[NET] drivers/net: statistics cleanup #1 -- save memory and shrink code

[net-next-2.6.git] / drivers / net / sb1250-mac.c

/*
 * Copyright (C) 2001,2002,2003,2004 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 *
 * This driver is designed for the Broadcom SiByte SOC built-in
 * Ethernet controllers. Written by Mitch Lichtenberg at Broadcom Corp.
 */
#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/init.h>
#include <linux/bitops.h>
#include <asm/processor.h>		/* Processor type for cache alignment. */
#include <asm/io.h>
#include <asm/cache.h>

/* This is only here until the firmware is ready.  In that case,
   the firmware leaves the ethernet address in the register for us. */
#ifdef CONFIG_SIBYTE_STANDALONE
#define SBMAC_ETH0_HWADDR "40:00:00:00:01:00"
#define SBMAC_ETH1_HWADDR "40:00:00:00:01:01"
#define SBMAC_ETH2_HWADDR "40:00:00:00:01:02"
#define SBMAC_ETH3_HWADDR "40:00:00:00:01:03"
#endif


/* These identify the driver base version and may not be removed. */
#if 0
static char version1[] __devinitdata =
"sb1250-mac.c:1.00 1/11/2001 Written by Mitch Lichtenberg\n";
#endif


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

#define CONFIG_SBMAC_COALESCE

#define MAX_UNITS 4		/* More are supported, limit only on options */

/* 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, S_IRUGO);
MODULE_PARM_DESC(debug, "Debug messages");

/* mii status msgs */
static int noisy_mii = 1;
module_param(noisy_mii, int, S_IRUGO);
MODULE_PARM_DESC(noisy_mii, "MII status messages");

/* Used to pass the media type, etc.
   Both 'options[]' and 'full_duplex[]' should exist for driver
   interoperability.
   The media type is usually passed in 'options[]'.
*/
#ifdef MODULE
static int options[MAX_UNITS] = {-1, -1, -1, -1};
module_param_array(options, int, NULL, S_IRUGO);
MODULE_PARM_DESC(options, "1-" __MODULE_STRING(MAX_UNITS));

static int full_duplex[MAX_UNITS] = {-1, -1, -1, -1};
module_param_array(full_duplex, int, NULL, S_IRUGO);
MODULE_PARM_DESC(full_duplex, "1-" __MODULE_STRING(MAX_UNITS));
#endif

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

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

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

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

#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 configuation
#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 configuation
#endif

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


typedef enum { sbmac_speed_auto, sbmac_speed_10,
	       sbmac_speed_100, sbmac_speed_1000 } sbmac_speed_t;

typedef enum { sbmac_duplex_auto, sbmac_duplex_half,
	       sbmac_duplex_full } sbmac_duplex_t;

typedef enum { sbmac_fc_auto, sbmac_fc_disabled, sbmac_fc_frame,
	       sbmac_fc_collision, sbmac_fc_carrier } sbmac_fc_t;

typedef enum { sbmac_state_uninit, sbmac_state_off, sbmac_state_on,
	       sbmac_state_broken } sbmac_state_t;


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


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


#define NUMCACHEBLKS(x) (((x)+SMP_CACHE_BYTES-1)/SMP_CACHE_BYTES)

#define SBMAC_MAX_TXDESCR	256
#define SBMAC_MAX_RXDESCR	256

#define ETHER_ALIGN	2
#define ETHER_ADDR_LEN	6
#define ENET_PACKET_SIZE	1518
/*#define ENET_PACKET_SIZE	9216 */

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

typedef struct sbdmadscr_s {
	uint64_t  dscr_a;
	uint64_t  dscr_b;
} sbdmadscr_t;

typedef unsigned long paddr_t;

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

typedef struct sbmacdma_s {

	/*
	 * 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

	volatile void __iomem *sbdma_config0;	/* DMA config register 0 */
	volatile void __iomem *sbdma_config1;	/* DMA config register 1 */
	volatile void __iomem *sbdma_dscrbase;	/* Descriptor base address */
	volatile void __iomem *sbdma_dscrcnt;   /* Descriptor count register */
	volatile void __iomem *sbdma_curdscr;	/* current descriptor address */
	volatile void __iomem *sbdma_oodpktlost;/* pkt drop (rx only) */


	/*
	 * This stuff is for maintenance of the ring
	 */

	sbdmadscr_t     *sbdma_dscrtable_unaligned;
	sbdmadscr_t     *sbdma_dscrtable;	/* base of descriptor table */
	sbdmadscr_t     *sbdma_dscrtable_end; /* end of descriptor table */

	struct sk_buff **sbdma_ctxtable;    /* context table, one per descr */

	paddr_t          sbdma_dscrtable_phys; /* and also the phys addr */
	sbdmadscr_t     *sbdma_addptr;	/* next dscr for sw to add */
	sbdmadscr_t     *sbdma_remptr;	/* next dscr for sw to remove */
} sbmacdma_t;


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

struct sbmac_softc {

	/*
	 * Linux-specific things
	 */

	struct net_device *sbm_dev;		/* pointer to linux device */
	struct napi_struct napi;
	spinlock_t sbm_lock;		/* spin lock */
	struct timer_list sbm_timer;     	/* for monitoring MII */
	int sbm_devflags;			/* current device flags */

	int	     sbm_phy_oldbmsr;
	int	     sbm_phy_oldanlpar;
	int	     sbm_phy_oldk1stsr;
	int	     sbm_phy_oldlinkstat;
	int sbm_buffersize;

	unsigned char sbm_phys[2];

