xref: /openbmc/linux/drivers/firewire/net.c (revision b868a02e) 
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  * saddr == NULL means use device source address.
206  * daddr == NULL means leave destination address (eg unresolved arp).
207  */
208 static int fwnet_header_create(struct sk_buff *skb, struct net_device *net,
209 			unsigned short type, const void *daddr,
210 			const void *saddr, unsigned len)
211 {
212 	struct fwnet_header *h;
213 
214 	h = skb_push(skb, sizeof(*h));
215 	put_unaligned_be16(type, &h->h_proto);
216 
217 	if (net->flags & (IFF_LOOPBACK | IFF_NOARP)) {
218 		memset(h->h_dest, 0, net->addr_len);
219 
220 		return net->hard_header_len;
221 	}
222 
223 	if (daddr) {
224 		memcpy(h->h_dest, daddr, net->addr_len);
225 
226 		return net->hard_header_len;
227 	}
228 
229 	return -net->hard_header_len;
230 }
231 
232 static int fwnet_header_cache(const struct neighbour *neigh,
233 			      struct hh_cache *hh, __be16 type)
234 {
235 	struct net_device *net;
236 	struct fwnet_header *h;
237 
238 	if (type == cpu_to_be16(ETH_P_802_3))
239 		return -1;
240 	net = neigh->dev;
241 	h = (struct fwnet_header *)((u8 *)hh->hh_data + HH_DATA_OFF(sizeof(*h)));
242 	h->h_proto = type;
243 	memcpy(h->h_dest, neigh->ha, net->addr_len);
244 
245 	/* Pairs with the READ_ONCE() in neigh_resolve_output(),
246 	 * neigh_hh_output() and neigh_update_hhs().
247 	 */
248 	smp_store_release(&hh->hh_len, FWNET_HLEN);
249 
250 	return 0;
251 }
252 
253 /* Called by Address Resolution module to notify changes in address. */
254 static void fwnet_header_cache_update(struct hh_cache *hh,
255 		const struct net_device *net, const unsigned char *haddr)
256 {
257 	memcpy((u8 *)hh->hh_data + HH_DATA_OFF(FWNET_HLEN), haddr, net->addr_len);
258 }
259 
260 static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr)
261 {
262 	memcpy(haddr, skb->dev->dev_addr, FWNET_ALEN);
263 
264 	return FWNET_ALEN;
265 }
266 
267 static const struct header_ops fwnet_header_ops = {
268 	.create         = fwnet_header_create,
269 	.cache		= fwnet_header_cache,
270 	.cache_update	= fwnet_header_cache_update,
271 	.parse          = fwnet_header_parse,
272 };
273 
274 /* FIXME: is this correct for all cases? */
275 static bool fwnet_frag_overlap(struct fwnet_partial_datagram *pd,
276 			       unsigned offset, unsigned len)
277 {
278 	struct fwnet_fragment_info *fi;
279 	unsigned end = offset + len;
280 
281 	list_for_each_entry(fi, &pd->fi_list, fi_link)
282 		if (offset < fi->offset + fi->len && end > fi->offset)
283 			return true;
284 
285 	return false;
286 }
287 
288 /* Assumes that new fragment does not overlap any existing fragments */
289 static struct fwnet_fragment_info *fwnet_frag_new(
290 	struct fwnet_partial_datagram *pd, unsigned offset, unsigned len)
291 {
292 	struct fwnet_fragment_info *fi, *fi2, *new;
293 	struct list_head *list;
294 
295 	list = &pd->fi_list;
296 	list_for_each_entry(fi, &pd->fi_list, fi_link) {
297 		if (fi->offset + fi->len == offset) {
298 			/* The new fragment can be tacked on to the end */
299 			/* Did the new fragment plug a hole? */
300 			fi2 = list_entry(fi->fi_link.next,
301 					 struct fwnet_fragment_info, fi_link);
302 			if (fi->offset + fi->len == fi2->offset) {
303 				/* glue fragments together */
304 				fi->len += len + fi2->len;
305 				list_del(&fi2->fi_link);
306 				kfree(fi2);
307 			} else {
308 				fi->len += len;
309 			}
310 
311 			return fi;
312 		}
313 		if (offset + len == fi->offset) {
314 			/* The new fragment can be tacked on to the beginning */
315 			/* Did the new fragment plug a hole? */
316 			fi2 = list_entry(fi->fi_link.prev,
317 					 struct fwnet_fragment_info, fi_link);
318 			if (fi2->offset + fi2->len == fi->offset) {
319 				/* glue fragments together */
320 				fi2->len += fi->len + len;
321 				list_del(&fi->fi_link);
322 				kfree(fi);
323 
324 				return fi2;
325 			}
326 			fi->offset = offset;
327 			fi->len += len;
328 
329 			return fi;
330 		}
331 		if (offset > fi->offset + fi->len) {
332 			list = &fi->fi_link;
333 			break;
334 		}
335 		if (offset + len < fi->offset) {
336 			list = fi->fi_link.prev;
337 			break;
338 		}
339 	}
340 
341 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
342 	if (!new)
343 		return NULL;
344 
345 	new->offset = offset;
346 	new->len = len;
347 	list_add(&new->fi_link, list);
348 
349 	return new;
350 }
351 
352 static struct fwnet_partial_datagram *fwnet_pd_new(struct net_device *net,
353 		struct fwnet_peer *peer, u16 datagram_label, unsigned dg_size,
354 		void *frag_buf, unsigned frag_off, unsigned frag_len)
355 {
356 	struct fwnet_partial_datagram *new;
357 	struct fwnet_fragment_info *fi;
358 
359 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
360 	if (!new)
361 		goto fail;
362 
363 	INIT_LIST_HEAD(&new->fi_list);
364 	fi = fwnet_frag_new(new, frag_off, frag_len);
365 	if (fi == NULL)
366 		goto fail_w_new;
367 
368 	new->datagram_label = datagram_label;
369 	new->datagram_size = dg_size;
370 	new->skb = dev_alloc_skb(dg_size + LL_RESERVED_SPACE(net));
371 	if (new->skb == NULL)
372 		goto fail_w_fi;
373 
374 	skb_reserve(new->skb, LL_RESERVED_SPACE(net));
375 	new->pbuf = skb_put(new->skb, dg_size);
376 	memcpy(new->pbuf + frag_off, frag_buf, frag_len);
377 	list_add_tail(&new->pd_link, &peer->pd_list);
378 
379 	return new;
380 
381 fail_w_fi:
382 	kfree(fi);
