xref: /openbmc/linux/drivers/firewire/net.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IPv4 over IEEE 1394, per RFC 2734
4  * IPv6 over IEEE 1394, per RFC 3146
5  *
6  * Copyright (C) 2009 Jay Fenlason <fenlason@redhat.com>
7  *
8  * based on eth1394 by Ben Collins et al
9  */
10 
11 #include <linux/bug.h>
12 #include <linux/compiler.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/ethtool.h>
16 #include <linux/firewire.h>
17 #include <linux/firewire-constants.h>
18 #include <linux/highmem.h>
19 #include <linux/in.h>
20 #include <linux/ip.h>
21 #include <linux/jiffies.h>
22 #include <linux/mod_devicetable.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/mutex.h>
26 #include <linux/netdevice.h>
27 #include <linux/skbuff.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 
31 #include <asm/unaligned.h>
32 #include <net/arp.h>
33 #include <net/firewire.h>
34 
35 /* rx limits */
36 #define FWNET_MAX_FRAGMENTS		30 /* arbitrary, > TX queue depth */
37 #define FWNET_ISO_PAGE_COUNT		(PAGE_SIZE < 16*1024 ? 4 : 2)
38 
39 /* tx limits */
40 #define FWNET_MAX_QUEUED_DATAGRAMS	20 /* < 64 = number of tlabels */
41 #define FWNET_MIN_QUEUED_DATAGRAMS	10 /* should keep AT DMA busy enough */
42 #define FWNET_TX_QUEUE_LEN		FWNET_MAX_QUEUED_DATAGRAMS /* ? */
43 
44 #define IEEE1394_BROADCAST_CHANNEL	31
45 #define IEEE1394_ALL_NODES		(0xffc0 | 0x003f)
46 #define IEEE1394_MAX_PAYLOAD_S100	512
47 #define FWNET_NO_FIFO_ADDR		(~0ULL)
48 
49 #define IANA_SPECIFIER_ID		0x00005eU
50 #define RFC2734_SW_VERSION		0x000001U
51 #define RFC3146_SW_VERSION		0x000002U
52 
53 #define IEEE1394_GASP_HDR_SIZE	8
54 
55 #define RFC2374_UNFRAG_HDR_SIZE	4
56 #define RFC2374_FRAG_HDR_SIZE	8
57 #define RFC2374_FRAG_OVERHEAD	4
58 
59 #define RFC2374_HDR_UNFRAG	0	/* unfragmented		*/
60 #define RFC2374_HDR_FIRSTFRAG	1	/* first fragment	*/
61 #define RFC2374_HDR_LASTFRAG	2	/* last fragment	*/
62 #define RFC2374_HDR_INTFRAG	3	/* interior fragment	*/
63 
64 static bool fwnet_hwaddr_is_multicast(u8 *ha)
65 {
66 	return !!(*ha & 1);
67 }
68 
69 /* IPv4 and IPv6 encapsulation header */
70 struct rfc2734_header {
71 	u32 w0;
72 	u32 w1;
73 };
74 
75 #define fwnet_get_hdr_lf(h)		(((h)->w0 & 0xc0000000) >> 30)
76 #define fwnet_get_hdr_ether_type(h)	(((h)->w0 & 0x0000ffff))
77 #define fwnet_get_hdr_dg_size(h)	((((h)->w0 & 0x0fff0000) >> 16) + 1)
78 #define fwnet_get_hdr_fg_off(h)		(((h)->w0 & 0x00000fff))
79 #define fwnet_get_hdr_dgl(h)		(((h)->w1 & 0xffff0000) >> 16)
80 
81 #define fwnet_set_hdr_lf(lf)		((lf) << 30)
82 #define fwnet_set_hdr_ether_type(et)	(et)
83 #define fwnet_set_hdr_dg_size(dgs)	(((dgs) - 1) << 16)
84 #define fwnet_set_hdr_fg_off(fgo)	(fgo)
85 
86 #define fwnet_set_hdr_dgl(dgl)		((dgl) << 16)
87 
88 static inline void fwnet_make_uf_hdr(struct rfc2734_header *hdr,
89 		unsigned ether_type)
90 {
91 	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_UNFRAG)
92 		  | fwnet_set_hdr_ether_type(ether_type);
93 }
94 
95 static inline void fwnet_make_ff_hdr(struct rfc2734_header *hdr,
96 		unsigned ether_type, unsigned dg_size, unsigned dgl)
97 {
98 	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_FIRSTFRAG)
99 		  | fwnet_set_hdr_dg_size(dg_size)
100 		  | fwnet_set_hdr_ether_type(ether_type);
101 	hdr->w1 = fwnet_set_hdr_dgl(dgl);
102 }
103 
104 static inline void fwnet_make_sf_hdr(struct rfc2734_header *hdr,
105 		unsigned lf, unsigned dg_size, unsigned fg_off, unsigned dgl)
106 {
107 	hdr->w0 = fwnet_set_hdr_lf(lf)
108 		  | fwnet_set_hdr_dg_size(dg_size)
109 		  | fwnet_set_hdr_fg_off(fg_off);
110 	hdr->w1 = fwnet_set_hdr_dgl(dgl);
111 }
112 
113 /* This list keeps track of what parts of the datagram have been filled in */
114 struct fwnet_fragment_info {
115 	struct list_head fi_link;
116 	u16 offset;
117 	u16 len;
118 };
119 
120 struct fwnet_partial_datagram {
121 	struct list_head pd_link;
122 	struct list_head fi_list;
123 	struct sk_buff *skb;
124 	/* FIXME Why not use skb->data? */
125 	char *pbuf;
126 	u16 datagram_label;
127 	u16 ether_type;
128 	u16 datagram_size;
129 };
130 
131 static DEFINE_MUTEX(fwnet_device_mutex);
132 static LIST_HEAD(fwnet_device_list);
133 
134 struct fwnet_device {
135 	struct list_head dev_link;
136 	spinlock_t lock;
137 	enum {
138 		FWNET_BROADCAST_ERROR,
139 		FWNET_BROADCAST_RUNNING,
140 		FWNET_BROADCAST_STOPPED,
141 	} broadcast_state;
142 	struct fw_iso_context *broadcast_rcv_context;
143 	struct fw_iso_buffer broadcast_rcv_buffer;
144 	void **broadcast_rcv_buffer_ptrs;
145 	unsigned broadcast_rcv_next_ptr;
146 	unsigned num_broadcast_rcv_ptrs;
147 	unsigned rcv_buffer_size;
148 	/*
149 	 * This value is the maximum unfragmented datagram size that can be
150 	 * sent by the hardware.  It already has the GASP overhead and the
151 	 * unfragmented datagram header overhead calculated into it.
152 	 */
153 	unsigned broadcast_xmt_max_payload;
154 	u16 broadcast_xmt_datagramlabel;
155 
156 	/*
157 	 * The CSR address that remote nodes must send datagrams to for us to
158 	 * receive them.
