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, 923 insertions, 0 deletions

diff --git a/linux/src/drivers/net/3c507.c b/linux/src/drivers/net/3c507.c
new file mode 100644
index 0000000..6005487
--- /dev/null
+++ b/linux/src/drivers/net/3c507.c
@@ -0,0 +1,923 @@
+/* 3c507.c: An EtherLink16 device driver for Linux. */
+/*
+	Written 1993,1994 by 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.
+
+	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
+
+	Thanks go to jennings@Montrouge.SMR.slb.com ( Patrick Jennings)
+	and jrs@world.std.com (Rick Sladkey) for testing and bugfixes.
+	Mark Salazar <leslie@access.digex.net> made the changes for cards with
+	only 16K packet buffers.
+
+	Things remaining to do:
+	Verify that the tx and rx buffers don't have fencepost errors.
+	Move the theory of operation and memory map documentation.
+	The statistics need to be updated correctly.
+*/
+
+static const char *version =
+	"3c507.c:v1.10 9/23/94 Donald Becker (becker@cesdis.gsfc.nasa.gov)\n";
+
+
+#include <linux/module.h>
+
+/*
+  Sources:
+	This driver wouldn't have been written with the availability of the
+	Crynwr driver source code.	It provided a known-working implementation
+	that filled in the gaping holes of the Intel documentation.  Three cheers
+	for Russ Nelson.
+
+	Intel Microcommunications Databook, Vol. 1, 1990.  It provides just enough
+	info that the casual reader might think that it documents the i82586 :-<.
+*/
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/in.h>
+#include <linux/string.h>
+#include <asm/system.h>
+#include <asm/bitops.h>
+#include <asm/io.h>
+#include <asm/dma.h>
+#include <linux/errno.h>
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/malloc.h>
+
+
+/* use 0 for production, 1 for verification, 2..7 for debug */
+#ifndef NET_DEBUG
+#define NET_DEBUG 1
+#endif
+static unsigned int net_debug = NET_DEBUG;
+
+/* A zero-terminated list of common I/O addresses to be probed. */
+static unsigned int netcard_portlist[] =
+	{ 0x300, 0x320, 0x340, 0x280, 0};
+
+/*
+  			Details of the i82586.
+
+   You'll really need the databook to understand the details of this part,
+   but the outline is that the i82586 has two separate processing units.
+   Both are started from a list of three configuration tables, of which only
+   the last, the System Control Block (SCB), is used after reset-time.  The SCB
+   has the following fields:
+		Status word
+		Command word
+		Tx/Command block addr.
+		Rx block addr.
+   The command word accepts the following controls for the Tx and Rx units:
+  */
+
+#define	 CUC_START	 0x0100
+#define	 CUC_RESUME	 0x0200
+#define	 CUC_SUSPEND 0x0300
+#define	 RX_START	 0x0010
+#define	 RX_RESUME	 0x0020
+#define	 RX_SUSPEND	 0x0030
+
+/* The Rx unit uses a list of frame descriptors and a list of data buffer
+   descriptors.  We use full-sized (1518 byte) data buffers, so there is
+   a one-to-one pairing of frame descriptors to buffer descriptors.
+
+   The Tx ("command") unit executes a list of commands that look like:
+		Status word		Written by the 82586 when the command is done.
+		Command word	Command in lower 3 bits, post-command action in upper 3
+		Link word		The address of the next command.
+		Parameters		(as needed).
+
+	Some definitions related to the Command Word are:
+ */
+#define CMD_EOL		0x8000			/* The last command of the list, stop. */
+#define CMD_SUSP	0x4000			/* Suspend after doing cmd. */
+#define CMD_INTR	0x2000			/* Interrupt after doing cmd. */
+
+enum commands {
+	CmdNOp = 0, CmdSASetup = 1, CmdConfigure = 2, CmdMulticastList = 3,
+	CmdTx = 4, CmdTDR = 5, CmdDump = 6, CmdDiagnose = 7};
+
+/* Information that need to be kept for each board. */
+struct net_local {
+	struct enet_statistics stats;
+	int last_restart;
+	ushort rx_head;
+	ushort rx_tail;
+	ushort tx_head;
+	ushort tx_cmd_link;
+	ushort tx_reap;
+};
+
+/*
+  		Details of the EtherLink16 Implementation
+  The 3c507 is a generic shared-memory i82586 implementation.
+  The host can map 16K, 32K, 48K, or 64K of the 64K memory into
+  0x0[CD][08]0000, or all 64K into 0xF[02468]0000.
