1/*
2 * Linux ARCnet driver - device-independent routines
3 *
4 * Written 1997 by David Woodhouse.
5 * Written 1994-1999 by Avery Pennarun.
6 * Written 1999-2000 by Martin Mares <mj@ucw.cz>.
7 * Derived from skeleton.c by Donald Becker.
8 *
9 * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
10 *  for sponsoring the further development of this driver.
11 *
12 * **********************
13 *
14 * The original copyright was as follows:
15 *
16 * skeleton.c Written 1993 by Donald Becker.
17 * Copyright 1993 United States Government as represented by the
18 * Director, National Security Agency.  This software may only be used
19 * and distributed according to the terms of the GNU General Public License as
20 * modified by SRC, incorporated herein by reference.
21 *
22 * **********************
23 *
24 * The change log is now in a file called ChangeLog in this directory.
25 *
26 * Sources:
27 *  - Crynwr arcnet.com/arcether.com packet drivers.
28 *  - arcnet.c v0.00 dated 1/1/94 and apparently by
29 *     Donald Becker - it didn't work :)
30 *  - skeleton.c v0.05 dated 11/16/93 by Donald Becker
31 *     (from Linux Kernel 1.1.45)
32 *  - RFC's 1201 and 1051 - re: TCP/IP over ARCnet
33 *  - The official ARCnet COM9026 data sheets (!) thanks to
34 *     Ken Cornetet <kcornete@nyx10.cs.du.edu>
35 *  - The official ARCnet COM20020 data sheets.
36 *  - Information on some more obscure ARCnet controller chips, thanks
37 *     to the nice people at SMSC.
38 *  - net/inet/eth.c (from kernel 1.1.50) for header-building info.
39 *  - Alternate Linux ARCnet source by V.Shergin <vsher@sao.stavropol.su>
40 *  - Textual information and more alternate source from Joachim Koenig
41 *     <jojo@repas.de>
42 */
43
44#define VERSION "arcnet: v3.94 BETA 2007/02/08 - by Avery Pennarun et al.\n"
45
46#include <linux/module.h>
47#include <linux/types.h>
48#include <linux/delay.h>
49#include <linux/netdevice.h>
50#include <linux/if_arp.h>
51#include <net/arp.h>
52#include <linux/init.h>
53#include <linux/arcdevice.h>
54#include <linux/jiffies.h>
55
56/* "do nothing" functions for protocol drivers */
57static void null_rx(struct net_device *dev, int bufnum,
58		    struct archdr *pkthdr, int length);
59static int null_build_header(struct sk_buff *skb, struct net_device *dev,
60			     unsigned short type, uint8_t daddr);
61static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
62			   int length, int bufnum);
63
64static void arcnet_rx(struct net_device *dev, int bufnum);
65
66/*
67 * one ArcProto per possible proto ID.  None of the elements of
68 * arc_proto_map are allowed to be NULL; they will get set to
69 * arc_proto_default instead.  It also must not be NULL; if you would like
70 * to set it to NULL, set it to &arc_proto_null instead.
71 */
72 struct ArcProto *arc_proto_map[256], *arc_proto_default,
73   *arc_bcast_proto, *arc_raw_proto;
74
75static struct ArcProto arc_proto_null =
76{
77	.suffix		= '?',
78	.mtu		= XMTU,
79	.is_ip          = 0,
80	.rx		= null_rx,
81	.build_header	= null_build_header,
82	.prepare_tx	= null_prepare_tx,
83	.continue_tx    = NULL,
84	.ack_tx         = NULL
85};
86
87/* Exported function prototypes */
88int arcnet_debug = ARCNET_DEBUG;
89
90EXPORT_SYMBOL(arc_proto_map);
91EXPORT_SYMBOL(arc_proto_default);
92EXPORT_SYMBOL(arc_bcast_proto);
93EXPORT_SYMBOL(arc_raw_proto);
94EXPORT_SYMBOL(arcnet_unregister_proto);
95EXPORT_SYMBOL(arcnet_debug);
96EXPORT_SYMBOL(alloc_arcdev);
97EXPORT_SYMBOL(arcnet_interrupt);
98EXPORT_SYMBOL(arcnet_open);
99EXPORT_SYMBOL(arcnet_close);
100EXPORT_SYMBOL(arcnet_send_packet);
101EXPORT_SYMBOL(arcnet_timeout);
102
103/* Internal function prototypes */
104static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
105			 unsigned short type, const void *daddr,
106			 const void *saddr, unsigned len);
107static int go_tx(struct net_device *dev);
108
109static int debug = ARCNET_DEBUG;
110module_param(debug, int, 0);
111MODULE_LICENSE("GPL");
112
113static int __init arcnet_init(void)
114{
115	int count;
116
117	arcnet_debug = debug;
118
119	printk("arcnet loaded.\n");
