ewrk3.c

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/*  ewrk3.c: A DIGITAL EtherWORKS 3 ethernet driver for Linux.

   Written 1994 by David C. Davies.

   Copyright 1994 Digital Equipment Corporation.

   This software may be used and distributed according to the terms of
   the GNU Public License, incorporated herein by reference.

   This driver is written for the Digital Equipment Corporation series
   of EtherWORKS ethernet cards:

   DE203 Turbo (BNC)
   DE204 Turbo (TP)
   DE205 Turbo (TP BNC)

   The driver has been tested on a relatively busy  network using the DE205
   card and benchmarked with 'ttcp': it transferred 16M  of data at 975kB/s
   (7.8Mb/s) to a DECstation 5000/200.

   The author may be reached at davies@maniac.ultranet.com.

   =========================================================================
   This driver has been written  substantially  from scratch, although  its
   inheritance of style and stack interface from 'depca.c' and in turn from
   Donald Becker's 'lance.c' should be obvious.

   The  DE203/4/5 boards  all  use a new proprietary   chip in place of the
   LANCE chip used in prior cards  (DEPCA, DE100, DE200/1/2, DE210, DE422).
   Use the depca.c driver in the standard distribution  for the LANCE based
   cards from DIGITAL; this driver will not work with them.

   The DE203/4/5 cards have 2  main modes: shared memory  and I/O only. I/O
   only makes  all the card accesses through  I/O transactions and  no high
   (shared)  memory is used. This  mode provides a >48% performance penalty
   and  is deprecated in this  driver,  although allowed to provide initial
   setup when hardstrapped.

   The shared memory mode comes in 3 flavours: 2kB, 32kB and 64kB. There is
   no point in using any mode other than the 2kB  mode - their performances
   are virtually identical, although the driver has  been tested in the 2kB
   and 32kB modes. I would suggest you uncomment the line:

   FORCE_2K_MODE;

   to allow the driver to configure the card as a  2kB card at your current
   base  address, thus leaving more  room to clutter  your  system box with
   other memory hungry boards.

   As many ISA  and EISA cards  can be supported  under this driver  as you
   wish, limited primarily  by the available IRQ lines,  rather than by the
   available I/O addresses  (24 ISA,  16 EISA).   I have  checked different
   configurations of  multiple  depca cards and  ewrk3 cards  and have  not
   found a problem yet (provided you have at least depca.c v0.38) ...

   The board IRQ setting   must be at  an unused  IRQ which is  auto-probed
   using  Donald  Becker's autoprobe  routines.   All  these cards   are at
   {5,10,11,15}.

   No 16MB memory  limitation should exist with this  driver as DMA is  not
   used and the common memory area is in low memory on the network card (my
   current system has 20MB and I've not had problems yet).

   The ability to load  this driver as a  loadable module has been included
   and used  extensively during the  driver development (to save those long
   reboot sequences). To utilise this ability, you have to do 8 things:

   0) have a copy of the loadable modules code installed on your system.
   1) copy ewrk3.c from the  /linux/drivers/net directory to your favourite
   temporary directory.
   2) edit the  source code near  line 1898 to reflect  the I/O address and
   IRQ you're using.
   3) compile  ewrk3.c, but include -DMODULE in  the command line to ensure
   that the correct bits are compiled (see end of source code).
   4) if you are wanting to add a new  card, goto 5. Otherwise, recompile a
   kernel with the ewrk3 configuration turned off and reboot.
   5) insmod ewrk3.o
   [Alan Cox: Changed this so you can insmod ewrk3.o irq=x io=y]
   6) run the net startup bits for your new eth?? interface manually
   (usually /etc/rc.inet[12] at boot time).
   7) enjoy!

   Note that autoprobing is not allowed in loadable modules - the system is
   already up and running and you're messing with interrupts.

   To unload a module, turn off the associated interface
   'ifconfig eth?? down' then 'rmmod ewrk3'.

   Promiscuous   mode has been  turned  off  in this driver,   but  all the
   multicast  address bits  have been   turned on. This  improved the  send
   performance on a busy network by about 13%.

   Ioctl's have now been provided (primarily because  I wanted to grab some
   packet size statistics). They  are patterned after 'plipconfig.c' from a
   suggestion by Alan Cox.  Using these  ioctls, you can enable promiscuous
   mode, add/delete multicast  addresses, change the hardware address,  get
   packet size distribution statistics and muck around with the control and
   status register. I'll add others if and when the need arises.

   TO DO:
   ------


   Revision History
   ----------------

   Version   Date        Description

   0.1     26-aug-94   Initial writing. ALPHA code release.
   0.11    31-aug-94   Fixed: 2k mode memory base calc.,
   LeMAC version calc.,
   IRQ vector assignments during autoprobe.
   0.12    31-aug-94   Tested working on LeMAC2 (DE20[345]-AC) card.
   Fixed up MCA hash table algorithm.
   0.20     4-sep-94   Added IOCTL functionality.
   0.21    14-sep-94   Added I/O mode.
   0.21axp 15-sep-94   Special version for ALPHA AXP Linux V1.0.
   0.22    16-sep-94   Added more IOCTLs & tidied up.
   0.23    21-sep-94   Added transmit cut through.
   0.24    31-oct-94   Added uid checks in some ioctls.
   0.30     1-nov-94   BETA code release.
   0.31     5-dec-94   Added check/allocate region code.
   0.32    16-jan-95   Broadcast packet fix.
   0.33    10-Feb-95   Fix recognition bug reported by <bkm@star.rl.ac.uk>.
   0.40    27-Dec-95   Rationalise MODULE and autoprobe code.
   Rewrite for portability & updated.
   ALPHA support from <jestabro@amt.tay1.dec.com>
   Added verify_area() calls in ewrk3_ioctl() from
   suggestion by <heiko@colossus.escape.de>.
   Add new multicasting code.
   0.41    20-Jan-96   Fix IRQ set up problem reported by
   <kenneth@bbs.sas.ntu.ac.sg>.
   0.42    22-Apr-96      Fix alloc_device() bug <jari@markkus2.fimr.fi>
   0.43    16-Aug-96      Update alloc_device() to conform to de4x5.c