+  */
+
+/* Offsets from the base I/O address. */
+#define	SA_DATA		0	/* Station address data, or 3Com signature. */
+#define MISC_CTRL	6	/* Switch the SA_DATA banks, and bus config bits. */
+#define RESET_IRQ	10	/* Reset the latched IRQ line. */
+#define SIGNAL_CA	11	/* Frob the 82586 Channel Attention line. */
+#define ROM_CONFIG	13
+#define MEM_CONFIG	14
+#define IRQ_CONFIG	15
+#define EL16_IO_EXTENT 16
+
+/* The ID port is used at boot-time to locate the ethercard. */
+#define ID_PORT		0x100
+
+/* Offsets to registers in the mailbox (SCB). */
+#define iSCB_STATUS	0x8
+#define iSCB_CMD		0xA
+#define iSCB_CBL		0xC	/* Command BLock offset. */
+#define iSCB_RFA		0xE	/* Rx Frame Area offset. */
+
+/*  Since the 3c507 maps the shared memory window so that the last byte is
+	at 82586 address FFFF, the first byte is at 82586 address 0, 16K, 32K, or
+	48K corresponding to window sizes of 64K, 48K, 32K and 16K respectively. 
+	We can account for this be setting the 'SBC Base' entry in the ISCP table
+	below for all the 16 bit offset addresses, and also adding the 'SCB Base'
+	value to all 24 bit physical addresses (in the SCP table and the TX and RX
+	Buffer Descriptors).
+					-Mark	
+	*/
+#define SCB_BASE		((unsigned)64*1024 - (dev->mem_end - dev->mem_start))
+ 
+/*
+  What follows in 'init_words[]' is the "program" that is downloaded to the
+  82586 memory.	 It's mostly tables and command blocks, and starts at the
+  reset address 0xfffff6.  This is designed to be similar to the EtherExpress,
+  thus the unusual location of the SCB at 0x0008.
+
+  Even with the additional "don't care" values, doing it this way takes less
+  program space than initializing the individual tables, and I feel it's much
+  cleaner.
+
+  The databook is particularly useless for the first two structures, I had
+  to use the Crynwr driver as an example.
+
+   The memory setup is as follows:
+   */
+
+#define CONFIG_CMD	0x0018
+#define SET_SA_CMD	0x0024
+#define SA_OFFSET	0x002A
+#define IDLELOOP	0x30
+#define TDR_CMD		0x38
+#define TDR_TIME	0x3C
+#define DUMP_CMD	0x40
+#define DIAG_CMD	0x48
+#define SET_MC_CMD	0x4E
+#define DUMP_DATA	0x56	/* A 170 byte buffer for dump and Set-MC into. */
+
+#define TX_BUF_START	0x0100
+#define NUM_TX_BUFS 	4
+#define TX_BUF_SIZE 	(1518+14+20+16) /* packet+header+TBD */
+
+#define RX_BUF_START	0x2000
+#define RX_BUF_SIZE 	(1518+14+18)	/* packet+header+RBD */
+#define RX_BUF_END		(dev->mem_end - dev->mem_start)
+
+/*
+  That's it: only 86 bytes to set up the beast, including every extra
+  command available.  The 170 byte buffer at DUMP_DATA is shared between the
+  Dump command (called only by the diagnostic program) and the SetMulticastList
+  command. 
+
+  To complete the memory setup you only have to write the station address at
+  SA_OFFSET and create the Tx & Rx buffer lists.
+
+  The Tx command chain and buffer list is setup as follows:
+  A Tx command table, with the data buffer pointing to...
+  A Tx data buffer descriptor.  The packet is in a single buffer, rather than
+	chaining together several smaller buffers.
+  A NoOp command, which initially points to itself,
+  And the packet data.
+
+  A transmit is done by filling in the Tx command table and data buffer,
+  re-writing the NoOp command, and finally changing the offset of the last
+  command to point to the current Tx command.  When the Tx command is finished,
+  it jumps to the NoOp, when it loops until the next Tx command changes the
+  "link offset" in the NoOp.  This way the 82586 never has to go through the
+  slow restart sequence.
+
+  The Rx buffer list is set up in the obvious ring structure.  We have enough
+  memory (and low enough interrupt latency) that we can avoid the complicated
+  Rx buffer linked lists by alway associating a full-size Rx data buffer with
+  each Rx data frame.
+
+  I current use four transmit buffers starting at TX_BUF_START (0x0100), and
+  use the rest of memory, from RX_BUF_START to RX_BUF_END, for Rx buffers.
