/* $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)
 *
 * TODO:
 *  - Now that the driver was significantly simplified, I need to rework
 *    the locking. I'm sure we don't need _2_ spinlocks, and we probably
 *    can avoid taking most of them for so long period of time (and schedule
 *    instead). The main issues at this point are caused by the netdev layer
 *    though:
 *
 *    gem_change_mtu() and gem_set_multicast() are called with a read_lock()
 *    help by net/core/dev.c, thus they can't schedule. That means they can't
 *    call napi_disable() neither, thus force gem_poll() to keep a spinlock
 *    where it could have been dropped. change_mtu especially would love also to
 *    be able to msleep instead of horrid locked delays when resetting the HW,
 *    but that read_lock() makes it impossible, unless I defer it's action to
 *    the reset task, which means it'll be asynchronous (won't take effect until
 *    the system schedules a bit).
 *
 *    Also, it would probably be possible to also remove most of the long-life
 *    locking in open/resume code path (gem_reinit_chip) by beeing more careful
 *    about when we can start taking interrupts or get xmit() called...
 */

#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/init.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/mutex.h>
#include <linux/mm.h>
#include <linux/gfp.h>

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

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

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

#include "sungem_phy.h"
#include "sungem.h"

/* Stripping FCS is causing problems, disabled for now */
#undef 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	"0.98"
#define DRV_RELDATE	"8/24/03"
#define DRV_AUTHOR	"David S. Miller (davem@redhat.com)"

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

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

#define GEM_MODULE_NAME	"gem"

static DEFINE_PCI_DEVICE_TABLE(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 __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 _phy_read(struct net_device *dev, int mii_id, int reg)
{
	struct gem *gp = netdev_priv(dev);
	return __phy_read(gp, mii_id, reg);
}

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

static void __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 _phy_write(struct net_device *dev, int mii_id, int reg, int val)
{
	struct gem *gp = netdev_priv(dev);
	__phy_write(gp, mii_id, reg, val & 0xffff);
}

static inline void phy_write(struct gem *gp, int reg, u16 val)
{
	__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);
}

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 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;
	}

	udelay(5000);

	/* 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) |
	       ((14 / 2) << 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) {
		u16 pci_cfg_stat;

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

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

	/* 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++;

		goto do_reset;
	}

	if (gem_status & GREG_STAT_PCS) {
		if (gem_pcs_interrupt(dev, gp, gem_status))
			goto do_reset;
	}

	if (gem_status & GREG_STAT_TXMAC) {
		if (gem_txmac_interrupt(dev, gp, gem_status))
			goto do_reset;
	}

	if (gem_status & GREG_STAT_RXMAC) {
		if (gem_rxmac_interrupt(dev, gp, gem_status))
			goto do_reset;
	}

	if (gem_status & GREG_STAT_MAC) {
		if (gem_mac_interrupt(dev, gp, gem_status))
			goto do_reset;
	}

	if (gem_status & GREG_STAT_MIF) {
		if (gem_mif_interrupt(dev, gp, gem_status))
			goto do_reset;
	}

	if (gem_status & GREG_STAT_PCIERR) {
		if (gem_pci_interrupt(dev, gp, gem_status))
			goto do_reset;
	}

	return 0;

do_reset:
	gp->reset_task_pending = 1;
	schedule_work(&gp->reset_task);

	return 1;
}

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

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

	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;

			pci_unmap_page(gp->pdev, dma_addr, dma_len, PCI_DMA_TODEVICE);
			entry = NEXT_TX(entry);
		}

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

	if (netif_queue_stopped(dev) &&
	    TX_BUFFS_AVAIL(gp) > (MAX_SKB_FRAGS + 1))
		netif_wake_queue(dev);
}

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;
	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);
	}
}

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;
	__sum16 csum;

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

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

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

			skb_reserve(copy_skb, 2);
			skb_put(copy_skb, len);
			pci_dma_sync_single_for_cpu(gp->pdev, dma_addr, len, PCI_DMA_FROMDEVICE);
			skb_copy_from_linear_data(skb, copy_skb->data, len);
			pci_dma_sync_single_for_device(gp->pdev, dma_addr, len, PCI_DMA_FROMDEVICE);

