|  | /* | 
|  | * Linux ARCnet driver - device-independent routines | 
|  | * | 
|  | * Written 1997 by David Woodhouse. | 
|  | * Written 1994-1999 by Avery Pennarun. | 
|  | * Written 1999-2000 by Martin Mares <mj@ucw.cz>. | 
|  | * Derived from skeleton.c by Donald Becker. | 
|  | * | 
|  | * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com) | 
|  | *  for sponsoring the further development of this driver. | 
|  | * | 
|  | * ********************** | 
|  | * | 
|  | * The original copyright was as follows: | 
|  | * | 
|  | * skeleton.c Written 1993 by Donald Becker. | 
|  | * Copyright 1993 United States Government as represented by the | 
|  | * Director, National Security Agency.  This software may only be used | 
|  | * and distributed according to the terms of the GNU General Public License as | 
|  | * modified by SRC, incorporated herein by reference. | 
|  | * | 
|  | * ********************** | 
|  | * | 
|  | * The change log is now in a file called ChangeLog in this directory. | 
|  | * | 
|  | * Sources: | 
|  | *  - Crynwr arcnet.com/arcether.com packet drivers. | 
|  | *  - arcnet.c v0.00 dated 1/1/94 and apparently by | 
|  | *     Donald Becker - it didn't work :) | 
|  | *  - skeleton.c v0.05 dated 11/16/93 by Donald Becker | 
|  | *     (from Linux Kernel 1.1.45) | 
|  | *  - RFC's 1201 and 1051 - re: TCP/IP over ARCnet | 
|  | *  - The official ARCnet COM9026 data sheets (!) thanks to | 
|  | *     Ken Cornetet <kcornete@nyx10.cs.du.edu> | 
|  | *  - The official ARCnet COM20020 data sheets. | 
|  | *  - Information on some more obscure ARCnet controller chips, thanks | 
|  | *     to the nice people at SMSC. | 
|  | *  - net/inet/eth.c (from kernel 1.1.50) for header-building info. | 
|  | *  - Alternate Linux ARCnet source by V.Shergin <vsher@sao.stavropol.su> | 
|  | *  - Textual information and more alternate source from Joachim Koenig | 
|  | *     <jojo@repas.de> | 
|  | */ | 
|  |  | 
|  | #define VERSION "arcnet: v3.94 BETA 2007/02/08 - by Avery Pennarun et al.\n" | 
|  |  | 
|  | #include <linux/module.h> | 
|  | #include <linux/types.h> | 
|  | #include <linux/delay.h> | 
|  | #include <linux/netdevice.h> | 
|  | #include <linux/if_arp.h> | 
|  | #include <net/arp.h> | 
|  | #include <linux/init.h> | 
|  | #include <linux/arcdevice.h> | 
|  | #include <linux/jiffies.h> | 
|  |  | 
|  | /* "do nothing" functions for protocol drivers */ | 
|  | static void null_rx(struct net_device *dev, int bufnum, | 
|  | struct archdr *pkthdr, int length); | 
|  | static int null_build_header(struct sk_buff *skb, struct net_device *dev, | 
|  | unsigned short type, uint8_t daddr); | 
|  | static int null_prepare_tx(struct net_device *dev, struct archdr *pkt, | 
|  | int length, int bufnum); | 
|  |  | 
|  | static void arcnet_rx(struct net_device *dev, int bufnum); | 
|  |  | 
|  | /* | 
|  | * one ArcProto per possible proto ID.  None of the elements of | 
|  | * arc_proto_map are allowed to be NULL; they will get set to | 
|  | * arc_proto_default instead.  It also must not be NULL; if you would like | 
|  | * to set it to NULL, set it to &arc_proto_null instead. | 
|  | */ | 
|  | struct ArcProto *arc_proto_map[256], *arc_proto_default, | 
|  | *arc_bcast_proto, *arc_raw_proto; | 
|  |  | 
|  | static struct ArcProto arc_proto_null = | 
|  | { | 
|  | .suffix		= '?', | 
|  | .mtu		= XMTU, | 
|  | .is_ip          = 0, | 
|  | .rx		= null_rx, | 
|  | .build_header	= null_build_header, | 
|  | .prepare_tx	= null_prepare_tx, | 
|  | .continue_tx    = NULL, | 
|  | .ack_tx         = NULL | 
|  | }; | 
|  |  | 
|  | /* Exported function prototypes */ | 
|  | int arcnet_debug = ARCNET_DEBUG; | 
|  |  | 
|  | EXPORT_SYMBOL(arc_proto_map); | 
|  | EXPORT_SYMBOL(arc_proto_default); | 
|  | EXPORT_SYMBOL(arc_bcast_proto); | 
|  | EXPORT_SYMBOL(arc_raw_proto); | 
|  | EXPORT_SYMBOL(arcnet_unregister_proto); | 
|  | EXPORT_SYMBOL(arcnet_debug); | 
|  | EXPORT_SYMBOL(alloc_arcdev); | 
|  | EXPORT_SYMBOL(arcnet_interrupt); | 
|  |  | 
|  | /* Internal function prototypes */ | 
|  | static int arcnet_open(struct net_device *dev); | 
|  | static int arcnet_close(struct net_device *dev); | 
|  | static int arcnet_send_packet(struct sk_buff *skb, struct net_device *dev); | 
|  | static void arcnet_timeout(struct net_device *dev); | 
|  | static int arcnet_header(struct sk_buff *skb, struct net_device *dev, | 
|  | unsigned short type, const void *daddr, | 
|  | const void *saddr, unsigned len); | 
|  | static int arcnet_rebuild_header(struct sk_buff *skb); | 
|  | static struct net_device_stats *arcnet_get_stats(struct net_device *dev); | 
|  | static int go_tx(struct net_device *dev); | 
|  |  | 