	/*
	 * Controller-specific things
	 */

	void __iomem		*sbm_base;          /* MAC's base address */
	sbmac_state_t    sbm_state;         /* current state */

	volatile void __iomem	*sbm_macenable;	/* MAC Enable Register */
	volatile void __iomem	*sbm_maccfg;	/* MAC Configuration Register */
	volatile void __iomem	*sbm_fifocfg;	/* FIFO configuration register */
	volatile void __iomem	*sbm_framecfg;	/* Frame configuration register */
	volatile void __iomem	*sbm_rxfilter;	/* receive filter register */
	volatile void __iomem	*sbm_isr;	/* Interrupt status register */
	volatile void __iomem	*sbm_imr;	/* Interrupt mask register */
	volatile void __iomem	*sbm_mdio;	/* MDIO register */

	sbmac_speed_t    sbm_speed;		/* current speed */
	sbmac_duplex_t   sbm_duplex;	/* current duplex */
	sbmac_fc_t       sbm_fc;		/* current flow control setting */

	unsigned char    sbm_hwaddr[ETHER_ADDR_LEN];

	sbmacdma_t       sbm_txdma;		/* for now, only use channel 0 */
	sbmacdma_t       sbm_rxdma;
	int              rx_hw_checksum;
	int 		 sbe_idx;
};


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

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

static void sbdma_initctx(sbmacdma_t *d,
			  struct sbmac_softc *s,
			  int chan,
			  int txrx,
			  int maxdescr);
static void sbdma_channel_start(sbmacdma_t *d, int rxtx);
static int sbdma_add_rcvbuffer(sbmacdma_t *d,struct sk_buff *m);
static int sbdma_add_txbuffer(sbmacdma_t *d,struct sk_buff *m);
static void sbdma_emptyring(sbmacdma_t *d);
static void sbdma_fillring(sbmacdma_t *d);
static int sbdma_rx_process(struct sbmac_softc *sc,sbmacdma_t *d, int work_to_do, int poll);
static void sbdma_tx_process(struct sbmac_softc *sc,sbmacdma_t *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 sbmac_state_t sbmac_set_channel_state(struct sbmac_softc *,sbmac_state_t);
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 int sbmac_start_tx(struct sk_buff *skb, struct net_device *dev);
static void sbmac_setmulti(struct sbmac_softc *sc);
static int sbmac_init(struct net_device *dev, int idx);
static int sbmac_set_speed(struct sbmac_softc *s,sbmac_speed_t speed);
static int sbmac_set_duplex(struct sbmac_softc *s,sbmac_duplex_t duplex,sbmac_fc_t fc);

static int sbmac_open(struct net_device *dev);
static void sbmac_timer(unsigned long data);
static void sbmac_tx_timeout (struct net_device *dev);
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 int sbmac_mii_poll(struct sbmac_softc *s,int noisy);
static int sbmac_mii_probe(struct net_device *dev);

static void sbmac_mii_sync(struct sbmac_softc *s);
static void sbmac_mii_senddata(struct sbmac_softc *s,unsigned int data, int bitcnt);
static unsigned int sbmac_mii_read(struct sbmac_softc *s,int phyaddr,int regidx);
static void sbmac_mii_write(struct sbmac_softc *s,int phyaddr,int regidx,
			    unsigned int regval);


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

static uint64_t sbmac_orig_hwaddr[MAX_UNITS];


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

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

#define BMCR_RESET     0x8000
#define BMCR_LOOPBACK  0x4000
#define BMCR_SPEED0    0x2000
#define BMCR_ANENABLE  0x1000
#define BMCR_POWERDOWN 0x0800
#define BMCR_ISOLATE   0x0400
#define BMCR_RESTARTAN 0x0200
#define BMCR_DUPLEX    0x0100
#define BMCR_COLTEST   0x0080
#define BMCR_SPEED1    0x0040
#define BMCR_SPEED1000	BMCR_SPEED1
#define BMCR_SPEED100	BMCR_SPEED0
#define BMCR_SPEED10 	0

#define BMSR_100BT4	0x8000
#define BMSR_100BT_FDX	0x4000
#define BMSR_100BT_HDX  0x2000
#define BMSR_10BT_FDX   0x1000
#define BMSR_10BT_HDX   0x0800
#define BMSR_100BT2_FDX 0x0400
#define BMSR_100BT2_HDX 0x0200
#define BMSR_1000BT_XSR	0x0100
#define BMSR_PRESUP	0x0040
#define BMSR_ANCOMPLT	0x0020
#define BMSR_REMFAULT	0x0010
#define BMSR_AUTONEG	0x0008
#define BMSR_LINKSTAT	0x0004
#define BMSR_JABDETECT	0x0002
#define BMSR_EXTCAPAB	0x0001

#define PHYIDR1 	0x2000
#define PHYIDR2		0x5C60

#define ANAR_NP		0x8000
#define ANAR_RF		0x2000
#define ANAR_ASYPAUSE	0x0800
#define ANAR_PAUSE	0x0400
#define ANAR_T4		0x0200
#define ANAR_TXFD	0x0100
#define ANAR_TXHD	0x0080
#define ANAR_10FD	0x0040
#define ANAR_10HD	0x0020
#define ANAR_PSB	0x0001

