Logo Search packages:      
Sourcecode: linux version File versions  Download package

arcnet.c

/*
 * Linux ARCnet driver - device-independent routines
 * 
 * Written 1997 by David Woodhouse.
 * Written 1994-1999 by Avery Pennarun.
 * Written 1999-2000 by Martin Mares <mj@ucw.cz>.
 * Derived from skeleton.c by Donald Becker.
 *
 * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
 *  for sponsoring the further development of this driver.
 *
 * **********************
 *
 * The original copyright was as follows:
 *
 * skeleton.c Written 1993 by Donald Becker.
 * Copyright 1993 United States Government as represented by the
 * Director, National Security Agency.  This software may only be used
 * and distributed according to the terms of the GNU General Public License as
 * modified by SRC, incorporated herein by reference.
 *
 * **********************
 * 
 * The change log is now in a file called ChangeLog in this directory.
 *
 * Sources:
 *  - Crynwr arcnet.com/arcether.com packet drivers.
 *  - arcnet.c v0.00 dated 1/1/94 and apparently by 
 *     Donald Becker - it didn't work :)
 *  - skeleton.c v0.05 dated 11/16/93 by Donald Becker
 *     (from Linux Kernel 1.1.45)
 *  - RFC's 1201 and 1051 - re: TCP/IP over ARCnet
 *  - The official ARCnet COM9026 data sheets (!) thanks to
 *     Ken Cornetet <kcornete@nyx10.cs.du.edu>
 *  - The official ARCnet COM20020 data sheets.
 *  - Information on some more obscure ARCnet controller chips, thanks
 *     to the nice people at SMSC.
 *  - net/inet/eth.c (from kernel 1.1.50) for header-building info.
 *  - Alternate Linux ARCnet source by V.Shergin <vsher@sao.stavropol.su>
 *  - Textual information and more alternate source from Joachim Koenig
 *     <jojo@repas.de>
 */

#define VERSION "arcnet: v3.94 BETA 2007/02/08 - by Avery Pennarun et al.\n"

#include <linux/module.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <net/arp.h>
#include <linux/init.h>
#include <linux/arcdevice.h>
#include <linux/jiffies.h>

/* "do nothing" functions for protocol drivers */
static void null_rx(struct net_device *dev, int bufnum,
                struct archdr *pkthdr, int length);
static int null_build_header(struct sk_buff *skb, struct net_device *dev,
                       unsigned short type, uint8_t daddr);
static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
                     int length, int bufnum);

static void arcnet_rx(struct net_device *dev, int bufnum);

/*
 * one ArcProto per possible proto ID.  None of the elements of
 * arc_proto_map are allowed to be NULL; they will get set to
 * arc_proto_default instead.  It also must not be NULL; if you would like
 * to set it to NULL, set it to &arc_proto_null instead.
 */
 struct ArcProto *arc_proto_map[256], *arc_proto_default,
   *arc_bcast_proto, *arc_raw_proto;

static struct ArcProto arc_proto_null =
{
      .suffix           = '?',
      .mtu        = XMTU,
      .is_ip          = 0,
      .rx         = null_rx,
      .build_header     = null_build_header,
      .prepare_tx = null_prepare_tx,
      .continue_tx    = NULL,
      .ack_tx         = NULL
};

/* Exported function prototypes */
int arcnet_debug = ARCNET_DEBUG;

EXPORT_SYMBOL(arc_proto_map);
EXPORT_SYMBOL(arc_proto_default);
EXPORT_SYMBOL(arc_bcast_proto);
EXPORT_SYMBOL(arc_raw_proto);
EXPORT_SYMBOL(arcnet_unregister_proto);
EXPORT_SYMBOL(arcnet_debug);
EXPORT_SYMBOL(alloc_arcdev);
EXPORT_SYMBOL(arcnet_interrupt);

/* Internal function prototypes */
static int arcnet_open(struct net_device *dev);
static int arcnet_close(struct net_device *dev);
static int arcnet_send_packet(struct sk_buff *skb, struct net_device *dev);
static void arcnet_timeout(struct net_device *dev);
static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
                   unsigned short type, const void *daddr,
                   const void *saddr, unsigned len);
static int arcnet_rebuild_header(struct sk_buff *skb);
static struct net_device_stats *arcnet_get_stats(struct net_device *dev);
static int go_tx(struct net_device *dev);

static int debug = ARCNET_DEBUG;
module_param(debug, int, 0);
MODULE_LICENSE("GPL");

static int __init arcnet_init(void)
{
      int count;

      arcnet_debug = debug;

      printk("arcnet loaded.\n");

