Linux-2.6.12-rc2v2.6.12-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 */