|  | static int debug = ARCNET_DEBUG; | 
|  | module_param(debug, int, 0); | 
|  | MODULE_LICENSE("GPL"); | 
|  |  | 
|  | static int __init arcnet_init(void) | 
|  | { | 
|  | int count; | 
|  |  | 
|  | arcnet_debug = debug; | 
|  |  | 
|  | printk("arcnet loaded.\n"); | 
|  |  | 
|  | #ifdef ALPHA_WARNING | 
|  | BUGLVL(D_EXTRA) { | 
|  | printk("arcnet: ***\n" | 
|  | "arcnet: * Read arcnet.txt for important release notes!\n" | 
|  | "arcnet: *\n" | 
|  | "arcnet: * This is an ALPHA version! (Last stable release: v3.02)  E-mail\n" | 
|  | "arcnet: * me if you have any questions, comments, or bug reports.\n" | 
|  | "arcnet: ***\n"); | 
|  | } | 
|  | #endif | 
|  |  | 
|  | /* initialize the protocol map */ | 
|  | arc_raw_proto = arc_proto_default = arc_bcast_proto = &arc_proto_null; | 
|  | for (count = 0; count < 256; count++) | 
|  | arc_proto_map[count] = arc_proto_default; | 
|  |  | 
|  | BUGLVL(D_DURING) | 
|  | printk("arcnet: struct sizes: %Zd %Zd %Zd %Zd %Zd\n", | 
|  | sizeof(struct arc_hardware), sizeof(struct arc_rfc1201), | 
|  | sizeof(struct arc_rfc1051), sizeof(struct arc_eth_encap), | 
|  | sizeof(struct archdr)); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static void __exit arcnet_exit(void) | 
|  | { | 
|  | } | 
|  |  | 
|  | module_init(arcnet_init); | 
|  | module_exit(arcnet_exit); | 
|  |  | 
|  | /* | 
|  | * Dump the contents of an sk_buff | 
|  | */ | 
|  | #if ARCNET_DEBUG_MAX & D_SKB | 
|  | void arcnet_dump_skb(struct net_device *dev, | 
|  | struct sk_buff *skb, char *desc) | 
|  | { | 
|  | int i; | 
|  |  | 
|  | printk(KERN_DEBUG "%6s: skb dump (%s) follows:", dev->name, desc); | 
|  | for (i = 0; i < skb->len; i++) { | 
|  | if (i % 16 == 0) | 
|  | printk("\n" KERN_DEBUG "[%04X] ", i); | 
|  | printk("%02X ", ((u_char *) skb->data)[i]); | 
|  | } | 
|  | printk("\n"); | 
|  | } | 
|  |  | 
|  | EXPORT_SYMBOL(arcnet_dump_skb); | 
|  | #endif | 
|  |  | 
|  |  | 
|  | /* | 
|  | * Dump the contents of an ARCnet buffer | 
|  | */ | 
|  | #if (ARCNET_DEBUG_MAX & (D_RX | D_TX)) | 
|  | static void arcnet_dump_packet(struct net_device *dev, int bufnum, | 
|  | char *desc, int take_arcnet_lock) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | int i, length; | 
|  | unsigned long flags = 0; | 
|  | static uint8_t buf[512]; | 
|  |  | 
|  | /* hw.copy_from_card expects IRQ context so take the IRQ lock | 
|  | to keep it single threaded */ | 
|  | if(take_arcnet_lock) | 
|  | spin_lock_irqsave(&lp->lock, flags); | 
|  |  | 
|  | lp->hw.copy_from_card(dev, bufnum, 0, buf, 512); | 
|  | if(take_arcnet_lock) | 
|  | spin_unlock_irqrestore(&lp->lock, flags); | 
|  |  | 
|  | /* if the offset[0] byte is nonzero, this is a 256-byte packet */ | 
|  | length = (buf[2] ? 256 : 512); | 
|  |  | 
|  | printk(KERN_DEBUG "%6s: packet dump (%s) follows:", dev->name, desc); | 
|  | for (i = 0; i < length; i++) { | 
|  | if (i % 16 == 0) | 
|  | printk("\n" KERN_DEBUG "[%04X] ", i); | 
|  | printk("%02X ", buf[i]); | 
|  | } | 
|  | printk("\n"); | 
|  |  | 
|  | } | 
|  |  | 
|  | #else | 
|  |  | 
|  | #define arcnet_dump_packet(dev, bufnum, desc,take_arcnet_lock) do { } while (0) | 
|  |  | 
|  | #endif | 
|  |  | 
|  |  | 
|  | /* | 
|  | * Unregister a protocol driver from the arc_proto_map.  Protocol drivers | 
|  | * are responsible for registering themselves, but the unregister routine | 
|  | * is pretty generic so we'll do it here. | 
|  | */ | 
|  | void arcnet_unregister_proto(struct ArcProto *proto) | 
|  | { | 
|  | int count; | 
|  |  | 
|  | if (arc_proto_default == proto) | 
|  | arc_proto_default = &arc_proto_null; | 
|  | if (arc_bcast_proto == proto) | 
|  | arc_bcast_proto = arc_proto_default; | 
|  | if (arc_raw_proto == proto) | 
|  | arc_raw_proto = arc_proto_default; | 
|  |  | 
|  | for (count = 0; count < 256; count++) { | 
|  | if (arc_proto_map[count] == proto) | 
|  | arc_proto_map[count] = arc_proto_default; | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * Add a buffer to the queue.  Only the interrupt handler is allowed to do | 
|  | * this, unless interrupts are disabled. | 
|  | * | 
|  | * Note: we don't check for a full queue, since there aren't enough buffers | 
|  | * to more than fill it. | 
|  | */ | 
|  | static void release_arcbuf(struct net_device *dev, int bufnum) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | int i; | 
|  |  | 
|  | lp->buf_queue[lp->first_free_buf++] = bufnum; | 
|  | lp->first_free_buf %= 5; | 
|  |  | 
|  | BUGLVL(D_DURING) { | 
|  | BUGMSG(D_DURING, "release_arcbuf: freed #%d; buffer queue is now: ", | 
|  | bufnum); | 
|  | for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5) | 