120
121#ifdef ALPHA_WARNING
122	BUGLVL(D_EXTRA) {
123		printk("arcnet: ***\n"
124		"arcnet: * Read arcnet.txt for important release notes!\n"
125		       "arcnet: *\n"
126		       "arcnet: * This is an ALPHA version! (Last stable release: v3.02)  E-mail\n"
127		       "arcnet: * me if you have any questions, comments, or bug reports.\n"
128		       "arcnet: ***\n");
129	}
130#endif
131
132	/* initialize the protocol map */
133	arc_raw_proto = arc_proto_default = arc_bcast_proto = &arc_proto_null;
134	for (count = 0; count < 256; count++)
135		arc_proto_map[count] = arc_proto_default;
136
137	BUGLVL(D_DURING)
138	    printk("arcnet: struct sizes: %Zd %Zd %Zd %Zd %Zd\n",
139		 sizeof(struct arc_hardware), sizeof(struct arc_rfc1201),
140		sizeof(struct arc_rfc1051), sizeof(struct arc_eth_encap),
141		   sizeof(struct archdr));
142
143	return 0;
144}
145
146static void __exit arcnet_exit(void)
147{
148}
149
150module_init(arcnet_init);
151module_exit(arcnet_exit);
152
153/*
154 * Dump the contents of an sk_buff
155 */
156#if ARCNET_DEBUG_MAX & D_SKB
157void arcnet_dump_skb(struct net_device *dev,
158		     struct sk_buff *skb, char *desc)
159{
160	char hdr[32];
161
162	/* dump the packet */
163	snprintf(hdr, sizeof(hdr), "%6s:%s skb->data:", dev->name, desc);
164	print_hex_dump(KERN_DEBUG, hdr, DUMP_PREFIX_OFFSET,
165		       16, 1, skb->data, skb->len, true);
166}
167
168EXPORT_SYMBOL(arcnet_dump_skb);
169#endif
170
171
172/*
173 * Dump the contents of an ARCnet buffer
174 */
175#if (ARCNET_DEBUG_MAX & (D_RX | D_TX))
176static void arcnet_dump_packet(struct net_device *dev, int bufnum,
177			       char *desc, int take_arcnet_lock)
178{
179	struct arcnet_local *lp = netdev_priv(dev);
180	int i, length;
181	unsigned long flags = 0;
182	static uint8_t buf[512];
183	char hdr[32];
184
185	/* hw.copy_from_card expects IRQ context so take the IRQ lock
186	   to keep it single threaded */
187	if(take_arcnet_lock)
188		spin_lock_irqsave(&lp->lock, flags);
189
190	lp->hw.copy_from_card(dev, bufnum, 0, buf, 512);
191	if(take_arcnet_lock)
192		spin_unlock_irqrestore(&lp->lock, flags);
193
194	/* if the offset[0] byte is nonzero, this is a 256-byte packet */
195	length = (buf[2] ? 256 : 512);
196
197	/* dump the packet */
198	snprintf(hdr, sizeof(hdr), "%6s:%s packet dump:", dev->name, desc);
199	print_hex_dump(KERN_DEBUG, hdr, DUMP_PREFIX_OFFSET,
200		       16, 1, buf, length, true);
201}
202
203#else
204
205#define arcnet_dump_packet(dev, bufnum, desc,take_arcnet_lock) do { } while (0)
206
207#endif
208
209
210/*
211 * Unregister a protocol driver from the arc_proto_map.  Protocol drivers
212 * are responsible for registering themselves, but the unregister routine
213 * is pretty generic so we'll do it here.
214 */
215void arcnet_unregister_proto(struct ArcProto *proto)
216{
217	int count;
218
219	if (arc_proto_default == proto)
220		arc_proto_default = &arc_proto_null;
221	if (arc_bcast_proto == proto)
222		arc_bcast_proto = arc_proto_default;
223	if (arc_raw_proto == proto)
224		arc_raw_proto = arc_proto_default;
225
226	for (count = 0; count < 256; count++) {
227		if (arc_proto_map[count] == proto)
228			arc_proto_map[count] = arc_proto_default;
229	}
230}
231
232
233/*
234 * Add a buffer to the queue.  Only the interrupt handler is allowed to do
235 * this, unless interrupts are disabled.
236 *
237 * Note: we don't check for a full queue, since there aren't enough buffers
238 * to more than fill it.
239 */
240static void release_arcbuf(struct net_device *dev, int bufnum)
241{
242	struct arcnet_local *lp = netdev_priv(dev);
243	int i;
244
245	lp->buf_queue[lp->first_free_buf++] = bufnum;
246	lp->first_free_buf %= 5;
247
248	BUGLVL(D_DURING) {
249		BUGMSG(D_DURING, "release_arcbuf: freed #%d; buffer queue is now: ",
250		       bufnum);
251		for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5)
252			BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]);
253		BUGMSG2(D_DURING, "\n");
254	}
255}
256
257
258/*
259 * Get a buffer from the queue.  If this returns -1, there are no buffers
260 * available.