   =========================================================================
 */

static const char *version = "ewrk3.c:v0.43 96/8/16 davies@maniac.ultranet.com\n";

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/malloc.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <asm/bitops.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/uaccess.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>

#include <linux/time.h>
#include <linux/types.h>
#include <linux/unistd.h>
#include <linux/ctype.h>

#include "ewrk3.h"

#ifdef EWRK3_DEBUG
static int ewrk3_debug = EWRK3_DEBUG;
#else
static int ewrk3_debug = 1;
#endif

#define EWRK3_NDA 0xffe0        /* No Device Address */

#define PROBE_LENGTH    32
#define ETH_PROM_SIG    0xAA5500FFUL

#ifndef EWRK3_SIGNATURE
#define EWRK3_SIGNATURE {"DE203","DE204","DE205",""}
#define EWRK3_STRLEN 8
#endif

#ifndef EWRK3_RAM_BASE_ADDRESSES
#define EWRK3_RAM_BASE_ADDRESSES {0xc0000,0xd0000,0x00000}
#endif

/*
   ** Sets up the I/O area for the autoprobe.
 */
#define EWRK3_IO_BASE 0x100     /* Start address for probe search */
#define EWRK3_IOP_INC 0x20      /* I/O address increment */
#define EWRK3_TOTAL_SIZE 0x20   /* required I/O address length */

#ifndef MAX_NUM_EWRK3S
#define MAX_NUM_EWRK3S 21
#endif

#ifndef EWRK3_EISA_IO_PORTS
#define EWRK3_EISA_IO_PORTS 0x0c00      /* I/O port base address, slot 0 */
#endif

#ifndef MAX_EISA_SLOTS
#define MAX_EISA_SLOTS 16
#define EISA_SLOT_INC 0x1000
#endif

#define CRC_POLYNOMIAL_BE 0x04c11db7UL  /* Ethernet CRC, big endian */
#define CRC_POLYNOMIAL_LE 0xedb88320UL  /* Ethernet CRC, little endian */

#define QUEUE_PKT_TIMEOUT (1*HZ)        /* Jiffies */

/*
   ** EtherWORKS 3 shared memory window sizes
 */
#define IO_ONLY         0x00
#define SHMEM_2K        0x800
#define SHMEM_32K       0x8000
#define SHMEM_64K       0x10000

/*
   ** EtherWORKS 3 IRQ ENABLE/DISABLE
 */
#define ENABLE_IRQs { \
  icr |= lp->irq_mask;\
  outb(icr, EWRK3_ICR);                     /* Enable the IRQs */\
}

#define DISABLE_IRQs { \
  icr = inb(EWRK3_ICR);\
  icr &= ~lp->irq_mask;\
  outb(icr, EWRK3_ICR);                     /* Disable the IRQs */\
}

/*
   ** EtherWORKS 3 START/STOP
 */
#define START_EWRK3 { \
  csr = inb(EWRK3_CSR);\
  csr &= ~(CSR_TXD|CSR_RXD);\
  outb(csr, EWRK3_CSR);                     /* Enable the TX and/or RX */\
}

#define STOP_EWRK3 { \
  csr = (CSR_TXD|CSR_RXD);\
  outb(csr, EWRK3_CSR);                     /* Disable the TX and/or RX */\
}

/*
   ** The EtherWORKS 3 private structure
 */
#define EWRK3_PKT_STAT_SZ 16
#define EWRK3_PKT_BIN_SZ  128   /* Should be >=100 unless you
                                   increase EWRK3_PKT_STAT_SZ */

struct ewrk3_private {
        char adapter_name[80];  /* Name exported to /proc/ioports */
        u_long shmem_base;      /* Shared memory start address */
        u_long shmem_length;    /* Shared memory window length */
        struct net_device_stats stats;  /* Public stats */
        struct {
                u32 bins[EWRK3_PKT_STAT_SZ];    /* Private stats counters */
                u32 unicast;
                u32 multicast;
                u32 broadcast;
                u32 excessive_collisions;
                u32 tx_underruns;
                u32 excessive_underruns;
        } pktStats;
        u_char irq_mask;        /* Adapter IRQ mask bits */
        u_char mPage;           /* Maximum 2kB Page number */
        u_char lemac;           /* Chip rev. level */
        u_char hard_strapped;   /* Don't allow a full open */
        u_char lock;            /* Lock the page register */
        u_char txc;             /* Transmit cut through */
        u_char *mctbl;          /* Pointer to the multicast table */
};

/*
   ** Force the EtherWORKS 3 card to be in 2kB MODE
 */
#define FORCE_2K_MODE { \
  shmem_length = SHMEM_2K;\
  outb(((mem_start - 0x80000) >> 11), EWRK3_MBR);\
}

