declance.c

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/*
 *    Lance ethernet driver for the MIPS processor based
 *      DECstation family
 *
 *
 *      adopted from sunlance.c by Richard van den Berg
 *
 *      Copyright (C) 2002, 2003, 2005, 2006  Maciej W. Rozycki
 *
 *      additional sources:
 *      - PMAD-AA TURBOchannel Ethernet Module Functional Specification,
 *        Revision 1.2
 *
 *      History:
 *
 *      v0.001: The kernel accepts the code and it shows the hardware address.
 *
 *      v0.002: Removed most sparc stuff, left only some module and dma stuff.
 *
 *      v0.003: Enhanced base address calculation from proposals by
 *              Harald Koerfgen and Thomas Riemer.
 *
 *      v0.004: lance-regs is pointing at the right addresses, added prom
 *              check. First start of address mapping and DMA.
 *
 *      v0.005: started to play around with LANCE-DMA. This driver will not
 *              work for non IOASIC lances. HK
 *
 *      v0.006: added pointer arrays to lance_private and setup routine for
 *              them in dec_lance_init. HK
 *
 *      v0.007: Big shit. The LANCE seems to use a different DMA mechanism to
 *              access the init block. This looks like one (short) word at a
 *              time, but the smallest amount the IOASIC can transfer is a
 *              (long) word. So we have a 2-2 padding here. Changed
 *              lance_init_block accordingly. The 16-16 padding for the buffers
 *              seems to be correct. HK
 *
 *      v0.008: mods to make PMAX_LANCE work. 01/09/1999 triemer
 *
 *      v0.009: Module support fixes, multiple interfaces support, various
 *              bits. macro
 *
 *      v0.010: Fixes for the PMAD mapping of the LANCE buffer and for the
 *              PMAX requirement to only use halfword accesses to the
 *              buffer. macro
 *
 *      v0.011: Converted the PMAD to the driver model. macro
 */

#include <linux/crc32.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/if_ether.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/tc.h>
#include <linux/types.h>

#include <asm/addrspace.h>

#include <asm/dec/interrupts.h>
#include <asm/dec/ioasic.h>
#include <asm/dec/ioasic_addrs.h>
#include <asm/dec/kn01.h>
#include <asm/dec/machtype.h>
#include <asm/dec/system.h>

static char version[] __devinitdata =
"declance.c: v0.011 by Linux MIPS DECstation task force\n";

MODULE_AUTHOR("Linux MIPS DECstation task force");
MODULE_DESCRIPTION("DEC LANCE (DECstation onboard, PMAD-xx) driver");
MODULE_LICENSE("GPL");

#define __unused __attribute__ ((unused))

/*
 * card types
 */
#define ASIC_LANCE 1
#define PMAD_LANCE 2
#define PMAX_LANCE 3


#define LE_CSR0 0
#define LE_CSR1 1
#define LE_CSR2 2
#define LE_CSR3 3

#define LE_MO_PROM      0x8000  /* Enable promiscuous mode */

#define LE_C0_ERR   0x8000  /* Error: set if BAB, SQE, MISS or ME is set */
#define LE_C0_BABL  0x4000  /* BAB:  Babble: tx timeout. */
#define LE_C0_CERR  0x2000  /* SQE:  Signal quality error */
#define LE_C0_MISS  0x1000  /* MISS: Missed a packet */
#define LE_C0_MERR  0x0800  /* ME:   Memory error */
#define LE_C0_RINT  0x0400  /* Received interrupt */
#define LE_C0_TINT  0x0200  /* Transmitter Interrupt */
#define LE_C0_IDON  0x0100  /* IFIN: Init finished. */
#define LE_C0_INTR  0x0080  /* Interrupt or error */
#define LE_C0_INEA  0x0040  /* Interrupt enable */
#define LE_C0_RXON  0x0020  /* Receiver on */
#define LE_C0_TXON  0x0010  /* Transmitter on */
#define LE_C0_TDMD  0x0008  /* Transmitter demand */
#define LE_C0_STOP  0x0004  /* Stop the card */
#define LE_C0_STRT  0x0002  /* Start the card */
#define LE_C0_INIT  0x0001  /* Init the card */

#define LE_C3_BSWP  0x4 /* SWAP */
#define LE_C3_ACON  0x2 /* ALE Control */
#define LE_C3_BCON  0x1 /* Byte control */

/* Receive message descriptor 1 */
#define LE_R1_OWN   0x8000  /* Who owns the entry */
#define LE_R1_ERR   0x4000  /* Error: if FRA, OFL, CRC or BUF is set */
#define LE_R1_FRA   0x2000  /* FRA: Frame error */
#define LE_R1_OFL   0x1000  /* OFL: Frame overflow */
#define LE_R1_CRC   0x0800  /* CRC error */
#define LE_R1_BUF   0x0400  /* BUF: Buffer error */
#define LE_R1_SOP   0x0200  /* Start of packet */
#define LE_R1_EOP   0x0100  /* End of packet */
#define LE_R1_POK   0x0300  /* Packet is complete: SOP + EOP */

/* Transmit message descriptor 1 */
#define LE_T1_OWN   0x8000  /* Lance owns the packet */
#define LE_T1_ERR   0x4000  /* Error summary */
#define LE_T1_EMORE 0x1000  /* Error: more than one retry needed */
#define LE_T1_EONE  0x0800  /* Error: one retry needed */
#define LE_T1_EDEF  0x0400  /* Error: deferred */
#define LE_T1_SOP   0x0200  /* Start of packet */
#define LE_T1_EOP   0x0100  /* End of packet */
#define LE_T1_POK   0x0300  /* Packet is complete: SOP + EOP */

#define LE_T3_BUF       0x8000  /* Buffer error */
#define LE_T3_UFL       0x4000  /* Error underflow */
#define LE_T3_LCOL      0x1000  /* Error late collision */
#define LE_T3_CLOS      0x0800  /* Error carrier loss */
#define LE_T3_RTY       0x0400  /* Error retry */
#define LE_T3_TDR       0x03ff  /* Time Domain Reflectometry counter */

