ieee1394: eth1394: reduce excessive function inlining

[linux-2.6] / drivers / ieee1394 / eth1394.c

/*
 * eth1394.c -- Ethernet driver for Linux IEEE-1394 Subsystem
 *
 * Copyright (C) 2001-2003 Ben Collins <bcollins@debian.org>
 *               2000 Bonin Franck <boninf@free.fr>
 *               2003 Steve Kinneberg <kinnebergsteve@acmsystems.com>
 *
 * Mainly based on work by Emanuel Pirker and Andreas E. Bombe
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/* This driver intends to support RFC 2734, which describes a method for
 * transporting IPv4 datagrams over IEEE-1394 serial busses. This driver
 * will ultimately support that method, but currently falls short in
 * several areas.
 *
 * TODO:
 * RFC 2734 related:
 * - Add MCAP. Limited Multicast exists only to 224.0.0.1 and 224.0.0.2.
 *
 * Non-RFC 2734 related:
 * - Handle fragmented skb's coming from the networking layer.
 * - Move generic GASP reception to core 1394 code
 * - Convert kmalloc/kfree for link fragments to use kmem_cache_* instead
 * - Stability improvements
 * - Performance enhancements
 * - Consider garbage collecting old partial datagrams after X amount of time
 */


#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/init.h>

#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <linux/tcp.h>
#include <linux/skbuff.h>
#include <linux/bitops.h>
#include <linux/ethtool.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
#include <asm/unaligned.h>
#include <net/arp.h>

#include "config_roms.h"
#include "csr1212.h"
#include "eth1394.h"
#include "highlevel.h"
#include "ieee1394.h"
#include "ieee1394_core.h"
#include "ieee1394_hotplug.h"
#include "ieee1394_transactions.h"
#include "ieee1394_types.h"
#include "iso.h"
#include "nodemgr.h"

#define ETH1394_PRINT_G(level, fmt, args...) \
        printk(level "%s: " fmt, driver_name, ## args)

#define ETH1394_PRINT(level, dev_name, fmt, args...) \
        printk(level "%s: %s: " fmt, driver_name, dev_name, ## args)

#define DEBUG(fmt, args...) \
        printk(KERN_ERR "%s:%s[%d]: " fmt "\n", driver_name, __FUNCTION__, __LINE__, ## args)
#define TRACE() printk(KERN_ERR "%s:%s[%d] ---- TRACE\n", driver_name, __FUNCTION__, __LINE__)

struct fragment_info {
        struct list_head list;
        int offset;
        int len;
};

struct partial_datagram {
        struct list_head list;
        u16 dgl;
        u16 dg_size;
        u16 ether_type;
        struct sk_buff *skb;
        char *pbuf;
        struct list_head frag_info;
};

struct pdg_list {
        struct list_head list;          /* partial datagram list per node       */
        unsigned int sz;                /* partial datagram list size per node  */
        spinlock_t lock;                /* partial datagram lock                */
};

struct eth1394_host_info {
        struct hpsb_host *host;
        struct net_device *dev;
};

struct eth1394_node_ref {
        struct unit_directory *ud;
        struct list_head list;
};

struct eth1394_node_info {
        u16 maxpayload;                 /* Max payload                  */
        u8 sspd;                        /* Max speed                    */
        u64 fifo;                       /* FIFO address                 */
        struct pdg_list pdg;            /* partial RX datagram lists    */
        int dgl;                        /* Outgoing datagram label      */
};

/* Our ieee1394 highlevel driver */
#define ETH1394_DRIVER_NAME "eth1394"
static const char driver_name[] = ETH1394_DRIVER_NAME;

static struct kmem_cache *packet_task_cache;

static struct hpsb_highlevel eth1394_highlevel;

/* Use common.lf to determine header len */
static const int hdr_type_len[] = {
        sizeof (struct eth1394_uf_hdr),
        sizeof (struct eth1394_ff_hdr),
        sizeof (struct eth1394_sf_hdr),
        sizeof (struct eth1394_sf_hdr)
};

/* Change this to IEEE1394_SPEED_S100 to make testing easier */
#define ETH1394_SPEED_DEF       IEEE1394_SPEED_MAX

/* For now, this needs to be 1500, so that XP works with us */
#define ETH1394_DATA_LEN        ETH_DATA_LEN

static const u16 eth1394_speedto_maxpayload[] = {
/*     S100, S200, S400, S800, S1600, S3200 */
        512, 1024, 2048, 4096,  4096,  4096
};

MODULE_AUTHOR("Ben Collins (bcollins@debian.org)");
MODULE_DESCRIPTION("IEEE 1394 IPv4 Driver (IPv4-over-1394 as per RFC 2734)");
MODULE_LICENSE("GPL");

/* The max_partial_datagrams parameter is the maximum number of fragmented
 * datagrams per node that eth1394 will keep in memory.  Providing an upper
 * bound allows us to limit the amount of memory that partial datagrams
 * consume in the event that some partial datagrams are never completed.
 */
static int max_partial_datagrams = 25;
module_param(max_partial_datagrams, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(max_partial_datagrams,
                 "Maximum number of partially received fragmented datagrams "
                 "(default = 25).");


static int ether1394_header(struct sk_buff *skb, struct net_device *dev,
                            unsigned short type, void *daddr, void *saddr,
                            unsigned len);
static int ether1394_rebuild_header(struct sk_buff *skb);
static int ether1394_header_parse(struct sk_buff *skb, unsigned char *haddr);
static int ether1394_header_cache(struct neighbour *neigh, struct hh_cache *hh);
static void ether1394_header_cache_update(struct hh_cache *hh,
                                          struct net_device *dev,
                                          unsigned char * haddr);
static int ether1394_mac_addr(struct net_device *dev, void *p);

static void purge_partial_datagram(struct list_head *old);
static int ether1394_tx(struct sk_buff *skb, struct net_device *dev);
static void ether1394_iso(struct hpsb_iso *iso);

static struct ethtool_ops ethtool_ops;

static int ether1394_write(struct hpsb_host *host, int srcid, int destid,
                           quadlet_t *data, u64 addr, size_t len, u16 flags);
static void ether1394_add_host (struct hpsb_host *host);
static void ether1394_remove_host (struct hpsb_host *host);
static void ether1394_host_reset (struct hpsb_host *host);

/* Function for incoming 1394 packets */
static struct hpsb_address_ops addr_ops = {
        .write =        ether1394_write,
};

/* Ieee1394 highlevel driver functions */
static struct hpsb_highlevel eth1394_highlevel = {
        .name =         driver_name,
        .add_host =     ether1394_add_host,
        .remove_host =  ether1394_remove_host,
        .host_reset =   ether1394_host_reset,
};


/* This is called after an "ifup" */
static int ether1394_open (struct net_device *dev)
{
        struct eth1394_priv *priv = netdev_priv(dev);
        int ret = 0;

        /* Something bad happened, don't even try */
        if (priv->bc_state == ETHER1394_BC_ERROR) {
                /* we'll try again */
                priv->iso = hpsb_iso_recv_init(priv->host,
                                               ETHER1394_ISO_BUF_SIZE,
                                               ETHER1394_GASP_BUFFERS,
                                               priv->broadcast_channel,
                                               HPSB_ISO_DMA_PACKET_PER_BUFFER,
                                               1, ether1394_iso);
                if (priv->iso == NULL) {
                        ETH1394_PRINT(KERN_ERR, dev->name,
                                      "Could not allocate isochronous receive "
                                      "context for the broadcast channel\n");
                        priv->bc_state = ETHER1394_BC_ERROR;
                        ret = -EAGAIN;
                } else {
                        if (hpsb_iso_recv_start(priv->iso, -1, (1 << 3), -1) < 0)
                                priv->bc_state = ETHER1394_BC_STOPPED;
                        else
                                priv->bc_state = ETHER1394_BC_RUNNING;
                }
        }

        if (ret)
                return ret;

        netif_start_queue (dev);
        return 0;
}

/* This is called after an "ifdown" */
static int ether1394_stop (struct net_device *dev)
{
        netif_stop_queue (dev);
        return 0;
}

