fwnet_receive_broadcast(struct fw_iso_context *context,
739 		u32 cycle, size_t header_length, void *header, void *data)
740 {
741 	struct fwnet_device *dev;
742 	struct fw_iso_packet packet;
743 	__be16 *hdr_ptr;
744 	__be32 *buf_ptr;
745 	int retval;
746 	u32 length;
747 	u16 source_node_id;
748 	u32 specifier_id;
749 	u32 ver;
750 	unsigned long offset;
751 	unsigned long flags;
752 
753 	dev = data;
754 	hdr_ptr = header;
755 	length = be16_to_cpup(hdr_ptr);
756 
757 	spin_lock_irqsave(&dev->lock, flags);
758 
759 	offset = dev->rcv_buffer_size * dev->broadcast_rcv_next_ptr;
760 	buf_ptr = dev->broadcast_rcv_buffer_ptrs[dev->broadcast_rcv_next_ptr++];
761 	if (dev->broadcast_rcv_next_ptr == dev->num_broadcast_rcv_ptrs)
762 		dev->broadcast_rcv_next_ptr = 0;
763 
764 	spin_unlock_irqrestore(&dev->lock, flags);
765 
766 	specifier_id =    (be32_to_cpu(buf_ptr[0]) & 0xffff) << 8
767 			| (be32_to_cpu(buf_ptr[1]) & 0xff000000) >> 24;
768 	ver = be32_to_cpu(buf_ptr[1]) & 0xffffff;
769 	source_node_id = be32_to_cpu(buf_ptr[0]) >> 16;
770 
771 	if (specifier_id == IANA_SPECIFIER_ID &&
772 	    (ver == RFC2734_SW_VERSION
773 #if IS_ENABLED(CONFIG_IPV6)
774 	     || ver == RFC3146_SW_VERSION
775 #endif
776 	    )) {
777 		buf_ptr += 2;
778 		length -= IEEE1394_GASP_HDR_SIZE;
779 		fwnet_incoming_packet(dev, buf_ptr, length, source_node_id,
780 				      context->card->generation, true);
781 	}
782 
783 	packet.payload_length = dev->rcv_buffer_size;
784 	packet.interrupt = 1;
785 	packet.skip = 0;
786 	packet.tag = 3;
787 	packet.sy = 0;
788 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
789 
790 	spin_lock_irqsave(&dev->lock, flags);
791 
792 	retval = fw_iso_context_queue(dev->broadcast_rcv_context, &packet,
793 				      &dev->broadcast_rcv_buffer, offset);
794 
795 	spin_unlock_irqrestore(&dev->lock, flags);
796 
797 	if (retval >= 0)
798 		fw_iso_context_queue_flush(dev->broadcast_rcv_context);
799 	else
800 		dev_err(&dev->netdev->dev, "requeue failed\n");
801 }
802 
803 static struct kmem_cache *fwnet_packet_task_cache;
804 
805 static void fwnet_free_ptask(struct fwnet_packet_task *ptask)
806 {
807 	dev_kfree_skb_any(ptask->skb);
808 	kmem_cache_free(fwnet_packet_task_cache, ptask);
809 }
810 
811 /* Caller must hold dev->lock. */
812 static void dec_queued_datagrams(struct fwnet_device *dev)
813 {
814 	if (--dev->queued_datagrams == FWNET_MIN_QUEUED_DATAGRAMS)
815 		netif_wake_queue(dev->netdev);
816 }
817 
818 static int fwnet_send_packet(struct fwnet_packet_task *ptask);
819 
820 static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
821 {
822 	struct fwnet_device *dev = ptask->dev;
823 	struct sk_buff *skb = ptask->skb;
824 	unsigned long flags;
825 	bool free;
826 
827 	spin_lock_irqsave(&dev->lock, flags);
828 
829 	ptask->outstanding_pkts--;
830 
831 	/* Check whether we or the networking TX soft-IRQ is last user. */
832 	free = (ptask->outstanding_pkts == 0 && ptask->enqueued);
833 	if (free)
834 		dec_queued_datagrams(dev);
835 
836 	if (ptask->outstanding_pkts == 0) {
837 		dev->netdev->stats.tx_packets++;
838 		dev->netdev->stats.tx_bytes += skb->len;
839 	}
840 
841 	spin_unlock_irqrestore(&dev->lock, flags);
842 
843 	if (ptask->outstanding_pkts > 0) {
844 		u16 dg_size;
845 		u16 fg_off;
846 		u16 datagram_label;
847 		u16 lf;
848 
849 		/* Update the ptask to point to the next fragment and send it */
850 		lf = fwnet_get_hdr_lf(&ptask->hdr);
851 		switch (lf) {
852 		case RFC2374_HDR_LASTFRAG:
853 		case RFC2374_HDR_UNFRAG:
854 		default:
855 			dev_err(&dev->netdev->dev,
856 				"outstanding packet %x lf %x, header %x,%x\n",
857 				ptask->outstanding_pkts, lf, ptask->hdr.w0,
858 				ptask->hdr.w1);
859 			BUG();
860 
861 		case RFC2374_HDR_FIRSTFRAG:
862 			/* Set frag type here for future interior fragments */
863 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
