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1da177e4 LT |
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: v3.93 BETA 2000/04/29 - by Avery Pennarun et al.\n" | |
45 | ||
46 | #include <linux/module.h> | |
47 | #include <linux/config.h> | |
48 | #include <linux/types.h> | |
49 | #include <linux/delay.h> | |
50 | #include <linux/netdevice.h> | |
51 | #include <linux/if_arp.h> | |
52 | #include <net/arp.h> | |
53 | #include <linux/init.h> | |
54 | #include <linux/arcdevice.h> | |
55 | ||
56 | /* "do nothing" functions for protocol drivers */ | |
57 | static void null_rx(struct net_device *dev, int bufnum, | |
58 | struct archdr *pkthdr, int length); | |
59 | static int null_build_header(struct sk_buff *skb, struct net_device *dev, | |
60 | unsigned short type, uint8_t daddr); | |
61 | static int null_prepare_tx(struct net_device *dev, struct archdr *pkt, | |
62 | int length, int bufnum); | |
63 | ||
64 | ||
65 | /* | |
66 | * one ArcProto per possible proto ID. None of the elements of | |
67 | * arc_proto_map are allowed to be NULL; they will get set to | |
68 | * arc_proto_default instead. It also must not be NULL; if you would like | |
69 | * to set it to NULL, set it to &arc_proto_null instead. | |
70 | */ | |
71 | struct ArcProto *arc_proto_map[256], *arc_proto_default, | |
72 | *arc_bcast_proto, *arc_raw_proto; | |
73 | ||
74 | struct ArcProto arc_proto_null = | |
75 | { | |
76 | .suffix = '?', | |
77 | .mtu = XMTU, | |
78 | .is_ip = 0, | |
79 | .rx = null_rx, | |
80 | .build_header = null_build_header, | |
81 | .prepare_tx = null_prepare_tx, | |
82 | .continue_tx = NULL, | |
83 | .ack_tx = NULL | |
84 | }; | |
85 | ||
86 | /* Exported function prototypes */ | |
87 | int arcnet_debug = ARCNET_DEBUG; | |
88 | ||
89 | EXPORT_SYMBOL(arc_proto_map); | |
90 | EXPORT_SYMBOL(arc_proto_default); | |
91 | EXPORT_SYMBOL(arc_bcast_proto); | |
92 | EXPORT_SYMBOL(arc_raw_proto); | |
93 | EXPORT_SYMBOL(arc_proto_null); | |
94 | EXPORT_SYMBOL(arcnet_unregister_proto); | |
95 | EXPORT_SYMBOL(arcnet_debug); | |
96 | EXPORT_SYMBOL(alloc_arcdev); | |
97 | EXPORT_SYMBOL(arcnet_interrupt); | |
98 | ||
99 | /* Internal function prototypes */ | |
100 | static int arcnet_open(struct net_device *dev); | |
101 | static int arcnet_close(struct net_device *dev); | |
102 | static int arcnet_send_packet(struct sk_buff *skb, struct net_device *dev); | |
103 | static void arcnet_timeout(struct net_device *dev); | |
104 | static int arcnet_header(struct sk_buff *skb, struct net_device *dev, | |
105 | unsigned short type, void *daddr, void *saddr, | |
106 | unsigned len); | |
107 | static int arcnet_rebuild_header(struct sk_buff *skb); | |
108 | static struct net_device_stats *arcnet_get_stats(struct net_device *dev); | |
109 | static int go_tx(struct net_device *dev); | |
110 | ||
111 | static int debug = ARCNET_DEBUG; | |
112 | module_param(debug, int, 0); | |
113 | MODULE_LICENSE("GPL"); | |
114 | ||
115 | static int __init arcnet_init(void) | |
116 | { | |
117 | int count; | |
118 | ||
119 | arcnet_debug = debug; | |
120 | ||
121 | printk(VERSION); | |
122 | ||
123 | #ifdef ALPHA_WARNING | |
124 | BUGLVL(D_EXTRA) { | |
125 | printk("arcnet: ***\n" | |
126 | "arcnet: * Read arcnet.txt for important release notes!\n" | |
127 | "arcnet: *\n" | |
128 | "arcnet: * This is an ALPHA version! (Last stable release: v3.02) E-mail\n" | |
129 | "arcnet: * me if you have any questions, comments, or bug reports.\n" | |
130 | "arcnet: ***\n"); | |
131 | } | |
132 | #endif | |
133 | ||
134 | /* initialize the protocol map */ | |
135 | arc_raw_proto = arc_proto_default = arc_bcast_proto = &arc_proto_null; | |
136 | for (count = 0; count < 256; count++) | |
137 | arc_proto_map[count] = arc_proto_default; | |
138 | ||
139 | BUGLVL(D_DURING) | |
140 | printk("arcnet: struct sizes: %Zd %Zd %Zd %Zd %Zd\n", | |
141 | sizeof(struct arc_hardware), sizeof(struct arc_rfc1201), | |
142 | sizeof(struct arc_rfc1051), sizeof(struct arc_eth_encap), | |
143 | sizeof(struct archdr)); | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | static void __exit arcnet_exit(void) | |
149 | { | |
150 | } | |
151 | ||
152 | module_init(arcnet_init); | |
153 | module_exit(arcnet_exit); | |
154 | ||
155 | /* | |
156 | * Dump the contents of an sk_buff | |
157 | */ | |
158 | #if ARCNET_DEBUG_MAX & D_SKB | |
159 | void arcnet_dump_skb(struct net_device *dev, | |
160 | struct sk_buff *skb, char *desc) | |
161 | { | |
162 | int i; | |
163 | ||
164 | printk(KERN_DEBUG "%6s: skb dump (%s) follows:", dev->name, desc); | |
165 | for (i = 0; i < skb->len; i++) { | |
166 | if (i % 16 == 0) | |
167 | printk("\n" KERN_DEBUG "[%04X] ", i); | |
