// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2001,2002,2003,2004 Broadcom Corporation
 * Copyright (c) 2006, 2007  Maciej W. Rozycki
 *
 * This driver is designed for the Broadcom SiByte SOC built-in
 * Ethernet controllers. Written by Mitch Lichtenberg at Broadcom Corp.
 *
 * Updated to the driver model and the PHY abstraction layer
 * by Maciej W. Rozycki.
 */

#include <linux/bug.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/prefetch.h>

#include <asm/cache.h>
#include <asm/io.h>
#include <asm/processor.h>      /* Processor type for cache alignment. */

/* Operational parameters that usually are not changed. */

#define CONFIG_SBMAC_COALESCE

/* Time in jiffies before concluding the transmitter is hung. */
#define TX_TIMEOUT  (2*HZ)


MODULE_AUTHOR("Mitch Lichtenberg (Broadcom Corp.)");
MODULE_DESCRIPTION("Broadcom SiByte SOC GB Ethernet driver");

/* A few user-configurable values which may be modified when a driver
   module is loaded. */

/* 1 normal messages, 0 quiet .. 7 verbose. */
static int debug = 1;
module_param(debug, int, 0444);
MODULE_PARM_DESC(debug, "Debug messages");

#ifdef CONFIG_SBMAC_COALESCE
static int int_pktcnt_tx = 255;
module_param(int_pktcnt_tx, int, 0444);
MODULE_PARM_DESC(int_pktcnt_tx, "TX packet count");

static int int_timeout_tx = 255;
module_param(int_timeout_tx, int, 0444);
MODULE_PARM_DESC(int_timeout_tx, "TX timeout value");

static int int_pktcnt_rx = 64;
module_param(int_pktcnt_rx, int, 0444);
MODULE_PARM_DESC(int_pktcnt_rx, "RX packet count");

static int int_timeout_rx = 64;
module_param(int_timeout_rx, int, 0444);
MODULE_PARM_DESC(int_timeout_rx, "RX timeout value");
#endif

#include <asm/sibyte/board.h>
#include <asm/sibyte/sb1250.h>
#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/bcm1480_int.h>
#define R_MAC_DMA_OODPKTLOST_RX R_MAC_DMA_OODPKTLOST
#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_int.h>
#else
#error invalid SiByte MAC configuration
#endif
#include <asm/sibyte/sb1250_scd.h>
#include <asm/sibyte/sb1250_mac.h>
#include <asm/sibyte/sb1250_dma.h>

#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
#define UNIT_INT(n)             (K_BCM1480_INT_MAC_0 + ((n) * 2))
#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
#define UNIT_INT(n)             (K_INT_MAC_0 + (n))
#else
#error invalid SiByte MAC configuration
#endif

#ifdef K_INT_PHY
#define SBMAC_PHY_INT                   K_INT_PHY
#else
#define SBMAC_PHY_INT                   PHY_POLL
#endif

/**********************************************************************
 *  Simple types
 ********************************************************************* */

enum sbmac_speed {
        sbmac_speed_none = 0,
        sbmac_speed_10 = SPEED_10,
        sbmac_speed_100 = SPEED_100,
        sbmac_speed_1000 = SPEED_1000,
};

enum sbmac_duplex {
        sbmac_duplex_none = -1,
        sbmac_duplex_half = DUPLEX_HALF,
        sbmac_duplex_full = DUPLEX_FULL,
};

enum sbmac_fc {
        sbmac_fc_none,
        sbmac_fc_disabled,
        sbmac_fc_frame,
        sbmac_fc_collision,
        sbmac_fc_carrier,
};

enum sbmac_state {
        sbmac_state_uninit,
        sbmac_state_off,
        sbmac_state_on,
        sbmac_state_broken,
};


/**********************************************************************
 *  Macros
 ********************************************************************* */


#define SBDMA_NEXTBUF(d,f) ((((d)->f+1) == (d)->sbdma_dscrtable_end) ? \
                          (d)->sbdma_dscrtable : (d)->f+1)


#define NUMCACHEBLKS(x) DIV_ROUND_UP(x, SMP_CACHE_BYTES)

#define SBMAC_MAX_TXDESCR       256
#define SBMAC_MAX_RXDESCR       256

#define ENET_PACKET_SIZE        1518
/*#define ENET_PACKET_SIZE      9216 */

/**********************************************************************
 *  DMA Descriptor structure
 ********************************************************************* */

struct sbdmadscr {
        uint64_t  dscr_a;
        uint64_t  dscr_b;
};

/**********************************************************************
 *  DMA Controller structure
 ********************************************************************* */

struct sbmacdma {

        /*
         * This stuff is used to identify the channel and the registers
         * associated with it.
         */
        struct sbmac_softc      *sbdma_eth;     /* back pointer to associated
                                                   MAC */
        int                     sbdma_channel;  /* channel number */
        int                     sbdma_txdir;    /* direction (1=transmit) */
        int                     sbdma_maxdescr; /* total # of descriptors
                                                   in ring */
#ifdef CONFIG_SBMAC_COALESCE
        int                     sbdma_int_pktcnt;
                                                /* # descriptors rx/tx
                                                   before interrupt */
        int                     sbdma_int_timeout;
                                                /* # usec rx/tx interrupt */
#endif
        void __iomem            *sbdma_config0; /* DMA config register 0 */
        void __iomem            *sbdma_config1; /* DMA config register 1 */
        void __iomem            *sbdma_dscrbase;
                                                /* descriptor base address */
        void __iomem            *sbdma_dscrcnt; /* descriptor count register */
        void __iomem            *sbdma_curdscr; /* current descriptor
                                                   address */
        void __iomem            *sbdma_oodpktlost;
                                                /* pkt drop (rx only) */

        /*
         * This stuff is for maintenance of the ring
         */
        void                    *sbdma_dscrtable_unaligned;
        struct sbdmadscr        *sbdma_dscrtable;
                                                /* base of descriptor table */
        struct sbdmadscr        *sbdma_dscrtable_end;
                                                /* end of descriptor table */
        struct sk_buff          **sbdma_ctxtable;
                                                /* context table, one
                                                   per descr */
        dma_addr_t              sbdma_dscrtable_phys;
                                                /* and also the phys addr */
        struct sbdmadscr        *sbdma_addptr;  /* next dscr for sw to add */
        struct sbdmadscr        *sbdma_remptr;  /* next dscr for sw
                                                   to remove */
};


/**********************************************************************
 *  Ethernet softc structure
 ********************************************************************* */

struct sbmac_softc {

        /*
         * Linux-specific things
         */
        struct net_device       *sbm_dev;       /* pointer to linux device */
        struct napi_struct      napi;
        struct phy_device       *phy_dev;       /* the associated PHY device */
        struct mii_bus          *mii_bus;       /* the MII bus */
        spinlock_t              sbm_lock;       /* spin lock */
        int                     sbm_devflags;   /* current device flags */

        /*
         * Controller-specific things
         */
        void __iomem            *sbm_base;      /* MAC's base address */
        enum sbmac_state        sbm_state;      /* current state */

        void __iomem            *sbm_macenable; /* MAC Enable Register */
        void __iomem            *sbm_maccfg;    /* MAC Config Register */
        void __iomem            *sbm_fifocfg;   /* FIFO Config Register */
        void __iomem            *sbm_framecfg;  /* Frame Config Register */
        void __iomem            *sbm_rxfilter;  /* Receive Filter Register */
        void __iomem            *sbm_isr;       /* Interrupt Status Register */
        void __iomem            *sbm_imr;       /* Interrupt Mask Register */
        void __iomem            *sbm_mdio;      /* MDIO Register */

        enum sbmac_speed        sbm_speed;      /* current speed */
        enum sbmac_duplex       sbm_duplex;     /* current duplex */
        enum sbmac_fc           sbm_fc;         /* cur. flow control setting */
        int                     sbm_pause;      /* current pause setting */
        int                     sbm_link;       /* current link state */

        unsigned char           sbm_hwaddr[ETH_ALEN];

        struct sbmacdma         sbm_txdma;      /* only channel 0 for now */
        struct sbmacdma         sbm_rxdma;
        int                     rx_hw_checksum;
        int                     sbe_idx;
};


/**********************************************************************
 *  Externs
 ********************************************************************* */

/**********************************************************************
 *  Prototypes
 ********************************************************************* */

static void sbdma_initctx(struct sbmacdma *d, struct sbmac_softc *s, int chan,
                          int txrx, int maxdescr);
static void sbdma_channel_start(struct sbmacdma *d, int rxtx);
static int sbdma_add_rcvbuffer(struct sbmac_softc *sc, struct sbmacdma *d,
                               struct sk_buff *m);
static int sbdma_add_txbuffer(struct sbmacdma *d, struct sk_buff *m);
static void sbdma_emptyring(struct sbmacdma *d);
static void sbdma_fillring(struct sbmac_softc *sc, struct sbmacdma *d);
static int sbdma_rx_process(struct sbmac_softc *sc, struct sbmacdma *d,
                            int work_to_do, int poll);
static void sbdma_tx_process(struct sbmac_softc *sc, struct sbmacdma *d,
                             int poll);
static int sbmac_initctx(struct sbmac_softc *s);
static void sbmac_channel_start(struct sbmac_softc *s);
static void sbmac_channel_stop(struct sbmac_softc *s);
static enum sbmac_state sbmac_set_channel_state(struct sbmac_softc *,
                                                enum sbmac_state);
static void sbmac_promiscuous_mode(struct sbmac_softc *sc, int onoff);
static uint64_t sbmac_addr2reg(unsigned char *ptr);
static irqreturn_t sbmac_intr(int irq, void *dev_instance);
static netdev_tx_t sbmac_start_tx(struct sk_buff *skb, struct net_device *dev);
static void sbmac_setmulti(struct sbmac_softc *sc);
static int sbmac_init(struct platform_device *pldev, long long base);
static int sbmac_set_speed(struct sbmac_softc *s, enum sbmac_speed speed);
static int sbmac_set_duplex(struct sbmac_softc *s, enum sbmac_duplex duplex,
                            enum sbmac_fc fc);

static int sbmac_open(struct net_device *dev);
static void sbmac_tx_timeout (struct net_device *dev, unsigned int txqueue);
static void sbmac_set_rx_mode(struct net_device *dev);
static int sbmac_mii_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
static int sbmac_close(struct net_device *dev);
static int sbmac_poll(struct napi_struct *napi, int budget);

static void sbmac_mii_poll(struct net_device *dev);
static int sbmac_mii_probe(struct net_device *dev);

static void sbmac_mii_sync(void __iomem *sbm_mdio);
static void sbmac_mii_senddata(void __iomem *sbm_mdio, unsigned int data,
                               int bitcnt);
static int sbmac_mii_read(struct mii_bus *bus, int phyaddr, int regidx);
static int sbmac_mii_write(struct mii_bus *bus, int phyaddr, int regidx,
                           u16 val);