/*
   ** Public Functions
 */
static int ewrk3_open(struct device *dev);
static int ewrk3_queue_pkt(struct sk_buff *skb, struct device *dev);
static void ewrk3_interrupt(int irq, void *dev_id, struct pt_regs *regs);
static int ewrk3_close(struct device *dev);
static struct net_device_stats *ewrk3_get_stats(struct device *dev);
static void set_multicast_list(struct device *dev);
static int ewrk3_ioctl(struct device *dev, struct ifreq *rq, int cmd);

/*
   ** Private functions
 */
static int ewrk3_hw_init(struct device *dev, u_long iobase);
static void ewrk3_init(struct device *dev);
static int ewrk3_rx(struct device *dev);
static int ewrk3_tx(struct device *dev);

static void EthwrkSignature(char *name, char *eeprom_image);
static int DevicePresent(u_long iobase);
static void SetMulticastFilter(struct device *dev);
static int EISA_signature(char *name, s32 eisa_id);

static int Read_EEPROM(u_long iobase, u_char eaddr);
static int Write_EEPROM(short data, u_long iobase, u_char eaddr);
static u_char get_hw_addr(struct device *dev, u_char * eeprom_image, char chipType);

static void isa_probe(struct device *dev, u_long iobase);
static void eisa_probe(struct device *dev, u_long iobase);
static struct device *alloc_device(struct device *dev, u_long iobase);
static int ewrk3_dev_index(char *s);
static struct device *insert_device(struct device *dev, u_long iobase, int (*init) (struct device *));


#ifdef MODULE
int init_module(void);
void cleanup_module(void);
static int autoprobed = 1, loading_module = 1;

#else
static u_char irq[] =
{5, 0, 10, 3, 11, 9, 15, 12};
static int autoprobed = 0, loading_module = 0;

#endif                          /* MODULE */

static char name[EWRK3_STRLEN + 1];
static int num_ewrk3s = 0, num_eth = 0;

/*
   ** Miscellaneous defines...
 */
#define INIT_EWRK3 {\
    outb(EEPROM_INIT, EWRK3_IOPR);\
    mdelay(1);\
}




__initfunc(int ewrk3_probe(struct device *dev))
{
        int tmp = num_ewrk3s, status = -ENODEV;
        u_long iobase = dev->base_addr;

        if ((iobase == 0) && loading_module) {
                printk("Autoprobing is not supported when loading a module based driver.\n");
                status = -EIO;
        } else {                /* First probe for the Ethernet */
                /* Address PROM pattern */
                isa_probe(dev, iobase);
                eisa_probe(dev, iobase);

                if ((tmp == num_ewrk3s) && (iobase != 0) && loading_module) {
                        printk("%s: ewrk3_probe() cannot find device at 0x%04lx.\n", dev->name,
                               iobase);
                }
                /*
                   ** Walk the device list to check that at least one device
                   ** initialised OK
                 */
                for (; (dev->priv == NULL) && (dev->next != NULL); dev = dev->next);

                if (dev->priv)
                        status = 0;
                if (iobase == 0)
                        autoprobed = 1;
        }

        return status;
}

__initfunc(static int
           ewrk3_hw_init(struct device *dev, u_long iobase))
{
        struct ewrk3_private *lp;
        int i, status = 0;
        u_long mem_start, shmem_length;
        u_char cr, cmr, icr, nicsr, lemac, hard_strapped = 0;
        u_char eeprom_image[EEPROM_MAX], chksum, eisa_cr = 0;

        /*
           ** Stop the EWRK3. Enable the DBR ROM. Disable interrupts and remote boot.
           ** This also disables the EISA_ENABLE bit in the EISA Control Register.
         */
        if (iobase > 0x400)
                eisa_cr = inb(EISA_CR);
        INIT_EWRK3;

        nicsr = inb(EWRK3_CSR);

        icr = inb(EWRK3_ICR);
        icr &= 0x70;
        outb(icr, EWRK3_ICR);   /* Disable all the IRQs */

        if (nicsr == (CSR_TXD | CSR_RXD)) {

                /* Check that the EEPROM is alive and well and not living on Pluto... */
                for (chksum = 0, i = 0; i < EEPROM_MAX; i += 2) {
                        union {
                                short val;
                                char c[2];
                        } tmp;

                        tmp.val = (short) Read_EEPROM(iobase, (i >> 1));
                        eeprom_image[i] = tmp.c[0];
                        eeprom_image[i + 1] = tmp.c[1];
                        chksum += eeprom_image[i] + eeprom_image[i + 1];
                }

                if (chksum != 0) {      /* Bad EEPROM Data! */
                        printk("%s: Device has a bad on-board EEPROM.\n", dev->name);
                        status = -ENXIO;
                } else {
                        EthwrkSignature(name, eeprom_image);
                        if (*name != '\0') {    /* found a EWRK3 device */
                                dev->base_addr = iobase;

                                if (iobase > 0x400) {
                                        outb(eisa_cr, EISA_CR);         /* Rewrite the EISA CR */
                                }
                                lemac = eeprom_image[EEPROM_CHIPVER];
                                cmr = inb(EWRK3_CMR);