/* Define: 2^4 Tx buffers and 2^4 Rx buffers */

#ifndef LANCE_LOG_TX_BUFFERS
#define LANCE_LOG_TX_BUFFERS 4
#define LANCE_LOG_RX_BUFFERS 4
#endif

#define TX_RING_SIZE            (1 << (LANCE_LOG_TX_BUFFERS))
#define TX_RING_MOD_MASK        (TX_RING_SIZE - 1)

#define RX_RING_SIZE            (1 << (LANCE_LOG_RX_BUFFERS))
#define RX_RING_MOD_MASK        (RX_RING_SIZE - 1)

#define PKT_BUF_SZ      1536
#define RX_BUFF_SIZE            PKT_BUF_SZ
#define TX_BUFF_SIZE            PKT_BUF_SZ

#undef TEST_HITS
#define ZERO 0

/*
 * The DS2100/3100 have a linear 64 kB buffer which supports halfword
 * accesses only.  Each halfword of the buffer is word-aligned in the
 * CPU address space.
 *
 * The PMAD-AA has a 128 kB buffer on-board.
 *
 * The IOASIC LANCE devices use a shared memory region.  This region
 * as seen from the CPU is (max) 128 kB long and has to be on an 128 kB
 * boundary.  The LANCE sees this as a 64 kB long continuous memory
 * region.
 *
 * The LANCE's DMA address is used as an index in this buffer and DMA
 * takes place in bursts of eight 16-bit words which are packed into
 * four 32-bit words by the IOASIC.  This leads to a strange padding:
 * 16 bytes of valid data followed by a 16 byte gap :-(.
 */

struct lance_rx_desc {
    unsigned short rmd0;        /* low address of packet */
    unsigned short rmd1;        /* high address of packet
                       and descriptor bits */
    short length;           /* 2s complement (negative!)
                       of buffer length */
    unsigned short mblength;    /* actual number of bytes received */
};

struct lance_tx_desc {
    unsigned short tmd0;        /* low address of packet */
    unsigned short tmd1;        /* high address of packet
                       and descriptor bits */
    short length;           /* 2s complement (negative!)
                       of buffer length */
    unsigned short misc;
};


/* First part of the LANCE initialization block, described in databook. */
struct lance_init_block {
    unsigned short mode;        /* pre-set mode (reg. 15) */

    unsigned short phys_addr[3];    /* physical ethernet address */
    unsigned short filter[4];   /* multicast filter */

    /* Receive and transmit ring base, along with extra bits. */
    unsigned short rx_ptr;      /* receive descriptor addr */
    unsigned short rx_len;      /* receive len and high addr */
    unsigned short tx_ptr;      /* transmit descriptor addr */
    unsigned short tx_len;      /* transmit len and high addr */

    short gap[4];

    /* The buffer descriptors */
    struct lance_rx_desc brx_ring[RX_RING_SIZE];
    struct lance_tx_desc btx_ring[TX_RING_SIZE];
};

#define BUF_OFFSET_CPU sizeof(struct lance_init_block)
#define BUF_OFFSET_LNC sizeof(struct lance_init_block)

#define shift_off(off, type)                        \
    (type == ASIC_LANCE || type == PMAX_LANCE ? off << 1 : off)

#define lib_off(rt, type)                       \
    shift_off(offsetof(struct lance_init_block, rt), type)

#define lib_ptr(ib, rt, type)                       \
    ((volatile u16 *)((u8 *)(ib) + lib_off(rt, type)))

#define rds_off(rt, type)                       \
    shift_off(offsetof(struct lance_rx_desc, rt), type)

#define rds_ptr(rd, rt, type)                       \
    ((volatile u16 *)((u8 *)(rd) + rds_off(rt, type)))

#define tds_off(rt, type)                       \
    shift_off(offsetof(struct lance_tx_desc, rt), type)

#define tds_ptr(td, rt, type)                       \
    ((volatile u16 *)((u8 *)(td) + tds_off(rt, type)))

struct lance_private {
    struct net_device *next;
    int type;
    int dma_irq;
    volatile struct lance_regs *ll;

    spinlock_t  lock;

    int rx_new, tx_new;
    int rx_old, tx_old;

    unsigned short busmaster_regval;

    struct timer_list       multicast_timer;

    /* Pointers to the ring buffers as seen from the CPU */
    char *rx_buf_ptr_cpu[RX_RING_SIZE];
    char *tx_buf_ptr_cpu[TX_RING_SIZE];

    /* Pointers to the ring buffers as seen from the LANCE */
    uint rx_buf_ptr_lnc[RX_RING_SIZE];
    uint tx_buf_ptr_lnc[TX_RING_SIZE];
};

#define TX_BUFFS_AVAIL ((lp->tx_old<=lp->tx_new)?\
            lp->tx_old+TX_RING_MOD_MASK-lp->tx_new:\
            lp->tx_old - lp->tx_new-1)

/* The lance control ports are at an absolute address, machine and tc-slot
 * dependent.
 * DECstations do only 32-bit access and the LANCE uses 16 bit addresses,
 * so we have to give the structure an extra member making rap pointing
 * at the right address
 */
struct lance_regs {
    volatile unsigned short rdp;    /* register data port */
    unsigned short pad;
    volatile unsigned short rap;    /* register address port */
};

int dec_lance_debug = 2;

static struct tc_driver dec_lance_tc_driver;
static struct net_device *root_lance_dev;

static inline void writereg(volatile unsigned short *regptr, short value)
{
    *regptr = value;
    iob();
}

/* Load the CSR registers */
static void load_csrs(struct lance_private *lp)
{
    volatile struct lance_regs *ll = lp->ll;
    uint leptr;

    /* The address space as seen from the LANCE
     * begins at address 0. HK
     */
    leptr = 0;

    writereg(&ll->rap, LE_CSR1);
    writereg(&ll->rdp, (leptr & 0xFFFF));
    writereg(&ll->rap, LE_CSR2);
    writereg(&ll->rdp, leptr >> 16);
    writereg(&ll->rap, LE_CSR3);
    writereg(&ll->rdp, lp->busmaster_regval);

