ibmveth.c

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/*
 * IBM Power Virtual Ethernet Device Driver
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright (C) IBM Corporation, 2003, 2010
 *
 * Authors: Dave Larson <[email protected]>
 *      Santiago Leon <[email protected]>
 *      Brian King <[email protected]>
 *      Robert Jennings <[email protected]>
 *      Anton Blanchard <[email protected]>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/pm.h>
#include <linux/ethtool.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/slab.h>
#include <asm/hvcall.h>
#include <linux/atomic.h>
#include <asm/vio.h>
#include <asm/iommu.h>
#include <asm/firmware.h>

#include "ibmveth.h"

static irqreturn_t ibmveth_interrupt(int irq, void *dev_instance);
static void ibmveth_rxq_harvest_buffer(struct ibmveth_adapter *adapter);
static unsigned long ibmveth_get_desired_dma(struct vio_dev *vdev);

static struct kobj_type ktype_veth_pool;


static const char ibmveth_driver_name[] = "ibmveth";
static const char ibmveth_driver_string[] = "IBM Power Virtual Ethernet Driver";
#define ibmveth_driver_version "1.04"

MODULE_AUTHOR("Santiago Leon <[email protected]>");
MODULE_DESCRIPTION("IBM Power Virtual Ethernet Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(ibmveth_driver_version);

static unsigned int tx_copybreak __read_mostly = 128;
module_param(tx_copybreak, uint, 0644);
MODULE_PARM_DESC(tx_copybreak,
    "Maximum size of packet that is copied to a new buffer on transmit");

static unsigned int rx_copybreak __read_mostly = 128;
module_param(rx_copybreak, uint, 0644);
MODULE_PARM_DESC(rx_copybreak,
    "Maximum size of packet that is copied to a new buffer on receive");

static unsigned int rx_flush __read_mostly = 0;
module_param(rx_flush, uint, 0644);
MODULE_PARM_DESC(rx_flush, "Flush receive buffers before use");

struct ibmveth_stat {
    char name[ETH_GSTRING_LEN];
    int offset;
};

#define IBMVETH_STAT_OFF(stat) offsetof(struct ibmveth_adapter, stat)
#define IBMVETH_GET_STAT(a, off) *((u64 *)(((unsigned long)(a)) + off))

struct ibmveth_stat ibmveth_stats[] = {
    { "replenish_task_cycles", IBMVETH_STAT_OFF(replenish_task_cycles) },
    { "replenish_no_mem", IBMVETH_STAT_OFF(replenish_no_mem) },
    { "replenish_add_buff_failure",
            IBMVETH_STAT_OFF(replenish_add_buff_failure) },
    { "replenish_add_buff_success",
            IBMVETH_STAT_OFF(replenish_add_buff_success) },
    { "rx_invalid_buffer", IBMVETH_STAT_OFF(rx_invalid_buffer) },
    { "rx_no_buffer", IBMVETH_STAT_OFF(rx_no_buffer) },
    { "tx_map_failed", IBMVETH_STAT_OFF(tx_map_failed) },
    { "tx_send_failed", IBMVETH_STAT_OFF(tx_send_failed) },
    { "fw_enabled_ipv4_csum", IBMVETH_STAT_OFF(fw_ipv4_csum_support) },
    { "fw_enabled_ipv6_csum", IBMVETH_STAT_OFF(fw_ipv6_csum_support) },
};

/* simple methods of getting data from the current rxq entry */
static inline u32 ibmveth_rxq_flags(struct ibmveth_adapter *adapter)
{
    return adapter->rx_queue.queue_addr[adapter->rx_queue.index].flags_off;
}

static inline int ibmveth_rxq_toggle(struct ibmveth_adapter *adapter)
{
    return (ibmveth_rxq_flags(adapter) & IBMVETH_RXQ_TOGGLE) >>
            IBMVETH_RXQ_TOGGLE_SHIFT;
}

static inline int ibmveth_rxq_pending_buffer(struct ibmveth_adapter *adapter)
{
    return ibmveth_rxq_toggle(adapter) == adapter->rx_queue.toggle;
}

static inline int ibmveth_rxq_buffer_valid(struct ibmveth_adapter *adapter)
{
    return ibmveth_rxq_flags(adapter) & IBMVETH_RXQ_VALID;
}

static inline int ibmveth_rxq_frame_offset(struct ibmveth_adapter *adapter)
{
    return ibmveth_rxq_flags(adapter) & IBMVETH_RXQ_OFF_MASK;
}

static inline int ibmveth_rxq_frame_length(struct ibmveth_adapter *adapter)
{
    return adapter->rx_queue.queue_addr[adapter->rx_queue.index].length;
}

static inline int ibmveth_rxq_csum_good(struct ibmveth_adapter *adapter)
{
    return ibmveth_rxq_flags(adapter) & IBMVETH_RXQ_CSUM_GOOD;
}

/* setup the initial settings for a buffer pool */
static void ibmveth_init_buffer_pool(struct ibmveth_buff_pool *pool,
                     u32 pool_index, u32 pool_size,
                     u32 buff_size, u32 pool_active)
{
    pool->size = pool_size;
    pool->index = pool_index;
    pool->buff_size = buff_size;
    pool->threshold = pool_size * 7 / 8;
    pool->active = pool_active;
}

/* allocate and setup an buffer pool - called during open */
static int ibmveth_alloc_buffer_pool(struct ibmveth_buff_pool *pool)
{
    int i;

    pool->free_map = kmalloc(sizeof(u16) * pool->size, GFP_KERNEL);

    if (!pool->free_map)
        return -1;

    pool->dma_addr = kmalloc(sizeof(dma_addr_t) * pool->size, GFP_KERNEL);
    if (!pool->dma_addr) {
        kfree(pool->free_map);
        pool->free_map = NULL;
        return -1;
    }

    pool->skbuff = kcalloc(pool->size, sizeof(void *), GFP_KERNEL);

    if (!pool->skbuff) {
        kfree(pool->dma_addr);
        pool->dma_addr = NULL;

        kfree(pool->free_map);
        pool->free_map = NULL;
        return -1;
    }

    memset(pool->dma_addr, 0, sizeof(dma_addr_t) * pool->size);

    for (i = 0; i < pool->size; ++i)
        pool->free_map[i] = i;

    atomic_set(&pool->available, 0);
    pool->producer_index = 0;
    pool->consumer_index = 0;

    return 0;
}

static inline void ibmveth_flush_buffer(void *addr, unsigned long length)
{
    unsigned long offset;

    for (offset = 0; offset < length; offset += SMP_CACHE_BYTES)
        asm("dcbfl %0,%1" :: "b" (addr), "r" (offset));
}