                                if (((lemac == LeMAC) && ((cmr & CMR_NO_EEPROM) != CMR_NO_EEPROM)) ||
                                ((lemac == LeMAC2) && !(cmr & CMR_HS))) {
                                        printk("%s: %s at %#4lx", dev->name, name, iobase);
                                        hard_strapped = 1;
                                } else if ((iobase & 0x0fff) == EWRK3_EISA_IO_PORTS) {
                                        /* EISA slot address */
                                        printk("%s: %s at %#4lx (EISA slot %ld)",
                                               dev->name, name, iobase, ((iobase >> 12) & 0x0f));
                                } else {        /* ISA port address */
                                        printk("%s: %s at %#4lx", dev->name, name, iobase);
                                }

                                if (!status) {
                                        printk(", h/w address ");
                                        if (lemac != LeMAC2)
                                                DevicePresent(iobase);  /* need after EWRK3_INIT */
                                        status = get_hw_addr(dev, eeprom_image, lemac);
                                        for (i = 0; i < ETH_ALEN - 1; i++) {    /* get the ethernet addr. */
                                                printk("%2.2x:", dev->dev_addr[i]);
                                        }
                                        printk("%2.2x,\n", dev->dev_addr[i]);

                                        if (status) {
                                                printk("      which has an EEPROM CRC error.\n");
                                                status = -ENXIO;
                                        } else {
                                                if (lemac == LeMAC2) {  /* Special LeMAC2 CMR things */
                                                        cmr &= ~(CMR_RA | CMR_WB | CMR_LINK | CMR_POLARITY | CMR_0WS);
                                                        if (eeprom_image[EEPROM_MISC0] & READ_AHEAD)
                                                                cmr |= CMR_RA;
                                                        if (eeprom_image[EEPROM_MISC0] & WRITE_BEHIND)
                                                                cmr |= CMR_WB;
                                                        if (eeprom_image[EEPROM_NETMAN0] & NETMAN_POL)
                                                                cmr |= CMR_POLARITY;
                                                        if (eeprom_image[EEPROM_NETMAN0] & NETMAN_LINK)
                                                                cmr |= CMR_LINK;
                                                        if (eeprom_image[EEPROM_MISC0] & _0WS_ENA)
                                                                cmr |= CMR_0WS;
                                                }
                                                if (eeprom_image[EEPROM_SETUP] & SETUP_DRAM)
                                                        cmr |= CMR_DRAM;
                                                outb(cmr, EWRK3_CMR);

                                                cr = inb(EWRK3_CR);     /* Set up the Control Register */
                                                cr |= eeprom_image[EEPROM_SETUP] & SETUP_APD;
                                                if (cr & SETUP_APD)
                                                        cr |= eeprom_image[EEPROM_SETUP] & SETUP_PS;
                                                cr |= eeprom_image[EEPROM_MISC0] & FAST_BUS;
                                                cr |= eeprom_image[EEPROM_MISC0] & ENA_16;
                                                outb(cr, EWRK3_CR);

                                                /*
                                                   ** Determine the base address and window length for the EWRK3
                                                   ** RAM from the memory base register.
                                                 */
                                                mem_start = inb(EWRK3_MBR);
                                                shmem_length = 0;
                                                if (mem_start != 0) {
                                                        if ((mem_start >= 0x0a) && (mem_start <= 0x0f)) {
                                                                mem_start *= SHMEM_64K;
                                                                shmem_length = SHMEM_64K;
                                                        } else if ((mem_start >= 0x14) && (mem_start <= 0x1f)) {
                                                                mem_start *= SHMEM_32K;
                                                                shmem_length = SHMEM_32K;
                                                        } else if ((mem_start >= 0x40) && (mem_start <= 0xff)) {
                                                                mem_start = mem_start * SHMEM_2K + 0x80000;
                                                                shmem_length = SHMEM_2K;
                                                        } else {
                                                                status = -ENXIO;
                                                        }
                                                }
                                                /*
                                                   ** See the top of this source code for comments about
                                                   ** uncommenting this line.
                                                 */
/*          FORCE_2K_MODE; */

                                                if (!status) {
                                                        if (hard_strapped) {
                                                                printk("      is hard strapped.\n");
                                                        } else if (mem_start) {
                                                                printk("      has a %dk RAM window", (int) (shmem_length >> 10));
                                                                printk(" at 0x%.5lx", mem_start);
                                                        } else {
                                                                printk("      is in I/O only mode");
                                                        }

                                                        /* private area & initialise */
                                                        dev->priv = (void *) kmalloc(sizeof(struct ewrk3_private),
                                                             GFP_KERNEL);
                                                        if (dev->priv == NULL) {
                                                                return -ENOMEM;
                                                        }
                                                        lp = (struct ewrk3_private *) dev->priv;
                                                        memset(dev->priv, 0, sizeof(struct ewrk3_private));
                                                        lp->shmem_base = mem_start;
                                                        lp->shmem_length = shmem_length;
                                                        lp->lemac = lemac;
                                                        lp->hard_strapped = hard_strapped;

                                                        lp->mPage = 64;
                                                        if (cmr & CMR_DRAM)
                                                                lp->mPage <<= 1;        /* 2 DRAMS on module */

                                                        sprintf(lp->adapter_name, "%s (%s)", name, dev->name);
                                                        request_region(iobase, EWRK3_TOTAL_SIZE, lp->adapter_name);

                                                        lp->irq_mask = ICR_TNEM | ICR_TXDM | ICR_RNEM | ICR_RXDM;

