xref: /linux/drivers/firewire/net.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae) 
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) + 1)
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) - 1) << 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_cache(const struct neighbour *neigh,
241 			      struct hh_cache *hh, __be16 type)
242 {
243 	struct net_device *net;
244 	struct fwnet_header *h;
245 
246 	if (type == cpu_to_be16(ETH_P_802_3))
247 		return -1;
248 	net = neigh->dev;
249 	h = (struct fwnet_header *)((u8 *)hh->hh_data + HH_DATA_OFF(sizeof(*h)));
250 	h->h_proto = type;
251 	memcpy(h->h_dest, neigh->ha, net->addr_len);
252 	hh->hh_len = FWNET_HLEN;
253 
254 	return 0;
255 }
256 
257 /* Called by Address Resolution module to notify changes in address. */
258 static void fwnet_header_cache_update(struct hh_cache *hh,
259 		const struct net_device *net, const unsigned char *haddr)
260 {
261 	memcpy((u8 *)hh->hh_data + HH_DATA_OFF(FWNET_HLEN), haddr, net->addr_len);
262 }
263 
264 static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr)
265 {
266 	memcpy(haddr, skb->dev->dev_addr, FWNET_ALEN);
267 
268 	return FWNET_ALEN;
269 }
270 
271 static const struct header_ops fwnet_header_ops = {
272 	.create         = fwnet_header_create,
273 	.cache		= fwnet_header_cache,
274 	.cache_update	= fwnet_header_cache_update,
275 	.parse          = fwnet_header_parse,
276 };
277 
278 /* FIXME: is this correct for all cases? */
279 static bool fwnet_frag_overlap(struct fwnet_partial_datagram *pd,
280 			       unsigned offset, unsigned len)
281 {
282 	struct fwnet_fragment_info *fi;
283 	unsigned end = offset + len;
284 
285 	list_for_each_entry(fi, &pd->fi_list, fi_link)
286 		if (offset < fi->offset + fi->len && end > fi->offset)
287 			return true;
288 
289 	return false;
290 }
291 
292 /* Assumes that new fragment does not overlap any existing fragments */
293 static struct fwnet_fragment_info *fwnet_frag_new(
294 	struct fwnet_partial_datagram *pd, unsigned offset, unsigned len)
295 {
296 	struct fwnet_fragment_info *fi, *fi2, *new;
297 	struct list_head *list;
298 
299 	list = &pd->fi_list;
300 	list_for_each_entry(fi, &pd->fi_list, fi_link) {
301 		if (fi->offset + fi->len == offset) {
302 			/* The new fragment can be tacked on to the end */
303 			/* Did the new fragment plug a hole? */
304 			fi2 = list_entry(fi->fi_link.next,
305 					 struct fwnet_fragment_info, fi_link);
306 			if (fi->offset + fi->len == fi2->offset) {
307 				/* glue fragments together */
308 				fi->len += len + fi2->len;
309 				list_del(&fi2->fi_link);
310 				kfree(fi2);
311 			} else {
312 				fi->len += len;
313 			}
314 
315 			return fi;
316 		}
317 		if (offset + len == fi->offset) {
318 			/* The new fragment can be tacked on to the beginning */
319 			/* Did the new fragment plug a hole? */
320 			fi2 = list_entry(fi->fi_link.prev,
321 					 struct fwnet_fragment_info, fi_link);
322 			if (fi2->offset + fi2->len == fi->offset) {
323 				/* glue fragments together */
324 				fi2->len += fi->len + len;
325 				list_del(&fi->fi_link);
326 				kfree(fi);
327 
328 				return fi2;
329 			}
330 			fi->offset = offset;
331 			fi->len += len;
332 
333 			return fi;
334 		}
335 		if (offset > fi->offset + fi->len) {
336 			list = &fi->fi_link;
337 			break;
338 		}
339 		if (offset + len < fi->offset) {
340 			list = fi->fi_link.prev;
341 			break;
342 		}
343 	}
344 
345 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
346 	if (!new)
347 		return NULL;
348 
349 	new->offset = offset;
350 	new->len = len;
351 	list_add(&new->fi_link, list);
352 
353 	return new;
354 }
355 
356 static struct fwnet_partial_datagram *fwnet_pd_new(struct net_device *net,
357 		struct fwnet_peer *peer, u16 datagram_label, unsigned dg_size,
358 		void *frag_buf, unsigned frag_off, unsigned frag_len)
359 {
360 	struct fwnet_partial_datagram *new;
361 	struct fwnet_fragment_info *fi;
362 
363 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
364 	if (!new)
365 		goto fail;
366 
367 	INIT_LIST_HEAD(&new->fi_list);
368 	fi = fwnet_frag_new(new, frag_off, frag_len);
369 	if (fi == NULL)
370 		goto fail_w_new;
371 
372 	new->datagram_label = datagram_label;
373 	new->datagram_size = dg_size;
374 	new->skb = dev_alloc_skb(dg_size + LL_RESERVED_SPACE(net));
375 	if (new->skb == NULL)
376 		goto fail_w_fi;
377 
378 	skb_reserve(new->skb, LL_RESERVED_SPACE(net));
379 	new->pbuf = skb_put(new->skb, dg_size);
380 	memcpy(new->pbuf + frag_off, frag_buf, frag_len);
381 	list_add_tail(&new->pd_link, &peer->pd_list);
382 
383 	return new;
384 
385 fail_w_fi:
386 	kfree(fi);
387 fail_w_new:
388 	kfree(new);
389 fail:
390 	return NULL;
391 }
392 
393 static struct fwnet_partial_datagram *fwnet_pd_find(struct fwnet_peer *peer,
394 						    u16 datagram_label)
395 {
396 	struct fwnet_partial_datagram *pd;
397 
398 	list_for_each_entry(pd, &peer->pd_list, pd_link)
399 		if (pd->datagram_label == datagram_label)
400 			return pd;
401 
402 	return NULL;
403 }
404 
405 
406 static void fwnet_pd_delete(struct fwnet_partial_datagram *old)
407 {
408 	struct fwnet_fragment_info *fi, *n;
409 
410 	list_for_each_entry_safe(fi, n, &old->fi_list, fi_link)
411 		kfree(fi);
412 
413 	list_del(&old->pd_link);
414 	dev_kfree_skb_any(old->skb);
415 	kfree(old);
416 }
417 
418 static bool fwnet_pd_update(struct fwnet_peer *peer,
419 		struct fwnet_partial_datagram *pd, void *frag_buf,
420 		unsigned frag_off, unsigned frag_len)
421 {
422 	if (fwnet_frag_new(pd, frag_off, frag_len) == NULL)
423 		return false;
424 
425 	memcpy(pd->pbuf + frag_off, frag_buf, frag_len);
426 
427 	/*
428 	 * Move list entry to beginning of list so that oldest partial
429 	 * datagrams percolate to the end of the list
430 	 */
431 	list_move_tail(&pd->pd_link, &peer->pd_list);
432 
433 	return true;
434 }
435 
436 static bool fwnet_pd_is_complete(struct fwnet_partial_datagram *pd)
437 {
438 	struct fwnet_fragment_info *fi;
439 
440 	fi = list_entry(pd->fi_list.next, struct fwnet_fragment_info, fi_link);