/* replenish the buffers for a pool.  note that we don't need to
 * skb_reserve these since they are used for incoming...
 */
static void ibmveth_replenish_buffer_pool(struct ibmveth_adapter *adapter,
                      struct ibmveth_buff_pool *pool)
{
    u32 i;
    u32 count = pool->size - atomic_read(&pool->available);
    u32 buffers_added = 0;
    struct sk_buff *skb;
    unsigned int free_index, index;
    u64 correlator;
    unsigned long lpar_rc;
    dma_addr_t dma_addr;

    mb();

    for (i = 0; i < count; ++i) {
        union ibmveth_buf_desc desc;

        skb = netdev_alloc_skb(adapter->netdev, pool->buff_size);

        if (!skb) {
            netdev_dbg(adapter->netdev,
                   "replenish: unable to allocate skb\n");
            adapter->replenish_no_mem++;
            break;
        }

        free_index = pool->consumer_index;
        pool->consumer_index++;
        if (pool->consumer_index >= pool->size)
            pool->consumer_index = 0;
        index = pool->free_map[free_index];

        BUG_ON(index == IBM_VETH_INVALID_MAP);
        BUG_ON(pool->skbuff[index] != NULL);

        dma_addr = dma_map_single(&adapter->vdev->dev, skb->data,
                pool->buff_size, DMA_FROM_DEVICE);

        if (dma_mapping_error(&adapter->vdev->dev, dma_addr))
            goto failure;

        pool->free_map[free_index] = IBM_VETH_INVALID_MAP;
        pool->dma_addr[index] = dma_addr;
        pool->skbuff[index] = skb;

        correlator = ((u64)pool->index << 32) | index;
        *(u64 *)skb->data = correlator;

        desc.fields.flags_len = IBMVETH_BUF_VALID | pool->buff_size;
        desc.fields.address = dma_addr;

        if (rx_flush) {
            unsigned int len = min(pool->buff_size,
                        adapter->netdev->mtu +
                        IBMVETH_BUFF_OH);
            ibmveth_flush_buffer(skb->data, len);
        }
        lpar_rc = h_add_logical_lan_buffer(adapter->vdev->unit_address,
                           desc.desc);

        if (lpar_rc != H_SUCCESS) {
            goto failure;
        } else {
            buffers_added++;
            adapter->replenish_add_buff_success++;
        }
    }

    mb();
    atomic_add(buffers_added, &(pool->available));
    return;

failure:
    pool->free_map[free_index] = index;
    pool->skbuff[index] = NULL;
    if (pool->consumer_index == 0)
        pool->consumer_index = pool->size - 1;
    else
        pool->consumer_index--;
    if (!dma_mapping_error(&adapter->vdev->dev, dma_addr))
        dma_unmap_single(&adapter->vdev->dev,
                         pool->dma_addr[index], pool->buff_size,
                         DMA_FROM_DEVICE);
    dev_kfree_skb_any(skb);
    adapter->replenish_add_buff_failure++;

    mb();
    atomic_add(buffers_added, &(pool->available));
}

/* replenish routine */
static void ibmveth_replenish_task(struct ibmveth_adapter *adapter)
{
    int i;

    adapter->replenish_task_cycles++;

    for (i = (IBMVETH_NUM_BUFF_POOLS - 1); i >= 0; i--) {
        struct ibmveth_buff_pool *pool = &adapter->rx_buff_pool[i];

        if (pool->active &&
            (atomic_read(&pool->available) < pool->threshold))
            ibmveth_replenish_buffer_pool(adapter, pool);
    }

    adapter->rx_no_buffer = *(u64 *)(((char*)adapter->buffer_list_addr) +
                        4096 - 8);
}

/* empty and free ana buffer pool - also used to do cleanup in error paths */
static void ibmveth_free_buffer_pool(struct ibmveth_adapter *adapter,
                     struct ibmveth_buff_pool *pool)
{
    int i;

    kfree(pool->free_map);
    pool->free_map = NULL;

    if (pool->skbuff && pool->dma_addr) {
        for (i = 0; i < pool->size; ++i) {
            struct sk_buff *skb = pool->skbuff[i];
            if (skb) {
                dma_unmap_single(&adapter->vdev->dev,
                         pool->dma_addr[i],
                         pool->buff_size,
                         DMA_FROM_DEVICE);
                dev_kfree_skb_any(skb);
                pool->skbuff[i] = NULL;
            }
        }
    }

    if (pool->dma_addr) {
        kfree(pool->dma_addr);
        pool->dma_addr = NULL;
    }

    if (pool->skbuff) {
        kfree(pool->skbuff);
        pool->skbuff = NULL;
    }
}

/* remove a buffer from a pool */
static void ibmveth_remove_buffer_from_pool(struct ibmveth_adapter *adapter,
                        u64 correlator)
{
    unsigned int pool  = correlator >> 32;
    unsigned int index = correlator & 0xffffffffUL;
    unsigned int free_index;
    struct sk_buff *skb;

    BUG_ON(pool >= IBMVETH_NUM_BUFF_POOLS);
    BUG_ON(index >= adapter->rx_buff_pool[pool].size);

    skb = adapter->rx_buff_pool[pool].skbuff[index];

    BUG_ON(skb == NULL);

    adapter->rx_buff_pool[pool].skbuff[index] = NULL;

    dma_unmap_single(&adapter->vdev->dev,
             adapter->rx_buff_pool[pool].dma_addr[index],
             adapter->rx_buff_pool[pool].buff_size,
             DMA_FROM_DEVICE);

    free_index = adapter->rx_buff_pool[pool].producer_index;
    adapter->rx_buff_pool[pool].producer_index++;
    if (adapter->rx_buff_pool[pool].producer_index >=
        adapter->rx_buff_pool[pool].size)
        adapter->rx_buff_pool[pool].producer_index = 0;
    adapter->rx_buff_pool[pool].free_map[free_index] = index;

    mb();

    atomic_dec(&(adapter->rx_buff_pool[pool].available));
}

/* get the current buffer on the rx queue */
static inline struct sk_buff *ibmveth_rxq_get_buffer(struct ibmveth_adapter *adapter)
{
    u64 correlator = adapter->rx_queue.queue_addr[adapter->rx_queue.index].correlator;
    unsigned int pool = correlator >> 32;
    unsigned int index = correlator & 0xffffffffUL;

    BUG_ON(pool >= IBMVETH_NUM_BUFF_POOLS);
    BUG_ON(index >= adapter->rx_buff_pool[pool].size);

    return adapter->rx_buff_pool[pool].skbuff[index];
}

/* recycle the current buffer on the rx queue */
static int ibmveth_rxq_recycle_buffer(struct ibmveth_adapter *adapter)
{
    u32 q_index = adapter->rx_queue.index;
    u64 correlator = adapter->rx_queue.queue_addr[q_index].correlator;
    unsigned int pool = correlator >> 32;
    unsigned int index = correlator & 0xffffffffUL;
    union ibmveth_buf_desc desc;
    unsigned long lpar_rc;
    int ret = 1;