159 	 */
160 	struct fw_address_handler handler;
161 	u64 local_fifo;
162 
163 	/* Number of tx datagrams that have been queued but not yet acked */
164 	int queued_datagrams;
165 
166 	int peer_count;
167 	struct list_head peer_list;
168 	struct fw_card *card;
169 	struct net_device *netdev;
170 };
171 
172 struct fwnet_peer {
173 	struct list_head peer_link;
174 	struct fwnet_device *dev;
175 	u64 guid;
176 
177 	/* guarded by dev->lock */
178 	struct list_head pd_list; /* received partial datagrams */
179 	unsigned pdg_size;        /* pd_list size */
180 
181 	u16 datagram_label;       /* outgoing datagram label */
182 	u16 max_payload;          /* includes RFC2374_FRAG_HDR_SIZE overhead */
183 	int node_id;
184 	int generation;
185 	unsigned speed;
186 };
187 
188 /* This is our task struct. It's used for the packet complete callback.  */
189 struct fwnet_packet_task {
190 	struct fw_transaction transaction;
191 	struct rfc2734_header hdr;
192 	struct sk_buff *skb;
193 	struct fwnet_device *dev;
194 
195 	int outstanding_pkts;
196 	u64 fifo_addr;
197 	u16 dest_node;
198 	u16 max_payload;
199 	u8 generation;
200 	u8 speed;
201 	u8 enqueued;
202 };
203 
204 /*
205  * Get fifo address embedded in hwaddr
206  */
207 static __u64 fwnet_hwaddr_fifo(union fwnet_hwaddr *ha)
208 {
209 	return (u64)get_unaligned_be16(&ha->uc.fifo_hi) << 32
210 	       | get_unaligned_be32(&ha->uc.fifo_lo);
211 }
212 
213 /*
214  * saddr == NULL means use device source address.
215  * daddr == NULL means leave destination address (eg unresolved arp).
216  */
217 static int fwnet_header_create(struct sk_buff *skb, struct net_device *net,
218 			unsigned short type, const void *daddr,
219 			const void *saddr, unsigned len)
220 {
221 	struct fwnet_header *h;
222 
223 	h = skb_push(skb, sizeof(*h));
224 	put_unaligned_be16(type, &h->h_proto);
225 
226 	if (net->flags & (IFF_LOOPBACK | IFF_NOARP)) {
227 		memset(h->h_dest, 0, net->addr_len);
228 
229 		return net->hard_header_len;
230 	}
231 
232 	if (daddr) {
233 		memcpy(h->h_dest, daddr, net->addr_len);
234 
235 		return net->hard_header_len;
236 	}
237 
238 	return -net->hard_header_len;
239 }
240 
241 static int fwnet_header_cache(const struct neighbour *neigh,
242 			      struct hh_cache *hh, __be16 type)
243 {
244 	struct net_device *net;
245 	struct fwnet_header *h;
246 
247 	if (type == cpu_to_be16(ETH_P_802_3))
248 		return -1;
249 	net = neigh->dev;
250 	h = (struct fwnet_header *)((u8 *)hh->hh_data + HH_DATA_OFF(sizeof(*h)));
251 	h->h_proto = type;
252 	memcpy(h->h_dest, neigh->ha, net->addr_len);
253 
254 	/* Pairs with the READ_ONCE() in neigh_resolve_output(),
255 	 * neigh_hh_output() and neigh_update_hhs().
256 	 */
257 	smp_store_release(&hh->hh_len, FWNET_HLEN);
258 
259 	return 0;
260 }
261 
262 /* Called by Address Resolution module to notify changes in address. */
263 static void fwnet_header_cache_update(struct hh_cache *hh,
264 		const struct net_device *net, const unsigned char *haddr)
265 {
266 	memcpy((u8 *)hh->hh_data + HH_DATA_OFF(FWNET_HLEN), haddr, net->addr_len);
267 }
268 
269 static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr)
270 {
271 	memcpy(haddr, skb->dev->dev_addr, FWNET_ALEN);
272 
273 	return FWNET_ALEN;
274 }
275 
276 static const struct header_ops fwnet_header_ops = {
277 	.create         = fwnet_header_create,
278 	.cache		= fwnet_header_cache,
279 	.cache_update	= fwnet_header_cache_update,
280 	.parse          = fwnet_header_parse,
281 };
282 
283 /* FIXME: is this correct for all cases? */
284 static bool fwnet_frag_overlap(struct fwnet_partial_datagram *pd,
285 			       unsigned offset, unsigned len)
286 {
287 	struct fwnet_fragment_info *fi;
288 	unsigned end = offset + len;
289 
290 	list_for_each_entry(fi, &pd->fi_list, fi_link)
291 		if (offset < fi->offset + fi->len && end > fi->offset)
292 			return true;
293 
294 	return false;
295 }
296 
297 /* Assumes that new fragment does not overlap any existing fragments */
298 static struct fwnet_fragment_info *fwnet_frag_new(
299 	struct fwnet_partial_datagram *pd, unsigned offset, unsigned len)
300 {
301 	struct fwnet_fragment_info *fi, *fi2, *new;
302 	struct list_head *list;
303 
304 	list = &pd->fi_list;
305 	list_for_each_entry(fi, &pd->fi_list, fi_link) {
306 		if (fi->offset + fi->len == offset) {
307 			/* The new fragment can be tacked on to the end */
308 			/* Did the new fragment plug a hole? */
309 			fi2 = list_entry(fi->fi_link.next,
310 					 struct fwnet_fragment_info, fi_link);
311 			if (fi->offset + fi->len == fi2->offset) {
312 				/* glue fragments together */
313 				fi->len += len + fi2->len;
314 				list_del(&fi2->fi_link);
315 				kfree(fi2);
316 			} else {
317 				fi->len += len;
318 			}
319 
320 			return fi;
321 		}
322 		if (offset + len == fi->offset) {
323 			/* The new fragment can be tacked on to the beginning */
324 			/* Did the new fragment plug a hole? */
325 			fi2 = list_entry(fi->fi_link.prev,
326 					 struct fwnet_fragment_info, fi_link);
327 			if (fi2->offset + fi2->len == fi->offset) {
328 				/* glue fragments together */
329 				fi2->len += fi->len + len;
330 				list_del(&fi->fi_link);
331 				kfree(fi);
332 
333 				return fi2;
334 			}
335 			fi->offset = offset;
336 			fi->len += len;
337 
338 			return fi;
339 		}
340 		if (offset > fi->offset + fi->len) {
341 			list = &fi->fi_link;
342 			break;
343 		}
344 		if (offset + len < fi->offset) {
345 			list = fi->fi_link.prev;
346 			break;
347 		}
348 	}
349 
350 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
351 	if (!new)
352 		return NULL;
353 
354 	new->offset = offset;
355 	new->len = len;
356 	list_add(&new->fi_link, list);
357 
358 	return new;
359 }
360 
361 static struct fwnet_partial_datagram *fwnet_pd_new(struct net_device *net,
362 		struct fwnet_peer *peer, u16 datagram_label, unsigned dg_size,
363 		void *frag_buf, unsigned frag_off, unsigned frag_len)
364 {
365 	struct fwnet_partial_datagram *new;
366 	struct fwnet_fragment_info *fi;
367 
368 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
369 	if (!new)
370 		goto fail;
371 