383 fail_w_new:
384 	kfree(new);
385 fail:
386 	return NULL;
387 }
388 
389 static struct fwnet_partial_datagram *fwnet_pd_find(struct fwnet_peer *peer,
390 						    u16 datagram_label)
391 {
392 	struct fwnet_partial_datagram *pd;
393 
394 	list_for_each_entry(pd, &peer->pd_list, pd_link)
395 		if (pd->datagram_label == datagram_label)
396 			return pd;
397 
398 	return NULL;
399 }
400 
401 
402 static void fwnet_pd_delete(struct fwnet_partial_datagram *old)
403 {
404 	struct fwnet_fragment_info *fi, *n;
405 
406 	list_for_each_entry_safe(fi, n, &old->fi_list, fi_link)
407 		kfree(fi);
408 
409 	list_del(&old->pd_link);
410 	dev_kfree_skb_any(old->skb);
411 	kfree(old);
412 }
413 
414 static bool fwnet_pd_update(struct fwnet_peer *peer,
415 		struct fwnet_partial_datagram *pd, void *frag_buf,
416 		unsigned frag_off, unsigned frag_len)
417 {
418 	if (fwnet_frag_new(pd, frag_off, frag_len) == NULL)
419 		return false;
420 
421 	memcpy(pd->pbuf + frag_off, frag_buf, frag_len);
422 
423 	/*
424 	 * Move list entry to beginning of list so that oldest partial
425 	 * datagrams percolate to the end of the list
426 	 */
427 	list_move_tail(&pd->pd_link, &peer->pd_list);
428 
429 	return true;
430 }
431 
432 static bool fwnet_pd_is_complete(struct fwnet_partial_datagram *pd)
433 {
434 	struct fwnet_fragment_info *fi;
435 
436 	fi = list_entry(pd->fi_list.next, struct fwnet_fragment_info, fi_link);
437 
438 	return fi->len == pd->datagram_size;
439 }
440 
441 /* caller must hold dev->lock */
442 static struct fwnet_peer *fwnet_peer_find_by_guid(struct fwnet_device *dev,
443 						  u64 guid)
444 {
445 	struct fwnet_peer *peer;
446 
447 	list_for_each_entry(peer, &dev->peer_list, peer_link)
448 		if (peer->guid == guid)
449 			return peer;
450 
451 	return NULL;
452 }
453 
454 /* caller must hold dev->lock */
455 static struct fwnet_peer *fwnet_peer_find_by_node_id(struct fwnet_device *dev,
456 						int node_id, int generation)
457 {
458 	struct fwnet_peer *peer;
459 
460 	list_for_each_entry(peer, &dev->peer_list, peer_link)
461 		if (peer->node_id    == node_id &&
462 		    peer->generation == generation)
463 			return peer;
464 
465 	return NULL;
466 }
467 
468 /* See IEEE 1394-2008 table 6-4, table 8-8, table 16-18. */
469 static unsigned fwnet_max_payload(unsigned max_rec, unsigned speed)
470 {
471 	max_rec = min(max_rec, speed + 8);
472 	max_rec = clamp(max_rec, 8U, 11U); /* 512...4096 */
473 
474 	return (1 << (max_rec + 1)) - RFC2374_FRAG_HDR_SIZE;
475 }
476 
477 
478 static int fwnet_finish_incoming_packet(struct net_device *net,
479 					struct sk_buff *skb, u16 source_node_id,
480 					bool is_broadcast, u16 ether_type)
481 {
482 	int status;
483 
484 	switch (ether_type) {
485 	case ETH_P_ARP:
486 	case ETH_P_IP:
487 #if IS_ENABLED(CONFIG_IPV6)
488 	case ETH_P_IPV6:
489 #endif
490 		break;
491 	default:
492 		goto err;
493 	}
494 
495 	/* Write metadata, and then pass to the receive level */
496 	skb->dev = net;
497 	skb->ip_summed = CHECKSUM_NONE;
498 
499 	/*
500 	 * Parse the encapsulation header. This actually does the job of
501 	 * converting to an ethernet-like pseudo frame header.
502 	 */
503 	if (dev_hard_header(skb, net, ether_type,
504 			   is_broadcast ? net->broadcast : net->dev_addr,
505 			   NULL, skb->len) >= 0) {
506 		struct fwnet_header *eth;
507 		u16 *rawp;
508 		__be16 protocol;
509 
510 		skb_reset_mac_header(skb);
511 		skb_pull(skb, sizeof(*eth));
512 		eth = (struct fwnet_header *)skb_mac_header(skb);
513 		if (fwnet_hwaddr_is_multicast(eth->h_dest)) {
514 			if (memcmp(eth->h_dest, net->broadcast,
515 				   net->addr_len) == 0)
516 				skb->pkt_type = PACKET_BROADCAST;
517 #if 0
518 			else
519 				skb->pkt_type = PACKET_MULTICAST;
520 #endif
521 		} else {
522 			if (memcmp(eth->h_dest, net->dev_addr, net->addr_len))
523 				skb->pkt_type = PACKET_OTHERHOST;
524 		}
525 		if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN) {
526 			protocol = eth->h_proto;
527 		} else {
528 			rawp = (u16 *)skb->data;
529 			if (*rawp == 0xffff)
530 				protocol = htons(ETH_P_802_3);
531 			else
532 				protocol = htons(ETH_P_802_2);
533 		}
534 		skb->protocol = protocol;
535 	}
536 	status = netif_rx(skb);
537 	if (status == NET_RX_DROP) {
538 		net->stats.rx_errors++;
539 		net->stats.rx_dropped++;
540 	} else {
541 		net->stats.rx_packets++;
542 		net->stats.rx_bytes += skb->len;
543 	}
544 
545 	return 0;
546 
547  err:
548 	net->stats.rx_errors++;
549 	net->stats.rx_dropped++;
550 
551 	dev_kfree_skb_any(skb);
552 
553 	return -ENOENT;
554 }
555 
556 static int fwnet_incoming_packet(struct fwnet_device *dev, __be32 *buf, int len,
557 				 int source_node_id, int generation,
558 				 bool is_broadcast)
559 {
560 	struct sk_buff *skb;
561 	struct net_device *net = dev->netdev;
562 	struct rfc2734_header hdr;
563 	unsigned lf;
564 	unsigned long flags;
565 	struct fwnet_peer *peer;
566 	struct fwnet_partial_datagram *pd;
567 	int fg_off;
568 	int dg_size;
569 	u16 datagram_label;
570 	int retval;
571 	u16 ether_type;
572 
573 	if (len <= RFC2374_UNFRAG_HDR_SIZE)
574 		return 0;
575 
576 	hdr.w0 = be32_to_cpu(buf[0]);
577 	lf = fwnet_get_hdr_lf(&hdr);
578 	if (lf == RFC2374_HDR_UNFRAG) {
579 		/*
580 		 * An unfragmented datagram has been received by the ieee1394
581 		 * bus. Build an skbuff around it so we can pass it to the
582 		 * high level network layer.
