[XFRM]: skb_cow_data() does not set proper owner for new skbs.

[linux-2.6/verdex.git] / drivers / net / cris / eth_v10.c

/* $Id: ethernet.c,v 1.31 2004/10/18 14:49:03 starvik Exp $
 *
 * e100net.c: A network driver for the ETRAX 100LX network controller.
 *
 * Copyright (c) 1998-2002 Axis Communications AB.
 *
 * The outline of this driver comes from skeleton.c.
 *
 * $Log: ethernet.c,v $
 * Revision 1.31  2004/10/18 14:49:03  starvik
 * Use RX interrupt as random source
 *
 * Revision 1.30  2004/09/29 10:44:04  starvik
 * Enabed MAC-address output again
 *
 * Revision 1.29  2004/08/24 07:14:05  starvik
 * Make use of generic MDIO interface and constants.
 *
 * Revision 1.28  2004/08/20 09:37:11  starvik
 * Added support for Intel LXT972A. Creds to Randy Scarborough.
 *
 * Revision 1.27  2004/08/16 12:37:22  starvik
 * Merge of Linux 2.6.8
 *
 * Revision 1.25  2004/06/21 10:29:57  starvik
 * Merge of Linux 2.6.7
 *
 * Revision 1.23  2004/06/09 05:29:22  starvik
 * Avoid any race where R_DMA_CH1_FIRST is NULL (may trigger cache bug).
 *
 * Revision 1.22  2004/05/14 07:58:03  starvik
 * Merge of changes from 2.4
 *
 * Revision 1.20  2004/03/11 11:38:40  starvik
 * Merge of Linux 2.6.4
 *
 * Revision 1.18  2003/12/03 13:45:46  starvik
 * Use hardware pad for short packets to prevent information leakage.
 *
 * Revision 1.17  2003/07/04 08:27:37  starvik
 * Merge of Linux 2.5.74
 *
 * Revision 1.16  2003/04/24 08:28:22  starvik
 * New LED behaviour: LED off when no link
 *
 * Revision 1.15  2003/04/09 05:20:47  starvik
 * Merge of Linux 2.5.67
 *
 * Revision 1.13  2003/03/06 16:11:01  henriken
 * Off by one error in group address register setting.
 *
 * Revision 1.12  2003/02/27 17:24:19  starvik
 * Corrected Rev to Revision
 *
 * Revision 1.11  2003/01/24 09:53:21  starvik
 * Oops. Initialize GA to 0, not to 1
 *
 * Revision 1.10  2003/01/24 09:50:55  starvik
 * Initialize GA_0 and GA_1 to 0 to avoid matching of unwanted packets
 *
 * Revision 1.9  2002/12/13 07:40:58  starvik
 * Added basic ethtool interface
 * Handled out of memory when allocating new buffers
 *
 * Revision 1.8  2002/12/11 13:13:57  starvik
 * Added arch/ to v10 specific includes
 * Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
 *
 * Revision 1.7  2002/11/26 09:41:42  starvik
 * Added e100_set_config (standard interface to set media type)
 * Added protection against preemptive scheduling
 * Added standard MII ioctls
 *
 * Revision 1.6  2002/11/21 07:18:18  starvik
 * Timers must be initialized in 2.5.48
 *
 * Revision 1.5  2002/11/20 11:56:11  starvik
 * Merge of Linux 2.5.48
 *
 * Revision 1.4  2002/11/18 07:26:46  starvik
 * Linux 2.5 port of latest Linux 2.4 ethernet driver
 *
 * Revision 1.33  2002/10/02 20:16:17  hp
 * SETF, SETS: Use underscored IO_x_ macros rather than incorrect token concatenation
 *
 * Revision 1.32  2002/09/16 06:05:58  starvik
 * Align memory returned by dev_alloc_skb
 * Moved handling of sent packets to interrupt to avoid reference counting problem
 *
 * Revision 1.31  2002/09/10 13:28:23  larsv
 * Return -EINVAL for unknown ioctls to avoid confusing tools that tests
 * for supported functionality by issuing special ioctls, i.e. wireless
 * extensions.
 *
 * Revision 1.30  2002/05/07 18:50:08  johana
 * Correct spelling in comments.
 *
 * Revision 1.29  2002/05/06 05:38:49  starvik
 * Performance improvements:
 *    Large packets are not copied (breakpoint set to 256 bytes)
 *    The cache bug workaround is delayed until half of the receive list
 *      has been used
 *    Added transmit list
 *    Transmit interrupts are only enabled when transmit queue is full
 *
 * Revision 1.28.2.1  2002/04/30 08:15:51  starvik
 * Performance improvements:
 *   Large packets are not copied (breakpoint set to 256 bytes)
 *   The cache bug workaround is delayed until half of the receive list
 *     has been used.
 *   Added transmit list
 *   Transmit interrupts are only enabled when transmit queue is full
 *
 * Revision 1.28  2002/04/22 11:47:21  johana
 * Fix according to 2.4.19-pre7. time_after/time_before and
 * missing end of comment.
 * The patch has a typo for ethernet.c in e100_clear_network_leds(),
 *  that is fixed here.
 *
 * Revision 1.27  2002/04/12 11:55:11  bjornw
 * Added TODO
 *
 * Revision 1.26  2002/03/15 17:11:02  bjornw
 * Use prepare_rx_descriptor after the CPU has touched the receiving descs
 *
 * Revision 1.25  2002/03/08 13:07:53  bjornw
 * Unnecessary spinlock removed
 *
 * Revision 1.24  2002/02/20 12:57:43  fredriks
 * Replaced MIN() with min().
 *
 * Revision 1.23  2002/02/20 10:58:14  fredriks
 * Strip the Ethernet checksum (4 bytes) before forwarding a frame to upper layers.
 *
 * Revision 1.22  2002/01/30 07:48:22  matsfg
 * Initiate R_NETWORK_TR_CTRL
 *
 * Revision 1.21  2001/11/23 11:54:49  starvik
 * Added IFF_PROMISC and IFF_ALLMULTI handling in set_multicast_list
 * Removed compiler warnings
 *
 * Revision 1.20  2001/11/12 19:26:00  pkj
 * * Corrected e100_negotiate() to not assign half to current_duplex when
 *   it was supposed to compare them...
 * * Cleaned up failure handling in e100_open().
 * * Fixed compiler warnings.
 *
 * Revision 1.19  2001/11/09 07:43:09  starvik
 * Added full duplex support
 * Added ioctl to set speed and duplex
 * Clear LED timer only runs when LED is lit
 *
 * Revision 1.18  2001/10/03 14:40:43  jonashg
 * Update rx_bytes counter.
 *
 * Revision 1.17  2001/06/11 12:43:46  olof
 * Modified defines for network LED behavior
 *
 * Revision 1.16  2001/05/30 06:12:46  markusl
 * TxDesc.next should not be set to NULL
 *
 * Revision 1.15  2001/05/29 10:27:04  markusl
 * Updated after review remarks:
 * +Use IO_EXTRACT
 * +Handle underrun
 *
 * Revision 1.14  2001/05/29 09:20:14  jonashg
 * Use driver name on printk output so one can tell which driver that complains.
 *
 * Revision 1.13  2001/05/09 12:35:59  johana
 * Use DMA_NBR and IRQ_NBR defines from dma.h and irq.h
 *
 * Revision 1.12  2001/04/05 11:43:11  tobiasa
 * Check dev before panic.
 *
 * Revision 1.11  2001/04/04 11:21:05  markusl
 * Updated according to review remarks
 *
 * Revision 1.10  2001/03/26 16:03:06  bjornw
 * Needs linux/config.h
 *
 * Revision 1.9  2001/03/19 14:47:48  pkj
 * * Make sure there is always a pause after the network LEDs are
 *   changed so they will not look constantly lit during heavy traffic.
 * * Always use HZ when setting times relative to jiffies.
 * * Use LED_NETWORK_SET() when setting the network LEDs.
 *
 * Revision 1.8  2001/02/27 13:52:48  bjornw
 * malloc.h -> slab.h
 *
 * Revision 1.7  2001/02/23 13:46:38  bjornw
 * Spellling check
 *
 * Revision 1.6  2001/01/26 15:21:04  starvik
 * Don't disable interrupts while reading MDIO registers (MDIO is slow)
 * Corrected promiscuous mode
 * Improved deallocation of IRQs ("ifconfig eth0 down" now works)
 *
 * Revision 1.5  2000/11/29 17:22:22  bjornw
 * Get rid of the udword types legacy stuff
 *
 * Revision 1.4  2000/11/22 16:36:09  bjornw
 * Please marketing by using the correct case when spelling Etrax.
 *
 * Revision 1.3  2000/11/21 16:43:04  bjornw
 * Minor short->int change
 *
 * Revision 1.2  2000/11/08 14:27:57  bjornw
 * 2.4 port
 *
 * Revision 1.1  2000/11/06 13:56:00  bjornw
 * Verbatim copy of the 1.24 version of e100net.c from elinux
 *
 * Revision 1.24  2000/10/04 15:55:23  bjornw
 * * Use virt_to_phys etc. for DMA addresses
 * * Removed bogus CHECKSUM_UNNECESSARY
 *
 *
 */

