Merge branch 'merge' into powerpc-next

[linux-2.6] / drivers / net / cassini.c

/* cassini.c: Sun Microsystems Cassini(+) ethernet driver.
 *
 * Copyright (C) 2004 Sun Microsystems Inc.
 * Copyright (C) 2003 Adrian Sun (asun@darksunrising.com)
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * This driver uses the sungem driver (c) David Miller
 * (davem@redhat.com) as its basis.
 *
 * The cassini chip has a number of features that distinguish it from
 * the gem chip:
 *  4 transmit descriptor rings that are used for either QoS (VLAN) or
 *      load balancing (non-VLAN mode)
 *  batching of multiple packets
 *  multiple CPU dispatching
 *  page-based RX descriptor engine with separate completion rings
 *  Gigabit support (GMII and PCS interface)
 *  MIF link up/down detection works
 *
 * RX is handled by page sized buffers that are attached as fragments to
 * the skb. here's what's done:
 *  -- driver allocates pages at a time and keeps reference counts
 *     on them.
 *  -- the upper protocol layers assume that the header is in the skb
 *     itself. as a result, cassini will copy a small amount (64 bytes)
 *     to make them happy.
 *  -- driver appends the rest of the data pages as frags to skbuffs
 *     and increments the reference count
 *  -- on page reclamation, the driver swaps the page with a spare page.
 *     if that page is still in use, it frees its reference to that page,
 *     and allocates a new page for use. otherwise, it just recycles the
 *     the page.
 *
 * NOTE: cassini can parse the header. however, it's not worth it
 *       as long as the network stack requires a header copy.
 *
 * TX has 4 queues. currently these queues are used in a round-robin
 * fashion for load balancing. They can also be used for QoS. for that
 * to work, however, QoS information needs to be exposed down to the driver
 * level so that subqueues get targetted to particular transmit rings.
 * alternatively, the queues can be configured via use of the all-purpose
 * ioctl.
 *
 * RX DATA: the rx completion ring has all the info, but the rx desc
 * ring has all of the data. RX can conceivably come in under multiple
 * interrupts, but the INT# assignment needs to be set up properly by
 * the BIOS and conveyed to the driver. PCI BIOSes don't know how to do
 * that. also, the two descriptor rings are designed to distinguish between
 * encrypted and non-encrypted packets, but we use them for buffering
 * instead.
 *
 * by default, the selective clear mask is set up to process rx packets.
 */


#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/list.h>
#include <linux/dma-mapping.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/crc32.h>
#include <linux/random.h>
#include <linux/mii.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/mutex.h>

#include <net/checksum.h>

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

#define cas_page_map(x)      kmap_atomic((x), KM_SKB_DATA_SOFTIRQ)
#define cas_page_unmap(x)    kunmap_atomic((x), KM_SKB_DATA_SOFTIRQ)
#define CAS_NCPUS            num_online_cpus()

#if defined(CONFIG_CASSINI_NAPI) && defined(HAVE_NETDEV_POLL)
#define USE_NAPI
#define cas_skb_release(x)  netif_receive_skb(x)
#else
#define cas_skb_release(x)  netif_rx(x)
#endif

/* select which firmware to use */
#define USE_HP_WORKAROUND
#define HP_WORKAROUND_DEFAULT /* select which firmware to use as default */
#define CAS_HP_ALT_FIRMWARE   cas_prog_null /* alternate firmware */

#include "cassini.h"

#define USE_TX_COMPWB      /* use completion writeback registers */
#define USE_CSMA_CD_PROTO  /* standard CSMA/CD */
#define USE_RX_BLANK       /* hw interrupt mitigation */
#undef USE_ENTROPY_DEV     /* don't test for entropy device */

/* NOTE: these aren't useable unless PCI interrupts can be assigned.
 * also, we need to make cp->lock finer-grained.
 */
#undef  USE_PCI_INTB
#undef  USE_PCI_INTC
#undef  USE_PCI_INTD
#undef  USE_QOS

#undef  USE_VPD_DEBUG       /* debug vpd information if defined */

/* rx processing options */
#define USE_PAGE_ORDER      /* specify to allocate large rx pages */
#define RX_DONT_BATCH  0    /* if 1, don't batch flows */
#define RX_COPY_ALWAYS 0    /* if 0, use frags */
#define RX_COPY_MIN    64   /* copy a little to make upper layers happy */
#undef  RX_COUNT_BUFFERS    /* define to calculate RX buffer stats */

#define DRV_MODULE_NAME         "cassini"
#define PFX DRV_MODULE_NAME     ": "
#define DRV_MODULE_VERSION      "1.6"
#define DRV_MODULE_RELDATE      "21 May 2008"

#define CAS_DEF_MSG_ENABLE        \
        (NETIF_MSG_DRV          | \
         NETIF_MSG_PROBE        | \
         NETIF_MSG_LINK         | \
         NETIF_MSG_TIMER        | \
         NETIF_MSG_IFDOWN       | \
         NETIF_MSG_IFUP         | \
         NETIF_MSG_RX_ERR       | \
         NETIF_MSG_TX_ERR)

/* length of time before we decide the hardware is borked,
 * and dev->tx_timeout() should be called to fix the problem
 */
#define CAS_TX_TIMEOUT                  (HZ)
#define CAS_LINK_TIMEOUT                (22*HZ/10)
#define CAS_LINK_FAST_TIMEOUT           (1)

/* timeout values for state changing. these specify the number
 * of 10us delays to be used before giving up.
 */
#define STOP_TRIES_PHY 1000
#define STOP_TRIES     5000

/* specify a minimum frame size to deal with some fifo issues
 * max mtu == 2 * page size - ethernet header - 64 - swivel =
 *            2 * page_size - 0x50
 */
#define CAS_MIN_FRAME                   97
#define CAS_1000MB_MIN_FRAME            255
#define CAS_MIN_MTU                     60
#define CAS_MAX_MTU                     min(((cp->page_size << 1) - 0x50), 9000)

#if 1
/*
 * Eliminate these and use separate atomic counters for each, to
 * avoid a race condition.
 */
#else
#define CAS_RESET_MTU                   1
#define CAS_RESET_ALL                   2
#define CAS_RESET_SPARE                 3
#endif

static char version[] __devinitdata =
        DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";

static int cassini_debug = -1;  /* -1 == use CAS_DEF_MSG_ENABLE as value */
static int link_mode;

MODULE_AUTHOR("Adrian Sun (asun@darksunrising.com)");
MODULE_DESCRIPTION("Sun Cassini(+) ethernet driver");
MODULE_LICENSE("GPL");
module_param(cassini_debug, int, 0);
MODULE_PARM_DESC(cassini_debug, "Cassini bitmapped debugging message enable value");
module_param(link_mode, int, 0);
MODULE_PARM_DESC(link_mode, "default link mode");

/*
 * Work around for a PCS bug in which the link goes down due to the chip
 * being confused and never showing a link status of "up."
 */
#define DEFAULT_LINKDOWN_TIMEOUT 5
/*
 * Value in seconds, for user input.
 */
static int linkdown_timeout = DEFAULT_LINKDOWN_TIMEOUT;
module_param(linkdown_timeout, int, 0);
MODULE_PARM_DESC(linkdown_timeout,
"min reset interval in sec. for PCS linkdown issue; disabled if not positive");

/*
 * value in 'ticks' (units used by jiffies). Set when we init the
 * module because 'HZ' in actually a function call on some flavors of
 * Linux.  This will default to DEFAULT_LINKDOWN_TIMEOUT * HZ.
 */
static int link_transition_timeout;



static u16 link_modes[] __devinitdata = {
        BMCR_ANENABLE,                   /* 0 : autoneg */
        0,                               /* 1 : 10bt half duplex */
        BMCR_SPEED100,                   /* 2 : 100bt half duplex */
        BMCR_FULLDPLX,                   /* 3 : 10bt full duplex */
        BMCR_SPEED100|BMCR_FULLDPLX,     /* 4 : 100bt full duplex */
        CAS_BMCR_SPEED1000|BMCR_FULLDPLX /* 5 : 1000bt full duplex */
};

static struct pci_device_id cas_pci_tbl[] __devinitdata = {
        { PCI_VENDOR_ID_SUN, PCI_DEVICE_ID_SUN_CASSINI,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
        { PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SATURN,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
        { 0, }
};

MODULE_DEVICE_TABLE(pci, cas_pci_tbl);

static void cas_set_link_modes(struct cas *cp);

static inline void cas_lock_tx(struct cas *cp)
{
        int i;

        for (i = 0; i < N_TX_RINGS; i++)
                spin_lock(&cp->tx_lock[i]);
}

static inline void cas_lock_all(struct cas *cp)
{
        spin_lock_irq(&cp->lock);
        cas_lock_tx(cp);
}

/* WTZ: QA was finding deadlock problems with the previous
 * versions after long test runs with multiple cards per machine.
 * See if replacing cas_lock_all with safer versions helps. The
 * symptoms QA is reporting match those we'd expect if interrupts
 * aren't being properly restored, and we fixed a previous deadlock
 * with similar symptoms by using save/restore versions in other
 * places.
 */
#define cas_lock_all_save(cp, flags) \
do { \
        struct cas *xxxcp = (cp); \
        spin_lock_irqsave(&xxxcp->lock, flags); \
        cas_lock_tx(xxxcp); \
} while (0)

static inline void cas_unlock_tx(struct cas *cp)
{
        int i;

        for (i = N_TX_RINGS; i > 0; i--)
                spin_unlock(&cp->tx_lock[i - 1]);
}

static inline void cas_unlock_all(struct cas *cp)
{
        cas_unlock_tx(cp);
        spin_unlock_irq(&cp->lock);
}

#define cas_unlock_all_restore(cp, flags) \
do { \
        struct cas *xxxcp = (cp); \
        cas_unlock_tx(xxxcp); \
        spin_unlock_irqrestore(&xxxcp->lock, flags); \
} while (0)

static void cas_disable_irq(struct cas *cp, const int ring)
{
        /* Make sure we won't get any more interrupts */
        if (ring == 0) {
                writel(0xFFFFFFFF, cp->regs + REG_INTR_MASK);
                return;
        }

        /* disable completion interrupts and selectively mask */
        if (cp->cas_flags & CAS_FLAG_REG_PLUS) {
                switch (ring) {
#if defined (USE_PCI_INTB) || defined(USE_PCI_INTC) || defined(USE_PCI_INTD)
#ifdef USE_PCI_INTB
                case 1:
#endif
#ifdef USE_PCI_INTC
                case 2:
#endif
#ifdef USE_PCI_INTD
                case 3:
#endif
                        writel(INTRN_MASK_CLEAR_ALL | INTRN_MASK_RX_EN,
                               cp->regs + REG_PLUS_INTRN_MASK(ring));
                        break;
#endif
                default:
                        writel(INTRN_MASK_CLEAR_ALL, cp->regs +
                               REG_PLUS_INTRN_MASK(ring));
                        break;
                }
        }
}

static inline void cas_mask_intr(struct cas *cp)
{
        int i;

        for (i = 0; i < N_RX_COMP_RINGS; i++)
                cas_disable_irq(cp, i);
}

static void cas_enable_irq(struct cas *cp, const int ring)
{
        if (ring == 0) { /* all but TX_DONE */
                writel(INTR_TX_DONE, cp->regs + REG_INTR_MASK);
                return;
        }

        if (cp->cas_flags & CAS_FLAG_REG_PLUS) {
                switch (ring) {
#if defined (USE_PCI_INTB) || defined(USE_PCI_INTC) || defined(USE_PCI_INTD)
#ifdef USE_PCI_INTB
                case 1:
#endif
#ifdef USE_PCI_INTC
                case 2:
#endif
#ifdef USE_PCI_INTD
                case 3:
#endif
                        writel(INTRN_MASK_RX_EN, cp->regs +
                               REG_PLUS_INTRN_MASK(ring));
                        break;
#endif
                default:
                        break;
                }
        }
}

static inline void cas_unmask_intr(struct cas *cp)
{
        int i;

        for (i = 0; i < N_RX_COMP_RINGS; i++)
                cas_enable_irq(cp, i);
}

static inline void cas_entropy_gather(struct cas *cp)
{
#ifdef USE_ENTROPY_DEV
        if ((cp->cas_flags & CAS_FLAG_ENTROPY_DEV) == 0)
                return;

        batch_entropy_store(readl(cp->regs + REG_ENTROPY_IV),
                            readl(cp->regs + REG_ENTROPY_IV),
                            sizeof(uint64_t)*8);
#endif
}

static inline void cas_entropy_reset(struct cas *cp)
{
#ifdef USE_ENTROPY_DEV
        if ((cp->cas_flags & CAS_FLAG_ENTROPY_DEV) == 0)
                return;

        writel(BIM_LOCAL_DEV_PAD | BIM_LOCAL_DEV_PROM | BIM_LOCAL_DEV_EXT,
               cp->regs + REG_BIM_LOCAL_DEV_EN);
        writeb(ENTROPY_RESET_STC_MODE, cp->regs + REG_ENTROPY_RESET);
        writeb(0x55, cp->regs + REG_ENTROPY_RAND_REG);

        /* if we read back 0x0, we don't have an entropy device */
        if (readb(cp->regs + REG_ENTROPY_RAND_REG) == 0)
                cp->cas_flags &= ~CAS_FLAG_ENTROPY_DEV;
#endif
}

/* access to the phy. the following assumes that we've initialized the MIF to
 * be in frame rather than bit-bang mode
 */
static u16 cas_phy_read(struct cas *cp, int reg)
{
        u32 cmd;
        int limit = STOP_TRIES_PHY;

        cmd = MIF_FRAME_ST | MIF_FRAME_OP_READ;
        cmd |= CAS_BASE(MIF_FRAME_PHY_ADDR, cp->phy_addr);
        cmd |= CAS_BASE(MIF_FRAME_REG_ADDR, reg);
        cmd |= MIF_FRAME_TURN_AROUND_MSB;
        writel(cmd, cp->regs + REG_MIF_FRAME);

        /* poll for completion */
        while (limit-- > 0) {
                udelay(10);
                cmd = readl(cp->regs + REG_MIF_FRAME);
                if (cmd & MIF_FRAME_TURN_AROUND_LSB)
                        return (cmd & MIF_FRAME_DATA_MASK);
        }
        return 0xFFFF; /* -1 */
}

static int cas_phy_write(struct cas *cp, int reg, u16 val)
{
        int limit = STOP_TRIES_PHY;
        u32 cmd;

        cmd = MIF_FRAME_ST | MIF_FRAME_OP_WRITE;
        cmd |= CAS_BASE(MIF_FRAME_PHY_ADDR, cp->phy_addr);
        cmd |= CAS_BASE(MIF_FRAME_REG_ADDR, reg);
        cmd |= MIF_FRAME_TURN_AROUND_MSB;
        cmd |= val & MIF_FRAME_DATA_MASK;
        writel(cmd, cp->regs + REG_MIF_FRAME);

        /* poll for completion */
        while (limit-- > 0) {
                udelay(10);
                cmd = readl(cp->regs + REG_MIF_FRAME);
                if (cmd & MIF_FRAME_TURN_AROUND_LSB)
                        return 0;
        }
        return -1;
}

static void cas_phy_powerup(struct cas *cp)
{
        u16 ctl = cas_phy_read(cp, MII_BMCR);

        if ((ctl & BMCR_PDOWN) == 0)
                return;
        ctl &= ~BMCR_PDOWN;
        cas_phy_write(cp, MII_BMCR, ctl);
}

static void cas_phy_powerdown(struct cas *cp)
{
        u16 ctl = cas_phy_read(cp, MII_BMCR);

        if (ctl & BMCR_PDOWN)
                return;
        ctl |= BMCR_PDOWN;
        cas_phy_write(cp, MII_BMCR, ctl);
}

/* cp->lock held. note: the last put_page will free the buffer */
static int cas_page_free(struct cas *cp, cas_page_t *page)
{
        pci_unmap_page(cp->pdev, page->dma_addr, cp->page_size,
                       PCI_DMA_FROMDEVICE);
        __free_pages(page->buffer, cp->page_order);
        kfree(page);
        return 0;
}

#ifdef RX_COUNT_BUFFERS
#define RX_USED_ADD(x, y)       ((x)->used += (y))
#define RX_USED_SET(x, y)       ((x)->used  = (y))
#else
#define RX_USED_ADD(x, y)
#define RX_USED_SET(x, y)
#endif

/* local page allocation routines for the receive buffers. jumbo pages
 * require at least 8K contiguous and 8K aligned buffers.
 */
static cas_page_t *cas_page_alloc(struct cas *cp, const gfp_t flags)
{
        cas_page_t *page;

        page = kmalloc(sizeof(cas_page_t), flags);
        if (!page)
                return NULL;

        INIT_LIST_HEAD(&page->list);
        RX_USED_SET(page, 0);
        page->buffer = alloc_pages(flags, cp->page_order);
        if (!page->buffer)
                goto page_err;
        page->dma_addr = pci_map_page(cp->pdev, page->buffer, 0,
                                      cp->page_size, PCI_DMA_FROMDEVICE);
        return page;

page_err:
        kfree(page);
        return NULL;
}

/* initialize spare pool of rx buffers, but allocate during the open */
static void cas_spare_init(struct cas *cp)
{
        spin_lock(&cp->rx_inuse_lock);
        INIT_LIST_HEAD(&cp->rx_inuse_list);
        spin_unlock(&cp->rx_inuse_lock);

        spin_lock(&cp->rx_spare_lock);
        INIT_LIST_HEAD(&cp->rx_spare_list);
        cp->rx_spares_needed = RX_SPARE_COUNT;
        spin_unlock(&cp->rx_spare_lock);
}

/* used on close. free all the spare buffers. */
static void cas_spare_free(struct cas *cp)
{
        struct list_head list, *elem, *tmp;

        /* free spare buffers */
        INIT_LIST_HEAD(&list);
        spin_lock(&cp->rx_spare_lock);
        list_splice_init(&cp->rx_spare_list, &list);
        spin_unlock(&cp->rx_spare_lock);
        list_for_each_safe(elem, tmp, &list) {
                cas_page_free(cp, list_entry(elem, cas_page_t, list));
        }

        INIT_LIST_HEAD(&list);
#if 1
        /*
         * Looks like Adrian had protected this with a different
         * lock than used everywhere else to manipulate this list.
         */
        spin_lock(&cp->rx_inuse_lock);
        list_splice_init(&cp->rx_inuse_list, &list);
        spin_unlock(&cp->rx_inuse_lock);
#else
        spin_lock(&cp->rx_spare_lock);
        list_splice_init(&cp->rx_inuse_list, &list);
        spin_unlock(&cp->rx_spare_lock);
#endif
        list_for_each_safe(elem, tmp, &list) {
                cas_page_free(cp, list_entry(elem, cas_page_t, list));
        }
}

/* replenish spares if needed */
static void cas_spare_recover(struct cas *cp, const gfp_t flags)
{
        struct list_head list, *elem, *tmp;
        int needed, i;

        /* check inuse list. if we don't need any more free buffers,
         * just free it
         */

        /* make a local copy of the list */
        INIT_LIST_HEAD(&list);
        spin_lock(&cp->rx_inuse_lock);
        list_splice_init(&cp->rx_inuse_list, &list);
        spin_unlock(&cp->rx_inuse_lock);

        list_for_each_safe(elem, tmp, &list) {
                cas_page_t *page = list_entry(elem, cas_page_t, list);

                if (page_count(page->buffer) > 1)
                        continue;

                list_del(elem);
                spin_lock(&cp->rx_spare_lock);
                if (cp->rx_spares_needed > 0) {
                        list_add(elem, &cp->rx_spare_list);
                        cp->rx_spares_needed--;
                        spin_unlock(&cp->rx_spare_lock);
                } else {
                        spin_unlock(&cp->rx_spare_lock);
                        cas_page_free(cp, page);
                }
        }

        /* put any inuse buffers back on the list */
        if (!list_empty(&list)) {
                spin_lock(&cp->rx_inuse_lock);
                list_splice(&list, &cp->rx_inuse_list);
                spin_unlock(&cp->rx_inuse_lock);
        }

        spin_lock(&cp->rx_spare_lock);
        needed = cp->rx_spares_needed;
        spin_unlock(&cp->rx_spare_lock);
        if (!needed)
                return;

        /* we still need spares, so try to allocate some */
        INIT_LIST_HEAD(&list);
        i = 0;
        while (i < needed) {
                cas_page_t *spare = cas_page_alloc(cp, flags);
                if (!spare)
                        break;
                list_add(&spare->list, &list);
                i++;
        }

        spin_lock(&cp->rx_spare_lock);
        list_splice(&list, &cp->rx_spare_list);
        cp->rx_spares_needed -= i;
        spin_unlock(&cp->rx_spare_lock);
}

/* pull a page from the list. */
static cas_page_t *cas_page_dequeue(struct cas *cp)
{
        struct list_head *entry;
        int recover;

        spin_lock(&cp->rx_spare_lock);
        if (list_empty(&cp->rx_spare_list)) {
                /* try to do a quick recovery */
                spin_unlock(&cp->rx_spare_lock);
                cas_spare_recover(cp, GFP_ATOMIC);
                spin_lock(&cp->rx_spare_lock);
                if (list_empty(&cp->rx_spare_list)) {
                        if (netif_msg_rx_err(cp))
                                printk(KERN_ERR "%s: no spare buffers "
                                       "available.\n", cp->dev->name);
                        spin_unlock(&cp->rx_spare_lock);
                        return NULL;
                }
        }

        entry = cp->rx_spare_list.next;
        list_del(entry);
        recover = ++cp->rx_spares_needed;
        spin_unlock(&cp->rx_spare_lock);

        /* trigger the timer to do the recovery */
        if ((recover & (RX_SPARE_RECOVER_VAL - 1)) == 0) {
#if 1
                atomic_inc(&cp->reset_task_pending);
                atomic_inc(&cp->reset_task_pending_spare);
                schedule_work(&cp->reset_task);
#else
                atomic_set(&cp->reset_task_pending, CAS_RESET_SPARE);
                schedule_work(&cp->reset_task);
#endif
        }
        return list_entry(entry, cas_page_t, list);
}


static void cas_mif_poll(struct cas *cp, const int enable)
{
        u32 cfg;

        cfg  = readl(cp->regs + REG_MIF_CFG);
        cfg &= (MIF_CFG_MDIO_0 | MIF_CFG_MDIO_1);

        if (cp->phy_type & CAS_PHY_MII_MDIO1)
                cfg |= MIF_CFG_PHY_SELECT;

        /* poll and interrupt on link status change. */
        if (enable) {
                cfg |= MIF_CFG_POLL_EN;
                cfg |= CAS_BASE(MIF_CFG_POLL_REG, MII_BMSR);
                cfg |= CAS_BASE(MIF_CFG_POLL_PHY, cp->phy_addr);
        }
        writel((enable) ? ~(BMSR_LSTATUS | BMSR_ANEGCOMPLETE) : 0xFFFF,
               cp->regs + REG_MIF_MASK);
        writel(cfg, cp->regs + REG_MIF_CFG);
}