#define ANLPAR_NP	0x8000
#define ANLPAR_ACK	0x4000
#define ANLPAR_RF	0x2000
#define ANLPAR_ASYPAUSE	0x0800
#define ANLPAR_PAUSE	0x0400
#define ANLPAR_T4	0x0200
#define ANLPAR_TXFD	0x0100
#define ANLPAR_TXHD	0x0080
#define ANLPAR_10FD	0x0040
#define ANLPAR_10HD	0x0020
#define ANLPAR_PSB	0x0001	/* 802.3 */

#define ANER_PDF	0x0010
#define ANER_LPNPABLE	0x0008
#define ANER_NPABLE	0x0004
#define ANER_PAGERX	0x0002
#define ANER_LPANABLE	0x0001

#define ANNPTR_NP	0x8000
#define ANNPTR_MP	0x2000
#define ANNPTR_ACK2	0x1000
#define ANNPTR_TOGTX	0x0800
#define ANNPTR_CODE	0x0008

#define ANNPRR_NP	0x8000
#define ANNPRR_MP	0x2000
#define ANNPRR_ACK3	0x1000
#define ANNPRR_TOGTX	0x0800
#define ANNPRR_CODE	0x0008

#define K1TCR_TESTMODE	0x0000
#define K1TCR_MSMCE	0x1000
#define K1TCR_MSCV	0x0800
#define K1TCR_RPTR	0x0400
#define K1TCR_1000BT_FDX 0x200
#define K1TCR_1000BT_HDX 0x100

#define K1STSR_MSMCFLT	0x8000
#define K1STSR_MSCFGRES	0x4000
#define K1STSR_LRSTAT	0x2000
#define K1STSR_RRSTAT	0x1000
#define K1STSR_LP1KFD	0x0800
#define K1STSR_LP1KHD   0x0400
#define K1STSR_LPASMDIR	0x0200

#define K1SCR_1KX_FDX	0x8000
#define K1SCR_1KX_HDX	0x4000
#define K1SCR_1KT_FDX	0x2000
#define K1SCR_1KT_HDX	0x1000

#define STRAP_PHY1	0x0800
#define STRAP_NCMODE	0x0400
#define STRAP_MANMSCFG	0x0200
#define STRAP_ANENABLE	0x0100
#define STRAP_MSVAL	0x0080
#define STRAP_1KHDXADV	0x0010
#define STRAP_1KFDXADV	0x0008
#define STRAP_100ADV	0x0004
#define STRAP_SPEEDSEL	0x0000
#define STRAP_SPEED100	0x0001

#define PHYSUP_SPEED1000 0x10
#define PHYSUP_SPEED100  0x08
#define PHYSUP_SPEED10   0x00
#define PHYSUP_LINKUP	 0x04
#define PHYSUP_FDX       0x02

#define	MII_BMCR	0x00 	/* Basic mode control register (rw) */
#define	MII_BMSR	0x01	/* Basic mode status register (ro) */
#define	MII_PHYIDR1	0x02
#define	MII_PHYIDR2	0x03

#define MII_K1STSR	0x0A	/* 1K Status Register (ro) */
#define	MII_ANLPAR	0x05	/* Autonegotiation lnk partner abilities (rw) */


#define M_MAC_MDIO_DIR_OUTPUT	0		/* for clarity */

#define ENABLE 		1
#define DISABLE		0

/**********************************************************************
 *  SBMAC_MII_SYNC(s)
 *
 *  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:
 *  	   s - sbmac structure
 *
 *  Return value:
 *  	   nothing
 ********************************************************************* */

static void sbmac_mii_sync(struct sbmac_softc *s)
{
	int cnt;
	uint64_t bits;
	int mac_mdio_genc;

	mac_mdio_genc = __raw_readq(s->sbm_mdio) & M_MAC_GENC;

	bits = M_MAC_MDIO_DIR_OUTPUT | M_MAC_MDIO_OUT;

	__raw_writeq(bits | mac_mdio_genc, s->sbm_mdio);

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

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

static void sbmac_mii_senddata(struct sbmac_softc *s,unsigned int data, int bitcnt)
{
	int i;
	uint64_t bits;
	unsigned int curmask;
	int mac_mdio_genc;

	mac_mdio_genc = __raw_readq(s->sbm_mdio) & M_MAC_GENC;

	bits = M_MAC_MDIO_DIR_OUTPUT;
	__raw_writeq(bits | mac_mdio_genc, s->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, s->sbm_mdio);
		__raw_writeq(bits | M_MAC_MDC | mac_mdio_genc, s->sbm_mdio);
		__raw_writeq(bits | mac_mdio_genc, s->sbm_mdio);
		curmask >>= 1;
	}
}



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

static unsigned int sbmac_mii_read(struct sbmac_softc *s,int phyaddr,int regidx)
{
	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(s);

	/*
	 * 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(s,MII_COMMAND_START, 2);
	sbmac_mii_senddata(s,MII_COMMAND_READ, 2);
	sbmac_mii_senddata(s,phyaddr, 5);
	sbmac_mii_senddata(s,regidx, 5);

	mac_mdio_genc = __raw_readq(s->sbm_mdio) & M_MAC_GENC;

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

	/*
	 * If an error occurred, the PHY will signal '1' back
	 */
	error = __raw_readq(s->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, s->sbm_mdio);
	__raw_writeq(M_MAC_MDIO_DIR_INPUT | mac_mdio_genc, s->sbm_mdio);

	regval = 0;

