[PATCH] via-rhine: zero pad short packets on Rhine I ethernet cards

[deliverable/linux.git] / drivers / net / sgiseeq.c

/*
 * sgiseeq.c: Seeq8003 ethernet driver for SGI machines.
 *
 * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/route.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/bitops.h>

#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/sgi/hpc3.h>
#include <asm/sgi/ip22.h>
#include <asm/sgialib.h>

#include "sgiseeq.h"

static char *sgiseeqstr = "SGI Seeq8003";

/*
 * If you want speed, you do something silly, it always has worked for me.  So,
 * with that in mind, I've decided to make this driver look completely like a
 * stupid Lance from a driver architecture perspective.  Only difference is that
 * here our "ring buffer" looks and acts like a real Lance one does but is
 * layed out like how the HPC DMA and the Seeq want it to.  You'd be surprised
 * how a stupid idea like this can pay off in performance, not to mention
 * making this driver 2,000 times easier to write. ;-)
 */

/* Tune these if we tend to run out often etc. */
#define SEEQ_RX_BUFFERS  16
#define SEEQ_TX_BUFFERS  16

#define PKT_BUF_SZ       1584

#define NEXT_RX(i)  (((i) + 1) & (SEEQ_RX_BUFFERS - 1))
#define NEXT_TX(i)  (((i) + 1) & (SEEQ_TX_BUFFERS - 1))
#define PREV_RX(i)  (((i) - 1) & (SEEQ_RX_BUFFERS - 1))
#define PREV_TX(i)  (((i) - 1) & (SEEQ_TX_BUFFERS - 1))

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

struct sgiseeq_rx_desc {
        volatile struct hpc_dma_desc rdma;
        volatile signed int buf_vaddr;
};

struct sgiseeq_tx_desc {
        volatile struct hpc_dma_desc tdma;
        volatile signed int buf_vaddr;
};

/*
 * Warning: This structure is layed out in a certain way because HPC dma
 *          descriptors must be 8-byte aligned.  So don't touch this without
 *          some care.
 */
struct sgiseeq_init_block { /* Note the name ;-) */
        struct sgiseeq_rx_desc rxvector[SEEQ_RX_BUFFERS];
        struct sgiseeq_tx_desc txvector[SEEQ_TX_BUFFERS];
};

struct sgiseeq_private {
        struct sgiseeq_init_block *srings;

        /* Ptrs to the descriptors in uncached space. */
        struct sgiseeq_rx_desc *rx_desc;
        struct sgiseeq_tx_desc *tx_desc;

        char *name;
        struct hpc3_ethregs *hregs;
        struct sgiseeq_regs *sregs;

        /* Ring entry counters. */
        unsigned int rx_new, tx_new;
        unsigned int rx_old, tx_old;

        int is_edlc;
        unsigned char control;
        unsigned char mode;

        struct net_device_stats stats;

        struct net_device *next_module;
        spinlock_t tx_lock;
};

/* A list of all installed seeq devices, for removing the driver module. */
static struct net_device *root_sgiseeq_dev;

static inline void hpc3_eth_reset(struct hpc3_ethregs *hregs)
{
        hregs->reset = HPC3_ERST_CRESET | HPC3_ERST_CLRIRQ;
        udelay(20);
        hregs->reset = 0;
}

static inline void reset_hpc3_and_seeq(struct hpc3_ethregs *hregs,
                                       struct sgiseeq_regs *sregs)
{
        hregs->rx_ctrl = hregs->tx_ctrl = 0;
        hpc3_eth_reset(hregs);
}