168 | printk("%02X ", ((u_char *) skb->data)[i]); | |
169 | } | |
170 | printk("\n"); | |
171 | } | |
172 | ||
173 | EXPORT_SYMBOL(arcnet_dump_skb); | |
174 | #endif | |
175 | ||
176 | ||
177 | /* | |
178 | * Dump the contents of an ARCnet buffer | |
179 | */ | |
180 | #if (ARCNET_DEBUG_MAX & (D_RX | D_TX)) | |
181 | void arcnet_dump_packet(struct net_device *dev, int bufnum, char *desc, | |
182 | int take_arcnet_lock) | |
183 | { | |
184 | struct arcnet_local *lp = dev->priv; | |
185 | int i, length; | |
186 | unsigned long flags = 0; | |
187 | static uint8_t buf[512]; | |
188 | ||
189 | /* hw.copy_from_card expects IRQ context so take the IRQ lock | |
190 | to keep it single threaded */ | |
191 | if(take_arcnet_lock) | |
192 | spin_lock_irqsave(&lp->lock, flags); | |
193 | ||
194 | lp->hw.copy_from_card(dev, bufnum, 0, buf, 512); | |
195 | if(take_arcnet_lock) | |
196 | spin_unlock_irqrestore(&lp->lock, flags); | |
197 | ||
198 | /* if the offset[0] byte is nonzero, this is a 256-byte packet */ | |
199 | length = (buf[2] ? 256 : 512); | |
200 | ||
201 | printk(KERN_DEBUG "%6s: packet dump (%s) follows:", dev->name, desc); | |
202 | for (i = 0; i < length; i++) { | |
203 | if (i % 16 == 0) | |
204 | printk("\n" KERN_DEBUG "[%04X] ", i); | |
205 | printk("%02X ", buf[i]); | |
206 | } | |
207 | printk("\n"); | |
208 | ||
209 | } | |
210 | ||
211 | EXPORT_SYMBOL(arcnet_dump_packet); | |
212 | #endif | |
213 | ||
214 | ||
215 | /* | |
216 | * Unregister a protocol driver from the arc_proto_map. Protocol drivers | |
217 | * are responsible for registering themselves, but the unregister routine | |
218 | * is pretty generic so we'll do it here. | |
219 | */ | |
220 | void arcnet_unregister_proto(struct ArcProto *proto) | |
221 | { | |
222 | int count; | |
223 | ||
224 | if (arc_proto_default == proto) | |
225 | arc_proto_default = &arc_proto_null; | |
226 | if (arc_bcast_proto == proto) | |
227 | arc_bcast_proto = arc_proto_default; | |
228 | if (arc_raw_proto == proto) | |
229 | arc_raw_proto = arc_proto_default; | |
230 | ||
231 | for (count = 0; count < 256; count++) { | |
232 | if (arc_proto_map[count] == proto) | |
233 | arc_proto_map[count] = arc_proto_default; | |
234 | } | |
235 | } | |
236 | ||
237 | ||
238 | /* | |
239 | * Add a buffer to the queue. Only the interrupt handler is allowed to do | |
240 | * this, unless interrupts are disabled. | |
241 | * | |
242 | * Note: we don't check for a full queue, since there aren't enough buffers | |
243 | * to more than fill it. | |
244 | */ | |
245 | static void release_arcbuf(struct net_device *dev, int bufnum) | |
246 | { | |
247 | struct arcnet_local *lp = dev->priv; | |
248 | int i; | |
249 | ||
250 | lp->buf_queue[lp->first_free_buf++] = bufnum; | |
251 | lp->first_free_buf %= 5; | |
252 | ||
253 | BUGLVL(D_DURING) { | |
254 | BUGMSG(D_DURING, "release_arcbuf: freed #%d; buffer queue is now: ", | |
255 | bufnum); | |
256 | for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5) | |
257 | BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]); | |
258 | BUGMSG2(D_DURING, "\n"); | |
259 | } | |
260 | } | |
261 | ||
262 | ||
263 | /* | |
264 | * Get a buffer from the queue. If this returns -1, there are no buffers | |
265 | * available. | |
266 | */ | |
267 | static int get_arcbuf(struct net_device *dev) | |
268 | { | |
269 | struct arcnet_local *lp = dev->priv; | |
270 | int buf = -1, i; | |
271 | ||
272 | if (!atomic_dec_and_test(&lp->buf_lock)) { | |
273 | /* already in this function */ | |
274 | BUGMSG(D_NORMAL, "get_arcbuf: overlap (%d)!\n", | |
275 | lp->buf_lock.counter); | |
276 | } | |
277 | else { /* we can continue */ | |
278 | if (lp->next_buf >= 5) | |
279 | lp->next_buf -= 5; | |
280 | ||
281 | if (lp->next_buf == lp->first_free_buf) | |
282 | BUGMSG(D_NORMAL, "get_arcbuf: BUG: no buffers are available??\n"); | |
283 | else { | |
284 | buf = lp->buf_queue[lp->next_buf++]; | |
285 | lp->next_buf %= 5; | |
286 | } | |
287 | } | |
288 | ||
289 | ||
290 | BUGLVL(D_DURING) { | |
291 | BUGMSG(D_DURING, "get_arcbuf: got #%d; buffer queue is now: ", buf); | |
292 | for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5) | |
293 | BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]); | |
294 | BUGMSG2(D_DURING, "\n"); | |
295 | } | |
296 | ||
297 | atomic_inc(&lp->buf_lock); | |
298 | return buf; | |
299 | } | |
300 | ||
301 | ||
302 | static int choose_mtu(void) | |
303 | { | |
304 | int count, mtu = 65535; | |
305 | ||
306 | /* choose the smallest MTU of all available encaps */ | |
307 | for (count = 0; count < 256; count++) { | |
308 | if (arc_proto_map[count] != &arc_proto_null | |