/**********************************************************************
 *  Globals
 ********************************************************************* */

static char sbmac_string[] = "sb1250-mac";

static char sbmac_mdio_string[] = "sb1250-mac-mdio";


/**********************************************************************
 *  MDIO constants
 ********************************************************************* */

#define MII_COMMAND_START       0x01
#define MII_COMMAND_READ        0x02
#define MII_COMMAND_WRITE       0x01
#define MII_COMMAND_ACK         0x02

#define M_MAC_MDIO_DIR_OUTPUT   0               /* for clarity */

#define ENABLE          1
#define DISABLE         0

/**********************************************************************
 *  SBMAC_MII_SYNC(sbm_mdio)
 *
 *  Synchronize with the MII - send a pattern of bits to the MII
 *  that will guarantee that it is ready to accept a command.
 *
 *  Input parameters:
 *         sbm_mdio - address of the MAC's MDIO register
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbmac_mii_sync(void __iomem *sbm_mdio)
{
        int cnt;
        uint64_t bits;
        int mac_mdio_genc;

        mac_mdio_genc = __raw_readq(sbm_mdio) & M_MAC_GENC;

        bits = M_MAC_MDIO_DIR_OUTPUT | M_MAC_MDIO_OUT;

        __raw_writeq(bits | mac_mdio_genc, sbm_mdio);

        for (cnt = 0; cnt < 32; cnt++) {
                __raw_writeq(bits | M_MAC_MDC | mac_mdio_genc, sbm_mdio);
                __raw_writeq(bits | mac_mdio_genc, sbm_mdio);
        }
}

/**********************************************************************
 *  SBMAC_MII_SENDDATA(sbm_mdio, data, bitcnt)
 *
 *  Send some bits to the MII.  The bits to be sent are right-
 *  justified in the 'data' parameter.
 *
 *  Input parameters:
 *         sbm_mdio - address of the MAC's MDIO register
 *         data     - data to send
 *         bitcnt   - number of bits to send
 ********************************************************************* */

static void sbmac_mii_senddata(void __iomem *sbm_mdio, unsigned int data,
                               int bitcnt)
{
        int i;
        uint64_t bits;
        unsigned int curmask;
        int mac_mdio_genc;

        mac_mdio_genc = __raw_readq(sbm_mdio) & M_MAC_GENC;

        bits = M_MAC_MDIO_DIR_OUTPUT;
        __raw_writeq(bits | mac_mdio_genc, sbm_mdio);

        curmask = 1 << (bitcnt - 1);

        for (i = 0; i < bitcnt; i++) {
                if (data & curmask)
                        bits |= M_MAC_MDIO_OUT;
                else bits &= ~M_MAC_MDIO_OUT;
                __raw_writeq(bits | mac_mdio_genc, sbm_mdio);
                __raw_writeq(bits | M_MAC_MDC | mac_mdio_genc, sbm_mdio);
                __raw_writeq(bits | mac_mdio_genc, sbm_mdio);
                curmask >>= 1;
        }
}



/**********************************************************************
 *  SBMAC_MII_READ(bus, phyaddr, regidx)
 *  Read a PHY register.
 *
 *  Input parameters:
 *         bus     - MDIO bus handle
 *         phyaddr - PHY's address
 *         regnum  - index of register to read
 *
 *  Return value:
 *         value read, or 0xffff if an error occurred.
 ********************************************************************* */

static int sbmac_mii_read(struct mii_bus *bus, int phyaddr, int regidx)
{
        struct sbmac_softc *sc = (struct sbmac_softc *)bus->priv;
        void __iomem *sbm_mdio = sc->sbm_mdio;
        int idx;
        int error;
        int regval;
        int mac_mdio_genc;

        /*
         * Synchronize ourselves so that the PHY knows the next
         * thing coming down is a command
         */
        sbmac_mii_sync(sbm_mdio);

        /*
         * Send the data to the PHY.  The sequence is
         * a "start" command (2 bits)
         * a "read" command (2 bits)
         * the PHY addr (5 bits)
         * the register index (5 bits)
         */
        sbmac_mii_senddata(sbm_mdio, MII_COMMAND_START, 2);
        sbmac_mii_senddata(sbm_mdio, MII_COMMAND_READ, 2);
        sbmac_mii_senddata(sbm_mdio, phyaddr, 5);
        sbmac_mii_senddata(sbm_mdio, regidx, 5);

        mac_mdio_genc = __raw_readq(sbm_mdio) & M_MAC_GENC;

        /*
         * Switch the port around without a clock transition.
         */
        __raw_writeq(M_MAC_MDIO_DIR_INPUT | mac_mdio_genc, sbm_mdio);

        /*
         * Send out a clock pulse to signal we want the status
         */
        __raw_writeq(M_MAC_MDIO_DIR_INPUT | M_MAC_MDC | mac_mdio_genc,
                     sbm_mdio);
        __raw_writeq(M_MAC_MDIO_DIR_INPUT | mac_mdio_genc, sbm_mdio);

        /*
         * If an error occurred, the PHY will signal '1' back
         */
        error = __raw_readq(sbm_mdio) & M_MAC_MDIO_IN;

        /*
         * Issue an 'idle' clock pulse, but keep the direction
         * the same.
         */
        __raw_writeq(M_MAC_MDIO_DIR_INPUT | M_MAC_MDC | mac_mdio_genc,
                     sbm_mdio);
        __raw_writeq(M_MAC_MDIO_DIR_INPUT | mac_mdio_genc, sbm_mdio);

        regval = 0;

        for (idx = 0; idx < 16; idx++) {
                regval <<= 1;

                if (error == 0) {
                        if (__raw_readq(sbm_mdio) & M_MAC_MDIO_IN)
                                regval |= 1;
                }

                __raw_writeq(M_MAC_MDIO_DIR_INPUT | M_MAC_MDC | mac_mdio_genc,
                             sbm_mdio);
                __raw_writeq(M_MAC_MDIO_DIR_INPUT | mac_mdio_genc, sbm_mdio);
        }

        /* Switch back to output */
        __raw_writeq(M_MAC_MDIO_DIR_OUTPUT | mac_mdio_genc, sbm_mdio);

        if (error == 0)
                return regval;
        return 0xffff;
}


/**********************************************************************
 *  SBMAC_MII_WRITE(bus, phyaddr, regidx, regval)
 *
 *  Write a value to a PHY register.
 *
 *  Input parameters:
 *         bus     - MDIO bus handle
 *         phyaddr - PHY to use
 *         regidx  - register within the PHY
 *         regval  - data to write to register
 *
 *  Return value:
 *         0 for success
 ********************************************************************* */

static int sbmac_mii_write(struct mii_bus *bus, int phyaddr, int regidx,
                           u16 regval)
{
        struct sbmac_softc *sc = (struct sbmac_softc *)bus->priv;
        void __iomem *sbm_mdio = sc->sbm_mdio;
        int mac_mdio_genc;

        sbmac_mii_sync(sbm_mdio);

        sbmac_mii_senddata(sbm_mdio, MII_COMMAND_START, 2);
        sbmac_mii_senddata(sbm_mdio, MII_COMMAND_WRITE, 2);
        sbmac_mii_senddata(sbm_mdio, phyaddr, 5);
        sbmac_mii_senddata(sbm_mdio, regidx, 5);
        sbmac_mii_senddata(sbm_mdio, MII_COMMAND_ACK, 2);
        sbmac_mii_senddata(sbm_mdio, regval, 16);

        mac_mdio_genc = __raw_readq(sbm_mdio) & M_MAC_GENC;

        __raw_writeq(M_MAC_MDIO_DIR_OUTPUT | mac_mdio_genc, sbm_mdio);

        return 0;
}



/**********************************************************************
 *  SBDMA_INITCTX(d,s,chan,txrx,maxdescr)
 *
 *  Initialize a DMA channel context.  Since there are potentially
 *  eight DMA channels per MAC, it's nice to do this in a standard
 *  way.
 *
 *  Input parameters:
 *         d - struct sbmacdma (DMA channel context)
 *         s - struct sbmac_softc (pointer to a MAC)
 *         chan - channel number (0..1 right now)
 *         txrx - Identifies DMA_TX or DMA_RX for channel direction
 *      maxdescr - number of descriptors
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbdma_initctx(struct sbmacdma *d, struct sbmac_softc *s, int chan,
                          int txrx, int maxdescr)
{
#ifdef CONFIG_SBMAC_COALESCE
        int int_pktcnt, int_timeout;
#endif

        /*
         * Save away interesting stuff in the structure
         */

        d->sbdma_eth       = s;
        d->sbdma_channel   = chan;
        d->sbdma_txdir     = txrx;

#if 0
        /* RMON clearing */
        s->sbe_idx =(s->sbm_base - A_MAC_BASE_0)/MAC_SPACING;
#endif

