// SPDX-License-Identifier: GPL-2.0
/* $Id: sungem.c,v 1.44.2.22 2002/03/13 01:18:12 davem Exp $
 * sungem.c: Sun GEM ethernet driver.
 *
 * Copyright (C) 2000, 2001, 2002, 2003 David S. Miller (davem@redhat.com)
 *
 * Support for Apple GMAC and assorted PHYs, WOL, Power Management
 * (C) 2001,2002,2003 Benjamin Herrenscmidt (benh@kernel.crashing.org)
 * (C) 2004,2005 Benjamin Herrenscmidt, IBM Corp.
 *
 * NAPI and NETPOLL support
 * (C) 2004 by Eric Lemoine (eric.lemoine@gmail.com)
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/crc32.h>
#include <linux/random.h>
#include <linux/workqueue.h>
#include <linux/if_vlan.h>
#include <linux/bitops.h>
#include <linux/mm.h>
#include <linux/gfp.h>

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

#ifdef CONFIG_SPARC
#include <asm/idprom.h>
#include <asm/prom.h>
#endif

#ifdef CONFIG_PPC_PMAC
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/pmac_feature.h>
#endif

#include <linux/sungem_phy.h>
#include "sungem.h"

#define STRIP_FCS

#define DEFAULT_MSG     (NETIF_MSG_DRV          | \
                         NETIF_MSG_PROBE        | \
                         NETIF_MSG_LINK)

#define ADVERTISE_MASK  (SUPPORTED_10baseT_Half | SUPPORTED_10baseT_Full | \
                         SUPPORTED_100baseT_Half | SUPPORTED_100baseT_Full | \
                         SUPPORTED_1000baseT_Half | SUPPORTED_1000baseT_Full | \
                         SUPPORTED_Pause | SUPPORTED_Autoneg)

#define DRV_NAME        "sungem"
#define DRV_VERSION     "1.0"
#define DRV_AUTHOR      "David S. Miller <davem@redhat.com>"

static char version[] =
        DRV_NAME ".c:v" DRV_VERSION " " DRV_AUTHOR "\n";

MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION("Sun GEM Gbit ethernet driver");
MODULE_LICENSE("GPL");

#define GEM_MODULE_NAME "gem"

static const struct pci_device_id gem_pci_tbl[] = {
        { PCI_VENDOR_ID_SUN, PCI_DEVICE_ID_SUN_GEM,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },

        /* These models only differ from the original GEM in
         * that their tx/rx fifos are of a different size and
         * they only support 10/100 speeds. -DaveM
         *
         * Apple's GMAC does support gigabit on machines with
         * the BCM54xx PHYs. -BenH
         */
        { PCI_VENDOR_ID_SUN, PCI_DEVICE_ID_SUN_RIO_GEM,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
        { PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_GMAC,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
        { PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_GMACP,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
        { PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_GMAC2,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
        { PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_K2_GMAC,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
        { PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_SH_SUNGEM,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
        { PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_IPID2_GMAC,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
        {0, }
};

MODULE_DEVICE_TABLE(pci, gem_pci_tbl);

static u16 __sungem_phy_read(struct gem *gp, int phy_addr, int reg)
{
        u32 cmd;
        int limit = 10000;

        cmd  = (1 << 30);
        cmd |= (2 << 28);
        cmd |= (phy_addr << 23) & MIF_FRAME_PHYAD;
        cmd |= (reg << 18) & MIF_FRAME_REGAD;
        cmd |= (MIF_FRAME_TAMSB);
        writel(cmd, gp->regs + MIF_FRAME);

        while (--limit) {
                cmd = readl(gp->regs + MIF_FRAME);
                if (cmd & MIF_FRAME_TALSB)
                        break;

                udelay(10);
        }

        if (!limit)
                cmd = 0xffff;

        return cmd & MIF_FRAME_DATA;
}

static inline int _sungem_phy_read(struct net_device *dev, int mii_id, int reg)
{
        struct gem *gp = netdev_priv(dev);
        return __sungem_phy_read(gp, mii_id, reg);
}

static inline u16 sungem_phy_read(struct gem *gp, int reg)
{
        return __sungem_phy_read(gp, gp->mii_phy_addr, reg);
}

static void __sungem_phy_write(struct gem *gp, int phy_addr, int reg, u16 val)
{
        u32 cmd;
        int limit = 10000;

        cmd  = (1 << 30);
        cmd |= (1 << 28);
        cmd |= (phy_addr << 23) & MIF_FRAME_PHYAD;
        cmd |= (reg << 18) & MIF_FRAME_REGAD;
        cmd |= (MIF_FRAME_TAMSB);
        cmd |= (val & MIF_FRAME_DATA);
        writel(cmd, gp->regs + MIF_FRAME);

        while (limit--) {
                cmd = readl(gp->regs + MIF_FRAME);
                if (cmd & MIF_FRAME_TALSB)
                        break;

                udelay(10);
        }
}

static inline void _sungem_phy_write(struct net_device *dev, int mii_id, int reg, int val)
{
        struct gem *gp = netdev_priv(dev);
        __sungem_phy_write(gp, mii_id, reg, val & 0xffff);
}

static inline void sungem_phy_write(struct gem *gp, int reg, u16 val)
{
        __sungem_phy_write(gp, gp->mii_phy_addr, reg, val);
}

static inline void gem_enable_ints(struct gem *gp)
{
        /* Enable all interrupts but TXDONE */
        writel(GREG_STAT_TXDONE, gp->regs + GREG_IMASK);
}

static inline void gem_disable_ints(struct gem *gp)
{
        /* Disable all interrupts, including TXDONE */
        writel(GREG_STAT_NAPI | GREG_STAT_TXDONE, gp->regs + GREG_IMASK);
        (void)readl(gp->regs + GREG_IMASK); /* write posting */
}

static void gem_get_cell(struct gem *gp)
{
        BUG_ON(gp->cell_enabled < 0);
        gp->cell_enabled++;
#ifdef CONFIG_PPC_PMAC
        if (gp->cell_enabled == 1) {
                mb();
                pmac_call_feature(PMAC_FTR_GMAC_ENABLE, gp->of_node, 0, 1);
                udelay(10);
        }
#endif /* CONFIG_PPC_PMAC */
}

/* Turn off the chip's clock */
static void gem_put_cell(struct gem *gp)
{
        BUG_ON(gp->cell_enabled <= 0);
        gp->cell_enabled--;
#ifdef CONFIG_PPC_PMAC
        if (gp->cell_enabled == 0) {
                mb();
                pmac_call_feature(PMAC_FTR_GMAC_ENABLE, gp->of_node, 0, 0);
                udelay(10);
        }
#endif /* CONFIG_PPC_PMAC */
}

static inline void gem_netif_stop(struct gem *gp)
{
        netif_trans_update(gp->dev);    /* prevent tx timeout */
        napi_disable(&gp->napi);
        netif_tx_disable(gp->dev);
}

static inline void gem_netif_start(struct gem *gp)
{
        /* NOTE: unconditional netif_wake_queue is only
         * appropriate so long as all callers are assured to
         * have free tx slots.
         */
        netif_wake_queue(gp->dev);
        napi_enable(&gp->napi);
}

static void gem_schedule_reset(struct gem *gp)
{
        gp->reset_task_pending = 1;
        schedule_work(&gp->reset_task);
}

static void gem_handle_mif_event(struct gem *gp, u32 reg_val, u32 changed_bits)
{
        if (netif_msg_intr(gp))
                printk(KERN_DEBUG "%s: mif interrupt\n", gp->dev->name);
}

static int gem_pcs_interrupt(struct net_device *dev, struct gem *gp, u32 gem_status)
{
        u32 pcs_istat = readl(gp->regs + PCS_ISTAT);
        u32 pcs_miistat;

        if (netif_msg_intr(gp))
                printk(KERN_DEBUG "%s: pcs interrupt, pcs_istat: 0x%x\n",
                        gp->dev->name, pcs_istat);

        if (!(pcs_istat & PCS_ISTAT_LSC)) {
                netdev_err(dev, "PCS irq but no link status change???\n");
                return 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.
         */
        pcs_miistat = readl(gp->regs + PCS_MIISTAT);
        if (!(pcs_miistat & PCS_MIISTAT_LS))
                pcs_miistat |=
                        (readl(gp->regs + PCS_MIISTAT) &
                         PCS_MIISTAT_LS);

        if (pcs_miistat & PCS_MIISTAT_ANC) {
                /* The remote-fault indication is only valid
                 * when autoneg has completed.
                 */
                if (pcs_miistat & PCS_MIISTAT_RF)
                        netdev_info(dev, "PCS AutoNEG complete, RemoteFault\n");
                else
                        netdev_info(dev, "PCS AutoNEG complete\n");
        }

        if (pcs_miistat & PCS_MIISTAT_LS) {
                netdev_info(dev, "PCS link is now up\n");
                netif_carrier_on(gp->dev);
        } else {
                netdev_info(dev, "PCS link is now down\n");
                netif_carrier_off(gp->dev);
                /* If this happens and the link timer is not running,
                 * reset so we re-negotiate.
                 */
                if (!timer_pending(&gp->link_timer))
                        return 1;
        }

        return 0;
}

static int gem_txmac_interrupt(struct net_device *dev, struct gem *gp, u32 gem_status)
{
        u32 txmac_stat = readl(gp->regs + MAC_TXSTAT);

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

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

        if (txmac_stat & MAC_TXSTAT_URUN) {
                netdev_err(dev, "TX MAC xmit underrun\n");
                dev->stats.tx_fifo_errors++;
        }

        if (txmac_stat & MAC_TXSTAT_MPE) {
                netdev_err(dev, "TX MAC max packet size error\n");
                dev->stats.tx_errors++;
        }

        /* The rest are all cases of one of the 16-bit TX
         * counters expiring.
         */
        if (txmac_stat & MAC_TXSTAT_NCE)
                dev->stats.collisions += 0x10000;

        if (txmac_stat & MAC_TXSTAT_ECE) {
                dev->stats.tx_aborted_errors += 0x10000;
                dev->stats.collisions += 0x10000;
        }

        if (txmac_stat & MAC_TXSTAT_LCE) {
                dev->stats.tx_aborted_errors += 0x10000;
                dev->stats.collisions += 0x10000;
        }

        /* We do not keep track of MAC_TXSTAT_FCE and
         * MAC_TXSTAT_PCE events.
         */
        return 0;
}

/* When we get a RX fifo overflow, the RX unit in GEM 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 gem_rxmac_reset(struct gem *gp)
{
        struct net_device *dev = gp->dev;
        int limit, i;
        u64 desc_dma;
        u32 val;

        /* First, reset & disable MAC RX. */
        writel(MAC_RXRST_CMD, gp->regs + MAC_RXRST);
        for (limit = 0; limit < 5000; limit++) {
                if (!(readl(gp->regs + MAC_RXRST) & MAC_RXRST_CMD))
                        break;
                udelay(10);
        }
        if (limit == 5000) {
                netdev_err(dev, "RX MAC will not reset, resetting whole chip\n");
                return 1;
        }

        writel(gp->mac_rx_cfg & ~MAC_RXCFG_ENAB,
               gp->regs + MAC_RXCFG);
        for (limit = 0; limit < 5000; limit++) {
                if (!(readl(gp->regs + MAC_RXCFG) & MAC_RXCFG_ENAB))
                        break;
                udelay(10);
        }
        if (limit == 5000) {
                netdev_err(dev, "RX MAC will not disable, resetting whole chip\n");
                return 1;
        }

        /* Second, disable RX DMA. */
        writel(0, gp->regs + RXDMA_CFG);
        for (limit = 0; limit < 5000; limit++) {
                if (!(readl(gp->regs + RXDMA_CFG) & RXDMA_CFG_ENABLE))
                        break;
                udelay(10);
        }
        if (limit == 5000) {
                netdev_err(dev, "RX DMA will not disable, resetting whole chip\n");
                return 1;
        }

        mdelay(5);

        /* Execute RX reset command. */
        writel(gp->swrst_base | GREG_SWRST_RXRST,
               gp->regs + GREG_SWRST);
        for (limit = 0; limit < 5000; limit++) {
                if (!(readl(gp->regs + GREG_SWRST) & GREG_SWRST_RXRST))
                        break;
                udelay(10);
        }
        if (limit == 5000) {
                netdev_err(dev, "RX reset command will not execute, resetting whole chip\n");
                return 1;
        }