864 			fg_off = ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
865 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
866 			break;
867 
868 		case RFC2374_HDR_INTFRAG:
869 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
870 			fg_off = fwnet_get_hdr_fg_off(&ptask->hdr)
871 				  + ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
872 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
873 			break;
874 		}
875 
876 		if (ptask->dest_node == IEEE1394_ALL_NODES) {
877 			skb_pull(skb,
878 				 ptask->max_payload + IEEE1394_GASP_HDR_SIZE);
879 		} else {
880 			skb_pull(skb, ptask->max_payload);
881 		}
882 		if (ptask->outstanding_pkts > 1) {
883 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_INTFRAG,
884 					  dg_size, fg_off, datagram_label);
885 		} else {
886 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_LASTFRAG,
887 					  dg_size, fg_off, datagram_label);
888 			ptask->max_payload = skb->len + RFC2374_FRAG_HDR_SIZE;
889 		}
890 		fwnet_send_packet(ptask);
891 	}
892 
893 	if (free)
894 		fwnet_free_ptask(ptask);
895 }
896 
897 static void fwnet_transmit_packet_failed(struct fwnet_packet_task *ptask)
898 {
899 	struct fwnet_device *dev = ptask->dev;
900 	unsigned long flags;
901 	bool free;
902 
903 	spin_lock_irqsave(&dev->lock, flags);
904 
905 	/* One fragment failed; don't try to send remaining fragments. */
906 	ptask->outstanding_pkts = 0;
907 
908 	/* Check whether we or the networking TX soft-IRQ is last user. */
909 	free = ptask->enqueued;
910 	if (free)
911 		dec_queued_datagrams(dev);
912 
913 	dev->netdev->stats.tx_dropped++;
914 	dev->netdev->stats.tx_errors++;
915 
916 	spin_unlock_irqrestore(&dev->lock, flags);
917 
918 	if (free)
919 		fwnet_free_ptask(ptask);
920 }
921 
922 static void fwnet_write_complete(struct fw_card *card, int rcode,
923 				 void *payload, size_t length, void *data)
924 {
925 	struct fwnet_packet_task *ptask = data;
926 	static unsigned long j;
927 	static int last_rcode, errors_skipped;
928 
929 	if (rcode == RCODE_COMPLETE) {
930 		fwnet_transmit_packet_done(ptask);
931 	} else {
932 		if (printk_timed_ratelimit(&j,  1000) || rcode != last_rcode) {
933 			dev_err(&ptask->dev->netdev->dev,
934 				"fwnet_write_complete failed: %x (skipped %d)\n",
935 				rcode, errors_skipped);
936 
937 			errors_skipped = 0;
938 			last_rcode = rcode;
939 		} else {
940 			errors_skipped++;
941 		}
942 		fwnet_transmit_packet_failed(ptask);
943 	}
944 }
945 
946 static int fwnet_send_packet(struct fwnet_packet_task *ptask)
947 {
948 	struct fwnet_device *dev;
949 	unsigned tx_len;
950 	struct rfc2734_header *bufhdr;
951 	unsigned long flags;
952 	bool free;
953 
954 	dev = ptask->dev;
955 	tx_len = ptask->max_payload;
956 	switch (fwnet_get_hdr_lf(&ptask->hdr)) {
957 	case RFC2374_HDR_UNFRAG:
958 		bufhdr = (struct rfc2734_header *)
959 				skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
960 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
961 		break;
962 
963 	case RFC2374_HDR_FIRSTFRAG:
964 	case RFC2374_HDR_INTFRAG:
965 	case RFC2374_HDR_LASTFRAG:
966 		bufhdr = (struct rfc2734_header *)
967 				skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
968 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
969 		put_unaligned_be32(ptask->hdr.w1, &bufhdr->w1);
970 		break;
971 
972 	default:
973 		BUG();
974 	}
975 	if (ptask->dest_node == IEEE1394_ALL_NODES) {
976 		u8 *p;
977 		int generation;
978 		int node_id;
979 		unsigned int sw_version;
980 
981 		/* ptask->generation may not have been set yet */
982 		generation = dev->card->generation;
983 		smp_rmb();
984 		node_id = dev->card->node_id;
985 
986 		switch (ptask->skb->protocol) {
987 		default:
988 			sw_version = RFC2734_SW_VERSION;
989 			break;
990 #if IS_ENABLED(CONFIG_IPV6)
991 		case htons(ETH_P_IPV6):
992 			sw_version = RFC3146_SW_VERSION;