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

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

		__raw_writeq(M_MAC_MDIO_DIR_INPUT|M_MAC_MDC | mac_mdio_genc, s->sbm_mdio);
		__raw_writeq(M_MAC_MDIO_DIR_INPUT | mac_mdio_genc, s->sbm_mdio);
	}

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

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


/**********************************************************************
 *  SBMAC_MII_WRITE(s,phyaddr,regidx,regval)
 *
 *  Write a value to a PHY register.
 *
 *  Input parameters:
 *  	   s - sbmac structure
 *  	   phyaddr - PHY to use
 *  	   regidx - register within the PHY
 *  	   regval - data to write to register
 *
 *  Return value:
 *  	   nothing
 ********************************************************************* */

static void sbmac_mii_write(struct sbmac_softc *s,int phyaddr,int regidx,
			    unsigned int regval)
{
	int mac_mdio_genc;

	sbmac_mii_sync(s);

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

	mac_mdio_genc = __raw_readq(s->sbm_mdio) & M_MAC_GENC;

	__raw_writeq(M_MAC_MDIO_DIR_OUTPUT | mac_mdio_genc, s->sbm_mdio);
}



/**********************************************************************
 *  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 - sbmacdma_t structure (DMA channel context)
 *  	   s - sbmac_softc structure (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(sbmacdma_t *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, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_TX_BYTES)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_COLLISIONS)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_LATE_COL)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_EX_COL)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_FCS_ERROR)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_TX_ABORT)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_TX_BAD)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_TX_GOOD)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_TX_RUNT)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_TX_OVERSIZE)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_BYTES)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_MCAST)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_BCAST)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_BAD)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_GOOD)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_RUNT)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_OVERSIZE)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_FCS_ERROR)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_LENGTH_ERROR)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, R_MAC_RMON_RX_CODE_ERROR)));
	__raw_writeq(0, IOADDR(A_MAC_REGISTER(s->sbe_idx, 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 =
	d->sbdma_dscrtable = (sbdmadscr_t *)
		kmalloc((d->sbdma_maxdescr+1)*sizeof(sbdmadscr_t), GFP_KERNEL);

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

	memset(d->sbdma_dscrtable,0,d->sbdma_maxdescr*sizeof(sbdmadscr_t));

	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(struct sk_buff *), 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(sbmacdma_t *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(sbmacdma_t *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 void sbdma_align_skb(struct sk_buff *skb,int power2,int offset)
{
	unsigned long addr;
	unsigned long newaddr;

	addr = (unsigned long) skb->data;

	newaddr = (addr + power2 - 1) & ~(power2 - 1);

	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:
 *  	   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(sbmacdma_t *d,struct sk_buff *sb)
{
	sbdmadscr_t *dsc;
	sbdmadscr_t *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 = dev_alloc_skb(ENET_PACKET_SIZE + SMP_CACHE_BYTES * 2 + ETHER_ALIGN);
		if (sb_new == NULL) {
			printk(KERN_INFO "%s: sk_buff allocation failed\n",
			       d->sbdma_eth->sbm_dev->name);
			return -ENOBUFS;
		}

		sbdma_align_skb(sb_new, SMP_CACHE_BYTES, ETHER_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+ETHER_ALIGN)) | 0;
#else
	dsc->dscr_a = virt_to_phys(sb_new->data) |
		V_DMA_DSCRA_A_SIZE(NUMCACHEBLKS(pktsize+ETHER_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(sbmacdma_t *d,struct sk_buff *sb)
{
	sbdmadscr_t *dsc;
	sbdmadscr_t *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(sbmacdma_t *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:
 *  	   d - DMA channel
 *
 *  Return value:
 *  	   nothing
 ********************************************************************* */

static void sbdma_fillring(sbmacdma_t *d)
{
	int idx;

	for (idx = 0; idx < SBMAC_MAX_RXDESCR-1; idx++) {
		if (sbdma_add_rcvbuffer(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,sbmacdma_t *d,
                             int work_to_do, int poll)
{
	struct net_device *dev = sc->sbm_dev;
	int curidx;
	int hwidx;
	sbdmadscr_t *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 = (int) (((__raw_readq(d->sbdma_curdscr) & M_DMA_CURDSCR_ADDR) -
				d->sbdma_dscrtable_phys) / sizeof(sbdmadscr_t));

		/*
		 * 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(d,NULL) ==
				      -ENOBUFS)) {
				dev->stats.rx_dropped++;
				sbdma_add_rcvbuffer(d,sb); /* re-add old buffer */
				/* 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 {
						sb->ip_summed = CHECKSUM_NONE;
					}
				}
				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(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,sbmacdma_t *d, int poll)
{
	struct net_device *dev = sc->sbm_dev;
	int curidx;
	int hwidx;
	sbdmadscr_t *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 = (int) (((__raw_readq(d->sbdma_curdscr) & M_DMA_CURDSCR_ADDR) -
			d->sbdma_dscrtable_phys) / sizeof(sbdmadscr_t));

	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_kfree_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;

	s->sbm_phys[0]   = 1;
	s->sbm_phys[1]   = 0;

	s->sbm_phy_oldbmsr = 0;
	s->sbm_phy_oldanlpar = 0;
	s->sbm_phy_oldk1stsr = 0;
	s->sbm_phy_oldlinkstat = 0;

	/*
	 * 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;

	/*
	 * Initial speed is (XXX TEMP) 10MBit/s HDX no FC
	 */

	s->sbm_speed = sbmac_speed_10;
	s->sbm_duplex = sbmac_duplex_half;
	s->sbm_fc = sbmac_fc_disabled;

	return 0;
}


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

	if (d->sbdma_ctxtable) {
		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;
	volatile 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_PL_THRSH(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;