                                                        if (!hard_strapped) {
                                                                /*
                                                                   ** Enable EWRK3 board interrupts for autoprobing
                                                                 */
                                                                icr |= ICR_IE;  /* Enable interrupts */
                                                                outb(icr, EWRK3_ICR);

                                                                /* The DMA channel may be passed in on this parameter. */
                                                                dev->dma = 0;

                                                                /* To auto-IRQ we enable the initialization-done and DMA err,
                                                                   interrupts. For now we will always get a DMA error. */
                                                                if (dev->irq < 2) {
#ifndef MODULE
                                                                        u_char irqnum;

                                                                        autoirq_setup(0);

                                                                        /*
                                                                           ** Trigger a TNE interrupt.
                                                                         */
                                                                        icr |= ICR_TNEM;
                                                                        outb(1, EWRK3_TDQ);     /* Write to the TX done queue */
                                                                        outb(icr, EWRK3_ICR);   /* Unmask the TXD interrupt */

                                                                        irqnum = irq[((icr & IRQ_SEL) >> 4)];

                                                                        dev->irq = autoirq_report(1);
                                                                        if ((dev->irq) && (irqnum == dev->irq)) {
                                                                                printk(" and uses IRQ%d.\n", dev->irq);
                                                                        } else {
                                                                                if (!dev->irq) {
                                                                                        printk(" and failed to detect IRQ line.\n");
                                                                                } else if ((irqnum == 1) && (lemac == LeMAC2)) {
                                                                                        printk(" and an illegal IRQ line detected.\n");
                                                                                } else {
                                                                                        printk(", but incorrect IRQ line detected.\n");
                                                                                }
                                                                                status = -ENXIO;
                                                                        }

                                                                        DISABLE_IRQs;   /* Mask all interrupts */

#endif                          /* MODULE */
                                                                } else {
                                                                        printk(" and requires IRQ%d.\n", dev->irq);
                                                                }
                                                        }
                                                        if (status)
                                                                release_region(iobase, EWRK3_TOTAL_SIZE);
                                                } else {
                                                        status = -ENXIO;
                                                }
                                        }
                                }
                        } else {
                                status = -ENXIO;
                        }
                }

                if (!status) {
                        if (ewrk3_debug > 1) {
                                printk(version);
                        }
                        /* The EWRK3-specific entries in the device structure. */
                        dev->open = &ewrk3_open;
                        dev->hard_start_xmit = &ewrk3_queue_pkt;
                        dev->stop = &ewrk3_close;
                        dev->get_stats = &ewrk3_get_stats;
                        dev->set_multicast_list = &set_multicast_list;
                        dev->do_ioctl = &ewrk3_ioctl;

                        dev->mem_start = 0;

                        /* Fill in the generic field of the device structure. */
                        ether_setup(dev);
                }
        } else {
                status = -ENXIO;
        }

        return status;
}


static int ewrk3_open(struct device *dev)
{
        struct ewrk3_private *lp = (struct ewrk3_private *) dev->priv;
        u_long iobase = dev->base_addr;
        int i, status = 0;
        u_char icr, csr;

        /*
           ** Stop the TX and RX...
         */
        STOP_EWRK3;

        if (!lp->hard_strapped) {
                if (request_irq(dev->irq, (void *) ewrk3_interrupt, 0, "ewrk3", dev)) {
                        printk("ewrk3_open(): Requested IRQ%d is busy\n", dev->irq);
                        status = -EAGAIN;
                } else {

                        /*
                           ** Re-initialize the EWRK3...
                         */
                        ewrk3_init(dev);

                        if (ewrk3_debug > 1) {
                                printk("%s: ewrk3 open with irq %d\n", dev->name, dev->irq);
                                printk("  physical address: ");
                                for (i = 0; i < 5; i++) {
                                        printk("%2.2x:", (u_char) dev->dev_addr[i]);
                                }
                                printk("%2.2x\n", (u_char) dev->dev_addr[i]);
                                if (lp->shmem_length == 0) {
                                        printk("  no shared memory, I/O only mode\n");
                                } else {
                                        printk("  start of shared memory: 0x%08lx\n", lp->shmem_base);
                                        printk("  window length: 0x%04lx\n", lp->shmem_length);
                                }
                                printk("  # of DRAMS: %d\n", ((inb(EWRK3_CMR) & 0x02) ? 2 : 1));
                                printk("  csr:  0x%02x\n", inb(EWRK3_CSR));
                                printk("  cr:   0x%02x\n", inb(EWRK3_CR));
                                printk("  icr:  0x%02x\n", inb(EWRK3_ICR));
                                printk("  cmr:  0x%02x\n", inb(EWRK3_CMR));
                                printk("  fmqc: 0x%02x\n", inb(EWRK3_FMQC));
                        }
                        dev->tbusy = 0;
                        dev->start = 1;
                        dev->interrupt = UNMASK_INTERRUPTS;

                        /*
                           ** Unmask EWRK3 board interrupts
                         */
                        icr = inb(EWRK3_ICR);
                        ENABLE_IRQs;

                }
        } else {
                dev->start = 0;
                dev->tbusy = 1;
                printk("%s: ewrk3 available for hard strapped set up only.\n", dev->name);
                printk("      Run the 'ewrk3setup' utility or remove the hard straps.\n");
        }

