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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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/jiffies.h>
54 #include <linux/errqueue.h>
55 
56 #include <linux/leds.h>
57 
58 #include "arcdevice.h"
59 #include "com9026.h"
60 
61 /* "do nothing" functions for protocol drivers */
62 static void null_rx(struct net_device *dev, int bufnum,
63 		    struct archdr *pkthdr, int length);
64 static int null_build_header(struct sk_buff *skb, struct net_device *dev,
65 			     unsigned short type, uint8_t daddr);
66 static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
67 			   int length, int bufnum);
68 
69 static void arcnet_rx(struct net_device *dev, int bufnum);
70 
71 /* one ArcProto per possible proto ID.  None of the elements of
72  * arc_proto_map are allowed to be NULL; they will get set to
73  * arc_proto_default instead.  It also must not be NULL; if you would like
74  * to set it to NULL, set it to &arc_proto_null instead.
75  */
76 struct ArcProto *arc_proto_map[256];
77 EXPORT_SYMBOL(arc_proto_map);
78 
79 struct ArcProto *arc_proto_default;
80 EXPORT_SYMBOL(arc_proto_default);
81 
82 struct ArcProto *arc_bcast_proto;
83 EXPORT_SYMBOL(arc_bcast_proto);
84 
85 struct ArcProto *arc_raw_proto;
86 EXPORT_SYMBOL(arc_raw_proto);
87 
88 static struct ArcProto arc_proto_null = {
89 	.suffix		= '?',
90 	.mtu		= XMTU,
91 	.is_ip          = 0,
92 	.rx		= null_rx,
93 	.build_header	= null_build_header,
94 	.prepare_tx	= null_prepare_tx,
95 	.continue_tx    = NULL,
96 	.ack_tx         = NULL
97 };
98 
99 /* Exported function prototypes */
100 int arcnet_debug = ARCNET_DEBUG;
101 EXPORT_SYMBOL(arcnet_debug);
102 
103 /* Internal function prototypes */
104 static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
105 			 unsigned short type, const void *daddr,
106 			 const void *saddr, unsigned len);
107 static int go_tx(struct net_device *dev);
108 
109 static int debug = ARCNET_DEBUG;
110 module_param(debug, int, 0);
111 MODULE_LICENSE("GPL");
112 
arcnet_init(void)113 static int __init arcnet_init(void)
114 {
115 	int count;
116 
117 	arcnet_debug = debug;
118 
119 	pr_info("arcnet loaded\n");
120 
121 	/* initialize the protocol map */
122 	arc_raw_proto = arc_proto_default = arc_bcast_proto = &arc_proto_null;
123 	for (count = 0; count < 256; count++)
124 		arc_proto_map[count] = arc_proto_default;
125 
126 	if (BUGLVL(D_DURING))
127 		pr_info("struct sizes: %zd %zd %zd %zd %zd\n",
128 			sizeof(struct arc_hardware),
129 			sizeof(struct arc_rfc1201),
130 			sizeof(struct arc_rfc1051),
131 			sizeof(struct arc_eth_encap),
132 			sizeof(struct archdr));
133 
134 	return 0;
135 }
136 
arcnet_exit(void)137 static void __exit arcnet_exit(void)
138 {
139 }
140 
141 module_init(arcnet_init);
142 module_exit(arcnet_exit);
143 
144 /* Dump the contents of an sk_buff */
145 #if ARCNET_DEBUG_MAX & D_SKB
arcnet_dump_skb(struct net_device * dev,struct sk_buff * skb,char * desc)146 void arcnet_dump_skb(struct net_device *dev,
147 		     struct sk_buff *skb, char *desc)
148 {
149 	char hdr[32];
150 
151 	/* dump the packet */
152 	snprintf(hdr, sizeof(hdr), "%6s:%s skb->data:", dev->name, desc);
153 	print_hex_dump(KERN_DEBUG, hdr, DUMP_PREFIX_OFFSET,
154 		       16, 1, skb->data, skb->len, true);
155 }
156 EXPORT_SYMBOL(arcnet_dump_skb);
157 #endif
158 
159 /* Dump the contents of an ARCnet buffer */
160 #if (ARCNET_DEBUG_MAX & (D_RX | D_TX))
arcnet_dump_packet(struct net_device * dev,int bufnum,char * desc,int take_arcnet_lock)161 static void arcnet_dump_packet(struct net_device *dev, int bufnum,
162 			       char *desc, int take_arcnet_lock)
163 {
164 	struct arcnet_local *lp = netdev_priv(dev);
165 	int i, length;
166 	unsigned long flags = 0;
167 	static uint8_t buf[512];
168 	char hdr[32];
169 
170 	/* hw.copy_from_card expects IRQ context so take the IRQ lock
171 	 * to keep it single threaded
172 	 */
173 	if (take_arcnet_lock)
174 		spin_lock_irqsave(&lp->lock, flags);
175 
176 	lp->hw.copy_from_card(dev, bufnum, 0, buf, 512);
177 	if (take_arcnet_lock)
178 		spin_unlock_irqrestore(&lp->lock, flags);
179 
180 	/* if the offset[0] byte is nonzero, this is a 256-byte packet */
181 	length = (buf[2] ? 256 : 512);
