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arcnet.c
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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 <[email protected]>.
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 <[email protected]>
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 <[email protected]>
40  * - Textual information and more alternate source from Joachim Koenig
41  * <[email protected]>
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 */
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 static 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 
75 static 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 */
88 int arcnet_debug = ARCNET_DEBUG;
89 
90 EXPORT_SYMBOL(arc_proto_map);
91 EXPORT_SYMBOL(arc_proto_default);
92 EXPORT_SYMBOL(arc_bcast_proto);
93 EXPORT_SYMBOL(arc_raw_proto);
94 EXPORT_SYMBOL(arcnet_unregister_proto);
95 EXPORT_SYMBOL(arcnet_debug);
96 EXPORT_SYMBOL(alloc_arcdev);
97 EXPORT_SYMBOL(arcnet_interrupt);
98 EXPORT_SYMBOL(arcnet_open);
99 EXPORT_SYMBOL(arcnet_close);
100 EXPORT_SYMBOL(arcnet_send_packet);
101 EXPORT_SYMBOL(arcnet_timeout);
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 arcnet_rebuild_header(struct sk_buff *skb);
108 static int go_tx(struct net_device *dev);
109 
110 static int debug = ARCNET_DEBUG;
111 module_param(debug, int, 0);
112 MODULE_LICENSE("GPL");
113 
114 static int __init arcnet_init(void)
115 {
116  int count;
117 
118  arcnet_debug = debug;
119 
120  printk("arcnet loaded.\n");
121 
122 #ifdef ALPHA_WARNING
123  BUGLVL(D_EXTRA) {
124  printk("arcnet: ***\n"
125  "arcnet: * Read arcnet.txt for important release notes!\n"
126  "arcnet: *\n"
127  "arcnet: * This is an ALPHA version! (Last stable release: v3.02) E-mail\n"
128  "arcnet: * me if you have any questions, comments, or bug reports.\n"
129  "arcnet: ***\n");
130  }
131 #endif
132 
133  /* initialize the protocol map */
134  arc_raw_proto = arc_proto_default = arc_bcast_proto = &arc_proto_null;
135  for (count = 0; count < 256; count++)
136  arc_proto_map[count] = arc_proto_default;
137 
138  BUGLVL(D_DURING)
139  printk("arcnet: struct sizes: %Zd %Zd %Zd %Zd %Zd\n",
140  sizeof(struct arc_hardware), sizeof(struct arc_rfc1201),
141  sizeof(struct arc_rfc1051), sizeof(struct arc_eth_encap),
142  sizeof(struct archdr));
143 
144  return 0;
145 }
146 
147 static void __exit arcnet_exit(void)
148 {
149 }
150 
151 module_init(arcnet_init);
152 module_exit(arcnet_exit);
153 
154 /*
155  * Dump the contents of an sk_buff
156  */
157 #if ARCNET_DEBUG_MAX & D_SKB
158 void arcnet_dump_skb(struct net_device *dev,
159  struct sk_buff *skb, char *desc)
160 {
161  char hdr[32];
162 
163  /* dump the packet */
164  snprintf(hdr, sizeof(hdr), "%6s:%s skb->data:", dev->name, desc);
165  print_hex_dump(KERN_DEBUG, hdr, DUMP_PREFIX_OFFSET,
166  16, 1, skb->data, skb->len, true);
167 }
168 
169 EXPORT_SYMBOL(arcnet_dump_skb);
170 #endif
171 
172 
173 /*
174  * Dump the contents of an ARCnet buffer
175  */
176 #if (ARCNET_DEBUG_MAX & (D_RX | D_TX))
177 static void arcnet_dump_packet(struct net_device *dev, int bufnum,
178  char *desc, int take_arcnet_lock)
179 {
180  struct arcnet_local *lp = netdev_priv(dev);
181  int i, length;
182  unsigned long flags = 0;
183  static uint8_t buf[512];
184  char hdr[32];
185 
186  /* hw.copy_from_card expects IRQ context so take the IRQ lock
187  to keep it single threaded */
188  if(take_arcnet_lock)
189  spin_lock_irqsave(&lp->lock, flags);
190 
191  lp->hw.copy_from_card(dev, bufnum, 0, buf, 512);
192  if(take_arcnet_lock)
193  spin_unlock_irqrestore(&lp->lock, flags);
194 
195  /* if the offset[0] byte is nonzero, this is a 256-byte packet */
196  length = (buf[2] ? 256 : 512);
197 
198  /* dump the packet */
199  snprintf(hdr, sizeof(hdr), "%6s:%s packet dump:", dev->name, desc);
200  print_hex_dump(KERN_DEBUG, hdr, DUMP_PREFIX_OFFSET,
201  16, 1, buf, length, true);
202 }
203 
204 #else
205 
206 #define arcnet_dump_packet(dev, bufnum, desc,take_arcnet_lock) do { } while (0)
207 
208 #endif
209 
210 
211 /*
212  * Unregister a protocol driver from the arc_proto_map. Protocol drivers
213  * are responsible for registering themselves, but the unregister routine
214  * is pretty generic so we'll do it here.
