Linux-2.6.12-rc2

[mirror_ubuntu-artful-kernel.git] / drivers / net / rrunner.c

/*
 * rrunner.c: Linux driver for the Essential RoadRunner HIPPI board.
 *
 * Copyright (C) 1998-2002 by Jes Sorensen, <jes@wildopensource.com>.
 *
 * Thanks to Essential Communication for providing us with hardware
 * and very comprehensive documentation without which I would not have
 * been able to write this driver. A special thank you to John Gibbon
 * for sorting out the legal issues, with the NDA, allowing the code to
 * be released under the GPL.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Thanks to Jayaram Bhat from ODS/Essential for fixing some of the
 * stupid bugs in my code.
 *
 * Softnet support and various other patches from Val Henson of
 * ODS/Essential.
 *
 * PCI DMA mapping code partly based on work by Francois Romieu.
 */


#define DEBUG 1
#define RX_DMA_SKBUFF 1
#define PKT_COPY_THRESHOLD 512

#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/hippidevice.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <net/sock.h>

#include <asm/system.h>
#include <asm/cache.h>
#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>

#define rr_if_busy(dev)     netif_queue_stopped(dev)
#define rr_if_running(dev)  netif_running(dev)

#include "rrunner.h"

#define RUN_AT(x) (jiffies + (x))


MODULE_AUTHOR("Jes Sorensen <jes@wildopensource.com>");
MODULE_DESCRIPTION("Essential RoadRunner HIPPI driver");
MODULE_LICENSE("GPL");

static char version[] __devinitdata = "rrunner.c: v0.50 11/11/2002  Jes Sorensen (jes@wildopensource.com)\n";

/*
 * Implementation notes:
 *
 * The DMA engine only allows for DMA within physical 64KB chunks of
 * memory. The current approach of the driver (and stack) is to use
 * linear blocks of memory for the skbuffs. However, as the data block
 * is always the first part of the skb and skbs are 2^n aligned so we
 * are guarantted to get the whole block within one 64KB align 64KB
 * chunk.
 *
 * On the long term, relying on being able to allocate 64KB linear
 * chunks of memory is not feasible and the skb handling code and the
 * stack will need to know about I/O vectors or something similar.
 */

/*
 * These are checked at init time to see if they are at least 256KB
 * and increased to 256KB if they are not. This is done to avoid ending
 * up with socket buffers smaller than the MTU size,
 */
extern __u32 sysctl_wmem_max;
extern __u32 sysctl_rmem_max;

static int __devinit rr_init_one(struct pci_dev *pdev,
        const struct pci_device_id *ent)
{
        struct net_device *dev;
        static int version_disp;
        u8 pci_latency;
        struct rr_private *rrpriv;
        void *tmpptr;
        dma_addr_t ring_dma;
        int ret = -ENOMEM;

        dev = alloc_hippi_dev(sizeof(struct rr_private));
        if (!dev)
                goto out3;

        ret = pci_enable_device(pdev);
        if (ret) {
                ret = -ENODEV;
                goto out2;
        }

        rrpriv = netdev_priv(dev);

        SET_MODULE_OWNER(dev);
        SET_NETDEV_DEV(dev, &pdev->dev);

        if (pci_request_regions(pdev, "rrunner")) {
                ret = -EIO;
                goto out;
        }

        pci_set_drvdata(pdev, dev);

        rrpriv->pci_dev = pdev;

        spin_lock_init(&rrpriv->lock);

        dev->irq = pdev->irq;
        dev->open = &rr_open;
        dev->hard_start_xmit = &rr_start_xmit;
        dev->stop = &rr_close;
        dev->get_stats = &rr_get_stats;
        dev->do_ioctl = &rr_ioctl;

        dev->base_addr = pci_resource_start(pdev, 0);

        /* display version info if adapter is found */
        if (!version_disp) {
                /* set display flag to TRUE so that */
                /* we only display this string ONCE */
                version_disp = 1;
                printk(version);
        }

        pci_read_config_byte(pdev, PCI_LATENCY_TIMER, &pci_latency);
        if (pci_latency <= 0x58){
                pci_latency = 0x58;
                pci_write_config_byte(pdev, PCI_LATENCY_TIMER, pci_latency);
        }

        pci_set_master(pdev);

        printk(KERN_INFO "%s: Essential RoadRunner serial HIPPI "
               "at 0x%08lx, irq %i, PCI latency %i\n", dev->name,
               dev->base_addr, dev->irq, pci_latency);

        /*
         * Remap the regs into kernel space.
         */

        rrpriv->regs = ioremap(dev->base_addr, 0x1000);

        if (!rrpriv->regs){
                printk(KERN_ERR "%s:  Unable to map I/O register, "
                        "RoadRunner will be disabled.\n", dev->name);
                ret = -EIO;
                goto out;
        }

        tmpptr = pci_alloc_consistent(pdev, TX_TOTAL_SIZE, &ring_dma);
        rrpriv->tx_ring = tmpptr;
        rrpriv->tx_ring_dma = ring_dma;

        if (!tmpptr) {
                ret = -ENOMEM;
                goto out;
        }

        tmpptr = pci_alloc_consistent(pdev, RX_TOTAL_SIZE, &ring_dma);
        rrpriv->rx_ring = tmpptr;
        rrpriv->rx_ring_dma = ring_dma;

        if (!tmpptr) {
                ret = -ENOMEM;
                goto out;
        }

        tmpptr = pci_alloc_consistent(pdev, EVT_RING_SIZE, &ring_dma);
        rrpriv->evt_ring = tmpptr;
        rrpriv->evt_ring_dma = ring_dma;

        if (!tmpptr) {
                ret = -ENOMEM;
                goto out;
        }

        /*
         * Don't access any register before this point!
         */
#ifdef __BIG_ENDIAN
        writel(readl(&rrpriv->regs->HostCtrl) | NO_SWAP,
                &rrpriv->regs->HostCtrl);
#endif
        /*
         * Need to add a case for little-endian 64-bit hosts here.
         */

        rr_init(dev);

        dev->base_addr = 0;

        ret = register_netdev(dev);
        if (ret)
                goto out;
        return 0;

 out:
        if (rrpriv->rx_ring)
                pci_free_consistent(pdev, RX_TOTAL_SIZE, rrpriv->rx_ring, 
                                    rrpriv->rx_ring_dma);
        if (rrpriv->tx_ring)
                pci_free_consistent(pdev, TX_TOTAL_SIZE, rrpriv->tx_ring,
                                    rrpriv->tx_ring_dma);
        if (rrpriv->regs)
                iounmap(rrpriv->regs);  
        if (pdev) {
                pci_release_regions(pdev);
                pci_set_drvdata(pdev, NULL);
        }
 out2:
        free_netdev(dev);
 out3:
        return ret;
}

static void __devexit rr_remove_one (struct pci_dev *pdev)
{
        struct net_device *dev = pci_get_drvdata(pdev);

        if (dev) {
                struct rr_private *rr = netdev_priv(dev);

                if (!(readl(&rr->regs->HostCtrl) & NIC_HALTED)){
                        printk(KERN_ERR "%s: trying to unload running NIC\n",
                               dev->name);
                        writel(HALT_NIC, &rr->regs->HostCtrl);
                }

                pci_free_consistent(pdev, EVT_RING_SIZE, rr->evt_ring,
                                    rr->evt_ring_dma);
                pci_free_consistent(pdev, RX_TOTAL_SIZE, rr->rx_ring,
                                    rr->rx_ring_dma);
                pci_free_consistent(pdev, TX_TOTAL_SIZE, rr->tx_ring,
                                    rr->tx_ring_dma);
                unregister_netdev(dev);
                iounmap(rr->regs);
                free_netdev(dev);
                pci_release_regions(pdev);
                pci_disable_device(pdev);
                pci_set_drvdata(pdev, NULL);
        }
}