182 
183 	/* dump the packet */
184 	snprintf(hdr, sizeof(hdr), "%6s:%s packet dump:", dev->name, desc);
185 	print_hex_dump(KERN_DEBUG, hdr, DUMP_PREFIX_OFFSET,
186 		       16, 1, buf, length, true);
187 }
188 
189 #else
190 
191 #define arcnet_dump_packet(dev, bufnum, desc, take_arcnet_lock) do { } while (0)
192 
193 #endif
194 
195 /* Trigger a LED event in response to a ARCNET device event */
arcnet_led_event(struct net_device * dev,enum arcnet_led_event event)196 void arcnet_led_event(struct net_device *dev, enum arcnet_led_event event)
197 {
198 	struct arcnet_local *lp = netdev_priv(dev);
199 
200 	switch (event) {
201 	case ARCNET_LED_EVENT_RECON:
202 		led_trigger_blink_oneshot(lp->recon_led_trig, 350, 350, 0);
203 		break;
204 	case ARCNET_LED_EVENT_OPEN:
205 		led_trigger_event(lp->tx_led_trig, LED_OFF);
206 		led_trigger_event(lp->recon_led_trig, LED_OFF);
207 		break;
208 	case ARCNET_LED_EVENT_STOP:
209 		led_trigger_event(lp->tx_led_trig, LED_OFF);
210 		led_trigger_event(lp->recon_led_trig, LED_OFF);
211 		break;
212 	case ARCNET_LED_EVENT_TX:
213 		led_trigger_blink_oneshot(lp->tx_led_trig, 50, 50, 0);
214 		break;
215 	}
216 }
217 EXPORT_SYMBOL_GPL(arcnet_led_event);
218 
arcnet_led_release(struct device * gendev,void * res)219 static void arcnet_led_release(struct device *gendev, void *res)
220 {
221 	struct arcnet_local *lp = netdev_priv(to_net_dev(gendev));
222 
223 	led_trigger_unregister_simple(lp->tx_led_trig);
224 	led_trigger_unregister_simple(lp->recon_led_trig);
225 }
226 
227 /* Register ARCNET LED triggers for a arcnet device
228  *
229  * This is normally called from a driver's probe function
230  */
devm_arcnet_led_init(struct net_device * netdev,int index,int subid)231 void devm_arcnet_led_init(struct net_device *netdev, int index, int subid)
232 {
233 	struct arcnet_local *lp = netdev_priv(netdev);
234 	void *res;
235 
236 	res = devres_alloc(arcnet_led_release, 0, GFP_KERNEL);
237 	if (!res) {
238 		netdev_err(netdev, "cannot register LED triggers\n");
239 		return;
240 	}
241 
242 	snprintf(lp->tx_led_trig_name, sizeof(lp->tx_led_trig_name),
243 		 "arc%d-%d-tx", index, subid);
244 	snprintf(lp->recon_led_trig_name, sizeof(lp->recon_led_trig_name),
245 		 "arc%d-%d-recon", index, subid);
246 
247 	led_trigger_register_simple(lp->tx_led_trig_name,
248 				    &lp->tx_led_trig);
249 	led_trigger_register_simple(lp->recon_led_trig_name,
250 				    &lp->recon_led_trig);
251 
252 	devres_add(&netdev->dev, res);
253 }
254 EXPORT_SYMBOL_GPL(devm_arcnet_led_init);
255 
256 /* Unregister a protocol driver from the arc_proto_map.  Protocol drivers
257  * are responsible for registering themselves, but the unregister routine
258  * is pretty generic so we'll do it here.
259  */
arcnet_unregister_proto(struct ArcProto * proto)260 void arcnet_unregister_proto(struct ArcProto *proto)
261 {
262 	int count;
263 
264 	if (arc_proto_default == proto)
265 		arc_proto_default = &arc_proto_null;
266 	if (arc_bcast_proto == proto)
267 		arc_bcast_proto = arc_proto_default;
268 	if (arc_raw_proto == proto)
269 		arc_raw_proto = arc_proto_default;
270 
271 	for (count = 0; count < 256; count++) {
272 		if (arc_proto_map[count] == proto)
273 			arc_proto_map[count] = arc_proto_default;
274 	}
275 }
276 EXPORT_SYMBOL(arcnet_unregister_proto);
277 
278 /* Add a buffer to the queue.  Only the interrupt handler is allowed to do
279  * this, unless interrupts are disabled.
280  *
281  * Note: we don't check for a full queue, since there aren't enough buffers
282  * to more than fill it.
283  */
release_arcbuf(struct net_device * dev,int bufnum)284 static void release_arcbuf(struct net_device *dev, int bufnum)
285 {
286 	struct arcnet_local *lp = netdev_priv(dev);
287 	int i;
288 
289 	lp->buf_queue[lp->first_free_buf++] = bufnum;
290 	lp->first_free_buf %= 5;
291 
292 	if (BUGLVL(D_DURING)) {
293 		arc_printk(D_DURING, dev, "release_arcbuf: freed #%d; buffer queue is now: ",
294 			   bufnum);
295 		for (i = lp->next_buf; i != lp->first_free_buf; i = (i + 1) % 5)
296 			arc_cont(D_DURING, "#%d ", lp->buf_queue[i]);
297 		arc_cont(D_DURING, "\n");
298 	}
299 }
300 
301 /* Get a buffer from the queue.
302  * If this returns -1, there are no buffers available.
