patch-2.3.6 linux/drivers/net/sk_mca.c

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diff -u --recursive --new-file v2.3.5/linux/drivers/net/sk_mca.c linux/drivers/net/sk_mca.c
@@ -0,0 +1,1143 @@
+/* 
+net-3-driver for the SKNET MCA-based cards
+
+This is an extension to the Linux operating system, and is covered by the
+same Gnu Public License that covers that work.
+
+Copyright 1999 by Alfred Arnold (alfred@ccac.rwth-aachen.de, aarnold@elsa.de)
+
+This driver is based both on the 3C523 driver and the SK_G16 driver.
+
+paper sources:
+  'PC Hardware: Aufbau, Funktionsweise, Programmierung' by 
+  Hans-Peter Messmer for the basic Microchannel stuff
+  
+  'Linux Geraetetreiber' by Allesandro Rubini, Kalle Dalheimer
+  for help on Ethernet driver programming
+
+  'Ethernet/IEEE 802.3 Family 1992 World Network Data Book/Handbook' by AMD
+  for documentation on the AM7990 LANCE
+
+  'SKNET Personal Technisches Manual', Version 1.2 by Schneider&Koch
+  for documentation on the Junior board
+
+  'SK-NET MC2+ Technical Manual", Version 1.1 by Schneider&Koch for
+  documentation on the MC2 bord
+  
+  A big thank you to the S&K support for providing me so quickly with
+  documentation!
+
+  Also see http://www.syskonnect.com/
+
+  Missing things:
+
+  -> set debug level via ioctl instead of compile-time switches
+  -> I didn't follow the development of the 2.1.x kernels, so my
+     assumptions about which things changed with which kernel version 
+     are probably nonsense
+
+History:
+  May 16th, 1999
+  	startup
+  May 22st, 1999
+	added private structure, methods
+        begun building data structures in RAM
+  May 23nd, 1999
+	can receive frames, send frames
+  May 24th, 1999
+        modularized intialization of LANCE
+        loadable as module
+	still Tx problem :-(
+  May 26th, 1999
+  	MC2 works
+  	support for multiple devices
+  	display media type for MC2+
+  May 28th, 1999
+	fixed problem in GetLANCE leaving interrupts turned off
+        increase TX queue to 4 packets to improve send performance
+  May 29th, 1999
+	a few corrections in statistics, caught rcvr overruns 
+        reinitialization of LANCE/board in critical situations
+        MCA info implemented
+	implemented LANCE multicast filter
+  Jun 6th, 1999
+	additions for Linux 2.2
+
+ *************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/malloc.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/time.h>
+#include <linux/mca.h>
+#include <asm/processor.h>
+#include <asm/bitops.h>
+#include <asm/io.h>
+
+#ifdef MODULE
+#include <linux/module.h>
+#include <linux/version.h>
+#endif
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+
+#define _SK_MCA_DRIVER_
+#include "sk_mca.h"
+
+/* ------------------------------------------------------------------------
+ * global static data - not more since we can handle multiple boards and
+ * have to pack all state info into the device struct!
+ * ------------------------------------------------------------------------ */
+
+static char *MediaNames[Media_Count]=
+            {"10Base2", "10BaseT", "10Base5", "Unknown"};
+
+static unsigned char poly[] =
+       {1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0,
+        1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0};
+
+/* ------------------------------------------------------------------------
+ * private subfunctions
+ * ------------------------------------------------------------------------ */
+
+/* dump parts of shared memory - only needed during debugging */
+
+#ifdef DEBUG
+static void dumpmem(struct device *dev, u32 start, u32 len)
+{
+  int z;
+
+  for (z = 0; z < len; z++)
+  {
+    if ((z & 15) == 0)
+      printk("%04x:", z);
+    printk(" %02x", readb(dev->mem_start + start + z));
+    if ((z & 15) == 15)
+      printk("\n");
+  }
+}
+
+/* print exact time - ditto */
+
+static void PrTime(void)
+{
+  struct timeval tv;
+
+  do_gettimeofday(&tv);
+  printk("%9d:%06d: ", tv.tv_sec, tv.tv_usec);
+}
+#endif
+
+/* deduce resources out of POS registers */
+
+static void getaddrs(int slot, int junior, int *base, int *irq,
+                     skmca_medium *medium)
+{
+  u_char pos0, pos1, pos2;
+  
+  if (junior)
+  {
+    pos0 = mca_read_stored_pos(slot, 2);
+    *base = ((pos0 & 0x0e) << 13) + 0xc0000;
+    *irq = ((pos0 & 0x10) >> 4) + 10;
+    *medium = Media_Unknown;
+  }
+  else
+  {
+    /* reset POS 104 Bits 0+1 so the shared memory region goes to the
+       configured area between 640K and 1M.  Afterwards, enable the MC2.
