ethernet-tx.c

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/*********************************************************************
 * Author: Cavium Networks
 *
 * Contact: [email protected]
 * This file is part of the OCTEON SDK
 *
 * Copyright (c) 2003-2010 Cavium Networks
 *
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, Version 2, as
 * published by the Free Software Foundation.
 *
 * This file is distributed in the hope that it will be useful, but
 * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
 * NONINFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this file; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 * or visit http://www.gnu.org/licenses/.
 *
 * This file may also be available under a different license from Cavium.
 * Contact Cavium Networks for more information
*********************************************************************/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/etherdevice.h>
#include <linux/ip.h>
#include <linux/ratelimit.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <net/dst.h>
#ifdef CONFIG_XFRM
#include <linux/xfrm.h>
#include <net/xfrm.h>
#endif /* CONFIG_XFRM */

#include <linux/atomic.h>

#include <asm/octeon/octeon.h>

#include "ethernet-defines.h"
#include "octeon-ethernet.h"
#include "ethernet-tx.h"
#include "ethernet-util.h"

#include <asm/octeon/cvmx-wqe.h>
#include <asm/octeon/cvmx-fau.h>
#include <asm/octeon/cvmx-pip.h>
#include <asm/octeon/cvmx-pko.h>
#include <asm/octeon/cvmx-helper.h>

#include <asm/octeon/cvmx-gmxx-defs.h>

#define CVM_OCT_SKB_CB(skb) ((u64 *)((skb)->cb))

/*
 * You can define GET_SKBUFF_QOS() to override how the skbuff output
 * function determines which output queue is used. The default
 * implementation always uses the base queue for the port. If, for
 * example, you wanted to use the skb->priority field, define
 * GET_SKBUFF_QOS as: #define GET_SKBUFF_QOS(skb) ((skb)->priority)
 */
#ifndef GET_SKBUFF_QOS
#define GET_SKBUFF_QOS(skb) 0
#endif

static void cvm_oct_tx_do_cleanup(unsigned long arg);
static DECLARE_TASKLET(cvm_oct_tx_cleanup_tasklet, cvm_oct_tx_do_cleanup, 0);

/* Maximum number of SKBs to try to free per xmit packet. */
#define MAX_SKB_TO_FREE (MAX_OUT_QUEUE_DEPTH * 2)

static inline int32_t cvm_oct_adjust_skb_to_free(int32_t skb_to_free, int fau)
{
    int32_t undo;
    undo = skb_to_free > 0 ? MAX_SKB_TO_FREE : skb_to_free + MAX_SKB_TO_FREE;
    if (undo > 0)
        cvmx_fau_atomic_add32(fau, -undo);
    skb_to_free = -skb_to_free > MAX_SKB_TO_FREE ? MAX_SKB_TO_FREE : -skb_to_free;
    return skb_to_free;
}

static void cvm_oct_kick_tx_poll_watchdog(void)
{
    union cvmx_ciu_timx ciu_timx;
    ciu_timx.u64 = 0;
    ciu_timx.s.one_shot = 1;
    ciu_timx.s.len = cvm_oct_tx_poll_interval;
    cvmx_write_csr(CVMX_CIU_TIMX(1), ciu_timx.u64);
}

void cvm_oct_free_tx_skbs(struct net_device *dev)
{
    int32_t skb_to_free;
    int qos, queues_per_port;
    int total_freed = 0;
    int total_remaining = 0;
    unsigned long flags;
    struct octeon_ethernet *priv = netdev_priv(dev);

    queues_per_port = cvmx_pko_get_num_queues(priv->port);
    /* Drain any pending packets in the free list */
    for (qos = 0; qos < queues_per_port; qos++) {
        if (skb_queue_len(&priv->tx_free_list[qos]) == 0)
            continue;
        skb_to_free = cvmx_fau_fetch_and_add32(priv->fau+qos*4, MAX_SKB_TO_FREE);
        skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau+qos*4);