/* Return statistics to the caller */
static struct net_device_stats *ether1394_stats (struct net_device *dev)
{
        return &(((struct eth1394_priv *)netdev_priv(dev))->stats);
}

/* What to do if we timeout. I think a host reset is probably in order, so
 * that's what we do. Should we increment the stat counters too?  */
static void ether1394_tx_timeout (struct net_device *dev)
{
        ETH1394_PRINT (KERN_ERR, dev->name, "Timeout, resetting host %s\n",
                       ((struct eth1394_priv *)netdev_priv(dev))->host->driver->name);

        highlevel_host_reset (((struct eth1394_priv *)netdev_priv(dev))->host);

        netif_wake_queue (dev);
}

static int ether1394_change_mtu(struct net_device *dev, int new_mtu)
{
        struct eth1394_priv *priv = netdev_priv(dev);

        if ((new_mtu < 68) ||
            (new_mtu > min(ETH1394_DATA_LEN,
                           (int)((1 << (priv->host->csr.max_rec + 1)) -
                                 (sizeof(union eth1394_hdr) +
                                  ETHER1394_GASP_OVERHEAD)))))
                return -EINVAL;
        dev->mtu = new_mtu;
        return 0;
}

static void purge_partial_datagram(struct list_head *old)
{
        struct partial_datagram *pd = list_entry(old, struct partial_datagram, list);
        struct list_head *lh, *n;

        list_for_each_safe(lh, n, &pd->frag_info) {
                struct fragment_info *fi = list_entry(lh, struct fragment_info, list);
                list_del(lh);
                kfree(fi);
        }
        list_del(old);
        kfree_skb(pd->skb);
        kfree(pd);
}

/******************************************
 * 1394 bus activity functions
 ******************************************/

static struct eth1394_node_ref *eth1394_find_node(struct list_head *inl,
                                                  struct unit_directory *ud)
{
        struct eth1394_node_ref *node;

        list_for_each_entry(node, inl, list)
                if (node->ud == ud)
                        return node;

        return NULL;
}

static struct eth1394_node_ref *eth1394_find_node_guid(struct list_head *inl,
                                                       u64 guid)
{
        struct eth1394_node_ref *node;

        list_for_each_entry(node, inl, list)
                if (node->ud->ne->guid == guid)
                        return node;

        return NULL;
}

static struct eth1394_node_ref *eth1394_find_node_nodeid(struct list_head *inl,
                                                         nodeid_t nodeid)
{
        struct eth1394_node_ref *node;
        list_for_each_entry(node, inl, list) {
                if (node->ud->ne->nodeid == nodeid)
                        return node;
        }

        return NULL;
}

static int eth1394_probe(struct device *dev)
{
        struct unit_directory *ud;
        struct eth1394_host_info *hi;
        struct eth1394_priv *priv;
        struct eth1394_node_ref *new_node;
        struct eth1394_node_info *node_info;

        ud = container_of(dev, struct unit_directory, device);

        hi = hpsb_get_hostinfo(&eth1394_highlevel, ud->ne->host);
        if (!hi)
                return -ENOENT;

        new_node = kmalloc(sizeof(*new_node),
                           in_interrupt() ? GFP_ATOMIC : GFP_KERNEL);
        if (!new_node)
                return -ENOMEM;

        node_info = kmalloc(sizeof(*node_info),
                            in_interrupt() ? GFP_ATOMIC : GFP_KERNEL);
        if (!node_info) {
                kfree(new_node);
                return -ENOMEM;
        }

        spin_lock_init(&node_info->pdg.lock);
        INIT_LIST_HEAD(&node_info->pdg.list);
        node_info->pdg.sz = 0;
        node_info->fifo = CSR1212_INVALID_ADDR_SPACE;

        ud->device.driver_data = node_info;
        new_node->ud = ud;

        priv = netdev_priv(hi->dev);
        list_add_tail(&new_node->list, &priv->ip_node_list);

        return 0;
}

static int eth1394_remove(struct device *dev)
{
        struct unit_directory *ud;
        struct eth1394_host_info *hi;
        struct eth1394_priv *priv;
        struct eth1394_node_ref *old_node;
        struct eth1394_node_info *node_info;
        struct list_head *lh, *n;
        unsigned long flags;

        ud = container_of(dev, struct unit_directory, device);
        hi = hpsb_get_hostinfo(&eth1394_highlevel, ud->ne->host);
        if (!hi)
                return -ENOENT;

        priv = netdev_priv(hi->dev);

        old_node = eth1394_find_node(&priv->ip_node_list, ud);

        if (old_node) {
                list_del(&old_node->list);
                kfree(old_node);

                node_info = (struct eth1394_node_info*)ud->device.driver_data;

                spin_lock_irqsave(&node_info->pdg.lock, flags);
                /* The partial datagram list should be empty, but we'll just
                 * make sure anyway... */
                list_for_each_safe(lh, n, &node_info->pdg.list) {
                        purge_partial_datagram(lh);
                }
                spin_unlock_irqrestore(&node_info->pdg.lock, flags);

                kfree(node_info);
                ud->device.driver_data = NULL;
        }
        return 0;
}

static int eth1394_update(struct unit_directory *ud)
{
        struct eth1394_host_info *hi;
        struct eth1394_priv *priv;
        struct eth1394_node_ref *node;
        struct eth1394_node_info *node_info;

        hi = hpsb_get_hostinfo(&eth1394_highlevel, ud->ne->host);
        if (!hi)
                return -ENOENT;

        priv = netdev_priv(hi->dev);

        node = eth1394_find_node(&priv->ip_node_list, ud);

        if (!node) {
                node = kmalloc(sizeof(*node),
                               in_interrupt() ? GFP_ATOMIC : GFP_KERNEL);
                if (!node)
                        return -ENOMEM;

                node_info = kmalloc(sizeof(*node_info),
                                    in_interrupt() ? GFP_ATOMIC : GFP_KERNEL);
                if (!node_info) {
                        kfree(node);
                        return -ENOMEM;
                }

                spin_lock_init(&node_info->pdg.lock);
                INIT_LIST_HEAD(&node_info->pdg.list);
                node_info->pdg.sz = 0;

                ud->device.driver_data = node_info;
                node->ud = ud;

                priv = netdev_priv(hi->dev);
                list_add_tail(&node->list, &priv->ip_node_list);
        }

        return 0;
}


static struct ieee1394_device_id eth1394_id_table[] = {
        {
                .match_flags = (IEEE1394_MATCH_SPECIFIER_ID |
                                IEEE1394_MATCH_VERSION),
                .specifier_id = ETHER1394_GASP_SPECIFIER_ID,
                .version = ETHER1394_GASP_VERSION,
        },
        {}
};