        /* Refresh the RX ring. */
        for (i = 0; i < RX_RING_SIZE; i++) {
                struct gem_rxd *rxd = &gp->init_block->rxd[i];

                if (gp->rx_skbs[i] == NULL) {
                        netdev_err(dev, "Parts of RX ring empty, resetting whole chip\n");
                        return 1;
                }

                rxd->status_word = cpu_to_le64(RXDCTRL_FRESH(gp));
        }
        gp->rx_new = gp->rx_old = 0;

        /* Now we must reprogram the rest of RX unit. */
        desc_dma = (u64) gp->gblock_dvma;
        desc_dma += (INIT_BLOCK_TX_RING_SIZE * sizeof(struct gem_txd));
        writel(desc_dma >> 32, gp->regs + RXDMA_DBHI);
        writel(desc_dma & 0xffffffff, gp->regs + RXDMA_DBLOW);
        writel(RX_RING_SIZE - 4, gp->regs + RXDMA_KICK);
        val = (RXDMA_CFG_BASE | (RX_OFFSET << 10) |
               (ETH_HLEN << 13) | RXDMA_CFG_FTHRESH_128);
        writel(val, gp->regs + RXDMA_CFG);
        if (readl(gp->regs + GREG_BIFCFG) & GREG_BIFCFG_M66EN)
                writel(((5 & RXDMA_BLANK_IPKTS) |
                        ((8 << 12) & RXDMA_BLANK_ITIME)),
                       gp->regs + RXDMA_BLANK);
        else
                writel(((5 & RXDMA_BLANK_IPKTS) |
                        ((4 << 12) & RXDMA_BLANK_ITIME)),
                       gp->regs + RXDMA_BLANK);
        val  = (((gp->rx_pause_off / 64) << 0) & RXDMA_PTHRESH_OFF);
        val |= (((gp->rx_pause_on / 64) << 12) & RXDMA_PTHRESH_ON);
        writel(val, gp->regs + RXDMA_PTHRESH);
        val = readl(gp->regs + RXDMA_CFG);
        writel(val | RXDMA_CFG_ENABLE, gp->regs + RXDMA_CFG);
        writel(MAC_RXSTAT_RCV, gp->regs + MAC_RXMASK);
        val = readl(gp->regs + MAC_RXCFG);
        writel(val | MAC_RXCFG_ENAB, gp->regs + MAC_RXCFG);

        return 0;
}

static int gem_rxmac_interrupt(struct net_device *dev, struct gem *gp, u32 gem_status)
{
        u32 rxmac_stat = readl(gp->regs + MAC_RXSTAT);
        int ret = 0;

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

        if (rxmac_stat & MAC_RXSTAT_OFLW) {
                u32 smac = readl(gp->regs + MAC_SMACHINE);

                netdev_err(dev, "RX MAC fifo overflow smac[%08x]\n", smac);
                dev->stats.rx_over_errors++;
                dev->stats.rx_fifo_errors++;

                ret = gem_rxmac_reset(gp);
        }

        if (rxmac_stat & MAC_RXSTAT_ACE)
                dev->stats.rx_frame_errors += 0x10000;

        if (rxmac_stat & MAC_RXSTAT_CCE)
                dev->stats.rx_crc_errors += 0x10000;

        if (rxmac_stat & MAC_RXSTAT_LCE)
                dev->stats.rx_length_errors += 0x10000;

        /* We do not track MAC_RXSTAT_FCE and MAC_RXSTAT_VCE
         * events.
         */
        return ret;
}

static int gem_mac_interrupt(struct net_device *dev, struct gem *gp, u32 gem_status)
{
        u32 mac_cstat = readl(gp->regs + MAC_CSTAT);

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

        /* 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 (mac_cstat & MAC_CSTAT_PS)
                gp->pause_entered++;

        if (mac_cstat & MAC_CSTAT_PRCV)
                gp->pause_last_time_recvd = (mac_cstat >> 16);

        return 0;
}

static int gem_mif_interrupt(struct net_device *dev, struct gem *gp, u32 gem_status)
{
        u32 mif_status = readl(gp->regs + MIF_STATUS);
        u32 reg_val, changed_bits;

        reg_val = (mif_status & MIF_STATUS_DATA) >> 16;
        changed_bits = (mif_status & MIF_STATUS_STAT);

        gem_handle_mif_event(gp, reg_val, changed_bits);

        return 0;
}

static int gem_pci_interrupt(struct net_device *dev, struct gem *gp, u32 gem_status)
{
        u32 pci_estat = readl(gp->regs + GREG_PCIESTAT);

        if (gp->pdev->vendor == PCI_VENDOR_ID_SUN &&
            gp->pdev->device == PCI_DEVICE_ID_SUN_GEM) {
                netdev_err(dev, "PCI error [%04x]", pci_estat);

                if (pci_estat & GREG_PCIESTAT_BADACK)
                        pr_cont(" <No ACK64# during ABS64 cycle>");
                if (pci_estat & GREG_PCIESTAT_DTRTO)
                        pr_cont(" <Delayed transaction timeout>");
                if (pci_estat & GREG_PCIESTAT_OTHER)
                        pr_cont(" <other>");
                pr_cont("\n");
        } else {
                pci_estat |= GREG_PCIESTAT_OTHER;
                netdev_err(dev, "PCI error\n");
        }

        if (pci_estat & GREG_PCIESTAT_OTHER) {
                int pci_errs;

                /* Interrogate PCI config space for the
                 * true cause.
                 */
                pci_errs = pci_status_get_and_clear_errors(gp->pdev);
                netdev_err(dev, "PCI status errors[%04x]\n", pci_errs);
                if (pci_errs & PCI_STATUS_PARITY)
                        netdev_err(dev, "PCI parity error detected\n");
                if (pci_errs & PCI_STATUS_SIG_TARGET_ABORT)
                        netdev_err(dev, "PCI target abort\n");
                if (pci_errs & PCI_STATUS_REC_TARGET_ABORT)
                        netdev_err(dev, "PCI master acks target abort\n");
                if (pci_errs & PCI_STATUS_REC_MASTER_ABORT)
                        netdev_err(dev, "PCI master abort\n");
                if (pci_errs & PCI_STATUS_SIG_SYSTEM_ERROR)
                        netdev_err(dev, "PCI system error SERR#\n");
                if (pci_errs & PCI_STATUS_DETECTED_PARITY)
                        netdev_err(dev, "PCI parity error\n");
        }

        /* 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 gem_abnormal_irq(struct net_device *dev, struct gem *gp, u32 gem_status)
{
        if (gem_status & GREG_STAT_RXNOBUF) {
                /* Frame arrived, no free RX buffers available. */
                if (netif_msg_rx_err(gp))
                        printk(KERN_DEBUG "%s: no buffer for rx frame\n",
                                gp->dev->name);
                dev->stats.rx_dropped++;
        }

        if (gem_status & GREG_STAT_RXTAGERR) {
                /* corrupt RX tag framing */
                if (netif_msg_rx_err(gp))
                        printk(KERN_DEBUG "%s: corrupt rx tag framing\n",
                                gp->dev->name);
                dev->stats.rx_errors++;

                return 1;
        }

        if (gem_status & GREG_STAT_PCS) {
                if (gem_pcs_interrupt(dev, gp, gem_status))
                        return 1;
        }

        if (gem_status & GREG_STAT_TXMAC) {
                if (gem_txmac_interrupt(dev, gp, gem_status))
                        return 1;
        }

        if (gem_status & GREG_STAT_RXMAC) {
                if (gem_rxmac_interrupt(dev, gp, gem_status))
                        return 1;
        }

        if (gem_status & GREG_STAT_MAC) {
                if (gem_mac_interrupt(dev, gp, gem_status))
                        return 1;
        }

        if (gem_status & GREG_STAT_MIF) {
                if (gem_mif_interrupt(dev, gp, gem_status))
                        return 1;
        }

        if (gem_status & GREG_STAT_PCIERR) {
                if (gem_pci_interrupt(dev, gp, gem_status))
                        return 1;
        }

        return 0;
}

static __inline__ void gem_tx(struct net_device *dev, struct gem *gp, u32 gem_status)
{
        int entry, limit;

        entry = gp->tx_old;
        limit = ((gem_status & GREG_STAT_TXNR) >> GREG_STAT_TXNR_SHIFT);
        while (entry != limit) {
                struct sk_buff *skb;
                struct gem_txd *txd;
                dma_addr_t dma_addr;
                u32 dma_len;
                int frag;

                if (netif_msg_tx_done(gp))
                        printk(KERN_DEBUG "%s: tx done, slot %d\n",
                                gp->dev->name, entry);
                skb = gp->tx_skbs[entry];
                if (skb_shinfo(skb)->nr_frags) {
                        int last = entry + skb_shinfo(skb)->nr_frags;
                        int walk = entry;
                        int incomplete = 0;

                        last &= (TX_RING_SIZE - 1);
                        for (;;) {
                                walk = NEXT_TX(walk);
                                if (walk == limit)
                                        incomplete = 1;
                                if (walk == last)
                                        break;
                        }
                        if (incomplete)
                                break;
                }
                gp->tx_skbs[entry] = NULL;
                dev->stats.tx_bytes += skb->len;

                for (frag = 0; frag <= skb_shinfo(skb)->nr_frags; frag++) {
                        txd = &gp->init_block->txd[entry];

                        dma_addr = le64_to_cpu(txd->buffer);
                        dma_len = le64_to_cpu(txd->control_word) & TXDCTRL_BUFSZ;

                        dma_unmap_page(&gp->pdev->dev, dma_addr, dma_len,
                                       DMA_TO_DEVICE);
                        entry = NEXT_TX(entry);
                }

                dev->stats.tx_packets++;
                dev_consume_skb_any(skb);
        }
        gp->tx_old = entry;

        /* Need to make the tx_old update visible to gem_start_xmit()
         * before checking for netif_queue_stopped().  Without the
         * memory barrier, there is a small possibility that gem_start_xmit()
         * will miss it and cause the queue to be stopped forever.
         */
        smp_mb();

        if (unlikely(netif_queue_stopped(dev) &&
                     TX_BUFFS_AVAIL(gp) > (MAX_SKB_FRAGS + 1))) {
                struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);

                __netif_tx_lock(txq, smp_processor_id());
                if (netif_queue_stopped(dev) &&
                    TX_BUFFS_AVAIL(gp) > (MAX_SKB_FRAGS + 1))
                        netif_wake_queue(dev);
                __netif_tx_unlock(txq);
        }
}

static __inline__ void gem_post_rxds(struct gem *gp, int limit)
{
        int cluster_start, curr, count, kick;

        cluster_start = curr = (gp->rx_new & ~(4 - 1));
        count = 0;
        kick = -1;
        dma_wmb();
        while (curr != limit) {
                curr = NEXT_RX(curr);
                if (++count == 4) {
                        struct gem_rxd *rxd =
                                &gp->init_block->rxd[cluster_start];
                        for (;;) {
                                rxd->status_word = cpu_to_le64(RXDCTRL_FRESH(gp));
                                rxd++;
                                cluster_start = NEXT_RX(cluster_start);
                                if (cluster_start == curr)
                                        break;
                        }
                        kick = curr;
                        count = 0;
                }
        }
        if (kick >= 0) {
                mb();
                writel(kick, gp->regs + RXDMA_KICK);
        }
}

#define ALIGNED_RX_SKB_ADDR(addr) \
        ((((unsigned long)(addr) + (64UL - 1UL)) & ~(64UL - 1UL)) - (unsigned long)(addr))
static __inline__ struct sk_buff *gem_alloc_skb(struct net_device *dev, int size,
                                                gfp_t gfp_flags)
{
        struct sk_buff *skb = alloc_skb(size + 64, gfp_flags);

        if (likely(skb)) {
                unsigned long offset = ALIGNED_RX_SKB_ADDR(skb->data);
                skb_reserve(skb, offset);
        }
        return skb;
}

static int gem_rx(struct gem *gp, int work_to_do)
{
        struct net_device *dev = gp->dev;
        int entry, drops, work_done = 0;
        u32 done;

        if (netif_msg_rx_status(gp))
                printk(KERN_DEBUG "%s: rx interrupt, done: %d, rx_new: %d\n",
                        gp->dev->name, readl(gp->regs + RXDMA_DONE), gp->rx_new);

        entry = gp->rx_new;
        drops = 0;
        done = readl(gp->regs + RXDMA_DONE);
        for (;;) {
                struct gem_rxd *rxd = &gp->init_block->rxd[entry];
                struct sk_buff *skb;
                u64 status = le64_to_cpu(rxd->status_word);
                dma_addr_t dma_addr;
                int len;

                if ((status & RXDCTRL_OWN) != 0)
                        break;

                if (work_done >= RX_RING_SIZE || work_done >= work_to_do)
                        break;