+       I really don't know what rode SK to do this... */
+       
+    mca_write_pos(slot, 4, mca_read_stored_pos(slot, 4) & 0xfc);
+    mca_write_pos(slot, 2, mca_read_stored_pos(slot, 2) | 0x01);
+       
+    pos1 = mca_read_stored_pos(slot, 3);
+    pos2 = mca_read_stored_pos(slot, 4);
+    *base = ((pos1 & 0x07) << 14) + 0xc0000;
+    switch (pos2 & 0x0c)
+    {
+      case 0: *irq = 3; break;
+      case 4: *irq = 5; break;
+      case 8: *irq = 10; break;
+      case 12: *irq = 11; break;
+    }
+    *medium = (pos2 >> 6) & 3;
+  }
+}
+
+/* check for both cards:
+   When the MC2 is turned off, it was configured for more than 15MB RAM,
+   is disabled and won't get detected using the standard probe.  We
+   therefore have to scan the slots manually :-( */
+
+static int dofind(int *junior, int firstslot)
+{
+  int slot;
+  unsigned int id;
+
+  for (slot = firstslot; slot < MCA_MAX_SLOT_NR; slot++)
+  {
+    id = mca_read_stored_pos(slot, 0)
+       + (((unsigned int) mca_read_stored_pos(slot, 1)) << 8);
+       
+    *junior = 0;
+    if (id == SKNET_MCA_ID)
+      return slot;
+    *junior = 1;
+    if (id == SKNET_JUNIOR_MCA_ID)
+      return slot;
+  }
+  return MCA_NOTFOUND;
+}
+
+/* reset the whole board */
+
+static void ResetBoard(struct device *dev)
+{
+  skmca_priv *priv = (skmca_priv*) dev->priv;
+
+  writeb(CTRL_RESET_ON, priv->ctrladdr);
+  udelay(10);
+  writeb(CTRL_RESET_OFF, priv->ctrladdr);
+}
+
+/* set LANCE register - must be atomic */
+
+static void SetLANCE(struct device *dev, u16 addr, u16 value)
+{
+  skmca_priv *priv = (skmca_priv*) dev->priv;
+  unsigned long flags;
+
+  /* disable interrupts */
+
+  save_flags(flags);
+  cli();
+
+  /* wait until no transfer is pending */
+  
+  while ((readb(priv->ctrladdr) & STAT_IO_BUSY) == STAT_IO_BUSY);
+
+  /* transfer register address to RAP */
+
+  writeb(CTRL_RESET_OFF | CTRL_RW_WRITE | CTRL_ADR_RAP, priv->ctrladdr);
+  writew(addr, priv->ioregaddr);
+  writeb(IOCMD_GO, priv->cmdaddr);
+  udelay(1);
+  while ((readb(priv->ctrladdr) & STAT_IO_BUSY) == STAT_IO_BUSY);
+
+  /* transfer data to register */
+
+  writeb(CTRL_RESET_OFF | CTRL_RW_WRITE | CTRL_ADR_DATA, priv->ctrladdr);
+  writew(value, priv->ioregaddr);
+  writeb(IOCMD_GO, priv->cmdaddr);
+  udelay(1);
+  while ((readb(priv->ctrladdr) & STAT_IO_BUSY) == STAT_IO_BUSY);
+
+  /* reenable interrupts */
+
+  restore_flags(flags);
+}
+
+/* get LANCE register */
+
+static u16 GetLANCE(struct device *dev, u16 addr)
+{
+  skmca_priv *priv = (skmca_priv*) dev->priv;
+  unsigned long flags;
+  unsigned int res;
+
+  /* disable interrupts */
+
+  save_flags(flags);
+  cli();
+
+  /* wait until no transfer is pending */
+
+  while ((readb(priv->ctrladdr) & STAT_IO_BUSY) == STAT_IO_BUSY);
+
+  /* transfer register address to RAP */
+
+  writeb(CTRL_RESET_OFF | CTRL_RW_WRITE | CTRL_ADR_RAP, priv->ctrladdr);
+  writew(addr, priv->ioregaddr);
+  writeb(IOCMD_GO, priv->cmdaddr);
+  udelay(1);
+  while ((readb(priv->ctrladdr) & STAT_IO_BUSY) == STAT_IO_BUSY);
+
+  /* transfer data from register */
+
+  writeb(CTRL_RESET_OFF | CTRL_RW_READ | CTRL_ADR_DATA, priv->ctrladdr);
+  writeb(IOCMD_GO, priv->cmdaddr);
+  udelay(1);
+  while ((readb(priv->ctrladdr) & STAT_IO_BUSY) == STAT_IO_BUSY);
+  res = readw(priv->ioregaddr);
+
+  /* reenable interrupts */
+
+  restore_flags(flags);
+
+  return res;
+}
+
+/* build up descriptors in shared RAM */
+
+static void InitDscrs(struct device *dev)
+{
+  u32 bufaddr;
+
+  /* Set up Tx descriptors. The board has only 16K RAM so bits 16..23