/* Must be invoked under cp->lock */
static void cas_begin_auto_negotiation(struct cas *cp, struct ethtool_cmd *ep)
{
        u16 ctl;
#if 1
        int lcntl;
        int changed = 0;
        int oldstate = cp->lstate;
        int link_was_not_down = !(oldstate == link_down);
#endif
        /* Setup link parameters */
        if (!ep)
                goto start_aneg;
        lcntl = cp->link_cntl;
        if (ep->autoneg == AUTONEG_ENABLE)
                cp->link_cntl = BMCR_ANENABLE;
        else {
                cp->link_cntl = 0;
                if (ep->speed == SPEED_100)
                        cp->link_cntl |= BMCR_SPEED100;
                else if (ep->speed == SPEED_1000)
                        cp->link_cntl |= CAS_BMCR_SPEED1000;
                if (ep->duplex == DUPLEX_FULL)
                        cp->link_cntl |= BMCR_FULLDPLX;
        }
#if 1
        changed = (lcntl != cp->link_cntl);
#endif
start_aneg:
        if (cp->lstate == link_up) {
                printk(KERN_INFO "%s: PCS link down.\n",
                       cp->dev->name);
        } else {
                if (changed) {
                        printk(KERN_INFO "%s: link configuration changed\n",
                               cp->dev->name);
                }
        }
        cp->lstate = link_down;
        cp->link_transition = LINK_TRANSITION_LINK_DOWN;
        if (!cp->hw_running)
                return;
#if 1
        /*
         * WTZ: If the old state was link_up, we turn off the carrier
         * to replicate everything we do elsewhere on a link-down
         * event when we were already in a link-up state..
         */
        if (oldstate == link_up)
                netif_carrier_off(cp->dev);
        if (changed  && link_was_not_down) {
                /*
                 * WTZ: This branch will simply schedule a full reset after
                 * we explicitly changed link modes in an ioctl. See if this
                 * fixes the link-problems we were having for forced mode.
                 */
                atomic_inc(&cp->reset_task_pending);
                atomic_inc(&cp->reset_task_pending_all);
                schedule_work(&cp->reset_task);
                cp->timer_ticks = 0;
                mod_timer(&cp->link_timer, jiffies + CAS_LINK_TIMEOUT);
                return;
        }
#endif
        if (cp->phy_type & CAS_PHY_SERDES) {
                u32 val = readl(cp->regs + REG_PCS_MII_CTRL);

                if (cp->link_cntl & BMCR_ANENABLE) {
                        val |= (PCS_MII_RESTART_AUTONEG | PCS_MII_AUTONEG_EN);
                        cp->lstate = link_aneg;
                } else {
                        if (cp->link_cntl & BMCR_FULLDPLX)
                                val |= PCS_MII_CTRL_DUPLEX;
                        val &= ~PCS_MII_AUTONEG_EN;
                        cp->lstate = link_force_ok;
                }
                cp->link_transition = LINK_TRANSITION_LINK_CONFIG;
                writel(val, cp->regs + REG_PCS_MII_CTRL);

        } else {
                cas_mif_poll(cp, 0);
                ctl = cas_phy_read(cp, MII_BMCR);
                ctl &= ~(BMCR_FULLDPLX | BMCR_SPEED100 |
                         CAS_BMCR_SPEED1000 | BMCR_ANENABLE);
                ctl |= cp->link_cntl;
                if (ctl & BMCR_ANENABLE) {
                        ctl |= BMCR_ANRESTART;
                        cp->lstate = link_aneg;
                } else {
                        cp->lstate = link_force_ok;
                }
                cp->link_transition = LINK_TRANSITION_LINK_CONFIG;
                cas_phy_write(cp, MII_BMCR, ctl);
                cas_mif_poll(cp, 1);
        }

        cp->timer_ticks = 0;
        mod_timer(&cp->link_timer, jiffies + CAS_LINK_TIMEOUT);
}

/* Must be invoked under cp->lock. */
static int cas_reset_mii_phy(struct cas *cp)
{
        int limit = STOP_TRIES_PHY;
        u16 val;

        cas_phy_write(cp, MII_BMCR, BMCR_RESET);
        udelay(100);
        while (limit--) {
                val = cas_phy_read(cp, MII_BMCR);
                if ((val & BMCR_RESET) == 0)
                        break;
                udelay(10);
        }
        return (limit <= 0);
}

static void cas_saturn_firmware_load(struct cas *cp)
{
        cas_saturn_patch_t *patch = cas_saturn_patch;

        cas_phy_powerdown(cp);

        /* expanded memory access mode */
        cas_phy_write(cp, DP83065_MII_MEM, 0x0);

        /* pointer configuration for new firmware */
        cas_phy_write(cp, DP83065_MII_REGE, 0x8ff9);
        cas_phy_write(cp, DP83065_MII_REGD, 0xbd);
        cas_phy_write(cp, DP83065_MII_REGE, 0x8ffa);
        cas_phy_write(cp, DP83065_MII_REGD, 0x82);
        cas_phy_write(cp, DP83065_MII_REGE, 0x8ffb);
        cas_phy_write(cp, DP83065_MII_REGD, 0x0);
        cas_phy_write(cp, DP83065_MII_REGE, 0x8ffc);
        cas_phy_write(cp, DP83065_MII_REGD, 0x39);

        /* download new firmware */
        cas_phy_write(cp, DP83065_MII_MEM, 0x1);
        cas_phy_write(cp, DP83065_MII_REGE, patch->addr);
        while (patch->addr) {
                cas_phy_write(cp, DP83065_MII_REGD, patch->val);
                patch++;
        }

        /* enable firmware */
        cas_phy_write(cp, DP83065_MII_REGE, 0x8ff8);
        cas_phy_write(cp, DP83065_MII_REGD, 0x1);
}


/* phy initialization */
static void cas_phy_init(struct cas *cp)
{
        u16 val;

        /* if we're in MII/GMII mode, set up phy */
        if (CAS_PHY_MII(cp->phy_type)) {
                writel(PCS_DATAPATH_MODE_MII,
                       cp->regs + REG_PCS_DATAPATH_MODE);

                cas_mif_poll(cp, 0);
                cas_reset_mii_phy(cp); /* take out of isolate mode */

                if (PHY_LUCENT_B0 == cp->phy_id) {
                        /* workaround link up/down issue with lucent */
                        cas_phy_write(cp, LUCENT_MII_REG, 0x8000);
                        cas_phy_write(cp, MII_BMCR, 0x00f1);
                        cas_phy_write(cp, LUCENT_MII_REG, 0x0);

                } else if (PHY_BROADCOM_B0 == (cp->phy_id & 0xFFFFFFFC)) {
                        /* workarounds for broadcom phy */
                        cas_phy_write(cp, BROADCOM_MII_REG8, 0x0C20);
                        cas_phy_write(cp, BROADCOM_MII_REG7, 0x0012);
                        cas_phy_write(cp, BROADCOM_MII_REG5, 0x1804);
                        cas_phy_write(cp, BROADCOM_MII_REG7, 0x0013);
                        cas_phy_write(cp, BROADCOM_MII_REG5, 0x1204);
                        cas_phy_write(cp, BROADCOM_MII_REG7, 0x8006);
                        cas_phy_write(cp, BROADCOM_MII_REG5, 0x0132);
                        cas_phy_write(cp, BROADCOM_MII_REG7, 0x8006);
                        cas_phy_write(cp, BROADCOM_MII_REG5, 0x0232);
                        cas_phy_write(cp, BROADCOM_MII_REG7, 0x201F);
                        cas_phy_write(cp, BROADCOM_MII_REG5, 0x0A20);

                } else if (PHY_BROADCOM_5411 == cp->phy_id) {
                        val = cas_phy_read(cp, BROADCOM_MII_REG4);
                        val = cas_phy_read(cp, BROADCOM_MII_REG4);
                        if (val & 0x0080) {
                                /* link workaround */
                                cas_phy_write(cp, BROADCOM_MII_REG4,
                                              val & ~0x0080);
                        }

                } else if (cp->cas_flags & CAS_FLAG_SATURN) {
                        writel((cp->phy_type & CAS_PHY_MII_MDIO0) ?
                               SATURN_PCFG_FSI : 0x0,
                               cp->regs + REG_SATURN_PCFG);

                        /* load firmware to address 10Mbps auto-negotiation
                         * issue. NOTE: this will need to be changed if the
                         * default firmware gets fixed.
                         */
                        if (PHY_NS_DP83065 == cp->phy_id) {
                                cas_saturn_firmware_load(cp);
                        }
                        cas_phy_powerup(cp);
                }

                /* advertise capabilities */
                val = cas_phy_read(cp, MII_BMCR);
                val &= ~BMCR_ANENABLE;
                cas_phy_write(cp, MII_BMCR, val);
                udelay(10);

                cas_phy_write(cp, MII_ADVERTISE,
                              cas_phy_read(cp, MII_ADVERTISE) |
                              (ADVERTISE_10HALF | ADVERTISE_10FULL |
                               ADVERTISE_100HALF | ADVERTISE_100FULL |
                               CAS_ADVERTISE_PAUSE |
                               CAS_ADVERTISE_ASYM_PAUSE));

                if (cp->cas_flags & CAS_FLAG_1000MB_CAP) {
                        /* make sure that we don't advertise half
                         * duplex to avoid a chip issue
                         */
                        val  = cas_phy_read(cp, CAS_MII_1000_CTRL);
                        val &= ~CAS_ADVERTISE_1000HALF;
                        val |= CAS_ADVERTISE_1000FULL;
                        cas_phy_write(cp, CAS_MII_1000_CTRL, val);
                }

        } else {
                /* reset pcs for serdes */
                u32 val;
                int limit;

                writel(PCS_DATAPATH_MODE_SERDES,
                       cp->regs + REG_PCS_DATAPATH_MODE);

                /* enable serdes pins on saturn */
                if (cp->cas_flags & CAS_FLAG_SATURN)
                        writel(0, cp->regs + REG_SATURN_PCFG);

                /* Reset PCS unit. */
                val = readl(cp->regs + REG_PCS_MII_CTRL);
                val |= PCS_MII_RESET;
                writel(val, cp->regs + REG_PCS_MII_CTRL);

                limit = STOP_TRIES;
                while (limit-- > 0) {
                        udelay(10);
                        if ((readl(cp->regs + REG_PCS_MII_CTRL) &
                             PCS_MII_RESET) == 0)
                                break;
                }
                if (limit <= 0)
                        printk(KERN_WARNING "%s: PCS reset bit would not "
                               "clear [%08x].\n", cp->dev->name,
                               readl(cp->regs + REG_PCS_STATE_MACHINE));

                /* Make sure PCS is disabled while changing advertisement
                 * configuration.
                 */
                writel(0x0, cp->regs + REG_PCS_CFG);

                /* Advertise all capabilities except half-duplex. */
                val  = readl(cp->regs + REG_PCS_MII_ADVERT);
                val &= ~PCS_MII_ADVERT_HD;
                val |= (PCS_MII_ADVERT_FD | PCS_MII_ADVERT_SYM_PAUSE |
                        PCS_MII_ADVERT_ASYM_PAUSE);
                writel(val, cp->regs + REG_PCS_MII_ADVERT);

                /* enable PCS */
                writel(PCS_CFG_EN, cp->regs + REG_PCS_CFG);

                /* pcs workaround: enable sync detect */
                writel(PCS_SERDES_CTRL_SYNCD_EN,
                       cp->regs + REG_PCS_SERDES_CTRL);
        }
}


static int cas_pcs_link_check(struct cas *cp)
{
        u32 stat, state_machine;
        int retval = 0;

        /* The link status bit latches on zero, so you must
         * read it twice in such a case to see a transition
         * to the link being up.
         */
        stat = readl(cp->regs + REG_PCS_MII_STATUS);
        if ((stat & PCS_MII_STATUS_LINK_STATUS) == 0)
                stat = readl(cp->regs + REG_PCS_MII_STATUS);

        /* The remote-fault indication is only valid
         * when autoneg has completed.
         */
        if ((stat & (PCS_MII_STATUS_AUTONEG_COMP |
                     PCS_MII_STATUS_REMOTE_FAULT)) ==
            (PCS_MII_STATUS_AUTONEG_COMP | PCS_MII_STATUS_REMOTE_FAULT)) {
                if (netif_msg_link(cp))
                        printk(KERN_INFO "%s: PCS RemoteFault\n",
                               cp->dev->name);
        }

        /* work around link detection issue by querying the PCS state
         * machine directly.
         */
        state_machine = readl(cp->regs + REG_PCS_STATE_MACHINE);
        if ((state_machine & PCS_SM_LINK_STATE_MASK) != SM_LINK_STATE_UP) {
                stat &= ~PCS_MII_STATUS_LINK_STATUS;
        } else if (state_machine & PCS_SM_WORD_SYNC_STATE_MASK) {
                stat |= PCS_MII_STATUS_LINK_STATUS;
        }

        if (stat & PCS_MII_STATUS_LINK_STATUS) {
                if (cp->lstate != link_up) {
                        if (cp->opened) {
                                cp->lstate = link_up;
                                cp->link_transition = LINK_TRANSITION_LINK_UP;

                                cas_set_link_modes(cp);
                                netif_carrier_on(cp->dev);
                        }
                }
        } else if (cp->lstate == link_up) {
                cp->lstate = link_down;
                if (link_transition_timeout != 0 &&
                    cp->link_transition != LINK_TRANSITION_REQUESTED_RESET &&
                    !cp->link_transition_jiffies_valid) {
                        /*
                         * force a reset, as a workaround for the
                         * link-failure problem. May want to move this to a
                         * point a bit earlier in the sequence. If we had
                         * generated a reset a short time ago, we'll wait for
                         * the link timer to check the status until a
                         * timer expires (link_transistion_jiffies_valid is
                         * true when the timer is running.)  Instead of using
                         * a system timer, we just do a check whenever the
                         * link timer is running - this clears the flag after
                         * a suitable delay.
                         */
                        retval = 1;
                        cp->link_transition = LINK_TRANSITION_REQUESTED_RESET;
                        cp->link_transition_jiffies = jiffies;
                        cp->link_transition_jiffies_valid = 1;
                } else {
                        cp->link_transition = LINK_TRANSITION_ON_FAILURE;
                }
                netif_carrier_off(cp->dev);
                if (cp->opened && netif_msg_link(cp)) {
                        printk(KERN_INFO "%s: PCS link down.\n",
                               cp->dev->name);
                }

                /* Cassini only: if you force a mode, there can be
                 * sync problems on link down. to fix that, the following
                 * things need to be checked:
                 * 1) read serialink state register
                 * 2) read pcs status register to verify link down.
                 * 3) if link down and serial link == 0x03, then you need
                 *    to global reset the chip.
                 */
                if ((cp->cas_flags & CAS_FLAG_REG_PLUS) == 0) {
                        /* should check to see if we're in a forced mode */
                        stat = readl(cp->regs + REG_PCS_SERDES_STATE);
                        if (stat == 0x03)
                                return 1;
                }
        } else if (cp->lstate == link_down) {
                if (link_transition_timeout != 0 &&
                    cp->link_transition != LINK_TRANSITION_REQUESTED_RESET &&
                    !cp->link_transition_jiffies_valid) {
                        /* force a reset, as a workaround for the
                         * link-failure problem.  May want to move
                         * this to a point a bit earlier in the
                         * sequence.
                         */
                        retval = 1;
                        cp->link_transition = LINK_TRANSITION_REQUESTED_RESET;
                        cp->link_transition_jiffies = jiffies;
                        cp->link_transition_jiffies_valid = 1;
                } else {
                        cp->link_transition = LINK_TRANSITION_STILL_FAILED;
                }
        }

        return retval;
}

static int cas_pcs_interrupt(struct net_device *dev,
                             struct cas *cp, u32 status)
{
        u32 stat = readl(cp->regs + REG_PCS_INTR_STATUS);

        if ((stat & PCS_INTR_STATUS_LINK_CHANGE) == 0)
                return 0;
        return cas_pcs_link_check(cp);
}

static int cas_txmac_interrupt(struct net_device *dev,
                               struct cas *cp, u32 status)
{
        u32 txmac_stat = readl(cp->regs + REG_MAC_TX_STATUS);

        if (!txmac_stat)
                return 0;

        if (netif_msg_intr(cp))
                printk(KERN_DEBUG "%s: txmac interrupt, txmac_stat: 0x%x\n",
                        cp->dev->name, txmac_stat);

        /* Defer timer expiration is quite normal,
         * don't even log the event.
         */
        if ((txmac_stat & MAC_TX_DEFER_TIMER) &&
            !(txmac_stat & ~MAC_TX_DEFER_TIMER))
                return 0;

        spin_lock(&cp->stat_lock[0]);
        if (txmac_stat & MAC_TX_UNDERRUN) {
                printk(KERN_ERR "%s: TX MAC xmit underrun.\n",
                       dev->name);
                cp->net_stats[0].tx_fifo_errors++;
        }

        if (txmac_stat & MAC_TX_MAX_PACKET_ERR) {
                printk(KERN_ERR "%s: TX MAC max packet size error.\n",
                       dev->name);
                cp->net_stats[0].tx_errors++;
        }

        /* The rest are all cases of one of the 16-bit TX
         * counters expiring.
         */
        if (txmac_stat & MAC_TX_COLL_NORMAL)
                cp->net_stats[0].collisions += 0x10000;

        if (txmac_stat & MAC_TX_COLL_EXCESS) {
                cp->net_stats[0].tx_aborted_errors += 0x10000;
                cp->net_stats[0].collisions += 0x10000;
        }

        if (txmac_stat & MAC_TX_COLL_LATE) {
                cp->net_stats[0].tx_aborted_errors += 0x10000;
                cp->net_stats[0].collisions += 0x10000;
        }
        spin_unlock(&cp->stat_lock[0]);

        /* We do not keep track of MAC_TX_COLL_FIRST and
         * MAC_TX_PEAK_ATTEMPTS events.
         */
        return 0;
}

static void cas_load_firmware(struct cas *cp, cas_hp_inst_t *firmware)
{
        cas_hp_inst_t *inst;
        u32 val;
        int i;

        i = 0;
        while ((inst = firmware) && inst->note) {
                writel(i, cp->regs + REG_HP_INSTR_RAM_ADDR);

                val = CAS_BASE(HP_INSTR_RAM_HI_VAL, inst->val);
                val |= CAS_BASE(HP_INSTR_RAM_HI_MASK, inst->mask);
                writel(val, cp->regs + REG_HP_INSTR_RAM_DATA_HI);

                val = CAS_BASE(HP_INSTR_RAM_MID_OUTARG, inst->outarg >> 10);
                val |= CAS_BASE(HP_INSTR_RAM_MID_OUTOP, inst->outop);
                val |= CAS_BASE(HP_INSTR_RAM_MID_FNEXT, inst->fnext);
                val |= CAS_BASE(HP_INSTR_RAM_MID_FOFF, inst->foff);
                val |= CAS_BASE(HP_INSTR_RAM_MID_SNEXT, inst->snext);
                val |= CAS_BASE(HP_INSTR_RAM_MID_SOFF, inst->soff);
                val |= CAS_BASE(HP_INSTR_RAM_MID_OP, inst->op);
                writel(val, cp->regs + REG_HP_INSTR_RAM_DATA_MID);

                val = CAS_BASE(HP_INSTR_RAM_LOW_OUTMASK, inst->outmask);
                val |= CAS_BASE(HP_INSTR_RAM_LOW_OUTSHIFT, inst->outshift);
                val |= CAS_BASE(HP_INSTR_RAM_LOW_OUTEN, inst->outenab);
                val |= CAS_BASE(HP_INSTR_RAM_LOW_OUTARG, inst->outarg);
                writel(val, cp->regs + REG_HP_INSTR_RAM_DATA_LOW);
                ++firmware;
                ++i;
        }
}

static void cas_init_rx_dma(struct cas *cp)
{
        u64 desc_dma = cp->block_dvma;
        u32 val;
        int i, size;

        /* rx free descriptors */
        val = CAS_BASE(RX_CFG_SWIVEL, RX_SWIVEL_OFF_VAL);
        val |= CAS_BASE(RX_CFG_DESC_RING, RX_DESC_RINGN_INDEX(0));
        val |= CAS_BASE(RX_CFG_COMP_RING, RX_COMP_RINGN_INDEX(0));
        if ((N_RX_DESC_RINGS > 1) &&
            (cp->cas_flags & CAS_FLAG_REG_PLUS))  /* do desc 2 */
                val |= CAS_BASE(RX_CFG_DESC_RING1, RX_DESC_RINGN_INDEX(1));
        writel(val, cp->regs + REG_RX_CFG);

        val = (unsigned long) cp->init_rxds[0] -
                (unsigned long) cp->init_block;
        writel((desc_dma + val) >> 32, cp->regs + REG_RX_DB_HI);
        writel((desc_dma + val) & 0xffffffff, cp->regs + REG_RX_DB_LOW);
        writel(RX_DESC_RINGN_SIZE(0) - 4, cp->regs + REG_RX_KICK);

        if (cp->cas_flags & CAS_FLAG_REG_PLUS) {
                /* rx desc 2 is for IPSEC packets. however,
                 * we don't it that for that purpose.
                 */
                val = (unsigned long) cp->init_rxds[1] -
                        (unsigned long) cp->init_block;
                writel((desc_dma + val) >> 32, cp->regs + REG_PLUS_RX_DB1_HI);
                writel((desc_dma + val) & 0xffffffff, cp->regs +
                       REG_PLUS_RX_DB1_LOW);
                writel(RX_DESC_RINGN_SIZE(1) - 4, cp->regs +
                       REG_PLUS_RX_KICK1);
        }

        /* rx completion registers */
        val = (unsigned long) cp->init_rxcs[0] -
                (unsigned long) cp->init_block;
        writel((desc_dma + val) >> 32, cp->regs + REG_RX_CB_HI);
        writel((desc_dma + val) & 0xffffffff, cp->regs + REG_RX_CB_LOW);

        if (cp->cas_flags & CAS_FLAG_REG_PLUS) {
                /* rx comp 2-4 */
                for (i = 1; i < MAX_RX_COMP_RINGS; i++) {
                        val = (unsigned long) cp->init_rxcs[i] -
                                (unsigned long) cp->init_block;
                        writel((desc_dma + val) >> 32, cp->regs +
                               REG_PLUS_RX_CBN_HI(i));
                        writel((desc_dma + val) & 0xffffffff, cp->regs +
                               REG_PLUS_RX_CBN_LOW(i));
                }
        }

        /* read selective clear regs to prevent spurious interrupts
         * on reset because complete == kick.
         * selective clear set up to prevent interrupts on resets
         */
        readl(cp->regs + REG_INTR_STATUS_ALIAS);
        writel(INTR_RX_DONE | INTR_RX_BUF_UNAVAIL, cp->regs + REG_ALIAS_CLEAR);
        if (cp->cas_flags & CAS_FLAG_REG_PLUS) {
                for (i = 1; i < N_RX_COMP_RINGS; i++)
                        readl(cp->regs + REG_PLUS_INTRN_STATUS_ALIAS(i));

                /* 2 is different from 3 and 4 */
                if (N_RX_COMP_RINGS > 1)
                        writel(INTR_RX_DONE_ALT | INTR_RX_BUF_UNAVAIL_1,
                               cp->regs + REG_PLUS_ALIASN_CLEAR(1));

                for (i = 2; i < N_RX_COMP_RINGS; i++)
                        writel(INTR_RX_DONE_ALT,
                               cp->regs + REG_PLUS_ALIASN_CLEAR(i));
        }

        /* set up pause thresholds */
        val  = CAS_BASE(RX_PAUSE_THRESH_OFF,
                        cp->rx_pause_off / RX_PAUSE_THRESH_QUANTUM);
        val |= CAS_BASE(RX_PAUSE_THRESH_ON,
                        cp->rx_pause_on / RX_PAUSE_THRESH_QUANTUM);
        writel(val, cp->regs + REG_RX_PAUSE_THRESH);

        /* zero out dma reassembly buffers */
        for (i = 0; i < 64; i++) {
                writel(i, cp->regs + REG_RX_TABLE_ADDR);
                writel(0x0, cp->regs + REG_RX_TABLE_DATA_LOW);
                writel(0x0, cp->regs + REG_RX_TABLE_DATA_MID);
                writel(0x0, cp->regs + REG_RX_TABLE_DATA_HI);
        }

        /* make sure address register is 0 for normal operation */
        writel(0x0, cp->regs + REG_RX_CTRL_FIFO_ADDR);
        writel(0x0, cp->regs + REG_RX_IPP_FIFO_ADDR);

        /* interrupt mitigation */
#ifdef USE_RX_BLANK
        val = CAS_BASE(RX_BLANK_INTR_TIME, RX_BLANK_INTR_TIME_VAL);
        val |= CAS_BASE(RX_BLANK_INTR_PKT, RX_BLANK_INTR_PKT_VAL);
        writel(val, cp->regs + REG_RX_BLANK);
#else
        writel(0x0, cp->regs + REG_RX_BLANK);
#endif

        /* interrupt generation as a function of low water marks for
         * free desc and completion entries. these are used to trigger
         * housekeeping for rx descs. we don't use the free interrupt
         * as it's not very useful
         */
        /* val = CAS_BASE(RX_AE_THRESH_FREE, RX_AE_FREEN_VAL(0)); */
        val = CAS_BASE(RX_AE_THRESH_COMP, RX_AE_COMP_VAL);
        writel(val, cp->regs + REG_RX_AE_THRESH);
        if (cp->cas_flags & CAS_FLAG_REG_PLUS) {
                val = CAS_BASE(RX_AE1_THRESH_FREE, RX_AE_FREEN_VAL(1));
                writel(val, cp->regs + REG_PLUS_RX_AE1_THRESH);
        }