#ifdef ALPHA_WARNING
      BUGLVL(D_EXTRA) {
            printk("arcnet: ***\n"
            "arcnet: * Read arcnet.txt for important release notes!\n"
                   "arcnet: *\n"
                   "arcnet: * This is an ALPHA version! (Last stable release: v3.02)  E-mail\n"
                   "arcnet: * me if you have any questions, comments, or bug reports.\n"
                   "arcnet: ***\n");
      }
#endif

      /* initialize the protocol map */
      arc_raw_proto = arc_proto_default = arc_bcast_proto = &arc_proto_null;
      for (count = 0; count < 256; count++)
            arc_proto_map[count] = arc_proto_default;

      BUGLVL(D_DURING)
          printk("arcnet: struct sizes: %Zd %Zd %Zd %Zd %Zd\n",
             sizeof(struct arc_hardware), sizeof(struct arc_rfc1201),
            sizeof(struct arc_rfc1051), sizeof(struct arc_eth_encap),
               sizeof(struct archdr));

      return 0;
}

static void __exit arcnet_exit(void)
{
}

module_init(arcnet_init);
module_exit(arcnet_exit);

/*
 * Dump the contents of an sk_buff
 */
#if ARCNET_DEBUG_MAX & D_SKB
void arcnet_dump_skb(struct net_device *dev,
                 struct sk_buff *skb, char *desc)
{
      int i;

      printk(KERN_DEBUG "%6s: skb dump (%s) follows:", dev->name, desc);
      for (i = 0; i < skb->len; i++) {
            if (i % 16 == 0)
                  printk("\n" KERN_DEBUG "[%04X] ", i);
            printk("%02X ", ((u_char *) skb->data)[i]);
      }
      printk("\n");
}

EXPORT_SYMBOL(arcnet_dump_skb);
#endif


/*
 * Dump the contents of an ARCnet buffer
 */
#if (ARCNET_DEBUG_MAX & (D_RX | D_TX))
static void arcnet_dump_packet(struct net_device *dev, int bufnum,
                         char *desc, int take_arcnet_lock)
{
      struct arcnet_local *lp = dev->priv;
      int i, length;
      unsigned long flags = 0;
      static uint8_t buf[512];

      /* hw.copy_from_card expects IRQ context so take the IRQ lock
         to keep it single threaded */
      if(take_arcnet_lock)
            spin_lock_irqsave(&lp->lock, flags);

      lp->hw.copy_from_card(dev, bufnum, 0, buf, 512);
      if(take_arcnet_lock)
            spin_unlock_irqrestore(&lp->lock, flags);

      /* if the offset[0] byte is nonzero, this is a 256-byte packet */
      length = (buf[2] ? 256 : 512);

      printk(KERN_DEBUG "%6s: packet dump (%s) follows:", dev->name, desc);
      for (i = 0; i < length; i++) {
            if (i % 16 == 0)
                  printk("\n" KERN_DEBUG "[%04X] ", i);
            printk("%02X ", buf[i]);
      }
      printk("\n");

}

#else

#define arcnet_dump_packet(dev, bufnum, desc,take_arcnet_lock) do { } while (0)

#endif


/*
 * Unregister a protocol driver from the arc_proto_map.  Protocol drivers
 * are responsible for registering themselves, but the unregister routine
 * is pretty generic so we'll do it here.
 */
void arcnet_unregister_proto(struct ArcProto *proto)
{
      int count;

      if (arc_proto_default == proto)
            arc_proto_default = &arc_proto_null;
      if (arc_bcast_proto == proto)
            arc_bcast_proto = arc_proto_default;
      if (arc_raw_proto == proto)
            arc_raw_proto = arc_proto_default;

      for (count = 0; count < 256; count++) {
            if (arc_proto_map[count] == proto)
                  arc_proto_map[count] = arc_proto_default;
      }
}


/*
 * Add a buffer to the queue.  Only the interrupt handler is allowed to do
 * this, unless interrupts are disabled.
 * 
 * Note: we don't check for a full queue, since there aren't enough buffers
 * to more than fill it.
 */
static void release_arcbuf(struct net_device *dev, int bufnum)
{
      struct arcnet_local *lp = dev->priv;
      int i;

      lp->buf_queue[lp->first_free_buf++] = bufnum;
      lp->first_free_buf %= 5;

      BUGLVL(D_DURING) {
            BUGMSG(D_DURING, "release_arcbuf: freed #%d; buffer queue is now: ",
                   bufnum);
            for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5)
                  BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]);
            BUGMSG2(D_DURING, "\n");
      }
}