#ifdef CONFIG_SB1_PASS_1_WORKAROUNDS
	/*
	 * Pass1 SOCs do not receive packets addressed to the
	 * destination address in the R_MAC_ETHERNET_ADDR register.
	 * Set the value to zero.
	 */
	__raw_writeq(0, port);
#else
	__raw_writeq(reg, port);
#endif

	/*
	 * 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->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 configuation
#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 sbmac_state_t sbmac_set_channel_state(struct sbmac_softc *sc,
					     sbmac_state_t state)
{
	sbmac_state_t 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 sbmac_speed_t enum)
 *
 *  Return value:
 *  	   1 if successful
 *      0 indicates invalid parameters
 ********************************************************************* */

static int sbmac_set_speed(struct sbmac_softc *s,sbmac_speed_t 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;

	case sbmac_speed_auto:		/* XXX not implemented */
		/* fall through */
	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 sbmac_duplex_t)
 *  	   fc - flow control setting (see sbmac_fc_t)
 *
 *  Return value:
 *  	   1 if ok
 *  	   0 if an invalid parameter combination was specified
 ********************************************************************* */

static int sbmac_set_duplex(struct sbmac_softc *s,sbmac_duplex_t duplex,sbmac_fc_t 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_auto:		/* XXX not implemented */
			/* fall through */
		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 */
		case sbmac_fc_auto:		/* XXX not implemented */
			/* fall through */
		default:
			return 0;
		}
		break;
	case sbmac_duplex_auto:
		/* XXX not implemented */
		break;
	}

	/*
	 * 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 (netif_rx_schedule_prep(dev, &sc->napi)) {
			__raw_writeq(0, sc->sbm_imr);
			__netif_rx_schedule(dev, &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 int sbmac_start_tx(struct sk_buff *skb, struct net_device *dev)
{
	struct sbmac_softc *sc = netdev_priv(dev);

	/* lock eth irq */
	spin_lock_irq (&sc->sbm_lock);

	/*
	 * 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_irq(&sc->sbm_lock);

		return 1;
	}

	dev->trans_start = jiffies;

	spin_unlock_irq (&sc->sbm_lock);

	return 0;
}

/**********************************************************************
 *  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;
	volatile void __iomem *port;
	int idx;
	struct dev_mc_list *mclist;
	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 */
	mclist = dev->mc_list;
	while (mclist && (idx < MAC_ADDR_COUNT)) {
		reg = sbmac_addr2reg(mclist->dmi_addr);
		port = sc->sbm_base + R_MAC_ADDR_BASE+(idx * sizeof(uint64_t));
		__raw_writeq(reg, port);
		idx++;
		mclist = mclist->next;
	}

	/*
	 * 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);
	}
}

#if defined(SBMAC_ETH0_HWADDR) || defined(SBMAC_ETH1_HWADDR) || defined(SBMAC_ETH2_HWADDR) || defined(SBMAC_ETH3_HWADDR)
/**********************************************************************
 *  SBMAC_PARSE_XDIGIT(str)
 *
 *  Parse a hex digit, returning its value
 *
 *  Input parameters:
 *  	   str - character
 *
 *  Return value:
 *  	   hex value, or -1 if invalid
 ********************************************************************* */

static int sbmac_parse_xdigit(char str)
{
	int digit;

	if ((str >= '0') && (str <= '9'))
		digit = str - '0';
	else if ((str >= 'a') && (str <= 'f'))
		digit = str - 'a' + 10;
	else if ((str >= 'A') && (str <= 'F'))
		digit = str - 'A' + 10;
	else
		return -1;

	return digit;
}

/**********************************************************************
 *  SBMAC_PARSE_HWADDR(str,hwaddr)
 *
 *  Convert a string in the form xx:xx:xx:xx:xx:xx into a 6-byte
 *  Ethernet address.
 *
 *  Input parameters:
 *  	   str - string
 *  	   hwaddr - pointer to hardware address
 *
 *  Return value:
 *  	   0 if ok, else -1
 ********************************************************************* */

static int sbmac_parse_hwaddr(char *str, unsigned char *hwaddr)
{
	int digit1,digit2;
	int idx = 6;

	while (*str && (idx > 0)) {
		digit1 = sbmac_parse_xdigit(*str);
		if (digit1 < 0)
			return -1;
		str++;
		if (!*str)
			return -1;

		if ((*str == ':') || (*str == '-')) {
			digit2 = digit1;
			digit1 = 0;
		}
		else {
			digit2 = sbmac_parse_xdigit(*str);
			if (digit2 < 0)
				return -1;
			str++;
		}

		*hwaddr++ = (digit1 << 4) | digit2;
		idx--;

		if (*str == '-')
			str++;
		if (*str == ':')
			str++;
	}
	return 0;
}
#endif

static int sb1250_change_mtu(struct net_device *_dev, int new_mtu)
{
	if (new_mtu >  ENET_PACKET_SIZE)
		return -EINVAL;
	_dev->mtu = new_mtu;
	printk(KERN_INFO "changing the mtu to %d\n", new_mtu);
	return 0;
}

/**********************************************************************
 *  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 net_device *dev, int idx)
{
	struct sbmac_softc *sc;
	unsigned char *eaddr;
	uint64_t ea_reg;
	int i;
	int err;

	sc = netdev_priv(dev);

