1998-11-30 OKUJI Yoshinori <okuji@kuicr.kyoto-u.ac.jp>

	Clean up linux emulation code to make it architecture-independent
	as much as possible.

	* linux: Renamed from linuxdev.
	* Makefile.in (objfiles): Add linux.o instead of linuxdev.o.
	(MAKE): New variable. Used for the linux.o target.
	* configure.in: Add AC_CHECK_TOOL(MAKE, make).
	* i386/i386/spl.h: Include <i386/ipl.h>, for compatibility with
	OSF Mach 3.0. Suggested by Elgin Lee <ehl@funghi.com>.
	* linux/src: Renamed from linux/linux.
	* linux/dev: Renamed from linux/mach.
	* linux/Drivers.in (AC_INIT): Use dev/include/linux/autoconf.h,
	instead of mach/include/linux/autoconf.h.
	* Makefile.in (all): Target ../linux.o instead of ../linuxdev.o.
	* linux/dev/drivers/block/genhd.c: Include <machine/spl.h> instead
	of <i386/ipl.h>.
	* linux/dev/drivers/net/auto_irq.c: Remove unneeded header files,
	<i386/ipl.h> and <i386/pic.h>.
	* linux/dev/init/main.c: Many i386-dependent codes moved to ...
	* linux/dev/arch/i386/irq.c: ... here.
	* linux/dev/arch/i386/setup.c: New file.
	* linux/dev/arch/i386/linux_emul.h: Likewise.
	* linux/dev/arch/i386/glue/timer.c: Merged into sched.c.
	* linux/dev/arch/i386/glue/sched.c: Include <machine/spl.h> instead
	of <i386/ipl.h>, and moved to ...
	* linux/dev/kernel/sched.c: ... here.
	* linux/dev/arch/i386/glue/block.c: Include <machine/spl.h> and
	<linux_emul.h>, instead of i386-dependent header files, and
	moved to ...
	* linux/dev/glue/blocl.c: ... here.
	* linux/dev/arch/i386/glue/net.c: Include <machine/spl.h> and
	<linux_emul.h>, instead of i386-dependent header files, and
	moved to ...
	* linux/dev/glue/net.c: ... here.
	* linux/dev/arch/i386/glue/misc.c: Remove `x86' and moved to ...
	* linux/dev/glue/misc.c: ... here.
	* linux/dev/arch/i386/glue/kmem.c: Moved to ...
	* linux/dev/glue/kmem.c: ... here.

1 files changed, 856 insertions, 0 deletions

diff --git a/linux/src/drivers/net/3c501.c b/linux/src/drivers/net/3c501.c
new file mode 100644
index 0000000..200b95c
--- /dev/null
+++ b/linux/src/drivers/net/3c501.c
@@ -0,0 +1,856 @@
+/* 3c501.c: A 3Com 3c501 ethernet driver for linux. */
+/*
+    Written 1992,1993,1994  Donald Becker
+
+    Copyright 1993 United States Government as represented by the
+    Director, National Security Agency.  This software may be used and
+    distributed according to the terms of the GNU Public License,
+    incorporated herein by reference.
+
+    This is a device driver for the 3Com Etherlink 3c501.
+    Do not purchase this card, even as a joke.  It's performance is horrible,
+    and it breaks in many ways.  
+
+    The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
+    Center of Excellence in Space Data and Information Sciences
+       Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
+       
+    Fixed (again!) the missing interrupt locking on TX/RX shifting.
+    		Alan Cox <Alan.Cox@linux.org>
+    		
+    Removed calls to init_etherdev since they are no longer needed, and
+    cleaned up modularization just a bit. The driver still allows only
+    the default address for cards when loaded as a module, but that's
+    really less braindead than anyone using a 3c501 board. :)
+		    19950208 (invid@msen.com)
+
+    Added traps for interrupts hitting the window as we clear and TX load
+    the board. Now getting 150K/second FTP with a 3c501 card. Still playing
+    with a TX-TX optimisation to see if we can touch 180-200K/second as seems
+    theoretically maximum.
+    		19950402 Alan Cox <Alan.Cox@linux.org>
+    		
+    Some notes on this thing if you have to hack it.  [Alan]
+    
+    1]	Some documentation is available from 3Com. Due to the boards age
+    	standard responses when you ask for this will range from 'be serious'
+    	to 'give it to a museum'. The documentation is incomplete and mostly
+    	of historical interest anyway.