+
+  */
+
+unsigned short init_words[] = {
+	/*	System Configuration Pointer (SCP). */
+	0x0000,					/* Set bus size to 16 bits. */
+	0,0,					/* pad words. */
+	0x0000,0x0000,			/* ISCP phys addr, set in init_82586_mem(). */
+
+	/*	Intermediate System Configuration Pointer (ISCP). */
+	0x0001,					/* Status word that's cleared when init is done. */
+	0x0008,0,0,				/* SCB offset, (skip, skip) */
+
+	/* System Control Block (SCB). */
+	0,0xf000|RX_START|CUC_START,	/* SCB status and cmd. */
+	CONFIG_CMD,				/* Command list pointer, points to Configure. */
+	RX_BUF_START,				/* Rx block list. */
+	0,0,0,0,				/* Error count: CRC, align, buffer, overrun. */
+
+	/* 0x0018: Configure command.  Change to put MAC data with packet. */
+	0, CmdConfigure,		/* Status, command.		*/
+	SET_SA_CMD,				/* Next command is Set Station Addr. */
+	0x0804,					/* "4" bytes of config data, 8 byte FIFO. */
+	0x2e40,					/* Magic values, including MAC data location. */
+	0,						/* Unused pad word. */
+
+	/* 0x0024: Setup station address command. */
+	0, CmdSASetup,
+	SET_MC_CMD,				/* Next command. */
+	0xaa00,0xb000,0x0bad,	/* Station address (to be filled in) */
+
+	/* 0x0030: NOP, looping back to itself.	 Point to first Tx buffer to Tx. */
+	0, CmdNOp, IDLELOOP, 0 /* pad */,
+
+	/* 0x0038: A unused Time-Domain Reflectometer command. */
+	0, CmdTDR, IDLELOOP, 0,
+
+	/* 0x0040: An unused Dump State command. */
+	0, CmdDump, IDLELOOP, DUMP_DATA,
+
+	/* 0x0048: An unused Diagnose command. */
+	0, CmdDiagnose, IDLELOOP,
+
+	/* 0x004E: An empty set-multicast-list command. */
+	0, CmdMulticastList, IDLELOOP, 0,
+};
+
+/* Index to functions, as function prototypes. */
+
+extern int el16_probe(struct device *dev);	/* Called from Space.c */
+
+static int	el16_probe1(struct device *dev, int ioaddr);
+static int	el16_open(struct device *dev);
+static int	el16_send_packet(struct sk_buff *skb, struct device *dev);
+static void	el16_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static void el16_rx(struct device *dev);
+static int	el16_close(struct device *dev);
+static struct enet_statistics *el16_get_stats(struct device *dev);
+
+static void hardware_send_packet(struct device *dev, void *buf, short length);
+void init_82586_mem(struct device *dev);
+
+
+#ifdef HAVE_DEVLIST
+struct netdev_entry netcard_drv =
+{"3c507", el16_probe1, EL16_IO_EXTENT, netcard_portlist};
+#endif
+
+/* Check for a network adaptor of this type, and return '0' iff one exists.
+	If dev->base_addr == 0, probe all likely locations.
+	If dev->base_addr == 1, always return failure.
+	If dev->base_addr == 2, (detachable devices only) allocate space for the
+	device and return success.
+	*/
+int
+el16_probe(struct device *dev)
+{
+	int base_addr = dev ? dev->base_addr : 0;
+	int i;
+
+	if (base_addr > 0x1ff)	/* Check a single specified location. */
+		return el16_probe1(dev, base_addr);
+	else if (base_addr != 0)
+		return ENXIO;		/* Don't probe at all. */
+
+	for (i = 0; netcard_portlist[i]; i++) {
+		int ioaddr = netcard_portlist[i];
+		if (check_region(ioaddr, EL16_IO_EXTENT))
+			continue;
+		if (el16_probe1(dev, ioaddr) == 0)
+			return 0;
+	}
+
+	return ENODEV;
+}
+