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

		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);

		netif_receive_skb(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;
	unsigned long flags;
	int work_done;

	/*
	 * NAPI locking nightmare: See comment at head of driver
	 */
	spin_lock_irqsave(&gp->lock, flags);

	work_done = 0;
	do {
		/* Handle anomalies */
		if (gp->status & GREG_STAT_ABNORMAL) {
			if (gem_abnormal_irq(dev, gp, gp->status))
				break;
		}

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

		spin_unlock_irqrestore(&gp->lock, flags);

		/* 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;

		spin_lock_irqsave(&gp->lock, flags);

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

	__napi_complete(napi);
	gem_enable_ints(gp);

	spin_unlock_irqrestore(&gp->lock, flags);

	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);
	unsigned long flags;

	/* Swallow interrupts when shutting the chip down, though
	 * that shouldn't happen, we should have done free_irq() at
	 * this point...
	 */
	if (!gp->running)
		return IRQ_HANDLED;

	spin_lock_irqsave(&gp->lock, flags);

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

		if (gem_status == 0) {
			napi_enable(&gp->napi);
			spin_unlock_irqrestore(&gp->lock, flags);
			return IRQ_NONE;
		}
		gp->status = gem_status;
		gem_disable_ints(gp);
		__napi_schedule(&gp->napi);
	}

	spin_unlock_irqrestore(&gp->lock, flags);

	/* 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)
{
	/* gem_interrupt is safe to reentrance so no need
	 * to disable_irq here.
	 */
	gem_interrupt(dev->irq, dev);
}
#endif

static void gem_tx_timeout(struct net_device *dev)
{
	struct gem *gp = netdev_priv(dev);

	netdev_err(dev, "transmit timed out, resetting\n");
	if (!gp->running) {
		netdev_err(dev, "hrm.. hw not running !\n");
		return;
	}
	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));

	spin_lock_irq(&gp->lock);
	spin_lock(&gp->tx_lock);

	gp->reset_task_pending = 1;
	schedule_work(&gp->reset_task);

	spin_unlock(&gp->tx_lock);
	spin_unlock_irq(&gp->lock);
}

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;
	unsigned long flags;

	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 (!spin_trylock_irqsave(&gp->tx_lock, flags)) {
		/* Tell upper layer to requeue */
		return NETDEV_TX_LOCKED;
	}
	/* We raced with gem_do_stop() */
	if (!gp->running) {
		spin_unlock_irqrestore(&gp->tx_lock, flags);
		return NETDEV_TX_BUSY;
	}

	/* This is a hard error, log it. */
	if (TX_BUFFS_AVAIL(gp) <= (skb_shinfo(skb)->nr_frags + 1)) {
		netif_stop_queue(dev);
		spin_unlock_irqrestore(&gp->tx_lock, flags);
		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 = pci_map_page(gp->pdev,
				       virt_to_page(skb->data),
				       offset_in_page(skb->data),
				       len, PCI_DMA_TODEVICE);
		ctrl |= TXDCTRL_SOF | TXDCTRL_EOF | len;
		if (gem_intme(entry))
			ctrl |= TXDCTRL_INTME;
		txd->buffer = cpu_to_le64(mapping);
		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 = pci_map_page(gp->pdev, virt_to_page(skb->data),
					     offset_in_page(skb->data),
					     first_len, PCI_DMA_TODEVICE);
		entry = NEXT_TX(entry);

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

			len = this_frag->size;
			mapping = pci_map_page(gp->pdev,
					       this_frag->page,
					       this_frag->page_offset,
					       len, PCI_DMA_TODEVICE);
			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);
			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);
		wmb();
		txd->control_word =
			cpu_to_le64(ctrl | TXDCTRL_SOF | intme | first_len);
	}

	gp->tx_new = entry;
	if (TX_BUFFS_AVAIL(gp) <= (MAX_SKB_FRAGS + 1))
		netif_stop_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);
	spin_unlock_irqrestore(&gp->tx_lock, flags);

	dev->trans_start = jiffies; /* NETIF_F_LLTX driver :( */

	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

/* Must be invoked under gp->lock and gp->tx_lock. */
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);
}