309 | && arc_proto_map[count]->mtu < mtu) { | |
310 | mtu = arc_proto_map[count]->mtu; | |
311 | } | |
312 | } | |
313 | ||
314 | return mtu == 65535 ? XMTU : mtu; | |
315 | } | |
316 | ||
317 | ||
318 | /* Setup a struct device for ARCnet. */ | |
319 | static void arcdev_setup(struct net_device *dev) | |
320 | { | |
321 | dev->type = ARPHRD_ARCNET; | |
322 | dev->hard_header_len = sizeof(struct archdr); | |
323 | dev->mtu = choose_mtu(); | |
324 | ||
325 | dev->addr_len = ARCNET_ALEN; | |
326 | dev->tx_queue_len = 100; | |
327 | dev->broadcast[0] = 0x00; /* for us, broadcasts are address 0 */ | |
328 | dev->watchdog_timeo = TX_TIMEOUT; | |
329 | ||
330 | /* New-style flags. */ | |
331 | dev->flags = IFF_BROADCAST; | |
332 | ||
333 | /* | |
334 | * Put in this stuff here, so we don't have to export the symbols to | |
335 | * the chipset drivers. | |
336 | */ | |
337 | dev->open = arcnet_open; | |
338 | dev->stop = arcnet_close; | |
339 | dev->hard_start_xmit = arcnet_send_packet; | |
340 | dev->tx_timeout = arcnet_timeout; | |
341 | dev->get_stats = arcnet_get_stats; | |
342 | dev->hard_header = arcnet_header; | |
343 | dev->rebuild_header = arcnet_rebuild_header; | |
344 | } | |
345 | ||
346 | struct net_device *alloc_arcdev(char *name) | |
347 | { | |
348 | struct net_device *dev; | |
349 | ||
350 | dev = alloc_netdev(sizeof(struct arcnet_local), | |
351 | name && *name ? name : "arc%d", arcdev_setup); | |
352 | if(dev) { | |
353 | struct arcnet_local *lp = (struct arcnet_local *) dev->priv; | |
354 | spin_lock_init(&lp->lock); | |
355 | } | |
356 | ||
357 | return dev; | |
358 | } | |
359 | ||
360 | /* | |
361 | * Open/initialize the board. This is called sometime after booting when | |
362 | * the 'ifconfig' program is run. | |
363 | * | |
364 | * This routine should set everything up anew at each open, even registers | |
365 | * that "should" only need to be set once at boot, so that there is | |
366 | * non-reboot way to recover if something goes wrong. | |
367 | */ | |
368 | static int arcnet_open(struct net_device *dev) | |
369 | { | |
370 | struct arcnet_local *lp = dev->priv; | |
371 | int count, newmtu, error; | |
372 | ||
373 | BUGMSG(D_INIT,"opened."); | |
374 | ||
375 | if (!try_module_get(lp->hw.owner)) | |
376 | return -ENODEV; | |
377 | ||
378 | BUGLVL(D_PROTO) { | |
379 | int count; | |
380 | BUGMSG(D_PROTO, "protocol map (default is '%c'): ", | |
381 | arc_proto_default->suffix); | |
382 | for (count = 0; count < 256; count++) | |
383 | BUGMSG2(D_PROTO, "%c", arc_proto_map[count]->suffix); | |
384 | BUGMSG2(D_PROTO, "\n"); | |
385 | } | |
386 | ||
387 | ||
388 | BUGMSG(D_INIT, "arcnet_open: resetting card.\n"); | |
389 | ||
390 | /* try to put the card in a defined state - if it fails the first | |
391 | * time, actually reset it. | |
392 | */ | |
393 | error = -ENODEV; | |
394 | if (ARCRESET(0) && ARCRESET(1)) | |
395 | goto out_module_put; | |
396 | ||
397 | newmtu = choose_mtu(); | |
398 | if (newmtu < dev->mtu) | |
399 | dev->mtu = newmtu; | |
400 | ||
401 | BUGMSG(D_INIT, "arcnet_open: mtu: %d.\n", dev->mtu); | |
402 | ||
403 | /* autodetect the encapsulation for each host. */ | |
404 | memset(lp->default_proto, 0, sizeof(lp->default_proto)); | |
405 | ||
406 | /* the broadcast address is special - use the 'bcast' protocol */ | |
407 | for (count = 0; count < 256; count++) { | |
408 | if (arc_proto_map[count] == arc_bcast_proto) { | |
409 | lp->default_proto[0] = count; | |
410 | break; | |
411 | } | |
412 | } | |
413 | ||
414 | /* initialize buffers */ | |
415 | atomic_set(&lp->buf_lock, 1); | |
416 | ||
417 | lp->next_buf = lp->first_free_buf = 0; | |
418 | release_arcbuf(dev, 0); | |
419 | release_arcbuf(dev, 1); | |
420 | release_arcbuf(dev, 2); | |
421 | release_arcbuf(dev, 3); | |
422 | lp->cur_tx = lp->next_tx = -1; | |
423 | lp->cur_rx = -1; | |
424 | ||
425 | lp->rfc1201.sequence = 1; | |
426 | ||
427 | /* bring up the hardware driver */ | |
428 | if (lp->hw.open) | |
429 | lp->hw.open(dev); | |
430 | ||
431 | if (dev->dev_addr[0] == 0) | |
432 | BUGMSG(D_NORMAL, "WARNING! Station address 00 is reserved " | |
433 | "for broadcasts!\n"); | |
434 | else if (dev->dev_addr[0] == 255) | |
435 | BUGMSG(D_NORMAL, "WARNING! Station address FF may confuse " | |
436 | "DOS networking programs!\n"); | |
437 | ||
438 | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | |
439 | if (ASTATUS() & RESETflag) { | |
440 | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | |
441 | ACOMMAND(CFLAGScmd | RESETclear); | |
442 | } | |
443 | ||
444 | ||
445 | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | |
446 | /* make sure we're ready to receive IRQ's. */ | |
447 | AINTMASK(0); | |
448 | udelay(1); /* give it time to set the mask before | |
449 | * we reset it again. (may not even be | |
450 | * necessary) | |
451 | */ | |
452 | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | |
453 | lp->intmask = NORXflag | RECONflag; | |
454 | AINTMASK(lp->intmask); | |
455 | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | |
456 | ||
457 | netif_start_queue(dev); | |
458 | ||
459 | return 0; | |
460 | ||
461 | out_module_put: | |
462 | module_put(lp->hw.owner); | |
463 | return error; | |
464 | } | |
465 | ||
466 | ||
467 | /* The inverse routine to arcnet_open - shuts down the card. */ | |
468 | static int arcnet_close(struct net_device *dev) | |
469 | { | |
470 | struct arcnet_local *lp = dev->priv; | |
471 | ||
472 | netif_stop_queue(dev); | |
473 | ||
474 | /* flush TX and disable RX */ | |
475 | AINTMASK(0); | |
476 | ACOMMAND(NOTXcmd); /* stop transmit */ | |
477 | ACOMMAND(NORXcmd); /* disable receive */ | |
478 | mdelay(1); | |
479 | ||
480 | /* shut down the card */ | |
481 | lp->hw.close(dev); | |
482 | module_put(lp->hw.owner); | |
483 | return 0; | |
484 | } | |
485 | ||
486 | ||
487 | static int arcnet_header(struct sk_buff *skb, struct net_device *dev, | |
488 | unsigned short type, void *daddr, void *saddr, | |
489 | unsigned len) | |
490 | { | |
491 | struct arcnet_local *lp = dev->priv; | |
492 | uint8_t _daddr, proto_num; | |
493 | struct ArcProto *proto; | |
494 | ||
495 | BUGMSG(D_DURING, | |
496 | "create header from %d to %d; protocol %d (%Xh); size %u.\n", | |
497 | saddr ? *(uint8_t *) saddr : -1, | |
498 | daddr ? *(uint8_t *) daddr : -1, | |
499 | type, type, len); | |
500 | ||
501 | if (skb->len!=0 && len != skb->len) | |
502 | BUGMSG(D_NORMAL, "arcnet_header: Yikes! skb->len(%d) != len(%d)!\n", | |
503 | skb->len, len); | |
504 | ||
505 | ||
506 | /* Type is host order - ? */ | |
507 | if(type == ETH_P_ARCNET) { | |
508 | proto = arc_raw_proto; | |
509 | BUGMSG(D_DEBUG, "arc_raw_proto used. proto='%c'\n",proto->suffix); | |
510 | _daddr = daddr ? *(uint8_t *) daddr : 0; | |
511 | } | |
512 | else if (!daddr) { | |
513 | /* | |
514 | * if the dest addr isn't provided, we can't choose an encapsulation! | |
515 | * Store the packet type (eg. ETH_P_IP) for now, and we'll push on a | |
516 | * real header when we do rebuild_header. | |
517 | */ | |
518 | *(uint16_t *) skb_push(skb, 2) = type; | |
519 | if (skb->nh.raw - skb->mac.raw != 2) | |
520 | BUGMSG(D_NORMAL, "arcnet_header: Yikes! diff (%d) is not 2!\n", | |
521 | (int)(skb->nh.raw - skb->mac.raw)); | |
522 | return -2; /* return error -- can't transmit yet! */ | |
523 | } | |
524 | else { | |
525 | /* otherwise, we can just add the header as usual. */ | |
526 | _daddr = *(uint8_t *) daddr; | |
527 | proto_num = lp->default_proto[_daddr]; | |
528 | proto = arc_proto_map[proto_num]; | |
529 | BUGMSG(D_DURING, "building header for %02Xh using protocol '%c'\n", | |
530 | proto_num, proto->suffix); | |
531 | if (proto == &arc_proto_null && arc_bcast_proto != proto) { | |
532 | BUGMSG(D_DURING, "actually, let's use '%c' instead.\n", | |
533 | arc_bcast_proto->suffix); | |
534 | proto = arc_bcast_proto; | |
535 | } | |
536 | } | |
537 | return proto->build_header(skb, dev, type, _daddr); | |
538 | } | |
539 | ||
540 | ||
541 | /* | |
542 | * Rebuild the ARCnet hard header. This is called after an ARP (or in the | |
543 | * future other address resolution) has completed on this sk_buff. We now | |
544 | * let ARP fill in the destination field. | |
545 | */ | |
546 | static int arcnet_rebuild_header(struct sk_buff *skb) | |
547 | { | |
548 | struct net_device *dev = skb->dev; | |
549 | struct arcnet_local *lp = dev->priv; | |
550 | int status = 0; /* default is failure */ | |
551 | unsigned short type; | |
552 | uint8_t daddr=0; | |
553 | struct ArcProto *proto; | |
554 | ||
555 | if (skb->nh.raw - skb->mac.raw != 2) { | |
556 | BUGMSG(D_NORMAL, | |
557 | "rebuild_header: shouldn't be here! (hdrsize=%d)\n", | |
558 | (int)(skb->nh.raw - skb->mac.raw)); | |
559 | return 0; | |
560 | } | |
561 | type = *(uint16_t *) skb_pull(skb, 2); | |
562 | BUGMSG(D_DURING, "rebuild header for protocol %Xh\n", type); | |
563 | ||
564 | if (type == ETH_P_IP) { | |
565 | #ifdef CONFIG_INET | |
566 | BUGMSG(D_DURING, "rebuild header for ethernet protocol %Xh\n", type); | |
567 | status = arp_find(&daddr, skb) ? 1 : 0; | |
568 | BUGMSG(D_DURING, " rebuilt: dest is %d; protocol %Xh\n", | |
569 | daddr, type); | |
570 | #endif | |
571 | } else { | |
572 | BUGMSG(D_NORMAL, | |
573 | "I don't understand ethernet protocol %Xh addresses!\n", type); | |