#define RSTAT_GO_BITS (SEEQ_RCMD_IGOOD | SEEQ_RCMD_IEOF | SEEQ_RCMD_ISHORT | \
                       SEEQ_RCMD_IDRIB | SEEQ_RCMD_ICRC)

static inline void seeq_go(struct sgiseeq_private *sp,
                           struct hpc3_ethregs *hregs,
                           struct sgiseeq_regs *sregs)
{
        sregs->rstat = sp->mode | RSTAT_GO_BITS;
        hregs->rx_ctrl = HPC3_ERXCTRL_ACTIVE;
}

static inline void __sgiseeq_set_mac_address(struct net_device *dev)
{
        struct sgiseeq_private *sp = netdev_priv(dev);
        struct sgiseeq_regs *sregs = sp->sregs;
        int i;

        sregs->tstat = SEEQ_TCMD_RB0;
        for (i = 0; i < 6; i++)
                sregs->rw.eth_addr[i] = dev->dev_addr[i];
}

static int sgiseeq_set_mac_address(struct net_device *dev, void *addr)
{
        struct sgiseeq_private *sp = netdev_priv(dev);
        struct sockaddr *sa = addr;

        memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);

        spin_lock_irq(&sp->tx_lock);
        __sgiseeq_set_mac_address(dev);
        spin_unlock_irq(&sp->tx_lock);

        return 0;
}

#define TCNTINFO_INIT (HPCDMA_EOX | HPCDMA_ETXD)
#define RCNTCFG_INIT  (HPCDMA_OWN | HPCDMA_EORP | HPCDMA_XIE)
#define RCNTINFO_INIT (RCNTCFG_INIT | (PKT_BUF_SZ & HPCDMA_BCNT))

static int seeq_init_ring(struct net_device *dev)
{
        struct sgiseeq_private *sp = netdev_priv(dev);
        int i;

        netif_stop_queue(dev);
        sp->rx_new = sp->tx_new = 0;
        sp->rx_old = sp->tx_old = 0;

        __sgiseeq_set_mac_address(dev);

        /* Setup tx ring. */
        for(i = 0; i < SEEQ_TX_BUFFERS; i++) {
                if (!sp->tx_desc[i].tdma.pbuf) {
                        unsigned long buffer;

                        buffer = (unsigned long) kmalloc(PKT_BUF_SZ, GFP_KERNEL);
                        if (!buffer)
                                return -ENOMEM;
                        sp->tx_desc[i].buf_vaddr = CKSEG1ADDR(buffer);
                        sp->tx_desc[i].tdma.pbuf = CPHYSADDR(buffer);
                }
                sp->tx_desc[i].tdma.cntinfo = TCNTINFO_INIT;
        }

        /* And now the rx ring. */
        for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
                if (!sp->rx_desc[i].rdma.pbuf) {
                        unsigned long buffer;

                        buffer = (unsigned long) kmalloc(PKT_BUF_SZ, GFP_KERNEL);
                        if (!buffer)
                                return -ENOMEM;
                        sp->rx_desc[i].buf_vaddr = CKSEG1ADDR(buffer);
                        sp->rx_desc[i].rdma.pbuf = CPHYSADDR(buffer);
                }
                sp->rx_desc[i].rdma.cntinfo = RCNTINFO_INIT;
        }
        sp->rx_desc[i - 1].rdma.cntinfo |= HPCDMA_EOR;
        return 0;
}

#ifdef DEBUG
static struct sgiseeq_private *gpriv;
static struct net_device *gdev;

static void sgiseeq_dump_rings(void)
{
        static int once;
        struct sgiseeq_rx_desc *r = gpriv->rx_desc;
        struct sgiseeq_tx_desc *t = gpriv->tx_desc;
        struct hpc3_ethregs *hregs = gpriv->hregs;
        int i;

        if (once)
                return;
        once++;
        printk("RING DUMP:\n");
        for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
                printk("RX [%d]: @(%p) [%08x,%08x,%08x] ",
                       i, (&r[i]), r[i].rdma.pbuf, r[i].rdma.cntinfo,
                       r[i].rdma.pnext);
                i += 1;
                printk("-- [%d]: @(%p) [%08x,%08x,%08x]\n",
                       i, (&r[i]), r[i].rdma.pbuf, r[i].rdma.cntinfo,
                       r[i].rdma.pnext);
        }
        for (i = 0; i < SEEQ_TX_BUFFERS; i++) {
                printk("TX [%d]: @(%p) [%08x,%08x,%08x] ",
                       i, (&t[i]), t[i].tdma.pbuf, t[i].tdma.cntinfo,
                       t[i].tdma.pnext);
                i += 1;
                printk("-- [%d]: @(%p) [%08x,%08x,%08x]\n",
                       i, (&t[i]), t[i].tdma.pbuf, t[i].tdma.cntinfo,
                       t[i].tdma.pnext);
        }
        printk("INFO: [rx_new = %d rx_old=%d] [tx_new = %d tx_old = %d]\n",
               gpriv->rx_new, gpriv->rx_old, gpriv->tx_new, gpriv->tx_old);
        printk("RREGS: rx_cbptr[%08x] rx_ndptr[%08x] rx_ctrl[%08x]\n",
               hregs->rx_cbptr, hregs->rx_ndptr, hregs->rx_ctrl);
        printk("TREGS: tx_cbptr[%08x] tx_ndptr[%08x] tx_ctrl[%08x]\n",
               hregs->tx_cbptr, hregs->tx_ndptr, hregs->tx_ctrl);
}
#endif