/*
 * Commands are considered to be slow, thus there is no reason to
 * inline this.
 */
static void rr_issue_cmd(struct rr_private *rrpriv, struct cmd *cmd)
{
        struct rr_regs __iomem *regs;
        u32 idx;

        regs = rrpriv->regs;
        /*
         * This is temporary - it will go away in the final version.
         * We probably also want to make this function inline.
         */
        if (readl(&regs->HostCtrl) & NIC_HALTED){
                printk("issuing command for halted NIC, code 0x%x, "
                       "HostCtrl %08x\n", cmd->code, readl(&regs->HostCtrl));
                if (readl(&regs->Mode) & FATAL_ERR)
                        printk("error codes Fail1 %02x, Fail2 %02x\n",
                               readl(&regs->Fail1), readl(&regs->Fail2));
        }

        idx = rrpriv->info->cmd_ctrl.pi;

        writel(*(u32*)(cmd), &regs->CmdRing[idx]);
        wmb();

        idx = (idx - 1) % CMD_RING_ENTRIES;
        rrpriv->info->cmd_ctrl.pi = idx;
        wmb();

        if (readl(&regs->Mode) & FATAL_ERR)
                printk("error code %02x\n", readl(&regs->Fail1));
}


/*
 * Reset the board in a sensible manner. The NIC is already halted
 * when we get here and a spin-lock is held.
 */
static int rr_reset(struct net_device *dev)
{
        struct rr_private *rrpriv;
        struct rr_regs __iomem *regs;
        struct eeprom *hw = NULL;
        u32 start_pc;
        int i;

        rrpriv = netdev_priv(dev);
        regs = rrpriv->regs;

        rr_load_firmware(dev);

        writel(0x01000000, &regs->TX_state);
        writel(0xff800000, &regs->RX_state);
        writel(0, &regs->AssistState);
        writel(CLEAR_INTA, &regs->LocalCtrl);
        writel(0x01, &regs->BrkPt);
        writel(0, &regs->Timer);
        writel(0, &regs->TimerRef);
        writel(RESET_DMA, &regs->DmaReadState);
        writel(RESET_DMA, &regs->DmaWriteState);
        writel(0, &regs->DmaWriteHostHi);
        writel(0, &regs->DmaWriteHostLo);
        writel(0, &regs->DmaReadHostHi);
        writel(0, &regs->DmaReadHostLo);
        writel(0, &regs->DmaReadLen);
        writel(0, &regs->DmaWriteLen);
        writel(0, &regs->DmaWriteLcl);
        writel(0, &regs->DmaWriteIPchecksum);
        writel(0, &regs->DmaReadLcl);
        writel(0, &regs->DmaReadIPchecksum);
        writel(0, &regs->PciState);
#if (BITS_PER_LONG == 64) && defined __LITTLE_ENDIAN
        writel(SWAP_DATA | PTR64BIT | PTR_WD_SWAP, &regs->Mode);
#elif (BITS_PER_LONG == 64)
        writel(SWAP_DATA | PTR64BIT | PTR_WD_NOSWAP, &regs->Mode);
#else
        writel(SWAP_DATA | PTR32BIT | PTR_WD_NOSWAP, &regs->Mode);
#endif

#if 0
        /*
         * Don't worry, this is just black magic.
         */
        writel(0xdf000, &regs->RxBase);
        writel(0xdf000, &regs->RxPrd);
        writel(0xdf000, &regs->RxCon);
        writel(0xce000, &regs->TxBase);
        writel(0xce000, &regs->TxPrd);
        writel(0xce000, &regs->TxCon);
        writel(0, &regs->RxIndPro);
        writel(0, &regs->RxIndCon);
        writel(0, &regs->RxIndRef);
        writel(0, &regs->TxIndPro);
        writel(0, &regs->TxIndCon);
        writel(0, &regs->TxIndRef);
        writel(0xcc000, &regs->pad10[0]);
        writel(0, &regs->DrCmndPro);
        writel(0, &regs->DrCmndCon);
        writel(0, &regs->DwCmndPro);
        writel(0, &regs->DwCmndCon);
        writel(0, &regs->DwCmndRef);
        writel(0, &regs->DrDataPro);
        writel(0, &regs->DrDataCon);
        writel(0, &regs->DrDataRef);
        writel(0, &regs->DwDataPro);
        writel(0, &regs->DwDataCon);
        writel(0, &regs->DwDataRef);
#endif

        writel(0xffffffff, &regs->MbEvent);
        writel(0, &regs->Event);

        writel(0, &regs->TxPi);
        writel(0, &regs->IpRxPi);

        writel(0, &regs->EvtCon);
        writel(0, &regs->EvtPrd);

        rrpriv->info->evt_ctrl.pi = 0;

        for (i = 0; i < CMD_RING_ENTRIES; i++)
                writel(0, &regs->CmdRing[i]);

/*
 * Why 32 ? is this not cache line size dependent?
 */
        writel(RBURST_64|WBURST_64, &regs->PciState);
        wmb();

        start_pc = rr_read_eeprom_word(rrpriv, &hw->rncd_info.FwStart);

#if (DEBUG > 1)
        printk("%s: Executing firmware at address 0x%06x\n",
               dev->name, start_pc);
#endif

        writel(start_pc + 0x800, &regs->Pc);
        wmb();
        udelay(5);

        writel(start_pc, &regs->Pc);
        wmb();

        return 0;
}


/*
 * Read a string from the EEPROM.
 */
static unsigned int rr_read_eeprom(struct rr_private *rrpriv,
                                unsigned long offset,
                                unsigned char *buf,
                                unsigned long length)
{
        struct rr_regs __iomem *regs = rrpriv->regs;
        u32 misc, io, host, i;

        io = readl(&regs->ExtIo);
        writel(0, &regs->ExtIo);
        misc = readl(&regs->LocalCtrl);
        writel(0, &regs->LocalCtrl);
        host = readl(&regs->HostCtrl);
        writel(host | HALT_NIC, &regs->HostCtrl);
        mb();

        for (i = 0; i < length; i++){
                writel((EEPROM_BASE + ((offset+i) << 3)), &regs->WinBase);
                mb();
                buf[i] = (readl(&regs->WinData) >> 24) & 0xff;
                mb();
        }

        writel(host, &regs->HostCtrl);
        writel(misc, &regs->LocalCtrl);
        writel(io, &regs->ExtIo);
        mb();
        return i;
}


/*
 * Shortcut to read one word (4 bytes) out of the EEPROM and convert
 * it to our CPU byte-order.
 */
static u32 rr_read_eeprom_word(struct rr_private *rrpriv,
                            void * offset)
{
        u32 word;

        if ((rr_read_eeprom(rrpriv, (unsigned long)offset,
                            (char *)&word, 4) == 4))
                return be32_to_cpu(word);
        return 0;
}