|  | BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]); | 
|  | BUGMSG2(D_DURING, "\n"); | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * Get a buffer from the queue.  If this returns -1, there are no buffers | 
|  | * available. | 
|  | */ | 
|  | static int get_arcbuf(struct net_device *dev) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | int buf = -1, i; | 
|  |  | 
|  | if (!atomic_dec_and_test(&lp->buf_lock)) { | 
|  | /* already in this function */ | 
|  | BUGMSG(D_NORMAL, "get_arcbuf: overlap (%d)!\n", | 
|  | lp->buf_lock.counter); | 
|  | } | 
|  | else {			/* we can continue */ | 
|  | if (lp->next_buf >= 5) | 
|  | lp->next_buf -= 5; | 
|  |  | 
|  | if (lp->next_buf == lp->first_free_buf) | 
|  | BUGMSG(D_NORMAL, "get_arcbuf: BUG: no buffers are available??\n"); | 
|  | else { | 
|  | buf = lp->buf_queue[lp->next_buf++]; | 
|  | lp->next_buf %= 5; | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | BUGLVL(D_DURING) { | 
|  | BUGMSG(D_DURING, "get_arcbuf: got #%d; buffer queue is now: ", buf); | 
|  | for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5) | 
|  | BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]); | 
|  | BUGMSG2(D_DURING, "\n"); | 
|  | } | 
|  |  | 
|  | atomic_inc(&lp->buf_lock); | 
|  | return buf; | 
|  | } | 
|  |  | 
|  |  | 
|  | static int choose_mtu(void) | 
|  | { | 
|  | int count, mtu = 65535; | 
|  |  | 
|  | /* choose the smallest MTU of all available encaps */ | 
|  | for (count = 0; count < 256; count++) { | 
|  | if (arc_proto_map[count] != &arc_proto_null | 
|  | && arc_proto_map[count]->mtu < mtu) { | 
|  | mtu = arc_proto_map[count]->mtu; | 
|  | } | 
|  | } | 
|  |  | 
|  | return mtu == 65535 ? XMTU : mtu; | 
|  | } | 
|  |  | 
|  | static const struct header_ops arcnet_header_ops = { | 
|  | .create = arcnet_header, | 
|  | .rebuild = arcnet_rebuild_header, | 
|  | }; | 
|  |  | 
|  |  | 
|  | /* Setup a struct device for ARCnet. */ | 
|  | static void arcdev_setup(struct net_device *dev) | 
|  | { | 
|  | dev->type = ARPHRD_ARCNET; | 
|  | dev->header_ops = &arcnet_header_ops; | 
|  | dev->hard_header_len = sizeof(struct archdr); | 
|  | dev->mtu = choose_mtu(); | 
|  |  | 
|  | dev->addr_len = ARCNET_ALEN; | 
|  | dev->tx_queue_len = 100; | 
|  | dev->broadcast[0] = 0x00;	/* for us, broadcasts are address 0 */ | 
|  | dev->watchdog_timeo = TX_TIMEOUT; | 
|  |  | 
|  | /* New-style flags. */ | 
|  | dev->flags = IFF_BROADCAST; | 
|  |  | 
|  | /* | 
|  | * Put in this stuff here, so we don't have to export the symbols to | 
|  | * the chipset drivers. | 
|  | */ | 
|  | dev->open = arcnet_open; | 
|  | dev->stop = arcnet_close; | 
|  | dev->hard_start_xmit = arcnet_send_packet; | 
|  | dev->tx_timeout = arcnet_timeout; | 
|  | dev->get_stats = arcnet_get_stats; | 
|  | } | 
|  |  | 
|  | struct net_device *alloc_arcdev(char *name) | 
|  | { | 
|  | struct net_device *dev; | 
|  |  | 
|  | dev = alloc_netdev(sizeof(struct arcnet_local), | 
|  | name && *name ? name : "arc%d", arcdev_setup); | 
|  | if(dev) { | 
|  | struct arcnet_local *lp = (struct arcnet_local *) dev->priv; | 
|  | spin_lock_init(&lp->lock); | 
|  | } | 
|  |  | 
|  | return dev; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Open/initialize the board.  This is called sometime after booting when | 
|  | * the 'ifconfig' program is run. | 
|  | * | 
|  | * This routine should set everything up anew at each open, even registers | 
|  | * that "should" only need to be set once at boot, so that there is | 
|  | * non-reboot way to recover if something goes wrong. | 
|  | */ | 
|  | static int arcnet_open(struct net_device *dev) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | int count, newmtu, error; | 
|  |  | 
|  | BUGMSG(D_INIT,"opened."); | 
|  |  | 
|  | if (!try_module_get(lp->hw.owner)) | 
|  | return -ENODEV; | 
|  |  | 
|  | BUGLVL(D_PROTO) { | 
|  | int count; | 
|  | BUGMSG(D_PROTO, "protocol map (default is '%c'): ", | 
|  | arc_proto_default->suffix); | 
|  | for (count = 0; count < 256; count++) | 
|  | BUGMSG2(D_PROTO, "%c", arc_proto_map[count]->suffix); | 
|  | BUGMSG2(D_PROTO, "\n"); | 
|  | } | 
|  |  | 
|  |  | 
|  | BUGMSG(D_INIT, "arcnet_open: resetting card.\n"); | 
|  |  | 
|  | /* try to put the card in a defined state - if it fails the first | 
|  | * time, actually reset it. | 
|  | */ | 
|  | error = -ENODEV; | 
|  | if (ARCRESET(0) && ARCRESET(1)) | 
|  | goto out_module_put; | 
|  |  | 
|  | newmtu = choose_mtu(); | 
|  | if (newmtu < dev->mtu) | 
|  | dev->mtu = newmtu; | 
|  |  | 
|  | BUGMSG(D_INIT, "arcnet_open: mtu: %d.\n", dev->mtu); | 
|  |  | 
|  | /* autodetect the encapsulation for each host. */ | 
