// SPDX-License-Identifier: GPL-2.0-or-later
/* drivers/net/ethernet/freescale/gianfar.c
 *
 * Gianfar Ethernet Driver
 * This driver is designed for the non-CPM ethernet controllers
 * on the 85xx and 83xx family of integrated processors
 * Based on 8260_io/fcc_enet.c
 *
 * Author: Andy Fleming
 * Maintainer: Kumar Gala
 * Modifier: Sandeep Gopalpet <sandeep.kumar@freescale.com>
 *
 * Copyright 2002-2009, 2011-2013 Freescale Semiconductor, Inc.
 * Copyright 2007 MontaVista Software, Inc.
 *
 *  Gianfar:  AKA Lambda Draconis, "Dragon"
 *  RA 11 31 24.2
 *  Dec +69 19 52
 *  V 3.84
 *  B-V +1.62
 *
 *  Theory of operation
 *
 *  The driver is initialized through of_device. Configuration information
 *  is therefore conveyed through an OF-style device tree.
 *
 *  The Gianfar Ethernet Controller uses a ring of buffer
 *  descriptors.  The beginning is indicated by a register
 *  pointing to the physical address of the start of the ring.
 *  The end is determined by a "wrap" bit being set in the
 *  last descriptor of the ring.
 *
 *  When a packet is received, the RXF bit in the
 *  IEVENT register is set, triggering an interrupt when the
 *  corresponding bit in the IMASK register is also set (if
 *  interrupt coalescing is active, then the interrupt may not
 *  happen immediately, but will wait until either a set number
 *  of frames or amount of time have passed).  In NAPI, the
 *  interrupt handler will signal there is work to be done, and
 *  exit. This method will start at the last known empty
 *  descriptor, and process every subsequent descriptor until there
 *  are none left with data (NAPI will stop after a set number of
 *  packets to give time to other tasks, but will eventually
 *  process all the packets).  The data arrives inside a
 *  pre-allocated skb, and so after the skb is passed up to the
 *  stack, a new skb must be allocated, and the address field in
 *  the buffer descriptor must be updated to indicate this new
 *  skb.
 *
 *  When the kernel requests that a packet be transmitted, the
 *  driver starts where it left off last time, and points the
 *  descriptor at the buffer which was passed in.  The driver
 *  then informs the DMA engine that there are packets ready to
 *  be transmitted.  Once the controller is finished transmitting
 *  the packet, an interrupt may be triggered (under the same
 *  conditions as for reception, but depending on the TXF bit).
 *  The driver then cleans up the buffer.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define DEBUG

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/if_vlan.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_mdio.h>
#include <linux/of_platform.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/in.h>
#include <linux/net_tstamp.h>

#include <asm/io.h>
#ifdef CONFIG_PPC
#include <asm/reg.h>
#include <asm/mpc85xx.h>
#endif
#include <asm/irq.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/crc32.h>
#include <linux/mii.h>
#include <linux/phy.h>
#include <linux/phy_fixed.h>
#include <linux/of.h>
#include <linux/of_net.h>

#include "gianfar.h"

#define TX_TIMEOUT      (5*HZ)

const char gfar_driver_version[] = "2.0";

static int gfar_enet_open(struct net_device *dev);
static netdev_tx_t gfar_start_xmit(struct sk_buff *skb, struct net_device *dev);
static void gfar_reset_task(struct work_struct *work);
static void gfar_timeout(struct net_device *dev);
static int gfar_close(struct net_device *dev);
static void gfar_alloc_rx_buffs(struct gfar_priv_rx_q *rx_queue,
                                int alloc_cnt);
static int gfar_set_mac_address(struct net_device *dev);
static int gfar_change_mtu(struct net_device *dev, int new_mtu);
static irqreturn_t gfar_error(int irq, void *dev_id);
static irqreturn_t gfar_transmit(int irq, void *dev_id);
static irqreturn_t gfar_interrupt(int irq, void *dev_id);
static void adjust_link(struct net_device *dev);
static noinline void gfar_update_link_state(struct gfar_private *priv);
static int init_phy(struct net_device *dev);
static int gfar_probe(struct platform_device *ofdev);
static int gfar_remove(struct platform_device *ofdev);
static void free_skb_resources(struct gfar_private *priv);
static void gfar_set_multi(struct net_device *dev);
static void gfar_set_hash_for_addr(struct net_device *dev, u8 *addr);
static void gfar_configure_serdes(struct net_device *dev);
static int gfar_poll_rx(struct napi_struct *napi, int budget);
static int gfar_poll_tx(struct napi_struct *napi, int budget);
static int gfar_poll_rx_sq(struct napi_struct *napi, int budget);
static int gfar_poll_tx_sq(struct napi_struct *napi, int budget);
#ifdef CONFIG_NET_POLL_CONTROLLER
static void gfar_netpoll(struct net_device *dev);
#endif
int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue, int rx_work_limit);
static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue);
static void gfar_process_frame(struct net_device *ndev, struct sk_buff *skb);
static void gfar_halt_nodisable(struct gfar_private *priv);
static void gfar_clear_exact_match(struct net_device *dev);
static void gfar_set_mac_for_addr(struct net_device *dev, int num,
                                  const u8 *addr);
static int gfar_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);

MODULE_AUTHOR("Freescale Semiconductor, Inc");
MODULE_DESCRIPTION("Gianfar Ethernet Driver");
MODULE_LICENSE("GPL");

static void gfar_init_rxbdp(struct gfar_priv_rx_q *rx_queue, struct rxbd8 *bdp,
                            dma_addr_t buf)
{
        u32 lstatus;

        bdp->bufPtr = cpu_to_be32(buf);

        lstatus = BD_LFLAG(RXBD_EMPTY | RXBD_INTERRUPT);
        if (bdp == rx_queue->rx_bd_base + rx_queue->rx_ring_size - 1)
                lstatus |= BD_LFLAG(RXBD_WRAP);

        gfar_wmb();

        bdp->lstatus = cpu_to_be32(lstatus);
}

static void gfar_init_bds(struct net_device *ndev)
{
        struct gfar_private *priv = netdev_priv(ndev);
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        struct gfar_priv_tx_q *tx_queue = NULL;
        struct gfar_priv_rx_q *rx_queue = NULL;
        struct txbd8 *txbdp;
        u32 __iomem *rfbptr;
        int i, j;

        for (i = 0; i < priv->num_tx_queues; i++) {
                tx_queue = priv->tx_queue[i];
                /* Initialize some variables in our dev structure */
                tx_queue->num_txbdfree = tx_queue->tx_ring_size;
                tx_queue->dirty_tx = tx_queue->tx_bd_base;
                tx_queue->cur_tx = tx_queue->tx_bd_base;
                tx_queue->skb_curtx = 0;
                tx_queue->skb_dirtytx = 0;

                /* Initialize Transmit Descriptor Ring */
                txbdp = tx_queue->tx_bd_base;
                for (j = 0; j < tx_queue->tx_ring_size; j++) {
                        txbdp->lstatus = 0;
                        txbdp->bufPtr = 0;
                        txbdp++;
                }

                /* Set the last descriptor in the ring to indicate wrap */
                txbdp--;
                txbdp->status = cpu_to_be16(be16_to_cpu(txbdp->status) |
                                            TXBD_WRAP);
        }

        rfbptr = &regs->rfbptr0;
        for (i = 0; i < priv->num_rx_queues; i++) {
                rx_queue = priv->rx_queue[i];

                rx_queue->next_to_clean = 0;
                rx_queue->next_to_use = 0;
                rx_queue->next_to_alloc = 0;

                /* make sure next_to_clean != next_to_use after this
                 * by leaving at least 1 unused descriptor
                 */
                gfar_alloc_rx_buffs(rx_queue, gfar_rxbd_unused(rx_queue));

                rx_queue->rfbptr = rfbptr;
                rfbptr += 2;
        }
}

static int gfar_alloc_skb_resources(struct net_device *ndev)
{
        void *vaddr;
        dma_addr_t addr;
        int i, j;
        struct gfar_private *priv = netdev_priv(ndev);
        struct device *dev = priv->dev;
        struct gfar_priv_tx_q *tx_queue = NULL;
        struct gfar_priv_rx_q *rx_queue = NULL;

        priv->total_tx_ring_size = 0;
        for (i = 0; i < priv->num_tx_queues; i++)
                priv->total_tx_ring_size += priv->tx_queue[i]->tx_ring_size;

        priv->total_rx_ring_size = 0;
        for (i = 0; i < priv->num_rx_queues; i++)
                priv->total_rx_ring_size += priv->rx_queue[i]->rx_ring_size;

        /* Allocate memory for the buffer descriptors */
        vaddr = dma_alloc_coherent(dev,
                                   (priv->total_tx_ring_size *
                                    sizeof(struct txbd8)) +
                                   (priv->total_rx_ring_size *
                                    sizeof(struct rxbd8)),
                                   &addr, GFP_KERNEL);
        if (!vaddr)
                return -ENOMEM;

        for (i = 0; i < priv->num_tx_queues; i++) {
                tx_queue = priv->tx_queue[i];
                tx_queue->tx_bd_base = vaddr;
                tx_queue->tx_bd_dma_base = addr;
                tx_queue->dev = ndev;
                /* enet DMA only understands physical addresses */
                addr  += sizeof(struct txbd8) * tx_queue->tx_ring_size;
                vaddr += sizeof(struct txbd8) * tx_queue->tx_ring_size;
        }

        /* Start the rx descriptor ring where the tx ring leaves off */
        for (i = 0; i < priv->num_rx_queues; i++) {
                rx_queue = priv->rx_queue[i];
                rx_queue->rx_bd_base = vaddr;
                rx_queue->rx_bd_dma_base = addr;
                rx_queue->ndev = ndev;
                rx_queue->dev = dev;
                addr  += sizeof(struct rxbd8) * rx_queue->rx_ring_size;
                vaddr += sizeof(struct rxbd8) * rx_queue->rx_ring_size;
        }

        /* Setup the skbuff rings */
        for (i = 0; i < priv->num_tx_queues; i++) {
                tx_queue = priv->tx_queue[i];
                tx_queue->tx_skbuff =
                        kmalloc_array(tx_queue->tx_ring_size,
                                      sizeof(*tx_queue->tx_skbuff),
                                      GFP_KERNEL);
                if (!tx_queue->tx_skbuff)
                        goto cleanup;

                for (j = 0; j < tx_queue->tx_ring_size; j++)
                        tx_queue->tx_skbuff[j] = NULL;
        }

        for (i = 0; i < priv->num_rx_queues; i++) {
                rx_queue = priv->rx_queue[i];
                rx_queue->rx_buff = kcalloc(rx_queue->rx_ring_size,
                                            sizeof(*rx_queue->rx_buff),
                                            GFP_KERNEL);
                if (!rx_queue->rx_buff)
                        goto cleanup;
        }

        gfar_init_bds(ndev);

        return 0;

cleanup:
        free_skb_resources(priv);
        return -ENOMEM;
}

static void gfar_init_tx_rx_base(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 __iomem *baddr;
        int i;

        baddr = &regs->tbase0;
        for (i = 0; i < priv->num_tx_queues; i++) {
                gfar_write(baddr, priv->tx_queue[i]->tx_bd_dma_base);
                baddr += 2;
        }

        baddr = &regs->rbase0;
        for (i = 0; i < priv->num_rx_queues; i++) {
                gfar_write(baddr, priv->rx_queue[i]->rx_bd_dma_base);
                baddr += 2;
        }
}

static void gfar_init_rqprm(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 __iomem *baddr;
        int i;

        baddr = &regs->rqprm0;
        for (i = 0; i < priv->num_rx_queues; i++) {
                gfar_write(baddr, priv->rx_queue[i]->rx_ring_size |
                           (DEFAULT_RX_LFC_THR << FBTHR_SHIFT));
                baddr++;
        }
}

static void gfar_rx_offload_en(struct gfar_private *priv)
{
        /* set this when rx hw offload (TOE) functions are being used */
        priv->uses_rxfcb = 0;

        if (priv->ndev->features & (NETIF_F_RXCSUM | NETIF_F_HW_VLAN_CTAG_RX))
                priv->uses_rxfcb = 1;

        if (priv->hwts_rx_en || priv->rx_filer_enable)
                priv->uses_rxfcb = 1;
}

static void gfar_mac_rx_config(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 rctrl = 0;

        if (priv->rx_filer_enable) {
                rctrl |= RCTRL_FILREN | RCTRL_PRSDEP_INIT;
                /* Program the RIR0 reg with the required distribution */
                if (priv->poll_mode == GFAR_SQ_POLLING)
                        gfar_write(&regs->rir0, DEFAULT_2RXQ_RIR0);
                else /* GFAR_MQ_POLLING */
                        gfar_write(&regs->rir0, DEFAULT_8RXQ_RIR0);
        }

