linux/drivers/net/arcnet/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 <mj@ucw.cz>.
   7 * Derived from skeleton.c by Donald Becker.
   8 *
   9 * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
  10 *  for sponsoring the further development of this driver.
  11 *
  12 * **********************
  13 *
  14 * The original copyright was as follows:
  15 *
  16 * skeleton.c Written 1993 by Donald Becker.
  17 * Copyright 1993 United States Government as represented by the
  18 * Director, National Security Agency.  This software may only be used
  19 * and distributed according to the terms of the GNU General Public License as
  20 * modified by SRC, incorporated herein by reference.
  21 *
  22 * **********************
  23 *
  24 * The change log is now in a file called ChangeLog in this directory.
  25 *
  26 * Sources:
  27 *  - Crynwr arcnet.com/arcether.com packet drivers.
  28 *  - arcnet.c v0.00 dated 1/1/94 and apparently by
  29 *     Donald Becker - it didn't work :)
  30 *  - skeleton.c v0.05 dated 11/16/93 by Donald Becker
  31 *     (from Linux Kernel 1.1.45)
  32 *  - RFC's 1201 and 1051 - re: TCP/IP over ARCnet
  33 *  - The official ARCnet COM9026 data sheets (!) thanks to
  34 *     Ken Cornetet <kcornete@nyx10.cs.du.edu>
  35 *  - The official ARCnet COM20020 data sheets.
  36 *  - Information on some more obscure ARCnet controller chips, thanks
  37 *     to the nice people at SMSC.
  38 *  - net/inet/eth.c (from kernel 1.1.50) for header-building info.
  39 *  - Alternate Linux ARCnet source by V.Shergin <vsher@sao.stavropol.su>
  40 *  - Textual information and more alternate source from Joachim Koenig
  41 *     <jojo@repas.de>
  42 */
  43
  44#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  45
  46#include <linux/module.h>
  47#include <linux/types.h>
  48#include <linux/delay.h>
  49#include <linux/netdevice.h>
  50#include <linux/if_arp.h>
  51#include <net/arp.h>
  52#include <linux/init.h>
  53#include <linux/jiffies.h>
  54#include <linux/errqueue.h>
  55
  56#include <linux/leds.h>
  57
  58#include "arcdevice.h"
  59#include "com9026.h"
  60
  61/* "do nothing" functions for protocol drivers */
  62static void null_rx(struct net_device *dev, int bufnum,
  63                    struct archdr *pkthdr, int length);
  64static int null_build_header(struct sk_buff *skb, struct net_device *dev,
  65                             unsigned short type, uint8_t daddr);
  66static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
  67                           int length, int bufnum);
  68
  69static void arcnet_rx(struct net_device *dev, int bufnum);
  70
  71/* one ArcProto per possible proto ID.  None of the elements of
  72 * arc_proto_map are allowed to be NULL; they will get set to
  73 * arc_proto_default instead.  It also must not be NULL; if you would like
  74 * to set it to NULL, set it to &arc_proto_null instead.
  75 */
  76struct ArcProto *arc_proto_map[256];
  77EXPORT_SYMBOL(arc_proto_map);
  78
  79struct ArcProto *arc_proto_default;
  80EXPORT_SYMBOL(arc_proto_default);
  81
  82struct ArcProto *arc_bcast_proto;
  83EXPORT_SYMBOL(arc_bcast_proto);
  84
  85struct ArcProto *arc_raw_proto;
  86EXPORT_SYMBOL(arc_raw_proto);
  87
  88static struct ArcProto arc_proto_null = {
  89        .suffix         = '?',
  90        .mtu            = XMTU,
  91        .is_ip          = 0,
  92        .rx             = null_rx,
  93        .build_header   = null_build_header,
  94        .prepare_tx     = null_prepare_tx,
  95        .continue_tx    = NULL,
  96        .ack_tx         = NULL
  97};
  98
  99/* Exported function prototypes */
 100int arcnet_debug = ARCNET_DEBUG;
 101EXPORT_SYMBOL(arcnet_debug);
 102
 103/* Internal function prototypes */
 104static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
 105                         unsigned short type, const void *daddr,
 106                         const void *saddr, unsigned len);
 107static int go_tx(struct net_device *dev);
 108
 109static int debug = ARCNET_DEBUG;
 110module_param(debug, int, 0);
 111MODULE_LICENSE("GPL");
 112
 113static int __init arcnet_init(void)
 114{
 115        int count;
 116
 117        arcnet_debug = debug;
 118
 119        pr_info("arcnet loaded\n");
 120
 121        /* initialize the protocol map */
 122        arc_raw_proto = arc_proto_default = arc_bcast_proto = &arc_proto_null;
 123        for (count = 0; count < 256; count++)
 124                arc_proto_map[count] = arc_proto_default;
 125
 126        if (BUGLVL(D_DURING))
 127                pr_info("struct sizes: %zd %zd %zd %zd %zd\n",
 128                        sizeof(struct arc_hardware),
 129                        sizeof(struct arc_rfc1201),
 130                        sizeof(struct arc_rfc1051),
 131                        sizeof(struct arc_eth_encap),
 132                        sizeof(struct archdr));
 133
 134        return 0;
 135}
 136
 137static void __exit arcnet_exit(void)
 138{
 139}
 140
 141module_init(arcnet_init);
 142module_exit(arcnet_exit);
 143
 144/* Dump the contents of an sk_buff */
 145#if ARCNET_DEBUG_MAX & D_SKB
 146void arcnet_dump_skb(struct net_device *dev,
 147                     struct sk_buff *skb, char *desc)
 148{
 149        char hdr[32];
 150
 151        /* dump the packet */
 152        snprintf(hdr, sizeof(hdr), "%6s:%s skb->data:", dev->name, desc);
 153        print_hex_dump(KERN_DEBUG, hdr, DUMP_PREFIX_OFFSET,
 154                       16, 1, skb->data, skb->len, true);
 155}
 156EXPORT_SYMBOL(arcnet_dump_skb);
 157#endif
 158
 159/* Dump the contents of an ARCnet buffer */