MODULE_DEVICE_TABLE(ieee1394, eth1394_id_table);

static struct hpsb_protocol_driver eth1394_proto_driver = {
        .name           = ETH1394_DRIVER_NAME,
        .id_table       = eth1394_id_table,
        .update         = eth1394_update,
        .driver         = {
                .probe          = eth1394_probe,
                .remove         = eth1394_remove,
        },
};


static void ether1394_reset_priv (struct net_device *dev, int set_mtu)
{
        unsigned long flags;
        int i;
        struct eth1394_priv *priv = netdev_priv(dev);
        struct hpsb_host *host = priv->host;
        u64 guid = get_unaligned((u64*)&(host->csr.rom->bus_info_data[3]));
        u16 maxpayload = 1 << (host->csr.max_rec + 1);
        int max_speed = IEEE1394_SPEED_MAX;

        spin_lock_irqsave (&priv->lock, flags);

        memset(priv->ud_list, 0, sizeof(struct node_entry*) * ALL_NODES);
        priv->bc_maxpayload = 512;

        /* Determine speed limit */
        for (i = 0; i < host->node_count; i++)
                if (max_speed > host->speed[i])
                        max_speed = host->speed[i];
        priv->bc_sspd = max_speed;

        /* We'll use our maxpayload as the default mtu */
        if (set_mtu) {
                dev->mtu = min(ETH1394_DATA_LEN,
                               (int)(maxpayload -
                                     (sizeof(union eth1394_hdr) +
                                      ETHER1394_GASP_OVERHEAD)));

                /* Set our hardware address while we're at it */
                memcpy(dev->dev_addr, &guid, sizeof(u64));
                memset(dev->broadcast, 0xff, sizeof(u64));
        }

        spin_unlock_irqrestore (&priv->lock, flags);
}

/* This function is called right before register_netdev */
static void ether1394_init_dev (struct net_device *dev)
{
        /* Our functions */
        dev->open               = ether1394_open;
        dev->stop               = ether1394_stop;
        dev->hard_start_xmit    = ether1394_tx;
        dev->get_stats          = ether1394_stats;
        dev->tx_timeout         = ether1394_tx_timeout;
        dev->change_mtu         = ether1394_change_mtu;

        dev->hard_header        = ether1394_header;
        dev->rebuild_header     = ether1394_rebuild_header;
        dev->hard_header_cache  = ether1394_header_cache;
        dev->header_cache_update= ether1394_header_cache_update;
        dev->hard_header_parse  = ether1394_header_parse;
        dev->set_mac_address    = ether1394_mac_addr;
        SET_ETHTOOL_OPS(dev, &ethtool_ops);

        /* Some constants */
        dev->watchdog_timeo     = ETHER1394_TIMEOUT;
        dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
        dev->features           = NETIF_F_HIGHDMA;
        dev->addr_len           = ETH1394_ALEN;
        dev->hard_header_len    = ETH1394_HLEN;
        dev->type               = ARPHRD_IEEE1394;

        ether1394_reset_priv (dev, 1);
}

/*
 * This function is called every time a card is found. It is generally called
 * when the module is installed. This is where we add all of our ethernet
 * devices. One for each host.
 */
static void ether1394_add_host (struct hpsb_host *host)
{
        struct eth1394_host_info *hi = NULL;
        struct net_device *dev = NULL;
        struct eth1394_priv *priv;
        u64 fifo_addr;

        if (!(host->config_roms & HPSB_CONFIG_ROM_ENTRY_IP1394))
                return;

        fifo_addr = hpsb_allocate_and_register_addrspace(
                        &eth1394_highlevel, host, &addr_ops,
                        ETHER1394_REGION_ADDR_LEN, ETHER1394_REGION_ADDR_LEN,
                        CSR1212_INVALID_ADDR_SPACE, CSR1212_INVALID_ADDR_SPACE);
        if (fifo_addr == CSR1212_INVALID_ADDR_SPACE) {
                ETH1394_PRINT_G(KERN_ERR, "Cannot register CSR space\n");
                return;
        }

        /* We should really have our own alloc_hpsbdev() function in
         * net_init.c instead of calling the one for ethernet then hijacking
         * it for ourselves.  That way we'd be a real networking device. */
        dev = alloc_etherdev(sizeof (struct eth1394_priv));

        if (dev == NULL) {
                ETH1394_PRINT_G (KERN_ERR, "Out of memory trying to allocate "
                                 "etherdevice for IEEE 1394 device %s-%d\n",
                                 host->driver->name, host->id);
                goto out;
        }

        SET_MODULE_OWNER(dev);
#if 0
        /* FIXME - Is this the correct parent device anyway? */
        SET_NETDEV_DEV(dev, &host->device);
#endif

        priv = netdev_priv(dev);

        INIT_LIST_HEAD(&priv->ip_node_list);

        spin_lock_init(&priv->lock);
        priv->host = host;
        priv->local_fifo = fifo_addr;

        hi = hpsb_create_hostinfo(&eth1394_highlevel, host, sizeof(*hi));

        if (hi == NULL) {
                ETH1394_PRINT_G (KERN_ERR, "Out of memory trying to create "
                                 "hostinfo for IEEE 1394 device %s-%d\n",
                                 host->driver->name, host->id);
                goto out;
        }

        ether1394_init_dev(dev);

        if (register_netdev (dev)) {
                ETH1394_PRINT (KERN_ERR, dev->name, "Error registering network driver\n");
                goto out;
        }

        ETH1394_PRINT (KERN_INFO, dev->name, "IEEE-1394 IPv4 over 1394 Ethernet (fw-host%d)\n",
                       host->id);

        hi->host = host;
        hi->dev = dev;

        /* Ignore validity in hopes that it will be set in the future.  It'll
         * be checked when the eth device is opened. */
        priv->broadcast_channel = host->csr.broadcast_channel & 0x3f;

        priv->iso = hpsb_iso_recv_init(host,
                                       ETHER1394_ISO_BUF_SIZE,
                                       ETHER1394_GASP_BUFFERS,
                                       priv->broadcast_channel,
                                       HPSB_ISO_DMA_PACKET_PER_BUFFER,
                                       1, ether1394_iso);
        if (priv->iso == NULL) {
                ETH1394_PRINT(KERN_ERR, dev->name,
                              "Could not allocate isochronous receive context "
                              "for the broadcast channel\n");
                priv->bc_state = ETHER1394_BC_ERROR;
        } else {
                if (hpsb_iso_recv_start(priv->iso, -1, (1 << 3), -1) < 0)
                        priv->bc_state = ETHER1394_BC_STOPPED;
                else
                        priv->bc_state = ETHER1394_BC_RUNNING;
        }
        return;
out:
        if (dev)
                free_netdev(dev);
        if (hi)
                hpsb_destroy_hostinfo(&eth1394_highlevel, host);
        hpsb_unregister_addrspace(&eth1394_highlevel, host, fifo_addr);
}

/* Remove a card from our list */
static void ether1394_remove_host (struct hpsb_host *host)
{
        struct eth1394_host_info *hi;
        struct eth1394_priv *priv;

        hi = hpsb_get_hostinfo(&eth1394_highlevel, host);
        if (!hi)
                return;
        priv = netdev_priv(hi->dev);
        hpsb_unregister_addrspace(&eth1394_highlevel, host, priv->local_fifo);
        if (priv->iso)
                hpsb_iso_shutdown(priv->iso);
        unregister_netdev(hi->dev);
        free_netdev(hi->dev);
}

/* A reset has just arisen */
static void ether1394_host_reset (struct hpsb_host *host)
{
        struct eth1394_host_info *hi;
        struct eth1394_priv *priv;
        struct net_device *dev;
        struct list_head *lh, *n;
        struct eth1394_node_ref *node;
        struct eth1394_node_info *node_info;
        unsigned long flags;

        hi = hpsb_get_hostinfo(&eth1394_highlevel, host);

        /* This can happen for hosts that we don't use */
        if (!hi)
                return;

        dev = hi->dev;
        priv = (struct eth1394_priv *)netdev_priv(dev);