303  */
get_arcbuf(struct net_device * dev)304 static int get_arcbuf(struct net_device *dev)
305 {
306 	struct arcnet_local *lp = netdev_priv(dev);
307 	int buf = -1, i;
308 
309 	if (!atomic_dec_and_test(&lp->buf_lock)) {
310 		/* already in this function */
311 		arc_printk(D_NORMAL, dev, "get_arcbuf: overlap (%d)!\n",
312 			   lp->buf_lock.counter);
313 	} else {			/* we can continue */
314 		if (lp->next_buf >= 5)
315 			lp->next_buf -= 5;
316 
317 		if (lp->next_buf == lp->first_free_buf) {
318 			arc_printk(D_NORMAL, dev, "get_arcbuf: BUG: no buffers are available??\n");
319 		} else {
320 			buf = lp->buf_queue[lp->next_buf++];
321 			lp->next_buf %= 5;
322 		}
323 	}
324 
325 	if (BUGLVL(D_DURING)) {
326 		arc_printk(D_DURING, dev, "get_arcbuf: got #%d; buffer queue is now: ",
327 			   buf);
328 		for (i = lp->next_buf; i != lp->first_free_buf; i = (i + 1) % 5)
329 			arc_cont(D_DURING, "#%d ", lp->buf_queue[i]);
330 		arc_cont(D_DURING, "\n");
331 	}
332 
333 	atomic_inc(&lp->buf_lock);
334 	return buf;
335 }
336 
choose_mtu(void)337 static int choose_mtu(void)
338 {
339 	int count, mtu = 65535;
340 
341 	/* choose the smallest MTU of all available encaps */
342 	for (count = 0; count < 256; count++) {
343 		if (arc_proto_map[count] != &arc_proto_null &&
344 		    arc_proto_map[count]->mtu < mtu) {
345 			mtu = arc_proto_map[count]->mtu;
346 		}
347 	}
348 
349 	return mtu == 65535 ? XMTU : mtu;
350 }
351 
352 static const struct header_ops arcnet_header_ops = {
353 	.create = arcnet_header,
354 };
355 
356 static const struct net_device_ops arcnet_netdev_ops = {
357 	.ndo_open	= arcnet_open,
358 	.ndo_stop	= arcnet_close,
359 	.ndo_start_xmit = arcnet_send_packet,
360 	.ndo_tx_timeout = arcnet_timeout,
361 };
362 
363 /* Setup a struct device for ARCnet. */
arcdev_setup(struct net_device * dev)364 static void arcdev_setup(struct net_device *dev)
365 {
366 	dev->type = ARPHRD_ARCNET;
367 	dev->netdev_ops = &arcnet_netdev_ops;
368 	dev->header_ops = &arcnet_header_ops;
369 	dev->hard_header_len = sizeof(struct arc_hardware);
370 	dev->mtu = choose_mtu();
371 
372 	dev->addr_len = ARCNET_ALEN;
373 	dev->tx_queue_len = 100;
374 	dev->broadcast[0] = 0x00;	/* for us, broadcasts are address 0 */
375 	dev->watchdog_timeo = TX_TIMEOUT;
376 
377 	/* New-style flags. */
378 	dev->flags = IFF_BROADCAST;
379 }
380 
arcnet_timer(struct timer_list * t)381 static void arcnet_timer(struct timer_list *t)
382 {
383 	struct arcnet_local *lp = from_timer(lp, t, timer);
384 	struct net_device *dev = lp->dev;
385 
386 	spin_lock_irq(&lp->lock);
387 
388 	if (!lp->reset_in_progress && !netif_carrier_ok(dev)) {
389 		netif_carrier_on(dev);
390 		netdev_info(dev, "link up\n");
391 	}
392 
393 	spin_unlock_irq(&lp->lock);
394 }
395 
reset_device_work(struct work_struct * work)396 static void reset_device_work(struct work_struct *work)
397 {
398 	struct arcnet_local *lp;
399 	struct net_device *dev;
400 
401 	lp = container_of(work, struct arcnet_local, reset_work);
402 	dev = lp->dev;
403 
404 	/* Do not bring the network interface back up if an ifdown
405 	 * was already done.
406 	 */
407 	if (!netif_running(dev) || !lp->reset_in_progress)
408 		return;
409 
410 	rtnl_lock();
411 
412 	/* Do another check, in case of an ifdown that was triggered in
413 	 * the small race window between the exit condition above and
414 	 * acquiring RTNL.
415 	 */
416 	if (!netif_running(dev) || !lp->reset_in_progress)
417 		goto out;
418 
419 	dev_close(dev);
420 	dev_open(dev, NULL);
421 
422 out:
423 	rtnl_unlock();
424 }
425 
arcnet_reply_tasklet(struct tasklet_struct * t)426 static void arcnet_reply_tasklet(struct tasklet_struct *t)
427 {
428 	struct arcnet_local *lp = from_tasklet(lp, t, reply_tasklet);
429 
430 	struct sk_buff *ackskb, *skb;
431 	struct sock_exterr_skb *serr;
432 	struct sock *sk;
433 	int ret;
434 
435 	local_irq_disable();
436 	skb = lp->outgoing.skb;
437 	if (!skb || !skb->sk) {
438 		local_irq_enable();
439 		return;
440 	}
441 
442 	sock_hold(skb->sk);
443 	sk = skb->sk;
444 	ackskb = skb_clone_sk(skb);
445 	sock_put(skb->sk);
446 
447 	if (!ackskb) {
448 		local_irq_enable();
449 		return;
450 	}
451 
452 	serr = SKB_EXT_ERR(ackskb);
453 	memset(serr, 0, sizeof(*serr));
454 	serr->ee.ee_errno = ENOMSG;
455 	serr->ee.ee_origin = SO_EE_ORIGIN_TXSTATUS;
456 	serr->ee.ee_data = skb_shinfo(skb)->tskey;
457 	serr->ee.ee_info = lp->reply_status;
458 
459 	/* finally erasing outgoing skb */
460 	dev_kfree_skb(lp->outgoing.skb);
461 	lp->outgoing.skb = NULL;
462 
463 	ackskb->dev = lp->dev;
464 
465 	ret = sock_queue_err_skb(sk, ackskb);
466 	if (ret)
467 		dev_kfree_skb_irq(ackskb);
468 
469 	local_irq_enable();
470 };
471 
alloc_arcdev(const char * name)472 struct net_device *alloc_arcdev(const char *name)
473 {
474 	struct net_device *dev;
475 
476 	dev = alloc_netdev(sizeof(struct arcnet_local),
477 			   name && *name ? name : "arc%d", NET_NAME_UNKNOWN,
478 			   arcdev_setup);
479 	if (dev) {
480 		struct arcnet_local *lp = netdev_priv(dev);
481 
482 		lp->dev = dev;
483 		spin_lock_init(&lp->lock);
484 		timer_setup(&lp->timer, arcnet_timer, 0);
485 		INIT_WORK(&lp->reset_work, reset_device_work);
486 	}
487 
488 	return dev;
489 }
490 EXPORT_SYMBOL(alloc_arcdev);
491 
free_arcdev(struct net_device * dev)492 void free_arcdev(struct net_device *dev)
493 {
494 	struct arcnet_local *lp = netdev_priv(dev);
495 
496 	/* Do not cancel this at ->ndo_close(), as the workqueue itself
497 	 * indirectly calls the ifdown path through dev_close().
498 	 */
499 	cancel_work_sync(&lp->reset_work);
500 	free_netdev(dev);
501 }
502 EXPORT_SYMBOL(free_arcdev);
503 
504 /* Open/initialize the board.  This is called sometime after booting when
505  * the 'ifconfig' program is run.
506  *
507  * This routine should set everything up anew at each open, even registers
508  * that "should" only need to be set once at boot, so that there is
509  * non-reboot way to recover if something goes wrong.