        /* Random early detect registers. useful for congestion avoidance.
         * this should be tunable.
         */
        writel(0x0, cp->regs + REG_RX_RED);

        /* receive page sizes. default == 2K (0x800) */
        val = 0;
        if (cp->page_size == 0x1000)
                val = 0x1;
        else if (cp->page_size == 0x2000)
                val = 0x2;
        else if (cp->page_size == 0x4000)
                val = 0x3;

        /* round mtu + offset. constrain to page size. */
        size = cp->dev->mtu + 64;
        if (size > cp->page_size)
                size = cp->page_size;

        if (size <= 0x400)
                i = 0x0;
        else if (size <= 0x800)
                i = 0x1;
        else if (size <= 0x1000)
                i = 0x2;
        else
                i = 0x3;

        cp->mtu_stride = 1 << (i + 10);
        val  = CAS_BASE(RX_PAGE_SIZE, val);
        val |= CAS_BASE(RX_PAGE_SIZE_MTU_STRIDE, i);
        val |= CAS_BASE(RX_PAGE_SIZE_MTU_COUNT, cp->page_size >> (i + 10));
        val |= CAS_BASE(RX_PAGE_SIZE_MTU_OFF, 0x1);
        writel(val, cp->regs + REG_RX_PAGE_SIZE);

        /* enable the header parser if desired */
        if (CAS_HP_FIRMWARE == cas_prog_null)
                return;

        val = CAS_BASE(HP_CFG_NUM_CPU, CAS_NCPUS > 63 ? 0 : CAS_NCPUS);
        val |= HP_CFG_PARSE_EN | HP_CFG_SYN_INC_MASK;
        val |= CAS_BASE(HP_CFG_TCP_THRESH, HP_TCP_THRESH_VAL);
        writel(val, cp->regs + REG_HP_CFG);
}

static inline void cas_rxc_init(struct cas_rx_comp *rxc)
{
        memset(rxc, 0, sizeof(*rxc));
        rxc->word4 = cpu_to_le64(RX_COMP4_ZERO);
}

/* NOTE: we use the ENC RX DESC ring for spares. the rx_page[0,1]
 * flipping is protected by the fact that the chip will not
 * hand back the same page index while it's being processed.
 */
static inline cas_page_t *cas_page_spare(struct cas *cp, const int index)
{
        cas_page_t *page = cp->rx_pages[1][index];
        cas_page_t *new;

        if (page_count(page->buffer) == 1)
                return page;

        new = cas_page_dequeue(cp);
        if (new) {
                spin_lock(&cp->rx_inuse_lock);
                list_add(&page->list, &cp->rx_inuse_list);
                spin_unlock(&cp->rx_inuse_lock);
        }
        return new;
}

/* this needs to be changed if we actually use the ENC RX DESC ring */
static cas_page_t *cas_page_swap(struct cas *cp, const int ring,
                                 const int index)
{
        cas_page_t **page0 = cp->rx_pages[0];
        cas_page_t **page1 = cp->rx_pages[1];

        /* swap if buffer is in use */
        if (page_count(page0[index]->buffer) > 1) {
                cas_page_t *new = cas_page_spare(cp, index);
                if (new) {
                        page1[index] = page0[index];
                        page0[index] = new;
                }
        }
        RX_USED_SET(page0[index], 0);
        return page0[index];
}

static void cas_clean_rxds(struct cas *cp)
{
        /* only clean ring 0 as ring 1 is used for spare buffers */
        struct cas_rx_desc *rxd = cp->init_rxds[0];
        int i, size;

        /* release all rx flows */
        for (i = 0; i < N_RX_FLOWS; i++) {
                struct sk_buff *skb;
                while ((skb = __skb_dequeue(&cp->rx_flows[i]))) {
                        cas_skb_release(skb);
                }
        }

        /* initialize descriptors */
        size = RX_DESC_RINGN_SIZE(0);
        for (i = 0; i < size; i++) {
                cas_page_t *page = cas_page_swap(cp, 0, i);
                rxd[i].buffer = cpu_to_le64(page->dma_addr);
                rxd[i].index  = cpu_to_le64(CAS_BASE(RX_INDEX_NUM, i) |
                                            CAS_BASE(RX_INDEX_RING, 0));
        }

        cp->rx_old[0]  = RX_DESC_RINGN_SIZE(0) - 4;
        cp->rx_last[0] = 0;
        cp->cas_flags &= ~CAS_FLAG_RXD_POST(0);
}

static void cas_clean_rxcs(struct cas *cp)
{
        int i, j;

        /* take ownership of rx comp descriptors */
        memset(cp->rx_cur, 0, sizeof(*cp->rx_cur)*N_RX_COMP_RINGS);
        memset(cp->rx_new, 0, sizeof(*cp->rx_new)*N_RX_COMP_RINGS);
        for (i = 0; i < N_RX_COMP_RINGS; i++) {
                struct cas_rx_comp *rxc = cp->init_rxcs[i];
                for (j = 0; j < RX_COMP_RINGN_SIZE(i); j++) {
                        cas_rxc_init(rxc + j);
                }
        }
}

#if 0
/* When we get a RX fifo overflow, the RX unit is probably hung
 * so we do the following.
 *
 * If any part of the reset goes wrong, we return 1 and that causes the
 * whole chip to be reset.
 */
static int cas_rxmac_reset(struct cas *cp)
{
        struct net_device *dev = cp->dev;
        int limit;
        u32 val;

        /* First, reset MAC RX. */
        writel(cp->mac_rx_cfg & ~MAC_RX_CFG_EN, cp->regs + REG_MAC_RX_CFG);
        for (limit = 0; limit < STOP_TRIES; limit++) {
                if (!(readl(cp->regs + REG_MAC_RX_CFG) & MAC_RX_CFG_EN))
                        break;
                udelay(10);
        }
        if (limit == STOP_TRIES) {
                printk(KERN_ERR "%s: RX MAC will not disable, resetting whole "
                       "chip.\n", dev->name);
                return 1;
        }

        /* Second, disable RX DMA. */
        writel(0, cp->regs + REG_RX_CFG);
        for (limit = 0; limit < STOP_TRIES; limit++) {
                if (!(readl(cp->regs + REG_RX_CFG) & RX_CFG_DMA_EN))
                        break;
                udelay(10);
        }
        if (limit == STOP_TRIES) {
                printk(KERN_ERR "%s: RX DMA will not disable, resetting whole "
                       "chip.\n", dev->name);
                return 1;
        }

        mdelay(5);

        /* Execute RX reset command. */
        writel(SW_RESET_RX, cp->regs + REG_SW_RESET);
        for (limit = 0; limit < STOP_TRIES; limit++) {
                if (!(readl(cp->regs + REG_SW_RESET) & SW_RESET_RX))
                        break;
                udelay(10);
        }
        if (limit == STOP_TRIES) {
                printk(KERN_ERR "%s: RX reset command will not execute, "
                       "resetting whole chip.\n", dev->name);
                return 1;
        }

        /* reset driver rx state */
        cas_clean_rxds(cp);
        cas_clean_rxcs(cp);

        /* Now, reprogram the rest of RX unit. */
        cas_init_rx_dma(cp);

        /* re-enable */
        val = readl(cp->regs + REG_RX_CFG);
        writel(val | RX_CFG_DMA_EN, cp->regs + REG_RX_CFG);
        writel(MAC_RX_FRAME_RECV, cp->regs + REG_MAC_RX_MASK);
        val = readl(cp->regs + REG_MAC_RX_CFG);
        writel(val | MAC_RX_CFG_EN, cp->regs + REG_MAC_RX_CFG);
        return 0;
}
#endif

static int cas_rxmac_interrupt(struct net_device *dev, struct cas *cp,
                               u32 status)
{
        u32 stat = readl(cp->regs + REG_MAC_RX_STATUS);

        if (!stat)
                return 0;

        if (netif_msg_intr(cp))
                printk(KERN_DEBUG "%s: rxmac interrupt, stat: 0x%x\n",
                        cp->dev->name, stat);

        /* these are all rollovers */
        spin_lock(&cp->stat_lock[0]);
        if (stat & MAC_RX_ALIGN_ERR)
                cp->net_stats[0].rx_frame_errors += 0x10000;

        if (stat & MAC_RX_CRC_ERR)
                cp->net_stats[0].rx_crc_errors += 0x10000;

        if (stat & MAC_RX_LEN_ERR)
                cp->net_stats[0].rx_length_errors += 0x10000;

        if (stat & MAC_RX_OVERFLOW) {
                cp->net_stats[0].rx_over_errors++;
                cp->net_stats[0].rx_fifo_errors++;
        }

        /* We do not track MAC_RX_FRAME_COUNT and MAC_RX_VIOL_ERR
         * events.
         */
        spin_unlock(&cp->stat_lock[0]);
        return 0;
}

static int cas_mac_interrupt(struct net_device *dev, struct cas *cp,
                             u32 status)
{
        u32 stat = readl(cp->regs + REG_MAC_CTRL_STATUS);

        if (!stat)
                return 0;

        if (netif_msg_intr(cp))
                printk(KERN_DEBUG "%s: mac interrupt, stat: 0x%x\n",
                        cp->dev->name, stat);

        /* This interrupt is just for pause frame and pause
         * tracking.  It is useful for diagnostics and debug
         * but probably by default we will mask these events.
         */
        if (stat & MAC_CTRL_PAUSE_STATE)
                cp->pause_entered++;

        if (stat & MAC_CTRL_PAUSE_RECEIVED)
                cp->pause_last_time_recvd = (stat >> 16);

        return 0;
}


/* Must be invoked under cp->lock. */
static inline int cas_mdio_link_not_up(struct cas *cp)
{
        u16 val;

        switch (cp->lstate) {
        case link_force_ret:
                if (netif_msg_link(cp))
                        printk(KERN_INFO "%s: Autoneg failed again, keeping"
                                " forced mode\n", cp->dev->name);
                cas_phy_write(cp, MII_BMCR, cp->link_fcntl);
                cp->timer_ticks = 5;
                cp->lstate = link_force_ok;
                cp->link_transition = LINK_TRANSITION_LINK_CONFIG;
                break;

        case link_aneg:
                val = cas_phy_read(cp, MII_BMCR);

                /* Try forced modes. we try things in the following order:
                 * 1000 full -> 100 full/half -> 10 half
                 */
                val &= ~(BMCR_ANRESTART | BMCR_ANENABLE);
                val |= BMCR_FULLDPLX;
                val |= (cp->cas_flags & CAS_FLAG_1000MB_CAP) ?
                        CAS_BMCR_SPEED1000 : BMCR_SPEED100;
                cas_phy_write(cp, MII_BMCR, val);
                cp->timer_ticks = 5;
                cp->lstate = link_force_try;
                cp->link_transition = LINK_TRANSITION_LINK_CONFIG;
                break;

        case link_force_try:
                /* Downgrade from 1000 to 100 to 10 Mbps if necessary. */
                val = cas_phy_read(cp, MII_BMCR);
                cp->timer_ticks = 5;
                if (val & CAS_BMCR_SPEED1000) { /* gigabit */
                        val &= ~CAS_BMCR_SPEED1000;
                        val |= (BMCR_SPEED100 | BMCR_FULLDPLX);
                        cas_phy_write(cp, MII_BMCR, val);
                        break;
                }

                if (val & BMCR_SPEED100) {
                        if (val & BMCR_FULLDPLX) /* fd failed */
                                val &= ~BMCR_FULLDPLX;
                        else { /* 100Mbps failed */
                                val &= ~BMCR_SPEED100;
                        }
                        cas_phy_write(cp, MII_BMCR, val);
                        break;
                }
        default:
                break;
        }
        return 0;
}


/* must be invoked with cp->lock held */
static int cas_mii_link_check(struct cas *cp, const u16 bmsr)
{
        int restart;

        if (bmsr & BMSR_LSTATUS) {
                /* Ok, here we got a link. If we had it due to a forced
                 * fallback, and we were configured for autoneg, we
                 * retry a short autoneg pass. If you know your hub is
                 * broken, use ethtool ;)
                 */
                if ((cp->lstate == link_force_try) &&
                    (cp->link_cntl & BMCR_ANENABLE)) {
                        cp->lstate = link_force_ret;
                        cp->link_transition = LINK_TRANSITION_LINK_CONFIG;
                        cas_mif_poll(cp, 0);
                        cp->link_fcntl = cas_phy_read(cp, MII_BMCR);
                        cp->timer_ticks = 5;
                        if (cp->opened && netif_msg_link(cp))
                                printk(KERN_INFO "%s: Got link after fallback, retrying"
                                       " autoneg once...\n", cp->dev->name);
                        cas_phy_write(cp, MII_BMCR,
                                      cp->link_fcntl | BMCR_ANENABLE |
                                      BMCR_ANRESTART);
                        cas_mif_poll(cp, 1);

                } else if (cp->lstate != link_up) {
                        cp->lstate = link_up;
                        cp->link_transition = LINK_TRANSITION_LINK_UP;

                        if (cp->opened) {
                                cas_set_link_modes(cp);
                                netif_carrier_on(cp->dev);
                        }
                }
                return 0;
        }

        /* link not up. if the link was previously up, we restart the
         * whole process
         */
        restart = 0;
        if (cp->lstate == link_up) {
                cp->lstate = link_down;
                cp->link_transition = LINK_TRANSITION_LINK_DOWN;

                netif_carrier_off(cp->dev);
                if (cp->opened && netif_msg_link(cp))
                        printk(KERN_INFO "%s: Link down\n",
                               cp->dev->name);
                restart = 1;

        } else if (++cp->timer_ticks > 10)
                cas_mdio_link_not_up(cp);

        return restart;
}

static int cas_mif_interrupt(struct net_device *dev, struct cas *cp,
                             u32 status)
{
        u32 stat = readl(cp->regs + REG_MIF_STATUS);
        u16 bmsr;

        /* check for a link change */
        if (CAS_VAL(MIF_STATUS_POLL_STATUS, stat) == 0)
                return 0;

        bmsr = CAS_VAL(MIF_STATUS_POLL_DATA, stat);
        return cas_mii_link_check(cp, bmsr);
}

static int cas_pci_interrupt(struct net_device *dev, struct cas *cp,
                             u32 status)
{
        u32 stat = readl(cp->regs + REG_PCI_ERR_STATUS);

        if (!stat)
                return 0;

        printk(KERN_ERR "%s: PCI error [%04x:%04x] ", dev->name, stat,
               readl(cp->regs + REG_BIM_DIAG));

        /* cassini+ has this reserved */
        if ((stat & PCI_ERR_BADACK) &&
            ((cp->cas_flags & CAS_FLAG_REG_PLUS) == 0))
                printk("<No ACK64# during ABS64 cycle> ");

        if (stat & PCI_ERR_DTRTO)
                printk("<Delayed transaction timeout> ");
        if (stat & PCI_ERR_OTHER)
                printk("<other> ");
        if (stat & PCI_ERR_BIM_DMA_WRITE)
                printk("<BIM DMA 0 write req> ");
        if (stat & PCI_ERR_BIM_DMA_READ)
                printk("<BIM DMA 0 read req> ");
        printk("\n");

        if (stat & PCI_ERR_OTHER) {
                u16 cfg;

                /* Interrogate PCI config space for the
                 * true cause.
                 */
                pci_read_config_word(cp->pdev, PCI_STATUS, &cfg);
                printk(KERN_ERR "%s: Read PCI cfg space status [%04x]\n",
                       dev->name, cfg);
                if (cfg & PCI_STATUS_PARITY)
                        printk(KERN_ERR "%s: PCI parity error detected.\n",
                               dev->name);
                if (cfg & PCI_STATUS_SIG_TARGET_ABORT)
                        printk(KERN_ERR "%s: PCI target abort.\n",
                               dev->name);
                if (cfg & PCI_STATUS_REC_TARGET_ABORT)
                        printk(KERN_ERR "%s: PCI master acks target abort.\n",
                               dev->name);
                if (cfg & PCI_STATUS_REC_MASTER_ABORT)
                        printk(KERN_ERR "%s: PCI master abort.\n", dev->name);
                if (cfg & PCI_STATUS_SIG_SYSTEM_ERROR)
                        printk(KERN_ERR "%s: PCI system error SERR#.\n",
                               dev->name);
                if (cfg & PCI_STATUS_DETECTED_PARITY)
                        printk(KERN_ERR "%s: PCI parity error.\n",
                               dev->name);

                /* Write the error bits back to clear them. */
                cfg &= (PCI_STATUS_PARITY |
                        PCI_STATUS_SIG_TARGET_ABORT |
                        PCI_STATUS_REC_TARGET_ABORT |
                        PCI_STATUS_REC_MASTER_ABORT |
                        PCI_STATUS_SIG_SYSTEM_ERROR |
                        PCI_STATUS_DETECTED_PARITY);
                pci_write_config_word(cp->pdev, PCI_STATUS, cfg);
        }

        /* For all PCI errors, we should reset the chip. */
        return 1;
}

/* All non-normal interrupt conditions get serviced here.
 * Returns non-zero if we should just exit the interrupt
 * handler right now (ie. if we reset the card which invalidates
 * all of the other original irq status bits).
 */
static int cas_abnormal_irq(struct net_device *dev, struct cas *cp,
                            u32 status)
{
        if (status & INTR_RX_TAG_ERROR) {
                /* corrupt RX tag framing */
                if (netif_msg_rx_err(cp))
                        printk(KERN_DEBUG "%s: corrupt rx tag framing\n",
                                cp->dev->name);
                spin_lock(&cp->stat_lock[0]);
                cp->net_stats[0].rx_errors++;
                spin_unlock(&cp->stat_lock[0]);
                goto do_reset;
        }

        if (status & INTR_RX_LEN_MISMATCH) {
                /* length mismatch. */
                if (netif_msg_rx_err(cp))
                        printk(KERN_DEBUG "%s: length mismatch for rx frame\n",
                                cp->dev->name);
                spin_lock(&cp->stat_lock[0]);
                cp->net_stats[0].rx_errors++;
                spin_unlock(&cp->stat_lock[0]);
                goto do_reset;
        }

        if (status & INTR_PCS_STATUS) {
                if (cas_pcs_interrupt(dev, cp, status))
                        goto do_reset;
        }

        if (status & INTR_TX_MAC_STATUS) {
                if (cas_txmac_interrupt(dev, cp, status))
                        goto do_reset;
        }

        if (status & INTR_RX_MAC_STATUS) {
                if (cas_rxmac_interrupt(dev, cp, status))
                        goto do_reset;
        }

        if (status & INTR_MAC_CTRL_STATUS) {
                if (cas_mac_interrupt(dev, cp, status))
                        goto do_reset;
        }

        if (status & INTR_MIF_STATUS) {
                if (cas_mif_interrupt(dev, cp, status))
                        goto do_reset;
        }

        if (status & INTR_PCI_ERROR_STATUS) {
                if (cas_pci_interrupt(dev, cp, status))
                        goto do_reset;
        }
        return 0;

do_reset:
#if 1
        atomic_inc(&cp->reset_task_pending);
        atomic_inc(&cp->reset_task_pending_all);
        printk(KERN_ERR "%s:reset called in cas_abnormal_irq [0x%x]\n",
               dev->name, status);
        schedule_work(&cp->reset_task);
#else
        atomic_set(&cp->reset_task_pending, CAS_RESET_ALL);
        printk(KERN_ERR "reset called in cas_abnormal_irq\n");
        schedule_work(&cp->reset_task);
#endif
        return 1;
}

/* NOTE: CAS_TABORT returns 1 or 2 so that it can be used when
 *       determining whether to do a netif_stop/wakeup
 */
#define CAS_TABORT(x)      (((x)->cas_flags & CAS_FLAG_TARGET_ABORT) ? 2 : 1)
#define CAS_ROUND_PAGE(x)  (((x) + PAGE_SIZE - 1) & PAGE_MASK)
static inline int cas_calc_tabort(struct cas *cp, const unsigned long addr,
                                  const int len)
{
        unsigned long off = addr + len;

        if (CAS_TABORT(cp) == 1)
                return 0;
        if ((CAS_ROUND_PAGE(off) - off) > TX_TARGET_ABORT_LEN)
                return 0;
        return TX_TARGET_ABORT_LEN;
}

static inline void cas_tx_ringN(struct cas *cp, int ring, int limit)
{
        struct cas_tx_desc *txds;
        struct sk_buff **skbs;
        struct net_device *dev = cp->dev;
        int entry, count;

        spin_lock(&cp->tx_lock[ring]);
        txds = cp->init_txds[ring];
        skbs = cp->tx_skbs[ring];
        entry = cp->tx_old[ring];

        count = TX_BUFF_COUNT(ring, entry, limit);
        while (entry != limit) {
                struct sk_buff *skb = skbs[entry];
                dma_addr_t daddr;
                u32 dlen;
                int frag;

                if (!skb) {
                        /* this should never occur */
                        entry = TX_DESC_NEXT(ring, entry);
                        continue;
                }

                /* however, we might get only a partial skb release. */
                count -= skb_shinfo(skb)->nr_frags +
                        + cp->tx_tiny_use[ring][entry].nbufs + 1;
                if (count < 0)
                        break;

                if (netif_msg_tx_done(cp))
                        printk(KERN_DEBUG "%s: tx[%d] done, slot %d\n",
                               cp->dev->name, ring, entry);

                skbs[entry] = NULL;
                cp->tx_tiny_use[ring][entry].nbufs = 0;

                for (frag = 0; frag <= skb_shinfo(skb)->nr_frags; frag++) {
                        struct cas_tx_desc *txd = txds + entry;

                        daddr = le64_to_cpu(txd->buffer);
                        dlen = CAS_VAL(TX_DESC_BUFLEN,
                                       le64_to_cpu(txd->control));
                        pci_unmap_page(cp->pdev, daddr, dlen,
                                       PCI_DMA_TODEVICE);
                        entry = TX_DESC_NEXT(ring, entry);

                        /* tiny buffer may follow */
                        if (cp->tx_tiny_use[ring][entry].used) {
                                cp->tx_tiny_use[ring][entry].used = 0;
                                entry = TX_DESC_NEXT(ring, entry);
                        }
                }

                spin_lock(&cp->stat_lock[ring]);
                cp->net_stats[ring].tx_packets++;
                cp->net_stats[ring].tx_bytes += skb->len;
                spin_unlock(&cp->stat_lock[ring]);
                dev_kfree_skb_irq(skb);
        }
        cp->tx_old[ring] = entry;

        /* this is wrong for multiple tx rings. the net device needs
         * multiple queues for this to do the right thing.  we wait
         * for 2*packets to be available when using tiny buffers
         */
        if (netif_queue_stopped(dev) &&
            (TX_BUFFS_AVAIL(cp, ring) > CAS_TABORT(cp)*(MAX_SKB_FRAGS + 1)))
                netif_wake_queue(dev);
        spin_unlock(&cp->tx_lock[ring]);
}

static void cas_tx(struct net_device *dev, struct cas *cp,
                   u32 status)
{
        int limit, ring;
#ifdef USE_TX_COMPWB
        u64 compwb = le64_to_cpu(cp->init_block->tx_compwb);
#endif
        if (netif_msg_intr(cp))
                printk(KERN_DEBUG "%s: tx interrupt, status: 0x%x, %llx\n",
                        cp->dev->name, status, (unsigned long long)compwb);
        /* process all the rings */
        for (ring = 0; ring < N_TX_RINGS; ring++) {
#ifdef USE_TX_COMPWB
                /* use the completion writeback registers */
                limit = (CAS_VAL(TX_COMPWB_MSB, compwb) << 8) |
                        CAS_VAL(TX_COMPWB_LSB, compwb);
                compwb = TX_COMPWB_NEXT(compwb);
#else
                limit = readl(cp->regs + REG_TX_COMPN(ring));
#endif
                if (cp->tx_old[ring] != limit)
                        cas_tx_ringN(cp, ring, limit);
        }
}


static int cas_rx_process_pkt(struct cas *cp, struct cas_rx_comp *rxc,
                              int entry, const u64 *words,
                              struct sk_buff **skbref)
{
        int dlen, hlen, len, i, alloclen;
        int off, swivel = RX_SWIVEL_OFF_VAL;
        struct cas_page *page;
        struct sk_buff *skb;
        void *addr, *crcaddr;
        __sum16 csum;
        char *p;

        hlen = CAS_VAL(RX_COMP2_HDR_SIZE, words[1]);
        dlen = CAS_VAL(RX_COMP1_DATA_SIZE, words[0]);
        len  = hlen + dlen;

        if (RX_COPY_ALWAYS || (words[2] & RX_COMP3_SMALL_PKT))
                alloclen = len;
        else
                alloclen = max(hlen, RX_COPY_MIN);

        skb = dev_alloc_skb(alloclen + swivel + cp->crc_size);
        if (skb == NULL)
                return -1;