215  */
216 void arcnet_unregister_proto(struct ArcProto *proto)
217 {
218  int count;
219 
220  if (arc_proto_default == proto)
221  arc_proto_default = &arc_proto_null;
222  if (arc_bcast_proto == proto)
223  arc_bcast_proto = arc_proto_default;
224  if (arc_raw_proto == proto)
225  arc_raw_proto = arc_proto_default;
226 
227  for (count = 0; count < 256; count++) {
228  if (arc_proto_map[count] == proto)
229  arc_proto_map[count] = arc_proto_default;
230  }
231 }
232 
233 
234 /*
235  * Add a buffer to the queue. Only the interrupt handler is allowed to do
236  * this, unless interrupts are disabled.
237  *
238  * Note: we don't check for a full queue, since there aren't enough buffers
239  * to more than fill it.
240  */
241 static void release_arcbuf(struct net_device *dev, int bufnum)
242 {
243  struct arcnet_local *lp = netdev_priv(dev);
244  int i;
245 
246  lp->buf_queue[lp->first_free_buf++] = bufnum;
247  lp->first_free_buf %= 5;
248 
249  BUGLVL(D_DURING) {
250  BUGMSG(D_DURING, "release_arcbuf: freed #%d; buffer queue is now: ",
251  bufnum);
252  for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5)
253  BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]);
254  BUGMSG2(D_DURING, "\n");
255  }
256 }
257 
258 
259 /*
260  * Get a buffer from the queue. If this returns -1, there are no buffers
261  * available.
262  */
263 static int get_arcbuf(struct net_device *dev)
264 {
265  struct arcnet_local *lp = netdev_priv(dev);
266  int buf = -1, i;
267 
268  if (!atomic_dec_and_test(&lp->buf_lock)) {
269  /* already in this function */
270  BUGMSG(D_NORMAL, "get_arcbuf: overlap (%d)!\n",
271  lp->buf_lock.counter);
272  }
273  else { /* we can continue */
274  if (lp->next_buf >= 5)
275  lp->next_buf -= 5;
276 
277  if (lp->next_buf == lp->first_free_buf)
278  BUGMSG(D_NORMAL, "get_arcbuf: BUG: no buffers are available??\n");
279  else {
280  buf = lp->buf_queue[lp->next_buf++];
281  lp->next_buf %= 5;
282  }
283  }
284 
285 
286  BUGLVL(D_DURING) {
287  BUGMSG(D_DURING, "get_arcbuf: got #%d; buffer queue is now: ", buf);
288  for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5)
289  BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]);
290  BUGMSG2(D_DURING, "\n");
291  }
292 
293  atomic_inc(&lp->buf_lock);
294  return buf;
295 }
296 
297 
298 static int choose_mtu(void)
299 {
300  int count, mtu = 65535;
301 
302  /* choose the smallest MTU of all available encaps */
303  for (count = 0; count < 256; count++) {
304  if (arc_proto_map[count] != &arc_proto_null &&
305  arc_proto_map[count]->mtu < mtu) {
306  mtu = arc_proto_map[count]->mtu;
307  }
308  }
309 
310  return mtu == 65535 ? XMTU : mtu;
311 }
312 
313 static const struct header_ops arcnet_header_ops = {
314  .create = arcnet_header,
315  .rebuild = arcnet_rebuild_header,
316 };
317 
318 static const struct net_device_ops arcnet_netdev_ops = {
319  .ndo_open = arcnet_open,
320  .ndo_stop = arcnet_close,
321  .ndo_start_xmit = arcnet_send_packet,
322  .ndo_tx_timeout = arcnet_timeout,
323 };
324 
325 /* Setup a struct device for ARCnet. */
326 static void arcdev_setup(struct net_device *dev)
327 {
328  dev->type = ARPHRD_ARCNET;
329  dev->netdev_ops = &arcnet_netdev_ops;
330  dev->header_ops = &arcnet_header_ops;
331  dev->hard_header_len = sizeof(struct archdr);
332  dev->mtu = choose_mtu();
333 
334  dev->addr_len = ARCNET_ALEN;
335  dev->tx_queue_len = 100;
336  dev->broadcast[0] = 0x00; /* for us, broadcasts are address 0 */
337  dev->watchdog_timeo = TX_TIMEOUT;
338 
339  /* New-style flags. */
340  dev->flags = IFF_BROADCAST;
341 
342 }
343 
344 struct net_device *alloc_arcdev(const char *name)
345 {
346  struct net_device *dev;
347 
348  dev = alloc_netdev(sizeof(struct arcnet_local),
349  name && *name ? name : "arc%d", arcdev_setup);
350  if(dev) {
351  struct arcnet_local *lp = netdev_priv(dev);
352  spin_lock_init(&lp->lock);
353  }
354 
355  return dev;
356 }
357 
358 /*
359  * Open/initialize the board. This is called sometime after booting when
360  * the 'ifconfig' program is run.