583 		 */
584 		ether_type = fwnet_get_hdr_ether_type(&hdr);
585 		buf++;
586 		len -= RFC2374_UNFRAG_HDR_SIZE;
587 
588 		skb = dev_alloc_skb(len + LL_RESERVED_SPACE(net));
589 		if (unlikely(!skb)) {
590 			net->stats.rx_dropped++;
591 
592 			return -ENOMEM;
593 		}
594 		skb_reserve(skb, LL_RESERVED_SPACE(net));
595 		skb_put_data(skb, buf, len);
596 
597 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
598 						    is_broadcast, ether_type);
599 	}
600 
601 	/* A datagram fragment has been received, now the fun begins. */
602 
603 	if (len <= RFC2374_FRAG_HDR_SIZE)
604 		return 0;
605 
606 	hdr.w1 = ntohl(buf[1]);
607 	buf += 2;
608 	len -= RFC2374_FRAG_HDR_SIZE;
609 	if (lf == RFC2374_HDR_FIRSTFRAG) {
610 		ether_type = fwnet_get_hdr_ether_type(&hdr);
611 		fg_off = 0;
612 	} else {
613 		ether_type = 0;
614 		fg_off = fwnet_get_hdr_fg_off(&hdr);
615 	}
616 	datagram_label = fwnet_get_hdr_dgl(&hdr);
617 	dg_size = fwnet_get_hdr_dg_size(&hdr);
618 
619 	if (fg_off + len > dg_size)
620 		return 0;
621 
622 	spin_lock_irqsave(&dev->lock, flags);
623 
624 	peer = fwnet_peer_find_by_node_id(dev, source_node_id, generation);
625 	if (!peer) {
626 		retval = -ENOENT;
627 		goto fail;
628 	}
629 
630 	pd = fwnet_pd_find(peer, datagram_label);
631 	if (pd == NULL) {
632 		while (peer->pdg_size >= FWNET_MAX_FRAGMENTS) {
633 			/* remove the oldest */
634 			fwnet_pd_delete(list_first_entry(&peer->pd_list,
635 				struct fwnet_partial_datagram, pd_link));
636 			peer->pdg_size--;
637 		}
638 		pd = fwnet_pd_new(net, peer, datagram_label,
639 				  dg_size, buf, fg_off, len);
640 		if (pd == NULL) {
641 			retval = -ENOMEM;
642 			goto fail;
643 		}
644 		peer->pdg_size++;
645 	} else {
646 		if (fwnet_frag_overlap(pd, fg_off, len) ||
647 		    pd->datagram_size != dg_size) {
648 			/*
649 			 * Differing datagram sizes or overlapping fragments,
650 			 * discard old datagram and start a new one.
651 			 */
652 			fwnet_pd_delete(pd);
653 			pd = fwnet_pd_new(net, peer, datagram_label,
654 					  dg_size, buf, fg_off, len);
655 			if (pd == NULL) {
656 				peer->pdg_size--;
657 				retval = -ENOMEM;
658 				goto fail;
659 			}
660 		} else {
661 			if (!fwnet_pd_update(peer, pd, buf, fg_off, len)) {
662 				/*
663 				 * Couldn't save off fragment anyway
664 				 * so might as well obliterate the
665 				 * datagram now.
666 				 */
667 				fwnet_pd_delete(pd);
668 				peer->pdg_size--;
669 				retval = -ENOMEM;
670 				goto fail;
671 			}
672 		}
673 	} /* new datagram or add to existing one */
674 
675 	if (lf == RFC2374_HDR_FIRSTFRAG)
676 		pd->ether_type = ether_type;
677 
678 	if (fwnet_pd_is_complete(pd)) {
679 		ether_type = pd->ether_type;
680 		peer->pdg_size--;
681 		skb = skb_get(pd->skb);
682 		fwnet_pd_delete(pd);
683 
684 		spin_unlock_irqrestore(&dev->lock, flags);
685 
686 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
687 						    false, ether_type);
688 	}
689 	/*
690 	 * Datagram is not complete, we're done for the
691 	 * moment.
692 	 */
693 	retval = 0;
694  fail:
695 	spin_unlock_irqrestore(&dev->lock, flags);
696 
697 	return retval;
698 }
699 
700 static void fwnet_receive_packet(struct fw_card *card, struct fw_request *r,
701 		int tcode, int destination, int source, int generation,
702 		unsigned long long offset, void *payload, size_t length,
703 		void *callback_data)
704 {
705 	struct fwnet_device *dev = callback_data;
706 	int rcode;
707 
708 	if (destination == IEEE1394_ALL_NODES) {
709 		kfree(r);
710 
711 		return;
712 	}
713 
714 	if (offset != dev->handler.offset)
715 		rcode = RCODE_ADDRESS_ERROR;
716 	else if (tcode != TCODE_WRITE_BLOCK_REQUEST)
717 		rcode = RCODE_TYPE_ERROR;
718 	else if (fwnet_incoming_packet(dev, payload, length,
719 				       source, generation, false) != 0) {
720 		dev_err(&dev->netdev->dev, "incoming packet failure\n");
721 		rcode = RCODE_CONFLICT_ERROR;
722 	} else
723 		rcode = RCODE_COMPLETE;
724 
725 	fw_send_response(card, r, rcode);
726 }
727 
728 static int gasp_source_id(__be32 *p)
729 {
730 	return be32_to_cpu(p[0]) >> 16;
731 }
732 
733 static u32 gasp_specifier_id(__be32 *p)
734 {
735 	return (be32_to_cpu(p[0]) & 0xffff) << 8 |
736 	       (be32_to_cpu(p[1]) & 0xff000000) >> 24;
737 }
738 
739 static u32 gasp_version(__be32 *p)
740 {
741 	return be32_to_cpu(p[1]) & 0xffffff;
742 }
743 
744 static void fwnet_receive_broadcast(struct fw_iso_context *context,
745 		u32 cycle, size_t header_length, void *header, void *data)
746 {
747 	struct fwnet_device *dev;
748 	struct fw_iso_packet packet;
749 	__be16 *hdr_ptr;
750 	__be32 *buf_ptr;
751 	int retval;
752 	u32 length;
753 	unsigned long offset;
754 	unsigned long flags;
755 
756 	dev = data;
757 	hdr_ptr = header;
758 	length = be16_to_cpup(hdr_ptr);
759 
760 	spin_lock_irqsave(&dev->lock, flags);
761 
762 	offset = dev->rcv_buffer_size * dev->broadcast_rcv_next_ptr;
763 	buf_ptr = dev->broadcast_rcv_buffer_ptrs[dev->broadcast_rcv_next_ptr++];
764 	if (dev->broadcast_rcv_next_ptr == dev->num_broadcast_rcv_ptrs)
765 		dev->broadcast_rcv_next_ptr = 0;
766 
767 	spin_unlock_irqrestore(&dev->lock, flags);
768 
769 	if (length > IEEE1394_GASP_HDR_SIZE &&
770 	    gasp_specifier_id(buf_ptr) == IANA_SPECIFIER_ID &&
771 	    (gasp_version(buf_ptr) == RFC2734_SW_VERSION
772 #if IS_ENABLED(CONFIG_IPV6)
773 	     || gasp_version(buf_ptr) == RFC3146_SW_VERSION
774 #endif
775 	    ))
776 		fwnet_incoming_packet(dev, buf_ptr + 2,
777 				      length - IEEE1394_GASP_HDR_SIZE,
778 				      gasp_source_id(buf_ptr),
779 				      context->card->generation, true);
780 
781 	packet.payload_length = dev->rcv_buffer_size;
782 	packet.interrupt = 1;