        *skbref = skb;
        skb_reserve(skb, swivel);

        p = skb->data;
        addr = crcaddr = NULL;
        if (hlen) { /* always copy header pages */
                i = CAS_VAL(RX_COMP2_HDR_INDEX, words[1]);
                page = cp->rx_pages[CAS_VAL(RX_INDEX_RING, i)][CAS_VAL(RX_INDEX_NUM, i)];
                off = CAS_VAL(RX_COMP2_HDR_OFF, words[1]) * 0x100 +
                        swivel;

                i = hlen;
                if (!dlen) /* attach FCS */
                        i += cp->crc_size;
                pci_dma_sync_single_for_cpu(cp->pdev, page->dma_addr + off, i,
                                    PCI_DMA_FROMDEVICE);
                addr = cas_page_map(page->buffer);
                memcpy(p, addr + off, i);
                pci_dma_sync_single_for_device(cp->pdev, page->dma_addr + off, i,
                                    PCI_DMA_FROMDEVICE);
                cas_page_unmap(addr);
                RX_USED_ADD(page, 0x100);
                p += hlen;
                swivel = 0;
        }


        if (alloclen < (hlen + dlen)) {
                skb_frag_t *frag = skb_shinfo(skb)->frags;

                /* normal or jumbo packets. we use frags */
                i = CAS_VAL(RX_COMP1_DATA_INDEX, words[0]);
                page = cp->rx_pages[CAS_VAL(RX_INDEX_RING, i)][CAS_VAL(RX_INDEX_NUM, i)];
                off = CAS_VAL(RX_COMP1_DATA_OFF, words[0]) + swivel;

                hlen = min(cp->page_size - off, dlen);
                if (hlen < 0) {
                        if (netif_msg_rx_err(cp)) {
                                printk(KERN_DEBUG "%s: rx page overflow: "
                                       "%d\n", cp->dev->name, hlen);
                        }
                        dev_kfree_skb_irq(skb);
                        return -1;
                }
                i = hlen;
                if (i == dlen)  /* attach FCS */
                        i += cp->crc_size;
                pci_dma_sync_single_for_cpu(cp->pdev, page->dma_addr + off, i,
                                    PCI_DMA_FROMDEVICE);

                /* make sure we always copy a header */
                swivel = 0;
                if (p == (char *) skb->data) { /* not split */
                        addr = cas_page_map(page->buffer);
                        memcpy(p, addr + off, RX_COPY_MIN);
                        pci_dma_sync_single_for_device(cp->pdev, page->dma_addr + off, i,
                                        PCI_DMA_FROMDEVICE);
                        cas_page_unmap(addr);
                        off += RX_COPY_MIN;
                        swivel = RX_COPY_MIN;
                        RX_USED_ADD(page, cp->mtu_stride);
                } else {
                        RX_USED_ADD(page, hlen);
                }
                skb_put(skb, alloclen);

                skb_shinfo(skb)->nr_frags++;
                skb->data_len += hlen - swivel;
                skb->truesize += hlen - swivel;
                skb->len      += hlen - swivel;

                get_page(page->buffer);
                frag->page = page->buffer;
                frag->page_offset = off;
                frag->size = hlen - swivel;

                /* any more data? */
                if ((words[0] & RX_COMP1_SPLIT_PKT) && ((dlen -= hlen) > 0)) {
                        hlen = dlen;
                        off = 0;

                        i = CAS_VAL(RX_COMP2_NEXT_INDEX, words[1]);
                        page = cp->rx_pages[CAS_VAL(RX_INDEX_RING, i)][CAS_VAL(RX_INDEX_NUM, i)];
                        pci_dma_sync_single_for_cpu(cp->pdev, page->dma_addr,
                                            hlen + cp->crc_size,
                                            PCI_DMA_FROMDEVICE);
                        pci_dma_sync_single_for_device(cp->pdev, page->dma_addr,
                                            hlen + cp->crc_size,
                                            PCI_DMA_FROMDEVICE);

                        skb_shinfo(skb)->nr_frags++;
                        skb->data_len += hlen;
                        skb->len      += hlen;
                        frag++;

                        get_page(page->buffer);
                        frag->page = page->buffer;
                        frag->page_offset = 0;
                        frag->size = hlen;
                        RX_USED_ADD(page, hlen + cp->crc_size);
                }

                if (cp->crc_size) {
                        addr = cas_page_map(page->buffer);
                        crcaddr  = addr + off + hlen;
                }

        } else {
                /* copying packet */
                if (!dlen)
                        goto end_copy_pkt;

                i = CAS_VAL(RX_COMP1_DATA_INDEX, words[0]);
                page = cp->rx_pages[CAS_VAL(RX_INDEX_RING, i)][CAS_VAL(RX_INDEX_NUM, i)];
                off = CAS_VAL(RX_COMP1_DATA_OFF, words[0]) + swivel;
                hlen = min(cp->page_size - off, dlen);
                if (hlen < 0) {
                        if (netif_msg_rx_err(cp)) {
                                printk(KERN_DEBUG "%s: rx page overflow: "
                                       "%d\n", cp->dev->name, hlen);
                        }
                        dev_kfree_skb_irq(skb);
                        return -1;
                }
                i = hlen;
                if (i == dlen) /* attach FCS */
                        i += cp->crc_size;
                pci_dma_sync_single_for_cpu(cp->pdev, page->dma_addr + off, i,
                                    PCI_DMA_FROMDEVICE);
                addr = cas_page_map(page->buffer);
                memcpy(p, addr + off, i);
                pci_dma_sync_single_for_device(cp->pdev, page->dma_addr + off, i,
                                    PCI_DMA_FROMDEVICE);
                cas_page_unmap(addr);
                if (p == (char *) skb->data) /* not split */
                        RX_USED_ADD(page, cp->mtu_stride);
                else
                        RX_USED_ADD(page, i);

                /* any more data? */
                if ((words[0] & RX_COMP1_SPLIT_PKT) && ((dlen -= hlen) > 0)) {
                        p += hlen;
                        i = CAS_VAL(RX_COMP2_NEXT_INDEX, words[1]);
                        page = cp->rx_pages[CAS_VAL(RX_INDEX_RING, i)][CAS_VAL(RX_INDEX_NUM, i)];
                        pci_dma_sync_single_for_cpu(cp->pdev, page->dma_addr,
                                            dlen + cp->crc_size,
                                            PCI_DMA_FROMDEVICE);
                        addr = cas_page_map(page->buffer);
                        memcpy(p, addr, dlen + cp->crc_size);
                        pci_dma_sync_single_for_device(cp->pdev, page->dma_addr,
                                            dlen + cp->crc_size,
                                            PCI_DMA_FROMDEVICE);
                        cas_page_unmap(addr);
                        RX_USED_ADD(page, dlen + cp->crc_size);
                }
end_copy_pkt:
                if (cp->crc_size) {
                        addr    = NULL;
                        crcaddr = skb->data + alloclen;
                }
                skb_put(skb, alloclen);
        }

        csum = (__force __sum16)htons(CAS_VAL(RX_COMP4_TCP_CSUM, words[3]));
        if (cp->crc_size) {
                /* checksum includes FCS. strip it out. */
                csum = csum_fold(csum_partial(crcaddr, cp->crc_size,
                                              csum_unfold(csum)));
                if (addr)
                        cas_page_unmap(addr);
        }
        skb->protocol = eth_type_trans(skb, cp->dev);
        if (skb->protocol == htons(ETH_P_IP)) {
                skb->csum = csum_unfold(~csum);
                skb->ip_summed = CHECKSUM_COMPLETE;
        } else
                skb->ip_summed = CHECKSUM_NONE;
        return len;
}


/* we can handle up to 64 rx flows at a time. we do the same thing
 * as nonreassm except that we batch up the buffers.
 * NOTE: we currently just treat each flow as a bunch of packets that
 *       we pass up. a better way would be to coalesce the packets
 *       into a jumbo packet. to do that, we need to do the following:
 *       1) the first packet will have a clean split between header and
 *          data. save both.
 *       2) each time the next flow packet comes in, extend the
 *          data length and merge the checksums.
 *       3) on flow release, fix up the header.
 *       4) make sure the higher layer doesn't care.
 * because packets get coalesced, we shouldn't run into fragment count
 * issues.
 */
static inline void cas_rx_flow_pkt(struct cas *cp, const u64 *words,
                                   struct sk_buff *skb)
{
        int flowid = CAS_VAL(RX_COMP3_FLOWID, words[2]) & (N_RX_FLOWS - 1);
        struct sk_buff_head *flow = &cp->rx_flows[flowid];

        /* this is protected at a higher layer, so no need to
         * do any additional locking here. stick the buffer
         * at the end.
         */
        __skb_insert(skb, flow->prev, (struct sk_buff *) flow, flow);
        if (words[0] & RX_COMP1_RELEASE_FLOW) {
                while ((skb = __skb_dequeue(flow))) {
                        cas_skb_release(skb);
                }
        }
}

/* put rx descriptor back on ring. if a buffer is in use by a higher
 * layer, this will need to put in a replacement.
 */
static void cas_post_page(struct cas *cp, const int ring, const int index)
{
        cas_page_t *new;
        int entry;

        entry = cp->rx_old[ring];

        new = cas_page_swap(cp, ring, index);
        cp->init_rxds[ring][entry].buffer = cpu_to_le64(new->dma_addr);
        cp->init_rxds[ring][entry].index  =
                cpu_to_le64(CAS_BASE(RX_INDEX_NUM, index) |
                            CAS_BASE(RX_INDEX_RING, ring));

        entry = RX_DESC_ENTRY(ring, entry + 1);
        cp->rx_old[ring] = entry;

        if (entry % 4)
                return;

        if (ring == 0)
                writel(entry, cp->regs + REG_RX_KICK);
        else if ((N_RX_DESC_RINGS > 1) &&
                 (cp->cas_flags & CAS_FLAG_REG_PLUS))
                writel(entry, cp->regs + REG_PLUS_RX_KICK1);
}


/* only when things are bad */
static int cas_post_rxds_ringN(struct cas *cp, int ring, int num)
{
        unsigned int entry, last, count, released;
        int cluster;
        cas_page_t **page = cp->rx_pages[ring];

        entry = cp->rx_old[ring];

        if (netif_msg_intr(cp))
                printk(KERN_DEBUG "%s: rxd[%d] interrupt, done: %d\n",
                       cp->dev->name, ring, entry);

        cluster = -1;
        count = entry & 0x3;
        last = RX_DESC_ENTRY(ring, num ? entry + num - 4: entry - 4);
        released = 0;
        while (entry != last) {
                /* make a new buffer if it's still in use */
                if (page_count(page[entry]->buffer) > 1) {
                        cas_page_t *new = cas_page_dequeue(cp);
                        if (!new) {
                                /* let the timer know that we need to
                                 * do this again
                                 */
                                cp->cas_flags |= CAS_FLAG_RXD_POST(ring);
                                if (!timer_pending(&cp->link_timer))
                                        mod_timer(&cp->link_timer, jiffies +
                                                  CAS_LINK_FAST_TIMEOUT);
                                cp->rx_old[ring]  = entry;
                                cp->rx_last[ring] = num ? num - released : 0;
                                return -ENOMEM;
                        }
                        spin_lock(&cp->rx_inuse_lock);
                        list_add(&page[entry]->list, &cp->rx_inuse_list);
                        spin_unlock(&cp->rx_inuse_lock);
                        cp->init_rxds[ring][entry].buffer =
                                cpu_to_le64(new->dma_addr);
                        page[entry] = new;

                }

                if (++count == 4) {
                        cluster = entry;
                        count = 0;
                }
                released++;
                entry = RX_DESC_ENTRY(ring, entry + 1);
        }
        cp->rx_old[ring] = entry;

        if (cluster < 0)
                return 0;

        if (ring == 0)
                writel(cluster, cp->regs + REG_RX_KICK);
        else if ((N_RX_DESC_RINGS > 1) &&
                 (cp->cas_flags & CAS_FLAG_REG_PLUS))
                writel(cluster, cp->regs + REG_PLUS_RX_KICK1);
        return 0;
}


/* process a completion ring. packets are set up in three basic ways:
 * small packets: should be copied header + data in single buffer.
 * large packets: header and data in a single buffer.
 * split packets: header in a separate buffer from data.
 *                data may be in multiple pages. data may be > 256
 *                bytes but in a single page.
 *
 * NOTE: RX page posting is done in this routine as well. while there's
 *       the capability of using multiple RX completion rings, it isn't
 *       really worthwhile due to the fact that the page posting will
 *       force serialization on the single descriptor ring.
 */
static int cas_rx_ringN(struct cas *cp, int ring, int budget)
{
        struct cas_rx_comp *rxcs = cp->init_rxcs[ring];
        int entry, drops;
        int npackets = 0;

        if (netif_msg_intr(cp))
                printk(KERN_DEBUG "%s: rx[%d] interrupt, done: %d/%d\n",
                       cp->dev->name, ring,
                       readl(cp->regs + REG_RX_COMP_HEAD),
                       cp->rx_new[ring]);

        entry = cp->rx_new[ring];
        drops = 0;
        while (1) {
                struct cas_rx_comp *rxc = rxcs + entry;
                struct sk_buff *skb;
                int type, len;
                u64 words[4];
                int i, dring;

                words[0] = le64_to_cpu(rxc->word1);
                words[1] = le64_to_cpu(rxc->word2);
                words[2] = le64_to_cpu(rxc->word3);
                words[3] = le64_to_cpu(rxc->word4);

                /* don't touch if still owned by hw */
                type = CAS_VAL(RX_COMP1_TYPE, words[0]);
                if (type == 0)
                        break;

                /* hw hasn't cleared the zero bit yet */
                if (words[3] & RX_COMP4_ZERO) {
                        break;
                }

                /* get info on the packet */
                if (words[3] & (RX_COMP4_LEN_MISMATCH | RX_COMP4_BAD)) {
                        spin_lock(&cp->stat_lock[ring]);
                        cp->net_stats[ring].rx_errors++;
                        if (words[3] & RX_COMP4_LEN_MISMATCH)
                                cp->net_stats[ring].rx_length_errors++;
                        if (words[3] & RX_COMP4_BAD)
                                cp->net_stats[ring].rx_crc_errors++;
                        spin_unlock(&cp->stat_lock[ring]);

                        /* We'll just return it to Cassini. */
                drop_it:
                        spin_lock(&cp->stat_lock[ring]);
                        ++cp->net_stats[ring].rx_dropped;
                        spin_unlock(&cp->stat_lock[ring]);
                        goto next;
                }

                len = cas_rx_process_pkt(cp, rxc, entry, words, &skb);
                if (len < 0) {
                        ++drops;
                        goto drop_it;
                }

                /* see if it's a flow re-assembly or not. the driver
                 * itself handles release back up.
                 */
                if (RX_DONT_BATCH || (type == 0x2)) {
                        /* non-reassm: these always get released */
                        cas_skb_release(skb);
                } else {
                        cas_rx_flow_pkt(cp, words, skb);
                }

                spin_lock(&cp->stat_lock[ring]);
                cp->net_stats[ring].rx_packets++;
                cp->net_stats[ring].rx_bytes += len;
                spin_unlock(&cp->stat_lock[ring]);
                cp->dev->last_rx = jiffies;

        next:
                npackets++;

                /* should it be released? */
                if (words[0] & RX_COMP1_RELEASE_HDR) {
                        i = CAS_VAL(RX_COMP2_HDR_INDEX, words[1]);
                        dring = CAS_VAL(RX_INDEX_RING, i);
                        i = CAS_VAL(RX_INDEX_NUM, i);
                        cas_post_page(cp, dring, i);
                }

                if (words[0] & RX_COMP1_RELEASE_DATA) {
                        i = CAS_VAL(RX_COMP1_DATA_INDEX, words[0]);
                        dring = CAS_VAL(RX_INDEX_RING, i);
                        i = CAS_VAL(RX_INDEX_NUM, i);
                        cas_post_page(cp, dring, i);
                }

                if (words[0] & RX_COMP1_RELEASE_NEXT) {
                        i = CAS_VAL(RX_COMP2_NEXT_INDEX, words[1]);
                        dring = CAS_VAL(RX_INDEX_RING, i);
                        i = CAS_VAL(RX_INDEX_NUM, i);
                        cas_post_page(cp, dring, i);
                }

                /* skip to the next entry */
                entry = RX_COMP_ENTRY(ring, entry + 1 +
                                      CAS_VAL(RX_COMP1_SKIP, words[0]));
#ifdef USE_NAPI
                if (budget && (npackets >= budget))
                        break;
#endif
        }
        cp->rx_new[ring] = entry;

        if (drops)
                printk(KERN_INFO "%s: Memory squeeze, deferring packet.\n",
                       cp->dev->name);
        return npackets;
}


/* put completion entries back on the ring */
static void cas_post_rxcs_ringN(struct net_device *dev,
                                struct cas *cp, int ring)
{
        struct cas_rx_comp *rxc = cp->init_rxcs[ring];
        int last, entry;

        last = cp->rx_cur[ring];
        entry = cp->rx_new[ring];
        if (netif_msg_intr(cp))
                printk(KERN_DEBUG "%s: rxc[%d] interrupt, done: %d/%d\n",
                       dev->name, ring, readl(cp->regs + REG_RX_COMP_HEAD),
                       entry);

        /* zero and re-mark descriptors */
        while (last != entry) {
                cas_rxc_init(rxc + last);
                last = RX_COMP_ENTRY(ring, last + 1);
        }
        cp->rx_cur[ring] = last;

        if (ring == 0)
                writel(last, cp->regs + REG_RX_COMP_TAIL);
        else if (cp->cas_flags & CAS_FLAG_REG_PLUS)
                writel(last, cp->regs + REG_PLUS_RX_COMPN_TAIL(ring));
}



/* cassini can use all four PCI interrupts for the completion ring.
 * rings 3 and 4 are identical
 */
#if defined(USE_PCI_INTC) || defined(USE_PCI_INTD)
static inline void cas_handle_irqN(struct net_device *dev,
                                   struct cas *cp, const u32 status,
                                   const int ring)
{
        if (status & (INTR_RX_COMP_FULL_ALT | INTR_RX_COMP_AF_ALT))
                cas_post_rxcs_ringN(dev, cp, ring);
}

static irqreturn_t cas_interruptN(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct cas *cp = netdev_priv(dev);
        unsigned long flags;
        int ring;
        u32 status = readl(cp->regs + REG_PLUS_INTRN_STATUS(ring));

        /* check for shared irq */
        if (status == 0)
                return IRQ_NONE;

        ring = (irq == cp->pci_irq_INTC) ? 2 : 3;
        spin_lock_irqsave(&cp->lock, flags);
        if (status & INTR_RX_DONE_ALT) { /* handle rx separately */
#ifdef USE_NAPI
                cas_mask_intr(cp);
                netif_rx_schedule(dev, &cp->napi);
#else
                cas_rx_ringN(cp, ring, 0);
#endif
                status &= ~INTR_RX_DONE_ALT;
        }

        if (status)
                cas_handle_irqN(dev, cp, status, ring);
        spin_unlock_irqrestore(&cp->lock, flags);
        return IRQ_HANDLED;
}
#endif

#ifdef USE_PCI_INTB
/* everything but rx packets */
static inline void cas_handle_irq1(struct cas *cp, const u32 status)
{
        if (status & INTR_RX_BUF_UNAVAIL_1) {
                /* Frame arrived, no free RX buffers available.
                 * NOTE: we can get this on a link transition. */
                cas_post_rxds_ringN(cp, 1, 0);
                spin_lock(&cp->stat_lock[1]);
                cp->net_stats[1].rx_dropped++;
                spin_unlock(&cp->stat_lock[1]);
        }

        if (status & INTR_RX_BUF_AE_1)
                cas_post_rxds_ringN(cp, 1, RX_DESC_RINGN_SIZE(1) -
                                    RX_AE_FREEN_VAL(1));

        if (status & (INTR_RX_COMP_AF | INTR_RX_COMP_FULL))
                cas_post_rxcs_ringN(cp, 1);
}

/* ring 2 handles a few more events than 3 and 4 */
static irqreturn_t cas_interrupt1(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct cas *cp = netdev_priv(dev);
        unsigned long flags;
        u32 status = readl(cp->regs + REG_PLUS_INTRN_STATUS(1));

        /* check for shared interrupt */
        if (status == 0)
                return IRQ_NONE;

        spin_lock_irqsave(&cp->lock, flags);
        if (status & INTR_RX_DONE_ALT) { /* handle rx separately */
#ifdef USE_NAPI
                cas_mask_intr(cp);
                netif_rx_schedule(dev, &cp->napi);
#else
                cas_rx_ringN(cp, 1, 0);
#endif
                status &= ~INTR_RX_DONE_ALT;
        }
        if (status)
                cas_handle_irq1(cp, status);
        spin_unlock_irqrestore(&cp->lock, flags);
        return IRQ_HANDLED;
}
#endif

static inline void cas_handle_irq(struct net_device *dev,
                                  struct cas *cp, const u32 status)
{
        /* housekeeping interrupts */
        if (status & INTR_ERROR_MASK)
                cas_abnormal_irq(dev, cp, status);

        if (status & INTR_RX_BUF_UNAVAIL) {
                /* Frame arrived, no free RX buffers available.
                 * NOTE: we can get this on a link transition.
                 */
                cas_post_rxds_ringN(cp, 0, 0);
                spin_lock(&cp->stat_lock[0]);
                cp->net_stats[0].rx_dropped++;
                spin_unlock(&cp->stat_lock[0]);
        } else if (status & INTR_RX_BUF_AE) {
                cas_post_rxds_ringN(cp, 0, RX_DESC_RINGN_SIZE(0) -
                                    RX_AE_FREEN_VAL(0));
        }

        if (status & (INTR_RX_COMP_AF | INTR_RX_COMP_FULL))
                cas_post_rxcs_ringN(dev, cp, 0);
}

static irqreturn_t cas_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct cas *cp = netdev_priv(dev);
        unsigned long flags;
        u32 status = readl(cp->regs + REG_INTR_STATUS);

        if (status == 0)
                return IRQ_NONE;

        spin_lock_irqsave(&cp->lock, flags);
        if (status & (INTR_TX_ALL | INTR_TX_INTME)) {
                cas_tx(dev, cp, status);
                status &= ~(INTR_TX_ALL | INTR_TX_INTME);
        }

        if (status & INTR_RX_DONE) {
#ifdef USE_NAPI
                cas_mask_intr(cp);
                netif_rx_schedule(dev, &cp->napi);
#else
                cas_rx_ringN(cp, 0, 0);
#endif
                status &= ~INTR_RX_DONE;
        }

        if (status)
                cas_handle_irq(dev, cp, status);
        spin_unlock_irqrestore(&cp->lock, flags);
        return IRQ_HANDLED;
}


#ifdef USE_NAPI
static int cas_poll(struct napi_struct *napi, int budget)
{
        struct cas *cp = container_of(napi, struct cas, napi);
        struct net_device *dev = cp->dev;
        int i, enable_intr, credits;
        u32 status = readl(cp->regs + REG_INTR_STATUS);
        unsigned long flags;

        spin_lock_irqsave(&cp->lock, flags);
        cas_tx(dev, cp, status);
        spin_unlock_irqrestore(&cp->lock, flags);

        /* NAPI rx packets. we spread the credits across all of the
         * rxc rings
         *
         * to make sure we're fair with the work we loop through each
         * ring N_RX_COMP_RING times with a request of
         * budget / N_RX_COMP_RINGS
         */
        enable_intr = 1;
        credits = 0;
        for (i = 0; i < N_RX_COMP_RINGS; i++) {
                int j;
                for (j = 0; j < N_RX_COMP_RINGS; j++) {
                        credits += cas_rx_ringN(cp, j, budget / N_RX_COMP_RINGS);
                        if (credits >= budget) {
                                enable_intr = 0;
                                goto rx_comp;
                        }
                }
        }

rx_comp:
        /* final rx completion */
        spin_lock_irqsave(&cp->lock, flags);
        if (status)
                cas_handle_irq(dev, cp, status);