#define TSTAT_INIT_SEEQ (SEEQ_TCMD_IPT|SEEQ_TCMD_I16|SEEQ_TCMD_IC|SEEQ_TCMD_IUF)
#define TSTAT_INIT_EDLC ((TSTAT_INIT_SEEQ) | SEEQ_TCMD_RB2)

static int init_seeq(struct net_device *dev, struct sgiseeq_private *sp,
                     struct sgiseeq_regs *sregs)
{
        struct hpc3_ethregs *hregs = sp->hregs;
        int err;

        reset_hpc3_and_seeq(hregs, sregs);
        err = seeq_init_ring(dev);
        if (err)
                return err;

        /* Setup to field the proper interrupt types. */
        if (sp->is_edlc) {
                sregs->tstat = TSTAT_INIT_EDLC;
                sregs->rw.wregs.control = sp->control;
                sregs->rw.wregs.frame_gap = 0;
        } else {
                sregs->tstat = TSTAT_INIT_SEEQ;
        }

        hregs->rx_ndptr = CPHYSADDR(sp->rx_desc);
        hregs->tx_ndptr = CPHYSADDR(sp->tx_desc);

        seeq_go(sp, hregs, sregs);
        return 0;
}

static inline void record_rx_errors(struct sgiseeq_private *sp,
                                    unsigned char status)
{
        if (status & SEEQ_RSTAT_OVERF ||
            status & SEEQ_RSTAT_SFRAME)
                sp->stats.rx_over_errors++;
        if (status & SEEQ_RSTAT_CERROR)
                sp->stats.rx_crc_errors++;
        if (status & SEEQ_RSTAT_DERROR)
                sp->stats.rx_frame_errors++;
        if (status & SEEQ_RSTAT_REOF)
                sp->stats.rx_errors++;
}

static inline void rx_maybe_restart(struct sgiseeq_private *sp,
                                    struct hpc3_ethregs *hregs,
                                    struct sgiseeq_regs *sregs)
{
        if (!(hregs->rx_ctrl & HPC3_ERXCTRL_ACTIVE)) {
                hregs->rx_ndptr = CPHYSADDR(sp->rx_desc + sp->rx_new);
                seeq_go(sp, hregs, sregs);
        }
}

#define for_each_rx(rd, sp) for((rd) = &(sp)->rx_desc[(sp)->rx_new]; \
                                !((rd)->rdma.cntinfo & HPCDMA_OWN); \
                                (rd) = &(sp)->rx_desc[(sp)->rx_new])

static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp,
                              struct hpc3_ethregs *hregs,
                              struct sgiseeq_regs *sregs)
{
        struct sgiseeq_rx_desc *rd;
        struct sk_buff *skb = NULL;
        unsigned char pkt_status;
        unsigned char *pkt_pointer = NULL;
        int len = 0;
        unsigned int orig_end = PREV_RX(sp->rx_new);

        /* Service every received packet. */
        for_each_rx(rd, sp) {
                len = PKT_BUF_SZ - (rd->rdma.cntinfo & HPCDMA_BCNT) - 3;
                pkt_pointer = (unsigned char *)(long)rd->buf_vaddr;
                pkt_status = pkt_pointer[len + 2];

                if (pkt_status & SEEQ_RSTAT_FIG) {
                        /* Packet is OK. */
                        skb = dev_alloc_skb(len + 2);