+int el16_probe1(struct device *dev, int ioaddr)
+{
+	static unsigned char init_ID_done = 0, version_printed = 0;
+	int i, irq, irqval;
+
+	if (init_ID_done == 0) {
+		ushort lrs_state = 0xff;
+		/* Send the ID sequence to the ID_PORT to enable the board(s). */
+		outb(0x00, ID_PORT);
+		for(i = 0; i < 255; i++) {
+			outb(lrs_state, ID_PORT);
+			lrs_state <<= 1;
+			if (lrs_state & 0x100)
+				lrs_state ^= 0xe7;
+		}
+		outb(0x00, ID_PORT);
+		init_ID_done = 1;
+	}
+
+	if (inb(ioaddr) == '*' && inb(ioaddr+1) == '3'
+		&& inb(ioaddr+2) == 'C' && inb(ioaddr+3) == 'O')
+		;
+	else
+		return ENODEV;
+
+	/* Allocate a new 'dev' if needed. */
+	if (dev == NULL)
+		dev = init_etherdev(0, sizeof(struct net_local));
+
+	if (net_debug  &&  version_printed++ == 0)
+		printk(version);
+
+	printk("%s: 3c507 at %#x,", dev->name, ioaddr);
+
+	/* We should make a few more checks here, like the first three octets of
+	   the S.A. for the manufacturer's code. */ 
+
+	irq = inb(ioaddr + IRQ_CONFIG) & 0x0f;
+
+	irqval = request_irq(irq, &el16_interrupt, 0, "3c507", NULL);
+	if (irqval) {
+		printk ("unable to get IRQ %d (irqval=%d).\n", irq, irqval);
+		return EAGAIN;
+	}
+	
+	/* We've committed to using the board, and can start filling in *dev. */
+	request_region(ioaddr, EL16_IO_EXTENT, "3c507");
+	dev->base_addr = ioaddr;
+
+	outb(0x01, ioaddr + MISC_CTRL);
+	for (i = 0; i < 6; i++) {
+		dev->dev_addr[i] = inb(ioaddr + i);
+		printk(" %02x", dev->dev_addr[i]);
+	}
+
+	if ((dev->mem_start & 0xf) > 0)
+		net_debug = dev->mem_start & 7;
+
+#ifdef MEM_BASE
+	dev->mem_start = MEM_BASE;
+	dev->mem_end = dev->mem_start + 0x10000;
+#else
+	{
+		int base;
+		int size;
+		char mem_config = inb(ioaddr + MEM_CONFIG);
+		if (mem_config & 0x20) {
+			size = 64*1024;
+			base = 0xf00000 + (mem_config & 0x08 ? 0x080000
+							   : ((mem_config & 3) << 17));
+		} else {
+			size = ((mem_config & 3) + 1) << 14;
+			base = 0x0c0000 + ( (mem_config & 0x18) << 12);
+		}
+		dev->mem_start = base;
+		dev->mem_end = base + size;
+	}
+#endif
+
+	dev->if_port = (inb(ioaddr + ROM_CONFIG) & 0x80) ? 1 : 0;
+	dev->irq = inb(ioaddr + IRQ_CONFIG) & 0x0f;
+
+	printk(", IRQ %d, %sternal xcvr, memory %#lx-%#lx.\n", dev->irq,
+		   dev->if_port ? "ex" : "in", dev->mem_start, dev->mem_end-1);
+
+	if (net_debug)
+		printk(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));
+
+	dev->open		= el16_open;
+	dev->stop		= el16_close;
+	dev->hard_start_xmit = el16_send_packet;
+	dev->get_stats	= el16_get_stats;
+
+	ether_setup(dev);	/* Generic ethernet behaviour */
+	
+	dev->flags&=~IFF_MULTICAST;	/* Multicast doesn't work */
+
+	return 0;
+}
+
+
+
+static int
+el16_open(struct device *dev)
+{
+	irq2dev_map[dev->irq] = dev;
+
+	/* Initialize the 82586 memory and start it. */
+	init_82586_mem(dev);
+
+	dev->tbusy = 0;
+	dev->interrupt = 0;
+	dev->start = 1;
+
+	MOD_INC_USE_COUNT;
+
+	return 0;
+}
+
+static int
+el16_send_packet(struct sk_buff *skb, struct device *dev)
+{
+	struct net_local *lp = (struct net_local *)dev->priv;
+	int ioaddr = dev->base_addr;
+	short *shmem = (short*)dev->mem_start;
+
+	if (dev->tbusy) {
+		/* If we get here, some higher level has decided we are broken.