372 	INIT_LIST_HEAD(&new->fi_list);
373 	fi = fwnet_frag_new(new, frag_off, frag_len);
374 	if (fi == NULL)
375 		goto fail_w_new;
376 
377 	new->datagram_label = datagram_label;
378 	new->datagram_size = dg_size;
379 	new->skb = dev_alloc_skb(dg_size + LL_RESERVED_SPACE(net));
380 	if (new->skb == NULL)
381 		goto fail_w_fi;
382 
383 	skb_reserve(new->skb, LL_RESERVED_SPACE(net));
384 	new->pbuf = skb_put(new->skb, dg_size);
385 	memcpy(new->pbuf + frag_off, frag_buf, frag_len);
386 	list_add_tail(&new->pd_link, &peer->pd_list);
387 
388 	return new;
389 
390 fail_w_fi:
391 	kfree(fi);
392 fail_w_new:
393 	kfree(new);
394 fail:
395 	return NULL;
396 }
397 
398 static struct fwnet_partial_datagram *fwnet_pd_find(struct fwnet_peer *peer,
399 						    u16 datagram_label)
400 {
401 	struct fwnet_partial_datagram *pd;
402 
403 	list_for_each_entry(pd, &peer->pd_list, pd_link)
404 		if (pd->datagram_label == datagram_label)
405 			return pd;
406 
407 	return NULL;
408 }
409 
410 
411 static void fwnet_pd_delete(struct fwnet_partial_datagram *old)
412 {
413 	struct fwnet_fragment_info *fi, *n;
414 
415 	list_for_each_entry_safe(fi, n, &old->fi_list, fi_link)
416 		kfree(fi);
417 
418 	list_del(&old->pd_link);
419 	dev_kfree_skb_any(old->skb);
420 	kfree(old);
421 }
422 
423 static bool fwnet_pd_update(struct fwnet_peer *peer,
424 		struct fwnet_partial_datagram *pd, void *frag_buf,
425 		unsigned frag_off, unsigned frag_len)
426 {
427 	if (fwnet_frag_new(pd, frag_off, frag_len) == NULL)
428 		return false;
429 
430 	memcpy(pd->pbuf + frag_off, frag_buf, frag_len);
431 
432 	/*
433 	 * Move list entry to beginning of list so that oldest partial
434 	 * datagrams percolate to the end of the list
435 	 */
436 	list_move_tail(&pd->pd_link, &peer->pd_list);
437 
438 	return true;
439 }
440 
441 static bool fwnet_pd_is_complete(struct fwnet_partial_datagram *pd)
442 {
443 	struct fwnet_fragment_info *fi;
444 
445 	fi = list_entry(pd->fi_list.next, struct fwnet_fragment_info, fi_link);
446 
447 	return fi->len == pd->datagram_size;
448 }
449 
450 /* caller must hold dev->lock */
451 static struct fwnet_peer *fwnet_peer_find_by_guid(struct fwnet_device *dev,
452 						  u64 guid)
453 {
454 	struct fwnet_peer *peer;
455 
456 	list_for_each_entry(peer, &dev->peer_list, peer_link)
457 		if (peer->guid == guid)
458 			return peer;
459 
460 	return NULL;
461 }
462 
463 /* caller must hold dev->lock */
464 static struct fwnet_peer *fwnet_peer_find_by_node_id(struct fwnet_device *dev,
465 						int node_id, int generation)
466 {
467 	struct fwnet_peer *peer;
468 
469 	list_for_each_entry(peer, &dev->peer_list, peer_link)
470 		if (peer->node_id    == node_id &&
471 		    peer->generation == generation)
472 			return peer;
473 
474 	return NULL;
475 }
476 
477 /* See IEEE 1394-2008 table 6-4, table 8-8, table 16-18. */
478 static unsigned fwnet_max_payload(unsigned max_rec, unsigned speed)
479 {
480 	max_rec = min(max_rec, speed + 8);
481 	max_rec = clamp(max_rec, 8U, 11U); /* 512...4096 */
482 
483 	return (1 << (max_rec + 1)) - RFC2374_FRAG_HDR_SIZE;
484 }
485 
486 
487 static int fwnet_finish_incoming_packet(struct net_device *net,
488 					struct sk_buff *skb, u16 source_node_id,
489 					bool is_broadcast, u16 ether_type)
490 {
491 	struct fwnet_device *dev;
492 	int status;
493 	__be64 guid;
494 
495 	switch (ether_type) {
496 	case ETH_P_ARP:
497 	case ETH_P_IP:
498 #if IS_ENABLED(CONFIG_IPV6)
499 	case ETH_P_IPV6:
500 #endif
501 		break;
502 	default:
503 		goto err;
504 	}
505 
506 	dev = netdev_priv(net);
507 	/* Write metadata, and then pass to the receive level */
508 	skb->dev = net;
509 	skb->ip_summed = CHECKSUM_NONE;
510 
511 	/*
512 	 * Parse the encapsulation header. This actually does the job of
513 	 * converting to an ethernet-like pseudo frame header.
514 	 */
515 	guid = cpu_to_be64(dev->card->guid);
516 	if (dev_hard_header(skb, net, ether_type,
517 			   is_broadcast ? net->broadcast : net->dev_addr,
518 			   NULL, skb->len) >= 0) {
519 		struct fwnet_header *eth;
520 		u16 *rawp;
521 		__be16 protocol;
522 
523 		skb_reset_mac_header(skb);
524 		skb_pull(skb, sizeof(*eth));
525 		eth = (struct fwnet_header *)skb_mac_header(skb);
526 		if (fwnet_hwaddr_is_multicast(eth->h_dest)) {
527 			if (memcmp(eth->h_dest, net->broadcast,
528 				   net->addr_len) == 0)
529 				skb->pkt_type = PACKET_BROADCAST;
530 #if 0
531 			else
532 				skb->pkt_type = PACKET_MULTICAST;
533 #endif
534 		} else {
535 			if (memcmp(eth->h_dest, net->dev_addr, net->addr_len))
536 				skb->pkt_type = PACKET_OTHERHOST;
537 		}
538 		if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN) {
539 			protocol = eth->h_proto;
540 		} else {
541 			rawp = (u16 *)skb->data;
542 			if (*rawp == 0xffff)
543 				protocol = htons(ETH_P_802_3);
544 			else
545 				protocol = htons(ETH_P_802_2);
546 		}
547 		skb->protocol = protocol;
548 	}
549 	status = netif_rx(skb);
550 	if (status == NET_RX_DROP) {
551 		net->stats.rx_errors++;
552 		net->stats.rx_dropped++;
553 	} else {
554 		net->stats.rx_packets++;
555 		net->stats.rx_bytes += skb->len;
556 	}
557 
558 	return 0;
559 
560  err:
561 	net->stats.rx_errors++;
562 	net->stats.rx_dropped++;
563 
564 	dev_kfree_skb_any(skb);
565 
566 	return -ENOENT;
567 }
568 
569 static int fwnet_incoming_packet(struct fwnet_device *dev, __be32 *buf, int len,
570 				 int source_node_id, int generation,
571 				 bool is_broadcast)
572 {
573 	struct sk_buff *skb;
574 	struct net_device *net = dev->netdev;
575 	struct rfc2734_header hdr;
576 	unsigned lf;
577 	unsigned long flags;
578 	struct fwnet_peer *peer;
579 	struct fwnet_partial_datagram *pd;
580 	int fg_off;
581 	int dg_size;
582 	u16 datagram_label;
583 	int retval;
584 	u16 ether_type;
585 
586 	if (len <= RFC2374_UNFRAG_HDR_SIZE)
587 		return 0;
588 
589 	hdr.w0 = be32_to_cpu(buf[0]);
590 	lf = fwnet_get_hdr_lf(&hdr);
591 	if (lf == RFC2374_HDR_UNFRAG) {
592 		/*
593 		 * An unfragmented datagram has been received by the ieee1394
594 		 * bus. Build an skbuff around it so we can pass it to the
595 		 * high level network layer.
