[PATCH] mv643xx: fix outstanding tx skb counter

[linux-2.6/kvm.git] / drivers / net / mv643xx_eth.c

/*
 * drivers/net/mv643xx_eth.c - Driver for MV643XX ethernet ports
 * Copyright (C) 2002 Matthew Dharm <mdharm@momenco.com>
 *
 * Based on the 64360 driver from:
 * Copyright (C) 2002 rabeeh@galileo.co.il
 *
 * Copyright (C) 2003 PMC-Sierra, Inc.,
 *      written by Manish Lachwani (lachwani@pmc-sierra.com)
 *
 * Copyright (C) 2003 Ralf Baechle <ralf@linux-mips.org>
 *
 * Copyright (C) 2004-2005 MontaVista Software, Inc.
 *                         Dale Farnsworth <dale@farnsworth.org>
 *
 * Copyright (C) 2004 Steven J. Hill <sjhill1@rockwellcollins.com>
 *                                   <sjhill@realitydiluted.com>
 *
 * 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.
 */
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/etherdevice.h>

#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/ethtool.h>
#include <asm/io.h>
#include <asm/types.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/delay.h>
#include "mv643xx_eth.h"

/*
 * The first part is the high level driver of the gigE ethernet ports.
 */

/* Constants */
#define VLAN_HLEN               4
#define FCS_LEN                 4
#define WRAP                    NET_IP_ALIGN + ETH_HLEN + VLAN_HLEN + FCS_LEN
#define RX_SKB_SIZE             ((dev->mtu + WRAP + 7) & ~0x7)

#define INT_CAUSE_UNMASK_ALL            0x0007ffff
#define INT_CAUSE_UNMASK_ALL_EXT        0x0011ffff
#ifdef MV643XX_RX_QUEUE_FILL_ON_TASK
#define INT_CAUSE_MASK_ALL              0x00000000
#define INT_CAUSE_CHECK_BITS            INT_CAUSE_UNMASK_ALL
#define INT_CAUSE_CHECK_BITS_EXT        INT_CAUSE_UNMASK_ALL_EXT
#endif

#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
#define MAX_DESCS_PER_SKB       (MAX_SKB_FRAGS + 1)
#else
#define MAX_DESCS_PER_SKB       1
#endif

#define PHY_WAIT_ITERATIONS     1000    /* 1000 iterations * 10uS = 10mS max */
#define PHY_WAIT_MICRO_SECONDS  10

/* Static function declarations */
static int eth_port_link_is_up(unsigned int eth_port_num);
static void eth_port_uc_addr_get(struct net_device *dev,
                                                unsigned char *MacAddr);
static int mv643xx_eth_real_open(struct net_device *);
static int mv643xx_eth_real_stop(struct net_device *);
static int mv643xx_eth_change_mtu(struct net_device *, int);
static struct net_device_stats *mv643xx_eth_get_stats(struct net_device *);
static void eth_port_init_mac_tables(unsigned int eth_port_num);
#ifdef MV643XX_NAPI
static int mv643xx_poll(struct net_device *dev, int *budget);
#endif
static void ethernet_phy_set(unsigned int eth_port_num, int phy_addr);
static int ethernet_phy_detect(unsigned int eth_port_num);
static struct ethtool_ops mv643xx_ethtool_ops;

static char mv643xx_driver_name[] = "mv643xx_eth";
static char mv643xx_driver_version[] = "1.0";

static void __iomem *mv643xx_eth_shared_base;

/* used to protect MV643XX_ETH_SMI_REG, which is shared across ports */
static spinlock_t mv643xx_eth_phy_lock = SPIN_LOCK_UNLOCKED;

static inline u32 mv_read(int offset)
{
        void __iomem *reg_base;

        reg_base = mv643xx_eth_shared_base - MV643XX_ETH_SHARED_REGS;

        return readl(reg_base + offset);
}

static inline void mv_write(int offset, u32 data)
{
        void __iomem *reg_base;

        reg_base = mv643xx_eth_shared_base - MV643XX_ETH_SHARED_REGS;
        writel(data, reg_base + offset);
}

/*
 * Changes MTU (maximum transfer unit) of the gigabit ethenret port
 *
 * Input :      pointer to ethernet interface network device structure
 *              new mtu size
 * Output :     0 upon success, -EINVAL upon failure
 */
static int mv643xx_eth_change_mtu(struct net_device *dev, int new_mtu)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned long flags;

        spin_lock_irqsave(&mp->lock, flags);

        if ((new_mtu > 9500) || (new_mtu < 64)) {
                spin_unlock_irqrestore(&mp->lock, flags);
                return -EINVAL;
        }

        dev->mtu = new_mtu;
        /*
         * Stop then re-open the interface. This will allocate RX skb's with
         * the new MTU.
         * There is a possible danger that the open will not successed, due
         * to memory is full, which might fail the open function.
         */
        if (netif_running(dev)) {
                if (mv643xx_eth_real_stop(dev))
                        printk(KERN_ERR
                                "%s: Fatal error on stopping device\n",
                                dev->name);
                if (mv643xx_eth_real_open(dev))
                        printk(KERN_ERR
                                "%s: Fatal error on opening device\n",
                                dev->name);
        }

        spin_unlock_irqrestore(&mp->lock, flags);
        return 0;
}

/*
 * mv643xx_eth_rx_task
 *
 * Fills / refills RX queue on a certain gigabit ethernet port
 *
 * Input :      pointer to ethernet interface network device structure
 * Output :     N/A
 */
static void mv643xx_eth_rx_task(void *data)
{
        struct net_device *dev = (struct net_device *)data;
        struct mv643xx_private *mp = netdev_priv(dev);
        struct pkt_info pkt_info;
        struct sk_buff *skb;

        if (test_and_set_bit(0, &mp->rx_task_busy))
                panic("%s: Error in test_set_bit / clear_bit", dev->name);

        while (mp->rx_ring_skbs < (mp->rx_ring_size - 5)) {
                skb = dev_alloc_skb(RX_SKB_SIZE);
                if (!skb)
                        break;
                mp->rx_ring_skbs++;
                pkt_info.cmd_sts = ETH_RX_ENABLE_INTERRUPT;
                pkt_info.byte_cnt = RX_SKB_SIZE;
                pkt_info.buf_ptr = dma_map_single(NULL, skb->data, RX_SKB_SIZE,
                                                        DMA_FROM_DEVICE);
                pkt_info.return_info = skb;
                if (eth_rx_return_buff(mp, &pkt_info) != ETH_OK) {
                        printk(KERN_ERR
                                "%s: Error allocating RX Ring\n", dev->name);
                        break;
                }
                skb_reserve(skb, 2);
        }
        clear_bit(0, &mp->rx_task_busy);
        /*
         * If RX ring is empty of SKB, set a timer to try allocating
         * again in a later time .
         */
        if ((mp->rx_ring_skbs == 0) && (mp->rx_timer_flag == 0)) {
                printk(KERN_INFO "%s: Rx ring is empty\n", dev->name);
                /* After 100mSec */
                mp->timeout.expires = jiffies + (HZ / 10);
                add_timer(&mp->timeout);
                mp->rx_timer_flag = 1;
        }
#ifdef MV643XX_RX_QUEUE_FILL_ON_TASK
        else {
                /* Return interrupts */
                mv_write(MV643XX_ETH_INTERRUPT_MASK_REG(mp->port_num),
                                                        INT_CAUSE_UNMASK_ALL);
        }
#endif
}

/*
 * mv643xx_eth_rx_task_timer_wrapper
 *
 * Timer routine to wake up RX queue filling task. This function is
 * used only in case the RX queue is empty, and all alloc_skb has
 * failed (due to out of memory event).
 *
 * Input :      pointer to ethernet interface network device structure
 * Output :     N/A
 */
static void mv643xx_eth_rx_task_timer_wrapper(unsigned long data)
{
        struct net_device *dev = (struct net_device *)data;
        struct mv643xx_private *mp = netdev_priv(dev);

        mp->rx_timer_flag = 0;
        mv643xx_eth_rx_task((void *)data);
}

/*
 * mv643xx_eth_update_mac_address
 *
 * Update the MAC address of the port in the address table
 *
 * Input :      pointer to ethernet interface network device structure
 * Output :     N/A
 */
static void mv643xx_eth_update_mac_address(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;

        eth_port_init_mac_tables(port_num);
        memcpy(mp->port_mac_addr, dev->dev_addr, 6);
        eth_port_uc_addr_set(port_num, mp->port_mac_addr);
}

/*
 * mv643xx_eth_set_rx_mode
 *
 * Change from promiscuos to regular rx mode
 *
 * Input :      pointer to ethernet interface network device structure
 * Output :     N/A
 */
static void mv643xx_eth_set_rx_mode(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        u32 config_reg;

        config_reg = ethernet_get_config_reg(mp->port_num);
        if (dev->flags & IFF_PROMISC)
                config_reg |= (u32) MV643XX_ETH_UNICAST_PROMISCUOUS_MODE;
        else
                config_reg &= ~(u32) MV643XX_ETH_UNICAST_PROMISCUOUS_MODE;
        ethernet_set_config_reg(mp->port_num, config_reg);
}

/*
 * mv643xx_eth_set_mac_address
 *
 * Change the interface's mac address.
 * No special hardware thing should be done because interface is always
 * put in promiscuous mode.
 *
 * Input :      pointer to ethernet interface network device structure and
 *              a pointer to the designated entry to be added to the cache.
 * Output :     zero upon success, negative upon failure
 */
static int mv643xx_eth_set_mac_address(struct net_device *dev, void *addr)
{
        int i;

        for (i = 0; i < 6; i++)
                /* +2 is for the offset of the HW addr type */
                dev->dev_addr[i] = ((unsigned char *)addr)[i + 2];
        mv643xx_eth_update_mac_address(dev);
        return 0;
}

/*
 * mv643xx_eth_tx_timeout
 *
 * Called upon a timeout on transmitting a packet
 *
 * Input :      pointer to ethernet interface network device structure.
 * Output :     N/A
 */
static void mv643xx_eth_tx_timeout(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        printk(KERN_INFO "%s: TX timeout  ", dev->name);

        /* Do the reset outside of interrupt context */
        schedule_work(&mp->tx_timeout_task);
}

/*
 * mv643xx_eth_tx_timeout_task
 *
 * Actual routine to reset the adapter when a timeout on Tx has occurred
 */
static void mv643xx_eth_tx_timeout_task(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        netif_device_detach(dev);
        eth_port_reset(mp->port_num);
        eth_port_start(mp);
        netif_device_attach(dev);
}

/*
 * mv643xx_eth_free_tx_queue
 *
 * Input :      dev - a pointer to the required interface
 *
 * Output :     0 if was able to release skb , nonzero otherwise
 */
static int mv643xx_eth_free_tx_queue(struct net_device *dev,
                                        unsigned int eth_int_cause_ext)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        struct net_device_stats *stats = &mp->stats;
        struct pkt_info pkt_info;
        int released = 1;

        if (!(eth_int_cause_ext & (BIT0 | BIT8)))
                return released;

        spin_lock(&mp->lock);

        /* Check only queue 0 */
        while (eth_tx_return_desc(mp, &pkt_info) == ETH_OK) {
                if (pkt_info.cmd_sts & BIT0) {
                        printk("%s: Error in TX\n", dev->name);
                        stats->tx_errors++;
                }

                /*
                 * If return_info is different than 0, release the skb.
                 * The case where return_info is not 0 is only in case
                 * when transmitted a scatter/gather packet, where only
                 * last skb releases the whole chain.
                 */
                if (pkt_info.return_info) {
                        if (skb_shinfo(pkt_info.return_info)->nr_frags)
                                dma_unmap_page(NULL, pkt_info.buf_ptr,
                                                pkt_info.byte_cnt,
                                                DMA_TO_DEVICE);
                        else
                                dma_unmap_single(NULL, pkt_info.buf_ptr,
                                                pkt_info.byte_cnt,
                                                DMA_TO_DEVICE);

                        dev_kfree_skb_irq(pkt_info.return_info);
                        released = 0;
                } else
                        dma_unmap_page(NULL, pkt_info.buf_ptr,
                                        pkt_info.byte_cnt, DMA_TO_DEVICE);
        }

        spin_unlock(&mp->lock);

        return released;
}

/*
 * mv643xx_eth_receive
 *
 * This function is forward packets that are received from the port's
 * queues toward kernel core or FastRoute them to another interface.
 *
 * Input :      dev - a pointer to the required interface
 *              max - maximum number to receive (0 means unlimted)
 *
 * Output :     number of served packets
 */
#ifdef MV643XX_NAPI
static int mv643xx_eth_receive_queue(struct net_device *dev, int budget)
#else
static int mv643xx_eth_receive_queue(struct net_device *dev)
#endif
{
        struct mv643xx_private *mp = netdev_priv(dev);
        struct net_device_stats *stats = &mp->stats;
        unsigned int received_packets = 0;
        struct sk_buff *skb;
        struct pkt_info pkt_info;

#ifdef MV643XX_NAPI
        while (budget-- > 0 && eth_port_receive(mp, &pkt_info) == ETH_OK) {
#else
        while (eth_port_receive(mp, &pkt_info) == ETH_OK) {
#endif
                mp->rx_ring_skbs--;
                received_packets++;