261 */
262static int get_arcbuf(struct net_device *dev)
263{
264	struct arcnet_local *lp = netdev_priv(dev);
265	int buf = -1, i;
266
267	if (!atomic_dec_and_test(&lp->buf_lock)) {
268		/* already in this function */
269		BUGMSG(D_NORMAL, "get_arcbuf: overlap (%d)!\n",
270		       lp->buf_lock.counter);
271	}
272	else {			/* we can continue */
273		if (lp->next_buf >= 5)
274			lp->next_buf -= 5;
275
276		if (lp->next_buf == lp->first_free_buf)
277			BUGMSG(D_NORMAL, "get_arcbuf: BUG: no buffers are available??\n");
278		else {
279			buf = lp->buf_queue[lp->next_buf++];
280			lp->next_buf %= 5;
281		}
282	}
283
284
285	BUGLVL(D_DURING) {
286		BUGMSG(D_DURING, "get_arcbuf: got #%d; buffer queue is now: ", buf);
287		for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5)
288			BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]);
289		BUGMSG2(D_DURING, "\n");
290	}
291
292	atomic_inc(&lp->buf_lock);
293	return buf;
294}
295
296
297static int choose_mtu(void)
298{
299	int count, mtu = 65535;
300
301	/* choose the smallest MTU of all available encaps */
302	for (count = 0; count < 256; count++) {
303		if (arc_proto_map[count] != &arc_proto_null &&
304		    arc_proto_map[count]->mtu < mtu) {
305			mtu = arc_proto_map[count]->mtu;
306		}
307	}
308
309	return mtu == 65535 ? XMTU : mtu;
310}
311
312static const struct header_ops arcnet_header_ops = {
313	.create = arcnet_header,
314};
315
316static const struct net_device_ops arcnet_netdev_ops = {
317	.ndo_open	= arcnet_open,
318	.ndo_stop	= arcnet_close,
319	.ndo_start_xmit = arcnet_send_packet,
320	.ndo_tx_timeout = arcnet_timeout,
321};
322
323/* Setup a struct device for ARCnet. */
324static void arcdev_setup(struct net_device *dev)
325{
326	dev->type = ARPHRD_ARCNET;
327	dev->netdev_ops = &arcnet_netdev_ops;
328	dev->header_ops = &arcnet_header_ops;
329	dev->hard_header_len = sizeof(struct archdr);
330	dev->mtu = choose_mtu();
331
332	dev->addr_len = ARCNET_ALEN;
333	dev->tx_queue_len = 100;
334	dev->broadcast[0] = 0x00;	/* for us, broadcasts are address 0 */
335	dev->watchdog_timeo = TX_TIMEOUT;
336
337	/* New-style flags. */
338	dev->flags = IFF_BROADCAST;
339
340}
341
342struct net_device *alloc_arcdev(const char *name)
343{
344	struct net_device *dev;
345
346	dev = alloc_netdev(sizeof(struct arcnet_local),
347			   name && *name ? name : "arc%d", NET_NAME_UNKNOWN,
348			   arcdev_setup);
349	if(dev) {
350		struct arcnet_local *lp = netdev_priv(dev);
351		spin_lock_init(&lp->lock);
352	}
353
354	return dev;
355}
356
357/*
358 * Open/initialize the board.  This is called sometime after booting when
359 * the 'ifconfig' program is run.
360 *
361 * This routine should set everything up anew at each open, even registers
362 * that "should" only need to be set once at boot, so that there is
363 * non-reboot way to recover if something goes wrong.
364 */
365int arcnet_open(struct net_device *dev)
366{
367	struct arcnet_local *lp = netdev_priv(dev);
368	int count, newmtu, error;
369
370	BUGMSG(D_INIT,"opened.");
371
372	if (!try_module_get(lp->hw.owner))
373		return -ENODEV;
374
375	BUGLVL(D_PROTO) {
376		BUGMSG(D_PROTO, "protocol map (default is '%c'): ",
377		       arc_proto_default->suffix);
378		for (count = 0; count < 256; count++)
379			BUGMSG2(D_PROTO, "%c", arc_proto_map[count]->suffix);
380		BUGMSG2(D_PROTO, "\n");
381	}
382
383
384	BUGMSG(D_INIT, "arcnet_open: resetting card.\n");
385
386	/* try to put the card in a defined state - if it fails the first
387	 * time, actually reset it.
