eexpress.c

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/* Intel EtherExpress 16 device driver for Linux
 *
 * Written by John Sullivan, 1995
 *  based on original code by Donald Becker, with changes by
 *  Alan Cox and Pauline Middelink.
 *
 * Support for 8-bit mode by Zoltan Szilagyi <[e-mail]>
 *
 * Many modifications, and currently maintained, by
 *  Philip Blundell <[e-mail]>
 * Added the Compaq LTE  Alan Cox <[e-mail]>
 * Added MCA support Adam Fritzler <[e-mail]>
 *
 * Note - this driver is experimental still - it has problems on faster
 * machines. Someone needs to sit down and go through it line by line with
 * a databook...
 */

/* The EtherExpress 16 is a fairly simple card, based on a shared-memory
 * design using the i82586 Ethernet coprocessor.  It bears no relationship,
 * as far as I know, to the similarly-named "EtherExpress Pro" range.
 *
 * Historically, Linux support for these cards has been very bad.  However,
 * things seem to be getting better slowly.
 */

/* If your card is confused about what sort of interface it has (eg it
 * persistently reports "10baseT" when none is fitted), running 'SOFTSET /BART'
 * or 'SOFTSET /LISA' from DOS seems to help.
 */

/* Here's the scoop on memory mapping.
 *
 * There are three ways to access EtherExpress card memory: either using the
 * shared-memory mapping, or using PIO through the dataport, or using PIO
 * through the "shadow memory" ports.
 *
 * The shadow memory system works by having the card map some of its memory
 * as follows:
 *
 * (the low five bits of the SMPTR are ignored)
 *
 *  base+0x4000..400f      memory at SMPTR+0..15
 *  base+0x8000..800f      memory at SMPTR+16..31
 *  base+0xc000..c007      dubious stuff (memory at SMPTR+16..23 apparently)
 *  base+0xc008..c00f      memory at 0x0008..0x000f
 *
 * This last set (the one at c008) is particularly handy because the SCB
 * lives at 0x0008.  So that set of ports gives us easy random access to data
 * in the SCB without having to mess around setting up pointers and the like.
 * We always use this method to access the SCB (via the scb_xx() functions).
 *
 * Dataport access works by aiming the appropriate (read or write) pointer
 * at the first address you're interested in, and then reading or writing from
 * the dataport.  The pointers auto-increment after each transfer.  We use
 * this for data transfer.
 *
 * We don't use the shared-memory system because it allegedly doesn't work on
 * all cards, and because it's a bit more prone to go wrong (it's one more
 * thing to configure...).
 */

/* Known bugs:
 *
 * - The card seems to want to give us two interrupts every time something
 *   happens, where just one would be better.
 */

/*
 *
 * Note by Zoltan Szilagyi 10-12-96:
 *
 * I've succeeded in eliminating the "CU wedged" messages, and hence the
 * lockups, which were only occurring with cards running in 8-bit mode ("force
 * 8-bit operation" in Intel's SoftSet utility). This version of the driver
 * sets the 82586 and the ASIC to 8-bit mode at startup; it also stops the
 * CU before submitting a packet for transmission, and then restarts it as soon
 * as the process of handing the packet is complete. This is definitely an
 * unnecessary slowdown if the card is running in 16-bit mode; therefore one
 * should detect 16-bit vs 8-bit mode from the EEPROM settings and act 
 * accordingly. In 8-bit mode with this bugfix I'm getting about 150 K/s for
 * ftp's, which is significantly better than I get in DOS, so the overhead of
 * stopping and restarting the CU with each transmit is not prohibitive in
 * practice.
 *
 * Update by David Woodhouse 11/5/99:
 *
 * I've seen "CU wedged" messages in 16-bit mode, on the Alpha architecture.
 * I assume that this is because 16-bit accesses are actually handled as two
 * 8-bit accesses.
 */

#ifdef __alpha__
#define LOCKUP16 1
#endif
#ifndef LOCKUP16
#define LOCKUP16 0
#endif
  
#include <linux/config.h>
#include <linux/module.h>

#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/string.h>
#include <linux/in.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/malloc.h>
#include <linux/mca.h>

#include <linux/spinlock.h>

#ifndef NET_DEBUG
#define NET_DEBUG 4
#endif

#include "eexpress.h"