441 
442 	return fi->len == pd->datagram_size;
443 }
444 
445 /* caller must hold dev->lock */
446 static struct fwnet_peer *fwnet_peer_find_by_guid(struct fwnet_device *dev,
447 						  u64 guid)
448 {
449 	struct fwnet_peer *peer;
450 
451 	list_for_each_entry(peer, &dev->peer_list, peer_link)
452 		if (peer->guid == guid)
453 			return peer;
454 
455 	return NULL;
456 }
457 
458 /* caller must hold dev->lock */
459 static struct fwnet_peer *fwnet_peer_find_by_node_id(struct fwnet_device *dev,
460 						int node_id, int generation)
461 {
462 	struct fwnet_peer *peer;
463 
464 	list_for_each_entry(peer, &dev->peer_list, peer_link)
465 		if (peer->node_id    == node_id &&
466 		    peer->generation == generation)
467 			return peer;
468 
469 	return NULL;
470 }
471 
472 /* See IEEE 1394-2008 table 6-4, table 8-8, table 16-18. */
473 static unsigned fwnet_max_payload(unsigned max_rec, unsigned speed)
474 {
475 	max_rec = min(max_rec, speed + 8);
476 	max_rec = clamp(max_rec, 8U, 11U); /* 512...4096 */
477 
478 	return (1 << (max_rec + 1)) - RFC2374_FRAG_HDR_SIZE;
479 }
480 
481 
482 static int fwnet_finish_incoming_packet(struct net_device *net,
483 					struct sk_buff *skb, u16 source_node_id,
484 					bool is_broadcast, u16 ether_type)
485 {
486 	struct fwnet_device *dev;
487 	int status;
488 	__be64 guid;
489 
490 	switch (ether_type) {
491 	case ETH_P_ARP:
492 	case ETH_P_IP:
493 #if IS_ENABLED(CONFIG_IPV6)
494 	case ETH_P_IPV6:
495 #endif
496 		break;
497 	default:
498 		goto err;
499 	}
500 
501 	dev = netdev_priv(net);
502 	/* Write metadata, and then pass to the receive level */
503 	skb->dev = net;
504 	skb->ip_summed = CHECKSUM_NONE;
505 
506 	/*
507 	 * Parse the encapsulation header. This actually does the job of
508 	 * converting to an ethernet-like pseudo frame header.
509 	 */
510 	guid = cpu_to_be64(dev->card->guid);
511 	if (dev_hard_header(skb, net, ether_type,
512 			   is_broadcast ? net->broadcast : net->dev_addr,
513 			   NULL, skb->len) >= 0) {
514 		struct fwnet_header *eth;
515 		u16 *rawp;
516 		__be16 protocol;
517 
518 		skb_reset_mac_header(skb);
519 		skb_pull(skb, sizeof(*eth));
520 		eth = (struct fwnet_header *)skb_mac_header(skb);
521 		if (fwnet_hwaddr_is_multicast(eth->h_dest)) {
522 			if (memcmp(eth->h_dest, net->broadcast,
523 				   net->addr_len) == 0)
524 				skb->pkt_type = PACKET_BROADCAST;
525 #if 0
526 			else
527 				skb->pkt_type = PACKET_MULTICAST;
528 #endif
529 		} else {
530 			if (memcmp(eth->h_dest, net->dev_addr, net->addr_len))
531 				skb->pkt_type = PACKET_OTHERHOST;
532 		}
533 		if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN) {
534 			protocol = eth->h_proto;
535 		} else {
536 			rawp = (u16 *)skb->data;
537 			if (*rawp == 0xffff)
538 				protocol = htons(ETH_P_802_3);
539 			else
540 				protocol = htons(ETH_P_802_2);
541 		}
542 		skb->protocol = protocol;
543 	}
544 	status = netif_rx(skb);
545 	if (status == NET_RX_DROP) {
546 		net->stats.rx_errors++;
547 		net->stats.rx_dropped++;
548 	} else {
549 		net->stats.rx_packets++;
550 		net->stats.rx_bytes += skb->len;
551 	}
552 
553 	return 0;
554 
555  err:
556 	net->stats.rx_errors++;
557 	net->stats.rx_dropped++;
558 
559 	dev_kfree_skb_any(skb);
560 
561 	return -ENOENT;
562 }
563 
564 static int fwnet_incoming_packet(struct fwnet_device *dev, __be32 *buf, int len,
565 				 int source_node_id, int generation,
566 				 bool is_broadcast)
567 {
568 	struct sk_buff *skb;
569 	struct net_device *net = dev->netdev;
570 	struct rfc2734_header hdr;
571 	unsigned lf;
572 	unsigned long flags;
573 	struct fwnet_peer *peer;
574 	struct fwnet_partial_datagram *pd;
575 	int fg_off;
576 	int dg_size;
577 	u16 datagram_label;
578 	int retval;
579 	u16 ether_type;
580 
581 	if (len <= RFC2374_UNFRAG_HDR_SIZE)
582 		return 0;
583 
584 	hdr.w0 = be32_to_cpu(buf[0]);
585 	lf = fwnet_get_hdr_lf(&hdr);
586 	if (lf == RFC2374_HDR_UNFRAG) {
587 		/*
588 		 * An unfragmented datagram has been received by the ieee1394
589 		 * bus. Build an skbuff around it so we can pass it to the
590 		 * high level network layer.
591 		 */
592 		ether_type = fwnet_get_hdr_ether_type(&hdr);
593 		buf++;
594 		len -= RFC2374_UNFRAG_HDR_SIZE;
595 
596 		skb = dev_alloc_skb(len + LL_RESERVED_SPACE(net));
597 		if (unlikely(!skb)) {
598 			net->stats.rx_dropped++;
599 
600 			return -ENOMEM;
601 		}
602 		skb_reserve(skb, LL_RESERVED_SPACE(net));
603 		memcpy(skb_put(skb, len), buf, len);
604 
605 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
606 						    is_broadcast, ether_type);
607 	}
608 
609 	/* A datagram fragment has been received, now the fun begins. */
610 
611 	if (len <= RFC2374_FRAG_HDR_SIZE)
612 		return 0;
613 
614 	hdr.w1 = ntohl(buf[1]);
615 	buf += 2;
616 	len -= RFC2374_FRAG_HDR_SIZE;
617 	if (lf == RFC2374_HDR_FIRSTFRAG) {
618 		ether_type = fwnet_get_hdr_ether_type(&hdr);
619 		fg_off = 0;
620 	} else {
621 		ether_type = 0;
622 		fg_off = fwnet_get_hdr_fg_off(&hdr);
623 	}
624 	datagram_label = fwnet_get_hdr_dgl(&hdr);
625 	dg_size = fwnet_get_hdr_dg_size(&hdr);
626 
627 	if (fg_off + len > dg_size)
628 		return 0;
629 
630 	spin_lock_irqsave(&dev->lock, flags);
631 
632 	peer = fwnet_peer_find_by_node_id(dev, source_node_id, generation);
633 	if (!peer) {
634 		retval = -ENOENT;
635 		goto fail;
636 	}
637 
638 	pd = fwnet_pd_find(peer, datagram_label);
639 	if (pd == NULL) {
640 		while (peer->pdg_size >= FWNET_MAX_FRAGMENTS) {
641 			/* remove the oldest */
642 			fwnet_pd_delete(list_first_entry(&peer->pd_list,
643 				struct fwnet_partial_datagram, pd_link));
644 			peer->pdg_size--;
645 		}
646 		pd = fwnet_pd_new(net, peer, datagram_label,
647 				  dg_size, buf, fg_off, len);
648 		if (pd == NULL) {
649 			retval = -ENOMEM;
650 			goto fail;
651 		}
652 		peer->pdg_size++;
653 	} else {
654 		if (fwnet_frag_overlap(pd, fg_off, len) ||
655 		    pd->datagram_size != dg_size) {
656 			/*
657 			 * Differing datagram sizes or overlapping fragments,
658 			 * discard old datagram and start a new one.