388	 */
389	error = -ENODEV;
390	if (ARCRESET(0) && ARCRESET(1))
391		goto out_module_put;
392
393	newmtu = choose_mtu();
394	if (newmtu < dev->mtu)
395		dev->mtu = newmtu;
396
397	BUGMSG(D_INIT, "arcnet_open: mtu: %d.\n", dev->mtu);
398
399	/* autodetect the encapsulation for each host. */
400	memset(lp->default_proto, 0, sizeof(lp->default_proto));
401
402	/* the broadcast address is special - use the 'bcast' protocol */
403	for (count = 0; count < 256; count++) {
404		if (arc_proto_map[count] == arc_bcast_proto) {
405			lp->default_proto[0] = count;
406			break;
407		}
408	}
409
410	/* initialize buffers */
411	atomic_set(&lp->buf_lock, 1);
412
413	lp->next_buf = lp->first_free_buf = 0;
414	release_arcbuf(dev, 0);
415	release_arcbuf(dev, 1);
416	release_arcbuf(dev, 2);
417	release_arcbuf(dev, 3);
418	lp->cur_tx = lp->next_tx = -1;
419	lp->cur_rx = -1;
420
421	lp->rfc1201.sequence = 1;
422
423	/* bring up the hardware driver */
424	if (lp->hw.open)
425		lp->hw.open(dev);
426
427	if (dev->dev_addr[0] == 0)
428		BUGMSG(D_NORMAL, "WARNING!  Station address 00 is reserved "
429		       "for broadcasts!\n");
430	else if (dev->dev_addr[0] == 255)
431		BUGMSG(D_NORMAL, "WARNING!  Station address FF may confuse "
432		       "DOS networking programs!\n");
433
434	BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
435	if (ASTATUS() & RESETflag) {
436	  	BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
437		ACOMMAND(CFLAGScmd | RESETclear);
438	}
439
440
441	BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
442	/* make sure we're ready to receive IRQ's. */
443	AINTMASK(0);
444	udelay(1);		/* give it time to set the mask before
445				 * we reset it again. (may not even be
446				 * necessary)
447				 */
448	BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
449	lp->intmask = NORXflag | RECONflag;
450	AINTMASK(lp->intmask);
451	BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
452
453	netif_start_queue(dev);
454
455	return 0;
456
457 out_module_put:
458	module_put(lp->hw.owner);
459	return error;
460}
461
462
463/* The inverse routine to arcnet_open - shuts down the card. */
464int arcnet_close(struct net_device *dev)
465{
466	struct arcnet_local *lp = netdev_priv(dev);
467
468	netif_stop_queue(dev);
469
470	/* flush TX and disable RX */
471	AINTMASK(0);
472	ACOMMAND(NOTXcmd);	/* stop transmit */
473	ACOMMAND(NORXcmd);	/* disable receive */
474	mdelay(1);
475
476	/* shut down the card */
477	lp->hw.close(dev);
478	module_put(lp->hw.owner);
479	return 0;
480}
481
482
483static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
484			 unsigned short type, const void *daddr,
485			 const void *saddr, unsigned len)
486{
487	const struct arcnet_local *lp = netdev_priv(dev);
488	uint8_t _daddr, proto_num;
489	struct ArcProto *proto;
490
491	BUGMSG(D_DURING,
492	    "create header from %d to %d; protocol %d (%Xh); size %u.\n",
493	       saddr ? *(uint8_t *) saddr : -1,
494	       daddr ? *(uint8_t *) daddr : -1,
495	       type, type, len);
496
497	if (skb->len!=0 && len != skb->len)
498		BUGMSG(D_NORMAL, "arcnet_header: Yikes!  skb->len(%d) != len(%d)!\n",
499		       skb->len, len);
500
501
502  	/* Type is host order - ? */
503  	if(type == ETH_P_ARCNET) {
504  		proto = arc_raw_proto;
505  		BUGMSG(D_DEBUG, "arc_raw_proto used. proto='%c'\n",proto->suffix);
506  		_daddr = daddr ? *(uint8_t *) daddr : 0;
507  	}
508	else if (!daddr) {
509		/*
510		 * if the dest addr isn't provided, we can't choose an encapsulation!
511		 * Store the packet type (eg. ETH_P_IP) for now, and we'll push on a
512		 * real header when we do rebuild_header.
513		 */
514		*(uint16_t *) skb_push(skb, 2) = type;
515		/*
516		 * XXX: Why not use skb->mac_len?