#include <linux/config.h>

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/init.h>

#include <linux/if.h>
#include <linux/mii.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>

#include <asm/arch/svinto.h>/* DMA and register descriptions */
#include <asm/io.h>         /* LED_* I/O functions */
#include <asm/irq.h>
#include <asm/dma.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/ethernet.h>
#include <asm/cache.h>

//#define ETHDEBUG
#define D(x)

/*
 * The name of the card. Is used for messages and in the requests for
 * io regions, irqs and dma channels
 */

static const char* cardname = "ETRAX 100LX built-in ethernet controller";

/* A default ethernet address. Highlevel SW will set the real one later */

static struct sockaddr default_mac = {
        0,
        { 0x00, 0x40, 0x8C, 0xCD, 0x00, 0x00 }
};

/* Information that need to be kept for each board. */
struct net_local {
        struct net_device_stats stats;
        struct mii_if_info mii_if;

        /* Tx control lock.  This protects the transmit buffer ring
         * state along with the "tx full" state of the driver.  This
         * means all netif_queue flow control actions are protected
         * by this lock as well.
         */
        spinlock_t lock;
};

typedef struct etrax_eth_descr
{
        etrax_dma_descr descr;
        struct sk_buff* skb;
} etrax_eth_descr;

/* Some transceivers requires special handling */
struct transceiver_ops
{
        unsigned int oui;
        void (*check_speed)(struct net_device* dev);
        void (*check_duplex)(struct net_device* dev);
};

struct transceiver_ops* transceiver;

/* Duplex settings */
enum duplex
{
        half,
        full,
        autoneg
};

/* Dma descriptors etc. */

#define MAX_MEDIA_DATA_SIZE 1518

#define MIN_PACKET_LEN      46
#define ETHER_HEAD_LEN      14

/*
** MDIO constants.
*/
#define MDIO_START                          0x1
#define MDIO_READ                           0x2
#define MDIO_WRITE                          0x1
#define MDIO_PREAMBLE              0xfffffffful

/* Broadcom specific */
#define MDIO_AUX_CTRL_STATUS_REG           0x18
#define MDIO_BC_FULL_DUPLEX_IND             0x1
#define MDIO_BC_SPEED                       0x2

/* TDK specific */
#define MDIO_TDK_DIAGNOSTIC_REG              18
#define MDIO_TDK_DIAGNOSTIC_RATE          0x400
#define MDIO_TDK_DIAGNOSTIC_DPLX          0x800

/*Intel LXT972A specific*/
#define MDIO_INT_STATUS_REG_2                   0x0011
#define MDIO_INT_FULL_DUPLEX_IND                ( 1 << 9 )
#define MDIO_INT_SPEED                          ( 1 << 14 )

/* Network flash constants */
#define NET_FLASH_TIME                  (HZ/50) /* 20 ms */
#define NET_FLASH_PAUSE                (HZ/100) /* 10 ms */
#define NET_LINK_UP_CHECK_INTERVAL       (2*HZ) /* 2 s   */
#define NET_DUPLEX_CHECK_INTERVAL        (2*HZ) /* 2 s   */

#define NO_NETWORK_ACTIVITY 0
#define NETWORK_ACTIVITY    1

#define NBR_OF_RX_DESC     64
#define NBR_OF_TX_DESC     256

/* Large packets are sent directly to upper layers while small packets are */
/* copied (to reduce memory waste). The following constant decides the breakpoint */
#define RX_COPYBREAK 256

/* Due to a chip bug we need to flush the cache when descriptors are returned */
/* to the DMA. To decrease performance impact we return descriptors in chunks. */
/* The following constant determines the number of descriptors to return. */
#define RX_QUEUE_THRESHOLD  NBR_OF_RX_DESC/2

#define GET_BIT(bit,val)   (((val) >> (bit)) & 0x01)

/* Define some macros to access ETRAX 100 registers */
#define SETF(var, reg, field, val) var = (var & ~IO_MASK_(reg##_, field##_)) | \
                                          IO_FIELD_(reg##_, field##_, val)
#define SETS(var, reg, field, val) var = (var & ~IO_MASK_(reg##_, field##_)) | \
                                          IO_STATE_(reg##_, field##_, _##val)

static etrax_eth_descr *myNextRxDesc;  /* Points to the next descriptor to
                                          to be processed */
static etrax_eth_descr *myLastRxDesc;  /* The last processed descriptor */
static etrax_eth_descr *myPrevRxDesc;  /* The descriptor right before myNextRxDesc */

static etrax_eth_descr RxDescList[NBR_OF_RX_DESC] __attribute__ ((aligned(32)));

static etrax_eth_descr* myFirstTxDesc; /* First packet not yet sent */
static etrax_eth_descr* myLastTxDesc;  /* End of send queue */
static etrax_eth_descr* myNextTxDesc;  /* Next descriptor to use */
static etrax_eth_descr TxDescList[NBR_OF_TX_DESC] __attribute__ ((aligned(32)));

static unsigned int network_rec_config_shadow = 0;
static unsigned int mdio_phy_addr; /* Transciever address */

static unsigned int network_tr_ctrl_shadow = 0;

/* Network speed indication. */
static struct timer_list speed_timer = TIMER_INITIALIZER(NULL, 0, 0);
static struct timer_list clear_led_timer = TIMER_INITIALIZER(NULL, 0, 0);
static int current_speed; /* Speed read from transceiver */
static int current_speed_selection; /* Speed selected by user */
static unsigned long led_next_time;
static int led_active;
static int rx_queue_len;

/* Duplex */
static struct timer_list duplex_timer = TIMER_INITIALIZER(NULL, 0, 0);
static int full_duplex;
static enum duplex current_duplex;

/* Index to functions, as function prototypes. */

static int etrax_ethernet_init(void);

static int e100_open(struct net_device *dev);
static int e100_set_mac_address(struct net_device *dev, void *addr);
static int e100_send_packet(struct sk_buff *skb, struct net_device *dev);
static irqreturn_t e100rxtx_interrupt(int irq, void *dev_id, struct pt_regs *regs);
static irqreturn_t e100nw_interrupt(int irq, void *dev_id, struct pt_regs *regs);
static void e100_rx(struct net_device *dev);
static int e100_close(struct net_device *dev);
static int e100_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
static int e100_ethtool_ioctl(struct net_device* dev, struct ifreq *ifr);
static int e100_set_config(struct net_device* dev, struct ifmap* map);
static void e100_tx_timeout(struct net_device *dev);
static struct net_device_stats *e100_get_stats(struct net_device *dev);
static void set_multicast_list(struct net_device *dev);
static void e100_hardware_send_packet(char *buf, int length);
static void update_rx_stats(struct net_device_stats *);
static void update_tx_stats(struct net_device_stats *);
static int e100_probe_transceiver(struct net_device* dev);

static void e100_check_speed(unsigned long priv);
static void e100_set_speed(struct net_device* dev, unsigned long speed);
static void e100_check_duplex(unsigned long priv);
static void e100_set_duplex(struct net_device* dev, enum duplex);
static void e100_negotiate(struct net_device* dev);

static int e100_get_mdio_reg(struct net_device *dev, int phy_id, int location);
static void e100_set_mdio_reg(struct net_device *dev, int phy_id, int location, int value);

static void e100_send_mdio_cmd(unsigned short cmd, int write_cmd);
static void e100_send_mdio_bit(unsigned char bit);
static unsigned char e100_receive_mdio_bit(void);
static void e100_reset_transceiver(struct net_device* net);

static void e100_clear_network_leds(unsigned long dummy);
static void e100_set_network_leds(int active);

static void broadcom_check_speed(struct net_device* dev);
static void broadcom_check_duplex(struct net_device* dev);
static void tdk_check_speed(struct net_device* dev);
static void tdk_check_duplex(struct net_device* dev);
static void intel_check_speed(struct net_device* dev);
static void intel_check_duplex(struct net_device* dev);
static void generic_check_speed(struct net_device* dev);
static void generic_check_duplex(struct net_device* dev);

struct transceiver_ops transceivers[] =
{
        {0x1018, broadcom_check_speed, broadcom_check_duplex},  /* Broadcom */
        {0xC039, tdk_check_speed, tdk_check_duplex},            /* TDK 2120 */
        {0x039C, tdk_check_speed, tdk_check_duplex},            /* TDK 2120C */
        {0x04de, intel_check_speed, intel_check_duplex},        /* Intel LXT972A*/
        {0x0000, generic_check_speed, generic_check_duplex}     /* Generic, must be last */
};