        /* Restore PROMISC mode */
        if (priv->ndev->flags & IFF_PROMISC)
                rctrl |= RCTRL_PROM;

        if (priv->ndev->features & NETIF_F_RXCSUM)
                rctrl |= RCTRL_CHECKSUMMING;

        if (priv->extended_hash)
                rctrl |= RCTRL_EXTHASH | RCTRL_EMEN;

        if (priv->padding) {
                rctrl &= ~RCTRL_PAL_MASK;
                rctrl |= RCTRL_PADDING(priv->padding);
        }

        /* Enable HW time stamping if requested from user space */
        if (priv->hwts_rx_en)
                rctrl |= RCTRL_PRSDEP_INIT | RCTRL_TS_ENABLE;

        if (priv->ndev->features & NETIF_F_HW_VLAN_CTAG_RX)
                rctrl |= RCTRL_VLEX | RCTRL_PRSDEP_INIT;

        /* Clear the LFC bit */
        gfar_write(&regs->rctrl, rctrl);
        /* Init flow control threshold values */
        gfar_init_rqprm(priv);
        gfar_write(&regs->ptv, DEFAULT_LFC_PTVVAL);
        rctrl |= RCTRL_LFC;

        /* Init rctrl based on our settings */
        gfar_write(&regs->rctrl, rctrl);
}

static void gfar_mac_tx_config(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 tctrl = 0;

        if (priv->ndev->features & NETIF_F_IP_CSUM)
                tctrl |= TCTRL_INIT_CSUM;

        if (priv->prio_sched_en)
                tctrl |= TCTRL_TXSCHED_PRIO;
        else {
                tctrl |= TCTRL_TXSCHED_WRRS;
                gfar_write(&regs->tr03wt, DEFAULT_WRRS_WEIGHT);
                gfar_write(&regs->tr47wt, DEFAULT_WRRS_WEIGHT);
        }

        if (priv->ndev->features & NETIF_F_HW_VLAN_CTAG_TX)
                tctrl |= TCTRL_VLINS;

        gfar_write(&regs->tctrl, tctrl);
}

static void gfar_configure_coalescing(struct gfar_private *priv,
                               unsigned long tx_mask, unsigned long rx_mask)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 __iomem *baddr;

        if (priv->mode == MQ_MG_MODE) {
                int i = 0;

                baddr = &regs->txic0;
                for_each_set_bit(i, &tx_mask, priv->num_tx_queues) {
                        gfar_write(baddr + i, 0);
                        if (likely(priv->tx_queue[i]->txcoalescing))
                                gfar_write(baddr + i, priv->tx_queue[i]->txic);
                }

                baddr = &regs->rxic0;
                for_each_set_bit(i, &rx_mask, priv->num_rx_queues) {
                        gfar_write(baddr + i, 0);
                        if (likely(priv->rx_queue[i]->rxcoalescing))
                                gfar_write(baddr + i, priv->rx_queue[i]->rxic);
                }
        } else {
                /* Backward compatible case -- even if we enable
                 * multiple queues, there's only single reg to program
                 */
                gfar_write(&regs->txic, 0);
                if (likely(priv->tx_queue[0]->txcoalescing))
                        gfar_write(&regs->txic, priv->tx_queue[0]->txic);

                gfar_write(&regs->rxic, 0);
                if (unlikely(priv->rx_queue[0]->rxcoalescing))
                        gfar_write(&regs->rxic, priv->rx_queue[0]->rxic);
        }
}

void gfar_configure_coalescing_all(struct gfar_private *priv)
{
        gfar_configure_coalescing(priv, 0xFF, 0xFF);
}

static struct net_device_stats *gfar_get_stats(struct net_device *dev)
{
        struct gfar_private *priv = netdev_priv(dev);
        unsigned long rx_packets = 0, rx_bytes = 0, rx_dropped = 0;
        unsigned long tx_packets = 0, tx_bytes = 0;
        int i;

        for (i = 0; i < priv->num_rx_queues; i++) {
                rx_packets += priv->rx_queue[i]->stats.rx_packets;
                rx_bytes   += priv->rx_queue[i]->stats.rx_bytes;
                rx_dropped += priv->rx_queue[i]->stats.rx_dropped;
        }

        dev->stats.rx_packets = rx_packets;
        dev->stats.rx_bytes   = rx_bytes;
        dev->stats.rx_dropped = rx_dropped;

        for (i = 0; i < priv->num_tx_queues; i++) {
                tx_bytes += priv->tx_queue[i]->stats.tx_bytes;
                tx_packets += priv->tx_queue[i]->stats.tx_packets;
        }

        dev->stats.tx_bytes   = tx_bytes;
        dev->stats.tx_packets = tx_packets;

        return &dev->stats;
}

static int gfar_set_mac_addr(struct net_device *dev, void *p)
{
        eth_mac_addr(dev, p);

        gfar_set_mac_for_addr(dev, 0, dev->dev_addr);

        return 0;
}

static const struct net_device_ops gfar_netdev_ops = {
        .ndo_open = gfar_enet_open,
        .ndo_start_xmit = gfar_start_xmit,
        .ndo_stop = gfar_close,
        .ndo_change_mtu = gfar_change_mtu,
        .ndo_set_features = gfar_set_features,
        .ndo_set_rx_mode = gfar_set_multi,
        .ndo_tx_timeout = gfar_timeout,
        .ndo_do_ioctl = gfar_ioctl,
        .ndo_get_stats = gfar_get_stats,
        .ndo_change_carrier = fixed_phy_change_carrier,
        .ndo_set_mac_address = gfar_set_mac_addr,
        .ndo_validate_addr = eth_validate_addr,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller = gfar_netpoll,
#endif
};

static void gfar_ints_disable(struct gfar_private *priv)
{
        int i;
        for (i = 0; i < priv->num_grps; i++) {
                struct gfar __iomem *regs = priv->gfargrp[i].regs;
                /* Clear IEVENT */
                gfar_write(&regs->ievent, IEVENT_INIT_CLEAR);

                /* Initialize IMASK */
                gfar_write(&regs->imask, IMASK_INIT_CLEAR);
        }
}

static void gfar_ints_enable(struct gfar_private *priv)
{
        int i;
        for (i = 0; i < priv->num_grps; i++) {
                struct gfar __iomem *regs = priv->gfargrp[i].regs;
                /* Unmask the interrupts we look for */
                gfar_write(&regs->imask, IMASK_DEFAULT);
        }
}

static int gfar_alloc_tx_queues(struct gfar_private *priv)
{
        int i;

        for (i = 0; i < priv->num_tx_queues; i++) {
                priv->tx_queue[i] = kzalloc(sizeof(struct gfar_priv_tx_q),
                                            GFP_KERNEL);
                if (!priv->tx_queue[i])
                        return -ENOMEM;

                priv->tx_queue[i]->tx_skbuff = NULL;
                priv->tx_queue[i]->qindex = i;
                priv->tx_queue[i]->dev = priv->ndev;
                spin_lock_init(&(priv->tx_queue[i]->txlock));
        }
        return 0;
}

static int gfar_alloc_rx_queues(struct gfar_private *priv)
{
        int i;

        for (i = 0; i < priv->num_rx_queues; i++) {
                priv->rx_queue[i] = kzalloc(sizeof(struct gfar_priv_rx_q),
                                            GFP_KERNEL);
                if (!priv->rx_queue[i])
                        return -ENOMEM;

                priv->rx_queue[i]->qindex = i;
                priv->rx_queue[i]->ndev = priv->ndev;
        }
        return 0;
}

static void gfar_free_tx_queues(struct gfar_private *priv)
{
        int i;

        for (i = 0; i < priv->num_tx_queues; i++)
                kfree(priv->tx_queue[i]);
}

static void gfar_free_rx_queues(struct gfar_private *priv)
{
        int i;

        for (i = 0; i < priv->num_rx_queues; i++)
                kfree(priv->rx_queue[i]);
}

static void unmap_group_regs(struct gfar_private *priv)
{
        int i;

        for (i = 0; i < MAXGROUPS; i++)
                if (priv->gfargrp[i].regs)
                        iounmap(priv->gfargrp[i].regs);
}

static void free_gfar_dev(struct gfar_private *priv)
{
        int i, j;

        for (i = 0; i < priv->num_grps; i++)
                for (j = 0; j < GFAR_NUM_IRQS; j++) {
                        kfree(priv->gfargrp[i].irqinfo[j]);
                        priv->gfargrp[i].irqinfo[j] = NULL;
                }

        free_netdev(priv->ndev);
}

static void disable_napi(struct gfar_private *priv)
{
        int i;

        for (i = 0; i < priv->num_grps; i++) {
                napi_disable(&priv->gfargrp[i].napi_rx);
                napi_disable(&priv->gfargrp[i].napi_tx);
        }
}

static void enable_napi(struct gfar_private *priv)
{
        int i;

        for (i = 0; i < priv->num_grps; i++) {
                napi_enable(&priv->gfargrp[i].napi_rx);
                napi_enable(&priv->gfargrp[i].napi_tx);
        }
}

static int gfar_parse_group(struct device_node *np,
                            struct gfar_private *priv, const char *model)
{
        struct gfar_priv_grp *grp = &priv->gfargrp[priv->num_grps];
        int i;

        for (i = 0; i < GFAR_NUM_IRQS; i++) {
                grp->irqinfo[i] = kzalloc(sizeof(struct gfar_irqinfo),
                                          GFP_KERNEL);
                if (!grp->irqinfo[i])
                        return -ENOMEM;
        }

        grp->regs = of_iomap(np, 0);
        if (!grp->regs)
                return -ENOMEM;

        gfar_irq(grp, TX)->irq = irq_of_parse_and_map(np, 0);

        /* If we aren't the FEC we have multiple interrupts */
        if (model && strcasecmp(model, "FEC")) {
                gfar_irq(grp, RX)->irq = irq_of_parse_and_map(np, 1);
                gfar_irq(grp, ER)->irq = irq_of_parse_and_map(np, 2);
                if (!gfar_irq(grp, TX)->irq ||
                    !gfar_irq(grp, RX)->irq ||
                    !gfar_irq(grp, ER)->irq)
                        return -EINVAL;
        }

        grp->priv = priv;
        spin_lock_init(&grp->grplock);
        if (priv->mode == MQ_MG_MODE) {
                u32 rxq_mask, txq_mask;
                int ret;

                grp->rx_bit_map = (DEFAULT_MAPPING >> priv->num_grps);
                grp->tx_bit_map = (DEFAULT_MAPPING >> priv->num_grps);

                ret = of_property_read_u32(np, "fsl,rx-bit-map", &rxq_mask);
                if (!ret) {
                        grp->rx_bit_map = rxq_mask ?
                        rxq_mask : (DEFAULT_MAPPING >> priv->num_grps);
                }

                ret = of_property_read_u32(np, "fsl,tx-bit-map", &txq_mask);
                if (!ret) {
                        grp->tx_bit_map = txq_mask ?
                        txq_mask : (DEFAULT_MAPPING >> priv->num_grps);
                }

                if (priv->poll_mode == GFAR_SQ_POLLING) {
                        /* One Q per interrupt group: Q0 to G0, Q1 to G1 */
                        grp->rx_bit_map = (DEFAULT_MAPPING >> priv->num_grps);
                        grp->tx_bit_map = (DEFAULT_MAPPING >> priv->num_grps);
                }
        } else {
                grp->rx_bit_map = 0xFF;
                grp->tx_bit_map = 0xFF;
        }

        /* bit_map's MSB is q0 (from q0 to q7) but, for_each_set_bit parses
         * right to left, so we need to revert the 8 bits to get the q index
         */
        grp->rx_bit_map = bitrev8(grp->rx_bit_map);
        grp->tx_bit_map = bitrev8(grp->tx_bit_map);

        /* Calculate RSTAT, TSTAT, RQUEUE and TQUEUE values,
         * also assign queues to groups
         */
        for_each_set_bit(i, &grp->rx_bit_map, priv->num_rx_queues) {
                if (!grp->rx_queue)
                        grp->rx_queue = priv->rx_queue[i];
                grp->num_rx_queues++;
                grp->rstat |= (RSTAT_CLEAR_RHALT >> i);
                priv->rqueue |= ((RQUEUE_EN0 | RQUEUE_EX0) >> i);
                priv->rx_queue[i]->grp = grp;
        }

        for_each_set_bit(i, &grp->tx_bit_map, priv->num_tx_queues) {
                if (!grp->tx_queue)
                        grp->tx_queue = priv->tx_queue[i];
                grp->num_tx_queues++;
                grp->tstat |= (TSTAT_CLEAR_THALT >> i);
                priv->tqueue |= (TQUEUE_EN0 >> i);
                priv->tx_queue[i]->grp = grp;
        }

        priv->num_grps++;

        return 0;
}

static int gfar_of_group_count(struct device_node *np)
{
        struct device_node *child;
        int num = 0;

        for_each_available_child_of_node(np, child)
                if (of_node_name_eq(child, "queue-group"))
                        num++;

        return num;
}

static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
{
        const char *model;
        const char *ctype;
        const void *mac_addr;
        int err = 0, i;
        struct net_device *dev = NULL;
        struct gfar_private *priv = NULL;
        struct device_node *np = ofdev->dev.of_node;
        struct device_node *child = NULL;
        u32 stash_len = 0;
        u32 stash_idx = 0;
        unsigned int num_tx_qs, num_rx_qs;
        unsigned short mode, poll_mode;

        if (!np)
                return -ENODEV;

        if (of_device_is_compatible(np, "fsl,etsec2")) {
                mode = MQ_MG_MODE;
                poll_mode = GFAR_SQ_POLLING;
        } else {
                mode = SQ_SG_MODE;
                poll_mode = GFAR_SQ_POLLING;
        }

        if (mode == SQ_SG_MODE) {
                num_tx_qs = 1;
                num_rx_qs = 1;
        } else { /* MQ_MG_MODE */
                /* get the actual number of supported groups */
                unsigned int num_grps = gfar_of_group_count(np);

                if (num_grps == 0 || num_grps > MAXGROUPS) {
                        dev_err(&ofdev->dev, "Invalid # of int groups(%d)\n",
                                num_grps);
                        pr_err("Cannot do alloc_etherdev, aborting\n");
                        return -EINVAL;
                }

                if (poll_mode == GFAR_SQ_POLLING) {
                        num_tx_qs = num_grps; /* one txq per int group */
                        num_rx_qs = num_grps; /* one rxq per int group */
                } else { /* GFAR_MQ_POLLING */
                        u32 tx_queues, rx_queues;
                        int ret;