        /* Reset our private host data, but not our mtu */
        netif_stop_queue (dev);
        ether1394_reset_priv (dev, 0);

        list_for_each_entry(node, &priv->ip_node_list, list) {
                node_info = (struct eth1394_node_info*)node->ud->device.driver_data;

                spin_lock_irqsave(&node_info->pdg.lock, flags);

                list_for_each_safe(lh, n, &node_info->pdg.list) {
                        purge_partial_datagram(lh);
                }

                INIT_LIST_HEAD(&(node_info->pdg.list));
                node_info->pdg.sz = 0;

                spin_unlock_irqrestore(&node_info->pdg.lock, flags);
        }

        netif_wake_queue (dev);
}

/******************************************
 * HW Header net device functions
 ******************************************/
/* These functions have been adapted from net/ethernet/eth.c */


/* Create a fake MAC header for an arbitrary protocol layer.
 * saddr=NULL means use device source address
 * daddr=NULL means leave destination address (eg unresolved arp). */
static int ether1394_header(struct sk_buff *skb, struct net_device *dev,
                            unsigned short type, void *daddr, void *saddr,
                            unsigned len)
{
        struct eth1394hdr *eth = (struct eth1394hdr *)skb_push(skb, ETH1394_HLEN);

        eth->h_proto = htons(type);

        if (dev->flags & (IFF_LOOPBACK|IFF_NOARP)) {
                memset(eth->h_dest, 0, dev->addr_len);
                return(dev->hard_header_len);
        }

        if (daddr) {
                memcpy(eth->h_dest,daddr,dev->addr_len);
                return dev->hard_header_len;
        }

        return -dev->hard_header_len;

}


/* Rebuild the faked MAC header. This is called after an ARP
 * (or in future other address resolution) has completed on this
 * sk_buff. We now let ARP fill in the other fields.
 *
 * This routine CANNOT use cached dst->neigh!
 * Really, it is used only when dst->neigh is wrong.
 */
static int ether1394_rebuild_header(struct sk_buff *skb)
{
        struct eth1394hdr *eth = (struct eth1394hdr *)skb->data;
        struct net_device *dev = skb->dev;

        switch (eth->h_proto) {

#ifdef CONFIG_INET
        case __constant_htons(ETH_P_IP):
                return arp_find((unsigned char*)&eth->h_dest, skb);
#endif
        default:
                ETH1394_PRINT(KERN_DEBUG, dev->name,
                              "unable to resolve type %04x addresses.\n",
                              ntohs(eth->h_proto));
                break;
        }

        return 0;
}

static int ether1394_header_parse(struct sk_buff *skb, unsigned char *haddr)
{
        struct net_device *dev = skb->dev;
        memcpy(haddr, dev->dev_addr, ETH1394_ALEN);
        return ETH1394_ALEN;
}


static int ether1394_header_cache(struct neighbour *neigh, struct hh_cache *hh)
{
        unsigned short type = hh->hh_type;
        struct eth1394hdr *eth = (struct eth1394hdr*)(((u8*)hh->hh_data) +
                                                      (16 - ETH1394_HLEN));
        struct net_device *dev = neigh->dev;

        if (type == htons(ETH_P_802_3))
                return -1;

        eth->h_proto = type;
        memcpy(eth->h_dest, neigh->ha, dev->addr_len);

        hh->hh_len = ETH1394_HLEN;
        return 0;
}

/* Called by Address Resolution module to notify changes in address. */
static void ether1394_header_cache_update(struct hh_cache *hh,
                                          struct net_device *dev,
                                          unsigned char * haddr)
{
        memcpy(((u8*)hh->hh_data) + (16 - ETH1394_HLEN), haddr, dev->addr_len);
}

static int ether1394_mac_addr(struct net_device *dev, void *p)
{
        if (netif_running(dev))
                return -EBUSY;

        /* Not going to allow setting the MAC address, we really need to use
         * the real one supplied by the hardware */
         return -EINVAL;
 }



/******************************************
 * Datagram reception code
 ******************************************/

/* Copied from net/ethernet/eth.c */
static u16 ether1394_type_trans(struct sk_buff *skb, struct net_device *dev)
{
        struct eth1394hdr *eth;
        unsigned char *rawp;

        skb_reset_mac_header(skb);
        skb_pull (skb, ETH1394_HLEN);
        eth = eth1394_hdr(skb);

        if (*eth->h_dest & 1) {
                if (memcmp(eth->h_dest, dev->broadcast, dev->addr_len)==0)
                        skb->pkt_type = PACKET_BROADCAST;
#if 0
                else
                        skb->pkt_type = PACKET_MULTICAST;
#endif
        } else {
                if (memcmp(eth->h_dest, dev->dev_addr, dev->addr_len))
                        skb->pkt_type = PACKET_OTHERHOST;
        }

        if (ntohs (eth->h_proto) >= 1536)
                return eth->h_proto;

        rawp = skb->data;

        if (*(unsigned short *)rawp == 0xFFFF)
                return htons (ETH_P_802_3);

        return htons (ETH_P_802_2);
}

/* Parse an encapsulated IP1394 header into an ethernet frame packet.
 * We also perform ARP translation here, if need be.  */
static u16 ether1394_parse_encap(struct sk_buff *skb, struct net_device *dev,
                                 nodeid_t srcid, nodeid_t destid,
                                 u16 ether_type)
{
        struct eth1394_priv *priv = netdev_priv(dev);
        u64 dest_hw;
        unsigned short ret = 0;

        /* Setup our hw addresses. We use these to build the
         * ethernet header.  */
        if (destid == (LOCAL_BUS | ALL_NODES))
                dest_hw = ~0ULL;  /* broadcast */
        else
                dest_hw = cpu_to_be64((((u64)priv->host->csr.guid_hi) << 32) |
                                      priv->host->csr.guid_lo);

        /* If this is an ARP packet, convert it. First, we want to make
         * use of some of the fields, since they tell us a little bit
         * about the sending machine.  */
        if (ether_type == htons(ETH_P_ARP)) {
                struct eth1394_arp *arp1394 = (struct eth1394_arp*)skb->data;
                struct arphdr *arp = (struct arphdr *)skb->data;
                unsigned char *arp_ptr = (unsigned char *)(arp + 1);
                u64 fifo_addr = (u64)ntohs(arp1394->fifo_hi) << 32 |
                        ntohl(arp1394->fifo_lo);
                u8 max_rec = min(priv->host->csr.max_rec,
                                 (u8)(arp1394->max_rec));
                int sspd = arp1394->sspd;
                u16 maxpayload;
                struct eth1394_node_ref *node;
                struct eth1394_node_info *node_info;
                __be64 guid;

                /* Sanity check. MacOSX seems to be sending us 131 in this
                 * field (atleast on my Panther G5). Not sure why. */
                if (sspd > 5 || sspd < 0)
                        sspd = 0;

                maxpayload = min(eth1394_speedto_maxpayload[sspd], (u16)(1 << (max_rec + 1)));

                guid = get_unaligned(&arp1394->s_uniq_id);
                node = eth1394_find_node_guid(&priv->ip_node_list,
                                              be64_to_cpu(guid));
                if (!node) {
                        return 0;
                }

                node_info = (struct eth1394_node_info*)node->ud->device.driver_data;

                /* Update our speed/payload/fifo_offset table */
                node_info->maxpayload = maxpayload;
                node_info->sspd =       sspd;
                node_info->fifo =       fifo_addr;