#define tx_done(dev) (*R_DMA_CH0_CMD == 0)

/*
 * Check for a network adaptor of this type, and return '0' if one exists.
 * If dev->base_addr == 0, probe all likely locations.
 * If dev->base_addr == 1, always return failure.
 * If dev->base_addr == 2, allocate space for the device and return success
 * (detachable devices only).
 */

static int __init
etrax_ethernet_init(void)
{
        struct net_device *dev;
        struct net_local* np;
        int i, err;

        printk(KERN_INFO
               "ETRAX 100LX 10/100MBit ethernet v2.0 (c) 2000-2003 Axis Communications AB\n");

        dev = alloc_etherdev(sizeof(struct net_local));
        np = dev->priv;

        if (!dev)
                return -ENOMEM;

        dev->base_addr = (unsigned int)R_NETWORK_SA_0; /* just to have something to show */

        /* now setup our etrax specific stuff */

        dev->irq = NETWORK_DMA_RX_IRQ_NBR; /* we really use DMATX as well... */
        dev->dma = NETWORK_RX_DMA_NBR;

        /* fill in our handlers so the network layer can talk to us in the future */

        dev->open               = e100_open;
        dev->hard_start_xmit    = e100_send_packet;
        dev->stop               = e100_close;
        dev->get_stats          = e100_get_stats;
        dev->set_multicast_list = set_multicast_list;
        dev->set_mac_address    = e100_set_mac_address;
        dev->do_ioctl           = e100_ioctl;
        dev->set_config         = e100_set_config;
        dev->tx_timeout         = e100_tx_timeout;

        /* Initialise the list of Etrax DMA-descriptors */

        /* Initialise receive descriptors */

        for (i = 0; i < NBR_OF_RX_DESC; i++) {
                /* Allocate two extra cachelines to make sure that buffer used by DMA
                 * does not share cacheline with any other data (to avoid cache bug)
                 */
                RxDescList[i].skb = dev_alloc_skb(MAX_MEDIA_DATA_SIZE + 2 * L1_CACHE_BYTES);
                RxDescList[i].descr.ctrl   = 0;
                RxDescList[i].descr.sw_len = MAX_MEDIA_DATA_SIZE;
                RxDescList[i].descr.next   = virt_to_phys(&RxDescList[i + 1]);
                RxDescList[i].descr.buf    = L1_CACHE_ALIGN(virt_to_phys(RxDescList[i].skb->data));
                RxDescList[i].descr.status = 0;
                RxDescList[i].descr.hw_len = 0;
                prepare_rx_descriptor(&RxDescList[i].descr);
        }

        RxDescList[NBR_OF_RX_DESC - 1].descr.ctrl   = d_eol;
        RxDescList[NBR_OF_RX_DESC - 1].descr.next   = virt_to_phys(&RxDescList[0]);
        rx_queue_len = 0;

        /* Initialize transmit descriptors */
        for (i = 0; i < NBR_OF_TX_DESC; i++) {
                TxDescList[i].descr.ctrl   = 0;
                TxDescList[i].descr.sw_len = 0;
                TxDescList[i].descr.next   = virt_to_phys(&TxDescList[i + 1].descr);
                TxDescList[i].descr.buf    = 0;
                TxDescList[i].descr.status = 0;
                TxDescList[i].descr.hw_len = 0;
                TxDescList[i].skb = 0;
        }

        TxDescList[NBR_OF_TX_DESC - 1].descr.ctrl   = d_eol;
        TxDescList[NBR_OF_TX_DESC - 1].descr.next   = virt_to_phys(&TxDescList[0].descr);

        /* Initialise initial pointers */

        myNextRxDesc  = &RxDescList[0];
        myLastRxDesc  = &RxDescList[NBR_OF_RX_DESC - 1];
        myPrevRxDesc  = &RxDescList[NBR_OF_RX_DESC - 1];
        myFirstTxDesc = &TxDescList[0];
        myNextTxDesc  = &TxDescList[0];
        myLastTxDesc  = &TxDescList[NBR_OF_TX_DESC - 1];

        /* Register device */
        err = register_netdev(dev);
        if (err) {
                free_netdev(dev);
                return err;
        }

        /* set the default MAC address */

        e100_set_mac_address(dev, &default_mac);

        /* Initialize speed indicator stuff. */

        current_speed = 10;
        current_speed_selection = 0; /* Auto */
        speed_timer.expires = jiffies + NET_LINK_UP_CHECK_INTERVAL;
        duplex_timer.data = (unsigned long)dev;
        speed_timer.function = e100_check_speed;

        clear_led_timer.function = e100_clear_network_leds;

        full_duplex = 0;
        current_duplex = autoneg;
        duplex_timer.expires = jiffies + NET_DUPLEX_CHECK_INTERVAL;
        duplex_timer.data = (unsigned long)dev;
        duplex_timer.function = e100_check_duplex;

        /* Initialize mii interface */
        np->mii_if.phy_id = mdio_phy_addr;
        np->mii_if.phy_id_mask = 0x1f;
        np->mii_if.reg_num_mask = 0x1f;
        np->mii_if.dev = dev;
        np->mii_if.mdio_read = e100_get_mdio_reg;
        np->mii_if.mdio_write = e100_set_mdio_reg;

        /* Initialize group address registers to make sure that no */
        /* unwanted addresses are matched */
        *R_NETWORK_GA_0 = 0x00000000;
        *R_NETWORK_GA_1 = 0x00000000;
        return 0;
}

/* set MAC address of the interface. called from the core after a
 * SIOCSIFADDR ioctl, and from the bootup above.
 */

static int
e100_set_mac_address(struct net_device *dev, void *p)
{
        struct net_local *np = (struct net_local *)dev->priv;
        struct sockaddr *addr = p;
        int i;

        spin_lock(&np->lock); /* preemption protection */

        /* remember it */

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

        /* Write it to the hardware.
         * Note the way the address is wrapped:
         * *R_NETWORK_SA_0 = a0_0 | (a0_1 << 8) | (a0_2 << 16) | (a0_3 << 24);
         * *R_NETWORK_SA_1 = a0_4 | (a0_5 << 8);
         */

        *R_NETWORK_SA_0 = dev->dev_addr[0] | (dev->dev_addr[1] << 8) |
                (dev->dev_addr[2] << 16) | (dev->dev_addr[3] << 24);
        *R_NETWORK_SA_1 = dev->dev_addr[4] | (dev->dev_addr[5] << 8);
        *R_NETWORK_SA_2 = 0;

        /* show it in the log as well */

        printk(KERN_INFO "%s: changed MAC to ", dev->name);

        for (i = 0; i < 5; i++)
                printk("%02X:", dev->dev_addr[i]);

        printk("%02X\n", dev->dev_addr[i]);

        spin_unlock(&np->lock);

        return 0;
}

/*
 * Open/initialize the board. This is called (in the current kernel)
 * sometime after booting when the 'ifconfig' program is run.
 *
 * This routine should set everything up anew at each open, even
 * registers that "should" only need to be set once at boot, so that
 * there is non-reboot way to recover if something goes wrong.
 */

static int
e100_open(struct net_device *dev)
{
        unsigned long flags;

        /* enable the MDIO output pin */

        *R_NETWORK_MGM_CTRL = IO_STATE(R_NETWORK_MGM_CTRL, mdoe, enable);

        *R_IRQ_MASK0_CLR =
                IO_STATE(R_IRQ_MASK0_CLR, overrun, clr) |
                IO_STATE(R_IRQ_MASK0_CLR, underrun, clr) |
                IO_STATE(R_IRQ_MASK0_CLR, excessive_col, clr);

        /* clear dma0 and 1 eop and descr irq masks */
        *R_IRQ_MASK2_CLR =
                IO_STATE(R_IRQ_MASK2_CLR, dma0_descr, clr) |
                IO_STATE(R_IRQ_MASK2_CLR, dma0_eop, clr) |
                IO_STATE(R_IRQ_MASK2_CLR, dma1_descr, clr) |
                IO_STATE(R_IRQ_MASK2_CLR, dma1_eop, clr);

        /* Reset and wait for the DMA channels */

        RESET_DMA(NETWORK_TX_DMA_NBR);
        RESET_DMA(NETWORK_RX_DMA_NBR);
        WAIT_DMA(NETWORK_TX_DMA_NBR);
        WAIT_DMA(NETWORK_RX_DMA_NBR);