        total_freed += skb_to_free;
        if (skb_to_free > 0) {
            struct sk_buff *to_free_list = NULL;
            spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
            while (skb_to_free > 0) {
                struct sk_buff *t = __skb_dequeue(&priv->tx_free_list[qos]);
                t->next = to_free_list;
                to_free_list = t;
                skb_to_free--;
            }
            spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
            /* Do the actual freeing outside of the lock. */
            while (to_free_list) {
                struct sk_buff *t = to_free_list;
                to_free_list = to_free_list->next;
                dev_kfree_skb_any(t);
            }
        }
        total_remaining += skb_queue_len(&priv->tx_free_list[qos]);
    }
    if (total_freed >= 0 && netif_queue_stopped(dev))
        netif_wake_queue(dev);
    if (total_remaining)
        cvm_oct_kick_tx_poll_watchdog();
}

int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev)
{
    cvmx_pko_command_word0_t pko_command;
    union cvmx_buf_ptr hw_buffer;
    uint64_t old_scratch;
    uint64_t old_scratch2;
    int qos;
    int i;
    enum {QUEUE_CORE, QUEUE_HW, QUEUE_DROP} queue_type;
    struct octeon_ethernet *priv = netdev_priv(dev);
    struct sk_buff *to_free_list;
    int32_t skb_to_free;
    int32_t buffers_to_free;
    u32 total_to_clean;
    unsigned long flags;
#if REUSE_SKBUFFS_WITHOUT_FREE
    unsigned char *fpa_head;
#endif

    /*
     * Prefetch the private data structure.  It is larger than the
     * one cache line.
     */
    prefetch(priv);

    /*
     * The check on CVMX_PKO_QUEUES_PER_PORT_* is designed to
     * completely remove "qos" in the event neither interface
     * supports multiple queues per port.
     */
    if ((CVMX_PKO_QUEUES_PER_PORT_INTERFACE0 > 1) ||
        (CVMX_PKO_QUEUES_PER_PORT_INTERFACE1 > 1)) {
        qos = GET_SKBUFF_QOS(skb);
        if (qos <= 0)
            qos = 0;
        else if (qos >= cvmx_pko_get_num_queues(priv->port))
            qos = 0;
    } else
        qos = 0;

    if (USE_ASYNC_IOBDMA) {
        /* Save scratch in case userspace is using it */
        CVMX_SYNCIOBDMA;
        old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
        old_scratch2 = cvmx_scratch_read64(CVMX_SCR_SCRATCH + 8);

        /*
         * Fetch and increment the number of packets to be
         * freed.
         */
        cvmx_fau_async_fetch_and_add32(CVMX_SCR_SCRATCH + 8,
                           FAU_NUM_PACKET_BUFFERS_TO_FREE,
                           0);
        cvmx_fau_async_fetch_and_add32(CVMX_SCR_SCRATCH,
                           priv->fau + qos * 4,
                           MAX_SKB_TO_FREE);
    }

    /*
     * We have space for 6 segment pointers, If there will be more
     * than that, we must linearize.
     */
    if (unlikely(skb_shinfo(skb)->nr_frags > 5)) {
        if (unlikely(__skb_linearize(skb))) {
            queue_type = QUEUE_DROP;
            if (USE_ASYNC_IOBDMA) {
                /* Get the number of skbuffs in use by the hardware */
                CVMX_SYNCIOBDMA;
                skb_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
            } else {
                /* Get the number of skbuffs in use by the hardware */
                skb_to_free = cvmx_fau_fetch_and_add32(priv->fau + qos * 4,
                                       MAX_SKB_TO_FREE);
            }
            skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau + qos * 4);
            spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
            goto skip_xmit;
        }
    }

    /*
     * The CN3XXX series of parts has an errata (GMX-401) which
     * causes the GMX block to hang if a collision occurs towards
     * the end of a <68 byte packet. As a workaround for this, we
     * pad packets to be 68 bytes whenever we are in half duplex
     * mode. We don't handle the case of having a small packet but
     * no room to add the padding.  The kernel should always give
     * us at least a cache line
     */
    if ((skb->len < 64) && OCTEON_IS_MODEL(OCTEON_CN3XXX)) {
        union cvmx_gmxx_prtx_cfg gmx_prt_cfg;
        int interface = INTERFACE(priv->port);
        int index = INDEX(priv->port);

        if (interface < 2) {
            /* We only need to pad packet in half duplex mode */
            gmx_prt_cfg.u64 =
                cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
            if (gmx_prt_cfg.s.duplex == 0) {
                int add_bytes = 64 - skb->len;
                if ((skb_tail_pointer(skb) + add_bytes) <=
                    skb_end_pointer(skb))
                    memset(__skb_put(skb, add_bytes), 0,
                           add_bytes);
            }
        }
    }