517		 */
518		if (skb->network_header - skb->mac_header != 2)
519			BUGMSG(D_NORMAL, "arcnet_header: Yikes!  diff (%d) is not 2!\n",
520			       (int)(skb->network_header - skb->mac_header));
521		return -2;	/* return error -- can't transmit yet! */
522	}
523	else {
524		/* otherwise, we can just add the header as usual. */
525		_daddr = *(uint8_t *) daddr;
526		proto_num = lp->default_proto[_daddr];
527		proto = arc_proto_map[proto_num];
528		BUGMSG(D_DURING, "building header for %02Xh using protocol '%c'\n",
529		       proto_num, proto->suffix);
530		if (proto == &arc_proto_null && arc_bcast_proto != proto) {
531			BUGMSG(D_DURING, "actually, let's use '%c' instead.\n",
532			       arc_bcast_proto->suffix);
533			proto = arc_bcast_proto;
534		}
535	}
536	return proto->build_header(skb, dev, type, _daddr);
537}
538
539/* Called by the kernel in order to transmit a packet. */
540netdev_tx_t arcnet_send_packet(struct sk_buff *skb,
541				     struct net_device *dev)
542{
543	struct arcnet_local *lp = netdev_priv(dev);
544	struct archdr *pkt;
545	struct arc_rfc1201 *soft;
546	struct ArcProto *proto;
547	int txbuf;
548	unsigned long flags;
549	int freeskb, retval;
550
551	BUGMSG(D_DURING,
552	       "transmit requested (status=%Xh, txbufs=%d/%d, len=%d, protocol %x)\n",
553	       ASTATUS(), lp->cur_tx, lp->next_tx, skb->len,skb->protocol);
554
555	pkt = (struct archdr *) skb->data;
556	soft = &pkt->soft.rfc1201;
557	proto = arc_proto_map[soft->proto];
558
559	BUGMSG(D_SKB_SIZE, "skb: transmitting %d bytes to %02X\n",
560		skb->len, pkt->hard.dest);
561	BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "tx");
562
563	/* fits in one packet? */
564	if (skb->len - ARC_HDR_SIZE > XMTU && !proto->continue_tx) {
565		BUGMSG(D_NORMAL, "fixme: packet too large: compensating badly!\n");
566		dev_kfree_skb(skb);
567		return NETDEV_TX_OK;	/* don't try again */
568	}
569
570	/* We're busy transmitting a packet... */
571	netif_stop_queue(dev);
572
573	spin_lock_irqsave(&lp->lock, flags);
574	AINTMASK(0);
575	if(lp->next_tx == -1)
576		txbuf = get_arcbuf(dev);
577	else {
578		txbuf = -1;
579	}
580	if (txbuf != -1) {
581		if (proto->prepare_tx(dev, pkt, skb->len, txbuf) &&
582		    !proto->ack_tx) {
583			/* done right away and we don't want to acknowledge
584			   the package later - forget about it now */
585			dev->stats.tx_bytes += skb->len;
586			freeskb = 1;
587		} else {
588			/* do it the 'split' way */
589			lp->outgoing.proto = proto;
590			lp->outgoing.skb = skb;
591			lp->outgoing.pkt = pkt;
592
593			freeskb = 0;
594
595			if (proto->continue_tx &&
596			    proto->continue_tx(dev, txbuf)) {
597			  BUGMSG(D_NORMAL,
598				 "bug! continue_tx finished the first time! "
599				 "(proto='%c')\n", proto->suffix);
600			}
601		}
602		retval = NETDEV_TX_OK;
603		lp->next_tx = txbuf;
604	} else {
605		retval = NETDEV_TX_BUSY;
606		freeskb = 0;
607	}
608
609	BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__func__,ASTATUS());
610	/* make sure we didn't ignore a TX IRQ while we were in here */
611	AINTMASK(0);
612
613	BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
614	lp->intmask |= TXFREEflag|EXCNAKflag;
615	AINTMASK(lp->intmask);
616	BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__func__,ASTATUS());
617
618	spin_unlock_irqrestore(&lp->lock, flags);
619	if (freeskb) {
620		dev_kfree_skb(skb);
621	}
622	return retval;		/* no need to try again */
623}
624
625
626/*
627 * Actually start transmitting a packet that was loaded into a buffer
628 * by prepare_tx.  This should _only_ be called by the interrupt handler.
629 */
630static int go_tx(struct net_device *dev)
631{
632	struct arcnet_local *lp = netdev_priv(dev);
633
634	BUGMSG(D_DURING, "go_tx: status=%Xh, intmask=%Xh, next_tx=%d, cur_tx=%d\n",
635	       ASTATUS(), lp->intmask, lp->next_tx, lp->cur_tx);
636
637	if (lp->cur_tx != -1 || lp->next_tx == -1)
638		return 0;
639
640	BUGLVL(D_TX) arcnet_dump_packet(dev, lp->next_tx, "go_tx", 0);
641
642	lp->cur_tx = lp->next_tx;
643	lp->next_tx = -1;
644
645	/* start sending */
646	ACOMMAND(TXcmd | (lp->cur_tx << 3));
647
648	dev->stats.tx_packets++;
649	lp->lasttrans_dest = lp->lastload_dest;
650	lp->lastload_dest = 0;
651	lp->excnak_pending = 0;
652	lp->intmask |= TXFREEflag|EXCNAKflag;
653
654	return 1;
655}
656
657
658/* Called by the kernel when transmit times out */
659void arcnet_timeout(struct net_device *dev)
660{
661	unsigned long flags;
662	struct arcnet_local *lp = netdev_priv(dev);
663	int status = ASTATUS();
664	char *msg;
665
666	spin_lock_irqsave(&lp->lock, flags);
667	if (status & TXFREEflag) {	/* transmit _DID_ finish */
668		msg = " - missed IRQ?";
669	} else {
670		msg = "";
671		dev->stats.tx_aborted_errors++;
672		lp->timed_out = 1;
673		ACOMMAND(NOTXcmd | (lp->cur_tx << 3));
674	}
675	dev->stats.tx_errors++;
676
677	/* make sure we didn't miss a TX or a EXC NAK IRQ */
678	AINTMASK(0);
679	lp->intmask |= TXFREEflag|EXCNAKflag;
680	AINTMASK(lp->intmask);
681
682	spin_unlock_irqrestore(&lp->lock, flags);
683
684	if (time_after(jiffies, lp->last_timeout + 10*HZ)) {
685		BUGMSG(D_EXTRA, "tx timed out%s (status=%Xh, intmask=%Xh, dest=%02Xh)\n",
686		       msg, status, lp->intmask, lp->lasttrans_dest);
687		lp->last_timeout = jiffies;
688	}
689
690	if (lp->cur_tx == -1)
691		netif_wake_queue(dev);
692}
693
694
695/*
696 * The typical workload of the driver: Handle the network interface
697 * interrupts. Establish which device needs attention, and call the correct
698 * chipset interrupt handler.