361  *
362  * This routine should set everything up anew at each open, even registers
363  * that "should" only need to be set once at boot, so that there is
364  * non-reboot way to recover if something goes wrong.
365  */
366 int arcnet_open(struct net_device *dev)
367 {
368  struct arcnet_local *lp = netdev_priv(dev);
369  int count, newmtu, error;
370 
371  BUGMSG(D_INIT,"opened.");
372 
373  if (!try_module_get(lp->hw.owner))
374  return -ENODEV;
375 
376  BUGLVL(D_PROTO) {
377  BUGMSG(D_PROTO, "protocol map (default is '%c'): ",
378  arc_proto_default->suffix);
379  for (count = 0; count < 256; count++)
380  BUGMSG2(D_PROTO, "%c", arc_proto_map[count]->suffix);
381  BUGMSG2(D_PROTO, "\n");
382  }
383 
384 
385  BUGMSG(D_INIT, "arcnet_open: resetting card.\n");
386 
387  /* try to put the card in a defined state - if it fails the first
388  * time, actually reset it.
389  */
390  error = -ENODEV;
391  if (ARCRESET(0) && ARCRESET(1))
392  goto out_module_put;
393 
394  newmtu = choose_mtu();
395  if (newmtu < dev->mtu)
396  dev->mtu = newmtu;
397 
398  BUGMSG(D_INIT, "arcnet_open: mtu: %d.\n", dev->mtu);
399 
400  /* autodetect the encapsulation for each host. */
401  memset(lp->default_proto, 0, sizeof(lp->default_proto));
402 
403  /* the broadcast address is special - use the 'bcast' protocol */
404  for (count = 0; count < 256; count++) {
405  if (arc_proto_map[count] == arc_bcast_proto) {
406  lp->default_proto[0] = count;
407  break;
408  }
409  }
410 
411  /* initialize buffers */
412  atomic_set(&lp->buf_lock, 1);
413 
414  lp->next_buf = lp->first_free_buf = 0;
415  release_arcbuf(dev, 0);
416  release_arcbuf(dev, 1);
417  release_arcbuf(dev, 2);
418  release_arcbuf(dev, 3);
419  lp->cur_tx = lp->next_tx = -1;
420  lp->cur_rx = -1;
421 
422  lp->rfc1201.sequence = 1;
423 
424  /* bring up the hardware driver */
425  if (lp->hw.open)
426  lp->hw.open(dev);
427 
428  if (dev->dev_addr[0] == 0)
429  BUGMSG(D_NORMAL, "WARNING! Station address 00 is reserved "
430  "for broadcasts!\n");
431  else if (dev->dev_addr[0] == 255)
432  BUGMSG(D_NORMAL, "WARNING! Station address FF may confuse "
433  "DOS networking programs!\n");
434 
435  BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
436  if (ASTATUS() & RESETflag) {
437  BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
438  ACOMMAND(CFLAGScmd | RESETclear);
439  }
440 
441 
442  BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
443  /* make sure we're ready to receive IRQ's. */
444  AINTMASK(0);
445  udelay(1); /* give it time to set the mask before
446  * we reset it again. (may not even be
447  * necessary)
448  */
449  BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
450  lp->intmask = NORXflag | RECONflag;
451  AINTMASK(lp->intmask);
452  BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
453 
454  netif_start_queue(dev);
455 
456  return 0;
457 
458  out_module_put:
459  module_put(lp->hw.owner);
460  return error;
461 }
462 
463 
464 /* The inverse routine to arcnet_open - shuts down the card. */
465 int arcnet_close(struct net_device *dev)
466 {
467  struct arcnet_local *lp = netdev_priv(dev);
468 
469  netif_stop_queue(dev);
470 
471  /* flush TX and disable RX */
472  AINTMASK(0);
473  ACOMMAND(NOTXcmd); /* stop transmit */
474  ACOMMAND(NORXcmd); /* disable receive */
475  mdelay(1);
476 
477  /* shut down the card */
478  lp->hw.close(dev);
479  module_put(lp->hw.owner);
480  return 0;
481 }
482 
483 
484 static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
485  unsigned short type, const void *daddr,
486  const void *saddr, unsigned len)
487 {
