3c501.c

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

load_it_again_sam:
		lp->tx_pkt_start = gp_start;
    		lp->collisions = 0;

		/*
		 *	Command mode with status cleared should [in theory]
		 *	mean no more interrupts can be pending on the card.
		 */
		 
#ifdef BLOCKOUT_1
		disable_irq(dev->irq);		 
#endif	
		outb_p(AX_SYS, AX_CMD);
		inb_p(RX_STATUS);
		inb_p(TX_STATUS);
	
		lp->loading=1;
	
		/* 
		 *	Turn interrupts back on while we spend a pleasant afternoon
		 *	loading bytes into the board 
		 */

		restore_flags(flags);
		outw(0x00, RX_BUF_CLR);		/* Set rx packet area to 0. */
		outw(gp_start, GP_LOW);		/* aim - packet will be loaded into buffer start */
		outsb(DATAPORT,buf,skb->len);	/* load buffer (usual thing each byte increments the pointer) */
		outw(gp_start, GP_LOW);		/* the board reuses the same register */
#ifndef BLOCKOUT_1		
		if(lp->loading==2)		/* A receive upset our load, despite our best efforts */
		{
			if(el_debug>2)
				printk("%s: burped during tx load.\n", dev->name);
			goto load_it_again_sam;	/* Sigh... */
		}
#endif
		outb(AX_XMIT, AX_CMD);		/* fire ... Trigger xmit.  */
		lp->loading=0;
#ifdef BLOCKOUT_1		
		enable_irq(dev->irq);
#endif		
		dev->trans_start = jiffies;
	}

	if (el_debug > 2)
		printk(" queued xmit.\n");
	dev_kfree_skb (skb, FREE_WRITE);
	return 0;
}


/*
 *	The typical workload of the driver:
 *	Handle the ether interface interrupts. 
 */

static void el_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct device *dev = (struct device *)(irq2dev_map[irq]);
	struct net_local *lp;
	int ioaddr;
	int axsr;			/* Aux. status reg. */

	if (dev == NULL  ||  dev->irq != irq) 
	{
		printk ("3c501 driver: irq %d for unknown device.\n", irq);
		return;
	}

	ioaddr = dev->base_addr;
	lp = (struct net_local *)dev->priv;

	/*
	 *	What happened ?
	 */
	 
	axsr = inb(AX_STATUS);

	/*
	 *	Log it
	 */

	if (el_debug > 3)
		printk("%s: el_interrupt() aux=%#02x", dev->name, axsr);
	if (dev->interrupt)
		printk("%s: Reentering the interrupt driver!\n", dev->name);
	dev->interrupt = 1;
#ifndef BLOCKOUT_1    
        if(lp->loading==1 && !dev->tbusy)
        	printk("%s: Inconsistent state loading while not in tx\n",
        		dev->name);
#endif        		
#ifdef BLOCKOUT_3
	lp->loading=2;		/* So we can spot loading interruptions */
#endif

	if (dev->tbusy) 
	{
    
    		/*
    		 *	Board in transmit mode. May be loading. If we are
    		 *	loading we shouldn't have got this.
    		 */
    	 
		int txsr = inb(TX_STATUS);
#ifdef BLOCKOUT_2		
		if(lp->loading==1)
		{
			if(el_debug > 2)
			{
				printk("%s: Interrupt while loading [", dev->name);
				printk(" txsr=%02x gp=%04x rp=%04x]\n", txsr, inw(GP_LOW),inw(RX_LOW));
			}
			lp->loading=2;		/* Force a reload */
			dev->interrupt = 0;
			return;
		}
#endif
		if (el_debug > 6)
			printk(" txsr=%02x gp=%04x rp=%04x", txsr, inw(GP_LOW),inw(RX_LOW));