        MOD_INC_USE_COUNT;

        return status;
}

/*
   ** Initialize the EtherWORKS 3 operating conditions
 */
static void ewrk3_init(struct device *dev)
{
        struct ewrk3_private *lp = (struct ewrk3_private *) dev->priv;
        u_char csr, page;
        u_long iobase = dev->base_addr;

        /*
           ** Enable any multicasts
         */
        set_multicast_list(dev);

        /*
           ** Clean out any remaining entries in all the queues here
         */
        while (inb(EWRK3_TQ));
        while (inb(EWRK3_TDQ));
        while (inb(EWRK3_RQ));
        while (inb(EWRK3_FMQ));

        /*
           ** Write a clean free memory queue
         */
        for (page = 1; page < lp->mPage; page++) {      /* Write the free page numbers */
                outb(page, EWRK3_FMQ);  /* to the Free Memory Queue */
        }

        lp->lock = 0;           /* Ensure there are no locks */

        START_EWRK3;            /* Enable the TX and/or RX */
}

/*
   ** Writes a socket buffer to the free page queue
 */
static int ewrk3_queue_pkt(struct sk_buff *skb, struct device *dev)
{
        struct ewrk3_private *lp = (struct ewrk3_private *) dev->priv;
        u_long iobase = dev->base_addr;
        int status = 0;
        u_char icr, csr;

        /* Transmitter timeout, serious problems. */
        if (dev->tbusy || lp->lock) {
                int tickssofar = jiffies - dev->trans_start;
                if (tickssofar < QUEUE_PKT_TIMEOUT) {
                        status = -1;
                } else if (!lp->hard_strapped) {
                        printk("%s: transmit timed/locked out, status %04x, resetting.\n",
                               dev->name, inb(EWRK3_CSR));

                        /*
                           ** Mask all board interrupts
                         */
                        DISABLE_IRQs;

                        /*
                           ** Stop the TX and RX...
                         */
                        STOP_EWRK3;

                        ewrk3_init(dev);

                        /*
                           ** Unmask EWRK3 board interrupts
                         */
                        ENABLE_IRQs;

                        dev->tbusy = 0;
                        dev->trans_start = jiffies;
                }
        } else if (skb->len > 0) {

                /*
                   ** Block a timer-based transmit from overlapping.  This could better be
                   ** done with atomic_swap(1, dev->tbusy), but set_bit() works as well.
                 */
                if (test_and_set_bit(0, (void *) &dev->tbusy) != 0)
                        printk("%s: Transmitter access conflict.\n", dev->name);

                DISABLE_IRQs;   /* So that the page # remains correct */

                /*
                   ** Get a free page from the FMQ when resources are available
                 */
                if (inb(EWRK3_FMQC) > 0) {
                        u_long buf = 0;
                        u_char page;

                        if ((page = inb(EWRK3_FMQ)) < lp->mPage) {
                                /*
                                   ** Set up shared memory window and pointer into the window
                                 */
                                while (test_and_set_bit(0, (void *) &lp->lock) != 0);   /* Wait for lock to free */
                                if (lp->shmem_length == IO_ONLY) {
                                        outb(page, EWRK3_IOPR);
                                } else if (lp->shmem_length == SHMEM_2K) {
                                        buf = lp->shmem_base;
                                        outb(page, EWRK3_MPR);
                                } else if (lp->shmem_length == SHMEM_32K) {
                                        buf = ((((short) page << 11) & 0x7800) + lp->shmem_base);
                                        outb((page >> 4), EWRK3_MPR);
                                } else if (lp->shmem_length == SHMEM_64K) {
                                        buf = ((((short) page << 11) & 0xf800) + lp->shmem_base);
                                        outb((page >> 5), EWRK3_MPR);
                                } else {
                                        status = -1;
                                        printk("%s: Oops - your private data area is hosed!\n", dev->name);
                                }

                                if (!status) {

                                        /*
                                           ** Set up the buffer control structures and copy the data from
                                           ** the socket buffer to the shared memory .
                                         */

                                        if (lp->shmem_length == IO_ONLY) {
                                                int i;
                                                u_char *p = skb->data;

                                                outb((char) (TCR_QMODE | TCR_PAD | TCR_IFC), EWRK3_DATA);
                                                outb((char) (skb->len & 0xff), EWRK3_DATA);
                                                outb((char) ((skb->len >> 8) & 0xff), EWRK3_DATA);
                                                outb((char) 0x04, EWRK3_DATA);
                                                for (i = 0; i < skb->len; i++) {
                                                        outb(*p++, EWRK3_DATA);
                                                }
                                                outb(page, EWRK3_TQ);   /* Start sending pkt */
                                        } else {
                                                writeb((char) (TCR_QMODE | TCR_PAD | TCR_IFC), (char *) buf);   /* ctrl byte */
                                                buf += 1;
                                                writeb((char) (skb->len & 0xff), (char *) buf);         /* length (16 bit xfer) */
                                                buf += 1;
                                                if (lp->txc) {
                                                        writeb((char) (((skb->len >> 8) & 0xff) | XCT), (char *) buf);
                                                        buf += 1;
                                                        writeb(0x04, (char *) buf);     /* index byte */
                                                        buf += 1;
                                                        writeb(0x00, (char *) (buf + skb->len));        /* Write the XCT flag */
                                                        memcpy_toio(buf, skb->data, PRELOAD);   /* Write PRELOAD bytes */
                                                        outb(page, EWRK3_TQ);   /* Start sending pkt */
                                                        memcpy_toio(buf + PRELOAD, skb->data + PRELOAD, skb->len - PRELOAD);
                                                        writeb(0xff, (char *) (buf + skb->len));        /* Write the XCT flag */
                                                } else {
                                                        writeb((char) ((skb->len >> 8) & 0xff), (char *) buf);
                                                        buf += 1;
                                                        writeb(0x04, (char *) buf);     /* index byte */
                                                        buf += 1;
                                                        memcpy_toio((char *) buf, skb->data, skb->len);         /* Write data bytes */
                                                        outb(page, EWRK3_TQ);   /* Start sending pkt */
                                                }
                                        }