                /* Update statistics. Note byte count includes 4 byte CRC count */
                stats->rx_packets++;
                stats->rx_bytes += pkt_info.byte_cnt;
                skb = pkt_info.return_info;
                /*
                 * In case received a packet without first / last bits on OR
                 * the error summary bit is on, the packets needs to be dropeed.
                 */
                if (((pkt_info.cmd_sts
                                & (ETH_RX_FIRST_DESC | ETH_RX_LAST_DESC)) !=
                                        (ETH_RX_FIRST_DESC | ETH_RX_LAST_DESC))
                                || (pkt_info.cmd_sts & ETH_ERROR_SUMMARY)) {
                        stats->rx_dropped++;
                        if ((pkt_info.cmd_sts & (ETH_RX_FIRST_DESC |
                                                        ETH_RX_LAST_DESC)) !=
                                (ETH_RX_FIRST_DESC | ETH_RX_LAST_DESC)) {
                                if (net_ratelimit())
                                        printk(KERN_ERR
                                                "%s: Received packet spread "
                                                "on multiple descriptors\n",
                                                dev->name);
                        }
                        if (pkt_info.cmd_sts & ETH_ERROR_SUMMARY)
                                stats->rx_errors++;

                        dev_kfree_skb_irq(skb);
                } else {
                        /*
                         * The -4 is for the CRC in the trailer of the
                         * received packet
                         */
                        skb_put(skb, pkt_info.byte_cnt - 4);
                        skb->dev = dev;

                        if (pkt_info.cmd_sts & ETH_LAYER_4_CHECKSUM_OK) {
                                skb->ip_summed = CHECKSUM_UNNECESSARY;
                                skb->csum = htons(
                                        (pkt_info.cmd_sts & 0x0007fff8) >> 3);
                        }
                        skb->protocol = eth_type_trans(skb, dev);
#ifdef MV643XX_NAPI
                        netif_receive_skb(skb);
#else
                        netif_rx(skb);
#endif
                }
        }

        return received_packets;
}

/*
 * mv643xx_eth_int_handler
 *
 * Main interrupt handler for the gigbit ethernet ports
 *
 * Input :      irq     - irq number (not used)
 *              dev_id  - a pointer to the required interface's data structure
 *              regs    - not used
 * Output :     N/A
 */

static irqreturn_t mv643xx_eth_int_handler(int irq, void *dev_id,
                                                        struct pt_regs *regs)
{
        struct net_device *dev = (struct net_device *)dev_id;
        struct mv643xx_private *mp = netdev_priv(dev);
        u32 eth_int_cause, eth_int_cause_ext = 0;
        unsigned int port_num = mp->port_num;

        /* Read interrupt cause registers */
        eth_int_cause = mv_read(MV643XX_ETH_INTERRUPT_CAUSE_REG(port_num)) &
                                                INT_CAUSE_UNMASK_ALL;

        if (eth_int_cause & BIT1)
                eth_int_cause_ext = mv_read(
                        MV643XX_ETH_INTERRUPT_CAUSE_EXTEND_REG(port_num)) &
                                                INT_CAUSE_UNMASK_ALL_EXT;

#ifdef MV643XX_NAPI
        if (!(eth_int_cause & 0x0007fffd)) {
                /* Dont ack the Rx interrupt */
#endif
                /*
                 * Clear specific ethernet port intrerrupt registers by
                 * acknowleding relevant bits.
                 */
                mv_write(MV643XX_ETH_INTERRUPT_CAUSE_REG(port_num),
                                                        ~eth_int_cause);
                if (eth_int_cause_ext != 0x0)
                        mv_write(MV643XX_ETH_INTERRUPT_CAUSE_EXTEND_REG
                                        (port_num), ~eth_int_cause_ext);

                /* UDP change : We may need this */
                if ((eth_int_cause_ext & 0x0000ffff) &&
                    (mv643xx_eth_free_tx_queue(dev, eth_int_cause_ext) == 0) &&
                    (mp->tx_ring_size > mp->tx_ring_skbs + MAX_DESCS_PER_SKB))
                        netif_wake_queue(dev);
#ifdef MV643XX_NAPI
        } else {
                if (netif_rx_schedule_prep(dev)) {
                        /* Mask all the interrupts */
                        mv_write(MV643XX_ETH_INTERRUPT_MASK_REG(port_num), 0);
                        mv_write(MV643XX_ETH_INTERRUPT_EXTEND_MASK_REG
                                                                (port_num), 0);
                        __netif_rx_schedule(dev);
                }
#else
                if (eth_int_cause & (BIT2 | BIT11))
                        mv643xx_eth_receive_queue(dev, 0);

                /*
                 * After forwarded received packets to upper layer, add a task
                 * in an interrupts enabled context that refills the RX ring
                 * with skb's.
                 */
#ifdef MV643XX_RX_QUEUE_FILL_ON_TASK
                /* Unmask all interrupts on ethernet port */
                mv_write(MV643XX_ETH_INTERRUPT_MASK_REG(port_num),
                                                        INT_CAUSE_MASK_ALL);
                queue_task(&mp->rx_task, &tq_immediate);
                mark_bh(IMMEDIATE_BH);
#else
                mp->rx_task.func(dev);
#endif
#endif
        }
        /* PHY status changed */
        if (eth_int_cause_ext & (BIT16 | BIT20)) {
                if (eth_port_link_is_up(port_num)) {
                        netif_carrier_on(dev);
                        netif_wake_queue(dev);
                        /* Start TX queue */
                        mv_write(MV643XX_ETH_TRANSMIT_QUEUE_COMMAND_REG
                                                                (port_num), 1);
                } else {
                        netif_carrier_off(dev);
                        netif_stop_queue(dev);
                }
        }

        /*
         * If no real interrupt occured, exit.
         * This can happen when using gigE interrupt coalescing mechanism.
         */
        if ((eth_int_cause == 0x0) && (eth_int_cause_ext == 0x0))
                return IRQ_NONE;

        return IRQ_HANDLED;
}

#ifdef MV643XX_COAL

/*
 * eth_port_set_rx_coal - Sets coalescing interrupt mechanism on RX path
 *
 * DESCRIPTION:
 *      This routine sets the RX coalescing interrupt mechanism parameter.
 *      This parameter is a timeout counter, that counts in 64 t_clk
 *      chunks ; that when timeout event occurs a maskable interrupt
 *      occurs.
 *      The parameter is calculated using the tClk of the MV-643xx chip
 *      , and the required delay of the interrupt in usec.
 *
 * INPUT:
 *      unsigned int eth_port_num       Ethernet port number
 *      unsigned int t_clk              t_clk of the MV-643xx chip in HZ units
 *      unsigned int delay              Delay in usec
 *
 * OUTPUT:
 *      Interrupt coalescing mechanism value is set in MV-643xx chip.
 *
 * RETURN:
 *      The interrupt coalescing value set in the gigE port.
 *
 */
static unsigned int eth_port_set_rx_coal(unsigned int eth_port_num,
                                        unsigned int t_clk, unsigned int delay)
{
        unsigned int coal = ((t_clk / 1000000) * delay) / 64;

        /* Set RX Coalescing mechanism */
        mv_write(MV643XX_ETH_SDMA_CONFIG_REG(eth_port_num),
                ((coal & 0x3fff) << 8) |
                (mv_read(MV643XX_ETH_SDMA_CONFIG_REG(eth_port_num))
                        & 0xffc000ff));

        return coal;
}
#endif

/*
 * eth_port_set_tx_coal - Sets coalescing interrupt mechanism on TX path
 *
 * DESCRIPTION:
 *      This routine sets the TX coalescing interrupt mechanism parameter.
 *      This parameter is a timeout counter, that counts in 64 t_clk
 *      chunks ; that when timeout event occurs a maskable interrupt
 *      occurs.
 *      The parameter is calculated using the t_cLK frequency of the
 *      MV-643xx chip and the required delay in the interrupt in uSec
 *
 * INPUT:
 *      unsigned int eth_port_num       Ethernet port number
 *      unsigned int t_clk              t_clk of the MV-643xx chip in HZ units
 *      unsigned int delay              Delay in uSeconds
 *
 * OUTPUT:
 *      Interrupt coalescing mechanism value is set in MV-643xx chip.
 *
 * RETURN:
 *      The interrupt coalescing value set in the gigE port.
 *
 */
static unsigned int eth_port_set_tx_coal(unsigned int eth_port_num,
                                        unsigned int t_clk, unsigned int delay)
{
        unsigned int coal;
        coal = ((t_clk / 1000000) * delay) / 64;
        /* Set TX Coalescing mechanism */
        mv_write(MV643XX_ETH_TX_FIFO_URGENT_THRESHOLD_REG(eth_port_num),
                                                                coal << 4);
        return coal;
}

/*
 * mv643xx_eth_open
 *
 * This function is called when openning the network device. The function
 * should initialize all the hardware, initialize cyclic Rx/Tx
 * descriptors chain and buffers and allocate an IRQ to the network
 * device.
 *
 * Input :      a pointer to the network device structure
 *
 * Output :     zero of success , nonzero if fails.
 */

static int mv643xx_eth_open(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;
        int err;

        spin_lock_irq(&mp->lock);

        err = request_irq(dev->irq, mv643xx_eth_int_handler,
                        SA_SHIRQ | SA_SAMPLE_RANDOM, dev->name, dev);

        if (err) {
                printk(KERN_ERR "Can not assign IRQ number to MV643XX_eth%d\n",
                                                                port_num);
                err = -EAGAIN;
                goto out;
        }

        if (mv643xx_eth_real_open(dev)) {
                printk("%s: Error opening interface\n", dev->name);
                err = -EBUSY;
                goto out_free;
        }

        spin_unlock_irq(&mp->lock);

        return 0;

out_free:
        free_irq(dev->irq, dev);

out:
        spin_unlock_irq(&mp->lock);

        return err;
}

/*
 * ether_init_rx_desc_ring - Curve a Rx chain desc list and buffer in memory.
 *
 * DESCRIPTION:
 *      This function prepares a Rx chained list of descriptors and packet
 *      buffers in a form of a ring. The routine must be called after port
 *      initialization routine and before port start routine.
 *      The Ethernet SDMA engine uses CPU bus addresses to access the various
 *      devices in the system (i.e. DRAM). This function uses the ethernet
 *      struct 'virtual to physical' routine (set by the user) to set the ring
 *      with physical addresses.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port Control srtuct.
 *
 * OUTPUT:
 *      The routine updates the Ethernet port control struct with information
 *      regarding the Rx descriptors and buffers.
 *
 * RETURN:
 *      None.
 */
static void ether_init_rx_desc_ring(struct mv643xx_private *mp)
{
        volatile struct eth_rx_desc *p_rx_desc;
        int rx_desc_num = mp->rx_ring_size;
        int i;

        /* initialize the next_desc_ptr links in the Rx descriptors ring */
        p_rx_desc = (struct eth_rx_desc *)mp->p_rx_desc_area;
        for (i = 0; i < rx_desc_num; i++) {
                p_rx_desc[i].next_desc_ptr = mp->rx_desc_dma +
                        ((i + 1) % rx_desc_num) * sizeof(struct eth_rx_desc);
        }

        /* Save Rx desc pointer to driver struct. */
        mp->rx_curr_desc_q = 0;
        mp->rx_used_desc_q = 0;

        mp->rx_desc_area_size = rx_desc_num * sizeof(struct eth_rx_desc);

        /* Add the queue to the list of RX queues of this port */
        mp->port_rx_queue_command |= 1;
}

/*
 * ether_init_tx_desc_ring - Curve a Tx chain desc list and buffer in memory.
 *
 * DESCRIPTION:
 *      This function prepares a Tx chained list of descriptors and packet
 *      buffers in a form of a ring. The routine must be called after port
 *      initialization routine and before port start routine.
 *      The Ethernet SDMA engine uses CPU bus addresses to access the various
 *      devices in the system (i.e. DRAM). This function uses the ethernet
 *      struct 'virtual to physical' routine (set by the user) to set the ring
 *      with physical addresses.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet Port Control srtuct.
 *
 * OUTPUT:
 *      The routine updates the Ethernet port control struct with information
 *      regarding the Tx descriptors and buffers.
 *
 * RETURN:
 *      None.
 */
static void ether_init_tx_desc_ring(struct mv643xx_private *mp)
{
        int tx_desc_num = mp->tx_ring_size;
        struct eth_tx_desc *p_tx_desc;
        int i;

        /* Initialize the next_desc_ptr links in the Tx descriptors ring */
        p_tx_desc = (struct eth_tx_desc *)mp->p_tx_desc_area;
        for (i = 0; i < tx_desc_num; i++) {
                p_tx_desc[i].next_desc_ptr = mp->tx_desc_dma +
                        ((i + 1) % tx_desc_num) * sizeof(struct eth_tx_desc);
        }

        mp->tx_curr_desc_q = 0;
        mp->tx_used_desc_q = 0;
#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
        mp->tx_first_desc_q = 0;
#endif

        mp->tx_desc_area_size = tx_desc_num * sizeof(struct eth_tx_desc);

        /* Add the queue to the list of Tx queues of this port */
        mp->port_tx_queue_command |= 1;
}

/* Helper function for mv643xx_eth_open */
static int mv643xx_eth_real_open(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;
        unsigned int size;

        /* Stop RX Queues */
        mv_write(MV643XX_ETH_RECEIVE_QUEUE_COMMAND_REG(port_num), 0x0000ff00);

        /* Clear the ethernet port interrupts */
        mv_write(MV643XX_ETH_INTERRUPT_CAUSE_REG(port_num), 0);
        mv_write(MV643XX_ETH_INTERRUPT_CAUSE_EXTEND_REG(port_num), 0);

        /* Unmask RX buffer and TX end interrupt */
        mv_write(MV643XX_ETH_INTERRUPT_MASK_REG(port_num),
                                                INT_CAUSE_UNMASK_ALL);

        /* Unmask phy and link status changes interrupts */
        mv_write(MV643XX_ETH_INTERRUPT_EXTEND_MASK_REG(port_num),
                                                INT_CAUSE_UNMASK_ALL_EXT);