        /* Initialise the etrax network controller */

        /* allocate the irq corresponding to the receiving DMA */

        if (request_irq(NETWORK_DMA_RX_IRQ_NBR, e100rxtx_interrupt,
                        SA_SAMPLE_RANDOM, cardname, (void *)dev)) {
                goto grace_exit0;
        }

        /* allocate the irq corresponding to the transmitting DMA */

        if (request_irq(NETWORK_DMA_TX_IRQ_NBR, e100rxtx_interrupt, 0,
                        cardname, (void *)dev)) {
                goto grace_exit1;
        }

        /* allocate the irq corresponding to the network errors etc */

        if (request_irq(NETWORK_STATUS_IRQ_NBR, e100nw_interrupt, 0,
                        cardname, (void *)dev)) {
                goto grace_exit2;
        }

        /* give the HW an idea of what MAC address we want */

        *R_NETWORK_SA_0 = dev->dev_addr[0] | (dev->dev_addr[1] << 8) |
                (dev->dev_addr[2] << 16) | (dev->dev_addr[3] << 24);
        *R_NETWORK_SA_1 = dev->dev_addr[4] | (dev->dev_addr[5] << 8);
        *R_NETWORK_SA_2 = 0;

#if 0
        /* use promiscuous mode for testing */
        *R_NETWORK_GA_0 = 0xffffffff;
        *R_NETWORK_GA_1 = 0xffffffff;

        *R_NETWORK_REC_CONFIG = 0xd; /* broadcast rec, individ. rec, ma0 enabled */
#else
        SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, broadcast, receive);
        SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, ma0, enable);
        SETF(network_rec_config_shadow, R_NETWORK_REC_CONFIG, duplex, full_duplex);
        *R_NETWORK_REC_CONFIG = network_rec_config_shadow;
#endif

        *R_NETWORK_GEN_CONFIG =
                IO_STATE(R_NETWORK_GEN_CONFIG, phy,    mii_clk) |
                IO_STATE(R_NETWORK_GEN_CONFIG, enable, on);

        SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, clr_error, clr);
        SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, delay, none);
        SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, cancel, dont);
        SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, cd, enable);
        SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, retry, enable);
        SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, pad, enable);
        SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, crc, enable);
        *R_NETWORK_TR_CTRL = network_tr_ctrl_shadow;

        save_flags(flags);
        cli();

        /* enable the irq's for ethernet DMA */

        *R_IRQ_MASK2_SET =
                IO_STATE(R_IRQ_MASK2_SET, dma0_eop, set) |
                IO_STATE(R_IRQ_MASK2_SET, dma1_eop, set);

        *R_IRQ_MASK0_SET =
                IO_STATE(R_IRQ_MASK0_SET, overrun,       set) |
                IO_STATE(R_IRQ_MASK0_SET, underrun,      set) |
                IO_STATE(R_IRQ_MASK0_SET, excessive_col, set);

        /* make sure the irqs are cleared */

        *R_DMA_CH0_CLR_INTR = IO_STATE(R_DMA_CH0_CLR_INTR, clr_eop, do);
        *R_DMA_CH1_CLR_INTR = IO_STATE(R_DMA_CH1_CLR_INTR, clr_eop, do);

        /* make sure the rec and transmit error counters are cleared */

        (void)*R_REC_COUNTERS;  /* dummy read */
        (void)*R_TR_COUNTERS;   /* dummy read */

        /* start the receiving DMA channel so we can receive packets from now on */

        *R_DMA_CH1_FIRST = virt_to_phys(myNextRxDesc);
        *R_DMA_CH1_CMD = IO_STATE(R_DMA_CH1_CMD, cmd, start);

        /* Set up transmit DMA channel so it can be restarted later */

        *R_DMA_CH0_FIRST = 0;
        *R_DMA_CH0_DESCR = virt_to_phys(myLastTxDesc);

        restore_flags(flags);

        /* Probe for transceiver */
        if (e100_probe_transceiver(dev))
                goto grace_exit3;

        /* Start duplex/speed timers */
        add_timer(&speed_timer);
        add_timer(&duplex_timer);

        /* We are now ready to accept transmit requeusts from
         * the queueing layer of the networking.
         */
        netif_start_queue(dev);

        return 0;

grace_exit3:
        free_irq(NETWORK_STATUS_IRQ_NBR, (void *)dev);
grace_exit2:
        free_irq(NETWORK_DMA_TX_IRQ_NBR, (void *)dev);
grace_exit1:
        free_irq(NETWORK_DMA_RX_IRQ_NBR, (void *)dev);
grace_exit0:
        return -EAGAIN;
}


static void
generic_check_speed(struct net_device* dev)
{
        unsigned long data;
        data = e100_get_mdio_reg(dev, mdio_phy_addr, MII_ADVERTISE);
        if ((data & ADVERTISE_100FULL) ||
            (data & ADVERTISE_100HALF))
                current_speed = 100;
        else
                current_speed = 10;
}

static void
tdk_check_speed(struct net_device* dev)
{
        unsigned long data;
        data = e100_get_mdio_reg(dev, mdio_phy_addr, MDIO_TDK_DIAGNOSTIC_REG);
        current_speed = (data & MDIO_TDK_DIAGNOSTIC_RATE ? 100 : 10);
}

static void
broadcom_check_speed(struct net_device* dev)
{
        unsigned long data;
        data = e100_get_mdio_reg(dev, mdio_phy_addr, MDIO_AUX_CTRL_STATUS_REG);
        current_speed = (data & MDIO_BC_SPEED ? 100 : 10);
}

static void
intel_check_speed(struct net_device* dev)
{
        unsigned long data;
        data = e100_get_mdio_reg(dev, mdio_phy_addr, MDIO_INT_STATUS_REG_2);
        current_speed = (data & MDIO_INT_SPEED ? 100 : 10);
}

static void
e100_check_speed(unsigned long priv)
{
        struct net_device* dev = (struct net_device*)priv;
        static int led_initiated = 0;
        unsigned long data;
        int old_speed = current_speed;

        data = e100_get_mdio_reg(dev, mdio_phy_addr, MII_BMSR);
        if (!(data & BMSR_LSTATUS)) {
                current_speed = 0;
        } else {
                transceiver->check_speed(dev);
        }

        if ((old_speed != current_speed) || !led_initiated) {
                led_initiated = 1;
                e100_set_network_leds(NO_NETWORK_ACTIVITY);
        }

        /* Reinitialize the timer. */
        speed_timer.expires = jiffies + NET_LINK_UP_CHECK_INTERVAL;
        add_timer(&speed_timer);
}

static void
e100_negotiate(struct net_device* dev)
{
        unsigned short data = e100_get_mdio_reg(dev, mdio_phy_addr, MII_ADVERTISE);

        /* Discard old speed and duplex settings */
        data &= ~(ADVERTISE_100HALF | ADVERTISE_100FULL |
                  ADVERTISE_10HALF | ADVERTISE_10FULL);

        switch (current_speed_selection) {
                case 10 :
                        if (current_duplex == full)
                                data |= ADVERTISE_10FULL;
                        else if (current_duplex == half)
                                data |= ADVERTISE_10HALF;
                        else
                                data |= ADVERTISE_10HALF | ADVERTISE_10FULL;
                        break;

                case 100 :
                         if (current_duplex == full)
                                data |= ADVERTISE_100FULL;
                        else if (current_duplex == half)
                                data |= ADVERTISE_100HALF;
                        else
                                data |= ADVERTISE_100HALF | ADVERTISE_100FULL;
                        break;

                case 0 : /* Auto */
                         if (current_duplex == full)
                                data |= ADVERTISE_100FULL | ADVERTISE_10FULL;
                        else if (current_duplex == half)
                                data |= ADVERTISE_100HALF | ADVERTISE_10HALF;
                        else
                                data |= ADVERTISE_10HALF | ADVERTISE_10FULL |
                                  ADVERTISE_100HALF | ADVERTISE_100FULL;
                        break;

                default : /* assume autoneg speed and duplex */
                        data |= ADVERTISE_10HALF | ADVERTISE_10FULL |
                                  ADVERTISE_100HALF | ADVERTISE_100FULL;
        }

        e100_set_mdio_reg(dev, mdio_phy_addr, MII_ADVERTISE, data);