596 		 */
597 		ether_type = fwnet_get_hdr_ether_type(&hdr);
598 		buf++;
599 		len -= RFC2374_UNFRAG_HDR_SIZE;
600 
601 		skb = dev_alloc_skb(len + LL_RESERVED_SPACE(net));
602 		if (unlikely(!skb)) {
603 			net->stats.rx_dropped++;
604 
605 			return -ENOMEM;
606 		}
607 		skb_reserve(skb, LL_RESERVED_SPACE(net));
608 		skb_put_data(skb, buf, len);
609 
610 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
611 						    is_broadcast, ether_type);
612 	}
613 
614 	/* A datagram fragment has been received, now the fun begins. */
615 
616 	if (len <= RFC2374_FRAG_HDR_SIZE)
617 		return 0;
618 
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);
631 
632 	if (fg_off + len > dg_size)
633 		return 0;
634 
635 	spin_lock_irqsave(&dev->lock, flags);
636 
637 	peer = fwnet_peer_find_by_node_id(dev, source_node_id, generation);
638 	if (!peer) {
639 		retval = -ENOENT;
640 		goto fail;
641 	}
642 
643 	pd = fwnet_pd_find(peer, datagram_label);
644 	if (pd == NULL) {
645 		while (peer->pdg_size >= FWNET_MAX_FRAGMENTS) {
646 			/* remove the oldest */
647 			fwnet_pd_delete(list_first_entry(&peer->pd_list,
648 				struct fwnet_partial_datagram, pd_link));
649 			peer->pdg_size--;
650 		}
651 		pd = fwnet_pd_new(net, peer, datagram_label,
652 				  dg_size, buf, fg_off, len);
653 		if (pd == NULL) {
654 			retval = -ENOMEM;
655 			goto fail;
656 		}
657 		peer->pdg_size++;
658 	} else {
659 		if (fwnet_frag_overlap(pd, fg_off, len) ||
660 		    pd->datagram_size != dg_size) {
661 			/*
662 			 * Differing datagram sizes or overlapping fragments,
663 			 * discard old datagram and start a new one.
664 			 */
665 			fwnet_pd_delete(pd);
666 			pd = fwnet_pd_new(net, peer, datagram_label,
667 					  dg_size, buf, fg_off, len);
668 			if (pd == NULL) {
669 				peer->pdg_size--;
670 				retval = -ENOMEM;
671 				goto fail;
672 			}
673 		} else {
674 			if (!fwnet_pd_update(peer, pd, buf, fg_off, len)) {
675 				/*
676 				 * Couldn't save off fragment anyway
677 				 * so might as well obliterate the
678 				 * datagram now.
679 				 */
680 				fwnet_pd_delete(pd);
681 				peer->pdg_size--;
682 				retval = -ENOMEM;
683 				goto fail;
684 			}
685 		}
686 	} /* new datagram or add to existing one */
687 
688 	if (lf == RFC2374_HDR_FIRSTFRAG)
689 		pd->ether_type = ether_type;
690 
691 	if (fwnet_pd_is_complete(pd)) {
692 		ether_type = pd->ether_type;
693 		peer->pdg_size--;
694 		skb = skb_get(pd->skb);
695 		fwnet_pd_delete(pd);
696 
697 		spin_unlock_irqrestore(&dev->lock, flags);
698 
699 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
700 						    false, ether_type);
701 	}
702 	/*
703 	 * Datagram is not complete, we're done for the
704 	 * moment.
705 	 */
706 	retval = 0;
707  fail:
708 	spin_unlock_irqrestore(&dev->lock, flags);
709 
710 	return retval;
711 }
712 
713 static void fwnet_receive_packet(struct fw_card *card, struct fw_request *r,
714 		int tcode, int destination, int source, int generation,
715 		unsigned long long offset, void *payload, size_t length,
716 		void *callback_data)
717 {
718 	struct fwnet_device *dev = callback_data;
719 	int rcode;
720 
721 	if (destination == IEEE1394_ALL_NODES) {
722 		kfree(r);
723 
724 		return;
725 	}
726 
727 	if (offset != dev->handler.offset)
728 		rcode = RCODE_ADDRESS_ERROR;
729 	else if (tcode != TCODE_WRITE_BLOCK_REQUEST)
730 		rcode = RCODE_TYPE_ERROR;
731 	else if (fwnet_incoming_packet(dev, payload, length,
732 				       source, generation, false) != 0) {
733 		dev_err(&dev->netdev->dev, "incoming packet failure\n");
734 		rcode = RCODE_CONFLICT_ERROR;
735 	} else
736 		rcode = RCODE_COMPLETE;
737 
738 	fw_send_response(card, r, rcode);
739 }
740 
741 static int gasp_source_id(__be32 *p)
742 {
743 	return be32_to_cpu(p[0]) >> 16;
744 }
745 
746 static u32 gasp_specifier_id(__be32 *p)
747 {
748 	return (be32_to_cpu(p[0]) & 0xffff) << 8 |
749 	       (be32_to_cpu(p[1]) & 0xff000000) >> 24;
750 }
751 
752 static u32 gasp_version(__be32 *p)
753 {
754 	return be32_to_cpu(p[1]) & 0xffffff;
755 }
756 
757 static void fwnet_receive_broadcast(struct fw_iso_context *context,
758 		u32 cycle, size_t header_length, void *header, void *data)
759 {
760 	struct fwnet_device *dev;
761 	struct fw_iso_packet packet;
762 	__be16 *hdr_ptr;
763 	__be32 *buf_ptr;
764 	int retval;
765 	u32 length;
766 	unsigned long offset;
767 	unsigned long flags;
768 
769 	dev = data;
770 	hdr_ptr = header;
771 	length = be16_to_cpup(hdr_ptr);
772 
773 	spin_lock_irqsave(&dev->lock, flags);
774 
775 	offset = dev->rcv_buffer_size * dev->broadcast_rcv_next_ptr;
776 	buf_ptr = dev->broadcast_rcv_buffer_ptrs[dev->broadcast_rcv_next_ptr++];
777 	if (dev->broadcast_rcv_next_ptr == dev->num_broadcast_rcv_ptrs)
778 		dev->broadcast_rcv_next_ptr = 0;
779 
780 	spin_unlock_irqrestore(&dev->lock, flags);
781 
782 	if (length > IEEE1394_GASP_HDR_SIZE &&
783 	    gasp_specifier_id(buf_ptr) == IANA_SPECIFIER_ID &&
784 	    (gasp_version(buf_ptr) == RFC2734_SW_VERSION