 160#if (ARCNET_DEBUG_MAX & (D_RX | D_TX))
 161static void arcnet_dump_packet(struct net_device *dev, int bufnum,
 162                               char *desc, int take_arcnet_lock)
 163{
 164        struct arcnet_local *lp = netdev_priv(dev);
 165        int i, length;
 166        unsigned long flags = 0;
 167        static uint8_t buf[512];
 168        char hdr[32];
 169
 170        /* hw.copy_from_card expects IRQ context so take the IRQ lock
 171         * to keep it single threaded
 172         */
 173        if (take_arcnet_lock)
 174                spin_lock_irqsave(&lp->lock, flags);
 175
 176        lp->hw.copy_from_card(dev, bufnum, 0, buf, 512);
 177        if (take_arcnet_lock)
 178                spin_unlock_irqrestore(&lp->lock, flags);
 179
 180        /* if the offset[0] byte is nonzero, this is a 256-byte packet */
 181        length = (buf[2] ? 256 : 512);
 182
 183        /* dump the packet */
 184        snprintf(hdr, sizeof(hdr), "%6s:%s packet dump:", dev->name, desc);
 185        print_hex_dump(KERN_DEBUG, hdr, DUMP_PREFIX_OFFSET,
 186                       16, 1, buf, length, true);
 187}
 188
 189#else
 190
 191#define arcnet_dump_packet(dev, bufnum, desc, take_arcnet_lock) do { } while (0)
 192
 193#endif
 194
 195/* Trigger a LED event in response to a ARCNET device event */
 196void arcnet_led_event(struct net_device *dev, enum arcnet_led_event event)
 197{
 198        struct arcnet_local *lp = netdev_priv(dev);
 199        unsigned long led_delay = 350;
 200        unsigned long tx_delay = 50;
 201
 202        switch (event) {
 203        case ARCNET_LED_EVENT_RECON:
 204                led_trigger_blink_oneshot(lp->recon_led_trig,
 205                                          &led_delay, &led_delay, 0);
 206                break;
 207        case ARCNET_LED_EVENT_OPEN:
 208                led_trigger_event(lp->tx_led_trig, LED_OFF);
 209                led_trigger_event(lp->recon_led_trig, LED_OFF);
 210                break;
 211        case ARCNET_LED_EVENT_STOP:
 212                led_trigger_event(lp->tx_led_trig, LED_OFF);
 213                led_trigger_event(lp->recon_led_trig, LED_OFF);
 214                break;
 215        case ARCNET_LED_EVENT_TX:
 216                led_trigger_blink_oneshot(lp->tx_led_trig,
 217                                          &tx_delay, &tx_delay, 0);
 218                break;
 219        }
 220}
 221EXPORT_SYMBOL_GPL(arcnet_led_event);
 222
 223static void arcnet_led_release(struct device *gendev, void *res)
 224{
 225        struct arcnet_local *lp = netdev_priv(to_net_dev(gendev));
 226
 227        led_trigger_unregister_simple(lp->tx_led_trig);
 228        led_trigger_unregister_simple(lp->recon_led_trig);
 229}
 230
 231/* Register ARCNET LED triggers for a arcnet device
 232 *
 233 * This is normally called from a driver's probe function
 234 */
 235void devm_arcnet_led_init(struct net_device *netdev, int index, int subid)
 236{
 237        struct arcnet_local *lp = netdev_priv(netdev);
 238        void *res;
 239
 240        res = devres_alloc(arcnet_led_release, 0, GFP_KERNEL);
 241        if (!res) {
 242                netdev_err(netdev, "cannot register LED triggers\n");
 243                return;
 244        }
 245
 246        snprintf(lp->tx_led_trig_name, sizeof(lp->tx_led_trig_name),
 247                 "arc%d-%d-tx", index, subid);
 248        snprintf(lp->recon_led_trig_name, sizeof(lp->recon_led_trig_name),
 249                 "arc%d-%d-recon", index, subid);
 250
 251        led_trigger_register_simple(lp->tx_led_trig_name,
 252                                    &lp->tx_led_trig);
 253        led_trigger_register_simple(lp->recon_led_trig_name,
 254                                    &lp->recon_led_trig);
 255
 256        devres_add(&netdev->dev, res);
 257}
 258EXPORT_SYMBOL_GPL(devm_arcnet_led_init);
 259
 260/* Unregister a protocol driver from the arc_proto_map.  Protocol drivers
 261 * are responsible for registering themselves, but the unregister routine
 262 * is pretty generic so we'll do it here.
 263 */
 264void arcnet_unregister_proto(struct ArcProto *proto)
 265{
 266        int count;
 267
 268        if (arc_proto_default == proto)
 269                arc_proto_default = &arc_proto_null;
 270        if (arc_bcast_proto == proto)
 271                arc_bcast_proto = arc_proto_default;
 272        if (arc_raw_proto == proto)
 273                arc_raw_proto = arc_proto_default;
 274
 275        for (count = 0; count < 256; count++) {
 276                if (arc_proto_map[count] == proto)
 277                        arc_proto_map[count] = arc_proto_default;
 278        }
 279}
 280EXPORT_SYMBOL(arcnet_unregister_proto);
 281
 282/* Add a buffer to the queue.  Only the interrupt handler is allowed to do
 283 * this, unless interrupts are disabled.
 284 *
 285 * Note: we don't check for a full queue, since there aren't enough buffers
 286 * to more than fill it.
 287 */
 288static void release_arcbuf(struct net_device *dev, int bufnum)
 289{
 290        struct arcnet_local *lp = netdev_priv(dev);
 291        int i;
 292
 293        lp->buf_queue[lp->first_free_buf++] = bufnum;
 294        lp->first_free_buf %= 5;
 295
 296        if (BUGLVL(D_DURING)) {
 297                arc_printk(D_DURING, dev, "release_arcbuf: freed #%d; buffer queue is now: ",
 298                           bufnum);
 299                for (i = lp->next_buf; i != lp->first_free_buf; i = (i + 1) % 5)
 300                        arc_cont(D_DURING, "#%d ", lp->buf_queue[i]);
 301                arc_cont(D_DURING, "\n");
 302        }
 303}
 304
 305/* Get a buffer from the queue.
