de600.c

powerpc内核mpc8241linux系统下net驱动程序

	}

	/* Start real output */
	PRINTK(("de600_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 */

#ifdef CHECK_LOST_DE600
	/* This costs about 40 instructions per packet... */
	de600_setup_address(NODE_ADDRESS, RW_ADDR);
	de600_read_byte(READ_DATA, dev);
	if (was_down || (de600_read_byte(READ_DATA, dev) != 0xde)) {
		if (adapter_init(dev)) {
			sti();
			return 1;
		}
	}
#endif

	de600_setup_address(transmit_from, RW_ADDR);
	for ( ; len > 0; --len, ++buffer)
		de600_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 a faked interrupt */
		de600_setup_address(transmit_from, TX_ADDR);
		de600_put_command(TX_ENABLE);
	}
	else {
		dev->tbusy = !free_tx_pages;
		select_prn();
	}

	sti(); /* interrupts back on */

#ifdef FAKE_SMALL_MAX
	/* This will "patch" the socket TCP proto at an early moment */
	if (skb->sk && (skb->sk->protocol == IPPROTO_TCP) &&
		(skb->sk->prot->rspace != &de600_rspace))
		skb->sk->prot->rspace = de600_rspace; /* Ugh! */
#endif

	dev_kfree_skb (skb);

	return 0;
}

/*
 * The typical workload of the driver:
 * Handle the network interface interrupts.
 */
static void
de600_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	struct device	*dev = dev_id;
	byte		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) || (DE600_IRQ != irq)) {
		printk("%s: bogus interrupt %d\n", dev?dev->name:"DE-600", irq);
		return;
	}

	dev->interrupt = 1;
	select_nic();
	irq_status = de600_read_status(dev);

	do {
		PRINTK(("de600_interrupt (%02X)\n", irq_status));

		if (irq_status & RX_GOOD)
			de600_rx_intr(dev);
		else if (!(irq_status & RX_BUSY))
			de600_put_command(RX_ENABLE);

		/* Any transmission in progress? */
		if (free_tx_pages < TX_PAGES)
			retrig = de600_tx_intr(dev, irq_status);
		else
			retrig = 0;

		irq_status = de600_read_status(dev);
	} while ( (irq_status & RX_GOOD) || ((++boguscount < 100) && 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 int
de600_tx_intr(struct device *dev, int irq_status)
{
	/*
	 * Returns 1 if tx still not done
	 */

	mark_bh(NET_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 net_device_stats *)(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;
		de600_setup_address(tx_fifo[tx_fifo_out], TX_ADDR);
		de600_put_command(TX_ENABLE);
		return 1;
	}
	/* else */

	return 0;
}

/*
 * We have a good packet, get it out of the adapter.
 */
static void
de600_rx_intr(struct device *dev)
{
	struct sk_buff	*skb;
	int		i;
	int		read_from;
	int		size;
	register unsigned char	*buffer;

	cli();
	/* Get size of received packet */
	size = de600_read_byte(RX_LEN, dev);	/* low byte */
	size += (de600_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();
	de600_put_command(RX_ENABLE);
	sti();

	if ((size < 32)  ||  (size > 1535)) {
		printk("%s: Bogus packet size %d.\n", dev->name, size);
		if (size > 10000)
			adapter_init(dev);
		return;
	}

	skb = dev_alloc_skb(size+2);
	sti();
	if (skb == NULL) {
		printk("%s: Couldn't allocate a sk_buff of size %d.\n",
			dev->name, size);
		return;
	}
	/* else */

	skb->dev = dev;
	skb_reserve(skb,2);	/* Align */

	/* 'skb->data' points to the start of sk_buff data area. */
	buffer = skb_put(skb,size);

	/* copy the packet into the buffer */
	de600_setup_address(read_from, RW_ADDR);
	for (i = size; i > 0; --i, ++buffer)
		*buffer = de600_read_byte(READ_DATA, dev);

	((struct net_device_stats *)(dev->priv))->rx_packets++; /* count all receives */

	skb->protocol=eth_type_trans(skb,dev);

	netif_rx(skb);
	/*
	 * If any worth-while packets have been received, netif_rx()
	 * has done a mark_bh(INET_BH) for us and will work on them
	 * when we get to the bottom-half routine.
	 */
}

__initfunc(int
de600_probe(struct device *dev))
{
	int	i;
	static struct net_device_stats de600_netstats;
	/*dev->priv = kmalloc(sizeof(struct net_device_stats), GFP_KERNEL);*/

	printk("%s: D-Link DE-600 pocket adapter", dev->name);
	/* Alpha testers must have the version number to report bugs. */
	if (de600_debug > 1)
		printk(version);

	/* probe for adapter */
	rx_page = 0;
	select_nic();
	(void)de600_read_status(dev);
	de600_put_command(RESET);
	de600_put_command(STOP_RESET);
	if (de600_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 */
	de600_setup_address(NODE_ADDRESS, RW_ADDR);
	for (i = 0; i < ETH_ALEN; i++) {
		dev->dev_addr[i] = de600_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;
	}