                        if (skb) {
                                skb->dev = dev;
                                skb_reserve(skb, 2);
                                skb_put(skb, len);

                                /* Copy out of kseg1 to avoid silly cache flush. */
                                eth_copy_and_sum(skb, pkt_pointer + 2, len, 0);
                                skb->protocol = eth_type_trans(skb, dev);

                                /* We don't want to receive our own packets */
                                if (memcmp(eth_hdr(skb)->h_source, dev->dev_addr, ETH_ALEN)) {
                                        netif_rx(skb);
                                        dev->last_rx = jiffies;
                                        sp->stats.rx_packets++;
                                        sp->stats.rx_bytes += len;
                                } else {
                                        /* Silently drop my own packets */
                                        dev_kfree_skb_irq(skb);
                                }
                        } else {
                                printk (KERN_NOTICE "%s: Memory squeeze, deferring packet.\n",
                                        dev->name);
                                sp->stats.rx_dropped++;
                        }
                } else {
                        record_rx_errors(sp, pkt_status);
                }

                /* Return the entry to the ring pool. */
                rd->rdma.cntinfo = RCNTINFO_INIT;
                sp->rx_new = NEXT_RX(sp->rx_new);
        }
        sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR);
        sp->rx_desc[PREV_RX(sp->rx_new)].rdma.cntinfo |= HPCDMA_EOR;
        rx_maybe_restart(sp, hregs, sregs);
}

static inline void tx_maybe_reset_collisions(struct sgiseeq_private *sp,
                                             struct sgiseeq_regs *sregs)
{
        if (sp->is_edlc) {
                sregs->rw.wregs.control = sp->control & ~(SEEQ_CTRL_XCNT);
                sregs->rw.wregs.control = sp->control;
        }
}

static inline void kick_tx(struct sgiseeq_tx_desc *td,
                           struct hpc3_ethregs *hregs)
{
        /* If the HPC aint doin nothin, and there are more packets
         * with ETXD cleared and XIU set we must make very certain
         * that we restart the HPC else we risk locking up the
         * adapter.  The following code is only safe iff the HPCDMA
         * is not active!
         */
        while ((td->tdma.cntinfo & (HPCDMA_XIU | HPCDMA_ETXD)) ==
              (HPCDMA_XIU | HPCDMA_ETXD))
                td = (struct sgiseeq_tx_desc *)(long) CKSEG1ADDR(td->tdma.pnext);
        if (td->tdma.cntinfo & HPCDMA_XIU) {
                hregs->tx_ndptr = CPHYSADDR(td);
                hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
        }
}

static inline void sgiseeq_tx(struct net_device *dev, struct sgiseeq_private *sp,
                              struct hpc3_ethregs *hregs,
                              struct sgiseeq_regs *sregs)
{
        struct sgiseeq_tx_desc *td;
        unsigned long status = hregs->tx_ctrl;
        int j;

        tx_maybe_reset_collisions(sp, sregs);

        if (!(status & (HPC3_ETXCTRL_ACTIVE | SEEQ_TSTAT_PTRANS))) {
                /* Oops, HPC detected some sort of error. */
                if (status & SEEQ_TSTAT_R16)
                        sp->stats.tx_aborted_errors++;
                if (status & SEEQ_TSTAT_UFLOW)
                        sp->stats.tx_fifo_errors++;
                if (status & SEEQ_TSTAT_LCLS)
                        sp->stats.collisions++;
        }

