8390.c

嵌入式系统的TCP/IP源代码

	   a real overrun, leaving the 8390 in a stopped state with rec'vr off. */
	outb_p(ENISR_RX+ENISR_RX_ERR, e8390_base+EN0_ISR);
	return;
}

/* 
 * We have a receiver overrun: we have to kick the 8390 to get it started
 * again. Problem is that you have to kick it exactly as NS prescribes in
 * the updated datasheets, or "the NIC may act in an unpredictable manner."
 * This includes causing "the NIC to defer indefinitely when it is stopped
 * on a busy network."  Ugh.
 * Called with lock held. Don't call this with the interrupts off or your
 * computer will hate you - it takes 10mS or so. 
 */

static void ei_rx_overrun(struct device *dev)
{
	long e8390_base = dev->base_addr;
	unsigned char was_txing, must_resend = 0;
	struct ei_device *ei_local = (struct ei_device *) dev->priv;
    
	/*
	 * Record whether a Tx was in progress and then issue the
	 * stop command.
	 */
	was_txing = inb_p(e8390_base+E8390_CMD) & E8390_TRANS;
	outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD);
    
	if (ei_debug > 1)
		printk(KERN_DEBUG "%s: Receiver overrun.\n", dev->name);
	ei_local->stat.rx_over_errors++;
    
	/* 
	 * Wait a full Tx time (1.2ms) + some guard time, NS says 1.6ms total.
	 * Early datasheets said to poll the reset bit, but now they say that
	 * it "is not a reliable indicator and subsequently should be ignored."
	 * We wait at least 10ms.
	 */

	udelay(10*1000);

	/*
	 * Reset RBCR[01] back to zero as per magic incantation.
	 */
	outb_p(0x00, e8390_base+EN0_RCNTLO);
	outb_p(0x00, e8390_base+EN0_RCNTHI);

	/*
	 * See if any Tx was interrupted or not. According to NS, this
	 * step is vital, and skipping it will cause no end of havoc.
	 */

	if (was_txing)
	{ 
		unsigned char tx_completed = inb_p(e8390_base+EN0_ISR) & (ENISR_TX+ENISR_TX_ERR);
		if (!tx_completed)
			must_resend = 1;
	}

	/*
	 * Have to enter loopback mode and then restart the NIC before
	 * you are allowed to slurp packets up off the ring.
	 */
	outb_p(E8390_TXOFF, e8390_base + EN0_TXCR);
	outb_p(E8390_NODMA + E8390_PAGE0 + E8390_START, e8390_base + E8390_CMD);

	/*
	 * Clear the Rx ring of all the debris, and ack the interrupt.
	 */
	ei_receive(dev);
	outb_p(ENISR_OVER, e8390_base+EN0_ISR);

	/*
	 * Leave loopback mode, and resend any packet that got stopped.
	 */
	outb_p(E8390_TXCONFIG, e8390_base + EN0_TXCR); 
	if (must_resend)
    		outb_p(E8390_NODMA + E8390_PAGE0 + E8390_START + E8390_TRANS, e8390_base + E8390_CMD);
}

/*
 *	Collect the stats. This is called unlocked and from several contexts.
 */
 
static struct net_device_stats *get_stats(struct device *dev)
{
	long ioaddr = dev->base_addr;
	struct ei_device *ei_local = (struct ei_device *) dev->priv;
	unsigned long flags;
    
	/* If the card is stopped, just return the present stats. */
	if (dev->start == 0) 
		return &ei_local->stat;

	spin_lock_irqsave(&ei_local->page_lock,flags);
	/* Read the counter registers, assuming we are in page 0. */
	ei_local->stat.rx_frame_errors += inb_p(ioaddr + EN0_COUNTER0);
	ei_local->stat.rx_crc_errors   += inb_p(ioaddr + EN0_COUNTER1);
	ei_local->stat.rx_missed_errors+= inb_p(ioaddr + EN0_COUNTER2);
	spin_unlock_irqrestore(&ei_local->page_lock, flags);
    
	return &ei_local->stat;
}

/*
 * Update the given Autodin II CRC value with another data byte.
 */

static inline u32 update_crc(u8 byte, u32 current_crc)
{
	int bit;
	u8 ah = 0;
	for (bit=0; bit<8; bit++) 
	{
		u8 carry = (current_crc>>31);
		current_crc <<= 1;
		ah = ((ah<<1) | carry) ^ byte;
		if (ah&1)
			current_crc ^= 0x04C11DB7;	/* CRC polynomial */
		ah >>= 1;
		byte >>= 1;
	}
	return current_crc;
}