    /* Build the PKO command */
    pko_command.u64 = 0;
    pko_command.s.n2 = 1;   /* Don't pollute L2 with the outgoing packet */
    pko_command.s.segs = 1;
    pko_command.s.total_bytes = skb->len;
    pko_command.s.size0 = CVMX_FAU_OP_SIZE_32;
    pko_command.s.subone0 = 1;

    pko_command.s.dontfree = 1;

    /* Build the PKO buffer pointer */
    hw_buffer.u64 = 0;
    if (skb_shinfo(skb)->nr_frags == 0) {
        hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)skb->data);
        hw_buffer.s.pool = 0;
        hw_buffer.s.size = skb->len;
    } else {
        hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)skb->data);
        hw_buffer.s.pool = 0;
        hw_buffer.s.size = skb_headlen(skb);
        CVM_OCT_SKB_CB(skb)[0] = hw_buffer.u64;
        for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
            struct skb_frag_struct *fs = skb_shinfo(skb)->frags + i;
            hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)(page_address(fs->page.p) + fs->page_offset));
            hw_buffer.s.size = fs->size;
            CVM_OCT_SKB_CB(skb)[i + 1] = hw_buffer.u64;
        }
        hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)CVM_OCT_SKB_CB(skb));
        hw_buffer.s.size = skb_shinfo(skb)->nr_frags + 1;
        pko_command.s.segs = skb_shinfo(skb)->nr_frags + 1;
        pko_command.s.gather = 1;
        goto dont_put_skbuff_in_hw;
    }

    /*
     * See if we can put this skb in the FPA pool. Any strange
     * behavior from the Linux networking stack will most likely
     * be caused by a bug in the following code. If some field is
     * in use by the network stack and gets carried over when a
     * buffer is reused, bad things may happen.  If in doubt and
     * you dont need the absolute best performance, disable the
     * define REUSE_SKBUFFS_WITHOUT_FREE. The reuse of buffers has
     * shown a 25% increase in performance under some loads.
     */
#if REUSE_SKBUFFS_WITHOUT_FREE
    fpa_head = skb->head + 256 - ((unsigned long)skb->head & 0x7f);
    if (unlikely(skb->data < fpa_head)) {
        /*
         * printk("TX buffer beginning can't meet FPA
         * alignment constraints\n");
         */
        goto dont_put_skbuff_in_hw;
    }
    if (unlikely
        ((skb_end_pointer(skb) - fpa_head) < CVMX_FPA_PACKET_POOL_SIZE)) {
        /*
           printk("TX buffer isn't large enough for the FPA\n");
         */
        goto dont_put_skbuff_in_hw;
    }
    if (unlikely(skb_shared(skb))) {
        /*
           printk("TX buffer sharing data with someone else\n");
         */
        goto dont_put_skbuff_in_hw;
    }
    if (unlikely(skb_cloned(skb))) {
        /*
           printk("TX buffer has been cloned\n");
         */
        goto dont_put_skbuff_in_hw;
    }
    if (unlikely(skb_header_cloned(skb))) {
        /*
           printk("TX buffer header has been cloned\n");
         */
        goto dont_put_skbuff_in_hw;
    }
    if (unlikely(skb->destructor)) {
        /*
           printk("TX buffer has a destructor\n");
         */
        goto dont_put_skbuff_in_hw;
    }
    if (unlikely(skb_shinfo(skb)->nr_frags)) {
        /*
           printk("TX buffer has fragments\n");
         */
        goto dont_put_skbuff_in_hw;
    }
    if (unlikely
        (skb->truesize !=
         sizeof(*skb) + skb_end_offset(skb))) {
        /*
           printk("TX buffer truesize has been changed\n");
         */
        goto dont_put_skbuff_in_hw;
    }

    /*
     * We can use this buffer in the FPA.  We don't need the FAU
     * update anymore
     */
    pko_command.s.dontfree = 0;

    hw_buffer.s.back = ((unsigned long)skb->data >> 7) - ((unsigned long)fpa_head >> 7);
    *(struct sk_buff **)(fpa_head - sizeof(void *)) = skb;

    /*
     * The skbuff will be reused without ever being freed. We must
     * cleanup a bunch of core things.
     */
    dst_release(skb_dst(skb));
    skb_dst_set(skb, NULL);
#ifdef CONFIG_XFRM
    secpath_put(skb->sp);
    skb->sp = NULL;
#endif
    nf_reset(skb);

