{	int		transmit_from;	int		len;	int		tickssofar;	unsigned char	*buffer = skb->data;	/*	 * If some higher layer thinks we've missed a	 * tx-done interrupt we are passed NULL.	 * Caution: dev_tint() handles the cli()/sti() itself.	 */	if (skb == NULL) {		dev_tint(dev);		return 0;	}	/* For ethernet, fill in the header (hardware addresses) with an arp. */	if (!skb->arp)		if(dev->rebuild_header(skb->data, dev)) {			skb->dev = dev;			arp_queue (skb);			return 0;		}	skb->arp = 1;	if (free_tx_pages <= 0) {	/* Do timeouts, to avoid hangs. */		tickssofar = jiffies - dev->trans_start;		if (tickssofar < 5)			return 1;		/* else */		printk("%s: transmit timed out (%d), %s?\n",			dev->name,			tickssofar,			"network cable problem"			);		/* Restart the adapter. */		adapter_init(dev);	}	/* Start real output */	PRINTK(("d_link_start_xmit:len=%d, page %d/%d\n", skb->len, tx_fifo_in, free_tx_pages));	if ((len = skb->len) < RUNT)		len = RUNT;	cli();	select_nic();	tx_fifo[tx_fifo_in] = transmit_from = tx_page_adr(tx_fifo_in) - len;	tx_fifo_in = (tx_fifo_in + 1) % TX_PAGES; /* Next free tx page */	d_link_setup_address(transmit_from, RW_ADDR);	for ( ; len > 0; --len, ++buffer)		d_link_put_byte(*buffer);	if (free_tx_pages-- == TX_PAGES) { /* No transmission going on */		dev->trans_start = jiffies;		dev->tbusy = 0;	/* allow more packets into adapter */		/* Send page and generate an interrupt */		d_link_setup_address(transmit_from, TX_ADDR);		d_link_put_command(TX_ENABLE);	}	else {		dev->tbusy = !free_tx_pages;		select_prn();	}		sti(); /* interrupts back on */		if (skb->free)		kfree_skb (skb, FREE_WRITE);	return 0;}/* * The typical workload of the driver: * Handle the network interface interrupts. */static voidd_link_interrupt(int reg_ptr){	int		irq = -(((struct pt_regs *)reg_ptr)->orig_eax+2);	struct device	*dev = irq2dev_map[irq];	unsigned char	irq_status;	int		retrig = 0;	int		boguscount = 0;	/* This might just as well be deleted now, no crummy drivers present :-) */	if ((dev == NULL) || (dev->start == 0) || (D_LINK_IRQ != irq)) {		printk("%s: bogus interrupt %d\n", dev?dev->name:"DE-600", irq);		return;	}	dev->interrupt = 1;	select_nic();	irq_status = d_link_read_status(dev);	do {		PRINTK(("d_link_interrupt (%2.2X)\n", irq_status));		if (irq_status & RX_GOOD)			d_link_rx_intr(dev);		else if (!(irq_status & RX_BUSY))			d_link_put_command(RX_ENABLE);		/* Any transmission in progress? */		if (free_tx_pages < TX_PAGES)			retrig = d_link_tx_intr(dev, irq_status);		else			retrig = 0;		irq_status = d_link_read_status(dev);	} while ( (irq_status & RX_GOOD) || ((++boguscount < 10) && retrig) );	/*	 * Yeah, it _looks_ like busy waiting, smells like busy waiting	 * and I know it's not PC, but please, it will only occur once	 * in a while and then only for a loop or so (< 1ms for sure!)	 */	/* Enable adapter interrupts */	dev->interrupt = 0;	select_prn();	if (retrig)		trigger_interrupt(dev);	sti();	return;}static intd_link_tx_intr(struct device *dev, int irq_status){	/*	 * Returns 1 if tx still not done	 */	mark_bh(INET_BH);	/* Check if current transmission is done yet */	if (irq_status & TX_BUSY)		return 1; /* tx not done, try again */	/* else */	/* If last transmission OK then bump fifo index */	if (!(irq_status & TX_FAILED16)) {		tx_fifo_out = (tx_fifo_out + 1) % TX_PAGES;		++free_tx_pages;		((struct netstats *)(dev->priv))->tx_packets++;		dev->tbusy = 0;	}	/* More to send, or resend last packet? */	if ((free_tx_pages < TX_PAGES) || (irq_status & TX_FAILED16)) {		dev->trans_start = jiffies;		d_link_setup_address(tx_fifo[tx_fifo_out], TX_ADDR);		d_link_put_command(TX_ENABLE);		return 1;	}	/* else */	return 0;}/* * We have a good packet, get it out of the adapter. */static voidd_link_rx_intr(struct device *dev){	struct sk_buff	*skb;	int		i;	int		read_from;	int		size;	int		sksize;	register unsigned char	*buffer;	cli();	/* Get size of received packet */	size = d_link_read_byte(RX_LEN, dev);	/* low byte */	size += (d_link_read_byte(RX_LEN, dev) << 8);	/* high byte */	size -= 4;	/* Ignore trailing 4 CRC-bytes */	/* Tell adapter where to store next incoming packet, enable receiver */	read_from = rx_page_adr();	next_rx_page();	d_link_put_command(RX_ENABLE);	sti();	if ((size < 32)  ||  (size > 1535))		printk("%s: Bogus packet size %d.\n", dev->name, size);	sksize = sizeof(struct sk_buff) + size;	skb = alloc_skb(sksize, GFP_ATOMIC);	sti();	if (skb == NULL) {		printk("%s: Couldn't allocate a sk_buff of size %d.