                                        lp->stats.tx_bytes += skb->len;
                                        dev->trans_start = jiffies;
                                        dev_kfree_skb(skb);
                                } else {        /* return unused page to the free memory queue */
                                        outb(page, EWRK3_FMQ);
                                }
                                lp->lock = 0;   /* unlock the page register */
                        } else {
                                printk("ewrk3_queue_pkt(): Invalid free memory page (%d).\n",
                                       (u_char) page);
                        }
                } else {
                        printk("ewrk3_queue_pkt(): No free resources...\n");
                        printk("ewrk3_queue_pkt(): CSR: %02x ICR: %02x FMQC: %02x\n", inb(EWRK3_CSR), inb(EWRK3_ICR), inb(EWRK3_FMQC));
                }

                /* Check for free resources: clear 'tbusy' if there are some */
                if (inb(EWRK3_FMQC) > 0) {
                        dev->tbusy = 0;
                }
                ENABLE_IRQs;
        }
        return status;
}

/*
   ** The EWRK3 interrupt handler.
 */
static void ewrk3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
        struct device *dev = dev_id;
        struct ewrk3_private *lp;
        u_long iobase;
        u_char icr, cr, csr;

        if (dev == NULL) {
                printk("ewrk3_interrupt(): irq %d for unknown device.\n", irq);
        } else {
                lp = (struct ewrk3_private *) dev->priv;
                iobase = dev->base_addr;

                if (dev->interrupt)
                        printk("%s: Re-entering the interrupt handler.\n", dev->name);

                dev->interrupt = MASK_INTERRUPTS;

                /* get the interrupt information */
                csr = inb(EWRK3_CSR);

                /*
                   ** Mask the EWRK3 board interrupts and turn on the LED
                 */
                DISABLE_IRQs;

                cr = inb(EWRK3_CR);
                cr |= CR_LED;
                outb(cr, EWRK3_CR);

                if (csr & CSR_RNE)      /* Rx interrupt (packet[s] arrived) */
                        ewrk3_rx(dev);

                if (csr & CSR_TNE)      /* Tx interrupt (packet sent) */
                        ewrk3_tx(dev);

                /*
                   ** Now deal with the TX/RX disable flags. These are set when there
                   ** are no more resources. If resources free up then enable these
                   ** interrupts, otherwise mask them - failure to do this will result
                   ** in the system hanging in an interrupt loop.
                 */
                if (inb(EWRK3_FMQC)) {  /* any resources available? */
                        lp->irq_mask |= ICR_TXDM | ICR_RXDM;    /* enable the interrupt source */
                        csr &= ~(CSR_TXD | CSR_RXD);    /* ensure restart of a stalled TX or RX */
                        outb(csr, EWRK3_CSR);
                        dev->tbusy = 0;         /* clear TX busy flag */
                        mark_bh(NET_BH);
                } else {
                        lp->irq_mask &= ~(ICR_TXDM | ICR_RXDM);         /* disable the interrupt source */
                }

                /* Unmask the EWRK3 board interrupts and turn off the LED */
                cr &= ~CR_LED;
                outb(cr, EWRK3_CR);

                dev->interrupt = UNMASK_INTERRUPTS;
                ENABLE_IRQs;
        }

        return;
}

static int ewrk3_rx(struct device *dev)
{
        struct ewrk3_private *lp = (struct ewrk3_private *) dev->priv;
        u_long iobase = dev->base_addr;
        int i, status = 0;
        u_char page, tmpPage = 0, tmpLock = 0;
        u_long buf = 0;

        while (inb(EWRK3_RQC) && !status) {     /* Whilst there's incoming data */
                if ((page = inb(EWRK3_RQ)) < lp->mPage) {       /* Get next entry's buffer page */
                        /*
                           ** Preempt any process using the current page register. Check for
                           ** an existing lock to reduce time taken in I/O transactions.
                         */
                        if ((tmpLock = test_and_set_bit(0, (void *) &lp->lock)) == 1) {         /* Assert lock */
                                if (lp->shmem_length == IO_ONLY) {      /* Get existing page */
                                        tmpPage = inb(EWRK3_IOPR);
                                } else {
                                        tmpPage = inb(EWRK3_MPR);
                                }
                        }
                        /*
                           ** Set up shared memory window and pointer into the window
                         */
                        if (lp->shmem_length == IO_ONLY) {
                                outb(page, EWRK3_IOPR);
                        } else if (lp->shmem_length == SHMEM_2K) {
                                buf = lp->shmem_base;
                                outb(page, EWRK3_MPR);
                        } else if (lp->shmem_length == SHMEM_32K) {
                                buf = ((((short) page << 11) & 0x7800) + lp->shmem_base);
                                outb((page >> 4), EWRK3_MPR);
                        } else if (lp->shmem_length == SHMEM_64K) {
                                buf = ((((short) page << 11) & 0xf800) + lp->shmem_base);
                                outb((page >> 5), EWRK3_MPR);
                        } else {
                                status = -1;
                                printk("%s: Oops - your private data area is hosed!\n", dev->name);
                        }