+     are always 0. */
+
+  bufaddr = RAM_DATABASE;
+  {
+    LANCE_TxDescr descr;
+    int z;
+
+    for (z = 0; z < TXCOUNT; z++)
+    {
+      descr.LowAddr = bufaddr;
+      descr.Flags = 0;
+      descr.Len = 0xf000;
+      descr.Status = 0;
+      memcpy_toio(dev->mem_start + RAM_TXBASE + (z * sizeof(LANCE_TxDescr)),
+                  &descr, sizeof(LANCE_TxDescr));
+      memset_io(dev->mem_start + bufaddr, 0, RAM_BUFSIZE);
+      bufaddr += RAM_BUFSIZE;
+    }
+  }
+
+  /* do the same for the Rx descriptors */
+ 
+  {
+    LANCE_RxDescr descr;
+    int z;
+
+    for (z = 0; z < RXCOUNT; z++)
+    {
+      descr.LowAddr = bufaddr;
+      descr.Flags = RXDSCR_FLAGS_OWN;
+      descr.MaxLen = -RAM_BUFSIZE;
+      descr.Len = 0;
+      memcpy_toio(dev->mem_start + RAM_RXBASE + (z * sizeof(LANCE_RxDescr)),
+                  &descr, sizeof(LANCE_RxDescr));
+      memset_io(dev->mem_start + bufaddr, 0, RAM_BUFSIZE);
+      bufaddr += RAM_BUFSIZE;
+    }
+  }
+}
+
+/* calculate the hash bit position for a given multicast address
+   taken more or less directly from the AMD datasheet... */
+
+static void UpdateCRC(unsigned char *CRC, int bit)
+{
+  int j;
+
+  /* shift CRC one bit */
+
+  memmove(CRC + 1, CRC, 32 * sizeof(unsigned char));
+  CRC[0] = 0;
+
+  /* if bit XOR controlbit = 1, set CRC = CRC XOR polynomial */
+
+  if (bit ^ CRC[32])
+    for (j = 0; j < 32; j++)
+      CRC[j] ^= poly[j];
+}
+
+static unsigned int GetHash(char *address)
+{
+  unsigned char CRC[33];
+  int i, byte, hashcode;
+
+  /* a multicast address has bit 0 in the first byte set */
+
+  if ((address[0] & 1) == 0)
+    return -1;
+
+  /* initialize CRC */
+
+  memset(CRC, 1, sizeof(CRC));
+
+  /* loop through address bits */
+
+  for (byte = 0; byte < 6; byte++)
+    for (i = 0; i < 8; i++)
+      UpdateCRC(CRC, (address[byte] >> i) & 1);
+
+  /* hashcode is the 6 least significant bits of the CRC */
+
+  hashcode = 0;
+  for (i = 0; i < 6; i++)
+    hashcode = (hashcode << 1) + CRC[i];
+  return hashcode;
+}
+
+/* feed ready-built initialization block into LANCE */
+
+static void InitLANCE(struct device *dev)
+{
+  skmca_priv *priv = (skmca_priv*) dev->priv;
+
+  /* build up descriptors. */
+
+  InitDscrs(dev);
+
+  /* next RX descriptor to be read is the first one.  Since the LANCE
+     will start from the beginning after initialization, we have to 
+     reset out pointers too. */
+
+  priv->nextrx = 0;
+
+  /* no TX descriptors active */
+
+  priv->nexttxput = priv->nexttxdone = priv->txbusy = 0;
+
+  /* set up the LANCE bus control register - constant for SKnet boards */
+
+  SetLANCE(dev, LANCE_CSR3, CSR3_BSWAP_OFF | CSR3_ALE_LOW | CSR3_BCON_HOLD);
+
+  /* write address of initialization block into LANCE */
+
+  SetLANCE(dev, LANCE_CSR1, RAM_INITBASE & 0xffff);
+  SetLANCE(dev, LANCE_CSR2, (RAM_INITBASE >> 16) & 0xff);
+
+  /* we don't get ready until the LANCE has read the init block */
+
+  dev->tbusy = 1;
+
+  /* let LANCE read the initialization block.  LANCE is ready
+     when we receive the corresponding interrupt. */
+
+  SetLANCE(dev, LANCE_CSR0, CSR0_INEA | CSR0_INIT);
+}
+
+/* stop the LANCE so we can reinitialize it */
+
+static void StopLANCE(struct device *dev)
+{
+  /* can't take frames any more */
+
+  dev->tbusy = 1;
+
+  /* disable interrupts, stop it */
+
+  SetLANCE(dev, LANCE_CSR0, CSR0_STOP);
+}
+
+/* initialize card and LANCE for proper operation */
+
+static void InitBoard(struct device *dev)
+{
+  LANCE_InitBlock block;
+
+  /* Lay out the shared RAM - first we create the init block for the LANCE.