/*
 * Write a string to the EEPROM.
 *
 * This is only called when the firmware is not running.
 */
static unsigned int write_eeprom(struct rr_private *rrpriv,
                                 unsigned long offset,
                                 unsigned char *buf,
                                 unsigned long length)
{
        struct rr_regs __iomem *regs = rrpriv->regs;
        u32 misc, io, data, i, j, ready, error = 0;

        io = readl(&regs->ExtIo);
        writel(0, &regs->ExtIo);
        misc = readl(&regs->LocalCtrl);
        writel(ENABLE_EEPROM_WRITE, &regs->LocalCtrl);
        mb();

        for (i = 0; i < length; i++){
                writel((EEPROM_BASE + ((offset+i) << 3)), &regs->WinBase);
                mb();
                data = buf[i] << 24;
                /*
                 * Only try to write the data if it is not the same
                 * value already.
                 */
                if ((readl(&regs->WinData) & 0xff000000) != data){
                        writel(data, &regs->WinData);
                        ready = 0;
                        j = 0;
                        mb();
                        while(!ready){
                                udelay(20);
                                if ((readl(&regs->WinData) & 0xff000000) ==
                                    data)
                                        ready = 1;
                                mb();
                                if (j++ > 5000){
                                        printk("data mismatch: %08x, "
                                               "WinData %08x\n", data,
                                               readl(&regs->WinData));
                                        ready = 1;
                                        error = 1;
                                }
                        }
                }
        }

        writel(misc, &regs->LocalCtrl);
        writel(io, &regs->ExtIo);
        mb();

        return error;
}


static int __init rr_init(struct net_device *dev)
{
        struct rr_private *rrpriv;
        struct rr_regs __iomem *regs;
        struct eeprom *hw = NULL;
        u32 sram_size, rev;
        int i;

        rrpriv = netdev_priv(dev);
        regs = rrpriv->regs;

        rev = readl(&regs->FwRev);
        rrpriv->fw_rev = rev;
        if (rev > 0x00020024)
                printk("  Firmware revision: %i.%i.%i\n", (rev >> 16),
                       ((rev >> 8) & 0xff), (rev & 0xff));
        else if (rev >= 0x00020000) {
                printk("  Firmware revision: %i.%i.%i (2.0.37 or "
                       "later is recommended)\n", (rev >> 16),
                       ((rev >> 8) & 0xff), (rev & 0xff));
        }else{
                printk("  Firmware revision too old: %i.%i.%i, please "
                       "upgrade to 2.0.37 or later.\n",
                       (rev >> 16), ((rev >> 8) & 0xff), (rev & 0xff));
        }

#if (DEBUG > 2)
        printk("  Maximum receive rings %i\n", readl(&regs->MaxRxRng));
#endif

        /*
         * Read the hardware address from the eeprom.  The HW address
         * is not really necessary for HIPPI but awfully convenient.
         * The pointer arithmetic to put it in dev_addr is ugly, but
         * Donald Becker does it this way for the GigE version of this
         * card and it's shorter and more portable than any
         * other method I've seen.  -VAL
         */

        *(u16 *)(dev->dev_addr) =
          htons(rr_read_eeprom_word(rrpriv, &hw->manf.BoardULA));
        *(u32 *)(dev->dev_addr+2) =
          htonl(rr_read_eeprom_word(rrpriv, &hw->manf.BoardULA[4]));
        
        printk("  MAC: ");

        for (i = 0; i < 5; i++)
                printk("%2.2x:", dev->dev_addr[i]);
        printk("%2.2x\n", dev->dev_addr[i]);

        sram_size = rr_read_eeprom_word(rrpriv, (void *)8);
        printk("  SRAM size 0x%06x\n", sram_size);

        if (sysctl_rmem_max < 262144){
                printk("  Receive socket buffer limit too low (%i), "
                       "setting to 262144\n", sysctl_rmem_max);
                sysctl_rmem_max = 262144;
        }

        if (sysctl_wmem_max < 262144){
                printk("  Transmit socket buffer limit too low (%i), "
                       "setting to 262144\n", sysctl_wmem_max);
                sysctl_wmem_max = 262144;
        }

        return 0;
}


static int rr_init1(struct net_device *dev)
{
        struct rr_private *rrpriv;
        struct rr_regs __iomem *regs;
        unsigned long myjif, flags;
        struct cmd cmd;
        u32 hostctrl;
        int ecode = 0;
        short i;

        rrpriv = netdev_priv(dev);
        regs = rrpriv->regs;

        spin_lock_irqsave(&rrpriv->lock, flags);

        hostctrl = readl(&regs->HostCtrl);
        writel(hostctrl | HALT_NIC | RR_CLEAR_INT, &regs->HostCtrl);
        wmb();

        if (hostctrl & PARITY_ERR){
                printk("%s: Parity error halting NIC - this is serious!\n",
                       dev->name);
                spin_unlock_irqrestore(&rrpriv->lock, flags);
                ecode = -EFAULT;
                goto error;
        }

        set_rxaddr(regs, rrpriv->rx_ctrl_dma);
        set_infoaddr(regs, rrpriv->info_dma);

        rrpriv->info->evt_ctrl.entry_size = sizeof(struct event);
        rrpriv->info->evt_ctrl.entries = EVT_RING_ENTRIES;
        rrpriv->info->evt_ctrl.mode = 0;
        rrpriv->info->evt_ctrl.pi = 0;
        set_rraddr(&rrpriv->info->evt_ctrl.rngptr, rrpriv->evt_ring_dma);

        rrpriv->info->cmd_ctrl.entry_size = sizeof(struct cmd);
        rrpriv->info->cmd_ctrl.entries = CMD_RING_ENTRIES;
        rrpriv->info->cmd_ctrl.mode = 0;
        rrpriv->info->cmd_ctrl.pi = 15;

        for (i = 0; i < CMD_RING_ENTRIES; i++) {
                writel(0, &regs->CmdRing[i]);
        }

        for (i = 0; i < TX_RING_ENTRIES; i++) {
                rrpriv->tx_ring[i].size = 0;
                set_rraddr(&rrpriv->tx_ring[i].addr, 0);
                rrpriv->tx_skbuff[i] = NULL;
        }
        rrpriv->info->tx_ctrl.entry_size = sizeof(struct tx_desc);
        rrpriv->info->tx_ctrl.entries = TX_RING_ENTRIES;
        rrpriv->info->tx_ctrl.mode = 0;
        rrpriv->info->tx_ctrl.pi = 0;
        set_rraddr(&rrpriv->info->tx_ctrl.rngptr, rrpriv->tx_ring_dma);

        /*
         * Set dirty_tx before we start receiving interrupts, otherwise
         * the interrupt handler might think it is supposed to process
         * tx ints before we are up and running, which may cause a null
         * pointer access in the int handler.
         */
        rrpriv->tx_full = 0;
        rrpriv->cur_rx = 0;
        rrpriv->dirty_rx = rrpriv->dirty_tx = 0;

        rr_reset(dev);