        __raw_writeq(0, s->sbm_base + R_MAC_RMON_TX_BYTES);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_COLLISIONS);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_LATE_COL);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_EX_COL);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_FCS_ERROR);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_TX_ABORT);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_TX_BAD);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_TX_GOOD);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_TX_RUNT);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_TX_OVERSIZE);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_BYTES);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_MCAST);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_BCAST);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_BAD);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_GOOD);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_RUNT);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_OVERSIZE);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_FCS_ERROR);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_LENGTH_ERROR);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_CODE_ERROR);
        __raw_writeq(0, s->sbm_base + R_MAC_RMON_RX_ALIGN_ERROR);

        /*
         * initialize register pointers
         */

        d->sbdma_config0 =
                s->sbm_base + R_MAC_DMA_REGISTER(txrx,chan,R_MAC_DMA_CONFIG0);
        d->sbdma_config1 =
                s->sbm_base + R_MAC_DMA_REGISTER(txrx,chan,R_MAC_DMA_CONFIG1);
        d->sbdma_dscrbase =
                s->sbm_base + R_MAC_DMA_REGISTER(txrx,chan,R_MAC_DMA_DSCR_BASE);
        d->sbdma_dscrcnt =
                s->sbm_base + R_MAC_DMA_REGISTER(txrx,chan,R_MAC_DMA_DSCR_CNT);
        d->sbdma_curdscr =
                s->sbm_base + R_MAC_DMA_REGISTER(txrx,chan,R_MAC_DMA_CUR_DSCRADDR);
        if (d->sbdma_txdir)
                d->sbdma_oodpktlost = NULL;
        else
                d->sbdma_oodpktlost =
                        s->sbm_base + R_MAC_DMA_REGISTER(txrx,chan,R_MAC_DMA_OODPKTLOST_RX);

        /*
         * Allocate memory for the ring
         */

        d->sbdma_maxdescr = maxdescr;

        d->sbdma_dscrtable_unaligned = kcalloc(d->sbdma_maxdescr + 1,
                                               sizeof(*d->sbdma_dscrtable),
                                               GFP_KERNEL);

        /*
         * The descriptor table must be aligned to at least 16 bytes or the
         * MAC will corrupt it.
         */
        d->sbdma_dscrtable = (struct sbdmadscr *)
                             ALIGN((unsigned long)d->sbdma_dscrtable_unaligned,
                                   sizeof(*d->sbdma_dscrtable));

        d->sbdma_dscrtable_end = d->sbdma_dscrtable + d->sbdma_maxdescr;

        d->sbdma_dscrtable_phys = virt_to_phys(d->sbdma_dscrtable);

        /*
         * And context table
         */

        d->sbdma_ctxtable = kcalloc(d->sbdma_maxdescr,
                                    sizeof(*d->sbdma_ctxtable), GFP_KERNEL);

#ifdef CONFIG_SBMAC_COALESCE
        /*
         * Setup Rx/Tx DMA coalescing defaults
         */

        int_pktcnt = (txrx == DMA_TX) ? int_pktcnt_tx : int_pktcnt_rx;
        if ( int_pktcnt ) {
                d->sbdma_int_pktcnt = int_pktcnt;
        } else {
                d->sbdma_int_pktcnt = 1;
        }

        int_timeout = (txrx == DMA_TX) ? int_timeout_tx : int_timeout_rx;
        if ( int_timeout ) {
                d->sbdma_int_timeout = int_timeout;
        } else {
                d->sbdma_int_timeout = 0;
        }
#endif

}

/**********************************************************************
 *  SBDMA_CHANNEL_START(d)
 *
 *  Initialize the hardware registers for a DMA channel.
 *
 *  Input parameters:
 *         d - DMA channel to init (context must be previously init'd
 *         rxtx - DMA_RX or DMA_TX depending on what type of channel
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbdma_channel_start(struct sbmacdma *d, int rxtx)
{
        /*
         * Turn on the DMA channel
         */

#ifdef CONFIG_SBMAC_COALESCE
        __raw_writeq(V_DMA_INT_TIMEOUT(d->sbdma_int_timeout) |
                       0, d->sbdma_config1);
        __raw_writeq(M_DMA_EOP_INT_EN |
                       V_DMA_RINGSZ(d->sbdma_maxdescr) |
                       V_DMA_INT_PKTCNT(d->sbdma_int_pktcnt) |
                       0, d->sbdma_config0);
#else
        __raw_writeq(0, d->sbdma_config1);
        __raw_writeq(V_DMA_RINGSZ(d->sbdma_maxdescr) |
                       0, d->sbdma_config0);
#endif

        __raw_writeq(d->sbdma_dscrtable_phys, d->sbdma_dscrbase);

        /*
         * Initialize ring pointers
         */

        d->sbdma_addptr = d->sbdma_dscrtable;
        d->sbdma_remptr = d->sbdma_dscrtable;
}

/**********************************************************************
 *  SBDMA_CHANNEL_STOP(d)
 *
 *  Initialize the hardware registers for a DMA channel.
 *
 *  Input parameters:
 *         d - DMA channel to init (context must be previously init'd
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbdma_channel_stop(struct sbmacdma *d)
{
        /*
         * Turn off the DMA channel
         */

        __raw_writeq(0, d->sbdma_config1);

        __raw_writeq(0, d->sbdma_dscrbase);

        __raw_writeq(0, d->sbdma_config0);

        /*
         * Zero ring pointers
         */

        d->sbdma_addptr = NULL;
        d->sbdma_remptr = NULL;
}

static inline void sbdma_align_skb(struct sk_buff *skb,
                                   unsigned int power2, unsigned int offset)
{
        unsigned char *addr = skb->data;
        unsigned char *newaddr = PTR_ALIGN(addr, power2);

        skb_reserve(skb, newaddr - addr + offset);
}


/**********************************************************************
 *  SBDMA_ADD_RCVBUFFER(d,sb)
 *
 *  Add a buffer to the specified DMA channel.   For receive channels,
 *  this queues a buffer for inbound packets.
 *
 *  Input parameters:
 *         sc - softc structure
 *          d - DMA channel descriptor
 *         sb - sk_buff to add, or NULL if we should allocate one
 *
 *  Return value:
 *         0 if buffer could not be added (ring is full)
 *         1 if buffer added successfully
 ********************************************************************* */


static int sbdma_add_rcvbuffer(struct sbmac_softc *sc, struct sbmacdma *d,
                               struct sk_buff *sb)
{
        struct net_device *dev = sc->sbm_dev;
        struct sbdmadscr *dsc;
        struct sbdmadscr *nextdsc;
        struct sk_buff *sb_new = NULL;
        int pktsize = ENET_PACKET_SIZE;

        /* get pointer to our current place in the ring */

        dsc = d->sbdma_addptr;
        nextdsc = SBDMA_NEXTBUF(d,sbdma_addptr);

        /*
         * figure out if the ring is full - if the next descriptor
         * is the same as the one that we're going to remove from
         * the ring, the ring is full
         */

        if (nextdsc == d->sbdma_remptr) {
                return -ENOSPC;
        }

        /*
         * Allocate a sk_buff if we don't already have one.
         * If we do have an sk_buff, reset it so that it's empty.
         *
         * Note: sk_buffs don't seem to be guaranteed to have any sort
         * of alignment when they are allocated.  Therefore, allocate enough
         * extra space to make sure that:
         *
         *    1. the data does not start in the middle of a cache line.
         *    2. The data does not end in the middle of a cache line
         *    3. The buffer can be aligned such that the IP addresses are
         *       naturally aligned.
         *
         *  Remember, the SOCs MAC writes whole cache lines at a time,
         *  without reading the old contents first.  So, if the sk_buff's
         *  data portion starts in the middle of a cache line, the SOC
         *  DMA will trash the beginning (and ending) portions.
         */

        if (sb == NULL) {
                sb_new = netdev_alloc_skb(dev, ENET_PACKET_SIZE +
                                               SMP_CACHE_BYTES * 2 +
                                               NET_IP_ALIGN);
                if (sb_new == NULL)
                        return -ENOBUFS;

                sbdma_align_skb(sb_new, SMP_CACHE_BYTES, NET_IP_ALIGN);
        }
        else {
                sb_new = sb;
                /*
                 * nothing special to reinit buffer, it's already aligned
                 * and sb->data already points to a good place.
                 */
        }

        /*
         * fill in the descriptor
         */

#ifdef CONFIG_SBMAC_COALESCE
        /*
         * Do not interrupt per DMA transfer.
         */
        dsc->dscr_a = virt_to_phys(sb_new->data) |
                V_DMA_DSCRA_A_SIZE(NUMCACHEBLKS(pktsize + NET_IP_ALIGN)) | 0;
#else
        dsc->dscr_a = virt_to_phys(sb_new->data) |
                V_DMA_DSCRA_A_SIZE(NUMCACHEBLKS(pktsize + NET_IP_ALIGN)) |
                M_DMA_DSCRA_INTERRUPT;
#endif

        /* receiving: no options */
        dsc->dscr_b = 0;

        /*
         * fill in the context
         */

        d->sbdma_ctxtable[dsc-d->sbdma_dscrtable] = sb_new;

        /*
         * point at next packet
         */

        d->sbdma_addptr = nextdsc;

        /*
         * Give the buffer to the DMA engine.
         */

        __raw_writeq(1, d->sbdma_dscrcnt);

        return 0;                                       /* we did it */
}

/**********************************************************************
 *  SBDMA_ADD_TXBUFFER(d,sb)
 *
 *  Add a transmit buffer to the specified DMA channel, causing a
 *  transmit to start.
 *
 *  Input parameters:
 *         d - DMA channel descriptor
 *         sb - sk_buff to add
 *
 *  Return value:
 *         0 transmit queued successfully
 *         otherwise error code
 ********************************************************************* */


static int sbdma_add_txbuffer(struct sbmacdma *d, struct sk_buff *sb)
{
        struct sbdmadscr *dsc;
        struct sbdmadscr *nextdsc;
        uint64_t phys;
        uint64_t ncb;
        int length;