	/* Determine controller base address */

	sc->sbm_base = IOADDR(dev->base_addr);
	sc->sbm_dev = dev;
	sc->sbe_idx = idx;

	eaddr = sc->sbm_hwaddr;

	/*
	 * Read the ethernet address.  The firwmare 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];
	}


	/*
	 * Init packet size
	 */

	sc->sbm_buffersize = ENET_PACKET_SIZE + SMP_CACHE_BYTES * 2 + ETHER_ALIGN;

	/*
	 * 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->open               = sbmac_open;
	dev->hard_start_xmit    = sbmac_start_tx;
	dev->stop               = sbmac_close;
	dev->set_multicast_list = sbmac_set_rx_mode;
	dev->do_ioctl           = sbmac_mii_ioctl;
	dev->tx_timeout         = sbmac_tx_timeout;
	dev->watchdog_timeo     = TX_TIMEOUT;

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

	dev->change_mtu         = sb1250_change_mtu;
#ifdef CONFIG_NET_POLL_CONTROLLER
	dev->poll_controller = sbmac_netpoll;
#endif

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

	err = register_netdev(dev);
	if (err)
		goto out_uninit;

	if (sc->rx_hw_checksum == ENABLE) {
		printk(KERN_INFO "%s: enabling TCP rcv checksum\n",
			sc->sbm_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)
	 */
	printk(KERN_INFO
	       "%s: SiByte Ethernet at 0x%08lX, address: %02X:%02X:%02X:%02X:%02X:%02X\n",
	       dev->name, dev->base_addr,
	       eaddr[0],eaddr[1],eaddr[2],eaddr[3],eaddr[4],eaddr[5]);


	return 0;

out_uninit:
	sbmac_uninitctx(sc);

	return err;
}


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

	if (debug > 1) {
		printk(KERN_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);
	if (request_irq(dev->irq, &sbmac_intr, IRQF_SHARED, dev->name, dev))
		return -EBUSY;

	/*
	 * Probe phy address
	 */

	if(sbmac_mii_probe(dev) == -1) {
		printk("%s: failed to probe PHY.\n", dev->name);
		return -EINVAL;
	}

	napi_enable(&sc->napi);

	/*
	 * Configure default speed
	 */

	sbmac_mii_poll(sc,noisy_mii);

	/*
	 * Turn on the channel
	 */

	sbmac_set_channel_state(sc,sbmac_state_on);

	/*
	 * XXX Station address is in dev->dev_addr
	 */

	if (dev->if_port == 0)
		dev->if_port = 0;

	netif_start_queue(dev);

	sbmac_set_rx_mode(dev);

	/* Set the timer to check for link beat. */
	init_timer(&sc->sbm_timer);
	sc->sbm_timer.expires = jiffies + 2 * HZ/100;
	sc->sbm_timer.data = (unsigned long)dev;
	sc->sbm_timer.function = &sbmac_timer;
	add_timer(&sc->sbm_timer);

	return 0;
}

static int sbmac_mii_probe(struct net_device *dev)
{
	int i;
	struct sbmac_softc *s = netdev_priv(dev);
	u16 bmsr, id1, id2;
	u32 vendor, device;

	for (i=1; i<31; i++) {
	bmsr = sbmac_mii_read(s, i, MII_BMSR);
		if (bmsr != 0) {
			s->sbm_phys[0] = i;
			id1 = sbmac_mii_read(s, i, MII_PHYIDR1);
			id2 = sbmac_mii_read(s, i, MII_PHYIDR2);
			vendor = ((u32)id1 << 6) | ((id2 >> 10) & 0x3f);
			device = (id2 >> 4) & 0x3f;

			printk(KERN_INFO "%s: found phy %d, vendor %06x part %02x\n",
				dev->name, i, vendor, device);
			return i;
		}
	}
	return -1;
}


static int sbmac_mii_poll(struct sbmac_softc *s,int noisy)
{
    int bmsr,bmcr,k1stsr,anlpar;
    int chg;
    char buffer[100];
    char *p = buffer;

    /* Read the mode status and mode control registers. */
    bmsr = sbmac_mii_read(s,s->sbm_phys[0],MII_BMSR);
    bmcr = sbmac_mii_read(s,s->sbm_phys[0],MII_BMCR);

    /* get the link partner status */
    anlpar = sbmac_mii_read(s,s->sbm_phys[0],MII_ANLPAR);

    /* if supported, read the 1000baseT register */
    if (bmsr & BMSR_1000BT_XSR) {
	k1stsr = sbmac_mii_read(s,s->sbm_phys[0],MII_K1STSR);
	}
    else {
	k1stsr = 0;
	}

    chg = 0;

    if ((bmsr & BMSR_LINKSTAT) == 0) {
	/*
	 * If link status is down, clear out old info so that when
	 * it comes back up it will force us to reconfigure speed
	 */
	s->sbm_phy_oldbmsr = 0;
	s->sbm_phy_oldanlpar = 0;
	s->sbm_phy_oldk1stsr = 0;
	return 0;
	}

    if ((s->sbm_phy_oldbmsr != bmsr) ||
	(s->sbm_phy_oldanlpar != anlpar) ||
	(s->sbm_phy_oldk1stsr != k1stsr)) {
	if (debug > 1) {
	    printk(KERN_DEBUG "%s: bmsr:%x/%x anlpar:%x/%x  k1stsr:%x/%x\n",
	       s->sbm_dev->name,
	       s->sbm_phy_oldbmsr,bmsr,
	       s->sbm_phy_oldanlpar,anlpar,
	       s->sbm_phy_oldk1stsr,k1stsr);
	    }
	s->sbm_phy_oldbmsr = bmsr;
	s->sbm_phy_oldanlpar = anlpar;
	s->sbm_phy_oldk1stsr = k1stsr;
	chg = 1;
	}