                        if (!status) {
                                char rx_status;
                                int pkt_len;

                                if (lp->shmem_length == IO_ONLY) {
                                        rx_status = inb(EWRK3_DATA);
                                        pkt_len = inb(EWRK3_DATA);
                                        pkt_len |= ((u_short) inb(EWRK3_DATA) << 8);
                                } else {
                                        rx_status = readb(buf);
                                        buf += 1;
                                        pkt_len = readw(buf);
                                        buf += 3;
                                }

                                if (!(rx_status & R_ROK)) {     /* There was an error. */
                                        lp->stats.rx_errors++;  /* Update the error stats. */
                                        if (rx_status & R_DBE)
                                                lp->stats.rx_frame_errors++;
                                        if (rx_status & R_CRC)
                                                lp->stats.rx_crc_errors++;
                                        if (rx_status & R_PLL)
                                                lp->stats.rx_fifo_errors++;
                                } else {
                                        struct sk_buff *skb;

                                        if ((skb = dev_alloc_skb(pkt_len + 2)) != NULL) {
                                                unsigned char *p;
                                                skb->dev = dev;
                                                skb_reserve(skb, 2);    /* Align to 16 bytes */
                                                p = skb_put(skb, pkt_len);

                                                if (lp->shmem_length == IO_ONLY) {
                                                        *p = inb(EWRK3_DATA);   /* dummy read */
                                                        for (i = 0; i < pkt_len; i++) {
                                                                *p++ = inb(EWRK3_DATA);
                                                        }
                                                } else {
                                                        memcpy_fromio(p, buf, pkt_len);
                                                }

                                                /*
                                                   ** Notify the upper protocol layers that there is another
                                                   ** packet to handle
                                                 */
                                                skb->protocol = eth_type_trans(skb, dev);
                                                netif_rx(skb);

                                                /*
                                                   ** Update stats
                                                 */
                                                lp->stats.rx_packets++;
                                                lp->stats.rx_bytes += pkt_len;
                                                for (i = 1; i < EWRK3_PKT_STAT_SZ - 1; i++) {
                                                        if (pkt_len < i * EWRK3_PKT_BIN_SZ) {
                                                                lp->pktStats.bins[i]++;
                                                                i = EWRK3_PKT_STAT_SZ;
                                                        }
                                                }
                                                p = skb->data;  /* Look at the dest addr */
                                                if (p[0] & 0x01) {      /* Multicast/Broadcast */
                                                        if ((*(s32 *) & p[0] == -1) && (*(s16 *) & p[4] == -1)) {
                                                                lp->pktStats.broadcast++;
                                                        } else {
                                                                lp->pktStats.multicast++;
                                                        }
                                                } else if ((*(s32 *) & p[0] == *(s32 *) & dev->dev_addr[0]) &&
                                                           (*(s16 *) & p[4] == *(s16 *) & dev->dev_addr[4])) {
                                                        lp->pktStats.unicast++;
                                                }
                                                lp->pktStats.bins[0]++;         /* Duplicates stats.rx_packets */
                                                if (lp->pktStats.bins[0] == 0) {        /* Reset counters */
                                                        memset(&lp->pktStats, 0, sizeof(lp->pktStats));
                                                }
                                        } else {
                                                printk("%s: Insufficient memory; nuking packet.\n", dev->name);
                                                lp->stats.rx_dropped++;         /* Really, deferred. */
                                                break;
                                        }
                                }
                        }
                        /*
                           ** Return the received buffer to the free memory queue
                         */
                        outb(page, EWRK3_FMQ);

                        if (tmpLock) {  /* If a lock was preempted */
                                if (lp->shmem_length == IO_ONLY) {      /* Replace old page */
                                        outb(tmpPage, EWRK3_IOPR);
                                } else {
                                        outb(tmpPage, EWRK3_MPR);
                                }
                        }
                        lp->lock = 0;   /* Unlock the page register */
                } else {
                        printk("ewrk3_rx(): Illegal page number, page %d\n", page);
                        printk("ewrk3_rx(): CSR: %02x ICR: %02x FMQC: %02x\n", inb(EWRK3_CSR), inb(EWRK3_ICR), inb(EWRK3_FMQC));
                }
        }
        return status;
}

/*
   ** Buffer sent - check for TX buffer errors.
 */
static int ewrk3_tx(struct device *dev)
{
        struct ewrk3_private *lp = (struct ewrk3_private *) dev->priv;
        u_long iobase = dev->base_addr;
        u_char tx_status;

        while ((tx_status = inb(EWRK3_TDQ)) > 0) {      /* Whilst there's old buffers */
                if (tx_status & T_VSTS) {       /* The status is valid */
                        if (tx_status & T_TXE) {
                                lp->stats.tx_errors++;
                                if (tx_status & T_NCL)
                                        lp->stats.tx_carrier_errors++;
                                if (tx_status & T_LCL)
                                        lp->stats.tx_window_errors++;
                                if (tx_status & T_CTU) {
                                        if ((tx_status & T_COLL) ^ T_XUR) {
                                                lp->pktStats.tx_underruns++;