#ifdef CONFIG_NET_SCHED
    skb->tc_index = 0;
#ifdef CONFIG_NET_CLS_ACT
    skb->tc_verd = 0;
#endif /* CONFIG_NET_CLS_ACT */
#endif /* CONFIG_NET_SCHED */
#endif /* REUSE_SKBUFFS_WITHOUT_FREE */

dont_put_skbuff_in_hw:

    /* Check if we can use the hardware checksumming */
    if (USE_HW_TCPUDP_CHECKSUM && (skb->protocol == htons(ETH_P_IP)) &&
        (ip_hdr(skb)->version == 4) && (ip_hdr(skb)->ihl == 5) &&
        ((ip_hdr(skb)->frag_off == 0) || (ip_hdr(skb)->frag_off == 1 << 14))
        && ((ip_hdr(skb)->protocol == IPPROTO_TCP)
        || (ip_hdr(skb)->protocol == IPPROTO_UDP))) {
        /* Use hardware checksum calc */
        pko_command.s.ipoffp1 = sizeof(struct ethhdr) + 1;
    }

    if (USE_ASYNC_IOBDMA) {
        /* Get the number of skbuffs in use by the hardware */
        CVMX_SYNCIOBDMA;
        skb_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
        buffers_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH + 8);
    } else {
        /* Get the number of skbuffs in use by the hardware */
        skb_to_free = cvmx_fau_fetch_and_add32(priv->fau + qos * 4,
                               MAX_SKB_TO_FREE);
        buffers_to_free =
            cvmx_fau_fetch_and_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE, 0);
    }

    skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau+qos*4);

    /*
     * If we're sending faster than the receive can free them then
     * don't do the HW free.
     */
    if ((buffers_to_free < -100) && !pko_command.s.dontfree)
        pko_command.s.dontfree = 1;

    if (pko_command.s.dontfree) {
        queue_type = QUEUE_CORE;
        pko_command.s.reg0 = priv->fau+qos*4;
    } else {
        queue_type = QUEUE_HW;
    }
    if (USE_ASYNC_IOBDMA)
        cvmx_fau_async_fetch_and_add32(CVMX_SCR_SCRATCH, FAU_TOTAL_TX_TO_CLEAN, 1);

    spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);

    /* Drop this packet if we have too many already queued to the HW */
    if (unlikely(skb_queue_len(&priv->tx_free_list[qos]) >= MAX_OUT_QUEUE_DEPTH)) {
        if (dev->tx_queue_len != 0) {
            /* Drop the lock when notifying the core.  */
            spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
            netif_stop_queue(dev);
            spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
        } else {
            /* If not using normal queueing.  */
            queue_type = QUEUE_DROP;
            goto skip_xmit;
        }
    }

    cvmx_pko_send_packet_prepare(priv->port, priv->queue + qos,
                     CVMX_PKO_LOCK_NONE);

    /* Send the packet to the output queue */
    if (unlikely(cvmx_pko_send_packet_finish(priv->port,
                         priv->queue + qos,
                         pko_command, hw_buffer,
                         CVMX_PKO_LOCK_NONE))) {
        printk_ratelimited("%s: Failed to send the packet\n", dev->name);
        queue_type = QUEUE_DROP;
    }
skip_xmit:
    to_free_list = NULL;

    switch (queue_type) {
    case QUEUE_DROP:
        skb->next = to_free_list;
        to_free_list = skb;
        priv->stats.tx_dropped++;
        break;
    case QUEUE_HW:
        cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE, -1);
        break;
    case QUEUE_CORE:
        __skb_queue_tail(&priv->tx_free_list[qos], skb);
        break;
    default:
        BUG();
    }

    while (skb_to_free > 0) {
        struct sk_buff *t = __skb_dequeue(&priv->tx_free_list[qos]);
        t->next = to_free_list;
        to_free_list = t;
        skb_to_free--;
    }

    spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);