510  */
arcnet_open(struct net_device * dev)511 int arcnet_open(struct net_device *dev)
512 {
513 	struct arcnet_local *lp = netdev_priv(dev);
514 	int count, newmtu, error;
515 
516 	arc_printk(D_INIT, dev, "opened.");
517 
518 	if (!try_module_get(lp->hw.owner))
519 		return -ENODEV;
520 
521 	if (BUGLVL(D_PROTO)) {
522 		arc_printk(D_PROTO, dev, "protocol map (default is '%c'): ",
523 			   arc_proto_default->suffix);
524 		for (count = 0; count < 256; count++)
525 			arc_cont(D_PROTO, "%c", arc_proto_map[count]->suffix);
526 		arc_cont(D_PROTO, "\n");
527 	}
528 
529 	tasklet_setup(&lp->reply_tasklet, arcnet_reply_tasklet);
530 
531 	arc_printk(D_INIT, dev, "arcnet_open: resetting card.\n");
532 
533 	/* try to put the card in a defined state - if it fails the first
534 	 * time, actually reset it.
535 	 */
536 	error = -ENODEV;
537 	if (lp->hw.reset(dev, 0) && lp->hw.reset(dev, 1))
538 		goto out_module_put;
539 
540 	newmtu = choose_mtu();
541 	if (newmtu < dev->mtu)
542 		dev->mtu = newmtu;
543 
544 	arc_printk(D_INIT, dev, "arcnet_open: mtu: %d.\n", dev->mtu);
545 
546 	/* autodetect the encapsulation for each host. */
547 	memset(lp->default_proto, 0, sizeof(lp->default_proto));
548 
549 	/* the broadcast address is special - use the 'bcast' protocol */
550 	for (count = 0; count < 256; count++) {
551 		if (arc_proto_map[count] == arc_bcast_proto) {
552 			lp->default_proto[0] = count;
553 			break;
554 		}
555 	}
556 
557 	/* initialize buffers */
558 	atomic_set(&lp->buf_lock, 1);
559 
560 	lp->next_buf = lp->first_free_buf = 0;
561 	release_arcbuf(dev, 0);
562 	release_arcbuf(dev, 1);
563 	release_arcbuf(dev, 2);
564 	release_arcbuf(dev, 3);
565 	lp->cur_tx = lp->next_tx = -1;
566 	lp->cur_rx = -1;
567 
568 	lp->rfc1201.sequence = 1;
569 
570 	/* bring up the hardware driver */
571 	if (lp->hw.open)
572 		lp->hw.open(dev);
573 
574 	if (dev->dev_addr[0] == 0)
575 		arc_printk(D_NORMAL, dev, "WARNING!  Station address 00 is reserved for broadcasts!\n");
576 	else if (dev->dev_addr[0] == 255)
577 		arc_printk(D_NORMAL, dev, "WARNING!  Station address FF may confuse DOS networking programs!\n");
578 
579 	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
580 	if (lp->hw.status(dev) & RESETflag) {
581 		arc_printk(D_DEBUG, dev, "%s: %d: %s\n",
582 			   __FILE__, __LINE__, __func__);
583 		lp->hw.command(dev, CFLAGScmd | RESETclear);
584 	}
585 
586 	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
587 	/* make sure we're ready to receive IRQ's. */
588 	lp->hw.intmask(dev, 0);
589 	udelay(1);		/* give it time to set the mask before
590 				 * we reset it again. (may not even be
591 				 * necessary)
592 				 */
593 	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
594 	lp->intmask = NORXflag | RECONflag;
595 	lp->hw.intmask(dev, lp->intmask);
596 	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
597 
598 	netif_carrier_off(dev);
599 	netif_start_queue(dev);
600 	mod_timer(&lp->timer, jiffies + msecs_to_jiffies(1000));
601 
602 	arcnet_led_event(dev, ARCNET_LED_EVENT_OPEN);
603 	return 0;
604 
605  out_module_put:
606 	module_put(lp->hw.owner);
607 	return error;
608 }
609 EXPORT_SYMBOL(arcnet_open);
610 
611 /* The inverse routine to arcnet_open - shuts down the card. */
arcnet_close(struct net_device * dev)612 int arcnet_close(struct net_device *dev)
613 {
614 	struct arcnet_local *lp = netdev_priv(dev);
615 
616 	arcnet_led_event(dev, ARCNET_LED_EVENT_STOP);
617 	del_timer_sync(&lp->timer);
618 
619 	netif_stop_queue(dev);
620 	netif_carrier_off(dev);
621 
622 	tasklet_kill(&lp->reply_tasklet);
623 
624 	/* flush TX and disable RX */
625 	lp->hw.intmask(dev, 0);
626 	lp->hw.command(dev, NOTXcmd);	/* stop transmit */
627 	lp->hw.command(dev, NORXcmd);	/* disable receive */
628 	mdelay(1);
629 
630 	/* shut down the card */
631 	lp->hw.close(dev);
632 
633 	/* reset counters */
634 	lp->reset_in_progress = 0;
635 
636 	module_put(lp->hw.owner);
637 	return 0;
638 }
639 EXPORT_SYMBOL(arcnet_close);
640 
arcnet_header(struct sk_buff * skb,struct net_device * dev,unsigned short type,const void * daddr,const void * saddr,unsigned len)641 static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
642 			 unsigned short type, const void *daddr,
643 			 const void *saddr, unsigned len)
644 {
645 	const struct arcnet_local *lp = netdev_priv(dev);
646 	uint8_t _daddr, proto_num;
647 	struct ArcProto *proto;
648 
649 	arc_printk(D_DURING, dev,
650 		   "create header from %d to %d; protocol %d (%Xh); size %u.\n",
651 		   saddr ? *(uint8_t *)saddr : -1,
652 		   daddr ? *(uint8_t *)daddr : -1,
653 		   type, type, len);
654 
655 	if (skb->len != 0 && len != skb->len)
656 		arc_printk(D_NORMAL, dev, "arcnet_header: Yikes!  skb->len(%d) != len(%d)!\n",
657 			   skb->len, len);
658 
659 	/* Type is host order - ? */
660 	if (type == ETH_P_ARCNET) {
661 		proto = arc_raw_proto;
662 		arc_printk(D_DEBUG, dev, "arc_raw_proto used. proto='%c'\n",
663 			   proto->suffix);
664 		_daddr = daddr ? *(uint8_t *)daddr : 0;
665 	} else if (!daddr) {
666 		/* if the dest addr isn't provided, we can't choose an
667 		 * encapsulation!  Store the packet type (eg. ETH_P_IP)
668 		 * for now, and we'll push on a real header when we do
669 		 * rebuild_header.
