arcnet.c

来自「linux 内核源代码」· C语言 代码 · 共 1,123 行 · 第 1/3 页

{
	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);