+     We do not overwrite it later because we need it again when we switch
+     promiscous mode on/off. */
+
+  block.Mode = 0;
+  if (dev->flags & IFF_PROMISC)
+    block.Mode |= LANCE_INIT_PROM;
+  memcpy(block.PAdr, dev->dev_addr, 6);
+  memset(block.LAdrF, 0, sizeof(block.LAdrF));
+  block.RdrP = (RAM_RXBASE & 0xffffff) | (LRXCOUNT << 29);
+  block.TdrP = (RAM_TXBASE & 0xffffff) | (LTXCOUNT << 29);
+
+  memcpy_toio(dev->mem_start + RAM_INITBASE, &block, sizeof(block));
+
+  /* initialize LANCE. Implicitly sets up other structures in RAM. */
+
+  InitLANCE(dev);
+}
+
+/* deinitialize card and LANCE */
+
+static void DeinitBoard(struct device *dev)
+{
+  /* stop LANCE */
+
+  StopLANCE(dev);
+
+  /* reset board */
+
+  ResetBoard(dev);
+}
+
+/* ------------------------------------------------------------------------
+ * interrupt handler(s)
+ * ------------------------------------------------------------------------ */
+
+/* LANCE has read initializazion block -> start it */
+
+static u16 irqstart_handler(struct device *dev, u16 oldcsr0)
+{
+  /* now we're ready to transmit */
+
+  dev->tbusy = 0;
+
+  /* reset IDON bit, start LANCE */
+
+  SetLANCE(dev, LANCE_CSR0, oldcsr0 | CSR0_IDON | CSR0_STRT);
+  return GetLANCE(dev, LANCE_CSR0);
+}
+
+/* receive interrupt */
+
+static u16 irqrx_handler(struct device *dev, u16 oldcsr0)
+{
+  skmca_priv *priv = (skmca_priv*) dev->priv;
+  LANCE_RxDescr descr;
+  unsigned int descraddr;
+
+  /* did we loose blocks due to a FIFO overrun ? */
+
+  if (oldcsr0 & CSR0_MISS)
+    priv->stat.rx_fifo_errors++;
+
+  /* run through queue until we reach a descriptor we do not own */
+
+  descraddr = RAM_RXBASE + (priv->nextrx * sizeof(LANCE_RxDescr));
+  while (1)
+  {
+    /* read descriptor */
+    memcpy_fromio(&descr, dev->mem_start + descraddr, sizeof(LANCE_RxDescr));
+ 
+    /* if we reach a descriptor we do not own, we're done */
+    if ((descr.Flags & RXDSCR_FLAGS_OWN) != 0)
+      break;
+
+#ifdef DEBUG
+    PrTime(); printk("Receive packet on descr %d len %d\n", priv->nextrx, descr.Len);
+#endif
+
+    /* erroneous packet ? */
+    if ((descr.Flags & RXDSCR_FLAGS_ERR) != 0)
+    {
+      priv->stat.rx_errors++;
+      if ((descr.Flags & RXDSCR_FLAGS_CRC) != 0)
+        priv->stat.rx_crc_errors++;
+      else if ((descr.Flags & RXDSCR_FLAGS_CRC) != 0)
+        priv->stat.rx_frame_errors++;
+      else if ((descr.Flags & RXDSCR_FLAGS_OFLO) != 0)
+        priv->stat.rx_fifo_errors++;
+    }
+
+    /* good packet ? */
+    else
+    {
+      struct sk_buff *skb;
+
+      skb = dev_alloc_skb(descr.Len + 2);
+      if (skb == NULL)
+        priv->stat.rx_dropped++;
+      else
+      {
+        memcpy_fromio(skb_put(skb, descr.Len),
+                      dev->mem_start + descr.LowAddr, descr.Len);
+        skb->dev = dev;
+        skb->protocol = eth_type_trans(skb, dev);
+        skb->ip_summed = CHECKSUM_NONE;
+        priv->stat.rx_packets++;
+#if LINUX_VERSION_CODE >= 0x020119       /* byte counters for >= 2.1.25 */
+        priv->stat.rx_bytes += descr.Len;
+#endif
+        netif_rx(skb);
+      }
+    }
+
+    /* give descriptor back to LANCE */
+    descr.Len = 0;
+    descr.Flags |= RXDSCR_FLAGS_OWN;
+