    BUG_ON(pool >= IBMVETH_NUM_BUFF_POOLS);
    BUG_ON(index >= adapter->rx_buff_pool[pool].size);

    if (!adapter->rx_buff_pool[pool].active) {
        ibmveth_rxq_harvest_buffer(adapter);
        ibmveth_free_buffer_pool(adapter, &adapter->rx_buff_pool[pool]);
        goto out;
    }

    desc.fields.flags_len = IBMVETH_BUF_VALID |
        adapter->rx_buff_pool[pool].buff_size;
    desc.fields.address = adapter->rx_buff_pool[pool].dma_addr[index];

    lpar_rc = h_add_logical_lan_buffer(adapter->vdev->unit_address, desc.desc);

    if (lpar_rc != H_SUCCESS) {
        netdev_dbg(adapter->netdev, "h_add_logical_lan_buffer failed "
               "during recycle rc=%ld", lpar_rc);
        ibmveth_remove_buffer_from_pool(adapter, adapter->rx_queue.queue_addr[adapter->rx_queue.index].correlator);
        ret = 0;
    }

    if (++adapter->rx_queue.index == adapter->rx_queue.num_slots) {
        adapter->rx_queue.index = 0;
        adapter->rx_queue.toggle = !adapter->rx_queue.toggle;
    }

out:
    return ret;
}

static void ibmveth_rxq_harvest_buffer(struct ibmveth_adapter *adapter)
{
    ibmveth_remove_buffer_from_pool(adapter, adapter->rx_queue.queue_addr[adapter->rx_queue.index].correlator);

    if (++adapter->rx_queue.index == adapter->rx_queue.num_slots) {
        adapter->rx_queue.index = 0;
        adapter->rx_queue.toggle = !adapter->rx_queue.toggle;
    }
}

static void ibmveth_cleanup(struct ibmveth_adapter *adapter)
{
    int i;
    struct device *dev = &adapter->vdev->dev;

    if (adapter->buffer_list_addr != NULL) {
        if (!dma_mapping_error(dev, adapter->buffer_list_dma)) {
            dma_unmap_single(dev, adapter->buffer_list_dma, 4096,
                    DMA_BIDIRECTIONAL);
            adapter->buffer_list_dma = DMA_ERROR_CODE;
        }
        free_page((unsigned long)adapter->buffer_list_addr);
        adapter->buffer_list_addr = NULL;
    }

    if (adapter->filter_list_addr != NULL) {
        if (!dma_mapping_error(dev, adapter->filter_list_dma)) {
            dma_unmap_single(dev, adapter->filter_list_dma, 4096,
                    DMA_BIDIRECTIONAL);
            adapter->filter_list_dma = DMA_ERROR_CODE;
        }
        free_page((unsigned long)adapter->filter_list_addr);
        adapter->filter_list_addr = NULL;
    }

    if (adapter->rx_queue.queue_addr != NULL) {
        dma_free_coherent(dev, adapter->rx_queue.queue_len,
                  adapter->rx_queue.queue_addr,
                  adapter->rx_queue.queue_dma);
        adapter->rx_queue.queue_addr = NULL;
    }

    for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
        if (adapter->rx_buff_pool[i].active)
            ibmveth_free_buffer_pool(adapter,
                         &adapter->rx_buff_pool[i]);

    if (adapter->bounce_buffer != NULL) {
        if (!dma_mapping_error(dev, adapter->bounce_buffer_dma)) {
            dma_unmap_single(&adapter->vdev->dev,
                    adapter->bounce_buffer_dma,
                    adapter->netdev->mtu + IBMVETH_BUFF_OH,
                    DMA_BIDIRECTIONAL);
            adapter->bounce_buffer_dma = DMA_ERROR_CODE;
        }
        kfree(adapter->bounce_buffer);
        adapter->bounce_buffer = NULL;
    }
}

static int ibmveth_register_logical_lan(struct ibmveth_adapter *adapter,
        union ibmveth_buf_desc rxq_desc, u64 mac_address)
{
    int rc, try_again = 1;

    /*
     * After a kexec the adapter will still be open, so our attempt to
     * open it will fail. So if we get a failure we free the adapter and
     * try again, but only once.
     */
retry:
    rc = h_register_logical_lan(adapter->vdev->unit_address,
                    adapter->buffer_list_dma, rxq_desc.desc,
                    adapter->filter_list_dma, mac_address);

    if (rc != H_SUCCESS && try_again) {
        do {
            rc = h_free_logical_lan(adapter->vdev->unit_address);
        } while (H_IS_LONG_BUSY(rc) || (rc == H_BUSY));

        try_again = 0;
        goto retry;
    }

    return rc;
}

static int ibmveth_open(struct net_device *netdev)
{
    struct ibmveth_adapter *adapter = netdev_priv(netdev);
    u64 mac_address = 0;
    int rxq_entries = 1;
    unsigned long lpar_rc;
    int rc;
    union ibmveth_buf_desc rxq_desc;
    int i;
    struct device *dev;

    netdev_dbg(netdev, "open starting\n");

    napi_enable(&adapter->napi);

    for(i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
        rxq_entries += adapter->rx_buff_pool[i].size;

    adapter->buffer_list_addr = (void*) get_zeroed_page(GFP_KERNEL);
    adapter->filter_list_addr = (void*) get_zeroed_page(GFP_KERNEL);

    if (!adapter->buffer_list_addr || !adapter->filter_list_addr) {
        netdev_err(netdev, "unable to allocate filter or buffer list "
               "pages\n");
        rc = -ENOMEM;
        goto err_out;
    }

    dev = &adapter->vdev->dev;

    adapter->rx_queue.queue_len = sizeof(struct ibmveth_rx_q_entry) *
                        rxq_entries;
    adapter->rx_queue.queue_addr =
        dma_alloc_coherent(dev, adapter->rx_queue.queue_len,
                   &adapter->rx_queue.queue_dma, GFP_KERNEL);

    if (!adapter->rx_queue.queue_addr) {
        netdev_err(netdev, "unable to allocate rx queue pages\n");
        rc = -ENOMEM;
        goto err_out;
    }

    adapter->buffer_list_dma = dma_map_single(dev,
            adapter->buffer_list_addr, 4096, DMA_BIDIRECTIONAL);
    adapter->filter_list_dma = dma_map_single(dev,
            adapter->filter_list_addr, 4096, DMA_BIDIRECTIONAL);

    if ((dma_mapping_error(dev, adapter->buffer_list_dma)) ||
        (dma_mapping_error(dev, adapter->filter_list_dma))) {
        netdev_err(netdev, "unable to map filter or buffer list "
               "pages\n");
        rc = -ENOMEM;
        goto err_out;
    }

    adapter->rx_queue.index = 0;
    adapter->rx_queue.num_slots = rxq_entries;
    adapter->rx_queue.toggle = 1;

    memcpy(&mac_address, netdev->dev_addr, netdev->addr_len);
    mac_address = mac_address >> 16;

    rxq_desc.fields.flags_len = IBMVETH_BUF_VALID |
                    adapter->rx_queue.queue_len;
    rxq_desc.fields.address = adapter->rx_queue.queue_dma;

    netdev_dbg(netdev, "buffer list @ 0x%p\n", adapter->buffer_list_addr);
    netdev_dbg(netdev, "filter list @ 0x%p\n", adapter->filter_list_addr);
    netdev_dbg(netdev, "receive q   @ 0x%p\n", adapter->rx_queue.queue_addr);