993 #endif
994 		}
995 
996 		p = skb_push(ptask->skb, IEEE1394_GASP_HDR_SIZE);
997 		put_unaligned_be32(node_id << 16 | IANA_SPECIFIER_ID >> 8, p);
998 		put_unaligned_be32((IANA_SPECIFIER_ID & 0xff) << 24
999 						| sw_version, &p[4]);
1000 
1001 		/* We should not transmit if broadcast_channel.valid == 0. */
1002 		fw_send_request(dev->card, &ptask->transaction,
1003 				TCODE_STREAM_DATA,
1004 				fw_stream_packet_destination_id(3,
1005 						IEEE1394_BROADCAST_CHANNEL, 0),
1006 				generation, SCODE_100, 0ULL, ptask->skb->data,
1007 				tx_len + 8, fwnet_write_complete, ptask);
1008 
1009 		spin_lock_irqsave(&dev->lock, flags);
1010 
1011 		/* If the AT tasklet already ran, we may be last user. */
1012 		free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1013 		if (!free)
1014 			ptask->enqueued = true;
1015 		else
1016 			dec_queued_datagrams(dev);
1017 
1018 		spin_unlock_irqrestore(&dev->lock, flags);
1019 
1020 		goto out;
1021 	}
1022 
1023 	fw_send_request(dev->card, &ptask->transaction,
1024 			TCODE_WRITE_BLOCK_REQUEST, ptask->dest_node,
1025 			ptask->generation, ptask->speed, ptask->fifo_addr,
1026 			ptask->skb->data, tx_len, fwnet_write_complete, ptask);
1027 
1028 	spin_lock_irqsave(&dev->lock, flags);
1029 
1030 	/* If the AT tasklet already ran, we may be last user. */
1031 	free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1032 	if (!free)
1033 		ptask->enqueued = true;
1034 	else
1035 		dec_queued_datagrams(dev);
1036 
1037 	spin_unlock_irqrestore(&dev->lock, flags);
1038 
1039 	dev->netdev->trans_start = jiffies;
1040  out:
1041 	if (free)
1042 		fwnet_free_ptask(ptask);
1043 
1044 	return 0;
1045 }
1046 
1047 static void fwnet_fifo_stop(struct fwnet_device *dev)
1048 {
1049 	if (dev->local_fifo == FWNET_NO_FIFO_ADDR)
1050 		return;
1051 
1052 	fw_core_remove_address_handler(&dev->handler);
1053 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1054 }
1055 
1056 static int fwnet_fifo_start(struct fwnet_device *dev)
1057 {
1058 	int retval;
1059 
1060 	if (dev->local_fifo != FWNET_NO_FIFO_ADDR)
1061 		return 0;
1062 
1063 	dev->handler.length = 4096;
1064 	dev->handler.address_callback = fwnet_receive_packet;
1065 	dev->handler.callback_data = dev;
1066 
1067 	retval = fw_core_add_address_handler(&dev->handler,
1068 					     &fw_high_memory_region);
1069 	if (retval < 0)
1070 		return retval;
1071 
1072 	dev->local_fifo = dev->handler.offset;
1073 
1074 	return 0;
1075 }
1076 
1077 static void __fwnet_broadcast_stop(struct fwnet_device *dev)
1078 {
1079 	unsigned u;
1080 
1081 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR) {
1082 		for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++)
1083 			kunmap(dev->broadcast_rcv_buffer.pages[u]);
1084 		fw_iso_buffer_destroy(&dev->broadcast_rcv_buffer, dev->card);
1085 	}
1086 	if (dev->broadcast_rcv_context) {
1087 		fw_iso_context_destroy(dev->broadcast_rcv_context);
1088 		dev->broadcast_rcv_context = NULL;
1089 	}
1090 	kfree(dev->broadcast_rcv_buffer_ptrs);
1091 	dev->broadcast_rcv_buffer_ptrs = NULL;
1092 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1093 }
1094 
1095 static void fwnet_broadcast_stop(struct fwnet_device *dev)
1096 {
1097 	if (dev->broadcast_state == FWNET_BROADCAST_ERROR)
1098 		return;
1099 	fw_iso_context_stop(dev->broadcast_rcv_context);
1100 	__fwnet_broadcast_stop(dev);
1101 }
1102 
1103 static int fwnet_broadcast_start(struct fwnet_device *dev)
1104 {
1105 	struct fw_iso_context *context;
1106 	int retval;
1107 	unsigned num_packets;
1108 	unsigned max_receive;
1109 	struct fw_iso_packet packet;
1110 	unsigned long offset;
1111 	void **ptrptr;
1112 	unsigned u;
1113 
1114 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR)
1115 		return 0;
1116 
1117 	max_receive = 1U << (dev->card->max_receive + 1);
1118 	num_packets = (FWNET_ISO_PAGE_COUNT * PAGE_SIZE) / max_receive;