|  | memset(lp->default_proto, 0, sizeof(lp->default_proto)); | 
|  |  | 
|  | /* the broadcast address is special - use the 'bcast' protocol */ | 
|  | for (count = 0; count < 256; count++) { | 
|  | if (arc_proto_map[count] == arc_bcast_proto) { | 
|  | lp->default_proto[0] = count; | 
|  | break; | 
|  | } | 
|  | } | 
|  |  | 
|  | /* initialize buffers */ | 
|  | atomic_set(&lp->buf_lock, 1); | 
|  |  | 
|  | lp->next_buf = lp->first_free_buf = 0; | 
|  | release_arcbuf(dev, 0); | 
|  | release_arcbuf(dev, 1); | 
|  | release_arcbuf(dev, 2); | 
|  | release_arcbuf(dev, 3); | 
|  | lp->cur_tx = lp->next_tx = -1; | 
|  | lp->cur_rx = -1; | 
|  |  | 
|  | lp->rfc1201.sequence = 1; | 
|  |  | 
|  | /* bring up the hardware driver */ | 
|  | if (lp->hw.open) | 
|  | lp->hw.open(dev); | 
|  |  | 
|  | if (dev->dev_addr[0] == 0) | 
|  | BUGMSG(D_NORMAL, "WARNING!  Station address 00 is reserved " | 
|  | "for broadcasts!\n"); | 
|  | else if (dev->dev_addr[0] == 255) | 
|  | BUGMSG(D_NORMAL, "WARNING!  Station address FF may confuse " | 
|  | "DOS networking programs!\n"); | 
|  |  | 
|  | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | 
|  | if (ASTATUS() & RESETflag) { | 
|  | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | 
|  | ACOMMAND(CFLAGScmd | RESETclear); | 
|  | } | 
|  |  | 
|  |  | 
|  | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | 
|  | /* make sure we're ready to receive IRQ's. */ | 
|  | AINTMASK(0); | 
|  | udelay(1);		/* give it time to set the mask before | 
|  | * we reset it again. (may not even be | 
|  | * necessary) | 
|  | */ | 
|  | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | 
|  | lp->intmask = NORXflag | RECONflag; | 
|  | AINTMASK(lp->intmask); | 
|  | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | 
|  |  | 
|  | netif_start_queue(dev); | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | out_module_put: | 
|  | module_put(lp->hw.owner); | 
|  | return error; | 
|  | } | 
|  |  | 
|  |  | 
|  | /* The inverse routine to arcnet_open - shuts down the card. */ | 
|  | static int arcnet_close(struct net_device *dev) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  |  | 
|  | netif_stop_queue(dev); | 
|  |  | 
|  | /* flush TX and disable RX */ | 
|  | AINTMASK(0); | 
|  | ACOMMAND(NOTXcmd);	/* stop transmit */ | 
|  | ACOMMAND(NORXcmd);	/* disable receive */ | 
|  | mdelay(1); | 
|  |  | 
|  | /* shut down the card */ | 
|  | lp->hw.close(dev); | 
|  | module_put(lp->hw.owner); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  |  | 
|  | static int arcnet_header(struct sk_buff *skb, struct net_device *dev, | 
|  | unsigned short type, const void *daddr, | 
|  | const void *saddr, unsigned len) | 
|  | { | 
|  | const struct arcnet_local *lp = netdev_priv(dev); | 
|  | uint8_t _daddr, proto_num; | 
|  | struct ArcProto *proto; | 
|  |  | 
|  | BUGMSG(D_DURING, | 
|  | "create header from %d to %d; protocol %d (%Xh); size %u.\n", | 
|  | saddr ? *(uint8_t *) saddr : -1, | 
|  | daddr ? *(uint8_t *) daddr : -1, | 
|  | type, type, len); | 
|  |  | 
|  | if (skb->len!=0 && len != skb->len) | 
|  | BUGMSG(D_NORMAL, "arcnet_header: Yikes!  skb->len(%d) != len(%d)!\n", | 
|  | skb->len, len); | 
|  |  | 
|  |  | 
|  | /* Type is host order - ? */ | 
|  | if(type == ETH_P_ARCNET) { | 
|  | proto = arc_raw_proto; | 
|  | BUGMSG(D_DEBUG, "arc_raw_proto used. proto='%c'\n",proto->suffix); | 
|  | _daddr = daddr ? *(uint8_t *) daddr : 0; | 
|  | } | 
|  | else if (!daddr) { | 
|  | /* | 
|  | * if the dest addr isn't provided, we can't choose an encapsulation! | 
|  | * Store the packet type (eg. ETH_P_IP) for now, and we'll push on a | 
|  | * real header when we do rebuild_header. | 
|  | */ | 
|  | *(uint16_t *) skb_push(skb, 2) = type; | 
|  | /* | 
|  | * XXX: Why not use skb->mac_len? | 
|  | */ | 
|  | if (skb->network_header - skb->mac_header != 2) | 
|  | BUGMSG(D_NORMAL, "arcnet_header: Yikes!  diff (%d) is not 2!\n", | 
|  | (int)(skb->network_header - skb->mac_header)); | 
|  | return -2;	/* return error -- can't transmit yet! */ | 
|  | } | 
|  | else { | 
|  | /* otherwise, we can just add the header as usual. */ | 
|  | _daddr = *(uint8_t *) daddr; | 
|  | proto_num = lp->default_proto[_daddr]; | 
|  | proto = arc_proto_map[proto_num]; | 
|  | BUGMSG(D_DURING, "building header for %02Xh using protocol '%c'\n", | 
|  | proto_num, proto->suffix); | 
|  | if (proto == &arc_proto_null && arc_bcast_proto != proto) { | 
|  | BUGMSG(D_DURING, "actually, let's use '%c' instead.\n", | 
|  | arc_bcast_proto->suffix); | 
|  | proto = arc_bcast_proto; | 
|  | } | 
|  | } | 