+		   There should really be a "kick me" function call instead. */
+		int tickssofar = jiffies - dev->trans_start;
+		if (tickssofar < 5)
+			return 1;
+		if (net_debug > 1)
+			printk("%s: transmit timed out, %s?  ", dev->name,
+				   shmem[iSCB_STATUS>>1] & 0x8000 ? "IRQ conflict" :
+				   "network cable problem");
+		/* Try to restart the adaptor. */
+		if (lp->last_restart == lp->stats.tx_packets) {
+			if (net_debug > 1) printk("Resetting board.\n");
+			/* Completely reset the adaptor. */
+			init_82586_mem(dev);
+		} else {
+			/* Issue the channel attention signal and hope it "gets better". */
+			if (net_debug > 1) printk("Kicking board.\n");
+			shmem[iSCB_CMD>>1] = 0xf000|CUC_START|RX_START;
+			outb(0, ioaddr + SIGNAL_CA);			/* Issue channel-attn. */
+			lp->last_restart = lp->stats.tx_packets;
+		}
+		dev->tbusy=0;
+		dev->trans_start = jiffies;
+	}
+
+	/* If some higher layer thinks we've missed an tx-done interrupt
+	   we are passed NULL. Caution: dev_tint() handles the cli()/sti()
+	   itself. */
+	if (skb == NULL) {
+		dev_tint(dev);
+		return 0;
+	}
+
+	/* Block a timer-based transmit from overlapping. */
+	if (set_bit(0, (void*)&dev->tbusy) != 0)
+		printk("%s: Transmitter access conflict.\n", dev->name);
+	else {
+		short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
+		unsigned char *buf = skb->data;
+
+		/* Disable the 82586's input to the interrupt line. */
+		outb(0x80, ioaddr + MISC_CTRL);
+		hardware_send_packet(dev, buf, length);
+		dev->trans_start = jiffies;
+		/* Enable the 82586 interrupt input. */
+		outb(0x84, ioaddr + MISC_CTRL);
+	}
+
+	dev_kfree_skb (skb, FREE_WRITE);
+
+	/* You might need to clean up and record Tx statistics here. */
+
+	return 0;
+}
+
+/*	The typical workload of the driver:
+	Handle the network interface interrupts. */
+static void
+el16_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct device *dev = (struct device *)(irq2dev_map[irq]);
+	struct net_local *lp;
+	int ioaddr, status, boguscount = 0;
+	ushort ack_cmd = 0;
+	ushort *shmem;
+	
+	if (dev == NULL) {
+		printk ("net_interrupt(): irq %d for unknown device.\n", irq);
+		return;
+	}
+	dev->interrupt = 1;
+	
+	ioaddr = dev->base_addr;
+	lp = (struct net_local *)dev->priv;
+	shmem = ((ushort*)dev->mem_start);
+	
+	status = shmem[iSCB_STATUS>>1];
+	
+	if (net_debug > 4) {
+		printk("%s: 3c507 interrupt, status %4.4x.\n", dev->name, status);
+	}
+
+	/* Disable the 82586's input to the interrupt line. */
+	outb(0x80, ioaddr + MISC_CTRL);
+
+	/* Reap the Tx packet buffers. */
+	while (lp->tx_reap != lp->tx_head) {
+	  unsigned short tx_status = shmem[lp->tx_reap>>1];
+
+	  if (tx_status == 0) {
+		if (net_debug > 5)  printk("Couldn't reap %#x.\n", lp->tx_reap);
+		break;
+	  }
+	  if (tx_status & 0x2000) {
+		lp->stats.tx_packets++;
+		lp->stats.collisions += tx_status & 0xf;
+		dev->tbusy = 0;
+		mark_bh(NET_BH);		/* Inform upper layers. */
+	  } else {
+		lp->stats.tx_errors++;
+		if (tx_status & 0x0600)  lp->stats.tx_carrier_errors++;
+		if (tx_status & 0x0100)  lp->stats.tx_fifo_errors++;
+		if (!(tx_status & 0x0040))  lp->stats.tx_heartbeat_errors++;
+		if (tx_status & 0x0020)  lp->stats.tx_aborted_errors++;
+	  }
+	  if (net_debug > 5)
+		  printk("Reaped %x, Tx status %04x.\n" , lp->tx_reap, tx_status);
+	  lp->tx_reap += TX_BUF_SIZE;
+	  if (lp->tx_reap > RX_BUF_START - TX_BUF_SIZE)
+		lp->tx_reap = TX_BUF_START;
+	  if (++boguscount > 4)
+		break;
+	}
+
+	if (status & 0x4000) { /* Packet received. */
+		if (net_debug > 5)
+			printk("Received packet, rx_head %04x.\n", lp->rx_head);
+		el16_rx(dev);
+	}
+
+	/* Acknowledge the interrupt sources. */
+	ack_cmd = status & 0xf000;
+
+	if ((status & 0x0700) != 0x0200 && dev->start) {
+		if (net_debug)
+			printk("%s: Command unit stopped, status %04x, restarting.\n",
+				   dev->name, status);
+		/* If this ever occurs we should really re-write the idle loop, reset
+		   the Tx list, and do a complete restart of the command unit.