659 			 */
660 			fwnet_pd_delete(pd);
661 			pd = fwnet_pd_new(net, peer, datagram_label,
662 					  dg_size, buf, fg_off, len);
663 			if (pd == NULL) {
664 				peer->pdg_size--;
665 				retval = -ENOMEM;
666 				goto fail;
667 			}
668 		} else {
669 			if (!fwnet_pd_update(peer, pd, buf, fg_off, len)) {
670 				/*
671 				 * Couldn't save off fragment anyway
672 				 * so might as well obliterate the
673 				 * datagram now.
674 				 */
675 				fwnet_pd_delete(pd);
676 				peer->pdg_size--;
677 				retval = -ENOMEM;
678 				goto fail;
679 			}
680 		}
681 	} /* new datagram or add to existing one */
682 
683 	if (lf == RFC2374_HDR_FIRSTFRAG)
684 		pd->ether_type = ether_type;
685 
686 	if (fwnet_pd_is_complete(pd)) {
687 		ether_type = pd->ether_type;
688 		peer->pdg_size--;
689 		skb = skb_get(pd->skb);
690 		fwnet_pd_delete(pd);
691 
692 		spin_unlock_irqrestore(&dev->lock, flags);
693 
694 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
695 						    false, ether_type);
696 	}
697 	/*
698 	 * Datagram is not complete, we're done for the
699 	 * moment.
700 	 */
701 	retval = 0;
702  fail:
703 	spin_unlock_irqrestore(&dev->lock, flags);
704 
705 	return retval;
706 }
707 
708 static void fwnet_receive_packet(struct fw_card *card, struct fw_request *r,
709 		int tcode, int destination, int source, int generation,
710 		unsigned long long offset, void *payload, size_t length,
711 		void *callback_data)
712 {
713 	struct fwnet_device *dev = callback_data;
714 	int rcode;
715 
716 	if (destination == IEEE1394_ALL_NODES) {
717 		kfree(r);
718 
719 		return;
720 	}
721 
722 	if (offset != dev->handler.offset)
723 		rcode = RCODE_ADDRESS_ERROR;
724 	else if (tcode != TCODE_WRITE_BLOCK_REQUEST)
725 		rcode = RCODE_TYPE_ERROR;
726 	else if (fwnet_incoming_packet(dev, payload, length,
727 				       source, generation, false) != 0) {
728 		dev_err(&dev->netdev->dev, "incoming packet failure\n");
729 		rcode = RCODE_CONFLICT_ERROR;
730 	} else
731 		rcode = RCODE_COMPLETE;
732 
733 	fw_send_response(card, r, rcode);
734 }
735 
736 static int gasp_source_id(__be32 *p)
737 {
738 	return be32_to_cpu(p[0]) >> 16;
739 }
740 
741 static u32 gasp_specifier_id(__be32 *p)
742 {
743 	return (be32_to_cpu(p[0]) & 0xffff) << 8 |
744 	       (be32_to_cpu(p[1]) & 0xff000000) >> 24;
745 }
746 
747 static u32 gasp_version(__be32 *p)
748 {
749 	return be32_to_cpu(p[1]) & 0xffffff;
750 }
751 
752 static void fwnet_receive_broadcast(struct fw_iso_context *context,
753 		u32 cycle, size_t header_length, void *header, void *data)
754 {
755 	struct fwnet_device *dev;
756 	struct fw_iso_packet packet;
757 	__be16 *hdr_ptr;
758 	__be32 *buf_ptr;
759 	int retval;
760 	u32 length;
761 	unsigned long offset;
762 	unsigned long flags;
763 
764 	dev = data;
765 	hdr_ptr = header;
766 	length = be16_to_cpup(hdr_ptr);
767 
768 	spin_lock_irqsave(&dev->lock, flags);
769 
770 	offset = dev->rcv_buffer_size * dev->broadcast_rcv_next_ptr;
771 	buf_ptr = dev->broadcast_rcv_buffer_ptrs[dev->broadcast_rcv_next_ptr++];
772 	if (dev->broadcast_rcv_next_ptr == dev->num_broadcast_rcv_ptrs)
773 		dev->broadcast_rcv_next_ptr = 0;
774 
775 	spin_unlock_irqrestore(&dev->lock, flags);
776 
777 	if (length > IEEE1394_GASP_HDR_SIZE &&
778 	    gasp_specifier_id(buf_ptr) == IANA_SPECIFIER_ID &&
779 	    (gasp_version(buf_ptr) == RFC2734_SW_VERSION
780 #if IS_ENABLED(CONFIG_IPV6)
781 	     || gasp_version(buf_ptr) == RFC3146_SW_VERSION
782 #endif
783 	    ))
784 		fwnet_incoming_packet(dev, buf_ptr + 2,
785 				      length - IEEE1394_GASP_HDR_SIZE,
786 				      gasp_source_id(buf_ptr),
787 				      context->card->generation, true);
788 
789 	packet.payload_length = dev->rcv_buffer_size;
790 	packet.interrupt = 1;
791 	packet.skip = 0;
792 	packet.tag = 3;
793 	packet.sy = 0;
794 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
795 
796 	spin_lock_irqsave(&dev->lock, flags);
797 
798 	retval = fw_iso_context_queue(dev->broadcast_rcv_context, &packet,
799 				      &dev->broadcast_rcv_buffer, offset);
800 
801 	spin_unlock_irqrestore(&dev->lock, flags);
802 
803 	if (retval >= 0)
804 		fw_iso_context_queue_flush(dev->broadcast_rcv_context);
805 	else
806 		dev_err(&dev->netdev->dev, "requeue failed\n");
807 }
808 
809 static struct kmem_cache *fwnet_packet_task_cache;
810 
811 static void fwnet_free_ptask(struct fwnet_packet_task *ptask)
812 {
813 	dev_kfree_skb_any(ptask->skb);
814 	kmem_cache_free(fwnet_packet_task_cache, ptask);
815 }
816 
817 /* Caller must hold dev->lock. */
818 static void dec_queued_datagrams(struct fwnet_device *dev)
819 {
820 	if (--dev->queued_datagrams == FWNET_MIN_QUEUED_DATAGRAMS)
821 		netif_wake_queue(dev->netdev);
822 }
823 
824 static int fwnet_send_packet(struct fwnet_packet_task *ptask);
825 
826 static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
827 {
828 	struct fwnet_device *dev = ptask->dev;
829 	struct sk_buff *skb = ptask->skb;
830 	unsigned long flags;
831 	bool free;
832 
833 	spin_lock_irqsave(&dev->lock, flags);
834 
835 	ptask->outstanding_pkts--;
836 
837 	/* Check whether we or the networking TX soft-IRQ is last user. */
838 	free = (ptask->outstanding_pkts == 0 && ptask->enqueued);
839 	if (free)
840 		dec_queued_datagrams(dev);