574 | lp->stats.tx_errors++; | |
575 | lp->stats.tx_aborted_errors++; | |
576 | } | |
577 | ||
578 | /* if we couldn't resolve the address... give up. */ | |
579 | if (!status) | |
580 | return 0; | |
581 | ||
582 | /* add the _real_ header this time! */ | |
583 | proto = arc_proto_map[lp->default_proto[daddr]]; | |
584 | proto->build_header(skb, dev, type, daddr); | |
585 | ||
586 | return 1; /* success */ | |
587 | } | |
588 | ||
589 | ||
590 | ||
591 | /* Called by the kernel in order to transmit a packet. */ | |
592 | static int arcnet_send_packet(struct sk_buff *skb, struct net_device *dev) | |
593 | { | |
594 | struct arcnet_local *lp = dev->priv; | |
595 | struct archdr *pkt; | |
596 | struct arc_rfc1201 *soft; | |
597 | struct ArcProto *proto; | |
598 | int txbuf; | |
599 | unsigned long flags; | |
c6bb15a0 | 600 | int freeskb, retval; |
1da177e4 LT |
601 | |
602 | BUGMSG(D_DURING, | |
603 | "transmit requested (status=%Xh, txbufs=%d/%d, len=%d, protocol %x)\n", | |
604 | ASTATUS(), lp->cur_tx, lp->next_tx, skb->len,skb->protocol); | |
605 | ||
606 | pkt = (struct archdr *) skb->data; | |
607 | soft = &pkt->soft.rfc1201; | |
608 | proto = arc_proto_map[soft->proto]; | |
609 | ||
610 | BUGMSG(D_SKB_SIZE, "skb: transmitting %d bytes to %02X\n", | |
611 | skb->len, pkt->hard.dest); | |
612 | BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "tx"); | |
613 | ||
614 | /* fits in one packet? */ | |
615 | if (skb->len - ARC_HDR_SIZE > XMTU && !proto->continue_tx) { | |
616 | BUGMSG(D_NORMAL, "fixme: packet too large: compensating badly!\n"); | |
617 | dev_kfree_skb(skb); | |
c6bb15a0 | 618 | return NETDEV_TX_OK; /* don't try again */ |
1da177e4 LT |
619 | } |
620 | ||
621 | /* We're busy transmitting a packet... */ | |
622 | netif_stop_queue(dev); | |
623 | ||
624 | spin_lock_irqsave(&lp->lock, flags); | |
625 | AINTMASK(0); | |
c6bb15a0 PD |
626 | if(lp->next_tx == -1) |
627 | txbuf = get_arcbuf(dev); | |
628 | else { | |
629 | txbuf = -1; | |
630 | } | |
1da177e4 LT |
631 | if (txbuf != -1) { |
632 | if (proto->prepare_tx(dev, pkt, skb->len, txbuf) && | |
633 | !proto->ack_tx) { | |
634 | /* done right away and we don't want to acknowledge | |
635 | the package later - forget about it now */ | |
636 | lp->stats.tx_bytes += skb->len; | |
637 | freeskb = 1; | |
638 | } else { | |
639 | /* do it the 'split' way */ | |
640 | lp->outgoing.proto = proto; | |
641 | lp->outgoing.skb = skb; | |
642 | lp->outgoing.pkt = pkt; | |
643 | ||
c6bb15a0 PD |
644 | freeskb = 0; |
645 | ||
1da177e4 LT |
646 | if (proto->continue_tx && |
647 | proto->continue_tx(dev, txbuf)) { | |
648 | BUGMSG(D_NORMAL, | |
649 | "bug! continue_tx finished the first time! " | |
650 | "(proto='%c')\n", proto->suffix); | |
651 | } | |
652 | } | |
c6bb15a0 PD |
653 | retval = NETDEV_TX_OK; |
654 | dev->trans_start = jiffies; | |
1da177e4 LT |
655 | lp->next_tx = txbuf; |
656 | } else { | |
c6bb15a0 PD |
657 | retval = NETDEV_TX_BUSY; |
658 | freeskb = 0; | |
1da177e4 LT |
659 | } |
660 | ||
661 | BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__FUNCTION__,ASTATUS()); | |
662 | /* make sure we didn't ignore a TX IRQ while we were in here */ | |
663 | AINTMASK(0); | |
664 | ||
665 | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | |
666 | lp->intmask |= TXFREEflag|EXCNAKflag; | |
667 | AINTMASK(lp->intmask); | |
668 | BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__FUNCTION__,ASTATUS()); | |
669 | ||
670 | spin_unlock_irqrestore(&lp->lock, flags); | |
671 | if (freeskb) { | |
672 | dev_kfree_skb(skb); | |
673 | } | |
c6bb15a0 | 674 | return retval; /* no need to try again */ |
1da177e4 LT |
675 | } |
676 | ||
677 | ||
678 | /* | |
679 | * Actually start transmitting a packet that was loaded into a buffer | |
680 | * by prepare_tx. This should _only_ be called by the interrupt handler. | |
681 | */ | |
682 | static int go_tx(struct net_device *dev) | |
683 | { | |
684 | struct arcnet_local *lp = dev->priv; | |
685 | ||
686 | BUGMSG(D_DURING, "go_tx: status=%Xh, intmask=%Xh, next_tx=%d, cur_tx=%d\n", | |
687 | ASTATUS(), lp->intmask, lp->next_tx, lp->cur_tx); | |
688 | ||
689 | if (lp->cur_tx != -1 || lp->next_tx == -1) | |
690 | return 0; | |
691 | ||
692 | BUGLVL(D_TX) arcnet_dump_packet(dev, lp->next_tx, "go_tx", 0); | |
693 | ||
694 | lp->cur_tx = lp->next_tx; | |
695 | lp->next_tx = -1; | |
696 | ||
697 | /* start sending */ | |
698 | ACOMMAND(TXcmd | (lp->cur_tx << 3)); | |
699 | ||
1da177e4 LT |
700 | lp->stats.tx_packets++; |
701 | lp->lasttrans_dest = lp->lastload_dest; | |
702 | lp->lastload_dest = 0; | |
703 | lp->excnak_pending = 0; | |