#ifdef USE_PCI_INTB
        if (N_RX_COMP_RINGS > 1) {
                status = readl(cp->regs + REG_PLUS_INTRN_STATUS(1));
                if (status)
                        cas_handle_irq1(dev, cp, status);
        }
#endif

#ifdef USE_PCI_INTC
        if (N_RX_COMP_RINGS > 2) {
                status = readl(cp->regs + REG_PLUS_INTRN_STATUS(2));
                if (status)
                        cas_handle_irqN(dev, cp, status, 2);
        }
#endif

#ifdef USE_PCI_INTD
        if (N_RX_COMP_RINGS > 3) {
                status = readl(cp->regs + REG_PLUS_INTRN_STATUS(3));
                if (status)
                        cas_handle_irqN(dev, cp, status, 3);
        }
#endif
        spin_unlock_irqrestore(&cp->lock, flags);
        if (enable_intr) {
                netif_rx_complete(dev, napi);
                cas_unmask_intr(cp);
        }
        return credits;
}
#endif

#ifdef CONFIG_NET_POLL_CONTROLLER
static void cas_netpoll(struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);

        cas_disable_irq(cp, 0);
        cas_interrupt(cp->pdev->irq, dev);
        cas_enable_irq(cp, 0);

#ifdef USE_PCI_INTB
        if (N_RX_COMP_RINGS > 1) {
                /* cas_interrupt1(); */
        }
#endif
#ifdef USE_PCI_INTC
        if (N_RX_COMP_RINGS > 2) {
                /* cas_interruptN(); */
        }
#endif
#ifdef USE_PCI_INTD
        if (N_RX_COMP_RINGS > 3) {
                /* cas_interruptN(); */
        }
#endif
}
#endif

static void cas_tx_timeout(struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);

        printk(KERN_ERR "%s: transmit timed out, resetting\n", dev->name);
        if (!cp->hw_running) {
                printk("%s: hrm.. hw not running!\n", dev->name);
                return;
        }

        printk(KERN_ERR "%s: MIF_STATE[%08x]\n",
               dev->name, readl(cp->regs + REG_MIF_STATE_MACHINE));

        printk(KERN_ERR "%s: MAC_STATE[%08x]\n",
               dev->name, readl(cp->regs + REG_MAC_STATE_MACHINE));

        printk(KERN_ERR "%s: TX_STATE[%08x:%08x:%08x] "
               "FIFO[%08x:%08x:%08x] SM1[%08x] SM2[%08x]\n",
               dev->name,
               readl(cp->regs + REG_TX_CFG),
               readl(cp->regs + REG_MAC_TX_STATUS),
               readl(cp->regs + REG_MAC_TX_CFG),
               readl(cp->regs + REG_TX_FIFO_PKT_CNT),
               readl(cp->regs + REG_TX_FIFO_WRITE_PTR),
               readl(cp->regs + REG_TX_FIFO_READ_PTR),
               readl(cp->regs + REG_TX_SM_1),
               readl(cp->regs + REG_TX_SM_2));

        printk(KERN_ERR "%s: RX_STATE[%08x:%08x:%08x]\n",
               dev->name,
               readl(cp->regs + REG_RX_CFG),
               readl(cp->regs + REG_MAC_RX_STATUS),
               readl(cp->regs + REG_MAC_RX_CFG));

        printk(KERN_ERR "%s: HP_STATE[%08x:%08x:%08x:%08x]\n",
               dev->name,
               readl(cp->regs + REG_HP_STATE_MACHINE),
               readl(cp->regs + REG_HP_STATUS0),
               readl(cp->regs + REG_HP_STATUS1),
               readl(cp->regs + REG_HP_STATUS2));

#if 1
        atomic_inc(&cp->reset_task_pending);
        atomic_inc(&cp->reset_task_pending_all);
        schedule_work(&cp->reset_task);
#else
        atomic_set(&cp->reset_task_pending, CAS_RESET_ALL);
        schedule_work(&cp->reset_task);
#endif
}

static inline int cas_intme(int ring, int entry)
{
        /* Algorithm: IRQ every 1/2 of descriptors. */
        if (!(entry & ((TX_DESC_RINGN_SIZE(ring) >> 1) - 1)))
                return 1;
        return 0;
}


static void cas_write_txd(struct cas *cp, int ring, int entry,
                          dma_addr_t mapping, int len, u64 ctrl, int last)
{
        struct cas_tx_desc *txd = cp->init_txds[ring] + entry;

        ctrl |= CAS_BASE(TX_DESC_BUFLEN, len);
        if (cas_intme(ring, entry))
                ctrl |= TX_DESC_INTME;
        if (last)
                ctrl |= TX_DESC_EOF;
        txd->control = cpu_to_le64(ctrl);
        txd->buffer = cpu_to_le64(mapping);
}

static inline void *tx_tiny_buf(struct cas *cp, const int ring,
                                const int entry)
{
        return cp->tx_tiny_bufs[ring] + TX_TINY_BUF_LEN*entry;
}

static inline dma_addr_t tx_tiny_map(struct cas *cp, const int ring,
                                     const int entry, const int tentry)
{
        cp->tx_tiny_use[ring][tentry].nbufs++;
        cp->tx_tiny_use[ring][entry].used = 1;
        return cp->tx_tiny_dvma[ring] + TX_TINY_BUF_LEN*entry;
}

static inline int cas_xmit_tx_ringN(struct cas *cp, int ring,
                                    struct sk_buff *skb)
{
        struct net_device *dev = cp->dev;
        int entry, nr_frags, frag, tabort, tentry;
        dma_addr_t mapping;
        unsigned long flags;
        u64 ctrl;
        u32 len;

        spin_lock_irqsave(&cp->tx_lock[ring], flags);

        /* This is a hard error, log it. */
        if (TX_BUFFS_AVAIL(cp, ring) <=
            CAS_TABORT(cp)*(skb_shinfo(skb)->nr_frags + 1)) {
                netif_stop_queue(dev);
                spin_unlock_irqrestore(&cp->tx_lock[ring], flags);
                printk(KERN_ERR PFX "%s: BUG! Tx Ring full when "
                       "queue awake!\n", dev->name);
                return 1;
        }

        ctrl = 0;
        if (skb->ip_summed == CHECKSUM_PARTIAL) {
                const u64 csum_start_off = skb_transport_offset(skb);
                const u64 csum_stuff_off = csum_start_off + skb->csum_offset;

                ctrl =  TX_DESC_CSUM_EN |
                        CAS_BASE(TX_DESC_CSUM_START, csum_start_off) |
                        CAS_BASE(TX_DESC_CSUM_STUFF, csum_stuff_off);
        }

        entry = cp->tx_new[ring];
        cp->tx_skbs[ring][entry] = skb;

        nr_frags = skb_shinfo(skb)->nr_frags;
        len = skb_headlen(skb);
        mapping = pci_map_page(cp->pdev, virt_to_page(skb->data),
                               offset_in_page(skb->data), len,
                               PCI_DMA_TODEVICE);

        tentry = entry;
        tabort = cas_calc_tabort(cp, (unsigned long) skb->data, len);
        if (unlikely(tabort)) {
                /* NOTE: len is always >  tabort */
                cas_write_txd(cp, ring, entry, mapping, len - tabort,
                              ctrl | TX_DESC_SOF, 0);
                entry = TX_DESC_NEXT(ring, entry);

                skb_copy_from_linear_data_offset(skb, len - tabort,
                              tx_tiny_buf(cp, ring, entry), tabort);
                mapping = tx_tiny_map(cp, ring, entry, tentry);
                cas_write_txd(cp, ring, entry, mapping, tabort, ctrl,
                              (nr_frags == 0));
        } else {
                cas_write_txd(cp, ring, entry, mapping, len, ctrl |
                              TX_DESC_SOF, (nr_frags == 0));
        }
        entry = TX_DESC_NEXT(ring, entry);

        for (frag = 0; frag < nr_frags; frag++) {
                skb_frag_t *fragp = &skb_shinfo(skb)->frags[frag];

                len = fragp->size;
                mapping = pci_map_page(cp->pdev, fragp->page,
                                       fragp->page_offset, len,
                                       PCI_DMA_TODEVICE);

                tabort = cas_calc_tabort(cp, fragp->page_offset, len);
                if (unlikely(tabort)) {
                        void *addr;

                        /* NOTE: len is always > tabort */
                        cas_write_txd(cp, ring, entry, mapping, len - tabort,
                                      ctrl, 0);
                        entry = TX_DESC_NEXT(ring, entry);

                        addr = cas_page_map(fragp->page);
                        memcpy(tx_tiny_buf(cp, ring, entry),
                               addr + fragp->page_offset + len - tabort,
                               tabort);
                        cas_page_unmap(addr);
                        mapping = tx_tiny_map(cp, ring, entry, tentry);
                        len     = tabort;
                }

                cas_write_txd(cp, ring, entry, mapping, len, ctrl,
                              (frag + 1 == nr_frags));
                entry = TX_DESC_NEXT(ring, entry);
        }

        cp->tx_new[ring] = entry;
        if (TX_BUFFS_AVAIL(cp, ring) <= CAS_TABORT(cp)*(MAX_SKB_FRAGS + 1))
                netif_stop_queue(dev);

        if (netif_msg_tx_queued(cp))
                printk(KERN_DEBUG "%s: tx[%d] queued, slot %d, skblen %d, "
                       "avail %d\n",
                       dev->name, ring, entry, skb->len,
                       TX_BUFFS_AVAIL(cp, ring));
        writel(entry, cp->regs + REG_TX_KICKN(ring));
        spin_unlock_irqrestore(&cp->tx_lock[ring], flags);
        return 0;
}

static int cas_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);

        /* this is only used as a load-balancing hint, so it doesn't
         * need to be SMP safe
         */
        static int ring;

        if (skb_padto(skb, cp->min_frame_size))
                return 0;

        /* XXX: we need some higher-level QoS hooks to steer packets to
         *      individual queues.
         */
        if (cas_xmit_tx_ringN(cp, ring++ & N_TX_RINGS_MASK, skb))
                return 1;
        dev->trans_start = jiffies;
        return 0;
}

static void cas_init_tx_dma(struct cas *cp)
{
        u64 desc_dma = cp->block_dvma;
        unsigned long off;
        u32 val;
        int i;

        /* set up tx completion writeback registers. must be 8-byte aligned */
#ifdef USE_TX_COMPWB
        off = offsetof(struct cas_init_block, tx_compwb);
        writel((desc_dma + off) >> 32, cp->regs + REG_TX_COMPWB_DB_HI);
        writel((desc_dma + off) & 0xffffffff, cp->regs + REG_TX_COMPWB_DB_LOW);
#endif

        /* enable completion writebacks, enable paced mode,
         * disable read pipe, and disable pre-interrupt compwbs
         */
        val =   TX_CFG_COMPWB_Q1 | TX_CFG_COMPWB_Q2 |
                TX_CFG_COMPWB_Q3 | TX_CFG_COMPWB_Q4 |
                TX_CFG_DMA_RDPIPE_DIS | TX_CFG_PACED_MODE |
                TX_CFG_INTR_COMPWB_DIS;

        /* write out tx ring info and tx desc bases */
        for (i = 0; i < MAX_TX_RINGS; i++) {
                off = (unsigned long) cp->init_txds[i] -
                        (unsigned long) cp->init_block;

                val |= CAS_TX_RINGN_BASE(i);
                writel((desc_dma + off) >> 32, cp->regs + REG_TX_DBN_HI(i));
                writel((desc_dma + off) & 0xffffffff, cp->regs +
                       REG_TX_DBN_LOW(i));
                /* don't zero out the kick register here as the system
                 * will wedge
                 */
        }
        writel(val, cp->regs + REG_TX_CFG);

        /* program max burst sizes. these numbers should be different
         * if doing QoS.
         */
#ifdef USE_QOS
        writel(0x800, cp->regs + REG_TX_MAXBURST_0);
        writel(0x1600, cp->regs + REG_TX_MAXBURST_1);
        writel(0x2400, cp->regs + REG_TX_MAXBURST_2);
        writel(0x4800, cp->regs + REG_TX_MAXBURST_3);
#else
        writel(0x800, cp->regs + REG_TX_MAXBURST_0);
        writel(0x800, cp->regs + REG_TX_MAXBURST_1);
        writel(0x800, cp->regs + REG_TX_MAXBURST_2);
        writel(0x800, cp->regs + REG_TX_MAXBURST_3);
#endif
}

/* Must be invoked under cp->lock. */
static inline void cas_init_dma(struct cas *cp)
{
        cas_init_tx_dma(cp);
        cas_init_rx_dma(cp);
}

/* Must be invoked under cp->lock. */
static u32 cas_setup_multicast(struct cas *cp)
{
        u32 rxcfg = 0;
        int i;

        if (cp->dev->flags & IFF_PROMISC) {
                rxcfg |= MAC_RX_CFG_PROMISC_EN;

        } else if (cp->dev->flags & IFF_ALLMULTI) {
                for (i=0; i < 16; i++)
                        writel(0xFFFF, cp->regs + REG_MAC_HASH_TABLEN(i));
                rxcfg |= MAC_RX_CFG_HASH_FILTER_EN;

        } else {
                u16 hash_table[16];
                u32 crc;
                struct dev_mc_list *dmi = cp->dev->mc_list;
                int i;

                /* use the alternate mac address registers for the
                 * first 15 multicast addresses
                 */
                for (i = 1; i <= CAS_MC_EXACT_MATCH_SIZE; i++) {
                        if (!dmi) {
                                writel(0x0, cp->regs + REG_MAC_ADDRN(i*3 + 0));
                                writel(0x0, cp->regs + REG_MAC_ADDRN(i*3 + 1));
                                writel(0x0, cp->regs + REG_MAC_ADDRN(i*3 + 2));
                                continue;
                        }
                        writel((dmi->dmi_addr[4] << 8) | dmi->dmi_addr[5],
                               cp->regs + REG_MAC_ADDRN(i*3 + 0));
                        writel((dmi->dmi_addr[2] << 8) | dmi->dmi_addr[3],
                               cp->regs + REG_MAC_ADDRN(i*3 + 1));
                        writel((dmi->dmi_addr[0] << 8) | dmi->dmi_addr[1],
                               cp->regs + REG_MAC_ADDRN(i*3 + 2));
                        dmi = dmi->next;
                }

                /* use hw hash table for the next series of
                 * multicast addresses
                 */
                memset(hash_table, 0, sizeof(hash_table));
                while (dmi) {
                        crc = ether_crc_le(ETH_ALEN, dmi->dmi_addr);
                        crc >>= 24;
                        hash_table[crc >> 4] |= 1 << (15 - (crc & 0xf));
                        dmi = dmi->next;
                }
                for (i=0; i < 16; i++)
                        writel(hash_table[i], cp->regs +
                               REG_MAC_HASH_TABLEN(i));
                rxcfg |= MAC_RX_CFG_HASH_FILTER_EN;
        }

        return rxcfg;
}

/* must be invoked under cp->stat_lock[N_TX_RINGS] */
static void cas_clear_mac_err(struct cas *cp)
{
        writel(0, cp->regs + REG_MAC_COLL_NORMAL);
        writel(0, cp->regs + REG_MAC_COLL_FIRST);
        writel(0, cp->regs + REG_MAC_COLL_EXCESS);
        writel(0, cp->regs + REG_MAC_COLL_LATE);
        writel(0, cp->regs + REG_MAC_TIMER_DEFER);
        writel(0, cp->regs + REG_MAC_ATTEMPTS_PEAK);
        writel(0, cp->regs + REG_MAC_RECV_FRAME);
        writel(0, cp->regs + REG_MAC_LEN_ERR);
        writel(0, cp->regs + REG_MAC_ALIGN_ERR);
        writel(0, cp->regs + REG_MAC_FCS_ERR);
        writel(0, cp->regs + REG_MAC_RX_CODE_ERR);
}


static void cas_mac_reset(struct cas *cp)
{
        int i;

        /* do both TX and RX reset */
        writel(0x1, cp->regs + REG_MAC_TX_RESET);
        writel(0x1, cp->regs + REG_MAC_RX_RESET);

        /* wait for TX */
        i = STOP_TRIES;
        while (i-- > 0) {
                if (readl(cp->regs + REG_MAC_TX_RESET) == 0)
                        break;
                udelay(10);
        }

        /* wait for RX */
        i = STOP_TRIES;
        while (i-- > 0) {
                if (readl(cp->regs + REG_MAC_RX_RESET) == 0)
                        break;
                udelay(10);
        }

        if (readl(cp->regs + REG_MAC_TX_RESET) |
            readl(cp->regs + REG_MAC_RX_RESET))
                printk(KERN_ERR "%s: mac tx[%d]/rx[%d] reset failed [%08x]\n",
                       cp->dev->name, readl(cp->regs + REG_MAC_TX_RESET),
                       readl(cp->regs + REG_MAC_RX_RESET),
                       readl(cp->regs + REG_MAC_STATE_MACHINE));
}


/* Must be invoked under cp->lock. */
static void cas_init_mac(struct cas *cp)
{
        unsigned char *e = &cp->dev->dev_addr[0];
        int i;
#ifdef CONFIG_CASSINI_MULTICAST_REG_WRITE
        u32 rxcfg;
#endif
        cas_mac_reset(cp);

        /* setup core arbitration weight register */
        writel(CAWR_RR_DIS, cp->regs + REG_CAWR);

        /* XXX Use pci_dma_burst_advice() */
#if !defined(CONFIG_SPARC64) && !defined(CONFIG_ALPHA)
        /* set the infinite burst register for chips that don't have
         * pci issues.
         */
        if ((cp->cas_flags & CAS_FLAG_TARGET_ABORT) == 0)
                writel(INF_BURST_EN, cp->regs + REG_INF_BURST);
#endif

        writel(0x1BF0, cp->regs + REG_MAC_SEND_PAUSE);

        writel(0x00, cp->regs + REG_MAC_IPG0);
        writel(0x08, cp->regs + REG_MAC_IPG1);
        writel(0x04, cp->regs + REG_MAC_IPG2);

        /* change later for 802.3z */
        writel(0x40, cp->regs + REG_MAC_SLOT_TIME);

        /* min frame + FCS */
        writel(ETH_ZLEN + 4, cp->regs + REG_MAC_FRAMESIZE_MIN);

        /* Ethernet payload + header + FCS + optional VLAN tag. NOTE: we
         * specify the maximum frame size to prevent RX tag errors on
         * oversized frames.
         */
        writel(CAS_BASE(MAC_FRAMESIZE_MAX_BURST, 0x2000) |
               CAS_BASE(MAC_FRAMESIZE_MAX_FRAME,
                        (CAS_MAX_MTU + ETH_HLEN + 4 + 4)),
               cp->regs + REG_MAC_FRAMESIZE_MAX);

        /* NOTE: crc_size is used as a surrogate for half-duplex.
         * workaround saturn half-duplex issue by increasing preamble
         * size to 65 bytes.
         */
        if ((cp->cas_flags & CAS_FLAG_SATURN) && cp->crc_size)
                writel(0x41, cp->regs + REG_MAC_PA_SIZE);
        else
                writel(0x07, cp->regs + REG_MAC_PA_SIZE);
        writel(0x04, cp->regs + REG_MAC_JAM_SIZE);
        writel(0x10, cp->regs + REG_MAC_ATTEMPT_LIMIT);
        writel(0x8808, cp->regs + REG_MAC_CTRL_TYPE);

        writel((e[5] | (e[4] << 8)) & 0x3ff, cp->regs + REG_MAC_RANDOM_SEED);

        writel(0, cp->regs + REG_MAC_ADDR_FILTER0);
        writel(0, cp->regs + REG_MAC_ADDR_FILTER1);
        writel(0, cp->regs + REG_MAC_ADDR_FILTER2);
        writel(0, cp->regs + REG_MAC_ADDR_FILTER2_1_MASK);
        writel(0, cp->regs + REG_MAC_ADDR_FILTER0_MASK);

        /* setup mac address in perfect filter array */
        for (i = 0; i < 45; i++)
                writel(0x0, cp->regs + REG_MAC_ADDRN(i));

        writel((e[4] << 8) | e[5], cp->regs + REG_MAC_ADDRN(0));
        writel((e[2] << 8) | e[3], cp->regs + REG_MAC_ADDRN(1));
        writel((e[0] << 8) | e[1], cp->regs + REG_MAC_ADDRN(2));

        writel(0x0001, cp->regs + REG_MAC_ADDRN(42));
        writel(0xc200, cp->regs + REG_MAC_ADDRN(43));
        writel(0x0180, cp->regs + REG_MAC_ADDRN(44));

#ifndef CONFIG_CASSINI_MULTICAST_REG_WRITE
        cp->mac_rx_cfg = cas_setup_multicast(cp);
#else
        /* WTZ: Do what Adrian did in cas_set_multicast. Doing
         * a writel does not seem to be necessary because Cassini
         * seems to preserve the configuration when we do the reset.
         * If the chip is in trouble, though, it is not clear if we
         * can really count on this behavior. cas_set_multicast uses
         * spin_lock_irqsave, but we are called only in cas_init_hw and
         * cas_init_hw is protected by cas_lock_all, which calls
         * spin_lock_irq (so it doesn't need to save the flags, and
         * we should be OK for the writel, as that is the only
         * difference).
         */
        cp->mac_rx_cfg = rxcfg = cas_setup_multicast(cp);
        writel(rxcfg, cp->regs + REG_MAC_RX_CFG);
#endif
        spin_lock(&cp->stat_lock[N_TX_RINGS]);
        cas_clear_mac_err(cp);
        spin_unlock(&cp->stat_lock[N_TX_RINGS]);

        /* Setup MAC interrupts.  We want to get all of the interesting
         * counter expiration events, but we do not want to hear about
         * normal rx/tx as the DMA engine tells us that.
         */
        writel(MAC_TX_FRAME_XMIT, cp->regs + REG_MAC_TX_MASK);
        writel(MAC_RX_FRAME_RECV, cp->regs + REG_MAC_RX_MASK);

        /* Don't enable even the PAUSE interrupts for now, we
         * make no use of those events other than to record them.
         */
        writel(0xffffffff, cp->regs + REG_MAC_CTRL_MASK);
}

/* Must be invoked under cp->lock. */
static void cas_init_pause_thresholds(struct cas *cp)
{
        /* Calculate pause thresholds.  Setting the OFF threshold to the
         * full RX fifo size effectively disables PAUSE generation
         */
        if (cp->rx_fifo_size <= (2 * 1024)) {
                cp->rx_pause_off = cp->rx_pause_on = cp->rx_fifo_size;
        } else {
                int max_frame = (cp->dev->mtu + ETH_HLEN + 4 + 4 + 64) & ~63;
                if (max_frame * 3 > cp->rx_fifo_size) {
                        cp->rx_pause_off = 7104;
                        cp->rx_pause_on  = 960;
                } else {
                        int off = (cp->rx_fifo_size - (max_frame * 2));
                        int on = off - max_frame;
                        cp->rx_pause_off = off;
                        cp->rx_pause_on = on;
                }
        }
}

static int cas_vpd_match(const void __iomem *p, const char *str)
{
        int len = strlen(str) + 1;
        int i;

        for (i = 0; i < len; i++) {
                if (readb(p + i) != str[i])
                        return 0;
        }
        return 1;
}


/* get the mac address by reading the vpd information in the rom.
 * also get the phy type and determine if there's an entropy generator.
 * NOTE: this is a bit convoluted for the following reasons:
 *  1) vpd info has order-dependent mac addresses for multinic cards
 *  2) the only way to determine the nic order is to use the slot
 *     number.
 *  3) fiber cards don't have bridges, so their slot numbers don't
 *     mean anything.
 *  4) we don't actually know we have a fiber card until after
 *     the mac addresses are parsed.
 */
static int cas_get_vpd_info(struct cas *cp, unsigned char *dev_addr,
                            const int offset)
{
        void __iomem *p = cp->regs + REG_EXPANSION_ROM_RUN_START;
        void __iomem *base, *kstart;
        int i, len;
        int found = 0;
#define VPD_FOUND_MAC        0x01
#define VPD_FOUND_PHY        0x02

        int phy_type = CAS_PHY_MII_MDIO0; /* default phy type */
        int mac_off  = 0;

        /* give us access to the PROM */
        writel(BIM_LOCAL_DEV_PROM | BIM_LOCAL_DEV_PAD,
               cp->regs + REG_BIM_LOCAL_DEV_EN);