841 
842 	if (ptask->outstanding_pkts == 0) {
843 		dev->netdev->stats.tx_packets++;
844 		dev->netdev->stats.tx_bytes += skb->len;
845 	}
846 
847 	spin_unlock_irqrestore(&dev->lock, flags);
848 
849 	if (ptask->outstanding_pkts > 0) {
850 		u16 dg_size;
851 		u16 fg_off;
852 		u16 datagram_label;
853 		u16 lf;
854 
855 		/* Update the ptask to point to the next fragment and send it */
856 		lf = fwnet_get_hdr_lf(&ptask->hdr);
857 		switch (lf) {
858 		case RFC2374_HDR_LASTFRAG:
859 		case RFC2374_HDR_UNFRAG:
860 		default:
861 			dev_err(&dev->netdev->dev,
862 				"outstanding packet %x lf %x, header %x,%x\n",
863 				ptask->outstanding_pkts, lf, ptask->hdr.w0,
864 				ptask->hdr.w1);
865 			BUG();
866 
867 		case RFC2374_HDR_FIRSTFRAG:
868 			/* Set frag type here for future interior fragments */
869 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
870 			fg_off = ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
871 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
872 			break;
873 
874 		case RFC2374_HDR_INTFRAG:
875 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
876 			fg_off = fwnet_get_hdr_fg_off(&ptask->hdr)
877 				  + ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
878 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
879 			break;
880 		}
881 
882 		if (ptask->dest_node == IEEE1394_ALL_NODES) {
883 			skb_pull(skb,
884 				 ptask->max_payload + IEEE1394_GASP_HDR_SIZE);
885 		} else {
886 			skb_pull(skb, ptask->max_payload);
887 		}
888 		if (ptask->outstanding_pkts > 1) {
889 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_INTFRAG,
890 					  dg_size, fg_off, datagram_label);
891 		} else {
892 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_LASTFRAG,
893 					  dg_size, fg_off, datagram_label);
894 			ptask->max_payload = skb->len + RFC2374_FRAG_HDR_SIZE;
895 		}
896 		fwnet_send_packet(ptask);
897 	}
898 
899 	if (free)
900 		fwnet_free_ptask(ptask);
901 }
902 
903 static void fwnet_transmit_packet_failed(struct fwnet_packet_task *ptask)
904 {
905 	struct fwnet_device *dev = ptask->dev;
906 	unsigned long flags;
907 	bool free;
908 
909 	spin_lock_irqsave(&dev->lock, flags);
910 
911 	/* One fragment failed; don't try to send remaining fragments. */
912 	ptask->outstanding_pkts = 0;
913 
914 	/* Check whether we or the networking TX soft-IRQ is last user. */
915 	free = ptask->enqueued;
916 	if (free)
917 		dec_queued_datagrams(dev);
918 
919 	dev->netdev->stats.tx_dropped++;
920 	dev->netdev->stats.tx_errors++;
921 
922 	spin_unlock_irqrestore(&dev->lock, flags);
923 
924 	if (free)
925 		fwnet_free_ptask(ptask);
926 }
927 
928 static void fwnet_write_complete(struct fw_card *card, int rcode,
929 				 void *payload, size_t length, void *data)
930 {
931 	struct fwnet_packet_task *ptask = data;
932 	static unsigned long j;
933 	static int last_rcode, errors_skipped;
934 
935 	if (rcode == RCODE_COMPLETE) {
936 		fwnet_transmit_packet_done(ptask);
937 	} else {
938 		if (printk_timed_ratelimit(&j,  1000) || rcode != last_rcode) {
939 			dev_err(&ptask->dev->netdev->dev,
940 				"fwnet_write_complete failed: %x (skipped %d)\n",
941 				rcode, errors_skipped);
942 
943 			errors_skipped = 0;
944 			last_rcode = rcode;
945 		} else {
946 			errors_skipped++;
947 		}
948 		fwnet_transmit_packet_failed(ptask);
949 	}
950 }
951 
952 static int fwnet_send_packet(struct fwnet_packet_task *ptask)
953 {
954 	struct fwnet_device *dev;
955 	unsigned tx_len;
956 	struct rfc2734_header *bufhdr;
957 	unsigned long flags;
958 	bool free;
959 
960 	dev = ptask->dev;
961 	tx_len = ptask->max_payload;
962 	switch (fwnet_get_hdr_lf(&ptask->hdr)) {
963 	case RFC2374_HDR_UNFRAG:
964 		bufhdr = (struct rfc2734_header *)
965 				skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
966 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
967 		break;
968 
969 	case RFC2374_HDR_FIRSTFRAG:
970 	case RFC2374_HDR_INTFRAG:
971 	case RFC2374_HDR_LASTFRAG:
972 		bufhdr = (struct rfc2734_header *)
973 				skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
974 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
975 		put_unaligned_be32(ptask->hdr.w1, &bufhdr->w1);
976 		break;
977 
978 	default:
979 		BUG();
980 	}
981 	if (ptask->dest_node == IEEE1394_ALL_NODES) {
982 		u8 *p;
983 		int generation;
984 		int node_id;
985 		unsigned int sw_version;
986 
987 		/* ptask->generation may not have been set yet */
988 		generation = dev->card->generation;
989 		smp_rmb();
990 		node_id = dev->card->node_id;
991 
992 		switch (ptask->skb->protocol) {
993 		default:
994 			sw_version = RFC2734_SW_VERSION;
995 			break;
996 #if IS_ENABLED(CONFIG_IPV6)
997 		case htons(ETH_P_IPV6):
998 			sw_version = RFC3146_SW_VERSION;
999 #endif
1000 		}
1001 
1002 		p = skb_push(ptask->skb, IEEE1394_GASP_HDR_SIZE);
1003 		put_unaligned_be32(node_id << 16 | IANA_SPECIFIER_ID >> 8, p);
1004 		put_unaligned_be32((IANA_SPECIFIER_ID & 0xff) << 24
1005 						| sw_version, &p[4]);
1006 
1007 		/* We should not transmit if broadcast_channel.valid == 0. */
1008 		fw_send_request(dev->card, &ptask->transaction,
1009 				TCODE_STREAM_DATA,
1010 				fw_stream_packet_destination_id(3,
1011 						IEEE1394_BROADCAST_CHANNEL, 0),
