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242 lines
6.3 KiB
242 lines
6.3 KiB
/* |
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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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