		if ((axsr & 0x80) && (txsr & TX_READY) == 0) 
		{
			/*
			 *	FIXME: is there a logic to whether to keep on trying or
			 *	reset immediately ?
			 */
			if(el_debug>1)
				printk("%s: Unusual interrupt during Tx, txsr=%02x axsr=%02x"
			  		" gp=%03x rp=%03x.\n", dev->name, txsr, axsr,
			inw(ioaddr + EL1_DATAPTR), inw(ioaddr + EL1_RXPTR));
			dev->tbusy = 0;
			mark_bh(NET_BH);
		} 
		else if (txsr & TX_16COLLISIONS) 
		{
			/*
			 *	Timed out
			 */
			if (el_debug)
				printk("%s: Transmit failed 16 times, ethernet jammed?\n",dev->name);
			outb(AX_SYS, AX_CMD);
			lp->stats.tx_aborted_errors++;
		}
		else if (txsr & TX_COLLISION) 
		{	
			/*
			 *	Retrigger xmit. 
			 */
			 
			if (el_debug > 6)
				printk(" retransmitting after a collision.\n");
			/*
			 *	Poor little chip can't reset its own start pointer
			 */
			
			outb(AX_SYS, AX_CMD);
			outw(lp->tx_pkt_start, GP_LOW);
			outb(AX_XMIT, AX_CMD);
			lp->stats.collisions++;
			dev->interrupt = 0;
			return;
		}
		else
		{
			/*
			 *	It worked.. we will now fall through and receive
			 */
			lp->stats.tx_packets++;
			if (el_debug > 6)
				printk(" Tx succeeded %s\n",
		       			(txsr & TX_RDY) ? "." : "but tx is busy!");
			/*
			 *	This is safe the interrupt is atomic WRT itself.
			 */

			dev->tbusy = 0;
			mark_bh(NET_BH);	/* In case more to transmit */
		}
	}
	else
	{
    		/*
    		 *	In receive mode.
    		 */
    	 
		int rxsr = inb(RX_STATUS);
		if (el_debug > 5)
			printk(" rxsr=%02x txsr=%02x rp=%04x", rxsr, inb(TX_STATUS),inw(RX_LOW));
		/*
		 *	Just reading rx_status fixes most errors. 
		 */
		if (rxsr & RX_MISSED)
			lp->stats.rx_missed_errors++;
		else if (rxsr & RX_RUNT) 
		{	/* Handled to avoid board lock-up. */
			lp->stats.rx_length_errors++;
			if (el_debug > 5) 
				printk(" runt.\n");
		} 
		else if (rxsr & RX_GOOD) 
		{
			/*
			 *	Receive worked.
			 */
			el_receive(dev);
		}
		else
		{
			/*
			 *	Nothing?  Something is broken!
			 */
			if (el_debug > 2)
				printk("%s: No packet seen, rxsr=%02x **resetting 3c501***\n",
					dev->name, rxsr);
			el_reset(dev);
		}
		if (el_debug > 3)
			printk(".\n");
	}

	/*
	 *	Move into receive mode 
	 */

	outb(AX_RX, AX_CMD);
	outw(0x00, RX_BUF_CLR);
	inb(RX_STATUS);		/* Be certain that interrupts are cleared. */
	inb(TX_STATUS);
	dev->interrupt = 0;
	return;
}


/*
 *	We have a good packet. Well, not really "good", just mostly not broken.
 *	We must check everything to see if it is good. 
 */

static void el_receive(struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	int ioaddr = dev->base_addr;
	int pkt_len;
	struct sk_buff *skb;

	pkt_len = inw(RX_LOW);

	if (el_debug > 4)
		printk(" el_receive %d.\n", pkt_len);

	if ((pkt_len < 60)  ||  (pkt_len > 1536)) 
	{
		if (el_debug)
			printk("%s: bogus packet, length=%d\n", dev->name, pkt_len);
		lp->stats.rx_over_errors++;
		return;
	}
    
	/*
	 *	Command mode so we can empty the buffer
	 */
     
	outb(AX_SYS, AX_CMD);
	skb = dev_alloc_skb(pkt_len+2);