        /* Ack 'em... */
        for (j = sp->tx_old; j != sp->tx_new; j = NEXT_TX(j)) {
                td = &sp->tx_desc[j];

                if (!(td->tdma.cntinfo & (HPCDMA_XIU)))
                        break;
                if (!(td->tdma.cntinfo & (HPCDMA_ETXD))) {
                        if (!(status & HPC3_ETXCTRL_ACTIVE)) {
                                hregs->tx_ndptr = CPHYSADDR(td);
                                hregs->tx_ctrl = HPC3_ETXCTRL_ACTIVE;
                        }
                        break;
                }
                sp->stats.tx_packets++;
                sp->tx_old = NEXT_TX(sp->tx_old);
                td->tdma.cntinfo &= ~(HPCDMA_XIU | HPCDMA_XIE);
                td->tdma.cntinfo |= HPCDMA_EOX;
        }
}

static irqreturn_t sgiseeq_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
        struct net_device *dev = (struct net_device *) dev_id;
        struct sgiseeq_private *sp = netdev_priv(dev);
        struct hpc3_ethregs *hregs = sp->hregs;
        struct sgiseeq_regs *sregs = sp->sregs;

        spin_lock(&sp->tx_lock);

        /* Ack the IRQ and set software state. */
        hregs->reset = HPC3_ERST_CLRIRQ;

        /* Always check for received packets. */
        sgiseeq_rx(dev, sp, hregs, sregs);

        /* Only check for tx acks if we have something queued. */
        if (sp->tx_old != sp->tx_new)
                sgiseeq_tx(dev, sp, hregs, sregs);

        if ((TX_BUFFS_AVAIL(sp) > 0) && netif_queue_stopped(dev)) {
                netif_wake_queue(dev);
        }
        spin_unlock(&sp->tx_lock);

        return IRQ_HANDLED;
}

static int sgiseeq_open(struct net_device *dev)
{
        struct sgiseeq_private *sp = netdev_priv(dev);
        struct sgiseeq_regs *sregs = sp->sregs;
        unsigned int irq = dev->irq;
        int err;

        if (request_irq(irq, sgiseeq_interrupt, 0, sgiseeqstr, dev)) {
                printk(KERN_ERR "Seeq8003: Can't get irq %d\n", dev->irq);
                err = -EAGAIN;
        }

        err = init_seeq(dev, sp, sregs);
        if (err)
                goto out_free_irq;

        netif_start_queue(dev);

        return 0;

out_free_irq:
        free_irq(irq, dev);

        return err;
}

static int sgiseeq_close(struct net_device *dev)
{
        struct sgiseeq_private *sp = netdev_priv(dev);
        struct sgiseeq_regs *sregs = sp->sregs;
        unsigned int irq = dev->irq;

        netif_stop_queue(dev);

        /* Shutdown the Seeq. */
        reset_hpc3_and_seeq(sp->hregs, sregs);
        free_irq(irq, dev);

        return 0;
}

static inline int sgiseeq_reset(struct net_device *dev)
{
        struct sgiseeq_private *sp = netdev_priv(dev);
        struct sgiseeq_regs *sregs = sp->sregs;
        int err;

        err = init_seeq(dev, sp, sregs);
        if (err)
                return err;

        dev->trans_start = jiffies;
        netif_wake_queue(dev);

        return 0;
}

static int sgiseeq_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct sgiseeq_private *sp = netdev_priv(dev);
        struct hpc3_ethregs *hregs = sp->hregs;
        unsigned long flags;
        struct sgiseeq_tx_desc *td;
        int skblen, len, entry;

        spin_lock_irqsave(&sp->tx_lock, flags);

        /* Setup... */
        skblen = skb->len;
        len = (skblen <= ETH_ZLEN) ? ETH_ZLEN : skblen;
        sp->stats.tx_bytes += len;
        entry = sp->tx_new;
        td = &sp->tx_desc[entry];

        /* Create entry.  There are so many races with adding a new
         * descriptor to the chain:
         * 1) Assume that the HPC is off processing a DMA chain while
         *    we are changing all of the following.
         * 2) Do no allow the HPC to look at a new descriptor until
         *    we have completely set up it's state.  This means, do
         *    not clear HPCDMA_EOX in the current last descritptor
         *    until the one we are adding looks consistent and could
         *    be processes right now.
         * 3) The tx interrupt code must notice when we've added a new
         *    entry and the HPC got to the end of the chain before we
         *    added this new entry and restarted it.
         */
        memcpy((char *)(long)td->buf_vaddr, skb->data, skblen);
        if (len != skblen)
                memset((char *)(long)td->buf_vaddr + skb->len, 0, len-skblen);
        td->tdma.cntinfo = (len & HPCDMA_BCNT) |
                           HPCDMA_XIU | HPCDMA_EOXP | HPCDMA_XIE | HPCDMA_EOX;
        if (sp->tx_old != sp->tx_new) {
                struct sgiseeq_tx_desc *backend;

                backend = &sp->tx_desc[PREV_TX(sp->tx_new)];
                backend->tdma.cntinfo &= ~HPCDMA_EOX;
        }
        sp->tx_new = NEXT_TX(sp->tx_new); /* Advance. */