/*
 * Get a buffer from the queue.  If this returns -1, there are no buffers
 * available.
 */
static int get_arcbuf(struct net_device *dev)
{
      struct arcnet_local *lp = dev->priv;
      int buf = -1, i;

      if (!atomic_dec_and_test(&lp->buf_lock)) {
            /* already in this function */
            BUGMSG(D_NORMAL, "get_arcbuf: overlap (%d)!\n",
                   lp->buf_lock.counter);
      }
      else {                  /* we can continue */
            if (lp->next_buf >= 5)
                  lp->next_buf -= 5;

            if (lp->next_buf == lp->first_free_buf)
                  BUGMSG(D_NORMAL, "get_arcbuf: BUG: no buffers are available??\n");
            else {
                  buf = lp->buf_queue[lp->next_buf++];
                  lp->next_buf %= 5;
            }
      }


      BUGLVL(D_DURING) {
            BUGMSG(D_DURING, "get_arcbuf: got #%d; buffer queue is now: ", buf);
            for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5)
                  BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]);
            BUGMSG2(D_DURING, "\n");
      }

      atomic_inc(&lp->buf_lock);
      return buf;
}


static int choose_mtu(void)
{
      int count, mtu = 65535;

      /* choose the smallest MTU of all available encaps */
      for (count = 0; count < 256; count++) {
            if (arc_proto_map[count] != &arc_proto_null
                && arc_proto_map[count]->mtu < mtu) {
                  mtu = arc_proto_map[count]->mtu;
            }
      }

      return mtu == 65535 ? XMTU : mtu;
}

static const struct header_ops arcnet_header_ops = {
      .create = arcnet_header,
      .rebuild = arcnet_rebuild_header,
};


/* Setup a struct device for ARCnet. */
static void arcdev_setup(struct net_device *dev)
{
      dev->type = ARPHRD_ARCNET;
      dev->header_ops = &arcnet_header_ops;
      dev->hard_header_len = sizeof(struct archdr);
      dev->mtu = choose_mtu();

      dev->addr_len = ARCNET_ALEN;
      dev->tx_queue_len = 100;
      dev->broadcast[0] = 0x00;     /* for us, broadcasts are address 0 */
      dev->watchdog_timeo = TX_TIMEOUT;

      /* New-style flags. */
      dev->flags = IFF_BROADCAST;

      /*
       * Put in this stuff here, so we don't have to export the symbols to
       * the chipset drivers.
       */
      dev->open = arcnet_open;
      dev->stop = arcnet_close;
      dev->hard_start_xmit = arcnet_send_packet;
      dev->tx_timeout = arcnet_timeout;
      dev->get_stats = arcnet_get_stats;
}

struct net_device *alloc_arcdev(char *name)
{
      struct net_device *dev;

      dev = alloc_netdev(sizeof(struct arcnet_local),
                     name && *name ? name : "arc%d", arcdev_setup);
      if(dev) {
            struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
            spin_lock_init(&lp->lock);
      }

      return dev;
}

/*
 * Open/initialize the board.  This is called sometime after booting when
 * the 'ifconfig' program is run.
 *
 * This routine should set everything up anew at each open, even registers
 * that "should" only need to be set once at boot, so that there is
 * non-reboot way to recover if something goes wrong.
 */
static int arcnet_open(struct net_device *dev)
{
      struct arcnet_local *lp = dev->priv;
      int count, newmtu, error;

      BUGMSG(D_INIT,"opened.");

      if (!try_module_get(lp->hw.owner))
            return -ENODEV;

      BUGLVL(D_PROTO) {
            int count;
            BUGMSG(D_PROTO, "protocol map (default is '%c'): ",
                   arc_proto_default->suffix);
            for (count = 0; count < 256; count++)
                  BUGMSG2(D_PROTO, "%c", arc_proto_map[count]->suffix);
            BUGMSG2(D_PROTO, "\n");
      }


      BUGMSG(D_INIT, "arcnet_open: resetting card.\n");

      /* try to put the card in a defined state - if it fails the first
       * time, actually reset it.
       */
      error = -ENODEV;
      if (ARCRESET(0) && ARCRESET(1))
            goto out_module_put;

      newmtu = choose_mtu();
      if (newmtu < dev->mtu)
            dev->mtu = newmtu;

      BUGMSG(D_INIT, "arcnet_open: mtu: %d.\n", dev->mtu);

      /* autodetect the encapsulation for each host. */
      memset(lp->default_proto, 0, sizeof(lp->default_proto));

      /* the broadcast address is special - use the 'bcast' protocol */
      for (count = 0; count < 256; count++) {
            if (arc_proto_map[count] == arc_bcast_proto) {
                  lp->default_proto[0] = count;
                  break;
            }
      }

      /* initialize buffers */
      atomic_set(&lp->buf_lock, 1);

      lp->next_buf = lp->first_free_buf = 0;
      release_arcbuf(dev, 0);
      release_arcbuf(dev, 1);
      release_arcbuf(dev, 2);
      release_arcbuf(dev, 3);
      lp->cur_tx = lp->next_tx = -1;
      lp->cur_rx = -1;

      lp->rfc1201.sequence = 1;