    h_vio_signal(adapter->vdev->unit_address, VIO_IRQ_DISABLE);

    lpar_rc = ibmveth_register_logical_lan(adapter, rxq_desc, mac_address);

    if (lpar_rc != H_SUCCESS) {
        netdev_err(netdev, "h_register_logical_lan failed with %ld\n",
               lpar_rc);
        netdev_err(netdev, "buffer TCE:0x%llx filter TCE:0x%llx rxq "
               "desc:0x%llx MAC:0x%llx\n",
                     adapter->buffer_list_dma,
                     adapter->filter_list_dma,
                     rxq_desc.desc,
                     mac_address);
        rc = -ENONET;
        goto err_out;
    }

    for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
        if (!adapter->rx_buff_pool[i].active)
            continue;
        if (ibmveth_alloc_buffer_pool(&adapter->rx_buff_pool[i])) {
            netdev_err(netdev, "unable to alloc pool\n");
            adapter->rx_buff_pool[i].active = 0;
            rc = -ENOMEM;
            goto err_out;
        }
    }

    netdev_dbg(netdev, "registering irq 0x%x\n", netdev->irq);
    rc = request_irq(netdev->irq, ibmveth_interrupt, 0, netdev->name,
             netdev);
    if (rc != 0) {
        netdev_err(netdev, "unable to request irq 0x%x, rc %d\n",
               netdev->irq, rc);
        do {
            lpar_rc = h_free_logical_lan(adapter->vdev->unit_address);
        } while (H_IS_LONG_BUSY(lpar_rc) || (lpar_rc == H_BUSY));

        goto err_out;
    }

    adapter->bounce_buffer =
        kmalloc(netdev->mtu + IBMVETH_BUFF_OH, GFP_KERNEL);
    if (!adapter->bounce_buffer) {
        netdev_err(netdev, "unable to allocate bounce buffer\n");
        rc = -ENOMEM;
        goto err_out_free_irq;
    }
    adapter->bounce_buffer_dma =
        dma_map_single(&adapter->vdev->dev, adapter->bounce_buffer,
               netdev->mtu + IBMVETH_BUFF_OH, DMA_BIDIRECTIONAL);
    if (dma_mapping_error(dev, adapter->bounce_buffer_dma)) {
        netdev_err(netdev, "unable to map bounce buffer\n");
        rc = -ENOMEM;
        goto err_out_free_irq;
    }

    netdev_dbg(netdev, "initial replenish cycle\n");
    ibmveth_interrupt(netdev->irq, netdev);

    netif_start_queue(netdev);

    netdev_dbg(netdev, "open complete\n");

    return 0;

err_out_free_irq:
    free_irq(netdev->irq, netdev);
err_out:
    ibmveth_cleanup(adapter);
    napi_disable(&adapter->napi);
    return rc;
}

static int ibmveth_close(struct net_device *netdev)
{
    struct ibmveth_adapter *adapter = netdev_priv(netdev);
    long lpar_rc;

    netdev_dbg(netdev, "close starting\n");

    napi_disable(&adapter->napi);

    if (!adapter->pool_config)
        netif_stop_queue(netdev);

    h_vio_signal(adapter->vdev->unit_address, VIO_IRQ_DISABLE);

    do {
        lpar_rc = h_free_logical_lan(adapter->vdev->unit_address);
    } while (H_IS_LONG_BUSY(lpar_rc) || (lpar_rc == H_BUSY));

    if (lpar_rc != H_SUCCESS) {
        netdev_err(netdev, "h_free_logical_lan failed with %lx, "
               "continuing with close\n", lpar_rc);
    }

    free_irq(netdev->irq, netdev);

    adapter->rx_no_buffer = *(u64 *)(((char *)adapter->buffer_list_addr) +
                        4096 - 8);

    ibmveth_cleanup(adapter);

    netdev_dbg(netdev, "close complete\n");

    return 0;
}

static int netdev_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
    cmd->supported = (SUPPORTED_1000baseT_Full | SUPPORTED_Autoneg |
                SUPPORTED_FIBRE);
    cmd->advertising = (ADVERTISED_1000baseT_Full | ADVERTISED_Autoneg |
                ADVERTISED_FIBRE);
    ethtool_cmd_speed_set(cmd, SPEED_1000);
    cmd->duplex = DUPLEX_FULL;
    cmd->port = PORT_FIBRE;
    cmd->phy_address = 0;
    cmd->transceiver = XCVR_INTERNAL;
    cmd->autoneg = AUTONEG_ENABLE;
    cmd->maxtxpkt = 0;
    cmd->maxrxpkt = 1;
    return 0;
}

static void netdev_get_drvinfo(struct net_device *dev,
                   struct ethtool_drvinfo *info)
{
    strncpy(info->driver, ibmveth_driver_name, sizeof(info->driver) - 1);
    strncpy(info->version, ibmveth_driver_version,
        sizeof(info->version) - 1);
}

static netdev_features_t ibmveth_fix_features(struct net_device *dev,
    netdev_features_t features)
{
    /*
     * Since the ibmveth firmware interface does not have the
     * concept of separate tx/rx checksum offload enable, if rx
     * checksum is disabled we also have to disable tx checksum
     * offload. Once we disable rx checksum offload, we are no
     * longer allowed to send tx buffers that are not properly
     * checksummed.
     */

    if (!(features & NETIF_F_RXCSUM))
        features &= ~NETIF_F_ALL_CSUM;

    return features;
}

static int ibmveth_set_csum_offload(struct net_device *dev, u32 data)
{
    struct ibmveth_adapter *adapter = netdev_priv(dev);
    unsigned long set_attr, clr_attr, ret_attr;
    unsigned long set_attr6, clr_attr6;
    long ret, ret4, ret6;
    int rc1 = 0, rc2 = 0;
    int restart = 0;

    if (netif_running(dev)) {
        restart = 1;
        adapter->pool_config = 1;
        ibmveth_close(dev);
        adapter->pool_config = 0;
    }

    set_attr = 0;
    clr_attr = 0;
    set_attr6 = 0;
    clr_attr6 = 0;

    if (data) {
        set_attr = IBMVETH_ILLAN_IPV4_TCP_CSUM;
        set_attr6 = IBMVETH_ILLAN_IPV6_TCP_CSUM;
    } else {
        clr_attr = IBMVETH_ILLAN_IPV4_TCP_CSUM;
        clr_attr6 = IBMVETH_ILLAN_IPV6_TCP_CSUM;
    }

    ret = h_illan_attributes(adapter->vdev->unit_address, 0, 0, &ret_attr);

    if (ret == H_SUCCESS && !(ret_attr & IBMVETH_ILLAN_ACTIVE_TRUNK) &&
        !(ret_attr & IBMVETH_ILLAN_TRUNK_PRI_MASK) &&
        (ret_attr & IBMVETH_ILLAN_PADDED_PKT_CSUM)) {
        ret4 = h_illan_attributes(adapter->vdev->unit_address, clr_attr,
                     set_attr, &ret_attr);

        if (ret4 != H_SUCCESS) {
            netdev_err(dev, "unable to change IPv4 checksum "
                    "offload settings. %d rc=%ld\n",
                    data, ret4);

            h_illan_attributes(adapter->vdev->unit_address,
                       set_attr, clr_attr, &ret_attr);

            if (data == 1)
                dev->features &= ~NETIF_F_IP_CSUM;