 306 * If this returns -1, there are no buffers available.
 307 */
 308static int get_arcbuf(struct net_device *dev)
 309{
 310        struct arcnet_local *lp = netdev_priv(dev);
 311        int buf = -1, i;
 312
 313        if (!atomic_dec_and_test(&lp->buf_lock)) {
 314                /* already in this function */
 315                arc_printk(D_NORMAL, dev, "get_arcbuf: overlap (%d)!\n",
 316                           lp->buf_lock.counter);
 317        } else {                        /* we can continue */
 318                if (lp->next_buf >= 5)
 319                        lp->next_buf -= 5;
 320
 321                if (lp->next_buf == lp->first_free_buf) {
 322                        arc_printk(D_NORMAL, dev, "get_arcbuf: BUG: no buffers are available??\n");
 323                } else {
 324                        buf = lp->buf_queue[lp->next_buf++];
 325                        lp->next_buf %= 5;
 326                }
 327        }
 328
 329        if (BUGLVL(D_DURING)) {
 330                arc_printk(D_DURING, dev, "get_arcbuf: got #%d; buffer queue is now: ",
 331                           buf);
 332                for (i = lp->next_buf; i != lp->first_free_buf; i = (i + 1) % 5)
 333                        arc_cont(D_DURING, "#%d ", lp->buf_queue[i]);
 334                arc_cont(D_DURING, "\n");
 335        }
 336
 337        atomic_inc(&lp->buf_lock);
 338        return buf;
 339}
 340
 341static int choose_mtu(void)
 342{
 343        int count, mtu = 65535;
 344
 345        /* choose the smallest MTU of all available encaps */
 346        for (count = 0; count < 256; count++) {
 347                if (arc_proto_map[count] != &arc_proto_null &&
 348                    arc_proto_map[count]->mtu < mtu) {
 349                        mtu = arc_proto_map[count]->mtu;
 350                }
 351        }
 352
 353        return mtu == 65535 ? XMTU : mtu;
 354}
 355
 356static const struct header_ops arcnet_header_ops = {
 357        .create = arcnet_header,
 358};
 359
 360static const struct net_device_ops arcnet_netdev_ops = {
 361        .ndo_open       = arcnet_open,
 362        .ndo_stop       = arcnet_close,
 363        .ndo_start_xmit = arcnet_send_packet,
 364        .ndo_tx_timeout = arcnet_timeout,
 365};
 366
 367/* Setup a struct device for ARCnet. */
 368static void arcdev_setup(struct net_device *dev)
 369{
 370        dev->type = ARPHRD_ARCNET;
 371        dev->netdev_ops = &arcnet_netdev_ops;
 372        dev->header_ops = &arcnet_header_ops;
 373        dev->hard_header_len = sizeof(struct arc_hardware);
 374        dev->mtu = choose_mtu();
 375
 376        dev->addr_len = ARCNET_ALEN;
 377        dev->tx_queue_len = 100;
 378        dev->broadcast[0] = 0x00;       /* for us, broadcasts are address 0 */
 379        dev->watchdog_timeo = TX_TIMEOUT;
 380
 381        /* New-style flags. */
 382        dev->flags = IFF_BROADCAST;
 383}
 384
 385static void arcnet_timer(struct timer_list *t)
 386{
 387        struct arcnet_local *lp = from_timer(lp, t, timer);
 388        struct net_device *dev = lp->dev;
 389
 390        if (!netif_carrier_ok(dev)) {
 391                netif_carrier_on(dev);
 392                netdev_info(dev, "link up\n");
 393        }
 394}
 395
 396static void arcnet_reply_tasklet(unsigned long data)
 397{
 398        struct arcnet_local *lp = (struct arcnet_local *)data;
 399
 400        struct sk_buff *ackskb, *skb;
 401        struct sock_exterr_skb *serr;
 402        struct sock *sk;
 403        int ret;
 404
 405        local_irq_disable();
 406        skb = lp->outgoing.skb;
 407        if (!skb || !skb->sk) {
 408                local_irq_enable();
 409                return;
 410        }
 411
 412        sock_hold(skb->sk);
 413        sk = skb->sk;
 414        ackskb = skb_clone_sk(skb);
 415        sock_put(skb->sk);
 416
 417        if (!ackskb) {
 418                local_irq_enable();
 419                return;
 420        }
 421
 422        serr = SKB_EXT_ERR(ackskb);
 423        memset(serr, 0, sizeof(*serr));
 424        serr->ee.ee_errno = ENOMSG;
 425        serr->ee.ee_origin = SO_EE_ORIGIN_TXSTATUS;
 426        serr->ee.ee_data = skb_shinfo(skb)->tskey;
 427        serr->ee.ee_info = lp->reply_status;
 428
 429        /* finally erasing outgoing skb */
 430        dev_kfree_skb(lp->outgoing.skb);
 431        lp->outgoing.skb = NULL;
 432
 433        ackskb->dev = lp->dev;
 434
 435        ret = sock_queue_err_skb(sk, ackskb);
 436        if (ret)
 437                kfree_skb(ackskb);
 438
 439        local_irq_enable();
 440};
 441
 442struct net_device *alloc_arcdev(const char *name)
 443{
 444        struct net_device *dev;
 445
 446        dev = alloc_netdev(sizeof(struct arcnet_local),
 447                           name && *name ? name : "arc%d", NET_NAME_UNKNOWN,
 448                           arcdev_setup);
 449        if (dev) {
 450                struct arcnet_local *lp = netdev_priv(dev);
 451
 452                lp->dev = dev;
 453                spin_lock_init(&lp->lock);
 454                timer_setup(&lp->timer, arcnet_timer, 0);
 455        }
 456
 457        return dev;
 458}
 459EXPORT_SYMBOL(alloc_arcdev);
 460
 461/* Open/initialize the board.  This is called sometime after booting when
 462 * the 'ifconfig' program is run.