        /* Renegotiate with link partner */
        data = e100_get_mdio_reg(dev, mdio_phy_addr, MII_BMCR);
        data |= BMCR_ANENABLE | BMCR_ANRESTART;

        e100_set_mdio_reg(dev, mdio_phy_addr, MII_BMCR, data);
}

static void
e100_set_speed(struct net_device* dev, unsigned long speed)
{
        if (speed != current_speed_selection) {
                current_speed_selection = speed;
                e100_negotiate(dev);
        }
}

static void
e100_check_duplex(unsigned long priv)
{
        struct net_device *dev = (struct net_device *)priv;
        struct net_local *np = (struct net_local *)dev->priv;
        int old_duplex = full_duplex;
        transceiver->check_duplex(dev);
        if (old_duplex != full_duplex) {
                /* Duplex changed */
                SETF(network_rec_config_shadow, R_NETWORK_REC_CONFIG, duplex, full_duplex);
                *R_NETWORK_REC_CONFIG = network_rec_config_shadow;
        }

        /* Reinitialize the timer. */
        duplex_timer.expires = jiffies + NET_DUPLEX_CHECK_INTERVAL;
        add_timer(&duplex_timer);
        np->mii_if.full_duplex = full_duplex;
}

static void
generic_check_duplex(struct net_device* dev)
{
        unsigned long data;
        data = e100_get_mdio_reg(dev, mdio_phy_addr, MII_ADVERTISE);
        if ((data & ADVERTISE_10FULL) ||
            (data & ADVERTISE_100FULL))
                full_duplex = 1;
        else
                full_duplex = 0;
}

static void
tdk_check_duplex(struct net_device* dev)
{
        unsigned long data;
        data = e100_get_mdio_reg(dev, mdio_phy_addr, MDIO_TDK_DIAGNOSTIC_REG);
        full_duplex = (data & MDIO_TDK_DIAGNOSTIC_DPLX) ? 1 : 0;
}

static void
broadcom_check_duplex(struct net_device* dev)
{
        unsigned long data;
        data = e100_get_mdio_reg(dev, mdio_phy_addr, MDIO_AUX_CTRL_STATUS_REG);
        full_duplex = (data & MDIO_BC_FULL_DUPLEX_IND) ? 1 : 0;
}

static void
intel_check_duplex(struct net_device* dev)
{
        unsigned long data;
        data = e100_get_mdio_reg(dev, mdio_phy_addr, MDIO_INT_STATUS_REG_2);
        full_duplex = (data & MDIO_INT_FULL_DUPLEX_IND) ? 1 : 0;
}

static void
e100_set_duplex(struct net_device* dev, enum duplex new_duplex)
{
        if (new_duplex != current_duplex) {
                current_duplex = new_duplex;
                e100_negotiate(dev);
        }
}

static int
e100_probe_transceiver(struct net_device* dev)
{
        unsigned int phyid_high;
        unsigned int phyid_low;
        unsigned int oui;
        struct transceiver_ops* ops = NULL;

        /* Probe MDIO physical address */
        for (mdio_phy_addr = 0; mdio_phy_addr <= 31; mdio_phy_addr++) {
                if (e100_get_mdio_reg(dev, mdio_phy_addr, MII_BMSR) != 0xffff)
                        break;
        }
        if (mdio_phy_addr == 32)
                 return -ENODEV;

        /* Get manufacturer */
        phyid_high = e100_get_mdio_reg(dev, mdio_phy_addr, MII_PHYSID1);
        phyid_low = e100_get_mdio_reg(dev, mdio_phy_addr, MII_PHYSID2);
        oui = (phyid_high << 6) | (phyid_low >> 10);

        for (ops = &transceivers[0]; ops->oui; ops++) {
                if (ops->oui == oui)
                        break;
        }
        transceiver = ops;

        return 0;
}

static int
e100_get_mdio_reg(struct net_device *dev, int phy_id, int location)
{
        unsigned short cmd;    /* Data to be sent on MDIO port */
        int data;   /* Data read from MDIO */
        int bitCounter;

        /* Start of frame, OP Code, Physical Address, Register Address */
        cmd = (MDIO_START << 14) | (MDIO_READ << 12) | (phy_id << 7) |
                (location << 2);

        e100_send_mdio_cmd(cmd, 0);

        data = 0;

        /* Data... */
        for (bitCounter=15; bitCounter>=0 ; bitCounter--) {
                data |= (e100_receive_mdio_bit() << bitCounter);
        }

        return data;
}

static void
e100_set_mdio_reg(struct net_device *dev, int phy_id, int location, int value)
{
        int bitCounter;
        unsigned short cmd;

        cmd = (MDIO_START << 14) | (MDIO_WRITE << 12) | (phy_id << 7) |
              (location << 2);

        e100_send_mdio_cmd(cmd, 1);

        /* Data... */
        for (bitCounter=15; bitCounter>=0 ; bitCounter--) {
                e100_send_mdio_bit(GET_BIT(bitCounter, value));
        }

}

static void
e100_send_mdio_cmd(unsigned short cmd, int write_cmd)
{
        int bitCounter;
        unsigned char data = 0x2;

        /* Preamble */
        for (bitCounter = 31; bitCounter>= 0; bitCounter--)
                e100_send_mdio_bit(GET_BIT(bitCounter, MDIO_PREAMBLE));

        for (bitCounter = 15; bitCounter >= 2; bitCounter--)
                e100_send_mdio_bit(GET_BIT(bitCounter, cmd));

        /* Turnaround */
        for (bitCounter = 1; bitCounter >= 0 ; bitCounter--)
                if (write_cmd)
                        e100_send_mdio_bit(GET_BIT(bitCounter, data));
                else
                        e100_receive_mdio_bit();
}

static void
e100_send_mdio_bit(unsigned char bit)
{
        *R_NETWORK_MGM_CTRL =
                IO_STATE(R_NETWORK_MGM_CTRL, mdoe, enable) |
                IO_FIELD(R_NETWORK_MGM_CTRL, mdio, bit);
        udelay(1);
        *R_NETWORK_MGM_CTRL =
                IO_STATE(R_NETWORK_MGM_CTRL, mdoe, enable) |
                IO_MASK(R_NETWORK_MGM_CTRL, mdck) |
                IO_FIELD(R_NETWORK_MGM_CTRL, mdio, bit);
        udelay(1);
}

static unsigned char
e100_receive_mdio_bit()
{
        unsigned char bit;
        *R_NETWORK_MGM_CTRL = 0;
        bit = IO_EXTRACT(R_NETWORK_STAT, mdio, *R_NETWORK_STAT);
        udelay(1);
        *R_NETWORK_MGM_CTRL = IO_MASK(R_NETWORK_MGM_CTRL, mdck);
        udelay(1);
        return bit;
}

static void
e100_reset_transceiver(struct net_device* dev)
{
        unsigned short cmd;
        unsigned short data;
        int bitCounter;

        data = e100_get_mdio_reg(dev, mdio_phy_addr, MII_BMCR);

        cmd = (MDIO_START << 14) | (MDIO_WRITE << 12) | (mdio_phy_addr << 7) | (MII_BMCR << 2);

        e100_send_mdio_cmd(cmd, 1);

        data |= 0x8000;

        for (bitCounter = 15; bitCounter >= 0 ; bitCounter--) {
                e100_send_mdio_bit(GET_BIT(bitCounter, data));
        }
}

/* Called by upper layers if they decide it took too long to complete
 * sending a packet - we need to reset and stuff.
 */

static void
e100_tx_timeout(struct net_device *dev)
{
        struct net_local *np = (struct net_local *)dev->priv;
        unsigned long flags;

        spin_lock_irqsave(&np->lock, flags);

        printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name,
               tx_done(dev) ? "IRQ problem" : "network cable problem");

        /* remember we got an error */

        np->stats.tx_errors++;

        /* reset the TX DMA in case it has hung on something */

        RESET_DMA(NETWORK_TX_DMA_NBR);
        WAIT_DMA(NETWORK_TX_DMA_NBR);

        /* Reset the transceiver. */

        e100_reset_transceiver(dev);

        /* and get rid of the packets that never got an interrupt */
        while (myFirstTxDesc != myNextTxDesc)
        {
                dev_kfree_skb(myFirstTxDesc->skb);
                myFirstTxDesc->skb = 0;
                myFirstTxDesc = phys_to_virt(myFirstTxDesc->descr.next);
        }

        /* Set up transmit DMA channel so it can be restarted later */
        *R_DMA_CH0_FIRST = 0;
        *R_DMA_CH0_DESCR = virt_to_phys(myLastTxDesc);

        /* tell the upper layers we're ok again */

        netif_wake_queue(dev);
        spin_unlock_irqrestore(&np->lock, flags);
}


/* This will only be invoked if the driver is _not_ in XOFF state.
 * What this means is that we need not check it, and that this
 * invariant will hold if we make sure that the netif_*_queue()
 * calls are done at the proper times.
 */

static int
e100_send_packet(struct sk_buff *skb, struct net_device *dev)
{
        struct net_local *np = (struct net_local *)dev->priv;
        unsigned char *buf = skb->data;
        unsigned long flags;