                /* When writing back RX descriptor, GEM writes status
                 * then buffer address, possibly in separate transactions.
                 * If we don't wait for the chip to write both, we could
                 * post a new buffer to this descriptor then have GEM spam
                 * on the buffer address.  We sync on the RX completion
                 * register to prevent this from happening.
                 */
                if (entry == done) {
                        done = readl(gp->regs + RXDMA_DONE);
                        if (entry == done)
                                break;
                }

                /* We can now account for the work we're about to do */
                work_done++;

                skb = gp->rx_skbs[entry];

                len = (status & RXDCTRL_BUFSZ) >> 16;
                if ((len < ETH_ZLEN) || (status & RXDCTRL_BAD)) {
                        dev->stats.rx_errors++;
                        if (len < ETH_ZLEN)
                                dev->stats.rx_length_errors++;
                        if (len & RXDCTRL_BAD)
                                dev->stats.rx_crc_errors++;

                        /* We'll just return it to GEM. */
                drop_it:
                        dev->stats.rx_dropped++;
                        goto next;
                }

                dma_addr = le64_to_cpu(rxd->buffer);
                if (len > RX_COPY_THRESHOLD) {
                        struct sk_buff *new_skb;

                        new_skb = gem_alloc_skb(dev, RX_BUF_ALLOC_SIZE(gp), GFP_ATOMIC);
                        if (new_skb == NULL) {
                                drops++;
                                goto drop_it;
                        }
                        dma_unmap_page(&gp->pdev->dev, dma_addr,
                                       RX_BUF_ALLOC_SIZE(gp), DMA_FROM_DEVICE);
                        gp->rx_skbs[entry] = new_skb;
                        skb_put(new_skb, (gp->rx_buf_sz + RX_OFFSET));
                        rxd->buffer = cpu_to_le64(dma_map_page(&gp->pdev->dev,
                                                               virt_to_page(new_skb->data),
                                                               offset_in_page(new_skb->data),
                                                               RX_BUF_ALLOC_SIZE(gp),
                                                               DMA_FROM_DEVICE));
                        skb_reserve(new_skb, RX_OFFSET);

                        /* Trim the original skb for the netif. */
                        skb_trim(skb, len);
                } else {
                        struct sk_buff *copy_skb = netdev_alloc_skb(dev, len + 2);

                        if (copy_skb == NULL) {
                                drops++;
                                goto drop_it;
                        }

                        skb_reserve(copy_skb, 2);
                        skb_put(copy_skb, len);
                        dma_sync_single_for_cpu(&gp->pdev->dev, dma_addr, len,
                                                DMA_FROM_DEVICE);
                        skb_copy_from_linear_data(skb, copy_skb->data, len);
                        dma_sync_single_for_device(&gp->pdev->dev, dma_addr,
                                                   len, DMA_FROM_DEVICE);

                        /* We'll reuse the original ring buffer. */
                        skb = copy_skb;
                }

                if (likely(dev->features & NETIF_F_RXCSUM)) {
                        __sum16 csum;

                        csum = (__force __sum16)htons((status & RXDCTRL_TCPCSUM) ^ 0xffff);
                        skb->csum = csum_unfold(csum);
                        skb->ip_summed = CHECKSUM_COMPLETE;
                }
                skb->protocol = eth_type_trans(skb, gp->dev);

                napi_gro_receive(&gp->napi, skb);

                dev->stats.rx_packets++;
                dev->stats.rx_bytes += len;

        next:
                entry = NEXT_RX(entry);
        }

        gem_post_rxds(gp, entry);

        gp->rx_new = entry;

        if (drops)
                netdev_info(gp->dev, "Memory squeeze, deferring packet\n");

        return work_done;
}

static int gem_poll(struct napi_struct *napi, int budget)
{
        struct gem *gp = container_of(napi, struct gem, napi);
        struct net_device *dev = gp->dev;
        int work_done;

        work_done = 0;
        do {
                /* Handle anomalies */
                if (unlikely(gp->status & GREG_STAT_ABNORMAL)) {
                        struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
                        int reset;

                        /* We run the abnormal interrupt handling code with
                         * the Tx lock. It only resets the Rx portion of the
                         * chip, but we need to guard it against DMA being
                         * restarted by the link poll timer
                         */
                        __netif_tx_lock(txq, smp_processor_id());
                        reset = gem_abnormal_irq(dev, gp, gp->status);
                        __netif_tx_unlock(txq);
                        if (reset) {
                                gem_schedule_reset(gp);
                                napi_complete(napi);
                                return work_done;
                        }
                }

                /* Run TX completion thread */
                gem_tx(dev, gp, gp->status);

                /* Run RX thread. We don't use any locking here,
                 * code willing to do bad things - like cleaning the
                 * rx ring - must call napi_disable(), which
                 * schedule_timeout()'s if polling is already disabled.
                 */
                work_done += gem_rx(gp, budget - work_done);

                if (work_done >= budget)
                        return work_done;

                gp->status = readl(gp->regs + GREG_STAT);
        } while (gp->status & GREG_STAT_NAPI);

        napi_complete_done(napi, work_done);
        gem_enable_ints(gp);

        return work_done;
}

static irqreturn_t gem_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct gem *gp = netdev_priv(dev);

        if (napi_schedule_prep(&gp->napi)) {
                u32 gem_status = readl(gp->regs + GREG_STAT);

                if (unlikely(gem_status == 0)) {
                        napi_enable(&gp->napi);
                        return IRQ_NONE;
                }
                if (netif_msg_intr(gp))
                        printk(KERN_DEBUG "%s: gem_interrupt() gem_status: 0x%x\n",
                               gp->dev->name, gem_status);

                gp->status = gem_status;
                gem_disable_ints(gp);
                __napi_schedule(&gp->napi);
        }

        /* If polling was disabled at the time we received that
         * interrupt, we may return IRQ_HANDLED here while we
         * should return IRQ_NONE. No big deal...
         */
        return IRQ_HANDLED;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void gem_poll_controller(struct net_device *dev)
{
        struct gem *gp = netdev_priv(dev);

        disable_irq(gp->pdev->irq);
        gem_interrupt(gp->pdev->irq, dev);
        enable_irq(gp->pdev->irq);
}
#endif

static void gem_tx_timeout(struct net_device *dev, unsigned int txqueue)
{
        struct gem *gp = netdev_priv(dev);

        netdev_err(dev, "transmit timed out, resetting\n");

        netdev_err(dev, "TX_STATE[%08x:%08x:%08x]\n",
                   readl(gp->regs + TXDMA_CFG),
                   readl(gp->regs + MAC_TXSTAT),
                   readl(gp->regs + MAC_TXCFG));
        netdev_err(dev, "RX_STATE[%08x:%08x:%08x]\n",
                   readl(gp->regs + RXDMA_CFG),
                   readl(gp->regs + MAC_RXSTAT),
                   readl(gp->regs + MAC_RXCFG));

        gem_schedule_reset(gp);
}

static __inline__ int gem_intme(int entry)
{
        /* Algorithm: IRQ every 1/2 of descriptors. */
        if (!(entry & ((TX_RING_SIZE>>1)-1)))
                return 1;

        return 0;
}

static netdev_tx_t gem_start_xmit(struct sk_buff *skb,
                                  struct net_device *dev)
{
        struct gem *gp = netdev_priv(dev);
        int entry;
        u64 ctrl;

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

                ctrl = (TXDCTRL_CENAB |
                        (csum_start_off << 15) |
                        (csum_stuff_off << 21));
        }

        if (unlikely(TX_BUFFS_AVAIL(gp) <= (skb_shinfo(skb)->nr_frags + 1))) {
                /* This is a hard error, log it. */
                if (!netif_queue_stopped(dev)) {
                        netif_stop_queue(dev);
                        netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
                }
                return NETDEV_TX_BUSY;
        }

        entry = gp->tx_new;
        gp->tx_skbs[entry] = skb;

        if (skb_shinfo(skb)->nr_frags == 0) {
                struct gem_txd *txd = &gp->init_block->txd[entry];
                dma_addr_t mapping;
                u32 len;

                len = skb->len;
                mapping = dma_map_page(&gp->pdev->dev,
                                       virt_to_page(skb->data),
                                       offset_in_page(skb->data),
                                       len, DMA_TO_DEVICE);
                ctrl |= TXDCTRL_SOF | TXDCTRL_EOF | len;
                if (gem_intme(entry))
                        ctrl |= TXDCTRL_INTME;
                txd->buffer = cpu_to_le64(mapping);
                dma_wmb();
                txd->control_word = cpu_to_le64(ctrl);
                entry = NEXT_TX(entry);
        } else {
                struct gem_txd *txd;
                u32 first_len;
                u64 intme;
                dma_addr_t first_mapping;
                int frag, first_entry = entry;

                intme = 0;
                if (gem_intme(entry))
                        intme |= TXDCTRL_INTME;

                /* We must give this initial chunk to the device last.
                 * Otherwise we could race with the device.
                 */
                first_len = skb_headlen(skb);
                first_mapping = dma_map_page(&gp->pdev->dev,
                                             virt_to_page(skb->data),
                                             offset_in_page(skb->data),
                                             first_len, DMA_TO_DEVICE);
                entry = NEXT_TX(entry);

                for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
                        const skb_frag_t *this_frag = &skb_shinfo(skb)->frags[frag];
                        u32 len;
                        dma_addr_t mapping;
                        u64 this_ctrl;

                        len = skb_frag_size(this_frag);
                        mapping = skb_frag_dma_map(&gp->pdev->dev, this_frag,
                                                   0, len, DMA_TO_DEVICE);
                        this_ctrl = ctrl;
                        if (frag == skb_shinfo(skb)->nr_frags - 1)
                                this_ctrl |= TXDCTRL_EOF;

                        txd = &gp->init_block->txd[entry];
                        txd->buffer = cpu_to_le64(mapping);
                        dma_wmb();
                        txd->control_word = cpu_to_le64(this_ctrl | len);

                        if (gem_intme(entry))
                                intme |= TXDCTRL_INTME;

                        entry = NEXT_TX(entry);
                }
                txd = &gp->init_block->txd[first_entry];
                txd->buffer = cpu_to_le64(first_mapping);
                dma_wmb();
                txd->control_word =
                        cpu_to_le64(ctrl | TXDCTRL_SOF | intme | first_len);
        }

        gp->tx_new = entry;
        if (unlikely(TX_BUFFS_AVAIL(gp) <= (MAX_SKB_FRAGS + 1))) {
                netif_stop_queue(dev);

                /* netif_stop_queue() must be done before checking
                 * checking tx index in TX_BUFFS_AVAIL() below, because
                 * in gem_tx(), we update tx_old before checking for
                 * netif_queue_stopped().
                 */
                smp_mb();
                if (TX_BUFFS_AVAIL(gp) > (MAX_SKB_FRAGS + 1))
                        netif_wake_queue(dev);
        }
        if (netif_msg_tx_queued(gp))
                printk(KERN_DEBUG "%s: tx queued, slot %d, skblen %d\n",
                       dev->name, entry, skb->len);
        mb();
        writel(gp->tx_new, gp->regs + TXDMA_KICK);

        return NETDEV_TX_OK;
}

static void gem_pcs_reset(struct gem *gp)
{
        int limit;
        u32 val;

        /* Reset PCS unit. */
        val = readl(gp->regs + PCS_MIICTRL);
        val |= PCS_MIICTRL_RST;
        writel(val, gp->regs + PCS_MIICTRL);

        limit = 32;
        while (readl(gp->regs + PCS_MIICTRL) & PCS_MIICTRL_RST) {
                udelay(100);
                if (limit-- <= 0)
                        break;
        }
        if (limit < 0)
                netdev_warn(gp->dev, "PCS reset bit would not clear\n");
}

static void gem_pcs_reinit_adv(struct gem *gp)
{
        u32 val;

        /* Make sure PCS is disabled while changing advertisement
         * configuration.
         */
        val = readl(gp->regs + PCS_CFG);
        val &= ~(PCS_CFG_ENABLE | PCS_CFG_TO);
        writel(val, gp->regs + PCS_CFG);

        /* Advertise all capabilities except asymmetric
         * pause.
         */
        val = readl(gp->regs + PCS_MIIADV);
        val |= (PCS_MIIADV_FD | PCS_MIIADV_HD |
                PCS_MIIADV_SP | PCS_MIIADV_AP);
        writel(val, gp->regs + PCS_MIIADV);