        /* get pointer to our current place in the ring */

        dsc = d->sbdma_addptr;
        nextdsc = SBDMA_NEXTBUF(d,sbdma_addptr);

        /*
         * figure out if the ring is full - if the next descriptor
         * is the same as the one that we're going to remove from
         * the ring, the ring is full
         */

        if (nextdsc == d->sbdma_remptr) {
                return -ENOSPC;
        }

        /*
         * Under Linux, it's not necessary to copy/coalesce buffers
         * like it is on NetBSD.  We think they're all contiguous,
         * but that may not be true for GBE.
         */

        length = sb->len;

        /*
         * fill in the descriptor.  Note that the number of cache
         * blocks in the descriptor is the number of blocks
         * *spanned*, so we need to add in the offset (if any)
         * while doing the calculation.
         */

        phys = virt_to_phys(sb->data);
        ncb = NUMCACHEBLKS(length+(phys & (SMP_CACHE_BYTES - 1)));

        dsc->dscr_a = phys |
                V_DMA_DSCRA_A_SIZE(ncb) |
#ifndef CONFIG_SBMAC_COALESCE
                M_DMA_DSCRA_INTERRUPT |
#endif
                M_DMA_ETHTX_SOP;

        /* transmitting: set outbound options and length */

        dsc->dscr_b = V_DMA_DSCRB_OPTIONS(K_DMA_ETHTX_APPENDCRC_APPENDPAD) |
                V_DMA_DSCRB_PKT_SIZE(length);

        /*
         * fill in the context
         */

        d->sbdma_ctxtable[dsc-d->sbdma_dscrtable] = sb;

        /*
         * point at next packet
         */

        d->sbdma_addptr = nextdsc;

        /*
         * Give the buffer to the DMA engine.
         */

        __raw_writeq(1, d->sbdma_dscrcnt);

        return 0;                                       /* we did it */
}




/**********************************************************************
 *  SBDMA_EMPTYRING(d)
 *
 *  Free all allocated sk_buffs on the specified DMA channel;
 *
 *  Input parameters:
 *         d  - DMA channel
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbdma_emptyring(struct sbmacdma *d)
{
        int idx;
        struct sk_buff *sb;

        for (idx = 0; idx < d->sbdma_maxdescr; idx++) {
                sb = d->sbdma_ctxtable[idx];
                if (sb) {
                        dev_kfree_skb(sb);
                        d->sbdma_ctxtable[idx] = NULL;
                }
        }
}


/**********************************************************************
 *  SBDMA_FILLRING(d)
 *
 *  Fill the specified DMA channel (must be receive channel)
 *  with sk_buffs
 *
 *  Input parameters:
 *         sc - softc structure
 *          d - DMA channel
 *

 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbdma_fillring(struct sbmac_softc *sc, struct sbmacdma *d)
{
        int idx;

        for (idx = 0; idx < SBMAC_MAX_RXDESCR - 1; idx++) {
                if (sbdma_add_rcvbuffer(sc, d, NULL) != 0)
                        break;
        }
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void sbmac_netpoll(struct net_device *netdev)
{
        struct sbmac_softc *sc = netdev_priv(netdev);
        int irq = sc->sbm_dev->irq;

        __raw_writeq(0, sc->sbm_imr);

        sbmac_intr(irq, netdev);

#ifdef CONFIG_SBMAC_COALESCE
        __raw_writeq(((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_TX_CH0) |
        ((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_RX_CH0),
        sc->sbm_imr);
#else
        __raw_writeq((M_MAC_INT_CHANNEL << S_MAC_TX_CH0) |
        (M_MAC_INT_CHANNEL << S_MAC_RX_CH0), sc->sbm_imr);
#endif
}
#endif

/**********************************************************************
 *  SBDMA_RX_PROCESS(sc,d,work_to_do,poll)
 *
 *  Process "completed" receive buffers on the specified DMA channel.
 *
 *  Input parameters:
 *            sc - softc structure
 *             d - DMA channel context
 *    work_to_do - no. of packets to process before enabling interrupt
 *                 again (for NAPI)
 *          poll - 1: using polling (for NAPI)
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static int sbdma_rx_process(struct sbmac_softc *sc, struct sbmacdma *d,
                            int work_to_do, int poll)
{
        struct net_device *dev = sc->sbm_dev;
        int curidx;
        int hwidx;
        struct sbdmadscr *dsc;
        struct sk_buff *sb;
        int len;
        int work_done = 0;
        int dropped = 0;

        prefetch(d);

again:
        /* Check if the HW dropped any frames */
        dev->stats.rx_fifo_errors
            += __raw_readq(sc->sbm_rxdma.sbdma_oodpktlost) & 0xffff;
        __raw_writeq(0, sc->sbm_rxdma.sbdma_oodpktlost);

        while (work_to_do-- > 0) {
                /*
                 * figure out where we are (as an index) and where
                 * the hardware is (also as an index)
                 *
                 * This could be done faster if (for example) the
                 * descriptor table was page-aligned and contiguous in
                 * both virtual and physical memory -- you could then
                 * just compare the low-order bits of the virtual address
                 * (sbdma_remptr) and the physical address (sbdma_curdscr CSR)
                 */

                dsc = d->sbdma_remptr;
                curidx = dsc - d->sbdma_dscrtable;

                prefetch(dsc);
                prefetch(&d->sbdma_ctxtable[curidx]);

                hwidx = ((__raw_readq(d->sbdma_curdscr) & M_DMA_CURDSCR_ADDR) -
                         d->sbdma_dscrtable_phys) /
                        sizeof(*d->sbdma_dscrtable);

                /*
                 * If they're the same, that means we've processed all
                 * of the descriptors up to (but not including) the one that
                 * the hardware is working on right now.
                 */

                if (curidx == hwidx)
                        goto done;

                /*
                 * Otherwise, get the packet's sk_buff ptr back
                 */

                sb = d->sbdma_ctxtable[curidx];
                d->sbdma_ctxtable[curidx] = NULL;

                len = (int)G_DMA_DSCRB_PKT_SIZE(dsc->dscr_b) - 4;

                /*
                 * Check packet status.  If good, process it.
                 * If not, silently drop it and put it back on the
                 * receive ring.
                 */

                if (likely (!(dsc->dscr_a & M_DMA_ETHRX_BAD))) {

                        /*
                         * Add a new buffer to replace the old one.  If we fail
                         * to allocate a buffer, we're going to drop this
                         * packet and put it right back on the receive ring.
                         */

                        if (unlikely(sbdma_add_rcvbuffer(sc, d, NULL) ==
                                     -ENOBUFS)) {
                                dev->stats.rx_dropped++;
                                /* Re-add old buffer */
                                sbdma_add_rcvbuffer(sc, d, sb);
                                /* No point in continuing at the moment */
                                printk(KERN_ERR "dropped packet (1)\n");
                                d->sbdma_remptr = SBDMA_NEXTBUF(d,sbdma_remptr);
                                goto done;
                        } else {
                                /*
                                 * Set length into the packet
                                 */
                                skb_put(sb,len);

                                /*
                                 * Buffer has been replaced on the
                                 * receive ring.  Pass the buffer to
                                 * the kernel
                                 */
                                sb->protocol = eth_type_trans(sb,d->sbdma_eth->sbm_dev);
                                /* Check hw IPv4/TCP checksum if supported */
                                if (sc->rx_hw_checksum == ENABLE) {
                                        if (!((dsc->dscr_a) & M_DMA_ETHRX_BADIP4CS) &&
                                            !((dsc->dscr_a) & M_DMA_ETHRX_BADTCPCS)) {
                                                sb->ip_summed = CHECKSUM_UNNECESSARY;
                                                /* don't need to set sb->csum */
                                        } else {
                                                skb_checksum_none_assert(sb);
                                        }
                                }
                                prefetch(sb->data);
                                prefetch((const void *)(((char *)sb->data)+32));
                                if (poll)
                                        dropped = netif_receive_skb(sb);
                                else
                                        dropped = netif_rx(sb);

                                if (dropped == NET_RX_DROP) {
                                        dev->stats.rx_dropped++;
                                        d->sbdma_remptr = SBDMA_NEXTBUF(d,sbdma_remptr);
                                        goto done;
                                }
                                else {
                                        dev->stats.rx_bytes += len;
                                        dev->stats.rx_packets++;
                                }
                        }
                } else {
                        /*
                         * Packet was mangled somehow.  Just drop it and
                         * put it back on the receive ring.
                         */
                        dev->stats.rx_errors++;
                        sbdma_add_rcvbuffer(sc, d, sb);
                }


                /*
                 * .. and advance to the next buffer.
                 */

                d->sbdma_remptr = SBDMA_NEXTBUF(d,sbdma_remptr);
                work_done++;
        }
        if (!poll) {
                work_to_do = 32;
                goto again; /* collect fifo drop statistics again */
        }
done:
        return work_done;
}

/**********************************************************************
 *  SBDMA_TX_PROCESS(sc,d)
 *
 *  Process "completed" transmit buffers on the specified DMA channel.
 *  This is normally called within the interrupt service routine.
 *  Note that this isn't really ideal for priority channels, since
 *  it processes all of the packets on a given channel before
 *  returning.
 *
 *  Input parameters:
 *      sc - softc structure
 *       d - DMA channel context
 *    poll - 1: using polling (for NAPI)
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbdma_tx_process(struct sbmac_softc *sc, struct sbmacdma *d,
                             int poll)
{
        struct net_device *dev = sc->sbm_dev;
        int curidx;
        int hwidx;
        struct sbdmadscr *dsc;
        struct sk_buff *sb;
        unsigned long flags;
        int packets_handled = 0;

        spin_lock_irqsave(&(sc->sbm_lock), flags);

        if (d->sbdma_remptr == d->sbdma_addptr)
          goto end_unlock;

        hwidx = ((__raw_readq(d->sbdma_curdscr) & M_DMA_CURDSCR_ADDR) -
                 d->sbdma_dscrtable_phys) / sizeof(*d->sbdma_dscrtable);

        for (;;) {
                /*
                 * figure out where we are (as an index) and where
                 * the hardware is (also as an index)
                 *
                 * This could be done faster if (for example) the
                 * descriptor table was page-aligned and contiguous in
                 * both virtual and physical memory -- you could then
                 * just compare the low-order bits of the virtual address
                 * (sbdma_remptr) and the physical address (sbdma_curdscr CSR)
                 */

                curidx = d->sbdma_remptr - d->sbdma_dscrtable;