|  | return proto->build_header(skb, dev, type, _daddr); | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * Rebuild the ARCnet hard header. This is called after an ARP (or in the | 
|  | * future other address resolution) has completed on this sk_buff. We now | 
|  | * let ARP fill in the destination field. | 
|  | */ | 
|  | static int arcnet_rebuild_header(struct sk_buff *skb) | 
|  | { | 
|  | struct net_device *dev = skb->dev; | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | int status = 0;		/* default is failure */ | 
|  | unsigned short type; | 
|  | uint8_t daddr=0; | 
|  | struct ArcProto *proto; | 
|  | /* | 
|  | * XXX: Why not use skb->mac_len? | 
|  | */ | 
|  | if (skb->network_header - skb->mac_header != 2) { | 
|  | BUGMSG(D_NORMAL, | 
|  | "rebuild_header: shouldn't be here! (hdrsize=%d)\n", | 
|  | (int)(skb->network_header - skb->mac_header)); | 
|  | return 0; | 
|  | } | 
|  | type = *(uint16_t *) skb_pull(skb, 2); | 
|  | BUGMSG(D_DURING, "rebuild header for protocol %Xh\n", type); | 
|  |  | 
|  | if (type == ETH_P_IP) { | 
|  | #ifdef CONFIG_INET | 
|  | BUGMSG(D_DURING, "rebuild header for ethernet protocol %Xh\n", type); | 
|  | status = arp_find(&daddr, skb) ? 1 : 0; | 
|  | BUGMSG(D_DURING, " rebuilt: dest is %d; protocol %Xh\n", | 
|  | daddr, type); | 
|  | #endif | 
|  | } else { | 
|  | BUGMSG(D_NORMAL, | 
|  | "I don't understand ethernet protocol %Xh addresses!\n", type); | 
|  | lp->stats.tx_errors++; | 
|  | lp->stats.tx_aborted_errors++; | 
|  | } | 
|  |  | 
|  | /* if we couldn't resolve the address... give up. */ | 
|  | if (!status) | 
|  | return 0; | 
|  |  | 
|  | /* add the _real_ header this time! */ | 
|  | proto = arc_proto_map[lp->default_proto[daddr]]; | 
|  | proto->build_header(skb, dev, type, daddr); | 
|  |  | 
|  | return 1;		/* success */ | 
|  | } | 
|  |  | 
|  |  | 
|  |  | 
|  | /* Called by the kernel in order to transmit a packet. */ | 
|  | static int arcnet_send_packet(struct sk_buff *skb, struct net_device *dev) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | struct archdr *pkt; | 
|  | struct arc_rfc1201 *soft; | 
|  | struct ArcProto *proto; | 
|  | int txbuf; | 
|  | unsigned long flags; | 
|  | int freeskb, retval; | 
|  |  | 
|  | BUGMSG(D_DURING, | 
|  | "transmit requested (status=%Xh, txbufs=%d/%d, len=%d, protocol %x)\n", | 
|  | ASTATUS(), lp->cur_tx, lp->next_tx, skb->len,skb->protocol); | 
|  |  | 
|  | pkt = (struct archdr *) skb->data; | 
|  | soft = &pkt->soft.rfc1201; | 
|  | proto = arc_proto_map[soft->proto]; | 
|  |  | 
|  | BUGMSG(D_SKB_SIZE, "skb: transmitting %d bytes to %02X\n", | 
|  | skb->len, pkt->hard.dest); | 
|  | BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "tx"); | 
|  |  | 
|  | /* fits in one packet? */ | 
|  | if (skb->len - ARC_HDR_SIZE > XMTU && !proto->continue_tx) { | 
|  | BUGMSG(D_NORMAL, "fixme: packet too large: compensating badly!\n"); | 
|  | dev_kfree_skb(skb); | 
|  | return NETDEV_TX_OK;	/* don't try again */ | 
|  | } | 
|  |  | 
|  | /* We're busy transmitting a packet... */ | 
|  | netif_stop_queue(dev); | 
|  |  | 
|  | spin_lock_irqsave(&lp->lock, flags); | 
|  | AINTMASK(0); | 
|  | if(lp->next_tx == -1) | 
|  | txbuf = get_arcbuf(dev); | 
|  | else { | 
|  | txbuf = -1; | 
|  | } | 
|  | if (txbuf != -1) { | 
|  | if (proto->prepare_tx(dev, pkt, skb->len, txbuf) && | 
|  | !proto->ack_tx) { | 
|  | /* done right away and we don't want to acknowledge | 
|  | the package later - forget about it now */ | 
|  | lp->stats.tx_bytes += skb->len; | 
|  | freeskb = 1; | 
|  | } else { | 
|  | /* do it the 'split' way */ | 
|  | lp->outgoing.proto = proto; | 
|  | lp->outgoing.skb = skb; | 
|  | lp->outgoing.pkt = pkt; | 
|  |  | 
|  | freeskb = 0; | 
|  |  | 
|  | if (proto->continue_tx && | 
|  | proto->continue_tx(dev, txbuf)) { | 
|  | BUGMSG(D_NORMAL, | 
|  | "bug! continue_tx finished the first time! " | 
|  | "(proto='%c')\n", proto->suffix); | 
|  | } | 
|  | } | 
|  | retval = NETDEV_TX_OK; | 
|  | dev->trans_start = jiffies; | 
|  | lp->next_tx = txbuf; | 
|  | } else { | 
|  | retval = NETDEV_TX_BUSY; | 
|  | freeskb = 0; | 
|  | } | 
|  |  | 
|  | BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__FUNCTION__,ASTATUS()); | 
|  | /* make sure we didn't ignore a TX IRQ while we were in here */ | 
|  | AINTMASK(0); | 
|  |  | 
|  | BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__); | 
|  | lp->intmask |= TXFREEflag|EXCNAKflag; | 
|  | AINTMASK(lp->intmask); | 
|  | BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__FUNCTION__,ASTATUS()); | 
|  |  | 
|  | spin_unlock_irqrestore(&lp->lock, flags); | 
|  | if (freeskb) { | 
|  | dev_kfree_skb(skb); | 
|  | } | 