+    	
+    2]  The basic system is a single buffer which can be used to receive or
+    	transmit a packet. A third command mode exists when you are setting
+    	things up.
+    	
+    3]	If it's transmitting it's not receiving and vice versa. In fact the 
+    	time to get the board back into useful state after an operation is
+    	quite large.
+    	
+    4]	The driver works by keeping the board in receive mode waiting for a
+    	packet to arrive. When one arrives it is copied out of the buffer
+    	and delivered to the kernel. The card is reloaded and off we go.
+    	
+    5]	When transmitting dev->tbusy is set and the card is reset (from
+    	receive mode) [possibly losing a packet just received] to command
+    	mode. A packet is loaded and transmit mode triggered. The interrupt
+    	handler runs different code for transmit interrupts and can handle
+    	returning to receive mode or retransmissions (yes you have to help
+    	out with those too).
+    	
+    Problems:
+    	There are a wide variety of undocumented error returns from the card
+    and you basically have to kick the board and pray if they turn up. Most 
+    only occur under extreme load or if you do something the board doesn't
+    like (eg touching a register at the wrong time).
+    
+    	The driver is less efficient than it could be. It switches through
+    receive mode even if more transmits are queued. If this worries you buy
+    a real ethernet card.
+    
+    	The combination of slow receive restart and no real multicast
+    filter makes the board unusable with a kernel compiled for IP
+    multicasting in a real multicast environment. That's down to the board, 
+    but even with no multicast programs running a multicast IP kernel is
+    in group 224.0.0.1 and you will therefore be listening to all multicasts.
+    One nv conference running over that ethernet and you can give up.
+    
+*/
+
+static const char *version =
+    "3c501.c: 9/23/94 Donald Becker (becker@cesdis.gsfc.nasa.gov).\n";
+
+/*
+ *	Braindamage remaining:
+ *	The 3c501 board.
+ */
+
+#include <linux/module.h>
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/ptrace.h>
+#include <linux/fcntl.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/malloc.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/config.h>	/* for CONFIG_IP_MULTICAST */
+
+#include <asm/bitops.h>
+#include <asm/io.h>
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+
+#define BLOCKOUT_2
+
+/* A zero-terminated list of I/O addresses to be probed.
+   The 3c501 can be at many locations, but here are the popular ones. */
+static unsigned int netcard_portlist[] =
+   { 0x280, 0x300, 0};
+
+
+/*
+ *	Index to functions. 
+ */
+ 
+int el1_probe(struct device *dev);
+static int  el1_probe1(struct device *dev, int ioaddr);
+static int  el_open(struct device *dev);
+static int  el_start_xmit(struct sk_buff *skb, struct device *dev);
+static void el_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static void el_receive(struct device *dev);
+static void el_reset(struct device *dev);
+static int  el1_close(struct device *dev);
+static struct enet_statistics *el1_get_stats(struct device *dev);
+static void set_multicast_list(struct device *dev);
+
+#define EL1_IO_EXTENT	16
+
+#ifndef EL_DEBUG
+#define EL_DEBUG  0	/* use 0 for production, 1 for devel., >2 for debug */
+#endif			/* Anything above 5 is wordy death! */
+static int el_debug = EL_DEBUG;
+ 
+/* 
+ *	Board-specific info in dev->priv. 
+ */
+ 
+struct net_local 
+{
+    struct enet_statistics stats;
+    int tx_pkt_start;		/* The length of the current Tx packet. */
+    int collisions;		/* Tx collisions this packet */
+    int loading;		/* Spot buffer load collisions */
+};
+
+
+#define RX_STATUS (ioaddr + 0x06)
+#define RX_CMD	  RX_STATUS
+#define TX_STATUS (ioaddr + 0x07)
+#define TX_CMD	  TX_STATUS
+#define GP_LOW 	  (ioaddr + 0x08)
+#define GP_HIGH   (ioaddr + 0x09)
+#define RX_BUF_CLR (ioaddr + 0x0A)
+#define RX_LOW	  (ioaddr + 0x0A)
+#define RX_HIGH   (ioaddr + 0x0B)
+#define SAPROM	  (ioaddr + 0x0C)
+#define AX_STATUS (ioaddr + 0x0E)
+#define AX_CMD	  AX_STATUS
+#define DATAPORT  (ioaddr + 0x0F)
+#define TX_RDY 0x08		/* In TX_STATUS */
+
+#define EL1_DATAPTR	0x08
+#define EL1_RXPTR	0x0A
+#define EL1_SAPROM	0x0C
+#define EL1_DATAPORT 	0x0f
+
+/*
+ *	Writes to the ax command register.