        /* Enable and restart auto-negotiation, disable wrapback/loopback,
         * and re-enable PCS.
         */
        val = readl(gp->regs + PCS_MIICTRL);
        val |= (PCS_MIICTRL_RAN | PCS_MIICTRL_ANE);
        val &= ~PCS_MIICTRL_WB;
        writel(val, gp->regs + PCS_MIICTRL);

        val = readl(gp->regs + PCS_CFG);
        val |= PCS_CFG_ENABLE;
        writel(val, gp->regs + PCS_CFG);

        /* Make sure serialink loopback is off.  The meaning
         * of this bit is logically inverted based upon whether
         * you are in Serialink or SERDES mode.
         */
        val = readl(gp->regs + PCS_SCTRL);
        if (gp->phy_type == phy_serialink)
                val &= ~PCS_SCTRL_LOOP;
        else
                val |= PCS_SCTRL_LOOP;
        writel(val, gp->regs + PCS_SCTRL);
}

#define STOP_TRIES 32

static void gem_reset(struct gem *gp)
{
        int limit;
        u32 val;

        /* Make sure we won't get any more interrupts */
        writel(0xffffffff, gp->regs + GREG_IMASK);

        /* Reset the chip */
        writel(gp->swrst_base | GREG_SWRST_TXRST | GREG_SWRST_RXRST,
               gp->regs + GREG_SWRST);

        limit = STOP_TRIES;

        do {
                udelay(20);
                val = readl(gp->regs + GREG_SWRST);
                if (limit-- <= 0)
                        break;
        } while (val & (GREG_SWRST_TXRST | GREG_SWRST_RXRST));

        if (limit < 0)
                netdev_err(gp->dev, "SW reset is ghetto\n");

        if (gp->phy_type == phy_serialink || gp->phy_type == phy_serdes)
                gem_pcs_reinit_adv(gp);
}

static void gem_start_dma(struct gem *gp)
{
        u32 val;

        /* We are ready to rock, turn everything on. */
        val = readl(gp->regs + TXDMA_CFG);
        writel(val | TXDMA_CFG_ENABLE, gp->regs + TXDMA_CFG);
        val = readl(gp->regs + RXDMA_CFG);
        writel(val | RXDMA_CFG_ENABLE, gp->regs + RXDMA_CFG);
        val = readl(gp->regs + MAC_TXCFG);
        writel(val | MAC_TXCFG_ENAB, gp->regs + MAC_TXCFG);
        val = readl(gp->regs + MAC_RXCFG);
        writel(val | MAC_RXCFG_ENAB, gp->regs + MAC_RXCFG);

        (void) readl(gp->regs + MAC_RXCFG);
        udelay(100);

        gem_enable_ints(gp);

        writel(RX_RING_SIZE - 4, gp->regs + RXDMA_KICK);
}

/* DMA won't be actually stopped before about 4ms tho ...
 */
static void gem_stop_dma(struct gem *gp)
{
        u32 val;

        /* We are done rocking, turn everything off. */
        val = readl(gp->regs + TXDMA_CFG);
        writel(val & ~TXDMA_CFG_ENABLE, gp->regs + TXDMA_CFG);
        val = readl(gp->regs + RXDMA_CFG);
        writel(val & ~RXDMA_CFG_ENABLE, gp->regs + RXDMA_CFG);
        val = readl(gp->regs + MAC_TXCFG);
        writel(val & ~MAC_TXCFG_ENAB, gp->regs + MAC_TXCFG);
        val = readl(gp->regs + MAC_RXCFG);
        writel(val & ~MAC_RXCFG_ENAB, gp->regs + MAC_RXCFG);

        (void) readl(gp->regs + MAC_RXCFG);

        /* Need to wait a bit ... done by the caller */
}


// XXX dbl check what that function should do when called on PCS PHY
static void gem_begin_auto_negotiation(struct gem *gp,
                                       const struct ethtool_link_ksettings *ep)
{
        u32 advertise, features;
        int autoneg;
        int speed;
        int duplex;
        u32 advertising;

        if (ep)
                ethtool_convert_link_mode_to_legacy_u32(
                        &advertising, ep->link_modes.advertising);

        if (gp->phy_type != phy_mii_mdio0 &&
            gp->phy_type != phy_mii_mdio1)
                goto non_mii;

        /* Setup advertise */
        if (found_mii_phy(gp))
                features = gp->phy_mii.def->features;
        else
                features = 0;

        advertise = features & ADVERTISE_MASK;
        if (gp->phy_mii.advertising != 0)
                advertise &= gp->phy_mii.advertising;

        autoneg = gp->want_autoneg;
        speed = gp->phy_mii.speed;
        duplex = gp->phy_mii.duplex;

        /* Setup link parameters */
        if (!ep)
                goto start_aneg;
        if (ep->base.autoneg == AUTONEG_ENABLE) {
                advertise = advertising;
                autoneg = 1;
        } else {
                autoneg = 0;
                speed = ep->base.speed;
                duplex = ep->base.duplex;
        }

start_aneg:
        /* Sanitize settings based on PHY capabilities */
        if ((features & SUPPORTED_Autoneg) == 0)
                autoneg = 0;
        if (speed == SPEED_1000 &&
            !(features & (SUPPORTED_1000baseT_Half | SUPPORTED_1000baseT_Full)))
                speed = SPEED_100;
        if (speed == SPEED_100 &&
            !(features & (SUPPORTED_100baseT_Half | SUPPORTED_100baseT_Full)))
                speed = SPEED_10;
        if (duplex == DUPLEX_FULL &&
            !(features & (SUPPORTED_1000baseT_Full |
                          SUPPORTED_100baseT_Full |
                          SUPPORTED_10baseT_Full)))
                duplex = DUPLEX_HALF;
        if (speed == 0)
                speed = SPEED_10;

        /* If we are asleep, we don't try to actually setup the PHY, we
         * just store the settings
         */
        if (!netif_device_present(gp->dev)) {
                gp->phy_mii.autoneg = gp->want_autoneg = autoneg;
                gp->phy_mii.speed = speed;
                gp->phy_mii.duplex = duplex;
                return;
        }

        /* Configure PHY & start aneg */
        gp->want_autoneg = autoneg;
        if (autoneg) {
                if (found_mii_phy(gp))
                        gp->phy_mii.def->ops->setup_aneg(&gp->phy_mii, advertise);
                gp->lstate = link_aneg;
        } else {
                if (found_mii_phy(gp))
                        gp->phy_mii.def->ops->setup_forced(&gp->phy_mii, speed, duplex);
                gp->lstate = link_force_ok;
        }

non_mii:
        gp->timer_ticks = 0;
        mod_timer(&gp->link_timer, jiffies + ((12 * HZ) / 10));
}

/* A link-up condition has occurred, initialize and enable the
 * rest of the chip.
 */
static int gem_set_link_modes(struct gem *gp)
{
        struct netdev_queue *txq = netdev_get_tx_queue(gp->dev, 0);
        int full_duplex, speed, pause;
        u32 val;

        full_duplex = 0;
        speed = SPEED_10;
        pause = 0;

        if (found_mii_phy(gp)) {
                if (gp->phy_mii.def->ops->read_link(&gp->phy_mii))
                        return 1;
                full_duplex = (gp->phy_mii.duplex == DUPLEX_FULL);
                speed = gp->phy_mii.speed;
                pause = gp->phy_mii.pause;
        } else if (gp->phy_type == phy_serialink ||
                   gp->phy_type == phy_serdes) {
                u32 pcs_lpa = readl(gp->regs + PCS_MIILP);

                if ((pcs_lpa & PCS_MIIADV_FD) || gp->phy_type == phy_serdes)
                        full_duplex = 1;
                speed = SPEED_1000;
        }

        netif_info(gp, link, gp->dev, "Link is up at %d Mbps, %s-duplex\n",
                   speed, (full_duplex ? "full" : "half"));


        /* We take the tx queue lock to avoid collisions between
         * this code, the tx path and the NAPI-driven error path
         */
        __netif_tx_lock(txq, smp_processor_id());

        val = (MAC_TXCFG_EIPG0 | MAC_TXCFG_NGU);
        if (full_duplex) {
                val |= (MAC_TXCFG_ICS | MAC_TXCFG_ICOLL);
        } else {
                /* MAC_TXCFG_NBO must be zero. */
        }
        writel(val, gp->regs + MAC_TXCFG);

        val = (MAC_XIFCFG_OE | MAC_XIFCFG_LLED);
        if (!full_duplex &&
            (gp->phy_type == phy_mii_mdio0 ||
             gp->phy_type == phy_mii_mdio1)) {
                val |= MAC_XIFCFG_DISE;
        } else if (full_duplex) {
                val |= MAC_XIFCFG_FLED;
        }

        if (speed == SPEED_1000)
                val |= (MAC_XIFCFG_GMII);

        writel(val, gp->regs + MAC_XIFCFG);

        /* If gigabit and half-duplex, enable carrier extension
         * mode.  Else, disable it.
         */
        if (speed == SPEED_1000 && !full_duplex) {
                val = readl(gp->regs + MAC_TXCFG);
                writel(val | MAC_TXCFG_TCE, gp->regs + MAC_TXCFG);

                val = readl(gp->regs + MAC_RXCFG);
                writel(val | MAC_RXCFG_RCE, gp->regs + MAC_RXCFG);
        } else {
                val = readl(gp->regs + MAC_TXCFG);
                writel(val & ~MAC_TXCFG_TCE, gp->regs + MAC_TXCFG);

                val = readl(gp->regs + MAC_RXCFG);
                writel(val & ~MAC_RXCFG_RCE, gp->regs + MAC_RXCFG);
        }

        if (gp->phy_type == phy_serialink ||
            gp->phy_type == phy_serdes) {
                u32 pcs_lpa = readl(gp->regs + PCS_MIILP);

                if (pcs_lpa & (PCS_MIIADV_SP | PCS_MIIADV_AP))
                        pause = 1;
        }

        if (!full_duplex)
                writel(512, gp->regs + MAC_STIME);
        else
                writel(64, gp->regs + MAC_STIME);
        val = readl(gp->regs + MAC_MCCFG);
        if (pause)
                val |= (MAC_MCCFG_SPE | MAC_MCCFG_RPE);
        else
                val &= ~(MAC_MCCFG_SPE | MAC_MCCFG_RPE);
        writel(val, gp->regs + MAC_MCCFG);

        gem_start_dma(gp);

        __netif_tx_unlock(txq);

        if (netif_msg_link(gp)) {
                if (pause) {
                        netdev_info(gp->dev,
                                    "Pause is enabled (rxfifo: %d off: %d on: %d)\n",
                                    gp->rx_fifo_sz,
                                    gp->rx_pause_off,
                                    gp->rx_pause_on);
                } else {
                        netdev_info(gp->dev, "Pause is disabled\n");
                }
        }

        return 0;
}

static int gem_mdio_link_not_up(struct gem *gp)
{
        switch (gp->lstate) {
        case link_force_ret:
                netif_info(gp, link, gp->dev,
                           "Autoneg failed again, keeping forced mode\n");
                gp->phy_mii.def->ops->setup_forced(&gp->phy_mii,
                        gp->last_forced_speed, DUPLEX_HALF);
                gp->timer_ticks = 5;
                gp->lstate = link_force_ok;
                return 0;
        case link_aneg:
                /* We try forced modes after a failed aneg only on PHYs that don't
                 * have "magic_aneg" bit set, which means they internally do the
                 * while forced-mode thingy. On these, we just restart aneg
                 */
                if (gp->phy_mii.def->magic_aneg)
                        return 1;
                netif_info(gp, link, gp->dev, "switching to forced 100bt\n");
                /* Try forced modes. */
                gp->phy_mii.def->ops->setup_forced(&gp->phy_mii, SPEED_100,
                        DUPLEX_HALF);
                gp->timer_ticks = 5;
                gp->lstate = link_force_try;
                return 0;
        case link_force_try:
                /* Downgrade from 100 to 10 Mbps if necessary.
                 * If already at 10Mbps, warn user about the
                 * situation every 10 ticks.
                 */
                if (gp->phy_mii.speed == SPEED_100) {
                        gp->phy_mii.def->ops->setup_forced(&gp->phy_mii, SPEED_10,
                                DUPLEX_HALF);
                        gp->timer_ticks = 5;
                        netif_info(gp, link, gp->dev,
                                   "switching to forced 10bt\n");
                        return 0;
                } else
                        return 1;
        default:
                return 0;
        }
}

static void gem_link_timer(struct timer_list *t)
{
        struct gem *gp = from_timer(gp, t, link_timer);
        struct net_device *dev = gp->dev;
        int restart_aneg = 0;