        /* Tuning values */
        writel(0x5000, &regs->ConRetry);
        writel(0x100, &regs->ConRetryTmr);
        writel(0x500000, &regs->ConTmout);
        writel(0x60, &regs->IntrTmr);
        writel(0x500000, &regs->TxDataMvTimeout);
        writel(0x200000, &regs->RxDataMvTimeout);
        writel(0x80, &regs->WriteDmaThresh);
        writel(0x80, &regs->ReadDmaThresh);

        rrpriv->fw_running = 0;
        wmb();

        hostctrl &= ~(HALT_NIC | INVALID_INST_B | PARITY_ERR);
        writel(hostctrl, &regs->HostCtrl);
        wmb();

        spin_unlock_irqrestore(&rrpriv->lock, flags);

        for (i = 0; i < RX_RING_ENTRIES; i++) {
                struct sk_buff *skb;
                dma_addr_t addr;

                rrpriv->rx_ring[i].mode = 0;
                skb = alloc_skb(dev->mtu + HIPPI_HLEN, GFP_ATOMIC);
                if (!skb) {
                        printk(KERN_WARNING "%s: Unable to allocate memory "
                               "for receive ring - halting NIC\n", dev->name);
                        ecode = -ENOMEM;
                        goto error;
                }
                rrpriv->rx_skbuff[i] = skb;
                addr = pci_map_single(rrpriv->pci_dev, skb->data,
                        dev->mtu + HIPPI_HLEN, PCI_DMA_FROMDEVICE);
                /*
                 * Sanity test to see if we conflict with the DMA
                 * limitations of the Roadrunner.
                 */
                if ((((unsigned long)skb->data) & 0xfff) > ~65320)
                        printk("skb alloc error\n");

                set_rraddr(&rrpriv->rx_ring[i].addr, addr);
                rrpriv->rx_ring[i].size = dev->mtu + HIPPI_HLEN;
        }

        rrpriv->rx_ctrl[4].entry_size = sizeof(struct rx_desc);
        rrpriv->rx_ctrl[4].entries = RX_RING_ENTRIES;
        rrpriv->rx_ctrl[4].mode = 8;
        rrpriv->rx_ctrl[4].pi = 0;
        wmb();
        set_rraddr(&rrpriv->rx_ctrl[4].rngptr, rrpriv->rx_ring_dma);

        udelay(1000);

        /*
         * Now start the FirmWare.
         */
        cmd.code = C_START_FW;
        cmd.ring = 0;
        cmd.index = 0;

        rr_issue_cmd(rrpriv, &cmd);

        /*
         * Give the FirmWare time to chew on the `get running' command.
         */
        myjif = jiffies + 5 * HZ;
        while (time_before(jiffies, myjif) && !rrpriv->fw_running)
                cpu_relax();

        netif_start_queue(dev);

        return ecode;

 error:
        /*
         * We might have gotten here because we are out of memory,
         * make sure we release everything we allocated before failing
         */
        for (i = 0; i < RX_RING_ENTRIES; i++) {
                struct sk_buff *skb = rrpriv->rx_skbuff[i];

                if (skb) {
                        pci_unmap_single(rrpriv->pci_dev, 
                                         rrpriv->rx_ring[i].addr.addrlo, 
                                         dev->mtu + HIPPI_HLEN,
                                         PCI_DMA_FROMDEVICE);
                        rrpriv->rx_ring[i].size = 0;
                        set_rraddr(&rrpriv->rx_ring[i].addr, 0);
                        dev_kfree_skb(skb);
                        rrpriv->rx_skbuff[i] = NULL;
                }
        }
        return ecode;
}


/*
 * All events are considered to be slow (RX/TX ints do not generate
 * events) and are handled here, outside the main interrupt handler,
 * to reduce the size of the handler.
 */
static u32 rr_handle_event(struct net_device *dev, u32 prodidx, u32 eidx)
{
        struct rr_private *rrpriv;
        struct rr_regs __iomem *regs;
        u32 tmp;

        rrpriv = netdev_priv(dev);
        regs = rrpriv->regs;

        while (prodidx != eidx){
                switch (rrpriv->evt_ring[eidx].code){
                case E_NIC_UP:
                        tmp = readl(&regs->FwRev);
                        printk(KERN_INFO "%s: Firmware revision %i.%i.%i "
                               "up and running\n", dev->name,
                               (tmp >> 16), ((tmp >> 8) & 0xff), (tmp & 0xff));
                        rrpriv->fw_running = 1;
                        writel(RX_RING_ENTRIES - 1, &regs->IpRxPi);
                        wmb();
                        break;
                case E_LINK_ON:
                        printk(KERN_INFO "%s: Optical link ON\n", dev->name);
                        break;
                case E_LINK_OFF:
                        printk(KERN_INFO "%s: Optical link OFF\n", dev->name);
                        break;
                case E_RX_IDLE:
                        printk(KERN_WARNING "%s: RX data not moving\n",
                               dev->name);
                        goto drop;
                case E_WATCHDOG:
                        printk(KERN_INFO "%s: The watchdog is here to see "
                               "us\n", dev->name);
                        break;
                case E_INTERN_ERR:
                        printk(KERN_ERR "%s: HIPPI Internal NIC error\n",
                               dev->name);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                case E_HOST_ERR:
                        printk(KERN_ERR "%s: Host software error\n",
                               dev->name);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                /*
                 * TX events.
                 */
                case E_CON_REJ:
                        printk(KERN_WARNING "%s: Connection rejected\n",
                               dev->name);
                        rrpriv->stats.tx_aborted_errors++;
                        break;
                case E_CON_TMOUT:
                        printk(KERN_WARNING "%s: Connection timeout\n",
                               dev->name);
                        break;
                case E_DISC_ERR:
                        printk(KERN_WARNING "%s: HIPPI disconnect error\n",
                               dev->name);
                        rrpriv->stats.tx_aborted_errors++;
                        break;
                case E_INT_PRTY:
                        printk(KERN_ERR "%s: HIPPI Internal Parity error\n",
                               dev->name);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                case E_TX_IDLE:
                        printk(KERN_WARNING "%s: Transmitter idle\n",
                               dev->name);
                        break;
                case E_TX_LINK_DROP:
                        printk(KERN_WARNING "%s: Link lost during transmit\n",
                               dev->name);
                        rrpriv->stats.tx_aborted_errors++;
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                case E_TX_INV_RNG:
                        printk(KERN_ERR "%s: Invalid send ring block\n",
                               dev->name);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                case E_TX_INV_BUF:
                        printk(KERN_ERR "%s: Invalid send buffer address\n",
                               dev->name);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                case E_TX_INV_DSC:
                        printk(KERN_ERR "%s: Invalid descriptor address\n",
                               dev->name);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                /*
                 * RX events.
                 */
                case E_RX_RNG_OUT:
                        printk(KERN_INFO "%s: Receive ring full\n", dev->name);
                        break;

