Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1217 insertions, 0 deletions

diff --git a/drivers/net/sk_mca.c b/drivers/net/sk_mca.c
new file mode 100644
index 000000000000..4c56b8d8221b
--- /dev/null
+++ b/drivers/net/sk_mca.c
@@ -0,0 +1,1217 @@
+/* 
+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 General Public License that covers that work.
+
+Copyright 1999 by Alfred Arnold (alfred@ccac.rwth-aachen.de,
+                                 alfred.arnold@lancom.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 initialization 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
+  Dec 25th, 1999
+  	unfortunately there seem to be newer MC2+ boards that react
+  	on IRQ 3/5/9/10 instead of 3/5/10/11, so we have to autoprobe
+  	in questionable cases...
+  Dec 28th, 1999
+	integrated patches from David Weinehall & Bill Wendling for 2.3
+	kernels (isa_...functions).  Things are defined in a way that
+        it still works with 2.0.x 8-)
+  Dec 30th, 1999
+	added handling of the remaining interrupt conditions.  That
+        should cure the spurious hangs.
+  Jan 30th, 2000
+	newer kernels automatically probe more than one board, so the
+	'startslot' as a variable is also needed here
+  June 1st, 2000
+	added changes for recent 2.3 kernels
+
+ *************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/time.h>
+#include <linux/mca-legacy.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/bitops.h>
+
+#include <asm/processor.h>
+#include <asm/io.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 net_device *dev, u32 start, u32 len)
+{
+	skmca_priv *priv = netdev_priv(dev);
+	int z;
+
+	for (z = 0; z < len; z++) {
+		if ((z & 15) == 0)
+			printk("%04x:", z);
+		printk(" %02x", readb(priv->base + 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 __init 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 __init 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 net_device *dev)
+{
+	skmca_priv *priv = netdev_priv(dev);
+
+	writeb(CTRL_RESET_ON, priv->ctrladdr);
+	udelay(10);
+	writeb(CTRL_RESET_OFF, priv->ctrladdr);
+}
+
+/* wait for LANCE interface to become not busy */
+
+static int WaitLANCE(struct net_device *dev)
+{
+	skmca_priv *priv = netdev_priv(dev);
+	int t = 0;
+
+	while ((readb(priv->ctrladdr) & STAT_IO_BUSY) ==
+	       STAT_IO_BUSY) {
+		udelay(1);
+		if (++t > 1000) {
+			printk("%s: LANCE access timeout", dev->name);
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+/* set LANCE register - must be atomic */
+
+static void SetLANCE(struct net_device *dev, u16 addr, u16 value)
+{
+	skmca_priv *priv = netdev_priv(dev);
+	unsigned long flags;
+
+	/* disable interrupts */
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	/* wait until no transfer is pending */
+
+	WaitLANCE(dev);
+
+	/* 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);
+	WaitLANCE(dev);
+
+	/* 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);
+	WaitLANCE(dev);
+
+	/* reenable interrupts */
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+/* get LANCE register */
+
+static u16 GetLANCE(struct net_device *dev, u16 addr)
+{
+	skmca_priv *priv = netdev_priv(dev);
+	unsigned long flags;
+	unsigned int res;
+
+	/* disable interrupts */
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	/* wait until no transfer is pending */
+
+	WaitLANCE(dev);
+
+	/* 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);
+	WaitLANCE(dev);
+
+	/* transfer data from register */
+
+	writeb(CTRL_RESET_OFF | CTRL_RW_READ | CTRL_ADR_DATA, priv->ctrladdr);
+	writeb(IOCMD_GO, priv->cmdaddr);
+	udelay(1);
+	WaitLANCE(dev);
+	res = readw(priv->ioregaddr);
+
+	/* reenable interrupts */
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return res;
+}
+
+/* build up descriptors in shared RAM */
+
+static void InitDscrs(struct net_device *dev)
+{
+	skmca_priv *priv = netdev_priv(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(priv->base + RAM_TXBASE +
+				   (z * sizeof(LANCE_TxDescr)), &descr,