        /* Maybe kick the HPC back into motion. */
        if (!(hregs->tx_ctrl & HPC3_ETXCTRL_ACTIVE))
                kick_tx(&sp->tx_desc[sp->tx_old], hregs);

        dev->trans_start = jiffies;
        dev_kfree_skb(skb);

        if (!TX_BUFFS_AVAIL(sp))
                netif_stop_queue(dev);
        spin_unlock_irqrestore(&sp->tx_lock, flags);

        return 0;
}

static void timeout(struct net_device *dev)
{
        printk(KERN_NOTICE "%s: transmit timed out, resetting\n", dev->name);
        sgiseeq_reset(dev);

        dev->trans_start = jiffies;
        netif_wake_queue(dev);
}

static struct net_device_stats *sgiseeq_get_stats(struct net_device *dev)
{
        struct sgiseeq_private *sp = netdev_priv(dev);

        return &sp->stats;
}

static void sgiseeq_set_multicast(struct net_device *dev)
{
        struct sgiseeq_private *sp = (struct sgiseeq_private *) dev->priv;
        unsigned char oldmode = sp->mode;

        if(dev->flags & IFF_PROMISC)
                sp->mode = SEEQ_RCMD_RANY;
        else if ((dev->flags & IFF_ALLMULTI) || dev->mc_count)
                sp->mode = SEEQ_RCMD_RBMCAST;
        else
                sp->mode = SEEQ_RCMD_RBCAST;

        /* XXX I know this sucks, but is there a better way to reprogram
         * XXX the receiver? At least, this shouldn't happen too often.
         */

        if (oldmode != sp->mode)
                sgiseeq_reset(dev);
}

static inline void setup_tx_ring(struct sgiseeq_tx_desc *buf, int nbufs)
{
        int i = 0;

        while (i < (nbufs - 1)) {
                buf[i].tdma.pnext = CPHYSADDR(buf + i + 1);
                buf[i].tdma.pbuf = 0;
                i++;
        }
        buf[i].tdma.pnext = CPHYSADDR(buf);
}

static inline void setup_rx_ring(struct sgiseeq_rx_desc *buf, int nbufs)
{
        int i = 0;

        while (i < (nbufs - 1)) {
                buf[i].rdma.pnext = CPHYSADDR(buf + i + 1);
                buf[i].rdma.pbuf = 0;
                i++;
        }
        buf[i].rdma.pbuf = 0;
        buf[i].rdma.pnext = CPHYSADDR(buf);
}

#define ALIGNED(x)  ((((unsigned long)(x)) + 0xf) & ~(0xf))

static int sgiseeq_init(struct hpc3_regs* hpcregs, int irq)
{
        struct sgiseeq_init_block *sr;
        struct sgiseeq_private *sp;
        struct net_device *dev;
        int err, i;

        dev = alloc_etherdev(sizeof (struct sgiseeq_private));
        if (!dev) {
                printk(KERN_ERR "Sgiseeq: Etherdev alloc failed, aborting.\n");
                err = -ENOMEM;
                goto err_out;
        }
        sp = netdev_priv(dev);

        /* Make private data page aligned */
        sr = (struct sgiseeq_init_block *) get_zeroed_page(GFP_KERNEL);
        if (!sr) {
                printk(KERN_ERR "Sgiseeq: Page alloc failed, aborting.\n");
                err = -ENOMEM;
                goto err_out_free_dev;
        }
        sp->srings = sr;

#define EADDR_NVOFS     250
        for (i = 0; i < 3; i++) {
                unsigned short tmp = ip22_nvram_read(EADDR_NVOFS / 2 + i);

                dev->dev_addr[2 * i]     = tmp >> 8;
                dev->dev_addr[2 * i + 1] = tmp & 0xff;
        }