    if (chg == 0)
	    return 0;

    p += sprintf(p,"Link speed: ");

    if (k1stsr & K1STSR_LP1KFD) {
	s->sbm_speed = sbmac_speed_1000;
	s->sbm_duplex = sbmac_duplex_full;
	s->sbm_fc = sbmac_fc_frame;
	p += sprintf(p,"1000BaseT FDX");
	}
    else if (k1stsr & K1STSR_LP1KHD) {
	s->sbm_speed = sbmac_speed_1000;
	s->sbm_duplex = sbmac_duplex_half;
	s->sbm_fc = sbmac_fc_disabled;
	p += sprintf(p,"1000BaseT HDX");
	}
    else if (anlpar & ANLPAR_TXFD) {
	s->sbm_speed = sbmac_speed_100;
	s->sbm_duplex = sbmac_duplex_full;
	s->sbm_fc = (anlpar & ANLPAR_PAUSE) ? sbmac_fc_frame : sbmac_fc_disabled;
	p += sprintf(p,"100BaseT FDX");
	}
    else if (anlpar & ANLPAR_TXHD) {
	s->sbm_speed = sbmac_speed_100;
	s->sbm_duplex = sbmac_duplex_half;
	s->sbm_fc = sbmac_fc_disabled;
	p += sprintf(p,"100BaseT HDX");
	}
    else if (anlpar & ANLPAR_10FD) {
	s->sbm_speed = sbmac_speed_10;
	s->sbm_duplex = sbmac_duplex_full;
	s->sbm_fc = sbmac_fc_frame;
	p += sprintf(p,"10BaseT FDX");
	}
    else if (anlpar & ANLPAR_10HD) {
	s->sbm_speed = sbmac_speed_10;
	s->sbm_duplex = sbmac_duplex_half;
	s->sbm_fc = sbmac_fc_collision;
	p += sprintf(p,"10BaseT HDX");
	}
    else {
	p += sprintf(p,"Unknown");
	}

    if (noisy) {
	    printk(KERN_INFO "%s: %s\n",s->sbm_dev->name,buffer);
	    }

    return 1;
}


static void sbmac_timer(unsigned long data)
{
	struct net_device *dev = (struct net_device *)data;
	struct sbmac_softc *sc = netdev_priv(dev);
	int next_tick = HZ;
	int mii_status;

	spin_lock_irq (&sc->sbm_lock);

	/* make IFF_RUNNING follow the MII status bit "Link established" */
	mii_status = sbmac_mii_read(sc, sc->sbm_phys[0], MII_BMSR);

	if ( (mii_status & BMSR_LINKSTAT) != (sc->sbm_phy_oldlinkstat) ) {
    	        sc->sbm_phy_oldlinkstat = mii_status & BMSR_LINKSTAT;
		if (mii_status & BMSR_LINKSTAT) {
			netif_carrier_on(dev);
		}
		else {
			netif_carrier_off(dev);
		}
	}

	/*
	 * Poll the PHY to see what speed we should be running at
	 */

	if (sbmac_mii_poll(sc,noisy_mii)) {
		if (sc->sbm_state != sbmac_state_off) {
			/*
			 * something changed, restart the channel
			 */
			if (debug > 1) {
				printk("%s: restarting channel because speed changed\n",
				       sc->sbm_dev->name);
			}
			sbmac_channel_stop(sc);
			sbmac_channel_start(sc);
		}
	}

	spin_unlock_irq (&sc->sbm_lock);

	sc->sbm_timer.expires = jiffies + next_tick;
	add_timer(&sc->sbm_timer);
}


static void sbmac_tx_timeout (struct net_device *dev)
{
	struct sbmac_softc *sc = netdev_priv(dev);

	spin_lock_irq (&sc->sbm_lock);


	dev->trans_start = jiffies;
	dev->stats.tx_errors++;

	spin_unlock_irq (&sc->sbm_lock);

	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);
	u16 *data = (u16 *)&rq->ifr_ifru;
	unsigned long flags;
	int retval;

	spin_lock_irqsave(&sc->sbm_lock, flags);
	retval = 0;

	switch(cmd) {
	case SIOCDEVPRIVATE:		/* Get the address of the PHY in use. */
		data[0] = sc->sbm_phys[0] & 0x1f;
		/* Fall Through */
	case SIOCDEVPRIVATE+1:		/* Read the specified MII register. */
		data[3] = sbmac_mii_read(sc, data[0] & 0x1f, data[1] & 0x1f);
		break;
	case SIOCDEVPRIVATE+2:		/* Write the specified MII register */
		if (!capable(CAP_NET_ADMIN)) {
			retval = -EPERM;
			break;
		}
		if (debug > 1) {
		    printk(KERN_DEBUG "%s: sbmac_mii_ioctl: write %02X %02X %02X\n",dev->name,
		       data[0],data[1],data[2]);
		    }
		sbmac_mii_write(sc, data[0] & 0x1f, data[1] & 0x1f, data[2]);
		break;
	default:
		retval = -EOPNOTSUPP;
	}