        /* check for an expansion rom */
        if (readb(p) != 0x55 || readb(p + 1) != 0xaa)
                goto use_random_mac_addr;

        /* search for beginning of vpd */
        base = NULL;
        for (i = 2; i < EXPANSION_ROM_SIZE; i++) {
                /* check for PCIR */
                if ((readb(p + i + 0) == 0x50) &&
                    (readb(p + i + 1) == 0x43) &&
                    (readb(p + i + 2) == 0x49) &&
                    (readb(p + i + 3) == 0x52)) {
                        base = p + (readb(p + i + 8) |
                                    (readb(p + i + 9) << 8));
                        break;
                }
        }

        if (!base || (readb(base) != 0x82))
                goto use_random_mac_addr;

        i = (readb(base + 1) | (readb(base + 2) << 8)) + 3;
        while (i < EXPANSION_ROM_SIZE) {
                if (readb(base + i) != 0x90) /* no vpd found */
                        goto use_random_mac_addr;

                /* found a vpd field */
                len = readb(base + i + 1) | (readb(base + i + 2) << 8);

                /* extract keywords */
                kstart = base + i + 3;
                p = kstart;
                while ((p - kstart) < len) {
                        int klen = readb(p + 2);
                        int j;
                        char type;

                        p += 3;

                        /* look for the following things:
                         * -- correct length == 29
                         * 3 (type) + 2 (size) +
                         * 18 (strlen("local-mac-address") + 1) +
                         * 6 (mac addr)
                         * -- VPD Instance 'I'
                         * -- VPD Type Bytes 'B'
                         * -- VPD data length == 6
                         * -- property string == local-mac-address
                         *
                         * -- correct length == 24
                         * 3 (type) + 2 (size) +
                         * 12 (strlen("entropy-dev") + 1) +
                         * 7 (strlen("vms110") + 1)
                         * -- VPD Instance 'I'
                         * -- VPD Type String 'B'
                         * -- VPD data length == 7
                         * -- property string == entropy-dev
                         *
                         * -- correct length == 18
                         * 3 (type) + 2 (size) +
                         * 9 (strlen("phy-type") + 1) +
                         * 4 (strlen("pcs") + 1)
                         * -- VPD Instance 'I'
                         * -- VPD Type String 'S'
                         * -- VPD data length == 4
                         * -- property string == phy-type
                         *
                         * -- correct length == 23
                         * 3 (type) + 2 (size) +
                         * 14 (strlen("phy-interface") + 1) +
                         * 4 (strlen("pcs") + 1)
                         * -- VPD Instance 'I'
                         * -- VPD Type String 'S'
                         * -- VPD data length == 4
                         * -- property string == phy-interface
                         */
                        if (readb(p) != 'I')
                                goto next;

                        /* finally, check string and length */
                        type = readb(p + 3);
                        if (type == 'B') {
                                if ((klen == 29) && readb(p + 4) == 6 &&
                                    cas_vpd_match(p + 5,
                                                  "local-mac-address")) {
                                        if (mac_off++ > offset)
                                                goto next;

                                        /* set mac address */
                                        for (j = 0; j < 6; j++)
                                                dev_addr[j] =
                                                        readb(p + 23 + j);
                                        goto found_mac;
                                }
                        }

                        if (type != 'S')
                                goto next;

#ifdef USE_ENTROPY_DEV
                        if ((klen == 24) &&
                            cas_vpd_match(p + 5, "entropy-dev") &&
                            cas_vpd_match(p + 17, "vms110")) {
                                cp->cas_flags |= CAS_FLAG_ENTROPY_DEV;
                                goto next;
                        }
#endif

                        if (found & VPD_FOUND_PHY)
                                goto next;

                        if ((klen == 18) && readb(p + 4) == 4 &&
                            cas_vpd_match(p + 5, "phy-type")) {
                                if (cas_vpd_match(p + 14, "pcs")) {
                                        phy_type = CAS_PHY_SERDES;
                                        goto found_phy;
                                }
                        }

                        if ((klen == 23) && readb(p + 4) == 4 &&
                            cas_vpd_match(p + 5, "phy-interface")) {
                                if (cas_vpd_match(p + 19, "pcs")) {
                                        phy_type = CAS_PHY_SERDES;
                                        goto found_phy;
                                }
                        }
found_mac:
                        found |= VPD_FOUND_MAC;
                        goto next;

found_phy:
                        found |= VPD_FOUND_PHY;

next:
                        p += klen;
                }
                i += len + 3;
        }

use_random_mac_addr:
        if (found & VPD_FOUND_MAC)
                goto done;

        /* Sun MAC prefix then 3 random bytes. */
        printk(PFX "MAC address not found in ROM VPD\n");
        dev_addr[0] = 0x08;
        dev_addr[1] = 0x00;
        dev_addr[2] = 0x20;
        get_random_bytes(dev_addr + 3, 3);

done:
        writel(0, cp->regs + REG_BIM_LOCAL_DEV_EN);
        return phy_type;
}

/* check pci invariants */
static void cas_check_pci_invariants(struct cas *cp)
{
        struct pci_dev *pdev = cp->pdev;

        cp->cas_flags = 0;
        if ((pdev->vendor == PCI_VENDOR_ID_SUN) &&
            (pdev->device == PCI_DEVICE_ID_SUN_CASSINI)) {
                if (pdev->revision >= CAS_ID_REVPLUS)
                        cp->cas_flags |= CAS_FLAG_REG_PLUS;
                if (pdev->revision < CAS_ID_REVPLUS02u)
                        cp->cas_flags |= CAS_FLAG_TARGET_ABORT;

                /* Original Cassini supports HW CSUM, but it's not
                 * enabled by default as it can trigger TX hangs.
                 */
                if (pdev->revision < CAS_ID_REV2)
                        cp->cas_flags |= CAS_FLAG_NO_HW_CSUM;
        } else {
                /* Only sun has original cassini chips.  */
                cp->cas_flags |= CAS_FLAG_REG_PLUS;

                /* We use a flag because the same phy might be externally
                 * connected.
                 */
                if ((pdev->vendor == PCI_VENDOR_ID_NS) &&
                    (pdev->device == PCI_DEVICE_ID_NS_SATURN))
                        cp->cas_flags |= CAS_FLAG_SATURN;
        }
}


static int cas_check_invariants(struct cas *cp)
{
        struct pci_dev *pdev = cp->pdev;
        u32 cfg;
        int i;

        /* get page size for rx buffers. */
        cp->page_order = 0;
#ifdef USE_PAGE_ORDER
        if (PAGE_SHIFT < CAS_JUMBO_PAGE_SHIFT) {
                /* see if we can allocate larger pages */
                struct page *page = alloc_pages(GFP_ATOMIC,
                                                CAS_JUMBO_PAGE_SHIFT -
                                                PAGE_SHIFT);
                if (page) {
                        __free_pages(page, CAS_JUMBO_PAGE_SHIFT - PAGE_SHIFT);
                        cp->page_order = CAS_JUMBO_PAGE_SHIFT - PAGE_SHIFT;
                } else {
                        printk(PFX "MTU limited to %d bytes\n", CAS_MAX_MTU);
                }
        }
#endif
        cp->page_size = (PAGE_SIZE << cp->page_order);

        /* Fetch the FIFO configurations. */
        cp->tx_fifo_size = readl(cp->regs + REG_TX_FIFO_SIZE) * 64;
        cp->rx_fifo_size = RX_FIFO_SIZE;

        /* finish phy determination. MDIO1 takes precedence over MDIO0 if
         * they're both connected.
         */
        cp->phy_type = cas_get_vpd_info(cp, cp->dev->dev_addr,
                                        PCI_SLOT(pdev->devfn));
        if (cp->phy_type & CAS_PHY_SERDES) {
                cp->cas_flags |= CAS_FLAG_1000MB_CAP;
                return 0; /* no more checking needed */
        }

        /* MII */
        cfg = readl(cp->regs + REG_MIF_CFG);
        if (cfg & MIF_CFG_MDIO_1) {
                cp->phy_type = CAS_PHY_MII_MDIO1;
        } else if (cfg & MIF_CFG_MDIO_0) {
                cp->phy_type = CAS_PHY_MII_MDIO0;
        }

        cas_mif_poll(cp, 0);
        writel(PCS_DATAPATH_MODE_MII, cp->regs + REG_PCS_DATAPATH_MODE);

        for (i = 0; i < 32; i++) {
                u32 phy_id;
                int j;

                for (j = 0; j < 3; j++) {
                        cp->phy_addr = i;
                        phy_id = cas_phy_read(cp, MII_PHYSID1) << 16;
                        phy_id |= cas_phy_read(cp, MII_PHYSID2);
                        if (phy_id && (phy_id != 0xFFFFFFFF)) {
                                cp->phy_id = phy_id;
                                goto done;
                        }
                }
        }
        printk(KERN_ERR PFX "MII phy did not respond [%08x]\n",
               readl(cp->regs + REG_MIF_STATE_MACHINE));
        return -1;

done:
        /* see if we can do gigabit */
        cfg = cas_phy_read(cp, MII_BMSR);
        if ((cfg & CAS_BMSR_1000_EXTEND) &&
            cas_phy_read(cp, CAS_MII_1000_EXTEND))
                cp->cas_flags |= CAS_FLAG_1000MB_CAP;
        return 0;
}

/* Must be invoked under cp->lock. */
static inline void cas_start_dma(struct cas *cp)
{
        int i;
        u32 val;
        int txfailed = 0;

        /* enable dma */
        val = readl(cp->regs + REG_TX_CFG) | TX_CFG_DMA_EN;
        writel(val, cp->regs + REG_TX_CFG);
        val = readl(cp->regs + REG_RX_CFG) | RX_CFG_DMA_EN;
        writel(val, cp->regs + REG_RX_CFG);

        /* enable the mac */
        val = readl(cp->regs + REG_MAC_TX_CFG) | MAC_TX_CFG_EN;
        writel(val, cp->regs + REG_MAC_TX_CFG);
        val = readl(cp->regs + REG_MAC_RX_CFG) | MAC_RX_CFG_EN;
        writel(val, cp->regs + REG_MAC_RX_CFG);

        i = STOP_TRIES;
        while (i-- > 0) {
                val = readl(cp->regs + REG_MAC_TX_CFG);
                if ((val & MAC_TX_CFG_EN))
                        break;
                udelay(10);
        }
        if (i < 0) txfailed = 1;
        i = STOP_TRIES;
        while (i-- > 0) {
                val = readl(cp->regs + REG_MAC_RX_CFG);
                if ((val & MAC_RX_CFG_EN)) {
                        if (txfailed) {
                          printk(KERN_ERR
                                 "%s: enabling mac failed [tx:%08x:%08x].\n",
                                 cp->dev->name,
                                 readl(cp->regs + REG_MIF_STATE_MACHINE),
                                 readl(cp->regs + REG_MAC_STATE_MACHINE));
                        }
                        goto enable_rx_done;
                }
                udelay(10);
        }
        printk(KERN_ERR "%s: enabling mac failed [%s:%08x:%08x].\n",
               cp->dev->name,
               (txfailed? "tx,rx":"rx"),
               readl(cp->regs + REG_MIF_STATE_MACHINE),
               readl(cp->regs + REG_MAC_STATE_MACHINE));

enable_rx_done:
        cas_unmask_intr(cp); /* enable interrupts */
        writel(RX_DESC_RINGN_SIZE(0) - 4, cp->regs + REG_RX_KICK);
        writel(0, cp->regs + REG_RX_COMP_TAIL);

        if (cp->cas_flags & CAS_FLAG_REG_PLUS) {
                if (N_RX_DESC_RINGS > 1)
                        writel(RX_DESC_RINGN_SIZE(1) - 4,
                               cp->regs + REG_PLUS_RX_KICK1);

                for (i = 1; i < N_RX_COMP_RINGS; i++)
                        writel(0, cp->regs + REG_PLUS_RX_COMPN_TAIL(i));
        }
}

/* Must be invoked under cp->lock. */
static void cas_read_pcs_link_mode(struct cas *cp, int *fd, int *spd,
                                   int *pause)
{
        u32 val = readl(cp->regs + REG_PCS_MII_LPA);
        *fd     = (val & PCS_MII_LPA_FD) ? 1 : 0;
        *pause  = (val & PCS_MII_LPA_SYM_PAUSE) ? 0x01 : 0x00;
        if (val & PCS_MII_LPA_ASYM_PAUSE)
                *pause |= 0x10;
        *spd = 1000;
}

/* Must be invoked under cp->lock. */
static void cas_read_mii_link_mode(struct cas *cp, int *fd, int *spd,
                                   int *pause)
{
        u32 val;

        *fd = 0;
        *spd = 10;
        *pause = 0;

        /* use GMII registers */
        val = cas_phy_read(cp, MII_LPA);
        if (val & CAS_LPA_PAUSE)
                *pause = 0x01;

        if (val & CAS_LPA_ASYM_PAUSE)
                *pause |= 0x10;

        if (val & LPA_DUPLEX)
                *fd = 1;
        if (val & LPA_100)
                *spd = 100;

        if (cp->cas_flags & CAS_FLAG_1000MB_CAP) {
                val = cas_phy_read(cp, CAS_MII_1000_STATUS);
                if (val & (CAS_LPA_1000FULL | CAS_LPA_1000HALF))
                        *spd = 1000;
                if (val & CAS_LPA_1000FULL)
                        *fd = 1;
        }
}

/* A link-up condition has occurred, initialize and enable the
 * rest of the chip.
 *
 * Must be invoked under cp->lock.
 */
static void cas_set_link_modes(struct cas *cp)
{
        u32 val;
        int full_duplex, speed, pause;

        full_duplex = 0;
        speed = 10;
        pause = 0;

        if (CAS_PHY_MII(cp->phy_type)) {
                cas_mif_poll(cp, 0);
                val = cas_phy_read(cp, MII_BMCR);
                if (val & BMCR_ANENABLE) {
                        cas_read_mii_link_mode(cp, &full_duplex, &speed,
                                               &pause);
                } else {
                        if (val & BMCR_FULLDPLX)
                                full_duplex = 1;

                        if (val & BMCR_SPEED100)
                                speed = 100;
                        else if (val & CAS_BMCR_SPEED1000)
                                speed = (cp->cas_flags & CAS_FLAG_1000MB_CAP) ?
                                        1000 : 100;
                }
                cas_mif_poll(cp, 1);

        } else {
                val = readl(cp->regs + REG_PCS_MII_CTRL);
                cas_read_pcs_link_mode(cp, &full_duplex, &speed, &pause);
                if ((val & PCS_MII_AUTONEG_EN) == 0) {
                        if (val & PCS_MII_CTRL_DUPLEX)
                                full_duplex = 1;
                }
        }

        if (netif_msg_link(cp))
                printk(KERN_INFO "%s: Link up at %d Mbps, %s-duplex.\n",
                       cp->dev->name, speed, (full_duplex ? "full" : "half"));

        val = MAC_XIF_TX_MII_OUTPUT_EN | MAC_XIF_LINK_LED;
        if (CAS_PHY_MII(cp->phy_type)) {
                val |= MAC_XIF_MII_BUFFER_OUTPUT_EN;
                if (!full_duplex)
                        val |= MAC_XIF_DISABLE_ECHO;
        }
        if (full_duplex)
                val |= MAC_XIF_FDPLX_LED;
        if (speed == 1000)
                val |= MAC_XIF_GMII_MODE;
        writel(val, cp->regs + REG_MAC_XIF_CFG);

        /* deal with carrier and collision detect. */
        val = MAC_TX_CFG_IPG_EN;
        if (full_duplex) {
                val |= MAC_TX_CFG_IGNORE_CARRIER;
                val |= MAC_TX_CFG_IGNORE_COLL;
        } else {
#ifndef USE_CSMA_CD_PROTO
                val |= MAC_TX_CFG_NEVER_GIVE_UP_EN;
                val |= MAC_TX_CFG_NEVER_GIVE_UP_LIM;
#endif
        }
        /* val now set up for REG_MAC_TX_CFG */

        /* If gigabit and half-duplex, enable carrier extension
         * mode.  increase slot time to 512 bytes as well.
         * else, disable it and make sure slot time is 64 bytes.
         * also activate checksum bug workaround
         */
        if ((speed == 1000) && !full_duplex) {
                writel(val | MAC_TX_CFG_CARRIER_EXTEND,
                       cp->regs + REG_MAC_TX_CFG);

                val = readl(cp->regs + REG_MAC_RX_CFG);
                val &= ~MAC_RX_CFG_STRIP_FCS; /* checksum workaround */
                writel(val | MAC_RX_CFG_CARRIER_EXTEND,
                       cp->regs + REG_MAC_RX_CFG);

                writel(0x200, cp->regs + REG_MAC_SLOT_TIME);

                cp->crc_size = 4;
                /* minimum size gigabit frame at half duplex */
                cp->min_frame_size = CAS_1000MB_MIN_FRAME;

        } else {
                writel(val, cp->regs + REG_MAC_TX_CFG);

                /* checksum bug workaround. don't strip FCS when in
                 * half-duplex mode
                 */
                val = readl(cp->regs + REG_MAC_RX_CFG);
                if (full_duplex) {
                        val |= MAC_RX_CFG_STRIP_FCS;
                        cp->crc_size = 0;
                        cp->min_frame_size = CAS_MIN_MTU;
                } else {
                        val &= ~MAC_RX_CFG_STRIP_FCS;
                        cp->crc_size = 4;
                        cp->min_frame_size = CAS_MIN_FRAME;
                }
                writel(val & ~MAC_RX_CFG_CARRIER_EXTEND,
                       cp->regs + REG_MAC_RX_CFG);
                writel(0x40, cp->regs + REG_MAC_SLOT_TIME);
        }

        if (netif_msg_link(cp)) {
                if (pause & 0x01) {
                        printk(KERN_INFO "%s: Pause is enabled "
                               "(rxfifo: %d off: %d on: %d)\n",
                               cp->dev->name,
                               cp->rx_fifo_size,
                               cp->rx_pause_off,
                               cp->rx_pause_on);
                } else if (pause & 0x10) {
                        printk(KERN_INFO "%s: TX pause enabled\n",
                               cp->dev->name);
                } else {
                        printk(KERN_INFO "%s: Pause is disabled\n",
                               cp->dev->name);
                }
        }

        val = readl(cp->regs + REG_MAC_CTRL_CFG);
        val &= ~(MAC_CTRL_CFG_SEND_PAUSE_EN | MAC_CTRL_CFG_RECV_PAUSE_EN);
        if (pause) { /* symmetric or asymmetric pause */
                val |= MAC_CTRL_CFG_SEND_PAUSE_EN;
                if (pause & 0x01) { /* symmetric pause */
                        val |= MAC_CTRL_CFG_RECV_PAUSE_EN;
                }
        }
        writel(val, cp->regs + REG_MAC_CTRL_CFG);
        cas_start_dma(cp);
}

/* Must be invoked under cp->lock. */
static void cas_init_hw(struct cas *cp, int restart_link)
{
        if (restart_link)
                cas_phy_init(cp);

        cas_init_pause_thresholds(cp);
        cas_init_mac(cp);
        cas_init_dma(cp);

        if (restart_link) {
                /* Default aneg parameters */
                cp->timer_ticks = 0;
                cas_begin_auto_negotiation(cp, NULL);
        } else if (cp->lstate == link_up) {
                cas_set_link_modes(cp);
                netif_carrier_on(cp->dev);
        }
}

/* Must be invoked under cp->lock. on earlier cassini boards,
 * SOFT_0 is tied to PCI reset. we use this to force a pci reset,
 * let it settle out, and then restore pci state.
 */
static void cas_hard_reset(struct cas *cp)
{
        writel(BIM_LOCAL_DEV_SOFT_0, cp->regs + REG_BIM_LOCAL_DEV_EN);
        udelay(20);
        pci_restore_state(cp->pdev);
}


static void cas_global_reset(struct cas *cp, int blkflag)
{
        int limit;

        /* issue a global reset. don't use RSTOUT. */
        if (blkflag && !CAS_PHY_MII(cp->phy_type)) {
                /* For PCS, when the blkflag is set, we should set the
                 * SW_REST_BLOCK_PCS_SLINK bit to prevent the results of
                 * the last autonegotiation from being cleared.  We'll
                 * need some special handling if the chip is set into a
                 * loopback mode.
                 */
                writel((SW_RESET_TX | SW_RESET_RX | SW_RESET_BLOCK_PCS_SLINK),
                       cp->regs + REG_SW_RESET);
        } else {
                writel(SW_RESET_TX | SW_RESET_RX, cp->regs + REG_SW_RESET);
        }

        /* need to wait at least 3ms before polling register */
        mdelay(3);

        limit = STOP_TRIES;
        while (limit-- > 0) {
                u32 val = readl(cp->regs + REG_SW_RESET);
                if ((val & (SW_RESET_TX | SW_RESET_RX)) == 0)
                        goto done;
                udelay(10);
        }
        printk(KERN_ERR "%s: sw reset failed.\n", cp->dev->name);

done:
        /* enable various BIM interrupts */
        writel(BIM_CFG_DPAR_INTR_ENABLE | BIM_CFG_RMA_INTR_ENABLE |
               BIM_CFG_RTA_INTR_ENABLE, cp->regs + REG_BIM_CFG);

        /* clear out pci error status mask for handled errors.
         * we don't deal with DMA counter overflows as they happen
         * all the time.
         */
        writel(0xFFFFFFFFU & ~(PCI_ERR_BADACK | PCI_ERR_DTRTO |
                               PCI_ERR_OTHER | PCI_ERR_BIM_DMA_WRITE |
                               PCI_ERR_BIM_DMA_READ), cp->regs +
               REG_PCI_ERR_STATUS_MASK);

        /* set up for MII by default to address mac rx reset timeout
         * issue
         */
        writel(PCS_DATAPATH_MODE_MII, cp->regs + REG_PCS_DATAPATH_MODE);
}

static void cas_reset(struct cas *cp, int blkflag)
{
        u32 val;

        cas_mask_intr(cp);
        cas_global_reset(cp, blkflag);
        cas_mac_reset(cp);
        cas_entropy_reset(cp);

        /* disable dma engines. */
        val = readl(cp->regs + REG_TX_CFG);
        val &= ~TX_CFG_DMA_EN;
        writel(val, cp->regs + REG_TX_CFG);

        val = readl(cp->regs + REG_RX_CFG);
        val &= ~RX_CFG_DMA_EN;
        writel(val, cp->regs + REG_RX_CFG);

        /* program header parser */
        if ((cp->cas_flags & CAS_FLAG_TARGET_ABORT) ||
            (CAS_HP_ALT_FIRMWARE == cas_prog_null)) {
                cas_load_firmware(cp, CAS_HP_FIRMWARE);
        } else {
                cas_load_firmware(cp, CAS_HP_ALT_FIRMWARE);
        }

        /* clear out error registers */
        spin_lock(&cp->stat_lock[N_TX_RINGS]);
        cas_clear_mac_err(cp);
        spin_unlock(&cp->stat_lock[N_TX_RINGS]);
}

/* Shut down the chip, must be called with pm_mutex held.  */
static void cas_shutdown(struct cas *cp)
{
        unsigned long flags;

        /* Make us not-running to avoid timers respawning */
        cp->hw_running = 0;

        del_timer_sync(&cp->link_timer);

        /* Stop the reset task */
#if 0
        while (atomic_read(&cp->reset_task_pending_mtu) ||
               atomic_read(&cp->reset_task_pending_spare) ||
               atomic_read(&cp->reset_task_pending_all))
                schedule();

#else
        while (atomic_read(&cp->reset_task_pending))
                schedule();
#endif
        /* Actually stop the chip */
        cas_lock_all_save(cp, flags);
        cas_reset(cp, 0);
        if (cp->cas_flags & CAS_FLAG_SATURN)
                cas_phy_powerdown(cp);
        cas_unlock_all_restore(cp, flags);
}

static int cas_change_mtu(struct net_device *dev, int new_mtu)
{
        struct cas *cp = netdev_priv(dev);

        if (new_mtu < CAS_MIN_MTU || new_mtu > CAS_MAX_MTU)
                return -EINVAL;

        dev->mtu = new_mtu;
        if (!netif_running(dev) || !netif_device_present(dev))
                return 0;