#define EEXP_IO_EXTENT  16

/*
 * Private data declarations
 */

struct net_local
{
	struct net_device_stats stats;
	unsigned long last_tx;       /* jiffies when last transmit started */
	unsigned long init_time;     /* jiffies when eexp_hw_init586 called */
	unsigned short rx_first;     /* first rx buf, same as RX_BUF_START */
	unsigned short rx_last;      /* last rx buf */
	unsigned short rx_ptr;       /* first rx buf to look at */
	unsigned short tx_head;      /* next free tx buf */
	unsigned short tx_reap;      /* first in-use tx buf */
	unsigned short tx_tail;      /* previous tx buf to tx_head */
	unsigned short tx_link;      /* last known-executing tx buf */
	unsigned short last_tx_restart;   /* set to tx_link when we
					     restart the CU */
	unsigned char started;
	unsigned short rx_buf_start;
	unsigned short rx_buf_end;
	unsigned short num_tx_bufs;
	unsigned short num_rx_bufs;
	unsigned char width;         /* 0 for 16bit, 1 for 8bit */
	unsigned char was_promisc;
	unsigned char old_mc_count;
	spinlock_t lock;
};

/* This is the code and data that is downloaded to the EtherExpress card's
 * memory at boot time.
 */

static unsigned short start_code[] = {
/* 0x0000 */
	0x0001,                 /* ISCP: busy - cleared after reset */
	0x0008,0x0000,0x0000,   /* offset,address (lo,hi) of SCB */

	0x0000,0x0000,          /* SCB: status, commands */
	0x0000,0x0000,          /* links to first command block,
				   first receive descriptor */
	0x0000,0x0000,          /* CRC error, alignment error counts */
	0x0000,0x0000,          /* out of resources, overrun error counts */

	0x0000,0x0000,          /* pad */
	0x0000,0x0000,

/* 0x20 -- start of 82586 CU program */
#define CONF_LINK 0x20
	0x0000,Cmd_Config,      
	0x0032,                 /* link to next command */
	0x080c,                 /* 12 bytes follow : fifo threshold=8 */
	0x2e40,                 /* don't rx bad frames
				 * SRDY/ARDY => ext. sync. : preamble len=8
	                         * take addresses from data buffers
				 * 6 bytes/address
				 */
	0x6000,                 /* default backoff method & priority
				 * interframe spacing = 0x60 */
	0xf200,                 /* slot time=0x200 
				 * max collision retry = 0xf */
#define CONF_PROMISC  0x2e
	0x0000,                 /* no HDLC : normal CRC : enable broadcast 
				 * disable promiscuous/multicast modes */
	0x003c,                 /* minimum frame length = 60 octets) */

	0x0000,Cmd_SetAddr,
	0x003e,                 /* link to next command */
#define CONF_HWADDR  0x38
	0x0000,0x0000,0x0000,   /* hardware address placed here */

	0x0000,Cmd_MCast,
	0x0076,                 /* link to next command */
#define CONF_NR_MULTICAST 0x44
	0x0000,                 /* number of multicast addresses */
#define CONF_MULTICAST 0x46
	0x0000, 0x0000, 0x0000, /* some addresses */
	0x0000, 0x0000, 0x0000,
	0x0000, 0x0000, 0x0000,
	0x0000, 0x0000, 0x0000,
	0x0000, 0x0000, 0x0000,
	0x0000, 0x0000, 0x0000,
	0x0000, 0x0000, 0x0000,
	0x0000, 0x0000, 0x0000,

#define CONF_DIAG_RESULT  0x76
	0x0000, Cmd_Diag,
	0x007c,                 /* link to next command */

	0x0000,Cmd_TDR|Cmd_INT,
	0x0084,
#define CONF_TDR_RESULT  0x82
	0x0000,

	0x0000,Cmd_END|Cmd_Nop, /* end of configure sequence */
	0x0084                  /* dummy link */
};

/* maps irq number to EtherExpress magic value */
static char irqrmap[] = { 0,0,1,2,3,4,0,0,0,1,5,6,0,0,0,0 };

#ifdef CONFIG_MCA
/* mapping of the first four bits of the second POS register */
static unsigned short mca_iomap[] = {
	0x270, 0x260, 0x250, 0x240, 0x230, 0x220, 0x210, 0x200,
	0x370, 0x360, 0x350, 0x340, 0x330, 0x320, 0x310, 0x300
};
/* bits 5-7 of the second POS register */
static char mca_irqmap[] = { 12, 9, 3, 4, 5, 10, 11, 15 };
#endif 

/*
 * Prototypes for Linux interface
 */

extern int express_probe(struct net_device *dev);
static int eexp_open(struct net_device *dev);
static int eexp_close(struct net_device *dev);
static void eexp_timeout(struct net_device *dev);
static struct net_device_stats *eexp_stats(struct net_device *dev);
static int eexp_xmit(struct sk_buff *buf, struct net_device *dev);

static void eexp_irq(int irq, void *dev_addr, struct pt_regs *regs);
static void eexp_set_multicast(struct net_device *dev);