488  const struct arcnet_local *lp = netdev_priv(dev);
489  uint8_t _daddr, proto_num;
490  struct ArcProto *proto;
491 
492  BUGMSG(D_DURING,
493  "create header from %d to %d; protocol %d (%Xh); size %u.\n",
494  saddr ? *(uint8_t *) saddr : -1,
495  daddr ? *(uint8_t *) daddr : -1,
496  type, type, len);
497 
498  if (skb->len!=0 && len != skb->len)
499  BUGMSG(D_NORMAL, "arcnet_header: Yikes! skb->len(%d) != len(%d)!\n",
500  skb->len, len);
501 
502 
503  /* Type is host order - ? */
504  if(type == ETH_P_ARCNET) {
505  proto = arc_raw_proto;
506  BUGMSG(D_DEBUG, "arc_raw_proto used. proto='%c'\n",proto->suffix);
507  _daddr = daddr ? *(uint8_t *) daddr : 0;
508  }
509  else if (!daddr) {
510  /*
511  * if the dest addr isn't provided, we can't choose an encapsulation!
512  * Store the packet type (eg. ETH_P_IP) for now, and we'll push on a
513  * real header when we do rebuild_header.
514  */
515  *(uint16_t *) skb_push(skb, 2) = type;
516  /*
517  * XXX: Why not use skb->mac_len?
518  */
519  if (skb->network_header - skb->mac_header != 2)
520  BUGMSG(D_NORMAL, "arcnet_header: Yikes! diff (%d) is not 2!\n",
521  (int)(skb->network_header - skb->mac_header));
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 = netdev_priv(dev);
550  int status = 0; /* default is failure */
551  unsigned short type;
552  uint8_t daddr=0;
553  struct ArcProto *proto;
554  /*
555  * XXX: Why not use skb->mac_len?
556  */
557  if (skb->network_header - skb->mac_header != 2) {
558  BUGMSG(D_NORMAL,
559  "rebuild_header: shouldn't be here! (hdrsize=%d)\n",
560  (int)(skb->network_header - skb->mac_header));
561  return 0;
562  }
563  type = *(uint16_t *) skb_pull(skb, 2);
564  BUGMSG(D_DURING, "rebuild header for protocol %Xh\n", type);
565 
566  if (type == ETH_P_IP) {
567 #ifdef CONFIG_INET
568  BUGMSG(D_DURING, "rebuild header for ethernet protocol %Xh\n", type);
569  status = arp_find(&daddr, skb) ? 1 : 0;
570  BUGMSG(D_DURING, " rebuilt: dest is %d; protocol %Xh\n",
571  daddr, type);
572 #endif
573  } else {
574  BUGMSG(D_NORMAL,
575  "I don't understand ethernet protocol %Xh addresses!\n", type);
576  dev->stats.tx_errors++;
577  dev->stats.tx_aborted_errors++;
578  }
579 
580  /* if we couldn't resolve the address... give up. */
581  if (!status)
582  return 0;
583 
584  /* add the _real_ header this time! */
585  proto = arc_proto_map[lp->default_proto[daddr]];
586  proto->build_header(skb, dev, type, daddr);
587 
588  return 1; /* success */
589 }
590 
591 
592 
593 /* Called by the kernel in order to transmit a packet. */
594 netdev_tx_t arcnet_send_packet(struct sk_buff *skb,
595  struct net_device *dev)
596 {
597  struct arcnet_local *lp = netdev_priv(dev);
598  struct archdr *pkt;
599  struct arc_rfc1201 *soft;
600  struct ArcProto *proto;
601  int txbuf;
602  unsigned long flags;
603  int freeskb, retval;
604 
605  BUGMSG(D_DURING,
606  "transmit requested (status=%Xh, txbufs=%d/%d, len=%d, protocol %x)\n",
607  ASTATUS(), lp->cur_tx, lp->next_tx, skb->len,skb->protocol);
608 
609  pkt = (struct archdr *) skb->data;
610  soft = &pkt->soft.rfc1201;
611  proto = arc_proto_map[soft->proto];
612 
613  BUGMSG(D_SKB_SIZE, "skb: transmitting %d bytes to %02X\n",
614  skb->len, pkt->hard.dest);
615  BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "tx");
616 
617  /* fits in one packet? */
618  if (skb->len - ARC_HDR_SIZE > XMTU && !proto->continue_tx) {
619  BUGMSG(D_NORMAL, "fixme: packet too large: compensating badly!\n");
620  dev_kfree_skb(skb);
621  return NETDEV_TX_OK; /* don't try again */
622  }
623 
624  /* We're busy transmitting a packet... */