      /* bring up the hardware driver */
      if (lp->hw.open)
            lp->hw.open(dev);

      if (dev->dev_addr[0] == 0)
            BUGMSG(D_NORMAL, "WARNING!  Station address 00 is reserved "
                   "for broadcasts!\n");
      else if (dev->dev_addr[0] == 255)
            BUGMSG(D_NORMAL, "WARNING!  Station address FF may confuse "
                   "DOS networking programs!\n");

      BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
      if (ASTATUS() & RESETflag) {
            BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
            ACOMMAND(CFLAGScmd | RESETclear);
      }


      BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
      /* make sure we're ready to receive IRQ's. */
      AINTMASK(0);
      udelay(1);        /* give it time to set the mask before
                         * we reset it again. (may not even be
                         * necessary)
                         */
      BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
      lp->intmask = NORXflag | RECONflag;
      AINTMASK(lp->intmask);
      BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);

      netif_start_queue(dev);

      return 0;

 out_module_put:
      module_put(lp->hw.owner);
      return error;
}


/* The inverse routine to arcnet_open - shuts down the card. */
static int arcnet_close(struct net_device *dev)
{
      struct arcnet_local *lp = dev->priv;

      netif_stop_queue(dev);

      /* flush TX and disable RX */
      AINTMASK(0);
      ACOMMAND(NOTXcmd);      /* stop transmit */
      ACOMMAND(NORXcmd);      /* disable receive */
      mdelay(1);

      /* shut down the card */
      lp->hw.close(dev);
      module_put(lp->hw.owner);
      return 0;
}


static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
                   unsigned short type, const void *daddr,
                   const void *saddr, unsigned len)
{
      const struct arcnet_local *lp = netdev_priv(dev);
      uint8_t _daddr, proto_num;
      struct ArcProto *proto;

      BUGMSG(D_DURING,
          "create header from %d to %d; protocol %d (%Xh); size %u.\n",
             saddr ? *(uint8_t *) saddr : -1,
             daddr ? *(uint8_t *) daddr : -1,
             type, type, len);

      if (skb->len!=0 && len != skb->len)
            BUGMSG(D_NORMAL, "arcnet_header: Yikes!  skb->len(%d) != len(%d)!\n",
                   skb->len, len);


      /* Type is host order - ? */
      if(type == ETH_P_ARCNET) {
            proto = arc_raw_proto;
            BUGMSG(D_DEBUG, "arc_raw_proto used. proto='%c'\n",proto->suffix);
            _daddr = daddr ? *(uint8_t *) daddr : 0;
      }
      else if (!daddr) {
            /*
             * if the dest addr isn't provided, we can't choose an encapsulation!
             * Store the packet type (eg. ETH_P_IP) for now, and we'll push on a
             * real header when we do rebuild_header.
             */
            *(uint16_t *) skb_push(skb, 2) = type;
            /*
             * XXX: Why not use skb->mac_len?
             */
            if (skb->network_header - skb->mac_header != 2)
                  BUGMSG(D_NORMAL, "arcnet_header: Yikes!  diff (%d) is not 2!\n",
                         (int)(skb->network_header - skb->mac_header));
            return -2;  /* return error -- can't transmit yet! */
      }
      else {
            /* otherwise, we can just add the header as usual. */
            _daddr = *(uint8_t *) daddr;
            proto_num = lp->default_proto[_daddr];
            proto = arc_proto_map[proto_num];
            BUGMSG(D_DURING, "building header for %02Xh using protocol '%c'\n",
                   proto_num, proto->suffix);
            if (proto == &arc_proto_null && arc_bcast_proto != proto) {
                  BUGMSG(D_DURING, "actually, let's use '%c' instead.\n",
                         arc_bcast_proto->suffix);
                  proto = arc_bcast_proto;
            }
      }
      return proto->build_header(skb, dev, type, _daddr);
}


/* 
 * Rebuild the ARCnet hard header. This is called after an ARP (or in the
 * future other address resolution) has completed on this sk_buff. We now
 * let ARP fill in the destination field.
 */
static int arcnet_rebuild_header(struct sk_buff *skb)
{
      struct net_device *dev = skb->dev;
      struct arcnet_local *lp = dev->priv;
      int status = 0;         /* default is failure */
      unsigned short type;
      uint8_t daddr=0;
      struct ArcProto *proto;
      /*
       * XXX: Why not use skb->mac_len?
       */
      if (skb->network_header - skb->mac_header != 2) {
            BUGMSG(D_NORMAL,
                   "rebuild_header: shouldn't be here! (hdrsize=%d)\n",
                   (int)(skb->network_header - skb->mac_header));
            return 0;
      }
      type = *(uint16_t *) skb_pull(skb, 2);
      BUGMSG(D_DURING, "rebuild header for protocol %Xh\n", type);

      if (type == ETH_P_IP) {
#ifdef CONFIG_INET
            BUGMSG(D_DURING, "rebuild header for ethernet protocol %Xh\n", type);
            status = arp_find(&daddr, skb) ? 1 : 0;
            BUGMSG(D_DURING, " rebuilt: dest is %d; protocol %Xh\n",
                   daddr, type);
#endif
      } else {
            BUGMSG(D_NORMAL,
                   "I don't understand ethernet protocol %Xh addresses!\n", type);
            lp->stats.tx_errors++;
            lp->stats.tx_aborted_errors++;
      }