 463 *
 464 * This routine should set everything up anew at each open, even registers
 465 * that "should" only need to be set once at boot, so that there is
 466 * non-reboot way to recover if something goes wrong.
 467 */
 468int arcnet_open(struct net_device *dev)
 469{
 470        struct arcnet_local *lp = netdev_priv(dev);
 471        int count, newmtu, error;
 472
 473        arc_printk(D_INIT, dev, "opened.");
 474
 475        if (!try_module_get(lp->hw.owner))
 476                return -ENODEV;
 477
 478        if (BUGLVL(D_PROTO)) {
 479                arc_printk(D_PROTO, dev, "protocol map (default is '%c'): ",
 480                           arc_proto_default->suffix);
 481                for (count = 0; count < 256; count++)
 482                        arc_cont(D_PROTO, "%c", arc_proto_map[count]->suffix);
 483                arc_cont(D_PROTO, "\n");
 484        }
 485
 486        tasklet_init(&lp->reply_tasklet, arcnet_reply_tasklet,
 487                     (unsigned long)lp);
 488
 489        arc_printk(D_INIT, dev, "arcnet_open: resetting card.\n");
 490
 491        /* try to put the card in a defined state - if it fails the first
 492         * time, actually reset it.
 493         */
 494        error = -ENODEV;
 495        if (lp->hw.reset(dev, 0) && lp->hw.reset(dev, 1))
 496                goto out_module_put;
 497
 498        newmtu = choose_mtu();
 499        if (newmtu < dev->mtu)
 500                dev->mtu = newmtu;
 501
 502        arc_printk(D_INIT, dev, "arcnet_open: mtu: %d.\n", dev->mtu);
 503
 504        /* autodetect the encapsulation for each host. */
 505        memset(lp->default_proto, 0, sizeof(lp->default_proto));
 506
 507        /* the broadcast address is special - use the 'bcast' protocol */
 508        for (count = 0; count < 256; count++) {
 509                if (arc_proto_map[count] == arc_bcast_proto) {
 510                        lp->default_proto[0] = count;
 511                        break;
 512                }
 513        }
 514
 515        /* initialize buffers */
 516        atomic_set(&lp->buf_lock, 1);
 517
 518        lp->next_buf = lp->first_free_buf = 0;
 519        release_arcbuf(dev, 0);
 520        release_arcbuf(dev, 1);
 521        release_arcbuf(dev, 2);
 522        release_arcbuf(dev, 3);
 523        lp->cur_tx = lp->next_tx = -1;
 524        lp->cur_rx = -1;
 525
 526        lp->rfc1201.sequence = 1;
 527
 528        /* bring up the hardware driver */
 529        if (lp->hw.open)
 530                lp->hw.open(dev);
 531
 532        if (dev->dev_addr[0] == 0)
 533                arc_printk(D_NORMAL, dev, "WARNING!  Station address 00 is reserved for broadcasts!\n");
 534        else if (dev->dev_addr[0] == 255)
 535                arc_printk(D_NORMAL, dev, "WARNING!  Station address FF may confuse DOS networking programs!\n");
 536
 537        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
 538        if (lp->hw.status(dev) & RESETflag) {
 539                arc_printk(D_DEBUG, dev, "%s: %d: %s\n",
 540                           __FILE__, __LINE__, __func__);
 541                lp->hw.command(dev, CFLAGScmd | RESETclear);
 542        }
 543
 544        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
 545        /* make sure we're ready to receive IRQ's. */
 546        lp->hw.intmask(dev, 0);
 547        udelay(1);              /* give it time to set the mask before
 548                                 * we reset it again. (may not even be
 549                                 * necessary)
 550                                 */
 551        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
 552        lp->intmask = NORXflag | RECONflag;
 553        lp->hw.intmask(dev, lp->intmask);
 554        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
 555
 556        netif_carrier_off(dev);
 557        netif_start_queue(dev);
 558        mod_timer(&lp->timer, jiffies + msecs_to_jiffies(1000));
 559
 560        arcnet_led_event(dev, ARCNET_LED_EVENT_OPEN);
 561        return 0;
 562
 563 out_module_put:
 564        module_put(lp->hw.owner);
 565        return error;
 566}
 567EXPORT_SYMBOL(arcnet_open);
 568
 569/* The inverse routine to arcnet_open - shuts down the card. */
 570int arcnet_close(struct net_device *dev)
 571{
 572        struct arcnet_local *lp = netdev_priv(dev);
 573
 574        arcnet_led_event(dev, ARCNET_LED_EVENT_STOP);
 575        del_timer_sync(&lp->timer);
 576
 577        netif_stop_queue(dev);
 578        netif_carrier_off(dev);
 579
 580        tasklet_kill(&lp->reply_tasklet);
 581
 582        /* flush TX and disable RX */
 583        lp->hw.intmask(dev, 0);
 584        lp->hw.command(dev, NOTXcmd);   /* stop transmit */
 585        lp->hw.command(dev, NORXcmd);   /* disable receive */
 586        mdelay(1);
 587
 588        /* shut down the card */
 589        lp->hw.close(dev);
 590        module_put(lp->hw.owner);
 591        return 0;
 592}
 593EXPORT_SYMBOL(arcnet_close);
 594
 595static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
 596                         unsigned short type, const void *daddr,
 597                         const void *saddr, unsigned len)
 598{
 599        const struct arcnet_local *lp = netdev_priv(dev);
 600        uint8_t _daddr, proto_num;
 601        struct ArcProto *proto;
 602
 603        arc_printk(D_DURING, dev,
 604                   "create header from %d to %d; protocol %d (%Xh); size %u.\n",
 605                   saddr ? *(uint8_t *)saddr : -1,
 606                   daddr ? *(uint8_t *)daddr : -1,
 607                   type, type, len);
 608
 609        if (skb->len != 0 && len != skb->len)
 610                arc_printk(D_NORMAL, dev, "arcnet_header: Yikes!  skb->len(%d) != len(%d)!\n",
 611                           skb->len, len);
 612
 613        /* Type is host order - ? */
 614        if (type == ETH_P_ARCNET) {
 615                proto = arc_raw_proto;
 616                arc_printk(D_DEBUG, dev, "arc_raw_proto used. proto='%c'\n",
 617                           proto->suffix);
 618                _daddr = daddr ? *(uint8_t *)daddr : 0;
 619        } else if (!daddr) {
 620                /* if the dest addr isn't provided, we can't choose an
 621                 * encapsulation!  Store the packet type (eg. ETH_P_IP)
 622                 * for now, and we'll push on a real header when we do
 623                 * rebuild_header.