                /* Now that we're done with the 1394 specific stuff, we'll
                 * need to alter some of the data.  Believe it or not, all
                 * that needs to be done is sender_IP_address needs to be
                 * moved, the destination hardware address get stuffed
                 * in and the hardware address length set to 8.
                 *
                 * IMPORTANT: The code below overwrites 1394 specific data
                 * needed above so keep the munging of the data for the
                 * higher level IP stack last. */

                arp->ar_hln = 8;
                arp_ptr += arp->ar_hln;         /* skip over sender unique id */
                *(u32*)arp_ptr = arp1394->sip;  /* move sender IP addr */
                arp_ptr += arp->ar_pln;         /* skip over sender IP addr */

                if (arp->ar_op == htons(ARPOP_REQUEST))
                        memset(arp_ptr, 0, sizeof(u64));
                else
                        memcpy(arp_ptr, dev->dev_addr, sizeof(u64));
        }

        /* Now add the ethernet header. */
        if (dev->hard_header(skb, dev, ntohs(ether_type), &dest_hw, NULL,
                             skb->len) >= 0)
                ret = ether1394_type_trans(skb, dev);

        return ret;
}

static int fragment_overlap(struct list_head *frag_list, int offset, int len)
{
        struct fragment_info *fi;

        list_for_each_entry(fi, frag_list, list) {
                if ( ! ((offset > (fi->offset + fi->len - 1)) ||
                       ((offset + len - 1) < fi->offset)))
                        return 1;
        }
        return 0;
}

static struct list_head *find_partial_datagram(struct list_head *pdgl, int dgl)
{
        struct partial_datagram *pd;

        list_for_each_entry(pd, pdgl, list) {
                if (pd->dgl == dgl)
                        return &pd->list;
        }
        return NULL;
}

/* Assumes that new fragment does not overlap any existing fragments */
static int new_fragment(struct list_head *frag_info, int offset, int len)
{
        struct list_head *lh;
        struct fragment_info *fi, *fi2, *new;

        list_for_each(lh, frag_info) {
                fi = list_entry(lh, struct fragment_info, list);
                if ((fi->offset + fi->len) == offset) {
                        /* The new fragment can be tacked on to the end */
                        fi->len += len;
                        /* Did the new fragment plug a hole? */
                        fi2 = list_entry(lh->next, struct fragment_info, list);
                        if ((fi->offset + fi->len) == fi2->offset) {
                                /* glue fragments together */
                                fi->len += fi2->len;
                                list_del(lh->next);
                                kfree(fi2);
                        }
                        return 0;
                } else if ((offset + len) == fi->offset) {
                        /* The new fragment can be tacked on to the beginning */
                        fi->offset = offset;
                        fi->len += len;
                        /* Did the new fragment plug a hole? */
                        fi2 = list_entry(lh->prev, struct fragment_info, list);
                        if ((fi2->offset + fi2->len) == fi->offset) {
                                /* glue fragments together */
                                fi2->len += fi->len;
                                list_del(lh);
                                kfree(fi);
                        }
                        return 0;
                } else if (offset > (fi->offset + fi->len)) {
                        break;
                } else if ((offset + len) < fi->offset) {
                        lh = lh->prev;
                        break;
                }
        }

        new = kmalloc(sizeof(*new), GFP_ATOMIC);
        if (!new)
                return -ENOMEM;

        new->offset = offset;
        new->len = len;

        list_add(&new->list, lh);

        return 0;
}

static int new_partial_datagram(struct net_device *dev, struct list_head *pdgl,
                                int dgl, int dg_size, char *frag_buf,
                                int frag_off, int frag_len)
{
        struct partial_datagram *new;

        new = kmalloc(sizeof(*new), GFP_ATOMIC);
        if (!new)
                return -ENOMEM;

        INIT_LIST_HEAD(&new->frag_info);

        if (new_fragment(&new->frag_info, frag_off, frag_len) < 0) {
                kfree(new);
                return -ENOMEM;
        }

        new->dgl = dgl;
        new->dg_size = dg_size;

        new->skb = dev_alloc_skb(dg_size + dev->hard_header_len + 15);
        if (!new->skb) {
                struct fragment_info *fi = list_entry(new->frag_info.next,
                                                      struct fragment_info,
                                                      list);
                kfree(fi);
                kfree(new);
                return -ENOMEM;
        }

        skb_reserve(new->skb, (dev->hard_header_len + 15) & ~15);
        new->pbuf = skb_put(new->skb, dg_size);
        memcpy(new->pbuf + frag_off, frag_buf, frag_len);

        list_add(&new->list, pdgl);

        return 0;
}

static int update_partial_datagram(struct list_head *pdgl, struct list_head *lh,
                                   char *frag_buf, int frag_off, int frag_len)
{
        struct partial_datagram *pd = list_entry(lh, struct partial_datagram, list);

        if (new_fragment(&pd->frag_info, frag_off, frag_len) < 0) {
                return -ENOMEM;
        }

        memcpy(pd->pbuf + frag_off, frag_buf, frag_len);

        /* Move list entry to beginnig of list so that oldest partial
         * datagrams percolate to the end of the list */
        list_move(lh, pdgl);

        return 0;
}

static int is_datagram_complete(struct list_head *lh, int dg_size)
{
        struct partial_datagram *pd;
        struct fragment_info *fi;

        pd = list_entry(lh, struct partial_datagram, list);
        fi = list_entry(pd->frag_info.next, struct fragment_info, list);

        return (fi->len == dg_size);
}

/* Packet reception. We convert the IP1394 encapsulation header to an
 * ethernet header, and fill it with some of our other fields. This is
 * an incoming packet from the 1394 bus.  */
static int ether1394_data_handler(struct net_device *dev, int srcid, int destid,
                                  char *buf, int len)
{
        struct sk_buff *skb;
        unsigned long flags;
        struct eth1394_priv *priv = netdev_priv(dev);
        union eth1394_hdr *hdr = (union eth1394_hdr *)buf;
        u16 ether_type = 0;  /* initialized to clear warning */
        int hdr_len;
        struct unit_directory *ud = priv->ud_list[NODEID_TO_NODE(srcid)];
        struct eth1394_node_info *node_info;

        if (!ud) {
                struct eth1394_node_ref *node;
                node = eth1394_find_node_nodeid(&priv->ip_node_list, srcid);
                if (!node) {
                        HPSB_PRINT(KERN_ERR, "ether1394 rx: sender nodeid "
                                   "lookup failure: " NODE_BUS_FMT,
                                   NODE_BUS_ARGS(priv->host, srcid));
                        priv->stats.rx_dropped++;
                        return -1;
                }
                ud = node->ud;

                priv->ud_list[NODEID_TO_NODE(srcid)] = ud;
        }

        node_info = (struct eth1394_node_info*)ud->device.driver_data;