#ifdef ETHDEBUG
        printk("send packet len %d\n", length);
#endif
        spin_lock_irqsave(&np->lock, flags);  /* protect from tx_interrupt and ourself */

        myNextTxDesc->skb = skb;

        dev->trans_start = jiffies;

        e100_hardware_send_packet(buf, skb->len);

        myNextTxDesc = phys_to_virt(myNextTxDesc->descr.next);

        /* Stop queue if full */
        if (myNextTxDesc == myFirstTxDesc) {
                netif_stop_queue(dev);
        }

        spin_unlock_irqrestore(&np->lock, flags);

        return 0;
}

/*
 * The typical workload of the driver:
 *   Handle the network interface interrupts.
 */

static irqreturn_t
e100rxtx_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
        struct net_device *dev = (struct net_device *)dev_id;
        struct net_local *np = (struct net_local *)dev->priv;
        unsigned long irqbits = *R_IRQ_MASK2_RD;

        /* Disable RX/TX IRQs to avoid reentrancy */
        *R_IRQ_MASK2_CLR =
          IO_STATE(R_IRQ_MASK2_CLR, dma0_eop, clr) |
          IO_STATE(R_IRQ_MASK2_CLR, dma1_eop, clr);

        /* Handle received packets */
        if (irqbits & IO_STATE(R_IRQ_MASK2_RD, dma1_eop, active)) {
                /* acknowledge the eop interrupt */

                *R_DMA_CH1_CLR_INTR = IO_STATE(R_DMA_CH1_CLR_INTR, clr_eop, do);

                /* check if one or more complete packets were indeed received */

                while ((*R_DMA_CH1_FIRST != virt_to_phys(myNextRxDesc)) &&
                       (myNextRxDesc != myLastRxDesc)) {
                        /* Take out the buffer and give it to the OS, then
                         * allocate a new buffer to put a packet in.
                         */
                        e100_rx(dev);
                        ((struct net_local *)dev->priv)->stats.rx_packets++;
                        /* restart/continue on the channel, for safety */
                        *R_DMA_CH1_CMD = IO_STATE(R_DMA_CH1_CMD, cmd, restart);
                        /* clear dma channel 1 eop/descr irq bits */
                        *R_DMA_CH1_CLR_INTR =
                                IO_STATE(R_DMA_CH1_CLR_INTR, clr_eop, do) |
                                IO_STATE(R_DMA_CH1_CLR_INTR, clr_descr, do);

                        /* now, we might have gotten another packet
                           so we have to loop back and check if so */
                }
        }

        /* Report any packets that have been sent */
        while (myFirstTxDesc != phys_to_virt(*R_DMA_CH0_FIRST) &&
               myFirstTxDesc != myNextTxDesc)
        {
                np->stats.tx_bytes += myFirstTxDesc->skb->len;
                np->stats.tx_packets++;

                /* dma is ready with the transmission of the data in tx_skb, so now
                   we can release the skb memory */
                dev_kfree_skb_irq(myFirstTxDesc->skb);
                myFirstTxDesc->skb = 0;
                myFirstTxDesc = phys_to_virt(myFirstTxDesc->descr.next);
        }

        if (irqbits & IO_STATE(R_IRQ_MASK2_RD, dma0_eop, active)) {
                /* acknowledge the eop interrupt and wake up queue */
                *R_DMA_CH0_CLR_INTR = IO_STATE(R_DMA_CH0_CLR_INTR, clr_eop, do);
                netif_wake_queue(dev);
        }

        /* Enable RX/TX IRQs again */
        *R_IRQ_MASK2_SET =
          IO_STATE(R_IRQ_MASK2_SET, dma0_eop, set) |
          IO_STATE(R_IRQ_MASK2_SET, dma1_eop, set);

        return IRQ_HANDLED;
}

static irqreturn_t
e100nw_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
        struct net_device *dev = (struct net_device *)dev_id;
        struct net_local *np = (struct net_local *)dev->priv;
        unsigned long irqbits = *R_IRQ_MASK0_RD;

        /* check for underrun irq */
        if (irqbits & IO_STATE(R_IRQ_MASK0_RD, underrun, active)) {
                SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, clr_error, clr);
                *R_NETWORK_TR_CTRL = network_tr_ctrl_shadow;
                SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, clr_error, nop);
                np->stats.tx_errors++;
                D(printk("ethernet receiver underrun!\n"));
        }

        /* check for overrun irq */
        if (irqbits & IO_STATE(R_IRQ_MASK0_RD, overrun, active)) {
                update_rx_stats(&np->stats); /* this will ack the irq */
                D(printk("ethernet receiver overrun!\n"));
        }
        /* check for excessive collision irq */
        if (irqbits & IO_STATE(R_IRQ_MASK0_RD, excessive_col, active)) {
                SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, clr_error, clr);
                *R_NETWORK_TR_CTRL = network_tr_ctrl_shadow;
                SETS(network_tr_ctrl_shadow, R_NETWORK_TR_CTRL, clr_error, nop);
                *R_NETWORK_TR_CTRL = IO_STATE(R_NETWORK_TR_CTRL, clr_error, clr);
                np->stats.tx_errors++;
                D(printk("ethernet excessive collisions!\n"));
        }
        return IRQ_HANDLED;
}

/* We have a good packet(s), get it/them out of the buffers. */
static void
e100_rx(struct net_device *dev)
{
        struct sk_buff *skb;
        int length = 0;
        struct net_local *np = (struct net_local *)dev->priv;
        unsigned char *skb_data_ptr;
#ifdef ETHDEBUG
        int i;
#endif

        if (!led_active && time_after(jiffies, led_next_time)) {
                /* light the network leds depending on the current speed. */
                e100_set_network_leds(NETWORK_ACTIVITY);

                /* Set the earliest time we may clear the LED */
                led_next_time = jiffies + NET_FLASH_TIME;
                led_active = 1;
                mod_timer(&clear_led_timer, jiffies + HZ/10);
        }

        length = myNextRxDesc->descr.hw_len - 4;
        ((struct net_local *)dev->priv)->stats.rx_bytes += length;

#ifdef ETHDEBUG
        printk("Got a packet of length %d:\n", length);
        /* dump the first bytes in the packet */
        skb_data_ptr = (unsigned char *)phys_to_virt(myNextRxDesc->descr.buf);
        for (i = 0; i < 8; i++) {
                printk("%d: %.2x %.2x %.2x %.2x %.2x %.2x %.2x %.2x\n", i * 8,
                       skb_data_ptr[0],skb_data_ptr[1],skb_data_ptr[2],skb_data_ptr[3],
                       skb_data_ptr[4],skb_data_ptr[5],skb_data_ptr[6],skb_data_ptr[7]);
                skb_data_ptr += 8;
        }
#endif

        if (length < RX_COPYBREAK) {
                /* Small packet, copy data */
                skb = dev_alloc_skb(length - ETHER_HEAD_LEN);
                if (!skb) {
                        np->stats.rx_errors++;
                        printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n", dev->name);
                        return;
                }

                skb_put(skb, length - ETHER_HEAD_LEN);        /* allocate room for the packet body */
                skb_data_ptr = skb_push(skb, ETHER_HEAD_LEN); /* allocate room for the header */

#ifdef ETHDEBUG
                printk("head = 0x%x, data = 0x%x, tail = 0x%x, end = 0x%x\n",
                  skb->head, skb->data, skb->tail, skb->end);
                printk("copying packet to 0x%x.\n", skb_data_ptr);
#endif

                memcpy(skb_data_ptr, phys_to_virt(myNextRxDesc->descr.buf), length);
        }
        else {
                /* Large packet, send directly to upper layers and allocate new
                 * memory (aligned to cache line boundary to avoid bug).
                 * Before sending the skb to upper layers we must make sure that
                 * skb->data points to the aligned start of the packet.
                 */
                int align;
                struct sk_buff *new_skb = dev_alloc_skb(MAX_MEDIA_DATA_SIZE + 2 * L1_CACHE_BYTES);
                if (!new_skb) {
                        np->stats.rx_errors++;
                        printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n", dev->name);
                        return;
                }
                skb = myNextRxDesc->skb;
                align = (int)phys_to_virt(myNextRxDesc->descr.buf) - (int)skb->data;
                skb_put(skb, length + align);
                skb_pull(skb, align); /* Remove alignment bytes */
                myNextRxDesc->skb = new_skb;
                myNextRxDesc->descr.buf = L1_CACHE_ALIGN(virt_to_phys(myNextRxDesc->skb->data));
        }

        skb->dev = dev;
        skb->protocol = eth_type_trans(skb, dev);