1119 
1120 	ptrptr = kmalloc(sizeof(void *) * num_packets, GFP_KERNEL);
1121 	if (!ptrptr) {
1122 		retval = -ENOMEM;
1123 		goto failed;
1124 	}
1125 	dev->broadcast_rcv_buffer_ptrs = ptrptr;
1126 
1127 	context = fw_iso_context_create(dev->card, FW_ISO_CONTEXT_RECEIVE,
1128 					IEEE1394_BROADCAST_CHANNEL,
1129 					dev->card->link_speed, 8,
1130 					fwnet_receive_broadcast, dev);
1131 	if (IS_ERR(context)) {
1132 		retval = PTR_ERR(context);
1133 		goto failed;
1134 	}
1135 
1136 	retval = fw_iso_buffer_init(&dev->broadcast_rcv_buffer, dev->card,
1137 				    FWNET_ISO_PAGE_COUNT, DMA_FROM_DEVICE);
1138 	if (retval < 0)
1139 		goto failed;
1140 
1141 	dev->broadcast_state = FWNET_BROADCAST_STOPPED;
1142 
1143 	for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++) {
1144 		void *ptr;
1145 		unsigned v;
1146 
1147 		ptr = kmap(dev->broadcast_rcv_buffer.pages[u]);
1148 		for (v = 0; v < num_packets / FWNET_ISO_PAGE_COUNT; v++)
1149 			*ptrptr++ = (void *) ((char *)ptr + v * max_receive);
1150 	}
1151 	dev->broadcast_rcv_context = context;
1152 
1153 	packet.payload_length = max_receive;
1154 	packet.interrupt = 1;
1155 	packet.skip = 0;
1156 	packet.tag = 3;
1157 	packet.sy = 0;
1158 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
1159 	offset = 0;
1160 
1161 	for (u = 0; u < num_packets; u++) {
1162 		retval = fw_iso_context_queue(context, &packet,
1163 				&dev->broadcast_rcv_buffer, offset);
1164 		if (retval < 0)
1165 			goto failed;
1166 
1167 		offset += max_receive;
1168 	}
1169 	dev->num_broadcast_rcv_ptrs = num_packets;
1170 	dev->rcv_buffer_size = max_receive;
1171 	dev->broadcast_rcv_next_ptr = 0U;
1172 	retval = fw_iso_context_start(context, -1, 0,
1173 			FW_ISO_CONTEXT_MATCH_ALL_TAGS); /* ??? sync */
1174 	if (retval < 0)
1175 		goto failed;
1176 
1177 	/* FIXME: adjust it according to the min. speed of all known peers? */
1178 	dev->broadcast_xmt_max_payload = IEEE1394_MAX_PAYLOAD_S100
1179 			- IEEE1394_GASP_HDR_SIZE - RFC2374_UNFRAG_HDR_SIZE;
1180 	dev->broadcast_state = FWNET_BROADCAST_RUNNING;
1181 
1182 	return 0;
1183 
1184  failed:
1185 	__fwnet_broadcast_stop(dev);
1186 	return retval;
1187 }
1188 
1189 static void set_carrier_state(struct fwnet_device *dev)
1190 {
1191 	if (dev->peer_count > 1)
1192 		netif_carrier_on(dev->netdev);
1193 	else
1194 		netif_carrier_off(dev->netdev);
1195 }
1196 
1197 /* ifup */
1198 static int fwnet_open(struct net_device *net)
1199 {
1200 	struct fwnet_device *dev = netdev_priv(net);
1201 	int ret;
1202 
1203 	ret = fwnet_broadcast_start(dev);
1204 	if (ret)
1205 		return ret;
1206 
1207 	netif_start_queue(net);
1208 
1209 	spin_lock_irq(&dev->lock);
1210 	set_carrier_state(dev);
1211 	spin_unlock_irq(&dev->lock);
1212 
1213 	return 0;
1214 }
1215 
1216 /* ifdown */
1217 static int fwnet_stop(struct net_device *net)
1218 {
1219 	struct fwnet_device *dev = netdev_priv(net);
1220 
1221 	netif_stop_queue(net);
1222 	fwnet_broadcast_stop(dev);
1223 
1224 	return 0;
1225 }
1226 
1227 static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
1228 {
1229 	struct fwnet_header hdr_buf;
1230 	struct fwnet_device *dev = netdev_priv(net);
1231 	__be16 proto;
1232 	u16 dest_node;
1233 	unsigned max_payload;
1234 	u16 dg_size;
1235 	u16 *datagram_label_ptr;
1236 	struct fwnet_packet_task *ptask;
1237 	struct fwnet_peer *peer;
1238 	unsigned long flags;
1239 
1240 	spin_lock_irqsave(&dev->lock, flags);
1241 
1242 	/* Can this happen? */
1243 	if (netif_queue_stopped(dev->netdev)) {
1244 		spin_unlock_irqrestore(&dev->lock, flags);
1245 
1246 		return NETDEV_TX_BUSY;
1247 	}
1248 
1249 	ptask = kmem_cache_alloc(fwnet_packet_task_cache, GFP_ATOMIC);
1250 	if (ptask == NULL)
1251 		goto fail;
1252 
1253 	skb = skb_share_check(skb, GFP_ATOMIC);
1254 	if (!skb)
1255 		goto fail;
1256 
1257 	/*
1258 	 * Make a copy of the driver-specific header.