        /* First, did we receive a fragmented or unfragmented datagram? */
        hdr->words.word1 = ntohs(hdr->words.word1);

        hdr_len = hdr_type_len[hdr->common.lf];

        if (hdr->common.lf == ETH1394_HDR_LF_UF) {
                /* An unfragmented datagram has been received by the ieee1394
                 * bus. Build an skbuff around it so we can pass it to the
                 * high level network layer. */

                skb = dev_alloc_skb(len + dev->hard_header_len + 15);
                if (!skb) {
                        HPSB_PRINT (KERN_ERR, "ether1394 rx: low on mem\n");
                        priv->stats.rx_dropped++;
                        return -1;
                }
                skb_reserve(skb, (dev->hard_header_len + 15) & ~15);
                memcpy(skb_put(skb, len - hdr_len), buf + hdr_len, len - hdr_len);
                ether_type = hdr->uf.ether_type;
        } else {
                /* A datagram fragment has been received, now the fun begins. */

                struct list_head *pdgl, *lh;
                struct partial_datagram *pd;
                int fg_off;
                int fg_len = len - hdr_len;
                int dg_size;
                int dgl;
                int retval;
                struct pdg_list *pdg = &(node_info->pdg);

                hdr->words.word3 = ntohs(hdr->words.word3);
                /* The 4th header word is reserved so no need to do ntohs() */

                if (hdr->common.lf == ETH1394_HDR_LF_FF) {
                        ether_type = hdr->ff.ether_type;
                        dgl = hdr->ff.dgl;
                        dg_size = hdr->ff.dg_size + 1;
                        fg_off = 0;
                } else {
                        hdr->words.word2 = ntohs(hdr->words.word2);
                        dgl = hdr->sf.dgl;
                        dg_size = hdr->sf.dg_size + 1;
                        fg_off = hdr->sf.fg_off;
                }
                spin_lock_irqsave(&pdg->lock, flags);

                pdgl = &(pdg->list);
                lh = find_partial_datagram(pdgl, dgl);

                if (lh == NULL) {
                        while (pdg->sz >= max_partial_datagrams) {
                                /* remove the oldest */
                                purge_partial_datagram(pdgl->prev);
                                pdg->sz--;
                        }

                        retval = new_partial_datagram(dev, pdgl, dgl, dg_size,
                                                      buf + hdr_len, fg_off,
                                                      fg_len);
                        if (retval < 0) {
                                spin_unlock_irqrestore(&pdg->lock, flags);
                                goto bad_proto;
                        }
                        pdg->sz++;
                        lh = find_partial_datagram(pdgl, dgl);
                } else {
                        struct partial_datagram *pd;

                        pd = list_entry(lh, struct partial_datagram, list);

                        if (fragment_overlap(&pd->frag_info, fg_off, fg_len)) {
                                /* Overlapping fragments, obliterate old
                                 * datagram and start new one. */
                                purge_partial_datagram(lh);
                                retval = new_partial_datagram(dev, pdgl, dgl,
                                                              dg_size,
                                                              buf + hdr_len,
                                                              fg_off, fg_len);
                                if (retval < 0) {
                                        pdg->sz--;
                                        spin_unlock_irqrestore(&pdg->lock, flags);
                                        goto bad_proto;
                                }
                        } else {
                                retval = update_partial_datagram(pdgl, lh,
                                                                 buf + hdr_len,
                                                                 fg_off, fg_len);
                                if (retval < 0) {
                                        /* Couldn't save off fragment anyway
                                         * so might as well obliterate the
                                         * datagram now. */
                                        purge_partial_datagram(lh);
                                        pdg->sz--;
                                        spin_unlock_irqrestore(&pdg->lock, flags);
                                        goto bad_proto;
                                }
                        } /* fragment overlap */
                } /* new datagram or add to existing one */

                pd = list_entry(lh, struct partial_datagram, list);

                if (hdr->common.lf == ETH1394_HDR_LF_FF) {
                        pd->ether_type = ether_type;
                }

                if (is_datagram_complete(lh, dg_size)) {
                        ether_type = pd->ether_type;
                        pdg->sz--;
                        skb = skb_get(pd->skb);
                        purge_partial_datagram(lh);
                        spin_unlock_irqrestore(&pdg->lock, flags);
                } else {
                        /* Datagram is not complete, we're done for the
                         * moment. */
                        spin_unlock_irqrestore(&pdg->lock, flags);
                        return 0;
                }
        } /* unframgented datagram or fragmented one */

        /* Write metadata, and then pass to the receive level */
        skb->dev = dev;
        skb->ip_summed = CHECKSUM_UNNECESSARY;  /* don't check it */

        /* Parse the encapsulation header. This actually does the job of
         * converting to an ethernet frame header, aswell as arp
         * conversion if needed. ARP conversion is easier in this
         * direction, since we are using ethernet as our backend.  */
        skb->protocol = ether1394_parse_encap(skb, dev, srcid, destid,
                                              ether_type);


        spin_lock_irqsave(&priv->lock, flags);
        if (!skb->protocol) {
                priv->stats.rx_errors++;
                priv->stats.rx_dropped++;
                dev_kfree_skb_any(skb);
                goto bad_proto;
        }

        if (netif_rx(skb) == NET_RX_DROP) {
                priv->stats.rx_errors++;
                priv->stats.rx_dropped++;
                goto bad_proto;
        }

        /* Statistics */
        priv->stats.rx_packets++;
        priv->stats.rx_bytes += skb->len;

bad_proto:
        if (netif_queue_stopped(dev))
                netif_wake_queue(dev);
        spin_unlock_irqrestore(&priv->lock, flags);

        dev->last_rx = jiffies;

        return 0;
}

static int ether1394_write(struct hpsb_host *host, int srcid, int destid,
                           quadlet_t *data, u64 addr, size_t len, u16 flags)
{
        struct eth1394_host_info *hi;

        hi = hpsb_get_hostinfo(&eth1394_highlevel, host);
        if (hi == NULL) {
                ETH1394_PRINT_G(KERN_ERR, "Could not find net device for host %s\n",
                                host->driver->name);
                return RCODE_ADDRESS_ERROR;
        }

        if (ether1394_data_handler(hi->dev, srcid, destid, (char*)data, len))
                return RCODE_ADDRESS_ERROR;
        else
                return RCODE_COMPLETE;
}

static void ether1394_iso(struct hpsb_iso *iso)
{
        quadlet_t *data;
        char *buf;
        struct eth1394_host_info *hi;
        struct net_device *dev;
        struct eth1394_priv *priv;
        unsigned int len;
        u32 specifier_id;
        u16 source_id;
        int i;
        int nready;

        hi = hpsb_get_hostinfo(&eth1394_highlevel, iso->host);
        if (hi == NULL) {
                ETH1394_PRINT_G(KERN_ERR, "Could not find net device for host %s\n",
                                iso->host->driver->name);
                return;
        }

        dev = hi->dev;

        nready = hpsb_iso_n_ready(iso);
        for (i = 0; i < nready; i++) {
                struct hpsb_iso_packet_info *info =
                        &iso->infos[(iso->first_packet + i) % iso->buf_packets];
                data = (quadlet_t*) (iso->data_buf.kvirt + info->offset);

                /* skip over GASP header */
                buf = (char *)data + 8;
                len = info->len - 8;

                specifier_id = (((be32_to_cpu(data[0]) & 0xffff) << 8) |
                                ((be32_to_cpu(data[1]) & 0xff000000) >> 24));
                source_id = be32_to_cpu(data[0]) >> 16;

                priv = netdev_priv(dev);

                if (info->channel != (iso->host->csr.broadcast_channel & 0x3f) ||
                   specifier_id != ETHER1394_GASP_SPECIFIER_ID) {
                        /* This packet is not for us */
                        continue;
                }
                ether1394_data_handler(dev, source_id, LOCAL_BUS | ALL_NODES,
                                       buf, len);
        }

        hpsb_iso_recv_release_packets(iso, i);

        dev->last_rx = jiffies;
}

/******************************************
 * Datagram transmission code
 ******************************************/