        /* Set the MAC Address */
        memcpy(mp->port_mac_addr, dev->dev_addr, 6);

        eth_port_init(mp);

        INIT_WORK(&mp->rx_task, (void (*)(void *))mv643xx_eth_rx_task, dev);

        memset(&mp->timeout, 0, sizeof(struct timer_list));
        mp->timeout.function = mv643xx_eth_rx_task_timer_wrapper;
        mp->timeout.data = (unsigned long)dev;

        mp->rx_task_busy = 0;
        mp->rx_timer_flag = 0;

        /* Allocate RX and TX skb rings */
        mp->rx_skb = kmalloc(sizeof(*mp->rx_skb) * mp->rx_ring_size,
                                                                GFP_KERNEL);
        if (!mp->rx_skb) {
                printk(KERN_ERR "%s: Cannot allocate Rx skb ring\n", dev->name);
                return -ENOMEM;
        }
        mp->tx_skb = kmalloc(sizeof(*mp->tx_skb) * mp->tx_ring_size,
                                                                GFP_KERNEL);
        if (!mp->tx_skb) {
                printk(KERN_ERR "%s: Cannot allocate Tx skb ring\n", dev->name);
                kfree(mp->rx_skb);
                return -ENOMEM;
        }

        /* Allocate TX ring */
        mp->tx_ring_skbs = 0;
        size = mp->tx_ring_size * sizeof(struct eth_tx_desc);
        mp->tx_desc_area_size = size;

        if (mp->tx_sram_size) {
                mp->p_tx_desc_area = ioremap(mp->tx_sram_addr,
                                                        mp->tx_sram_size);
                mp->tx_desc_dma = mp->tx_sram_addr;
        } else
                mp->p_tx_desc_area = dma_alloc_coherent(NULL, size,
                                                        &mp->tx_desc_dma,
                                                        GFP_KERNEL);

        if (!mp->p_tx_desc_area) {
                printk(KERN_ERR "%s: Cannot allocate Tx Ring (size %d bytes)\n",
                                                        dev->name, size);
                kfree(mp->rx_skb);
                kfree(mp->tx_skb);
                return -ENOMEM;
        }
        BUG_ON((u32) mp->p_tx_desc_area & 0xf); /* check 16-byte alignment */
        memset((void *)mp->p_tx_desc_area, 0, mp->tx_desc_area_size);

        ether_init_tx_desc_ring(mp);

        /* Allocate RX ring */
        mp->rx_ring_skbs = 0;
        size = mp->rx_ring_size * sizeof(struct eth_rx_desc);
        mp->rx_desc_area_size = size;

        if (mp->rx_sram_size) {
                mp->p_rx_desc_area = ioremap(mp->rx_sram_addr,
                                                        mp->rx_sram_size);
                mp->rx_desc_dma = mp->rx_sram_addr;
        } else
                mp->p_rx_desc_area = dma_alloc_coherent(NULL, size,
                                                        &mp->rx_desc_dma,
                                                        GFP_KERNEL);

        if (!mp->p_rx_desc_area) {
                printk(KERN_ERR "%s: Cannot allocate Rx ring (size %d bytes)\n",
                                                        dev->name, size);
                printk(KERN_ERR "%s: Freeing previously allocated TX queues...",
                                                        dev->name);
                if (mp->rx_sram_size)
                        iounmap(mp->p_rx_desc_area);
                else
                        dma_free_coherent(NULL, mp->tx_desc_area_size,
                                        mp->p_tx_desc_area, mp->tx_desc_dma);
                kfree(mp->rx_skb);
                kfree(mp->tx_skb);
                return -ENOMEM;
        }
        memset((void *)mp->p_rx_desc_area, 0, size);

        ether_init_rx_desc_ring(mp);

        mv643xx_eth_rx_task(dev);       /* Fill RX ring with skb's */

        eth_port_start(mp);

        /* Interrupt Coalescing */

#ifdef MV643XX_COAL
        mp->rx_int_coal =
                eth_port_set_rx_coal(port_num, 133000000, MV643XX_RX_COAL);
#endif

        mp->tx_int_coal =
                eth_port_set_tx_coal(port_num, 133000000, MV643XX_TX_COAL);

        netif_start_queue(dev);

        return 0;
}

static void mv643xx_eth_free_tx_rings(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;
        unsigned int curr;

        /* Stop Tx Queues */
        mv_write(MV643XX_ETH_TRANSMIT_QUEUE_COMMAND_REG(port_num), 0x0000ff00);

        /* Free outstanding skb's on TX rings */
        for (curr = 0; mp->tx_ring_skbs && curr < mp->tx_ring_size; curr++) {
                if (mp->tx_skb[curr]) {
                        dev_kfree_skb(mp->tx_skb[curr]);
                        mp->tx_ring_skbs--;
                }
        }
        if (mp->tx_ring_skbs)
                printk("%s: Error on Tx descriptor free - could not free %d"
                                " descriptors\n", dev->name, mp->tx_ring_skbs);

        /* Free TX ring */
        if (mp->tx_sram_size)
                iounmap(mp->p_tx_desc_area);
        else
                dma_free_coherent(NULL, mp->tx_desc_area_size,
                                mp->p_tx_desc_area, mp->tx_desc_dma);
}

static void mv643xx_eth_free_rx_rings(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;
        int curr;

        /* Stop RX Queues */
        mv_write(MV643XX_ETH_RECEIVE_QUEUE_COMMAND_REG(port_num), 0x0000ff00);

        /* Free preallocated skb's on RX rings */
        for (curr = 0; mp->rx_ring_skbs && curr < mp->rx_ring_size; curr++) {
                if (mp->rx_skb[curr]) {
                        dev_kfree_skb(mp->rx_skb[curr]);
                        mp->rx_ring_skbs--;
                }
        }

        if (mp->rx_ring_skbs)
                printk(KERN_ERR
                        "%s: Error in freeing Rx Ring. %d skb's still"
                        " stuck in RX Ring - ignoring them\n", dev->name,
                        mp->rx_ring_skbs);
        /* Free RX ring */
        if (mp->rx_sram_size)
                iounmap(mp->p_rx_desc_area);
        else
                dma_free_coherent(NULL, mp->rx_desc_area_size,
                                mp->p_rx_desc_area, mp->rx_desc_dma);
}

/*
 * mv643xx_eth_stop
 *
 * This function is used when closing the network device.
 * It updates the hardware,
 * release all memory that holds buffers and descriptors and release the IRQ.
 * Input :      a pointer to the device structure
 * Output :     zero if success , nonzero if fails
 */

/* Helper function for mv643xx_eth_stop */

static int mv643xx_eth_real_stop(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int port_num = mp->port_num;

        netif_carrier_off(dev);
        netif_stop_queue(dev);

        mv643xx_eth_free_tx_rings(dev);
        mv643xx_eth_free_rx_rings(dev);

        eth_port_reset(mp->port_num);

        /* Disable ethernet port interrupts */
        mv_write(MV643XX_ETH_INTERRUPT_CAUSE_REG(port_num), 0);
        mv_write(MV643XX_ETH_INTERRUPT_CAUSE_EXTEND_REG(port_num), 0);

        /* Mask RX buffer and TX end interrupt */
        mv_write(MV643XX_ETH_INTERRUPT_MASK_REG(port_num), 0);

        /* Mask phy and link status changes interrupts */
        mv_write(MV643XX_ETH_INTERRUPT_EXTEND_MASK_REG(port_num), 0);

        return 0;
}

static int mv643xx_eth_stop(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        spin_lock_irq(&mp->lock);

        mv643xx_eth_real_stop(dev);

        free_irq(dev->irq, dev);
        spin_unlock_irq(&mp->lock);

        return 0;
}

#ifdef MV643XX_NAPI
static void mv643xx_tx(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        struct pkt_info pkt_info;

        while (eth_tx_return_desc(mp, &pkt_info) == ETH_OK) {
                if (pkt_info.return_info) {
                        if (skb_shinfo(pkt_info.return_info)->nr_frags)
                                dma_unmap_page(NULL, pkt_info.buf_ptr,
                                                pkt_info.byte_cnt,
                                                DMA_TO_DEVICE);
                        else
                                dma_unmap_single(NULL, pkt_info.buf_ptr,
                                                pkt_info.byte_cnt,
                                                DMA_TO_DEVICE);

                        dev_kfree_skb_irq(pkt_info.return_info);
                } else
                        dma_unmap_page(NULL, pkt_info.buf_ptr,
                                        pkt_info.byte_cnt, DMA_TO_DEVICE);
        }

        if (netif_queue_stopped(dev) &&
                        mp->tx_ring_size > mp->tx_ring_skbs + MAX_DESCS_PER_SKB)
                netif_wake_queue(dev);
}

/*
 * mv643xx_poll
 *
 * This function is used in case of NAPI
 */
static int mv643xx_poll(struct net_device *dev, int *budget)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        int done = 1, orig_budget, work_done;
        unsigned int port_num = mp->port_num;
        unsigned long flags;

#ifdef MV643XX_TX_FAST_REFILL
        if (++mp->tx_clean_threshold > 5) {
                spin_lock_irqsave(&mp->lock, flags);
                mv643xx_tx(dev);
                mp->tx_clean_threshold = 0;
                spin_unlock_irqrestore(&mp->lock, flags);
        }
#endif

        if ((mv_read(MV643XX_ETH_RX_CURRENT_QUEUE_DESC_PTR_0(port_num)))
                                                != (u32) mp->rx_used_desc_q) {
                orig_budget = *budget;
                if (orig_budget > dev->quota)
                        orig_budget = dev->quota;
                work_done = mv643xx_eth_receive_queue(dev, orig_budget);
                mp->rx_task.func(dev);
                *budget -= work_done;
                dev->quota -= work_done;
                if (work_done >= orig_budget)
                        done = 0;
        }

        if (done) {
                spin_lock_irqsave(&mp->lock, flags);
                __netif_rx_complete(dev);
                mv_write(MV643XX_ETH_INTERRUPT_CAUSE_REG(port_num), 0);
                mv_write(MV643XX_ETH_INTERRUPT_CAUSE_EXTEND_REG(port_num), 0);
                mv_write(MV643XX_ETH_INTERRUPT_MASK_REG(port_num),
                                                INT_CAUSE_UNMASK_ALL);
                mv_write(MV643XX_ETH_INTERRUPT_EXTEND_MASK_REG(port_num),
                                                INT_CAUSE_UNMASK_ALL_EXT);
                spin_unlock_irqrestore(&mp->lock, flags);
        }

        return done ? 0 : 1;
}
#endif

/*
 * mv643xx_eth_start_xmit
 *
 * This function is queues a packet in the Tx descriptor for
 * required port.
 *
 * Input :      skb - a pointer to socket buffer
 *              dev - a pointer to the required port
 *
 * Output :     zero upon success
 */
static int mv643xx_eth_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        struct net_device_stats *stats = &mp->stats;
        ETH_FUNC_RET_STATUS status;
        unsigned long flags;
        struct pkt_info pkt_info;

        if (netif_queue_stopped(dev)) {
                printk(KERN_ERR
                        "%s: Tried sending packet when interface is stopped\n",
                        dev->name);
                return 1;
        }

        /* This is a hard error, log it. */
        if ((mp->tx_ring_size - mp->tx_ring_skbs) <=
                                        (skb_shinfo(skb)->nr_frags + 1)) {
                netif_stop_queue(dev);
                printk(KERN_ERR
                        "%s: Bug in mv643xx_eth - Trying to transmit when"
                        " queue full !\n", dev->name);
                return 1;
        }

        /* Paranoid check - this shouldn't happen */
        if (skb == NULL) {
                stats->tx_dropped++;
                printk(KERN_ERR "mv64320_eth paranoid check failed\n");
                return 1;
        }

        spin_lock_irqsave(&mp->lock, flags);

        /* Update packet info data structure -- DMA owned, first last */
#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
        if (!skb_shinfo(skb)->nr_frags) {
linear:
                if (skb->ip_summed != CHECKSUM_HW) {
                        /* Errata BTS #50, IHL must be 5 if no HW checksum */
                        pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT |
                                           ETH_TX_FIRST_DESC |
                                           ETH_TX_LAST_DESC |
                                           5 << ETH_TX_IHL_SHIFT;
                        pkt_info.l4i_chk = 0;
                } else {

                        pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT |
                                           ETH_TX_FIRST_DESC |
                                           ETH_TX_LAST_DESC |
                                           ETH_GEN_TCP_UDP_CHECKSUM |
                                           ETH_GEN_IP_V_4_CHECKSUM |
                                           skb->nh.iph->ihl << ETH_TX_IHL_SHIFT;
                        /* CPU already calculated pseudo header checksum. */
                        if (skb->nh.iph->protocol == IPPROTO_UDP) {
                                pkt_info.cmd_sts |= ETH_UDP_FRAME;
                                pkt_info.l4i_chk = skb->h.uh->check;
                        } else if (skb->nh.iph->protocol == IPPROTO_TCP)
                                pkt_info.l4i_chk = skb->h.th->check;
                        else {
                                printk(KERN_ERR
                                        "%s: chksum proto != TCP or UDP\n",
                                        dev->name);
                                spin_unlock_irqrestore(&mp->lock, flags);
                                return 1;
                        }
                }
                pkt_info.byte_cnt = skb->len;
                pkt_info.buf_ptr = dma_map_single(NULL, skb->data, skb->len,
                                                        DMA_TO_DEVICE);
                pkt_info.return_info = skb;
                status = eth_port_send(mp, &pkt_info);
                if ((status == ETH_ERROR) || (status == ETH_QUEUE_FULL))
                        printk(KERN_ERR "%s: Error on transmitting packet\n",
                                                                dev->name);
                stats->tx_bytes += pkt_info.byte_cnt;
        } else {
                unsigned int frag;