        } else {
            adapter->fw_ipv4_csum_support = data;
        }

        ret6 = h_illan_attributes(adapter->vdev->unit_address,
                     clr_attr6, set_attr6, &ret_attr);

        if (ret6 != H_SUCCESS) {
            netdev_err(dev, "unable to change IPv6 checksum "
                    "offload settings. %d rc=%ld\n",
                    data, ret6);

            h_illan_attributes(adapter->vdev->unit_address,
                       set_attr6, clr_attr6, &ret_attr);

            if (data == 1)
                dev->features &= ~NETIF_F_IPV6_CSUM;

        } else
            adapter->fw_ipv6_csum_support = data;

        if (ret4 == H_SUCCESS || ret6 == H_SUCCESS)
            adapter->rx_csum = data;
        else
            rc1 = -EIO;
    } else {
        rc1 = -EIO;
        netdev_err(dev, "unable to change checksum offload settings."
                     " %d rc=%ld ret_attr=%lx\n", data, ret,
                     ret_attr);
    }

    if (restart)
        rc2 = ibmveth_open(dev);

    return rc1 ? rc1 : rc2;
}

static int ibmveth_set_features(struct net_device *dev,
    netdev_features_t features)
{
    struct ibmveth_adapter *adapter = netdev_priv(dev);
    int rx_csum = !!(features & NETIF_F_RXCSUM);
    int rc;

    if (rx_csum == adapter->rx_csum)
        return 0;

    rc = ibmveth_set_csum_offload(dev, rx_csum);
    if (rc && !adapter->rx_csum)
        dev->features = features & ~(NETIF_F_ALL_CSUM | NETIF_F_RXCSUM);

    return rc;
}

static void ibmveth_get_strings(struct net_device *dev, u32 stringset, u8 *data)
{
    int i;

    if (stringset != ETH_SS_STATS)
        return;

    for (i = 0; i < ARRAY_SIZE(ibmveth_stats); i++, data += ETH_GSTRING_LEN)
        memcpy(data, ibmveth_stats[i].name, ETH_GSTRING_LEN);
}

static int ibmveth_get_sset_count(struct net_device *dev, int sset)
{
    switch (sset) {
    case ETH_SS_STATS:
        return ARRAY_SIZE(ibmveth_stats);
    default:
        return -EOPNOTSUPP;
    }
}

static void ibmveth_get_ethtool_stats(struct net_device *dev,
                      struct ethtool_stats *stats, u64 *data)
{
    int i;
    struct ibmveth_adapter *adapter = netdev_priv(dev);

    for (i = 0; i < ARRAY_SIZE(ibmveth_stats); i++)
        data[i] = IBMVETH_GET_STAT(adapter, ibmveth_stats[i].offset);
}

static const struct ethtool_ops netdev_ethtool_ops = {
    .get_drvinfo        = netdev_get_drvinfo,
    .get_settings       = netdev_get_settings,
    .get_link       = ethtool_op_get_link,
    .get_strings        = ibmveth_get_strings,
    .get_sset_count     = ibmveth_get_sset_count,
    .get_ethtool_stats  = ibmveth_get_ethtool_stats,
};

static int ibmveth_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
    return -EOPNOTSUPP;
}

#define page_offset(v) ((unsigned long)(v) & ((1 << 12) - 1))

static int ibmveth_send(struct ibmveth_adapter *adapter,
            union ibmveth_buf_desc *descs)
{
    unsigned long correlator;
    unsigned int retry_count;
    unsigned long ret;

    /*
     * The retry count sets a maximum for the number of broadcast and
     * multicast destinations within the system.
     */
    retry_count = 1024;
    correlator = 0;
    do {
        ret = h_send_logical_lan(adapter->vdev->unit_address,
                         descs[0].desc, descs[1].desc,
                         descs[2].desc, descs[3].desc,
                         descs[4].desc, descs[5].desc,
                         correlator, &correlator);
    } while ((ret == H_BUSY) && (retry_count--));

    if (ret != H_SUCCESS && ret != H_DROPPED) {
        netdev_err(adapter->netdev, "tx: h_send_logical_lan failed "
               "with rc=%ld\n", ret);
        return 1;
    }

    return 0;
}

static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
                      struct net_device *netdev)
{
    struct ibmveth_adapter *adapter = netdev_priv(netdev);
    unsigned int desc_flags;
    union ibmveth_buf_desc descs[6];
    int last, i;
    int force_bounce = 0;
    dma_addr_t dma_addr;

    /*
     * veth handles a maximum of 6 segments including the header, so
     * we have to linearize the skb if there are more than this.
     */
    if (skb_shinfo(skb)->nr_frags > 5 && __skb_linearize(skb)) {
        netdev->stats.tx_dropped++;
        goto out;
    }

    /* veth can't checksum offload UDP */
    if (skb->ip_summed == CHECKSUM_PARTIAL &&
        ((skb->protocol == htons(ETH_P_IP) &&
          ip_hdr(skb)->protocol != IPPROTO_TCP) ||
         (skb->protocol == htons(ETH_P_IPV6) &&
          ipv6_hdr(skb)->nexthdr != IPPROTO_TCP)) &&
        skb_checksum_help(skb)) {

        netdev_err(netdev, "tx: failed to checksum packet\n");
        netdev->stats.tx_dropped++;
        goto out;
    }

    desc_flags = IBMVETH_BUF_VALID;

    if (skb->ip_summed == CHECKSUM_PARTIAL) {
        unsigned char *buf = skb_transport_header(skb) +
                        skb->csum_offset;

        desc_flags |= (IBMVETH_BUF_NO_CSUM | IBMVETH_BUF_CSUM_GOOD);

        /* Need to zero out the checksum */
        buf[0] = 0;
        buf[1] = 0;
    }

retry_bounce:
    memset(descs, 0, sizeof(descs));

    /*
     * If a linear packet is below the rx threshold then
     * copy it into the static bounce buffer. This avoids the
     * cost of a TCE insert and remove.
     */
    if (force_bounce || (!skb_is_nonlinear(skb) &&
                (skb->len < tx_copybreak))) {
        skb_copy_from_linear_data(skb, adapter->bounce_buffer,
                      skb->len);

        descs[0].fields.flags_len = desc_flags | skb->len;
        descs[0].fields.address = adapter->bounce_buffer_dma;

        if (ibmveth_send(adapter, descs)) {
            adapter->tx_send_failed++;
            netdev->stats.tx_dropped++;
        } else {
            netdev->stats.tx_packets++;
            netdev->stats.tx_bytes += skb->len;
        }

        goto out;
    }

    /* Map the header */
    dma_addr = dma_map_single(&adapter->vdev->dev, skb->data,
                  skb_headlen(skb), DMA_TO_DEVICE);
    if (dma_mapping_error(&adapter->vdev->dev, dma_addr))
        goto map_failed;

    descs[0].fields.flags_len = desc_flags | skb_headlen(skb);
    descs[0].fields.address = dma_addr;