                        /* parse the num of HW tx and rx queues */
                        ret = of_property_read_u32(np, "fsl,num_tx_queues",
                                                   &tx_queues);
                        num_tx_qs = ret ? 1 : tx_queues;

                        ret = of_property_read_u32(np, "fsl,num_rx_queues",
                                                   &rx_queues);
                        num_rx_qs = ret ? 1 : rx_queues;
                }
        }

        if (num_tx_qs > MAX_TX_QS) {
                pr_err("num_tx_qs(=%d) greater than MAX_TX_QS(=%d)\n",
                       num_tx_qs, MAX_TX_QS);
                pr_err("Cannot do alloc_etherdev, aborting\n");
                return -EINVAL;
        }

        if (num_rx_qs > MAX_RX_QS) {
                pr_err("num_rx_qs(=%d) greater than MAX_RX_QS(=%d)\n",
                       num_rx_qs, MAX_RX_QS);
                pr_err("Cannot do alloc_etherdev, aborting\n");
                return -EINVAL;
        }

        *pdev = alloc_etherdev_mq(sizeof(*priv), num_tx_qs);
        dev = *pdev;
        if (NULL == dev)
                return -ENOMEM;

        priv = netdev_priv(dev);
        priv->ndev = dev;

        priv->mode = mode;
        priv->poll_mode = poll_mode;

        priv->num_tx_queues = num_tx_qs;
        netif_set_real_num_rx_queues(dev, num_rx_qs);
        priv->num_rx_queues = num_rx_qs;

        err = gfar_alloc_tx_queues(priv);
        if (err)
                goto tx_alloc_failed;

        err = gfar_alloc_rx_queues(priv);
        if (err)
                goto rx_alloc_failed;

        err = of_property_read_string(np, "model", &model);
        if (err) {
                pr_err("Device model property missing, aborting\n");
                goto rx_alloc_failed;
        }

        /* Init Rx queue filer rule set linked list */
        INIT_LIST_HEAD(&priv->rx_list.list);
        priv->rx_list.count = 0;
        mutex_init(&priv->rx_queue_access);

        for (i = 0; i < MAXGROUPS; i++)
                priv->gfargrp[i].regs = NULL;

        /* Parse and initialize group specific information */
        if (priv->mode == MQ_MG_MODE) {
                for_each_available_child_of_node(np, child) {
                        if (!of_node_name_eq(child, "queue-group"))
                                continue;

                        err = gfar_parse_group(child, priv, model);
                        if (err)
                                goto err_grp_init;
                }
        } else { /* SQ_SG_MODE */
                err = gfar_parse_group(np, priv, model);
                if (err)
                        goto err_grp_init;
        }

        if (of_property_read_bool(np, "bd-stash")) {
                priv->device_flags |= FSL_GIANFAR_DEV_HAS_BD_STASHING;
                priv->bd_stash_en = 1;
        }

        err = of_property_read_u32(np, "rx-stash-len", &stash_len);

        if (err == 0)
                priv->rx_stash_size = stash_len;

        err = of_property_read_u32(np, "rx-stash-idx", &stash_idx);

        if (err == 0)
                priv->rx_stash_index = stash_idx;

        if (stash_len || stash_idx)
                priv->device_flags |= FSL_GIANFAR_DEV_HAS_BUF_STASHING;

        mac_addr = of_get_mac_address(np);

        if (!IS_ERR(mac_addr))
                ether_addr_copy(dev->dev_addr, mac_addr);

        if (model && !strcasecmp(model, "TSEC"))
                priv->device_flags |= FSL_GIANFAR_DEV_HAS_GIGABIT |
                                     FSL_GIANFAR_DEV_HAS_COALESCE |
                                     FSL_GIANFAR_DEV_HAS_RMON |
                                     FSL_GIANFAR_DEV_HAS_MULTI_INTR;

        if (model && !strcasecmp(model, "eTSEC"))
                priv->device_flags |= FSL_GIANFAR_DEV_HAS_GIGABIT |
                                     FSL_GIANFAR_DEV_HAS_COALESCE |
                                     FSL_GIANFAR_DEV_HAS_RMON |
                                     FSL_GIANFAR_DEV_HAS_MULTI_INTR |
                                     FSL_GIANFAR_DEV_HAS_CSUM |
                                     FSL_GIANFAR_DEV_HAS_VLAN |
                                     FSL_GIANFAR_DEV_HAS_MAGIC_PACKET |
                                     FSL_GIANFAR_DEV_HAS_EXTENDED_HASH |
                                     FSL_GIANFAR_DEV_HAS_TIMER |
                                     FSL_GIANFAR_DEV_HAS_RX_FILER;

        err = of_property_read_string(np, "phy-connection-type", &ctype);

        /* We only care about rgmii-id.  The rest are autodetected */
        if (err == 0 && !strcmp(ctype, "rgmii-id"))
                priv->interface = PHY_INTERFACE_MODE_RGMII_ID;
        else
                priv->interface = PHY_INTERFACE_MODE_MII;

        if (of_find_property(np, "fsl,magic-packet", NULL))
                priv->device_flags |= FSL_GIANFAR_DEV_HAS_MAGIC_PACKET;

        if (of_get_property(np, "fsl,wake-on-filer", NULL))
                priv->device_flags |= FSL_GIANFAR_DEV_HAS_WAKE_ON_FILER;

        priv->phy_node = of_parse_phandle(np, "phy-handle", 0);

        /* In the case of a fixed PHY, the DT node associated
         * to the PHY is the Ethernet MAC DT node.
         */
        if (!priv->phy_node && of_phy_is_fixed_link(np)) {
                err = of_phy_register_fixed_link(np);
                if (err)
                        goto err_grp_init;

                priv->phy_node = of_node_get(np);
        }

        /* Find the TBI PHY.  If it's not there, we don't support SGMII */
        priv->tbi_node = of_parse_phandle(np, "tbi-handle", 0);

        return 0;

err_grp_init:
        unmap_group_regs(priv);
rx_alloc_failed:
        gfar_free_rx_queues(priv);
tx_alloc_failed:
        gfar_free_tx_queues(priv);
        free_gfar_dev(priv);
        return err;
}

static int gfar_hwtstamp_set(struct net_device *netdev, struct ifreq *ifr)
{
        struct hwtstamp_config config;
        struct gfar_private *priv = netdev_priv(netdev);

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

        /* reserved for future extensions */
        if (config.flags)
                return -EINVAL;

        switch (config.tx_type) {
        case HWTSTAMP_TX_OFF:
                priv->hwts_tx_en = 0;
                break;
        case HWTSTAMP_TX_ON:
                if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER))
                        return -ERANGE;
                priv->hwts_tx_en = 1;
                break;
        default:
                return -ERANGE;
        }

        switch (config.rx_filter) {
        case HWTSTAMP_FILTER_NONE:
                if (priv->hwts_rx_en) {
                        priv->hwts_rx_en = 0;
                        reset_gfar(netdev);
                }
                break;
        default:
                if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER))
                        return -ERANGE;
                if (!priv->hwts_rx_en) {
                        priv->hwts_rx_en = 1;
                        reset_gfar(netdev);
                }
                config.rx_filter = HWTSTAMP_FILTER_ALL;
                break;
        }

        return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
                -EFAULT : 0;
}

static int gfar_hwtstamp_get(struct net_device *netdev, struct ifreq *ifr)
{
        struct hwtstamp_config config;
        struct gfar_private *priv = netdev_priv(netdev);

        config.flags = 0;
        config.tx_type = priv->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
        config.rx_filter = (priv->hwts_rx_en ?
                            HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE);

        return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
                -EFAULT : 0;
}

static int gfar_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
        struct phy_device *phydev = dev->phydev;

        if (!netif_running(dev))
                return -EINVAL;

        if (cmd == SIOCSHWTSTAMP)
                return gfar_hwtstamp_set(dev, rq);
        if (cmd == SIOCGHWTSTAMP)
                return gfar_hwtstamp_get(dev, rq);

        if (!phydev)
                return -ENODEV;

        return phy_mii_ioctl(phydev, rq, cmd);
}

static u32 cluster_entry_per_class(struct gfar_private *priv, u32 rqfar,
                                   u32 class)
{
        u32 rqfpr = FPR_FILER_MASK;
        u32 rqfcr = 0x0;

        rqfar--;
        rqfcr = RQFCR_CLE | RQFCR_PID_MASK | RQFCR_CMP_EXACT;
        priv->ftp_rqfpr[rqfar] = rqfpr;
        priv->ftp_rqfcr[rqfar] = rqfcr;
        gfar_write_filer(priv, rqfar, rqfcr, rqfpr);

        rqfar--;
        rqfcr = RQFCR_CMP_NOMATCH;
        priv->ftp_rqfpr[rqfar] = rqfpr;
        priv->ftp_rqfcr[rqfar] = rqfcr;
        gfar_write_filer(priv, rqfar, rqfcr, rqfpr);

        rqfar--;
        rqfcr = RQFCR_CMP_EXACT | RQFCR_PID_PARSE | RQFCR_CLE | RQFCR_AND;
        rqfpr = class;
        priv->ftp_rqfcr[rqfar] = rqfcr;
        priv->ftp_rqfpr[rqfar] = rqfpr;
        gfar_write_filer(priv, rqfar, rqfcr, rqfpr);

        rqfar--;
        rqfcr = RQFCR_CMP_EXACT | RQFCR_PID_MASK | RQFCR_AND;
        rqfpr = class;
        priv->ftp_rqfcr[rqfar] = rqfcr;
        priv->ftp_rqfpr[rqfar] = rqfpr;
        gfar_write_filer(priv, rqfar, rqfcr, rqfpr);

        return rqfar;
}

static void gfar_init_filer_table(struct gfar_private *priv)
{
        int i = 0x0;
        u32 rqfar = MAX_FILER_IDX;
        u32 rqfcr = 0x0;
        u32 rqfpr = FPR_FILER_MASK;

        /* Default rule */
        rqfcr = RQFCR_CMP_MATCH;
        priv->ftp_rqfcr[rqfar] = rqfcr;
        priv->ftp_rqfpr[rqfar] = rqfpr;
        gfar_write_filer(priv, rqfar, rqfcr, rqfpr);

        rqfar = cluster_entry_per_class(priv, rqfar, RQFPR_IPV6);
        rqfar = cluster_entry_per_class(priv, rqfar, RQFPR_IPV6 | RQFPR_UDP);
        rqfar = cluster_entry_per_class(priv, rqfar, RQFPR_IPV6 | RQFPR_TCP);
        rqfar = cluster_entry_per_class(priv, rqfar, RQFPR_IPV4);
        rqfar = cluster_entry_per_class(priv, rqfar, RQFPR_IPV4 | RQFPR_UDP);
        rqfar = cluster_entry_per_class(priv, rqfar, RQFPR_IPV4 | RQFPR_TCP);

        /* cur_filer_idx indicated the first non-masked rule */
        priv->cur_filer_idx = rqfar;

        /* Rest are masked rules */
        rqfcr = RQFCR_CMP_NOMATCH;
        for (i = 0; i < rqfar; i++) {
                priv->ftp_rqfcr[i] = rqfcr;
                priv->ftp_rqfpr[i] = rqfpr;
                gfar_write_filer(priv, i, rqfcr, rqfpr);
        }
}

#ifdef CONFIG_PPC
static void __gfar_detect_errata_83xx(struct gfar_private *priv)
{
        unsigned int pvr = mfspr(SPRN_PVR);
        unsigned int svr = mfspr(SPRN_SVR);
        unsigned int mod = (svr >> 16) & 0xfff6; /* w/o E suffix */
        unsigned int rev = svr & 0xffff;