625  netif_stop_queue(dev);
626 
627  spin_lock_irqsave(&lp->lock, flags);
628  AINTMASK(0);
629  if(lp->next_tx == -1)
630  txbuf = get_arcbuf(dev);
631  else {
632  txbuf = -1;
633  }
634  if (txbuf != -1) {
635  if (proto->prepare_tx(dev, pkt, skb->len, txbuf) &&
636  !proto->ack_tx) {
637  /* done right away and we don't want to acknowledge
638  the package later - forget about it now */
639  dev->stats.tx_bytes += skb->len;
640  freeskb = 1;
641  } else {
642  /* do it the 'split' way */
643  lp->outgoing.proto = proto;
644  lp->outgoing.skb = skb;
645  lp->outgoing.pkt = pkt;
646 
647  freeskb = 0;
648 
649  if (proto->continue_tx &&
650  proto->continue_tx(dev, txbuf)) {
651  BUGMSG(D_NORMAL,
652  "bug! continue_tx finished the first time! "
653  "(proto='%c')\n", proto->suffix);
654  }
655  }
656  retval = NETDEV_TX_OK;
657  lp->next_tx = txbuf;
658  } else {
659  retval = NETDEV_TX_BUSY;
660  freeskb = 0;
661  }
662 
663  BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__func__,ASTATUS());
664  /* make sure we didn't ignore a TX IRQ while we were in here */
665  AINTMASK(0);
666 
667  BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__func__);
668  lp->intmask |= TXFREEflag|EXCNAKflag;
669  AINTMASK(lp->intmask);
670  BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__func__,ASTATUS());
671 
672  spin_unlock_irqrestore(&lp->lock, flags);
673  if (freeskb) {
674  dev_kfree_skb(skb);
675  }
676  return retval; /* no need to try again */
677 }
678 
679 
680 /*
681  * Actually start transmitting a packet that was loaded into a buffer
682  * by prepare_tx. This should _only_ be called by the interrupt handler.
683  */
684 static int go_tx(struct net_device *dev)
685 {
686  struct arcnet_local *lp = netdev_priv(dev);
687 
688  BUGMSG(D_DURING, "go_tx: status=%Xh, intmask=%Xh, next_tx=%d, cur_tx=%d\n",
689  ASTATUS(), lp->intmask, lp->next_tx, lp->cur_tx);
690 
691  if (lp->cur_tx != -1 || lp->next_tx == -1)
692  return 0;
693 
694  BUGLVL(D_TX) arcnet_dump_packet(dev, lp->next_tx, "go_tx", 0);
695 
696  lp->cur_tx = lp->next_tx;
697  lp->next_tx = -1;
698 
699  /* start sending */
700  ACOMMAND(TXcmd | (lp->cur_tx << 3));
701 
702  dev->stats.tx_packets++;
703  lp->lasttrans_dest = lp->lastload_dest;
704  lp->lastload_dest = 0;
705  lp->excnak_pending = 0;
706  lp->intmask |= TXFREEflag|EXCNAKflag;
707 
708  return 1;
709 }
710 
711 
712 /* Called by the kernel when transmit times out */
713 void arcnet_timeout(struct net_device *dev)
714 {
715  unsigned long flags;
716  struct arcnet_local *lp = netdev_priv(dev);
717  int status = ASTATUS();
718  char *msg;
719 
720  spin_lock_irqsave(&lp->lock, flags);
721  if (status & TXFREEflag) { /* transmit _DID_ finish */
722  msg = " - missed IRQ?";
723  } else {
724  msg = "";
725  dev->stats.tx_aborted_errors++;
726  lp->timed_out = 1;
727  ACOMMAND(NOTXcmd | (lp->cur_tx << 3));
728  }
729  dev->stats.tx_errors++;
730 
731  /* make sure we didn't miss a TX or a EXC NAK IRQ */
732  AINTMASK(0);
733  lp->intmask |= TXFREEflag|EXCNAKflag;
734  AINTMASK(lp->intmask);
735 
736  spin_unlock_irqrestore(&lp->lock, flags);
737 
738  if (time_after(jiffies, lp->last_timeout + 10*HZ)) {
739  BUGMSG(D_EXTRA, "tx timed out%s (status=%Xh, intmask=%Xh, dest=%02Xh)\n",
740  msg, status, lp->intmask, lp->lasttrans_dest);
741  lp->last_timeout = jiffies;
742  }
743 
744  if (lp->cur_tx == -1)
745  netif_wake_queue(dev);
746 }
747 
748 
749 /*
750  * The typical workload of the driver: Handle the network interface
751  * interrupts. Establish which device needs attention, and call the correct
752  * chipset interrupt handler.