+ */
+ 
+#define AX_OFF	0x00			/* Irq off, buffer access on */
+#define AX_SYS  0x40			/* Load the buffer */
+#define AX_XMIT 0x44			/* Transmit a packet */
+#define AX_RX	0x48			/* Receive a packet */
+#define AX_LOOP	0x0C			/* Loopback mode */
+#define AX_RESET 0x80
+
+/*
+ *	Normal receive mode written to RX_STATUS.  We must intr on short packets
+ *	to avoid bogus rx lockups.
+ */
+ 
+#define RX_NORM 0xA8		/* 0x68 == all addrs, 0xA8 only to me. */
+#define RX_PROM 0x68		/* Senior Prom, uhmm promiscuous mode. */
+#define RX_MULT 0xE8		/* Accept multicast packets. */
+#define TX_NORM 0x0A		/* Interrupt on everything that might hang the chip */
+
+/*
+ *	TX_STATUS register. 
+ */
+ 
+#define TX_COLLISION 0x02
+#define TX_16COLLISIONS 0x04
+#define TX_READY 0x08
+
+#define RX_RUNT 0x08
+#define RX_MISSED 0x01		/* Missed a packet due to 3c501 braindamage. */
+#define RX_GOOD	0x30		/* Good packet 0x20, or simple overflow 0x10. */
+
+
+/*
+ *	The boilerplate probe code.
+ */
+ 
+#ifdef HAVE_DEVLIST
+struct netdev_entry el1_drv = {"3c501", el1_probe1, EL1_IO_EXTENT, netcard_portlist};
+#else
+
+int el1_probe(struct device *dev)
+{
+	int i;
+	int base_addr = dev ? dev->base_addr : 0;
+
+	if (base_addr > 0x1ff)	/* Check a single specified location. */
+		return el1_probe1(dev, base_addr);
+	else if (base_addr != 0)	/* Don't probe at all. */
+		return ENXIO;
+
+	for (i = 0; netcard_portlist[i]; i++) 
+	{
+		int ioaddr = netcard_portlist[i];
+		if (check_region(ioaddr, EL1_IO_EXTENT))
+			continue;
+		if (el1_probe1(dev, ioaddr) == 0)
+			return 0;
+	}
+
+	return ENODEV;
+}
+#endif
+
+/*
+ *	The actual probe. 
+ */ 
+
+static int el1_probe1(struct device *dev, int ioaddr)
+{
+	const char *mname;		/* Vendor name */
+	unsigned char station_addr[6];
+	int autoirq = 0;
+	int i;
+
+	/*
+	 *	Read the station address PROM data from the special port.  
+	 */
+	 
+	for (i = 0; i < 6; i++) 
+	{
+		outw(i, ioaddr + EL1_DATAPTR);
+		station_addr[i] = inb(ioaddr + EL1_SAPROM);
+	}
+	/*
+	 *	Check the first three octets of the S.A. for 3Com's prefix, or
+	 *	for the Sager NP943 prefix. 
+	 */ 
+	 
+	if (station_addr[0] == 0x02  &&  station_addr[1] == 0x60
+		&& station_addr[2] == 0x8c) 
+	{
+		mname = "3c501";
+	} else if (station_addr[0] == 0x00  &&  station_addr[1] == 0x80
+	&& station_addr[2] == 0xC8) 
+	{
+		mname = "NP943";
+    	}
+    	else
+		return ENODEV;
+
+	/*
+	 *	Grab the region so we can find the another board if autoIRQ fails. 
+	 */
+
+	request_region(ioaddr, EL1_IO_EXTENT,"3c501");
+
+	/*	
+	 *	We auto-IRQ by shutting off the interrupt line and letting it float
+	 *	high.