                /* Since hardware can't handle unaligned fragments smaller
                 * than 9 bytes, if we find any, we linearize the skb
                 * and start again.  When I've seen it, it's always been
                 * the first frag (probably near the end of the page),
                 * but we check all frags to be safe.
                 */
                for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
                        skb_frag_t *fragp;

                        fragp = &skb_shinfo(skb)->frags[frag];
                        if (fragp->size <= 8 && fragp->page_offset & 0x7) {
                                skb_linearize(skb, GFP_ATOMIC);
                                printk(KERN_DEBUG "%s: unaligned tiny fragment"
                                                "%d of %d, fixed\n",
                                                dev->name, frag,
                                                skb_shinfo(skb)->nr_frags);
                                goto linear;
                        }
                }

                /* first frag which is skb header */
                pkt_info.byte_cnt = skb_headlen(skb);
                pkt_info.buf_ptr = dma_map_single(NULL, skb->data,
                                                        skb_headlen(skb),
                                                        DMA_TO_DEVICE);
                pkt_info.l4i_chk = 0;
                pkt_info.return_info = 0;

                if (skb->ip_summed != CHECKSUM_HW)
                        /* Errata BTS #50, IHL must be 5 if no HW checksum */
                        pkt_info.cmd_sts = ETH_TX_FIRST_DESC |
                                           5 << ETH_TX_IHL_SHIFT;
                else {
                        pkt_info.cmd_sts = ETH_TX_FIRST_DESC |
                                           ETH_GEN_TCP_UDP_CHECKSUM |
                                           ETH_GEN_IP_V_4_CHECKSUM |
                                           skb->nh.iph->ihl << ETH_TX_IHL_SHIFT;
                        /* CPU already calculated pseudo header checksum. */
                        if (skb->nh.iph->protocol == IPPROTO_UDP) {
                                pkt_info.cmd_sts |= ETH_UDP_FRAME;
                                pkt_info.l4i_chk = skb->h.uh->check;
                        } else if (skb->nh.iph->protocol == IPPROTO_TCP)
                                pkt_info.l4i_chk = skb->h.th->check;
                        else {
                                printk(KERN_ERR
                                        "%s: chksum proto != TCP or UDP\n",
                                        dev->name);
                                spin_unlock_irqrestore(&mp->lock, flags);
                                return 1;
                        }
                }

                status = eth_port_send(mp, &pkt_info);
                if (status != ETH_OK) {
                        if ((status == ETH_ERROR))
                                printk(KERN_ERR
                                        "%s: Error on transmitting packet\n",
                                        dev->name);
                        if (status == ETH_QUEUE_FULL)
                                printk("Error on Queue Full \n");
                        if (status == ETH_QUEUE_LAST_RESOURCE)
                                printk("Tx resource error \n");
                }
                stats->tx_bytes += pkt_info.byte_cnt;

                /* Check for the remaining frags */
                for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
                        skb_frag_t *this_frag = &skb_shinfo(skb)->frags[frag];
                        pkt_info.l4i_chk = 0x0000;
                        pkt_info.cmd_sts = 0x00000000;

                        /* Last Frag enables interrupt and frees the skb */
                        if (frag == (skb_shinfo(skb)->nr_frags - 1)) {
                                pkt_info.cmd_sts |= ETH_TX_ENABLE_INTERRUPT |
                                                        ETH_TX_LAST_DESC;
                                pkt_info.return_info = skb;
                        } else {
                                pkt_info.return_info = 0;
                        }
                        pkt_info.l4i_chk = 0;
                        pkt_info.byte_cnt = this_frag->size;

                        pkt_info.buf_ptr = dma_map_page(NULL, this_frag->page,
                                                        this_frag->page_offset,
                                                        this_frag->size,
                                                        DMA_TO_DEVICE);

                        status = eth_port_send(mp, &pkt_info);

                        if (status != ETH_OK) {
                                if ((status == ETH_ERROR))
                                        printk(KERN_ERR "%s: Error on "
                                                        "transmitting packet\n",
                                                        dev->name);

                                if (status == ETH_QUEUE_LAST_RESOURCE)
                                        printk("Tx resource error \n");

                                if (status == ETH_QUEUE_FULL)
                                        printk("Queue is full \n");
                        }
                        stats->tx_bytes += pkt_info.byte_cnt;
                }
        }
#else
        pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT | ETH_TX_FIRST_DESC |
                                                        ETH_TX_LAST_DESC;
        pkt_info.l4i_chk = 0;
        pkt_info.byte_cnt = skb->len;
        pkt_info.buf_ptr = dma_map_single(NULL, skb->data, skb->len,
                                                                DMA_TO_DEVICE);
        pkt_info.return_info = skb;
        status = eth_port_send(mp, &pkt_info);
        if ((status == ETH_ERROR) || (status == ETH_QUEUE_FULL))
                printk(KERN_ERR "%s: Error on transmitting packet\n",
                                                                dev->name);
        stats->tx_bytes += pkt_info.byte_cnt;
#endif

        /* Check if TX queue can handle another skb. If not, then
         * signal higher layers to stop requesting TX
         */
        if (mp->tx_ring_size <= (mp->tx_ring_skbs + MAX_DESCS_PER_SKB))
                /*
                 * Stop getting skb's from upper layers.
                 * Getting skb's from upper layers will be enabled again after
                 * packets are released.
                 */
                netif_stop_queue(dev);

        /* Update statistics and start of transmittion time */
        stats->tx_packets++;
        dev->trans_start = jiffies;

        spin_unlock_irqrestore(&mp->lock, flags);

        return 0;               /* success */
}

/*
 * mv643xx_eth_get_stats
 *
 * Returns a pointer to the interface statistics.
 *
 * Input :      dev - a pointer to the required interface
 *
 * Output :     a pointer to the interface's statistics
 */

static struct net_device_stats *mv643xx_eth_get_stats(struct net_device *dev)
{
        struct mv643xx_private *mp = netdev_priv(dev);

        return &mp->stats;
}

/*/
 * mv643xx_eth_probe
 *
 * First function called after registering the network device.
 * It's purpose is to initialize the device as an ethernet device,
 * fill the ethernet device structure with pointers * to functions,
 * and set the MAC address of the interface
 *
 * Input :      struct device *
 * Output :     -ENOMEM if failed , 0 if success
 */
static int mv643xx_eth_probe(struct device *ddev)
{
        struct platform_device *pdev = to_platform_device(ddev);
        struct mv643xx_eth_platform_data *pd;
        int port_num = pdev->id;
        struct mv643xx_private *mp;
        struct net_device *dev;
        u8 *p;
        struct resource *res;
        int err;

        dev = alloc_etherdev(sizeof(struct mv643xx_private));
        if (!dev)
                return -ENOMEM;

        dev_set_drvdata(ddev, dev);

        mp = netdev_priv(dev);

        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        BUG_ON(!res);
        dev->irq = res->start;

        mp->port_num = port_num;

        dev->open = mv643xx_eth_open;
        dev->stop = mv643xx_eth_stop;
        dev->hard_start_xmit = mv643xx_eth_start_xmit;
        dev->get_stats = mv643xx_eth_get_stats;
        dev->set_mac_address = mv643xx_eth_set_mac_address;
        dev->set_multicast_list = mv643xx_eth_set_rx_mode;

        /* No need to Tx Timeout */
        dev->tx_timeout = mv643xx_eth_tx_timeout;
#ifdef MV643XX_NAPI
        dev->poll = mv643xx_poll;
        dev->weight = 64;
#endif

        dev->watchdog_timeo = 2 * HZ;
        dev->tx_queue_len = mp->tx_ring_size;
        dev->base_addr = 0;
        dev->change_mtu = mv643xx_eth_change_mtu;
        SET_ETHTOOL_OPS(dev, &mv643xx_ethtool_ops);

#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
#ifdef MAX_SKB_FRAGS
        /*
         * Zero copy can only work if we use Discovery II memory. Else, we will
         * have to map the buffers to ISA memory which is only 16 MB
         */
        dev->features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_HW_CSUM;
#endif
#endif

        /* Configure the timeout task */
        INIT_WORK(&mp->tx_timeout_task,
                        (void (*)(void *))mv643xx_eth_tx_timeout_task, dev);

        spin_lock_init(&mp->lock);

        /* set default config values */
        eth_port_uc_addr_get(dev, dev->dev_addr);
        mp->port_config = MV643XX_ETH_PORT_CONFIG_DEFAULT_VALUE;
        mp->port_config_extend = MV643XX_ETH_PORT_CONFIG_EXTEND_DEFAULT_VALUE;
        mp->port_sdma_config = MV643XX_ETH_PORT_SDMA_CONFIG_DEFAULT_VALUE;
        mp->port_serial_control = MV643XX_ETH_PORT_SERIAL_CONTROL_DEFAULT_VALUE;
        mp->rx_ring_size = MV643XX_ETH_PORT_DEFAULT_RECEIVE_QUEUE_SIZE;
        mp->tx_ring_size = MV643XX_ETH_PORT_DEFAULT_TRANSMIT_QUEUE_SIZE;

        pd = pdev->dev.platform_data;
        if (pd) {
                if (pd->mac_addr != NULL)
                        memcpy(dev->dev_addr, pd->mac_addr, 6);

                if (pd->phy_addr || pd->force_phy_addr)
                        ethernet_phy_set(port_num, pd->phy_addr);

                if (pd->port_config || pd->force_port_config)
                        mp->port_config = pd->port_config;

                if (pd->port_config_extend || pd->force_port_config_extend)
                        mp->port_config_extend = pd->port_config_extend;

                if (pd->port_sdma_config || pd->force_port_sdma_config)
                        mp->port_sdma_config = pd->port_sdma_config;

                if (pd->port_serial_control || pd->force_port_serial_control)
                        mp->port_serial_control = pd->port_serial_control;

                if (pd->rx_queue_size)
                        mp->rx_ring_size = pd->rx_queue_size;

                if (pd->tx_queue_size)
                        mp->tx_ring_size = pd->tx_queue_size;

                if (pd->tx_sram_size) {
                        mp->tx_sram_size = pd->tx_sram_size;
                        mp->tx_sram_addr = pd->tx_sram_addr;
                }

                if (pd->rx_sram_size) {
                        mp->rx_sram_size = pd->rx_sram_size;
                        mp->rx_sram_addr = pd->rx_sram_addr;
                }
        }

        err = ethernet_phy_detect(port_num);
        if (err) {
                pr_debug("MV643xx ethernet port %d: "
                                        "No PHY detected at addr %d\n",
                                        port_num, ethernet_phy_get(port_num));
                return err;
        }

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

        p = dev->dev_addr;
        printk(KERN_NOTICE
                "%s: port %d with MAC address %02x:%02x:%02x:%02x:%02x:%02x\n",
                dev->name, port_num, p[0], p[1], p[2], p[3], p[4], p[5]);

        if (dev->features & NETIF_F_SG)
                printk(KERN_NOTICE "%s: Scatter Gather Enabled\n", dev->name);

        if (dev->features & NETIF_F_IP_CSUM)
                printk(KERN_NOTICE "%s: TX TCP/IP Checksumming Supported\n",
                                                                dev->name);

#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
        printk(KERN_NOTICE "%s: RX TCP/UDP Checksum Offload ON \n", dev->name);
#endif

#ifdef MV643XX_COAL
        printk(KERN_NOTICE "%s: TX and RX Interrupt Coalescing ON \n",
                                                                dev->name);
#endif

#ifdef MV643XX_NAPI
        printk(KERN_NOTICE "%s: RX NAPI Enabled \n", dev->name);
#endif

        return 0;

out:
        free_netdev(dev);

        return err;
}

static int mv643xx_eth_remove(struct device *ddev)
{
        struct net_device *dev = dev_get_drvdata(ddev);

        unregister_netdev(dev);
        flush_scheduled_work();

        free_netdev(dev);
        dev_set_drvdata(ddev, NULL);
        return 0;
}

static int mv643xx_eth_shared_probe(struct device *ddev)
{
        struct platform_device *pdev = to_platform_device(ddev);
        struct resource *res;

        printk(KERN_NOTICE "MV-643xx 10/100/1000 Ethernet Driver\n");

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL)
                return -ENODEV;

        mv643xx_eth_shared_base = ioremap(res->start,
                                                MV643XX_ETH_SHARED_REGS_SIZE);
        if (mv643xx_eth_shared_base == NULL)
                return -ENOMEM;

        return 0;

}

static int mv643xx_eth_shared_remove(struct device *ddev)
{
        iounmap(mv643xx_eth_shared_base);
        mv643xx_eth_shared_base = NULL;

        return 0;
}

static struct device_driver mv643xx_eth_driver = {
        .name = MV643XX_ETH_NAME,
        .bus = &platform_bus_type,
        .probe = mv643xx_eth_probe,
        .remove = mv643xx_eth_remove,
};

static struct device_driver mv643xx_eth_shared_driver = {
        .name = MV643XX_ETH_SHARED_NAME,
        .bus = &platform_bus_type,
        .probe = mv643xx_eth_shared_probe,
        .remove = mv643xx_eth_shared_remove,
};

/*
 * mv643xx_init_module
 *
 * Registers the network drivers into the Linux kernel
 *
 * Input :      N/A
 *
 * Output :     N/A
 */
static int __init mv643xx_init_module(void)
{
        int rc;

        rc = driver_register(&mv643xx_eth_shared_driver);
        if (!rc) {
                rc = driver_register(&mv643xx_eth_driver);
                if (rc)
                        driver_unregister(&mv643xx_eth_shared_driver);
        }
        return rc;
}