/*
 * Form the 64 bit 8390 multicast table from the linked list of addresses
 * associated with this dev structure.
 */
 
static inline void make_mc_bits(u8 *bits, struct device *dev)
{
	struct dev_mc_list *dmi;

	for (dmi=dev->mc_list; dmi; dmi=dmi->next) 
	{
		int i;
		u32 crc;
		if (dmi->dmi_addrlen != ETH_ALEN) 
		{
			printk(KERN_INFO "%s: invalid multicast address length given.\n", dev->name);
			continue;
		}
		crc = 0xffffffff;	/* initial CRC value */
		for (i=0; i<ETH_ALEN; i++)
			crc = update_crc(dmi->dmi_addr[i], crc);
		/* 
		 * The 8390 uses the 6 most significant bits of the
		 * CRC to index the multicast table.
		 */
		bits[crc>>29] |= (1<<((crc>>26)&7));
	}
}

/*
 *	Set or clear the multicast filter for this adaptor. May be called
 *	from a BH in 2.1.x. Must be called with lock held. 
 */
 
static void do_set_multicast_list(struct device *dev)
{
	long e8390_base = dev->base_addr;
	int i;
	struct ei_device *ei_local = (struct ei_device*)dev->priv;

	if (!(dev->flags&(IFF_PROMISC|IFF_ALLMULTI))) 
	{
		memset(ei_local->mcfilter, 0, 8);
		if (dev->mc_list)
			make_mc_bits(ei_local->mcfilter, dev);
	}
	else
		memset(ei_local->mcfilter, 0xFF, 8);	/* mcast set to accept-all */

	/* 
	 * DP8390 manuals don't specify any magic sequence for altering
	 * the multicast regs on an already running card. To be safe, we
	 * ensure multicast mode is off prior to loading up the new hash
	 * table. If this proves to be not enough, we can always resort
	 * to stopping the NIC, loading the table and then restarting.
	 *
	 * Bug Alert!  The MC regs on the SMC 83C690 (SMC Elite and SMC 
	 * Elite16) appear to be write-only. The NS 8390 data sheet lists
	 * them as r/w so this is a bug.  The SMC 83C790 (SMC Ultra and
	 * Ultra32 EISA) appears to have this bug fixed.
	 */
	 
	if (dev->start)
		outb_p(E8390_RXCONFIG, e8390_base + EN0_RXCR);
	outb_p(E8390_NODMA + E8390_PAGE1, e8390_base + E8390_CMD);
	for(i = 0; i < 8; i++) 
	{
		outb_p(ei_local->mcfilter[i], e8390_base + EN1_MULT_SHIFT(i));
#ifndef BUG_83C690
		if(inb_p(e8390_base + EN1_MULT_SHIFT(i))!=ei_local->mcfilter[i])
			printk(KERN_ERR "Multicast filter read/write mismap %d\n",i);
#endif
	}
	outb_p(E8390_NODMA + E8390_PAGE0, e8390_base + E8390_CMD);

  	if(dev->flags&IFF_PROMISC)
  		outb_p(E8390_RXCONFIG | 0x18, e8390_base + EN0_RXCR);
	else if(dev->flags&IFF_ALLMULTI || dev->mc_list)
  		outb_p(E8390_RXCONFIG | 0x08, e8390_base + EN0_RXCR);
  	else
  		outb_p(E8390_RXCONFIG, e8390_base + EN0_RXCR);
 }

/*
 *	Called without lock held. This is invoked from user context and may
 *	be parallel to just about everything else. Its also fairly quick and
 *	not called too often. Must protect against both bh and irq users
 */
 
static void set_multicast_list(struct device *dev)
{
	unsigned long flags;
	struct ei_device *ei_local = (struct ei_device*)dev->priv;
	
	spin_lock_irqsave(&ei_local->page_lock, flags);
	do_set_multicast_list(dev);
	spin_unlock_irqrestore(&ei_local->page_lock, flags);
}	

/*
 * Initialize the rest of the 8390 device structure.  Do NOT __initfunc
 * this, as it is used by 8390 based modular drivers too.
 */

int ethdev_init(struct device *dev)
{
	if (ei_debug > 1)
		printk(version);
    
	if (dev->priv == NULL) 
	{
		struct ei_device *ei_local;
		
		dev->priv = kmalloc(sizeof(struct ei_device), GFP_KERNEL);
		if (dev->priv == NULL)
			return -ENOMEM;
		memset(dev->priv, 0, sizeof(struct ei_device));
		ei_local = (struct ei_device *)dev->priv;
		spin_lock_init(&ei_local->page_lock);
	}
    
	dev->hard_start_xmit = &ei_start_xmit;
	dev->get_stats	= get_stats;
	dev->set_multicast_list = &set_multicast_list;

	ether_setup(dev);
        
	return 0;
}



/* This page of functions should be 8390 generic */
/* Follow National Semi's recommendations for initializing the "NIC". */