        /* There's no point doing anything if we're going to be reset */
        if (gp->reset_task_pending)
                return;

        if (gp->phy_type == phy_serialink ||
            gp->phy_type == phy_serdes) {
                u32 val = readl(gp->regs + PCS_MIISTAT);

                if (!(val & PCS_MIISTAT_LS))
                        val = readl(gp->regs + PCS_MIISTAT);

                if ((val & PCS_MIISTAT_LS) != 0) {
                        if (gp->lstate == link_up)
                                goto restart;

                        gp->lstate = link_up;
                        netif_carrier_on(dev);
                        (void)gem_set_link_modes(gp);
                }
                goto restart;
        }
        if (found_mii_phy(gp) && gp->phy_mii.def->ops->poll_link(&gp->phy_mii)) {
                /* Ok, here we got a link. If we had it due to a forced
                 * fallback, and we were configured for autoneg, we do
                 * retry a short autoneg pass. If you know your hub is
                 * broken, use ethtool ;)
                 */
                if (gp->lstate == link_force_try && gp->want_autoneg) {
                        gp->lstate = link_force_ret;
                        gp->last_forced_speed = gp->phy_mii.speed;
                        gp->timer_ticks = 5;
                        if (netif_msg_link(gp))
                                netdev_info(dev,
                                            "Got link after fallback, retrying autoneg once...\n");
                        gp->phy_mii.def->ops->setup_aneg(&gp->phy_mii, gp->phy_mii.advertising);
                } else if (gp->lstate != link_up) {
                        gp->lstate = link_up;
                        netif_carrier_on(dev);
                        if (gem_set_link_modes(gp))
                                restart_aneg = 1;
                }
        } else {
                /* If the link was previously up, we restart the
                 * whole process
                 */
                if (gp->lstate == link_up) {
                        gp->lstate = link_down;
                        netif_info(gp, link, dev, "Link down\n");
                        netif_carrier_off(dev);
                        gem_schedule_reset(gp);
                        /* The reset task will restart the timer */
                        return;
                } else if (++gp->timer_ticks > 10) {
                        if (found_mii_phy(gp))
                                restart_aneg = gem_mdio_link_not_up(gp);
                        else
                                restart_aneg = 1;
                }
        }
        if (restart_aneg) {
                gem_begin_auto_negotiation(gp, NULL);
                return;
        }
restart:
        mod_timer(&gp->link_timer, jiffies + ((12 * HZ) / 10));
}

static void gem_clean_rings(struct gem *gp)
{
        struct gem_init_block *gb = gp->init_block;
        struct sk_buff *skb;
        int i;
        dma_addr_t dma_addr;

        for (i = 0; i < RX_RING_SIZE; i++) {
                struct gem_rxd *rxd;

                rxd = &gb->rxd[i];
                if (gp->rx_skbs[i] != NULL) {
                        skb = gp->rx_skbs[i];
                        dma_addr = le64_to_cpu(rxd->buffer);
                        dma_unmap_page(&gp->pdev->dev, dma_addr,
                                       RX_BUF_ALLOC_SIZE(gp),
                                       DMA_FROM_DEVICE);
                        dev_kfree_skb_any(skb);
                        gp->rx_skbs[i] = NULL;
                }
                rxd->status_word = 0;
                dma_wmb();
                rxd->buffer = 0;
        }

        for (i = 0; i < TX_RING_SIZE; i++) {
                if (gp->tx_skbs[i] != NULL) {
                        struct gem_txd *txd;
                        int frag;

                        skb = gp->tx_skbs[i];
                        gp->tx_skbs[i] = NULL;

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

                                txd = &gb->txd[ent];
                                dma_addr = le64_to_cpu(txd->buffer);
                                dma_unmap_page(&gp->pdev->dev, dma_addr,
                                               le64_to_cpu(txd->control_word) &
                                               TXDCTRL_BUFSZ, DMA_TO_DEVICE);

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

static void gem_init_rings(struct gem *gp)
{
        struct gem_init_block *gb = gp->init_block;
        struct net_device *dev = gp->dev;
        int i;
        dma_addr_t dma_addr;

        gp->rx_new = gp->rx_old = gp->tx_new = gp->tx_old = 0;

        gem_clean_rings(gp);

        gp->rx_buf_sz = max(dev->mtu + ETH_HLEN + VLAN_HLEN,
                            (unsigned)VLAN_ETH_FRAME_LEN);

        for (i = 0; i < RX_RING_SIZE; i++) {
                struct sk_buff *skb;
                struct gem_rxd *rxd = &gb->rxd[i];

                skb = gem_alloc_skb(dev, RX_BUF_ALLOC_SIZE(gp), GFP_KERNEL);
                if (!skb) {
                        rxd->buffer = 0;
                        rxd->status_word = 0;
                        continue;
                }

                gp->rx_skbs[i] = skb;
                skb_put(skb, (gp->rx_buf_sz + RX_OFFSET));
                dma_addr = dma_map_page(&gp->pdev->dev,
                                        virt_to_page(skb->data),
                                        offset_in_page(skb->data),
                                        RX_BUF_ALLOC_SIZE(gp),
                                        DMA_FROM_DEVICE);
                rxd->buffer = cpu_to_le64(dma_addr);
                dma_wmb();
                rxd->status_word = cpu_to_le64(RXDCTRL_FRESH(gp));
                skb_reserve(skb, RX_OFFSET);
        }

        for (i = 0; i < TX_RING_SIZE; i++) {
                struct gem_txd *txd = &gb->txd[i];

                txd->control_word = 0;
                dma_wmb();
                txd->buffer = 0;
        }
        wmb();
}

/* Init PHY interface and start link poll state machine */
static void gem_init_phy(struct gem *gp)
{
        u32 mifcfg;

        /* Revert MIF CFG setting done on stop_phy */
        mifcfg = readl(gp->regs + MIF_CFG);
        mifcfg &= ~MIF_CFG_BBMODE;
        writel(mifcfg, gp->regs + MIF_CFG);

        if (gp->pdev->vendor == PCI_VENDOR_ID_APPLE) {
                int i;

                /* Those delay sucks, the HW seem to love them though, I'll
                 * serisouly consider breaking some locks here to be able
                 * to schedule instead
                 */
                for (i = 0; i < 3; i++) {
#ifdef CONFIG_PPC_PMAC
                        pmac_call_feature(PMAC_FTR_GMAC_PHY_RESET, gp->of_node, 0, 0);
                        msleep(20);
#endif
                        /* Some PHYs used by apple have problem getting back to us,
                         * we do an additional reset here
                         */
                        sungem_phy_write(gp, MII_BMCR, BMCR_RESET);
                        msleep(20);
                        if (sungem_phy_read(gp, MII_BMCR) != 0xffff)
                                break;
                        if (i == 2)
                                netdev_warn(gp->dev, "GMAC PHY not responding !\n");
                }
        }

        if (gp->pdev->vendor == PCI_VENDOR_ID_SUN &&
            gp->pdev->device == PCI_DEVICE_ID_SUN_GEM) {
                u32 val;

                /* Init datapath mode register. */
                if (gp->phy_type == phy_mii_mdio0 ||
                    gp->phy_type == phy_mii_mdio1) {
                        val = PCS_DMODE_MGM;
                } else if (gp->phy_type == phy_serialink) {
                        val = PCS_DMODE_SM | PCS_DMODE_GMOE;
                } else {
                        val = PCS_DMODE_ESM;
                }

                writel(val, gp->regs + PCS_DMODE);
        }

        if (gp->phy_type == phy_mii_mdio0 ||
            gp->phy_type == phy_mii_mdio1) {
                /* Reset and detect MII PHY */
                sungem_phy_probe(&gp->phy_mii, gp->mii_phy_addr);

                /* Init PHY */
                if (gp->phy_mii.def && gp->phy_mii.def->ops->init)
                        gp->phy_mii.def->ops->init(&gp->phy_mii);
        } else {
                gem_pcs_reset(gp);
                gem_pcs_reinit_adv(gp);
        }

        /* Default aneg parameters */
        gp->timer_ticks = 0;
        gp->lstate = link_down;
        netif_carrier_off(gp->dev);

        /* Print things out */
        if (gp->phy_type == phy_mii_mdio0 ||
            gp->phy_type == phy_mii_mdio1)
                netdev_info(gp->dev, "Found %s PHY\n",
                            gp->phy_mii.def ? gp->phy_mii.def->name : "no");

        gem_begin_auto_negotiation(gp, NULL);
}

static void gem_init_dma(struct gem *gp)
{
        u64 desc_dma = (u64) gp->gblock_dvma;
        u32 val;

        val = (TXDMA_CFG_BASE | (0x7ff << 10) | TXDMA_CFG_PMODE);
        writel(val, gp->regs + TXDMA_CFG);

        writel(desc_dma >> 32, gp->regs + TXDMA_DBHI);
        writel(desc_dma & 0xffffffff, gp->regs + TXDMA_DBLOW);
        desc_dma += (INIT_BLOCK_TX_RING_SIZE * sizeof(struct gem_txd));

        writel(0, gp->regs + TXDMA_KICK);

        val = (RXDMA_CFG_BASE | (RX_OFFSET << 10) |
               (ETH_HLEN << 13) | RXDMA_CFG_FTHRESH_128);
        writel(val, gp->regs + RXDMA_CFG);

        writel(desc_dma >> 32, gp->regs + RXDMA_DBHI);
        writel(desc_dma & 0xffffffff, gp->regs + RXDMA_DBLOW);

        writel(RX_RING_SIZE - 4, gp->regs + RXDMA_KICK);

        val  = (((gp->rx_pause_off / 64) << 0) & RXDMA_PTHRESH_OFF);
        val |= (((gp->rx_pause_on / 64) << 12) & RXDMA_PTHRESH_ON);
        writel(val, gp->regs + RXDMA_PTHRESH);

        if (readl(gp->regs + GREG_BIFCFG) & GREG_BIFCFG_M66EN)
                writel(((5 & RXDMA_BLANK_IPKTS) |
                        ((8 << 12) & RXDMA_BLANK_ITIME)),
                       gp->regs + RXDMA_BLANK);
        else
                writel(((5 & RXDMA_BLANK_IPKTS) |
                        ((4 << 12) & RXDMA_BLANK_ITIME)),
                       gp->regs + RXDMA_BLANK);
}

static u32 gem_setup_multicast(struct gem *gp)
{
        u32 rxcfg = 0;
        int i;

        if ((gp->dev->flags & IFF_ALLMULTI) ||
            (netdev_mc_count(gp->dev) > 256)) {
                for (i=0; i<16; i++)
                        writel(0xffff, gp->regs + MAC_HASH0 + (i << 2));
                rxcfg |= MAC_RXCFG_HFE;
        } else if (gp->dev->flags & IFF_PROMISC) {
                rxcfg |= MAC_RXCFG_PROM;
        } else {
                u16 hash_table[16];
                u32 crc;
                struct netdev_hw_addr *ha;
                int i;

                memset(hash_table, 0, sizeof(hash_table));
                netdev_for_each_mc_addr(ha, gp->dev) {
                        crc = ether_crc_le(6, ha->addr);
                        crc >>= 24;
                        hash_table[crc >> 4] |= 1 << (15 - (crc & 0xf));
                }
                for (i=0; i<16; i++)
                        writel(hash_table[i], gp->regs + MAC_HASH0 + (i << 2));
                rxcfg |= MAC_RXCFG_HFE;
        }

        return rxcfg;
}

static void gem_init_mac(struct gem *gp)
{
        unsigned char *e = &gp->dev->dev_addr[0];

        writel(0x1bf0, gp->regs + MAC_SNDPAUSE);

        writel(0x00, gp->regs + MAC_IPG0);
        writel(0x08, gp->regs + MAC_IPG1);
        writel(0x04, gp->regs + MAC_IPG2);
        writel(0x40, gp->regs + MAC_STIME);
        writel(0x40, gp->regs + MAC_MINFSZ);

        /* Ethernet payload + header + FCS + optional VLAN tag. */
        writel(0x20000000 | (gp->rx_buf_sz + 4), gp->regs + MAC_MAXFSZ);

        writel(0x07, gp->regs + MAC_PASIZE);
        writel(0x04, gp->regs + MAC_JAMSIZE);
        writel(0x10, gp->regs + MAC_ATTLIM);
        writel(0x8808, gp->regs + MAC_MCTYPE);