/* Convert a standard ARP packet to 1394 ARP. The first 8 bytes (the entire
 * arphdr) is the same format as the ip1394 header, so they overlap.  The rest
 * needs to be munged a bit.  The remainder of the arphdr is formatted based
 * on hwaddr len and ipaddr len.  We know what they'll be, so it's easy to
 * judge.
 *
 * Now that the EUI is used for the hardware address all we need to do to make
 * this work for 1394 is to insert 2 quadlets that contain max_rec size,
 * speed, and unicast FIFO address information between the sender_unique_id
 * and the IP addresses.
 */
static void ether1394_arp_to_1394arp(struct sk_buff *skb,
                                     struct net_device *dev)
{
        struct eth1394_priv *priv = netdev_priv(dev);

        struct arphdr *arp = (struct arphdr *)skb->data;
        unsigned char *arp_ptr = (unsigned char *)(arp + 1);
        struct eth1394_arp *arp1394 = (struct eth1394_arp *)skb->data;

        /* Believe it or not, all that need to happen is sender IP get moved
         * and set hw_addr_len, max_rec, sspd, fifo_hi and fifo_lo.  */
        arp1394->hw_addr_len    = 16;
        arp1394->sip            = *(u32*)(arp_ptr + ETH1394_ALEN);
        arp1394->max_rec        = priv->host->csr.max_rec;
        arp1394->sspd           = priv->host->csr.lnk_spd;
        arp1394->fifo_hi        = htons (priv->local_fifo >> 32);
        arp1394->fifo_lo        = htonl (priv->local_fifo & ~0x0);

        return;
}

/* We need to encapsulate the standard header with our own. We use the
 * ethernet header's proto for our own. */
static unsigned int ether1394_encapsulate_prep(unsigned int max_payload,
                                               __be16 proto,
                                               union eth1394_hdr *hdr,
                                               u16 dg_size, u16 dgl)
{
        unsigned int adj_max_payload = max_payload - hdr_type_len[ETH1394_HDR_LF_UF];

        /* Does it all fit in one packet? */
        if (dg_size <= adj_max_payload) {
                hdr->uf.lf = ETH1394_HDR_LF_UF;
                hdr->uf.ether_type = proto;
        } else {
                hdr->ff.lf = ETH1394_HDR_LF_FF;
                hdr->ff.ether_type = proto;
                hdr->ff.dg_size = dg_size - 1;
                hdr->ff.dgl = dgl;
                adj_max_payload = max_payload - hdr_type_len[ETH1394_HDR_LF_FF];
        }
        return((dg_size + (adj_max_payload - 1)) / adj_max_payload);
}

static unsigned int ether1394_encapsulate(struct sk_buff *skb,
                                          unsigned int max_payload,
                                          union eth1394_hdr *hdr)
{
        union eth1394_hdr *bufhdr;
        int ftype = hdr->common.lf;
        int hdrsz = hdr_type_len[ftype];
        unsigned int adj_max_payload = max_payload - hdrsz;

        switch(ftype) {
        case ETH1394_HDR_LF_UF:
                bufhdr = (union eth1394_hdr *)skb_push(skb, hdrsz);
                bufhdr->words.word1 = htons(hdr->words.word1);
                bufhdr->words.word2 = hdr->words.word2;
                break;

        case ETH1394_HDR_LF_FF:
                bufhdr = (union eth1394_hdr *)skb_push(skb, hdrsz);
                bufhdr->words.word1 = htons(hdr->words.word1);
                bufhdr->words.word2 = hdr->words.word2;
                bufhdr->words.word3 = htons(hdr->words.word3);
                bufhdr->words.word4 = 0;

                /* Set frag type here for future interior fragments */
                hdr->common.lf = ETH1394_HDR_LF_IF;
                hdr->sf.fg_off = 0;
                break;

        default:
                hdr->sf.fg_off += adj_max_payload;
                bufhdr = (union eth1394_hdr *)skb_pull(skb, adj_max_payload);
                if (max_payload >= skb->len)
                        hdr->common.lf = ETH1394_HDR_LF_LF;
                bufhdr->words.word1 = htons(hdr->words.word1);
                bufhdr->words.word2 = htons(hdr->words.word2);
                bufhdr->words.word3 = htons(hdr->words.word3);
                bufhdr->words.word4 = 0;
        }

        return min(max_payload, skb->len);
}

static struct hpsb_packet *ether1394_alloc_common_packet(struct hpsb_host *host)
{
        struct hpsb_packet *p;

        p = hpsb_alloc_packet(0);
        if (p) {
                p->host = host;
                p->generation = get_hpsb_generation(host);
                p->type = hpsb_async;
        }
        return p;
}

static int ether1394_prep_write_packet(struct hpsb_packet *p,
                                       struct hpsb_host *host, nodeid_t node,
                                       u64 addr, void * data, int tx_len)
{
        p->node_id = node;
        p->data = NULL;

        p->tcode = TCODE_WRITEB;
        p->header[1] = (host->node_id << 16) | (addr >> 32);
        p->header[2] = addr & 0xffffffff;

        p->header_size = 16;
        p->expect_response = 1;

        if (hpsb_get_tlabel(p)) {
                ETH1394_PRINT_G(KERN_ERR, "No more tlabels left while sending "
                                "to node " NODE_BUS_FMT "\n", NODE_BUS_ARGS(host, node));
                return -1;
        }
        p->header[0] = (p->node_id << 16) | (p->tlabel << 10)
                | (1 << 8) | (TCODE_WRITEB << 4);

        p->header[3] = tx_len << 16;
        p->data_size = (tx_len + 3) & ~3;
        p->data = (quadlet_t*)data;

        return 0;
}

static void ether1394_prep_gasp_packet(struct hpsb_packet *p,
                                       struct eth1394_priv *priv,
                                       struct sk_buff *skb, int length)
{
        p->header_size = 4;
        p->tcode = TCODE_STREAM_DATA;

        p->header[0] = (length << 16) | (3 << 14)
                | ((priv->broadcast_channel) << 8)
                | (TCODE_STREAM_DATA << 4);
        p->data_size = length;
        p->data = ((quadlet_t*)skb->data) - 2;
        p->data[0] = cpu_to_be32((priv->host->node_id << 16) |
                                 ETHER1394_GASP_SPECIFIER_ID_HI);
        p->data[1] = cpu_to_be32((ETHER1394_GASP_SPECIFIER_ID_LO << 24) |
                                 ETHER1394_GASP_VERSION);

        /* Setting the node id to ALL_NODES (not LOCAL_BUS | ALL_NODES)
         * prevents hpsb_send_packet() from setting the speed to an arbitrary
         * value based on packet->node_id if packet->node_id is not set. */
        p->node_id = ALL_NODES;
        p->speed_code = priv->bc_sspd;
}

static void ether1394_free_packet(struct hpsb_packet *packet)
{
        if (packet->tcode != TCODE_STREAM_DATA)
                hpsb_free_tlabel(packet);
        hpsb_free_packet(packet);
}

static void ether1394_complete_cb(void *__ptask);

static int ether1394_send_packet(struct packet_task *ptask, unsigned int tx_len)
{
        struct eth1394_priv *priv = ptask->priv;
        struct hpsb_packet *packet = NULL;

        packet = ether1394_alloc_common_packet(priv->host);
        if (!packet)
                return -1;

        if (ptask->tx_type == ETH1394_GASP) {
                int length = tx_len + (2 * sizeof(quadlet_t));

                ether1394_prep_gasp_packet(packet, priv, ptask->skb, length);
        } else if (ether1394_prep_write_packet(packet, priv->host,
                                               ptask->dest_node,
                                               ptask->addr, ptask->skb->data,
                                               tx_len)) {
                hpsb_free_packet(packet);
                return -1;
        }

        ptask->packet = packet;
        hpsb_set_packet_complete_task(ptask->packet, ether1394_complete_cb,
                                      ptask);

        if (hpsb_send_packet(packet) < 0) {
                ether1394_free_packet(packet);
                return -1;
        }

        return 0;
}


/* Task function to be run when a datagram transmission is completed */
static void ether1394_dg_complete(struct packet_task *ptask, int fail)
{
        struct sk_buff *skb = ptask->skb;
        struct net_device *dev = skb->dev;
        struct eth1394_priv *priv = netdev_priv(dev);
        unsigned long flags;