        /* let the reset task handle it */
#if 1
        atomic_inc(&cp->reset_task_pending);
        if ((cp->phy_type & CAS_PHY_SERDES)) {
                atomic_inc(&cp->reset_task_pending_all);
        } else {
                atomic_inc(&cp->reset_task_pending_mtu);
        }
        schedule_work(&cp->reset_task);
#else
        atomic_set(&cp->reset_task_pending, (cp->phy_type & CAS_PHY_SERDES) ?
                   CAS_RESET_ALL : CAS_RESET_MTU);
        printk(KERN_ERR "reset called in cas_change_mtu\n");
        schedule_work(&cp->reset_task);
#endif

        flush_scheduled_work();
        return 0;
}

static void cas_clean_txd(struct cas *cp, int ring)
{
        struct cas_tx_desc *txd = cp->init_txds[ring];
        struct sk_buff *skb, **skbs = cp->tx_skbs[ring];
        u64 daddr, dlen;
        int i, size;

        size = TX_DESC_RINGN_SIZE(ring);
        for (i = 0; i < size; i++) {
                int frag;

                if (skbs[i] == NULL)
                        continue;

                skb = skbs[i];
                skbs[i] = NULL;

                for (frag = 0; frag <= skb_shinfo(skb)->nr_frags;  frag++) {
                        int ent = i & (size - 1);

                        /* first buffer is never a tiny buffer and so
                         * needs to be unmapped.
                         */
                        daddr = le64_to_cpu(txd[ent].buffer);
                        dlen  =  CAS_VAL(TX_DESC_BUFLEN,
                                         le64_to_cpu(txd[ent].control));
                        pci_unmap_page(cp->pdev, daddr, dlen,
                                       PCI_DMA_TODEVICE);

                        if (frag != skb_shinfo(skb)->nr_frags) {
                                i++;

                                /* next buffer might by a tiny buffer.
                                 * skip past it.
                                 */
                                ent = i & (size - 1);
                                if (cp->tx_tiny_use[ring][ent].used)
                                        i++;
                        }
                }
                dev_kfree_skb_any(skb);
        }

        /* zero out tiny buf usage */
        memset(cp->tx_tiny_use[ring], 0, size*sizeof(*cp->tx_tiny_use[ring]));
}

/* freed on close */
static inline void cas_free_rx_desc(struct cas *cp, int ring)
{
        cas_page_t **page = cp->rx_pages[ring];
        int i, size;

        size = RX_DESC_RINGN_SIZE(ring);
        for (i = 0; i < size; i++) {
                if (page[i]) {
                        cas_page_free(cp, page[i]);
                        page[i] = NULL;
                }
        }
}

static void cas_free_rxds(struct cas *cp)
{
        int i;

        for (i = 0; i < N_RX_DESC_RINGS; i++)
                cas_free_rx_desc(cp, i);
}

/* Must be invoked under cp->lock. */
static void cas_clean_rings(struct cas *cp)
{
        int i;

        /* need to clean all tx rings */
        memset(cp->tx_old, 0, sizeof(*cp->tx_old)*N_TX_RINGS);
        memset(cp->tx_new, 0, sizeof(*cp->tx_new)*N_TX_RINGS);
        for (i = 0; i < N_TX_RINGS; i++)
                cas_clean_txd(cp, i);

        /* zero out init block */
        memset(cp->init_block, 0, sizeof(struct cas_init_block));
        cas_clean_rxds(cp);
        cas_clean_rxcs(cp);
}

/* allocated on open */
static inline int cas_alloc_rx_desc(struct cas *cp, int ring)
{
        cas_page_t **page = cp->rx_pages[ring];
        int size, i = 0;

        size = RX_DESC_RINGN_SIZE(ring);
        for (i = 0; i < size; i++) {
                if ((page[i] = cas_page_alloc(cp, GFP_KERNEL)) == NULL)
                        return -1;
        }
        return 0;
}

static int cas_alloc_rxds(struct cas *cp)
{
        int i;

        for (i = 0; i < N_RX_DESC_RINGS; i++) {
                if (cas_alloc_rx_desc(cp, i) < 0) {
                        cas_free_rxds(cp);
                        return -1;
                }
        }
        return 0;
}

static void cas_reset_task(struct work_struct *work)
{
        struct cas *cp = container_of(work, struct cas, reset_task);
#if 0
        int pending = atomic_read(&cp->reset_task_pending);
#else
        int pending_all = atomic_read(&cp->reset_task_pending_all);
        int pending_spare = atomic_read(&cp->reset_task_pending_spare);
        int pending_mtu = atomic_read(&cp->reset_task_pending_mtu);

        if (pending_all == 0 && pending_spare == 0 && pending_mtu == 0) {
                /* We can have more tasks scheduled than actually
                 * needed.
                 */
                atomic_dec(&cp->reset_task_pending);
                return;
        }
#endif
        /* The link went down, we reset the ring, but keep
         * DMA stopped. Use this function for reset
         * on error as well.
         */
        if (cp->hw_running) {
                unsigned long flags;

                /* Make sure we don't get interrupts or tx packets */
                netif_device_detach(cp->dev);
                cas_lock_all_save(cp, flags);

                if (cp->opened) {
                        /* We call cas_spare_recover when we call cas_open.
                         * but we do not initialize the lists cas_spare_recover
                         * uses until cas_open is called.
                         */
                        cas_spare_recover(cp, GFP_ATOMIC);
                }
#if 1
                /* test => only pending_spare set */
                if (!pending_all && !pending_mtu)
                        goto done;
#else
                if (pending == CAS_RESET_SPARE)
                        goto done;
#endif
                /* when pending == CAS_RESET_ALL, the following
                 * call to cas_init_hw will restart auto negotiation.
                 * Setting the second argument of cas_reset to
                 * !(pending == CAS_RESET_ALL) will set this argument
                 * to 1 (avoiding reinitializing the PHY for the normal
                 * PCS case) when auto negotiation is not restarted.
                 */
#if 1
                cas_reset(cp, !(pending_all > 0));
                if (cp->opened)
                        cas_clean_rings(cp);
                cas_init_hw(cp, (pending_all > 0));
#else
                cas_reset(cp, !(pending == CAS_RESET_ALL));
                if (cp->opened)
                        cas_clean_rings(cp);
                cas_init_hw(cp, pending == CAS_RESET_ALL);
#endif

done:
                cas_unlock_all_restore(cp, flags);
                netif_device_attach(cp->dev);
        }
#if 1
        atomic_sub(pending_all, &cp->reset_task_pending_all);
        atomic_sub(pending_spare, &cp->reset_task_pending_spare);
        atomic_sub(pending_mtu, &cp->reset_task_pending_mtu);
        atomic_dec(&cp->reset_task_pending);
#else
        atomic_set(&cp->reset_task_pending, 0);
#endif
}

static void cas_link_timer(unsigned long data)
{
        struct cas *cp = (struct cas *) data;
        int mask, pending = 0, reset = 0;
        unsigned long flags;

        if (link_transition_timeout != 0 &&
            cp->link_transition_jiffies_valid &&
            ((jiffies - cp->link_transition_jiffies) >
              (link_transition_timeout))) {
                /* One-second counter so link-down workaround doesn't
                 * cause resets to occur so fast as to fool the switch
                 * into thinking the link is down.
                 */
                cp->link_transition_jiffies_valid = 0;
        }

        if (!cp->hw_running)
                return;

        spin_lock_irqsave(&cp->lock, flags);
        cas_lock_tx(cp);
        cas_entropy_gather(cp);

        /* If the link task is still pending, we just
         * reschedule the link timer
         */
#if 1
        if (atomic_read(&cp->reset_task_pending_all) ||
            atomic_read(&cp->reset_task_pending_spare) ||
            atomic_read(&cp->reset_task_pending_mtu))
                goto done;
#else
        if (atomic_read(&cp->reset_task_pending))
                goto done;
#endif

        /* check for rx cleaning */
        if ((mask = (cp->cas_flags & CAS_FLAG_RXD_POST_MASK))) {
                int i, rmask;

                for (i = 0; i < MAX_RX_DESC_RINGS; i++) {
                        rmask = CAS_FLAG_RXD_POST(i);
                        if ((mask & rmask) == 0)
                                continue;

                        /* post_rxds will do a mod_timer */
                        if (cas_post_rxds_ringN(cp, i, cp->rx_last[i]) < 0) {
                                pending = 1;
                                continue;
                        }
                        cp->cas_flags &= ~rmask;
                }
        }

        if (CAS_PHY_MII(cp->phy_type)) {
                u16 bmsr;
                cas_mif_poll(cp, 0);
                bmsr = cas_phy_read(cp, MII_BMSR);
                /* WTZ: Solaris driver reads this twice, but that
                 * may be due to the PCS case and the use of a
                 * common implementation. Read it twice here to be
                 * safe.
                 */
                bmsr = cas_phy_read(cp, MII_BMSR);
                cas_mif_poll(cp, 1);
                readl(cp->regs + REG_MIF_STATUS); /* avoid dups */
                reset = cas_mii_link_check(cp, bmsr);
        } else {
                reset = cas_pcs_link_check(cp);
        }

        if (reset)
                goto done;

        /* check for tx state machine confusion */
        if ((readl(cp->regs + REG_MAC_TX_STATUS) & MAC_TX_FRAME_XMIT) == 0) {
                u32 val = readl(cp->regs + REG_MAC_STATE_MACHINE);
                u32 wptr, rptr;
                int tlm  = CAS_VAL(MAC_SM_TLM, val);

                if (((tlm == 0x5) || (tlm == 0x3)) &&
                    (CAS_VAL(MAC_SM_ENCAP_SM, val) == 0)) {
                        if (netif_msg_tx_err(cp))
                                printk(KERN_DEBUG "%s: tx err: "
                                       "MAC_STATE[%08x]\n",
                                       cp->dev->name, val);
                        reset = 1;
                        goto done;
                }

                val  = readl(cp->regs + REG_TX_FIFO_PKT_CNT);
                wptr = readl(cp->regs + REG_TX_FIFO_WRITE_PTR);
                rptr = readl(cp->regs + REG_TX_FIFO_READ_PTR);
                if ((val == 0) && (wptr != rptr)) {
                        if (netif_msg_tx_err(cp))
                                printk(KERN_DEBUG "%s: tx err: "
                                       "TX_FIFO[%08x:%08x:%08x]\n",
                                       cp->dev->name, val, wptr, rptr);
                        reset = 1;
                }

                if (reset)
                        cas_hard_reset(cp);
        }

done:
        if (reset) {
#if 1
                atomic_inc(&cp->reset_task_pending);
                atomic_inc(&cp->reset_task_pending_all);
                schedule_work(&cp->reset_task);
#else
                atomic_set(&cp->reset_task_pending, CAS_RESET_ALL);
                printk(KERN_ERR "reset called in cas_link_timer\n");
                schedule_work(&cp->reset_task);
#endif
        }

        if (!pending)
                mod_timer(&cp->link_timer, jiffies + CAS_LINK_TIMEOUT);
        cas_unlock_tx(cp);
        spin_unlock_irqrestore(&cp->lock, flags);
}

/* tiny buffers are used to avoid target abort issues with
 * older cassini's
 */
static void cas_tx_tiny_free(struct cas *cp)
{
        struct pci_dev *pdev = cp->pdev;
        int i;

        for (i = 0; i < N_TX_RINGS; i++) {
                if (!cp->tx_tiny_bufs[i])
                        continue;

                pci_free_consistent(pdev, TX_TINY_BUF_BLOCK,
                                    cp->tx_tiny_bufs[i],
                                    cp->tx_tiny_dvma[i]);
                cp->tx_tiny_bufs[i] = NULL;
        }
}

static int cas_tx_tiny_alloc(struct cas *cp)
{
        struct pci_dev *pdev = cp->pdev;
        int i;

        for (i = 0; i < N_TX_RINGS; i++) {
                cp->tx_tiny_bufs[i] =
                        pci_alloc_consistent(pdev, TX_TINY_BUF_BLOCK,
                                             &cp->tx_tiny_dvma[i]);
                if (!cp->tx_tiny_bufs[i]) {
                        cas_tx_tiny_free(cp);
                        return -1;
                }
        }
        return 0;
}


static int cas_open(struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);
        int hw_was_up, err;
        unsigned long flags;

        mutex_lock(&cp->pm_mutex);

        hw_was_up = cp->hw_running;

        /* The power-management mutex protects the hw_running
         * etc. state so it is safe to do this bit without cp->lock
         */
        if (!cp->hw_running) {
                /* Reset the chip */
                cas_lock_all_save(cp, flags);
                /* We set the second arg to cas_reset to zero
                 * because cas_init_hw below will have its second
                 * argument set to non-zero, which will force
                 * autonegotiation to start.
                 */
                cas_reset(cp, 0);
                cp->hw_running = 1;
                cas_unlock_all_restore(cp, flags);
        }

        if (cas_tx_tiny_alloc(cp) < 0)
                return -ENOMEM;

        /* alloc rx descriptors */
        err = -ENOMEM;
        if (cas_alloc_rxds(cp) < 0)
                goto err_tx_tiny;

        /* allocate spares */
        cas_spare_init(cp);
        cas_spare_recover(cp, GFP_KERNEL);

        /* We can now request the interrupt as we know it's masked
         * on the controller. cassini+ has up to 4 interrupts
         * that can be used, but you need to do explicit pci interrupt
         * mapping to expose them
         */
        if (request_irq(cp->pdev->irq, cas_interrupt,
                        IRQF_SHARED, dev->name, (void *) dev)) {
                printk(KERN_ERR "%s: failed to request irq !\n",
                       cp->dev->name);
                err = -EAGAIN;
                goto err_spare;
        }

#ifdef USE_NAPI
        napi_enable(&cp->napi);
#endif
        /* init hw */
        cas_lock_all_save(cp, flags);
        cas_clean_rings(cp);
        cas_init_hw(cp, !hw_was_up);
        cp->opened = 1;
        cas_unlock_all_restore(cp, flags);

        netif_start_queue(dev);
        mutex_unlock(&cp->pm_mutex);
        return 0;

err_spare:
        cas_spare_free(cp);
        cas_free_rxds(cp);
err_tx_tiny:
        cas_tx_tiny_free(cp);
        mutex_unlock(&cp->pm_mutex);
        return err;
}

static int cas_close(struct net_device *dev)
{
        unsigned long flags;
        struct cas *cp = netdev_priv(dev);

#ifdef USE_NAPI
        napi_disable(&cp->napi);
#endif
        /* Make sure we don't get distracted by suspend/resume */
        mutex_lock(&cp->pm_mutex);

        netif_stop_queue(dev);

        /* Stop traffic, mark us closed */
        cas_lock_all_save(cp, flags);
        cp->opened = 0;
        cas_reset(cp, 0);
        cas_phy_init(cp);
        cas_begin_auto_negotiation(cp, NULL);
        cas_clean_rings(cp);
        cas_unlock_all_restore(cp, flags);

        free_irq(cp->pdev->irq, (void *) dev);
        cas_spare_free(cp);
        cas_free_rxds(cp);
        cas_tx_tiny_free(cp);
        mutex_unlock(&cp->pm_mutex);
        return 0;
}

static struct {
        const char name[ETH_GSTRING_LEN];
} ethtool_cassini_statnames[] = {
        {"collisions"},
        {"rx_bytes"},
        {"rx_crc_errors"},
        {"rx_dropped"},
        {"rx_errors"},
        {"rx_fifo_errors"},
        {"rx_frame_errors"},
        {"rx_length_errors"},
        {"rx_over_errors"},
        {"rx_packets"},
        {"tx_aborted_errors"},
        {"tx_bytes"},
        {"tx_dropped"},
        {"tx_errors"},
        {"tx_fifo_errors"},
        {"tx_packets"}
};
#define CAS_NUM_STAT_KEYS ARRAY_SIZE(ethtool_cassini_statnames)

static struct {
        const int offsets;      /* neg. values for 2nd arg to cas_read_phy */
} ethtool_register_table[] = {
        {-MII_BMSR},
        {-MII_BMCR},
        {REG_CAWR},
        {REG_INF_BURST},
        {REG_BIM_CFG},
        {REG_RX_CFG},
        {REG_HP_CFG},
        {REG_MAC_TX_CFG},
        {REG_MAC_RX_CFG},
        {REG_MAC_CTRL_CFG},
        {REG_MAC_XIF_CFG},
        {REG_MIF_CFG},
        {REG_PCS_CFG},
        {REG_SATURN_PCFG},
        {REG_PCS_MII_STATUS},
        {REG_PCS_STATE_MACHINE},
        {REG_MAC_COLL_EXCESS},
        {REG_MAC_COLL_LATE}
};
#define CAS_REG_LEN     ARRAY_SIZE(ethtool_register_table)
#define CAS_MAX_REGS    (sizeof (u32)*CAS_REG_LEN)

static void cas_read_regs(struct cas *cp, u8 *ptr, int len)
{
        u8 *p;
        int i;
        unsigned long flags;

        spin_lock_irqsave(&cp->lock, flags);
        for (i = 0, p = ptr; i < len ; i ++, p += sizeof(u32)) {
                u16 hval;
                u32 val;
                if (ethtool_register_table[i].offsets < 0) {
                        hval = cas_phy_read(cp,
                                    -ethtool_register_table[i].offsets);
                        val = hval;
                } else {
                        val= readl(cp->regs+ethtool_register_table[i].offsets);
                }
                memcpy(p, (u8 *)&val, sizeof(u32));
        }
        spin_unlock_irqrestore(&cp->lock, flags);
}

static struct net_device_stats *cas_get_stats(struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);
        struct net_device_stats *stats = cp->net_stats;
        unsigned long flags;
        int i;
        unsigned long tmp;

        /* we collate all of the stats into net_stats[N_TX_RING] */
        if (!cp->hw_running)
                return stats + N_TX_RINGS;

        /* collect outstanding stats */
        /* WTZ: the Cassini spec gives these as 16 bit counters but
         * stored in 32-bit words.  Added a mask of 0xffff to be safe,
         * in case the chip somehow puts any garbage in the other bits.
         * Also, counter usage didn't seem to mach what Adrian did
         * in the parts of the code that set these quantities. Made
         * that consistent.
         */
        spin_lock_irqsave(&cp->stat_lock[N_TX_RINGS], flags);
        stats[N_TX_RINGS].rx_crc_errors +=
          readl(cp->regs + REG_MAC_FCS_ERR) & 0xffff;
        stats[N_TX_RINGS].rx_frame_errors +=
                readl(cp->regs + REG_MAC_ALIGN_ERR) &0xffff;
        stats[N_TX_RINGS].rx_length_errors +=
                readl(cp->regs + REG_MAC_LEN_ERR) & 0xffff;
#if 1
        tmp = (readl(cp->regs + REG_MAC_COLL_EXCESS) & 0xffff) +
                (readl(cp->regs + REG_MAC_COLL_LATE) & 0xffff);
        stats[N_TX_RINGS].tx_aborted_errors += tmp;
        stats[N_TX_RINGS].collisions +=
          tmp + (readl(cp->regs + REG_MAC_COLL_NORMAL) & 0xffff);
#else
        stats[N_TX_RINGS].tx_aborted_errors +=
                readl(cp->regs + REG_MAC_COLL_EXCESS);
        stats[N_TX_RINGS].collisions += readl(cp->regs + REG_MAC_COLL_EXCESS) +
                readl(cp->regs + REG_MAC_COLL_LATE);
#endif
        cas_clear_mac_err(cp);

        /* saved bits that are unique to ring 0 */
        spin_lock(&cp->stat_lock[0]);
        stats[N_TX_RINGS].collisions        += stats[0].collisions;
        stats[N_TX_RINGS].rx_over_errors    += stats[0].rx_over_errors;
        stats[N_TX_RINGS].rx_frame_errors   += stats[0].rx_frame_errors;
        stats[N_TX_RINGS].rx_fifo_errors    += stats[0].rx_fifo_errors;
        stats[N_TX_RINGS].tx_aborted_errors += stats[0].tx_aborted_errors;
        stats[N_TX_RINGS].tx_fifo_errors    += stats[0].tx_fifo_errors;
        spin_unlock(&cp->stat_lock[0]);

        for (i = 0; i < N_TX_RINGS; i++) {
                spin_lock(&cp->stat_lock[i]);
                stats[N_TX_RINGS].rx_length_errors +=
                        stats[i].rx_length_errors;
                stats[N_TX_RINGS].rx_crc_errors += stats[i].rx_crc_errors;
                stats[N_TX_RINGS].rx_packets    += stats[i].rx_packets;
                stats[N_TX_RINGS].tx_packets    += stats[i].tx_packets;
                stats[N_TX_RINGS].rx_bytes      += stats[i].rx_bytes;
                stats[N_TX_RINGS].tx_bytes      += stats[i].tx_bytes;
                stats[N_TX_RINGS].rx_errors     += stats[i].rx_errors;
                stats[N_TX_RINGS].tx_errors     += stats[i].tx_errors;
                stats[N_TX_RINGS].rx_dropped    += stats[i].rx_dropped;
                stats[N_TX_RINGS].tx_dropped    += stats[i].tx_dropped;
                memset(stats + i, 0, sizeof(struct net_device_stats));
                spin_unlock(&cp->stat_lock[i]);
        }
        spin_unlock_irqrestore(&cp->stat_lock[N_TX_RINGS], flags);
        return stats + N_TX_RINGS;
}


static void cas_set_multicast(struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);
        u32 rxcfg, rxcfg_new;
        unsigned long flags;
        int limit = STOP_TRIES;

        if (!cp->hw_running)
                return;

        spin_lock_irqsave(&cp->lock, flags);
        rxcfg = readl(cp->regs + REG_MAC_RX_CFG);

        /* disable RX MAC and wait for completion */
        writel(rxcfg & ~MAC_RX_CFG_EN, cp->regs + REG_MAC_RX_CFG);
        while (readl(cp->regs + REG_MAC_RX_CFG) & MAC_RX_CFG_EN) {
                if (!limit--)
                        break;
                udelay(10);
        }

        /* disable hash filter and wait for completion */
        limit = STOP_TRIES;
        rxcfg &= ~(MAC_RX_CFG_PROMISC_EN | MAC_RX_CFG_HASH_FILTER_EN);
        writel(rxcfg & ~MAC_RX_CFG_EN, cp->regs + REG_MAC_RX_CFG);
        while (readl(cp->regs + REG_MAC_RX_CFG) & MAC_RX_CFG_HASH_FILTER_EN) {
                if (!limit--)
                        break;
                udelay(10);
        }

        /* program hash filters */
        cp->mac_rx_cfg = rxcfg_new = cas_setup_multicast(cp);
        rxcfg |= rxcfg_new;
        writel(rxcfg, cp->regs + REG_MAC_RX_CFG);
        spin_unlock_irqrestore(&cp->lock, flags);
}

static void cas_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
        struct cas *cp = netdev_priv(dev);
        strncpy(info->driver, DRV_MODULE_NAME, ETHTOOL_BUSINFO_LEN);
        strncpy(info->version, DRV_MODULE_VERSION, ETHTOOL_BUSINFO_LEN);
        info->fw_version[0] = '\0';
        strncpy(info->bus_info, pci_name(cp->pdev), ETHTOOL_BUSINFO_LEN);
        info->regdump_len = cp->casreg_len < CAS_MAX_REGS ?
                cp->casreg_len : CAS_MAX_REGS;
        info->n_stats = CAS_NUM_STAT_KEYS;
}

static int cas_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct cas *cp = netdev_priv(dev);
        u16 bmcr;
        int full_duplex, speed, pause;
        unsigned long flags;
        enum link_state linkstate = link_up;

        cmd->advertising = 0;
        cmd->supported = SUPPORTED_Autoneg;
        if (cp->cas_flags & CAS_FLAG_1000MB_CAP) {
                cmd->supported |= SUPPORTED_1000baseT_Full;
                cmd->advertising |= ADVERTISED_1000baseT_Full;
        }

        /* Record PHY settings if HW is on. */
        spin_lock_irqsave(&cp->lock, flags);
        bmcr = 0;
        linkstate = cp->lstate;
        if (CAS_PHY_MII(cp->phy_type)) {
                cmd->port = PORT_MII;
                cmd->transceiver = (cp->cas_flags & CAS_FLAG_SATURN) ?
                        XCVR_INTERNAL : XCVR_EXTERNAL;
                cmd->phy_address = cp->phy_addr;
                cmd->advertising |= ADVERTISED_TP | ADVERTISED_MII |
                        ADVERTISED_10baseT_Half |
                        ADVERTISED_10baseT_Full |
                        ADVERTISED_100baseT_Half |
                        ADVERTISED_100baseT_Full;

                cmd->supported |=
                        (SUPPORTED_10baseT_Half |
                         SUPPORTED_10baseT_Full |
                         SUPPORTED_100baseT_Half |
                         SUPPORTED_100baseT_Full |
                         SUPPORTED_TP | SUPPORTED_MII);

                if (cp->hw_running) {
                        cas_mif_poll(cp, 0);
                        bmcr = cas_phy_read(cp, MII_BMCR);
                        cas_read_mii_link_mode(cp, &full_duplex,
                                               &speed, &pause);
                        cas_mif_poll(cp, 1);
                }