/*
 * mv643xx_cleanup_module
 *
 * Registers the network drivers into the Linux kernel
 *
 * Input :      N/A
 *
 * Output :     N/A
 */
static void __exit mv643xx_cleanup_module(void)
{
        driver_unregister(&mv643xx_eth_driver);
        driver_unregister(&mv643xx_eth_shared_driver);
}

module_init(mv643xx_init_module);
module_exit(mv643xx_cleanup_module);

MODULE_LICENSE("GPL");
MODULE_AUTHOR(  "Rabeeh Khoury, Assaf Hoffman, Matthew Dharm, Manish Lachwani"
                " and Dale Farnsworth");
MODULE_DESCRIPTION("Ethernet driver for Marvell MV643XX");

/*
 * The second part is the low level driver of the gigE ethernet ports.
 */

/*
 * Marvell's Gigabit Ethernet controller low level driver
 *
 * DESCRIPTION:
 *      This file introduce low level API to Marvell's Gigabit Ethernet
 *              controller. This Gigabit Ethernet Controller driver API controls
 *              1) Operations (i.e. port init, start, reset etc').
 *              2) Data flow (i.e. port send, receive etc').
 *              Each Gigabit Ethernet port is controlled via
 *              struct mv643xx_private.
 *              This struct includes user configuration information as well as
 *              driver internal data needed for its operations.
 *
 *              Supported Features:
 *              - This low level driver is OS independent. Allocating memory for
 *                the descriptor rings and buffers are not within the scope of
 *                this driver.
 *              - The user is free from Rx/Tx queue managing.
 *              - This low level driver introduce functionality API that enable
 *                the to operate Marvell's Gigabit Ethernet Controller in a
 *                convenient way.
 *              - Simple Gigabit Ethernet port operation API.
 *              - Simple Gigabit Ethernet port data flow API.
 *              - Data flow and operation API support per queue functionality.
 *              - Support cached descriptors for better performance.
 *              - Enable access to all four DRAM banks and internal SRAM memory
 *                spaces.
 *              - PHY access and control API.
 *              - Port control register configuration API.
 *              - Full control over Unicast and Multicast MAC configurations.
 *
 *              Operation flow:
 *
 *              Initialization phase
 *              This phase complete the initialization of the the
 *              mv643xx_private struct.
 *              User information regarding port configuration has to be set
 *              prior to calling the port initialization routine.
 *
 *              In this phase any port Tx/Rx activity is halted, MIB counters
 *              are cleared, PHY address is set according to user parameter and
 *              access to DRAM and internal SRAM memory spaces.
 *
 *              Driver ring initialization
 *              Allocating memory for the descriptor rings and buffers is not
 *              within the scope of this driver. Thus, the user is required to
 *              allocate memory for the descriptors ring and buffers. Those
 *              memory parameters are used by the Rx and Tx ring initialization
 *              routines in order to curve the descriptor linked list in a form
 *              of a ring.
 *              Note: Pay special attention to alignment issues when using
 *              cached descriptors/buffers. In this phase the driver store
 *              information in the mv643xx_private struct regarding each queue
 *              ring.
 *
 *              Driver start
 *              This phase prepares the Ethernet port for Rx and Tx activity.
 *              It uses the information stored in the mv643xx_private struct to
 *              initialize the various port registers.
 *
 *              Data flow:
 *              All packet references to/from the driver are done using
 *              struct pkt_info.
 *              This struct is a unified struct used with Rx and Tx operations.
 *              This way the user is not required to be familiar with neither
 *              Tx nor Rx descriptors structures.
 *              The driver's descriptors rings are management by indexes.
 *              Those indexes controls the ring resources and used to indicate
 *              a SW resource error:
 *              'current'
 *              This index points to the current available resource for use. For
 *              example in Rx process this index will point to the descriptor
 *              that will be passed to the user upon calling the receive
 *              routine.  In Tx process, this index will point to the descriptor
 *              that will be assigned with the user packet info and transmitted.
 *              'used'
 *              This index points to the descriptor that need to restore its
 *              resources. For example in Rx process, using the Rx buffer return
 *              API will attach the buffer returned in packet info to the
 *              descriptor pointed by 'used'. In Tx process, using the Tx
 *              descriptor return will merely return the user packet info with
 *              the command status of the transmitted buffer pointed by the
 *              'used' index. Nevertheless, it is essential to use this routine
 *              to update the 'used' index.
 *              'first'
 *              This index supports Tx Scatter-Gather. It points to the first
 *              descriptor of a packet assembled of multiple buffers. For
 *              example when in middle of Such packet we have a Tx resource
 *              error the 'curr' index get the value of 'first' to indicate
 *              that the ring returned to its state before trying to transmit
 *              this packet.
 *
 *              Receive operation:
 *              The eth_port_receive API set the packet information struct,
 *              passed by the caller, with received information from the
 *              'current' SDMA descriptor.
 *              It is the user responsibility to return this resource back
 *              to the Rx descriptor ring to enable the reuse of this source.
 *              Return Rx resource is done using the eth_rx_return_buff API.
 *
 *              Transmit operation:
 *              The eth_port_send API supports Scatter-Gather which enables to
 *              send a packet spanned over multiple buffers. This means that
 *              for each packet info structure given by the user and put into
 *              the Tx descriptors ring, will be transmitted only if the 'LAST'
 *              bit will be set in the packet info command status field. This
 *              API also consider restriction regarding buffer alignments and
 *              sizes.
 *              The user must return a Tx resource after ensuring the buffer
 *              has been transmitted to enable the Tx ring indexes to update.
 *
 *              BOARD LAYOUT
 *              This device is on-board.  No jumper diagram is necessary.
 *
 *              EXTERNAL INTERFACE
 *
 *      Prior to calling the initialization routine eth_port_init() the user
 *      must set the following fields under mv643xx_private struct:
 *      port_num                User Ethernet port number.
 *      port_mac_addr[6]        User defined port MAC address.
 *      port_config             User port configuration value.
 *      port_config_extend      User port config extend value.
 *      port_sdma_config        User port SDMA config value.
 *      port_serial_control     User port serial control value.
 *
 *              This driver data flow is done using the struct pkt_info which
 *              is a unified struct for Rx and Tx operations:
 *
 *              byte_cnt        Tx/Rx descriptor buffer byte count.
 *              l4i_chk         CPU provided TCP Checksum. For Tx operation
 *                              only.
 *              cmd_sts         Tx/Rx descriptor command status.
 *              buf_ptr         Tx/Rx descriptor buffer pointer.
 *              return_info     Tx/Rx user resource return information.
 */

/* defines */
/* SDMA command macros */
#define ETH_ENABLE_TX_QUEUE(eth_port) \
        mv_write(MV643XX_ETH_TRANSMIT_QUEUE_COMMAND_REG(eth_port), 1)

/* locals */

/* PHY routines */
static int ethernet_phy_get(unsigned int eth_port_num);
static void ethernet_phy_set(unsigned int eth_port_num, int phy_addr);

/* Ethernet Port routines */
static int eth_port_uc_addr(unsigned int eth_port_num, unsigned char uc_nibble,
                                                                int option);

/*
 * eth_port_init - Initialize the Ethernet port driver
 *
 * DESCRIPTION:
 *      This function prepares the ethernet port to start its activity:
 *      1) Completes the ethernet port driver struct initialization toward port
 *              start routine.
 *      2) Resets the device to a quiescent state in case of warm reboot.
 *      3) Enable SDMA access to all four DRAM banks as well as internal SRAM.
 *      4) Clean MAC tables. The reset status of those tables is unknown.
 *      5) Set PHY address.
 *      Note: Call this routine prior to eth_port_start routine and after
 *      setting user values in the user fields of Ethernet port control
 *      struct.
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet port control struct
 *
 * OUTPUT:
 *      See description.
 *
 * RETURN:
 *      None.
 */
static void eth_port_init(struct mv643xx_private *mp)
{
        mp->port_rx_queue_command = 0;
        mp->port_tx_queue_command = 0;

        mp->rx_resource_err = 0;
        mp->tx_resource_err = 0;

        eth_port_reset(mp->port_num);

        eth_port_init_mac_tables(mp->port_num);

        ethernet_phy_reset(mp->port_num);
}

/*
 * eth_port_start - Start the Ethernet port activity.
 *
 * DESCRIPTION:
 *      This routine prepares the Ethernet port for Rx and Tx activity:
 *       1. Initialize Tx and Rx Current Descriptor Pointer for each queue that
 *          has been initialized a descriptor's ring (using
 *          ether_init_tx_desc_ring for Tx and ether_init_rx_desc_ring for Rx)
 *       2. Initialize and enable the Ethernet configuration port by writing to
 *          the port's configuration and command registers.
 *       3. Initialize and enable the SDMA by writing to the SDMA's
 *          configuration and command registers.  After completing these steps,
 *          the ethernet port SDMA can starts to perform Rx and Tx activities.
 *
 *      Note: Each Rx and Tx queue descriptor's list must be initialized prior
 *      to calling this function (use ether_init_tx_desc_ring for Tx queues
 *      and ether_init_rx_desc_ring for Rx queues).
 *
 * INPUT:
 *      struct mv643xx_private *mp      Ethernet port control struct
 *
 * OUTPUT:
 *      Ethernet port is ready to receive and transmit.
 *
 * RETURN:
 *      None.
 */
static void eth_port_start(struct mv643xx_private *mp)
{
        unsigned int port_num = mp->port_num;
        int tx_curr_desc, rx_curr_desc;

        /* Assignment of Tx CTRP of given queue */
        tx_curr_desc = mp->tx_curr_desc_q;
        mv_write(MV643XX_ETH_TX_CURRENT_QUEUE_DESC_PTR_0(port_num),
                (u32)((struct eth_tx_desc *)mp->tx_desc_dma + tx_curr_desc));

        /* Assignment of Rx CRDP of given queue */
        rx_curr_desc = mp->rx_curr_desc_q;
        mv_write(MV643XX_ETH_RX_CURRENT_QUEUE_DESC_PTR_0(port_num),
                (u32)((struct eth_rx_desc *)mp->rx_desc_dma + rx_curr_desc));

        /* Add the assigned Ethernet address to the port's address table */
        eth_port_uc_addr_set(port_num, mp->port_mac_addr);

        /* Assign port configuration and command. */
        mv_write(MV643XX_ETH_PORT_CONFIG_REG(port_num), mp->port_config);

        mv_write(MV643XX_ETH_PORT_CONFIG_EXTEND_REG(port_num),
                                                mp->port_config_extend);


        /* Increase the Rx side buffer size if supporting GigE */
        if (mp->port_serial_control & MV643XX_ETH_SET_GMII_SPEED_TO_1000)
                mv_write(MV643XX_ETH_PORT_SERIAL_CONTROL_REG(port_num),
                        (mp->port_serial_control & 0xfff1ffff) | (0x5 << 17));
        else
                mv_write(MV643XX_ETH_PORT_SERIAL_CONTROL_REG(port_num),
                                                mp->port_serial_control);

        mv_write(MV643XX_ETH_PORT_SERIAL_CONTROL_REG(port_num),
                mv_read(MV643XX_ETH_PORT_SERIAL_CONTROL_REG(port_num)) |
                                                MV643XX_ETH_SERIAL_PORT_ENABLE);

        /* Assign port SDMA configuration */
        mv_write(MV643XX_ETH_SDMA_CONFIG_REG(port_num),
                                                        mp->port_sdma_config);

        /* Enable port Rx. */
        mv_write(MV643XX_ETH_RECEIVE_QUEUE_COMMAND_REG(port_num),
                                                mp->port_rx_queue_command);
}

/*
 * eth_port_uc_addr_set - This function Set the port Unicast address.
 *
 * DESCRIPTION:
 *              This function Set the port Ethernet MAC address.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Port number.
 *      char *          p_addr          Address to be set
 *
 * OUTPUT:
 *      Set MAC address low and high registers. also calls eth_port_uc_addr()
 *      To set the unicast table with the proper information.
 *
 * RETURN:
 *      N/A.
 *
 */
static void eth_port_uc_addr_set(unsigned int eth_port_num,
                                                        unsigned char *p_addr)
{
        unsigned int mac_h;
        unsigned int mac_l;

        mac_l = (p_addr[4] << 8) | (p_addr[5]);
        mac_h = (p_addr[0] << 24) | (p_addr[1] << 16) | (p_addr[2] << 8) |
                                                        (p_addr[3] << 0);

        mv_write(MV643XX_ETH_MAC_ADDR_LOW(eth_port_num), mac_l);
        mv_write(MV643XX_ETH_MAC_ADDR_HIGH(eth_port_num), mac_h);

        /* Accept frames of this address */
        eth_port_uc_addr(eth_port_num, p_addr[5], ACCEPT_MAC_ADDR);

        return;
}

/*
 * eth_port_uc_addr_get - This function retrieves the port Unicast address
 * (MAC address) from the ethernet hw registers.
 *
 * DESCRIPTION:
 *              This function retrieves the port Ethernet MAC address.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Port number.
 *      char            *MacAddr        pointer where the MAC address is stored
 *
 * OUTPUT:
 *      Copy the MAC address to the location pointed to by MacAddr
 *
 * RETURN:
 *      N/A.
 *
 */
static void eth_port_uc_addr_get(struct net_device *dev, unsigned char *p_addr)
{
        struct mv643xx_private *mp = netdev_priv(dev);
        unsigned int mac_h;
        unsigned int mac_l;

        mac_h = mv_read(MV643XX_ETH_MAC_ADDR_HIGH(mp->port_num));
        mac_l = mv_read(MV643XX_ETH_MAC_ADDR_LOW(mp->port_num));

        p_addr[0] = (mac_h >> 24) & 0xff;
        p_addr[1] = (mac_h >> 16) & 0xff;
        p_addr[2] = (mac_h >> 8) & 0xff;
        p_addr[3] = mac_h & 0xff;
        p_addr[4] = (mac_l >> 8) & 0xff;
        p_addr[5] = mac_l & 0xff;
}