    /* Map the frags */
    for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
        const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];

        dma_addr = skb_frag_dma_map(&adapter->vdev->dev, frag, 0,
                        skb_frag_size(frag), DMA_TO_DEVICE);

        if (dma_mapping_error(&adapter->vdev->dev, dma_addr))
            goto map_failed_frags;

        descs[i+1].fields.flags_len = desc_flags | skb_frag_size(frag);
        descs[i+1].fields.address = dma_addr;
    }

    if (ibmveth_send(adapter, descs)) {
        adapter->tx_send_failed++;
        netdev->stats.tx_dropped++;
    } else {
        netdev->stats.tx_packets++;
        netdev->stats.tx_bytes += skb->len;
    }

    dma_unmap_single(&adapter->vdev->dev,
             descs[0].fields.address,
             descs[0].fields.flags_len & IBMVETH_BUF_LEN_MASK,
             DMA_TO_DEVICE);

    for (i = 1; i < skb_shinfo(skb)->nr_frags + 1; i++)
        dma_unmap_page(&adapter->vdev->dev, descs[i].fields.address,
                   descs[i].fields.flags_len & IBMVETH_BUF_LEN_MASK,
                   DMA_TO_DEVICE);

out:
    dev_kfree_skb(skb);
    return NETDEV_TX_OK;

map_failed_frags:
    last = i+1;
    for (i = 0; i < last; i++)
        dma_unmap_page(&adapter->vdev->dev, descs[i].fields.address,
                   descs[i].fields.flags_len & IBMVETH_BUF_LEN_MASK,
                   DMA_TO_DEVICE);

map_failed:
    if (!firmware_has_feature(FW_FEATURE_CMO))
        netdev_err(netdev, "tx: unable to map xmit buffer\n");
    adapter->tx_map_failed++;
    skb_linearize(skb);
    force_bounce = 1;
    goto retry_bounce;
}

static int ibmveth_poll(struct napi_struct *napi, int budget)
{
    struct ibmveth_adapter *adapter =
            container_of(napi, struct ibmveth_adapter, napi);
    struct net_device *netdev = adapter->netdev;
    int frames_processed = 0;
    unsigned long lpar_rc;

restart_poll:
    do {
        if (!ibmveth_rxq_pending_buffer(adapter))
            break;

        smp_rmb();
        if (!ibmveth_rxq_buffer_valid(adapter)) {
            wmb(); /* suggested by larson1 */
            adapter->rx_invalid_buffer++;
            netdev_dbg(netdev, "recycling invalid buffer\n");
            ibmveth_rxq_recycle_buffer(adapter);
        } else {
            struct sk_buff *skb, *new_skb;
            int length = ibmveth_rxq_frame_length(adapter);
            int offset = ibmveth_rxq_frame_offset(adapter);
            int csum_good = ibmveth_rxq_csum_good(adapter);

            skb = ibmveth_rxq_get_buffer(adapter);

            new_skb = NULL;
            if (length < rx_copybreak)
                new_skb = netdev_alloc_skb(netdev, length);

            if (new_skb) {
                skb_copy_to_linear_data(new_skb,
                            skb->data + offset,
                            length);
                if (rx_flush)
                    ibmveth_flush_buffer(skb->data,
                        length + offset);
                if (!ibmveth_rxq_recycle_buffer(adapter))
                    kfree_skb(skb);
                skb = new_skb;
            } else {
                ibmveth_rxq_harvest_buffer(adapter);
                skb_reserve(skb, offset);
            }

            skb_put(skb, length);
            skb->protocol = eth_type_trans(skb, netdev);

            if (csum_good)
                skb->ip_summed = CHECKSUM_UNNECESSARY;

            netif_receive_skb(skb); /* send it up */

            netdev->stats.rx_packets++;
            netdev->stats.rx_bytes += length;
            frames_processed++;
        }
    } while (frames_processed < budget);

    ibmveth_replenish_task(adapter);

    if (frames_processed < budget) {
        /* We think we are done - reenable interrupts,
         * then check once more to make sure we are done.
         */
        lpar_rc = h_vio_signal(adapter->vdev->unit_address,
                       VIO_IRQ_ENABLE);

        BUG_ON(lpar_rc != H_SUCCESS);

        napi_complete(napi);

        if (ibmveth_rxq_pending_buffer(adapter) &&
            napi_reschedule(napi)) {
            lpar_rc = h_vio_signal(adapter->vdev->unit_address,
                           VIO_IRQ_DISABLE);
            goto restart_poll;
        }
    }

    return frames_processed;
}

static irqreturn_t ibmveth_interrupt(int irq, void *dev_instance)
{
    struct net_device *netdev = dev_instance;
    struct ibmveth_adapter *adapter = netdev_priv(netdev);
    unsigned long lpar_rc;

    if (napi_schedule_prep(&adapter->napi)) {
        lpar_rc = h_vio_signal(adapter->vdev->unit_address,
                       VIO_IRQ_DISABLE);
        BUG_ON(lpar_rc != H_SUCCESS);
        __napi_schedule(&adapter->napi);
    }
    return IRQ_HANDLED;
}

static void ibmveth_set_multicast_list(struct net_device *netdev)
{
    struct ibmveth_adapter *adapter = netdev_priv(netdev);
    unsigned long lpar_rc;

    if ((netdev->flags & IFF_PROMISC) ||
        (netdev_mc_count(netdev) > adapter->mcastFilterSize)) {
        lpar_rc = h_multicast_ctrl(adapter->vdev->unit_address,
                       IbmVethMcastEnableRecv |
                       IbmVethMcastDisableFiltering,
                       0);
        if (lpar_rc != H_SUCCESS) {
            netdev_err(netdev, "h_multicast_ctrl rc=%ld when "
                   "entering promisc mode\n", lpar_rc);
        }
    } else {
        struct netdev_hw_addr *ha;
        /* clear the filter table & disable filtering */
        lpar_rc = h_multicast_ctrl(adapter->vdev->unit_address,
                       IbmVethMcastEnableRecv |
                       IbmVethMcastDisableFiltering |
                       IbmVethMcastClearFilterTable,
                       0);
        if (lpar_rc != H_SUCCESS) {
            netdev_err(netdev, "h_multicast_ctrl rc=%ld when "
                   "attempting to clear filter table\n",
                   lpar_rc);
        }
        /* add the addresses to the filter table */
        netdev_for_each_mc_addr(ha, netdev) {
            /* add the multicast address to the filter table */
            unsigned long mcast_addr = 0;
            memcpy(((char *)&mcast_addr)+2, ha->addr, 6);
            lpar_rc = h_multicast_ctrl(adapter->vdev->unit_address,
                           IbmVethMcastAddFilter,
                           mcast_addr);
            if (lpar_rc != H_SUCCESS) {
                netdev_err(netdev, "h_multicast_ctrl rc=%ld "
                       "when adding an entry to the filter "
                       "table\n", lpar_rc);
            }
        }