#ifdef DEBUG
        gpriv = sp;
        gdev = dev;
#endif
        sp->sregs = (struct sgiseeq_regs *) &hpcregs->eth_ext[0];
        sp->hregs = &hpcregs->ethregs;
        sp->name = sgiseeqstr;
        sp->mode = SEEQ_RCMD_RBCAST;

        sp->rx_desc = (struct sgiseeq_rx_desc *)
                      CKSEG1ADDR(ALIGNED(&sp->srings->rxvector[0]));
        dma_cache_wback_inv((unsigned long)&sp->srings->rxvector,
                            sizeof(sp->srings->rxvector));
        sp->tx_desc = (struct sgiseeq_tx_desc *)
                      CKSEG1ADDR(ALIGNED(&sp->srings->txvector[0]));
        dma_cache_wback_inv((unsigned long)&sp->srings->txvector,
                            sizeof(sp->srings->txvector));

        /* A couple calculations now, saves many cycles later. */
        setup_rx_ring(sp->rx_desc, SEEQ_RX_BUFFERS);
        setup_tx_ring(sp->tx_desc, SEEQ_TX_BUFFERS);

        /* Setup PIO and DMA transfer timing */
        sp->hregs->pconfig = 0x161;
        sp->hregs->dconfig = HPC3_EDCFG_FIRQ | HPC3_EDCFG_FEOP |
                             HPC3_EDCFG_FRXDC | HPC3_EDCFG_PTO | 0x026;

        /* Reset the chip. */
        hpc3_eth_reset(sp->hregs);

        sp->is_edlc = !(sp->sregs->rw.rregs.collision_tx[0] & 0xff);
        if (sp->is_edlc)
                sp->control = SEEQ_CTRL_XCNT | SEEQ_CTRL_ACCNT |
                              SEEQ_CTRL_SFLAG | SEEQ_CTRL_ESHORT |
                              SEEQ_CTRL_ENCARR;

        dev->open               = sgiseeq_open;
        dev->stop               = sgiseeq_close;
        dev->hard_start_xmit    = sgiseeq_start_xmit;
        dev->tx_timeout         = timeout;
        dev->watchdog_timeo     = (200 * HZ) / 1000;
        dev->get_stats          = sgiseeq_get_stats;
        dev->set_multicast_list = sgiseeq_set_multicast;
        dev->set_mac_address    = sgiseeq_set_mac_address;
        dev->irq                = irq;

        if (register_netdev(dev)) {
                printk(KERN_ERR "Sgiseeq: Cannot register net device, "
                       "aborting.\n");
                err = -ENODEV;
                goto err_out_free_page;
        }

        printk(KERN_INFO "%s: %s ", dev->name, sgiseeqstr);
        for (i = 0; i < 6; i++)
                printk("%2.2x%c", dev->dev_addr[i], i == 5 ? '\n' : ':');

        sp->next_module = root_sgiseeq_dev;
        root_sgiseeq_dev = dev;

        return 0;

err_out_free_page:
        free_page((unsigned long) sp->srings);
err_out_free_dev:
        kfree(dev);

err_out:
        return err;
}

static int __init sgiseeq_probe(void)
{
        /* On board adapter on 1st HPC is always present */
        return sgiseeq_init(hpc3c0, SGI_ENET_IRQ);
}

static void __exit sgiseeq_exit(void)
{
        struct net_device *next, *dev;
        struct sgiseeq_private *sp;

        for (dev = root_sgiseeq_dev; dev; dev = next) {
                sp = (struct sgiseeq_private *) netdev_priv(dev);
                next = sp->next_module;
                unregister_netdev(dev);
                free_page((unsigned long) sp->srings);
                free_netdev(dev);
        }
}

module_init(sgiseeq_probe);
module_exit(sgiseeq_exit);

MODULE_DESCRIPTION("SGI Seeq 8003 driver");
MODULE_AUTHOR("Linux/MIPS Mailing List <linux-mips@linux-mips.org>");
MODULE_LICENSE("GPL");