704 | lp->intmask |= TXFREEflag|EXCNAKflag; | |
705 | ||
706 | return 1; | |
707 | } | |
708 | ||
709 | ||
710 | /* Called by the kernel when transmit times out */ | |
711 | static void arcnet_timeout(struct net_device *dev) | |
712 | { | |
713 | unsigned long flags; | |
714 | struct arcnet_local *lp = dev->priv; | |
715 | int status = ASTATUS(); | |
716 | char *msg; | |
717 | ||
718 | spin_lock_irqsave(&lp->lock, flags); | |
719 | if (status & TXFREEflag) { /* transmit _DID_ finish */ | |
720 | msg = " - missed IRQ?"; | |
721 | } else { | |
722 | msg = ""; | |
723 | lp->stats.tx_aborted_errors++; | |
724 | lp->timed_out = 1; | |
725 | ACOMMAND(NOTXcmd | (lp->cur_tx << 3)); | |
726 | } | |
727 | lp->stats.tx_errors++; | |
728 | ||
729 | /* make sure we didn't miss a TX or a EXC NAK IRQ */ | |
730 | AINTMASK(0); | |
731 | lp->intmask |= TXFREEflag|EXCNAKflag; | |
732 | AINTMASK(lp->intmask); | |
733 | ||
734 | spin_unlock_irqrestore(&lp->lock, flags); | |
735 | ||
736 | if (jiffies - lp->last_timeout > 10*HZ) { | |
737 | BUGMSG(D_EXTRA, "tx timed out%s (status=%Xh, intmask=%Xh, dest=%02Xh)\n", | |
738 | msg, status, lp->intmask, lp->lasttrans_dest); | |
739 | lp->last_timeout = jiffies; | |
740 | } | |
741 | ||
742 | if (lp->cur_tx == -1) | |
743 | netif_wake_queue(dev); | |
744 | } | |
745 | ||
746 | ||
747 | /* | |
748 | * The typical workload of the driver: Handle the network interface | |
749 | * interrupts. Establish which device needs attention, and call the correct | |
750 | * chipset interrupt handler. | |
751 | */ | |
752 | irqreturn_t arcnet_interrupt(int irq, void *dev_id, struct pt_regs *regs) | |
753 | { | |
754 | struct net_device *dev = dev_id; | |
755 | struct arcnet_local *lp; | |
756 | int recbuf, status, diagstatus, didsomething, boguscount; | |
757 | int retval = IRQ_NONE; | |
758 | ||
759 | BUGMSG(D_DURING, "\n"); | |
760 | ||
761 | BUGMSG(D_DURING, "in arcnet_interrupt\n"); | |
762 | ||
763 | lp = dev->priv; | |
764 | if (!lp) | |
765 | BUG(); | |
766 | ||
767 | spin_lock(&lp->lock); | |
768 | ||
769 | /* | |
770 | * RESET flag was enabled - if device is not running, we must clear it right | |
771 | * away (but nothing else). | |
772 | */ | |
773 | if (!netif_running(dev)) { | |
774 | if (ASTATUS() & RESETflag) | |
775 | ACOMMAND(CFLAGScmd | RESETclear); | |
776 | AINTMASK(0); | |
777 | spin_unlock(&lp->lock); | |
778 | return IRQ_HANDLED; | |
779 | } | |
780 | ||
781 | BUGMSG(D_DURING, "in arcnet_inthandler (status=%Xh, intmask=%Xh)\n", | |
782 | ASTATUS(), lp->intmask); | |
783 | ||
784 | boguscount = 5; | |
785 | do { | |
786 | status = ASTATUS(); | |
787 | diagstatus = (status >> 8) & 0xFF; | |
788 | ||
789 | BUGMSG(D_DEBUG, "%s: %d: %s: status=%x\n", | |
790 | __FILE__,__LINE__,__FUNCTION__,status); | |
791 | didsomething = 0; | |
792 | ||
793 | /* | |
794 | * RESET flag was enabled - card is resetting and if RX is | |
795 | * disabled, it's NOT because we just got a packet. | |
796 | * | |
797 | * The card is in an undefined state. Clear it out and start over. | |
798 | */ | |
799 | if (status & RESETflag) { | |
800 | BUGMSG(D_NORMAL, "spurious reset (status=%Xh)\n", status); | |
801 | arcnet_close(dev); | |
802 | arcnet_open(dev); | |
803 | ||
804 | /* get out of the interrupt handler! */ | |
805 | break; | |
806 | } | |
807 | /* | |
808 | * RX is inhibited - we must have received something. Prepare to | |
809 | * receive into the next buffer. | |
810 | * | |
811 | * We don't actually copy the received packet from the card until | |
812 | * after the transmit handler runs (and possibly launches the next | |
813 | * tx); this should improve latency slightly if we get both types | |
814 | * of interrupts at once. | |
815 | */ | |
816 | recbuf = -1; | |
817 | if (status & lp->intmask & NORXflag) { | |
818 | recbuf = lp->cur_rx; | |
819 | BUGMSG(D_DURING, "Buffer #%d: receive irq (status=%Xh)\n", | |
820 | recbuf, status); | |
821 | ||
822 | lp->cur_rx = get_arcbuf(dev); | |
823 | if (lp->cur_rx != -1) { | |
824 | BUGMSG(D_DURING, "enabling receive to buffer #%d\n", | |
825 | lp->cur_rx); | |
826 | ACOMMAND(RXcmd | (lp->cur_rx << 3) | RXbcasts); | |
827 | } | |
828 | didsomething++; | |
829 | } | |
830 | ||
831 | if((diagstatus & EXCNAKflag)) { | |
832 | BUGMSG(D_DURING, "EXCNAK IRQ (diagstat=%Xh)\n", | |
833 | diagstatus); | |
834 | ||
835 | ACOMMAND(NOTXcmd); /* disable transmit */ | |
836 | lp->excnak_pending = 1; | |
837 | ||
838 | ACOMMAND(EXCNAKclear); | |
839 | lp->intmask &= ~(EXCNAKflag); | |
840 | didsomething++; | |
841 | } | |
842 | ||
843 | ||
844 | /* a transmit finished, and we're interested in it. */ | |