        /* MPC8313 Rev 2.0 and higher; All MPC837x */
        if ((pvr == 0x80850010 && mod == 0x80b0 && rev >= 0x0020) ||
            (pvr == 0x80861010 && (mod & 0xfff9) == 0x80c0))
                priv->errata |= GFAR_ERRATA_74;

        /* MPC8313 and MPC837x all rev */
        if ((pvr == 0x80850010 && mod == 0x80b0) ||
            (pvr == 0x80861010 && (mod & 0xfff9) == 0x80c0))
                priv->errata |= GFAR_ERRATA_76;

        /* MPC8313 Rev < 2.0 */
        if (pvr == 0x80850010 && mod == 0x80b0 && rev < 0x0020)
                priv->errata |= GFAR_ERRATA_12;
}

static void __gfar_detect_errata_85xx(struct gfar_private *priv)
{
        unsigned int svr = mfspr(SPRN_SVR);

        if ((SVR_SOC_VER(svr) == SVR_8548) && (SVR_REV(svr) == 0x20))
                priv->errata |= GFAR_ERRATA_12;
        /* P2020/P1010 Rev 1; MPC8548 Rev 2 */
        if (((SVR_SOC_VER(svr) == SVR_P2020) && (SVR_REV(svr) < 0x20)) ||
            ((SVR_SOC_VER(svr) == SVR_P2010) && (SVR_REV(svr) < 0x20)) ||
            ((SVR_SOC_VER(svr) == SVR_8548) && (SVR_REV(svr) < 0x31)))
                priv->errata |= GFAR_ERRATA_76; /* aka eTSEC 20 */
}
#endif

static void gfar_detect_errata(struct gfar_private *priv)
{
        struct device *dev = &priv->ofdev->dev;

        /* no plans to fix */
        priv->errata |= GFAR_ERRATA_A002;

#ifdef CONFIG_PPC
        if (pvr_version_is(PVR_VER_E500V1) || pvr_version_is(PVR_VER_E500V2))
                __gfar_detect_errata_85xx(priv);
        else /* non-mpc85xx parts, i.e. e300 core based */
                __gfar_detect_errata_83xx(priv);
#endif

        if (priv->errata)
                dev_info(dev, "enabled errata workarounds, flags: 0x%x\n",
                         priv->errata);
}

void gfar_mac_reset(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 tempval;

        /* Reset MAC layer */
        gfar_write(&regs->maccfg1, MACCFG1_SOFT_RESET);

        /* We need to delay at least 3 TX clocks */
        udelay(3);

        /* the soft reset bit is not self-resetting, so we need to
         * clear it before resuming normal operation
         */
        gfar_write(&regs->maccfg1, 0);

        udelay(3);

        gfar_rx_offload_en(priv);

        /* Initialize the max receive frame/buffer lengths */
        gfar_write(&regs->maxfrm, GFAR_JUMBO_FRAME_SIZE);
        gfar_write(&regs->mrblr, GFAR_RXB_SIZE);

        /* Initialize the Minimum Frame Length Register */
        gfar_write(&regs->minflr, MINFLR_INIT_SETTINGS);

        /* Initialize MACCFG2. */
        tempval = MACCFG2_INIT_SETTINGS;

        /* eTSEC74 erratum: Rx frames of length MAXFRM or MAXFRM-1
         * are marked as truncated.  Avoid this by MACCFG2[Huge Frame]=1,
         * and by checking RxBD[LG] and discarding larger than MAXFRM.
         */
        if (gfar_has_errata(priv, GFAR_ERRATA_74))
                tempval |= MACCFG2_HUGEFRAME | MACCFG2_LENGTHCHECK;

        gfar_write(&regs->maccfg2, tempval);

        /* Clear mac addr hash registers */
        gfar_write(&regs->igaddr0, 0);
        gfar_write(&regs->igaddr1, 0);
        gfar_write(&regs->igaddr2, 0);
        gfar_write(&regs->igaddr3, 0);
        gfar_write(&regs->igaddr4, 0);
        gfar_write(&regs->igaddr5, 0);
        gfar_write(&regs->igaddr6, 0);
        gfar_write(&regs->igaddr7, 0);

        gfar_write(&regs->gaddr0, 0);
        gfar_write(&regs->gaddr1, 0);
        gfar_write(&regs->gaddr2, 0);
        gfar_write(&regs->gaddr3, 0);
        gfar_write(&regs->gaddr4, 0);
        gfar_write(&regs->gaddr5, 0);
        gfar_write(&regs->gaddr6, 0);
        gfar_write(&regs->gaddr7, 0);

        if (priv->extended_hash)
                gfar_clear_exact_match(priv->ndev);

        gfar_mac_rx_config(priv);

        gfar_mac_tx_config(priv);

        gfar_set_mac_address(priv->ndev);

        gfar_set_multi(priv->ndev);

        /* clear ievent and imask before configuring coalescing */
        gfar_ints_disable(priv);

        /* Configure the coalescing support */
        gfar_configure_coalescing_all(priv);
}

static void gfar_hw_init(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 attrs;

        /* Stop the DMA engine now, in case it was running before
         * (The firmware could have used it, and left it running).
         */
        gfar_halt(priv);

        gfar_mac_reset(priv);

        /* Zero out the rmon mib registers if it has them */
        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_RMON) {
                memset_io(&(regs->rmon), 0, sizeof(struct rmon_mib));

                /* Mask off the CAM interrupts */
                gfar_write(&regs->rmon.cam1, 0xffffffff);
                gfar_write(&regs->rmon.cam2, 0xffffffff);
        }

        /* Initialize ECNTRL */
        gfar_write(&regs->ecntrl, ECNTRL_INIT_SETTINGS);

        /* Set the extraction length and index */
        attrs = ATTRELI_EL(priv->rx_stash_size) |
                ATTRELI_EI(priv->rx_stash_index);

        gfar_write(&regs->attreli, attrs);

        /* Start with defaults, and add stashing
         * depending on driver parameters
         */
        attrs = ATTR_INIT_SETTINGS;

        if (priv->bd_stash_en)
                attrs |= ATTR_BDSTASH;

        if (priv->rx_stash_size != 0)
                attrs |= ATTR_BUFSTASH;

        gfar_write(&regs->attr, attrs);

        /* FIFO configs */
        gfar_write(&regs->fifo_tx_thr, DEFAULT_FIFO_TX_THR);
        gfar_write(&regs->fifo_tx_starve, DEFAULT_FIFO_TX_STARVE);
        gfar_write(&regs->fifo_tx_starve_shutoff, DEFAULT_FIFO_TX_STARVE_OFF);

        /* Program the interrupt steering regs, only for MG devices */
        if (priv->num_grps > 1)
                gfar_write_isrg(priv);
}

static void gfar_init_addr_hash_table(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;

        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_EXTENDED_HASH) {
                priv->extended_hash = 1;
                priv->hash_width = 9;

                priv->hash_regs[0] = &regs->igaddr0;
                priv->hash_regs[1] = &regs->igaddr1;
                priv->hash_regs[2] = &regs->igaddr2;
                priv->hash_regs[3] = &regs->igaddr3;
                priv->hash_regs[4] = &regs->igaddr4;
                priv->hash_regs[5] = &regs->igaddr5;
                priv->hash_regs[6] = &regs->igaddr6;
                priv->hash_regs[7] = &regs->igaddr7;
                priv->hash_regs[8] = &regs->gaddr0;
                priv->hash_regs[9] = &regs->gaddr1;
                priv->hash_regs[10] = &regs->gaddr2;
                priv->hash_regs[11] = &regs->gaddr3;
                priv->hash_regs[12] = &regs->gaddr4;
                priv->hash_regs[13] = &regs->gaddr5;
                priv->hash_regs[14] = &regs->gaddr6;
                priv->hash_regs[15] = &regs->gaddr7;

        } else {
                priv->extended_hash = 0;
                priv->hash_width = 8;

                priv->hash_regs[0] = &regs->gaddr0;
                priv->hash_regs[1] = &regs->gaddr1;
                priv->hash_regs[2] = &regs->gaddr2;
                priv->hash_regs[3] = &regs->gaddr3;
                priv->hash_regs[4] = &regs->gaddr4;
                priv->hash_regs[5] = &regs->gaddr5;
                priv->hash_regs[6] = &regs->gaddr6;
                priv->hash_regs[7] = &regs->gaddr7;
        }
}

/* Set up the ethernet device structure, private data,
 * and anything else we need before we start
 */
static int gfar_probe(struct platform_device *ofdev)
{
        struct device_node *np = ofdev->dev.of_node;
        struct net_device *dev = NULL;
        struct gfar_private *priv = NULL;
        int err = 0, i;

        err = gfar_of_init(ofdev, &dev);

        if (err)
                return err;

        priv = netdev_priv(dev);
        priv->ndev = dev;
        priv->ofdev = ofdev;
        priv->dev = &ofdev->dev;
        SET_NETDEV_DEV(dev, &ofdev->dev);

        INIT_WORK(&priv->reset_task, gfar_reset_task);

        platform_set_drvdata(ofdev, priv);

        gfar_detect_errata(priv);

        /* Set the dev->base_addr to the gfar reg region */
        dev->base_addr = (unsigned long) priv->gfargrp[0].regs;

        /* Fill in the dev structure */
        dev->watchdog_timeo = TX_TIMEOUT;
        /* MTU range: 50 - 9586 */
        dev->mtu = 1500;
        dev->min_mtu = 50;
        dev->max_mtu = GFAR_JUMBO_FRAME_SIZE - ETH_HLEN;
        dev->netdev_ops = &gfar_netdev_ops;
        dev->ethtool_ops = &gfar_ethtool_ops;

        /* Register for napi ...We are registering NAPI for each grp */
        for (i = 0; i < priv->num_grps; i++) {
                if (priv->poll_mode == GFAR_SQ_POLLING) {
                        netif_napi_add(dev, &priv->gfargrp[i].napi_rx,
                                       gfar_poll_rx_sq, GFAR_DEV_WEIGHT);
                        netif_tx_napi_add(dev, &priv->gfargrp[i].napi_tx,
                                       gfar_poll_tx_sq, 2);
                } else {
                        netif_napi_add(dev, &priv->gfargrp[i].napi_rx,
                                       gfar_poll_rx, GFAR_DEV_WEIGHT);
                        netif_tx_napi_add(dev, &priv->gfargrp[i].napi_tx,
                                       gfar_poll_tx, 2);
                }
        }

        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_CSUM) {
                dev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG |
                                   NETIF_F_RXCSUM;
                dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG |
                                 NETIF_F_RXCSUM | NETIF_F_HIGHDMA;
        }

        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_VLAN) {
                dev->hw_features |= NETIF_F_HW_VLAN_CTAG_TX |
                                    NETIF_F_HW_VLAN_CTAG_RX;
                dev->features |= NETIF_F_HW_VLAN_CTAG_RX;
        }

        dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;

        gfar_init_addr_hash_table(priv);

        /* Insert receive time stamps into padding alignment bytes, and
         * plus 2 bytes padding to ensure the cpu alignment.
         */
        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER)
                priv->padding = 8 + DEFAULT_PADDING;

        if (dev->features & NETIF_F_IP_CSUM ||
            priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER)
                dev->needed_headroom = GMAC_FCB_LEN;

        /* Initializing some of the rx/tx queue level parameters */
        for (i = 0; i < priv->num_tx_queues; i++) {
                priv->tx_queue[i]->tx_ring_size = DEFAULT_TX_RING_SIZE;
                priv->tx_queue[i]->num_txbdfree = DEFAULT_TX_RING_SIZE;
                priv->tx_queue[i]->txcoalescing = DEFAULT_TX_COALESCE;
                priv->tx_queue[i]->txic = DEFAULT_TXIC;
        }

        for (i = 0; i < priv->num_rx_queues; i++) {
                priv->rx_queue[i]->rx_ring_size = DEFAULT_RX_RING_SIZE;
                priv->rx_queue[i]->rxcoalescing = DEFAULT_RX_COALESCE;
                priv->rx_queue[i]->rxic = DEFAULT_RXIC;
        }

        /* Always enable rx filer if available */
        priv->rx_filer_enable =
            (priv->device_flags & FSL_GIANFAR_DEV_HAS_RX_FILER) ? 1 : 0;
        /* Enable most messages by default */
        priv->msg_enable = (NETIF_MSG_IFUP << 1 ) - 1;
        /* use pritority h/w tx queue scheduling for single queue devices */
        if (priv->num_tx_queues == 1)
                priv->prio_sched_en = 1;

        set_bit(GFAR_DOWN, &priv->state);

        gfar_hw_init(priv);

        /* Carrier starts down, phylib will bring it up */
        netif_carrier_off(dev);

        err = register_netdev(dev);

        if (err) {
                pr_err("%s: Cannot register net device, aborting\n", dev->name);
                goto register_fail;
        }

        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_MAGIC_PACKET)
                priv->wol_supported |= GFAR_WOL_MAGIC;

        if ((priv->device_flags & FSL_GIANFAR_DEV_HAS_WAKE_ON_FILER) &&
            priv->rx_filer_enable)
                priv->wol_supported |= GFAR_WOL_FILER_UCAST;

        device_set_wakeup_capable(&ofdev->dev, priv->wol_supported);