1012 				generation, SCODE_100, 0ULL, ptask->skb->data,
1013 				tx_len + 8, fwnet_write_complete, ptask);
1014 
1015 		spin_lock_irqsave(&dev->lock, flags);
1016 
1017 		/* If the AT tasklet already ran, we may be last user. */
1018 		free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1019 		if (!free)
1020 			ptask->enqueued = true;
1021 		else
1022 			dec_queued_datagrams(dev);
1023 
1024 		spin_unlock_irqrestore(&dev->lock, flags);
1025 
1026 		goto out;
1027 	}
1028 
1029 	fw_send_request(dev->card, &ptask->transaction,
1030 			TCODE_WRITE_BLOCK_REQUEST, ptask->dest_node,
1031 			ptask->generation, ptask->speed, ptask->fifo_addr,
1032 			ptask->skb->data, tx_len, fwnet_write_complete, ptask);
1033 
1034 	spin_lock_irqsave(&dev->lock, flags);
1035 
1036 	/* If the AT tasklet already ran, we may be last user. */
1037 	free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1038 	if (!free)
1039 		ptask->enqueued = true;
1040 	else
1041 		dec_queued_datagrams(dev);
1042 
1043 	spin_unlock_irqrestore(&dev->lock, flags);
1044 
1045 	netif_trans_update(dev->netdev);
1046  out:
1047 	if (free)
1048 		fwnet_free_ptask(ptask);
1049 
1050 	return 0;
1051 }
1052 
1053 static void fwnet_fifo_stop(struct fwnet_device *dev)
1054 {
1055 	if (dev->local_fifo == FWNET_NO_FIFO_ADDR)
1056 		return;
1057 
1058 	fw_core_remove_address_handler(&dev->handler);
1059 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1060 }
1061 
1062 static int fwnet_fifo_start(struct fwnet_device *dev)
1063 {
1064 	int retval;
1065 
1066 	if (dev->local_fifo != FWNET_NO_FIFO_ADDR)
1067 		return 0;
1068 
1069 	dev->handler.length = 4096;
1070 	dev->handler.address_callback = fwnet_receive_packet;
1071 	dev->handler.callback_data = dev;
1072 
1073 	retval = fw_core_add_address_handler(&dev->handler,
1074 					     &fw_high_memory_region);
1075 	if (retval < 0)
1076 		return retval;
1077 
1078 	dev->local_fifo = dev->handler.offset;
1079 
1080 	return 0;
1081 }
1082 
1083 static void __fwnet_broadcast_stop(struct fwnet_device *dev)
1084 {
1085 	unsigned u;
1086 
1087 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR) {
1088 		for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++)
1089 			kunmap(dev->broadcast_rcv_buffer.pages[u]);
1090 		fw_iso_buffer_destroy(&dev->broadcast_rcv_buffer, dev->card);
1091 	}
1092 	if (dev->broadcast_rcv_context) {
1093 		fw_iso_context_destroy(dev->broadcast_rcv_context);
1094 		dev->broadcast_rcv_context = NULL;
1095 	}
1096 	kfree(dev->broadcast_rcv_buffer_ptrs);
1097 	dev->broadcast_rcv_buffer_ptrs = NULL;
1098 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1099 }
1100 
1101 static void fwnet_broadcast_stop(struct fwnet_device *dev)
1102 {
1103 	if (dev->broadcast_state == FWNET_BROADCAST_ERROR)
1104 		return;
1105 	fw_iso_context_stop(dev->broadcast_rcv_context);
1106 	__fwnet_broadcast_stop(dev);
1107 }
1108 
1109 static int fwnet_broadcast_start(struct fwnet_device *dev)
1110 {
1111 	struct fw_iso_context *context;
1112 	int retval;
1113 	unsigned num_packets;
1114 	unsigned max_receive;
1115 	struct fw_iso_packet packet;
1116 	unsigned long offset;
1117 	void **ptrptr;
1118 	unsigned u;
1119 
1120 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR)
1121 		return 0;
1122 
1123 	max_receive = 1U << (dev->card->max_receive + 1);
1124 	num_packets = (FWNET_ISO_PAGE_COUNT * PAGE_SIZE) / max_receive;
1125 
1126 	ptrptr = kmalloc(sizeof(void *) * num_packets, GFP_KERNEL);
1127 	if (!ptrptr) {
1128 		retval = -ENOMEM;
1129 		goto failed;
1130 	}
1131 	dev->broadcast_rcv_buffer_ptrs = ptrptr;
1132 
1133 	context = fw_iso_context_create(dev->card, FW_ISO_CONTEXT_RECEIVE,
1134 					IEEE1394_BROADCAST_CHANNEL,
1135 					dev->card->link_speed, 8,
1136 					fwnet_receive_broadcast, dev);
1137 	if (IS_ERR(context)) {
1138 		retval = PTR_ERR(context);
1139 		goto failed;
1140 	}
1141 
1142 	retval = fw_iso_buffer_init(&dev->broadcast_rcv_buffer, dev->card,
1143 				    FWNET_ISO_PAGE_COUNT, DMA_FROM_DEVICE);
1144 	if (retval < 0)
1145 		goto failed;
1146 
1147 	dev->broadcast_state = FWNET_BROADCAST_STOPPED;
1148 
1149 	for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++) {
1150 		void *ptr;
1151 		unsigned v;
1152 
1153 		ptr = kmap(dev->broadcast_rcv_buffer.pages[u]);
1154 		for (v = 0; v < num_packets / FWNET_ISO_PAGE_COUNT; v++)
1155 			*ptrptr++ = (void *) ((char *)ptr + v * max_receive);
1156 	}
1157 	dev->broadcast_rcv_context = context;
1158 
1159 	packet.payload_length = max_receive;
1160 	packet.interrupt = 1;
1161 	packet.skip = 0;
1162 	packet.tag = 3;
1163 	packet.sy = 0;
1164 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
1165 	offset = 0;
1166 
1167 	for (u = 0; u < num_packets; u++) {
1168 		retval = fw_iso_context_queue(context, &packet,
1169 				&dev->broadcast_rcv_buffer, offset);
1170 		if (retval < 0)
1171 			goto failed;
1172 
1173 		offset += max_receive;
1174 	}
1175 	dev->num_broadcast_rcv_ptrs = num_packets;
1176 	dev->rcv_buffer_size = max_receive;
1177 	dev->broadcast_rcv_next_ptr = 0U;
1178 	retval = fw_iso_context_start(context, -1, 0,
1179 			FW_ISO_CONTEXT_MATCH_ALL_TAGS); /* ??? sync */
1180 	if (retval < 0)
1181 		goto failed;
1182 