783 	packet.skip = 0;
784 	packet.tag = 3;
785 	packet.sy = 0;
786 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
787 
788 	spin_lock_irqsave(&dev->lock, flags);
789 
790 	retval = fw_iso_context_queue(dev->broadcast_rcv_context, &packet,
791 				      &dev->broadcast_rcv_buffer, offset);
792 
793 	spin_unlock_irqrestore(&dev->lock, flags);
794 
795 	if (retval >= 0)
796 		fw_iso_context_queue_flush(dev->broadcast_rcv_context);
797 	else
798 		dev_err(&dev->netdev->dev, "requeue failed\n");
799 }
800 
801 static struct kmem_cache *fwnet_packet_task_cache;
802 
803 static void fwnet_free_ptask(struct fwnet_packet_task *ptask)
804 {
805 	dev_kfree_skb_any(ptask->skb);
806 	kmem_cache_free(fwnet_packet_task_cache, ptask);
807 }
808 
809 /* Caller must hold dev->lock. */
810 static void dec_queued_datagrams(struct fwnet_device *dev)
811 {
812 	if (--dev->queued_datagrams == FWNET_MIN_QUEUED_DATAGRAMS)
813 		netif_wake_queue(dev->netdev);
814 }
815 
816 static int fwnet_send_packet(struct fwnet_packet_task *ptask);
817 
818 static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
819 {
820 	struct fwnet_device *dev = ptask->dev;
821 	struct sk_buff *skb = ptask->skb;
822 	unsigned long flags;
823 	bool free;
824 
825 	spin_lock_irqsave(&dev->lock, flags);
826 
827 	ptask->outstanding_pkts--;
828 
829 	/* Check whether we or the networking TX soft-IRQ is last user. */
830 	free = (ptask->outstanding_pkts == 0 && ptask->enqueued);
831 	if (free)
832 		dec_queued_datagrams(dev);
833 
834 	if (ptask->outstanding_pkts == 0) {
835 		dev->netdev->stats.tx_packets++;
836 		dev->netdev->stats.tx_bytes += skb->len;
837 	}
838 
839 	spin_unlock_irqrestore(&dev->lock, flags);
840 
841 	if (ptask->outstanding_pkts > 0) {
842 		u16 dg_size;
843 		u16 fg_off;
844 		u16 datagram_label;
845 		u16 lf;
846 
847 		/* Update the ptask to point to the next fragment and send it */
848 		lf = fwnet_get_hdr_lf(&ptask->hdr);
849 		switch (lf) {
850 		case RFC2374_HDR_LASTFRAG:
851 		case RFC2374_HDR_UNFRAG:
852 		default:
853 			dev_err(&dev->netdev->dev,
854 				"outstanding packet %x lf %x, header %x,%x\n",
855 				ptask->outstanding_pkts, lf, ptask->hdr.w0,
856 				ptask->hdr.w1);
857 			BUG();
858 
859 		case RFC2374_HDR_FIRSTFRAG:
860 			/* Set frag type here for future interior fragments */
861 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
862 			fg_off = ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
863 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
864 			break;
865 
866 		case RFC2374_HDR_INTFRAG:
867 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
868 			fg_off = fwnet_get_hdr_fg_off(&ptask->hdr)
869 				  + ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
870 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
871 			break;
872 		}
873 
874 		if (ptask->dest_node == IEEE1394_ALL_NODES) {
875 			skb_pull(skb,
876 				 ptask->max_payload + IEEE1394_GASP_HDR_SIZE);
877 		} else {
878 			skb_pull(skb, ptask->max_payload);
879 		}
880 		if (ptask->outstanding_pkts > 1) {
881 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_INTFRAG,
882 					  dg_size, fg_off, datagram_label);
883 		} else {
884 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_LASTFRAG,
885 					  dg_size, fg_off, datagram_label);
886 			ptask->max_payload = skb->len + RFC2374_FRAG_HDR_SIZE;
887 		}
888 		fwnet_send_packet(ptask);
889 	}
890 
891 	if (free)
892 		fwnet_free_ptask(ptask);
893 }
894 
895 static void fwnet_transmit_packet_failed(struct fwnet_packet_task *ptask)
896 {
897 	struct fwnet_device *dev = ptask->dev;
898 	unsigned long flags;
899 	bool free;
900 
901 	spin_lock_irqsave(&dev->lock, flags);
902 
903 	/* One fragment failed; don't try to send remaining fragments. */
904 	ptask->outstanding_pkts = 0;
905 
906 	/* Check whether we or the networking TX soft-IRQ is last user. */
907 	free = ptask->enqueued;
908 	if (free)
909 		dec_queued_datagrams(dev);
910 
911 	dev->netdev->stats.tx_dropped++;
912 	dev->netdev->stats.tx_errors++;
913 
914 	spin_unlock_irqrestore(&dev->lock, flags);
915 
916 	if (free)
917 		fwnet_free_ptask(ptask);
918 }
919 
920 static void fwnet_write_complete(struct fw_card *card, int rcode,
921 				 void *payload, size_t length, void *data)
922 {
923 	struct fwnet_packet_task *ptask = data;
924 	static unsigned long j;
925 	static int last_rcode, errors_skipped;
926 
927 	if (rcode == RCODE_COMPLETE) {
928 		fwnet_transmit_packet_done(ptask);
929 	} else {
930 		if (printk_timed_ratelimit(&j,  1000) || rcode != last_rcode) {
931 			dev_err(&ptask->dev->netdev->dev,
932 				"fwnet_write_complete failed: %x (skipped %d)\n",
933 				rcode, errors_skipped);
934 
935 			errors_skipped = 0;
936 			last_rcode = rcode;
937 		} else {
938 			errors_skipped++;
939 		}
940 		fwnet_transmit_packet_failed(ptask);
941 	}
942 }
943 
944 static int fwnet_send_packet(struct fwnet_packet_task *ptask)
945 {
946 	struct fwnet_device *dev;
947 	unsigned tx_len;
948 	struct rfc2734_header *bufhdr;
949 	unsigned long flags;
950 	bool free;
951 
952 	dev = ptask->dev;
953 	tx_len = ptask->max_payload;
954 	switch (fwnet_get_hdr_lf(&ptask->hdr)) {
955 	case RFC2374_HDR_UNFRAG:
956 		bufhdr = skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
957 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
958 		break;
959 
960 	case RFC2374_HDR_FIRSTFRAG:
961 	case RFC2374_HDR_INTFRAG:
962 	case RFC2374_HDR_LASTFRAG:
963 		bufhdr = skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
964 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
965 		put_unaligned_be32(ptask->hdr.w1, &bufhdr->w1);
966 		break;
967 
968 	default:
969 		BUG();
970 	}