/*
 * eth_port_uc_addr - This function Set the port unicast address table
 *
 * DESCRIPTION:
 *      This function locates the proper entry in the Unicast table for the
 *      specified MAC nibble and sets its properties according to function
 *      parameters.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Port number.
 *      unsigned char   uc_nibble       Unicast MAC Address last nibble.
 *      int             option          0 = Add, 1 = remove address.
 *
 * OUTPUT:
 *      This function add/removes MAC addresses from the port unicast address
 *      table.
 *
 * RETURN:
 *      true is output succeeded.
 *      false if option parameter is invalid.
 *
 */
static int eth_port_uc_addr(unsigned int eth_port_num, unsigned char uc_nibble,
                                                                int option)
{
        unsigned int unicast_reg;
        unsigned int tbl_offset;
        unsigned int reg_offset;

        /* Locate the Unicast table entry */
        uc_nibble = (0xf & uc_nibble);
        tbl_offset = (uc_nibble / 4) * 4;       /* Register offset from unicast table base */
        reg_offset = uc_nibble % 4;     /* Entry offset within the above register */

        switch (option) {
        case REJECT_MAC_ADDR:
                /* Clear accepts frame bit at given unicast DA table entry */
                unicast_reg = mv_read((MV643XX_ETH_DA_FILTER_UNICAST_TABLE_BASE
                                                (eth_port_num) + tbl_offset));

                unicast_reg &= (0x0E << (8 * reg_offset));

                mv_write((MV643XX_ETH_DA_FILTER_UNICAST_TABLE_BASE
                                (eth_port_num) + tbl_offset), unicast_reg);
                break;

        case ACCEPT_MAC_ADDR:
                /* Set accepts frame bit at unicast DA filter table entry */
                unicast_reg =
                        mv_read((MV643XX_ETH_DA_FILTER_UNICAST_TABLE_BASE
                                                (eth_port_num) + tbl_offset));

                unicast_reg |= (0x01 << (8 * reg_offset));

                mv_write((MV643XX_ETH_DA_FILTER_UNICAST_TABLE_BASE
                                (eth_port_num) + tbl_offset), unicast_reg);

                break;

        default:
                return 0;
        }

        return 1;
}

/*
 * eth_port_init_mac_tables - Clear all entrance in the UC, SMC and OMC tables
 *
 * DESCRIPTION:
 *      Go through all the DA filter tables (Unicast, Special Multicast &
 *      Other Multicast) and set each entry to 0.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *
 * OUTPUT:
 *      Multicast and Unicast packets are rejected.
 *
 * RETURN:
 *      None.
 */
static void eth_port_init_mac_tables(unsigned int eth_port_num)
{
        int table_index;

        /* Clear DA filter unicast table (Ex_dFUT) */
        for (table_index = 0; table_index <= 0xC; table_index += 4)
                mv_write((MV643XX_ETH_DA_FILTER_UNICAST_TABLE_BASE
                                        (eth_port_num) + table_index), 0);

        for (table_index = 0; table_index <= 0xFC; table_index += 4) {
                /* Clear DA filter special multicast table (Ex_dFSMT) */
                mv_write((MV643XX_ETH_DA_FILTER_SPECIAL_MULTICAST_TABLE_BASE
                                        (eth_port_num) + table_index), 0);
                /* Clear DA filter other multicast table (Ex_dFOMT) */
                mv_write((MV643XX_ETH_DA_FILTER_OTHER_MULTICAST_TABLE_BASE
                                        (eth_port_num) + table_index), 0);
        }
}

/*
 * eth_clear_mib_counters - Clear all MIB counters
 *
 * DESCRIPTION:
 *      This function clears all MIB counters of a specific ethernet port.
 *      A read from the MIB counter will reset the counter.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *
 * OUTPUT:
 *      After reading all MIB counters, the counters resets.
 *
 * RETURN:
 *      MIB counter value.
 *
 */
static void eth_clear_mib_counters(unsigned int eth_port_num)
{
        int i;

        /* Perform dummy reads from MIB counters */
        for (i = ETH_MIB_GOOD_OCTETS_RECEIVED_LOW; i < ETH_MIB_LATE_COLLISION;
                                                                        i += 4)
                mv_read(MV643XX_ETH_MIB_COUNTERS_BASE(eth_port_num) + i);
}

static inline u32 read_mib(struct mv643xx_private *mp, int offset)
{
        return mv_read(MV643XX_ETH_MIB_COUNTERS_BASE(mp->port_num) + offset);
}

static void eth_update_mib_counters(struct mv643xx_private *mp)
{
        struct mv643xx_mib_counters *p = &mp->mib_counters;
        int offset;

        p->good_octets_received +=
                read_mib(mp, ETH_MIB_GOOD_OCTETS_RECEIVED_LOW);
        p->good_octets_received +=
                (u64)read_mib(mp, ETH_MIB_GOOD_OCTETS_RECEIVED_HIGH) << 32;

        for (offset = ETH_MIB_BAD_OCTETS_RECEIVED;
                        offset <= ETH_MIB_FRAMES_1024_TO_MAX_OCTETS;
                        offset += 4)
                *(u32 *)((char *)p + offset) = read_mib(mp, offset);

        p->good_octets_sent += read_mib(mp, ETH_MIB_GOOD_OCTETS_SENT_LOW);
        p->good_octets_sent +=
                (u64)read_mib(mp, ETH_MIB_GOOD_OCTETS_SENT_HIGH) << 32;

        for (offset = ETH_MIB_GOOD_FRAMES_SENT;
                        offset <= ETH_MIB_LATE_COLLISION;
                        offset += 4)
                *(u32 *)((char *)p + offset) = read_mib(mp, offset);
}

/*
 * ethernet_phy_detect - Detect whether a phy is present
 *
 * DESCRIPTION:
 *      This function tests whether there is a PHY present on
 *      the specified port.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *
 * OUTPUT:
 *      None
 *
 * RETURN:
 *      0 on success
 *      -ENODEV on failure
 *
 */
static int ethernet_phy_detect(unsigned int port_num)
{
        unsigned int phy_reg_data0;
        int auto_neg;

        eth_port_read_smi_reg(port_num, 0, &phy_reg_data0);
        auto_neg = phy_reg_data0 & 0x1000;
        phy_reg_data0 ^= 0x1000;        /* invert auto_neg */
        eth_port_write_smi_reg(port_num, 0, phy_reg_data0);

        eth_port_read_smi_reg(port_num, 0, &phy_reg_data0);
        if ((phy_reg_data0 & 0x1000) == auto_neg)
                return -ENODEV;                         /* change didn't take */

        phy_reg_data0 ^= 0x1000;
        eth_port_write_smi_reg(port_num, 0, phy_reg_data0);
        return 0;
}

/*
 * ethernet_phy_get - Get the ethernet port PHY address.
 *
 * DESCRIPTION:
 *      This routine returns the given ethernet port PHY address.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *
 * OUTPUT:
 *      None.
 *
 * RETURN:
 *      PHY address.
 *
 */
static int ethernet_phy_get(unsigned int eth_port_num)
{
        unsigned int reg_data;

        reg_data = mv_read(MV643XX_ETH_PHY_ADDR_REG);

        return ((reg_data >> (5 * eth_port_num)) & 0x1f);
}

/*
 * ethernet_phy_set - Set the ethernet port PHY address.
 *
 * DESCRIPTION:
 *      This routine sets the given ethernet port PHY address.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *      int             phy_addr        PHY address.
 *
 * OUTPUT:
 *      None.
 *
 * RETURN:
 *      None.
 *
 */
static void ethernet_phy_set(unsigned int eth_port_num, int phy_addr)
{
        u32 reg_data;
        int addr_shift = 5 * eth_port_num;

        reg_data = mv_read(MV643XX_ETH_PHY_ADDR_REG);
        reg_data &= ~(0x1f << addr_shift);
        reg_data |= (phy_addr & 0x1f) << addr_shift;
        mv_write(MV643XX_ETH_PHY_ADDR_REG, reg_data);
}

/*
 * ethernet_phy_reset - Reset Ethernet port PHY.
 *
 * DESCRIPTION:
 *      This routine utilizes the SMI interface to reset the ethernet port PHY.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *
 * OUTPUT:
 *      The PHY is reset.
 *
 * RETURN:
 *      None.
 *
 */
static void ethernet_phy_reset(unsigned int eth_port_num)
{
        unsigned int phy_reg_data;

        /* Reset the PHY */
        eth_port_read_smi_reg(eth_port_num, 0, &phy_reg_data);
        phy_reg_data |= 0x8000; /* Set bit 15 to reset the PHY */
        eth_port_write_smi_reg(eth_port_num, 0, phy_reg_data);
}

/*
 * eth_port_reset - Reset Ethernet port
 *
 * DESCRIPTION:
 *      This routine resets the chip by aborting any SDMA engine activity and
 *      clearing the MIB counters. The Receiver and the Transmit unit are in
 *      idle state after this command is performed and the port is disabled.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *
 * OUTPUT:
 *      Channel activity is halted.
 *
 * RETURN:
 *      None.
 *
 */
static void eth_port_reset(unsigned int port_num)
{
        unsigned int reg_data;

        /* Stop Tx port activity. Check port Tx activity. */
        reg_data = mv_read(MV643XX_ETH_TRANSMIT_QUEUE_COMMAND_REG(port_num));

        if (reg_data & 0xFF) {
                /* Issue stop command for active channels only */
                mv_write(MV643XX_ETH_TRANSMIT_QUEUE_COMMAND_REG(port_num),
                                                        (reg_data << 8));

                /* Wait for all Tx activity to terminate. */
                /* Check port cause register that all Tx queues are stopped */
                while (mv_read(MV643XX_ETH_TRANSMIT_QUEUE_COMMAND_REG(port_num))
                                                                        & 0xFF)
                        udelay(10);
        }

        /* Stop Rx port activity. Check port Rx activity. */
        reg_data = mv_read(MV643XX_ETH_RECEIVE_QUEUE_COMMAND_REG(port_num));

        if (reg_data & 0xFF) {
                /* Issue stop command for active channels only */
                mv_write(MV643XX_ETH_RECEIVE_QUEUE_COMMAND_REG(port_num),
                                                        (reg_data << 8));

                /* Wait for all Rx activity to terminate. */
                /* Check port cause register that all Rx queues are stopped */
                while (mv_read(MV643XX_ETH_RECEIVE_QUEUE_COMMAND_REG(port_num))
                                                                        & 0xFF)
                        udelay(10);
        }

        /* Clear all MIB counters */
        eth_clear_mib_counters(port_num);

        /* Reset the Enable bit in the Configuration Register */
        reg_data = mv_read(MV643XX_ETH_PORT_SERIAL_CONTROL_REG(port_num));
        reg_data &= ~MV643XX_ETH_SERIAL_PORT_ENABLE;
        mv_write(MV643XX_ETH_PORT_SERIAL_CONTROL_REG(port_num), reg_data);
}

/*
 * ethernet_set_config_reg - Set specified bits in configuration register.
 *
 * DESCRIPTION:
 *      This function sets specified bits in the given ethernet
 *      configuration register.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *      unsigned int    value           32 bit value.
 *
 * OUTPUT:
 *      The set bits in the value parameter are set in the configuration
 *      register.
 *
 * RETURN:
 *      None.
 *
 */
static void ethernet_set_config_reg(unsigned int eth_port_num,
                                                        unsigned int value)
{
        unsigned int eth_config_reg;

        eth_config_reg = mv_read(MV643XX_ETH_PORT_CONFIG_REG(eth_port_num));
        eth_config_reg |= value;
        mv_write(MV643XX_ETH_PORT_CONFIG_REG(eth_port_num), eth_config_reg);
}

static int eth_port_autoneg_supported(unsigned int eth_port_num)
{
        unsigned int phy_reg_data0;

        eth_port_read_smi_reg(eth_port_num, 0, &phy_reg_data0);

        return phy_reg_data0 & 0x1000;
}

static int eth_port_link_is_up(unsigned int eth_port_num)
{
        unsigned int phy_reg_data1;

        eth_port_read_smi_reg(eth_port_num, 1, &phy_reg_data1);

        if (eth_port_autoneg_supported(eth_port_num)) {
                if (phy_reg_data1 & 0x20)       /* auto-neg complete */
                        return 1;
        } else if (phy_reg_data1 & 0x4)         /* link up */
                return 1;

        return 0;
}

/*
 * ethernet_get_config_reg - Get the port configuration register
 *
 * DESCRIPTION:
 *      This function returns the configuration register value of the given
 *      ethernet port.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *
 * OUTPUT:
 *      None.
 *
 * RETURN:
 *      Port configuration register value.
 */
static unsigned int ethernet_get_config_reg(unsigned int eth_port_num)
{
        unsigned int eth_config_reg;

        eth_config_reg = mv_read(MV643XX_ETH_PORT_CONFIG_EXTEND_REG
                                                                (eth_port_num));
        return eth_config_reg;
}