        /* re-enable filtering */
        lpar_rc = h_multicast_ctrl(adapter->vdev->unit_address,
                       IbmVethMcastEnableFiltering,
                       0);
        if (lpar_rc != H_SUCCESS) {
            netdev_err(netdev, "h_multicast_ctrl rc=%ld when "
                   "enabling filtering\n", lpar_rc);
        }
    }
}

static int ibmveth_change_mtu(struct net_device *dev, int new_mtu)
{
    struct ibmveth_adapter *adapter = netdev_priv(dev);
    struct vio_dev *viodev = adapter->vdev;
    int new_mtu_oh = new_mtu + IBMVETH_BUFF_OH;
    int i, rc;
    int need_restart = 0;

    if (new_mtu < IBMVETH_MIN_MTU)
        return -EINVAL;

    for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
        if (new_mtu_oh < adapter->rx_buff_pool[i].buff_size)
            break;

    if (i == IBMVETH_NUM_BUFF_POOLS)
        return -EINVAL;

    /* Deactivate all the buffer pools so that the next loop can activate
       only the buffer pools necessary to hold the new MTU */
    if (netif_running(adapter->netdev)) {
        need_restart = 1;
        adapter->pool_config = 1;
        ibmveth_close(adapter->netdev);
        adapter->pool_config = 0;
    }

    /* Look for an active buffer pool that can hold the new MTU */
    for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
        adapter->rx_buff_pool[i].active = 1;

        if (new_mtu_oh < adapter->rx_buff_pool[i].buff_size) {
            dev->mtu = new_mtu;
            vio_cmo_set_dev_desired(viodev,
                        ibmveth_get_desired_dma
                        (viodev));
            if (need_restart) {
                return ibmveth_open(adapter->netdev);
            }
            return 0;
        }
    }

    if (need_restart && (rc = ibmveth_open(adapter->netdev)))
        return rc;

    return -EINVAL;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void ibmveth_poll_controller(struct net_device *dev)
{
    ibmveth_replenish_task(netdev_priv(dev));
    ibmveth_interrupt(dev->irq, dev);
}
#endif

static unsigned long ibmveth_get_desired_dma(struct vio_dev *vdev)
{
    struct net_device *netdev = dev_get_drvdata(&vdev->dev);
    struct ibmveth_adapter *adapter;
    unsigned long ret;
    int i;
    int rxqentries = 1;

    /* netdev inits at probe time along with the structures we need below*/
    if (netdev == NULL)
        return IOMMU_PAGE_ALIGN(IBMVETH_IO_ENTITLEMENT_DEFAULT);

    adapter = netdev_priv(netdev);

    ret = IBMVETH_BUFF_LIST_SIZE + IBMVETH_FILT_LIST_SIZE;
    ret += IOMMU_PAGE_ALIGN(netdev->mtu);

    for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
        /* add the size of the active receive buffers */
        if (adapter->rx_buff_pool[i].active)
            ret +=
                adapter->rx_buff_pool[i].size *
                IOMMU_PAGE_ALIGN(adapter->rx_buff_pool[i].
                        buff_size);
        rxqentries += adapter->rx_buff_pool[i].size;
    }
    /* add the size of the receive queue entries */
    ret += IOMMU_PAGE_ALIGN(rxqentries * sizeof(struct ibmveth_rx_q_entry));

    return ret;
}

static const struct net_device_ops ibmveth_netdev_ops = {
    .ndo_open       = ibmveth_open,
    .ndo_stop       = ibmveth_close,
    .ndo_start_xmit     = ibmveth_start_xmit,
    .ndo_set_rx_mode    = ibmveth_set_multicast_list,
    .ndo_do_ioctl       = ibmveth_ioctl,
    .ndo_change_mtu     = ibmveth_change_mtu,
    .ndo_fix_features   = ibmveth_fix_features,
    .ndo_set_features   = ibmveth_set_features,
    .ndo_validate_addr  = eth_validate_addr,
    .ndo_set_mac_address    = eth_mac_addr,
#ifdef CONFIG_NET_POLL_CONTROLLER
    .ndo_poll_controller    = ibmveth_poll_controller,
#endif
};

static int __devinit ibmveth_probe(struct vio_dev *dev,
                   const struct vio_device_id *id)
{
    int rc, i;
    struct net_device *netdev;
    struct ibmveth_adapter *adapter;
    unsigned char *mac_addr_p;
    unsigned int *mcastFilterSize_p;

    dev_dbg(&dev->dev, "entering ibmveth_probe for UA 0x%x\n",
        dev->unit_address);

    mac_addr_p = (unsigned char *)vio_get_attribute(dev, VETH_MAC_ADDR,
                            NULL);
    if (!mac_addr_p) {
        dev_err(&dev->dev, "Can't find VETH_MAC_ADDR attribute\n");
        return -EINVAL;
    }

    mcastFilterSize_p = (unsigned int *)vio_get_attribute(dev,
                        VETH_MCAST_FILTER_SIZE, NULL);
    if (!mcastFilterSize_p) {
        dev_err(&dev->dev, "Can't find VETH_MCAST_FILTER_SIZE "
            "attribute\n");
        return -EINVAL;
    }

    netdev = alloc_etherdev(sizeof(struct ibmveth_adapter));

    if (!netdev)
        return -ENOMEM;

    adapter = netdev_priv(netdev);
    dev_set_drvdata(&dev->dev, netdev);

    adapter->vdev = dev;
    adapter->netdev = netdev;
    adapter->mcastFilterSize = *mcastFilterSize_p;
    adapter->pool_config = 0;

    netif_napi_add(netdev, &adapter->napi, ibmveth_poll, 16);

    /*
     * Some older boxes running PHYP non-natively have an OF that returns
     * a 8-byte local-mac-address field (and the first 2 bytes have to be
     * ignored) while newer boxes' OF return a 6-byte field. Note that
     * IEEE 1275 specifies that local-mac-address must be a 6-byte field.
     * The RPA doc specifies that the first byte must be 10b, so we'll
     * just look for it to solve this 8 vs. 6 byte field issue
     */
    if ((*mac_addr_p & 0x3) != 0x02)
        mac_addr_p += 2;

    adapter->mac_addr = 0;
    memcpy(&adapter->mac_addr, mac_addr_p, 6);

    netdev->irq = dev->irq;
    netdev->netdev_ops = &ibmveth_netdev_ops;
    netdev->ethtool_ops = &netdev_ethtool_ops;
    SET_NETDEV_DEV(netdev, &dev->dev);
    netdev->hw_features = NETIF_F_SG | NETIF_F_RXCSUM |
        NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
    netdev->features |= netdev->hw_features;

    memcpy(netdev->dev_addr, &adapter->mac_addr, netdev->addr_len);

    for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
        struct kobject *kobj = &adapter->rx_buff_pool[i].kobj;
        int error;