1183 	/* FIXME: adjust it according to the min. speed of all known peers? */
1184 	dev->broadcast_xmt_max_payload = IEEE1394_MAX_PAYLOAD_S100
1185 			- IEEE1394_GASP_HDR_SIZE - RFC2374_UNFRAG_HDR_SIZE;
1186 	dev->broadcast_state = FWNET_BROADCAST_RUNNING;
1187 
1188 	return 0;
1189 
1190  failed:
1191 	__fwnet_broadcast_stop(dev);
1192 	return retval;
1193 }
1194 
1195 static void set_carrier_state(struct fwnet_device *dev)
1196 {
1197 	if (dev->peer_count > 1)
1198 		netif_carrier_on(dev->netdev);
1199 	else
1200 		netif_carrier_off(dev->netdev);
1201 }
1202 
1203 /* ifup */
1204 static int fwnet_open(struct net_device *net)
1205 {
1206 	struct fwnet_device *dev = netdev_priv(net);
1207 	int ret;
1208 
1209 	ret = fwnet_broadcast_start(dev);
1210 	if (ret)
1211 		return ret;
1212 
1213 	netif_start_queue(net);
1214 
1215 	spin_lock_irq(&dev->lock);
1216 	set_carrier_state(dev);
1217 	spin_unlock_irq(&dev->lock);
1218 
1219 	return 0;
1220 }
1221 
1222 /* ifdown */
1223 static int fwnet_stop(struct net_device *net)
1224 {
1225 	struct fwnet_device *dev = netdev_priv(net);
1226 
1227 	netif_stop_queue(net);
1228 	fwnet_broadcast_stop(dev);
1229 
1230 	return 0;
1231 }
1232 
1233 static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
1234 {
1235 	struct fwnet_header hdr_buf;
1236 	struct fwnet_device *dev = netdev_priv(net);
1237 	__be16 proto;
1238 	u16 dest_node;
1239 	unsigned max_payload;
1240 	u16 dg_size;
1241 	u16 *datagram_label_ptr;
1242 	struct fwnet_packet_task *ptask;
1243 	struct fwnet_peer *peer;
1244 	unsigned long flags;
1245 
1246 	spin_lock_irqsave(&dev->lock, flags);
1247 
1248 	/* Can this happen? */
1249 	if (netif_queue_stopped(dev->netdev)) {
1250 		spin_unlock_irqrestore(&dev->lock, flags);
1251 
1252 		return NETDEV_TX_BUSY;
1253 	}
1254 
1255 	ptask = kmem_cache_alloc(fwnet_packet_task_cache, GFP_ATOMIC);
1256 	if (ptask == NULL)
1257 		goto fail;
1258 
1259 	skb = skb_share_check(skb, GFP_ATOMIC);
1260 	if (!skb)
1261 		goto fail;
1262 
1263 	/*
1264 	 * Make a copy of the driver-specific header.
1265 	 * We might need to rebuild the header on tx failure.
1266 	 */
1267 	memcpy(&hdr_buf, skb->data, sizeof(hdr_buf));
1268 	proto = hdr_buf.h_proto;
1269 
1270 	switch (proto) {
1271 	case htons(ETH_P_ARP):
1272 	case htons(ETH_P_IP):
1273 #if IS_ENABLED(CONFIG_IPV6)
1274 	case htons(ETH_P_IPV6):
1275 #endif
1276 		break;
1277 	default:
1278 		goto fail;
1279 	}
1280 
1281 	skb_pull(skb, sizeof(hdr_buf));
1282 	dg_size = skb->len;
1283 
1284 	/*
1285 	 * Set the transmission type for the packet.  ARP packets and IP
1286 	 * broadcast packets are sent via GASP.
1287 	 */
1288 	if (fwnet_hwaddr_is_multicast(hdr_buf.h_dest)) {
1289 		max_payload        = dev->broadcast_xmt_max_payload;
1290 		datagram_label_ptr = &dev->broadcast_xmt_datagramlabel;
1291 
1292 		ptask->fifo_addr   = FWNET_NO_FIFO_ADDR;
1293 		ptask->generation  = 0;
1294 		ptask->dest_node   = IEEE1394_ALL_NODES;
1295 		ptask->speed       = SCODE_100;
1296 	} else {
1297 		union fwnet_hwaddr *ha = (union fwnet_hwaddr *)hdr_buf.h_dest;
1298 		__be64 guid = get_unaligned(&ha->uc.uniq_id);
1299 		u8 generation;
1300 
1301 		peer = fwnet_peer_find_by_guid(dev, be64_to_cpu(guid));
1302 		if (!peer)
1303 			goto fail;
1304 
1305 		generation         = peer->generation;
1306 		dest_node          = peer->node_id;
1307 		max_payload        = peer->max_payload;
1308 		datagram_label_ptr = &peer->datagram_label;
1309 
1310 		ptask->fifo_addr   = fwnet_hwaddr_fifo(ha);
1311 		ptask->generation  = generation;
1312 		ptask->dest_node   = dest_node;
1313 		ptask->speed       = peer->speed;
1314 	}
1315 
1316 	ptask->hdr.w0 = 0;
1317 	ptask->hdr.w1 = 0;
1318 	ptask->skb = skb;
1319 	ptask->dev = dev;
1320 
1321 	/* Does it all fit in one packet? */
1322 	if (dg_size <= max_payload) {
1323 		fwnet_make_uf_hdr(&ptask->hdr, ntohs(proto));
1324 		ptask->outstanding_pkts = 1;
1325 		max_payload = dg_size + RFC2374_UNFRAG_HDR_SIZE;
1326 	} else {
1327 		u16 datagram_label;
1328 
1329 		max_payload -= RFC2374_FRAG_OVERHEAD;
1330 		datagram_label = (*datagram_label_ptr)++;
1331 		fwnet_make_ff_hdr(&ptask->hdr, ntohs(proto), dg_size,
1332 				  datagram_label);
1333 		ptask->outstanding_pkts = DIV_ROUND_UP(dg_size, max_payload);
1334 		max_payload += RFC2374_FRAG_HDR_SIZE;
1335 	}
1336 
1337 	if (++dev->queued_datagrams == FWNET_MAX_QUEUED_DATAGRAMS)
1338 		netif_stop_queue(dev->netdev);
1339 
1340 	spin_unlock_irqrestore(&dev->lock, flags);
1341 
1342 	ptask->max_payload = max_payload;
1343 	ptask->enqueued    = 0;
1344 
1345 	fwnet_send_packet(ptask);
1346 
1347 	return NETDEV_TX_OK;
1348 
1349  fail:
1350 	spin_unlock_irqrestore(&dev->lock, flags);
1351 
1352 	if (ptask)
1353 		kmem_cache_free(fwnet_packet_task_cache, ptask);
1354 
1355 	if (skb != NULL)
1356 		dev_kfree_skb(skb);
1357 
1358 	net->stats.tx_dropped++;
1359 	net->stats.tx_errors++;
1360 
1361 	/*
1362 	 * FIXME: According to a patch from 2003-02-26, "returning non-zero
1363 	 * causes serious problems" here, allegedly.  Before that patch,
1364 	 * -ERRNO was returned which is not appropriate under Linux 2.6.
1365 	 * Perhaps more needs to be done?  Stop the queue in serious
1366 	 * conditions and restart it elsewhere?
