IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

[net-next-2.6.git] / drivers / scsi / seagate.c

/*
 *    seagate.c Copyright (C) 1992, 1993 Drew Eckhardt
 *      low level scsi driver for ST01/ST02, Future Domain TMC-885,
 *      TMC-950 by Drew Eckhardt <drew@colorado.edu>
 *
 *      Note : TMC-880 boards don't work because they have two bits in
 *              the status register flipped, I'll fix this "RSN"
 *	[why do I have strong feeling that above message is from 1993? :-)
 *	        pavel@ucw.cz]
 *
 *      This card does all the I/O via memory mapped I/O, so there is no need
 *      to check or allocate a region of the I/O address space.
 */

/* 1996 - to use new read{b,w,l}, write{b,w,l}, and phys_to_virt
 * macros, replaced assembler routines with C. There's probably a
 * performance hit, but I only have a cdrom and can't tell. Define
 * SEAGATE_USE_ASM if you want the old assembler code -- SJT
 *
 * 1998-jul-29 - created DPRINTK macros and made it work under 
 * linux 2.1.112, simplified some #defines etc. <pavel@ucw.cz>
 *
 * Aug 2000 - aeb - deleted seagate_st0x_biosparam(). It would try to
 * read the physical disk geometry, a bad mistake. Of course it doesn't
 * matter much what geometry one invents, but on large disks it
 * returned 256 (or more) heads, causing all kind of failures.
 * Of course this means that people might see a different geometry now,
 * so boot parameters may be necessary in some cases.
 */

/*
 * Configuration :
 * To use without BIOS -DOVERRIDE=base_address -DCONTROLLER=FD or SEAGATE
 * -DIRQ will override the default of 5.
 * Note: You can now set these options from the kernel's "command line".
 * The syntax is:
 *
 *     st0x=ADDRESS,IRQ                (for a Seagate controller)
 * or:
 *     tmc8xx=ADDRESS,IRQ              (for a TMC-8xx or TMC-950 controller)
 * eg:
 *     tmc8xx=0xC8000,15
 *
 * will configure the driver for a TMC-8xx style controller using IRQ 15
 * with a base address of 0xC8000.
 *
 * -DARBITRATE 
 *      Will cause the host adapter to arbitrate for the
 *      bus for better SCSI-II compatibility, rather than just
 *      waiting for BUS FREE and then doing its thing.  Should
 *      let us do one command per Lun when I integrate my
 *      reorganization changes into the distribution sources.
 *
 * -DDEBUG=65535
 *      Will activate debug code.
 *
 * -DFAST or -DFAST32 
 *      Will use blind transfers where possible
 *
 * -DPARITY  
 *      This will enable parity.
 *
 * -DSEAGATE_USE_ASM
 *      Will use older seagate assembly code. should be (very small amount)
 *      Faster.
 *
 * -DSLOW_RATE=50
 *      Will allow compatibility with broken devices that don't
 *      handshake fast enough (ie, some CD ROM's) for the Seagate
 *      code.
 *
 *      50 is some number, It will let you specify a default
 *      transfer rate if handshaking isn't working correctly.
 *
 * -DOLDCNTDATASCEME  There is a new sceme to set the CONTROL
 *                    and DATA reigsters which complies more closely
 *                    with the SCSI2 standard. This hopefully eliminates
 *                    the need to swap the order these registers are
 *                    'messed' with. It makes the following two options
 *                    obsolete. To reenable the old sceme define this.
 *
 * The following to options are patches from the SCSI.HOWTO
 *
 * -DSWAPSTAT  This will swap the definitions for STAT_MSG and STAT_CD.
 *
 * -DSWAPCNTDATA  This will swap the order that seagate.c messes with
 *                the CONTROL an DATA registers.
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/signal.h>
#include <linux/string.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/stat.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>

#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi.h>

#include <scsi/scsi_dbg.h>
#include <scsi/scsi_host.h>


#ifdef DEBUG
#define DPRINTK( when, msg... ) do { if ( (DEBUG & (when)) == (when) ) printk( msg ); } while (0)
#else
#define DPRINTK( when, msg... ) do { } while (0)
#endif
#define DANY( msg... ) DPRINTK( 0xffff, msg );