670 		 */
671 		*(uint16_t *)skb_push(skb, 2) = type;
672 		/* XXX: Why not use skb->mac_len? */
673 		if (skb->network_header - skb->mac_header != 2)
674 			arc_printk(D_NORMAL, dev, "arcnet_header: Yikes!  diff (%u) is not 2!\n",
675 				   skb->network_header - skb->mac_header);
676 		return -2;	/* return error -- can't transmit yet! */
677 	} else {
678 		/* otherwise, we can just add the header as usual. */
679 		_daddr = *(uint8_t *)daddr;
680 		proto_num = lp->default_proto[_daddr];
681 		proto = arc_proto_map[proto_num];
682 		arc_printk(D_DURING, dev, "building header for %02Xh using protocol '%c'\n",
683 			   proto_num, proto->suffix);
684 		if (proto == &arc_proto_null && arc_bcast_proto != proto) {
685 			arc_printk(D_DURING, dev, "actually, let's use '%c' instead.\n",
686 				   arc_bcast_proto->suffix);
687 			proto = arc_bcast_proto;
688 		}
689 	}
690 	return proto->build_header(skb, dev, type, _daddr);
691 }
692 
693 /* Called by the kernel in order to transmit a packet. */
arcnet_send_packet(struct sk_buff * skb,struct net_device * dev)694 netdev_tx_t arcnet_send_packet(struct sk_buff *skb,
695 			       struct net_device *dev)
696 {
697 	struct arcnet_local *lp = netdev_priv(dev);
698 	struct archdr *pkt;
699 	struct arc_rfc1201 *soft;
700 	struct ArcProto *proto;
701 	int txbuf;
702 	unsigned long flags;
703 	int retval;
704 
705 	arc_printk(D_DURING, dev,
706 		   "transmit requested (status=%Xh, txbufs=%d/%d, len=%d, protocol %x)\n",
707 		   lp->hw.status(dev), lp->cur_tx, lp->next_tx, skb->len, skb->protocol);
708 
709 	pkt = (struct archdr *)skb->data;
710 	soft = &pkt->soft.rfc1201;
711 	proto = arc_proto_map[soft->proto];
712 
713 	arc_printk(D_SKB_SIZE, dev, "skb: transmitting %d bytes to %02X\n",
714 		   skb->len, pkt->hard.dest);
715 	if (BUGLVL(D_SKB))
716 		arcnet_dump_skb(dev, skb, "tx");
717 
718 	/* fits in one packet? */
719 	if (skb->len - ARC_HDR_SIZE > XMTU && !proto->continue_tx) {
720 		arc_printk(D_NORMAL, dev, "fixme: packet too large: compensating badly!\n");
721 		dev_kfree_skb(skb);
722 		return NETDEV_TX_OK;	/* don't try again */
723 	}
724 
725 	/* We're busy transmitting a packet... */
726 	netif_stop_queue(dev);
727 
728 	spin_lock_irqsave(&lp->lock, flags);
729 	lp->hw.intmask(dev, 0);
730 	if (lp->next_tx == -1)
731 		txbuf = get_arcbuf(dev);
732 	else
733 		txbuf = -1;
734 
735 	if (txbuf != -1) {
736 		lp->outgoing.skb = skb;
737 		if (proto->prepare_tx(dev, pkt, skb->len, txbuf) &&
738 		    !proto->ack_tx) {
739 			/* done right away and we don't want to acknowledge
740 			 *  the package later - forget about it now
741 			 */
742 			dev->stats.tx_bytes += skb->len;
743 		} else {
744 			/* do it the 'split' way */
745 			lp->outgoing.proto = proto;
746 			lp->outgoing.skb = skb;
747 			lp->outgoing.pkt = pkt;
748 
749 			if (proto->continue_tx &&
750 			    proto->continue_tx(dev, txbuf)) {
751 				arc_printk(D_NORMAL, dev,
752 					   "bug! continue_tx finished the first time! (proto='%c')\n",
753 					   proto->suffix);
754 			}
755 		}
756 		retval = NETDEV_TX_OK;
757 		lp->next_tx = txbuf;
758 	} else {
759 		retval = NETDEV_TX_BUSY;
760 	}
761 
762 	arc_printk(D_DEBUG, dev, "%s: %d: %s, status: %x\n",
763 		   __FILE__, __LINE__, __func__, lp->hw.status(dev));
764 	/* make sure we didn't ignore a TX IRQ while we were in here */
765 	lp->hw.intmask(dev, 0);
766 
767 	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
768 	lp->intmask |= TXFREEflag | EXCNAKflag;
769 	lp->hw.intmask(dev, lp->intmask);
770 	arc_printk(D_DEBUG, dev, "%s: %d: %s, status: %x\n",
771 		   __FILE__, __LINE__, __func__, lp->hw.status(dev));
772 
773 	arcnet_led_event(dev, ARCNET_LED_EVENT_TX);
774 
775 	spin_unlock_irqrestore(&lp->lock, flags);
776 	return retval;		/* no need to try again */
777 }
778 EXPORT_SYMBOL(arcnet_send_packet);
779 
780 /* Actually start transmitting a packet that was loaded into a buffer
781  * by prepare_tx.  This should _only_ be called by the interrupt handler.