753  */
754 irqreturn_t arcnet_interrupt(int irq, void *dev_id)
755 {
756  struct net_device *dev = dev_id;
757  struct arcnet_local *lp;
758  int recbuf, status, diagstatus, didsomething, boguscount;
759  int retval = IRQ_NONE;
760 
761  BUGMSG(D_DURING, "\n");
762 
763  BUGMSG(D_DURING, "in arcnet_interrupt\n");
764 
765  lp = netdev_priv(dev);
766  BUG_ON(!lp);
767 
768  spin_lock(&lp->lock);
769 
770  /*
771  * RESET flag was enabled - if device is not running, we must clear it right
772  * away (but nothing else).
773  */
774  if (!netif_running(dev)) {
775  if (ASTATUS() & RESETflag)
776  ACOMMAND(CFLAGScmd | RESETclear);
777  AINTMASK(0);
778  spin_unlock(&lp->lock);
779  return IRQ_HANDLED;
780  }
781 
782  BUGMSG(D_DURING, "in arcnet_inthandler (status=%Xh, intmask=%Xh)\n",
783  ASTATUS(), lp->intmask);
784 
785  boguscount = 5;
786  do {
787  status = ASTATUS();
788  diagstatus = (status >> 8) & 0xFF;
789 
790  BUGMSG(D_DEBUG, "%s: %d: %s: status=%x\n",
791  __FILE__,__LINE__,__func__,status);
792  didsomething = 0;
793 
794  /*
795  * RESET flag was enabled - card is resetting and if RX is
796  * disabled, it's NOT because we just got a packet.
797  *
798  * The card is in an undefined state. Clear it out and start over.
799  */
800  if (status & RESETflag) {
801  BUGMSG(D_NORMAL, "spurious reset (status=%Xh)\n", status);
802  arcnet_close(dev);
803  arcnet_open(dev);
804 
805  /* get out of the interrupt handler! */
806  break;
807  }
808  /*
809  * RX is inhibited - we must have received something. Prepare to
810  * receive into the next buffer.
811  *
812  * We don't actually copy the received packet from the card until
813  * after the transmit handler runs (and possibly launches the next
814  * tx); this should improve latency slightly if we get both types
815  * of interrupts at once.
816  */
817  recbuf = -1;
818  if (status & lp->intmask & NORXflag) {
819  recbuf = lp->cur_rx;
820  BUGMSG(D_DURING, "Buffer #%d: receive irq (status=%Xh)\n",
821  recbuf, status);
822 
823  lp->cur_rx = get_arcbuf(dev);
824  if (lp->cur_rx != -1) {
825  BUGMSG(D_DURING, "enabling receive to buffer #%d\n",
826  lp->cur_rx);
827  ACOMMAND(RXcmd | (lp->cur_rx << 3) | RXbcasts);
828  }
829  didsomething++;
830  }
831 
832  if((diagstatus & EXCNAKflag)) {
833  BUGMSG(D_DURING, "EXCNAK IRQ (diagstat=%Xh)\n",
834  diagstatus);
835 
836  ACOMMAND(NOTXcmd); /* disable transmit */
837  lp->excnak_pending = 1;
838 
839  ACOMMAND(EXCNAKclear);
840  lp->intmask &= ~(EXCNAKflag);
841  didsomething++;
842  }
843 
844 
845  /* a transmit finished, and we're interested in it. */
846  if ((status & lp->intmask & TXFREEflag) || lp->timed_out) {
847  lp->intmask &= ~(TXFREEflag|EXCNAKflag);
848 
849  BUGMSG(D_DURING, "TX IRQ (stat=%Xh)\n", status);
850 
851  if (lp->cur_tx != -1 && !lp->timed_out) {
852  if(!(status & TXACKflag)) {
853  if (lp->lasttrans_dest != 0) {
854  BUGMSG(D_EXTRA,
855  "transmit was not acknowledged! "
856  "(status=%Xh, dest=%02Xh)\n",
857  status, lp->lasttrans_dest);
858  dev->stats.tx_errors++;
859  dev->stats.tx_carrier_errors++;
860  } else {
861  BUGMSG(D_DURING,
862  "broadcast was not acknowledged; that's normal "
863  "(status=%Xh, dest=%02Xh)\n",
864  status, lp->lasttrans_dest);
865  }
866  }
867 
868  if (lp->outgoing.proto &&
869  lp->outgoing.proto->ack_tx) {
870  int ackstatus;
871  if(status & TXACKflag)
872  ackstatus=2;
873  else if(lp->excnak_pending)
874  ackstatus=1;
875  else
876  ackstatus=0;
877 
878  lp->outgoing.proto
879  ->ack_tx(dev, ackstatus);
880  }
881  }