      /* if we couldn't resolve the address... give up. */
      if (!status)
            return 0;

      /* add the _real_ header this time! */
      proto = arc_proto_map[lp->default_proto[daddr]];
      proto->build_header(skb, dev, type, daddr);

      return 1;         /* success */
}



/* Called by the kernel in order to transmit a packet. */
static int arcnet_send_packet(struct sk_buff *skb, struct net_device *dev)
{
      struct arcnet_local *lp = dev->priv;
      struct archdr *pkt;
      struct arc_rfc1201 *soft;
      struct ArcProto *proto;
      int txbuf;
      unsigned long flags;
      int freeskb, retval;

      BUGMSG(D_DURING,
             "transmit requested (status=%Xh, txbufs=%d/%d, len=%d, protocol %x)\n",
             ASTATUS(), lp->cur_tx, lp->next_tx, skb->len,skb->protocol);

      pkt = (struct archdr *) skb->data;
      soft = &pkt->soft.rfc1201;
      proto = arc_proto_map[soft->proto];

      BUGMSG(D_SKB_SIZE, "skb: transmitting %d bytes to %02X\n",
            skb->len, pkt->hard.dest);
      BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "tx");

      /* fits in one packet? */
      if (skb->len - ARC_HDR_SIZE > XMTU && !proto->continue_tx) {
            BUGMSG(D_NORMAL, "fixme: packet too large: compensating badly!\n");
            dev_kfree_skb(skb);
            return NETDEV_TX_OK;    /* don't try again */
      }

      /* We're busy transmitting a packet... */
      netif_stop_queue(dev);

      spin_lock_irqsave(&lp->lock, flags);
      AINTMASK(0);
      if(lp->next_tx == -1)
            txbuf = get_arcbuf(dev);
      else {
            txbuf = -1;
      }
      if (txbuf != -1) {
            if (proto->prepare_tx(dev, pkt, skb->len, txbuf) &&
                !proto->ack_tx) {
                  /* done right away and we don't want to acknowledge
                     the package later - forget about it now */
                  lp->stats.tx_bytes += skb->len;
                  freeskb = 1;
            } else {
                  /* do it the 'split' way */
                  lp->outgoing.proto = proto;
                  lp->outgoing.skb = skb;
                  lp->outgoing.pkt = pkt;

                  freeskb = 0;

                  if (proto->continue_tx &&
                      proto->continue_tx(dev, txbuf)) {
                    BUGMSG(D_NORMAL,
                         "bug! continue_tx finished the first time! "
                         "(proto='%c')\n", proto->suffix);
                  }
            }
            retval = NETDEV_TX_OK;
            dev->trans_start = jiffies;
            lp->next_tx = txbuf;
      } else {
            retval = NETDEV_TX_BUSY;
            freeskb = 0;
      }

      BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__FUNCTION__,ASTATUS());
      /* make sure we didn't ignore a TX IRQ while we were in here */
      AINTMASK(0);

      BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
      lp->intmask |= TXFREEflag|EXCNAKflag;
      AINTMASK(lp->intmask);
      BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__FUNCTION__,ASTATUS());

      spin_unlock_irqrestore(&lp->lock, flags);
      if (freeskb) {
            dev_kfree_skb(skb);
      }
      return retval;          /* no need to try again */
}


/*
 * Actually start transmitting a packet that was loaded into a buffer
 * by prepare_tx.  This should _only_ be called by the interrupt handler.
 */
static int go_tx(struct net_device *dev)
{
      struct arcnet_local *lp = dev->priv;

      BUGMSG(D_DURING, "go_tx: status=%Xh, intmask=%Xh, next_tx=%d, cur_tx=%d\n",
             ASTATUS(), lp->intmask, lp->next_tx, lp->cur_tx);

      if (lp->cur_tx != -1 || lp->next_tx == -1)
            return 0;

      BUGLVL(D_TX) arcnet_dump_packet(dev, lp->next_tx, "go_tx", 0);

      lp->cur_tx = lp->next_tx;
      lp->next_tx = -1;