1259 	 * We might need to rebuild the header on tx failure.
1260 	 */
1261 	memcpy(&hdr_buf, skb->data, sizeof(hdr_buf));
1262 	proto = hdr_buf.h_proto;
1263 
1264 	switch (proto) {
1265 	case htons(ETH_P_ARP):
1266 	case htons(ETH_P_IP):
1267 #if IS_ENABLED(CONFIG_IPV6)
1268 	case htons(ETH_P_IPV6):
1269 #endif
1270 		break;
1271 	default:
1272 		goto fail;
1273 	}
1274 
1275 	skb_pull(skb, sizeof(hdr_buf));
1276 	dg_size = skb->len;
1277 
1278 	/*
1279 	 * Set the transmission type for the packet.  ARP packets and IP
1280 	 * broadcast packets are sent via GASP.
1281 	 */
1282 	if (fwnet_hwaddr_is_multicast(hdr_buf.h_dest)) {
1283 		max_payload        = dev->broadcast_xmt_max_payload;
1284 		datagram_label_ptr = &dev->broadcast_xmt_datagramlabel;
1285 
1286 		ptask->fifo_addr   = FWNET_NO_FIFO_ADDR;
1287 		ptask->generation  = 0;
1288 		ptask->dest_node   = IEEE1394_ALL_NODES;
1289 		ptask->speed       = SCODE_100;
1290 	} else {
1291 		union fwnet_hwaddr *ha = (union fwnet_hwaddr *)hdr_buf.h_dest;
1292 		__be64 guid = get_unaligned(&ha->uc.uniq_id);
1293 		u8 generation;
1294 
1295 		peer = fwnet_peer_find_by_guid(dev, be64_to_cpu(guid));
1296 		if (!peer)
1297 			goto fail;
1298 
1299 		generation         = peer->generation;
1300 		dest_node          = peer->node_id;
1301 		max_payload        = peer->max_payload;
1302 		datagram_label_ptr = &peer->datagram_label;
1303 
1304 		ptask->fifo_addr   = fwnet_hwaddr_fifo(ha);
1305 		ptask->generation  = generation;
1306 		ptask->dest_node   = dest_node;
1307 		ptask->speed       = peer->speed;
1308 	}
1309 
1310 	ptask->hdr.w0 = 0;
1311 	ptask->hdr.w1 = 0;
1312 	ptask->skb = skb;
1313 	ptask->dev = dev;
1314 
1315 	/* Does it all fit in one packet? */
1316 	if (dg_size <= max_payload) {
1317 		fwnet_make_uf_hdr(&ptask->hdr, ntohs(proto));
1318 		ptask->outstanding_pkts = 1;
1319 		max_payload = dg_size + RFC2374_UNFRAG_HDR_SIZE;
1320 	} else {
1321 		u16 datagram_label;
1322 
1323 		max_payload -= RFC2374_FRAG_OVERHEAD;
1324 		datagram_label = (*datagram_label_ptr)++;
1325 		fwnet_make_ff_hdr(&ptask->hdr, ntohs(proto), dg_size,
1326 				  datagram_label);
1327 		ptask->outstanding_pkts = DIV_ROUND_UP(dg_size, max_payload);
1328 		max_payload += RFC2374_FRAG_HDR_SIZE;
1329 	}
1330 
1331 	if (++dev->queued_datagrams == FWNET_MAX_QUEUED_DATAGRAMS)
1332 		netif_stop_queue(dev->netdev);
1333 
1334 	spin_unlock_irqrestore(&dev->lock, flags);
1335 
1336 	ptask->max_payload = max_payload;
1337 	ptask->enqueued    = 0;
1338 
1339 	fwnet_send_packet(ptask);
1340 
1341 	return NETDEV_TX_OK;
1342 
1343  fail:
1344 	spin_unlock_irqrestore(&dev->lock, flags);
1345 
1346 	if (ptask)
1347 		kmem_cache_free(fwnet_packet_task_cache, ptask);
1348 
1349 	if (skb != NULL)
1350 		dev_kfree_skb(skb);
1351 
1352 	net->stats.tx_dropped++;
1353 	net->stats.tx_errors++;
1354 
1355 	/*
1356 	 * FIXME: According to a patch from 2003-02-26, "returning non-zero
1357 	 * causes serious problems" here, allegedly.  Before that patch,
1358 	 * -ERRNO was returned which is not appropriate under Linux 2.6.