845 | if ((status & lp->intmask & TXFREEflag) || lp->timed_out) { | |
846 | lp->intmask &= ~(TXFREEflag|EXCNAKflag); | |
847 | ||
848 | BUGMSG(D_DURING, "TX IRQ (stat=%Xh)\n", status); | |
849 | ||
850 | if (lp->cur_tx != -1 && !lp->timed_out) { | |
851 | if(!(status & TXACKflag)) { | |
852 | if (lp->lasttrans_dest != 0) { | |
853 | BUGMSG(D_EXTRA, | |
854 | "transmit was not acknowledged! " | |
855 | "(status=%Xh, dest=%02Xh)\n", | |
856 | status, lp->lasttrans_dest); | |
857 | lp->stats.tx_errors++; | |
858 | lp->stats.tx_carrier_errors++; | |
859 | } else { | |
860 | BUGMSG(D_DURING, | |
861 | "broadcast was not acknowledged; that's normal " | |
862 | "(status=%Xh, dest=%02Xh)\n", | |
863 | status, lp->lasttrans_dest); | |
864 | } | |
865 | } | |
866 | ||
867 | if (lp->outgoing.proto && | |
868 | lp->outgoing.proto->ack_tx) { | |
869 | int ackstatus; | |
870 | if(status & TXACKflag) | |
871 | ackstatus=2; | |
872 | else if(lp->excnak_pending) | |
873 | ackstatus=1; | |
874 | else | |
875 | ackstatus=0; | |
876 | ||
877 | lp->outgoing.proto | |
878 | ->ack_tx(dev, ackstatus); | |
879 | } | |
880 | } | |
881 | if (lp->cur_tx != -1) | |
882 | release_arcbuf(dev, lp->cur_tx); | |
883 | ||
884 | lp->cur_tx = -1; | |
885 | lp->timed_out = 0; | |
886 | didsomething++; | |
887 | ||
888 | /* send another packet if there is one */ | |
889 | go_tx(dev); | |
890 | ||
891 | /* continue a split packet, if any */ | |
892 | if (lp->outgoing.proto && lp->outgoing.proto->continue_tx) { | |
893 | int txbuf = get_arcbuf(dev); | |
894 | if (txbuf != -1) { | |
895 | if (lp->outgoing.proto->continue_tx(dev, txbuf)) { | |
896 | /* that was the last segment */ | |
897 | lp->stats.tx_bytes += lp->outgoing.skb->len; | |
898 | if(!lp->outgoing.proto->ack_tx) | |
899 | { | |
900 | dev_kfree_skb_irq(lp->outgoing.skb); | |
901 | lp->outgoing.proto = NULL; | |
902 | } | |
903 | } | |
904 | lp->next_tx = txbuf; | |
905 | } | |
906 | } | |
907 | /* inform upper layers of idleness, if necessary */ | |
908 | if (lp->cur_tx == -1) | |
909 | netif_wake_queue(dev); | |
910 | } | |
911 | /* now process the received packet, if any */ | |
912 | if (recbuf != -1) { | |
913 | BUGLVL(D_RX) arcnet_dump_packet(dev, recbuf, "rx irq", 0); | |
914 | ||
915 | arcnet_rx(dev, recbuf); | |
916 | release_arcbuf(dev, recbuf); | |
917 | ||
918 | didsomething++; | |
919 | } | |
920 | if (status & lp->intmask & RECONflag) { | |
921 | ACOMMAND(CFLAGScmd | CONFIGclear); | |
922 | lp->stats.tx_carrier_errors++; | |
923 | ||
924 | BUGMSG(D_RECON, "Network reconfiguration detected (status=%Xh)\n", | |
925 | status); | |
c6bb15a0 PD |
926 | /* MYRECON bit is at bit 7 of diagstatus */ |
927 | if(diagstatus & 0x80) | |
928 | BUGMSG(D_RECON,"Put out that recon myself\n"); | |
1da177e4 LT |
929 | |
930 | /* is the RECON info empty or old? */ | |
931 | if (!lp->first_recon || !lp->last_recon || | |
932 | jiffies - lp->last_recon > HZ * 10) { | |
933 | if (lp->network_down) | |
934 | BUGMSG(D_NORMAL, "reconfiguration detected: cabling restored?\n"); | |
935 | lp->first_recon = lp->last_recon = jiffies; | |
936 | lp->num_recons = lp->network_down = 0; | |
937 | ||
938 | BUGMSG(D_DURING, "recon: clearing counters.\n"); | |
939 | } else { /* add to current RECON counter */ | |
940 | lp->last_recon = jiffies; | |
941 | lp->num_recons++; | |
942 | ||
943 | BUGMSG(D_DURING, "recon: counter=%d, time=%lds, net=%d\n", | |
944 | lp->num_recons, | |
945 | (lp->last_recon - lp->first_recon) / HZ, | |
946 | lp->network_down); | |
947 | ||
948 | /* if network is marked up; | |
949 | * and first_recon and last_recon are 60+ apart; | |
950 | * and the average no. of recons counted is | |
951 | * > RECON_THRESHOLD/min; | |
952 | * then print a warning message. | |
953 | */ | |
954 | if (!lp->network_down | |
955 | && (lp->last_recon - lp->first_recon) <= HZ * 60 | |
956 | && lp->num_recons >= RECON_THRESHOLD) { | |
957 | lp->network_down = 1; | |
958 | BUGMSG(D_NORMAL, "many reconfigurations detected: cabling problem?\n"); | |
959 | } else if (!lp->network_down | |
960 | && lp->last_recon - lp->first_recon > HZ * 60) { | |
961 | /* reset counters if we've gone for over a minute. */ | |
962 | lp->first_recon = lp->last_recon; | |
963 | lp->num_recons = 1; | |
964 | } | |
965 | } | |
966 | } else if (lp->network_down && jiffies - lp->last_recon > HZ * 10) { | |
967 | if (lp->network_down) | |
968 | BUGMSG(D_NORMAL, "cabling restored?\n"); | |
969 | lp->first_recon = lp->last_recon = 0; | |
970 | lp->num_recons = lp->network_down = 0; | |
971 | ||
972 | BUGMSG(D_DURING, "not recon: clearing counters anyway.\n"); | |
973 | } | |
974 | ||
975 | if(didsomething) { | |
