Btrfs: stop the readahead threads on failed mount
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / arcnet / rfc1051.c
blobf81db4070a574500172fa4dd5521859cc6e063e3
1 /*
2 * Linux ARCnet driver - RFC1051 ("simple" standard) packet encapsulation
3 *
4 * Written 1994-1999 by Avery Pennarun.
5 * Derived from skeleton.c by Donald Becker.
7 * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
8 * for sponsoring the further development of this driver.
10 * **********************
12 * The original copyright of skeleton.c was as follows:
14 * skeleton.c Written 1993 by Donald Becker.
15 * Copyright 1993 United States Government as represented by the
16 * Director, National Security Agency. This software may only be used
17 * and distributed according to the terms of the GNU General Public License as
18 * modified by SRC, incorporated herein by reference.
20 * **********************
22 * For more details, see drivers/net/arcnet.c
24 * **********************
26 #include <linux/module.h>
27 #include <linux/gfp.h>
28 #include <linux/init.h>
29 #include <linux/if_arp.h>
30 #include <net/arp.h>
31 #include <linux/netdevice.h>
32 #include <linux/skbuff.h>
33 #include <linux/arcdevice.h>
35 #define VERSION "arcnet: RFC1051 \"simple standard\" (`s') encapsulation support loaded.\n"
38 static __be16 type_trans(struct sk_buff *skb, struct net_device *dev);
39 static void rx(struct net_device *dev, int bufnum,
40 struct archdr *pkthdr, int length);
41 static int build_header(struct sk_buff *skb, struct net_device *dev,
42 unsigned short type, uint8_t daddr);
43 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
44 int bufnum);
47 static struct ArcProto rfc1051_proto =
49 .suffix = 's',
50 .mtu = XMTU - RFC1051_HDR_SIZE,
51 .is_ip = 1,
52 .rx = rx,
53 .build_header = build_header,
54 .prepare_tx = prepare_tx,
55 .continue_tx = NULL,
56 .ack_tx = NULL
60 static int __init arcnet_rfc1051_init(void)
62 printk(VERSION);
64 arc_proto_map[ARC_P_IP_RFC1051]
65 = arc_proto_map[ARC_P_ARP_RFC1051]
66 = &rfc1051_proto;
68 /* if someone else already owns the broadcast, we won't take it */
69 if (arc_bcast_proto == arc_proto_default)
70 arc_bcast_proto = &rfc1051_proto;
72 return 0;
75 static void __exit arcnet_rfc1051_exit(void)
77 arcnet_unregister_proto(&rfc1051_proto);
80 module_init(arcnet_rfc1051_init);
81 module_exit(arcnet_rfc1051_exit);
83 MODULE_LICENSE("GPL");
86 * Determine a packet's protocol ID.
88 * With ARCnet we have to convert everything to Ethernet-style stuff.
90 static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
92 struct archdr *pkt = (struct archdr *) skb->data;
93 struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
94 int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
96 /* Pull off the arcnet header. */
97 skb_reset_mac_header(skb);
98 skb_pull(skb, hdr_size);
100 if (pkt->hard.dest == 0)
101 skb->pkt_type = PACKET_BROADCAST;
102 else if (dev->flags & IFF_PROMISC) {
103 /* if we're not sending to ourselves :) */
104 if (pkt->hard.dest != dev->dev_addr[0])
105 skb->pkt_type = PACKET_OTHERHOST;
107 /* now return the protocol number */
108 switch (soft->proto) {
109 case ARC_P_IP_RFC1051:
110 return htons(ETH_P_IP);
111 case ARC_P_ARP_RFC1051:
112 return htons(ETH_P_ARP);
114 default:
115 dev->stats.rx_errors++;
116 dev->stats.rx_crc_errors++;
117 return 0;
120 return htons(ETH_P_IP);
124 /* packet receiver */
125 static void rx(struct net_device *dev, int bufnum,
126 struct archdr *pkthdr, int length)
128 struct arcnet_local *lp = netdev_priv(dev);
129 struct sk_buff *skb;
130 struct archdr *pkt = pkthdr;
131 int ofs;
133 BUGMSG(D_DURING, "it's a raw packet (length=%d)\n", length);
135 if (length >= MinTU)
136 ofs = 512 - length;
137 else
138 ofs = 256 - length;
140 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
141 if (skb == NULL) {
142 BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
143 dev->stats.rx_dropped++;
144 return;
146 skb_put(skb, length + ARC_HDR_SIZE);
147 skb->dev = dev;
149 pkt = (struct archdr *) skb->data;
151 /* up to sizeof(pkt->soft) has already been copied from the card */
152 memcpy(pkt, pkthdr, sizeof(struct archdr));
153 if (length > sizeof(pkt->soft))
154 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
155 pkt->soft.raw + sizeof(pkt->soft),
156 length - sizeof(pkt->soft));
158 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
160 skb->protocol = type_trans(skb, dev);
161 netif_rx(skb);
166 * Create the ARCnet hard/soft headers for RFC1051.
168 static int build_header(struct sk_buff *skb, struct net_device *dev,
169 unsigned short type, uint8_t daddr)
171 int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
172 struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
173 struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
175 /* set the protocol ID according to RFC1051 */
176 switch (type) {
177 case ETH_P_IP:
178 soft->proto = ARC_P_IP_RFC1051;
179 break;
180 case ETH_P_ARP:
181 soft->proto = ARC_P_ARP_RFC1051;
182 break;
183 default:
184 BUGMSG(D_NORMAL, "RFC1051: I don't understand protocol %d (%Xh)\n",
185 type, type);
186 dev->stats.tx_errors++;
187 dev->stats.tx_aborted_errors++;
188 return 0;
193 * Set the source hardware address.
195 * This is pretty pointless for most purposes, but it can help in
196 * debugging. ARCnet does not allow us to change the source address in
197 * the actual packet sent)
199 pkt->hard.source = *dev->dev_addr;
201 /* see linux/net/ethernet/eth.c to see where I got the following */
203 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
205 * FIXME: fill in the last byte of the dest ipaddr here to better
206 * comply with RFC1051 in "noarp" mode.
208 pkt->hard.dest = 0;
209 return hdr_size;
211 /* otherwise, just fill it in and go! */
212 pkt->hard.dest = daddr;
214 return hdr_size; /* success */
218 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
219 int bufnum)
221 struct arcnet_local *lp = netdev_priv(dev);
222 struct arc_hardware *hard = &pkt->hard;
223 int ofs;
225 BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
226 lp->next_tx, lp->cur_tx, bufnum);
228 length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
230 if (length > XMTU) {
231 /* should never happen! other people already check for this. */
232 BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n",
233 length, XMTU);
234 length = XMTU;
236 if (length > MinTU) {
237 hard->offset[0] = 0;
238 hard->offset[1] = ofs = 512 - length;
239 } else if (length > MTU) {
240 hard->offset[0] = 0;
241 hard->offset[1] = ofs = 512 - length - 3;
242 } else
243 hard->offset[0] = ofs = 256 - length;
245 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
246 lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
248 lp->lastload_dest = hard->dest;
250 return 1; /* done */