    /* Point back to csr0 */
    writereg(&ll->rap, LE_CSR0);
}

/*
 * Our specialized copy routines
 *
 */
static void cp_to_buf(const int type, void *to, const void *from, int len)
{
    unsigned short *tp;
    const unsigned short *fp;
    unsigned short clen;
    unsigned char *rtp;
    const unsigned char *rfp;

    if (type == PMAD_LANCE) {
        memcpy(to, from, len);
    } else if (type == PMAX_LANCE) {
        clen = len >> 1;
        tp = to;
        fp = from;

        while (clen--) {
            *tp++ = *fp++;
            tp++;
        }

        clen = len & 1;
        rtp = tp;
        rfp = fp;
        while (clen--) {
            *rtp++ = *rfp++;
        }
    } else {
        /*
         * copy 16 Byte chunks
         */
        clen = len >> 4;
        tp = to;
        fp = from;
        while (clen--) {
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            tp += 8;
        }

        /*
         * do the rest, if any.
         */
        clen = len & 15;
        rtp = (unsigned char *) tp;
        rfp = (unsigned char *) fp;
        while (clen--) {
            *rtp++ = *rfp++;
        }
    }

    iob();
}

static void cp_from_buf(const int type, void *to, const void *from, int len)
{
    unsigned short *tp;
    const unsigned short *fp;
    unsigned short clen;
    unsigned char *rtp;
    const unsigned char *rfp;

    if (type == PMAD_LANCE) {
        memcpy(to, from, len);
    } else if (type == PMAX_LANCE) {
        clen = len >> 1;
        tp = to;
        fp = from;
        while (clen--) {
            *tp++ = *fp++;
            fp++;
        }

        clen = len & 1;

        rtp = tp;
        rfp = fp;

        while (clen--) {
            *rtp++ = *rfp++;
        }
    } else {

        /*
         * copy 16 Byte chunks
         */
        clen = len >> 4;
        tp = to;
        fp = from;
        while (clen--) {
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            *tp++ = *fp++;
            fp += 8;
        }

        /*
         * do the rest, if any.
         */
        clen = len & 15;
        rtp = (unsigned char *) tp;
        rfp = (unsigned char *) fp;
        while (clen--) {
            *rtp++ = *rfp++;
        }


    }

}

/* Setup the Lance Rx and Tx rings */
static void lance_init_ring(struct net_device *dev)
{
    struct lance_private *lp = netdev_priv(dev);
    volatile u16 *ib = (volatile u16 *)dev->mem_start;
    uint leptr;
    int i;

    /* Lock out other processes while setting up hardware */
    netif_stop_queue(dev);
    lp->rx_new = lp->tx_new = 0;
    lp->rx_old = lp->tx_old = 0;

    /* Copy the ethernet address to the lance init block.
     * XXX bit 0 of the physical address registers has to be zero
     */
    *lib_ptr(ib, phys_addr[0], lp->type) = (dev->dev_addr[1] << 8) |
                     dev->dev_addr[0];
    *lib_ptr(ib, phys_addr[1], lp->type) = (dev->dev_addr[3] << 8) |
                     dev->dev_addr[2];
    *lib_ptr(ib, phys_addr[2], lp->type) = (dev->dev_addr[5] << 8) |
                     dev->dev_addr[4];
    /* Setup the initialization block */

    /* Setup rx descriptor pointer */
    leptr = offsetof(struct lance_init_block, brx_ring);
    *lib_ptr(ib, rx_len, lp->type) = (LANCE_LOG_RX_BUFFERS << 13) |
                     (leptr >> 16);
    *lib_ptr(ib, rx_ptr, lp->type) = leptr;
    if (ZERO)
        printk("RX ptr: %8.8x(%8.8x)\n",
               leptr, lib_off(brx_ring, lp->type));

    /* Setup tx descriptor pointer */
    leptr = offsetof(struct lance_init_block, btx_ring);
    *lib_ptr(ib, tx_len, lp->type) = (LANCE_LOG_TX_BUFFERS << 13) |
                     (leptr >> 16);
    *lib_ptr(ib, tx_ptr, lp->type) = leptr;
    if (ZERO)
        printk("TX ptr: %8.8x(%8.8x)\n",
               leptr, lib_off(btx_ring, lp->type));

    if (ZERO)
        printk("TX rings:\n");

    /* Setup the Tx ring entries */
    for (i = 0; i < TX_RING_SIZE; i++) {
        leptr = lp->tx_buf_ptr_lnc[i];
        *lib_ptr(ib, btx_ring[i].tmd0, lp->type) = leptr;
        *lib_ptr(ib, btx_ring[i].tmd1, lp->type) = (leptr >> 16) &
                               0xff;
        *lib_ptr(ib, btx_ring[i].length, lp->type) = 0xf000;
                        /* The ones required by tmd2 */
        *lib_ptr(ib, btx_ring[i].misc, lp->type) = 0;
        if (i < 3 && ZERO)
            printk("%d: 0x%8.8x(0x%8.8x)\n",
                   i, leptr, (uint)lp->tx_buf_ptr_cpu[i]);
    }

    /* Setup the Rx ring entries */
    if (ZERO)
        printk("RX rings:\n");
    for (i = 0; i < RX_RING_SIZE; i++) {
        leptr = lp->rx_buf_ptr_lnc[i];
        *lib_ptr(ib, brx_ring[i].rmd0, lp->type) = leptr;
        *lib_ptr(ib, brx_ring[i].rmd1, lp->type) = ((leptr >> 16) &
                                0xff) |
                               LE_R1_OWN;
        *lib_ptr(ib, brx_ring[i].length, lp->type) = -RX_BUFF_SIZE |
                                 0xf000;
        *lib_ptr(ib, brx_ring[i].mblength, lp->type) = 0;
        if (i < 3 && ZERO)
            printk("%d: 0x%8.8x(0x%8.8x)\n",
                   i, leptr, (uint)lp->rx_buf_ptr_cpu[i]);
    }
    iob();
}

static int init_restart_lance(struct lance_private *lp)
{
    volatile struct lance_regs *ll = lp->ll;
    int i;

    writereg(&ll->rap, LE_CSR0);
    writereg(&ll->rdp, LE_C0_INIT);