699 */
700irqreturn_t arcnet_interrupt(int irq, void *dev_id)
701{
702	struct net_device *dev = dev_id;
703	struct arcnet_local *lp;
704	int recbuf, status, diagstatus, didsomething, boguscount;
705	int retval = IRQ_NONE;
706
707	BUGMSG(D_DURING, "\n");
708
709	BUGMSG(D_DURING, "in arcnet_interrupt\n");
710
711	lp = netdev_priv(dev);
712	BUG_ON(!lp);
713
714	spin_lock(&lp->lock);
715
716	/*
717	 * RESET flag was enabled - if device is not running, we must clear it right
718	 * away (but nothing else).
719	 */
720	if (!netif_running(dev)) {
721		if (ASTATUS() & RESETflag)
722			ACOMMAND(CFLAGScmd | RESETclear);
723		AINTMASK(0);
724		spin_unlock(&lp->lock);
725		return retval;
726	}
727
728	BUGMSG(D_DURING, "in arcnet_inthandler (status=%Xh, intmask=%Xh)\n",
729	       ASTATUS(), lp->intmask);
730
731	boguscount = 5;
732	do {
733		status = ASTATUS();
734                diagstatus = (status >> 8) & 0xFF;
735
736		BUGMSG(D_DEBUG, "%s: %d: %s: status=%x\n",
737			__FILE__,__LINE__,__func__,status);
738		didsomething = 0;
739
740		/*
741		 * RESET flag was enabled - card is resetting and if RX is
742		 * disabled, it's NOT because we just got a packet.
743		 *
744		 * The card is in an undefined state.  Clear it out and start over.
745		 */
746		if (status & RESETflag) {
747			BUGMSG(D_NORMAL, "spurious reset (status=%Xh)\n", status);
748			arcnet_close(dev);
749			arcnet_open(dev);
750
751			/* get out of the interrupt handler! */
752			break;
753		}
754		/*
755		 * RX is inhibited - we must have received something. Prepare to
756		 * receive into the next buffer.
757		 *
758		 * We don't actually copy the received packet from the card until
759		 * after the transmit handler runs (and possibly launches the next
760		 * tx); this should improve latency slightly if we get both types
761		 * of interrupts at once.