 624                 */
 625                *(uint16_t *)skb_push(skb, 2) = type;
 626                /* XXX: Why not use skb->mac_len? */
 627                if (skb->network_header - skb->mac_header != 2)
 628                        arc_printk(D_NORMAL, dev, "arcnet_header: Yikes!  diff (%u) is not 2!\n",
 629                                   skb->network_header - skb->mac_header);
 630                return -2;      /* return error -- can't transmit yet! */
 631        } else {
 632                /* otherwise, we can just add the header as usual. */
 633                _daddr = *(uint8_t *)daddr;
 634                proto_num = lp->default_proto[_daddr];
 635                proto = arc_proto_map[proto_num];
 636                arc_printk(D_DURING, dev, "building header for %02Xh using protocol '%c'\n",
 637                           proto_num, proto->suffix);
 638                if (proto == &arc_proto_null && arc_bcast_proto != proto) {
 639                        arc_printk(D_DURING, dev, "actually, let's use '%c' instead.\n",
 640                                   arc_bcast_proto->suffix);
 641                        proto = arc_bcast_proto;
 642                }
 643        }
 644        return proto->build_header(skb, dev, type, _daddr);
 645}
 646
 647/* Called by the kernel in order to transmit a packet. */
 648netdev_tx_t arcnet_send_packet(struct sk_buff *skb,
 649                               struct net_device *dev)
 650{
 651        struct arcnet_local *lp = netdev_priv(dev);
 652        struct archdr *pkt;
 653        struct arc_rfc1201 *soft;
 654        struct ArcProto *proto;
 655        int txbuf;
 656        unsigned long flags;
 657        int retval;
 658
 659        arc_printk(D_DURING, dev,
 660                   "transmit requested (status=%Xh, txbufs=%d/%d, len=%d, protocol %x)\n",
 661                   lp->hw.status(dev), lp->cur_tx, lp->next_tx, skb->len, skb->protocol);
 662
 663        pkt = (struct archdr *)skb->data;
 664        soft = &pkt->soft.rfc1201;
 665        proto = arc_proto_map[soft->proto];
 666
 667        arc_printk(D_SKB_SIZE, dev, "skb: transmitting %d bytes to %02X\n",
 668                   skb->len, pkt->hard.dest);
 669        if (BUGLVL(D_SKB))
 670                arcnet_dump_skb(dev, skb, "tx");
 671
 672        /* fits in one packet? */
 673        if (skb->len - ARC_HDR_SIZE > XMTU && !proto->continue_tx) {
 674                arc_printk(D_NORMAL, dev, "fixme: packet too large: compensating badly!\n");
 675                dev_kfree_skb(skb);
 676                return NETDEV_TX_OK;    /* don't try again */
 677        }
 678
 679        /* We're busy transmitting a packet... */
 680        netif_stop_queue(dev);
 681
 682        spin_lock_irqsave(&lp->lock, flags);
 683        lp->hw.intmask(dev, 0);
 684        if (lp->next_tx == -1)
 685                txbuf = get_arcbuf(dev);
 686        else
 687                txbuf = -1;
 688
 689        if (txbuf != -1) {
 690                lp->outgoing.skb = skb;
 691                if (proto->prepare_tx(dev, pkt, skb->len, txbuf) &&
 692                    !proto->ack_tx) {
 693                        /* done right away and we don't want to acknowledge
 694                         *  the package later - forget about it now
 695                         */
 696                        dev->stats.tx_bytes += skb->len;
 697                } else {
 698                        /* do it the 'split' way */
 699                        lp->outgoing.proto = proto;
 700                        lp->outgoing.skb = skb;
 701                        lp->outgoing.pkt = pkt;
 702
 703                        if (proto->continue_tx &&
 704                            proto->continue_tx(dev, txbuf)) {
 705                                arc_printk(D_NORMAL, dev,
 706                                           "bug! continue_tx finished the first time! (proto='%c')\n",
 707                                           proto->suffix);
 708                        }
 709                }
 710                retval = NETDEV_TX_OK;
 711                lp->next_tx = txbuf;
 712        } else {
 713                retval = NETDEV_TX_BUSY;
 714        }
 715
 716        arc_printk(D_DEBUG, dev, "%s: %d: %s, status: %x\n",
 717                   __FILE__, __LINE__, __func__, lp->hw.status(dev));
 718        /* make sure we didn't ignore a TX IRQ while we were in here */
 719        lp->hw.intmask(dev, 0);
 720
 721        arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
 722        lp->intmask |= TXFREEflag | EXCNAKflag;
 723        lp->hw.intmask(dev, lp->intmask);
 724        arc_printk(D_DEBUG, dev, "%s: %d: %s, status: %x\n",
 725                   __FILE__, __LINE__, __func__, lp->hw.status(dev));
 726
 727        arcnet_led_event(dev, ARCNET_LED_EVENT_TX);
 728
 729        spin_unlock_irqrestore(&lp->lock, flags);
 730        return retval;          /* no need to try again */
 731}
 732EXPORT_SYMBOL(arcnet_send_packet);
 733
 734/* Actually start transmitting a packet that was loaded into a buffer
 735 * by prepare_tx.  This should _only_ be called by the interrupt handler.