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

        writel((e[4] << 8) | e[5], gp->regs + MAC_ADDR0);
        writel((e[2] << 8) | e[3], gp->regs + MAC_ADDR1);
        writel((e[0] << 8) | e[1], gp->regs + MAC_ADDR2);

        writel(0, gp->regs + MAC_ADDR3);
        writel(0, gp->regs + MAC_ADDR4);
        writel(0, gp->regs + MAC_ADDR5);

        writel(0x0001, gp->regs + MAC_ADDR6);
        writel(0xc200, gp->regs + MAC_ADDR7);
        writel(0x0180, gp->regs + MAC_ADDR8);

        writel(0, gp->regs + MAC_AFILT0);
        writel(0, gp->regs + MAC_AFILT1);
        writel(0, gp->regs + MAC_AFILT2);
        writel(0, gp->regs + MAC_AF21MSK);
        writel(0, gp->regs + MAC_AF0MSK);

        gp->mac_rx_cfg = gem_setup_multicast(gp);
#ifdef STRIP_FCS
        gp->mac_rx_cfg |= MAC_RXCFG_SFCS;
#endif
        writel(0, gp->regs + MAC_NCOLL);
        writel(0, gp->regs + MAC_FASUCC);
        writel(0, gp->regs + MAC_ECOLL);
        writel(0, gp->regs + MAC_LCOLL);
        writel(0, gp->regs + MAC_DTIMER);
        writel(0, gp->regs + MAC_PATMPS);
        writel(0, gp->regs + MAC_RFCTR);
        writel(0, gp->regs + MAC_LERR);
        writel(0, gp->regs + MAC_AERR);
        writel(0, gp->regs + MAC_FCSERR);
        writel(0, gp->regs + MAC_RXCVERR);

        /* Clear RX/TX/MAC/XIF config, we will set these up and enable
         * them once a link is established.
         */
        writel(0, gp->regs + MAC_TXCFG);
        writel(gp->mac_rx_cfg, gp->regs + MAC_RXCFG);
        writel(0, gp->regs + MAC_MCCFG);
        writel(0, gp->regs + MAC_XIFCFG);

        /* 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_TXSTAT_XMIT, gp->regs + MAC_TXMASK);
        writel(MAC_RXSTAT_RCV, gp->regs + MAC_RXMASK);

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

        /* Don't enable GEM's WOL in normal operations
         */
        if (gp->has_wol)
                writel(0, gp->regs + WOL_WAKECSR);
}

static void gem_init_pause_thresholds(struct gem *gp)
{
        u32 cfg;

        /* Calculate pause thresholds.  Setting the OFF threshold to the
         * full RX fifo size effectively disables PAUSE generation which
         * is what we do for 10/100 only GEMs which have FIFOs too small
         * to make real gains from PAUSE.
         */
        if (gp->rx_fifo_sz <= (2 * 1024)) {
                gp->rx_pause_off = gp->rx_pause_on = gp->rx_fifo_sz;
        } else {
                int max_frame = (gp->rx_buf_sz + 4 + 64) & ~63;
                int off = (gp->rx_fifo_sz - (max_frame * 2));
                int on = off - max_frame;

                gp->rx_pause_off = off;
                gp->rx_pause_on = on;
        }


        /* Configure the chip "burst" DMA mode & enable some
         * HW bug fixes on Apple version
         */
        cfg  = 0;
        if (gp->pdev->vendor == PCI_VENDOR_ID_APPLE)
                cfg |= GREG_CFG_RONPAULBIT | GREG_CFG_ENBUG2FIX;
#if !defined(CONFIG_SPARC64) && !defined(CONFIG_ALPHA)
        cfg |= GREG_CFG_IBURST;
#endif
        cfg |= ((31 << 1) & GREG_CFG_TXDMALIM);
        cfg |= ((31 << 6) & GREG_CFG_RXDMALIM);
        writel(cfg, gp->regs + GREG_CFG);

        /* If Infinite Burst didn't stick, then use different
         * thresholds (and Apple bug fixes don't exist)
         */
        if (!(readl(gp->regs + GREG_CFG) & GREG_CFG_IBURST)) {
                cfg = ((2 << 1) & GREG_CFG_TXDMALIM);
                cfg |= ((8 << 6) & GREG_CFG_RXDMALIM);
                writel(cfg, gp->regs + GREG_CFG);
        }
}

static int gem_check_invariants(struct gem *gp)
{
        struct pci_dev *pdev = gp->pdev;
        u32 mif_cfg;

        /* On Apple's sungem, we can't rely on registers as the chip
         * was been powered down by the firmware. The PHY is looked
         * up later on.
         */
        if (pdev->vendor == PCI_VENDOR_ID_APPLE) {
                gp->phy_type = phy_mii_mdio0;
                gp->tx_fifo_sz = readl(gp->regs + TXDMA_FSZ) * 64;
                gp->rx_fifo_sz = readl(gp->regs + RXDMA_FSZ) * 64;
                gp->swrst_base = 0;

                mif_cfg = readl(gp->regs + MIF_CFG);
                mif_cfg &= ~(MIF_CFG_PSELECT|MIF_CFG_POLL|MIF_CFG_BBMODE|MIF_CFG_MDI1);
                mif_cfg |= MIF_CFG_MDI0;
                writel(mif_cfg, gp->regs + MIF_CFG);
                writel(PCS_DMODE_MGM, gp->regs + PCS_DMODE);
                writel(MAC_XIFCFG_OE, gp->regs + MAC_XIFCFG);

                /* We hard-code the PHY address so we can properly bring it out of
                 * reset later on, we can't really probe it at this point, though
                 * that isn't an issue.
                 */
                if (gp->pdev->device == PCI_DEVICE_ID_APPLE_K2_GMAC)
                        gp->mii_phy_addr = 1;
                else
                        gp->mii_phy_addr = 0;

                return 0;
        }

        mif_cfg = readl(gp->regs + MIF_CFG);

        if (pdev->vendor == PCI_VENDOR_ID_SUN &&
            pdev->device == PCI_DEVICE_ID_SUN_RIO_GEM) {
                /* One of the MII PHYs _must_ be present
                 * as this chip has no gigabit PHY.
                 */
                if ((mif_cfg & (MIF_CFG_MDI0 | MIF_CFG_MDI1)) == 0) {
                        pr_err("RIO GEM lacks MII phy, mif_cfg[%08x]\n",
                               mif_cfg);
                        return -1;
                }
        }

        /* Determine initial PHY interface type guess.  MDIO1 is the
         * external PHY and thus takes precedence over MDIO0.
         */

        if (mif_cfg & MIF_CFG_MDI1) {
                gp->phy_type = phy_mii_mdio1;
                mif_cfg |= MIF_CFG_PSELECT;
                writel(mif_cfg, gp->regs + MIF_CFG);
        } else if (mif_cfg & MIF_CFG_MDI0) {
                gp->phy_type = phy_mii_mdio0;
                mif_cfg &= ~MIF_CFG_PSELECT;
                writel(mif_cfg, gp->regs + MIF_CFG);
        } else {
#ifdef CONFIG_SPARC
                const char *p;

                p = of_get_property(gp->of_node, "shared-pins", NULL);
                if (p && !strcmp(p, "serdes"))
                        gp->phy_type = phy_serdes;
                else
#endif
                        gp->phy_type = phy_serialink;
        }
        if (gp->phy_type == phy_mii_mdio1 ||
            gp->phy_type == phy_mii_mdio0) {
                int i;

                for (i = 0; i < 32; i++) {
                        gp->mii_phy_addr = i;
                        if (sungem_phy_read(gp, MII_BMCR) != 0xffff)
                                break;
                }
                if (i == 32) {
                        if (pdev->device != PCI_DEVICE_ID_SUN_GEM) {
                                pr_err("RIO MII phy will not respond\n");
                                return -1;
                        }
                        gp->phy_type = phy_serdes;
                }
        }

        /* Fetch the FIFO configurations now too. */
        gp->tx_fifo_sz = readl(gp->regs + TXDMA_FSZ) * 64;
        gp->rx_fifo_sz = readl(gp->regs + RXDMA_FSZ) * 64;

        if (pdev->vendor == PCI_VENDOR_ID_SUN) {
                if (pdev->device == PCI_DEVICE_ID_SUN_GEM) {
                        if (gp->tx_fifo_sz != (9 * 1024) ||
                            gp->rx_fifo_sz != (20 * 1024)) {
                                pr_err("GEM has bogus fifo sizes tx(%d) rx(%d)\n",
                                       gp->tx_fifo_sz, gp->rx_fifo_sz);
                                return -1;
                        }
                        gp->swrst_base = 0;
                } else {
                        if (gp->tx_fifo_sz != (2 * 1024) ||
                            gp->rx_fifo_sz != (2 * 1024)) {
                                pr_err("RIO GEM has bogus fifo sizes tx(%d) rx(%d)\n",
                                       gp->tx_fifo_sz, gp->rx_fifo_sz);
                                return -1;
                        }
                        gp->swrst_base = (64 / 4) << GREG_SWRST_CACHE_SHIFT;
                }
        }

        return 0;
}

static void gem_reinit_chip(struct gem *gp)
{
        /* Reset the chip */
        gem_reset(gp);

        /* Make sure ints are disabled */
        gem_disable_ints(gp);

        /* Allocate & setup ring buffers */
        gem_init_rings(gp);

        /* Configure pause thresholds */
        gem_init_pause_thresholds(gp);

        /* Init DMA & MAC engines */
        gem_init_dma(gp);
        gem_init_mac(gp);
}


static void gem_stop_phy(struct gem *gp, int wol)
{
        u32 mifcfg;

        /* Let the chip settle down a bit, it seems that helps
         * for sleep mode on some models
         */
        msleep(10);

        /* Make sure we aren't polling PHY status change. We
         * don't currently use that feature though
         */
        mifcfg = readl(gp->regs + MIF_CFG);
        mifcfg &= ~MIF_CFG_POLL;
        writel(mifcfg, gp->regs + MIF_CFG);

        if (wol && gp->has_wol) {
                unsigned char *e = &gp->dev->dev_addr[0];
                u32 csr;

                /* Setup wake-on-lan for MAGIC packet */
                writel(MAC_RXCFG_HFE | MAC_RXCFG_SFCS | MAC_RXCFG_ENAB,
                       gp->regs + MAC_RXCFG);
                writel((e[4] << 8) | e[5], gp->regs + WOL_MATCH0);
                writel((e[2] << 8) | e[3], gp->regs + WOL_MATCH1);
                writel((e[0] << 8) | e[1], gp->regs + WOL_MATCH2);

                writel(WOL_MCOUNT_N | WOL_MCOUNT_M, gp->regs + WOL_MCOUNT);
                csr = WOL_WAKECSR_ENABLE;
                if ((readl(gp->regs + MAC_XIFCFG) & MAC_XIFCFG_GMII) == 0)
                        csr |= WOL_WAKECSR_MII;
                writel(csr, gp->regs + WOL_WAKECSR);
        } else {
                writel(0, gp->regs + MAC_RXCFG);
                (void)readl(gp->regs + MAC_RXCFG);
                /* Machine sleep will die in strange ways if we
                 * dont wait a bit here, looks like the chip takes
                 * some time to really shut down
                 */
                msleep(10);
        }

        writel(0, gp->regs + MAC_TXCFG);
        writel(0, gp->regs + MAC_XIFCFG);
        writel(0, gp->regs + TXDMA_CFG);
        writel(0, gp->regs + RXDMA_CFG);

        if (!wol) {
                gem_reset(gp);
                writel(MAC_TXRST_CMD, gp->regs + MAC_TXRST);
                writel(MAC_RXRST_CMD, gp->regs + MAC_RXRST);

                if (found_mii_phy(gp) && gp->phy_mii.def->ops->suspend)
                        gp->phy_mii.def->ops->suspend(&gp->phy_mii);

                /* According to Apple, we must set the MDIO pins to this begnign
                 * state or we may 1) eat more current, 2) damage some PHYs
                 */
                writel(mifcfg | MIF_CFG_BBMODE, gp->regs + MIF_CFG);
                writel(0, gp->regs + MIF_BBCLK);
                writel(0, gp->regs + MIF_BBDATA);
                writel(0, gp->regs + MIF_BBOENAB);
                writel(MAC_XIFCFG_GMII | MAC_XIFCFG_LBCK, gp->regs + MAC_XIFCFG);
                (void) readl(gp->regs + MAC_XIFCFG);
        }
}

static int gem_do_start(struct net_device *dev)
{
        struct gem *gp = netdev_priv(dev);
        int rc;

        pci_set_master(gp->pdev);

        /* Init & setup chip hardware */
        gem_reinit_chip(gp);

        /* An interrupt might come in handy */
        rc = request_irq(gp->pdev->irq, gem_interrupt,
                         IRQF_SHARED, dev->name, (void *)dev);
        if (rc) {
                netdev_err(dev, "failed to request irq !\n");

                gem_reset(gp);
                gem_clean_rings(gp);
                gem_put_cell(gp);
                return rc;
        }