+	 */
+
+	if (dev->irq < 2) 
+	{
+		autoirq_setup(2);
+		inb(RX_STATUS);		/* Clear pending interrupts. */
+		inb(TX_STATUS);
+		outb(AX_LOOP + 1, AX_CMD);
+
+		outb(0x00, AX_CMD);
+	
+		autoirq = autoirq_report(1);
+
+		if (autoirq == 0) 
+		{
+			printk("%s probe at %#x failed to detect IRQ line.\n",
+				mname, ioaddr);
+			return EAGAIN;
+		}
+	}
+
+	outb(AX_RESET+AX_LOOP, AX_CMD);			/* Loopback mode. */
+	dev->base_addr = ioaddr;
+	memcpy(dev->dev_addr, station_addr, ETH_ALEN);
+
+	if (dev->mem_start & 0xf)
+		el_debug = dev->mem_start & 0x7;
+	if (autoirq)
+		dev->irq = autoirq;
+
+	printk("%s: %s EtherLink at %#lx, using %sIRQ %d.\n", dev->name, mname, dev->base_addr,
+			autoirq ? "auto":"assigned ", dev->irq);
+	   
+#ifdef CONFIG_IP_MULTICAST
+	printk("WARNING: Use of the 3c501 in a multicast kernel is NOT recommended.\n");
+#endif    
+
+	if (el_debug)
+		printk("%s", version);
+
+	/*
+	 *	Initialize the device structure. 
+	 */
+	 
+	dev->priv = kmalloc(sizeof(struct net_local), GFP_KERNEL);
+	if (dev->priv == NULL)
+		return -ENOMEM;
+	memset(dev->priv, 0, sizeof(struct net_local));
+
+	/*
+	 *	The EL1-specific entries in the device structure. 
+	 */
+	 
+	dev->open = &el_open;
+	dev->hard_start_xmit = &el_start_xmit;
+	dev->stop = &el1_close;
+	dev->get_stats = &el1_get_stats;
+	dev->set_multicast_list = &set_multicast_list;
+
+	/*
+	 *	Setup the generic properties 
+	 */
+
+	ether_setup(dev);
+
+	return 0;
+}
+
+/*
+ *	Open/initialize the board. 
+ */
+ 
+static int el_open(struct device *dev)
+{
+	int ioaddr = dev->base_addr;
+
+	if (el_debug > 2)
+		printk("%s: Doing el_open()...", dev->name);
+
+	if (request_irq(dev->irq, &el_interrupt, 0, "3c501", NULL)) 
+		return -EAGAIN;
+
+	irq2dev_map[dev->irq] = dev;
+	el_reset(dev);
+
+	dev->start = 1;
+
+	outb(AX_RX, AX_CMD);	/* Aux control, irq and receive enabled */
+	MOD_INC_USE_COUNT;
+	return 0;
+}
+
+static int el_start_xmit(struct sk_buff *skb, struct device *dev)
+{
+	struct net_local *lp = (struct net_local *)dev->priv;
+	int ioaddr = dev->base_addr;
+	unsigned long flags;
+	
+	if(dev->interrupt)		/* May be unloading, don't stamp on */
+		return 1;		/* the packet buffer this time      */
+
+	if (dev->tbusy) 
+	{
+		if (jiffies - dev->trans_start < 20) 
+		{
+			if (el_debug > 2)
+				printk(" transmitter busy, deferred.\n");
+			return 1;
+		}
+		if (el_debug)
+			printk ("%s: transmit timed out, txsr %#2x axsr=%02x rxsr=%02x.\n",
+				dev->name, inb(TX_STATUS), inb(AX_STATUS), inb(RX_STATUS));
+		lp->stats.tx_errors++;
+		outb(TX_NORM, TX_CMD);
+		outb(RX_NORM, RX_CMD);
+		outb(AX_OFF, AX_CMD);	/* Just trigger a false interrupt. */
+		outb(AX_RX, AX_CMD);	/* Aux control, irq and receive enabled */
+		dev->tbusy = 0;
+		dev->trans_start = jiffies;
+	}
+
+	if (skb == NULL) 
+	{
+		dev_tint(dev);
+		return 0;
+	}
+
+	save_flags(flags);
+
+	/*
+	 *	Avoid incoming interrupts between us flipping tbusy and flipping
+	 *	mode as the driver assumes tbusy is a faithful indicator of card
+	 *	state
+	 */
+	 
+	cli();
+	
+	/*
+	 *	Avoid timer-based retransmission conflicts. 
+	 */
+	 
+	if (set_bit(0, (void*)&dev->tbusy) != 0)
+	{
+		restore_flags(flags);
+		printk("%s: Transmitter access conflict.\n", dev->name);
+	}
+	else
+	{
+		int gp_start = 0x800 - (ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN);
+		unsigned char *buf = skb->data;
+
+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:
+ */