762		 */
763		recbuf = -1;
764		if (status & lp->intmask & NORXflag) {
765			recbuf = lp->cur_rx;
766			BUGMSG(D_DURING, "Buffer #%d: receive irq (status=%Xh)\n",
767			       recbuf, status);
768
769			lp->cur_rx = get_arcbuf(dev);
770			if (lp->cur_rx != -1) {
771				BUGMSG(D_DURING, "enabling receive to buffer #%d\n",
772				       lp->cur_rx);
773				ACOMMAND(RXcmd | (lp->cur_rx << 3) | RXbcasts);
774			}
775			didsomething++;
776		}
777
778		if((diagstatus & EXCNAKflag)) {
779			BUGMSG(D_DURING, "EXCNAK IRQ (diagstat=%Xh)\n",
780			       diagstatus);
781
782                        ACOMMAND(NOTXcmd);      /* disable transmit */
783                        lp->excnak_pending = 1;
784
785                        ACOMMAND(EXCNAKclear);
786			lp->intmask &= ~(EXCNAKflag);
787                        didsomething++;
788                }
789
790
791		/* a transmit finished, and we're interested in it. */
792		if ((status & lp->intmask & TXFREEflag) || lp->timed_out) {
793			lp->intmask &= ~(TXFREEflag|EXCNAKflag);
794
795			BUGMSG(D_DURING, "TX IRQ (stat=%Xh)\n", status);
796
797			if (lp->cur_tx != -1 && !lp->timed_out) {
798				if(!(status & TXACKflag)) {
799					if (lp->lasttrans_dest != 0) {
800						BUGMSG(D_EXTRA,
801						       "transmit was not acknowledged! "
802						       "(status=%Xh, dest=%02Xh)\n",
803						       status, lp->lasttrans_dest);
804						dev->stats.tx_errors++;
805						dev->stats.tx_carrier_errors++;
806					} else {
807						BUGMSG(D_DURING,
808						       "broadcast was not acknowledged; that's normal "
809						       "(status=%Xh, dest=%02Xh)\n",
810						       status, lp->lasttrans_dest);
811					}
812				}
813
814				if (lp->outgoing.proto &&
815				    lp->outgoing.proto->ack_tx) {
816				  int ackstatus;
817				  if(status & TXACKflag)
818                                    ackstatus=2;
819                                  else if(lp->excnak_pending)
820                                    ackstatus=1;
821                                  else
822                                    ackstatus=0;
823
824                                  lp->outgoing.proto
825                                    ->ack_tx(dev, ackstatus);
826				}
827			}
828			if (lp->cur_tx != -1)
829				release_arcbuf(dev, lp->cur_tx);
830
831			lp->cur_tx = -1;
832			lp->timed_out = 0;
833			didsomething++;
834
835			/* send another packet if there is one */
836			go_tx(dev);
837
838			/* continue a split packet, if any */
839			if (lp->outgoing.proto && lp->outgoing.proto->continue_tx) {
840				int txbuf = get_arcbuf(dev);
841				if (txbuf != -1) {
842					if (lp->outgoing.proto->continue_tx(dev, txbuf)) {
843						/* that was the last segment */
844						dev->stats.tx_bytes += lp->outgoing.skb->len;
845						if(!lp->outgoing.proto->ack_tx)
846						  {
847						    dev_kfree_skb_irq(lp->outgoing.skb);
848						    lp->outgoing.proto = NULL;
849						  }
850					}
851					lp->next_tx = txbuf;
852				}
853			}
854			/* inform upper layers of idleness, if necessary */
855			if (lp->cur_tx == -1)
856				netif_wake_queue(dev);
857		}
858		/* now process the received packet, if any */
859		if (recbuf != -1) {
860			BUGLVL(D_RX) arcnet_dump_packet(dev, recbuf, "rx irq", 0);
861
862			arcnet_rx(dev, recbuf);
863			release_arcbuf(dev, recbuf);
864
865			didsomething++;
866		}
867		if (status & lp->intmask & RECONflag) {
868			ACOMMAND(CFLAGScmd | CONFIGclear);
869			dev->stats.tx_carrier_errors++;
870
871			BUGMSG(D_RECON, "Network reconfiguration detected (status=%Xh)\n",
872			       status);
873			/* MYRECON bit is at bit 7 of diagstatus */
874			if(diagstatus & 0x80)
875				BUGMSG(D_RECON,"Put out that recon myself\n");
876
877			/* is the RECON info empty or old? */
878			if (!lp->first_recon || !lp->last_recon ||
879			    time_after(jiffies, lp->last_recon + HZ * 10)) {
880				if (lp->network_down)
881					BUGMSG(D_NORMAL, "reconfiguration detected: cabling restored?\n");
882				lp->first_recon = lp->last_recon = jiffies;
883				lp->num_recons = lp->network_down = 0;
884
885				BUGMSG(D_DURING, "recon: clearing counters.\n");
886			} else {	/* add to current RECON counter */
887				lp->last_recon = jiffies;
888				lp->num_recons++;
889
890				BUGMSG(D_DURING, "recon: counter=%d, time=%lds, net=%d\n",
891				       lp->num_recons,
892				 (lp->last_recon - lp->first_recon) / HZ,
893				       lp->network_down);
894
895				/* if network is marked up;
896				 * and first_recon and last_recon are 60+ apart;
897				 * and the average no. of recons counted is
898				 *    > RECON_THRESHOLD/min;
899				 * then print a warning message.
