depca.c

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		       &lp->rx_ring[i].base);
		writew(-RX_BUFF_SZ, &lp->rx_ring[i].buf_length);
		lp->rx_buff[i] = lp->sh_mem + offset;
	}

	for (i = 0; i <= lp->txRingMask; i++) {
		offset = lp->buffs_offset + (i + lp->rxRingMask+1)*TX_BUFF_SZ;
		writel((lp->device_ram_start + offset) & 0x00ffffff,
	               &lp->tx_ring[i].base);
		lp->tx_buff[i] = lp->sh_mem + offset;
	}

	/* Set up the initialization block */
	lp->init_block.rx_ring = (lp->device_ram_start + lp->rx_ring_offset) | lp->rx_rlen;
	lp->init_block.tx_ring = (lp->device_ram_start + lp->tx_ring_offset) | lp->tx_rlen;

	SetMulticastFilter(dev);

	for (i = 0; i < ETH_ALEN; i++) {
		lp->init_block.phys_addr[i] = dev->dev_addr[i];
	}

	lp->init_block.mode = 0x0000;            /* Enable the Tx and Rx */
}


static void depca_tx_timeout (struct net_device *dev)
{
	u_long ioaddr = dev->base_addr;

	printk ("%s: transmit timed out, status %04x, resetting.\n",
		dev->name, inw (DEPCA_DATA));

	STOP_DEPCA;
	depca_init_ring (dev);
	LoadCSRs (dev);
	dev->trans_start = jiffies;
	netif_wake_queue (dev);
	InitRestartDepca (dev);
}


/* 
** Writes a socket buffer to TX descriptor ring and starts transmission 
*/
static int depca_start_xmit (struct sk_buff *skb, struct net_device *dev)
{
	struct depca_private *lp = (struct depca_private *) dev->priv;
	u_long ioaddr = dev->base_addr;
	int status = 0;

	/* Transmitter timeout, serious problems. */
	if (skb->len < 1)
		goto out;

	netif_stop_queue (dev);

	if (TX_BUFFS_AVAIL) {	/* Fill in a Tx ring entry */
		status = load_packet (dev, skb);

		if (!status) {
			/* Trigger an immediate send demand. */
			outw (CSR0, DEPCA_ADDR);
			outw (INEA | TDMD, DEPCA_DATA);

			dev->trans_start = jiffies;
			dev_kfree_skb (skb);
		}
		if (TX_BUFFS_AVAIL)
			netif_start_queue (dev);
	} else
		status = -1;

out:
	return status;
}

/*
** The DEPCA interrupt handler. 
*/
static void depca_interrupt (int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = dev_id;
	struct depca_private *lp;
	s16 csr0, nicsr;
	u_long ioaddr;

	if (dev == NULL) {
		printk ("depca_interrupt(): irq %d for unknown device.\n", irq);
		return;
	}

	lp = (struct depca_private *) dev->priv;
	ioaddr = dev->base_addr;

	spin_lock (&lp->lock);

	/* mask the DEPCA board interrupts and turn on the LED */
	nicsr = inb (DEPCA_NICSR);
	nicsr |= (IM | LED);
	outb (nicsr, DEPCA_NICSR);

	outw (CSR0, DEPCA_ADDR);
	csr0 = inw (DEPCA_DATA);

	/* Acknowledge all of the current interrupt sources ASAP. */
	outw (csr0 & INTE, DEPCA_DATA);

	if (csr0 & RINT)	/* Rx interrupt (packet arrived) */
		depca_rx (dev);

	if (csr0 & TINT)	/* Tx interrupt (packet sent) */
		depca_tx (dev);

	/* Any resources available? */
	if ((TX_BUFFS_AVAIL >= 0) && netif_queue_stopped(dev)) {
		netif_wake_queue (dev);
	}

	/* Unmask the DEPCA board interrupts and turn off the LED */
	nicsr = (nicsr & ~IM & ~LED);
	outb (nicsr, DEPCA_NICSR);

	spin_unlock (&lp->lock);
}


static int
depca_rx(struct net_device *dev)
{
  struct depca_private *lp = (struct depca_private *)dev->priv;
  int i, entry;
  s32 status;

  for (entry=lp->rx_new; 
       !(readl(&lp->rx_ring[entry].base) & R_OWN);
       entry=lp->rx_new){
    status = readl(&lp->rx_ring[entry].base) >> 16 ;
    if (status & R_STP) {                      /* Remember start of frame */
      lp->rx_old = entry;
    }
    if (status & R_ENP) {                      /* Valid frame status */
      if (status & R_ERR) {	               /* There was an error. */
	lp->stats.rx_errors++;                 /* Update the error stats. */
	if (status & R_FRAM) lp->stats.rx_frame_errors++;
	if (status & R_OFLO) lp->stats.rx_over_errors++;
	if (status & R_CRC)  lp->stats.rx_crc_errors++;
	if (status & R_BUFF) lp->stats.rx_fifo_errors++;
      } else {	
	short len, pkt_len = readw(&lp->rx_ring[entry].msg_length) - 4;
	struct sk_buff *skb;