1359 	 * Perhaps more needs to be done?  Stop the queue in serious
1360 	 * conditions and restart it elsewhere?
1361 	 */
1362 	return NETDEV_TX_OK;
1363 }
1364 
1365 static int fwnet_change_mtu(struct net_device *net, int new_mtu)
1366 {
1367 	if (new_mtu < 68)
1368 		return -EINVAL;
1369 
1370 	net->mtu = new_mtu;
1371 	return 0;
1372 }
1373 
1374 static const struct ethtool_ops fwnet_ethtool_ops = {
1375 	.get_link	= ethtool_op_get_link,
1376 };
1377 
1378 static const struct net_device_ops fwnet_netdev_ops = {
1379 	.ndo_open       = fwnet_open,
1380 	.ndo_stop	= fwnet_stop,
1381 	.ndo_start_xmit = fwnet_tx,
1382 	.ndo_change_mtu = fwnet_change_mtu,
1383 };
1384 
1385 static void fwnet_init_dev(struct net_device *net)
1386 {
1387 	net->header_ops		= &fwnet_header_ops;
1388 	net->netdev_ops		= &fwnet_netdev_ops;
1389 	net->watchdog_timeo	= 2 * HZ;
1390 	net->flags		= IFF_BROADCAST | IFF_MULTICAST;
1391 	net->features		= NETIF_F_HIGHDMA;
1392 	net->addr_len		= FWNET_ALEN;
1393 	net->hard_header_len	= FWNET_HLEN;
1394 	net->type		= ARPHRD_IEEE1394;
1395 	net->tx_queue_len	= FWNET_TX_QUEUE_LEN;
1396 	net->ethtool_ops	= &fwnet_ethtool_ops;
1397 }
1398 
1399 /* caller must hold fwnet_device_mutex */
1400 static struct fwnet_device *fwnet_dev_find(struct fw_card *card)
1401 {
1402 	struct fwnet_device *dev;
1403 
1404 	list_for_each_entry(dev, &fwnet_device_list, dev_link)
1405 		if (dev->card == card)
1406 			return dev;
1407 
1408 	return NULL;
1409 }
1410 
1411 static int fwnet_add_peer(struct fwnet_device *dev,
1412 			  struct fw_unit *unit, struct fw_device *device)
1413 {
1414 	struct fwnet_peer *peer;
1415 
1416 	peer = kmalloc(sizeof(*peer), GFP_KERNEL);
1417 	if (!peer)
1418 		return -ENOMEM;
1419 
1420 	dev_set_drvdata(&unit->device, peer);
1421 
1422 	peer->dev = dev;
1423 	peer->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1424 	INIT_LIST_HEAD(&peer->pd_list);
1425 	peer->pdg_size = 0;
1426 	peer->datagram_label = 0;
1427 	peer->speed = device->max_speed;
1428 	peer->max_payload = fwnet_max_payload(device->max_rec, peer->speed);
1429 
1430 	peer->generation = device->generation;
1431 	smp_rmb();
1432 	peer->node_id = device->node_id;
1433 
1434 	spin_lock_irq(&dev->lock);
1435 	list_add_tail(&peer->peer_link, &dev->peer_list);
1436 	dev->peer_count++;
1437 	set_carrier_state(dev);
1438 	spin_unlock_irq(&dev->lock);
1439 
1440 	return 0;
1441 }
1442 
1443 static int fwnet_probe(struct fw_unit *unit,
1444 		       const struct ieee1394_device_id *id)
1445 {
1446 	struct fw_device *device = fw_parent_device(unit);
1447 	struct fw_card *card = device->card;
1448 	struct net_device *net;
1449 	bool allocated_netdev = false;
1450 	struct fwnet_device *dev;
1451 	unsigned max_mtu;
1452 	int ret;
1453 	union fwnet_hwaddr *ha;
1454 
1455 	mutex_lock(&fwnet_device_mutex);
1456 
1457 	dev = fwnet_dev_find(card);
1458 	if (dev) {
1459 		net = dev->netdev;
1460 		goto have_dev;
1461 	}
1462 
1463 	net = alloc_netdev(sizeof(*dev), "firewire%d", fwnet_init_dev);
1464 	if (net == NULL) {
1465 		ret = -ENOMEM;
1466 		goto out;
1467 	}
1468 
1469 	allocated_netdev = true;
1470 	SET_NETDEV_DEV(net, card->device);
1471 	dev = netdev_priv(net);
1472 
1473 	spin_lock_init(&dev->lock);
1474 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1475 	dev->broadcast_rcv_context = NULL;
1476 	dev->broadcast_xmt_max_payload = 0;
1477 	dev->broadcast_xmt_datagramlabel = 0;
1478 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1479 	dev->queued_datagrams = 0;
1480 	INIT_LIST_HEAD(&dev->peer_list);
1481 	dev->card = card;