+				   sizeof(LANCE_TxDescr));
+			memset_io(priv->base + 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(priv->base + RAM_RXBASE +
+				   (z * sizeof(LANCE_RxDescr)), &descr,
+				   sizeof(LANCE_RxDescr));
+			memset_io(priv->base + 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 net_device *dev)
+{
+	skmca_priv *priv = netdev_priv(dev);
+
+	/* 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 */
+
+	netif_stop_queue(dev);
+
+	/* 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 net_device *dev)
+{
+	/* can't take frames any more */
+
+	netif_stop_queue(dev);
+
+	/* disable interrupts, stop it */
+
+	SetLANCE(dev, LANCE_CSR0, CSR0_STOP);
+}
+
+/* initialize card and LANCE for proper operation */
+
+static void InitBoard(struct net_device *dev)
+{
+	skmca_priv *priv = netdev_priv(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(priv->base + RAM_INITBASE, &block, sizeof(block));
+
+	/* initialize LANCE. Implicitly sets up other structures in RAM. */
+
+	InitLANCE(dev);
+}
+
+/* deinitialize card and LANCE */
+
+static void DeinitBoard(struct net_device *dev)
+{
+	/* stop LANCE */
+
+	StopLANCE(dev);
+
+	/* reset board */
+
+	ResetBoard(dev);
+}
+
+/* probe for device's irq */
+
+static int __init ProbeIRQ(struct net_device *dev)
+{
+	unsigned long imaskval, njiffies, irq;
+	u16 csr0val;
+
+	/* enable all interrupts */
+
+	imaskval = probe_irq_on();
+
+	/* initialize the board. Wait for interrupt 'Initialization done'. */
+
+	ResetBoard(dev);
+	InitBoard(dev);
+
+	njiffies = jiffies + HZ;
+	do {
+		csr0val = GetLANCE(dev, LANCE_CSR0);
+	}
+	while (((csr0val & CSR0_IDON) == 0) && (jiffies != njiffies));
+
+	/* turn of interrupts again */
+
+	irq = probe_irq_off(imaskval);
+
+	/* if we found something, ack the interrupt */
+
+	if (irq)
+		SetLANCE(dev, LANCE_CSR0, csr0val | CSR0_IDON);
+
+	/* back to idle state */
+
+	DeinitBoard(dev);
+
+	return irq;
+}
+
+/* ------------------------------------------------------------------------
+ * interrupt handler(s)
+ * ------------------------------------------------------------------------ */
+
+/* LANCE has read initialization block -> start it */
+
+static u16 irqstart_handler(struct net_device *dev, u16 oldcsr0)
+{
+	/* now we're ready to transmit */
+
+	netif_wake_queue(dev);
+
+	/* reset IDON bit, start LANCE */
+
+	SetLANCE(dev, LANCE_CSR0, oldcsr0 | CSR0_IDON | CSR0_STRT);
+	return GetLANCE(dev, LANCE_CSR0);
+}
+
+/* did we lose blocks due to a FIFO overrun ? */
+
+static u16 irqmiss_handler(struct net_device *dev, u16 oldcsr0)
+{
+	skmca_priv *priv = netdev_priv(dev);
+
+	/* update statistics */
+
+	priv->stat.rx_fifo_errors++;
+
+	/* reset MISS bit */
+
+	SetLANCE(dev, LANCE_CSR0, oldcsr0 | CSR0_MISS);
+	return GetLANCE(dev, LANCE_CSR0);
+}
+
+/* receive interrupt */
+
+static u16 irqrx_handler(struct net_device *dev, u16 oldcsr0)
+{
+	skmca_priv *priv = netdev_priv(dev);
+	LANCE_RxDescr descr;
+	unsigned int descraddr;
+
+	/* 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, priv->base + 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),
+					     priv->base +
+					     descr.LowAddr, descr.Len);
+				skb->dev = dev;
+				skb->protocol = eth_type_trans(skb, dev);
+				skb->ip_summed = CHECKSUM_NONE;
+				priv->stat.rx_packets++;
+				priv->stat.rx_bytes += descr.Len;
+				netif_rx(skb);
+				dev->last_rx = jiffies;
+			}
+		}
+
+		/* give descriptor back to LANCE */
+		descr.Len = 0;
+		descr.Flags |= RXDSCR_FLAGS_OWN;
+
+		/* update descriptor in shared RAM */
+		memcpy_toio(priv->base + 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 net_device *dev, u16 oldcsr0)
+{
+	skmca_priv *priv = netdev_priv(dev);
+	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, priv->base + 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++;
+			priv->stat.tx_bytes++;
+		} 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 */
+	/* inform upper layers we're in business again */
+
+	netif_wake_queue(dev);
+
+	return oldcsr0;
+}
+