971 	if (ptask->dest_node == IEEE1394_ALL_NODES) {
972 		u8 *p;
973 		int generation;
974 		int node_id;
975 		unsigned int sw_version;
976 
977 		/* ptask->generation may not have been set yet */
978 		generation = dev->card->generation;
979 		smp_rmb();
980 		node_id = dev->card->node_id;
981 
982 		switch (ptask->skb->protocol) {
983 		default:
984 			sw_version = RFC2734_SW_VERSION;
985 			break;
986 #if IS_ENABLED(CONFIG_IPV6)
987 		case htons(ETH_P_IPV6):
988 			sw_version = RFC3146_SW_VERSION;
989 #endif
990 		}
991 
992 		p = skb_push(ptask->skb, IEEE1394_GASP_HDR_SIZE);
993 		put_unaligned_be32(node_id << 16 | IANA_SPECIFIER_ID >> 8, p);
994 		put_unaligned_be32((IANA_SPECIFIER_ID & 0xff) << 24
995 						| sw_version, &p[4]);
996 
997 		/* We should not transmit if broadcast_channel.valid == 0. */
998 		fw_send_request(dev->card, &ptask->transaction,
999 				TCODE_STREAM_DATA,
1000 				fw_stream_packet_destination_id(3,
1001 						IEEE1394_BROADCAST_CHANNEL, 0),
1002 				generation, SCODE_100, 0ULL, ptask->skb->data,
1003 				tx_len + 8, fwnet_write_complete, ptask);
1004 
1005 		spin_lock_irqsave(&dev->lock, flags);
1006 
1007 		/* If the AT tasklet already ran, we may be last user. */
1008 		free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1009 		if (!free)
1010 			ptask->enqueued = true;
1011 		else
1012 			dec_queued_datagrams(dev);
1013 
1014 		spin_unlock_irqrestore(&dev->lock, flags);
1015 
1016 		goto out;
1017 	}
1018 
1019 	fw_send_request(dev->card, &ptask->transaction,
1020 			TCODE_WRITE_BLOCK_REQUEST, ptask->dest_node,
1021 			ptask->generation, ptask->speed, ptask->fifo_addr,
1022 			ptask->skb->data, tx_len, fwnet_write_complete, ptask);
1023 
1024 	spin_lock_irqsave(&dev->lock, flags);
1025 
1026 	/* If the AT tasklet already ran, we may be last user. */
1027 	free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1028 	if (!free)
1029 		ptask->enqueued = true;
1030 	else
1031 		dec_queued_datagrams(dev);
1032 
1033 	spin_unlock_irqrestore(&dev->lock, flags);
1034 
1035 	netif_trans_update(dev->netdev);
1036  out:
1037 	if (free)
1038 		fwnet_free_ptask(ptask);
1039 
1040 	return 0;
1041 }
1042 
1043 static void fwnet_fifo_stop(struct fwnet_device *dev)
1044 {
1045 	if (dev->local_fifo == FWNET_NO_FIFO_ADDR)
1046 		return;
1047 
1048 	fw_core_remove_address_handler(&dev->handler);
1049 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1050 }
1051 
1052 static int fwnet_fifo_start(struct fwnet_device *dev)
1053 {
1054 	int retval;
1055 
1056 	if (dev->local_fifo != FWNET_NO_FIFO_ADDR)
1057 		return 0;
1058 
1059 	dev->handler.length = 4096;
1060 	dev->handler.address_callback = fwnet_receive_packet;
1061 	dev->handler.callback_data = dev;
1062 
1063 	retval = fw_core_add_address_handler(&dev->handler,
1064 					     &fw_high_memory_region);
1065 	if (retval < 0)
1066 		return retval;
1067 
1068 	dev->local_fifo = dev->handler.offset;
1069 
1070 	return 0;
1071 }
1072 
1073 static void __fwnet_broadcast_stop(struct fwnet_device *dev)
1074 {
1075 	unsigned u;
1076 
1077 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR) {
1078 		for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++)
1079 			kunmap(dev->broadcast_rcv_buffer.pages[u]);
1080 		fw_iso_buffer_destroy(&dev->broadcast_rcv_buffer, dev->card);
1081 	}
1082 	if (dev->broadcast_rcv_context) {
1083 		fw_iso_context_destroy(dev->broadcast_rcv_context);
1084 		dev->broadcast_rcv_context = NULL;
1085 	}
1086 	kfree(dev->broadcast_rcv_buffer_ptrs);
1087 	dev->broadcast_rcv_buffer_ptrs = NULL;
1088 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1089 }
1090 
1091 static void fwnet_broadcast_stop(struct fwnet_device *dev)
1092 {
1093 	if (dev->broadcast_state == FWNET_BROADCAST_ERROR)
1094 		return;
1095 	fw_iso_context_stop(dev->broadcast_rcv_context);
1096 	__fwnet_broadcast_stop(dev);
1097 }
1098 
1099 static int fwnet_broadcast_start(struct fwnet_device *dev)
1100 {
1101 	struct fw_iso_context *context;
1102 	int retval;
1103 	unsigned num_packets;
1104 	unsigned max_receive;
1105 	struct fw_iso_packet packet;
1106 	unsigned long offset;
1107 	void **ptrptr;
1108 	unsigned u;
1109 
1110 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR)
1111 		return 0;
1112 
1113 	max_receive = 1U << (dev->card->max_receive + 1);
1114 	num_packets = (FWNET_ISO_PAGE_COUNT * PAGE_SIZE) / max_receive;
1115 
1116 	ptrptr = kmalloc_array(num_packets, sizeof(void *), GFP_KERNEL);
1117 	if (!ptrptr) {
1118 		retval = -ENOMEM;
1119 		goto failed;
1120 	}
1121 	dev->broadcast_rcv_buffer_ptrs = ptrptr;
1122 
1123 	context = fw_iso_context_create(dev->card, FW_ISO_CONTEXT_RECEIVE,
1124 					IEEE1394_BROADCAST_CHANNEL,
1125 					dev->card->link_speed, 8,
1126 					fwnet_receive_broadcast, dev);
1127 	if (IS_ERR(context)) {
1128 		retval = PTR_ERR(context);
1129 		goto failed;
1130 	}
1131 
1132 	retval = fw_iso_buffer_init(&dev->broadcast_rcv_buffer, dev->card,
1133 				    FWNET_ISO_PAGE_COUNT, DMA_FROM_DEVICE);
1134 	if (retval < 0)
1135 		goto failed;
1136 
1137 	dev->broadcast_state = FWNET_BROADCAST_STOPPED;
1138 
1139 	for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++) {
1140 		void *ptr;
1141 		unsigned v;
1142 
1143 		ptr = kmap(dev->broadcast_rcv_buffer.pages[u]);
1144 		for (v = 0; v < num_packets / FWNET_ISO_PAGE_COUNT; v++)
1145 			*ptrptr++ = (void *) ((char *)ptr + v * max_receive);
1146 	}
1147 	dev->broadcast_rcv_context = context;
1148 
1149 	packet.payload_length = max_receive;
1150 	packet.interrupt = 1;
1151 	packet.skip = 0;
1152 	packet.tag = 3;
1153 	packet.sy = 0;
1154 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
1155 	offset = 0;
1156 