                case E_RX_PAR_ERR:
                        printk(KERN_WARNING "%s: Receive parity error\n",
                               dev->name);
                        goto drop;
                case E_RX_LLRC_ERR:
                        printk(KERN_WARNING "%s: Receive LLRC error\n",
                               dev->name);
                        goto drop;
                case E_PKT_LN_ERR:
                        printk(KERN_WARNING "%s: Receive packet length "
                               "error\n", dev->name);
                        goto drop;
                case E_DTA_CKSM_ERR:
                        printk(KERN_WARNING "%s: Data checksum error\n",
                               dev->name);
                        goto drop;
                case E_SHT_BST:
                        printk(KERN_WARNING "%s: Unexpected short burst "
                               "error\n", dev->name);
                        goto drop;
                case E_STATE_ERR:
                        printk(KERN_WARNING "%s: Recv. state transition"
                               " error\n", dev->name);
                        goto drop;
                case E_UNEXP_DATA:
                        printk(KERN_WARNING "%s: Unexpected data error\n",
                               dev->name);
                        goto drop;
                case E_LST_LNK_ERR:
                        printk(KERN_WARNING "%s: Link lost error\n",
                               dev->name);
                        goto drop;
                case E_FRM_ERR:
                        printk(KERN_WARNING "%s: Framming Error\n",
                               dev->name);
                        goto drop;
                case E_FLG_SYN_ERR:
                        printk(KERN_WARNING "%s: Flag sync. lost during"
                               "packet\n", dev->name);
                        goto drop;
                case E_RX_INV_BUF:
                        printk(KERN_ERR "%s: Invalid receive buffer "
                               "address\n", dev->name);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                case E_RX_INV_DSC:
                        printk(KERN_ERR "%s: Invalid receive descriptor "
                               "address\n", dev->name);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                case E_RNG_BLK:
                        printk(KERN_ERR "%s: Invalid ring block\n",
                               dev->name);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        wmb();
                        break;
                drop:
                        /* Label packet to be dropped.
                         * Actual dropping occurs in rx
                         * handling.
                         *
                         * The index of packet we get to drop is
                         * the index of the packet following
                         * the bad packet. -kbf
                         */
                        {
                                u16 index = rrpriv->evt_ring[eidx].index;
                                index = (index + (RX_RING_ENTRIES - 1)) %
                                        RX_RING_ENTRIES;
                                rrpriv->rx_ring[index].mode |=
                                        (PACKET_BAD | PACKET_END);
                        }
                        break;
                default:
                        printk(KERN_WARNING "%s: Unhandled event 0x%02x\n",
                               dev->name, rrpriv->evt_ring[eidx].code);
                }
                eidx = (eidx + 1) % EVT_RING_ENTRIES;
        }

        rrpriv->info->evt_ctrl.pi = eidx;
        wmb();
        return eidx;
}


static void rx_int(struct net_device *dev, u32 rxlimit, u32 index)
{
        struct rr_private *rrpriv = netdev_priv(dev);
        struct rr_regs __iomem *regs = rrpriv->regs;

        do {
                struct rx_desc *desc;
                u32 pkt_len;

                desc = &(rrpriv->rx_ring[index]);
                pkt_len = desc->size;
#if (DEBUG > 2)
                printk("index %i, rxlimit %i\n", index, rxlimit);
                printk("len %x, mode %x\n", pkt_len, desc->mode);
#endif
                if ( (rrpriv->rx_ring[index].mode & PACKET_BAD) == PACKET_BAD){
                        rrpriv->stats.rx_dropped++;
                        goto defer;
                }

                if (pkt_len > 0){
                        struct sk_buff *skb, *rx_skb;

                        rx_skb = rrpriv->rx_skbuff[index];

                        if (pkt_len < PKT_COPY_THRESHOLD) {
                                skb = alloc_skb(pkt_len, GFP_ATOMIC);
                                if (skb == NULL){
                                        printk(KERN_WARNING "%s: Unable to allocate skb (%i bytes), deferring packet\n", dev->name, pkt_len);
                                        rrpriv->stats.rx_dropped++;
                                        goto defer;
                                } else {
                                        pci_dma_sync_single_for_cpu(rrpriv->pci_dev,
                                                                    desc->addr.addrlo,
                                                                    pkt_len,
                                                                    PCI_DMA_FROMDEVICE);

                                        memcpy(skb_put(skb, pkt_len),
                                               rx_skb->data, pkt_len);

                                        pci_dma_sync_single_for_device(rrpriv->pci_dev,
                                                                       desc->addr.addrlo,
                                                                       pkt_len,
                                                                       PCI_DMA_FROMDEVICE);
                                }
                        }else{
                                struct sk_buff *newskb;

                                newskb = alloc_skb(dev->mtu + HIPPI_HLEN,
                                        GFP_ATOMIC);
                                if (newskb){
                                        dma_addr_t addr;

                                        pci_unmap_single(rrpriv->pci_dev, 
                                                desc->addr.addrlo, dev->mtu + 
                                                HIPPI_HLEN, PCI_DMA_FROMDEVICE);
                                        skb = rx_skb;
                                        skb_put(skb, pkt_len);
                                        rrpriv->rx_skbuff[index] = newskb;
                                        addr = pci_map_single(rrpriv->pci_dev, 
                                                newskb->data, 
                                                dev->mtu + HIPPI_HLEN, 
                                                PCI_DMA_FROMDEVICE);
                                        set_rraddr(&desc->addr, addr);
                                } else {
                                        printk("%s: Out of memory, deferring "
                                               "packet\n", dev->name);
                                        rrpriv->stats.rx_dropped++;
                                        goto defer;
                                }
                        }
                        skb->dev = dev;
                        skb->protocol = hippi_type_trans(skb, dev);

                        netif_rx(skb);          /* send it up */

                        dev->last_rx = jiffies;
                        rrpriv->stats.rx_packets++;
                        rrpriv->stats.rx_bytes += pkt_len;
                }
        defer:
                desc->mode = 0;
                desc->size = dev->mtu + HIPPI_HLEN;

                if ((index & 7) == 7)
                        writel(index, &regs->IpRxPi);

                index = (index + 1) % RX_RING_ENTRIES;
        } while(index != rxlimit);

        rrpriv->cur_rx = index;
        wmb();
}


static irqreturn_t rr_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
{
        struct rr_private *rrpriv;
        struct rr_regs __iomem *regs;
        struct net_device *dev = (struct net_device *)dev_id;
        u32 prodidx, rxindex, eidx, txcsmr, rxlimit, txcon;

        rrpriv = netdev_priv(dev);
        regs = rrpriv->regs;

        if (!(readl(&regs->HostCtrl) & RR_INT))
                return IRQ_NONE;

        spin_lock(&rrpriv->lock);

        prodidx = readl(&regs->EvtPrd);
        txcsmr = (prodidx >> 8) & 0xff;
        rxlimit = (prodidx >> 16) & 0xff;
        prodidx &= 0xff;

#if (DEBUG > 2)
        printk("%s: interrupt, prodidx = %i, eidx = %i\n", dev->name,
               prodidx, rrpriv->info->evt_ctrl.pi);
#endif
        /*
         * Order here is important.  We must handle events
         * before doing anything else in order to catch
         * such things as LLRC errors, etc -kbf
         */

        eidx = rrpriv->info->evt_ctrl.pi;
        if (prodidx != eidx)
                eidx = rr_handle_event(dev, prodidx, eidx);

        rxindex = rrpriv->cur_rx;
        if (rxindex != rxlimit)
                rx_int(dev, rxlimit, rxindex);

        txcon = rrpriv->dirty_tx;
        if (txcsmr != txcon) {
                do {
                        /* Due to occational firmware TX producer/consumer out
                         * of sync. error need to check entry in ring -kbf
                         */
                        if(rrpriv->tx_skbuff[txcon]){
                                struct tx_desc *desc;
                                struct sk_buff *skb;

                                desc = &(rrpriv->tx_ring[txcon]);
                                skb = rrpriv->tx_skbuff[txcon];

                                rrpriv->stats.tx_packets++;
                                rrpriv->stats.tx_bytes += skb->len;

                                pci_unmap_single(rrpriv->pci_dev,
                                                 desc->addr.addrlo, skb->len,
                                                 PCI_DMA_TODEVICE);
                                dev_kfree_skb_irq(skb);