	/*
	 *	Start of frame
	 */

	outw(0x00, GP_LOW);
	if (skb == NULL) 
	{
		printk("%s: Memory squeeze, dropping packet.\n", dev->name);
		lp->stats.rx_dropped++;
		return;
	}
	else
	{
    		skb_reserve(skb,2);	/* Force 16 byte alignment */
		skb->dev = dev;
		/*
		 *	The read increments through the bytes. The interrupt
		 *	handler will fix the pointer when it returns to 
		 *	receive mode.
		 */
		insb(DATAPORT, skb_put(skb,pkt_len), pkt_len);
		skb->protocol=eth_type_trans(skb,dev);
		netif_rx(skb);
		lp->stats.rx_packets++;
	}
	return;
}

static void  el_reset(struct device *dev)
{
	int ioaddr = dev->base_addr;

	if (el_debug> 2)
		printk("3c501 reset...");
	outb(AX_RESET, AX_CMD);		/* Reset the chip */
	outb(AX_LOOP, AX_CMD);		/* Aux control, irq and loopback enabled */
	{
		int i;
		for (i = 0; i < 6; i++)	/* Set the station address. */
			outb(dev->dev_addr[i], ioaddr + i);
	}
    
	outw(0, RX_BUF_CLR);		/* Set rx packet area to 0. */
	cli();				/* Avoid glitch on writes to CMD regs */
	outb(TX_NORM, TX_CMD);		/* tx irq on done, collision */
	outb(RX_NORM, RX_CMD);		/* Set Rx commands. */
	inb(RX_STATUS);			/* Clear status. */
	inb(TX_STATUS);
	dev->interrupt = 0;
	dev->tbusy = 0;
	sti();
}

static int el1_close(struct device *dev)
{
	int ioaddr = dev->base_addr;

	if (el_debug > 2)
		printk("%s: Shutting down ethercard at %#x.\n", dev->name, ioaddr);

	dev->tbusy = 1;
	dev->start = 0;

	/*
	 *	Free and disable the IRQ. 
	 */

	free_irq(dev->irq, NULL);
	outb(AX_RESET, AX_CMD);		/* Reset the chip */
	irq2dev_map[dev->irq] = 0;

	MOD_DEC_USE_COUNT;
	return 0;
}

static struct enet_statistics *el1_get_stats(struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	return &lp->stats;
}

/*
 *	Set or clear the multicast filter for this adaptor.
 *			best-effort filtering.
 */

static void set_multicast_list(struct device *dev)
{
	int ioaddr = dev->base_addr;

	if(dev->flags&IFF_PROMISC)
	{    
		outb(RX_PROM, RX_CMD);
		inb(RX_STATUS);
	}
	else if (dev->mc_list || dev->flags&IFF_ALLMULTI)
	{
		outb(RX_MULT, RX_CMD);	/* Multicast or all multicast is the same */
		inb(RX_STATUS);		/* Clear status. */
	}
	else 
	{
		outb(RX_NORM, RX_CMD);
		inb(RX_STATUS);
	}
}

#ifdef MODULE

static char devicename[9] = { 0, };

static struct device dev_3c501 = 
{
	devicename, /* device name is inserted by linux/drivers/net/net_init.c */
	0, 0, 0, 0,
	0x280, 5,
	0, 0, 0, NULL, el1_probe 
};

static int io=0x280;
static int irq=5;
	
int init_module(void)
{
	dev_3c501.irq=irq;
	dev_3c501.base_addr=io;
	if (register_netdev(&dev_3c501) != 0)
		return -EIO;
	return 0;
}

void cleanup_module(void)
{
	/*
	 *	No need to check MOD_IN_USE, as sys_delete_module() checks.
	 */
	 
	unregister_netdev(&dev_3c501);

	/*
	 *	Free up the private structure, or leak memory :-) 
	 */
	 
	kfree(dev_3c501.priv);
	dev_3c501.priv = NULL;	/* gets re-allocated by el1_probe1 */

	/*
	 *	If we don't do this, we can't re-insmod it later. 
	 */
	release_region(dev_3c501.base_addr, EL1_IO_EXTENT);
}

#endif /* MODULE */

/*
 * Local variables:
 *  compile-command: "gcc -D__KERNEL__ -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer  -m486 -c -o 3c501.o 3c501.c"
 *  kept-new-versions: 5
 * End:
 */