882  if (lp->cur_tx != -1)
883  release_arcbuf(dev, lp->cur_tx);
884 
885  lp->cur_tx = -1;
886  lp->timed_out = 0;
887  didsomething++;
888 
889  /* send another packet if there is one */
890  go_tx(dev);
891 
892  /* continue a split packet, if any */
893  if (lp->outgoing.proto && lp->outgoing.proto->continue_tx) {
894  int txbuf = get_arcbuf(dev);
895  if (txbuf != -1) {
896  if (lp->outgoing.proto->continue_tx(dev, txbuf)) {
897  /* that was the last segment */
898  dev->stats.tx_bytes += lp->outgoing.skb->len;
899  if(!lp->outgoing.proto->ack_tx)
900  {
901  dev_kfree_skb_irq(lp->outgoing.skb);
902  lp->outgoing.proto = NULL;
903  }
904  }
905  lp->next_tx = txbuf;
906  }
907  }
908  /* inform upper layers of idleness, if necessary */
909  if (lp->cur_tx == -1)
910  netif_wake_queue(dev);
911  }
912  /* now process the received packet, if any */
913  if (recbuf != -1) {
914  BUGLVL(D_RX) arcnet_dump_packet(dev, recbuf, "rx irq", 0);
915 
916  arcnet_rx(dev, recbuf);
917  release_arcbuf(dev, recbuf);
918 
919  didsomething++;
920  }
921  if (status & lp->intmask & RECONflag) {
922  ACOMMAND(CFLAGScmd | CONFIGclear);
923  dev->stats.tx_carrier_errors++;
924 
925  BUGMSG(D_RECON, "Network reconfiguration detected (status=%Xh)\n",
926  status);
927  /* MYRECON bit is at bit 7 of diagstatus */
928  if(diagstatus & 0x80)
929  BUGMSG(D_RECON,"Put out that recon myself\n");
930 
931  /* is the RECON info empty or old? */
932  if (!lp->first_recon || !lp->last_recon ||
933  time_after(jiffies, lp->last_recon + HZ * 10)) {
934  if (lp->network_down)
935  BUGMSG(D_NORMAL, "reconfiguration detected: cabling restored?\n");
936  lp->first_recon = lp->last_recon = jiffies;
937  lp->num_recons = lp->network_down = 0;
938 
939  BUGMSG(D_DURING, "recon: clearing counters.\n");
940  } else { /* add to current RECON counter */
941  lp->last_recon = jiffies;
942  lp->num_recons++;
943 
944  BUGMSG(D_DURING, "recon: counter=%d, time=%lds, net=%d\n",
945  lp->num_recons,
946  (lp->last_recon - lp->first_recon) / HZ,
947  lp->network_down);
948 
949  /* if network is marked up;
950  * and first_recon and last_recon are 60+ apart;
951  * and the average no. of recons counted is
952  * > RECON_THRESHOLD/min;
953  * then print a warning message.
954  */
955  if (!lp->network_down &&
956  (lp->last_recon - lp->first_recon) <= HZ * 60 &&
957  lp->num_recons >= RECON_THRESHOLD) {
958  lp->network_down = 1;
959  BUGMSG(D_NORMAL, "many reconfigurations detected: cabling problem?\n");
960  } else if (!lp->network_down &&
961  lp->last_recon - lp->first_recon > HZ * 60) {
962  /* reset counters if we've gone for over a minute. */
963  lp->first_recon = lp->last_recon;
964  lp->num_recons = 1;
965  }
966  }
967  } else if (lp->network_down &&
968  time_after(jiffies, lp->last_recon + HZ * 10)) {
969  if (lp->network_down)
970  BUGMSG(D_NORMAL, "cabling restored?\n");
971  lp->first_recon = lp->last_recon = 0;
972  lp->num_recons = lp->network_down = 0;
973 
974  BUGMSG(D_DURING, "not recon: clearing counters anyway.\n");
975  }
976 
977  if(didsomething) {
978  retval |= IRQ_HANDLED;
979  }
980  }
981  while (--boguscount && didsomething);
982 
983  BUGMSG(D_DURING, "arcnet_interrupt complete (status=%Xh, count=%d)\n",
984  ASTATUS(), boguscount);
985  BUGMSG(D_DURING, "\n");
986 
987 
988  AINTMASK(0);
989  udelay(1);
990  AINTMASK(lp->intmask);
991 
992  spin_unlock(&lp->lock);
993  return retval;
994 }
995 
996 
997 /*
998  * This is a generic packet receiver that calls arcnet??_rx depending on the
999  * protocol ID found.