	skb = dev_alloc_skb(pkt_len+2);
	if (skb != NULL) {
	  unsigned char *buf;
	  skb_reserve(skb,2);               /* 16 byte align the IP header */
	  buf = skb_put(skb,pkt_len);
	  skb->dev = dev;
	  if (entry < lp->rx_old) {         /* Wrapped buffer */
	    len = (lp->rxRingMask - lp->rx_old + 1) * RX_BUFF_SZ;
	    memcpy_fromio(buf, lp->rx_buff[lp->rx_old], len);
	    memcpy_fromio(buf + len, lp->rx_buff[0], pkt_len-len);
	  } else {                          /* Linear buffer */
	    memcpy_fromio(buf, lp->rx_buff[lp->rx_old], pkt_len);
	  }

	  /* 
	  ** Notify the upper protocol layers that there is another 
	  ** packet to handle
	  */
	  skb->protocol=eth_type_trans(skb,dev);
	  netif_rx(skb);
 
	  /*
	  ** Update stats
	  */
	  lp->stats.rx_packets++;
	  for (i=1; i<DEPCA_PKT_STAT_SZ-1; i++) {
	    if (pkt_len < (i*DEPCA_PKT_BIN_SZ)) {
	      lp->pktStats.bins[i]++;
	      i = DEPCA_PKT_STAT_SZ;
	    }
	  }
	  if (buf[0] & 0x01) {              /* Multicast/Broadcast */
	    if ((*(s16 *)&buf[0] == -1) &&
		(*(s16 *)&buf[2] == -1) &&
		(*(s16 *)&buf[4] == -1)) {
	      lp->pktStats.broadcast++;
	    } else {
	      lp->pktStats.multicast++;
	    }
	  } else if ((*(s16 *)&buf[0] == *(s16 *)&dev->dev_addr[0]) &&
		     (*(s16 *)&buf[2] == *(s16 *)&dev->dev_addr[2]) &&
		     (*(s16 *)&buf[4] == *(s16 *)&dev->dev_addr[4])) {
	    lp->pktStats.unicast++;
	  }
	  
	  lp->pktStats.bins[0]++;           /* Duplicates stats.rx_packets */
	  if (lp->pktStats.bins[0] == 0) {  /* Reset counters */
	    memset((char *)&lp->pktStats, 0, sizeof(lp->pktStats));
	  }
	} else {
	  printk("%s: Memory squeeze, deferring packet.\n", dev->name);
	  lp->stats.rx_dropped++;	/* Really, deferred. */
	  break;
	}
      }
      /* Change buffer ownership for this last frame, back to the adapter */
      for (; lp->rx_old!=entry; lp->rx_old=(++lp->rx_old)&lp->rxRingMask) {
	writel(readl(&lp->rx_ring[lp->rx_old].base) | R_OWN, 
	                                        &lp->rx_ring[lp->rx_old].base);
      }
      writel(readl(&lp->rx_ring[entry].base) | R_OWN, &lp->rx_ring[entry].base);
    }

    /*
    ** Update entry information
    */
    lp->rx_new = (++lp->rx_new) & lp->rxRingMask;
    }

    return 0;
}

/*
** Buffer sent - check for buffer errors.
*/
static int
depca_tx(struct net_device *dev)
{
  struct depca_private *lp = (struct depca_private *)dev->priv;
  int entry;
  s32 status;
  u_long ioaddr = dev->base_addr;

  for (entry = lp->tx_old; entry != lp->tx_new; entry = lp->tx_old) {
    status = readl(&lp->tx_ring[entry].base) >> 16 ;

    if (status < 0) {                          /* Packet not yet sent! */
      break;
    } else if (status & T_ERR) {               /* An error occurred. */
      status = readl(&lp->tx_ring[entry].misc);
      lp->stats.tx_errors++;
      if (status & TMD3_RTRY) lp->stats.tx_aborted_errors++;
      if (status & TMD3_LCAR) lp->stats.tx_carrier_errors++;
      if (status & TMD3_LCOL) lp->stats.tx_window_errors++;
      if (status & TMD3_UFLO) lp->stats.tx_fifo_errors++;
      if (status & (TMD3_BUFF | TMD3_UFLO)) {
	/* Trigger an immediate send demand. */
	outw(CSR0, DEPCA_ADDR);
	outw(INEA | TDMD, DEPCA_DATA);
      }
    } else if (status & (T_MORE | T_ONE)) {
      lp->stats.collisions++;
    } else {
      lp->stats.tx_packets++;
    }