                /*
                 * If they're the same, that means we've processed all
                 * of the descriptors up to (but not including) the one that
                 * the hardware is working on right now.
                 */

                if (curidx == hwidx)
                        break;

                /*
                 * Otherwise, get the packet's sk_buff ptr back
                 */

                dsc = &(d->sbdma_dscrtable[curidx]);
                sb = d->sbdma_ctxtable[curidx];
                d->sbdma_ctxtable[curidx] = NULL;

                /*
                 * Stats
                 */

                dev->stats.tx_bytes += sb->len;
                dev->stats.tx_packets++;

                /*
                 * for transmits, we just free buffers.
                 */

                dev_consume_skb_irq(sb);

                /*
                 * .. and advance to the next buffer.
                 */

                d->sbdma_remptr = SBDMA_NEXTBUF(d,sbdma_remptr);

                packets_handled++;

        }

        /*
         * Decide if we should wake up the protocol or not.
         * Other drivers seem to do this when we reach a low
         * watermark on the transmit queue.
         */

        if (packets_handled)
                netif_wake_queue(d->sbdma_eth->sbm_dev);

end_unlock:
        spin_unlock_irqrestore(&(sc->sbm_lock), flags);

}



/**********************************************************************
 *  SBMAC_INITCTX(s)
 *
 *  Initialize an Ethernet context structure - this is called
 *  once per MAC on the 1250.  Memory is allocated here, so don't
 *  call it again from inside the ioctl routines that bring the
 *  interface up/down
 *
 *  Input parameters:
 *         s - sbmac context structure
 *
 *  Return value:
 *         0
 ********************************************************************* */

static int sbmac_initctx(struct sbmac_softc *s)
{

        /*
         * figure out the addresses of some ports
         */

        s->sbm_macenable = s->sbm_base + R_MAC_ENABLE;
        s->sbm_maccfg    = s->sbm_base + R_MAC_CFG;
        s->sbm_fifocfg   = s->sbm_base + R_MAC_THRSH_CFG;
        s->sbm_framecfg  = s->sbm_base + R_MAC_FRAMECFG;
        s->sbm_rxfilter  = s->sbm_base + R_MAC_ADFILTER_CFG;
        s->sbm_isr       = s->sbm_base + R_MAC_STATUS;
        s->sbm_imr       = s->sbm_base + R_MAC_INT_MASK;
        s->sbm_mdio      = s->sbm_base + R_MAC_MDIO;

        /*
         * Initialize the DMA channels.  Right now, only one per MAC is used
         * Note: Only do this _once_, as it allocates memory from the kernel!
         */

        sbdma_initctx(&(s->sbm_txdma),s,0,DMA_TX,SBMAC_MAX_TXDESCR);
        sbdma_initctx(&(s->sbm_rxdma),s,0,DMA_RX,SBMAC_MAX_RXDESCR);

        /*
         * initial state is OFF
         */

        s->sbm_state = sbmac_state_off;

        return 0;
}


static void sbdma_uninitctx(struct sbmacdma *d)
{
        kfree(d->sbdma_dscrtable_unaligned);
        d->sbdma_dscrtable_unaligned = d->sbdma_dscrtable = NULL;

        kfree(d->sbdma_ctxtable);
        d->sbdma_ctxtable = NULL;
}


static void sbmac_uninitctx(struct sbmac_softc *sc)
{
        sbdma_uninitctx(&(sc->sbm_txdma));
        sbdma_uninitctx(&(sc->sbm_rxdma));
}


/**********************************************************************
 *  SBMAC_CHANNEL_START(s)
 *
 *  Start packet processing on this MAC.
 *
 *  Input parameters:
 *         s - sbmac structure
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbmac_channel_start(struct sbmac_softc *s)
{
        uint64_t reg;
        void __iomem *port;
        uint64_t cfg,fifo,framecfg;
        int idx, th_value;

        /*
         * Don't do this if running
         */

        if (s->sbm_state == sbmac_state_on)
                return;

        /*
         * Bring the controller out of reset, but leave it off.
         */

        __raw_writeq(0, s->sbm_macenable);

        /*
         * Ignore all received packets
         */

        __raw_writeq(0, s->sbm_rxfilter);

        /*
         * Calculate values for various control registers.
         */

        cfg = M_MAC_RETRY_EN |
                M_MAC_TX_HOLD_SOP_EN |
                V_MAC_TX_PAUSE_CNT_16K |
                M_MAC_AP_STAT_EN |
                M_MAC_FAST_SYNC |
                M_MAC_SS_EN |
                0;

        /*
         * Be sure that RD_THRSH+WR_THRSH <= 32 for pass1 pars
         * and make sure that RD_THRSH + WR_THRSH <=128 for pass2 and above
         * Use a larger RD_THRSH for gigabit
         */
        if (soc_type == K_SYS_SOC_TYPE_BCM1250 && periph_rev < 2)
                th_value = 28;
        else
                th_value = 64;

        fifo = V_MAC_TX_WR_THRSH(4) |   /* Must be '4' or '8' */
                ((s->sbm_speed == sbmac_speed_1000)
                 ? V_MAC_TX_RD_THRSH(th_value) : V_MAC_TX_RD_THRSH(4)) |
                V_MAC_TX_RL_THRSH(4) |
                V_MAC_RX_PL_THRSH(4) |
                V_MAC_RX_RD_THRSH(4) |  /* Must be '4' */
                V_MAC_RX_RL_THRSH(8) |
                0;

        framecfg = V_MAC_MIN_FRAMESZ_DEFAULT |
                V_MAC_MAX_FRAMESZ_DEFAULT |
                V_MAC_BACKOFF_SEL(1);

        /*
         * Clear out the hash address map
         */

        port = s->sbm_base + R_MAC_HASH_BASE;
        for (idx = 0; idx < MAC_HASH_COUNT; idx++) {
                __raw_writeq(0, port);
                port += sizeof(uint64_t);
        }

        /*
         * Clear out the exact-match table
         */

        port = s->sbm_base + R_MAC_ADDR_BASE;
        for (idx = 0; idx < MAC_ADDR_COUNT; idx++) {
                __raw_writeq(0, port);
                port += sizeof(uint64_t);
        }

        /*
         * Clear out the DMA Channel mapping table registers
         */

        port = s->sbm_base + R_MAC_CHUP0_BASE;
        for (idx = 0; idx < MAC_CHMAP_COUNT; idx++) {
                __raw_writeq(0, port);
                port += sizeof(uint64_t);
        }


        port = s->sbm_base + R_MAC_CHLO0_BASE;
        for (idx = 0; idx < MAC_CHMAP_COUNT; idx++) {
                __raw_writeq(0, port);
                port += sizeof(uint64_t);
        }

        /*
         * Program the hardware address.  It goes into the hardware-address
         * register as well as the first filter register.
         */

        reg = sbmac_addr2reg(s->sbm_hwaddr);

        port = s->sbm_base + R_MAC_ADDR_BASE;
        __raw_writeq(reg, port);
        port = s->sbm_base + R_MAC_ETHERNET_ADDR;

        __raw_writeq(reg, port);

        /*
         * Set the receive filter for no packets, and write values
         * to the various config registers
         */

        __raw_writeq(0, s->sbm_rxfilter);
        __raw_writeq(0, s->sbm_imr);
        __raw_writeq(framecfg, s->sbm_framecfg);
        __raw_writeq(fifo, s->sbm_fifocfg);
        __raw_writeq(cfg, s->sbm_maccfg);

        /*
         * Initialize DMA channels (rings should be ok now)
         */

        sbdma_channel_start(&(s->sbm_rxdma), DMA_RX);
        sbdma_channel_start(&(s->sbm_txdma), DMA_TX);

        /*
         * Configure the speed, duplex, and flow control
         */

        sbmac_set_speed(s,s->sbm_speed);
        sbmac_set_duplex(s,s->sbm_duplex,s->sbm_fc);

        /*
         * Fill the receive ring
         */

        sbdma_fillring(s, &(s->sbm_rxdma));

        /*
         * Turn on the rest of the bits in the enable register
         */

#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
        __raw_writeq(M_MAC_RXDMA_EN0 |
                       M_MAC_TXDMA_EN0, s->sbm_macenable);
#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
        __raw_writeq(M_MAC_RXDMA_EN0 |
                       M_MAC_TXDMA_EN0 |
                       M_MAC_RX_ENABLE |
                       M_MAC_TX_ENABLE, s->sbm_macenable);
#else
#error invalid SiByte MAC configuration
#endif

#ifdef CONFIG_SBMAC_COALESCE
        __raw_writeq(((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_TX_CH0) |
                       ((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_RX_CH0), s->sbm_imr);
#else
        __raw_writeq((M_MAC_INT_CHANNEL << S_MAC_TX_CH0) |
                       (M_MAC_INT_CHANNEL << S_MAC_RX_CH0), s->sbm_imr);
#endif

        /*
         * Enable receiving unicasts and broadcasts
         */

        __raw_writeq(M_MAC_UCAST_EN | M_MAC_BCAST_EN, s->sbm_rxfilter);

        /*
         * we're running now.
         */

        s->sbm_state = sbmac_state_on;

        /*
         * Program multicast addresses
         */

        sbmac_setmulti(s);