1000  */
1001 static void arcnet_rx(struct net_device *dev, int bufnum)
1002 {
1003  struct arcnet_local *lp = netdev_priv(dev);
1004  struct archdr pkt;
1005  struct arc_rfc1201 *soft;
1006  int length, ofs;
1007 
1008  soft = &pkt.soft.rfc1201;
1009 
1010  lp->hw.copy_from_card(dev, bufnum, 0, &pkt, sizeof(ARC_HDR_SIZE));
1011  if (pkt.hard.offset[0]) {
1012  ofs = pkt.hard.offset[0];
1013  length = 256 - ofs;
1014  } else {
1015  ofs = pkt.hard.offset[1];
1016  length = 512 - ofs;
1017  }
1018 
1019  /* get the full header, if possible */
1020  if (sizeof(pkt.soft) <= length)
1021  lp->hw.copy_from_card(dev, bufnum, ofs, soft, sizeof(pkt.soft));
1022  else {
1023  memset(&pkt.soft, 0, sizeof(pkt.soft));
1024  lp->hw.copy_from_card(dev, bufnum, ofs, soft, length);
1025  }
1026 
1027  BUGMSG(D_DURING, "Buffer #%d: received packet from %02Xh to %02Xh "
1028  "(%d+4 bytes)\n",
1029  bufnum, pkt.hard.source, pkt.hard.dest, length);
1030 
1031  dev->stats.rx_packets++;
1032  dev->stats.rx_bytes += length + ARC_HDR_SIZE;
1033 
1034  /* call the right receiver for the protocol */
1035  if (arc_proto_map[soft->proto]->is_ip) {
1036  BUGLVL(D_PROTO) {
1037  struct ArcProto
1038  *oldp = arc_proto_map[lp->default_proto[pkt.hard.source]],
1039  *newp = arc_proto_map[soft->proto];
1040 
1041  if (oldp != newp) {
1042  BUGMSG(D_PROTO,
1043  "got protocol %02Xh; encap for host %02Xh is now '%c'"
1044  " (was '%c')\n", soft->proto, pkt.hard.source,
1045  newp->suffix, oldp->suffix);
1046  }
1047  }
1048 
1049  /* broadcasts will always be done with the last-used encap. */
1050  lp->default_proto[0] = soft->proto;
1051 
1052  /* in striking contrast, the following isn't a hack. */
1053  lp->default_proto[pkt.hard.source] = soft->proto;
1054  }
1055  /* call the protocol-specific receiver. */
1056  arc_proto_map[soft->proto]->rx(dev, bufnum, &pkt, length);
1057 }
1058 
1059 
1060 static void null_rx(struct net_device *dev, int bufnum,
1061  struct archdr *pkthdr, int length)
1062 {
1063  BUGMSG(D_PROTO,
1064  "rx: don't know how to deal with proto %02Xh from host %02Xh.\n",
1065  pkthdr->soft.rfc1201.proto, pkthdr->hard.source);
1066 }
1067 
1068 
1069 static int null_build_header(struct sk_buff *skb, struct net_device *dev,
1070  unsigned short type, uint8_t daddr)
1071 {
1072  struct arcnet_local *lp = netdev_priv(dev);
1073 
1074  BUGMSG(D_PROTO,
1075  "tx: can't build header for encap %02Xh; load a protocol driver.\n",
1076  lp->default_proto[daddr]);
1077 
1078  /* always fails */
1079  return 0;
1080 }
1081 
1082 
1083 /* the "do nothing" prepare_tx function warns that there's nothing to do. */
1084 static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
1085  int length, int bufnum)
1086 {
1087  struct arcnet_local *lp = netdev_priv(dev);
1088  struct arc_hardware newpkt;
1089 
1090  BUGMSG(D_PROTO, "tx: no encap for this host; load a protocol driver.\n");
1091 
1092  /* send a packet to myself -- will never get received, of course */
1093  newpkt.source = newpkt.dest = dev->dev_addr[0];
1094 
1095  /* only one byte of actual data (and it's random) */
1096  newpkt.offset[0] = 0xFF;
1097 
1098  lp->hw.copy_to_card(dev, bufnum, 0, &newpkt, ARC_HDR_SIZE);
1099 
1100  return 1; /* done */
1101 }
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