+    /* update descriptor in shared RAM */
+    memcpy_toio(dev->mem_start + descraddr, &descr, sizeof(LANCE_RxDescr));
+
+    /* go to next descriptor */
+    priv->nextrx++; descraddr += sizeof(LANCE_RxDescr);
+    if (priv->nextrx >= RXCOUNT)
+    {
+      priv->nextrx = 0;
+      descraddr = RAM_RXBASE;
+    }
+  }
+
+  /* reset RINT bit */
+
+  SetLANCE(dev, LANCE_CSR0, oldcsr0 | CSR0_RINT);
+  return GetLANCE(dev, LANCE_CSR0);
+}
+
+/* transmit interrupt */
+
+static u16 irqtx_handler(struct device *dev, u16 oldcsr0)
+{
+  skmca_priv *priv = (skmca_priv*) dev->priv;
+  LANCE_TxDescr descr;
+  unsigned int descraddr;
+
+  /* check descriptors at most until no busy one is left */
+
+  descraddr = RAM_TXBASE + (priv->nexttxdone * sizeof(LANCE_TxDescr));
+  while (priv->txbusy > 0)
+  {
+    /* read descriptor */
+    memcpy_fromio(&descr, dev->mem_start + descraddr, sizeof(LANCE_TxDescr));
+
+    /* if the LANCE still owns this one, we've worked out all sent packets */
+    if ((descr.Flags & TXDSCR_FLAGS_OWN) != 0)
+      break;
+
+#ifdef DEBUG
+    PrTime(); printk("Send packet done on descr %d\n", priv->nexttxdone);
+#endif
+
+    /* update statistics */
+    if ((descr.Flags & TXDSCR_FLAGS_ERR) == 0)
+    {
+      priv->stat.tx_packets++;
+#if LINUX_VERSION_CODE >= 0x020119       /* byte counters for >= 2.1.25 */
+      priv->stat.tx_bytes++;
+#endif
+    }
+    else
+    {
+      priv->stat.tx_errors++;
+      if ((descr.Status & TXDSCR_STATUS_UFLO) != 0)
+      {
+        priv->stat.tx_fifo_errors++;
+        InitLANCE(dev);
+      }
+      else if ((descr.Status & TXDSCR_STATUS_LCOL) != 0)
+        priv->stat.tx_window_errors++;
+      else if ((descr.Status & TXDSCR_STATUS_LCAR) != 0)
+        priv->stat.tx_carrier_errors++;
+      else if ((descr.Status & TXDSCR_STATUS_RTRY) != 0)
+        priv->stat.tx_aborted_errors++;
+    }
+
+    /* go to next descriptor */
+    priv->nexttxdone++;
+    descraddr += sizeof(LANCE_TxDescr);
+    if (priv->nexttxdone >= TXCOUNT)
+    {
+      priv->nexttxdone = 0;
+      descraddr = RAM_TXBASE;
+    }
+    priv->txbusy--;
+  }
+
+  /* reset TX interrupt bit */
+
+  SetLANCE(dev, LANCE_CSR0, oldcsr0 | CSR0_TINT);
+  oldcsr0 = GetLANCE(dev, LANCE_CSR0);
+
+  /* at least one descriptor is freed.  Therefore we can accept
+     a new one */
+
+  dev->tbusy = 0;
+
+  /* inform upper layers we're in business again */
+
+  mark_bh(NET_BH);
+
+  return oldcsr0;
+}
+
+/* general interrupt entry */
+
+static void irq_handler(int irq, void *device, struct pt_regs *regs)
+{
+  struct device *dev = (struct device*) device;
+  u16 csr0val;
+
+  /* read CSR0 to get interrupt cause */
+
+  csr0val = GetLANCE(dev, LANCE_CSR0);
+
+  /* in case we're not meant... */
+
+  if ((csr0val & CSR0_INTR) == 0)
+    return;
+
+  dev->interrupt = 1;
+
+  /* loop through the interrupt bits until everything is clear */
+
+  do
+  {
+    if ((csr0val & CSR0_IDON) != 0)
+      csr0val = irqstart_handler(dev, csr0val);
+    if ((csr0val & CSR0_RINT) != 0)
+      csr0val = irqrx_handler(dev, csr0val);
+    if ((csr0val & CSR0_TINT) != 0)
+      csr0val = irqtx_handler(dev, csr0val);
+  }
+  while ((csr0val & CSR0_INTR) != 0);
+
+  dev->interrupt = 0;