        /* Mark us as attached again if we come from resume(), this has
         * no effect if we weren't detached and needs to be done now.
         */
        netif_device_attach(dev);

        /* Restart NAPI & queues */
        gem_netif_start(gp);

        /* Detect & init PHY, start autoneg etc... this will
         * eventually result in starting DMA operations when
         * the link is up
         */
        gem_init_phy(gp);

        return 0;
}

static void gem_do_stop(struct net_device *dev, int wol)
{
        struct gem *gp = netdev_priv(dev);

        /* Stop NAPI and stop tx queue */
        gem_netif_stop(gp);

        /* Make sure ints are disabled. We don't care about
         * synchronizing as NAPI is disabled, thus a stray
         * interrupt will do nothing bad (our irq handler
         * just schedules NAPI)
         */
        gem_disable_ints(gp);

        /* Stop the link timer */
        del_timer_sync(&gp->link_timer);

        /* We cannot cancel the reset task while holding the
         * rtnl lock, we'd get an A->B / B->A deadlock stituation
         * if we did. This is not an issue however as the reset
         * task is synchronized vs. us (rtnl_lock) and will do
         * nothing if the device is down or suspended. We do
         * still clear reset_task_pending to avoid a spurrious
         * reset later on in case we do resume before it gets
         * scheduled.
         */
        gp->reset_task_pending = 0;

        /* If we are going to sleep with WOL */
        gem_stop_dma(gp);
        msleep(10);
        if (!wol)
                gem_reset(gp);
        msleep(10);

        /* Get rid of rings */
        gem_clean_rings(gp);

        /* No irq needed anymore */
        free_irq(gp->pdev->irq, (void *) dev);

        /* Shut the PHY down eventually and setup WOL */
        gem_stop_phy(gp, wol);
}

static void gem_reset_task(struct work_struct *work)
{
        struct gem *gp = container_of(work, struct gem, reset_task);

        /* Lock out the network stack (essentially shield ourselves
         * against a racing open, close, control call, or suspend
         */
        rtnl_lock();

        /* Skip the reset task if suspended or closed, or if it's
         * been cancelled by gem_do_stop (see comment there)
         */
        if (!netif_device_present(gp->dev) ||
            !netif_running(gp->dev) ||
            !gp->reset_task_pending) {
                rtnl_unlock();
                return;
        }

        /* Stop the link timer */
        del_timer_sync(&gp->link_timer);

        /* Stop NAPI and tx */
        gem_netif_stop(gp);

        /* Reset the chip & rings */
        gem_reinit_chip(gp);
        if (gp->lstate == link_up)
                gem_set_link_modes(gp);

        /* Restart NAPI and Tx */
        gem_netif_start(gp);

        /* We are back ! */
        gp->reset_task_pending = 0;

        /* If the link is not up, restart autoneg, else restart the
         * polling timer
         */
        if (gp->lstate != link_up)
                gem_begin_auto_negotiation(gp, NULL);
        else
                mod_timer(&gp->link_timer, jiffies + ((12 * HZ) / 10));

        rtnl_unlock();
}

static int gem_open(struct net_device *dev)
{
        struct gem *gp = netdev_priv(dev);
        int rc;

        /* We allow open while suspended, we just do nothing,
         * the chip will be initialized in resume()
         */
        if (netif_device_present(dev)) {
                /* Enable the cell */
                gem_get_cell(gp);

                /* Make sure PCI access and bus master are enabled */
                rc = pci_enable_device(gp->pdev);
                if (rc) {
                        netdev_err(dev, "Failed to enable chip on PCI bus !\n");

                        /* Put cell and forget it for now, it will be considered
                         *as still asleep, a new sleep cycle may bring it back
                         */
                        gem_put_cell(gp);
                        return -ENXIO;
                }
                return gem_do_start(dev);
        }

        return 0;
}

static int gem_close(struct net_device *dev)
{
        struct gem *gp = netdev_priv(dev);

        if (netif_device_present(dev)) {
                gem_do_stop(dev, 0);

                /* Make sure bus master is disabled */
                pci_disable_device(gp->pdev);

                /* Cell not needed neither if no WOL */
                if (!gp->asleep_wol)
                        gem_put_cell(gp);
        }
        return 0;
}

static int __maybe_unused gem_suspend(struct device *dev_d)
{
        struct net_device *dev = dev_get_drvdata(dev_d);
        struct gem *gp = netdev_priv(dev);

        /* Lock the network stack first to avoid racing with open/close,
         * reset task and setting calls
         */
        rtnl_lock();

        /* Not running, mark ourselves non-present, no need for
         * a lock here
         */
        if (!netif_running(dev)) {
                netif_device_detach(dev);
                rtnl_unlock();
                return 0;
        }
        netdev_info(dev, "suspending, WakeOnLan %s\n",
                    (gp->wake_on_lan && netif_running(dev)) ?
                    "enabled" : "disabled");

        /* Tell the network stack we're gone. gem_do_stop() below will
         * synchronize with TX, stop NAPI etc...
         */
        netif_device_detach(dev);

        /* Switch off chip, remember WOL setting */
        gp->asleep_wol = !!gp->wake_on_lan;
        gem_do_stop(dev, gp->asleep_wol);

        /* Cell not needed neither if no WOL */
        if (!gp->asleep_wol)
                gem_put_cell(gp);

        /* Unlock the network stack */
        rtnl_unlock();

        return 0;
}

static int __maybe_unused gem_resume(struct device *dev_d)
{
        struct net_device *dev = dev_get_drvdata(dev_d);
        struct gem *gp = netdev_priv(dev);

        /* See locking comment in gem_suspend */
        rtnl_lock();

        /* Not running, mark ourselves present, no need for
         * a lock here
         */
        if (!netif_running(dev)) {
                netif_device_attach(dev);
                rtnl_unlock();
                return 0;
        }

        /* Enable the cell */
        gem_get_cell(gp);

        /* Restart chip. If that fails there isn't much we can do, we
         * leave things stopped.
         */
        gem_do_start(dev);

        /* If we had WOL enabled, the cell clock was never turned off during
         * sleep, so we end up beeing unbalanced. Fix that here
         */
        if (gp->asleep_wol)
                gem_put_cell(gp);

        /* Unlock the network stack */
        rtnl_unlock();

        return 0;
}

static struct net_device_stats *gem_get_stats(struct net_device *dev)
{
        struct gem *gp = netdev_priv(dev);

        /* I have seen this being called while the PM was in progress,
         * so we shield against this. Let's also not poke at registers
         * while the reset task is going on.
         *
         * TODO: Move stats collection elsewhere (link timer ?) and
         * make this a nop to avoid all those synchro issues
         */
        if (!netif_device_present(dev) || !netif_running(dev))
                goto bail;

        /* Better safe than sorry... */
        if (WARN_ON(!gp->cell_enabled))
                goto bail;

        dev->stats.rx_crc_errors += readl(gp->regs + MAC_FCSERR);
        writel(0, gp->regs + MAC_FCSERR);

        dev->stats.rx_frame_errors += readl(gp->regs + MAC_AERR);
        writel(0, gp->regs + MAC_AERR);

        dev->stats.rx_length_errors += readl(gp->regs + MAC_LERR);
        writel(0, gp->regs + MAC_LERR);

        dev->stats.tx_aborted_errors += readl(gp->regs + MAC_ECOLL);
        dev->stats.collisions +=
                (readl(gp->regs + MAC_ECOLL) + readl(gp->regs + MAC_LCOLL));
        writel(0, gp->regs + MAC_ECOLL);
        writel(0, gp->regs + MAC_LCOLL);
 bail:
        return &dev->stats;
}

static int gem_set_mac_address(struct net_device *dev, void *addr)
{
        struct sockaddr *macaddr = (struct sockaddr *) addr;
        struct gem *gp = netdev_priv(dev);
        unsigned char *e = &dev->dev_addr[0];

        if (!is_valid_ether_addr(macaddr->sa_data))
                return -EADDRNOTAVAIL;

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

        /* We'll just catch it later when the device is up'd or resumed */
        if (!netif_running(dev) || !netif_device_present(dev))
                return 0;

        /* Better safe than sorry... */
        if (WARN_ON(!gp->cell_enabled))
                return 0;

        writel((e[4] << 8) | e[5], gp->regs + MAC_ADDR0);
        writel((e[2] << 8) | e[3], gp->regs + MAC_ADDR1);
        writel((e[0] << 8) | e[1], gp->regs + MAC_ADDR2);

        return 0;
}

static void gem_set_multicast(struct net_device *dev)
{
        struct gem *gp = netdev_priv(dev);
        u32 rxcfg, rxcfg_new;
        int limit = 10000;

        if (!netif_running(dev) || !netif_device_present(dev))
                return;

        /* Better safe than sorry... */
        if (gp->reset_task_pending || WARN_ON(!gp->cell_enabled))
                return;

        rxcfg = readl(gp->regs + MAC_RXCFG);
        rxcfg_new = gem_setup_multicast(gp);
#ifdef STRIP_FCS
        rxcfg_new |= MAC_RXCFG_SFCS;
#endif
        gp->mac_rx_cfg = rxcfg_new;

        writel(rxcfg & ~MAC_RXCFG_ENAB, gp->regs + MAC_RXCFG);
        while (readl(gp->regs + MAC_RXCFG) & MAC_RXCFG_ENAB) {
                if (!limit--)
                        break;
                udelay(10);
        }

        rxcfg &= ~(MAC_RXCFG_PROM | MAC_RXCFG_HFE);
        rxcfg |= rxcfg_new;

        writel(rxcfg, gp->regs + MAC_RXCFG);
}

/* Jumbo-grams don't seem to work :-( */
#define GEM_MIN_MTU     ETH_MIN_MTU
#if 1
#define GEM_MAX_MTU     ETH_DATA_LEN
#else
#define GEM_MAX_MTU     9000
#endif

static int gem_change_mtu(struct net_device *dev, int new_mtu)
{
        struct gem *gp = netdev_priv(dev);

        dev->mtu = new_mtu;

        /* We'll just catch it later when the device is up'd or resumed */
        if (!netif_running(dev) || !netif_device_present(dev))
                return 0;

        /* Better safe than sorry... */
        if (WARN_ON(!gp->cell_enabled))
                return 0;

        gem_netif_stop(gp);
        gem_reinit_chip(gp);
        if (gp->lstate == link_up)
                gem_set_link_modes(gp);
        gem_netif_start(gp);

        return 0;
}

static void gem_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
        struct gem *gp = netdev_priv(dev);

        strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
        strlcpy(info->version, DRV_VERSION, sizeof(info->version));
        strlcpy(info->bus_info, pci_name(gp->pdev), sizeof(info->bus_info));
}

static int gem_get_link_ksettings(struct net_device *dev,
                                  struct ethtool_link_ksettings *cmd)
{
        struct gem *gp = netdev_priv(dev);
        u32 supported, advertising;

        if (gp->phy_type == phy_mii_mdio0 ||
            gp->phy_type == phy_mii_mdio1) {
                if (gp->phy_mii.def)
                        supported = gp->phy_mii.def->features;
                else
                        supported = (SUPPORTED_10baseT_Half |
                                          SUPPORTED_10baseT_Full);

                /* XXX hardcoded stuff for now */
                cmd->base.port = PORT_MII;
                cmd->base.phy_address = 0; /* XXX fixed PHYAD */

                /* Return current PHY settings */
                cmd->base.autoneg = gp->want_autoneg;
                cmd->base.speed = gp->phy_mii.speed;
                cmd->base.duplex = gp->phy_mii.duplex;
                advertising = gp->phy_mii.advertising;

                /* If we started with a forced mode, we don't have a default
                 * advertise set, we need to return something sensible so
                 * userland can re-enable autoneg properly.
                 */
                if (advertising == 0)
                        advertising = supported;
        } else { // XXX PCS ?
                supported =
                        (SUPPORTED_10baseT_Half | SUPPORTED_10baseT_Full |
                         SUPPORTED_100baseT_Half | SUPPORTED_100baseT_Full |
                         SUPPORTED_Autoneg);
                advertising = supported;
                cmd->base.speed = 0;
                cmd->base.duplex = 0;
                cmd->base.port = 0;
                cmd->base.phy_address = 0;
                cmd->base.autoneg = 0;

                /* serdes means usually a Fibre connector, with most fixed */
                if (gp->phy_type == phy_serdes) {
                        cmd->base.port = PORT_FIBRE;
                        supported = (SUPPORTED_1000baseT_Half |
                                SUPPORTED_1000baseT_Full |
                                SUPPORTED_FIBRE | SUPPORTED_Autoneg |
                                SUPPORTED_Pause | SUPPORTED_Asym_Pause);
                        advertising = supported;
                        if (gp->lstate == link_up)
                                cmd->base.speed = SPEED_1000;
                        cmd->base.duplex = DUPLEX_FULL;
                        cmd->base.autoneg = 1;
                }
        }

        ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported,
                                                supported);
        ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.advertising,
                                                advertising);

        return 0;
}

static int gem_set_link_ksettings(struct net_device *dev,
                                  const struct ethtool_link_ksettings *cmd)
{
        struct gem *gp = netdev_priv(dev);
        u32 speed = cmd->base.speed;
        u32 advertising;

        ethtool_convert_link_mode_to_legacy_u32(&advertising,
                                                cmd->link_modes.advertising);

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

        if (cmd->base.autoneg == AUTONEG_ENABLE &&
            advertising == 0)
                return -EINVAL;

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

        /* Apply settings and restart link process. */
        if (netif_device_present(gp->dev)) {
                del_timer_sync(&gp->link_timer);
                gem_begin_auto_negotiation(gp, cmd);
        }

        return 0;
}

static int gem_nway_reset(struct net_device *dev)
{
        struct gem *gp = netdev_priv(dev);

        if (!gp->want_autoneg)
                return -EINVAL;

        /* Restart link process  */
        if (netif_device_present(gp->dev)) {
                del_timer_sync(&gp->link_timer);
                gem_begin_auto_negotiation(gp, NULL);
        }

        return 0;
}

static u32 gem_get_msglevel(struct net_device *dev)
{
        struct gem *gp = netdev_priv(dev);
        return gp->msg_enable;
}

static void gem_set_msglevel(struct net_device *dev, u32 value)
{
        struct gem *gp = netdev_priv(dev);
        gp->msg_enable = value;
}


/* Add more when I understand how to program the chip */
/* like WAKE_UCAST | WAKE_MCAST | WAKE_BCAST */

#define WOL_SUPPORTED_MASK      (WAKE_MAGIC)

static void gem_get_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
{
        struct gem *gp = netdev_priv(dev);

        /* Add more when I understand how to program the chip */
        if (gp->has_wol) {
                wol->supported = WOL_SUPPORTED_MASK;
                wol->wolopts = gp->wake_on_lan;
        } else {
                wol->supported = 0;
                wol->wolopts = 0;
        }
}

static int gem_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
{
        struct gem *gp = netdev_priv(dev);

        if (!gp->has_wol)
                return -EOPNOTSUPP;
        gp->wake_on_lan = wol->wolopts & WOL_SUPPORTED_MASK;
        return 0;
}

static const struct ethtool_ops gem_ethtool_ops = {
        .get_drvinfo            = gem_get_drvinfo,
        .get_link               = ethtool_op_get_link,
        .nway_reset             = gem_nway_reset,
        .get_msglevel           = gem_get_msglevel,
        .set_msglevel           = gem_set_msglevel,
        .get_wol                = gem_get_wol,
        .set_wol                = gem_set_wol,
        .get_link_ksettings     = gem_get_link_ksettings,
        .set_link_ksettings     = gem_set_link_ksettings,
};

static int gem_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        struct gem *gp = netdev_priv(dev);
        struct mii_ioctl_data *data = if_mii(ifr);
        int rc = -EOPNOTSUPP;

        /* For SIOCGMIIREG and SIOCSMIIREG the core checks for us that
         * netif_device_present() is true and holds rtnl_lock for us
         * so we have nothing to worry about
         */

        switch (cmd) {
        case SIOCGMIIPHY:               /* Get address of MII PHY in use. */
                data->phy_id = gp->mii_phy_addr;
                fallthrough;

        case SIOCGMIIREG:               /* Read MII PHY register. */
                data->val_out = __sungem_phy_read(gp, data->phy_id & 0x1f,
                                           data->reg_num & 0x1f);
                rc = 0;
                break;

        case SIOCSMIIREG:               /* Write MII PHY register. */
                __sungem_phy_write(gp, data->phy_id & 0x1f, data->reg_num & 0x1f,
                            data->val_in);
                rc = 0;
                break;
        }
        return rc;
}

#if (!defined(CONFIG_SPARC) && !defined(CONFIG_PPC_PMAC))
/* Fetch MAC address from vital product data of PCI ROM. */
static int find_eth_addr_in_vpd(void __iomem *rom_base, int len, unsigned char *dev_addr)
{
        int this_offset;

        for (this_offset = 0x20; this_offset < len; this_offset++) {
                void __iomem *p = rom_base + this_offset;
                int i;

                if (readb(p + 0) != 0x90 ||
                    readb(p + 1) != 0x00 ||
                    readb(p + 2) != 0x09 ||
                    readb(p + 3) != 0x4e ||
                    readb(p + 4) != 0x41 ||
                    readb(p + 5) != 0x06)
                        continue;

                this_offset += 6;
                p += 6;

                for (i = 0; i < 6; i++)
                        dev_addr[i] = readb(p + i);
                return 1;
        }
        return 0;
}

static void get_gem_mac_nonobp(struct pci_dev *pdev, unsigned char *dev_addr)
{
        size_t size;
        void __iomem *p = pci_map_rom(pdev, &size);

        if (p) {
                int found;

                found = readb(p) == 0x55 &&
                        readb(p + 1) == 0xaa &&
                        find_eth_addr_in_vpd(p, (64 * 1024), dev_addr);
                pci_unmap_rom(pdev, p);
                if (found)
                        return;
        }

        /* Sun MAC prefix then 3 random bytes. */
        dev_addr[0] = 0x08;
        dev_addr[1] = 0x00;
        dev_addr[2] = 0x20;
        get_random_bytes(dev_addr + 3, 3);
}
#endif /* not Sparc and not PPC */

static int gem_get_device_address(struct gem *gp)
{
#if defined(CONFIG_SPARC) || defined(CONFIG_PPC_PMAC)
        struct net_device *dev = gp->dev;
        const unsigned char *addr;

        addr = of_get_property(gp->of_node, "local-mac-address", NULL);
        if (addr == NULL) {
#ifdef CONFIG_SPARC
                addr = idprom->id_ethaddr;
#else
                printk("\n");
                pr_err("%s: can't get mac-address\n", dev->name);
                return -1;
#endif
        }
        memcpy(dev->dev_addr, addr, ETH_ALEN);
#else
        get_gem_mac_nonobp(gp->pdev, gp->dev->dev_addr);
#endif
        return 0;
}

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

        if (dev) {
                struct gem *gp = netdev_priv(dev);

                unregister_netdev(dev);

                /* Ensure reset task is truly gone */
                cancel_work_sync(&gp->reset_task);

                /* Free resources */
                dma_free_coherent(&pdev->dev, sizeof(struct gem_init_block),
                                  gp->init_block, gp->gblock_dvma);
                iounmap(gp->regs);
                pci_release_regions(pdev);
                free_netdev(dev);
        }
}

static const struct net_device_ops gem_netdev_ops = {
        .ndo_open               = gem_open,
        .ndo_stop               = gem_close,
        .ndo_start_xmit         = gem_start_xmit,
        .ndo_get_stats          = gem_get_stats,
        .ndo_set_rx_mode        = gem_set_multicast,
        .ndo_do_ioctl           = gem_ioctl,
        .ndo_tx_timeout         = gem_tx_timeout,
        .ndo_change_mtu         = gem_change_mtu,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_set_mac_address    = gem_set_mac_address,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = gem_poll_controller,
#endif
};

static int gem_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        unsigned long gemreg_base, gemreg_len;
        struct net_device *dev;
        struct gem *gp;
        int err, pci_using_dac;

        printk_once(KERN_INFO "%s", version);

        /* Apple gmac note: during probe, the chip is powered up by
         * the arch code to allow the code below to work (and to let
         * the chip be probed on the config space. It won't stay powered
         * up until the interface is brought up however, so we can't rely
         * on register configuration done at this point.
         */
        err = pci_enable_device(pdev);
        if (err) {
                pr_err("Cannot enable MMIO operation, aborting\n");
                return err;
        }
        pci_set_master(pdev);

        /* Configure DMA attributes. */

        /* All of the GEM documentation states that 64-bit DMA addressing
         * is fully supported and should work just fine.  However the
         * front end for RIO based GEMs is different and only supports
         * 32-bit addressing.
         *
         * For now we assume the various PPC GEMs are 32-bit only as well.
         */
        if (pdev->vendor == PCI_VENDOR_ID_SUN &&
            pdev->device == PCI_DEVICE_ID_SUN_GEM &&
            !dma_set_mask(&pdev->dev, DMA_BIT_MASK(64))) {
                pci_using_dac = 1;
        } else {
                err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
                if (err) {
                        pr_err("No usable DMA configuration, aborting\n");
                        goto err_disable_device;
                }
                pci_using_dac = 0;
        }

        gemreg_base = pci_resource_start(pdev, 0);
        gemreg_len = pci_resource_len(pdev, 0);

        if ((pci_resource_flags(pdev, 0) & IORESOURCE_IO) != 0) {
                pr_err("Cannot find proper PCI device base address, aborting\n");
                err = -ENODEV;
                goto err_disable_device;
        }

        dev = alloc_etherdev(sizeof(*gp));
        if (!dev) {
                err = -ENOMEM;
                goto err_disable_device;
        }
        SET_NETDEV_DEV(dev, &pdev->dev);

        gp = netdev_priv(dev);

        err = pci_request_regions(pdev, DRV_NAME);
        if (err) {
                pr_err("Cannot obtain PCI resources, aborting\n");
                goto err_out_free_netdev;
        }

        gp->pdev = pdev;
        gp->dev = dev;

        gp->msg_enable = DEFAULT_MSG;

        timer_setup(&gp->link_timer, gem_link_timer, 0);

        INIT_WORK(&gp->reset_task, gem_reset_task);

        gp->lstate = link_down;
        gp->timer_ticks = 0;
        netif_carrier_off(dev);

        gp->regs = ioremap(gemreg_base, gemreg_len);
        if (!gp->regs) {
                pr_err("Cannot map device registers, aborting\n");
                err = -EIO;
                goto err_out_free_res;
        }

        /* On Apple, we want a reference to the Open Firmware device-tree
         * node. We use it for clock control.
         */
#if defined(CONFIG_PPC_PMAC) || defined(CONFIG_SPARC)
        gp->of_node = pci_device_to_OF_node(pdev);
#endif

        /* Only Apple version supports WOL afaik */
        if (pdev->vendor == PCI_VENDOR_ID_APPLE)
                gp->has_wol = 1;

        /* Make sure cell is enabled */
        gem_get_cell(gp);

        /* Make sure everything is stopped and in init state */
        gem_reset(gp);

        /* Fill up the mii_phy structure (even if we won't use it) */
        gp->phy_mii.dev = dev;
        gp->phy_mii.mdio_read = _sungem_phy_read;
        gp->phy_mii.mdio_write = _sungem_phy_write;
#ifdef CONFIG_PPC_PMAC
        gp->phy_mii.platform_data = gp->of_node;
#endif
        /* By default, we start with autoneg */
        gp->want_autoneg = 1;

        /* Check fifo sizes, PHY type, etc... */
        if (gem_check_invariants(gp)) {
                err = -ENODEV;
                goto err_out_iounmap;
        }

        /* It is guaranteed that the returned buffer will be at least
         * PAGE_SIZE aligned.
         */
        gp->init_block = dma_alloc_coherent(&pdev->dev, sizeof(struct gem_init_block),
                                            &gp->gblock_dvma, GFP_KERNEL);
        if (!gp->init_block) {
                pr_err("Cannot allocate init block, aborting\n");
                err = -ENOMEM;
                goto err_out_iounmap;
        }

        err = gem_get_device_address(gp);
        if (err)
                goto err_out_free_consistent;

        dev->netdev_ops = &gem_netdev_ops;
        netif_napi_add(dev, &gp->napi, gem_poll, 64);
        dev->ethtool_ops = &gem_ethtool_ops;
        dev->watchdog_timeo = 5 * HZ;
        dev->dma = 0;

        /* Set that now, in case PM kicks in now */
        pci_set_drvdata(pdev, dev);

        /* We can do scatter/gather and HW checksum */
        dev->hw_features = NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
        dev->features = dev->hw_features;
        if (pci_using_dac)
                dev->features |= NETIF_F_HIGHDMA;

        /* MTU range: 68 - 1500 (Jumbo mode is broken) */
        dev->min_mtu = GEM_MIN_MTU;
        dev->max_mtu = GEM_MAX_MTU;

        /* Register with kernel */
        if (register_netdev(dev)) {