        /*
         * If channel was in promiscuous mode before, turn that on
         */

        if (s->sbm_devflags & IFF_PROMISC) {
                sbmac_promiscuous_mode(s,1);
        }

}


/**********************************************************************
 *  SBMAC_CHANNEL_STOP(s)
 *
 *  Stop packet processing on this MAC.
 *
 *  Input parameters:
 *         s - sbmac structure
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbmac_channel_stop(struct sbmac_softc *s)
{
        /* don't do this if already stopped */

        if (s->sbm_state == sbmac_state_off)
                return;

        /* don't accept any packets, disable all interrupts */

        __raw_writeq(0, s->sbm_rxfilter);
        __raw_writeq(0, s->sbm_imr);

        /* Turn off ticker */

        /* XXX */

        /* turn off receiver and transmitter */

        __raw_writeq(0, s->sbm_macenable);

        /* We're stopped now. */

        s->sbm_state = sbmac_state_off;

        /*
         * Stop DMA channels (rings should be ok now)
         */

        sbdma_channel_stop(&(s->sbm_rxdma));
        sbdma_channel_stop(&(s->sbm_txdma));

        /* Empty the receive and transmit rings */

        sbdma_emptyring(&(s->sbm_rxdma));
        sbdma_emptyring(&(s->sbm_txdma));

}

/**********************************************************************
 *  SBMAC_SET_CHANNEL_STATE(state)
 *
 *  Set the channel's state ON or OFF
 *
 *  Input parameters:
 *         state - new state
 *
 *  Return value:
 *         old state
 ********************************************************************* */
static enum sbmac_state sbmac_set_channel_state(struct sbmac_softc *sc,
                                                enum sbmac_state state)
{
        enum sbmac_state oldstate = sc->sbm_state;

        /*
         * If same as previous state, return
         */

        if (state == oldstate) {
                return oldstate;
        }

        /*
         * If new state is ON, turn channel on
         */

        if (state == sbmac_state_on) {
                sbmac_channel_start(sc);
        }
        else {
                sbmac_channel_stop(sc);
        }

        /*
         * Return previous state
         */

        return oldstate;
}


/**********************************************************************
 *  SBMAC_PROMISCUOUS_MODE(sc,onoff)
 *
 *  Turn on or off promiscuous mode
 *
 *  Input parameters:
 *         sc - softc
 *      onoff - 1 to turn on, 0 to turn off
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbmac_promiscuous_mode(struct sbmac_softc *sc,int onoff)
{
        uint64_t reg;

        if (sc->sbm_state != sbmac_state_on)
                return;

        if (onoff) {
                reg = __raw_readq(sc->sbm_rxfilter);
                reg |= M_MAC_ALLPKT_EN;
                __raw_writeq(reg, sc->sbm_rxfilter);
        }
        else {
                reg = __raw_readq(sc->sbm_rxfilter);
                reg &= ~M_MAC_ALLPKT_EN;
                __raw_writeq(reg, sc->sbm_rxfilter);
        }
}

/**********************************************************************
 *  SBMAC_SETIPHDR_OFFSET(sc,onoff)
 *
 *  Set the iphdr offset as 15 assuming ethernet encapsulation
 *
 *  Input parameters:
 *         sc - softc
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbmac_set_iphdr_offset(struct sbmac_softc *sc)
{
        uint64_t reg;

        /* Hard code the off set to 15 for now */
        reg = __raw_readq(sc->sbm_rxfilter);
        reg &= ~M_MAC_IPHDR_OFFSET | V_MAC_IPHDR_OFFSET(15);
        __raw_writeq(reg, sc->sbm_rxfilter);

        /* BCM1250 pass1 didn't have hardware checksum.  Everything
           later does.  */
        if (soc_type == K_SYS_SOC_TYPE_BCM1250 && periph_rev < 2) {
                sc->rx_hw_checksum = DISABLE;
        } else {
                sc->rx_hw_checksum = ENABLE;
        }
}


/**********************************************************************
 *  SBMAC_ADDR2REG(ptr)
 *
 *  Convert six bytes into the 64-bit register value that
 *  we typically write into the SBMAC's address/mcast registers
 *
 *  Input parameters:
 *         ptr - pointer to 6 bytes
 *
 *  Return value:
 *         register value
 ********************************************************************* */

static uint64_t sbmac_addr2reg(unsigned char *ptr)
{
        uint64_t reg = 0;

        ptr += 6;

        reg |= (uint64_t) *(--ptr);
        reg <<= 8;
        reg |= (uint64_t) *(--ptr);
        reg <<= 8;
        reg |= (uint64_t) *(--ptr);
        reg <<= 8;
        reg |= (uint64_t) *(--ptr);
        reg <<= 8;
        reg |= (uint64_t) *(--ptr);
        reg <<= 8;
        reg |= (uint64_t) *(--ptr);

        return reg;
}


/**********************************************************************
 *  SBMAC_SET_SPEED(s,speed)
 *
 *  Configure LAN speed for the specified MAC.
 *  Warning: must be called when MAC is off!
 *
 *  Input parameters:
 *         s - sbmac structure
 *         speed - speed to set MAC to (see enum sbmac_speed)
 *
 *  Return value:
 *         1 if successful
 *      0 indicates invalid parameters
 ********************************************************************* */

static int sbmac_set_speed(struct sbmac_softc *s, enum sbmac_speed speed)
{
        uint64_t cfg;
        uint64_t framecfg;

        /*
         * Save new current values
         */

        s->sbm_speed = speed;

        if (s->sbm_state == sbmac_state_on)
                return 0;       /* save for next restart */

        /*
         * Read current register values
         */

        cfg = __raw_readq(s->sbm_maccfg);
        framecfg = __raw_readq(s->sbm_framecfg);

        /*
         * Mask out the stuff we want to change
         */

        cfg &= ~(M_MAC_BURST_EN | M_MAC_SPEED_SEL);
        framecfg &= ~(M_MAC_IFG_RX | M_MAC_IFG_TX | M_MAC_IFG_THRSH |
                      M_MAC_SLOT_SIZE);

        /*
         * Now add in the new bits
         */

        switch (speed) {
        case sbmac_speed_10:
                framecfg |= V_MAC_IFG_RX_10 |
                        V_MAC_IFG_TX_10 |
                        K_MAC_IFG_THRSH_10 |
                        V_MAC_SLOT_SIZE_10;
                cfg |= V_MAC_SPEED_SEL_10MBPS;
                break;

        case sbmac_speed_100:
                framecfg |= V_MAC_IFG_RX_100 |
                        V_MAC_IFG_TX_100 |
                        V_MAC_IFG_THRSH_100 |
                        V_MAC_SLOT_SIZE_100;
                cfg |= V_MAC_SPEED_SEL_100MBPS ;
                break;

        case sbmac_speed_1000:
                framecfg |= V_MAC_IFG_RX_1000 |
                        V_MAC_IFG_TX_1000 |
                        V_MAC_IFG_THRSH_1000 |
                        V_MAC_SLOT_SIZE_1000;
                cfg |= V_MAC_SPEED_SEL_1000MBPS | M_MAC_BURST_EN;
                break;

        default:
                return 0;
        }

        /*
         * Send the bits back to the hardware
         */

        __raw_writeq(framecfg, s->sbm_framecfg);
        __raw_writeq(cfg, s->sbm_maccfg);

        return 1;
}

/**********************************************************************
 *  SBMAC_SET_DUPLEX(s,duplex,fc)
 *
 *  Set Ethernet duplex and flow control options for this MAC
 *  Warning: must be called when MAC is off!
 *
 *  Input parameters:
 *         s - sbmac structure
 *         duplex - duplex setting (see enum sbmac_duplex)
 *         fc - flow control setting (see enum sbmac_fc)
 *
 *  Return value:
 *         1 if ok
 *         0 if an invalid parameter combination was specified
 ********************************************************************* */

static int sbmac_set_duplex(struct sbmac_softc *s, enum sbmac_duplex duplex,
                            enum sbmac_fc fc)
{
        uint64_t cfg;

        /*
         * Save new current values
         */

        s->sbm_duplex = duplex;
        s->sbm_fc = fc;

        if (s->sbm_state == sbmac_state_on)
                return 0;       /* save for next restart */

        /*
         * Read current register values
         */

        cfg = __raw_readq(s->sbm_maccfg);

        /*
         * Mask off the stuff we're about to change
         */

        cfg &= ~(M_MAC_FC_SEL | M_MAC_FC_CMD | M_MAC_HDX_EN);


        switch (duplex) {
        case sbmac_duplex_half:
                switch (fc) {
                case sbmac_fc_disabled:
                        cfg |= M_MAC_HDX_EN | V_MAC_FC_CMD_DISABLED;
                        break;

                case sbmac_fc_collision:
                        cfg |= M_MAC_HDX_EN | V_MAC_FC_CMD_ENABLED;
                        break;

                case sbmac_fc_carrier:
                        cfg |= M_MAC_HDX_EN | V_MAC_FC_CMD_ENAB_FALSECARR;
                        break;

                case sbmac_fc_frame:            /* not valid in half duplex */
                default:                        /* invalid selection */
                        return 0;
                }
                break;

        case sbmac_duplex_full:
                switch (fc) {
                case sbmac_fc_disabled:
                        cfg |= V_MAC_FC_CMD_DISABLED;
                        break;

                case sbmac_fc_frame:
                        cfg |= V_MAC_FC_CMD_ENABLED;
                        break;

                case sbmac_fc_collision:        /* not valid in full duplex */
                case sbmac_fc_carrier:          /* not valid in full duplex */
                default:
                        return 0;
                }
                break;
        default:
                return 0;
        }