    /* Do the actual freeing outside of the lock. */
    while (to_free_list) {
        struct sk_buff *t = to_free_list;
        to_free_list = to_free_list->next;
        dev_kfree_skb_any(t);
    }

    if (USE_ASYNC_IOBDMA) {
        CVMX_SYNCIOBDMA;
        total_to_clean = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
        /* Restore the scratch area */
        cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
        cvmx_scratch_write64(CVMX_SCR_SCRATCH + 8, old_scratch2);
    } else {
        total_to_clean = cvmx_fau_fetch_and_add32(FAU_TOTAL_TX_TO_CLEAN, 1);
    }

    if (total_to_clean & 0x3ff) {
        /*
         * Schedule the cleanup tasklet every 1024 packets for
         * the pathological case of high traffic on one port
         * delaying clean up of packets on a different port
         * that is blocked waiting for the cleanup.
         */
        tasklet_schedule(&cvm_oct_tx_cleanup_tasklet);
    }

    cvm_oct_kick_tx_poll_watchdog();

    return NETDEV_TX_OK;
}

int cvm_oct_xmit_pow(struct sk_buff *skb, struct net_device *dev)
{
    struct octeon_ethernet *priv = netdev_priv(dev);
    void *packet_buffer;
    void *copy_location;

    /* Get a work queue entry */
    cvmx_wqe_t *work = cvmx_fpa_alloc(CVMX_FPA_WQE_POOL);
    if (unlikely(work == NULL)) {
        printk_ratelimited("%s: Failed to allocate a work "
                   "queue entry\n", dev->name);
        priv->stats.tx_dropped++;
        dev_kfree_skb(skb);
        return 0;
    }

    /* Get a packet buffer */
    packet_buffer = cvmx_fpa_alloc(CVMX_FPA_PACKET_POOL);
    if (unlikely(packet_buffer == NULL)) {
        printk_ratelimited("%s: Failed to allocate a packet buffer\n",
                   dev->name);
        cvmx_fpa_free(work, CVMX_FPA_WQE_POOL, DONT_WRITEBACK(1));
        priv->stats.tx_dropped++;
        dev_kfree_skb(skb);
        return 0;
    }

    /*
     * Calculate where we need to copy the data to. We need to
     * leave 8 bytes for a next pointer (unused). We also need to
     * include any configure skip. Then we need to align the IP
     * packet src and dest into the same 64bit word. The below
     * calculation may add a little extra, but that doesn't
     * hurt.
     */
    copy_location = packet_buffer + sizeof(uint64_t);
    copy_location += ((CVMX_HELPER_FIRST_MBUFF_SKIP + 7) & 0xfff8) + 6;

    /*
     * We have to copy the packet since whoever processes this
     * packet will free it to a hardware pool. We can't use the
     * trick of counting outstanding packets like in
     * cvm_oct_xmit.
     */
    memcpy(copy_location, skb->data, skb->len);

    /*
     * Fill in some of the work queue fields. We may need to add
     * more if the software at the other end needs them.
     */
    work->hw_chksum = skb->csum;
    work->len = skb->len;
    work->ipprt = priv->port;
    work->qos = priv->port & 0x7;
    work->grp = pow_send_group;
    work->tag_type = CVMX_HELPER_INPUT_TAG_TYPE;
    work->tag = pow_send_group; /* FIXME */
    /* Default to zero. Sets of zero later are commented out */
    work->word2.u64 = 0;
    work->word2.s.bufs = 1;
    work->packet_ptr.u64 = 0;
    work->packet_ptr.s.addr = cvmx_ptr_to_phys(copy_location);
    work->packet_ptr.s.pool = CVMX_FPA_PACKET_POOL;
    work->packet_ptr.s.size = CVMX_FPA_PACKET_POOL_SIZE;
    work->packet_ptr.s.back = (copy_location - packet_buffer) >> 7;