976 | retval |= IRQ_HANDLED; | |
977 | } | |
978 | } | |
979 | while (--boguscount && didsomething); | |
980 | ||
981 | BUGMSG(D_DURING, "arcnet_interrupt complete (status=%Xh, count=%d)\n", | |
982 | ASTATUS(), boguscount); | |
983 | BUGMSG(D_DURING, "\n"); | |
984 | ||
985 | ||
986 | AINTMASK(0); | |
987 | udelay(1); | |
988 | AINTMASK(lp->intmask); | |
989 | ||
990 | spin_unlock(&lp->lock); | |
991 | return retval; | |
992 | } | |
993 | ||
994 | ||
995 | /* | |
996 | * This is a generic packet receiver that calls arcnet??_rx depending on the | |
997 | * protocol ID found. | |
998 | */ | |
999 | void arcnet_rx(struct net_device *dev, int bufnum) | |
1000 | { | |
1001 | struct arcnet_local *lp = dev->priv; | |
1002 | struct archdr pkt; | |
1003 | struct arc_rfc1201 *soft; | |
1004 | int length, ofs; | |
1005 | ||
1006 | soft = &pkt.soft.rfc1201; | |
1007 | ||
1008 | lp->hw.copy_from_card(dev, bufnum, 0, &pkt, sizeof(ARC_HDR_SIZE)); | |
1009 | if (pkt.hard.offset[0]) { | |
1010 | ofs = pkt.hard.offset[0]; | |
1011 | length = 256 - ofs; | |
1012 | } else { | |
1013 | ofs = pkt.hard.offset[1]; | |
1014 | length = 512 - ofs; | |
1015 | } | |
1016 | ||
1017 | /* get the full header, if possible */ | |
1018 | if (sizeof(pkt.soft) <= length) | |
1019 | lp->hw.copy_from_card(dev, bufnum, ofs, soft, sizeof(pkt.soft)); | |
1020 | else { | |
1021 | memset(&pkt.soft, 0, sizeof(pkt.soft)); | |
1022 | lp->hw.copy_from_card(dev, bufnum, ofs, soft, length); | |
1023 | } | |
1024 | ||
1025 | BUGMSG(D_DURING, "Buffer #%d: received packet from %02Xh to %02Xh " | |
1026 | "(%d+4 bytes)\n", | |
1027 | bufnum, pkt.hard.source, pkt.hard.dest, length); | |
1028 | ||
1029 | lp->stats.rx_packets++; | |
1030 | lp->stats.rx_bytes += length + ARC_HDR_SIZE; | |
1031 | ||
1032 | /* call the right receiver for the protocol */ | |
1033 | if (arc_proto_map[soft->proto]->is_ip) { | |
1034 | BUGLVL(D_PROTO) { | |
1035 | struct ArcProto | |
1036 | *oldp = arc_proto_map[lp->default_proto[pkt.hard.source]], | |
1037 | *newp = arc_proto_map[soft->proto]; | |
1038 | ||
1039 | if (oldp != newp) { | |
1040 | BUGMSG(D_PROTO, | |
1041 | "got protocol %02Xh; encap for host %02Xh is now '%c'" | |
1042 | " (was '%c')\n", soft->proto, pkt.hard.source, | |
1043 | newp->suffix, oldp->suffix); | |
1044 | } | |
1045 | } | |
1046 | ||
1047 | /* broadcasts will always be done with the last-used encap. */ | |
1048 | lp->default_proto[0] = soft->proto; | |
1049 | ||
1050 | /* in striking contrast, the following isn't a hack. */ | |
1051 | lp->default_proto[pkt.hard.source] = soft->proto; | |
1052 | } | |
1053 | /* call the protocol-specific receiver. */ | |
1054 | arc_proto_map[soft->proto]->rx(dev, bufnum, &pkt, length); | |
1055 | } | |
1056 | ||
1057 | ||
1058 | ||
1059 | /* | |
1060 | * Get the current statistics. This may be called with the card open or | |
1061 | * closed. | |
1062 | */ | |
1063 | static struct net_device_stats *arcnet_get_stats(struct net_device *dev) | |
1064 | { | |
1065 | struct arcnet_local *lp = dev->priv; | |
1066 | return &lp->stats; | |
1067 | } | |
1068 | ||
1069 | ||
1070 | static void null_rx(struct net_device *dev, int bufnum, | |
1071 | struct archdr *pkthdr, int length) | |
1072 | { | |
1073 | BUGMSG(D_PROTO, | |
1074 | "rx: don't know how to deal with proto %02Xh from host %02Xh.\n", | |
1075 | pkthdr->soft.rfc1201.proto, pkthdr->hard.source); | |
1076 | } | |
1077 | ||
1078 | ||
1079 | static int null_build_header(struct sk_buff *skb, struct net_device *dev, | |
1080 | unsigned short type, uint8_t daddr) | |
1081 | { | |
1082 | struct arcnet_local *lp = dev->priv; | |
1083 | ||
1084 | BUGMSG(D_PROTO, | |
1085 | "tx: can't build header for encap %02Xh; load a protocol driver.\n", | |
1086 | lp->default_proto[daddr]); | |
1087 | ||
1088 | /* always fails */ | |
1089 | return 0; | |
1090 | } | |
1091 | ||
1092 | ||
1093 | /* the "do nothing" prepare_tx function warns that there's nothing to do. */ | |
1094 | static int null_prepare_tx(struct net_device *dev, struct archdr *pkt, | |
1095 | int length, int bufnum) | |
1096 | { | |
1097 | struct arcnet_local *lp = dev->priv; | |
1098 | struct arc_hardware newpkt; | |
1099 | ||
1100 | BUGMSG(D_PROTO, "tx: no encap for this host; load a protocol driver.\n"); | |
1101 | ||
1102 | /* send a packet to myself -- will never get received, of course */ | |
1103 | newpkt.source = newpkt.dest = dev->dev_addr[0]; | |
1104 | ||
1105 | /* only one byte of actual data (and it's random) */ | |
1106 | newpkt.offset[0] = 0xFF; | |
1107 | ||
1108 | lp->hw.copy_to_card(dev, bufnum, 0, &newpkt, ARC_HDR_SIZE); | |
1109 | ||
1110 | return 1; /* done */ | |
1111 | } |