782  */
go_tx(struct net_device * dev)783 static int go_tx(struct net_device *dev)
784 {
785 	struct arcnet_local *lp = netdev_priv(dev);
786 
787 	arc_printk(D_DURING, dev, "go_tx: status=%Xh, intmask=%Xh, next_tx=%d, cur_tx=%d\n",
788 		   lp->hw.status(dev), lp->intmask, lp->next_tx, lp->cur_tx);
789 
790 	if (lp->cur_tx != -1 || lp->next_tx == -1)
791 		return 0;
792 
793 	if (BUGLVL(D_TX))
794 		arcnet_dump_packet(dev, lp->next_tx, "go_tx", 0);
795 
796 	lp->cur_tx = lp->next_tx;
797 	lp->next_tx = -1;
798 
799 	/* start sending */
800 	lp->hw.command(dev, TXcmd | (lp->cur_tx << 3));
801 
802 	dev->stats.tx_packets++;
803 	lp->lasttrans_dest = lp->lastload_dest;
804 	lp->lastload_dest = 0;
805 	lp->excnak_pending = 0;
806 	lp->intmask |= TXFREEflag | EXCNAKflag;
807 
808 	return 1;
809 }
810 
811 /* Called by the kernel when transmit times out */
arcnet_timeout(struct net_device * dev,unsigned int txqueue)812 void arcnet_timeout(struct net_device *dev, unsigned int txqueue)
813 {
814 	unsigned long flags;
815 	struct arcnet_local *lp = netdev_priv(dev);
816 	int status = lp->hw.status(dev);
817 	char *msg;
818 
819 	spin_lock_irqsave(&lp->lock, flags);
820 	if (status & TXFREEflag) {	/* transmit _DID_ finish */
821 		msg = " - missed IRQ?";
822 	} else {
823 		msg = "";
824 		dev->stats.tx_aborted_errors++;
825 		lp->timed_out = 1;
826 		lp->hw.command(dev, NOTXcmd | (lp->cur_tx << 3));
827 	}
828 	dev->stats.tx_errors++;
829 
830 	/* make sure we didn't miss a TX or a EXC NAK IRQ */
831 	lp->hw.intmask(dev, 0);
832 	lp->intmask |= TXFREEflag | EXCNAKflag;
833 	lp->hw.intmask(dev, lp->intmask);
834 
835 	spin_unlock_irqrestore(&lp->lock, flags);
836 
837 	if (time_after(jiffies, lp->last_timeout + 10 * HZ)) {
838 		arc_printk(D_EXTRA, dev, "tx timed out%s (status=%Xh, intmask=%Xh, dest=%02Xh)\n",
839 			   msg, status, lp->intmask, lp->lasttrans_dest);
840 		lp->last_timeout = jiffies;
841 	}
842 
843 	if (lp->cur_tx == -1)
844 		netif_wake_queue(dev);
845 }
846 EXPORT_SYMBOL(arcnet_timeout);
847 
848 /* The typical workload of the driver: Handle the network interface
849  * interrupts. Establish which device needs attention, and call the correct
850  * chipset interrupt handler.
851  */
arcnet_interrupt(int irq,void * dev_id)852 irqreturn_t arcnet_interrupt(int irq, void *dev_id)
853 {
854 	struct net_device *dev = dev_id;
855 	struct arcnet_local *lp;
856 	int recbuf, status, diagstatus, didsomething, boguscount;
857 	unsigned long flags;
858 	int retval = IRQ_NONE;
859 
860 	arc_printk(D_DURING, dev, "\n");
861 
862 	arc_printk(D_DURING, dev, "in arcnet_interrupt\n");
863 
864 	lp = netdev_priv(dev);
865 	BUG_ON(!lp);
866 
867 	spin_lock_irqsave(&lp->lock, flags);
868 
869 	if (lp->reset_in_progress)
870 		goto out;
871 
872 	/* RESET flag was enabled - if device is not running, we must
873 	 * clear it right away (but nothing else).
874 	 */
875 	if (!netif_running(dev)) {
876 		if (lp->hw.status(dev) & RESETflag)
877 			lp->hw.command(dev, CFLAGScmd | RESETclear);
878 		lp->hw.intmask(dev, 0);
879 		spin_unlock_irqrestore(&lp->lock, flags);
880 		return retval;
881 	}
882 
883 	arc_printk(D_DURING, dev, "in arcnet_inthandler (status=%Xh, intmask=%Xh)\n",
884 		   lp->hw.status(dev), lp->intmask);
885 
886 	boguscount = 5;
887 	do {
888 		status = lp->hw.status(dev);
889 		diagstatus = (status >> 8) & 0xFF;
890 
891 		arc_printk(D_DEBUG, dev, "%s: %d: %s: status=%x\n",
892 			   __FILE__, __LINE__, __func__, status);
893 		didsomething = 0;
894 
895 		/* RESET flag was enabled - card is resetting and if RX is
896 		 * disabled, it's NOT because we just got a packet.
897 		 *
898 		 * The card is in an undefined state.
899 		 * Clear it out and start over.
900 		 */
901 		if (status & RESETflag) {
902 			arc_printk(D_NORMAL, dev, "spurious reset (status=%Xh)\n",
903 				   status);
904 
905 			lp->reset_in_progress = 1;
906 			netif_stop_queue(dev);
907 			netif_carrier_off(dev);
908 			schedule_work(&lp->reset_work);
909 
910 			/* get out of the interrupt handler! */
911 			goto out;
912 		}
913 		/* RX is inhibited - we must have received something.
914 		 * Prepare to receive into the next buffer.
915 		 *
916 		 * We don't actually copy the received packet from the card
917 		 * until after the transmit handler runs (and possibly
918 		 * launches the next tx); this should improve latency slightly
919 		 * if we get both types of interrupts at once.