    /* Update all the pointers */
    lp->tx_old = (++lp->tx_old) & lp->txRingMask;
  }

  return 0;
}

static int
depca_close(struct net_device *dev)
{
  struct depca_private *lp = (struct depca_private *)dev->priv;
  s16 nicsr;
  u_long ioaddr = dev->base_addr;

  netif_stop_queue(dev);

  outw(CSR0, DEPCA_ADDR);

  if (depca_debug > 1) {
    printk("%s: Shutting down ethercard, status was %2.2x.\n",
	   dev->name, inw(DEPCA_DATA));
  }

  /* 
  ** We stop the DEPCA here -- it occasionally polls
  ** memory if we don't. 
  */
  outw(STOP, DEPCA_DATA);

  /*
  ** Give back the ROM in case the user wants to go to DOS
  */
  if (lp->adapter != DEPCA) {
    nicsr = inb(DEPCA_NICSR);
    nicsr &= ~SHE;
    outb(nicsr, DEPCA_NICSR);
  }

  /*
  ** Free the associated irq
  */
  free_irq(dev->irq, dev);

  MOD_DEC_USE_COUNT;

  return 0;
}

static void LoadCSRs(struct net_device *dev)
{
  struct depca_private *lp = (struct depca_private *)dev->priv;
  u_long ioaddr = dev->base_addr;

  outw(CSR1, DEPCA_ADDR);                /* initialisation block address LSW */
  outw((u16)lp->device_ram_start, DEPCA_DATA);
  outw(CSR2, DEPCA_ADDR);                /* initialisation block address MSW */
  outw((u16)(lp->device_ram_start >> 16), DEPCA_DATA);
  outw(CSR3, DEPCA_ADDR);                /* ALE control */
  outw(ACON, DEPCA_DATA);

  outw(CSR0, DEPCA_ADDR);                /* Point back to CSR0 */

  return;
}

static int InitRestartDepca(struct net_device *dev)
{
  struct depca_private *lp = (struct depca_private *)dev->priv;
  u_long ioaddr = dev->base_addr;
  int i, status=0;

  /* Copy the shadow init_block to shared memory */
  memcpy_toio(lp->sh_mem, &lp->init_block, sizeof(struct depca_init));

  outw(CSR0, DEPCA_ADDR);                /* point back to CSR0 */
  outw(INIT, DEPCA_DATA);                /* initialize DEPCA */

  /* wait for lance to complete initialisation */
  for (i=0;(i<100) && !(inw(DEPCA_DATA) & IDON); i++); 

  if (i!=100) {
    /* clear IDON by writing a "1", enable interrupts and start lance */
    outw(IDON | INEA | STRT, DEPCA_DATA);
    if (depca_debug > 2) {
      printk("%s: DEPCA open after %d ticks, init block 0x%08lx csr0 %4.4x.\n",
	     dev->name, i, virt_to_phys(lp->sh_mem), inw(DEPCA_DATA));
    }
  } else {
    printk("%s: DEPCA unopen after %d ticks, init block 0x%08lx csr0 %4.4x.\n",
	     dev->name, i, virt_to_phys(lp->sh_mem), inw(DEPCA_DATA));
    status = -1;
  }

  return status;
}

static struct net_device_stats *
depca_get_stats(struct net_device *dev)
{
    struct depca_private *lp = (struct depca_private *)dev->priv;

    /* Null body since there is no framing error counter */

    return &lp->stats;
}

/*
** Set or clear the multicast filter for this adaptor.
*/
static void
set_multicast_list(struct net_device *dev)
{
  struct depca_private *lp = (struct depca_private *)dev->priv;
  u_long ioaddr = dev->base_addr;
  
  if (dev) {
    netif_stop_queue(dev);
    while(lp->tx_old != lp->tx_new);  /* Wait for the ring to empty */

    STOP_DEPCA;                       /* Temporarily stop the depca.  */
    depca_init_ring(dev);             /* Initialize the descriptor rings */

    if (dev->flags & IFF_PROMISC) {   /* Set promiscuous mode */
      lp->init_block.mode |= PROM;
    } else {
      SetMulticastFilter(dev);
      lp->init_block.mode &= ~PROM;   /* Unset promiscuous mode */
    }

    LoadCSRs(dev);                    /* Reload CSR3 */
    InitRestartDepca(dev);            /* Resume normal operation. */
    netif_start_queue(dev);           /* Unlock the TX ring */
  }
}

/*
** Calculate the hash code and update the logical address filter
** from a list of ethernet multicast addresses.
** Big endian crc one liner is mine, all mine, ha ha ha ha!
** LANCE calculates its hash codes big endian.
*/
static void SetMulticastFilter(struct net_device *dev)
{
  struct depca_private *lp = (struct depca_private *)dev->priv;
  struct dev_mc_list *dmi=dev->mc_list;
  char *addrs;
  int i, j, bit, byte;
  u16 hashcode;
  s32 crc, poly = CRC_POLYNOMIAL_BE;

  if (dev->flags & IFF_ALLMULTI) {         /* Set all multicast bits */
    for (i=0; i<(HASH_TABLE_LEN>>3); i++) {