        /*
         * Send the bits back to the hardware
         */

        __raw_writeq(cfg, s->sbm_maccfg);

        return 1;
}




/**********************************************************************
 *  SBMAC_INTR()
 *
 *  Interrupt handler for MAC interrupts
 *
 *  Input parameters:
 *         MAC structure
 *
 *  Return value:
 *         nothing
 ********************************************************************* */
static irqreturn_t sbmac_intr(int irq,void *dev_instance)
{
        struct net_device *dev = (struct net_device *) dev_instance;
        struct sbmac_softc *sc = netdev_priv(dev);
        uint64_t isr;
        int handled = 0;

        /*
         * Read the ISR (this clears the bits in the real
         * register, except for counter addr)
         */

        isr = __raw_readq(sc->sbm_isr) & ~M_MAC_COUNTER_ADDR;

        if (isr == 0)
                return IRQ_RETVAL(0);
        handled = 1;

        /*
         * Transmits on channel 0
         */

        if (isr & (M_MAC_INT_CHANNEL << S_MAC_TX_CH0))
                sbdma_tx_process(sc,&(sc->sbm_txdma), 0);

        if (isr & (M_MAC_INT_CHANNEL << S_MAC_RX_CH0)) {
                if (napi_schedule_prep(&sc->napi)) {
                        __raw_writeq(0, sc->sbm_imr);
                        __napi_schedule(&sc->napi);
                        /* Depend on the exit from poll to reenable intr */
                }
                else {
                        /* may leave some packets behind */
                        sbdma_rx_process(sc,&(sc->sbm_rxdma),
                                         SBMAC_MAX_RXDESCR * 2, 0);
                }

        }
        return IRQ_RETVAL(handled);
}

/**********************************************************************
 *  SBMAC_START_TX(skb,dev)
 *
 *  Start output on the specified interface.  Basically, we
 *  queue as many buffers as we can until the ring fills up, or
 *  we run off the end of the queue, whichever comes first.
 *
 *  Input parameters:
 *
 *
 *  Return value:
 *         nothing
 ********************************************************************* */
static netdev_tx_t sbmac_start_tx(struct sk_buff *skb, struct net_device *dev)
{
        struct sbmac_softc *sc = netdev_priv(dev);
        unsigned long flags;

        /* lock eth irq */
        spin_lock_irqsave(&sc->sbm_lock, flags);

        /*
         * Put the buffer on the transmit ring.  If we
         * don't have room, stop the queue.
         */

        if (sbdma_add_txbuffer(&(sc->sbm_txdma),skb)) {
                /* XXX save skb that we could not send */
                netif_stop_queue(dev);
                spin_unlock_irqrestore(&sc->sbm_lock, flags);

                return NETDEV_TX_BUSY;
        }

        spin_unlock_irqrestore(&sc->sbm_lock, flags);

        return NETDEV_TX_OK;
}

/**********************************************************************
 *  SBMAC_SETMULTI(sc)
 *
 *  Reprogram the multicast table into the hardware, given
 *  the list of multicasts associated with the interface
 *  structure.
 *
 *  Input parameters:
 *         sc - softc
 *
 *  Return value:
 *         nothing
 ********************************************************************* */

static void sbmac_setmulti(struct sbmac_softc *sc)
{
        uint64_t reg;
        void __iomem *port;
        int idx;
        struct netdev_hw_addr *ha;
        struct net_device *dev = sc->sbm_dev;

        /*
         * Clear out entire multicast table.  We do this by nuking
         * the entire hash table and all the direct matches except
         * the first one, which is used for our station address
         */

        for (idx = 1; idx < MAC_ADDR_COUNT; idx++) {
                port = sc->sbm_base + R_MAC_ADDR_BASE+(idx*sizeof(uint64_t));
                __raw_writeq(0, port);
        }

        for (idx = 0; idx < MAC_HASH_COUNT; idx++) {
                port = sc->sbm_base + R_MAC_HASH_BASE+(idx*sizeof(uint64_t));
                __raw_writeq(0, port);
        }

        /*
         * Clear the filter to say we don't want any multicasts.
         */

        reg = __raw_readq(sc->sbm_rxfilter);
        reg &= ~(M_MAC_MCAST_INV | M_MAC_MCAST_EN);
        __raw_writeq(reg, sc->sbm_rxfilter);

        if (dev->flags & IFF_ALLMULTI) {
                /*
                 * Enable ALL multicasts.  Do this by inverting the
                 * multicast enable bit.
                 */
                reg = __raw_readq(sc->sbm_rxfilter);
                reg |= (M_MAC_MCAST_INV | M_MAC_MCAST_EN);
                __raw_writeq(reg, sc->sbm_rxfilter);
                return;
        }


        /*
         * Progam new multicast entries.  For now, only use the
         * perfect filter.  In the future we'll need to use the
         * hash filter if the perfect filter overflows
         */

        /* XXX only using perfect filter for now, need to use hash
         * XXX if the table overflows */

        idx = 1;                /* skip station address */
        netdev_for_each_mc_addr(ha, dev) {
                if (idx == MAC_ADDR_COUNT)
                        break;
                reg = sbmac_addr2reg(ha->addr);
                port = sc->sbm_base + R_MAC_ADDR_BASE+(idx * sizeof(uint64_t));
                __raw_writeq(reg, port);
                idx++;
        }

        /*
         * Enable the "accept multicast bits" if we programmed at least one
         * multicast.
         */

        if (idx > 1) {
                reg = __raw_readq(sc->sbm_rxfilter);
                reg |= M_MAC_MCAST_EN;
                __raw_writeq(reg, sc->sbm_rxfilter);
        }
}

static const struct net_device_ops sbmac_netdev_ops = {
        .ndo_open               = sbmac_open,
        .ndo_stop               = sbmac_close,
        .ndo_start_xmit         = sbmac_start_tx,
        .ndo_set_rx_mode        = sbmac_set_rx_mode,
        .ndo_tx_timeout         = sbmac_tx_timeout,
        .ndo_eth_ioctl          = sbmac_mii_ioctl,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_set_mac_address    = eth_mac_addr,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = sbmac_netpoll,
#endif
};

/**********************************************************************
 *  SBMAC_INIT(dev)
 *
 *  Attach routine - init hardware and hook ourselves into linux
 *
 *  Input parameters:
 *         dev - net_device structure
 *
 *  Return value:
 *         status
 ********************************************************************* */

static int sbmac_init(struct platform_device *pldev, long long base)
{
        struct net_device *dev = platform_get_drvdata(pldev);
        int idx = pldev->id;
        struct sbmac_softc *sc = netdev_priv(dev);
        unsigned char *eaddr;
        uint64_t ea_reg;
        int i;
        int err;

        sc->sbm_dev = dev;
        sc->sbe_idx = idx;

        eaddr = sc->sbm_hwaddr;

        /*
         * Read the ethernet address.  The firmware left this programmed
         * for us in the ethernet address register for each mac.
         */

        ea_reg = __raw_readq(sc->sbm_base + R_MAC_ETHERNET_ADDR);
        __raw_writeq(0, sc->sbm_base + R_MAC_ETHERNET_ADDR);
        for (i = 0; i < 6; i++) {
                eaddr[i] = (uint8_t) (ea_reg & 0xFF);
                ea_reg >>= 8;
        }

        for (i = 0; i < 6; i++) {
                dev->dev_addr[i] = eaddr[i];
        }

        /*
         * Initialize context (get pointers to registers and stuff), then
         * allocate the memory for the descriptor tables.
         */

        sbmac_initctx(sc);

        /*
         * Set up Linux device callins
         */

        spin_lock_init(&(sc->sbm_lock));

        dev->netdev_ops = &sbmac_netdev_ops;
        dev->watchdog_timeo = TX_TIMEOUT;
        dev->min_mtu = 0;
        dev->max_mtu = ENET_PACKET_SIZE;

        netif_napi_add(dev, &sc->napi, sbmac_poll, 16);

        dev->irq                = UNIT_INT(idx);

        /* This is needed for PASS2 for Rx H/W checksum feature */
        sbmac_set_iphdr_offset(sc);

        sc->mii_bus = mdiobus_alloc();
        if (sc->mii_bus == NULL) {
                err = -ENOMEM;
                goto uninit_ctx;
        }

        sc->mii_bus->name = sbmac_mdio_string;
        snprintf(sc->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
                pldev->name, idx);
        sc->mii_bus->priv = sc;
        sc->mii_bus->read = sbmac_mii_read;
        sc->mii_bus->write = sbmac_mii_write;

        sc->mii_bus->parent = &pldev->dev;
        /*
         * Probe PHY address
         */
        err = mdiobus_register(sc->mii_bus);
        if (err) {
                printk(KERN_ERR "%s: unable to register MDIO bus\n",
                       dev->name);
                goto free_mdio;
        }
        platform_set_drvdata(pldev, sc->mii_bus);

        err = register_netdev(dev);
        if (err) {
                printk(KERN_ERR "%s.%d: unable to register netdev\n",
                       sbmac_string, idx);
                goto unreg_mdio;
        }

        pr_info("%s.%d: registered as %s\n", sbmac_string, idx, dev->name);

        if (sc->rx_hw_checksum == ENABLE)
                pr_info("%s: enabling TCP rcv checksum\n", dev->name);

        /*
         * Display Ethernet address (this is called during the config
         * process so we need to finish off the config message that
         * was being displayed)
         */
        pr_info("%s: SiByte Ethernet at 0x%08Lx, address: %pM\n",
               dev->name, base, eaddr);

        return 0;
unreg_mdio:
        mdiobus_unregister(sc->mii_bus);
free_mdio:
        mdiobus_free(sc->mii_bus);
uninit_ctx:
        sbmac_uninitctx(sc);
        return err;
}


static int sbmac_open(struct net_device *dev)
{
        struct sbmac_softc *sc = netdev_priv(dev);
        int err;

        if (debug > 1)
                pr_debug("%s: sbmac_open() irq %d.\n", dev->name, dev->irq);

        /*
         * map/route interrupt (clear status first, in case something
         * weird is pending; we haven't initialized the mac registers
         * yet)
         */