    /* Wait for the lance to complete initialization */
    for (i = 0; (i < 100) && !(ll->rdp & LE_C0_IDON); i++) {
        udelay(10);
    }
    if ((i == 100) || (ll->rdp & LE_C0_ERR)) {
        printk("LANCE unopened after %d ticks, csr0=%4.4x.\n",
               i, ll->rdp);
        return -1;
    }
    if ((ll->rdp & LE_C0_ERR)) {
        printk("LANCE unopened after %d ticks, csr0=%4.4x.\n",
               i, ll->rdp);
        return -1;
    }
    writereg(&ll->rdp, LE_C0_IDON);
    writereg(&ll->rdp, LE_C0_STRT);
    writereg(&ll->rdp, LE_C0_INEA);

    return 0;
}

static int lance_rx(struct net_device *dev)
{
    struct lance_private *lp = netdev_priv(dev);
    volatile u16 *ib = (volatile u16 *)dev->mem_start;
    volatile u16 *rd;
    unsigned short bits;
    int entry, len;
    struct sk_buff *skb;

#ifdef TEST_HITS
    {
        int i;

        printk("[");
        for (i = 0; i < RX_RING_SIZE; i++) {
            if (i == lp->rx_new)
                printk("%s", *lib_ptr(ib, brx_ring[i].rmd1,
                              lp->type) &
                         LE_R1_OWN ? "_" : "X");
            else
                printk("%s", *lib_ptr(ib, brx_ring[i].rmd1,
                              lp->type) &
                         LE_R1_OWN ? "." : "1");
        }
        printk("]");
    }
#endif

    for (rd = lib_ptr(ib, brx_ring[lp->rx_new], lp->type);
         !((bits = *rds_ptr(rd, rmd1, lp->type)) & LE_R1_OWN);
         rd = lib_ptr(ib, brx_ring[lp->rx_new], lp->type)) {
        entry = lp->rx_new;

        /* We got an incomplete frame? */
        if ((bits & LE_R1_POK) != LE_R1_POK) {
            dev->stats.rx_over_errors++;
            dev->stats.rx_errors++;
        } else if (bits & LE_R1_ERR) {
            /* Count only the end frame as a rx error,
             * not the beginning
             */
            if (bits & LE_R1_BUF)
                dev->stats.rx_fifo_errors++;
            if (bits & LE_R1_CRC)
                dev->stats.rx_crc_errors++;
            if (bits & LE_R1_OFL)
                dev->stats.rx_over_errors++;
            if (bits & LE_R1_FRA)
                dev->stats.rx_frame_errors++;
            if (bits & LE_R1_EOP)
                dev->stats.rx_errors++;
        } else {
            len = (*rds_ptr(rd, mblength, lp->type) & 0xfff) - 4;
            skb = netdev_alloc_skb(dev, len + 2);

            if (skb == 0) {
                printk("%s: Memory squeeze, deferring packet.\n",
                       dev->name);
                dev->stats.rx_dropped++;
                *rds_ptr(rd, mblength, lp->type) = 0;
                *rds_ptr(rd, rmd1, lp->type) =
                    ((lp->rx_buf_ptr_lnc[entry] >> 16) &
                     0xff) | LE_R1_OWN;
                lp->rx_new = (entry + 1) & RX_RING_MOD_MASK;
                return 0;
            }
            dev->stats.rx_bytes += len;

            skb_reserve(skb, 2);    /* 16 byte align */
            skb_put(skb, len);  /* make room */

            cp_from_buf(lp->type, skb->data,
                    lp->rx_buf_ptr_cpu[entry], len);

            skb->protocol = eth_type_trans(skb, dev);
            netif_rx(skb);
            dev->stats.rx_packets++;
        }

        /* Return the packet to the pool */
        *rds_ptr(rd, mblength, lp->type) = 0;
        *rds_ptr(rd, length, lp->type) = -RX_BUFF_SIZE | 0xf000;
        *rds_ptr(rd, rmd1, lp->type) =
            ((lp->rx_buf_ptr_lnc[entry] >> 16) & 0xff) | LE_R1_OWN;
        lp->rx_new = (entry + 1) & RX_RING_MOD_MASK;
    }
    return 0;
}

static void lance_tx(struct net_device *dev)
{
    struct lance_private *lp = netdev_priv(dev);
    volatile u16 *ib = (volatile u16 *)dev->mem_start;
    volatile struct lance_regs *ll = lp->ll;
    volatile u16 *td;
    int i, j;
    int status;

    j = lp->tx_old;

    spin_lock(&lp->lock);

    for (i = j; i != lp->tx_new; i = j) {
        td = lib_ptr(ib, btx_ring[i], lp->type);
        /* If we hit a packet not owned by us, stop */
        if (*tds_ptr(td, tmd1, lp->type) & LE_T1_OWN)
            break;

        if (*tds_ptr(td, tmd1, lp->type) & LE_T1_ERR) {
            status = *tds_ptr(td, misc, lp->type);

            dev->stats.tx_errors++;
            if (status & LE_T3_RTY)
                dev->stats.tx_aborted_errors++;
            if (status & LE_T3_LCOL)
                dev->stats.tx_window_errors++;

            if (status & LE_T3_CLOS) {
                dev->stats.tx_carrier_errors++;
                printk("%s: Carrier Lost\n", dev->name);
                /* Stop the lance */
                writereg(&ll->rap, LE_CSR0);
                writereg(&ll->rdp, LE_C0_STOP);
                lance_init_ring(dev);
                load_csrs(lp);
                init_restart_lance(lp);
                goto out;
            }
            /* Buffer errors and underflows turn off the
             * transmitter, restart the adapter.
             */
            if (status & (LE_T3_BUF | LE_T3_UFL)) {
                dev->stats.tx_fifo_errors++;

                printk("%s: Tx: ERR_BUF|ERR_UFL, restarting\n",
                       dev->name);
                /* Stop the lance */
                writereg(&ll->rap, LE_CSR0);
                writereg(&ll->rdp, LE_C0_STOP);
                lance_init_ring(dev);
                load_csrs(lp);
                init_restart_lance(lp);
                goto out;
            }
        } else if ((*tds_ptr(td, tmd1, lp->type) & LE_T1_POK) ==
               LE_T1_POK) {
            /*
             * So we don't count the packet more than once.
             */
            *tds_ptr(td, tmd1, lp->type) &= ~(LE_T1_POK);