+/* general interrupt entry */
+
+static irqreturn_t irq_handler(int irq, void *device, struct pt_regs *regs)
+{
+	struct net_device *dev = (struct net_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 IRQ_NONE;
+
+#if 0
+	set_bit(LINK_STATE_RXSEM, &dev->state);
+#endif
+
+	/* 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_MISS) != 0)
+			csr0val = irqmiss_handler(dev, csr0val);
+		if ((csr0val & CSR0_TINT) != 0)
+			csr0val = irqtx_handler(dev, csr0val);
+		if ((csr0val & CSR0_MERR) != 0) {
+			SetLANCE(dev, LANCE_CSR0, csr0val | CSR0_MERR);
+			csr0val = GetLANCE(dev, LANCE_CSR0);
+		}
+		if ((csr0val & CSR0_BABL) != 0) {
+			SetLANCE(dev, LANCE_CSR0, csr0val | CSR0_BABL);
+			csr0val = GetLANCE(dev, LANCE_CSR0);
+		}
+	}
+	while ((csr0val & CSR0_INTR) != 0);
+
+#if 0
+	clear_bit(LINK_STATE_RXSEM, &dev->state);
+#endif
+	return IRQ_HANDLED;
+}
+
+/* ------------------------------------------------------------------------
+ * driver methods
+ * ------------------------------------------------------------------------ */
+
+/* MCA info */
+
+static int skmca_getinfo(char *buf, int slot, void *d)
+{
+	int len = 0, i;
+	struct net_device *dev = (struct net_device *) d;
+	skmca_priv *priv;
+
+	/* can't say anything about an uninitialized device... */
+
+	if (dev == NULL)
+		return len;
+	priv = netdev_priv(dev);
+
+	/* 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 net_device *dev)
+{
+	int result;
+	skmca_priv *priv = netdev_priv(dev);
+
+	/* 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);
+
+	/* set up flags */
+
+	netif_start_queue(dev);
+
+	return 0;
+}
+
+/* close driver.  Shut down board and free allocated resources */
+
+static int skmca_close(struct net_device *dev)
+{
+	/* turn off board */
+	DeinitBoard(dev);
+
+	/* release resources */
+	if (dev->irq != 0)
+		free_irq(dev->irq, dev);
+	dev->irq = 0;
+
+	return 0;
+}
+
+/* transmit a block. */
+
+static int skmca_tx(struct sk_buff *skb, struct net_device *dev)
+{
+	skmca_priv *priv = netdev_priv(dev);
+	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, priv->base + 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(priv->base + descr.LowAddr +
+				   destoffs, fill, l);
+			destoffs += l;
+		}
+	}
+
+	/* do the real data copying */
+	memcpy_toio(priv->base + 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 */
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	priv->nexttxput++;
+	if (priv->nexttxput >= TXCOUNT)
+		priv->nexttxput = 0;
+	priv->txbusy++;
+
+	/* are we saturated ? */
+
+	if (priv->txbusy >= TXCOUNT)
+		netif_stop_queue(dev);
+
+	/* write descriptor back to RAM */
+	memcpy_toio(priv->base + 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);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+      tx_done:
+
+	dev_kfree_skb(skb);
+
+	return retval;
+}
+
+/* return pointer to Ethernet statistics */
+
+static struct net_device_stats *skmca_stats(struct net_device *dev)
+{
+	skmca_priv *priv = netdev_priv(dev);
+
+	return &(priv->stat);
+}
+
+/* switch receiver mode.  We use the LANCE's multicast filter to prefilter
+   multicast addresses. */
+
+static void skmca_set_multicast_list(struct net_device *dev)
+{
+	skmca_priv *priv = netdev_priv(dev);
+	LANCE_InitBlock block;
+
+	/* first stop the LANCE... */
+	StopLANCE(dev);
+
+	/* ...then modify the initialization block... */
+	memcpy_fromio(&block, priv->base + 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, 0xff, sizeof(block.LAdrF));
+	} else {		/* get selected/no multicasts */
+
+		struct dev_mc_list *mptr;
+		int code;
+
+		memset(block.LAdrF, 0, sizeof(block.LAdrF));
+		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(priv->base + RAM_INITBASE, &block, sizeof(block));
+
+	/* ...then reinit LANCE with the correct flags */
+	InitLANCE(dev);
+}
+
+/* ------------------------------------------------------------------------
+ * hardware check
+ * ------------------------------------------------------------------------ */
+