 736 */
 737static int go_tx(struct net_device *dev)
 738{
 739        struct arcnet_local *lp = netdev_priv(dev);
 740
 741        arc_printk(D_DURING, dev, "go_tx: status=%Xh, intmask=%Xh, next_tx=%d, cur_tx=%d\n",
 742                   lp->hw.status(dev), lp->intmask, lp->next_tx, lp->cur_tx);
 743
 744        if (lp->cur_tx != -1 || lp->next_tx == -1)
 745                return 0;
 746
 747        if (BUGLVL(D_TX))
 748                arcnet_dump_packet(dev, lp->next_tx, "go_tx", 0);
 749
 750        lp->cur_tx = lp->next_tx;
 751        lp->next_tx = -1;
 752
 753        /* start sending */
 754        lp->hw.command(dev, TXcmd | (lp->cur_tx << 3));
 755
 756        dev->stats.tx_packets++;
 757        lp->lasttrans_dest = lp->lastload_dest;
 758        lp->lastload_dest = 0;
 759        lp->excnak_pending = 0;
 760        lp->intmask |= TXFREEflag | EXCNAKflag;
 761
 762        return 1;
 763}
 764
 765/* Called by the kernel when transmit times out */
 766void arcnet_timeout(struct net_device *dev)
 767{
 768        unsigned long flags;
 769        struct arcnet_local *lp = netdev_priv(dev);
 770        int status = lp->hw.status(dev);
 771        char *msg;
 772
 773        spin_lock_irqsave(&lp->lock, flags);
 774        if (status & TXFREEflag) {      /* transmit _DID_ finish */
 775                msg = " - missed IRQ?";
 776        } else {
 777                msg = "";
 778                dev->stats.tx_aborted_errors++;
 779                lp->timed_out = 1;
 780                lp->hw.command(dev, NOTXcmd | (lp->cur_tx << 3));
 781        }
 782        dev->stats.tx_errors++;
 783
 784        /* make sure we didn't miss a TX or a EXC NAK IRQ */
 785        lp->hw.intmask(dev, 0);
 786        lp->intmask |= TXFREEflag | EXCNAKflag;
 787        lp->hw.intmask(dev, lp->intmask);
 788
 789        spin_unlock_irqrestore(&lp->lock, flags);
 790
 791        if (time_after(jiffies, lp->last_timeout + 10 * HZ)) {
 792                arc_printk(D_EXTRA, dev, "tx timed out%s (status=%Xh, intmask=%Xh, dest=%02Xh)\n",
 793                           msg, status, lp->intmask, lp->lasttrans_dest);
 794                lp->last_timeout = jiffies;
 795        }
 796
 797        if (lp->cur_tx == -1)
 798                netif_wake_queue(dev);
 799}
 800EXPORT_SYMBOL(arcnet_timeout);
 801
 802/* The typical workload of the driver: Handle the network interface
 803 * interrupts. Establish which device needs attention, and call the correct
 804 * chipset interrupt handler.
 805 */
 806irqreturn_t arcnet_interrupt(int irq, void *dev_id)
 807{
 808        struct net_device *dev = dev_id;
 809        struct arcnet_local *lp;
 810        int recbuf, status, diagstatus, didsomething, boguscount;
 811        unsigned long flags;
 812        int retval = IRQ_NONE;
 813
 814        arc_printk(D_DURING, dev, "\n");
 815
 816        arc_printk(D_DURING, dev, "in arcnet_interrupt\n");
 817
 818        lp = netdev_priv(dev);
 819        BUG_ON(!lp);
 820
 821        spin_lock_irqsave(&lp->lock, flags);
 822
 823        /* RESET flag was enabled - if device is not running, we must
 824         * clear it right away (but nothing else).
 825         */
 826        if (!netif_running(dev)) {
 827                if (lp->hw.status(dev) & RESETflag)
 828                        lp->hw.command(dev, CFLAGScmd | RESETclear);
 829                lp->hw.intmask(dev, 0);
 830                spin_unlock_irqrestore(&lp->lock, flags);
 831                return retval;
 832        }
 833
 834        arc_printk(D_DURING, dev, "in arcnet_inthandler (status=%Xh, intmask=%Xh)\n",
 835                   lp->hw.status(dev), lp->intmask);
 836
 837        boguscount = 5;
 838        do {
 839                status = lp->hw.status(dev);
 840                diagstatus = (status >> 8) & 0xFF;
 841
 842                arc_printk(D_DEBUG, dev, "%s: %d: %s: status=%x\n",
 843                           __FILE__, __LINE__, __func__, status);
 844                didsomething = 0;
 845
 846                /* RESET flag was enabled - card is resetting and if RX is
 847                 * disabled, it's NOT because we just got a packet.
 848                 *
 849                 * The card is in an undefined state.
 850                 * Clear it out and start over.
 851                 */
 852                if (status & RESETflag) {
 853                        arc_printk(D_NORMAL, dev, "spurious reset (status=%Xh)\n",
 854                                   status);
 855                        arcnet_close(dev);
 856                        arcnet_open(dev);
 857
 858                        /* get out of the interrupt handler! */
 859                        break;
 860                }
 861                /* RX is inhibited - we must have received something.
 862                 * Prepare to receive into the next buffer.
 863                 *
 864                 * We don't actually copy the received packet from the card
 865                 * until after the transmit handler runs (and possibly
 866                 * launches the next tx); this should improve latency slightly
 867                 * if we get both types of interrupts at once.