\n",			dev->name, sksize);		return;	}	/* else */	skb->lock = 0;	skb->mem_len = sksize;	skb->mem_addr = skb;	/* 'skb->data' points to the start of sk_buff data area. */	buffer = skb->data;	/* copy the packet into the buffer */	d_link_setup_address(read_from, RW_ADDR);	for (i = size; i > 0; --i, ++buffer)		*buffer = d_link_read_byte(READ_DATA, dev);		((struct netstats *)(dev->priv))->rx_packets++; /* count all receives */	if (dev_rint((unsigned char *)skb, size, IN_SKBUFF, dev))		printk("%s: receive buffers full.\n", dev->name);	/*	 * If any worth-while packets have been received, dev_rint()	 * has done a mark_bh(INET_BH) for us and will work on them	 * when we get to the bottom-half routine.	 */}intd_link_init(struct device *dev){	int	i;	printk("%s: D-Link DE-600 pocket adapter", dev->name);	/* Alpha testers must have the version number to report bugs. */	if (d_link_debug > 1)		printk(version);	/* probe for adapter */	rx_page = 0;	select_nic();	(void)d_link_read_status(dev);	d_link_put_command(RESET);	d_link_put_command(STOP_RESET);	if (d_link_read_status(dev) & 0xf0) {		printk(": not at I/O %#3x.\n", DATA_PORT);		return ENODEV;	}	/*	 * Maybe we found one,	 * have to check if it is a D-Link DE-600 adapter...	 */	/* Get the adapter ethernet address from the ROM */	d_link_setup_address(NODE_ADDRESS, RW_ADDR);	for (i = 0; i < ETH_ALEN; i++) {		dev->dev_addr[i] = d_link_read_byte(READ_DATA, dev);		dev->broadcast[i] = 0xff;	}	/* Check magic code */	if ((dev->dev_addr[1] == 0xde) && (dev->dev_addr[2] == 0x15)) {		/* OK, install real address */		dev->dev_addr[0] = 0x00;		dev->dev_addr[1] = 0x80;		dev->dev_addr[2] = 0xc8;		dev->dev_addr[3] &= 0x0f;		dev->dev_addr[3] |= 0x70;	} else {		printk(" not identified in the printer port\n");		return ENODEV;	}	printk(", Ethernet Address: %2.2X", dev->dev_addr[0]);	for (i = 1; i < ETH_ALEN; i++)		printk(":%2.2X",dev->dev_addr[i]);	printk("\n");	/* Initialize the device structure. */	dev->priv = kmalloc(sizeof(struct netstats), GFP_KERNEL);	memset(dev->priv, 0, sizeof(struct netstats));	for (i = 0; i < DEV_NUMBUFFS; i++)		dev->buffs[i] = NULL;	dev->get_stats = get_stats;	dev->hard_header = eth_header;	dev->add_arp = eth_add_arp;	dev->queue_xmit = dev_queue_xmit;	dev->rebuild_header = eth_rebuild_header;	dev->type_trans = eth_type_trans;	dev->open = d_link_open;	dev->stop = d_link_close;	dev->hard_start_xmit = &d_link_start_xmit;	/* These are ethernet specific. */	dev->type = ARPHRD_ETHER;	dev->hard_header_len = ETH_HLEN;	dev->mtu = 1500; /* eth_mtu */	dev->addr_len	= ETH_ALEN;	/* New-style flags. */	dev->flags = IFF_BROADCAST;	dev->family = AF_INET;	dev->pa_addr = 0;	dev->pa_brdaddr = 0;	dev->pa_mask = 0;	dev->pa_alen = sizeof(unsigned long);	select_prn();	return 0;}static voidadapter_init(struct device *dev){	int	i;	cli();	dev->tbusy = 0;		/* Transmit busy...  */	dev->interrupt = 0;	dev->start = 1;	select_nic();	rx_page = 0; /* used by RESET */	d_link_put_command(RESET);	d_link_put_command(STOP_RESET);	tx_fifo_in = 0;	tx_fifo_out = 0;	free_tx_pages = TX_PAGES;	/* set the ether address. */	d_link_setup_address(NODE_ADDRESS, RW_ADDR);	for (i = 0; i < ETH_ALEN; i++)		d_link_put_byte(dev->dev_addr[i]);	/* where to start saving incoming packets */	rx_page = RX_BP | RX_BASE_PAGE;	d_link_setup_address(MEM_4K, RW_ADDR);	/* Enable receiver */	d_link_put_command(RX_ENABLE);	select_prn();	sti();}#define D_LINK_MIN_WINDOW 1024#define D_LINK_MAX_WINDOW 2048#define D_LINK_TCP_WINDOW_DIFF 1024/* * Copied from sock.c * * Sets a lower max receive window in order to achieve <= 2 * packets arriving at the adapter in fast succession. * (No way that a DE-600 can cope with an ethernet saturated with its packets :-) * * Since there are only 2 receive buffers in the DE-600 * and it takes some time to copy from the adapter, * this is absolutely necessary for any TCP performance whatsoever! * */#define min(a,b)	((a)<(b)?(a):(b))static unsigned longd_link_rspace(struct sock *sk){  int amt;  if (sk != NULL) {/* * Hack! You might want to play with commenting away the following line, * if you know what you do! */  	sk->max_unacked = D_LINK_MAX_WINDOW - D_LINK_TCP_WINDOW_DIFF;	if (sk->rmem_alloc >= SK_RMEM_MAX-2*D_LINK_MIN_WINDOW) return(0);	amt = min((SK_RMEM_MAX-sk->rmem_alloc)/2-D_LINK_MIN_WINDOW, D_LINK_MAX_WINDOW);	if (amt < 0) return(0);	return(amt);  }  return(0);}