+		   For now we rely on the Tx timeout if the resume doesn't work. */
+		ack_cmd |= CUC_RESUME;
+	}
+
+	if ((status & 0x0070) != 0x0040  &&  dev->start) {
+	  static void init_rx_bufs(struct device *);
+		/* The Rx unit is not ready, it must be hung.  Restart the receiver by
+		   initializing the rx buffers, and issuing an Rx start command. */
+		if (net_debug)
+			printk("%s: Rx unit stopped, status %04x, restarting.\n",
+				   dev->name, status);
+		init_rx_bufs(dev);
+		shmem[iSCB_RFA >> 1] = RX_BUF_START;
+		ack_cmd |= RX_START;
+	}
+
+	shmem[iSCB_CMD>>1] = ack_cmd;
+	outb(0, ioaddr + SIGNAL_CA);			/* Issue channel-attn. */
+
+	/* Clear the latched interrupt. */
+	outb(0, ioaddr + RESET_IRQ);
+
+	/* Enable the 82586's interrupt input. */
+	outb(0x84, ioaddr + MISC_CTRL);
+
+	return;
+}
+
+static int
+el16_close(struct device *dev)
+{
+	int ioaddr = dev->base_addr;
+	ushort *shmem = (short*)dev->mem_start;
+
+	dev->tbusy = 1;
+	dev->start = 0;
+
+	/* Flush the Tx and disable Rx. */
+	shmem[iSCB_CMD >> 1] = RX_SUSPEND | CUC_SUSPEND;
+	outb(0, ioaddr + SIGNAL_CA);
+
+	/* Disable the 82586's input to the interrupt line. */
+	outb(0x80, ioaddr + MISC_CTRL);
+
+	/* We always physically use the IRQ line, so we don't do free_irq().
+	   We do remove ourselves from the map. */
+
+	irq2dev_map[dev->irq] = 0;
+
+	/* Update the statistics here. */
+
+	MOD_DEC_USE_COUNT;
+
+	return 0;
+}
+
+/* Get the current statistics.	This may be called with the card open or
+   closed. */
+static struct enet_statistics *
+el16_get_stats(struct device *dev)
+{
+	struct net_local *lp = (struct net_local *)dev->priv;
+
+	/* ToDo: decide if there are any useful statistics from the SCB. */
+
+	return &lp->stats;
+}
+
+/* Initialize the Rx-block list. */
+static void
+init_rx_bufs(struct device *dev)
+{
+	struct net_local *lp = (struct net_local *)dev->priv;
+	unsigned short *write_ptr;
+	unsigned short SCB_base = SCB_BASE;
+
+	int cur_rxbuf = lp->rx_head = RX_BUF_START;
+	
+	/* Initialize each Rx frame + data buffer. */
+	do {	/* While there is room for one more. */
+
+	  write_ptr = (unsigned short *)(dev->mem_start + cur_rxbuf);
+
+		*write_ptr++ = 0x0000; 				/* Status */
+		*write_ptr++ = 0x0000;				/* Command */
+		*write_ptr++ = cur_rxbuf + RX_BUF_SIZE; /* Link */
+		*write_ptr++ = cur_rxbuf + 22;		/* Buffer offset */
+		*write_ptr++ = 0x0000; 				/* Pad for dest addr. */
+		*write_ptr++ = 0x0000;
+		*write_ptr++ = 0x0000;
+		*write_ptr++ = 0x0000; 				/* Pad for source addr. */
+		*write_ptr++ = 0x0000;
+		*write_ptr++ = 0x0000;
+		*write_ptr++ = 0x0000;				/* Pad for protocol. */
+		
+		*write_ptr++ = 0x0000;				/* Buffer: Actual count */
+		*write_ptr++ = -1;					/* Buffer: Next (none). */
+		*write_ptr++ = cur_rxbuf + 0x20 + SCB_base;	/* Buffer: Address low */
+		*write_ptr++ = 0x0000;
+		/* Finally, the number of bytes in the buffer. */
+		*write_ptr++ = 0x8000 + RX_BUF_SIZE-0x20;
+		
+		lp->rx_tail = cur_rxbuf;
+		cur_rxbuf += RX_BUF_SIZE;
+	} while (cur_rxbuf <= RX_BUF_END - RX_BUF_SIZE);
+	
+	/* Terminate the list by setting the EOL bit, and wrap the pointer to make
+	   the list a ring. */
+	write_ptr = (unsigned short *)
+	  (dev->mem_start + lp->rx_tail + 2);
+	*write_ptr++ = 0xC000;					/* Command, mark as last. */
+	*write_ptr++ = lp->rx_head;				/* Link */
+
+}
+
+void
+init_82586_mem(struct device *dev)
+{
+	struct net_local *lp = (struct net_local *)dev->priv;