        /* fill out IRQ number and name fields */
        for (i = 0; i < priv->num_grps; i++) {
                struct gfar_priv_grp *grp = &priv->gfargrp[i];
                if (priv->device_flags & FSL_GIANFAR_DEV_HAS_MULTI_INTR) {
                        sprintf(gfar_irq(grp, TX)->name, "%s%s%c%s",
                                dev->name, "_g", '0' + i, "_tx");
                        sprintf(gfar_irq(grp, RX)->name, "%s%s%c%s",
                                dev->name, "_g", '0' + i, "_rx");
                        sprintf(gfar_irq(grp, ER)->name, "%s%s%c%s",
                                dev->name, "_g", '0' + i, "_er");
                } else
                        strcpy(gfar_irq(grp, TX)->name, dev->name);
        }

        /* Initialize the filer table */
        gfar_init_filer_table(priv);

        /* Print out the device info */
        netdev_info(dev, "mac: %pM\n", dev->dev_addr);

        /* Even more device info helps when determining which kernel
         * provided which set of benchmarks.
         */
        netdev_info(dev, "Running with NAPI enabled\n");
        for (i = 0; i < priv->num_rx_queues; i++)
                netdev_info(dev, "RX BD ring size for Q[%d]: %d\n",
                            i, priv->rx_queue[i]->rx_ring_size);
        for (i = 0; i < priv->num_tx_queues; i++)
                netdev_info(dev, "TX BD ring size for Q[%d]: %d\n",
                            i, priv->tx_queue[i]->tx_ring_size);

        return 0;

register_fail:
        if (of_phy_is_fixed_link(np))
                of_phy_deregister_fixed_link(np);
        unmap_group_regs(priv);
        gfar_free_rx_queues(priv);
        gfar_free_tx_queues(priv);
        of_node_put(priv->phy_node);
        of_node_put(priv->tbi_node);
        free_gfar_dev(priv);
        return err;
}

static int gfar_remove(struct platform_device *ofdev)
{
        struct gfar_private *priv = platform_get_drvdata(ofdev);
        struct device_node *np = ofdev->dev.of_node;

        of_node_put(priv->phy_node);
        of_node_put(priv->tbi_node);

        unregister_netdev(priv->ndev);

        if (of_phy_is_fixed_link(np))
                of_phy_deregister_fixed_link(np);

        unmap_group_regs(priv);
        gfar_free_rx_queues(priv);
        gfar_free_tx_queues(priv);
        free_gfar_dev(priv);

        return 0;
}

#ifdef CONFIG_PM

static void __gfar_filer_disable(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 temp;

        temp = gfar_read(&regs->rctrl);
        temp &= ~(RCTRL_FILREN | RCTRL_PRSDEP_INIT);
        gfar_write(&regs->rctrl, temp);
}

static void __gfar_filer_enable(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 temp;

        temp = gfar_read(&regs->rctrl);
        temp |= RCTRL_FILREN | RCTRL_PRSDEP_INIT;
        gfar_write(&regs->rctrl, temp);
}

/* Filer rules implementing wol capabilities */
static void gfar_filer_config_wol(struct gfar_private *priv)
{
        unsigned int i;
        u32 rqfcr;

        __gfar_filer_disable(priv);

        /* clear the filer table, reject any packet by default */
        rqfcr = RQFCR_RJE | RQFCR_CMP_MATCH;
        for (i = 0; i <= MAX_FILER_IDX; i++)
                gfar_write_filer(priv, i, rqfcr, 0);

        i = 0;
        if (priv->wol_opts & GFAR_WOL_FILER_UCAST) {
                /* unicast packet, accept it */
                struct net_device *ndev = priv->ndev;
                /* get the default rx queue index */
                u8 qindex = (u8)priv->gfargrp[0].rx_queue->qindex;
                u32 dest_mac_addr = (ndev->dev_addr[0] << 16) |
                                    (ndev->dev_addr[1] << 8) |
                                     ndev->dev_addr[2];

                rqfcr = (qindex << 10) | RQFCR_AND |
                        RQFCR_CMP_EXACT | RQFCR_PID_DAH;

                gfar_write_filer(priv, i++, rqfcr, dest_mac_addr);

                dest_mac_addr = (ndev->dev_addr[3] << 16) |
                                (ndev->dev_addr[4] << 8) |
                                 ndev->dev_addr[5];
                rqfcr = (qindex << 10) | RQFCR_GPI |
                        RQFCR_CMP_EXACT | RQFCR_PID_DAL;
                gfar_write_filer(priv, i++, rqfcr, dest_mac_addr);
        }

        __gfar_filer_enable(priv);
}

static void gfar_filer_restore_table(struct gfar_private *priv)
{
        u32 rqfcr, rqfpr;
        unsigned int i;

        __gfar_filer_disable(priv);

        for (i = 0; i <= MAX_FILER_IDX; i++) {
                rqfcr = priv->ftp_rqfcr[i];
                rqfpr = priv->ftp_rqfpr[i];
                gfar_write_filer(priv, i, rqfcr, rqfpr);
        }

        __gfar_filer_enable(priv);
}

/* gfar_start() for Rx only and with the FGPI filer interrupt enabled */
static void gfar_start_wol_filer(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 tempval;
        int i = 0;

        /* Enable Rx hw queues */
        gfar_write(&regs->rqueue, priv->rqueue);

        /* Initialize DMACTRL to have WWR and WOP */
        tempval = gfar_read(&regs->dmactrl);
        tempval |= DMACTRL_INIT_SETTINGS;
        gfar_write(&regs->dmactrl, tempval);

        /* Make sure we aren't stopped */
        tempval = gfar_read(&regs->dmactrl);
        tempval &= ~DMACTRL_GRS;
        gfar_write(&regs->dmactrl, tempval);

        for (i = 0; i < priv->num_grps; i++) {
                regs = priv->gfargrp[i].regs;
                /* Clear RHLT, so that the DMA starts polling now */
                gfar_write(&regs->rstat, priv->gfargrp[i].rstat);
                /* enable the Filer General Purpose Interrupt */
                gfar_write(&regs->imask, IMASK_FGPI);
        }

        /* Enable Rx DMA */
        tempval = gfar_read(&regs->maccfg1);
        tempval |= MACCFG1_RX_EN;
        gfar_write(&regs->maccfg1, tempval);
}

static int gfar_suspend(struct device *dev)
{
        struct gfar_private *priv = dev_get_drvdata(dev);
        struct net_device *ndev = priv->ndev;
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 tempval;
        u16 wol = priv->wol_opts;

        if (!netif_running(ndev))
                return 0;

        disable_napi(priv);
        netif_tx_lock(ndev);
        netif_device_detach(ndev);
        netif_tx_unlock(ndev);

        gfar_halt(priv);

        if (wol & GFAR_WOL_MAGIC) {
                /* Enable interrupt on Magic Packet */
                gfar_write(&regs->imask, IMASK_MAG);

                /* Enable Magic Packet mode */
                tempval = gfar_read(&regs->maccfg2);
                tempval |= MACCFG2_MPEN;
                gfar_write(&regs->maccfg2, tempval);

                /* re-enable the Rx block */
                tempval = gfar_read(&regs->maccfg1);
                tempval |= MACCFG1_RX_EN;
                gfar_write(&regs->maccfg1, tempval);

        } else if (wol & GFAR_WOL_FILER_UCAST) {
                gfar_filer_config_wol(priv);
                gfar_start_wol_filer(priv);

        } else {
                phy_stop(ndev->phydev);
        }

        return 0;
}

static int gfar_resume(struct device *dev)
{
        struct gfar_private *priv = dev_get_drvdata(dev);
        struct net_device *ndev = priv->ndev;
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 tempval;
        u16 wol = priv->wol_opts;

        if (!netif_running(ndev))
                return 0;

        if (wol & GFAR_WOL_MAGIC) {
                /* Disable Magic Packet mode */
                tempval = gfar_read(&regs->maccfg2);
                tempval &= ~MACCFG2_MPEN;
                gfar_write(&regs->maccfg2, tempval);

        } else if (wol & GFAR_WOL_FILER_UCAST) {
                /* need to stop rx only, tx is already down */
                gfar_halt(priv);
                gfar_filer_restore_table(priv);

        } else {
                phy_start(ndev->phydev);
        }

        gfar_start(priv);

        netif_device_attach(ndev);
        enable_napi(priv);

        return 0;
}

static int gfar_restore(struct device *dev)
{
        struct gfar_private *priv = dev_get_drvdata(dev);
        struct net_device *ndev = priv->ndev;

        if (!netif_running(ndev)) {
                netif_device_attach(ndev);

                return 0;
        }

        gfar_init_bds(ndev);

        gfar_mac_reset(priv);

        gfar_init_tx_rx_base(priv);

        gfar_start(priv);

        priv->oldlink = 0;
        priv->oldspeed = 0;
        priv->oldduplex = -1;

        if (ndev->phydev)
                phy_start(ndev->phydev);

        netif_device_attach(ndev);
        enable_napi(priv);

        return 0;
}

static const struct dev_pm_ops gfar_pm_ops = {
        .suspend = gfar_suspend,
        .resume = gfar_resume,
        .freeze = gfar_suspend,
        .thaw = gfar_resume,
        .restore = gfar_restore,
};

#define GFAR_PM_OPS (&gfar_pm_ops)

#else

#define GFAR_PM_OPS NULL

#endif

/* Reads the controller's registers to determine what interface
 * connects it to the PHY.
 */
static phy_interface_t gfar_get_interface(struct net_device *dev)
{
        struct gfar_private *priv = netdev_priv(dev);
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 ecntrl;

        ecntrl = gfar_read(&regs->ecntrl);

        if (ecntrl & ECNTRL_SGMII_MODE)
                return PHY_INTERFACE_MODE_SGMII;

        if (ecntrl & ECNTRL_TBI_MODE) {
                if (ecntrl & ECNTRL_REDUCED_MODE)
                        return PHY_INTERFACE_MODE_RTBI;
                else
                        return PHY_INTERFACE_MODE_TBI;
        }

        if (ecntrl & ECNTRL_REDUCED_MODE) {
                if (ecntrl & ECNTRL_REDUCED_MII_MODE) {
                        return PHY_INTERFACE_MODE_RMII;
                }
                else {
                        phy_interface_t interface = priv->interface;

                        /* This isn't autodetected right now, so it must
                         * be set by the device tree or platform code.
                         */
                        if (interface == PHY_INTERFACE_MODE_RGMII_ID)
                                return PHY_INTERFACE_MODE_RGMII_ID;

                        return PHY_INTERFACE_MODE_RGMII;
                }
        }

        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_GIGABIT)
                return PHY_INTERFACE_MODE_GMII;

        return PHY_INTERFACE_MODE_MII;
}


/* Initializes driver's PHY state, and attaches to the PHY.
 * Returns 0 on success.
 */
static int init_phy(struct net_device *dev)
{
        __ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
        struct gfar_private *priv = netdev_priv(dev);
        phy_interface_t interface;
        struct phy_device *phydev;
        struct ethtool_eee edata;

        linkmode_set_bit_array(phy_10_100_features_array,
                               ARRAY_SIZE(phy_10_100_features_array),
                               mask);
        linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, mask);
        linkmode_set_bit(ETHTOOL_LINK_MODE_MII_BIT, mask);
        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_GIGABIT)
                linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, mask);

        priv->oldlink = 0;
        priv->oldspeed = 0;
        priv->oldduplex = -1;

        interface = gfar_get_interface(dev);

        phydev = of_phy_connect(dev, priv->phy_node, &adjust_link, 0,
                                interface);
        if (!phydev) {
                dev_err(&dev->dev, "could not attach to PHY\n");
                return -ENODEV;
        }

        if (interface == PHY_INTERFACE_MODE_SGMII)
                gfar_configure_serdes(dev);

        /* Remove any features not supported by the controller */
        linkmode_and(phydev->supported, phydev->supported, mask);
        linkmode_copy(phydev->advertising, phydev->supported);

        /* Add support for flow control */
        phy_support_asym_pause(phydev);

        /* disable EEE autoneg, EEE not supported by eTSEC */
        memset(&edata, 0, sizeof(struct ethtool_eee));
        phy_ethtool_set_eee(phydev, &edata);

        return 0;
}

/* Initialize TBI PHY interface for communicating with the
 * SERDES lynx PHY on the chip.  We communicate with this PHY
 * through the MDIO bus on each controller, treating it as a
 * "normal" PHY at the address found in the TBIPA register.  We assume
 * that the TBIPA register is valid.  Either the MDIO bus code will set
 * it to a value that doesn't conflict with other PHYs on the bus, or the
 * value doesn't matter, as there are no other PHYs on the bus.
 */
static void gfar_configure_serdes(struct net_device *dev)
{
        struct gfar_private *priv = netdev_priv(dev);
        struct phy_device *tbiphy;

        if (!priv->tbi_node) {
                dev_warn(&dev->dev, "error: SGMII mode requires that the "
                                    "device tree specify a tbi-handle\n");
                return;
        }

        tbiphy = of_phy_find_device(priv->tbi_node);
        if (!tbiphy) {
                dev_err(&dev->dev, "error: Could not get TBI device\n");
                return;
        }