                                rrpriv->tx_skbuff[txcon] = NULL;
                                desc->size = 0;
                                set_rraddr(&rrpriv->tx_ring[txcon].addr, 0);
                                desc->mode = 0;
                        }
                        txcon = (txcon + 1) % TX_RING_ENTRIES;
                } while (txcsmr != txcon);
                wmb();

                rrpriv->dirty_tx = txcon;
                if (rrpriv->tx_full && rr_if_busy(dev) &&
                    (((rrpriv->info->tx_ctrl.pi + 1) % TX_RING_ENTRIES)
                     != rrpriv->dirty_tx)){
                        rrpriv->tx_full = 0;
                        netif_wake_queue(dev);
                }
        }

        eidx |= ((txcsmr << 8) | (rxlimit << 16));
        writel(eidx, &regs->EvtCon);
        wmb();

        spin_unlock(&rrpriv->lock);
        return IRQ_HANDLED;
}

static inline void rr_raz_tx(struct rr_private *rrpriv,
                             struct net_device *dev)
{
        int i;

        for (i = 0; i < TX_RING_ENTRIES; i++) {
                struct sk_buff *skb = rrpriv->tx_skbuff[i];

                if (skb) {
                        struct tx_desc *desc = &(rrpriv->tx_ring[i]);

                        pci_unmap_single(rrpriv->pci_dev, desc->addr.addrlo,
                                skb->len, PCI_DMA_TODEVICE);
                        desc->size = 0;
                        set_rraddr(&desc->addr, 0);
                        dev_kfree_skb(skb);
                        rrpriv->tx_skbuff[i] = NULL;
                }
        }
}


static inline void rr_raz_rx(struct rr_private *rrpriv,
                             struct net_device *dev)
{
        int i;

        for (i = 0; i < RX_RING_ENTRIES; i++) {
                struct sk_buff *skb = rrpriv->rx_skbuff[i];

                if (skb) {
                        struct rx_desc *desc = &(rrpriv->rx_ring[i]);

                        pci_unmap_single(rrpriv->pci_dev, desc->addr.addrlo,
                                dev->mtu + HIPPI_HLEN, PCI_DMA_FROMDEVICE);
                        desc->size = 0;
                        set_rraddr(&desc->addr, 0);
                        dev_kfree_skb(skb);
                        rrpriv->rx_skbuff[i] = NULL;
                }
        }
}

static void rr_timer(unsigned long data)
{
        struct net_device *dev = (struct net_device *)data;
        struct rr_private *rrpriv = netdev_priv(dev);
        struct rr_regs __iomem *regs = rrpriv->regs;
        unsigned long flags;

        if (readl(&regs->HostCtrl) & NIC_HALTED){
                printk("%s: Restarting nic\n", dev->name);
                memset(rrpriv->rx_ctrl, 0, 256 * sizeof(struct ring_ctrl));
                memset(rrpriv->info, 0, sizeof(struct rr_info));
                wmb();

                rr_raz_tx(rrpriv, dev);
                rr_raz_rx(rrpriv, dev);

                if (rr_init1(dev)) {
                        spin_lock_irqsave(&rrpriv->lock, flags);
                        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, 
                               &regs->HostCtrl);
                        spin_unlock_irqrestore(&rrpriv->lock, flags);
                }
        }
        rrpriv->timer.expires = RUN_AT(5*HZ);
        add_timer(&rrpriv->timer);
}


static int rr_open(struct net_device *dev)
{
        struct rr_private *rrpriv = netdev_priv(dev);
        struct pci_dev *pdev = rrpriv->pci_dev;
        struct rr_regs __iomem *regs;
        int ecode = 0;
        unsigned long flags;
        dma_addr_t dma_addr;

        regs = rrpriv->regs;

        if (rrpriv->fw_rev < 0x00020000) {
                printk(KERN_WARNING "%s: trying to configure device with "
                       "obsolete firmware\n", dev->name);
                ecode = -EBUSY;
                goto error;
        }

        rrpriv->rx_ctrl = pci_alloc_consistent(pdev,
                                               256 * sizeof(struct ring_ctrl),
                                               &dma_addr);
        if (!rrpriv->rx_ctrl) {
                ecode = -ENOMEM;
                goto error;
        }
        rrpriv->rx_ctrl_dma = dma_addr;
        memset(rrpriv->rx_ctrl, 0, 256*sizeof(struct ring_ctrl));

        rrpriv->info = pci_alloc_consistent(pdev, sizeof(struct rr_info),
                                            &dma_addr);
        if (!rrpriv->info) {
                ecode = -ENOMEM;
                goto error;
        }
        rrpriv->info_dma = dma_addr;
        memset(rrpriv->info, 0, sizeof(struct rr_info));
        wmb();

        spin_lock_irqsave(&rrpriv->lock, flags);
        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, &regs->HostCtrl);
        readl(&regs->HostCtrl);
        spin_unlock_irqrestore(&rrpriv->lock, flags);

        if (request_irq(dev->irq, rr_interrupt, SA_SHIRQ, dev->name, dev)) {
                printk(KERN_WARNING "%s: Requested IRQ %d is busy\n",
                       dev->name, dev->irq);
                ecode = -EAGAIN;
                goto error;
        }

        if ((ecode = rr_init1(dev)))
                goto error;

        /* Set the timer to switch to check for link beat and perhaps switch
           to an alternate media type. */
        init_timer(&rrpriv->timer);
        rrpriv->timer.expires = RUN_AT(5*HZ);           /* 5 sec. watchdog */
        rrpriv->timer.data = (unsigned long)dev;
        rrpriv->timer.function = &rr_timer;               /* timer handler */
        add_timer(&rrpriv->timer);

        netif_start_queue(dev);

        return ecode;

 error:
        spin_lock_irqsave(&rrpriv->lock, flags);
        writel(readl(&regs->HostCtrl)|HALT_NIC|RR_CLEAR_INT, &regs->HostCtrl);
        spin_unlock_irqrestore(&rrpriv->lock, flags);

        if (rrpriv->info) {
                pci_free_consistent(pdev, sizeof(struct rr_info), rrpriv->info,
                                    rrpriv->info_dma);
                rrpriv->info = NULL;
        }
        if (rrpriv->rx_ctrl) {
                pci_free_consistent(pdev, sizeof(struct ring_ctrl),
                                    rrpriv->rx_ctrl, rrpriv->rx_ctrl_dma);
                rrpriv->rx_ctrl = NULL;
        }

        netif_stop_queue(dev);
        
        return ecode;
}


static void rr_dump(struct net_device *dev)
{
        struct rr_private *rrpriv;
        struct rr_regs __iomem *regs;
        u32 index, cons;
        short i;
        int len;

        rrpriv = netdev_priv(dev);
        regs = rrpriv->regs;

        printk("%s: dumping NIC TX rings\n", dev->name);

        printk("RxPrd %08x, TxPrd %02x, EvtPrd %08x, TxPi %02x, TxCtrlPi %02x\n",
               readl(&regs->RxPrd), readl(&regs->TxPrd),
               readl(&regs->EvtPrd), readl(&regs->TxPi),
               rrpriv->info->tx_ctrl.pi);

        printk("Error code 0x%x\n", readl(&regs->Fail1));

        index = (((readl(&regs->EvtPrd) >> 8) & 0xff ) - 1) % EVT_RING_ENTRIES;
        cons = rrpriv->dirty_tx;
        printk("TX ring index %i, TX consumer %i\n",
               index, cons);