/*
 *	Must be called with lock held.
 */

void NS8390_init(struct device *dev, int startp)
{
	long e8390_base = dev->base_addr;
	struct ei_device *ei_local = (struct ei_device *) dev->priv;
	int i;
	int endcfg = ei_local->word16 ? (0x48 | ENDCFG_WTS) : 0x48;
    
	if(sizeof(struct e8390_pkt_hdr)!=4)
    		panic("8390.c: header struct mispacked\n");    
	/* Follow National Semi's recommendations for initing the DP83902. */
	outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD); /* 0x21 */
	outb_p(endcfg, e8390_base + EN0_DCFG);	/* 0x48 or 0x49 */
	/* Clear the remote byte count registers. */
	outb_p(0x00,  e8390_base + EN0_RCNTLO);
	outb_p(0x00,  e8390_base + EN0_RCNTHI);
	/* Set to monitor and loopback mode -- this is vital!. */
	outb_p(E8390_RXOFF, e8390_base + EN0_RXCR); /* 0x20 */
	outb_p(E8390_TXOFF, e8390_base + EN0_TXCR); /* 0x02 */
	/* Set the transmit page and receive ring. */
	outb_p(ei_local->tx_start_page, e8390_base + EN0_TPSR);
	ei_local->tx1 = ei_local->tx2 = 0;
	outb_p(ei_local->rx_start_page, e8390_base + EN0_STARTPG);
	outb_p(ei_local->stop_page-1, e8390_base + EN0_BOUNDARY);	/* 3c503 says 0x3f,NS0x26*/
	ei_local->current_page = ei_local->rx_start_page;		/* assert boundary+1 */
	outb_p(ei_local->stop_page, e8390_base + EN0_STOPPG);
	/* Clear the pending interrupts and mask. */
	outb_p(0xFF, e8390_base + EN0_ISR);
	outb_p(0x00,  e8390_base + EN0_IMR);
    
	/* Copy the station address into the DS8390 registers. */

	outb_p(E8390_NODMA + E8390_PAGE1 + E8390_STOP, e8390_base+E8390_CMD); /* 0x61 */
	for(i = 0; i < 6; i++) 
	{
		outb_p(dev->dev_addr[i], e8390_base + EN1_PHYS_SHIFT(i));
		if(inb_p(e8390_base + EN1_PHYS_SHIFT(i))!=dev->dev_addr[i])
			printk(KERN_ERR "Hw. address read/write mismap %d\n",i);
	}

	outb_p(ei_local->rx_start_page, e8390_base + EN1_CURPAG);
	outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD);

	dev->tbusy = 0;
	dev->interrupt = 0;
	ei_local->tx1 = ei_local->tx2 = 0;
	ei_local->txing = 0;

	if (startp) 
	{
		outb_p(0xff,  e8390_base + EN0_ISR);
		outb_p(ENISR_ALL,  e8390_base + EN0_IMR);
		outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base+E8390_CMD);
		outb_p(E8390_TXCONFIG, e8390_base + EN0_TXCR); /* xmit on. */
		/* 3c503 TechMan says rxconfig only after the NIC is started. */
		outb_p(E8390_RXCONFIG, e8390_base + EN0_RXCR); /* rx on,  */
		do_set_multicast_list(dev);	/* (re)load the mcast table */
	}
	return;
}

/* Trigger a transmit start, assuming the length is valid. 
   Always called with the page lock held */
   
static void NS8390_trigger_send(struct device *dev, unsigned int length,
								int start_page)
{
	long e8390_base = dev->base_addr;
 	struct ei_device *ei_local = (struct ei_device *) dev->priv;
   
	outb_p(E8390_NODMA+E8390_PAGE0, e8390_base+E8390_CMD);
    
	if (inb_p(e8390_base) & E8390_TRANS) 
	{
		printk(KERN_WARNING "%s: trigger_send() called with the transmitter busy.\n",
			dev->name);
		return;
	}
	outb_p(length & 0xff, e8390_base + EN0_TCNTLO);
	outb_p(length >> 8, e8390_base + EN0_TCNTHI);
	outb_p(start_page, e8390_base + EN0_TPSR);
	outb_p(E8390_NODMA+E8390_TRANS+E8390_START, e8390_base+E8390_CMD);
}

#ifdef MODULE

EXPORT_SYMBOL(ei_open);
EXPORT_SYMBOL(ei_close);
EXPORT_SYMBOL(ei_interrupt);
EXPORT_SYMBOL(ethdev_init);
EXPORT_SYMBOL(NS8390_init);

struct module *NS8390_module = NULL;

int init_module(void)
{
	NS8390_module = &__this_module;
	return 0;
}

void cleanup_module(void)
{
	NS8390_module = NULL;
}

#endif /* MODULE */

/*
 * Local variables:
 *  compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/net/inet -Wall -Wstrict-prototypes -O6 -m486 -c 8390.c"
 *  version-control: t
 *  kept-new-versions: 5
 *  c-indent-level: 4
 *  tab-width: 4
 * End:
 */