/*
 * eth_port_read_smi_reg - Read PHY registers
 *
 * DESCRIPTION:
 *      This routine utilize the SMI interface to interact with the PHY in
 *      order to perform PHY register read.
 *
 * INPUT:
 *      unsigned int    port_num        Ethernet Port number.
 *      unsigned int    phy_reg         PHY register address offset.
 *      unsigned int    *value          Register value buffer.
 *
 * OUTPUT:
 *      Write the value of a specified PHY register into given buffer.
 *
 * RETURN:
 *      false if the PHY is busy or read data is not in valid state.
 *      true otherwise.
 *
 */
static void eth_port_read_smi_reg(unsigned int port_num,
                                unsigned int phy_reg, unsigned int *value)
{
        int phy_addr = ethernet_phy_get(port_num);
        unsigned long flags;
        int i;

        /* the SMI register is a shared resource */
        spin_lock_irqsave(&mv643xx_eth_phy_lock, flags);

        /* wait for the SMI register to become available */
        for (i = 0; mv_read(MV643XX_ETH_SMI_REG) & ETH_SMI_BUSY; i++) {
                if (i == PHY_WAIT_ITERATIONS) {
                        printk("mv643xx PHY busy timeout, port %d\n", port_num);
                        goto out;
                }
                udelay(PHY_WAIT_MICRO_SECONDS);
        }

        mv_write(MV643XX_ETH_SMI_REG,
                (phy_addr << 16) | (phy_reg << 21) | ETH_SMI_OPCODE_READ);

        /* now wait for the data to be valid */
        for (i = 0; !(mv_read(MV643XX_ETH_SMI_REG) & ETH_SMI_READ_VALID); i++) {
                if (i == PHY_WAIT_ITERATIONS) {
                        printk("mv643xx PHY read timeout, port %d\n", port_num);
                        goto out;
                }
                udelay(PHY_WAIT_MICRO_SECONDS);
        }

        *value = mv_read(MV643XX_ETH_SMI_REG) & 0xffff;
out:
        spin_unlock_irqrestore(&mv643xx_eth_phy_lock, flags);
}

/*
 * eth_port_write_smi_reg - Write to PHY registers
 *
 * DESCRIPTION:
 *      This routine utilize the SMI interface to interact with the PHY in
 *      order to perform writes to PHY registers.
 *
 * INPUT:
 *      unsigned int    eth_port_num    Ethernet Port number.
 *      unsigned int    phy_reg         PHY register address offset.
 *      unsigned int    value           Register value.
 *
 * OUTPUT:
 *      Write the given value to the specified PHY register.
 *
 * RETURN:
 *      false if the PHY is busy.
 *      true otherwise.
 *
 */
static void eth_port_write_smi_reg(unsigned int eth_port_num,
                                   unsigned int phy_reg, unsigned int value)
{
        int phy_addr;
        int i;
        unsigned long flags;

        phy_addr = ethernet_phy_get(eth_port_num);

        /* the SMI register is a shared resource */
        spin_lock_irqsave(&mv643xx_eth_phy_lock, flags);

        /* wait for the SMI register to become available */
        for (i = 0; mv_read(MV643XX_ETH_SMI_REG) & ETH_SMI_BUSY; i++) {
                if (i == PHY_WAIT_ITERATIONS) {
                        printk("mv643xx PHY busy timeout, port %d\n",
                                                                eth_port_num);
                        goto out;
                }
                udelay(PHY_WAIT_MICRO_SECONDS);
        }

        mv_write(MV643XX_ETH_SMI_REG, (phy_addr << 16) | (phy_reg << 21) |
                                ETH_SMI_OPCODE_WRITE | (value & 0xffff));
out:
        spin_unlock_irqrestore(&mv643xx_eth_phy_lock, flags);
}

/*
 * eth_port_send - Send an Ethernet packet
 *
 * DESCRIPTION:
 *      This routine send a given packet described by p_pktinfo parameter. It
 *      supports transmitting of a packet spaned over multiple buffers. The
 *      routine updates 'curr' and 'first' indexes according to the packet
 *      segment passed to the routine. In case the packet segment is first,
 *      the 'first' index is update. In any case, the 'curr' index is updated.
 *      If the routine get into Tx resource error it assigns 'curr' index as
 *      'first'. This way the function can abort Tx process of multiple
 *      descriptors per packet.
 *
 * INPUT:
 *      struct mv643xx_private  *mp             Ethernet Port Control srtuct.
 *      struct pkt_info         *p_pkt_info     User packet buffer.
 *
 * OUTPUT:
 *      Tx ring 'curr' and 'first' indexes are updated.
 *
 * RETURN:
 *      ETH_QUEUE_FULL in case of Tx resource error.
 *      ETH_ERROR in case the routine can not access Tx desc ring.
 *      ETH_QUEUE_LAST_RESOURCE if the routine uses the last Tx resource.
 *      ETH_OK otherwise.
 *
 */
#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
/*
 * Modified to include the first descriptor pointer in case of SG
 */
static ETH_FUNC_RET_STATUS eth_port_send(struct mv643xx_private *mp,
                                         struct pkt_info *p_pkt_info)
{
        int tx_desc_curr, tx_desc_used, tx_first_desc, tx_next_desc;
        struct eth_tx_desc *current_descriptor;
        struct eth_tx_desc *first_descriptor;
        u32 command;

        /* Do not process Tx ring in case of Tx ring resource error */
        if (mp->tx_resource_err)
                return ETH_QUEUE_FULL;

        /*
         * The hardware requires that each buffer that is <= 8 bytes
         * in length must be aligned on an 8 byte boundary.
         */
        if (p_pkt_info->byte_cnt <= 8 && p_pkt_info->buf_ptr & 0x7) {
                printk(KERN_ERR
                        "mv643xx_eth port %d: packet size <= 8 problem\n",
                        mp->port_num);
                return ETH_ERROR;
        }

        mp->tx_ring_skbs++;
        BUG_ON(mp->tx_ring_skbs > mp->tx_ring_size);

        /* Get the Tx Desc ring indexes */
        tx_desc_curr = mp->tx_curr_desc_q;
        tx_desc_used = mp->tx_used_desc_q;

        current_descriptor = &mp->p_tx_desc_area[tx_desc_curr];

        tx_next_desc = (tx_desc_curr + 1) % mp->tx_ring_size;

        current_descriptor->buf_ptr = p_pkt_info->buf_ptr;
        current_descriptor->byte_cnt = p_pkt_info->byte_cnt;
        current_descriptor->l4i_chk = p_pkt_info->l4i_chk;
        mp->tx_skb[tx_desc_curr] = p_pkt_info->return_info;

        command = p_pkt_info->cmd_sts | ETH_ZERO_PADDING | ETH_GEN_CRC |
                                                        ETH_BUFFER_OWNED_BY_DMA;
        if (command & ETH_TX_FIRST_DESC) {
                tx_first_desc = tx_desc_curr;
                mp->tx_first_desc_q = tx_first_desc;
                first_descriptor = current_descriptor;
                mp->tx_first_command = command;
        } else {
                tx_first_desc = mp->tx_first_desc_q;
                first_descriptor = &mp->p_tx_desc_area[tx_first_desc];
                BUG_ON(first_descriptor == NULL);
                current_descriptor->cmd_sts = command;
        }

        if (command & ETH_TX_LAST_DESC) {
                wmb();
                first_descriptor->cmd_sts = mp->tx_first_command;

                wmb();
                ETH_ENABLE_TX_QUEUE(mp->port_num);

                /*
                 * Finish Tx packet. Update first desc in case of Tx resource
                 * error */
                tx_first_desc = tx_next_desc;
                mp->tx_first_desc_q = tx_first_desc;
        }

        /* Check for ring index overlap in the Tx desc ring */
        if (tx_next_desc == tx_desc_used) {
                mp->tx_resource_err = 1;
                mp->tx_curr_desc_q = tx_first_desc;

                return ETH_QUEUE_LAST_RESOURCE;
        }

        mp->tx_curr_desc_q = tx_next_desc;

        return ETH_OK;
}
#else
static ETH_FUNC_RET_STATUS eth_port_send(struct mv643xx_private *mp,
                                         struct pkt_info *p_pkt_info)
{
        int tx_desc_curr;
        int tx_desc_used;
        struct eth_tx_desc *current_descriptor;
        unsigned int command_status;

        /* Do not process Tx ring in case of Tx ring resource error */
        if (mp->tx_resource_err)
                return ETH_QUEUE_FULL;

        mp->tx_ring_skbs++;
        BUG_ON(mp->tx_ring_skbs > mp->tx_ring_size);

        /* Get the Tx Desc ring indexes */
        tx_desc_curr = mp->tx_curr_desc_q;
        tx_desc_used = mp->tx_used_desc_q;
        current_descriptor = &mp->p_tx_desc_area[tx_desc_curr];

        command_status = p_pkt_info->cmd_sts | ETH_ZERO_PADDING | ETH_GEN_CRC;
        current_descriptor->buf_ptr = p_pkt_info->buf_ptr;
        current_descriptor->byte_cnt = p_pkt_info->byte_cnt;
        mp->tx_skb[tx_desc_curr] = p_pkt_info->return_info;

        /* Set last desc with DMA ownership and interrupt enable. */
        wmb();
        current_descriptor->cmd_sts = command_status |
                        ETH_BUFFER_OWNED_BY_DMA | ETH_TX_ENABLE_INTERRUPT;

        wmb();
        ETH_ENABLE_TX_QUEUE(mp->port_num);

        /* Finish Tx packet. Update first desc in case of Tx resource error */
        tx_desc_curr = (tx_desc_curr + 1) % mp->tx_ring_size;

        /* Update the current descriptor */
        mp->tx_curr_desc_q = tx_desc_curr;

        /* Check for ring index overlap in the Tx desc ring */
        if (tx_desc_curr == tx_desc_used) {
                mp->tx_resource_err = 1;
                return ETH_QUEUE_LAST_RESOURCE;
        }

        return ETH_OK;
}
#endif

/*
 * eth_tx_return_desc - Free all used Tx descriptors
 *
 * DESCRIPTION:
 *      This routine returns the transmitted packet information to the caller.
 *      It uses the 'first' index to support Tx desc return in case a transmit
 *      of a packet spanned over multiple buffer still in process.
 *      In case the Tx queue was in "resource error" condition, where there are
 *      no available Tx resources, the function resets the resource error flag.
 *
 * INPUT:
 *      struct mv643xx_private  *mp             Ethernet Port Control srtuct.
 *      struct pkt_info         *p_pkt_info     User packet buffer.
 *
 * OUTPUT:
 *      Tx ring 'first' and 'used' indexes are updated.
 *
 * RETURN:
 *      ETH_ERROR in case the routine can not access Tx desc ring.
 *      ETH_RETRY in case there is transmission in process.
 *      ETH_END_OF_JOB if the routine has nothing to release.
 *      ETH_OK otherwise.
 *
 */
static ETH_FUNC_RET_STATUS eth_tx_return_desc(struct mv643xx_private *mp,
                                                struct pkt_info *p_pkt_info)
{
        int tx_desc_used;
#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
        int tx_busy_desc = mp->tx_first_desc_q;
#else
        int tx_busy_desc = mp->tx_curr_desc_q;
#endif
        struct eth_tx_desc *p_tx_desc_used;
        unsigned int command_status;

        /* Get the Tx Desc ring indexes */
        tx_desc_used = mp->tx_used_desc_q;

        p_tx_desc_used = &mp->p_tx_desc_area[tx_desc_used];

        /* Sanity check */
        if (p_tx_desc_used == NULL)
                return ETH_ERROR;

        /* Stop release. About to overlap the current available Tx descriptor */
        if (tx_desc_used == tx_busy_desc && !mp->tx_resource_err)
                return ETH_END_OF_JOB;

        command_status = p_tx_desc_used->cmd_sts;

        /* Still transmitting... */
        if (command_status & (ETH_BUFFER_OWNED_BY_DMA))
                return ETH_RETRY;

        /* Pass the packet information to the caller */
        p_pkt_info->cmd_sts = command_status;
        p_pkt_info->return_info = mp->tx_skb[tx_desc_used];
        mp->tx_skb[tx_desc_used] = NULL;

        /* Update the next descriptor to release. */
        mp->tx_used_desc_q = (tx_desc_used + 1) % mp->tx_ring_size;

        /* Any Tx return cancels the Tx resource error status */
        mp->tx_resource_err = 0;

        BUG_ON(mp->tx_ring_skbs == 0);
        mp->tx_ring_skbs--;

        return ETH_OK;
}

/*
 * eth_port_receive - Get received information from Rx ring.
 *
 * DESCRIPTION:
 *      This routine returns the received data to the caller. There is no
 *      data copying during routine operation. All information is returned
 *      using pointer to packet information struct passed from the caller.
 *      If the routine exhausts Rx ring resources then the resource error flag
 *      is set.
 *
 * INPUT:
 *      struct mv643xx_private  *mp             Ethernet Port Control srtuct.
 *      struct pkt_info         *p_pkt_info     User packet buffer.
 *
 * OUTPUT:
 *      Rx ring current and used indexes are updated.
 *
 * RETURN:
 *      ETH_ERROR in case the routine can not access Rx desc ring.
 *      ETH_QUEUE_FULL if Rx ring resources are exhausted.
 *      ETH_END_OF_JOB if there is no received data.
 *      ETH_OK otherwise.
 */
static ETH_FUNC_RET_STATUS eth_port_receive(struct mv643xx_private *mp,
                                                struct pkt_info *p_pkt_info)
{
        int rx_next_curr_desc, rx_curr_desc, rx_used_desc;
        volatile struct eth_rx_desc *p_rx_desc;
        unsigned int command_status;

        /* Do not process Rx ring in case of Rx ring resource error */
        if (mp->rx_resource_err)
                return ETH_QUEUE_FULL;