/* Must be invoked under gp->lock and gp->tx_lock. */
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);
}

/* Must be invoked under gp->lock and gp->tx_lock. 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 */
}


/* Must be invoked under gp->lock and gp->tx_lock. */
// XXX dbl check what that function should do when called on PCS PHY
static void gem_begin_auto_negotiation(struct gem *gp, struct ethtool_cmd *ep)
{
	u32 advertise, features;
	int autoneg;
	int speed;
	int duplex;

	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->autoneg == AUTONEG_ENABLE) {
		advertise = ep->advertising;
		autoneg = 1;
	} else {
		autoneg = 0;
		speed = ethtool_cmd_speed(ep);
		duplex = ep->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 (gp->asleep) {
		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.
 *
 * Must be invoked under gp->lock and gp->tx_lock.
 */
static int gem_set_link_modes(struct gem *gp)
{
	u32 val;
	int full_duplex, speed, pause;

	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"));

	if (!gp->running)
		return 0;

	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 (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");
		}
	}

	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);

	return 0;
}

/* Must be invoked under gp->lock and gp->tx_lock. */
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(unsigned long data)
{
	struct gem *gp = (struct gem *) data;
	int restart_aneg = 0;

	if (gp->asleep)
		return;

	spin_lock_irq(&gp->lock);
	spin_lock(&gp->tx_lock);
	gem_get_cell(gp);

	/* If the reset task is still pending, we just
	 * reschedule the link timer
	 */
	if (gp->reset_task_pending)
		goto restart;

	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(gp->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(gp->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(gp->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, gp->dev, "Link down\n");
			netif_carrier_off(gp->dev);
			gp->reset_task_pending = 1;
			schedule_work(&gp->reset_task);
			restart_aneg = 1;
		} 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);
		goto out_unlock;
	}
restart:
	mod_timer(&gp->link_timer, jiffies + ((12 * HZ) / 10));
out_unlock:
	gem_put_cell(gp);
	spin_unlock(&gp->tx_lock);
	spin_unlock_irq(&gp->lock);
}

/* Must be invoked under gp->lock and gp->tx_lock. */
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);
			pci_unmap_page(gp->pdev, dma_addr,
				       RX_BUF_ALLOC_SIZE(gp),
				       PCI_DMA_FROMDEVICE);
			dev_kfree_skb_any(skb);
			gp->rx_skbs[i] = NULL;
		}
		rxd->status_word = 0;
		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);
				pci_unmap_page(gp->pdev, dma_addr,
					       le64_to_cpu(txd->control_word) &
					       TXDCTRL_BUFSZ, PCI_DMA_TODEVICE);

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

/* Must be invoked under gp->lock and gp->tx_lock. */
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(RX_BUF_ALLOC_SIZE(gp), GFP_ATOMIC);
		if (!skb) {
			rxd->buffer = 0;
			rxd->status_word = 0;
			continue;
		}

		gp->rx_skbs[i] = skb;
		skb->dev = dev;
		skb_put(skb, (gp->rx_buf_sz + RX_OFFSET));
		dma_addr = pci_map_page(gp->pdev,
					virt_to_page(skb->data),
					offset_in_page(skb->data),
					RX_BUF_ALLOC_SIZE(gp),
					PCI_DMA_FROMDEVICE);
		rxd->buffer = cpu_to_le64(dma_addr);
		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;
		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
			 */
			phy_write(gp, MII_BMCR, BMCR_RESET);
			msleep(20);
			if (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) {
	    	// XXX check for errors
		mii_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);

	/* Can I advertise gigabit here ? I'd need BCM PHY docs... */
	spin_lock_irq(&gp->lock);
	gem_begin_auto_negotiation(gp, NULL);
	spin_unlock_irq(&gp->lock);
}

/* Must be invoked under gp->lock and gp->tx_lock. */
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) |
	       ((14 / 2) << 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);
}

/* Must be invoked under gp->lock and gp->tx_lock. */
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) {
			char *addrs = ha->addr;

			if (!(*addrs & 1))
				continue;

 			crc = ether_crc_le(6, addrs);
			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;
}

/* Must be invoked under gp->lock and gp->tx_lock. */
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);
}

/* M…