 868                 */
 869                recbuf = -1;
 870                if (status & lp->intmask & NORXflag) {
 871                        recbuf = lp->cur_rx;
 872                        arc_printk(D_DURING, dev, "Buffer #%d: receive irq (status=%Xh)\n",
 873                                   recbuf, status);
 874
 875                        lp->cur_rx = get_arcbuf(dev);
 876                        if (lp->cur_rx != -1) {
 877                                arc_printk(D_DURING, dev, "enabling receive to buffer #%d\n",
 878                                           lp->cur_rx);
 879                                lp->hw.command(dev, RXcmd | (lp->cur_rx << 3) | RXbcasts);
 880                        }
 881                        didsomething++;
 882                }
 883
 884                if ((diagstatus & EXCNAKflag)) {
 885                        arc_printk(D_DURING, dev, "EXCNAK IRQ (diagstat=%Xh)\n",
 886                                   diagstatus);
 887
 888                        lp->hw.command(dev, NOTXcmd);      /* disable transmit */
 889                        lp->excnak_pending = 1;
 890
 891                        lp->hw.command(dev, EXCNAKclear);
 892                        lp->intmask &= ~(EXCNAKflag);
 893                        didsomething++;
 894                }
 895
 896                /* a transmit finished, and we're interested in it. */
 897                if ((status & lp->intmask & TXFREEflag) || lp->timed_out) {
 898                        int ackstatus;
 899                        lp->intmask &= ~(TXFREEflag | EXCNAKflag);
 900
 901                        if (status & TXACKflag)
 902                                ackstatus = 2;
 903                        else if (lp->excnak_pending)
 904                                ackstatus = 1;
 905                        else
 906                                ackstatus = 0;
 907
 908                        arc_printk(D_DURING, dev, "TX IRQ (stat=%Xh)\n",
 909                                   status);
 910
 911                        if (lp->cur_tx != -1 && !lp->timed_out) {
 912                                if (!(status & TXACKflag)) {
 913                                        if (lp->lasttrans_dest != 0) {
 914                                                arc_printk(D_EXTRA, dev,
 915                                                           "transmit was not acknowledged! (status=%Xh, dest=%02Xh)\n",
 916                                                           status,
 917                                                           lp->lasttrans_dest);
 918                                                dev->stats.tx_errors++;
 919                                                dev->stats.tx_carrier_errors++;
 920                                        } else {
 921                                                arc_printk(D_DURING, dev,
 922                                                           "broadcast was not acknowledged; that's normal (status=%Xh, dest=%02Xh)\n",
 923                                                           status,
 924                                                           lp->lasttrans_dest);
 925                                        }
 926                                }
 927
 928                                if (lp->outgoing.proto &&
 929                                    lp->outgoing.proto->ack_tx) {
 930                                        lp->outgoing.proto
 931                                                ->ack_tx(dev, ackstatus);
 932                                }
 933                                lp->reply_status = ackstatus;
 934                                tasklet_hi_schedule(&lp->reply_tasklet);
 935                        }
 936                        if (lp->cur_tx != -1)
 937                                release_arcbuf(dev, lp->cur_tx);
 938
 939                        lp->cur_tx = -1;
 940                        lp->timed_out = 0;
 941                        didsomething++;
 942
 943                        /* send another packet if there is one */
 944                        go_tx(dev);
 945
 946                        /* continue a split packet, if any */
 947                        if (lp->outgoing.proto &&
 948                            lp->outgoing.proto->continue_tx) {
 949                                int txbuf = get_arcbuf(dev);
 950
 951                                if (txbuf != -1) {
 952                                        if (lp->outgoing.proto->continue_tx(dev, txbuf)) {
 953                                                /* that was the last segment */
 954                                                dev->stats.tx_bytes += lp->outgoing.skb->len;
 955                                                if (!lp->outgoing.proto->ack_tx) {
 956                                                        dev_kfree_skb_irq(lp->outgoing.skb);
 957                                                        lp->outgoing.proto = NULL;
 958                                                }
 959                                        }
 960                                        lp->next_tx = txbuf;
 961                                }
 962                        }
 963                        /* inform upper layers of idleness, if necessary */
 964                        if (lp->cur_tx == -1)
 965                                netif_wake_queue(dev);
 966                }
 967                /* now process the received packet, if any */
 968                if (recbuf != -1) {
 969                        if (BUGLVL(D_RX))
 970                                arcnet_dump_packet(dev, recbuf, "rx irq", 0);
 971
 972                        arcnet_rx(dev, recbuf);
 973                        release_arcbuf(dev, recbuf);
 974
 975                        didsomething++;
 976                }
 977                if (status & lp->intmask & RECONflag) {
 978                        lp->hw.command(dev, CFLAGScmd | CONFIGclear);
 979                        dev->stats.tx_carrier_errors++;
 980
 981                        arc_printk(D_RECON, dev, "Network reconfiguration detected (status=%Xh)\n",
 982                                   status);
 983                        if (netif_carrier_ok(dev)) {
 984                                netif_carrier_off(dev);
 985                                netdev_info(dev, "link down\n");
 986                        }
 987                        mod_timer(&lp->timer, jiffies + msecs_to_jiffies(1000));
 988
 989                        arcnet_led_event(dev, ARCNET_LED_EVENT_RECON);
 990                        /* MYRECON bit is at bit 7 of diagstatus */
 991                        if (diagstatus & 0x80)
 992                                arc_printk(D_RECON, dev, "Put out that recon myself\n");
 993
 994                        /* is the RECON info empty or old? */
 995                        if (!lp->first_recon || !lp->last_recon ||
 996                            time_after(jiffies, lp->last_recon + HZ * 10)) {
 997                                if (lp->network_down)
 998                                        arc_printk(D_NORMAL, dev, "reconfiguration detected: cabling restored?\n");
 999                                lp->first_recon = lp->last_recon = jiffies;
1000                                lp->num_recons = lp->network_down = 0;
1001
1002                                arc_printk(D_DURING, dev, "recon: clearing counters.\n");
1003                        } else {        /* add to current RECON counter */
1004                                lp->last_recon = jiffies;
1005                                lp->num_recons++;
1006
1007                                arc_printk(D_DURING, dev, "recon: counter=%d, time=%lds, net=%d\n",
1008                                           lp->num_recons,
1009                                           (lp->last_recon - lp->first_recon) / HZ,
1010                                           lp->network_down);
1011
1012                                /* if network is marked up;
1013                                 * and first_recon and last_recon are 60+ apart;
1014                                 * and the average no. of recons counted is
1015                                 *    > RECON_THRESHOLD/min;
1016                                 * then print a warning message.
1017                                 */
1018                                if (!lp->network_down &&
1019                                    (lp->last_recon - lp->first_recon) <= HZ * 60 &&
1020                                    lp->num_recons >= RECON_THRESHOLD) {
1021                                        lp->network_down = 1;
1022                                        arc_printk(D_NORMAL, dev, "many reconfigurations detected: cabling problem?\n");
1023                                } else if (!lp->network_down &&
1024                                           lp->last_recon - lp->first_recon > HZ * 60) {
1025                                        /* reset counters if we've gone for
1026                                         *  over a minute.