        } else {
                cmd->port = PORT_FIBRE;
                cmd->transceiver = XCVR_INTERNAL;
                cmd->phy_address = 0;
                cmd->supported   |= SUPPORTED_FIBRE;
                cmd->advertising |= ADVERTISED_FIBRE;

                if (cp->hw_running) {
                        /* pcs uses the same bits as mii */
                        bmcr = readl(cp->regs + REG_PCS_MII_CTRL);
                        cas_read_pcs_link_mode(cp, &full_duplex,
                                               &speed, &pause);
                }
        }
        spin_unlock_irqrestore(&cp->lock, flags);

        if (bmcr & BMCR_ANENABLE) {
                cmd->advertising |= ADVERTISED_Autoneg;
                cmd->autoneg = AUTONEG_ENABLE;
                cmd->speed = ((speed == 10) ?
                              SPEED_10 :
                              ((speed == 1000) ?
                               SPEED_1000 : SPEED_100));
                cmd->duplex = full_duplex ? DUPLEX_FULL : DUPLEX_HALF;
        } else {
                cmd->autoneg = AUTONEG_DISABLE;
                cmd->speed =
                        (bmcr & CAS_BMCR_SPEED1000) ?
                        SPEED_1000 :
                        ((bmcr & BMCR_SPEED100) ? SPEED_100:
                         SPEED_10);
                cmd->duplex =
                        (bmcr & BMCR_FULLDPLX) ?
                        DUPLEX_FULL : DUPLEX_HALF;
        }
        if (linkstate != link_up) {
                /* Force these to "unknown" if the link is not up and
                 * autonogotiation in enabled. We can set the link
                 * speed to 0, but not cmd->duplex,
                 * because its legal values are 0 and 1.  Ethtool will
                 * print the value reported in parentheses after the
                 * word "Unknown" for unrecognized values.
                 *
                 * If in forced mode, we report the speed and duplex
                 * settings that we configured.
                 */
                if (cp->link_cntl & BMCR_ANENABLE) {
                        cmd->speed = 0;
                        cmd->duplex = 0xff;
                } else {
                        cmd->speed = SPEED_10;
                        if (cp->link_cntl & BMCR_SPEED100) {
                                cmd->speed = SPEED_100;
                        } else if (cp->link_cntl & CAS_BMCR_SPEED1000) {
                                cmd->speed = SPEED_1000;
                        }
                        cmd->duplex = (cp->link_cntl & BMCR_FULLDPLX)?
                                DUPLEX_FULL : DUPLEX_HALF;
                }
        }
        return 0;
}

static int cas_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct cas *cp = netdev_priv(dev);
        unsigned long flags;

        /* Verify the settings we care about. */
        if (cmd->autoneg != AUTONEG_ENABLE &&
            cmd->autoneg != AUTONEG_DISABLE)
                return -EINVAL;

        if (cmd->autoneg == AUTONEG_DISABLE &&
            ((cmd->speed != SPEED_1000 &&
              cmd->speed != SPEED_100 &&
              cmd->speed != SPEED_10) ||
             (cmd->duplex != DUPLEX_HALF &&
              cmd->duplex != DUPLEX_FULL)))
                return -EINVAL;

        /* Apply settings and restart link process. */
        spin_lock_irqsave(&cp->lock, flags);
        cas_begin_auto_negotiation(cp, cmd);
        spin_unlock_irqrestore(&cp->lock, flags);
        return 0;
}

static int cas_nway_reset(struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);
        unsigned long flags;

        if ((cp->link_cntl & BMCR_ANENABLE) == 0)
                return -EINVAL;

        /* Restart link process. */
        spin_lock_irqsave(&cp->lock, flags);
        cas_begin_auto_negotiation(cp, NULL);
        spin_unlock_irqrestore(&cp->lock, flags);

        return 0;
}

static u32 cas_get_link(struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);
        return cp->lstate == link_up;
}

static u32 cas_get_msglevel(struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);
        return cp->msg_enable;
}

static void cas_set_msglevel(struct net_device *dev, u32 value)
{
        struct cas *cp = netdev_priv(dev);
        cp->msg_enable = value;
}

static int cas_get_regs_len(struct net_device *dev)
{
        struct cas *cp = netdev_priv(dev);
        return cp->casreg_len < CAS_MAX_REGS ? cp->casreg_len: CAS_MAX_REGS;
}

static void cas_get_regs(struct net_device *dev, struct ethtool_regs *regs,
                             void *p)
{
        struct cas *cp = netdev_priv(dev);
        regs->version = 0;
        /* cas_read_regs handles locks (cp->lock).  */
        cas_read_regs(cp, p, regs->len / sizeof(u32));
}

static int cas_get_sset_count(struct net_device *dev, int sset)
{
        switch (sset) {
        case ETH_SS_STATS:
                return CAS_NUM_STAT_KEYS;
        default:
                return -EOPNOTSUPP;
        }
}

static void cas_get_strings(struct net_device *dev, u32 stringset, u8 *data)
{
         memcpy(data, &ethtool_cassini_statnames,
                                         CAS_NUM_STAT_KEYS * ETH_GSTRING_LEN);
}

static void cas_get_ethtool_stats(struct net_device *dev,
                                      struct ethtool_stats *estats, u64 *data)
{
        struct cas *cp = netdev_priv(dev);
        struct net_device_stats *stats = cas_get_stats(cp->dev);
        int i = 0;
        data[i++] = stats->collisions;
        data[i++] = stats->rx_bytes;
        data[i++] = stats->rx_crc_errors;
        data[i++] = stats->rx_dropped;
        data[i++] = stats->rx_errors;
        data[i++] = stats->rx_fifo_errors;
        data[i++] = stats->rx_frame_errors;
        data[i++] = stats->rx_length_errors;
        data[i++] = stats->rx_over_errors;
        data[i++] = stats->rx_packets;
        data[i++] = stats->tx_aborted_errors;
        data[i++] = stats->tx_bytes;
        data[i++] = stats->tx_dropped;
        data[i++] = stats->tx_errors;
        data[i++] = stats->tx_fifo_errors;
        data[i++] = stats->tx_packets;
        BUG_ON(i != CAS_NUM_STAT_KEYS);
}

static const struct ethtool_ops cas_ethtool_ops = {
        .get_drvinfo            = cas_get_drvinfo,
        .get_settings           = cas_get_settings,
        .set_settings           = cas_set_settings,
        .nway_reset             = cas_nway_reset,
        .get_link               = cas_get_link,
        .get_msglevel           = cas_get_msglevel,
        .set_msglevel           = cas_set_msglevel,
        .get_regs_len           = cas_get_regs_len,
        .get_regs               = cas_get_regs,
        .get_sset_count         = cas_get_sset_count,
        .get_strings            = cas_get_strings,
        .get_ethtool_stats      = cas_get_ethtool_stats,
};

static int cas_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        struct cas *cp = netdev_priv(dev);
        struct mii_ioctl_data *data = if_mii(ifr);
        unsigned long flags;
        int rc = -EOPNOTSUPP;

        /* Hold the PM mutex while doing ioctl's or we may collide
         * with open/close and power management and oops.
         */
        mutex_lock(&cp->pm_mutex);
        switch (cmd) {
        case SIOCGMIIPHY:               /* Get address of MII PHY in use. */
                data->phy_id = cp->phy_addr;
                /* Fallthrough... */

        case SIOCGMIIREG:               /* Read MII PHY register. */
                spin_lock_irqsave(&cp->lock, flags);
                cas_mif_poll(cp, 0);
                data->val_out = cas_phy_read(cp, data->reg_num & 0x1f);
                cas_mif_poll(cp, 1);
                spin_unlock_irqrestore(&cp->lock, flags);
                rc = 0;
                break;

        case SIOCSMIIREG:               /* Write MII PHY register. */
                if (!capable(CAP_NET_ADMIN)) {
                        rc = -EPERM;
                        break;
                }
                spin_lock_irqsave(&cp->lock, flags);
                cas_mif_poll(cp, 0);
                rc = cas_phy_write(cp, data->reg_num & 0x1f, data->val_in);
                cas_mif_poll(cp, 1);
                spin_unlock_irqrestore(&cp->lock, flags);
                break;
        default:
                break;
        };

        mutex_unlock(&cp->pm_mutex);
        return rc;
}

/* When this chip sits underneath an Intel 31154 bridge, it is the
 * only subordinate device and we can tweak the bridge settings to
 * reflect that fact.
 */
static void __devinit cas_program_bridge(struct pci_dev *cas_pdev)
{
        struct pci_dev *pdev = cas_pdev->bus->self;
        u32 val;

        if (!pdev)
                return;

        if (pdev->vendor != 0x8086 || pdev->device != 0x537c)
                return;

        /* Clear bit 10 (Bus Parking Control) in the Secondary
         * Arbiter Control/Status Register which lives at offset
         * 0x41.  Using a 32-bit word read/modify/write at 0x40
         * is much simpler so that's how we do this.
         */
        pci_read_config_dword(pdev, 0x40, &val);
        val &= ~0x00040000;
        pci_write_config_dword(pdev, 0x40, val);

        /* Max out the Multi-Transaction Timer settings since
         * Cassini is the only device present.
         *
         * The register is 16-bit and lives at 0x50.  When the
         * settings are enabled, it extends the GRANT# signal
         * for a requestor after a transaction is complete.  This
         * allows the next request to run without first needing
         * to negotiate the GRANT# signal back.
         *
         * Bits 12:10 define the grant duration:
         *
         *      1       --      16 clocks
         *      2       --      32 clocks
         *      3       --      64 clocks
         *      4       --      128 clocks
         *      5       --      256 clocks
         *
         * All other values are illegal.
         *
         * Bits 09:00 define which REQ/GNT signal pairs get the
         * GRANT# signal treatment.  We set them all.
         */
        pci_write_config_word(pdev, 0x50, (5 << 10) | 0x3ff);

        /* The Read Prefecth Policy register is 16-bit and sits at
         * offset 0x52.  It enables a "smart" pre-fetch policy.  We
         * enable it and max out all of the settings since only one
         * device is sitting underneath and thus bandwidth sharing is
         * not an issue.
         *
         * The register has several 3 bit fields, which indicates a
         * multiplier applied to the base amount of prefetching the
         * chip would do.  These fields are at:
         *
         *      15:13   ---     ReRead Primary Bus
         *      12:10   ---     FirstRead Primary Bus
         *      09:07   ---     ReRead Secondary Bus
         *      06:04   ---     FirstRead Secondary Bus
         *
         * Bits 03:00 control which REQ/GNT pairs the prefetch settings
         * get enabled on.  Bit 3 is a grouped enabler which controls
         * all of the REQ/GNT pairs from [8:3].  Bits 2 to 0 control
         * the individual REQ/GNT pairs [2:0].
         */
        pci_write_config_word(pdev, 0x52,
                              (0x7 << 13) |
                              (0x7 << 10) |
                              (0x7 <<  7) |
                              (0x7 <<  4) |
                              (0xf <<  0));

        /* Force cacheline size to 0x8 */
        pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE, 0x08);

        /* Force latency timer to maximum setting so Cassini can
         * sit on the bus as long as it likes.
         */
        pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0xff);
}

static int __devinit cas_init_one(struct pci_dev *pdev,
                                  const struct pci_device_id *ent)
{
        static int cas_version_printed = 0;
        unsigned long casreg_len;
        struct net_device *dev;
        struct cas *cp;
        int i, err, pci_using_dac;
        u16 pci_cmd;
        u8 orig_cacheline_size = 0, cas_cacheline_size = 0;
        DECLARE_MAC_BUF(mac);

        if (cas_version_printed++ == 0)
                printk(KERN_INFO "%s", version);

        err = pci_enable_device(pdev);
        if (err) {
                dev_err(&pdev->dev, "Cannot enable PCI device, aborting.\n");
                return err;
        }

        if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
                dev_err(&pdev->dev, "Cannot find proper PCI device "
                       "base address, aborting.\n");
                err = -ENODEV;
                goto err_out_disable_pdev;
        }

        dev = alloc_etherdev(sizeof(*cp));
        if (!dev) {
                dev_err(&pdev->dev, "Etherdev alloc failed, aborting.\n");
                err = -ENOMEM;
                goto err_out_disable_pdev;
        }
        SET_NETDEV_DEV(dev, &pdev->dev);

        err = pci_request_regions(pdev, dev->name);
        if (err) {
                dev_err(&pdev->dev, "Cannot obtain PCI resources, aborting.\n");
                goto err_out_free_netdev;
        }
        pci_set_master(pdev);

        /* we must always turn on parity response or else parity
         * doesn't get generated properly. disable SERR/PERR as well.
         * in addition, we want to turn MWI on.
         */
        pci_read_config_word(pdev, PCI_COMMAND, &pci_cmd);
        pci_cmd &= ~PCI_COMMAND_SERR;
        pci_cmd |= PCI_COMMAND_PARITY;
        pci_write_config_word(pdev, PCI_COMMAND, pci_cmd);
        if (pci_try_set_mwi(pdev))
                printk(KERN_WARNING PFX "Could not enable MWI for %s\n",
                       pci_name(pdev));

        cas_program_bridge(pdev);

        /*
         * On some architectures, the default cache line size set
         * by pci_try_set_mwi reduces perforamnce.  We have to increase
         * it for this case.  To start, we'll print some configuration
         * data.
         */
#if 1
        pci_read_config_byte(pdev, PCI_CACHE_LINE_SIZE,
                             &orig_cacheline_size);
        if (orig_cacheline_size < CAS_PREF_CACHELINE_SIZE) {
                cas_cacheline_size =
                        (CAS_PREF_CACHELINE_SIZE < SMP_CACHE_BYTES) ?
                        CAS_PREF_CACHELINE_SIZE : SMP_CACHE_BYTES;
                if (pci_write_config_byte(pdev,
                                          PCI_CACHE_LINE_SIZE,
                                          cas_cacheline_size)) {
                        dev_err(&pdev->dev, "Could not set PCI cache "
                               "line size\n");
                        goto err_write_cacheline;
                }
        }
#endif


        /* Configure DMA attributes. */
        if (!pci_set_dma_mask(pdev, DMA_64BIT_MASK)) {
                pci_using_dac = 1;
                err = pci_set_consistent_dma_mask(pdev,
                                                  DMA_64BIT_MASK);
                if (err < 0) {
                        dev_err(&pdev->dev, "Unable to obtain 64-bit DMA "
                               "for consistent allocations\n");
                        goto err_out_free_res;
                }

        } else {
                err = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
                if (err) {
                        dev_err(&pdev->dev, "No usable DMA configuration, "
                               "aborting.\n");
                        goto err_out_free_res;
                }
                pci_using_dac = 0;
        }

        casreg_len = pci_resource_len(pdev, 0);

        cp = netdev_priv(dev);
        cp->pdev = pdev;
#if 1
        /* A value of 0 indicates we never explicitly set it */
        cp->orig_cacheline_size = cas_cacheline_size ? orig_cacheline_size: 0;
#endif
        cp->dev = dev;
        cp->msg_enable = (cassini_debug < 0) ? CAS_DEF_MSG_ENABLE :
          cassini_debug;

        cp->link_transition = LINK_TRANSITION_UNKNOWN;
        cp->link_transition_jiffies_valid = 0;

        spin_lock_init(&cp->lock);
        spin_lock_init(&cp->rx_inuse_lock);
        spin_lock_init(&cp->rx_spare_lock);
        for (i = 0; i < N_TX_RINGS; i++) {
                spin_lock_init(&cp->stat_lock[i]);
                spin_lock_init(&cp->tx_lock[i]);
        }
        spin_lock_init(&cp->stat_lock[N_TX_RINGS]);
        mutex_init(&cp->pm_mutex);

        init_timer(&cp->link_timer);
        cp->link_timer.function = cas_link_timer;
        cp->link_timer.data = (unsigned long) cp;

#if 1
        /* Just in case the implementation of atomic operations
         * change so that an explicit initialization is necessary.
         */
        atomic_set(&cp->reset_task_pending, 0);
        atomic_set(&cp->reset_task_pending_all, 0);
        atomic_set(&cp->reset_task_pending_spare, 0);
        atomic_set(&cp->reset_task_pending_mtu, 0);
#endif
        INIT_WORK(&cp->reset_task, cas_reset_task);

        /* Default link parameters */
        if (link_mode >= 0 && link_mode <= 6)
                cp->link_cntl = link_modes[link_mode];
        else
                cp->link_cntl = BMCR_ANENABLE;
        cp->lstate = link_down;
        cp->link_transition = LINK_TRANSITION_LINK_DOWN;
        netif_carrier_off(cp->dev);
        cp->timer_ticks = 0;

        /* give us access to cassini registers */
        cp->regs = pci_iomap(pdev, 0, casreg_len);
        if (!cp->regs) {
                dev_err(&pdev->dev, "Cannot map device registers, aborting.\n");
                goto err_out_free_res;
        }
        cp->casreg_len = casreg_len;

        pci_save_state(pdev);
        cas_check_pci_invariants(cp);
        cas_hard_reset(cp);
        cas_reset(cp, 0);
        if (cas_check_invariants(cp))
                goto err_out_iounmap;

        cp->init_block = (struct cas_init_block *)
                pci_alloc_consistent(pdev, sizeof(struct cas_init_block),
                                     &cp->block_dvma);
        if (!cp->init_block) {
                dev_err(&pdev->dev, "Cannot allocate init block, aborting.\n");
                goto err_out_iounmap;
        }

        for (i = 0; i < N_TX_RINGS; i++)
                cp->init_txds[i] = cp->init_block->txds[i];

        for (i = 0; i < N_RX_DESC_RINGS; i++)
                cp->init_rxds[i] = cp->init_block->rxds[i];

        for (i = 0; i < N_RX_COMP_RINGS; i++)
                cp->init_rxcs[i] = cp->init_block->rxcs[i];

        for (i = 0; i < N_RX_FLOWS; i++)
                skb_queue_head_init(&cp->rx_flows[i]);

        dev->open = cas_open;
        dev->stop = cas_close;
        dev->hard_start_xmit = cas_start_xmit;
        dev->get_stats = cas_get_stats;
        dev->set_multicast_list = cas_set_multicast;
        dev->do_ioctl = cas_ioctl;
        dev->ethtool_ops = &cas_ethtool_ops;
        dev->tx_timeout = cas_tx_timeout;
        dev->watchdog_timeo = CAS_TX_TIMEOUT;
        dev->change_mtu = cas_change_mtu;
#ifdef USE_NAPI
        netif_napi_add(dev, &cp->napi, cas_poll, 64);
#endif
#ifdef CONFIG_NET_POLL_CONTROLLER
        dev->poll_controller = cas_netpoll;
#endif
        dev->irq = pdev->irq;
        dev->dma = 0;

        /* Cassini features. */
        if ((cp->cas_flags & CAS_FLAG_NO_HW_CSUM) == 0)
                dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;

        if (pci_using_dac)
                dev->features |= NETIF_F_HIGHDMA;

        if (register_netdev(dev)) {
                dev_err(&pdev->dev, "Cannot register net device, aborting.\n");
                goto err_out_free_consistent;
        }

        i = readl(cp->regs + REG_BIM_CFG);
        printk(KERN_INFO "%s: Sun Cassini%s (%sbit/%sMHz PCI/%s) "
               "Ethernet[%d] %s\n",  dev->name,
               (cp->cas_flags & CAS_FLAG_REG_PLUS) ? "+" : "",
               (i & BIM_CFG_32BIT) ? "32" : "64",
               (i & BIM_CFG_66MHZ) ? "66" : "33",
               (cp->phy_type == CAS_PHY_SERDES) ? "Fi" : "Cu", pdev->irq,
               print_mac(mac, dev->dev_addr));

        pci_set_drvdata(pdev, dev);
        cp->hw_running = 1;
        cas_entropy_reset(cp);
        cas_phy_init(cp);
        cas_begin_auto_negotiation(cp, NULL);
        return 0;

err_out_free_consistent:
        pci_free_consistent(pdev, sizeof(struct cas_init_block),
                            cp->init_block, cp->block_dvma);

err_out_iounmap:
        mutex_lock(&cp->pm_mutex);
        if (cp->hw_running)
                cas_shutdown(cp);
        mutex_unlock(&cp->pm_mutex);

        pci_iounmap(pdev, cp->regs);


err_out_free_res:
        pci_release_regions(pdev);

err_write_cacheline:
        /* Try to restore it in case the error occured after we
         * set it.
         */
        pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE, orig_cacheline_size);

err_out_free_netdev:
        free_netdev(dev);

err_out_disable_pdev:
        pci_disable_device(pdev);
        pci_set_drvdata(pdev, NULL);
        return -ENODEV;
}

static void __devexit cas_remove_one(struct pci_dev *pdev)
{
        struct net_device *dev = pci_get_drvdata(pdev);
        struct cas *cp;
        if (!dev)
                return;

        cp = netdev_priv(dev);
        unregister_netdev(dev);

        mutex_lock(&cp->pm_mutex);
        flush_scheduled_work();
        if (cp->hw_running)
                cas_shutdown(cp);
        mutex_unlock(&cp->pm_mutex);

#if 1
        if (cp->orig_cacheline_size) {
                /* Restore the cache line size if we had modified
                 * it.
                 */
                pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE,
                                      cp->orig_cacheline_size);
        }
#endif
        pci_free_consistent(pdev, sizeof(struct cas_init_block),
                            cp->init_block, cp->block_dvma);
        pci_iounmap(pdev, cp->regs);
        free_netdev(dev);
        pci_release_regions(pdev);
        pci_disable_device(pdev);
        pci_set_drvdata(pdev, NULL);
}

#ifdef CONFIG_PM
static int cas_suspend(struct pci_dev *pdev, pm_message_t state)
{
        struct net_device *dev = pci_get_drvdata(pdev);
        struct cas *cp = netdev_priv(dev);
        unsigned long flags;

        mutex_lock(&cp->pm_mutex);

        /* If the driver is opened, we stop the DMA */
        if (cp->opened) {
                netif_device_detach(dev);

                cas_lock_all_save(cp, flags);

                /* We can set the second arg of cas_reset to 0
                 * because on resume, we'll call cas_init_hw with
                 * its second arg set so that autonegotiation is
                 * restarted.
                 */
                cas_reset(cp, 0);
                cas_clean_rings(cp);
                cas_unlock_all_restore(cp, flags);
        }

        if (cp->hw_running)
                cas_shutdown(cp);
        mutex_unlock(&cp->pm_mutex);

        return 0;
}

static int cas_resume(struct pci_dev *pdev)
{
        struct net_device *dev = pci_get_drvdata(pdev);
        struct cas *cp = netdev_priv(dev);

        printk(KERN_INFO "%s: resuming\n", dev->name);

        mutex_lock(&cp->pm_mutex);
        cas_hard_reset(cp);
        if (cp->opened) {
                unsigned long flags;
                cas_lock_all_save(cp, flags);
                cas_reset(cp, 0);
                cp->hw_running = 1;
                cas_clean_rings(cp);
                cas_init_hw(cp, 1);
                cas_unlock_all_restore(cp, flags);

                netif_device_attach(dev);
        }
        mutex_unlock(&cp->pm_mutex);
        return 0;
}
#endif /* CONFIG_PM */

static struct pci_driver cas_driver = {
        .name           = DRV_MODULE_NAME,
        .id_table       = cas_pci_tbl,
        .probe          = cas_init_one,
        .remove         = __devexit_p(cas_remove_one),
#ifdef CONFIG_PM
        .suspend        = cas_suspend,
        .resume         = cas_resume
#endif
};

static int __init cas_init(void)
{
        if (linkdown_timeout > 0)
                link_transition_timeout = linkdown_timeout * HZ;
        else
                link_transition_timeout = 0;

        return pci_register_driver(&cas_driver);
}

static void __exit cas_cleanup(void)
{
        pci_unregister_driver(&cas_driver);
}

module_init(cas_init);
module_exit(cas_cleanup);