900				 */
901				if (!lp->network_down &&
902				    (lp->last_recon - lp->first_recon) <= HZ * 60 &&
903				    lp->num_recons >= RECON_THRESHOLD) {
904					lp->network_down = 1;
905					BUGMSG(D_NORMAL, "many reconfigurations detected: cabling problem?\n");
906				} else if (!lp->network_down &&
907					   lp->last_recon - lp->first_recon > HZ * 60) {
908					/* reset counters if we've gone for over a minute. */
909					lp->first_recon = lp->last_recon;
910					lp->num_recons = 1;
911				}
912			}
913		} else if (lp->network_down &&
914				time_after(jiffies, lp->last_recon + HZ * 10)) {
915			if (lp->network_down)
916				BUGMSG(D_NORMAL, "cabling restored?\n");
917			lp->first_recon = lp->last_recon = 0;
918			lp->num_recons = lp->network_down = 0;
919
920			BUGMSG(D_DURING, "not recon: clearing counters anyway.\n");
921		}
922
923		if(didsomething) {
924			retval |= IRQ_HANDLED;
925		}
926	}
927	while (--boguscount && didsomething);
928
929	BUGMSG(D_DURING, "arcnet_interrupt complete (status=%Xh, count=%d)\n",
930	       ASTATUS(), boguscount);
931	BUGMSG(D_DURING, "\n");
932
933
934	AINTMASK(0);
935	udelay(1);
936	AINTMASK(lp->intmask);
937
938	spin_unlock(&lp->lock);
939	return retval;
940}
941
942
943/*
944 * This is a generic packet receiver that calls arcnet??_rx depending on the
945 * protocol ID found.
946 */
947static void arcnet_rx(struct net_device *dev, int bufnum)
948{
949	struct arcnet_local *lp = netdev_priv(dev);
950	struct archdr pkt;
951	struct arc_rfc1201 *soft;
952	int length, ofs;
953
954	soft = &pkt.soft.rfc1201;
955
956	lp->hw.copy_from_card(dev, bufnum, 0, &pkt, ARC_HDR_SIZE);
957	if (pkt.hard.offset[0]) {
958		ofs = pkt.hard.offset[0];
959		length = 256 - ofs;
960	} else {
961		ofs = pkt.hard.offset[1];
962		length = 512 - ofs;
963	}
964
965	/* get the full header, if possible */
966	if (sizeof(pkt.soft) <= length)
967		lp->hw.copy_from_card(dev, bufnum, ofs, soft, sizeof(pkt.soft));
968	else {
969		memset(&pkt.soft, 0, sizeof(pkt.soft));
970		lp->hw.copy_from_card(dev, bufnum, ofs, soft, length);
971	}
972
973	BUGMSG(D_DURING, "Buffer #%d: received packet from %02Xh to %02Xh "
974	       "(%d+4 bytes)\n",
975	       bufnum, pkt.hard.source, pkt.hard.dest, length);
976
977	dev->stats.rx_packets++;
978	dev->stats.rx_bytes += length + ARC_HDR_SIZE;
979
980	/* call the right receiver for the protocol */
981	if (arc_proto_map[soft->proto]->is_ip) {
982		BUGLVL(D_PROTO) {
983			struct ArcProto
984			*oldp = arc_proto_map[lp->default_proto[pkt.hard.source]],
985			*newp = arc_proto_map[soft->proto];
986
987			if (oldp != newp) {
988				BUGMSG(D_PROTO,
989				       "got protocol %02Xh; encap for host %02Xh is now '%c'"
990				       " (was '%c')\n", soft->proto, pkt.hard.source,
991				       newp->suffix, oldp->suffix);
992			}
993		}
994
995		/* broadcasts will always be done with the last-used encap. */
996		lp->default_proto[0] = soft->proto;
997
998		/* in striking contrast, the following isn't a hack. */
999		lp->default_proto[pkt.hard.source] = soft->proto;
1000	}
1001	/* call the protocol-specific receiver. */
1002	arc_proto_map[soft->proto]->rx(dev, bufnum, &pkt, length);
1003}
1004
1005
1006static void null_rx(struct net_device *dev, int bufnum,
1007		    struct archdr *pkthdr, int length)
1008{
1009	BUGMSG(D_PROTO,
1010	"rx: don't know how to deal with proto %02Xh from host %02Xh.\n",
1011	       pkthdr->soft.rfc1201.proto, pkthdr->hard.source);
1012}
1013
1014
1015static int null_build_header(struct sk_buff *skb, struct net_device *dev,
1016			     unsigned short type, uint8_t daddr)
1017{
1018	struct arcnet_local *lp = netdev_priv(dev);
1019
1020	BUGMSG(D_PROTO,
1021	       "tx: can't build header for encap %02Xh; load a protocol driver.\n",
1022	       lp->default_proto[daddr]);
1023
1024	/* always fails */
1025	return 0;
1026}
1027
1028
1029/* the "do nothing" prepare_tx function warns that there's nothing to do. */
1030static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
1031			   int length, int bufnum)
1032{
1033	struct arcnet_local *lp = netdev_priv(dev);
1034	struct arc_hardware newpkt;
1035
1036	BUGMSG(D_PROTO, "tx: no encap for this host; load a protocol driver.\n");
1037
1038	/* send a packet to myself -- will never get received, of course */
1039	newpkt.source = newpkt.dest = dev->dev_addr[0];
1040
1041	/* only one byte of actual data (and it's random) */
1042	newpkt.offset[0] = 0xFF;
1043
1044	lp->hw.copy_to_card(dev, bufnum, 0, &newpkt, ARC_HDR_SIZE);
1045
1046	return 1;		/* done */
1047}
1048