drivers/net/arcnet/arcnet.c

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