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