/*
 * Prototypes for hardware access functions
 */

static void eexp_hw_rx_pio(struct net_device *dev);
static void eexp_hw_tx_pio(struct net_device *dev, unsigned short *buf,
		       unsigned short len);
static int eexp_hw_probe(struct net_device *dev,unsigned short ioaddr);
static unsigned short eexp_hw_readeeprom(unsigned short ioaddr,
					 unsigned char location);

static unsigned short eexp_hw_lasttxstat(struct net_device *dev);
static void eexp_hw_txrestart(struct net_device *dev);

static void eexp_hw_txinit    (struct net_device *dev);
static void eexp_hw_rxinit    (struct net_device *dev);

static void eexp_hw_init586   (struct net_device *dev);
static void eexp_setup_filter (struct net_device *dev);

static char *eexp_ifmap[]={"AUI", "BNC", "RJ45"};
enum eexp_iftype {AUI=0, BNC=1, TPE=2};

#define STARTED_RU      2
#define STARTED_CU      1

/*
 * Primitive hardware access functions.
 */

static inline unsigned short scb_status(struct net_device *dev)
{
	return inw(dev->base_addr + 0xc008);
}

static inline unsigned short scb_rdcmd(struct net_device *dev)
{
	return inw(dev->base_addr + 0xc00a);
}

static inline void scb_command(struct net_device *dev, unsigned short cmd)
{
	outw(cmd, dev->base_addr + 0xc00a);
}

static inline void scb_wrcbl(struct net_device *dev, unsigned short val)
{
	outw(val, dev->base_addr + 0xc00c);
}

static inline void scb_wrrfa(struct net_device *dev, unsigned short val)
{
	outw(val, dev->base_addr + 0xc00e);
}

static inline void set_loopback(struct net_device *dev)
{
	outb(inb(dev->base_addr + Config) | 2, dev->base_addr + Config);
}

static inline void clear_loopback(struct net_device *dev)
{
	outb(inb(dev->base_addr + Config) & ~2, dev->base_addr + Config);
}

static inline unsigned short int SHADOW(short int addr)
{
	addr &= 0x1f;
	if (addr > 0xf) addr += 0x3ff0;
	return addr + 0x4000;
}

/*
 * Linux interface
 */

/*
 * checks for presence of EtherExpress card
 */

int __init express_probe(struct net_device *dev)
{
	unsigned short *port;
	static unsigned short ports[] = { 0x300,0x310,0x270,0x320,0x340,0 };
	unsigned short ioaddr = dev->base_addr;

	SET_MODULE_OWNER(dev);

	dev->if_port = 0xff; /* not set */

#ifdef CONFIG_MCA
	if (MCA_bus) {
		int slot = 0;

		/*
		 * Only find one card at a time.  Subsequent calls
		 * will find others, however, proper multicard MCA
		 * probing and setup can't be done with the
		 * old-style Space.c init routines.  -- ASF
		 */
		while (slot != MCA_NOTFOUND) {
			int pos0, pos1;
			
			slot = mca_find_unused_adapter(0x628B, slot);
			if (slot == MCA_NOTFOUND)
				break;

			pos0 = mca_read_stored_pos(slot, 2);
			pos1 = mca_read_stored_pos(slot, 3);
			ioaddr = mca_iomap[pos1&0xf];

			dev->irq = mca_irqmap[(pos1>>4)&0x7];
			
			/*
			 * XXX: Transciever selection is done
			 * differently on the MCA version.  
			 * How to get it to select something
			 * other than external/AUI is currently
			 * unknown.  This code is just for looks. -- ASF
			 */
			if ((pos0 & 0x7) == 0x1)
				dev->if_port = AUI;
			else if ((pos0 & 0x7) == 0x5) {
				if (pos1 & 0x80)
					dev->if_port = BNC;
				else
					dev->if_port = TPE;
			}

			mca_set_adapter_name(slot, "Intel EtherExpress 16 MCA");
			mca_set_adapter_procfn(slot, NULL, dev);
			mca_mark_as_used(slot);

			break;
		}
	}
#endif
	if (ioaddr&0xfe00)
		return eexp_hw_probe(dev,ioaddr);
	else if (ioaddr)
		return -ENXIO;

	for (port=&ports[0] ; *port ; port++ )
	{
		unsigned short sum = 0;
		int i;
		for ( i=0 ; i<4 ; i++ )
		{
			unsigned short t;
			t = inb(*port + ID_PORT);
			sum |= (t>>4) << ((t & 0x03)<<2);
		}
		if (sum==0xbaba && !eexp_hw_probe(dev,*port))
			return 0;
	}
	return -ENODEV;
}