      /* start sending */
      ACOMMAND(TXcmd | (lp->cur_tx << 3));

      lp->stats.tx_packets++;
      lp->lasttrans_dest = lp->lastload_dest;
      lp->lastload_dest = 0;
      lp->excnak_pending = 0;
      lp->intmask |= TXFREEflag|EXCNAKflag;

      return 1;
}


/* Called by the kernel when transmit times out */
static void arcnet_timeout(struct net_device *dev)
{
      unsigned long flags;
      struct arcnet_local *lp = dev->priv;
      int status = ASTATUS();
      char *msg;

      spin_lock_irqsave(&lp->lock, flags);
      if (status & TXFREEflag) {    /* transmit _DID_ finish */
            msg = " - missed IRQ?";
      } else {
            msg = "";
            lp->stats.tx_aborted_errors++;
            lp->timed_out = 1;
            ACOMMAND(NOTXcmd | (lp->cur_tx << 3));
      }
      lp->stats.tx_errors++;

      /* make sure we didn't miss a TX or a EXC NAK IRQ */
      AINTMASK(0);
      lp->intmask |= TXFREEflag|EXCNAKflag;
      AINTMASK(lp->intmask);
      
      spin_unlock_irqrestore(&lp->lock, flags);

      if (time_after(jiffies, lp->last_timeout + 10*HZ)) {
            BUGMSG(D_EXTRA, "tx timed out%s (status=%Xh, intmask=%Xh, dest=%02Xh)\n",
                   msg, status, lp->intmask, lp->lasttrans_dest);
            lp->last_timeout = jiffies;
      }

      if (lp->cur_tx == -1)
            netif_wake_queue(dev);
}


/*
 * The typical workload of the driver: Handle the network interface
 * interrupts. Establish which device needs attention, and call the correct
 * chipset interrupt handler.
 */
irqreturn_t arcnet_interrupt(int irq, void *dev_id)
{
      struct net_device *dev = dev_id;
      struct arcnet_local *lp;
      int recbuf, status, diagstatus, didsomething, boguscount;
      int retval = IRQ_NONE;

      BUGMSG(D_DURING, "\n");

      BUGMSG(D_DURING, "in arcnet_interrupt\n");
      
      lp = dev->priv;
      BUG_ON(!lp);
            
      spin_lock(&lp->lock);

      /*
       * RESET flag was enabled - if device is not running, we must clear it right
       * away (but nothing else).
       */
      if (!netif_running(dev)) {
            if (ASTATUS() & RESETflag)
                  ACOMMAND(CFLAGScmd | RESETclear);
            AINTMASK(0);
            spin_unlock(&lp->lock);
            return IRQ_HANDLED;
      }

      BUGMSG(D_DURING, "in arcnet_inthandler (status=%Xh, intmask=%Xh)\n",
             ASTATUS(), lp->intmask);

      boguscount = 5;
      do {
            status = ASTATUS();
                diagstatus = (status >> 8) & 0xFF;

            BUGMSG(D_DEBUG, "%s: %d: %s: status=%x\n",
                  __FILE__,__LINE__,__FUNCTION__,status);
            didsomething = 0;

            /*
             * RESET flag was enabled - card is resetting and if RX is
             * disabled, it's NOT because we just got a packet.
             * 
             * The card is in an undefined state.  Clear it out and start over.
             */
            if (status & RESETflag) {
                  BUGMSG(D_NORMAL, "spurious reset (status=%Xh)\n", status);
                  arcnet_close(dev);
                  arcnet_open(dev);

                  /* get out of the interrupt handler! */
                  break;
            }
            /* 
             * RX is inhibited - we must have received something. Prepare to
             * receive into the next buffer.
             * 
             * We don't actually copy the received packet from the card until
             * after the transmit handler runs (and possibly launches the next
             * tx); this should improve latency slightly if we get both types
             * of interrupts at once. 
             */
            recbuf = -1;
            if (status & lp->intmask & NORXflag) {
                  recbuf = lp->cur_rx;
                  BUGMSG(D_DURING, "Buffer #%d: receive irq (status=%Xh)\n",
                         recbuf, status);

                  lp->cur_rx = get_arcbuf(dev);
                  if (lp->cur_rx != -1) {
                        BUGMSG(D_DURING, "enabling receive to buffer #%d\n",
                               lp->cur_rx);
                        ACOMMAND(RXcmd | (lp->cur_rx << 3) | RXbcasts);
                  }
                  didsomething++;
            }

            if((diagstatus & EXCNAKflag)) {
                  BUGMSG(D_DURING, "EXCNAK IRQ (diagstat=%Xh)\n",
                         diagstatus);

                        ACOMMAND(NOTXcmd);      /* disable transmit */
                        lp->excnak_pending = 1;

                        ACOMMAND(EXCNAKclear);
                  lp->intmask &= ~(EXCNAKflag);
                        didsomething++;
                }