        /* Send the packet to the upper layers */
        netif_rx(skb);

        /* Prepare for next packet */
        myNextRxDesc->descr.status = 0;
        myPrevRxDesc = myNextRxDesc;
        myNextRxDesc = phys_to_virt(myNextRxDesc->descr.next);

        rx_queue_len++;

        /* Check if descriptors should be returned */
        if (rx_queue_len == RX_QUEUE_THRESHOLD) {
                flush_etrax_cache();
                myPrevRxDesc->descr.ctrl |= d_eol;
                myLastRxDesc->descr.ctrl &= ~d_eol;
                myLastRxDesc = myPrevRxDesc;
                rx_queue_len = 0;
        }
}

/* The inverse routine to net_open(). */
static int
e100_close(struct net_device *dev)
{
        struct net_local *np = (struct net_local *)dev->priv;

        printk(KERN_INFO "Closing %s.\n", dev->name);

        netif_stop_queue(dev);

        *R_IRQ_MASK0_CLR =
                IO_STATE(R_IRQ_MASK0_CLR, overrun, clr) |
                IO_STATE(R_IRQ_MASK0_CLR, underrun, clr) |
                IO_STATE(R_IRQ_MASK0_CLR, excessive_col, clr);

        *R_IRQ_MASK2_CLR =
                IO_STATE(R_IRQ_MASK2_CLR, dma0_descr, clr) |
                IO_STATE(R_IRQ_MASK2_CLR, dma0_eop, clr) |
                IO_STATE(R_IRQ_MASK2_CLR, dma1_descr, clr) |
                IO_STATE(R_IRQ_MASK2_CLR, dma1_eop, clr);

        /* Stop the receiver and the transmitter */

        RESET_DMA(NETWORK_TX_DMA_NBR);
        RESET_DMA(NETWORK_RX_DMA_NBR);

        /* Flush the Tx and disable Rx here. */

        free_irq(NETWORK_DMA_RX_IRQ_NBR, (void *)dev);
        free_irq(NETWORK_DMA_TX_IRQ_NBR, (void *)dev);
        free_irq(NETWORK_STATUS_IRQ_NBR, (void *)dev);

        /* Update the statistics here. */

        update_rx_stats(&np->stats);
        update_tx_stats(&np->stats);

        /* Stop speed/duplex timers */
        del_timer(&speed_timer);
        del_timer(&duplex_timer);

        return 0;
}

static int
e100_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        struct mii_ioctl_data *data = if_mii(ifr);
        struct net_local *np = netdev_priv(dev);

        spin_lock(&np->lock); /* Preempt protection */
        switch (cmd) {
                case SIOCETHTOOL:
                        return e100_ethtool_ioctl(dev,ifr);
                case SIOCGMIIPHY: /* Get PHY address */
                        data->phy_id = mdio_phy_addr;
                        break;
                case SIOCGMIIREG: /* Read MII register */
                        data->val_out = e100_get_mdio_reg(dev, mdio_phy_addr, data->reg_num);
                        break;
                case SIOCSMIIREG: /* Write MII register */
                        e100_set_mdio_reg(dev, mdio_phy_addr, data->reg_num, data->val_in);
                        break;
                /* The ioctls below should be considered obsolete but are */
                /* still present for compatability with old scripts/apps  */
                case SET_ETH_SPEED_10:                  /* 10 Mbps */
                        e100_set_speed(dev, 10);
                        break;
                case SET_ETH_SPEED_100:                /* 100 Mbps */
                        e100_set_speed(dev, 100);
                        break;
                case SET_ETH_SPEED_AUTO:              /* Auto negotiate speed */
                        e100_set_speed(dev, 0);
                        break;
                case SET_ETH_DUPLEX_HALF:              /* Half duplex. */
                        e100_set_duplex(dev, half);
                        break;
                case SET_ETH_DUPLEX_FULL:              /* Full duplex. */
                        e100_set_duplex(dev, full);
                        break;
                case SET_ETH_DUPLEX_AUTO:             /* Autonegotiate duplex*/
                        e100_set_duplex(dev, autoneg);
                        break;
                default:
                        return -EINVAL;
        }
        spin_unlock(&np->lock);
        return 0;
}

static int
e100_ethtool_ioctl(struct net_device *dev, struct ifreq *ifr)
{
        struct ethtool_cmd ecmd;

        if (copy_from_user(&ecmd, ifr->ifr_data, sizeof (ecmd)))
                return -EFAULT;

        switch (ecmd.cmd) {
                case ETHTOOL_GSET:
                {
                        memset((void *) &ecmd, 0, sizeof (ecmd));
                        ecmd.supported =
                          SUPPORTED_Autoneg | SUPPORTED_TP | SUPPORTED_MII |
                          SUPPORTED_10baseT_Half | SUPPORTED_10baseT_Full |
                          SUPPORTED_100baseT_Half | SUPPORTED_100baseT_Full;
                        ecmd.port = PORT_TP;
                        ecmd.transceiver = XCVR_EXTERNAL;
                        ecmd.phy_address = mdio_phy_addr;
                        ecmd.speed = current_speed;
                        ecmd.duplex = full_duplex ? DUPLEX_FULL : DUPLEX_HALF;
                        ecmd.advertising = ADVERTISED_TP;
                        if (current_duplex == autoneg && current_speed_selection == 0)
                                ecmd.advertising |= ADVERTISED_Autoneg;
                        else {
                                ecmd.advertising |=
                                  ADVERTISED_10baseT_Half | ADVERTISED_10baseT_Full |
                                  ADVERTISED_100baseT_Half | ADVERTISED_100baseT_Full;
                                if (current_speed_selection == 10)
                                        ecmd.advertising &= ~(ADVERTISED_100baseT_Half | ADVERTISED_100baseT_Full);
                                else if (current_speed_selection == 100)
                                        ecmd.advertising &= ~(ADVERTISED_10baseT_Half | ADVERTISED_10baseT_Full);
                                if (current_duplex == half)
                                        ecmd.advertising &= ~(ADVERTISED_10baseT_Full | ADVERTISED_100baseT_Full);
                                else if (current_duplex == full)
                                        ecmd.advertising &= ~(ADVERTISED_10baseT_Half | ADVERTISED_100baseT_Half);
                        }
                        ecmd.autoneg = AUTONEG_ENABLE;
                        if (copy_to_user(ifr->ifr_data, &ecmd, sizeof (ecmd)))
                                return -EFAULT;
                }
                break;
                case ETHTOOL_SSET:
                {
                        if (!capable(CAP_NET_ADMIN)) {
                                return -EPERM;
                        }
                        if (ecmd.autoneg == AUTONEG_ENABLE) {
                                e100_set_duplex(dev, autoneg);
                                e100_set_speed(dev, 0);
                        } else {
                                e100_set_duplex(dev, ecmd.duplex == DUPLEX_HALF ? half : full);
                                e100_set_speed(dev, ecmd.speed == SPEED_10 ? 10: 100);
                        }
                }
                break;
                case ETHTOOL_GDRVINFO:
                {
                        struct ethtool_drvinfo info;
                        memset((void *) &info, 0, sizeof (info));
                        strncpy(info.driver, "ETRAX 100LX", sizeof(info.driver) - 1);
                        strncpy(info.version, "$Revision: 1.31 $", sizeof(info.version) - 1);
                        strncpy(info.fw_version, "N/A", sizeof(info.fw_version) - 1);
                        strncpy(info.bus_info, "N/A", sizeof(info.bus_info) - 1);
                        info.regdump_len = 0;
                        info.eedump_len = 0;
                        info.testinfo_len = 0;
                        if (copy_to_user(ifr->ifr_data, &info, sizeof (info)))
                                return -EFAULT;
                }
                break;
                case ETHTOOL_NWAY_RST:
                        if (current_duplex == autoneg && current_speed_selection == 0)
                                e100_negotiate(dev);
                break;
                default:
                        return -EOPNOTSUPP;
                break;
        }
        return 0;
}

static int
e100_set_config(struct net_device *dev, struct ifmap *map)
{
        struct net_local *np = (struct net_local *)dev->priv;
        spin_lock(&np->lock); /* Preempt protection */

        switch(map->port) {
                case IF_PORT_UNKNOWN:
                        /* Use autoneg */
                        e100_set_speed(dev, 0);
                        e100_set_duplex(dev, autoneg);
                        break;
                case IF_PORT_10BASET:
                        e100_set_speed(dev, 10);
                        e100_set_duplex(dev, autoneg);
                        break;
                case IF_PORT_100BASET:
                case IF_PORT_100BASETX:
                        e100_set_speed(dev, 100);
                        e100_set_duplex(dev, autoneg);
                        break;
                case IF_PORT_100BASEFX:
                case IF_PORT_10BASE2:
                case IF_PORT_AUI:
                        spin_unlock(&np->lock);
                        return -EOPNOTSUPP;
                        break;
                default:
                        printk(KERN_ERR "%s: Invalid media selected", dev->name);
                        spin_unlock(&np->lock);
                        return -EINVAL;
        }
        spin_unlock(&np->lock);
        return 0;
}