|  | return retval;		/* no need to try again */ | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * Actually start transmitting a packet that was loaded into a buffer | 
|  | * by prepare_tx.  This should _only_ be called by the interrupt handler. | 
|  | */ | 
|  | static int go_tx(struct net_device *dev) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  |  | 
|  | BUGMSG(D_DURING, "go_tx: status=%Xh, intmask=%Xh, next_tx=%d, cur_tx=%d\n", | 
|  | ASTATUS(), lp->intmask, lp->next_tx, lp->cur_tx); | 
|  |  | 
|  | if (lp->cur_tx != -1 || lp->next_tx == -1) | 
|  | return 0; | 
|  |  | 
|  | BUGLVL(D_TX) arcnet_dump_packet(dev, lp->next_tx, "go_tx", 0); | 
|  |  | 
|  | lp->cur_tx = lp->next_tx; | 
|  | lp->next_tx = -1; | 
|  |  | 
|  | /* start sending */ | 
|  | ACOMMAND(TXcmd | (lp->cur_tx << 3)); | 
|  |  | 
|  | lp->stats.tx_packets++; | 
|  | lp->lasttrans_dest = lp->lastload_dest; | 
|  | lp->lastload_dest = 0; | 
|  | lp->excnak_pending = 0; | 
|  | lp->intmask |= TXFREEflag|EXCNAKflag; | 
|  |  | 
|  | return 1; | 
|  | } | 
|  |  | 
|  |  | 
|  | /* Called by the kernel when transmit times out */ | 
|  | static void arcnet_timeout(struct net_device *dev) | 
|  | { | 
|  | unsigned long flags; | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | int status = ASTATUS(); | 
|  | char *msg; | 
|  |  | 
|  | spin_lock_irqsave(&lp->lock, flags); | 
|  | if (status & TXFREEflag) {	/* transmit _DID_ finish */ | 
|  | msg = " - missed IRQ?"; | 
|  | } else { | 
|  | msg = ""; | 
|  | lp->stats.tx_aborted_errors++; | 
|  | lp->timed_out = 1; | 
|  | ACOMMAND(NOTXcmd | (lp->cur_tx << 3)); | 
|  | } | 
|  | lp->stats.tx_errors++; | 
|  |  | 
|  | /* make sure we didn't miss a TX or a EXC NAK IRQ */ | 
|  | AINTMASK(0); | 
|  | lp->intmask |= TXFREEflag|EXCNAKflag; | 
|  | AINTMASK(lp->intmask); | 
|  |  | 
|  | spin_unlock_irqrestore(&lp->lock, flags); | 
|  |  | 
|  | if (time_after(jiffies, lp->last_timeout + 10*HZ)) { | 
|  | BUGMSG(D_EXTRA, "tx timed out%s (status=%Xh, intmask=%Xh, dest=%02Xh)\n", | 
|  | msg, status, lp->intmask, lp->lasttrans_dest); | 
|  | lp->last_timeout = jiffies; | 
|  | } | 
|  |  | 
|  | if (lp->cur_tx == -1) | 
|  | netif_wake_queue(dev); | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * The typical workload of the driver: Handle the network interface | 
|  | * interrupts. Establish which device needs attention, and call the correct | 
|  | * chipset interrupt handler. | 
|  | */ | 
|  | irqreturn_t arcnet_interrupt(int irq, void *dev_id) | 
|  | { | 
|  | struct net_device *dev = dev_id; | 
|  | struct arcnet_local *lp; | 
|  | int recbuf, status, diagstatus, didsomething, boguscount; | 
|  | int retval = IRQ_NONE; | 
|  |  | 
|  | BUGMSG(D_DURING, "\n"); | 
|  |  | 
|  | BUGMSG(D_DURING, "in arcnet_interrupt\n"); | 
|  |  | 
|  | lp = dev->priv; | 
|  | BUG_ON(!lp); | 
|  |  | 
|  | spin_lock(&lp->lock); | 
|  |  | 
|  | /* | 
|  | * RESET flag was enabled - if device is not running, we must clear it right | 
|  | * away (but nothing else). | 
|  | */ | 
|  | if (!netif_running(dev)) { | 
|  | if (ASTATUS() & RESETflag) | 
|  | ACOMMAND(CFLAGScmd | RESETclear); | 
|  | AINTMASK(0); | 
|  | spin_unlock(&lp->lock); | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | BUGMSG(D_DURING, "in arcnet_inthandler (status=%Xh, intmask=%Xh)\n", | 
|  | ASTATUS(), lp->intmask); | 
|  |  | 
|  | boguscount = 5; | 
|  | do { | 
|  | status = ASTATUS(); | 
|  | diagstatus = (status >> 8) & 0xFF; | 
|  |  | 
|  | BUGMSG(D_DEBUG, "%s: %d: %s: status=%x\n", | 
|  | __FILE__,__LINE__,__FUNCTION__,status); | 
|  | didsomething = 0; | 
|  |  | 
|  | /* | 
|  | * RESET flag was enabled - card is resetting and if RX is | 
|  | * disabled, it's NOT because we just got a packet. | 
|  | * | 
|  | * The card is in an undefined state.  Clear it out and start over. | 
|  | */ | 
|  | if (status & RESETflag) { | 
|  | BUGMSG(D_NORMAL, "spurious reset (status=%Xh)\n", status); | 
|  | arcnet_close(dev); | 
|  | arcnet_open(dev); | 
|  |  | 
|  | /* get out of the interrupt handler! */ | 
|  | break; | 
|  | } | 
|  | /* | 
|  | * RX is inhibited - we must have received something. Prepare to | 
|  | * receive into the next buffer. | 
|  | * | 
|  | * We don't actually copy the received packet from the card until | 
|  | * after the transmit handler runs (and possibly launches the next | 
|  | * tx); this should improve latency slightly if we get both types | 
|  | * of interrupts at once. | 
|  | */ | 
|  | recbuf = -1; | 
|  | if (status & lp->intmask & NORXflag) { | 
|  | recbuf = lp->cur_rx; | 
|  | BUGMSG(D_DURING, "Buffer #%d: receive irq (status=%Xh)\n", | 
|  | recbuf, status); | 
|  |  | 
|  | lp->cur_rx = get_arcbuf(dev); | 