1027                                         */
1028                                        lp->first_recon = lp->last_recon;
1029                                        lp->num_recons = 1;
1030                                }
1031                        }
1032                } else if (lp->network_down &&
1033                           time_after(jiffies, lp->last_recon + HZ * 10)) {
1034                        if (lp->network_down)
1035                                arc_printk(D_NORMAL, dev, "cabling restored?\n");
1036                        lp->first_recon = lp->last_recon = 0;
1037                        lp->num_recons = lp->network_down = 0;
1038
1039                        arc_printk(D_DURING, dev, "not recon: clearing counters anyway.\n");
1040                        netif_carrier_on(dev);
1041                }
1042
1043                if (didsomething)
1044                        retval |= IRQ_HANDLED;
1045        } while (--boguscount && didsomething);
1046
1047        arc_printk(D_DURING, dev, "arcnet_interrupt complete (status=%Xh, count=%d)\n",
1048                   lp->hw.status(dev), boguscount);
1049        arc_printk(D_DURING, dev, "\n");
1050
1051        lp->hw.intmask(dev, 0);
1052        udelay(1);
1053        lp->hw.intmask(dev, lp->intmask);
1054
1055        spin_unlock_irqrestore(&lp->lock, flags);
1056        return retval;
1057}
1058EXPORT_SYMBOL(arcnet_interrupt);
1059
1060/* This is a generic packet receiver that calls arcnet??_rx depending on the
1061 * protocol ID found.
1062 */
1063static void arcnet_rx(struct net_device *dev, int bufnum)
1064{
1065        struct arcnet_local *lp = netdev_priv(dev);
1066        union {
1067                struct archdr pkt;
1068                char buf[512];
1069        } rxdata;
1070        struct arc_rfc1201 *soft;
1071        int length, ofs;
1072
1073        soft = &rxdata.pkt.soft.rfc1201;
1074
1075        lp->hw.copy_from_card(dev, bufnum, 0, &rxdata.pkt, ARC_HDR_SIZE);
1076        if (rxdata.pkt.hard.offset[0]) {
1077                ofs = rxdata.pkt.hard.offset[0];
1078                length = 256 - ofs;
1079        } else {
1080                ofs = rxdata.pkt.hard.offset[1];
1081                length = 512 - ofs;
1082        }
1083
1084        /* get the full header, if possible */
1085        if (sizeof(rxdata.pkt.soft) <= length) {
1086                lp->hw.copy_from_card(dev, bufnum, ofs, soft, sizeof(rxdata.pkt.soft));
1087        } else {
1088                memset(&rxdata.pkt.soft, 0, sizeof(rxdata.pkt.soft));
1089                lp->hw.copy_from_card(dev, bufnum, ofs, soft, length);
1090        }
1091
1092        arc_printk(D_DURING, dev, "Buffer #%d: received packet from %02Xh to %02Xh (%d+4 bytes)\n",
1093                   bufnum, rxdata.pkt.hard.source, rxdata.pkt.hard.dest, length);
1094
1095        dev->stats.rx_packets++;
1096        dev->stats.rx_bytes += length + ARC_HDR_SIZE;
1097
1098        /* call the right receiver for the protocol */
1099        if (arc_proto_map[soft->proto]->is_ip) {
1100                if (BUGLVL(D_PROTO)) {
1101                        struct ArcProto
1102                        *oldp = arc_proto_map[lp->default_proto[rxdata.pkt.hard.source]],
1103                        *newp = arc_proto_map[soft->proto];
1104
1105                        if (oldp != newp) {
1106                                arc_printk(D_PROTO, dev,
1107                                           "got protocol %02Xh; encap for host %02Xh is now '%c' (was '%c')\n",
1108                                           soft->proto, rxdata.pkt.hard.source,
1109                                           newp->suffix, oldp->suffix);
1110                        }
1111                }
1112
1113                /* broadcasts will always be done with the last-used encap. */
1114                lp->default_proto[0] = soft->proto;
1115
1116                /* in striking contrast, the following isn't a hack. */
1117                lp->default_proto[rxdata.pkt.hard.source] = soft->proto;
1118        }
1119        /* call the protocol-specific receiver. */
1120        arc_proto_map[soft->proto]->rx(dev, bufnum, &rxdata.pkt, length);
1121}
1122
1123static void null_rx(struct net_device *dev, int bufnum,
1124                    struct archdr *pkthdr, int length)
1125{
1126        arc_printk(D_PROTO, dev,
1127                   "rx: don't know how to deal with proto %02Xh from host %02Xh.\n",
1128                   pkthdr->soft.rfc1201.proto, pkthdr->hard.source);
1129}
1130
1131static int null_build_header(struct sk_buff *skb, struct net_device *dev,
1132                             unsigned short type, uint8_t daddr)
1133{
1134        struct arcnet_local *lp = netdev_priv(dev);
1135
1136        arc_printk(D_PROTO, dev,
1137                   "tx: can't build header for encap %02Xh; load a protocol driver.\n",
1138                   lp->default_proto[daddr]);
1139
1140        /* always fails */
1141        return 0;
1142}
1143
1144/* the "do nothing" prepare_tx function warns that there's nothing to do. */
1145static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
1146                           int length, int bufnum)
1147{
1148        struct arcnet_local *lp = netdev_priv(dev);
1149        struct arc_hardware newpkt;
1150
1151        arc_printk(D_PROTO, dev, "tx: no encap for this host; load a protocol driver.\n");
1152
1153        /* send a packet to myself -- will never get received, of course */
1154        newpkt.source = newpkt.dest = dev->dev_addr[0];
1155
1156        /* only one byte of actual data (and it's random) */
1157        newpkt.offset[0] = 0xFF;
1158
1159        lp->hw.copy_to_card(dev, bufnum, 0, &newpkt, ARC_HDR_SIZE);
1160
1161        return 1;               /* done */
1162}
1163