#ifndef IRQ
#define IRQ 5
#endif

#ifdef FAST32
#define FAST
#endif

#undef LINKED			/* Linked commands are currently broken! */

#if defined(OVERRIDE) && !defined(CONTROLLER)
#error Please use -DCONTROLLER=SEAGATE or -DCONTROLLER=FD to override controller type
#endif

#ifndef __i386__
#undef SEAGATE_USE_ASM
#endif

/*
	Thanks to Brian Antoine for the example code in his Messy-Loss ST-01
		driver, and Mitsugu Suzuki for information on the ST-01
		SCSI host.
*/

/*
	CONTROL defines
*/

#define CMD_RST 		0x01
#define CMD_SEL 		0x02
#define CMD_BSY 		0x04
#define CMD_ATTN    		0x08
#define CMD_START_ARB		0x10
#define CMD_EN_PARITY		0x20
#define CMD_INTR		0x40
#define CMD_DRVR_ENABLE		0x80

/*
	STATUS
*/
#ifdef SWAPSTAT
#define STAT_MSG		0x08
#define STAT_CD			0x02
#else
#define STAT_MSG		0x02
#define STAT_CD			0x08
#endif

#define STAT_BSY		0x01
#define STAT_IO			0x04
#define STAT_REQ		0x10
#define STAT_SEL		0x20
#define STAT_PARITY		0x40
#define STAT_ARB_CMPL		0x80

/* 
	REQUESTS
*/

#define REQ_MASK (STAT_CD |  STAT_IO | STAT_MSG)
#define REQ_DATAOUT 0
#define REQ_DATAIN STAT_IO
#define REQ_CMDOUT STAT_CD
#define REQ_STATIN (STAT_CD | STAT_IO)
#define REQ_MSGOUT (STAT_MSG | STAT_CD)
#define REQ_MSGIN (STAT_MSG | STAT_CD | STAT_IO)

extern volatile int seagate_st0x_timeout;

#ifdef PARITY
#define BASE_CMD CMD_EN_PARITY
#else
#define BASE_CMD  0
#endif

/*
	Debugging code
*/

#define PHASE_BUS_FREE 1
#define PHASE_ARBITRATION 2
#define PHASE_SELECTION 4
#define PHASE_DATAIN 8
#define PHASE_DATAOUT 0x10
#define PHASE_CMDOUT 0x20
#define PHASE_MSGIN 0x40
#define PHASE_MSGOUT 0x80
#define PHASE_STATUSIN 0x100
#define PHASE_ETC (PHASE_DATAIN | PHASE_DATAOUT | PHASE_CMDOUT | PHASE_MSGIN | PHASE_MSGOUT | PHASE_STATUSIN)
#define PRINT_COMMAND 0x200
#define PHASE_EXIT 0x400
#define PHASE_RESELECT 0x800
#define DEBUG_FAST 0x1000
#define DEBUG_SG   0x2000
#define DEBUG_LINKED	0x4000
#define DEBUG_BORKEN	0x8000

/* 
 *	Control options - these are timeouts specified in .01 seconds.
 */

/* 30, 20 work */
#define ST0X_BUS_FREE_DELAY 25
#define ST0X_SELECTION_DELAY 25

#define SEAGATE 1		/* these determine the type of the controller */
#define FD	2

#define ST0X_ID_STR	"Seagate ST-01/ST-02"
#define FD_ID_STR	"TMC-8XX/TMC-950"

static int internal_command (unsigned char target, unsigned char lun,
			     const void *cmnd,
			     void *buff, int bufflen, int reselect);

static int incommand;		/* set if arbitration has finished
				   and we are in some command phase. */

static unsigned int base_address = 0;	/* Where the card ROM starts, used to 
					   calculate memory mapped register
					   location.  */

static void __iomem *st0x_cr_sr;	/* control register write, status
					   register read.  256 bytes in
					   length.
					   Read is status of SCSI BUS, as per 
					   STAT masks.  */

static void __iomem *st0x_dr;	/* data register, read write 256
				   bytes in length.  */

static volatile int st0x_aborted = 0;	/* set when we are aborted, ie by a
					   time out, etc.  */

static unsigned char controller_type = 0;	/* set to SEAGATE for ST0x
						   boards or FD for TMC-8xx
						   boards */
static int irq = IRQ;

module_param(base_address, uint, 0);
module_param(controller_type, byte, 0);
module_param(irq, int, 0);
MODULE_LICENSE("GPL");