|  | if (lp->cur_rx != -1) { | 
|  | BUGMSG(D_DURING, "enabling receive to buffer #%d\n", | 
|  | lp->cur_rx); | 
|  | ACOMMAND(RXcmd | (lp->cur_rx << 3) | RXbcasts); | 
|  | } | 
|  | didsomething++; | 
|  | } | 
|  |  | 
|  | if((diagstatus & EXCNAKflag)) { | 
|  | BUGMSG(D_DURING, "EXCNAK IRQ (diagstat=%Xh)\n", | 
|  | diagstatus); | 
|  |  | 
|  | ACOMMAND(NOTXcmd);      /* disable transmit */ | 
|  | lp->excnak_pending = 1; | 
|  |  | 
|  | ACOMMAND(EXCNAKclear); | 
|  | lp->intmask &= ~(EXCNAKflag); | 
|  | didsomething++; | 
|  | } | 
|  |  | 
|  |  | 
|  | /* a transmit finished, and we're interested in it. */ | 
|  | if ((status & lp->intmask & TXFREEflag) || lp->timed_out) { | 
|  | lp->intmask &= ~(TXFREEflag|EXCNAKflag); | 
|  |  | 
|  | BUGMSG(D_DURING, "TX IRQ (stat=%Xh)\n", status); | 
|  |  | 
|  | if (lp->cur_tx != -1 && !lp->timed_out) { | 
|  | if(!(status & TXACKflag)) { | 
|  | if (lp->lasttrans_dest != 0) { | 
|  | BUGMSG(D_EXTRA, | 
|  | "transmit was not acknowledged! " | 
|  | "(status=%Xh, dest=%02Xh)\n", | 
|  | status, lp->lasttrans_dest); | 
|  | lp->stats.tx_errors++; | 
|  | lp->stats.tx_carrier_errors++; | 
|  | } else { | 
|  | BUGMSG(D_DURING, | 
|  | "broadcast was not acknowledged; that's normal " | 
|  | "(status=%Xh, dest=%02Xh)\n", | 
|  | status, lp->lasttrans_dest); | 
|  | } | 
|  | } | 
|  |  | 
|  | if (lp->outgoing.proto && | 
|  | lp->outgoing.proto->ack_tx) { | 
|  | int ackstatus; | 
|  | if(status & TXACKflag) | 
|  | ackstatus=2; | 
|  | else if(lp->excnak_pending) | 
|  | ackstatus=1; | 
|  | else | 
|  | ackstatus=0; | 
|  |  | 
|  | lp->outgoing.proto | 
|  | ->ack_tx(dev, ackstatus); | 
|  | } | 
|  | } | 
|  | if (lp->cur_tx != -1) | 
|  | release_arcbuf(dev, lp->cur_tx); | 
|  |  | 
|  | lp->cur_tx = -1; | 
|  | lp->timed_out = 0; | 
|  | didsomething++; | 
|  |  | 
|  | /* send another packet if there is one */ | 
|  | go_tx(dev); | 
|  |  | 
|  | /* continue a split packet, if any */ | 
|  | if (lp->outgoing.proto && lp->outgoing.proto->continue_tx) { | 
|  | int txbuf = get_arcbuf(dev); | 
|  | if (txbuf != -1) { | 
|  | if (lp->outgoing.proto->continue_tx(dev, txbuf)) { | 
|  | /* that was the last segment */ | 
|  | lp->stats.tx_bytes += lp->outgoing.skb->len; | 
|  | if(!lp->outgoing.proto->ack_tx) | 
|  | { | 
|  | dev_kfree_skb_irq(lp->outgoing.skb); | 
|  | lp->outgoing.proto = NULL; | 
|  | } | 
|  | } | 
|  | lp->next_tx = txbuf; | 
|  | } | 
|  | } | 
|  | /* inform upper layers of idleness, if necessary */ | 
|  | if (lp->cur_tx == -1) | 
|  | netif_wake_queue(dev); | 
|  | } | 
|  | /* now process the received packet, if any */ | 
|  | if (recbuf != -1) { | 
|  | BUGLVL(D_RX) arcnet_dump_packet(dev, recbuf, "rx irq", 0); | 
|  |  | 
|  | arcnet_rx(dev, recbuf); | 
|  | release_arcbuf(dev, recbuf); | 
|  |  | 
|  | didsomething++; | 
|  | } | 
|  | if (status & lp->intmask & RECONflag) { | 
|  | ACOMMAND(CFLAGScmd | CONFIGclear); | 
|  | lp->stats.tx_carrier_errors++; | 
|  |  | 
|  | BUGMSG(D_RECON, "Network reconfiguration detected (status=%Xh)\n", | 
|  | status); | 
|  | /* MYRECON bit is at bit 7 of diagstatus */ | 
|  | if(diagstatus & 0x80) | 
|  | BUGMSG(D_RECON,"Put out that recon myself\n"); | 
|  |  | 
|  | /* is the RECON info empty or old? */ | 
|  | if (!lp->first_recon || !lp->last_recon || | 
|  | jiffies - lp->last_recon > HZ * 10) { | 
|  | if (lp->network_down) | 
|  | BUGMSG(D_NORMAL, "reconfiguration detected: cabling restored?\n"); | 
|  | lp->first_recon = lp->last_recon = jiffies; | 
|  | lp->num_recons = lp->network_down = 0; | 
|  |  | 
|  | BUGMSG(D_DURING, "recon: clearing counters.\n"); | 
|  | } else {	/* add to current RECON counter */ | 
|  | lp->last_recon = jiffies; | 
|  | lp->num_recons++; | 
|  |  | 
|  | BUGMSG(D_DURING, "recon: counter=%d, time=%lds, net=%d\n", | 
|  | lp->num_recons, | 
|  | (lp->last_recon - lp->first_recon) / HZ, | 
|  | lp->network_down); | 
|  |  | 
|  | /* if network is marked up; | 
|  | * and first_recon and last_recon are 60+ apart; | 
|  | * and the average no. of recons counted is | 
|  | *    > RECON_THRESHOLD/min; | 
|  | * then print a warning message. | 
|  | */ | 
|  | if (!lp->network_down | 
|  | && (lp->last_recon - lp->first_recon) <= HZ * 60 | 
|  | && lp->num_recons >= RECON_THRESHOLD) { | 
|  | lp->network_down = 1; | 
|  | BUGMSG(D_NORMAL, "many reconfigurations detected: cabling problem?\n"); | 
|  | } else if (!lp->network_down | 
|  | && lp->last_recon - lp->first_recon > HZ * 60) { | 
|  | /* reset counters if we've gone for over a minute. */ | 
|  | lp->first_recon = lp->last_recon; | 
|  | lp->num_recons = 1; | 
|  | } | 
|  | } | 