        /* If the link is already up, we must already be ok, and don't need to
         * configure and reset the TBI<->SerDes link.  Maybe U-Boot configured
         * everything for us?  Resetting it takes the link down and requires
         * several seconds for it to come back.
         */
        if (phy_read(tbiphy, MII_BMSR) & BMSR_LSTATUS) {
                put_device(&tbiphy->mdio.dev);
                return;
        }

        /* Single clk mode, mii mode off(for serdes communication) */
        phy_write(tbiphy, MII_TBICON, TBICON_CLK_SELECT);

        phy_write(tbiphy, MII_ADVERTISE,
                  ADVERTISE_1000XFULL | ADVERTISE_1000XPAUSE |
                  ADVERTISE_1000XPSE_ASYM);

        phy_write(tbiphy, MII_BMCR,
                  BMCR_ANENABLE | BMCR_ANRESTART | BMCR_FULLDPLX |
                  BMCR_SPEED1000);

        put_device(&tbiphy->mdio.dev);
}

static int __gfar_is_rx_idle(struct gfar_private *priv)
{
        u32 res;

        /* Normaly TSEC should not hang on GRS commands, so we should
         * actually wait for IEVENT_GRSC flag.
         */
        if (!gfar_has_errata(priv, GFAR_ERRATA_A002))
                return 0;

        /* Read the eTSEC register at offset 0xD1C. If bits 7-14 are
         * the same as bits 23-30, the eTSEC Rx is assumed to be idle
         * and the Rx can be safely reset.
         */
        res = gfar_read((void __iomem *)priv->gfargrp[0].regs + 0xd1c);
        res &= 0x7f807f80;
        if ((res & 0xffff) == (res >> 16))
                return 1;

        return 0;
}

/* Halt the receive and transmit queues */
static void gfar_halt_nodisable(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 tempval;
        unsigned int timeout;
        int stopped;

        gfar_ints_disable(priv);

        if (gfar_is_dma_stopped(priv))
                return;

        /* Stop the DMA, and wait for it to stop */
        tempval = gfar_read(&regs->dmactrl);
        tempval |= (DMACTRL_GRS | DMACTRL_GTS);
        gfar_write(&regs->dmactrl, tempval);

retry:
        timeout = 1000;
        while (!(stopped = gfar_is_dma_stopped(priv)) && timeout) {
                cpu_relax();
                timeout--;
        }

        if (!timeout)
                stopped = gfar_is_dma_stopped(priv);

        if (!stopped && !gfar_is_rx_dma_stopped(priv) &&
            !__gfar_is_rx_idle(priv))
                goto retry;
}

/* Halt the receive and transmit queues */
void gfar_halt(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 tempval;

        /* Dissable the Rx/Tx hw queues */
        gfar_write(&regs->rqueue, 0);
        gfar_write(&regs->tqueue, 0);

        mdelay(10);

        gfar_halt_nodisable(priv);

        /* Disable Rx/Tx DMA */
        tempval = gfar_read(&regs->maccfg1);
        tempval &= ~(MACCFG1_RX_EN | MACCFG1_TX_EN);
        gfar_write(&regs->maccfg1, tempval);
}

void stop_gfar(struct net_device *dev)
{
        struct gfar_private *priv = netdev_priv(dev);

        netif_tx_stop_all_queues(dev);

        smp_mb__before_atomic();
        set_bit(GFAR_DOWN, &priv->state);
        smp_mb__after_atomic();

        disable_napi(priv);

        /* disable ints and gracefully shut down Rx/Tx DMA */
        gfar_halt(priv);

        phy_stop(dev->phydev);

        free_skb_resources(priv);
}

static void free_skb_tx_queue(struct gfar_priv_tx_q *tx_queue)
{
        struct txbd8 *txbdp;
        struct gfar_private *priv = netdev_priv(tx_queue->dev);
        int i, j;

        txbdp = tx_queue->tx_bd_base;

        for (i = 0; i < tx_queue->tx_ring_size; i++) {
                if (!tx_queue->tx_skbuff[i])
                        continue;

                dma_unmap_single(priv->dev, be32_to_cpu(txbdp->bufPtr),
                                 be16_to_cpu(txbdp->length), DMA_TO_DEVICE);
                txbdp->lstatus = 0;
                for (j = 0; j < skb_shinfo(tx_queue->tx_skbuff[i])->nr_frags;
                     j++) {
                        txbdp++;
                        dma_unmap_page(priv->dev, be32_to_cpu(txbdp->bufPtr),
                                       be16_to_cpu(txbdp->length),
                                       DMA_TO_DEVICE);
                }
                txbdp++;
                dev_kfree_skb_any(tx_queue->tx_skbuff[i]);
                tx_queue->tx_skbuff[i] = NULL;
        }
        kfree(tx_queue->tx_skbuff);
        tx_queue->tx_skbuff = NULL;
}

static void free_skb_rx_queue(struct gfar_priv_rx_q *rx_queue)
{
        int i;

        struct rxbd8 *rxbdp = rx_queue->rx_bd_base;

        if (rx_queue->skb)
                dev_kfree_skb(rx_queue->skb);

        for (i = 0; i < rx_queue->rx_ring_size; i++) {
                struct  gfar_rx_buff *rxb = &rx_queue->rx_buff[i];

                rxbdp->lstatus = 0;
                rxbdp->bufPtr = 0;
                rxbdp++;

                if (!rxb->page)
                        continue;

                dma_unmap_page(rx_queue->dev, rxb->dma,
                               PAGE_SIZE, DMA_FROM_DEVICE);
                __free_page(rxb->page);

                rxb->page = NULL;
        }

        kfree(rx_queue->rx_buff);
        rx_queue->rx_buff = NULL;
}

/* If there are any tx skbs or rx skbs still around, free them.
 * Then free tx_skbuff and rx_skbuff
 */
static void free_skb_resources(struct gfar_private *priv)
{
        struct gfar_priv_tx_q *tx_queue = NULL;
        struct gfar_priv_rx_q *rx_queue = NULL;
        int i;

        /* Go through all the buffer descriptors and free their data buffers */
        for (i = 0; i < priv->num_tx_queues; i++) {
                struct netdev_queue *txq;

                tx_queue = priv->tx_queue[i];
                txq = netdev_get_tx_queue(tx_queue->dev, tx_queue->qindex);
                if (tx_queue->tx_skbuff)
                        free_skb_tx_queue(tx_queue);
                netdev_tx_reset_queue(txq);
        }

        for (i = 0; i < priv->num_rx_queues; i++) {
                rx_queue = priv->rx_queue[i];
                if (rx_queue->rx_buff)
                        free_skb_rx_queue(rx_queue);
        }

        dma_free_coherent(priv->dev,
                          sizeof(struct txbd8) * priv->total_tx_ring_size +
                          sizeof(struct rxbd8) * priv->total_rx_ring_size,
                          priv->tx_queue[0]->tx_bd_base,
                          priv->tx_queue[0]->tx_bd_dma_base);
}

void gfar_start(struct gfar_private *priv)
{
        struct gfar __iomem *regs = priv->gfargrp[0].regs;
        u32 tempval;
        int i = 0;

        /* Enable Rx/Tx hw queues */
        gfar_write(&regs->rqueue, priv->rqueue);
        gfar_write(&regs->tqueue, priv->tqueue);

        /* Initialize DMACTRL to have WWR and WOP */
        tempval = gfar_read(&regs->dmactrl);
        tempval |= DMACTRL_INIT_SETTINGS;
        gfar_write(&regs->dmactrl, tempval);

        /* Make sure we aren't stopped */
        tempval = gfar_read(&regs->dmactrl);
        tempval &= ~(DMACTRL_GRS | DMACTRL_GTS);
        gfar_write(&regs->dmactrl, tempval);

        for (i = 0; i < priv->num_grps; i++) {
                regs = priv->gfargrp[i].regs;
                /* Clear THLT/RHLT, so that the DMA starts polling now */
                gfar_write(&regs->tstat, priv->gfargrp[i].tstat);
                gfar_write(&regs->rstat, priv->gfargrp[i].rstat);
        }

        /* Enable Rx/Tx DMA */
        tempval = gfar_read(&regs->maccfg1);
        tempval |= (MACCFG1_RX_EN | MACCFG1_TX_EN);
        gfar_write(&regs->maccfg1, tempval);

        gfar_ints_enable(priv);

        netif_trans_update(priv->ndev); /* prevent tx timeout */
}

static void free_grp_irqs(struct gfar_priv_grp *grp)
{
        free_irq(gfar_irq(grp, TX)->irq, grp);
        free_irq(gfar_irq(grp, RX)->irq, grp);
        free_irq(gfar_irq(grp, ER)->irq, grp);
}

static int register_grp_irqs(struct gfar_priv_grp *grp)
{
        struct gfar_private *priv = grp->priv;
        struct net_device *dev = priv->ndev;
        int err;

        /* If the device has multiple interrupts, register for
         * them.  Otherwise, only register for the one
         */
        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_MULTI_INTR) {
                /* Install our interrupt handlers for Error,
                 * Transmit, and Receive
                 */
                err = request_irq(gfar_irq(grp, ER)->irq, gfar_error, 0,
                                  gfar_irq(grp, ER)->name, grp);
                if (err < 0) {
                        netif_err(priv, intr, dev, "Can't get IRQ %d\n",
                                  gfar_irq(grp, ER)->irq);

                        goto err_irq_fail;
                }
                enable_irq_wake(gfar_irq(grp, ER)->irq);

                err = request_irq(gfar_irq(grp, TX)->irq, gfar_transmit, 0,
                                  gfar_irq(grp, TX)->name, grp);
                if (err < 0) {
                        netif_err(priv, intr, dev, "Can't get IRQ %d\n",
                                  gfar_irq(grp, TX)->irq);
                        goto tx_irq_fail;
                }
                err = request_irq(gfar_irq(grp, RX)->irq, gfar_receive, 0,
                                  gfar_irq(grp, RX)->name, grp);
                if (err < 0) {
                        netif_err(priv, intr, dev, "Can't get IRQ %d\n",
                                  gfar_irq(grp, RX)->irq);
                        goto rx_irq_fail;
                }
                enable_irq_wake(gfar_irq(grp, RX)->irq);

        } else {
                err = request_irq(gfar_irq(grp, TX)->irq, gfar_interrupt, 0,
                                  gfar_irq(grp, TX)->name, grp);
                if (err < 0) {
                        netif_err(priv, intr, dev, "Can't get IRQ %d\n",
                                  gfar_irq(grp, TX)->irq);
                        goto err_irq_fail;
                }
                enable_irq_wake(gfar_irq(grp, TX)->irq);
        }

        return 0;

rx_irq_fail:
        free_irq(gfar_irq(grp, TX)->irq, grp);
tx_irq_fail:
        free_irq(gfar_irq(grp, ER)->irq, grp);
err_irq_fail:
        return err;

}

static void gfar_free_irq(struct gfar_private *priv)
{
        int i;

        /* Free the IRQs */
        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_MULTI_INTR) {
                for (i = 0; i < priv->num_grps; i++)
                        free_grp_irqs(&priv->gfargrp[i]);
        } else {
                for (i = 0; i < priv->num_grps; i++)
                        free_irq(gfar_irq(&priv->gfargrp[i], TX)->irq,
                                 &priv->gfargrp[i]);
        }
}

static int gfar_request_irq(struct gfar_private *priv)
{
        int err, i, j;

        for (i = 0; i < priv->num_grps; i++) {
                err = register_grp_irqs(&priv->gfargrp[i]);
                if (err) {
                        for (j = 0; j < i; j++)
                                free_grp_irqs(&priv->gfargrp[j]);
                        return err;
                }
        }

        return 0;
}

/* Bring the controller up and running */
int startup_gfar(struct net_device *ndev)
{
        struct gfar_private *priv = netdev_priv(ndev);
        int err;

        gfar_mac_reset(priv);

        err = gfar_alloc_skb_resources(ndev);
        if (err)
                return err;

        gfar_init_tx_rx_base(priv);

        smp_mb__before_atomic();
        clear_bit(GFAR_DOWN, &priv->state);
        smp_mb__after_atomic();

        /* Start Rx/Tx DMA and enable the interrupts */
        gfar_start(priv);

        /* force link state update after mac reset */
        priv->oldlink = 0;
        priv->oldspeed = 0;
        priv->oldduplex = -1;

        phy_start(ndev->phydev);

        enable_napi(priv);

        netif_tx_wake_all_queues(ndev);

        return 0;
}

/* Called when something needs to use the ethernet device
 * Returns 0 for success.
 */
static int gfar_enet_open(struct net_device *dev)
{
        struct gfar_private *priv = netdev_priv(dev);
        int err;

        err = init_phy(dev);
        if (err)
                return err;

        err = gfar_request_irq(priv);
        if (err)
                return err;

        err = startup_gfar(dev);
        if (err)
                return err;

        return err;
}

static inline struct txfcb *gfar_add_fcb(struct sk_buff *skb)
{
        struct txfcb *fcb = skb_push(skb, GMAC_FCB_LEN);

        memset(fcb, 0, GMAC_FCB_LEN);

        return fcb;
}

static inline void gfar_tx_checksum(struct sk_buff *skb, struct txfcb *fcb,
                                    int fcb_length)
{
        /* If we're here, it's a IP packet with a TCP or UDP
         * payload.  We set it to checksum, using a pseudo-header
         * we provide
         */
        u8 flags = TXFCB_DEFAULT;