+}
+
+/* ------------------------------------------------------------------------
+ * driver methods
+ * ------------------------------------------------------------------------ */
+
+/* MCA info */
+
+static int skmca_getinfo(char *buf, int slot, void *d)
+{
+  int len = 0, i;
+  struct device *dev = (struct device*) d;
+  skmca_priv *priv;
+  
+  /* can't say anything about an uninitialized device... */
+
+  if (dev == NULL)
+    return len;
+  if (dev->priv == NULL)
+    return len;
+  priv = (skmca_priv*) dev->priv;
+
+  /* print info */
+
+  len += sprintf(buf + len, "IRQ: %d\n", priv->realirq);
+  len += sprintf(buf + len, "Memory: %#lx-%#lx\n", dev->mem_start,
+                 dev->mem_end - 1);
+  len += sprintf(buf + len, "Transceiver: %s\n", MediaNames[priv->medium]);
+  len += sprintf(buf + len, "Device: %s\n", dev->name);
+  len += sprintf(buf + len, "MAC address:");
+  for (i = 0; i < 6; i ++ )
+    len += sprintf( buf+len, " %02x", dev->dev_addr[i] );
+  buf[len++] = '\n';
+  buf[len] = 0;
+
+  return len;
+}
+
+/* open driver.  Means also initialization and start of LANCE */
+
+static int skmca_open(struct device *dev)
+{
+  int result;
+  skmca_priv *priv = (skmca_priv*) dev->priv;
+
+  /* register resources - only necessary for IRQ */
+  result = request_irq(priv->realirq, irq_handler, SA_SHIRQ | SA_SAMPLE_RANDOM,
+                       "sk_mca", dev);
+  if (result != 0)
+  {
+    printk("%s: failed to register irq %d\n", dev->name, dev->irq);
+    return result;
+  }
+  dev->irq = priv->realirq;
+
+  /* set up the card and LANCE */
+  InitBoard(dev);
+
+#ifdef MODULE
+  MOD_INC_USE_COUNT;
+#endif
+
+  return 0;
+}
+
+/* close driver.  Shut down board and free allocated resources */
+
+static int skmca_close(struct device *dev)
+{
+  /* turn off board */
+  DeinitBoard(dev);
+
+  /* release resources */
+  if (dev->irq != 0)
+    free_irq(dev->irq, dev);
+  dev->irq = 0;
+
+#ifdef MODULE
+  MOD_DEC_USE_COUNT;
+#endif
+
+  return 0;
+}
+
+/* transmit a block. */
+
+static int skmca_tx(struct sk_buff *skb, struct device *dev)
+{
+  skmca_priv *priv = (skmca_priv*) dev->priv;
+  LANCE_TxDescr descr;
+  unsigned int address;
+  int tmplen, retval = 0;
+  unsigned long flags;
+
+  /* if we get called with a NULL descriptor, the Ethernet layer thinks 
+     our card is stuck an we should reset it.  We'll do this completely: */
+
+  if (skb == NULL)
+  {
+    DeinitBoard(dev);
+    InitBoard(dev);
+    return 0; /* don't try to free the block here ;-) */
+  }
+
+  /* is there space in the Tx queue ? If no, the upper layer gave us a
+     packet in spite of us not being ready and is really in trouble.
+     We'll do the dropping for him: */
+  if (priv->txbusy >= TXCOUNT)
+  {
+    priv->stat.tx_dropped++;
+    retval = -EIO;
+    goto tx_done;
+  }
+
+  /* get TX descriptor */
+  address = RAM_TXBASE + (priv->nexttxput * sizeof(LANCE_TxDescr));
+  memcpy_fromio(&descr, dev->mem_start + address, sizeof(LANCE_TxDescr));
+
+  /* enter packet length as 2s complement - assure minimum length */
+  tmplen = skb->len;
+  if (tmplen < 60)
+    tmplen = 60;
+  descr.Len = 65536 - tmplen;
+
+  /* copy filler into RAM - in case we're filling up... 
