243 lines
6.3 KiB
C
243 lines
6.3 KiB
C
/*
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* Linux ARCnet driver - RFC1051 ("simple" standard) packet encapsulation
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*
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* Written 1994-1999 by Avery Pennarun.
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* Derived from skeleton.c by Donald Becker.
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*
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* Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
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* for sponsoring the further development of this driver.
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*
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* **********************
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*
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* The original copyright of skeleton.c was as follows:
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*
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* skeleton.c Written 1993 by Donald Becker.
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* Copyright 1993 United States Government as represented by the
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* Director, National Security Agency. This software may only be used
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* and distributed according to the terms of the GNU General Public License as
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* modified by SRC, incorporated herein by reference.
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*
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* **********************
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*
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* For more details, see drivers/net/arcnet.c
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*
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* **********************
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*/
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#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/gfp.h>
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#include <linux/init.h>
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#include <linux/if_arp.h>
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#include <net/arp.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include "arcdevice.h"
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static __be16 type_trans(struct sk_buff *skb, struct net_device *dev);
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static void rx(struct net_device *dev, int bufnum,
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struct archdr *pkthdr, int length);
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static int build_header(struct sk_buff *skb, struct net_device *dev,
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unsigned short type, uint8_t daddr);
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static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
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int bufnum);
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static struct ArcProto rfc1051_proto = {
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.suffix = 's',
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.mtu = XMTU - RFC1051_HDR_SIZE,
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.is_ip = 1,
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.rx = rx,
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.build_header = build_header,
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.prepare_tx = prepare_tx,
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.continue_tx = NULL,
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.ack_tx = NULL
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};
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static int __init arcnet_rfc1051_init(void)
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{
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pr_info("%s\n", "RFC1051 \"simple standard\" (`s') encapsulation support loaded");
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arc_proto_map[ARC_P_IP_RFC1051]
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= arc_proto_map[ARC_P_ARP_RFC1051]
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= &rfc1051_proto;
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/* if someone else already owns the broadcast, we won't take it */
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if (arc_bcast_proto == arc_proto_default)
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arc_bcast_proto = &rfc1051_proto;
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return 0;
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}
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static void __exit arcnet_rfc1051_exit(void)
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{
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arcnet_unregister_proto(&rfc1051_proto);
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}
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module_init(arcnet_rfc1051_init);
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module_exit(arcnet_rfc1051_exit);
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MODULE_LICENSE("GPL");
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/* Determine a packet's protocol ID.
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*
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* With ARCnet we have to convert everything to Ethernet-style stuff.
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*/
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static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
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{
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struct archdr *pkt = (struct archdr *)skb->data;
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struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
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int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
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/* Pull off the arcnet header. */
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skb_reset_mac_header(skb);
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skb_pull(skb, hdr_size);
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if (pkt->hard.dest == 0) {
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skb->pkt_type = PACKET_BROADCAST;
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} else if (dev->flags & IFF_PROMISC) {
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/* if we're not sending to ourselves :) */
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if (pkt->hard.dest != dev->dev_addr[0])
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skb->pkt_type = PACKET_OTHERHOST;
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}
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/* now return the protocol number */
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switch (soft->proto) {
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case ARC_P_IP_RFC1051:
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return htons(ETH_P_IP);
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case ARC_P_ARP_RFC1051:
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return htons(ETH_P_ARP);
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default:
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dev->stats.rx_errors++;
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dev->stats.rx_crc_errors++;
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return 0;
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}
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return htons(ETH_P_IP);
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}
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/* packet receiver */
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static void rx(struct net_device *dev, int bufnum,
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struct archdr *pkthdr, int length)
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{
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struct arcnet_local *lp = netdev_priv(dev);
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struct sk_buff *skb;
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struct archdr *pkt = pkthdr;
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int ofs;
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arc_printk(D_DURING, dev, "it's a raw packet (length=%d)\n", length);
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if (length >= MinTU)
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ofs = 512 - length;
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else
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ofs = 256 - length;
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skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
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if (!skb) {
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dev->stats.rx_dropped++;
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return;
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}
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skb_put(skb, length + ARC_HDR_SIZE);
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skb->dev = dev;
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pkt = (struct archdr *)skb->data;
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/* up to sizeof(pkt->soft) has already been copied from the card */
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memcpy(pkt, pkthdr, sizeof(struct archdr));
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if (length > sizeof(pkt->soft))
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lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
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pkt->soft.raw + sizeof(pkt->soft),
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length - sizeof(pkt->soft));
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if (BUGLVL(D_SKB))
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arcnet_dump_skb(dev, skb, "rx");
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skb->protocol = type_trans(skb, dev);
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netif_rx(skb);
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}
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/* Create the ARCnet hard/soft headers for RFC1051 */
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static int build_header(struct sk_buff *skb, struct net_device *dev,
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unsigned short type, uint8_t daddr)
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{
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int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
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struct archdr *pkt = skb_push(skb, hdr_size);
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struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
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/* set the protocol ID according to RFC1051 */
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switch (type) {
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case ETH_P_IP:
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soft->proto = ARC_P_IP_RFC1051;
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break;
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case ETH_P_ARP:
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soft->proto = ARC_P_ARP_RFC1051;
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break;
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default:
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arc_printk(D_NORMAL, dev, "RFC1051: I don't understand protocol %d (%Xh)\n",
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type, type);
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dev->stats.tx_errors++;
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dev->stats.tx_aborted_errors++;
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return 0;
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}
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/* Set the source hardware address.
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*
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* This is pretty pointless for most purposes, but it can help in
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* debugging. ARCnet does not allow us to change the source address
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* in the actual packet sent.
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*/
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pkt->hard.source = *dev->dev_addr;
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/* see linux/net/ethernet/eth.c to see where I got the following */
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if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
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/* FIXME: fill in the last byte of the dest ipaddr here to
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* better comply with RFC1051 in "noarp" mode.
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*/
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pkt->hard.dest = 0;
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return hdr_size;
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}
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/* otherwise, just fill it in and go! */
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pkt->hard.dest = daddr;
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return hdr_size; /* success */
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}
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static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
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int bufnum)
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{
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struct arcnet_local *lp = netdev_priv(dev);
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struct arc_hardware *hard = &pkt->hard;
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int ofs;
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arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n",
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lp->next_tx, lp->cur_tx, bufnum);
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/* hard header is not included in packet length */
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length -= ARC_HDR_SIZE;
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if (length > XMTU) {
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/* should never happen! other people already check for this. */
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arc_printk(D_NORMAL, dev, "Bug! prepare_tx with size %d (> %d)\n",
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length, XMTU);
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length = XMTU;
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}
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if (length > MinTU) {
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hard->offset[0] = 0;
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hard->offset[1] = ofs = 512 - length;
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} else if (length > MTU) {
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hard->offset[0] = 0;
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hard->offset[1] = ofs = 512 - length - 3;
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} else {
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hard->offset[0] = ofs = 256 - length;
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}
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lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
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lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
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lp->lastload_dest = hard->dest;
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return 1; /* done */
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}
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