        /* Tell the controller what the protocol is
         * And provide the already calculated phcs
         */
        if (ip_hdr(skb)->protocol == IPPROTO_UDP) {
                flags |= TXFCB_UDP;
                fcb->phcs = (__force __be16)(udp_hdr(skb)->check);
        } else
                fcb->phcs = (__force __be16)(tcp_hdr(skb)->check);

        /* l3os is the distance between the start of the
         * frame (skb->data) and the start of the IP hdr.
         * l4os is the distance between the start of the
         * l3 hdr and the l4 hdr
         */
        fcb->l3os = (u8)(skb_network_offset(skb) - fcb_length);
        fcb->l4os = skb_network_header_len(skb);

        fcb->flags = flags;
}

static inline void gfar_tx_vlan(struct sk_buff *skb, struct txfcb *fcb)
{
        fcb->flags |= TXFCB_VLN;
        fcb->vlctl = cpu_to_be16(skb_vlan_tag_get(skb));
}

static inline struct txbd8 *skip_txbd(struct txbd8 *bdp, int stride,
                                      struct txbd8 *base, int ring_size)
{
        struct txbd8 *new_bd = bdp + stride;

        return (new_bd >= (base + ring_size)) ? (new_bd - ring_size) : new_bd;
}

static inline struct txbd8 *next_txbd(struct txbd8 *bdp, struct txbd8 *base,
                                      int ring_size)
{
        return skip_txbd(bdp, 1, base, ring_size);
}

/* eTSEC12: csum generation not supported for some fcb offsets */
static inline bool gfar_csum_errata_12(struct gfar_private *priv,
                                       unsigned long fcb_addr)
{
        return (gfar_has_errata(priv, GFAR_ERRATA_12) &&
               (fcb_addr % 0x20) > 0x18);
}

/* eTSEC76: csum generation for frames larger than 2500 may
 * cause excess delays before start of transmission
 */
static inline bool gfar_csum_errata_76(struct gfar_private *priv,
                                       unsigned int len)
{
        return (gfar_has_errata(priv, GFAR_ERRATA_76) &&
               (len > 2500));
}

/* This is called by the kernel when a frame is ready for transmission.
 * It is pointed to by the dev->hard_start_xmit function pointer
 */
static netdev_tx_t gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct gfar_private *priv = netdev_priv(dev);
        struct gfar_priv_tx_q *tx_queue = NULL;
        struct netdev_queue *txq;
        struct gfar __iomem *regs = NULL;
        struct txfcb *fcb = NULL;
        struct txbd8 *txbdp, *txbdp_start, *base, *txbdp_tstamp = NULL;
        u32 lstatus;
        skb_frag_t *frag;
        int i, rq = 0;
        int do_tstamp, do_csum, do_vlan;
        u32 bufaddr;
        unsigned int nr_frags, nr_txbds, bytes_sent, fcb_len = 0;

        rq = skb->queue_mapping;
        tx_queue = priv->tx_queue[rq];
        txq = netdev_get_tx_queue(dev, rq);
        base = tx_queue->tx_bd_base;
        regs = tx_queue->grp->regs;

        do_csum = (CHECKSUM_PARTIAL == skb->ip_summed);
        do_vlan = skb_vlan_tag_present(skb);
        do_tstamp = (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
                    priv->hwts_tx_en;

        if (do_csum || do_vlan)
                fcb_len = GMAC_FCB_LEN;

        /* check if time stamp should be generated */
        if (unlikely(do_tstamp))
                fcb_len = GMAC_FCB_LEN + GMAC_TXPAL_LEN;

        /* make space for additional header when fcb is needed */
        if (fcb_len && unlikely(skb_headroom(skb) < fcb_len)) {
                struct sk_buff *skb_new;

                skb_new = skb_realloc_headroom(skb, fcb_len);
                if (!skb_new) {
                        dev->stats.tx_errors++;
                        dev_kfree_skb_any(skb);
                        return NETDEV_TX_OK;
                }

                if (skb->sk)
                        skb_set_owner_w(skb_new, skb->sk);
                dev_consume_skb_any(skb);
                skb = skb_new;
        }

        /* total number of fragments in the SKB */
        nr_frags = skb_shinfo(skb)->nr_frags;

        /* calculate the required number of TxBDs for this skb */
        if (unlikely(do_tstamp))
                nr_txbds = nr_frags + 2;
        else
                nr_txbds = nr_frags + 1;

        /* check if there is space to queue this packet */
        if (nr_txbds > tx_queue->num_txbdfree) {
                /* no space, stop the queue */
                netif_tx_stop_queue(txq);
                dev->stats.tx_fifo_errors++;
                return NETDEV_TX_BUSY;
        }

        /* Update transmit stats */
        bytes_sent = skb->len;
        tx_queue->stats.tx_bytes += bytes_sent;
        /* keep Tx bytes on wire for BQL accounting */
        GFAR_CB(skb)->bytes_sent = bytes_sent;
        tx_queue->stats.tx_packets++;

        txbdp = txbdp_start = tx_queue->cur_tx;
        lstatus = be32_to_cpu(txbdp->lstatus);

        /* Add TxPAL between FCB and frame if required */
        if (unlikely(do_tstamp)) {
                skb_push(skb, GMAC_TXPAL_LEN);
                memset(skb->data, 0, GMAC_TXPAL_LEN);
        }

        /* Add TxFCB if required */
        if (fcb_len) {
                fcb = gfar_add_fcb(skb);
                lstatus |= BD_LFLAG(TXBD_TOE);
        }

        /* Set up checksumming */
        if (do_csum) {
                gfar_tx_checksum(skb, fcb, fcb_len);

                if (unlikely(gfar_csum_errata_12(priv, (unsigned long)fcb)) ||
                    unlikely(gfar_csum_errata_76(priv, skb->len))) {
                        __skb_pull(skb, GMAC_FCB_LEN);
                        skb_checksum_help(skb);
                        if (do_vlan || do_tstamp) {
                                /* put back a new fcb for vlan/tstamp TOE */
                                fcb = gfar_add_fcb(skb);
                        } else {
                                /* Tx TOE not used */
                                lstatus &= ~(BD_LFLAG(TXBD_TOE));
                                fcb = NULL;
                        }
                }
        }

        if (do_vlan)
                gfar_tx_vlan(skb, fcb);

        bufaddr = dma_map_single(priv->dev, skb->data, skb_headlen(skb),
                                 DMA_TO_DEVICE);
        if (unlikely(dma_mapping_error(priv->dev, bufaddr)))
                goto dma_map_err;

        txbdp_start->bufPtr = cpu_to_be32(bufaddr);

        /* Time stamp insertion requires one additional TxBD */
        if (unlikely(do_tstamp))
                txbdp_tstamp = txbdp = next_txbd(txbdp, base,
                                                 tx_queue->tx_ring_size);

        if (likely(!nr_frags)) {
                if (likely(!do_tstamp))
                        lstatus |= BD_LFLAG(TXBD_LAST | TXBD_INTERRUPT);
        } else {
                u32 lstatus_start = lstatus;

                /* Place the fragment addresses and lengths into the TxBDs */
                frag = &skb_shinfo(skb)->frags[0];
                for (i = 0; i < nr_frags; i++, frag++) {
                        unsigned int size;

                        /* Point at the next BD, wrapping as needed */
                        txbdp = next_txbd(txbdp, base, tx_queue->tx_ring_size);

                        size = skb_frag_size(frag);

                        lstatus = be32_to_cpu(txbdp->lstatus) | size |
                                  BD_LFLAG(TXBD_READY);

                        /* Handle the last BD specially */
                        if (i == nr_frags - 1)
                                lstatus |= BD_LFLAG(TXBD_LAST | TXBD_INTERRUPT);

                        bufaddr = skb_frag_dma_map(priv->dev, frag, 0,
                                                   size, DMA_TO_DEVICE);
                        if (unlikely(dma_mapping_error(priv->dev, bufaddr)))
                                goto dma_map_err;

                        /* set the TxBD length and buffer pointer */
                        txbdp->bufPtr = cpu_to_be32(bufaddr);
                        txbdp->lstatus = cpu_to_be32(lstatus);
                }

                lstatus = lstatus_start;
        }

        /* If time stamping is requested one additional TxBD must be set up. The
         * first TxBD points to the FCB and must have a data length of
         * GMAC_FCB_LEN. The second TxBD points to the actual frame data with
         * the full frame length.
         */
        if (unlikely(do_tstamp)) {
                u32 lstatus_ts = be32_to_cpu(txbdp_tstamp->lstatus);

                bufaddr = be32_to_cpu(txbdp_start->bufPtr);
                bufaddr += fcb_len;

                lstatus_ts |= BD_LFLAG(TXBD_READY) |
                              (skb_headlen(skb) - fcb_len);
                if (!nr_frags)
                        lstatus_ts |= BD_LFLAG(TXBD_LAST | TXBD_INTERRUPT);

                txbdp_tstamp->bufPtr = cpu_to_be32(bufaddr);
                txbdp_tstamp->lstatus = cpu_to_be32(lstatus_ts);
                lstatus |= BD_LFLAG(TXBD_CRC | TXBD_READY) | GMAC_FCB_LEN;

                /* Setup tx hardware time stamping */
                skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
                fcb->ptp = 1;
        } else {
                lstatus |= BD_LFLAG(TXBD_CRC | TXBD_READY) | skb_headlen(skb);
        }

        netdev_tx_sent_queue(txq, bytes_sent);

        gfar_wmb();

        txbdp_start->lstatus = cpu_to_be32(lstatus);

        gfar_wmb(); /* force lstatus write before tx_skbuff */

        tx_queue->tx_skbuff[tx_queue->skb_curtx] = skb;

        /* Update the current skb pointer to the next entry we will use
         * (wrapping if necessary)
         */
        tx_queue->skb_curtx = (tx_queue->skb_curtx + 1) &
                              TX_RING_MOD_MASK(tx_queue->tx_ring_size);

        tx_queue->cur_tx = next_txbd(txbdp, base, tx_queue->tx_ring_size);

        /* We can work in parallel with gfar_clean_tx_ring(), except
         * when modifying num_txbdfree. Note that we didn't grab the lock
         * when we were reading the num_txbdfree and checking for available
         * space, that's because outside of this function it can only grow.
         */
        spin_lock_bh(&tx_queue->txlock);
        /* reduce TxBD free count */
        tx_queue->num_txbdfree -= (nr_txbds);
        spin_unlock_bh(&tx_queue->txlock);

        /* If the next BD still needs to be cleaned up, then the bds
         * are full.  We need to tell the kernel to stop sending us stuff.
         */
        if (!tx_queue->num_txbdfree) {
                netif_tx_stop_queue(txq);

                dev->stats.tx_fifo_errors++;
        }

        /* Tell the DMA to go go go */
        gfar_write(&regs->tstat, TSTAT_CLEAR_THALT >> tx_queue->qindex);

        return NETDEV_TX_OK;

dma_map_err:
        txbdp = next_txbd(txbdp_start, base, tx_queue->tx_ring_size);
        if (do_tstamp)
                txbdp = next_txbd(txbdp, base, tx_queue->tx_ring_size);
        for (i = 0; i < nr_frags; i++) {
                lstatus = be32_to_cpu(txbdp->lstatus);
                if (!(lstatus & BD_LFLAG(TXBD_READY)))
                        break;

                lstatus &= ~BD_LFLAG(TXBD_READY);
                txbdp->lstatus = cpu_to_be32(lstatus);
                bufaddr = be32_to_cpu(txbdp->bufPtr);
                dma_unmap_page(priv->dev, bufaddr, be16_to_cpu(txbdp->length),
                               DMA_TO_DEVICE);
                txbdp = next_txbd(txbdp, base, tx_queue->tx_ring_size);
        }
        gfar_wmb();
        dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
}

/* Stops the kernel queue, and halts the controller */
static int gfar_close(struct net_device *dev)
{
        struct gfar_private *priv = netdev_priv(dev);

        cancel_work_sync(&priv->reset_task);
        stop_gfar(dev);