    if (skb->protocol == htons(ETH_P_IP)) {
        work->word2.s.ip_offset = 14;
#if 0
        work->word2.s.vlan_valid = 0;   /* FIXME */
        work->word2.s.vlan_cfi = 0; /* FIXME */
        work->word2.s.vlan_id = 0;  /* FIXME */
        work->word2.s.dec_ipcomp = 0;   /* FIXME */
#endif
        work->word2.s.tcp_or_udp =
            (ip_hdr(skb)->protocol == IPPROTO_TCP)
            || (ip_hdr(skb)->protocol == IPPROTO_UDP);
#if 0
        /* FIXME */
        work->word2.s.dec_ipsec = 0;
        /* We only support IPv4 right now */
        work->word2.s.is_v6 = 0;
        /* Hardware would set to zero */
        work->word2.s.software = 0;
        /* No error, packet is internal */
        work->word2.s.L4_error = 0;
#endif
        work->word2.s.is_frag = !((ip_hdr(skb)->frag_off == 0)
                      || (ip_hdr(skb)->frag_off ==
                          1 << 14));
#if 0
        /* Assume Linux is sending a good packet */
        work->word2.s.IP_exc = 0;
#endif
        work->word2.s.is_bcast = (skb->pkt_type == PACKET_BROADCAST);
        work->word2.s.is_mcast = (skb->pkt_type == PACKET_MULTICAST);
#if 0
        /* This is an IP packet */
        work->word2.s.not_IP = 0;
        /* No error, packet is internal */
        work->word2.s.rcv_error = 0;
        /* No error, packet is internal */
        work->word2.s.err_code = 0;
#endif

        /*
         * When copying the data, include 4 bytes of the
         * ethernet header to align the same way hardware
         * does.
         */
        memcpy(work->packet_data, skb->data + 10,
               sizeof(work->packet_data));
    } else {
#if 0
        work->word2.snoip.vlan_valid = 0;   /* FIXME */
        work->word2.snoip.vlan_cfi = 0; /* FIXME */
        work->word2.snoip.vlan_id = 0;  /* FIXME */
        work->word2.snoip.software = 0; /* Hardware would set to zero */
#endif
        work->word2.snoip.is_rarp = skb->protocol == htons(ETH_P_RARP);
        work->word2.snoip.is_arp = skb->protocol == htons(ETH_P_ARP);
        work->word2.snoip.is_bcast =
            (skb->pkt_type == PACKET_BROADCAST);
        work->word2.snoip.is_mcast =
            (skb->pkt_type == PACKET_MULTICAST);
        work->word2.snoip.not_IP = 1;   /* IP was done up above */
#if 0
        /* No error, packet is internal */
        work->word2.snoip.rcv_error = 0;
        /* No error, packet is internal */
        work->word2.snoip.err_code = 0;
#endif
        memcpy(work->packet_data, skb->data, sizeof(work->packet_data));
    }

    /* Submit the packet to the POW */
    cvmx_pow_work_submit(work, work->tag, work->tag_type, work->qos,
                 work->grp);
    priv->stats.tx_packets++;
    priv->stats.tx_bytes += skb->len;
    dev_kfree_skb(skb);
    return 0;
}

void cvm_oct_tx_shutdown_dev(struct net_device *dev)
{
    struct octeon_ethernet *priv = netdev_priv(dev);
    unsigned long flags;
    int qos;

    for (qos = 0; qos < 16; qos++) {
        spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
        while (skb_queue_len(&priv->tx_free_list[qos]))
            dev_kfree_skb_any(__skb_dequeue
                      (&priv->tx_free_list[qos]));
        spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
    }
}

static void cvm_oct_tx_do_cleanup(unsigned long arg)
{
    int port;

    for (port = 0; port < TOTAL_NUMBER_OF_PORTS; port++) {
        if (cvm_oct_device[port]) {
            struct net_device *dev = cvm_oct_device[port];
            cvm_oct_free_tx_skbs(dev);
        }
    }
}

static irqreturn_t cvm_oct_tx_cleanup_watchdog(int cpl, void *dev_id)
{
    /* Disable the interrupt.  */
    cvmx_write_csr(CVMX_CIU_TIMX(1), 0);
    /* Do the work in the tasklet.  */
    tasklet_schedule(&cvm_oct_tx_cleanup_tasklet);
    return IRQ_HANDLED;
}

void cvm_oct_tx_initialize(void)
{
    int i;

    /* Disable the interrupt.  */
    cvmx_write_csr(CVMX_CIU_TIMX(1), 0);
    /* Register an IRQ hander for to receive CIU_TIMX(1) interrupts */
    i = request_irq(OCTEON_IRQ_TIMER1,
            cvm_oct_tx_cleanup_watchdog, 0,
            "Ethernet", cvm_oct_device);

    if (i)
        panic("Could not acquire Ethernet IRQ %d\n", OCTEON_IRQ_TIMER1);
}

void cvm_oct_tx_shutdown(void)
{
    /* Free the interrupt handler */
    free_irq(OCTEON_IRQ_TIMER1, cvm_oct_device);
}