        if (rrpriv->tx_skbuff[index]){
                len = min_t(int, 0x80, rrpriv->tx_skbuff[index]->len);
                printk("skbuff for index %i is valid - dumping data (0x%x bytes - DMA len 0x%x)\n", index, len, rrpriv->tx_ring[index].size);
                for (i = 0; i < len; i++){
                        if (!(i & 7))
                                printk("\n");
                        printk("%02x ", (unsigned char) rrpriv->tx_skbuff[index]->data[i]);
                }
                printk("\n");
        }

        if (rrpriv->tx_skbuff[cons]){
                len = min_t(int, 0x80, rrpriv->tx_skbuff[cons]->len);
                printk("skbuff for cons %i is valid - dumping data (0x%x bytes - skbuff len 0x%x)\n", cons, len, rrpriv->tx_skbuff[cons]->len);
                printk("mode 0x%x, size 0x%x,\n phys %08Lx, skbuff-addr %08lx, truesize 0x%x\n",
                       rrpriv->tx_ring[cons].mode,
                       rrpriv->tx_ring[cons].size,
                       (unsigned long long) rrpriv->tx_ring[cons].addr.addrlo,
                       (unsigned long)rrpriv->tx_skbuff[cons]->data,
                       (unsigned int)rrpriv->tx_skbuff[cons]->truesize);
                for (i = 0; i < len; i++){
                        if (!(i & 7))
                                printk("\n");
                        printk("%02x ", (unsigned char)rrpriv->tx_ring[cons].size);
                }
                printk("\n");
        }

        printk("dumping TX ring info:\n");
        for (i = 0; i < TX_RING_ENTRIES; i++)
                printk("mode 0x%x, size 0x%x, phys-addr %08Lx\n",
                       rrpriv->tx_ring[i].mode,
                       rrpriv->tx_ring[i].size,
                       (unsigned long long) rrpriv->tx_ring[i].addr.addrlo);

}


static int rr_close(struct net_device *dev)
{
        struct rr_private *rrpriv;
        struct rr_regs __iomem *regs;
        unsigned long flags;
        u32 tmp;
        short i;

        netif_stop_queue(dev);

        rrpriv = netdev_priv(dev);
        regs = rrpriv->regs;

        /*
         * Lock to make sure we are not cleaning up while another CPU
         * is handling interrupts.
         */
        spin_lock_irqsave(&rrpriv->lock, flags);

        tmp = readl(&regs->HostCtrl);
        if (tmp & NIC_HALTED){
                printk("%s: NIC already halted\n", dev->name);
                rr_dump(dev);
        }else{
                tmp |= HALT_NIC | RR_CLEAR_INT;
                writel(tmp, &regs->HostCtrl);
                readl(&regs->HostCtrl);
        }

        rrpriv->fw_running = 0;

        del_timer_sync(&rrpriv->timer);

        writel(0, &regs->TxPi);
        writel(0, &regs->IpRxPi);

        writel(0, &regs->EvtCon);
        writel(0, &regs->EvtPrd);

        for (i = 0; i < CMD_RING_ENTRIES; i++)
                writel(0, &regs->CmdRing[i]);

        rrpriv->info->tx_ctrl.entries = 0;
        rrpriv->info->cmd_ctrl.pi = 0;
        rrpriv->info->evt_ctrl.pi = 0;
        rrpriv->rx_ctrl[4].entries = 0;

        rr_raz_tx(rrpriv, dev);
        rr_raz_rx(rrpriv, dev);

        pci_free_consistent(rrpriv->pci_dev, 256 * sizeof(struct ring_ctrl),
                            rrpriv->rx_ctrl, rrpriv->rx_ctrl_dma);
        rrpriv->rx_ctrl = NULL;

        pci_free_consistent(rrpriv->pci_dev, sizeof(struct rr_info),
                            rrpriv->info, rrpriv->info_dma);
        rrpriv->info = NULL;

        free_irq(dev->irq, dev);
        spin_unlock_irqrestore(&rrpriv->lock, flags);

        return 0;
}


static int rr_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct rr_private *rrpriv = netdev_priv(dev);
        struct rr_regs __iomem *regs = rrpriv->regs;
        struct ring_ctrl *txctrl;
        unsigned long flags;
        u32 index, len = skb->len;
        u32 *ifield;
        struct sk_buff *new_skb;

        if (readl(&regs->Mode) & FATAL_ERR)
                printk("error codes Fail1 %02x, Fail2 %02x\n",
                       readl(&regs->Fail1), readl(&regs->Fail2));

        /*
         * We probably need to deal with tbusy here to prevent overruns.
         */

        if (skb_headroom(skb) < 8){
                printk("incoming skb too small - reallocating\n");
                if (!(new_skb = dev_alloc_skb(len + 8))) {
                        dev_kfree_skb(skb);
                        netif_wake_queue(dev);
                        return -EBUSY;
                }
                skb_reserve(new_skb, 8);
                skb_put(new_skb, len);
                memcpy(new_skb->data, skb->data, len);
                dev_kfree_skb(skb);
                skb = new_skb;
        }

        ifield = (u32 *)skb_push(skb, 8);

        ifield[0] = 0;
        ifield[1] = skb->private.ifield;

        /*
         * We don't need the lock before we are actually going to start
         * fiddling with the control blocks.
         */
        spin_lock_irqsave(&rrpriv->lock, flags);

        txctrl = &rrpriv->info->tx_ctrl;

        index = txctrl->pi;

        rrpriv->tx_skbuff[index] = skb;
        set_rraddr(&rrpriv->tx_ring[index].addr, pci_map_single(
                rrpriv->pci_dev, skb->data, len + 8, PCI_DMA_TODEVICE));
        rrpriv->tx_ring[index].size = len + 8; /* include IFIELD */
        rrpriv->tx_ring[index].mode = PACKET_START | PACKET_END;
        txctrl->pi = (index + 1) % TX_RING_ENTRIES;
        wmb();
        writel(txctrl->pi, &regs->TxPi);

        if (txctrl->pi == rrpriv->dirty_tx){
                rrpriv->tx_full = 1;
                netif_stop_queue(dev);
        }

        spin_unlock_irqrestore(&rrpriv->lock, flags);

        dev->trans_start = jiffies;
        return 0;
}


static struct net_device_stats *rr_get_stats(struct net_device *dev)
{
        struct rr_private *rrpriv;

        rrpriv = netdev_priv(dev);

        return(&rrpriv->stats);
}


/*
 * Read the firmware out of the EEPROM and put it into the SRAM
 * (or from user space - later)
 *
 * This operation requires the NIC to be halted and is performed with
 * interrupts disabled and with the spinlock hold.
 */
static int rr_load_firmware(struct net_device *dev)
{
        struct rr_private *rrpriv;
        struct rr_regs __iomem *regs;
        unsigned long eptr, segptr;
        int i, j;
        u32 localctrl, sptr, len, tmp;
        u32 p2len, p2size, nr_seg, revision, io, sram_size;
        struct eeprom *hw = NULL;

        rrpriv = netdev_priv(dev);
        regs = rrpriv->regs;

        if (dev->flags & IFF_UP)
                return -EBUSY;

        if (!(readl(&regs->HostCtrl) & NIC_HALTED)){
                printk("%s: Trying to load firmware to a running NIC.\n", 
                       dev->name);
                return -EBUSY;
        }

        localctrl = readl(&regs->LocalCtrl);
        writel(0, &regs->LocalCtrl);

        writel(0, &regs->EvtPrd);
        writel(0, &regs->RxPrd);
        writel(0, &regs->TxPrd);