+static int startslot;		/* counts through slots when probing multiple devices */
+
+static void cleanup_card(struct net_device *dev)
+{
+	skmca_priv *priv = netdev_priv(dev);
+	DeinitBoard(dev);
+	if (dev->irq != 0)
+		free_irq(dev->irq, dev);
+	iounmap(priv->base);
+	mca_mark_as_unused(priv->slot);
+	mca_set_adapter_procfn(priv->slot, NULL, NULL);
+}
+
+struct net_device * __init skmca_probe(int unit)
+{
+	struct net_device *dev;
+	int force_detect = 0;
+	int junior, slot, i;
+	int base = 0, irq = 0;
+	skmca_priv *priv;
+	skmca_medium medium;
+	int err;
+
+	/* can't work without an MCA bus ;-) */
+
+	if (MCA_bus == 0)
+		return ERR_PTR(-ENODEV);
+
+	dev = alloc_etherdev(sizeof(skmca_priv));
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	if (unit >= 0) {
+		sprintf(dev->name, "eth%d", unit);
+		netdev_boot_setup_check(dev);
+	}
+
+	SET_MODULE_OWNER(dev);
+
+	/* start address of 1 --> forced detection */
+
+	if (dev->mem_start == 1)
+		force_detect = 1;
+
+	/* search through slots */
+
+	base = dev->mem_start;
+	irq = dev->base_addr;
+	for (slot = startslot; (slot = dofind(&junior, slot)) != -1; slot++) {
+		/* deduce card addresses */
+
+		getaddrs(slot, junior, &base, &irq, &medium);
+
+		/* slot already in use ? */
+
+		if (mca_is_adapter_used(slot))
+			continue;
+
+		/* were we looking for something different ? */
+
+		if (dev->irq && dev->irq != irq)
+			continue;
+		if (dev->mem_start && dev->mem_start != base)
+			continue;
+
+		/* found something that matches */
+
+		break;
+	}
+
+	/* nothing found ? */
+
+	if (slot == -1) {
+		free_netdev(dev);
+		return (base || irq) ? ERR_PTR(-ENXIO) : ERR_PTR(-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);
+
+	mca_mark_as_used(slot);
+
+	/* announce success */
+	printk("%s: SKNet %s adapter found in slot %d\n", dev->name,
+	       junior ? "Junior MC2" : "MC2+", slot + 1);
+
+	priv = netdev_priv(dev);
+	priv->base = ioremap(base, 0x4000);
+	if (!priv->base) {
+		mca_set_adapter_procfn(slot, NULL, NULL);
+		mca_mark_as_unused(slot);
+		free_netdev(dev);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	priv->slot = slot;
+	priv->macbase = priv->base + 0x3fc0;
+	priv->ioregaddr = priv->base + 0x3ff0;
+	priv->ctrladdr = priv->base + 0x3ff2;
+	priv->cmdaddr = priv->base + 0x3ff3;
+	priv->medium = medium;
+	memset(&priv->stat, 0, sizeof(struct net_device_stats));
+	spin_lock_init(&priv->lock);
+
+	/* set base + irq for this device (irq not allocated so far) */
+	dev->irq = 0;
+	dev->mem_start = base;
+	dev->mem_end = base + 0x4000;
+
+	/* autoprobe ? */
+	if (irq < 0) {
+		int nirq;
+
+		printk
+		    ("%s: ambigous POS bit combination, must probe for IRQ...\n",
+		     dev->name);
+		nirq = ProbeIRQ(dev);
+		if (nirq <= 0)
+			printk("%s: IRQ probe failed, assuming IRQ %d",
+			       dev->name, priv->realirq = -irq);
+		else
+			priv->realirq = nirq;
+	} else
+		priv->realirq = irq;
+
+	/* set methods */
+	dev->open = skmca_open;
+	dev->stop = skmca_close;
+	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;
+
+	/* 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);
+
+	startslot = slot + 1;
+
+	err = register_netdev(dev);
+	if (err) {
+		cleanup_card(dev);
+		free_netdev(dev);
+		dev = ERR_PTR(err);
+	}
+	return dev;
+}
+
+/* ------------------------------------------------------------------------
+ * modularization support
+ * ------------------------------------------------------------------------ */
+
+#ifdef MODULE
+MODULE_LICENSE("GPL");
+
+#define DEVMAX 5
+
+static struct net_device *moddevs[DEVMAX];
+
+int init_module(void)
+{
+	int z;
+
+	startslot = 0;
+	for (z = 0; z < DEVMAX; z++) {
+		struct net_device *dev = skmca_probe(-1);
+		if (IS_ERR(dev))
+			break;
+		moddevs[z] = dev;
+	}
+	if (!z)
+		return -EIO;
+	return 0;
+}
+
+void cleanup_module(void)
+{
+	int z;
+
+	for (z = 0; z < DEVMAX; z++) {
+		struct net_device *dev = moddevs[z];
+		if (dev) {
+			unregister_netdev(dev);
+			cleanup_card(dev);
+			free_netdev(dev);
+		}
+	}
+}
+#endif				/* MODULE */