1367 	 */
1368 	return NETDEV_TX_OK;
1369 }
1370 
1371 static int fwnet_change_mtu(struct net_device *net, int new_mtu)
1372 {
1373 	if (new_mtu < 68)
1374 		return -EINVAL;
1375 
1376 	net->mtu = new_mtu;
1377 	return 0;
1378 }
1379 
1380 static const struct ethtool_ops fwnet_ethtool_ops = {
1381 	.get_link	= ethtool_op_get_link,
1382 };
1383 
1384 static const struct net_device_ops fwnet_netdev_ops = {
1385 	.ndo_open       = fwnet_open,
1386 	.ndo_stop	= fwnet_stop,
1387 	.ndo_start_xmit = fwnet_tx,
1388 	.ndo_change_mtu = fwnet_change_mtu,
1389 };
1390 
1391 static void fwnet_init_dev(struct net_device *net)
1392 {
1393 	net->header_ops		= &fwnet_header_ops;
1394 	net->netdev_ops		= &fwnet_netdev_ops;
1395 	net->watchdog_timeo	= 2 * HZ;
1396 	net->flags		= IFF_BROADCAST | IFF_MULTICAST;
1397 	net->features		= NETIF_F_HIGHDMA;
1398 	net->addr_len		= FWNET_ALEN;
1399 	net->hard_header_len	= FWNET_HLEN;
1400 	net->type		= ARPHRD_IEEE1394;
1401 	net->tx_queue_len	= FWNET_TX_QUEUE_LEN;
1402 	net->ethtool_ops	= &fwnet_ethtool_ops;
1403 }
1404 
1405 /* caller must hold fwnet_device_mutex */
1406 static struct fwnet_device *fwnet_dev_find(struct fw_card *card)
1407 {
1408 	struct fwnet_device *dev;
1409 
1410 	list_for_each_entry(dev, &fwnet_device_list, dev_link)
1411 		if (dev->card == card)
1412 			return dev;
1413 
1414 	return NULL;
1415 }
1416 
1417 static int fwnet_add_peer(struct fwnet_device *dev,
1418 			  struct fw_unit *unit, struct fw_device *device)
1419 {
1420 	struct fwnet_peer *peer;
1421 
1422 	peer = kmalloc(sizeof(*peer), GFP_KERNEL);
1423 	if (!peer)
1424 		return -ENOMEM;
1425 
1426 	dev_set_drvdata(&unit->device, peer);
1427 
1428 	peer->dev = dev;
1429 	peer->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1430 	INIT_LIST_HEAD(&peer->pd_list);
1431 	peer->pdg_size = 0;
1432 	peer->datagram_label = 0;
1433 	peer->speed = device->max_speed;
1434 	peer->max_payload = fwnet_max_payload(device->max_rec, peer->speed);
1435 
1436 	peer->generation = device->generation;
1437 	smp_rmb();
1438 	peer->node_id = device->node_id;
1439 
1440 	spin_lock_irq(&dev->lock);
1441 	list_add_tail(&peer->peer_link, &dev->peer_list);
1442 	dev->peer_count++;
1443 	set_carrier_state(dev);
1444 	spin_unlock_irq(&dev->lock);
1445 
1446 	return 0;
1447 }
1448 
1449 static int fwnet_probe(struct fw_unit *unit,
1450 		       const struct ieee1394_device_id *id)
1451 {
1452 	struct fw_device *device = fw_parent_device(unit);
1453 	struct fw_card *card = device->card;
1454 	struct net_device *net;
1455 	bool allocated_netdev = false;
1456 	struct fwnet_device *dev;
1457 	unsigned max_mtu;
1458 	int ret;
1459 	union fwnet_hwaddr *ha;
1460 
1461 	mutex_lock(&fwnet_device_mutex);
1462 
1463 	dev = fwnet_dev_find(card);
1464 	if (dev) {
1465 		net = dev->netdev;
1466 		goto have_dev;
1467 	}
1468 
1469 	net = alloc_netdev(sizeof(*dev), "firewire%d", NET_NAME_UNKNOWN,
1470 			   fwnet_init_dev);
1471 	if (net == NULL) {
1472 		mutex_unlock(&fwnet_device_mutex);
1473 		return -ENOMEM;
1474 	}
1475 
1476 	allocated_netdev = true;
1477 	SET_NETDEV_DEV(net, card->device);
1478 	dev = netdev_priv(net);
1479 
1480 	spin_lock_init(&dev->lock);
1481 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1482 	dev->broadcast_rcv_context = NULL;
1483 	dev->broadcast_xmt_max_payload = 0;
1484 	dev->broadcast_xmt_datagramlabel = 0;
1485 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1486 	dev->queued_datagrams = 0;
1487 	INIT_LIST_HEAD(&dev->peer_list);
1488 	dev->card = card;
1489 	dev->netdev = net;
1490 
1491 	ret = fwnet_fifo_start(dev);
1492 	if (ret < 0)
1493 		goto out;
1494 	dev->local_fifo = dev->handler.offset;
1495 
1496 	/*
1497 	 * Use the RFC 2734 default 1500 octets or the maximum payload
1498 	 * as initial MTU
1499 	 */
1500 	max_mtu = (1 << (card->max_receive + 1))
1501 		  - sizeof(struct rfc2734_header) - IEEE1394_GASP_HDR_SIZE;
1502 	net->mtu = min(1500U, max_mtu);
1503 
1504 	/* Set our hardware address while we're at it */
1505 	ha = (union fwnet_hwaddr *)net->dev_addr;
1506 	put_unaligned_be64(card->guid, &ha->uc.uniq_id);
1507 	ha->uc.max_rec = dev->card->max_receive;
1508 	ha->uc.sspd = dev->card->link_speed;
1509 	put_unaligned_be16(dev->local_fifo >> 32, &ha->uc.fifo_hi);
1510 	put_unaligned_be32(dev->local_fifo & 0xffffffff, &ha->uc.fifo_lo);
1511 
1512 	memset(net->broadcast, -1, net->addr_len);
1513 
1514 	ret = register_netdev(net);
1515 	if (ret)
1516 		goto out;
1517 
1518 	list_add_tail(&dev->dev_link, &fwnet_device_list);
1519 	dev_notice(&net->dev, "IP over IEEE 1394 on card %s\n",
1520 		   dev_name(card->device));
1521  have_dev:
1522 	ret = fwnet_add_peer(dev, unit, device);
1523 	if (ret && allocated_netdev) {
1524 		unregister_netdev(net);
1525 		list_del(&dev->dev_link);
1526  out:
1527 		fwnet_fifo_stop(dev);
1528 		free_netdev(net);
1529 	}
1530 
1531 	mutex_unlock(&fwnet_device_mutex);
1532 
1533 	return ret;
1534 }
1535 
1536 /*
1537  * FIXME abort partially sent fragmented datagrams,
1538  * discard partially received fragmented datagrams
1539  */
1540 static void fwnet_update(struct fw_unit *unit)
1541 {
1542 	struct fw_device *device = fw_parent_device(unit);
1543 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1544 	int generation;
1545 
1546 	generation = device->generation;
1547 