            /* One collision before packet was sent. */
            if (*tds_ptr(td, tmd1, lp->type) & LE_T1_EONE)
                dev->stats.collisions++;

            /* More than one collision, be optimistic. */
            if (*tds_ptr(td, tmd1, lp->type) & LE_T1_EMORE)
                dev->stats.collisions += 2;

            dev->stats.tx_packets++;
        }
        j = (j + 1) & TX_RING_MOD_MASK;
    }
    lp->tx_old = j;
out:
    if (netif_queue_stopped(dev) &&
        TX_BUFFS_AVAIL > 0)
        netif_wake_queue(dev);

    spin_unlock(&lp->lock);
}

static irqreturn_t lance_dma_merr_int(int irq, void *dev_id)
{
    struct net_device *dev = dev_id;

    printk(KERN_ERR "%s: DMA error\n", dev->name);
    return IRQ_HANDLED;
}

static irqreturn_t lance_interrupt(int irq, void *dev_id)
{
    struct net_device *dev = dev_id;
    struct lance_private *lp = netdev_priv(dev);
    volatile struct lance_regs *ll = lp->ll;
    int csr0;

    writereg(&ll->rap, LE_CSR0);
    csr0 = ll->rdp;

    /* Acknowledge all the interrupt sources ASAP */
    writereg(&ll->rdp, csr0 & (LE_C0_INTR | LE_C0_TINT | LE_C0_RINT));

    if ((csr0 & LE_C0_ERR)) {
        /* Clear the error condition */
        writereg(&ll->rdp, LE_C0_BABL | LE_C0_ERR | LE_C0_MISS |
             LE_C0_CERR | LE_C0_MERR);
    }
    if (csr0 & LE_C0_RINT)
        lance_rx(dev);

    if (csr0 & LE_C0_TINT)
        lance_tx(dev);

    if (csr0 & LE_C0_BABL)
        dev->stats.tx_errors++;

    if (csr0 & LE_C0_MISS)
        dev->stats.rx_errors++;

    if (csr0 & LE_C0_MERR) {
        printk("%s: Memory error, status %04x\n", dev->name, csr0);

        writereg(&ll->rdp, LE_C0_STOP);

        lance_init_ring(dev);
        load_csrs(lp);
        init_restart_lance(lp);
        netif_wake_queue(dev);
    }

    writereg(&ll->rdp, LE_C0_INEA);
    writereg(&ll->rdp, LE_C0_INEA);
    return IRQ_HANDLED;
}

static int lance_open(struct net_device *dev)
{
    volatile u16 *ib = (volatile u16 *)dev->mem_start;
    struct lance_private *lp = netdev_priv(dev);
    volatile struct lance_regs *ll = lp->ll;
    int status = 0;

    /* Stop the Lance */
    writereg(&ll->rap, LE_CSR0);
    writereg(&ll->rdp, LE_C0_STOP);

    /* Set mode and clear multicast filter only at device open,
     * so that lance_init_ring() called at any error will not
     * forget multicast filters.
     *
     * BTW it is common bug in all lance drivers! --ANK
     */
    *lib_ptr(ib, mode, lp->type) = 0;
    *lib_ptr(ib, filter[0], lp->type) = 0;
    *lib_ptr(ib, filter[1], lp->type) = 0;
    *lib_ptr(ib, filter[2], lp->type) = 0;
    *lib_ptr(ib, filter[3], lp->type) = 0;

    lance_init_ring(dev);
    load_csrs(lp);

    netif_start_queue(dev);

    /* Associate IRQ with lance_interrupt */
    if (request_irq(dev->irq, lance_interrupt, 0, "lance", dev)) {
        printk("%s: Can't get IRQ %d\n", dev->name, dev->irq);
        return -EAGAIN;
    }
    if (lp->dma_irq >= 0) {
        unsigned long flags;

        if (request_irq(lp->dma_irq, lance_dma_merr_int, 0,
                "lance error", dev)) {
            free_irq(dev->irq, dev);
            printk("%s: Can't get DMA IRQ %d\n", dev->name,
                lp->dma_irq);
            return -EAGAIN;
        }

        spin_lock_irqsave(&ioasic_ssr_lock, flags);

        fast_mb();
        /* Enable I/O ASIC LANCE DMA.  */
        ioasic_write(IO_REG_SSR,
                 ioasic_read(IO_REG_SSR) | IO_SSR_LANCE_DMA_EN);

        fast_mb();
        spin_unlock_irqrestore(&ioasic_ssr_lock, flags);
    }

    status = init_restart_lance(lp);
    return status;
}

static int lance_close(struct net_device *dev)
{
    struct lance_private *lp = netdev_priv(dev);
    volatile struct lance_regs *ll = lp->ll;

    netif_stop_queue(dev);
    del_timer_sync(&lp->multicast_timer);