#define retcode(result) (((result) << 16) | (message << 8) | status)
#define STATUS ((u8) readb(st0x_cr_sr))
#define DATA ((u8) readb(st0x_dr))
#define WRITE_CONTROL(d) { writeb((d), st0x_cr_sr); }
#define WRITE_DATA(d) { writeb((d), st0x_dr); }

#ifndef OVERRIDE
static unsigned int seagate_bases[] = {
	0xc8000, 0xca000, 0xcc000,
	0xce000, 0xdc000, 0xde000
};

typedef struct {
	const unsigned char *signature;
	unsigned offset;
	unsigned length;
	unsigned char type;
} Signature;

static Signature __initdata signatures[] = {
	{"ST01 v1.7  (C) Copyright 1987 Seagate", 15, 37, SEAGATE},
	{"SCSI BIOS 2.00  (C) Copyright 1987 Seagate", 15, 40, SEAGATE},

/*
 * The following two lines are NOT mistakes.  One detects ROM revision
 * 3.0.0, the other 3.2.  Since seagate has only one type of SCSI adapter,
 * and this is not going to change, the "SEAGATE" and "SCSI" together
 * are probably "good enough"
 */

	{"SEAGATE SCSI BIOS ", 16, 17, SEAGATE},
	{"SEAGATE SCSI BIOS ", 17, 17, SEAGATE},

/*
 * However, future domain makes several incompatible SCSI boards, so specific
 * signatures must be used.
 */

	{"FUTURE DOMAIN CORP. (C) 1986-1989 V5.0C2/14/89", 5, 46, FD},
	{"FUTURE DOMAIN CORP. (C) 1986-1989 V6.0A7/28/89", 5, 46, FD},
	{"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0105/31/90", 5, 47, FD},
	{"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0209/18/90", 5, 47, FD},
	{"FUTURE DOMAIN CORP. (C) 1986-1990 V7.009/18/90", 5, 46, FD},
	{"FUTURE DOMAIN CORP. (C) 1992 V8.00.004/02/92", 5, 44, FD},
	{"IBM F1 BIOS V1.1004/30/92", 5, 25, FD},
	{"FUTURE DOMAIN TMC-950", 5, 21, FD},
	/* Added for 2.2.16 by Matthias_Heidbrink@b.maus.de */
	{"IBM F1 V1.2009/22/93", 5, 25, FD},
};

#define NUM_SIGNATURES ARRAY_SIZE(signatures)
#endif				/* n OVERRIDE */

/*
 * hostno stores the hostnumber, as told to us by the init routine.
 */

static int hostno = -1;
static void seagate_reconnect_intr (int, void *);
static irqreturn_t do_seagate_reconnect_intr (int, void *);
static int seagate_st0x_bus_reset(struct scsi_cmnd *);

#ifdef FAST
static int fast = 1;
#else
#define fast 0
#endif

#ifdef SLOW_RATE
/*
 * Support for broken devices :
 * The Seagate board has a handshaking problem.  Namely, a lack
 * thereof for slow devices.  You can blast 600K/second through
 * it if you are polling for each byte, more if you do a blind
 * transfer.  In the first case, with a fast device, REQ will
 * transition high-low or high-low-high before your loop restarts
 * and you'll have no problems.  In the second case, the board
 * will insert wait states for up to 13.2 usecs for REQ to
 * transition low->high, and everything will work.
 *
 * However, there's nothing in the state machine that says
 * you *HAVE* to see a high-low-high set of transitions before
 * sending the next byte, and slow things like the Trantor CD ROMS
 * will break because of this.
 *
 * So, we need to slow things down, which isn't as simple as it
 * seems.  We can't slow things down period, because then people
 * who don't recompile their kernels will shoot me for ruining
 * their performance.  We need to do it on a case per case basis.
 *
 * The best for performance will be to, only for borken devices
 * (this is stored on a per-target basis in the scsi_devices array)
 *
 * Wait for a low->high transition before continuing with that
 * transfer.  If we timeout, continue anyways.  We don't need
 * a long timeout, because REQ should only be asserted until the
 * corresponding ACK is received and processed.
 *
 * Note that we can't use the system timer for this, because of
 * resolution, and we *really* can't use the timer chip since
 * gettimeofday() and the beeper routines use that.  So,
 * the best thing for us to do will be to calibrate a timing
 * loop in the initialization code using the timer chip before
 * gettimeofday() can screw with it.
 *
 * FIXME: this is broken (not borken :-). Empty loop costs less than
 * loop with ISA access in it! -- pavel@ucw.cz
 */