        /* Statistics */
        spin_lock_irqsave(&priv->lock, flags);
        if (fail) {
                priv->stats.tx_dropped++;
                priv->stats.tx_errors++;
        } else {
                priv->stats.tx_bytes += skb->len;
                priv->stats.tx_packets++;
        }
        spin_unlock_irqrestore(&priv->lock, flags);

        dev_kfree_skb_any(skb);
        kmem_cache_free(packet_task_cache, ptask);
}


/* Callback for when a packet has been sent and the status of that packet is
 * known */
static void ether1394_complete_cb(void *__ptask)
{
        struct packet_task *ptask = (struct packet_task *)__ptask;
        struct hpsb_packet *packet = ptask->packet;
        int fail = 0;

        if (packet->tcode != TCODE_STREAM_DATA)
                fail = hpsb_packet_success(packet);

        ether1394_free_packet(packet);

        ptask->outstanding_pkts--;
        if (ptask->outstanding_pkts > 0 && !fail) {
                int tx_len;

                /* Add the encapsulation header to the fragment */
                tx_len = ether1394_encapsulate(ptask->skb, ptask->max_payload,
                                               &ptask->hdr);
                if (ether1394_send_packet(ptask, tx_len))
                        ether1394_dg_complete(ptask, 1);
        } else {
                ether1394_dg_complete(ptask, fail);
        }
}



/* Transmit a packet (called by kernel) */
static int ether1394_tx (struct sk_buff *skb, struct net_device *dev)
{
        gfp_t kmflags = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;
        struct eth1394hdr *eth;
        struct eth1394_priv *priv = netdev_priv(dev);
        __be16 proto;
        unsigned long flags;
        nodeid_t dest_node;
        eth1394_tx_type tx_type;
        int ret = 0;
        unsigned int tx_len;
        unsigned int max_payload;
        u16 dg_size;
        u16 dgl;
        struct packet_task *ptask;
        struct eth1394_node_ref *node;
        struct eth1394_node_info *node_info = NULL;

        ptask = kmem_cache_alloc(packet_task_cache, kmflags);
        if (ptask == NULL) {
                ret = -ENOMEM;
                goto fail;
        }

        /* XXX Ignore this for now. Noticed that when MacOSX is the IRM,
         * it does not set our validity bit. We need to compensate for
         * that somewhere else, but not in eth1394. */
#if 0
        if ((priv->host->csr.broadcast_channel & 0xc0000000) != 0xc0000000) {
                ret = -EAGAIN;
                goto fail;
        }
#endif

        if ((skb = skb_share_check (skb, kmflags)) == NULL) {
                ret = -ENOMEM;
                goto fail;
        }

        /* Get rid of the fake eth1394 header, but save a pointer */
        eth = (struct eth1394hdr*)skb->data;
        skb_pull(skb, ETH1394_HLEN);

        proto = eth->h_proto;
        dg_size = skb->len;

        /* Set the transmission type for the packet.  ARP packets and IP
         * broadcast packets are sent via GASP. */
        if (memcmp(eth->h_dest, dev->broadcast, ETH1394_ALEN) == 0 ||
            proto == htons(ETH_P_ARP) ||
            (proto == htons(ETH_P_IP) &&
             IN_MULTICAST(ntohl(ip_hdr(skb)->daddr)))) {
                tx_type = ETH1394_GASP;
                dest_node = LOCAL_BUS | ALL_NODES;
                max_payload = priv->bc_maxpayload - ETHER1394_GASP_OVERHEAD;
                BUG_ON(max_payload < (512 - ETHER1394_GASP_OVERHEAD));
                dgl = priv->bc_dgl;
                if (max_payload < dg_size + hdr_type_len[ETH1394_HDR_LF_UF])
                        priv->bc_dgl++;
        } else {
                __be64 guid = get_unaligned((u64 *)eth->h_dest);

                node = eth1394_find_node_guid(&priv->ip_node_list,
                                              be64_to_cpu(guid));
                if (!node) {
                        ret = -EAGAIN;
                        goto fail;
                }
                node_info = (struct eth1394_node_info*)node->ud->device.driver_data;
                if (node_info->fifo == CSR1212_INVALID_ADDR_SPACE) {
                        ret = -EAGAIN;
                        goto fail;
                }

                dest_node = node->ud->ne->nodeid;
                max_payload = node_info->maxpayload;
                BUG_ON(max_payload < (512 - ETHER1394_GASP_OVERHEAD));

                dgl = node_info->dgl;
                if (max_payload < dg_size + hdr_type_len[ETH1394_HDR_LF_UF])
                        node_info->dgl++;
                tx_type = ETH1394_WRREQ;
        }

        /* If this is an ARP packet, convert it */
        if (proto == htons(ETH_P_ARP))
                ether1394_arp_to_1394arp (skb, dev);

        ptask->hdr.words.word1 = 0;
        ptask->hdr.words.word2 = 0;
        ptask->hdr.words.word3 = 0;
        ptask->hdr.words.word4 = 0;
        ptask->skb = skb;
        ptask->priv = priv;
        ptask->tx_type = tx_type;

        if (tx_type != ETH1394_GASP) {
                u64 addr;

                spin_lock_irqsave(&priv->lock, flags);
                addr = node_info->fifo;
                spin_unlock_irqrestore(&priv->lock, flags);

                ptask->addr = addr;
                ptask->dest_node = dest_node;
        }

        ptask->tx_type = tx_type;
        ptask->max_payload = max_payload;
        ptask->outstanding_pkts = ether1394_encapsulate_prep(max_payload, proto,
                                                             &ptask->hdr, dg_size,
                                                             dgl);

        /* Add the encapsulation header to the fragment */
        tx_len = ether1394_encapsulate(skb, max_payload, &ptask->hdr);
        dev->trans_start = jiffies;
        if (ether1394_send_packet(ptask, tx_len))
                goto fail;

        netif_wake_queue(dev);
        return 0;
fail:
        if (ptask)
                kmem_cache_free(packet_task_cache, ptask);

        if (skb != NULL)
                dev_kfree_skb(skb);

        spin_lock_irqsave (&priv->lock, flags);
        priv->stats.tx_dropped++;
        priv->stats.tx_errors++;
        spin_unlock_irqrestore (&priv->lock, flags);

        if (netif_queue_stopped(dev))
                netif_wake_queue(dev);

        return 0;  /* returning non-zero causes serious problems */
}

static void ether1394_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
        strcpy (info->driver, driver_name);
        /* FIXME XXX provide sane businfo */
        strcpy (info->bus_info, "ieee1394");
}

static struct ethtool_ops ethtool_ops = {
        .get_drvinfo = ether1394_get_drvinfo
};

static int __init ether1394_init_module (void)
{
        packet_task_cache = kmem_cache_create("packet_task", sizeof(struct packet_task),
                                              0, 0, NULL, NULL);

        /* Register ourselves as a highlevel driver */
        hpsb_register_highlevel(&eth1394_highlevel);

        return hpsb_register_protocol(&eth1394_proto_driver);
}

static void __exit ether1394_exit_module (void)
{
        hpsb_unregister_protocol(&eth1394_proto_driver);
        hpsb_unregister_highlevel(&eth1394_highlevel);
        kmem_cache_destroy(packet_task_cache);
}

module_init(ether1394_init_module);
module_exit(ether1394_exit_module);