1157 	for (u = 0; u < num_packets; u++) {
1158 		retval = fw_iso_context_queue(context, &packet,
1159 				&dev->broadcast_rcv_buffer, offset);
1160 		if (retval < 0)
1161 			goto failed;
1162 
1163 		offset += max_receive;
1164 	}
1165 	dev->num_broadcast_rcv_ptrs = num_packets;
1166 	dev->rcv_buffer_size = max_receive;
1167 	dev->broadcast_rcv_next_ptr = 0U;
1168 	retval = fw_iso_context_start(context, -1, 0,
1169 			FW_ISO_CONTEXT_MATCH_ALL_TAGS); /* ??? sync */
1170 	if (retval < 0)
1171 		goto failed;
1172 
1173 	/* FIXME: adjust it according to the min. speed of all known peers? */
1174 	dev->broadcast_xmt_max_payload = IEEE1394_MAX_PAYLOAD_S100
1175 			- IEEE1394_GASP_HDR_SIZE - RFC2374_UNFRAG_HDR_SIZE;
1176 	dev->broadcast_state = FWNET_BROADCAST_RUNNING;
1177 
1178 	return 0;
1179 
1180  failed:
1181 	__fwnet_broadcast_stop(dev);
1182 	return retval;
1183 }
1184 
1185 static void set_carrier_state(struct fwnet_device *dev)
1186 {
1187 	if (dev->peer_count > 1)
1188 		netif_carrier_on(dev->netdev);
1189 	else
1190 		netif_carrier_off(dev->netdev);
1191 }
1192 
1193 /* ifup */
1194 static int fwnet_open(struct net_device *net)
1195 {
1196 	struct fwnet_device *dev = netdev_priv(net);
1197 	int ret;
1198 
1199 	ret = fwnet_broadcast_start(dev);
1200 	if (ret)
1201 		return ret;
1202 
1203 	netif_start_queue(net);
1204 
1205 	spin_lock_irq(&dev->lock);
1206 	set_carrier_state(dev);
1207 	spin_unlock_irq(&dev->lock);
1208 
1209 	return 0;
1210 }
1211 
1212 /* ifdown */
1213 static int fwnet_stop(struct net_device *net)
1214 {
1215 	struct fwnet_device *dev = netdev_priv(net);
1216 
1217 	netif_stop_queue(net);
1218 	fwnet_broadcast_stop(dev);
1219 
1220 	return 0;
1221 }
1222 
1223 static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
1224 {
1225 	struct fwnet_header hdr_buf;
1226 	struct fwnet_device *dev = netdev_priv(net);
1227 	__be16 proto;
1228 	u16 dest_node;
1229 	unsigned max_payload;
1230 	u16 dg_size;
1231 	u16 *datagram_label_ptr;
1232 	struct fwnet_packet_task *ptask;
1233 	struct fwnet_peer *peer;
1234 	unsigned long flags;
1235 
1236 	spin_lock_irqsave(&dev->lock, flags);
1237 
1238 	/* Can this happen? */
1239 	if (netif_queue_stopped(dev->netdev)) {
1240 		spin_unlock_irqrestore(&dev->lock, flags);
1241 
1242 		return NETDEV_TX_BUSY;
1243 	}
1244 
1245 	ptask = kmem_cache_alloc(fwnet_packet_task_cache, GFP_ATOMIC);
1246 	if (ptask == NULL)
1247 		goto fail;
1248 
1249 	skb = skb_share_check(skb, GFP_ATOMIC);
1250 	if (!skb)
1251 		goto fail;
1252 
1253 	/*
1254 	 * Make a copy of the driver-specific header.
1255 	 * We might need to rebuild the header on tx failure.
1256 	 */
1257 	memcpy(&hdr_buf, skb->data, sizeof(hdr_buf));
1258 	proto = hdr_buf.h_proto;
1259 
1260 	switch (proto) {
1261 	case htons(ETH_P_ARP):
1262 	case htons(ETH_P_IP):
1263 #if IS_ENABLED(CONFIG_IPV6)
1264 	case htons(ETH_P_IPV6):
1265 #endif
1266 		break;
1267 	default:
1268 		goto fail;
1269 	}
1270 
1271 	skb_pull(skb, sizeof(hdr_buf));
1272 	dg_size = skb->len;
1273 
1274 	/*
1275 	 * Set the transmission type for the packet.  ARP packets and IP
1276 	 * broadcast packets are sent via GASP.
1277 	 */
1278 	if (fwnet_hwaddr_is_multicast(hdr_buf.h_dest)) {
1279 		max_payload        = dev->broadcast_xmt_max_payload;
1280 		datagram_label_ptr = &dev->broadcast_xmt_datagramlabel;
1281 
1282 		ptask->fifo_addr   = FWNET_NO_FIFO_ADDR;
1283 		ptask->generation  = 0;
1284 		ptask->dest_node   = IEEE1394_ALL_NODES;
1285 		ptask->speed       = SCODE_100;
1286 	} else {
1287 		union fwnet_hwaddr *ha = (union fwnet_hwaddr *)hdr_buf.h_dest;
1288 		__be64 guid = get_unaligned(&ha->uc.uniq_id);
1289 		u8 generation;
1290 
1291 		peer = fwnet_peer_find_by_guid(dev, be64_to_cpu(guid));
1292 		if (!peer)
1293 			goto fail;
1294 
1295 		generation         = peer->generation;
1296 		dest_node          = peer->node_id;
1297 		max_payload        = peer->max_payload;
1298 		datagram_label_ptr = &peer->datagram_label;
1299 
1300 		ptask->fifo_addr   = get_unaligned_be48(ha->uc.fifo);
1301 		ptask->generation  = generation;
1302 		ptask->dest_node   = dest_node;
1303 		ptask->speed       = peer->speed;
1304 	}
1305 
1306 	ptask->hdr.w0 = 0;
1307 	ptask->hdr.w1 = 0;
1308 	ptask->skb = skb;
1309 	ptask->dev = dev;
1310 
1311 	/* Does it all fit in one packet? */
1312 	if (dg_size <= max_payload) {
1313 		fwnet_make_uf_hdr(&ptask->hdr, ntohs(proto));
1314 		ptask->outstanding_pkts = 1;
1315 		max_payload = dg_size + RFC2374_UNFRAG_HDR_SIZE;
1316 	} else {
1317 		u16 datagram_label;
1318 
1319 		max_payload -= RFC2374_FRAG_OVERHEAD;
1320 		datagram_label = (*datagram_label_ptr)++;
1321 		fwnet_make_ff_hdr(&ptask->hdr, ntohs(proto), dg_size,
1322 				  datagram_label);
1323 		ptask->outstanding_pkts = DIV_ROUND_UP(dg_size, max_payload);
1324 		max_payload += RFC2374_FRAG_HDR_SIZE;
1325 	}
1326 
1327 	if (++dev->queued_datagrams == FWNET_MAX_QUEUED_DATAGRAMS)
1328 		netif_stop_queue(dev->netdev);
1329 
1330 	spin_unlock_irqrestore(&dev->lock, flags);
1331 
1332 	ptask->max_payload = max_payload;
1333 	ptask->enqueued    = 0;
1334 
1335 	fwnet_send_packet(ptask);
1336 
1337 	return NETDEV_TX_OK;
1338 
1339  fail:
1340 	spin_unlock_irqrestore(&dev->lock, flags);
1341 
1342 	if (ptask)
1343 		kmem_cache_free(fwnet_packet_task_cache, ptask);
1344 
1345 	if (skb != NULL)
1346 		dev_kfree_skb(skb);
1347 
1348 	net->stats.tx_dropped++;
1349 	net->stats.tx_errors++;
1350 
1351 	/*
1352 	 * FIXME: According to a patch from 2003-02-26, "returning non-zero
1353 	 * causes serious problems" here, allegedly.  Before that patch,
1354 	 * -ERRNO was returned which is not appropriate under Linux 2.6.