1482 	dev->netdev = net;
1483 
1484 	ret = fwnet_fifo_start(dev);
1485 	if (ret < 0)
1486 		goto out;
1487 	dev->local_fifo = dev->handler.offset;
1488 
1489 	/*
1490 	 * Use the RFC 2734 default 1500 octets or the maximum payload
1491 	 * as initial MTU
1492 	 */
1493 	max_mtu = (1 << (card->max_receive + 1))
1494 		  - sizeof(struct rfc2734_header) - IEEE1394_GASP_HDR_SIZE;
1495 	net->mtu = min(1500U, max_mtu);
1496 
1497 	/* Set our hardware address while we're at it */
1498 	ha = (union fwnet_hwaddr *)net->dev_addr;
1499 	put_unaligned_be64(card->guid, &ha->uc.uniq_id);
1500 	ha->uc.max_rec = dev->card->max_receive;
1501 	ha->uc.sspd = dev->card->link_speed;
1502 	put_unaligned_be16(dev->local_fifo >> 32, &ha->uc.fifo_hi);
1503 	put_unaligned_be32(dev->local_fifo & 0xffffffff, &ha->uc.fifo_lo);
1504 
1505 	memset(net->broadcast, -1, net->addr_len);
1506 
1507 	ret = register_netdev(net);
1508 	if (ret)
1509 		goto out;
1510 
1511 	list_add_tail(&dev->dev_link, &fwnet_device_list);
1512 	dev_notice(&net->dev, "IP over IEEE 1394 on card %s\n",
1513 		   dev_name(card->device));
1514  have_dev:
1515 	ret = fwnet_add_peer(dev, unit, device);
1516 	if (ret && allocated_netdev) {
1517 		unregister_netdev(net);
1518 		list_del(&dev->dev_link);
1519  out:
1520 		fwnet_fifo_stop(dev);
1521 		free_netdev(net);
1522 	}
1523 
1524 	mutex_unlock(&fwnet_device_mutex);
1525 
1526 	return ret;
1527 }
1528 
1529 /*
1530  * FIXME abort partially sent fragmented datagrams,
1531  * discard partially received fragmented datagrams
1532  */
1533 static void fwnet_update(struct fw_unit *unit)
1534 {
1535 	struct fw_device *device = fw_parent_device(unit);
1536 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1537 	int generation;
1538 
1539 	generation = device->generation;
1540 
1541 	spin_lock_irq(&peer->dev->lock);
1542 	peer->node_id    = device->node_id;
1543 	peer->generation = generation;
1544 	spin_unlock_irq(&peer->dev->lock);
1545 }
1546 
1547 static void fwnet_remove_peer(struct fwnet_peer *peer, struct fwnet_device *dev)
1548 {
1549 	struct fwnet_partial_datagram *pd, *pd_next;
1550 
1551 	spin_lock_irq(&dev->lock);
1552 	list_del(&peer->peer_link);
1553 	dev->peer_count--;
1554 	set_carrier_state(dev);
1555 	spin_unlock_irq(&dev->lock);
1556 
1557 	list_for_each_entry_safe(pd, pd_next, &peer->pd_list, pd_link)
1558 		fwnet_pd_delete(pd);
1559 
1560 	kfree(peer);
1561 }
1562 
1563 static void fwnet_remove(struct fw_unit *unit)
1564 {
1565 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1566 	struct fwnet_device *dev = peer->dev;
1567 	struct net_device *net;
1568 	int i;
1569 
1570 	mutex_lock(&fwnet_device_mutex);
1571 
1572 	net = dev->netdev;
1573 
1574 	fwnet_remove_peer(peer, dev);
1575 
1576 	if (list_empty(&dev->peer_list)) {
1577 		unregister_netdev(net);
1578 
1579 		fwnet_fifo_stop(dev);
1580 
1581 		for (i = 0; dev->queued_datagrams && i < 5; i++)
1582 			ssleep(1);
1583 		WARN_ON(dev->queued_datagrams);
1584 		list_del(&dev->dev_link);
1585 
1586 		free_netdev(net);
1587 	}
1588 
1589 	mutex_unlock(&fwnet_device_mutex);
1590 }
1591 
1592 static const struct ieee1394_device_id fwnet_id_table[] = {
1593 	{
1594 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1595 				IEEE1394_MATCH_VERSION,
1596 		.specifier_id = IANA_SPECIFIER_ID,
1597 		.version      = RFC2734_SW_VERSION,
1598 	},
1599 #if IS_ENABLED(CONFIG_IPV6)
1600 	{
1601 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1602 				IEEE1394_MATCH_VERSION,
1603 		.specifier_id = IANA_SPECIFIER_ID,
1604 		.version      = RFC3146_SW_VERSION,