|  | } else if (lp->network_down && jiffies - lp->last_recon > HZ * 10) { | 
|  | if (lp->network_down) | 
|  | BUGMSG(D_NORMAL, "cabling restored?\n"); | 
|  | lp->first_recon = lp->last_recon = 0; | 
|  | lp->num_recons = lp->network_down = 0; | 
|  |  | 
|  | BUGMSG(D_DURING, "not recon: clearing counters anyway.\n"); | 
|  | } | 
|  |  | 
|  | if(didsomething) { | 
|  | retval |= IRQ_HANDLED; | 
|  | } | 
|  | } | 
|  | while (--boguscount && didsomething); | 
|  |  | 
|  | BUGMSG(D_DURING, "arcnet_interrupt complete (status=%Xh, count=%d)\n", | 
|  | ASTATUS(), boguscount); | 
|  | BUGMSG(D_DURING, "\n"); | 
|  |  | 
|  |  | 
|  | AINTMASK(0); | 
|  | udelay(1); | 
|  | AINTMASK(lp->intmask); | 
|  |  | 
|  | spin_unlock(&lp->lock); | 
|  | return retval; | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * This is a generic packet receiver that calls arcnet??_rx depending on the | 
|  | * protocol ID found. | 
|  | */ | 
|  | static void arcnet_rx(struct net_device *dev, int bufnum) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | struct archdr pkt; | 
|  | struct arc_rfc1201 *soft; | 
|  | int length, ofs; | 
|  |  | 
|  | soft = &pkt.soft.rfc1201; | 
|  |  | 
|  | lp->hw.copy_from_card(dev, bufnum, 0, &pkt, sizeof(ARC_HDR_SIZE)); | 
|  | if (pkt.hard.offset[0]) { | 
|  | ofs = pkt.hard.offset[0]; | 
|  | length = 256 - ofs; | 
|  | } else { | 
|  | ofs = pkt.hard.offset[1]; | 
|  | length = 512 - ofs; | 
|  | } | 
|  |  | 
|  | /* get the full header, if possible */ | 
|  | if (sizeof(pkt.soft) <= length) | 
|  | lp->hw.copy_from_card(dev, bufnum, ofs, soft, sizeof(pkt.soft)); | 
|  | else { | 
|  | memset(&pkt.soft, 0, sizeof(pkt.soft)); | 
|  | lp->hw.copy_from_card(dev, bufnum, ofs, soft, length); | 
|  | } | 
|  |  | 
|  | BUGMSG(D_DURING, "Buffer #%d: received packet from %02Xh to %02Xh " | 
|  | "(%d+4 bytes)\n", | 
|  | bufnum, pkt.hard.source, pkt.hard.dest, length); | 
|  |  | 
|  | lp->stats.rx_packets++; | 
|  | lp->stats.rx_bytes += length + ARC_HDR_SIZE; | 
|  |  | 
|  | /* call the right receiver for the protocol */ | 
|  | if (arc_proto_map[soft->proto]->is_ip) { | 
|  | BUGLVL(D_PROTO) { | 
|  | struct ArcProto | 
|  | *oldp = arc_proto_map[lp->default_proto[pkt.hard.source]], | 
|  | *newp = arc_proto_map[soft->proto]; | 
|  |  | 
|  | if (oldp != newp) { | 
|  | BUGMSG(D_PROTO, | 
|  | "got protocol %02Xh; encap for host %02Xh is now '%c'" | 
|  | " (was '%c')\n", soft->proto, pkt.hard.source, | 
|  | newp->suffix, oldp->suffix); | 
|  | } | 
|  | } | 
|  |  | 
|  | /* broadcasts will always be done with the last-used encap. */ | 
|  | lp->default_proto[0] = soft->proto; | 
|  |  | 
|  | /* in striking contrast, the following isn't a hack. */ | 
|  | lp->default_proto[pkt.hard.source] = soft->proto; | 
|  | } | 
|  | /* call the protocol-specific receiver. */ | 
|  | arc_proto_map[soft->proto]->rx(dev, bufnum, &pkt, length); | 
|  | } | 
|  |  | 
|  |  | 
|  |  | 
|  | /* | 
|  | * Get the current statistics.  This may be called with the card open or | 
|  | * closed. | 
|  | */ | 
|  | static struct net_device_stats *arcnet_get_stats(struct net_device *dev) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | return &lp->stats; | 
|  | } | 
|  |  | 
|  |  | 
|  | static void null_rx(struct net_device *dev, int bufnum, | 
|  | struct archdr *pkthdr, int length) | 
|  | { | 
|  | BUGMSG(D_PROTO, | 
|  | "rx: don't know how to deal with proto %02Xh from host %02Xh.\n", | 
|  | pkthdr->soft.rfc1201.proto, pkthdr->hard.source); | 
|  | } | 
|  |  | 
|  |  | 
|  | static int null_build_header(struct sk_buff *skb, struct net_device *dev, | 
|  | unsigned short type, uint8_t daddr) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  |  | 
|  | BUGMSG(D_PROTO, | 
|  | "tx: can't build header for encap %02Xh; load a protocol driver.\n", | 
|  | lp->default_proto[daddr]); | 
|  |  | 
|  | /* always fails */ | 
|  | return 0; | 
|  | } | 
|  |  | 
|  |  | 
|  | /* the "do nothing" prepare_tx function warns that there's nothing to do. */ | 
|  | static int null_prepare_tx(struct net_device *dev, struct archdr *pkt, | 
|  | int length, int bufnum) | 
|  | { | 
|  | struct arcnet_local *lp = dev->priv; | 
|  | struct arc_hardware newpkt; | 
|  |  | 
|  | BUGMSG(D_PROTO, "tx: no encap for this host; load a protocol driver.\n"); | 
|  |  | 
|  | /* send a packet to myself -- will never get received, of course */ | 
|  | newpkt.source = newpkt.dest = dev->dev_addr[0]; | 
|  |  | 
|  | /* only one byte of actual data (and it's random) */ | 
|  | newpkt.offset[0] = 0xFF; | 
|  |  | 
|  | lp->hw.copy_to_card(dev, bufnum, 0, &newpkt, ARC_HDR_SIZE); | 
|  |  | 
|  | return 1;		/* done */ | 
|  | } |