920 		 */
921 		recbuf = -1;
922 		if (status & lp->intmask & NORXflag) {
923 			recbuf = lp->cur_rx;
924 			arc_printk(D_DURING, dev, "Buffer #%d: receive irq (status=%Xh)\n",
925 				   recbuf, status);
926 
927 			lp->cur_rx = get_arcbuf(dev);
928 			if (lp->cur_rx != -1) {
929 				arc_printk(D_DURING, dev, "enabling receive to buffer #%d\n",
930 					   lp->cur_rx);
931 				lp->hw.command(dev, RXcmd | (lp->cur_rx << 3) | RXbcasts);
932 			}
933 			didsomething++;
934 		}
935 
936 		if ((diagstatus & EXCNAKflag)) {
937 			arc_printk(D_DURING, dev, "EXCNAK IRQ (diagstat=%Xh)\n",
938 				   diagstatus);
939 
940 			lp->hw.command(dev, NOTXcmd);      /* disable transmit */
941 			lp->excnak_pending = 1;
942 
943 			lp->hw.command(dev, EXCNAKclear);
944 			lp->intmask &= ~(EXCNAKflag);
945 			didsomething++;
946 		}
947 
948 		/* a transmit finished, and we're interested in it. */
949 		if ((status & lp->intmask & TXFREEflag) || lp->timed_out) {
950 			int ackstatus;
951 			lp->intmask &= ~(TXFREEflag | EXCNAKflag);
952 
953 			if (status & TXACKflag)
954 				ackstatus = 2;
955 			else if (lp->excnak_pending)
956 				ackstatus = 1;
957 			else
958 				ackstatus = 0;
959 
960 			arc_printk(D_DURING, dev, "TX IRQ (stat=%Xh)\n",
961 				   status);
962 
963 			if (lp->cur_tx != -1 && !lp->timed_out) {
964 				if (!(status & TXACKflag)) {
965 					if (lp->lasttrans_dest != 0) {
966 						arc_printk(D_EXTRA, dev,
967 							   "transmit was not acknowledged! (status=%Xh, dest=%02Xh)\n",
968 							   status,
969 							   lp->lasttrans_dest);
970 						dev->stats.tx_errors++;
971 						dev->stats.tx_carrier_errors++;
972 					} else {
973 						arc_printk(D_DURING, dev,
974 							   "broadcast was not acknowledged; that's normal (status=%Xh, dest=%02Xh)\n",
975 							   status,
976 							   lp->lasttrans_dest);
977 					}
978 				}
979 
980 				if (lp->outgoing.proto &&
981 				    lp->outgoing.proto->ack_tx) {
982 					lp->outgoing.proto
983 						->ack_tx(dev, ackstatus);
984 				}
985 				lp->reply_status = ackstatus;
986 				tasklet_hi_schedule(&lp->reply_tasklet);
987 			}
988 			if (lp->cur_tx != -1)
989 				release_arcbuf(dev, lp->cur_tx);
990 
991 			lp->cur_tx = -1;
992 			lp->timed_out = 0;
993 			didsomething++;
994 
995 			/* send another packet if there is one */
996 			go_tx(dev);
997 
998 			/* continue a split packet, if any */
999 			if (lp->outgoing.proto &&
1000 			    lp->outgoing.proto->continue_tx) {
1001 				int txbuf = get_arcbuf(dev);
1002 
1003 				if (txbuf != -1) {
1004 					if (lp->outgoing.proto->continue_tx(dev, txbuf)) {
1005 						/* that was the last segment */
1006 						dev->stats.tx_bytes += lp->outgoing.skb->len;
1007 						if (!lp->outgoing.proto->ack_tx) {
1008 							dev_kfree_skb_irq(lp->outgoing.skb);
1009 							lp->outgoing.proto = NULL;
1010 						}
1011 					}
1012 					lp->next_tx = txbuf;
1013 				}
1014 			}
1015 			/* inform upper layers of idleness, if necessary */
1016 			if (lp->cur_tx == -1)
1017 				netif_wake_queue(dev);
1018 		}
1019 		/* now process the received packet, if any */
1020 		if (recbuf != -1) {
1021 			if (BUGLVL(D_RX))
1022 				arcnet_dump_packet(dev, recbuf, "rx irq", 0);
1023 
1024 			arcnet_rx(dev, recbuf);
1025 			release_arcbuf(dev, recbuf);
1026 
1027 			didsomething++;
1028 		}
1029 		if (status & lp->intmask & RECONflag) {
1030 			lp->hw.command(dev, CFLAGScmd | CONFIGclear);
1031 			dev->stats.tx_carrier_errors++;
1032 
1033 			arc_printk(D_RECON, dev, "Network reconfiguration detected (status=%Xh)\n",
1034 				   status);
1035 			if (netif_carrier_ok(dev)) {
1036 				netif_carrier_off(dev);
1037 				netdev_info(dev, "link down\n");
1038 			}
1039 			mod_timer(&lp->timer, jiffies + msecs_to_jiffies(1000));
1040 
1041 			arcnet_led_event(dev, ARCNET_LED_EVENT_RECON);
1042 			/* MYRECON bit is at bit 7 of diagstatus */
1043 			if (diagstatus & 0x80)
1044 				arc_printk(D_RECON, dev, "Put out that recon myself\n");
1045 
1046 			/* is the RECON info empty or old? */
1047 			if (!lp->first_recon || !lp->last_recon ||
1048 			    time_after(jiffies, lp->last_recon + HZ * 10)) {
1049 				if (lp->network_down)
1050 					arc_printk(D_NORMAL, dev, "reconfiguration detected: cabling restored?\n");
1051 				lp->first_recon = lp->last_recon = jiffies;
1052 				lp->num_recons = lp->network_down = 0;
1053 
1054 				arc_printk(D_DURING, dev, "recon: clearing counters.\n");
1055 			} else {	/* add to current RECON counter */
1056 				lp->last_recon = jiffies;
1057 				lp->num_recons++;
1058 
1059 				arc_printk(D_DURING, dev, "recon: counter=%d, time=%lds, net=%d\n",
1060 					   lp->num_recons,
1061 					   (lp->last_recon - lp->first_recon) / HZ,
1062 					   lp->network_down);
1063 
1064 				/* if network is marked up;
1065 				 * and first_recon and last_recon are 60+ apart;
1066 				 * and the average no. of recons counted is
1067 				 *    > RECON_THRESHOLD/min;
1068 				 * then print a warning message.
1069 				 */
1070 				if (!lp->network_down &&
1071 				    (lp->last_recon - lp->first_recon) <= HZ * 60 &&
1072 				    lp->num_recons >= RECON_THRESHOLD) {
1073 					lp->network_down = 1;
1074 					arc_printk(D_NORMAL, dev, "many reconfigurations detected: cabling problem?\n");
1075 				} else if (!lp->network_down &&
1076 					   lp->last_recon - lp->first_recon > HZ * 60) {
1077 					/* reset counters if we've gone for
1078 					 *  over a minute.