785 #if IS_ENABLED(CONFIG_IPV6)
786 	     || gasp_version(buf_ptr) == RFC3146_SW_VERSION
787 #endif
788 	    ))
789 		fwnet_incoming_packet(dev, buf_ptr + 2,
790 				      length - IEEE1394_GASP_HDR_SIZE,
791 				      gasp_source_id(buf_ptr),
792 				      context->card->generation, true);
793 
794 	packet.payload_length = dev->rcv_buffer_size;
795 	packet.interrupt = 1;
796 	packet.skip = 0;
797 	packet.tag = 3;
798 	packet.sy = 0;
799 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
800 
801 	spin_lock_irqsave(&dev->lock, flags);
802 
803 	retval = fw_iso_context_queue(dev->broadcast_rcv_context, &packet,
804 				      &dev->broadcast_rcv_buffer, offset);
805 
806 	spin_unlock_irqrestore(&dev->lock, flags);
807 
808 	if (retval >= 0)
809 		fw_iso_context_queue_flush(dev->broadcast_rcv_context);
810 	else
811 		dev_err(&dev->netdev->dev, "requeue failed\n");
812 }
813 
814 static struct kmem_cache *fwnet_packet_task_cache;
815 
816 static void fwnet_free_ptask(struct fwnet_packet_task *ptask)
817 {
818 	dev_kfree_skb_any(ptask->skb);
819 	kmem_cache_free(fwnet_packet_task_cache, ptask);
820 }
821 
822 /* Caller must hold dev->lock. */
823 static void dec_queued_datagrams(struct fwnet_device *dev)
824 {
825 	if (--dev->queued_datagrams == FWNET_MIN_QUEUED_DATAGRAMS)
826 		netif_wake_queue(dev->netdev);
827 }
828 
829 static int fwnet_send_packet(struct fwnet_packet_task *ptask);
830 
831 static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
832 {
833 	struct fwnet_device *dev = ptask->dev;
834 	struct sk_buff *skb = ptask->skb;
835 	unsigned long flags;
836 	bool free;
837 
838 	spin_lock_irqsave(&dev->lock, flags);
839 
840 	ptask->outstanding_pkts--;
841 
842 	/* Check whether we or the networking TX soft-IRQ is last user. */
843 	free = (ptask->outstanding_pkts == 0 && ptask->enqueued);
844 	if (free)
845 		dec_queued_datagrams(dev);
846 
847 	if (ptask->outstanding_pkts == 0) {
848 		dev->netdev->stats.tx_packets++;
849 		dev->netdev->stats.tx_bytes += skb->len;
850 	}
851 
852 	spin_unlock_irqrestore(&dev->lock, flags);
853 
854 	if (ptask->outstanding_pkts > 0) {
855 		u16 dg_size;
856 		u16 fg_off;
857 		u16 datagram_label;
858 		u16 lf;
859 
860 		/* Update the ptask to point to the next fragment and send it */
861 		lf = fwnet_get_hdr_lf(&ptask->hdr);
862 		switch (lf) {
863 		case RFC2374_HDR_LASTFRAG:
864 		case RFC2374_HDR_UNFRAG:
865 		default:
866 			dev_err(&dev->netdev->dev,
867 				"outstanding packet %x lf %x, header %x,%x\n",
868 				ptask->outstanding_pkts, lf, ptask->hdr.w0,
869 				ptask->hdr.w1);
870 			BUG();
871 
872 		case RFC2374_HDR_FIRSTFRAG:
873 			/* Set frag type here for future interior fragments */
874 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
875 			fg_off = ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
876 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
877 			break;
878 
879 		case RFC2374_HDR_INTFRAG:
880 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
881 			fg_off = fwnet_get_hdr_fg_off(&ptask->hdr)
882 				  + ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
883 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
884 			break;
885 		}
886 
887 		if (ptask->dest_node == IEEE1394_ALL_NODES) {
888 			skb_pull(skb,
889 				 ptask->max_payload + IEEE1394_GASP_HDR_SIZE);
890 		} else {
891 			skb_pull(skb, ptask->max_payload);
892 		}
893 		if (ptask->outstanding_pkts > 1) {
894 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_INTFRAG,
895 					  dg_size, fg_off, datagram_label);
896 		} else {
897 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_LASTFRAG,
898 					  dg_size, fg_off, datagram_label);
899 			ptask->max_payload = skb->len + RFC2374_FRAG_HDR_SIZE;
900 		}
901 		fwnet_send_packet(ptask);
902 	}
903 
904 	if (free)
905 		fwnet_free_ptask(ptask);
906 }
907 
908 static void fwnet_transmit_packet_failed(struct fwnet_packet_task *ptask)
909 {
910 	struct fwnet_device *dev = ptask->dev;
911 	unsigned long flags;
912 	bool free;
913 
914 	spin_lock_irqsave(&dev->lock, flags);
915 
916 	/* One fragment failed; don't try to send remaining fragments. */
917 	ptask->outstanding_pkts = 0;
918 
919 	/* Check whether we or the networking TX soft-IRQ is last user. */
920 	free = ptask->enqueued;
921 	if (free)
922 		dec_queued_datagrams(dev);
923 
924 	dev->netdev->stats.tx_dropped++;
925 	dev->netdev->stats.tx_errors++;
926 
927 	spin_unlock_irqrestore(&dev->lock, flags);
928 
929 	if (free)
930 		fwnet_free_ptask(ptask);
931 }
932 
933 static void fwnet_write_complete(struct fw_card *card, int rcode,
934 				 void *payload, size_t length, void *data)
935 {
936 	struct fwnet_packet_task *ptask = data;
937 	static unsigned long j;
938 	static int last_rcode, errors_skipped;
939 
940 	if (rcode == RCODE_COMPLETE) {
941 		fwnet_transmit_packet_done(ptask);
942 	} else {
943 		if (printk_timed_ratelimit(&j,  1000) || rcode != last_rcode) {
944 			dev_err(&ptask->dev->netdev->dev,