#if 0 /* Not yet */
	if (check_region(DE600_IO, 3)) {
		printk(", port 0x%x busy\n", DE600_IO);
		return EBUSY;
	}
#endif
	request_region(DE600_IO, 3, "de600");

	printk(", Ethernet Address: %02X", dev->dev_addr[0]);
	for (i = 1; i < ETH_ALEN; i++)
		printk(":%02X",dev->dev_addr[i]);
	printk("\n");

	/* Initialize the device structure. */
	dev->priv = &de600_netstats;

	memset(dev->priv, 0, sizeof(struct net_device_stats));
	dev->get_stats = get_stats;

	dev->open = de600_open;
	dev->stop = de600_close;
	dev->hard_start_xmit = &de600_start_xmit;

	ether_setup(dev);

	dev->flags&=~IFF_MULTICAST;

	select_prn();
	return 0;
}

static int
adapter_init(struct device *dev)
{
	int	i;
	long flags;

	save_flags(flags);
	cli();

	select_nic();
	rx_page = 0; /* used by RESET */
	de600_put_command(RESET);
	de600_put_command(STOP_RESET);
#ifdef CHECK_LOST_DE600
	/* Check if it is still there... */
	/* Get the some bytes of the adapter ethernet address from the ROM */
	de600_setup_address(NODE_ADDRESS, RW_ADDR);
	de600_read_byte(READ_DATA, dev);
	if ((de600_read_byte(READ_DATA, dev) != 0xde) ||
	    (de600_read_byte(READ_DATA, dev) != 0x15)) {
	/* was: if (de600_read_status(dev) & 0xf0) { */
		printk("Something has happened to the DE-600!  Please check it"
#ifdef SHUTDOWN_WHEN_LOST
			" and do a new ifconfig"
#endif /* SHUTDOWN_WHEN_LOST */
			"!\n");
#ifdef SHUTDOWN_WHEN_LOST
		/* Goodbye, cruel world... */
		dev->flags &= ~IFF_UP;
		de600_close(dev);
#endif /* SHUTDOWN_WHEN_LOST */
		was_down = 1;
		dev->tbusy = 1;		/* Transmit busy...  */
		restore_flags(flags);
		return 1; /* failed */
	}
#endif /* CHECK_LOST_DE600 */
	if (was_down) {
		printk("Thanks, I feel much better now!\n");
		was_down = 0;
	}

	dev->tbusy = 0;		/* Transmit busy...  */
	dev->interrupt = 0;
	tx_fifo_in = 0;
	tx_fifo_out = 0;
	free_tx_pages = TX_PAGES;

	/* set the ether address. */
	de600_setup_address(NODE_ADDRESS, RW_ADDR);
	for (i = 0; i < ETH_ALEN; i++)
		de600_put_byte(dev->dev_addr[i]);

	/* where to start saving incoming packets */
	rx_page = RX_BP | RX_BASE_PAGE;
	de600_setup_address(MEM_4K, RW_ADDR);
	/* Enable receiver */
	de600_put_command(RX_ENABLE);
	select_prn();
	restore_flags(flags);

	return 0; /* OK */
}

#ifdef FAKE_SMALL_MAX
/*
 *	The new router code (coming soon 8-) ) will fix this properly.
 */
#define DE600_MIN_WINDOW 1024
#define DE600_MAX_WINDOW 2048
#define DE600_TCP_WINDOW_DIFF 1024
/*
 * Copied from "net/inet/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 keep up with a net saturated
 *  with packets homing in on it :-( )
 *
 * 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!
 *
 * Note that the returned window info will never be smaller than
 * DE600_MIN_WINDOW, i.e. 1024
 * This differs from the standard function, that can return an
 * arbitrarily small window!
 */
#define min(a,b)	((a)<(b)?(a):(b))
static unsigned long
de600_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 = DE600_MAX_WINDOW - DE600_TCP_WINDOW_DIFF;
 */

	if (atomic_read(&sk->rmem_alloc) >= sk->rcvbuf-2*DE600_MIN_WINDOW) return(0);
	amt = min((sk->rcvbuf-atomic_read(&sk->rmem_alloc))/2/*-DE600_MIN_WINDOW*/, DE600_MAX_WINDOW);
	if (amt < 0) return(0);
	return(amt);
  }
  return(0);
}
#endif

#ifdef MODULE
static char nullname[8];
static struct device de600_dev = {
	nullname, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, de600_probe };

int
init_module(void)
{
	if (register_netdev(&de600_dev) != 0)
		return -EIO;
	return 0;
}

void
cleanup_module(void)
{
	unregister_netdev(&de600_dev);
	release_region(DE600_IO, 3);
}
#endif /* MODULE */
/*
 * Local variables:
 *  kernel-compile-command: "gcc -D__KERNEL__ -Ilinux/include -I../../net/inet -Wall -Wstrict-prototypes -O2 -m486 -c de600.c"
 *  module-compile-command: "gcc -D__KERNEL__ -DMODULE -Ilinux/include -I../../net/inet -Wall -Wstrict-prototypes -O2 -m486 -c de600.c"
 *  compile-command: "gcc -D__KERNEL__ -DMODULE -Ilinux/include -I../../net/inet -Wall -Wstrict-prototypes -O2 -m486 -c de600.c"
 * End:
 */