static void
update_rx_stats(struct net_device_stats *es)
{
        unsigned long r = *R_REC_COUNTERS;
        /* update stats relevant to reception errors */
        es->rx_fifo_errors += IO_EXTRACT(R_REC_COUNTERS, congestion, r);
        es->rx_crc_errors += IO_EXTRACT(R_REC_COUNTERS, crc_error, r);
        es->rx_frame_errors += IO_EXTRACT(R_REC_COUNTERS, alignment_error, r);
        es->rx_length_errors += IO_EXTRACT(R_REC_COUNTERS, oversize, r);
}

static void
update_tx_stats(struct net_device_stats *es)
{
        unsigned long r = *R_TR_COUNTERS;
        /* update stats relevant to transmission errors */
        es->collisions +=
                IO_EXTRACT(R_TR_COUNTERS, single_col, r) +
                IO_EXTRACT(R_TR_COUNTERS, multiple_col, r);
        es->tx_errors += IO_EXTRACT(R_TR_COUNTERS, deferred, r);
}

/*
 * Get the current statistics.
 * This may be called with the card open or closed.
 */
static struct net_device_stats *
e100_get_stats(struct net_device *dev)
{
        struct net_local *lp = (struct net_local *)dev->priv;
        unsigned long flags;
        spin_lock_irqsave(&lp->lock, flags);

        update_rx_stats(&lp->stats);
        update_tx_stats(&lp->stats);

        spin_unlock_irqrestore(&lp->lock, flags);
        return &lp->stats;
}

/*
 * Set or clear the multicast filter for this adaptor.
 * num_addrs == -1      Promiscuous mode, receive all packets
 * num_addrs == 0       Normal mode, clear multicast list
 * num_addrs > 0        Multicast mode, receive normal and MC packets,
 *                      and do best-effort filtering.
 */
static void
set_multicast_list(struct net_device *dev)
{
        struct net_local *lp = (struct net_local *)dev->priv;
        int num_addr = dev->mc_count;
        unsigned long int lo_bits;
        unsigned long int hi_bits;
        spin_lock(&lp->lock);
        if (dev->flags & IFF_PROMISC)
        {
                /* promiscuous mode */
                lo_bits = 0xfffffffful;
                hi_bits = 0xfffffffful;

                /* Enable individual receive */
                SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, individual, receive);
                *R_NETWORK_REC_CONFIG = network_rec_config_shadow;
        } else if (dev->flags & IFF_ALLMULTI) {
                /* enable all multicasts */
                lo_bits = 0xfffffffful;
                hi_bits = 0xfffffffful;

                /* Disable individual receive */
                SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, individual, discard);
                *R_NETWORK_REC_CONFIG =  network_rec_config_shadow;
        } else if (num_addr == 0) {
                /* Normal, clear the mc list */
                lo_bits = 0x00000000ul;
                hi_bits = 0x00000000ul;

                /* Disable individual receive */
                SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, individual, discard);
                *R_NETWORK_REC_CONFIG =  network_rec_config_shadow;
        } else {
                /* MC mode, receive normal and MC packets */
                char hash_ix;
                struct dev_mc_list *dmi = dev->mc_list;
                int i;
                char *baddr;
                lo_bits = 0x00000000ul;
                hi_bits = 0x00000000ul;
                for (i=0; i<num_addr; i++) {
                        /* Calculate the hash index for the GA registers */

                        hash_ix = 0;
                        baddr = dmi->dmi_addr;
                        hash_ix ^= (*baddr) & 0x3f;
                        hash_ix ^= ((*baddr) >> 6) & 0x03;
                        ++baddr;
                        hash_ix ^= ((*baddr) << 2) & 0x03c;
                        hash_ix ^= ((*baddr) >> 4) & 0xf;
                        ++baddr;
                        hash_ix ^= ((*baddr) << 4) & 0x30;
                        hash_ix ^= ((*baddr) >> 2) & 0x3f;
                        ++baddr;
                        hash_ix ^= (*baddr) & 0x3f;
                        hash_ix ^= ((*baddr) >> 6) & 0x03;
                        ++baddr;
                        hash_ix ^= ((*baddr) << 2) & 0x03c;
                        hash_ix ^= ((*baddr) >> 4) & 0xf;
                        ++baddr;
                        hash_ix ^= ((*baddr) << 4) & 0x30;
                        hash_ix ^= ((*baddr) >> 2) & 0x3f;

                        hash_ix &= 0x3f;

                        if (hash_ix >= 32) {
                                hi_bits |= (1 << (hash_ix-32));
                        }
                        else {
                                lo_bits |= (1 << hash_ix);
                        }
                        dmi = dmi->next;
                }
                /* Disable individual receive */
                SETS(network_rec_config_shadow, R_NETWORK_REC_CONFIG, individual, discard);
                *R_NETWORK_REC_CONFIG = network_rec_config_shadow;
        }
        *R_NETWORK_GA_0 = lo_bits;
        *R_NETWORK_GA_1 = hi_bits;
        spin_unlock(&lp->lock);
}

void
e100_hardware_send_packet(char *buf, int length)
{
        D(printk("e100 send pack, buf 0x%x len %d\n", buf, length));

        if (!led_active && time_after(jiffies, led_next_time)) {
                /* light the network leds depending on the current speed. */
                e100_set_network_leds(NETWORK_ACTIVITY);

                /* Set the earliest time we may clear the LED */
                led_next_time = jiffies + NET_FLASH_TIME;
                led_active = 1;
                mod_timer(&clear_led_timer, jiffies + HZ/10);
        }

        /* configure the tx dma descriptor */
        myNextTxDesc->descr.sw_len = length;
        myNextTxDesc->descr.ctrl = d_eop | d_eol | d_wait;
        myNextTxDesc->descr.buf = virt_to_phys(buf);

        /* Move end of list */
        myLastTxDesc->descr.ctrl &= ~d_eol;
        myLastTxDesc = myNextTxDesc;

        /* Restart DMA channel */
        *R_DMA_CH0_CMD = IO_STATE(R_DMA_CH0_CMD, cmd, restart);
}

static void
e100_clear_network_leds(unsigned long dummy)
{
        if (led_active && time_after(jiffies, led_next_time)) {
                e100_set_network_leds(NO_NETWORK_ACTIVITY);

                /* Set the earliest time we may set the LED */
                led_next_time = jiffies + NET_FLASH_PAUSE;
                led_active = 0;
        }
}

static void
e100_set_network_leds(int active)
{
#if defined(CONFIG_ETRAX_NETWORK_LED_ON_WHEN_LINK)
        int light_leds = (active == NO_NETWORK_ACTIVITY);
#elif defined(CONFIG_ETRAX_NETWORK_LED_ON_WHEN_ACTIVITY)
        int light_leds = (active == NETWORK_ACTIVITY);
#else
#error "Define either CONFIG_ETRAX_NETWORK_LED_ON_WHEN_LINK or CONFIG_ETRAX_NETWORK_LED_ON_WHEN_ACTIVITY"
#endif

        if (!current_speed) {
                /* Make LED red, link is down */
#if defined(CONFIG_ETRAX_NETWORK_RED_ON_NO_CONNECTION)
                LED_NETWORK_SET(LED_RED);
#else
                LED_NETWORK_SET(LED_OFF);
#endif
        }
        else if (light_leds) {
                if (current_speed == 10) {
                        LED_NETWORK_SET(LED_ORANGE);
                } else {
                        LED_NETWORK_SET(LED_GREEN);
                }
        }
        else {
                LED_NETWORK_SET(LED_OFF);
        }
}

static int
etrax_init_module(void)
{
        return etrax_ethernet_init();
}

static int __init
e100_boot_setup(char* str)
{
        struct sockaddr sa = {0};
        int i;

        /* Parse the colon separated Ethernet station address */
        for (i = 0; i <  ETH_ALEN; i++) {
                unsigned int tmp;
                if (sscanf(str + 3*i, "%2x", &tmp) != 1) {
                        printk(KERN_WARNING "Malformed station address");
                        return 0;
                }
                sa.sa_data[i] = (char)tmp;
        }

        default_mac = sa;
        return 1;
}

__setup("etrax100_eth=", e100_boot_setup);

module_init(etrax_init_module);