1355 	 * Perhaps more needs to be done?  Stop the queue in serious
1356 	 * conditions and restart it elsewhere?
1357 	 */
1358 	return NETDEV_TX_OK;
1359 }
1360 
1361 static const struct ethtool_ops fwnet_ethtool_ops = {
1362 	.get_link	= ethtool_op_get_link,
1363 };
1364 
1365 static const struct net_device_ops fwnet_netdev_ops = {
1366 	.ndo_open       = fwnet_open,
1367 	.ndo_stop	= fwnet_stop,
1368 	.ndo_start_xmit = fwnet_tx,
1369 };
1370 
1371 static void fwnet_init_dev(struct net_device *net)
1372 {
1373 	net->header_ops		= &fwnet_header_ops;
1374 	net->netdev_ops		= &fwnet_netdev_ops;
1375 	net->watchdog_timeo	= 2 * HZ;
1376 	net->flags		= IFF_BROADCAST | IFF_MULTICAST;
1377 	net->features		= NETIF_F_HIGHDMA;
1378 	net->addr_len		= FWNET_ALEN;
1379 	net->hard_header_len	= FWNET_HLEN;
1380 	net->type		= ARPHRD_IEEE1394;
1381 	net->tx_queue_len	= FWNET_TX_QUEUE_LEN;
1382 	net->ethtool_ops	= &fwnet_ethtool_ops;
1383 }
1384 
1385 /* caller must hold fwnet_device_mutex */
1386 static struct fwnet_device *fwnet_dev_find(struct fw_card *card)
1387 {
1388 	struct fwnet_device *dev;
1389 
1390 	list_for_each_entry(dev, &fwnet_device_list, dev_link)
1391 		if (dev->card == card)
1392 			return dev;
1393 
1394 	return NULL;
1395 }
1396 
1397 static int fwnet_add_peer(struct fwnet_device *dev,
1398 			  struct fw_unit *unit, struct fw_device *device)
1399 {
1400 	struct fwnet_peer *peer;
1401 
1402 	peer = kmalloc(sizeof(*peer), GFP_KERNEL);
1403 	if (!peer)
1404 		return -ENOMEM;
1405 
1406 	dev_set_drvdata(&unit->device, peer);
1407 
1408 	peer->dev = dev;
1409 	peer->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1410 	INIT_LIST_HEAD(&peer->pd_list);
1411 	peer->pdg_size = 0;
1412 	peer->datagram_label = 0;
1413 	peer->speed = device->max_speed;
1414 	peer->max_payload = fwnet_max_payload(device->max_rec, peer->speed);
1415 
1416 	peer->generation = device->generation;
1417 	smp_rmb();
1418 	peer->node_id = device->node_id;
1419 
1420 	spin_lock_irq(&dev->lock);
1421 	list_add_tail(&peer->peer_link, &dev->peer_list);
1422 	dev->peer_count++;
1423 	set_carrier_state(dev);
1424 	spin_unlock_irq(&dev->lock);
1425 
1426 	return 0;
1427 }
1428 
1429 static int fwnet_probe(struct fw_unit *unit,
1430 		       const struct ieee1394_device_id *id)
1431 {
1432 	struct fw_device *device = fw_parent_device(unit);
1433 	struct fw_card *card = device->card;
1434 	struct net_device *net;
1435 	bool allocated_netdev = false;
1436 	struct fwnet_device *dev;
1437 	union fwnet_hwaddr ha;
1438 	int ret;
1439 
1440 	mutex_lock(&fwnet_device_mutex);
1441 
1442 	dev = fwnet_dev_find(card);
1443 	if (dev) {
1444 		net = dev->netdev;
1445 		goto have_dev;
1446 	}
1447 
1448 	net = alloc_netdev(sizeof(*dev), "firewire%d", NET_NAME_UNKNOWN,
1449 			   fwnet_init_dev);
1450 	if (net == NULL) {
1451 		mutex_unlock(&fwnet_device_mutex);
1452 		return -ENOMEM;
1453 	}
1454 
1455 	allocated_netdev = true;
1456 	SET_NETDEV_DEV(net, card->device);
1457 	dev = netdev_priv(net);
1458 
1459 	spin_lock_init(&dev->lock);
1460 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1461 	dev->broadcast_rcv_context = NULL;
1462 	dev->broadcast_xmt_max_payload = 0;
1463 	dev->broadcast_xmt_datagramlabel = 0;
1464 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1465 	dev->queued_datagrams = 0;
1466 	INIT_LIST_HEAD(&dev->peer_list);
1467 	dev->card = card;
1468 	dev->netdev = net;
1469 
1470 	ret = fwnet_fifo_start(dev);
1471 	if (ret < 0)
1472 		goto out;
1473 	dev->local_fifo = dev->handler.offset;
1474 
1475 	/*
1476 	 * default MTU: RFC 2734 cl. 4, RFC 3146 cl. 4
1477 	 * maximum MTU: RFC 2734 cl. 4.2, fragment encapsulation header's
1478 	 *              maximum possible datagram_size + 1 = 0xfff + 1
1479 	 */
1480 	net->mtu = 1500U;
1481 	net->min_mtu = ETH_MIN_MTU;
1482 	net->max_mtu = 4096U;
1483 
1484 	/* Set our hardware address while we're at it */
1485 	ha.uc.uniq_id = cpu_to_be64(card->guid);
1486 	ha.uc.max_rec = dev->card->max_receive;
1487 	ha.uc.sspd = dev->card->link_speed;
1488 	put_unaligned_be48(dev->local_fifo, ha.uc.fifo);
1489 	dev_addr_set(net, ha.u);
1490 
1491 	memset(net->broadcast, -1, net->addr_len);
1492 
1493 	ret = register_netdev(net);
1494 	if (ret)
1495 		goto out;
1496 
1497 	list_add_tail(&dev->dev_link, &fwnet_device_list);
1498 	dev_notice(&net->dev, "IP over IEEE 1394 on card %s\n",
1499 		   dev_name(card->device));
1500  have_dev:
1501 	ret = fwnet_add_peer(dev, unit, device);
1502 	if (ret && allocated_netdev) {
1503 		unregister_netdev(net);
1504 		list_del(&dev->dev_link);
1505  out:
1506 		fwnet_fifo_stop(dev);
1507 		free_netdev(net);
1508 	}
1509 
1510 	mutex_unlock(&fwnet_device_mutex);
1511 
1512 	return ret;
1513 }
1514 
1515 /*
1516  * FIXME abort partially sent fragmented datagrams,
1517  * discard partially received fragmented datagrams
1518  */
1519 static void fwnet_update(struct fw_unit *unit)
1520 {
1521 	struct fw_device *device = fw_parent_device(unit);
1522 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1523 	int generation;
1524 
1525 	generation = device->generation;
1526 
1527 	spin_lock_irq(&peer->dev->lock);
1528 	peer->node_id    = device->node_id;
1529 	peer->generation = generation;