        __raw_readq(sc->sbm_isr);
        err = request_irq(dev->irq, sbmac_intr, IRQF_SHARED, dev->name, dev);
        if (err) {
                printk(KERN_ERR "%s: unable to get IRQ %d\n", dev->name,
                       dev->irq);
                goto out_err;
        }

        sc->sbm_speed = sbmac_speed_none;
        sc->sbm_duplex = sbmac_duplex_none;
        sc->sbm_fc = sbmac_fc_none;
        sc->sbm_pause = -1;
        sc->sbm_link = 0;

        /*
         * Attach to the PHY
         */
        err = sbmac_mii_probe(dev);
        if (err)
                goto out_unregister;

        /*
         * Turn on the channel
         */

        sbmac_set_channel_state(sc,sbmac_state_on);

        netif_start_queue(dev);

        sbmac_set_rx_mode(dev);

        phy_start(sc->phy_dev);

        napi_enable(&sc->napi);

        return 0;

out_unregister:
        free_irq(dev->irq, dev);
out_err:
        return err;
}

static int sbmac_mii_probe(struct net_device *dev)
{
        struct sbmac_softc *sc = netdev_priv(dev);
        struct phy_device *phy_dev;

        phy_dev = phy_find_first(sc->mii_bus);
        if (!phy_dev) {
                printk(KERN_ERR "%s: no PHY found\n", dev->name);
                return -ENXIO;
        }

        phy_dev = phy_connect(dev, dev_name(&phy_dev->mdio.dev),
                              &sbmac_mii_poll, PHY_INTERFACE_MODE_GMII);
        if (IS_ERR(phy_dev)) {
                printk(KERN_ERR "%s: could not attach to PHY\n", dev->name);
                return PTR_ERR(phy_dev);
        }

        /* Remove any features not supported by the controller */
        phy_set_max_speed(phy_dev, SPEED_1000);
        phy_support_asym_pause(phy_dev);

        phy_attached_info(phy_dev);

        sc->phy_dev = phy_dev;

        return 0;
}


static void sbmac_mii_poll(struct net_device *dev)
{
        struct sbmac_softc *sc = netdev_priv(dev);
        struct phy_device *phy_dev = sc->phy_dev;
        unsigned long flags;
        enum sbmac_fc fc;
        int link_chg, speed_chg, duplex_chg, pause_chg, fc_chg;

        link_chg = (sc->sbm_link != phy_dev->link);
        speed_chg = (sc->sbm_speed != phy_dev->speed);
        duplex_chg = (sc->sbm_duplex != phy_dev->duplex);
        pause_chg = (sc->sbm_pause != phy_dev->pause);

        if (!link_chg && !speed_chg && !duplex_chg && !pause_chg)
                return;                                 /* Hmmm... */

        if (!phy_dev->link) {
                if (link_chg) {
                        sc->sbm_link = phy_dev->link;
                        sc->sbm_speed = sbmac_speed_none;
                        sc->sbm_duplex = sbmac_duplex_none;
                        sc->sbm_fc = sbmac_fc_disabled;
                        sc->sbm_pause = -1;
                        pr_info("%s: link unavailable\n", dev->name);
                }
                return;
        }

        if (phy_dev->duplex == DUPLEX_FULL) {
                if (phy_dev->pause)
                        fc = sbmac_fc_frame;
                else
                        fc = sbmac_fc_disabled;
        } else
                fc = sbmac_fc_collision;
        fc_chg = (sc->sbm_fc != fc);

        pr_info("%s: link available: %dbase-%cD\n", dev->name, phy_dev->speed,
                phy_dev->duplex == DUPLEX_FULL ? 'F' : 'H');

        spin_lock_irqsave(&sc->sbm_lock, flags);

        sc->sbm_speed = phy_dev->speed;
        sc->sbm_duplex = phy_dev->duplex;
        sc->sbm_fc = fc;
        sc->sbm_pause = phy_dev->pause;
        sc->sbm_link = phy_dev->link;

        if ((speed_chg || duplex_chg || fc_chg) &&
            sc->sbm_state != sbmac_state_off) {
                /*
                 * something changed, restart the channel
                 */
                if (debug > 1)
                        pr_debug("%s: restarting channel "
                                 "because PHY state changed\n", dev->name);
                sbmac_channel_stop(sc);
                sbmac_channel_start(sc);
        }

        spin_unlock_irqrestore(&sc->sbm_lock, flags);
}


static void sbmac_tx_timeout (struct net_device *dev, unsigned int txqueue)
{
        struct sbmac_softc *sc = netdev_priv(dev);
        unsigned long flags;

        spin_lock_irqsave(&sc->sbm_lock, flags);


        netif_trans_update(dev); /* prevent tx timeout */
        dev->stats.tx_errors++;

        spin_unlock_irqrestore(&sc->sbm_lock, flags);

        printk (KERN_WARNING "%s: Transmit timed out\n",dev->name);
}




static void sbmac_set_rx_mode(struct net_device *dev)
{
        unsigned long flags;
        struct sbmac_softc *sc = netdev_priv(dev);

        spin_lock_irqsave(&sc->sbm_lock, flags);
        if ((dev->flags ^ sc->sbm_devflags) & IFF_PROMISC) {
                /*
                 * Promiscuous changed.
                 */

                if (dev->flags & IFF_PROMISC) {
                        sbmac_promiscuous_mode(sc,1);
                }
                else {
                        sbmac_promiscuous_mode(sc,0);
                }
        }
        spin_unlock_irqrestore(&sc->sbm_lock, flags);

        /*
         * Program the multicasts.  Do this every time.
         */

        sbmac_setmulti(sc);

}

static int sbmac_mii_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
        struct sbmac_softc *sc = netdev_priv(dev);

        if (!netif_running(dev) || !sc->phy_dev)
                return -EINVAL;

        return phy_mii_ioctl(sc->phy_dev, rq, cmd);
}

static int sbmac_close(struct net_device *dev)
{
        struct sbmac_softc *sc = netdev_priv(dev);

        napi_disable(&sc->napi);

        phy_stop(sc->phy_dev);

        sbmac_set_channel_state(sc, sbmac_state_off);

        netif_stop_queue(dev);

        if (debug > 1)
                pr_debug("%s: Shutting down ethercard\n", dev->name);

        phy_disconnect(sc->phy_dev);
        sc->phy_dev = NULL;
        free_irq(dev->irq, dev);

        sbdma_emptyring(&(sc->sbm_txdma));
        sbdma_emptyring(&(sc->sbm_rxdma));

        return 0;
}

static int sbmac_poll(struct napi_struct *napi, int budget)
{
        struct sbmac_softc *sc = container_of(napi, struct sbmac_softc, napi);
        int work_done;

        work_done = sbdma_rx_process(sc, &(sc->sbm_rxdma), budget, 1);
        sbdma_tx_process(sc, &(sc->sbm_txdma), 1);

        if (work_done < budget) {
                napi_complete_done(napi, work_done);

#ifdef CONFIG_SBMAC_COALESCE
                __raw_writeq(((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_TX_CH0) |
                             ((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_RX_CH0),
                             sc->sbm_imr);
#else
                __raw_writeq((M_MAC_INT_CHANNEL << S_MAC_TX_CH0) |
                             (M_MAC_INT_CHANNEL << S_MAC_RX_CH0), sc->sbm_imr);
#endif
        }

        return work_done;
}


static int sbmac_probe(struct platform_device *pldev)
{
        struct net_device *dev;
        struct sbmac_softc *sc;
        void __iomem *sbm_base;
        struct resource *res;
        u64 sbmac_orig_hwaddr;
        int err;

        res = platform_get_resource(pldev, IORESOURCE_MEM, 0);
        BUG_ON(!res);
        sbm_base = ioremap(res->start, resource_size(res));
        if (!sbm_base) {
                printk(KERN_ERR "%s: unable to map device registers\n",
                       dev_name(&pldev->dev));
                err = -ENOMEM;
                goto out_out;
        }

        /*
         * The R_MAC_ETHERNET_ADDR register will be set to some nonzero
         * value for us by the firmware if we're going to use this MAC.
         * If we find a zero, skip this MAC.
         */
        sbmac_orig_hwaddr = __raw_readq(sbm_base + R_MAC_ETHERNET_ADDR);
        pr_debug("%s: %sconfiguring MAC at 0x%08Lx\n", dev_name(&pldev->dev),
                 sbmac_orig_hwaddr ? "" : "not ", (long long)res->start);
        if (sbmac_orig_hwaddr == 0) {
                err = 0;
                goto out_unmap;
        }

        /*
         * Okay, cool.  Initialize this MAC.
         */
        dev = alloc_etherdev(sizeof(struct sbmac_softc));
        if (!dev) {
                err = -ENOMEM;
                goto out_unmap;
        }

        platform_set_drvdata(pldev, dev);
        SET_NETDEV_DEV(dev, &pldev->dev);

        sc = netdev_priv(dev);
        sc->sbm_base = sbm_base;

        err = sbmac_init(pldev, res->start);
        if (err)
                goto out_kfree;

        return 0;

out_kfree:
        free_netdev(dev);
        __raw_writeq(sbmac_orig_hwaddr, sbm_base + R_MAC_ETHERNET_ADDR);

out_unmap:
        iounmap(sbm_base);

out_out:
        return err;
}

static int sbmac_remove(struct platform_device *pldev)
{
        struct net_device *dev = platform_get_drvdata(pldev);
        struct sbmac_softc *sc = netdev_priv(dev);

        unregister_netdev(dev);
        sbmac_uninitctx(sc);
        mdiobus_unregister(sc->mii_bus);
        mdiobus_free(sc->mii_bus);
        iounmap(sc->sbm_base);
        free_netdev(dev);

        return 0;
}

static struct platform_driver sbmac_driver = {
        .probe = sbmac_probe,
        .remove = sbmac_remove,
        .driver = {
                .name = sbmac_string,
        },
};

module_platform_driver(sbmac_driver);
MODULE_LICENSE("GPL");