    /* Stop the card */
    writereg(&ll->rap, LE_CSR0);
    writereg(&ll->rdp, LE_C0_STOP);

    if (lp->dma_irq >= 0) {
        unsigned long flags;

        spin_lock_irqsave(&ioasic_ssr_lock, flags);

        fast_mb();
        /* Disable I/O ASIC LANCE DMA.  */
        ioasic_write(IO_REG_SSR,
                 ioasic_read(IO_REG_SSR) & ~IO_SSR_LANCE_DMA_EN);

        fast_iob();
        spin_unlock_irqrestore(&ioasic_ssr_lock, flags);

        free_irq(lp->dma_irq, dev);
    }
    free_irq(dev->irq, dev);
    return 0;
}

static inline int lance_reset(struct net_device *dev)
{
    struct lance_private *lp = netdev_priv(dev);
    volatile struct lance_regs *ll = lp->ll;
    int status;

    /* Stop the lance */
    writereg(&ll->rap, LE_CSR0);
    writereg(&ll->rdp, LE_C0_STOP);

    lance_init_ring(dev);
    load_csrs(lp);
    dev->trans_start = jiffies; /* prevent tx timeout */
    status = init_restart_lance(lp);
    return status;
}

static void lance_tx_timeout(struct net_device *dev)
{
    struct lance_private *lp = netdev_priv(dev);
    volatile struct lance_regs *ll = lp->ll;

    printk(KERN_ERR "%s: transmit timed out, status %04x, reset\n",
        dev->name, ll->rdp);
    lance_reset(dev);
    netif_wake_queue(dev);
}

static int lance_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
    struct lance_private *lp = netdev_priv(dev);
    volatile struct lance_regs *ll = lp->ll;
    volatile u16 *ib = (volatile u16 *)dev->mem_start;
    unsigned long flags;
    int entry, len;

    len = skb->len;

    if (len < ETH_ZLEN) {
        if (skb_padto(skb, ETH_ZLEN))
            return NETDEV_TX_OK;
        len = ETH_ZLEN;
    }

    dev->stats.tx_bytes += len;

    spin_lock_irqsave(&lp->lock, flags);

    entry = lp->tx_new;
    *lib_ptr(ib, btx_ring[entry].length, lp->type) = (-len);
    *lib_ptr(ib, btx_ring[entry].misc, lp->type) = 0;

    cp_to_buf(lp->type, lp->tx_buf_ptr_cpu[entry], skb->data, len);

    /* Now, give the packet to the lance */
    *lib_ptr(ib, btx_ring[entry].tmd1, lp->type) =
        ((lp->tx_buf_ptr_lnc[entry] >> 16) & 0xff) |
        (LE_T1_POK | LE_T1_OWN);
    lp->tx_new = (entry + 1) & TX_RING_MOD_MASK;

    if (TX_BUFFS_AVAIL <= 0)
        netif_stop_queue(dev);

    /* Kick the lance: transmit now */
    writereg(&ll->rdp, LE_C0_INEA | LE_C0_TDMD);

    spin_unlock_irqrestore(&lp->lock, flags);

    dev_kfree_skb(skb);

    return NETDEV_TX_OK;
}

static void lance_load_multicast(struct net_device *dev)
{
    struct lance_private *lp = netdev_priv(dev);
    volatile u16 *ib = (volatile u16 *)dev->mem_start;
    struct netdev_hw_addr *ha;
    u32 crc;

    /* set all multicast bits */
    if (dev->flags & IFF_ALLMULTI) {
        *lib_ptr(ib, filter[0], lp->type) = 0xffff;
        *lib_ptr(ib, filter[1], lp->type) = 0xffff;
        *lib_ptr(ib, filter[2], lp->type) = 0xffff;
        *lib_ptr(ib, filter[3], lp->type) = 0xffff;
        return;
    }
    /* clear the multicast filter */
    *lib_ptr(ib, filter[0], lp->type) = 0;
    *lib_ptr(ib, filter[1], lp->type) = 0;
    *lib_ptr(ib, filter[2], lp->type) = 0;
    *lib_ptr(ib, filter[3], lp->type) = 0;

    /* Add addresses */
    netdev_for_each_mc_addr(ha, dev) {
        crc = ether_crc_le(ETH_ALEN, ha->addr);
        crc = crc >> 26;
        *lib_ptr(ib, filter[crc >> 4], lp->type) |= 1 << (crc & 0xf);
    }
}

static void lance_set_multicast(struct net_device *dev)
{
    struct lance_private *lp = netdev_priv(dev);
    volatile u16 *ib = (volatile u16 *)dev->mem_start;
    volatile struct lance_regs *ll = lp->ll;

    if (!netif_running(dev))
        return;

    if (lp->tx_old != lp->tx_new) {
        mod_timer(&lp->multicast_timer, jiffies + 4 * HZ/100);
        netif_wake_queue(dev);
        return;
    }

    netif_stop_queue(dev);

    writereg(&ll->rap, LE_CSR0);
    writereg(&ll->rdp, LE_C0_STOP);

    lance_init_ring(dev);

    if (dev->flags & IFF_PROMISC) {
        *lib_ptr(ib, mode, lp->type) |= LE_MO_PROM;
    } else {
        *lib_ptr(ib, mode, lp->type) &= ~LE_MO_PROM;
        lance_load_multicast(dev);
    }
    load_csrs(lp);
    init_restart_lance(lp);
    netif_wake_queue(dev);
}

static void lance_set_multicast_retry(unsigned long _opaque)
{
    struct net_device *dev = (struct net_device *) _opaque;

    lance_set_multicast(dev);
}

static const struct net_device_ops lance_netdev_ops = {
    .ndo_open       = lance_open,
    .ndo_stop       = lance_close,
    .ndo_start_xmit     = lance_start_xmit,
    .ndo_tx_timeout     = lance_tx_timeout,
    .ndo_set_rx_mode    = lance_set_multicast,
    .ndo_change_mtu     = eth_change_mtu,
    .ndo_validate_addr  = eth_validate_addr,
    .ndo_set_mac_address    = eth_mac_addr,
};

static int __devinit dec_lance_probe(struct device *bdev, const int type)
{
    static unsigned version_printed;
    static const char fmt[] = "declance%d";
    char name[10];
    struct net_device *dev;
    struct lance_private *lp;
    volatile struct lance_regs *ll;
    resource_size_t start = 0, len = 0;
    int i, ret;
    unsigned long esar_base;
    unsigned char *esar;

    if (dec_lance_debug && version_printed++ == 0)
        printk(version);

    if (bdev)
        snprintf(name, sizeof(name), "%s", dev_name(bdev));
    else {
        i = 0;
        dev = root_lance_dev;
        while (dev) {
            i++;
            lp = netdev_priv(dev);
            dev = lp->next;
        }
        snprintf(name, sizeof(name), fmt, i);
    }

    dev = alloc_etherdev(sizeof(struct lance_private));
    if (!dev) {
        ret = -ENOMEM;
        goto err_out;
    }