/*
 * open and initialize the adapter, ready for use
 */

static int eexp_open(struct net_device *dev)
{
	int ret;
	unsigned short ioaddr = dev->base_addr;
	struct net_local *lp = (struct net_local *)dev->priv;

#if NET_DEBUG > 6
	printk(KERN_DEBUG "%s: eexp_open()\n", dev->name);
#endif

	if (!dev->irq || !irqrmap[dev->irq])
		return -ENXIO;

	ret = request_irq(dev->irq,&eexp_irq,0,dev->name,dev);
	if (ret) return ret;

	request_region(ioaddr, EEXP_IO_EXTENT, "EtherExpress");
	request_region(ioaddr+0x4000, 16, "EtherExpress shadow");
	request_region(ioaddr+0x8000, 16, "EtherExpress shadow");
	request_region(ioaddr+0xc000, 16, "EtherExpress shadow");
	
	if (lp->width) {
		printk("%s: forcing ASIC to 8-bit mode\n", dev->name);
		outb(inb(dev->base_addr+Config)&~4, dev->base_addr+Config);
	}

	eexp_hw_init586(dev);
	netif_start_queue(dev);
#if NET_DEBUG > 6
	printk(KERN_DEBUG "%s: leaving eexp_open()\n", dev->name);
#endif
	return 0;
}

/*
 * close and disable the interface, leaving the 586 in reset.
 */

static int eexp_close(struct net_device *dev)
{
	unsigned short ioaddr = dev->base_addr;
	struct net_local *lp = dev->priv;

	int irq = dev->irq;

	netif_stop_queue(dev);
	
	outb(SIRQ_dis|irqrmap[irq],ioaddr+SET_IRQ);
	lp->started = 0;
	scb_command(dev, SCB_CUsuspend|SCB_RUsuspend);
	outb(0,ioaddr+SIGNAL_CA);
	free_irq(irq,dev);
	outb(i586_RST,ioaddr+EEPROM_Ctrl);
	release_region(ioaddr, EEXP_IO_EXTENT);
	release_region(ioaddr+0x4000, 16);
	release_region(ioaddr+0x8000, 16);
	release_region(ioaddr+0xc000, 16);

	return 0;
}

/*
 * Return interface stats
 */

static struct net_device_stats *eexp_stats(struct net_device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;

	return &lp->stats;
}

/*
 * This gets called when a higher level thinks we are broken.  Check that
 * nothing has become jammed in the CU.
 */

static void unstick_cu(struct net_device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	unsigned short ioaddr = dev->base_addr;

	if (lp->started)
	{
		if ((jiffies - dev->trans_start)>50)
		{
			if (lp->tx_link==lp->last_tx_restart)
			{
				unsigned short boguscount=200,rsst;
				printk(KERN_WARNING "%s: Retransmit timed out, status %04x, resetting...\n",
				       dev->name, scb_status(dev));
				eexp_hw_txinit(dev);
				lp->last_tx_restart = 0;
				scb_wrcbl(dev, lp->tx_link);
				scb_command(dev, SCB_CUstart);
				outb(0,ioaddr+SIGNAL_CA);
				while (!SCB_complete(rsst=scb_status(dev)))
				{
					if (!--boguscount)
					{
						boguscount=200;
						printk(KERN_WARNING "%s: Reset timed out status %04x, retrying...\n",
						       dev->name,rsst);
						scb_wrcbl(dev, lp->tx_link);
						scb_command(dev, SCB_CUstart);
						outb(0,ioaddr+SIGNAL_CA);
					}
				}
				netif_wake_queue(dev);
			}
			else
			{
				unsigned short status = scb_status(dev);
				if (SCB_CUdead(status))
				{
					unsigned short txstatus = eexp_hw_lasttxstat(dev);
					printk(KERN_WARNING "%s: Transmit timed out, CU not active status %04x %04x, restarting...\n",
					       dev->name, status, txstatus);
					eexp_hw_txrestart(dev);
				}
				else
				{
					unsigned short txstatus = eexp_hw_lasttxstat(dev);
					if (netif_queue_stopped(dev) && !txstatus)
					{
						printk(KERN_WARNING "%s: CU wedged, status %04x %04x, resetting...\n",
						       dev->name,status,txstatus);
						eexp_hw_init586(dev);
						netif_wake_queue(dev);
					}
					else
					{
						printk(KERN_WARNING "%s: transmit timed out\n", dev->name);
					}
				}
			}
		}
	}
	else
	{