        /* Disconnect from the PHY */
        phy_disconnect(dev->phydev);

        gfar_free_irq(priv);

        return 0;
}

/* Changes the mac address if the controller is not running. */
static int gfar_set_mac_address(struct net_device *dev)
{
        gfar_set_mac_for_addr(dev, 0, dev->dev_addr);

        return 0;
}

static int gfar_change_mtu(struct net_device *dev, int new_mtu)
{
        struct gfar_private *priv = netdev_priv(dev);

        while (test_and_set_bit_lock(GFAR_RESETTING, &priv->state))
                cpu_relax();

        if (dev->flags & IFF_UP)
                stop_gfar(dev);

        dev->mtu = new_mtu;

        if (dev->flags & IFF_UP)
                startup_gfar(dev);

        clear_bit_unlock(GFAR_RESETTING, &priv->state);

        return 0;
}

void reset_gfar(struct net_device *ndev)
{
        struct gfar_private *priv = netdev_priv(ndev);

        while (test_and_set_bit_lock(GFAR_RESETTING, &priv->state))
                cpu_relax();

        stop_gfar(ndev);
        startup_gfar(ndev);

        clear_bit_unlock(GFAR_RESETTING, &priv->state);
}

/* gfar_reset_task gets scheduled when a packet has not been
 * transmitted after a set amount of time.
 * For now, assume that clearing out all the structures, and
 * starting over will fix the problem.
 */
static void gfar_reset_task(struct work_struct *work)
{
        struct gfar_private *priv = container_of(work, struct gfar_private,
                                                 reset_task);
        reset_gfar(priv->ndev);
}

static void gfar_timeout(struct net_device *dev)
{
        struct gfar_private *priv = netdev_priv(dev);

        dev->stats.tx_errors++;
        schedule_work(&priv->reset_task);
}

/* Interrupt Handler for Transmit complete */
static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
{
        struct net_device *dev = tx_queue->dev;
        struct netdev_queue *txq;
        struct gfar_private *priv = netdev_priv(dev);
        struct txbd8 *bdp, *next = NULL;
        struct txbd8 *lbdp = NULL;
        struct txbd8 *base = tx_queue->tx_bd_base;
        struct sk_buff *skb;
        int skb_dirtytx;
        int tx_ring_size = tx_queue->tx_ring_size;
        int frags = 0, nr_txbds = 0;
        int i;
        int howmany = 0;
        int tqi = tx_queue->qindex;
        unsigned int bytes_sent = 0;
        u32 lstatus;
        size_t buflen;

        txq = netdev_get_tx_queue(dev, tqi);
        bdp = tx_queue->dirty_tx;
        skb_dirtytx = tx_queue->skb_dirtytx;

        while ((skb = tx_queue->tx_skbuff[skb_dirtytx])) {

                frags = skb_shinfo(skb)->nr_frags;

                /* When time stamping, one additional TxBD must be freed.
                 * Also, we need to dma_unmap_single() the TxPAL.
                 */
                if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
                        nr_txbds = frags + 2;
                else
                        nr_txbds = frags + 1;

                lbdp = skip_txbd(bdp, nr_txbds - 1, base, tx_ring_size);

                lstatus = be32_to_cpu(lbdp->lstatus);

                /* Only clean completed frames */
                if ((lstatus & BD_LFLAG(TXBD_READY)) &&
                    (lstatus & BD_LENGTH_MASK))
                        break;

                if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) {
                        next = next_txbd(bdp, base, tx_ring_size);
                        buflen = be16_to_cpu(next->length) +
                                 GMAC_FCB_LEN + GMAC_TXPAL_LEN;
                } else
                        buflen = be16_to_cpu(bdp->length);

                dma_unmap_single(priv->dev, be32_to_cpu(bdp->bufPtr),
                                 buflen, DMA_TO_DEVICE);

                if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) {
                        struct skb_shared_hwtstamps shhwtstamps;
                        u64 *ns = (u64 *)(((uintptr_t)skb->data + 0x10) &
                                          ~0x7UL);

                        memset(&shhwtstamps, 0, sizeof(shhwtstamps));
                        shhwtstamps.hwtstamp = ns_to_ktime(be64_to_cpu(*ns));
                        skb_pull(skb, GMAC_FCB_LEN + GMAC_TXPAL_LEN);
                        skb_tstamp_tx(skb, &shhwtstamps);
                        gfar_clear_txbd_status(bdp);
                        bdp = next;
                }

                gfar_clear_txbd_status(bdp);
                bdp = next_txbd(bdp, base, tx_ring_size);

                for (i = 0; i < frags; i++) {
                        dma_unmap_page(priv->dev, be32_to_cpu(bdp->bufPtr),
                                       be16_to_cpu(bdp->length),
                                       DMA_TO_DEVICE);
                        gfar_clear_txbd_status(bdp);
                        bdp = next_txbd(bdp, base, tx_ring_size);
                }

                bytes_sent += GFAR_CB(skb)->bytes_sent;

                dev_kfree_skb_any(skb);

                tx_queue->tx_skbuff[skb_dirtytx] = NULL;

                skb_dirtytx = (skb_dirtytx + 1) &
                              TX_RING_MOD_MASK(tx_ring_size);

                howmany++;
                spin_lock(&tx_queue->txlock);
                tx_queue->num_txbdfree += nr_txbds;
                spin_unlock(&tx_queue->txlock);
        }

        /* If we freed a buffer, we can restart transmission, if necessary */
        if (tx_queue->num_txbdfree &&
            netif_tx_queue_stopped(txq) &&
            !(test_bit(GFAR_DOWN, &priv->state)))
                netif_wake_subqueue(priv->ndev, tqi);

        /* Update dirty indicators */
        tx_queue->skb_dirtytx = skb_dirtytx;
        tx_queue->dirty_tx = bdp;

        netdev_tx_completed_queue(txq, howmany, bytes_sent);
}

static bool gfar_new_page(struct gfar_priv_rx_q *rxq, struct gfar_rx_buff *rxb)
{
        struct page *page;
        dma_addr_t addr;

        page = dev_alloc_page();
        if (unlikely(!page))
                return false;

        addr = dma_map_page(rxq->dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
        if (unlikely(dma_mapping_error(rxq->dev, addr))) {
                __free_page(page);

                return false;
        }

        rxb->dma = addr;
        rxb->page = page;
        rxb->page_offset = 0;

        return true;
}

static void gfar_rx_alloc_err(struct gfar_priv_rx_q *rx_queue)
{
        struct gfar_private *priv = netdev_priv(rx_queue->ndev);
        struct gfar_extra_stats *estats = &priv->extra_stats;

        netdev_err(rx_queue->ndev, "Can't alloc RX buffers\n");
        atomic64_inc(&estats->rx_alloc_err);
}

static void gfar_alloc_rx_buffs(struct gfar_priv_rx_q *rx_queue,
                                int alloc_cnt)
{
        struct rxbd8 *bdp;
        struct gfar_rx_buff *rxb;
        int i;

        i = rx_queue->next_to_use;
        bdp = &rx_queue->rx_bd_base[i];
        rxb = &rx_queue->rx_buff[i];

        while (alloc_cnt--) {
                /* try reuse page */
                if (unlikely(!rxb->page)) {
                        if (unlikely(!gfar_new_page(rx_queue, rxb))) {
                                gfar_rx_alloc_err(rx_queue);
                                break;
                        }
                }

                /* Setup the new RxBD */
                gfar_init_rxbdp(rx_queue, bdp,
                                rxb->dma + rxb->page_offset + RXBUF_ALIGNMENT);

                /* Update to the next pointer */
                bdp++;
                rxb++;

                if (unlikely(++i == rx_queue->rx_ring_size)) {
                        i = 0;
                        bdp = rx_queue->rx_bd_base;
                        rxb = rx_queue->rx_buff;
                }
        }

        rx_queue->next_to_use = i;
        rx_queue->next_to_alloc = i;
}

static void count_errors(u32 lstatus, struct net_device *ndev)
{
        struct gfar_private *priv = netdev_priv(ndev);
        struct net_device_stats *stats = &ndev->stats;
        struct gfar_extra_stats *estats = &priv->extra_stats;

        /* If the packet was truncated, none of the other errors matter */
        if (lstatus & BD_LFLAG(RXBD_TRUNCATED)) {
                stats->rx_length_errors++;

                atomic64_inc(&estats->rx_trunc);

                return;
        }
        /* Count the errors, if there were any */
        if (lstatus & BD_LFLAG(RXBD_LARGE | RXBD_SHORT)) {
                stats->rx_length_errors++;

                if (lstatus & BD_LFLAG(RXBD_LARGE))
                        atomic64_inc(&estats->rx_large);
                else
                        atomic64_inc(&estats->rx_short);
        }
        if (lstatus & BD_LFLAG(RXBD_NONOCTET)) {
                stats->rx_frame_errors++;
                atomic64_inc(&estats->rx_nonoctet);
        }
        if (lstatus & BD_LFLAG(RXBD_CRCERR)) {
                atomic64_inc(&estats->rx_crcerr);
                stats->rx_crc_errors++;
        }
        if (lstatus & BD_LFLAG(RXBD_OVERRUN)) {
                atomic64_inc(&estats->rx_overrun);
                stats->rx_over_errors++;
        }
}

irqreturn_t gfar_receive(int irq, void *grp_id)
{
        struct gfar_priv_grp *grp = (struct gfar_priv_grp *)grp_id;
        unsigned long flags;
        u32 imask, ievent;

        ievent = gfar_read(&grp->regs->ievent);

        if (unlikely(ievent & IEVENT_FGPI)) {
                gfar_write(&grp->regs->ievent, IEVENT_FGPI);
                return IRQ_HANDLED;
        }

        if (likely(napi_schedule_prep(&grp->napi_rx))) {
                spin_lock_irqsave(&grp->grplock, flags);
                imask = gfar_read(&grp->regs->imask);
                imask &= IMASK_RX_DISABLED;
                gfar_write(&grp->regs->imask, imask);
                spin_unlock_irqrestore(&grp->grplock, flags);
                __napi_schedule(&grp->napi_rx);
        } else {
                /* Clear IEVENT, so interrupts aren't called again
                 * because of the packets that have already arrived.
                 */
                gfar_write(&grp->regs->ievent, IEVENT_RX_MASK);
        }

        return IRQ_HANDLED;
}

/* Interrupt Handler for Transmit complete */
static irqreturn_t gfar_transmit(int irq, void *grp_id)
{
        struct gfar_priv_grp *grp = (struct gfar_priv_grp *)grp_id;
        unsigned long flags;
        u32 imask;

        if (likely(napi_schedule_prep(&grp->napi_tx))) {
                spin_lock_irqsave(&grp->grplock, flags);
                imask = gfar_read(&grp->regs->imask);
                imask &= IMASK_TX_DISABLED;
                gfar_write(&grp->regs->imask, imask);
                spin_unlock_irqrestore(&grp->grplock, flags);
                __napi_schedule(&grp->napi_tx);
        } else {
                /* Clear IEVENT, so interrupts aren't called again
                 * because of the packets that have already arrived.
                 */
                gfar_write(&grp->regs->ievent, IEVENT_TX_MASK);
        }

        return IRQ_HANDLED;
}

static bool gfar_add_rx_frag(struct gfar_rx_buff *rxb, u32 lstatus,
                             struct sk_buff *skb, bool first)
{
        int size = lstatus & BD_LENGTH_MASK;
        struct page *page = rxb->page;

        if (likely(first)) {
                skb_put(skb, size);
        } else {
                /* the last fragments' length contains the full frame length */
                if (lstatus & BD_LFLAG(RXBD_LAST))
                        size -= skb->len;

                skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
                                rxb->page_offset + RXBUF_ALIGNMENT,
                                size, GFAR_RXB_TRUESIZE);
        }

        /* try reuse page */
        if (unlikely(page_count(page) != 1 || page_is_pfmemalloc(page)))
                return false;

        /* change offset to the other half */
        rxb->page_offset ^= GFAR_RXB_TRUESIZE;

        page_ref_inc(page);

        return true;
}

static void gfar_reuse_rx_page(struct gfar_priv_rx_q *rxq,
                               struct gfar_rx_buff *old_rxb)
{
        struct gfar_rx_buff *new_rxb;
        u16 nta = rxq->next_to_alloc;

        new_rxb = &rxq->rx_buff[nta];

        /* find next buf that can reuse a page */
        nta++;
        rxq->next_to_alloc = (nta < rxq->rx_ring_size) ? nta : 0;

        /* copy page reference */
        *new_rxb = *old_rxb;

        /* sync for use by the device */
        dma_sync_single_range_for_device(rxq->dev, old_rxb->dma,
                                         old_rxb->page_offset,
                                         GFAR_RXB_TRUESIZE, DMA_FROM_DEVICE);
}

static struct sk_buff *gfar_get_next_rxbuff(struct gfar_priv_rx_q *rx_queue,
                                            u32 lstatus, struct sk_buff *skb)
{
        struct gfar_rx_buff *rxb = &rx_queue->rx_buff[rx_queue->next_to_clean];
        struct page *page = rxb->page;
        bool first = false;

        if (likely(!skb)) {
                void *buff_addr = page_address(page) + rxb->page_offset;

                skb = build_skb(buff_addr, GFAR_SKBFRAG_SIZE);
                if (unlikely(!skb)) {
                        gfar_rx_alloc_err(rx_queue);
                        return NULL;
                }
                skb_reserve(skb, RXBUF_ALIGNMENT);
                first = true;