            /* a transmit finished, and we're interested in it. */
            if ((status & lp->intmask & TXFREEflag) || lp->timed_out) {
                  lp->intmask &= ~(TXFREEflag|EXCNAKflag);

                  BUGMSG(D_DURING, "TX IRQ (stat=%Xh)\n", status);

                  if (lp->cur_tx != -1 && !lp->timed_out) {
                        if(!(status & TXACKflag)) {
                              if (lp->lasttrans_dest != 0) {
                                    BUGMSG(D_EXTRA,
                                           "transmit was not acknowledged! "
                                           "(status=%Xh, dest=%02Xh)\n",
                                           status, lp->lasttrans_dest);
                                    lp->stats.tx_errors++;
                                    lp->stats.tx_carrier_errors++;
                              } else {
                                    BUGMSG(D_DURING,
                                           "broadcast was not acknowledged; that's normal "
                                           "(status=%Xh, dest=%02Xh)\n",
                                           status, lp->lasttrans_dest);
                              }
                        }

                        if (lp->outgoing.proto &&
                            lp->outgoing.proto->ack_tx) {
                          int ackstatus;
                          if(status & TXACKflag)
                                    ackstatus=2;
                                  else if(lp->excnak_pending)
                                    ackstatus=1;
                                  else
                                    ackstatus=0;

                                  lp->outgoing.proto
                                    ->ack_tx(dev, ackstatus);
                        }
                  }
                  if (lp->cur_tx != -1)
                        release_arcbuf(dev, lp->cur_tx);

                  lp->cur_tx = -1;
                  lp->timed_out = 0;
                  didsomething++;

                  /* send another packet if there is one */
                  go_tx(dev);

                  /* continue a split packet, if any */
                  if (lp->outgoing.proto && lp->outgoing.proto->continue_tx) {
                        int txbuf = get_arcbuf(dev);
                        if (txbuf != -1) {
                              if (lp->outgoing.proto->continue_tx(dev, txbuf)) {
                                    /* that was the last segment */
                                    lp->stats.tx_bytes += lp->outgoing.skb->len;
                                    if(!lp->outgoing.proto->ack_tx)
                                      {
                                        dev_kfree_skb_irq(lp->outgoing.skb);
                                        lp->outgoing.proto = NULL;
                                      }
                              }
                              lp->next_tx = txbuf;
                        }
                  }
                  /* inform upper layers of idleness, if necessary */
                  if (lp->cur_tx == -1)
                        netif_wake_queue(dev);
            }
            /* now process the received packet, if any */
            if (recbuf != -1) {
                  BUGLVL(D_RX) arcnet_dump_packet(dev, recbuf, "rx irq", 0);

                  arcnet_rx(dev, recbuf);
                  release_arcbuf(dev, recbuf);

                  didsomething++;
            }
            if (status & lp->intmask & RECONflag) {
                  ACOMMAND(CFLAGScmd | CONFIGclear);
                  lp->stats.tx_carrier_errors++;

                  BUGMSG(D_RECON, "Network reconfiguration detected (status=%Xh)\n",
                         status);
                  /* MYRECON bit is at bit 7 of diagstatus */
                  if(diagstatus & 0x80)
                        BUGMSG(D_RECON,"Put out that recon myself\n");

                  /* is the RECON info empty or old? */
                  if (!lp->first_recon || !lp->last_recon ||
                      jiffies - lp->last_recon > HZ * 10) {
                        if (lp->network_down)
                              BUGMSG(D_NORMAL, "reconfiguration detected: cabling restored?\n");
                        lp->first_recon = lp->last_recon = jiffies;
                        lp->num_recons = lp->network_down = 0;

                        BUGMSG(D_DURING, "recon: clearing counters.\n");
                  } else {    /* add to current RECON counter */
                        lp->last_recon = jiffies;
                        lp->num_recons++;

                        BUGMSG(D_DURING, "recon: counter=%d, time=%lds, net=%d\n",
                               lp->num_recons,
                         (lp->last_recon - lp->first_recon) / HZ,
                               lp->network_down);

                        /* if network is marked up;
                         * and first_recon and last_recon are 60+ apart;
                         * and the average no. of recons counted is
                         *    > RECON_THRESHOLD/min;
                         * then print a warning message.
                         */
                        if (!lp->network_down
                            && (lp->last_recon - lp->first_recon) <= HZ * 60
                          && lp->num_recons >= RECON_THRESHOLD) {
                              lp->network_down = 1;
                              BUGMSG(D_NORMAL, "many reconfigurations detected: cabling problem?\n");
                        } else if (!lp->network_down
                                 && lp->last_recon - lp->first_recon > HZ * 60) {
                              /* reset counters if we've gone for over a minute. */
                              lp->first_recon = lp->last_recon;
                              lp->num_recons = 1;
                        }
                  }
            } else if (lp->network_down && jiffies - lp->last_recon > HZ * 10) {
                  if (lp->network_down)
                        BUGMSG(D_NORMAL, "cabling restored?\n");
                  lp->first_recon = lp->last_recon = 0;
                  lp->num_recons = lp->network_down = 0;