1548 	spin_lock_irq(&peer->dev->lock);
1549 	peer->node_id    = device->node_id;
1550 	peer->generation = generation;
1551 	spin_unlock_irq(&peer->dev->lock);
1552 }
1553 
1554 static void fwnet_remove_peer(struct fwnet_peer *peer, struct fwnet_device *dev)
1555 {
1556 	struct fwnet_partial_datagram *pd, *pd_next;
1557 
1558 	spin_lock_irq(&dev->lock);
1559 	list_del(&peer->peer_link);
1560 	dev->peer_count--;
1561 	set_carrier_state(dev);
1562 	spin_unlock_irq(&dev->lock);
1563 
1564 	list_for_each_entry_safe(pd, pd_next, &peer->pd_list, pd_link)
1565 		fwnet_pd_delete(pd);
1566 
1567 	kfree(peer);
1568 }
1569 
1570 static void fwnet_remove(struct fw_unit *unit)
1571 {
1572 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1573 	struct fwnet_device *dev = peer->dev;
1574 	struct net_device *net;
1575 	int i;
1576 
1577 	mutex_lock(&fwnet_device_mutex);
1578 
1579 	net = dev->netdev;
1580 
1581 	fwnet_remove_peer(peer, dev);
1582 
1583 	if (list_empty(&dev->peer_list)) {
1584 		unregister_netdev(net);
1585 
1586 		fwnet_fifo_stop(dev);
1587 
1588 		for (i = 0; dev->queued_datagrams && i < 5; i++)
1589 			ssleep(1);
1590 		WARN_ON(dev->queued_datagrams);
1591 		list_del(&dev->dev_link);
1592 
1593 		free_netdev(net);
1594 	}
1595 
1596 	mutex_unlock(&fwnet_device_mutex);
1597 }
1598 
1599 static const struct ieee1394_device_id fwnet_id_table[] = {
1600 	{
1601 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1602 				IEEE1394_MATCH_VERSION,
1603 		.specifier_id = IANA_SPECIFIER_ID,
1604 		.version      = RFC2734_SW_VERSION,
1605 	},
1606 #if IS_ENABLED(CONFIG_IPV6)
1607 	{
1608 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1609 				IEEE1394_MATCH_VERSION,
1610 		.specifier_id = IANA_SPECIFIER_ID,
1611 		.version      = RFC3146_SW_VERSION,
1612 	},
1613 #endif
1614 	{ }
1615 };
1616 
1617 static struct fw_driver fwnet_driver = {
1618 	.driver = {
1619 		.owner  = THIS_MODULE,
1620 		.name   = KBUILD_MODNAME,
1621 		.bus    = &fw_bus_type,
1622 	},
1623 	.probe    = fwnet_probe,
1624 	.update   = fwnet_update,
1625 	.remove   = fwnet_remove,
1626 	.id_table = fwnet_id_table,
1627 };
1628 
1629 static const u32 rfc2374_unit_directory_data[] = {
1630 	0x00040000,	/* directory_length		*/
1631 	0x1200005e,	/* unit_specifier_id: IANA	*/
1632 	0x81000003,	/* textual descriptor offset	*/
1633 	0x13000001,	/* unit_sw_version: RFC 2734	*/
1634 	0x81000005,	/* textual descriptor offset	*/
1635 	0x00030000,	/* descriptor_length		*/
1636 	0x00000000,	/* text				*/
1637 	0x00000000,	/* minimal ASCII, en		*/
1638 	0x49414e41,	/* I A N A			*/
1639 	0x00030000,	/* descriptor_length		*/
1640 	0x00000000,	/* text				*/
1641 	0x00000000,	/* minimal ASCII, en		*/
1642 	0x49507634,	/* I P v 4			*/
1643 };
1644 
1645 static struct fw_descriptor rfc2374_unit_directory = {
1646 	.length = ARRAY_SIZE(rfc2374_unit_directory_data),
1647 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1648 	.data   = rfc2374_unit_directory_data
1649 };
1650 
1651 #if IS_ENABLED(CONFIG_IPV6)
1652 static const u32 rfc3146_unit_directory_data[] = {
1653 	0x00040000,	/* directory_length		*/
1654 	0x1200005e,	/* unit_specifier_id: IANA	*/
1655 	0x81000003,	/* textual descriptor offset	*/
1656 	0x13000002,	/* unit_sw_version: RFC 3146	*/
1657 	0x81000005,	/* textual descriptor offset	*/
1658 	0x00030000,	/* descriptor_length		*/
1659 	0x00000000,	/* text				*/
1660 	0x00000000,	/* minimal ASCII, en		*/
1661 	0x49414e41,	/* I A N A			*/
1662 	0x00030000,	/* descriptor_length		*/
1663 	0x00000000,	/* text				*/
1664 	0x00000000,	/* minimal ASCII, en		*/
1665 	0x49507636,	/* I P v 6			*/
1666 };
1667 
1668 static struct fw_descriptor rfc3146_unit_directory = {
1669 	.length = ARRAY_SIZE(rfc3146_unit_directory_data),
1670 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1671 	.data   = rfc3146_unit_directory_data
1672 };
1673 #endif
1674 
1675 static int __init fwnet_init(void)
1676 {
1677 	int err;
1678 
1679 	err = fw_core_add_descriptor(&rfc2374_unit_directory);
1680 	if (err)
1681 		return err;
1682 
1683 #if IS_ENABLED(CONFIG_IPV6)
1684 	err = fw_core_add_descriptor(&rfc3146_unit_directory);
1685 	if (err)
1686 		goto out;
1687 #endif
1688 
1689 	fwnet_packet_task_cache = kmem_cache_create("packet_task",
1690 			sizeof(struct fwnet_packet_task), 0, 0, NULL);
1691 	if (!fwnet_packet_task_cache) {
1692 		err = -ENOMEM;
1693 		goto out2;
1694 	}
1695 
1696 	err = driver_register(&fwnet_driver.driver);
1697 	if (!err)
1698 		return 0;
1699 
1700 	kmem_cache_destroy(fwnet_packet_task_cache);
1701 out2:
1702 #if IS_ENABLED(CONFIG_IPV6)
1703 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1704 out:
1705 #endif
1706 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1707 
1708 	return err;
1709 }
1710 module_init(fwnet_init);
1711 
1712 static void __exit fwnet_cleanup(void)
1713 {
1714 	driver_unregister(&fwnet_driver.driver);
1715 	kmem_cache_destroy(fwnet_packet_task_cache);
1716 #if IS_ENABLED(CONFIG_IPV6)
1717 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1718 #endif
1719 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1720 }
1721 module_exit(fwnet_cleanup);
1722 
1723 MODULE_AUTHOR("Jay Fenlason <fenlason@redhat.com>");
1724 MODULE_DESCRIPTION("IP over IEEE1394 as per RFC 2734/3146");
1725 MODULE_LICENSE("GPL");
1726 MODULE_DEVICE_TABLE(ieee1394, fwnet_id_table);
1727