1605 	},
1606 #endif
1607 	{ }
1608 };
1609 
1610 static struct fw_driver fwnet_driver = {
1611 	.driver = {
1612 		.owner  = THIS_MODULE,
1613 		.name   = KBUILD_MODNAME,
1614 		.bus    = &fw_bus_type,
1615 	},
1616 	.probe    = fwnet_probe,
1617 	.update   = fwnet_update,
1618 	.remove   = fwnet_remove,
1619 	.id_table = fwnet_id_table,
1620 };
1621 
1622 static const u32 rfc2374_unit_directory_data[] = {
1623 	0x00040000,	/* directory_length		*/
1624 	0x1200005e,	/* unit_specifier_id: IANA	*/
1625 	0x81000003,	/* textual descriptor offset	*/
1626 	0x13000001,	/* unit_sw_version: RFC 2734	*/
1627 	0x81000005,	/* textual descriptor offset	*/
1628 	0x00030000,	/* descriptor_length		*/
1629 	0x00000000,	/* text				*/
1630 	0x00000000,	/* minimal ASCII, en		*/
1631 	0x49414e41,	/* I A N A			*/
1632 	0x00030000,	/* descriptor_length		*/
1633 	0x00000000,	/* text				*/
1634 	0x00000000,	/* minimal ASCII, en		*/
1635 	0x49507634,	/* I P v 4			*/
1636 };
1637 
1638 static struct fw_descriptor rfc2374_unit_directory = {
1639 	.length = ARRAY_SIZE(rfc2374_unit_directory_data),
1640 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1641 	.data   = rfc2374_unit_directory_data
1642 };
1643 
1644 #if IS_ENABLED(CONFIG_IPV6)
1645 static const u32 rfc3146_unit_directory_data[] = {
1646 	0x00040000,	/* directory_length		*/
1647 	0x1200005e,	/* unit_specifier_id: IANA	*/
1648 	0x81000003,	/* textual descriptor offset	*/
1649 	0x13000002,	/* unit_sw_version: RFC 3146	*/
1650 	0x81000005,	/* textual descriptor offset	*/
1651 	0x00030000,	/* descriptor_length		*/
1652 	0x00000000,	/* text				*/
1653 	0x00000000,	/* minimal ASCII, en		*/
1654 	0x49414e41,	/* I A N A			*/
1655 	0x00030000,	/* descriptor_length		*/
1656 	0x00000000,	/* text				*/
1657 	0x00000000,	/* minimal ASCII, en		*/
1658 	0x49507636,	/* I P v 6			*/
1659 };
1660 
1661 static struct fw_descriptor rfc3146_unit_directory = {
1662 	.length = ARRAY_SIZE(rfc3146_unit_directory_data),
1663 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1664 	.data   = rfc3146_unit_directory_data
1665 };
1666 #endif
1667 
1668 static int __init fwnet_init(void)
1669 {
1670 	int err;
1671 
1672 	err = fw_core_add_descriptor(&rfc2374_unit_directory);
1673 	if (err)
1674 		return err;
1675 
1676 #if IS_ENABLED(CONFIG_IPV6)
1677 	err = fw_core_add_descriptor(&rfc3146_unit_directory);
1678 	if (err)
1679 		goto out;
1680 #endif
1681 
1682 	fwnet_packet_task_cache = kmem_cache_create("packet_task",
1683 			sizeof(struct fwnet_packet_task), 0, 0, NULL);
1684 	if (!fwnet_packet_task_cache) {
1685 		err = -ENOMEM;
1686 		goto out2;
1687 	}
1688 
1689 	err = driver_register(&fwnet_driver.driver);
1690 	if (!err)
1691 		return 0;
1692 
1693 	kmem_cache_destroy(fwnet_packet_task_cache);
1694 out2:
1695 #if IS_ENABLED(CONFIG_IPV6)
1696 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1697 out:
1698 #endif
1699 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1700 
1701 	return err;
1702 }
1703 module_init(fwnet_init);
1704 
1705 static void __exit fwnet_cleanup(void)
1706 {
1707 	driver_unregister(&fwnet_driver.driver);
1708 	kmem_cache_destroy(fwnet_packet_task_cache);
1709 #if IS_ENABLED(CONFIG_IPV6)
1710 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1711 #endif
1712 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1713 }
1714 module_exit(fwnet_cleanup);
1715 
1716 MODULE_AUTHOR("Jay Fenlason <fenlason@redhat.com>");
1717 MODULE_DESCRIPTION("IP over IEEE1394 as per RFC 2734/3146");
1718 MODULE_LICENSE("GPL");
1719 MODULE_DEVICE_TABLE(ieee1394, fwnet_id_table);
1720