    /*
     * alloc_etherdev ensures the data structures used by the LANCE
     * are aligned.
     */
    lp = netdev_priv(dev);
    spin_lock_init(&lp->lock);

    lp->type = type;
    switch (type) {
    case ASIC_LANCE:
        dev->base_addr = CKSEG1ADDR(dec_kn_slot_base + IOASIC_LANCE);

        /* buffer space for the on-board LANCE shared memory */
        /*
         * FIXME: ugly hack!
         */
        dev->mem_start = CKSEG1ADDR(0x00020000);
        dev->mem_end = dev->mem_start + 0x00020000;
        dev->irq = dec_interrupt[DEC_IRQ_LANCE];
        esar_base = CKSEG1ADDR(dec_kn_slot_base + IOASIC_ESAR);

        /* Workaround crash with booting KN04 2.1k from Disk */
        memset((void *)dev->mem_start, 0,
               dev->mem_end - dev->mem_start);

        /*
         * setup the pointer arrays, this sucks [tm] :-(
         */
        for (i = 0; i < RX_RING_SIZE; i++) {
            lp->rx_buf_ptr_cpu[i] =
                (char *)(dev->mem_start + 2 * BUF_OFFSET_CPU +
                     2 * i * RX_BUFF_SIZE);
            lp->rx_buf_ptr_lnc[i] =
                (BUF_OFFSET_LNC + i * RX_BUFF_SIZE);
        }
        for (i = 0; i < TX_RING_SIZE; i++) {
            lp->tx_buf_ptr_cpu[i] =
                (char *)(dev->mem_start + 2 * BUF_OFFSET_CPU +
                     2 * RX_RING_SIZE * RX_BUFF_SIZE +
                     2 * i * TX_BUFF_SIZE);
            lp->tx_buf_ptr_lnc[i] =
                (BUF_OFFSET_LNC +
                 RX_RING_SIZE * RX_BUFF_SIZE +
                 i * TX_BUFF_SIZE);
        }

        /* Setup I/O ASIC LANCE DMA.  */
        lp->dma_irq = dec_interrupt[DEC_IRQ_LANCE_MERR];
        ioasic_write(IO_REG_LANCE_DMA_P,
                 CPHYSADDR(dev->mem_start) << 3);

        break;
#ifdef CONFIG_TC
    case PMAD_LANCE:
        dev_set_drvdata(bdev, dev);

        start = to_tc_dev(bdev)->resource.start;
        len = to_tc_dev(bdev)->resource.end - start + 1;
        if (!request_mem_region(start, len, dev_name(bdev))) {
            printk(KERN_ERR
                   "%s: Unable to reserve MMIO resource\n",
                   dev_name(bdev));
            ret = -EBUSY;
            goto err_out_dev;
        }

        dev->mem_start = CKSEG1ADDR(start);
        dev->mem_end = dev->mem_start + 0x100000;
        dev->base_addr = dev->mem_start + 0x100000;
        dev->irq = to_tc_dev(bdev)->interrupt;
        esar_base = dev->mem_start + 0x1c0002;
        lp->dma_irq = -1;

        for (i = 0; i < RX_RING_SIZE; i++) {
            lp->rx_buf_ptr_cpu[i] =
                (char *)(dev->mem_start + BUF_OFFSET_CPU +
                     i * RX_BUFF_SIZE);
            lp->rx_buf_ptr_lnc[i] =
                (BUF_OFFSET_LNC + i * RX_BUFF_SIZE);
        }
        for (i = 0; i < TX_RING_SIZE; i++) {
            lp->tx_buf_ptr_cpu[i] =
                (char *)(dev->mem_start + BUF_OFFSET_CPU +
                     RX_RING_SIZE * RX_BUFF_SIZE +
                     i * TX_BUFF_SIZE);
            lp->tx_buf_ptr_lnc[i] =
                (BUF_OFFSET_LNC +
                 RX_RING_SIZE * RX_BUFF_SIZE +
                 i * TX_BUFF_SIZE);
        }

        break;
#endif
    case PMAX_LANCE:
        dev->irq = dec_interrupt[DEC_IRQ_LANCE];
        dev->base_addr = CKSEG1ADDR(KN01_SLOT_BASE + KN01_LANCE);
        dev->mem_start = CKSEG1ADDR(KN01_SLOT_BASE + KN01_LANCE_MEM);
        dev->mem_end = dev->mem_start + KN01_SLOT_SIZE;
        esar_base = CKSEG1ADDR(KN01_SLOT_BASE + KN01_ESAR + 1);
        lp->dma_irq = -1;

        /*
         * setup the pointer arrays, this sucks [tm] :-(
         */
        for (i = 0; i < RX_RING_SIZE; i++) {
            lp->rx_buf_ptr_cpu[i] =
                (char *)(dev->mem_start + 2 * BUF_OFFSET_CPU +
                     2 * i * RX_BUFF_SIZE);
            lp->rx_buf_ptr_lnc[i] =
                (BUF_OFFSET_LNC + i * RX_BUFF_SIZE);
        }
        for (i = 0; i < TX_RING_SIZE; i++) {
            lp->tx_buf_ptr_cpu[i] =
                (char *)(dev->mem_start + 2 * BUF_OFFSET_CPU +
                     2 * RX_RING_SIZE * RX_BUFF_SIZE +
                     2 * i * TX_BUFF_SIZE);
            lp->tx_buf_ptr_lnc[i] =
                (BUF_OFFSET_LNC +
                 RX_RING_SIZE * RX_BUFF_SIZE +
                 i * TX_BUFF_SIZE);
        }

        break;

    default:
        printk(KERN_ERR "%s: declance_init called with unknown type\n",
            name);
        ret = -ENODEV;
        goto err_out_dev;
    }

    ll = (struct lance_regs *) dev->base_addr;
    esar = (unsigned char *) esar_base;