+     we're filling a bit more than necessary, but that doesn't harm
+     since the buffer is far larger... */
+  if (tmplen > skb->len)
+  {
+    char *fill = "NetBSD is a nice OS too! ";
+    unsigned int destoffs = 0, l = strlen(fill);
+
+    while (destoffs < tmplen)
+    {
+      memcpy_toio(dev->mem_start + descr.LowAddr + destoffs, fill, l);
+      destoffs += l;
+    }
+  }
+
+  /* do the real data copying */
+  memcpy_toio(dev->mem_start + descr.LowAddr, skb->data, skb->len);
+
+  /* hand descriptor over to LANCE - this is the first and last chunk */
+  descr.Flags = TXDSCR_FLAGS_OWN | TXDSCR_FLAGS_STP | TXDSCR_FLAGS_ENP;
+
+#ifdef DEBUG
+  PrTime(); printk("Send packet on descr %d len %d\n", priv->nexttxput, skb->len);
+#endif
+
+  /* one more descriptor busy */
+  save_flags(flags);
+  cli();
+  priv->nexttxput++;
+  if (priv->nexttxput >= TXCOUNT)
+    priv->nexttxput = 0;
+  priv->txbusy++;
+  dev->tbusy = (priv->txbusy >= TXCOUNT);
+
+  /* write descriptor back to RAM */
+  memcpy_toio(dev->mem_start + address, &descr, sizeof(LANCE_TxDescr));
+
+  /* if no descriptors were active, give the LANCE a hint to read it
+     immediately */
+
+  if (priv->txbusy == 0)
+    SetLANCE(dev, LANCE_CSR0, CSR0_INEA | CSR0_TDMD);
+
+  restore_flags(flags);
+
+tx_done:
+
+  /* When did that change exactly ? */
+
+#if LINUX_VERSION_CODE >= 0x020200
+  dev_kfree_skb(skb);
+#else
+  dev_kfree_skb(skb, FREE_WRITE);
+#endif
+  return retval;
+}
+
+/* return pointer to Ethernet statistics */
+
+static struct enet_statistics *skmca_stats(struct device *dev)
+{
+  skmca_priv *priv = (skmca_priv*) dev->priv;
+
+  return &(priv->stat);
+}
+
+/* we don't support runtime reconfiguration, since am MCA card can
+   be unambigously identified by its POS registers. */
+
+static int skmca_config(struct device *dev, struct ifmap *map)
+{
+  return 0;
+}
+
+/* switch receiver mode.  We use the LANCE's multicast filter to prefilter
+   multicast addresses. */
+
+static void skmca_set_multicast_list(struct device *dev)
+{
+  LANCE_InitBlock block;
+
+  /* first stop the LANCE... */
+  StopLANCE(dev);
+
+  /* ...then modify the initialization block... */
+  memcpy_fromio(&block, dev->mem_start + RAM_INITBASE, sizeof(block));
+  if (dev->flags & IFF_PROMISC)
+    block.Mode |= LANCE_INIT_PROM;
+  else
+    block.Mode &= ~LANCE_INIT_PROM;
+
+  if (dev->flags & IFF_ALLMULTI)   /* get all multicasts */
+  {
+    memset(block.LAdrF, 8, 0xff);
+  }
+  else                             /* get selected/no multicasts */
+  {
+    struct dev_mc_list *mptr;
+    int code;
+
+    memset(block.LAdrF, 8, 0x00);
+    for (mptr = dev->mc_list; mptr != NULL; mptr = mptr->next)
+    {
+      code = GetHash(mptr->dmi_addr);
+      block.LAdrF[(code >> 3) & 7] |= 1 << (code & 7);
+    }
+  }
+
+  memcpy_toio(dev->mem_start + RAM_INITBASE, &block, sizeof(block));
+
+  /* ...then reinit LANCE with the correct flags */
+  InitLANCE(dev);
+}
+
+/* ------------------------------------------------------------------------
+ * hardware check
+ * ------------------------------------------------------------------------ */
+
+#ifdef MODULE
+static int startslot; /* counts through slots when probing multiple devices */
+#else
+#define startslot 0   /* otherwise a dummy, since there is only eth0 in-kern*/
+#endif
+
+int skmca_probe(struct device *dev)
+{
+  int force_detect = 0;
+  int junior, slot, i;
+  int base = 0, irq = 0;
+  skmca_priv *priv;
+  skmca_medium medium;
+
+  /* can't work without an MCA bus ;-) */
+  
+  if (MCA_bus == 0)
+    return ENODEV;
+    
+  /* start address of 1 --> forced detection */
+  
+  if (dev->mem_start == 1)
+    force_detect = 1;
+
+  /* search through slots */
+  
+  if (dev != NULL)
+  {
+    base = dev->mem_start;
+    irq = dev->irq;
+  }
+  slot = dofind(&junior, startslot);
+
+  while (slot != -1)
+  {
+    /* deduce card addresses */
+
+    getaddrs(slot, junior, &base, &irq, &medium);
+
+#if 0
+    /* this should work, but it doesn't with 2.2.9 :-( 
+       somehow 'mca_is_adapter_used()' is missing in kernel syms... */
+#if LINUX_VERSION_CODE >= 0x020200
+    /* slot already in use ? */
+
+    if (mca_is_adapter_used(slot))
+    {
+      slot = dofind(&junior, slot + 1);
+      continue;
+    }
+#endif
+#endif
+
+    /* were we looking for something different ? */