                  BUGMSG(D_DURING, "not recon: clearing counters anyway.\n");
            }

            if(didsomething) {
                  retval |= IRQ_HANDLED;
            }
      }
      while (--boguscount && didsomething);

      BUGMSG(D_DURING, "arcnet_interrupt complete (status=%Xh, count=%d)\n",
             ASTATUS(), boguscount);
      BUGMSG(D_DURING, "\n");


      AINTMASK(0);
      udelay(1);
      AINTMASK(lp->intmask);
      
      spin_unlock(&lp->lock);
      return retval;
}


/*
 * This is a generic packet receiver that calls arcnet??_rx depending on the
 * protocol ID found.
 */
static void arcnet_rx(struct net_device *dev, int bufnum)
{
      struct arcnet_local *lp = dev->priv;
      struct archdr pkt;
      struct arc_rfc1201 *soft;
      int length, ofs;

      soft = &pkt.soft.rfc1201;

      lp->hw.copy_from_card(dev, bufnum, 0, &pkt, sizeof(ARC_HDR_SIZE));
      if (pkt.hard.offset[0]) {
            ofs = pkt.hard.offset[0];
            length = 256 - ofs;
      } else {
            ofs = pkt.hard.offset[1];
            length = 512 - ofs;
      }

      /* get the full header, if possible */
      if (sizeof(pkt.soft) <= length)
            lp->hw.copy_from_card(dev, bufnum, ofs, soft, sizeof(pkt.soft));
      else {
            memset(&pkt.soft, 0, sizeof(pkt.soft));
            lp->hw.copy_from_card(dev, bufnum, ofs, soft, length);
      }

      BUGMSG(D_DURING, "Buffer #%d: received packet from %02Xh to %02Xh "
             "(%d+4 bytes)\n",
             bufnum, pkt.hard.source, pkt.hard.dest, length);

      lp->stats.rx_packets++;
      lp->stats.rx_bytes += length + ARC_HDR_SIZE;

      /* call the right receiver for the protocol */
      if (arc_proto_map[soft->proto]->is_ip) {
            BUGLVL(D_PROTO) {
                  struct ArcProto
                  *oldp = arc_proto_map[lp->default_proto[pkt.hard.source]],
                  *newp = arc_proto_map[soft->proto];

                  if (oldp != newp) {
                        BUGMSG(D_PROTO,
                               "got protocol %02Xh; encap for host %02Xh is now '%c'"
                               " (was '%c')\n", soft->proto, pkt.hard.source,
                               newp->suffix, oldp->suffix);
                  }
            }

            /* broadcasts will always be done with the last-used encap. */
            lp->default_proto[0] = soft->proto;

            /* in striking contrast, the following isn't a hack. */
            lp->default_proto[pkt.hard.source] = soft->proto;
      }
      /* call the protocol-specific receiver. */
      arc_proto_map[soft->proto]->rx(dev, bufnum, &pkt, length);
}



/* 
 * Get the current statistics.  This may be called with the card open or
 * closed.
 */
static struct net_device_stats *arcnet_get_stats(struct net_device *dev)
{
      struct arcnet_local *lp = dev->priv;
      return &lp->stats;
}


static void null_rx(struct net_device *dev, int bufnum,
                struct archdr *pkthdr, int length)
{
      BUGMSG(D_PROTO,
      "rx: don't know how to deal with proto %02Xh from host %02Xh.\n",
             pkthdr->soft.rfc1201.proto, pkthdr->hard.source);
}


static int null_build_header(struct sk_buff *skb, struct net_device *dev,
                       unsigned short type, uint8_t daddr)
{
      struct arcnet_local *lp = dev->priv;

      BUGMSG(D_PROTO,
             "tx: can't build header for encap %02Xh; load a protocol driver.\n",
             lp->default_proto[daddr]);

      /* always fails */
      return 0;
}


/* the "do nothing" prepare_tx function warns that there's nothing to do. */
static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
                     int length, int bufnum)
{
      struct arcnet_local *lp = dev->priv;
      struct arc_hardware newpkt;

      BUGMSG(D_PROTO, "tx: no encap for this host; load a protocol driver.\n");

      /* send a packet to myself -- will never get received, of course */
      newpkt.source = newpkt.dest = dev->dev_addr[0];

      /* only one byte of actual data (and it's random) */
      newpkt.offset[0] = 0xFF;

      lp->hw.copy_to_card(dev, bufnum, 0, &newpkt, ARC_HDR_SIZE);

      return 1;         /* done */
}

Generated by  Doxygen 1.6.0   Back to index