1079 					 */
1080 					lp->first_recon = lp->last_recon;
1081 					lp->num_recons = 1;
1082 				}
1083 			}
1084 		} else if (lp->network_down &&
1085 			   time_after(jiffies, lp->last_recon + HZ * 10)) {
1086 			if (lp->network_down)
1087 				arc_printk(D_NORMAL, dev, "cabling restored?\n");
1088 			lp->first_recon = lp->last_recon = 0;
1089 			lp->num_recons = lp->network_down = 0;
1090 
1091 			arc_printk(D_DURING, dev, "not recon: clearing counters anyway.\n");
1092 			netif_carrier_on(dev);
1093 		}
1094 
1095 		if (didsomething)
1096 			retval |= IRQ_HANDLED;
1097 	} while (--boguscount && didsomething);
1098 
1099 	arc_printk(D_DURING, dev, "arcnet_interrupt complete (status=%Xh, count=%d)\n",
1100 		   lp->hw.status(dev), boguscount);
1101 	arc_printk(D_DURING, dev, "\n");
1102 
1103 	lp->hw.intmask(dev, 0);
1104 	udelay(1);
1105 	lp->hw.intmask(dev, lp->intmask);
1106 
1107 out:
1108 	spin_unlock_irqrestore(&lp->lock, flags);
1109 	return retval;
1110 }
1111 EXPORT_SYMBOL(arcnet_interrupt);
1112 
1113 /* This is a generic packet receiver that calls arcnet??_rx depending on the
1114  * protocol ID found.
1115  */
arcnet_rx(struct net_device * dev,int bufnum)1116 static void arcnet_rx(struct net_device *dev, int bufnum)
1117 {
1118 	struct arcnet_local *lp = netdev_priv(dev);
1119 	union {
1120 		struct archdr pkt;
1121 		char buf[512];
1122 	} rxdata;
1123 	struct arc_rfc1201 *soft;
1124 	int length, ofs;
1125 
1126 	soft = &rxdata.pkt.soft.rfc1201;
1127 
1128 	lp->hw.copy_from_card(dev, bufnum, 0, &rxdata.pkt, ARC_HDR_SIZE);
1129 	if (rxdata.pkt.hard.offset[0]) {
1130 		ofs = rxdata.pkt.hard.offset[0];
1131 		length = 256 - ofs;
1132 	} else {
1133 		ofs = rxdata.pkt.hard.offset[1];
1134 		length = 512 - ofs;
1135 	}
1136 
1137 	/* get the full header, if possible */
1138 	if (sizeof(rxdata.pkt.soft) <= length) {
1139 		lp->hw.copy_from_card(dev, bufnum, ofs, soft, sizeof(rxdata.pkt.soft));
1140 	} else {
1141 		memset(&rxdata.pkt.soft, 0, sizeof(rxdata.pkt.soft));
1142 		lp->hw.copy_from_card(dev, bufnum, ofs, soft, length);
1143 	}
1144 
1145 	arc_printk(D_DURING, dev, "Buffer #%d: received packet from %02Xh to %02Xh (%d+4 bytes)\n",
1146 		   bufnum, rxdata.pkt.hard.source, rxdata.pkt.hard.dest, length);
1147 
1148 	dev->stats.rx_packets++;
1149 	dev->stats.rx_bytes += length + ARC_HDR_SIZE;
1150 
1151 	/* call the right receiver for the protocol */
1152 	if (arc_proto_map[soft->proto]->is_ip) {
1153 		if (BUGLVL(D_PROTO)) {
1154 			struct ArcProto
1155 			*oldp = arc_proto_map[lp->default_proto[rxdata.pkt.hard.source]],
1156 			*newp = arc_proto_map[soft->proto];
1157 
1158 			if (oldp != newp) {
1159 				arc_printk(D_PROTO, dev,
1160 					   "got protocol %02Xh; encap for host %02Xh is now '%c' (was '%c')\n",
1161 					   soft->proto, rxdata.pkt.hard.source,
1162 					   newp->suffix, oldp->suffix);
1163 			}
1164 		}
1165 
1166 		/* broadcasts will always be done with the last-used encap. */
1167 		lp->default_proto[0] = soft->proto;
1168 
1169 		/* in striking contrast, the following isn't a hack. */
1170 		lp->default_proto[rxdata.pkt.hard.source] = soft->proto;
1171 	}
1172 	/* call the protocol-specific receiver. */
1173 	arc_proto_map[soft->proto]->rx(dev, bufnum, &rxdata.pkt, length);
1174 }
1175 
null_rx(struct net_device * dev,int bufnum,struct archdr * pkthdr,int length)1176 static void null_rx(struct net_device *dev, int bufnum,
1177 		    struct archdr *pkthdr, int length)
1178 {
1179 	arc_printk(D_PROTO, dev,
1180 		   "rx: don't know how to deal with proto %02Xh from host %02Xh.\n",
1181 		   pkthdr->soft.rfc1201.proto, pkthdr->hard.source);
1182 }
1183 
null_build_header(struct sk_buff * skb,struct net_device * dev,unsigned short type,uint8_t daddr)1184 static int null_build_header(struct sk_buff *skb, struct net_device *dev,
1185 			     unsigned short type, uint8_t daddr)
1186 {
1187 	struct arcnet_local *lp = netdev_priv(dev);
1188 
1189 	arc_printk(D_PROTO, dev,
1190 		   "tx: can't build header for encap %02Xh; load a protocol driver.\n",
1191 		   lp->default_proto[daddr]);
1192 
1193 	/* always fails */
1194 	return 0;
1195 }
1196 
1197 /* the "do nothing" prepare_tx function warns that there's nothing to do. */
null_prepare_tx(struct net_device * dev,struct archdr * pkt,int length,int bufnum)1198 static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
1199 			   int length, int bufnum)
1200 {
1201 	struct arcnet_local *lp = netdev_priv(dev);
1202 	struct arc_hardware newpkt;
1203 
1204 	arc_printk(D_PROTO, dev, "tx: no encap for this host; load a protocol driver.\n");
1205 
1206 	/* send a packet to myself -- will never get received, of course */
1207 	newpkt.source = newpkt.dest = dev->dev_addr[0];
1208 
1209 	/* only one byte of actual data (and it's random) */
1210 	newpkt.offset[0] = 0xFF;
1211 
1212 	lp->hw.copy_to_card(dev, bufnum, 0, &newpkt, ARC_HDR_SIZE);
1213 
1214 	return 1;		/* done */
1215 }
1216