+    
+    if ((dev->irq != 0) || (dev->mem_start != 0))
+    {
+      if ((dev->irq != 0) && (dev->irq != irq))
+      {
+        slot = dofind(&junior, slot + 1);
+        continue;
+      }
+      if ((dev->mem_start != 0) && (dev->mem_start != base))
+      {
+        slot = dofind(&junior, slot + 1);
+        continue;
+      }
+    }
+  
+    /* found something that matches */
+    
+    break;
+  }
+
+  /* nothing found ? */
+  
+  if (slot == -1)
+    return ((base != 0) || (irq != 0)) ? ENXIO : ENODEV;
+    
+  /* make procfs entries */
+    
+  if (junior)
+    mca_set_adapter_name(slot, "SKNET junior MC2 Ethernet Adapter");
+  else
+    mca_set_adapter_name(slot, "SKNET MC2+ Ethernet Adapter");
+  mca_set_adapter_procfn(slot, (MCA_ProcFn) skmca_getinfo, dev);
+
+#if LINUX_VERSION_CODE >= 0x020200
+  mca_mark_as_used(slot);
+#endif
+  
+  /* announce success */
+  printk("%s: SKNet %s adapter found in slot %d\n", dev->name, 
+         junior ? "Junior MC2" : "MC2+", slot + 1);
+
+  /* allocate structure */
+  priv = dev->priv = (skmca_priv*) kmalloc(sizeof(skmca_priv), GFP_KERNEL);
+  priv->slot = slot;
+  priv->macbase = base + 0x3fc0;
+  priv->ioregaddr = base + 0x3ff0;
+  priv->ctrladdr = base + 0x3ff2;
+  priv->cmdaddr = base + 0x3ff3;
+  priv->realirq = irq;
+  priv->medium = medium;
+  memset(&(priv->stat), 0, sizeof(struct enet_statistics));
+  
+  /* set base + irq for this device (irq not allocated so far) */
+  dev->irq = 0;
+  dev->mem_start = base;
+  dev->mem_end = base + 0x4000;
+ 
+  /* set methods */
+  dev->open = skmca_open;
+  dev->stop = skmca_close;
+  dev->set_config = skmca_config;
+  dev->hard_start_xmit = skmca_tx;
+  dev->do_ioctl = NULL;
+  dev->get_stats = skmca_stats;
+  dev->set_multicast_list = skmca_set_multicast_list;
+  dev->flags |= IFF_MULTICAST;
+
+  /* generic setup */
+  ether_setup(dev);
+  dev->interrupt = 0;
+  dev->tbusy = 0;
+  dev->start = 0;
+ 
+  /* copy out MAC address */
+  for (i = 0; i < 6; i++)
+    dev->dev_addr[i] = readb(priv->macbase + (i << 1));
+
+  /* print config */
+  printk("%s: IRQ %d, memory %#lx-%#lx, "
+         "MAC address %02x:%02x:%02x:%02x:%02x:%02x.\n",
+         dev->name, priv->realirq,  dev->mem_start, dev->mem_end - 1,
+         dev->dev_addr[0], dev->dev_addr[1], dev->dev_addr[2],
+         dev->dev_addr[3], dev->dev_addr[4], dev->dev_addr[5]);
+  printk("%s: %s medium\n", dev->name, MediaNames[priv->medium]);
+
+  /* reset board */
+
+  ResetBoard(dev);
+
+#ifdef MODULE
+  startslot = slot + 1;
+#endif
+
+  return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * modularization support
+ * ------------------------------------------------------------------------ */
+
+#ifdef MODULE
+
+#define DEVMAX 5
+
+static char NameSpace[8 * DEVMAX];
+static struct device moddevs[DEVMAX] =
+       {{NameSpace +  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, skmca_probe},
+        {NameSpace +  8, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, skmca_probe},
+        {NameSpace + 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, skmca_probe},
+        {NameSpace + 24, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, skmca_probe},
+        {NameSpace + 32, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, skmca_probe}};
+
+int irq=0;
+int io=0;
+
+int init_module(void)
+{
+  int z, res;
+
+  startslot = 0;
+  for (z = 0; z < DEVMAX; z++)
+  {
+    strcpy(moddevs[z].name, "     ");
+    res = register_netdev(moddevs + z);
+    if (res != 0)
+      return (z > 0) ? 0 : -EIO;
+  }
+
+  return 0;
+}
+
+void cleanup_module(void)
+{
+  struct device *dev;
+  skmca_priv *priv;
+  int z;
+
+  if (MOD_IN_USE)
+  {
+    printk("cannot unload, module in use\n");
+    return;
+  }
+
+  for (z = 0; z < DEVMAX; z++)
+  {
+    dev = moddevs + z;
+    if (dev->priv != NULL)
+    {
+      priv = (skmca_priv*) dev->priv;
+      DeinitBoard(dev);
+      if (dev->irq != 0)
+        free_irq(dev->irq, dev);
+      dev->irq = 0;
+      unregister_netdev(dev);
+#if LINUX_VERSION_CODE >= 0x020200
+      mca_mark_as_unused(priv->slot);
+#endif
+      mca_set_adapter_procfn(priv->slot, NULL, NULL);
+      kfree_s(dev->priv, sizeof(skmca_priv));
+      dev->priv = NULL;
+    }
+  }
+}
+#endif /* MODULE */
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)