        /* Get the Rx Desc ring 'curr and 'used' indexes */
        rx_curr_desc = mp->rx_curr_desc_q;
        rx_used_desc = mp->rx_used_desc_q;

        p_rx_desc = &mp->p_rx_desc_area[rx_curr_desc];

        /* The following parameters are used to save readings from memory */
        command_status = p_rx_desc->cmd_sts;
        rmb();

        /* Nothing to receive... */
        if (command_status & (ETH_BUFFER_OWNED_BY_DMA))
                return ETH_END_OF_JOB;

        p_pkt_info->byte_cnt = (p_rx_desc->byte_cnt) - RX_BUF_OFFSET;
        p_pkt_info->cmd_sts = command_status;
        p_pkt_info->buf_ptr = (p_rx_desc->buf_ptr) + RX_BUF_OFFSET;
        p_pkt_info->return_info = mp->rx_skb[rx_curr_desc];
        p_pkt_info->l4i_chk = p_rx_desc->buf_size;

        /* Clean the return info field to indicate that the packet has been */
        /* moved to the upper layers                                        */
        mp->rx_skb[rx_curr_desc] = NULL;

        /* Update current index in data structure */
        rx_next_curr_desc = (rx_curr_desc + 1) % mp->rx_ring_size;
        mp->rx_curr_desc_q = rx_next_curr_desc;

        /* Rx descriptors exhausted. Set the Rx ring resource error flag */
        if (rx_next_curr_desc == rx_used_desc)
                mp->rx_resource_err = 1;

        return ETH_OK;
}

/*
 * eth_rx_return_buff - Returns a Rx buffer back to the Rx ring.
 *
 * DESCRIPTION:
 *      This routine returns a Rx buffer back to the Rx ring. It retrieves the
 *      next 'used' descriptor and attached the returned buffer to it.
 *      In case the Rx ring was in "resource error" condition, where there are
 *      no available Rx resources, the function resets the resource error flag.
 *
 * INPUT:
 *      struct mv643xx_private  *mp             Ethernet Port Control srtuct.
 *      struct pkt_info         *p_pkt_info     Information on returned buffer.
 *
 * OUTPUT:
 *      New available Rx resource in Rx descriptor ring.
 *
 * RETURN:
 *      ETH_ERROR in case the routine can not access Rx desc ring.
 *      ETH_OK otherwise.
 */
static ETH_FUNC_RET_STATUS eth_rx_return_buff(struct mv643xx_private *mp,
                                                struct pkt_info *p_pkt_info)
{
        int used_rx_desc;       /* Where to return Rx resource */
        volatile struct eth_rx_desc *p_used_rx_desc;

        /* Get 'used' Rx descriptor */
        used_rx_desc = mp->rx_used_desc_q;
        p_used_rx_desc = &mp->p_rx_desc_area[used_rx_desc];

        p_used_rx_desc->buf_ptr = p_pkt_info->buf_ptr;
        p_used_rx_desc->buf_size = p_pkt_info->byte_cnt;
        mp->rx_skb[used_rx_desc] = p_pkt_info->return_info;

        /* Flush the write pipe */

        /* Return the descriptor to DMA ownership */
        wmb();
        p_used_rx_desc->cmd_sts =
                        ETH_BUFFER_OWNED_BY_DMA | ETH_RX_ENABLE_INTERRUPT;
        wmb();

        /* Move the used descriptor pointer to the next descriptor */
        mp->rx_used_desc_q = (used_rx_desc + 1) % mp->rx_ring_size;

        /* Any Rx return cancels the Rx resource error status */
        mp->rx_resource_err = 0;

        return ETH_OK;
}

/************* Begin ethtool support *************************/

struct mv643xx_stats {
        char stat_string[ETH_GSTRING_LEN];
        int sizeof_stat;
        int stat_offset;
};

#define MV643XX_STAT(m) sizeof(((struct mv643xx_private *)0)->m), \
                      offsetof(struct mv643xx_private, m)

static const struct mv643xx_stats mv643xx_gstrings_stats[] = {
        { "rx_packets", MV643XX_STAT(stats.rx_packets) },
        { "tx_packets", MV643XX_STAT(stats.tx_packets) },
        { "rx_bytes", MV643XX_STAT(stats.rx_bytes) },
        { "tx_bytes", MV643XX_STAT(stats.tx_bytes) },
        { "rx_errors", MV643XX_STAT(stats.rx_errors) },
        { "tx_errors", MV643XX_STAT(stats.tx_errors) },
        { "rx_dropped", MV643XX_STAT(stats.rx_dropped) },
        { "tx_dropped", MV643XX_STAT(stats.tx_dropped) },
        { "good_octets_received", MV643XX_STAT(mib_counters.good_octets_received) },
        { "bad_octets_received", MV643XX_STAT(mib_counters.bad_octets_received) },
        { "internal_mac_transmit_err", MV643XX_STAT(mib_counters.internal_mac_transmit_err) },
        { "good_frames_received", MV643XX_STAT(mib_counters.good_frames_received) },
        { "bad_frames_received", MV643XX_STAT(mib_counters.bad_frames_received) },
        { "broadcast_frames_received", MV643XX_STAT(mib_counters.broadcast_frames_received) },
        { "multicast_frames_received", MV643XX_STAT(mib_counters.multicast_frames_received) },
        { "frames_64_octets", MV643XX_STAT(mib_counters.frames_64_octets) },
        { "frames_65_to_127_octets", MV643XX_STAT(mib_counters.frames_65_to_127_octets) },
        { "frames_128_to_255_octets", MV643XX_STAT(mib_counters.frames_128_to_255_octets) },
        { "frames_256_to_511_octets", MV643XX_STAT(mib_counters.frames_256_to_511_octets) },
        { "frames_512_to_1023_octets", MV643XX_STAT(mib_counters.frames_512_to_1023_octets) },
        { "frames_1024_to_max_octets", MV643XX_STAT(mib_counters.frames_1024_to_max_octets) },
        { "good_octets_sent", MV643XX_STAT(mib_counters.good_octets_sent) },
        { "good_frames_sent", MV643XX_STAT(mib_counters.good_frames_sent) },
        { "excessive_collision", MV643XX_STAT(mib_counters.excessive_collision) },
        { "multicast_frames_sent", MV643XX_STAT(mib_counters.multicast_frames_sent) },
        { "broadcast_frames_sent", MV643XX_STAT(mib_counters.broadcast_frames_sent) },
        { "unrec_mac_control_received", MV643XX_STAT(mib_counters.unrec_mac_control_received) },
        { "fc_sent", MV643XX_STAT(mib_counters.fc_sent) },
        { "good_fc_received", MV643XX_STAT(mib_counters.good_fc_received) },
        { "bad_fc_received", MV643XX_STAT(mib_counters.bad_fc_received) },
        { "undersize_received", MV643XX_STAT(mib_counters.undersize_received) },
        { "fragments_received", MV643XX_STAT(mib_counters.fragments_received) },
        { "oversize_received", MV643XX_STAT(mib_counters.oversize_received) },
        { "jabber_received", MV643XX_STAT(mib_counters.jabber_received) },
        { "mac_receive_error", MV643XX_STAT(mib_counters.mac_receive_error) },
        { "bad_crc_event", MV643XX_STAT(mib_counters.bad_crc_event) },
        { "collision", MV643XX_STAT(mib_counters.collision) },
        { "late_collision", MV643XX_STAT(mib_counters.late_collision) },
};

#define MV643XX_STATS_LEN       \
        sizeof(mv643xx_gstrings_stats) / sizeof(struct mv643xx_stats)

static int
mv643xx_get_settings(struct net_device *netdev, struct ethtool_cmd *ecmd)
{
        struct mv643xx_private *mp = netdev->priv;
        int port_num = mp->port_num;
        int autoneg = eth_port_autoneg_supported(port_num);
        int mode_10_bit;
        int auto_duplex;
        int half_duplex = 0;
        int full_duplex = 0;
        int auto_speed;
        int speed_10 = 0;
        int speed_100 = 0;
        int speed_1000 = 0;

        u32 pcs = mv_read(MV643XX_ETH_PORT_SERIAL_CONTROL_REG(port_num));
        u32 psr = mv_read(MV643XX_ETH_PORT_STATUS_REG(port_num));

        mode_10_bit = psr & MV643XX_ETH_PORT_STATUS_MODE_10_BIT;

        if (mode_10_bit) {
                ecmd->supported = SUPPORTED_10baseT_Half;
        } else {
                ecmd->supported = (SUPPORTED_10baseT_Half               |
                                   SUPPORTED_10baseT_Full               |
                                   SUPPORTED_100baseT_Half              |
                                   SUPPORTED_100baseT_Full              |
                                   SUPPORTED_1000baseT_Full             |
                                   (autoneg ? SUPPORTED_Autoneg : 0)    |
                                   SUPPORTED_TP);

                auto_duplex = !(pcs & MV643XX_ETH_DISABLE_AUTO_NEG_FOR_DUPLX);
                auto_speed = !(pcs & MV643XX_ETH_DISABLE_AUTO_NEG_SPEED_GMII);

                ecmd->advertising = ADVERTISED_TP;

                if (autoneg) {
                        ecmd->advertising |= ADVERTISED_Autoneg;

                        if (auto_duplex) {
                                half_duplex = 1;
                                full_duplex = 1;
                        } else {
                                if (pcs & MV643XX_ETH_SET_FULL_DUPLEX_MODE)
                                        full_duplex = 1;
                                else
                                        half_duplex = 1;
                        }

                        if (auto_speed) {
                                speed_10 = 1;
                                speed_100 = 1;
                                speed_1000 = 1;
                        } else {
                                if (pcs & MV643XX_ETH_SET_GMII_SPEED_TO_1000)
                                        speed_1000 = 1;
                                else if (pcs & MV643XX_ETH_SET_MII_SPEED_TO_100)
                                        speed_100 = 1;
                                else
                                        speed_10 = 1;
                        }

                        if (speed_10 & half_duplex)
                                ecmd->advertising |= ADVERTISED_10baseT_Half;
                        if (speed_10 & full_duplex)
                                ecmd->advertising |= ADVERTISED_10baseT_Full;
                        if (speed_100 & half_duplex)
                                ecmd->advertising |= ADVERTISED_100baseT_Half;
                        if (speed_100 & full_duplex)
                                ecmd->advertising |= ADVERTISED_100baseT_Full;
                        if (speed_1000)
                                ecmd->advertising |= ADVERTISED_1000baseT_Full;
                }
        }

        ecmd->port = PORT_TP;
        ecmd->phy_address = ethernet_phy_get(port_num);

        ecmd->transceiver = XCVR_EXTERNAL;

        if (netif_carrier_ok(netdev)) {
                if (mode_10_bit)
                        ecmd->speed = SPEED_10;
                else {
                        if (psr & MV643XX_ETH_PORT_STATUS_GMII_1000)
                                ecmd->speed = SPEED_1000;
                        else if (psr & MV643XX_ETH_PORT_STATUS_MII_100)
                                ecmd->speed = SPEED_100;
                        else
                                ecmd->speed = SPEED_10;
                }

                if (psr & MV643XX_ETH_PORT_STATUS_FULL_DUPLEX)
                        ecmd->duplex = DUPLEX_FULL;
                else
                        ecmd->duplex = DUPLEX_HALF;
        } else {
                ecmd->speed = -1;
                ecmd->duplex = -1;
        }

        ecmd->autoneg = autoneg ? AUTONEG_ENABLE : AUTONEG_DISABLE;
        return 0;
}

static void
mv643xx_get_drvinfo(struct net_device *netdev,
                       struct ethtool_drvinfo *drvinfo)
{
        strncpy(drvinfo->driver,  mv643xx_driver_name, 32);
        strncpy(drvinfo->version, mv643xx_driver_version, 32);
        strncpy(drvinfo->fw_version, "N/A", 32);
        strncpy(drvinfo->bus_info, "mv643xx", 32);
        drvinfo->n_stats = MV643XX_STATS_LEN;
}

static int 
mv643xx_get_stats_count(struct net_device *netdev)
{
        return MV643XX_STATS_LEN;
}

static void 
mv643xx_get_ethtool_stats(struct net_device *netdev, 
                struct ethtool_stats *stats, uint64_t *data)
{
        struct mv643xx_private *mp = netdev->priv;
        int i;

        eth_update_mib_counters(mp);

        for(i = 0; i < MV643XX_STATS_LEN; i++) {
                char *p = (char *)mp+mv643xx_gstrings_stats[i].stat_offset;     
                data[i] = (mv643xx_gstrings_stats[i].sizeof_stat == 
                        sizeof(uint64_t)) ? *(uint64_t *)p : *(uint32_t *)p;
        }
}

static void 
mv643xx_get_strings(struct net_device *netdev, uint32_t stringset, uint8_t *data)
{
        int i;

        switch(stringset) {
        case ETH_SS_STATS:
                for (i=0; i < MV643XX_STATS_LEN; i++) {
                        memcpy(data + i * ETH_GSTRING_LEN, 
                        mv643xx_gstrings_stats[i].stat_string,
                        ETH_GSTRING_LEN);
                }
                break;
        }
}

static struct ethtool_ops mv643xx_ethtool_ops = {
        .get_settings           = mv643xx_get_settings,
        .get_drvinfo            = mv643xx_get_drvinfo,
        .get_link               = ethtool_op_get_link,
        .get_sg                 = ethtool_op_get_sg,
        .set_sg                 = ethtool_op_set_sg,
        .get_strings            = mv643xx_get_strings,
        .get_stats_count        = mv643xx_get_stats_count,
        .get_ethtool_stats      = mv643xx_get_ethtool_stats,
};

/************* End ethtool support *************************/