945 				"fwnet_write_complete failed: %x (skipped %d)\n",
946 				rcode, errors_skipped);
947 
948 			errors_skipped = 0;
949 			last_rcode = rcode;
950 		} else {
951 			errors_skipped++;
952 		}
953 		fwnet_transmit_packet_failed(ptask);
954 	}
955 }
956 
957 static int fwnet_send_packet(struct fwnet_packet_task *ptask)
958 {
959 	struct fwnet_device *dev;
960 	unsigned tx_len;
961 	struct rfc2734_header *bufhdr;
962 	unsigned long flags;
963 	bool free;
964 
965 	dev = ptask->dev;
966 	tx_len = ptask->max_payload;
967 	switch (fwnet_get_hdr_lf(&ptask->hdr)) {
968 	case RFC2374_HDR_UNFRAG:
969 		bufhdr = skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
970 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
971 		break;
972 
973 	case RFC2374_HDR_FIRSTFRAG:
974 	case RFC2374_HDR_INTFRAG:
975 	case RFC2374_HDR_LASTFRAG:
976 		bufhdr = skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
977 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
978 		put_unaligned_be32(ptask->hdr.w1, &bufhdr->w1);
979 		break;
980 
981 	default:
982 		BUG();
983 	}
984 	if (ptask->dest_node == IEEE1394_ALL_NODES) {
985 		u8 *p;
986 		int generation;
987 		int node_id;
988 		unsigned int sw_version;
989 
990 		/* ptask->generation may not have been set yet */
991 		generation = dev->card->generation;
992 		smp_rmb();
993 		node_id = dev->card->node_id;
994 
995 		switch (ptask->skb->protocol) {
996 		default:
997 			sw_version = RFC2734_SW_VERSION;
998 			break;
999 #if IS_ENABLED(CONFIG_IPV6)
1000 		case htons(ETH_P_IPV6):
1001 			sw_version = RFC3146_SW_VERSION;
1002 #endif
1003 		}
1004 
1005 		p = skb_push(ptask->skb, IEEE1394_GASP_HDR_SIZE);
1006 		put_unaligned_be32(node_id << 16 | IANA_SPECIFIER_ID >> 8, p);
1007 		put_unaligned_be32((IANA_SPECIFIER_ID & 0xff) << 24
1008 						| sw_version, &p[4]);
1009 
1010 		/* We should not transmit if broadcast_channel.valid == 0. */
1011 		fw_send_request(dev->card, &ptask->transaction,
1012 				TCODE_STREAM_DATA,
1013 				fw_stream_packet_destination_id(3,
1014 						IEEE1394_BROADCAST_CHANNEL, 0),
1015 				generation, SCODE_100, 0ULL, ptask->skb->data,
1016 				tx_len + 8, fwnet_write_complete, ptask);
1017 
1018 		spin_lock_irqsave(&dev->lock, flags);
1019 
1020 		/* If the AT tasklet already ran, we may be last user. */
1021 		free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1022 		if (!free)
1023 			ptask->enqueued = true;
1024 		else
1025 			dec_queued_datagrams(dev);
1026 
1027 		spin_unlock_irqrestore(&dev->lock, flags);
1028 
1029 		goto out;
1030 	}
1031 
1032 	fw_send_request(dev->card, &ptask->transaction,
1033 			TCODE_WRITE_BLOCK_REQUEST, ptask->dest_node,
1034 			ptask->generation, ptask->speed, ptask->fifo_addr,
1035 			ptask->skb->data, tx_len, fwnet_write_complete, ptask);
1036 
1037 	spin_lock_irqsave(&dev->lock, flags);
1038 
1039 	/* If the AT tasklet already ran, we may be last user. */
1040 	free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1041 	if (!free)
1042 		ptask->enqueued = true;
1043 	else
1044 		dec_queued_datagrams(dev);
1045 
1046 	spin_unlock_irqrestore(&dev->lock, flags);
1047 
1048 	netif_trans_update(dev->netdev);
1049  out:
1050 	if (free)
1051 		fwnet_free_ptask(ptask);
1052 
1053 	return 0;
1054 }
1055 
1056 static void fwnet_fifo_stop(struct fwnet_device *dev)
1057 {
1058 	if (dev->local_fifo == FWNET_NO_FIFO_ADDR)
1059 		return;
1060 
1061 	fw_core_remove_address_handler(&dev->handler);
1062 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1063 }
1064 
1065 static int fwnet_fifo_start(struct fwnet_device *dev)
1066 {
1067 	int retval;
1068 
1069 	if (dev->local_fifo != FWNET_NO_FIFO_ADDR)
1070 		return 0;
1071 
1072 	dev->handler.length = 4096;
1073 	dev->handler.address_callback = fwnet_receive_packet;
1074 	dev->handler.callback_data = dev;
1075 
1076 	retval = fw_core_add_address_handler(&dev->handler,
1077 					     &fw_high_memory_region);
1078 	if (retval < 0)
1079 		return retval;
1080 
1081 	dev->local_fifo = dev->handler.offset;
1082 
1083 	return 0;
1084 }
1085 
1086 static void __fwnet_broadcast_stop(struct fwnet_device *dev)
1087 {
1088 	unsigned u;
1089 
1090 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR) {
1091 		for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++)
1092 			kunmap(dev->broadcast_rcv_buffer.pages[u]);
1093 		fw_iso_buffer_destroy(&dev->broadcast_rcv_buffer, dev->card);
1094 	}
1095 	if (dev->broadcast_rcv_context) {
1096 		fw_iso_context_destroy(dev->broadcast_rcv_context);
1097 		dev->broadcast_rcv_context = NULL;
1098 	}
1099 	kfree(dev->broadcast_rcv_buffer_ptrs);
1100 	dev->broadcast_rcv_buffer_ptrs = NULL;
1101 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1102 }
1103 
1104 static void fwnet_broadcast_stop(struct fwnet_device *dev)
1105 {
1106 	if (dev->broadcast_state == FWNET_BROADCAST_ERROR)
1107 		return;
1108 	fw_iso_context_stop(dev->broadcast_rcv_context);
1109 	__fwnet_broadcast_stop(dev);