        ibmveth_init_buffer_pool(&adapter->rx_buff_pool[i], i,
                     pool_count[i], pool_size[i],
                     pool_active[i]);
        error = kobject_init_and_add(kobj, &ktype_veth_pool,
                         &dev->dev.kobj, "pool%d", i);
        if (!error)
            kobject_uevent(kobj, KOBJ_ADD);
    }

    netdev_dbg(netdev, "adapter @ 0x%p\n", adapter);

    adapter->buffer_list_dma = DMA_ERROR_CODE;
    adapter->filter_list_dma = DMA_ERROR_CODE;
    adapter->rx_queue.queue_dma = DMA_ERROR_CODE;

    netdev_dbg(netdev, "registering netdev...\n");

    ibmveth_set_features(netdev, netdev->features);

    rc = register_netdev(netdev);

    if (rc) {
        netdev_dbg(netdev, "failed to register netdev rc=%d\n", rc);
        free_netdev(netdev);
        return rc;
    }

    netdev_dbg(netdev, "registered\n");

    return 0;
}

static int __devexit ibmveth_remove(struct vio_dev *dev)
{
    struct net_device *netdev = dev_get_drvdata(&dev->dev);
    struct ibmveth_adapter *adapter = netdev_priv(netdev);
    int i;

    for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
        kobject_put(&adapter->rx_buff_pool[i].kobj);

    unregister_netdev(netdev);

    free_netdev(netdev);
    dev_set_drvdata(&dev->dev, NULL);

    return 0;
}

static struct attribute veth_active_attr;
static struct attribute veth_num_attr;
static struct attribute veth_size_attr;

static ssize_t veth_pool_show(struct kobject *kobj,
                  struct attribute *attr, char *buf)
{
    struct ibmveth_buff_pool *pool = container_of(kobj,
                              struct ibmveth_buff_pool,
                              kobj);

    if (attr == &veth_active_attr)
        return sprintf(buf, "%d\n", pool->active);
    else if (attr == &veth_num_attr)
        return sprintf(buf, "%d\n", pool->size);
    else if (attr == &veth_size_attr)
        return sprintf(buf, "%d\n", pool->buff_size);
    return 0;
}

static ssize_t veth_pool_store(struct kobject *kobj, struct attribute *attr,
                   const char *buf, size_t count)
{
    struct ibmveth_buff_pool *pool = container_of(kobj,
                              struct ibmveth_buff_pool,
                              kobj);
    struct net_device *netdev = dev_get_drvdata(
        container_of(kobj->parent, struct device, kobj));
    struct ibmveth_adapter *adapter = netdev_priv(netdev);
    long value = simple_strtol(buf, NULL, 10);
    long rc;

    if (attr == &veth_active_attr) {
        if (value && !pool->active) {
            if (netif_running(netdev)) {
                if (ibmveth_alloc_buffer_pool(pool)) {
                    netdev_err(netdev,
                           "unable to alloc pool\n");
                    return -ENOMEM;
                }
                pool->active = 1;
                adapter->pool_config = 1;
                ibmveth_close(netdev);
                adapter->pool_config = 0;
                if ((rc = ibmveth_open(netdev)))
                    return rc;
            } else {
                pool->active = 1;
            }
        } else if (!value && pool->active) {
            int mtu = netdev->mtu + IBMVETH_BUFF_OH;
            int i;
            /* Make sure there is a buffer pool with buffers that
               can hold a packet of the size of the MTU */
            for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
                if (pool == &adapter->rx_buff_pool[i])
                    continue;
                if (!adapter->rx_buff_pool[i].active)
                    continue;
                if (mtu <= adapter->rx_buff_pool[i].buff_size)
                    break;
            }

            if (i == IBMVETH_NUM_BUFF_POOLS) {
                netdev_err(netdev, "no active pool >= MTU\n");
                return -EPERM;
            }

            if (netif_running(netdev)) {
                adapter->pool_config = 1;
                ibmveth_close(netdev);
                pool->active = 0;
                adapter->pool_config = 0;
                if ((rc = ibmveth_open(netdev)))
                    return rc;
            }
            pool->active = 0;
        }
    } else if (attr == &veth_num_attr) {
        if (value <= 0 || value > IBMVETH_MAX_POOL_COUNT) {
            return -EINVAL;
        } else {
            if (netif_running(netdev)) {
                adapter->pool_config = 1;
                ibmveth_close(netdev);
                adapter->pool_config = 0;
                pool->size = value;
                if ((rc = ibmveth_open(netdev)))
                    return rc;
            } else {
                pool->size = value;
            }
        }
    } else if (attr == &veth_size_attr) {
        if (value <= IBMVETH_BUFF_OH || value > IBMVETH_MAX_BUF_SIZE) {
            return -EINVAL;
        } else {
            if (netif_running(netdev)) {
                adapter->pool_config = 1;
                ibmveth_close(netdev);
                adapter->pool_config = 0;
                pool->buff_size = value;
                if ((rc = ibmveth_open(netdev)))
                    return rc;
            } else {
                pool->buff_size = value;
            }
        }
    }

    /* kick the interrupt handler to allocate/deallocate pools */
    ibmveth_interrupt(netdev->irq, netdev);
    return count;
}


#define ATTR(_name, _mode)              \
    struct attribute veth_##_name##_attr = {    \
    .name = __stringify(_name), .mode = _mode,  \
    };

static ATTR(active, 0644);
static ATTR(num, 0644);
static ATTR(size, 0644);

static struct attribute *veth_pool_attrs[] = {
    &veth_active_attr,
    &veth_num_attr,
    &veth_size_attr,
    NULL,
};

static const struct sysfs_ops veth_pool_ops = {
    .show   = veth_pool_show,
    .store  = veth_pool_store,
};

static struct kobj_type ktype_veth_pool = {
    .release        = NULL,
    .sysfs_ops      = &veth_pool_ops,
    .default_attrs  = veth_pool_attrs,
};

static int ibmveth_resume(struct device *dev)
{
    struct net_device *netdev = dev_get_drvdata(dev);
    ibmveth_interrupt(netdev->irq, netdev);
    return 0;
}

static struct vio_device_id ibmveth_device_table[] __devinitdata = {
    { "network", "IBM,l-lan"},
    { "", "" }
};
MODULE_DEVICE_TABLE(vio, ibmveth_device_table);

static struct dev_pm_ops ibmveth_pm_ops = {
    .resume = ibmveth_resume
};

static struct vio_driver ibmveth_driver = {
    .id_table   = ibmveth_device_table,
    .probe      = ibmveth_probe,
    .remove     = ibmveth_remove,
    .get_desired_dma = ibmveth_get_desired_dma,
    .name       = ibmveth_driver_name,
    .pm     = &ibmveth_pm_ops,
};

static int __init ibmveth_module_init(void)
{
    printk(KERN_DEBUG "%s: %s %s\n", ibmveth_driver_name,
           ibmveth_driver_string, ibmveth_driver_version);

    return vio_register_driver(&ibmveth_driver);
}

static void __exit ibmveth_module_exit(void)
{
    vio_unregister_driver(&ibmveth_driver);
}

module_init(ibmveth_module_init);
module_exit(ibmveth_module_exit);