+	short ioaddr = dev->base_addr;
+	ushort *shmem = (short*)dev->mem_start;
+
+	/* Enable loopback to protect the wire while starting up,
+	   and hold the 586 in reset during the memory initialization. */
+	outb(0x20, ioaddr + MISC_CTRL);
+
+	/* Fix the ISCP address and base. */
+	init_words[3] = SCB_BASE;
+	init_words[7] = SCB_BASE;
+
+	/* Write the words at 0xfff6 (address-aliased to 0xfffff6). */
+	memcpy((void*)dev->mem_end-10, init_words, 10);
+
+	/* Write the words at 0x0000. */
+	memcpy((char*)dev->mem_start, init_words + 5, sizeof(init_words) - 10);
+
+	/* Fill in the station address. */
+	memcpy((char*)dev->mem_start+SA_OFFSET, dev->dev_addr,
+		   sizeof(dev->dev_addr));
+
+	/* The Tx-block list is written as needed.  We just set up the values. */
+	lp->tx_cmd_link = IDLELOOP + 4;
+	lp->tx_head = lp->tx_reap = TX_BUF_START;
+
+	init_rx_bufs(dev);
+
+	/* Start the 586 by releasing the reset line, but leave loopback. */
+	outb(0xA0, ioaddr + MISC_CTRL);
+
+	/* This was time consuming to track down: you need to give two channel
+	   attention signals to reliably start up the i82586. */
+	outb(0, ioaddr + SIGNAL_CA);
+
+	{
+		int boguscnt = 50;
+		while (shmem[iSCB_STATUS>>1] == 0)
+			if (--boguscnt == 0) {
+				printk("%s: i82586 initialization timed out with status %04x,"
+					   "cmd %04x.\n", dev->name,
+					   shmem[iSCB_STATUS>>1], shmem[iSCB_CMD>>1]);
+				break;
+			}
+		/* Issue channel-attn -- the 82586 won't start. */
+		outb(0, ioaddr + SIGNAL_CA);
+	}
+
+	/* Disable loopback and enable interrupts. */
+	outb(0x84, ioaddr + MISC_CTRL);
+	if (net_debug > 4)
+		printk("%s: Initialized 82586, status %04x.\n", dev->name,
+			   shmem[iSCB_STATUS>>1]);
+	return;
+}
+
+static void
+hardware_send_packet(struct device *dev, void *buf, short length)
+{
+	struct net_local *lp = (struct net_local *)dev->priv;
+	short ioaddr = dev->base_addr;
+	ushort tx_block = lp->tx_head;
+	ushort *write_ptr =	  (ushort *)(dev->mem_start + tx_block);
+
+	/* Set the write pointer to the Tx block, and put out the header. */
+	*write_ptr++ = 0x0000;				/* Tx status */
+	*write_ptr++ = CMD_INTR|CmdTx;		/* Tx command */
+	*write_ptr++ = tx_block+16;			/* Next command is a NoOp. */
+	*write_ptr++ = tx_block+8;			/* Data Buffer offset. */
+
+	/* Output the data buffer descriptor. */
+	*write_ptr++ = length | 0x8000;		/* Byte count parameter. */
+	*write_ptr++ = -1;					/* No next data buffer. */
+	*write_ptr++ = tx_block+22+SCB_BASE;/* Buffer follows the NoOp command. */
+	*write_ptr++ = 0x0000;				/* Buffer address high bits (always zero). */
+
+	/* Output the Loop-back NoOp command. */
+	*write_ptr++ = 0x0000;				/* Tx status */
+	*write_ptr++ = CmdNOp;				/* Tx command */
+	*write_ptr++ = tx_block+16;			/* Next is myself. */
+
+	/* Output the packet at the write pointer. */
+	memcpy(write_ptr, buf, length);
+
+	/* Set the old command link pointing to this send packet. */
+	*(ushort*)(dev->mem_start + lp->tx_cmd_link) = tx_block;
+	lp->tx_cmd_link = tx_block + 20;
+
+	/* Set the next free tx region. */
+	lp->tx_head = tx_block + TX_BUF_SIZE;
+	if (lp->tx_head > RX_BUF_START - TX_BUF_SIZE)
+		lp->tx_head = TX_BUF_START;
+
+	if (net_debug > 4) {
+		printk("%s: 3c507 @%x send length = %d, tx_block %3x, next %3x.\n",
+			   dev->name, ioaddr, length, tx_block, lp->tx_head);
+	}
+
+	if (lp->tx_head != lp->tx_reap)
+		dev->tbusy = 0;