1110 }
1111 
1112 static int fwnet_broadcast_start(struct fwnet_device *dev)
1113 {
1114 	struct fw_iso_context *context;
1115 	int retval;
1116 	unsigned num_packets;
1117 	unsigned max_receive;
1118 	struct fw_iso_packet packet;
1119 	unsigned long offset;
1120 	void **ptrptr;
1121 	unsigned u;
1122 
1123 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR)
1124 		return 0;
1125 
1126 	max_receive = 1U << (dev->card->max_receive + 1);
1127 	num_packets = (FWNET_ISO_PAGE_COUNT * PAGE_SIZE) / max_receive;
1128 
1129 	ptrptr = kmalloc_array(num_packets, sizeof(void *), GFP_KERNEL);
1130 	if (!ptrptr) {
1131 		retval = -ENOMEM;
1132 		goto failed;
1133 	}
1134 	dev->broadcast_rcv_buffer_ptrs = ptrptr;
1135 
1136 	context = fw_iso_context_create(dev->card, FW_ISO_CONTEXT_RECEIVE,
1137 					IEEE1394_BROADCAST_CHANNEL,
1138 					dev->card->link_speed, 8,
1139 					fwnet_receive_broadcast, dev);
1140 	if (IS_ERR(context)) {
1141 		retval = PTR_ERR(context);
1142 		goto failed;
1143 	}
1144 
1145 	retval = fw_iso_buffer_init(&dev->broadcast_rcv_buffer, dev->card,
1146 				    FWNET_ISO_PAGE_COUNT, DMA_FROM_DEVICE);
1147 	if (retval < 0)
1148 		goto failed;
1149 
1150 	dev->broadcast_state = FWNET_BROADCAST_STOPPED;
1151 
1152 	for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++) {
1153 		void *ptr;
1154 		unsigned v;
1155 
1156 		ptr = kmap(dev->broadcast_rcv_buffer.pages[u]);
1157 		for (v = 0; v < num_packets / FWNET_ISO_PAGE_COUNT; v++)
1158 			*ptrptr++ = (void *) ((char *)ptr + v * max_receive);
1159 	}
1160 	dev->broadcast_rcv_context = context;
1161 
1162 	packet.payload_length = max_receive;
1163 	packet.interrupt = 1;
1164 	packet.skip = 0;
1165 	packet.tag = 3;
1166 	packet.sy = 0;
1167 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
1168 	offset = 0;
1169 
1170 	for (u = 0; u < num_packets; u++) {
1171 		retval = fw_iso_context_queue(context, &packet,
1172 				&dev->broadcast_rcv_buffer, offset);
1173 		if (retval < 0)
1174 			goto failed;
1175 
1176 		offset += max_receive;
1177 	}
1178 	dev->num_broadcast_rcv_ptrs = num_packets;
1179 	dev->rcv_buffer_size = max_receive;
1180 	dev->broadcast_rcv_next_ptr = 0U;
1181 	retval = fw_iso_context_start(context, -1, 0,
1182 			FW_ISO_CONTEXT_MATCH_ALL_TAGS); /* ??? sync */
1183 	if (retval < 0)
1184 		goto failed;
1185 
1186 	/* FIXME: adjust it according to the min. speed of all known peers? */
1187 	dev->broadcast_xmt_max_payload = IEEE1394_MAX_PAYLOAD_S100
1188 			- IEEE1394_GASP_HDR_SIZE - RFC2374_UNFRAG_HDR_SIZE;
1189 	dev->broadcast_state = FWNET_BROADCAST_RUNNING;
1190 
1191 	return 0;
1192 
1193  failed:
1194 	__fwnet_broadcast_stop(dev);
1195 	return retval;
1196 }
1197 
1198 static void set_carrier_state(struct fwnet_device *dev)
1199 {
1200 	if (dev->peer_count > 1)
1201 		netif_carrier_on(dev->netdev);
1202 	else
1203 		netif_carrier_off(dev->netdev);
1204 }
1205 
1206 /* ifup */
1207 static int fwnet_open(struct net_device *net)
1208 {
1209 	struct fwnet_device *dev = netdev_priv(net);
1210 	int ret;
1211 
1212 	ret = fwnet_broadcast_start(dev);
1213 	if (ret)
1214 		return ret;
1215 
1216 	netif_start_queue(net);
1217 
1218 	spin_lock_irq(&dev->lock);
1219 	set_carrier_state(dev);
1220 	spin_unlock_irq(&dev->lock);
1221 
1222 	return 0;
1223 }
1224 
1225 /* ifdown */
1226 static int fwnet_stop(struct net_device *net)
1227 {
1228 	struct fwnet_device *dev = netdev_priv(net);
1229 
1230 	netif_stop_queue(net);
1231 	fwnet_broadcast_stop(dev);
1232 
1233 	return 0;
1234 }
1235 
1236 static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
1237 {
1238 	struct fwnet_header hdr_buf;
1239 	struct fwnet_device *dev = netdev_priv(net);
1240 	__be16 proto;
1241 	u16 dest_node;
1242 	unsigned max_payload;
1243 	u16 dg_size;
1244 	u16 *datagram_label_ptr;
1245 	struct fwnet_packet_task *ptask;
1246 	struct fwnet_peer *peer;
1247 	unsigned long flags;
1248 
1249 	spin_lock_irqsave(&dev->lock, flags);
1250 
1251 	/* Can this happen? */
1252 	if (netif_queue_stopped(dev->netdev)) {
1253 		spin_unlock_irqrestore(&dev->lock, flags);
1254 
1255 		return NETDEV_TX_BUSY;
1256 	}
1257 
1258 	ptask = kmem_cache_alloc(fwnet_packet_task_cache, GFP_ATOMIC);
1259 	if (ptask == NULL)
1260 		goto fail;
1261 
1262 	skb = skb_share_check(skb, GFP_ATOMIC);
1263 	if (!skb)
1264 		goto fail;
1265 
1266 	/*
1267 	 * Make a copy of the driver-specific header.
1268 	 * We might need to rebuild the header on tx failure.
1269 	 */
1270 	memcpy(&hdr_buf, skb->data, sizeof(hdr_buf));
1271 	proto = hdr_buf.h_proto;
1272 
1273 	switch (proto) {
1274 	case htons(ETH_P_ARP):
1275 	case htons(ETH_P_IP):
1276 #if IS_ENABLED(CONFIG_IPV6)
1277 	case htons(ETH_P_IPV6):
1278 #endif
1279 		break;
1280 	default:
1281 		goto fail;
1282 	}
1283 
1284 	skb_pull(skb, sizeof(hdr_buf));
1285 	dg_size = skb->len;
1286 
1287 	/*
1288 	 * Set the transmission type for the packet.  ARP packets and IP
1289 	 * broadcast packets are sent via GASP.