1530 	spin_unlock_irq(&peer->dev->lock);
1531 }
1532 
1533 static void fwnet_remove_peer(struct fwnet_peer *peer, struct fwnet_device *dev)
1534 {
1535 	struct fwnet_partial_datagram *pd, *pd_next;
1536 
1537 	spin_lock_irq(&dev->lock);
1538 	list_del(&peer->peer_link);
1539 	dev->peer_count--;
1540 	set_carrier_state(dev);
1541 	spin_unlock_irq(&dev->lock);
1542 
1543 	list_for_each_entry_safe(pd, pd_next, &peer->pd_list, pd_link)
1544 		fwnet_pd_delete(pd);
1545 
1546 	kfree(peer);
1547 }
1548 
1549 static void fwnet_remove(struct fw_unit *unit)
1550 {
1551 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1552 	struct fwnet_device *dev = peer->dev;
1553 	struct net_device *net;
1554 	int i;
1555 
1556 	mutex_lock(&fwnet_device_mutex);
1557 
1558 	net = dev->netdev;
1559 
1560 	fwnet_remove_peer(peer, dev);
1561 
1562 	if (list_empty(&dev->peer_list)) {
1563 		unregister_netdev(net);
1564 
1565 		fwnet_fifo_stop(dev);
1566 
1567 		for (i = 0; dev->queued_datagrams && i < 5; i++)
1568 			ssleep(1);
1569 		WARN_ON(dev->queued_datagrams);
1570 		list_del(&dev->dev_link);
1571 
1572 		free_netdev(net);
1573 	}
1574 
1575 	mutex_unlock(&fwnet_device_mutex);
1576 }
1577 
1578 static const struct ieee1394_device_id fwnet_id_table[] = {
1579 	{
1580 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1581 				IEEE1394_MATCH_VERSION,
1582 		.specifier_id = IANA_SPECIFIER_ID,
1583 		.version      = RFC2734_SW_VERSION,
1584 	},
1585 #if IS_ENABLED(CONFIG_IPV6)
1586 	{
1587 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1588 				IEEE1394_MATCH_VERSION,
1589 		.specifier_id = IANA_SPECIFIER_ID,
1590 		.version      = RFC3146_SW_VERSION,
1591 	},
1592 #endif
1593 	{ }
1594 };
1595 
1596 static struct fw_driver fwnet_driver = {
1597 	.driver = {
1598 		.owner  = THIS_MODULE,
1599 		.name   = KBUILD_MODNAME,
1600 		.bus    = &fw_bus_type,
1601 	},
1602 	.probe    = fwnet_probe,
1603 	.update   = fwnet_update,
1604 	.remove   = fwnet_remove,
1605 	.id_table = fwnet_id_table,
1606 };
1607 
1608 static const u32 rfc2374_unit_directory_data[] = {
1609 	0x00040000,	/* directory_length		*/
1610 	0x1200005e,	/* unit_specifier_id: IANA	*/
1611 	0x81000003,	/* textual descriptor offset	*/
1612 	0x13000001,	/* unit_sw_version: RFC 2734	*/
1613 	0x81000005,	/* textual descriptor offset	*/
1614 	0x00030000,	/* descriptor_length		*/
1615 	0x00000000,	/* text				*/
1616 	0x00000000,	/* minimal ASCII, en		*/
1617 	0x49414e41,	/* I A N A			*/
1618 	0x00030000,	/* descriptor_length		*/
1619 	0x00000000,	/* text				*/
1620 	0x00000000,	/* minimal ASCII, en		*/
1621 	0x49507634,	/* I P v 4			*/
1622 };
1623 
1624 static struct fw_descriptor rfc2374_unit_directory = {
1625 	.length = ARRAY_SIZE(rfc2374_unit_directory_data),
1626 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1627 	.data   = rfc2374_unit_directory_data
1628 };
1629 
1630 #if IS_ENABLED(CONFIG_IPV6)
1631 static const u32 rfc3146_unit_directory_data[] = {
1632 	0x00040000,	/* directory_length		*/
1633 	0x1200005e,	/* unit_specifier_id: IANA	*/
1634 	0x81000003,	/* textual descriptor offset	*/
1635 	0x13000002,	/* unit_sw_version: RFC 3146	*/
1636 	0x81000005,	/* textual descriptor offset	*/
1637 	0x00030000,	/* descriptor_length		*/
1638 	0x00000000,	/* text				*/
1639 	0x00000000,	/* minimal ASCII, en		*/
1640 	0x49414e41,	/* I A N A			*/
1641 	0x00030000,	/* descriptor_length		*/
1642 	0x00000000,	/* text				*/
1643 	0x00000000,	/* minimal ASCII, en		*/
1644 	0x49507636,	/* I P v 6			*/
1645 };
1646 
1647 static struct fw_descriptor rfc3146_unit_directory = {
1648 	.length = ARRAY_SIZE(rfc3146_unit_directory_data),
1649 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1650 	.data   = rfc3146_unit_directory_data
1651 };
1652 #endif
1653 
1654 static int __init fwnet_init(void)
1655 {
1656 	int err;
1657 
1658 	err = fw_core_add_descriptor(&rfc2374_unit_directory);
1659 	if (err)
1660 		return err;
1661 
1662 #if IS_ENABLED(CONFIG_IPV6)
1663 	err = fw_core_add_descriptor(&rfc3146_unit_directory);
1664 	if (err)
1665 		goto out;
1666 #endif
1667 
1668 	fwnet_packet_task_cache = kmem_cache_create("packet_task",
1669 			sizeof(struct fwnet_packet_task), 0, 0, NULL);
1670 	if (!fwnet_packet_task_cache) {
1671 		err = -ENOMEM;
1672 		goto out2;
1673 	}
1674 
1675 	err = driver_register(&fwnet_driver.driver);
1676 	if (!err)
1677 		return 0;
1678 
1679 	kmem_cache_destroy(fwnet_packet_task_cache);
1680 out2:
1681 #if IS_ENABLED(CONFIG_IPV6)
1682 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1683 out:
1684 #endif
1685 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1686 
1687 	return err;
1688 }
1689 module_init(fwnet_init);
1690 
1691 static void __exit fwnet_cleanup(void)
1692 {
1693 	driver_unregister(&fwnet_driver.driver);
1694 	kmem_cache_destroy(fwnet_packet_task_cache);
1695 #if IS_ENABLED(CONFIG_IPV6)
1696 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1697 #endif
1698 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1699 }
1700 module_exit(fwnet_cleanup);
1701 
1702 MODULE_AUTHOR("Jay Fenlason <fenlason@redhat.com>");
1703 MODULE_DESCRIPTION("IP over IEEE1394 as per RFC 2734/3146");
1704 MODULE_LICENSE("GPL");
1705 MODULE_DEVICE_TABLE(ieee1394, fwnet_id_table);
1706