+}
+
+static void
+el16_rx(struct device *dev)
+{
+	struct net_local *lp = (struct net_local *)dev->priv;
+	short *shmem = (short*)dev->mem_start;
+	ushort rx_head = lp->rx_head;
+	ushort rx_tail = lp->rx_tail;
+	ushort boguscount = 10;
+	short frame_status;
+
+	while ((frame_status = shmem[rx_head>>1]) < 0) {   /* Command complete */
+		ushort *read_frame =  (short *)(dev->mem_start + rx_head);
+		ushort rfd_cmd = read_frame[1];
+		ushort next_rx_frame = read_frame[2];
+		ushort data_buffer_addr = read_frame[3];
+		ushort *data_frame = (short *)(dev->mem_start + data_buffer_addr);
+		ushort pkt_len = data_frame[0];
+
+		if (rfd_cmd != 0 || data_buffer_addr != rx_head + 22
+			|| (pkt_len & 0xC000) != 0xC000) {
+			printk("%s: Rx frame at %#x corrupted, status %04x cmd %04x"
+				   "next %04x data-buf @%04x %04x.\n", dev->name, rx_head,
+				   frame_status, rfd_cmd, next_rx_frame, data_buffer_addr,
+				   pkt_len);
+		} else if ((frame_status & 0x2000) == 0) {
+			/* Frame Rxed, but with error. */
+			lp->stats.rx_errors++;
+			if (frame_status & 0x0800) lp->stats.rx_crc_errors++;
+			if (frame_status & 0x0400) lp->stats.rx_frame_errors++;
+			if (frame_status & 0x0200) lp->stats.rx_fifo_errors++;
+			if (frame_status & 0x0100) lp->stats.rx_over_errors++;
+			if (frame_status & 0x0080) lp->stats.rx_length_errors++;
+		} else {
+			/* Malloc up new buffer. */
+			struct sk_buff *skb;
+
+			pkt_len &= 0x3fff;
+			skb = dev_alloc_skb(pkt_len+2);
+			if (skb == NULL) {
+				printk("%s: Memory squeeze, dropping packet.\n", dev->name);
+				lp->stats.rx_dropped++;
+				break;
+			}
+			
+			skb_reserve(skb,2);
+			skb->dev = dev;
+
+			/* 'skb->data' points to the start of sk_buff data area. */
+			memcpy(skb_put(skb,pkt_len), data_frame + 5, pkt_len);
+		
+			skb->protocol=eth_type_trans(skb,dev);
+			netif_rx(skb);
+			lp->stats.rx_packets++;
+		}
+
+		/* Clear the status word and set End-of-List on the rx frame. */
+		read_frame[0] = 0;
+		read_frame[1] = 0xC000;
+		/* Clear the end-of-list on the prev. RFD. */
+		*(short*)(dev->mem_start + rx_tail + 2) = 0x0000;
+
+		rx_tail = rx_head;
+		rx_head = next_rx_frame;
+		if (--boguscount == 0)
+			break;
+	}
+
+	lp->rx_head = rx_head;
+	lp->rx_tail = rx_tail;
+}
+#ifdef MODULE
+static char devicename[9] = { 0, };
+static struct device dev_3c507 = {
+	devicename, /* device name is inserted by linux/drivers/net/net_init.c */
+	0, 0, 0, 0,
+	0, 0,
+	0, 0, 0, NULL, el16_probe
+};
+
+static int io = 0x300;
+static int irq = 0;
+
+int init_module(void)
+{
+	if (io == 0)
+		printk("3c507: You should not use auto-probing with insmod!\n");
+	dev_3c507.base_addr = io;
+	dev_3c507.irq       = irq;
+	if (register_netdev(&dev_3c507) != 0) {
+		printk("3c507: register_netdev() returned non-zero.\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+void
+cleanup_module(void)
+{
+	unregister_netdev(&dev_3c507);
+	kfree(dev_3c507.priv);
+	dev_3c507.priv = NULL;
+
+	/* If we don't do this, we can't re-insmod it later. */
+	free_irq(dev_3c507.irq, NULL);
+	release_region(dev_3c507.base_addr, EL16_IO_EXTENT);
+}
+#endif /* MODULE */
+
+/*
+ * Local variables:
+ *  compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/net/inet -I/usr/src/linux/drivers/net -Wall -Wstrict-prototypes -O6 -m486 -c 3c507.c"
+ *  version-control: t
+ *  kept-new-versions: 5
+ *  tab-width: 4
+ *  c-indent-level: 4
+ * End:
+ */