1290 	 */
1291 	if (fwnet_hwaddr_is_multicast(hdr_buf.h_dest)) {
1292 		max_payload        = dev->broadcast_xmt_max_payload;
1293 		datagram_label_ptr = &dev->broadcast_xmt_datagramlabel;
1294 
1295 		ptask->fifo_addr   = FWNET_NO_FIFO_ADDR;
1296 		ptask->generation  = 0;
1297 		ptask->dest_node   = IEEE1394_ALL_NODES;
1298 		ptask->speed       = SCODE_100;
1299 	} else {
1300 		union fwnet_hwaddr *ha = (union fwnet_hwaddr *)hdr_buf.h_dest;
1301 		__be64 guid = get_unaligned(&ha->uc.uniq_id);
1302 		u8 generation;
1303 
1304 		peer = fwnet_peer_find_by_guid(dev, be64_to_cpu(guid));
1305 		if (!peer)
1306 			goto fail;
1307 
1308 		generation         = peer->generation;
1309 		dest_node          = peer->node_id;
1310 		max_payload        = peer->max_payload;
1311 		datagram_label_ptr = &peer->datagram_label;
1312 
1313 		ptask->fifo_addr   = fwnet_hwaddr_fifo(ha);
1314 		ptask->generation  = generation;
1315 		ptask->dest_node   = dest_node;
1316 		ptask->speed       = peer->speed;
1317 	}
1318 
1319 	ptask->hdr.w0 = 0;
1320 	ptask->hdr.w1 = 0;
1321 	ptask->skb = skb;
1322 	ptask->dev = dev;
1323 
1324 	/* Does it all fit in one packet? */
1325 	if (dg_size <= max_payload) {
1326 		fwnet_make_uf_hdr(&ptask->hdr, ntohs(proto));
1327 		ptask->outstanding_pkts = 1;
1328 		max_payload = dg_size + RFC2374_UNFRAG_HDR_SIZE;
1329 	} else {
1330 		u16 datagram_label;
1331 
1332 		max_payload -= RFC2374_FRAG_OVERHEAD;
1333 		datagram_label = (*datagram_label_ptr)++;
1334 		fwnet_make_ff_hdr(&ptask->hdr, ntohs(proto), dg_size,
1335 				  datagram_label);
1336 		ptask->outstanding_pkts = DIV_ROUND_UP(dg_size, max_payload);
1337 		max_payload += RFC2374_FRAG_HDR_SIZE;
1338 	}
1339 
1340 	if (++dev->queued_datagrams == FWNET_MAX_QUEUED_DATAGRAMS)
1341 		netif_stop_queue(dev->netdev);
1342 
1343 	spin_unlock_irqrestore(&dev->lock, flags);
1344 
1345 	ptask->max_payload = max_payload;
1346 	ptask->enqueued    = 0;
1347 
1348 	fwnet_send_packet(ptask);
1349 
1350 	return NETDEV_TX_OK;
1351 
1352  fail:
1353 	spin_unlock_irqrestore(&dev->lock, flags);
1354 
1355 	if (ptask)
1356 		kmem_cache_free(fwnet_packet_task_cache, ptask);
1357 
1358 	if (skb != NULL)
1359 		dev_kfree_skb(skb);
1360 
1361 	net->stats.tx_dropped++;
1362 	net->stats.tx_errors++;
1363 
1364 	/*
1365 	 * FIXME: According to a patch from 2003-02-26, "returning non-zero
1366 	 * causes serious problems" here, allegedly.  Before that patch,
1367 	 * -ERRNO was returned which is not appropriate under Linux 2.6.
1368 	 * Perhaps more needs to be done?  Stop the queue in serious
1369 	 * conditions and restart it elsewhere?
1370 	 */
1371 	return NETDEV_TX_OK;
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 };
1383 
1384 static void fwnet_init_dev(struct net_device *net)
1385 {
1386 	net->header_ops		= &fwnet_header_ops;
1387 	net->netdev_ops		= &fwnet_netdev_ops;
1388 	net->watchdog_timeo	= 2 * HZ;
1389 	net->flags		= IFF_BROADCAST | IFF_MULTICAST;
1390 	net->features		= NETIF_F_HIGHDMA;
1391 	net->addr_len		= FWNET_ALEN;
1392 	net->hard_header_len	= FWNET_HLEN;
1393 	net->type		= ARPHRD_IEEE1394;
1394 	net->tx_queue_len	= FWNET_TX_QUEUE_LEN;
1395 	net->ethtool_ops	= &fwnet_ethtool_ops;
1396 }
1397 
1398 /* caller must hold fwnet_device_mutex */
1399 static struct fwnet_device *fwnet_dev_find(struct fw_card *card)
1400 {
1401 	struct fwnet_device *dev;
1402 
1403 	list_for_each_entry(dev, &fwnet_device_list, dev_link)
1404 		if (dev->card == card)
1405 			return dev;
1406 
1407 	return NULL;
1408 }
1409 
1410 static int fwnet_add_peer(struct fwnet_device *dev,
1411 			  struct fw_unit *unit, struct fw_device *device)
1412 {
1413 	struct fwnet_peer *peer;
1414 
1415 	peer = kmalloc(sizeof(*peer), GFP_KERNEL);
1416 	if (!peer)
1417 		return -ENOMEM;
1418 
1419 	dev_set_drvdata(&unit->device, peer);
1420 
1421 	peer->dev = dev;
1422 	peer->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1423 	INIT_LIST_HEAD(&peer->pd_list);
1424 	peer->pdg_size = 0;
1425 	peer->datagram_label = 0;
1426 	peer->speed = device->max_speed;
1427 	peer->max_payload = fwnet_max_payload(device->max_rec, peer->speed);
1428 
1429 	peer->generation = device->generation;
1430 	smp_rmb();
1431 	peer->node_id = device->node_id;
1432 
1433 	spin_lock_irq(&dev->lock);
1434 	list_add_tail(&peer->peer_link, &dev->peer_list);
1435 	dev->peer_count++;
1436 	set_carrier_state(dev);
1437 	spin_unlock_irq(&dev->lock);
1438 
1439 	return 0;
1440 }
1441 
1442 static int fwnet_probe(struct fw_unit *unit,
1443 		       const struct ieee1394_device_id *id)
1444 {
1445 	struct fw_device *device = fw_parent_device(unit);
1446 	struct fw_card *card = device->card;
1447 	struct net_device *net;
1448 	bool allocated_netdev = false;
1449 	struct fwnet_device *dev;
1450 	int ret;
1451 	union fwnet_hwaddr *ha;
1452 
1453 	mutex_lock(&fwnet_device_mutex);
1454 
1455 	dev = fwnet_dev_find(card);
1456 	if (dev) {
1457 		net = dev->netdev;
1458 		goto have_dev;
1459 	}
1460 
1461 	net = alloc_netdev(sizeof(*dev), "firewire%d", NET_NAME_UNKNOWN,
1462 			   fwnet_init_dev);
1463 	if (net == NULL) {
1464 		mutex_unlock(&fwnet_device_mutex);
1465 		return -ENOMEM;
1466 	}
1467 
1468 	allocated_netdev = true;
1469 	SET_NETDEV_DEV(net, card->device);
1470 	dev = netdev_priv(net);
1471 
1472 	spin_lock_init(&dev->lock);
1473 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1474 	dev->broadcast_rcv_context = NULL;
1475 	dev->broadcast_xmt_max_payload = 0;
1476 	dev->broadcast_xmt_datagramlabel = 0;
1477 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1478 	dev->queued_datagrams = 0;
1479 	INIT_LIST_HEAD(&dev->peer_list);
1480 	dev->card = card;
1481 	dev->netdev = net;
1482 
1483 	ret = fwnet_fifo_start(dev);
1484 	if (ret < 0)
1485 		goto out;
1486 	dev->local_fifo = dev->handler.offset;
1487 
1488 	/*
1489 	 * default MTU: RFC 2734 cl. 4, RFC 3146 cl. 4
1490 	 * maximum MTU: RFC 2734 cl. 4.2, fragment encapsulation header's
1491 	 *              maximum possible datagram_size + 1 = 0xfff + 1
1492 	 */
1493 	net->mtu = 1500U;
1494 	net->min_mtu = ETH_MIN_MTU;
1495 	net->max_mtu = 4096U;
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