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

static int sbmac_close(struct net_device *dev)
{
	struct sbmac_softc *sc = netdev_priv(dev);
	unsigned long flags;
	int irq;

	napi_disable(&sc->napi);

	sbmac_set_channel_state(sc,sbmac_state_off);

	del_timer_sync(&sc->sbm_timer);

	spin_lock_irqsave(&sc->sbm_lock, flags);

	netif_stop_queue(dev);

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

	spin_unlock_irqrestore(&sc->sbm_lock, flags);

	irq = dev->irq;
	synchronize_irq(irq);
	free_irq(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);
	struct net_device *dev = sc->sbm_dev;
	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) {
		netif_rx_complete(dev, napi);

#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;
}

#if defined(SBMAC_ETH0_HWADDR) || defined(SBMAC_ETH1_HWADDR) || defined(SBMAC_ETH2_HWADDR) || defined(SBMAC_ETH3_HWADDR)
static void
sbmac_setup_hwaddr(int chan,char *addr)
{
	uint8_t eaddr[6];
	uint64_t val;
	unsigned long port;

	port = A_MAC_CHANNEL_BASE(chan);
	sbmac_parse_hwaddr(addr,eaddr);
	val = sbmac_addr2reg(eaddr);
	__raw_writeq(val, IOADDR(port+R_MAC_ETHERNET_ADDR));
	val = __raw_readq(IOADDR(port+R_MAC_ETHERNET_ADDR));
}
#endif

static struct net_device *dev_sbmac[MAX_UNITS];

static int __init
sbmac_init_module(void)
{
	int idx;
	struct net_device *dev;
	unsigned long port;
	int chip_max_units;

	/* Set the number of available units based on the SOC type.  */
	switch (soc_type) {
	case K_SYS_SOC_TYPE_BCM1250:
	case K_SYS_SOC_TYPE_BCM1250_ALT:
		chip_max_units = 3;
		break;
	case K_SYS_SOC_TYPE_BCM1120:
	case K_SYS_SOC_TYPE_BCM1125:
	case K_SYS_SOC_TYPE_BCM1125H:
	case K_SYS_SOC_TYPE_BCM1250_ALT2: /* Hybrid */
		chip_max_units = 2;
		break;
	case K_SYS_SOC_TYPE_BCM1x55:
	case K_SYS_SOC_TYPE_BCM1x80:
		chip_max_units = 4;
		break;
	default:
		chip_max_units = 0;
		break;
	}
	if (chip_max_units > MAX_UNITS)
		chip_max_units = MAX_UNITS;

	/*
	 * For bringup when not using the firmware, we can pre-fill
	 * the MAC addresses using the environment variables
	 * specified in this file (or maybe from the config file?)
	 */
#ifdef SBMAC_ETH0_HWADDR
	if (chip_max_units > 0)
	  sbmac_setup_hwaddr(0,SBMAC_ETH0_HWADDR);
#endif
#ifdef SBMAC_ETH1_HWADDR
	if (chip_max_units > 1)
	  sbmac_setup_hwaddr(1,SBMAC_ETH1_HWADDR);
#endif
#ifdef SBMAC_ETH2_HWADDR
	if (chip_max_units > 2)
	  sbmac_setup_hwaddr(2,SBMAC_ETH2_HWADDR);
#endif
#ifdef SBMAC_ETH3_HWADDR
	if (chip_max_units > 3)
	  sbmac_setup_hwaddr(3,SBMAC_ETH3_HWADDR);
#endif

	/*
	 * Walk through the Ethernet controllers and find
	 * those who have their MAC addresses set.
	 */
	for (idx = 0; idx < chip_max_units; idx++) {

	        /*
	         * This is the base address of the MAC.
		 */

	        port = A_MAC_CHANNEL_BASE(idx);

		/*
		 * The R_MAC_ETHERNET_ADDR register will be set to some nonzero
		 * value for us by the firmware if we are going to use this MAC.
		 * If we find a zero, skip this MAC.
		 */

		sbmac_orig_hwaddr[idx] = __raw_readq(IOADDR(port+R_MAC_ETHERNET_ADDR));
		if (sbmac_orig_hwaddr[idx] == 0) {
			printk(KERN_DEBUG "sbmac: not configuring MAC at "
			       "%lx\n", port);
		    continue;
		}

		/*
		 * Okay, cool.  Initialize this MAC.
		 */

		dev = alloc_etherdev(sizeof(struct sbmac_softc));
		if (!dev)
			return -ENOMEM;

		printk(KERN_DEBUG "sbmac: configuring MAC at %lx\n", port);

		dev->irq = UNIT_INT(idx);
		dev->base_addr = port;
		dev->mem_end = 0;
		if (sbmac_init(dev, idx)) {
			port = A_MAC_CHANNEL_BASE(idx);
			__raw_writeq(sbmac_orig_hwaddr[idx], IOADDR(port+R_MAC_ETHERNET_ADDR));
			free_netdev(dev);
			continue;
		}
		dev_sbmac[idx] = dev;
	}
	return 0;
}


static void __exit
sbmac_cleanup_module(void)
{
	struct net_device *dev;
	int idx;

	for (idx = 0; idx < MAX_UNITS; idx++) {
		struct sbmac_softc *sc;
		dev = dev_sbmac[idx];
		if (!dev)
			continue;

		sc = netdev_priv(dev);
		unregister_netdev(dev);
		sbmac_uninitctx(sc);
		free_netdev(dev);
	}
}

module_init(sbmac_init_module);
module_exit(sbmac_cleanup_module);