        /*
         * First wipe the entire SRAM, otherwise we might run into all
         * kinds of trouble ... sigh, this took almost all afternoon
         * to track down ;-(
         */
        io = readl(&regs->ExtIo);
        writel(0, &regs->ExtIo);
        sram_size = rr_read_eeprom_word(rrpriv, (void *)8);

        for (i = 200; i < sram_size / 4; i++){
                writel(i * 4, &regs->WinBase);
                mb();
                writel(0, &regs->WinData);
                mb();
        }
        writel(io, &regs->ExtIo);
        mb();

        eptr = (unsigned long)rr_read_eeprom_word(rrpriv,
                                               &hw->rncd_info.AddrRunCodeSegs);
        eptr = ((eptr & 0x1fffff) >> 3);

        p2len = rr_read_eeprom_word(rrpriv, (void *)(0x83*4));
        p2len = (p2len << 2);
        p2size = rr_read_eeprom_word(rrpriv, (void *)(0x84*4));
        p2size = ((p2size & 0x1fffff) >> 3);

        if ((eptr < p2size) || (eptr > (p2size + p2len))){
                printk("%s: eptr is invalid\n", dev->name);
                goto out;
        }

        revision = rr_read_eeprom_word(rrpriv, &hw->manf.HeaderFmt);

        if (revision != 1){
                printk("%s: invalid firmware format (%i)\n",
                       dev->name, revision);
                goto out;
        }

        nr_seg = rr_read_eeprom_word(rrpriv, (void *)eptr);
        eptr +=4;
#if (DEBUG > 1)
        printk("%s: nr_seg %i\n", dev->name, nr_seg);
#endif

        for (i = 0; i < nr_seg; i++){
                sptr = rr_read_eeprom_word(rrpriv, (void *)eptr);
                eptr += 4;
                len = rr_read_eeprom_word(rrpriv, (void *)eptr);
                eptr += 4;
                segptr = (unsigned long)rr_read_eeprom_word(rrpriv, (void *)eptr);
                segptr = ((segptr & 0x1fffff) >> 3);
                eptr += 4;
#if (DEBUG > 1)
                printk("%s: segment %i, sram address %06x, length %04x, segptr %06x\n",
                       dev->name, i, sptr, len, segptr);
#endif
                for (j = 0; j < len; j++){
                        tmp = rr_read_eeprom_word(rrpriv, (void *)segptr);
                        writel(sptr, &regs->WinBase);
                        mb();
                        writel(tmp, &regs->WinData);
                        mb();
                        segptr += 4;
                        sptr += 4;
                }
        }

out:
        writel(localctrl, &regs->LocalCtrl);
        mb();
        return 0;
}


static int rr_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
        struct rr_private *rrpriv;
        unsigned char *image, *oldimage;
        unsigned long flags;
        unsigned int i;
        int error = -EOPNOTSUPP;

        rrpriv = netdev_priv(dev);

        switch(cmd){
        case SIOCRRGFW:
                if (!capable(CAP_SYS_RAWIO)){
                        return -EPERM;
                }

                image = kmalloc(EEPROM_WORDS * sizeof(u32), GFP_KERNEL);
                if (!image){
                        printk(KERN_ERR "%s: Unable to allocate memory "
                               "for EEPROM image\n", dev->name);
                        return -ENOMEM;
                }


                if (rrpriv->fw_running){
                        printk("%s: Firmware already running\n", dev->name);
                        error = -EPERM;
                        goto gf_out;
                }

                spin_lock_irqsave(&rrpriv->lock, flags);
                i = rr_read_eeprom(rrpriv, 0, image, EEPROM_BYTES);
                spin_unlock_irqrestore(&rrpriv->lock, flags);
                if (i != EEPROM_BYTES){
                        printk(KERN_ERR "%s: Error reading EEPROM\n",
                               dev->name);
                        error = -EFAULT;
                        goto gf_out;
                }
                error = copy_to_user(rq->ifr_data, image, EEPROM_BYTES);
                if (error)
                        error = -EFAULT;
        gf_out:
                kfree(image);
                return error;
                
        case SIOCRRPFW:
                if (!capable(CAP_SYS_RAWIO)){
                        return -EPERM;
                }

                image = kmalloc(EEPROM_WORDS * sizeof(u32), GFP_KERNEL);
                oldimage = kmalloc(EEPROM_WORDS * sizeof(u32), GFP_KERNEL);
                if (!image || !oldimage) {
                        printk(KERN_ERR "%s: Unable to allocate memory "
                               "for EEPROM image\n", dev->name);
                        error = -ENOMEM;
                        goto wf_out;
                }

                error = copy_from_user(image, rq->ifr_data, EEPROM_BYTES);
                if (error) {
                        error = -EFAULT;
                        goto wf_out;
                }

                if (rrpriv->fw_running){
                        printk("%s: Firmware already running\n", dev->name);
                        error = -EPERM;
                        goto wf_out;
                }

                printk("%s: Updating EEPROM firmware\n", dev->name);

                spin_lock_irqsave(&rrpriv->lock, flags);
                error = write_eeprom(rrpriv, 0, image, EEPROM_BYTES);
                if (error)
                        printk(KERN_ERR "%s: Error writing EEPROM\n",
                               dev->name);

                i = rr_read_eeprom(rrpriv, 0, oldimage, EEPROM_BYTES);
                spin_unlock_irqrestore(&rrpriv->lock, flags);

                if (i != EEPROM_BYTES)
                        printk(KERN_ERR "%s: Error reading back EEPROM "
                               "image\n", dev->name);

                error = memcmp(image, oldimage, EEPROM_BYTES);
                if (error){
                        printk(KERN_ERR "%s: Error verifying EEPROM image\n",
                               dev->name);
                        error = -EFAULT;
                }
        wf_out:
                if (oldimage)
                        kfree(oldimage);
                if (image)
                        kfree(image);
                return error;
                
        case SIOCRRID:
                return put_user(0x52523032, (int __user *)rq->ifr_data);
        default:
                return error;
        }
}

static struct pci_device_id rr_pci_tbl[] = {
        { PCI_VENDOR_ID_ESSENTIAL, PCI_DEVICE_ID_ESSENTIAL_ROADRUNNER,
                PCI_ANY_ID, PCI_ANY_ID, },
        { 0,}
};
MODULE_DEVICE_TABLE(pci, rr_pci_tbl);

static struct pci_driver rr_driver = {
        .name           = "rrunner",
        .id_table       = rr_pci_tbl,
        .probe          = rr_init_one,
        .remove         = __devexit_p(rr_remove_one),
};

static int __init rr_init_module(void)
{
        return pci_module_init(&rr_driver);
}

static void __exit rr_cleanup_module(void)
{
        pci_unregister_driver(&rr_driver);
}

module_init(rr_init_module);
module_exit(rr_cleanup_module);

/*
 * Local variables:
 * compile-command: "gcc -D__KERNEL__ -I../../include -Wall -Wstrict-prototypes -O2 -pipe -fomit-frame-pointer -fno-strength-reduce -m486 -malign-loops=2 -malign-jumps=2 -malign-functions=2 -DMODULE -DMODVERSIONS -include ../../include/linux/modversions.h -c rrunner.c"
 * End:
 */