    /* prom checks */
    /* First, check for test pattern */
    if (esar[0x60] != 0xff && esar[0x64] != 0x00 &&
        esar[0x68] != 0x55 && esar[0x6c] != 0xaa) {
        printk(KERN_ERR
            "%s: Ethernet station address prom not found!\n",
            name);
        ret = -ENODEV;
        goto err_out_resource;
    }
    /* Check the prom contents */
    for (i = 0; i < 8; i++) {
        if (esar[i * 4] != esar[0x3c - i * 4] &&
            esar[i * 4] != esar[0x40 + i * 4] &&
            esar[0x3c - i * 4] != esar[0x40 + i * 4]) {
            printk(KERN_ERR "%s: Something is wrong with the "
                "ethernet station address prom!\n", name);
            ret = -ENODEV;
            goto err_out_resource;
        }
    }

    /* Copy the ethernet address to the device structure, later to the
     * lance initialization block so the lance gets it every time it's
     * (re)initialized.
     */
    switch (type) {
    case ASIC_LANCE:
        printk("%s: IOASIC onboard LANCE", name);
        break;
    case PMAD_LANCE:
        printk("%s: PMAD-AA", name);
        break;
    case PMAX_LANCE:
        printk("%s: PMAX onboard LANCE", name);
        break;
    }
    for (i = 0; i < 6; i++)
        dev->dev_addr[i] = esar[i * 4];

    printk(", addr = %pM, irq = %d\n", dev->dev_addr, dev->irq);

    dev->netdev_ops = &lance_netdev_ops;
    dev->watchdog_timeo = 5*HZ;

    /* lp->ll is the location of the registers for lance card */
    lp->ll = ll;

    /* busmaster_regval (CSR3) should be zero according to the PMAD-AA
     * specification.
     */
    lp->busmaster_regval = 0;

    dev->dma = 0;

    /* We cannot sleep if the chip is busy during a
     * multicast list update event, because such events
     * can occur from interrupts (ex. IPv6).  So we
     * use a timer to try again later when necessary. -DaveM
     */
    init_timer(&lp->multicast_timer);
    lp->multicast_timer.data = (unsigned long) dev;
    lp->multicast_timer.function = lance_set_multicast_retry;

    ret = register_netdev(dev);
    if (ret) {
        printk(KERN_ERR
            "%s: Unable to register netdev, aborting.\n", name);
        goto err_out_resource;
    }

    if (!bdev) {
        lp->next = root_lance_dev;
        root_lance_dev = dev;
    }

    printk("%s: registered as %s.\n", name, dev->name);
    return 0;

err_out_resource:
    if (bdev)
        release_mem_region(start, len);

err_out_dev:
    free_netdev(dev);

err_out:
    return ret;
}

static void __exit dec_lance_remove(struct device *bdev)
{
    struct net_device *dev = dev_get_drvdata(bdev);
    resource_size_t start, len;

    unregister_netdev(dev);
    start = to_tc_dev(bdev)->resource.start;
    len = to_tc_dev(bdev)->resource.end - start + 1;
    release_mem_region(start, len);
    free_netdev(dev);
}

/* Find all the lance cards on the system and initialize them */
static int __init dec_lance_platform_probe(void)
{
    int count = 0;

    if (dec_interrupt[DEC_IRQ_LANCE] >= 0) {
        if (dec_interrupt[DEC_IRQ_LANCE_MERR] >= 0) {
            if (dec_lance_probe(NULL, ASIC_LANCE) >= 0)
                count++;
        } else if (!TURBOCHANNEL) {
            if (dec_lance_probe(NULL, PMAX_LANCE) >= 0)
                count++;
        }
    }

    return (count > 0) ? 0 : -ENODEV;
}

static void __exit dec_lance_platform_remove(void)
{
    while (root_lance_dev) {
        struct net_device *dev = root_lance_dev;
        struct lance_private *lp = netdev_priv(dev);

        unregister_netdev(dev);
        root_lance_dev = lp->next;
        free_netdev(dev);
    }
}

#ifdef CONFIG_TC
static int __devinit dec_lance_tc_probe(struct device *dev);
static int __exit dec_lance_tc_remove(struct device *dev);

static const struct tc_device_id dec_lance_tc_table[] = {
    { "DEC     ", "PMAD-AA " },
    { }
};
MODULE_DEVICE_TABLE(tc, dec_lance_tc_table);

static struct tc_driver dec_lance_tc_driver = {
    .id_table   = dec_lance_tc_table,
    .driver     = {
        .name   = "declance",
        .bus    = &tc_bus_type,
        .probe  = dec_lance_tc_probe,
        .remove = __exit_p(dec_lance_tc_remove),
    },
};

static int __devinit dec_lance_tc_probe(struct device *dev)
{
        int status = dec_lance_probe(dev, PMAD_LANCE);
        if (!status)
                get_device(dev);
        return status;
}

static int __exit dec_lance_tc_remove(struct device *dev)
{
        put_device(dev);
        dec_lance_remove(dev);
        return 0;
}
#endif

static int __init dec_lance_init(void)
{
    int status;

    status = tc_register_driver(&dec_lance_tc_driver);
    if (!status)
        dec_lance_platform_probe();
    return status;
}

static void __exit dec_lance_exit(void)
{
    dec_lance_platform_remove();
    tc_unregister_driver(&dec_lance_tc_driver);
}


module_init(dec_lance_init);
module_exit(dec_lance_exit);