static int borken_calibration = 0;

static void __init borken_init (void)
{
	register int count = 0, start = jiffies + 1, stop = start + 25;

	/* FIXME: There may be a better approach, this is a straight port for
	   now */
	preempt_disable();
	while (time_before (jiffies, start))
		cpu_relax();
	for (; time_before (jiffies, stop); ++count)
		cpu_relax();
	preempt_enable();

/*
 * Ok, we now have a count for .25 seconds.  Convert to a
 * count per second and divide by transfer rate in K.  */

	borken_calibration = (count * 4) / (SLOW_RATE * 1024);

	if (borken_calibration < 1)
		borken_calibration = 1;
}

static inline void borken_wait (void)
{
	register int count;

	for (count = borken_calibration; count && (STATUS & STAT_REQ); --count)
		cpu_relax();
	     	
#if (DEBUG & DEBUG_BORKEN)
	if (count)
		printk ("scsi%d : borken timeout\n", hostno);
#endif
}

#endif				/* def SLOW_RATE */

/* These beasts only live on ISA, and ISA means 8MHz. Each ULOOP()
 * contains at least one ISA access, which takes more than 0.125
 * usec. So if we loop 8 times time in usec, we are safe.
 */

#define ULOOP( i ) for (clock = i*8;;)
#define TIMEOUT (!(clock--))

int __init seagate_st0x_detect (struct scsi_host_template * tpnt)
{
	struct Scsi_Host *instance;
	int i, j;
	unsigned long cr, dr;

	tpnt->proc_name = "seagate";
/*
 *	First, we try for the manual override.
 */
	DANY ("Autodetecting ST0x / TMC-8xx\n");

	if (hostno != -1) {
		printk (KERN_ERR "seagate_st0x_detect() called twice?!\n");
		return 0;
	}

/* If the user specified the controller type from the command line,
   controller_type will be non-zero, so don't try to detect one */

	if (!controller_type) {
#ifdef OVERRIDE
		base_address = OVERRIDE;
		controller_type = CONTROLLER;

		DANY ("Base address overridden to %x, controller type is %s\n",
		      base_address,
		      controller_type == SEAGATE ? "SEAGATE" : "FD");
#else				/* OVERRIDE */
/*
 * 	To detect this card, we simply look for the signature
 *      from the BIOS version notice in all the possible locations
 *      of the ROM's.  This has a nice side effect of not trashing
 *      any register locations that might be used by something else.
 *
 * XXX - note that we probably should be probing the address
 * space for the on-board RAM instead.
 */

		for (i = 0; i < ARRAY_SIZE(seagate_bases); ++i) {
			void __iomem *p = ioremap(seagate_bases[i], 0x2000);
			if (!p)
				continue;
			for (j = 0; j < NUM_SIGNATURES; ++j)
				if (check_signature(p + signatures[j].offset, signatures[j].signature, signatures[j].length)) {
					base_address = seagate_bases[i];
					controller_type = signatures[j].type;
					break;
				}
			iounmap(p);
		}
#endif				/* OVERRIDE */
	}
	/* (! controller_type) */
	tpnt->this_id = (controller_type == SEAGATE) ? 7 : 6;
	tpnt->name = (controller_type == SEAGATE) ? ST0X_ID_STR : FD_ID_STR;

	if (!base_address) {
		printk(KERN_INFO "seagate: ST0x/TMC-8xx not detected.\n");
		return 0;
	}

	cr = base_address + (controller_type == SEAGATE ? 0x1a00 : 0x1c00);
	dr = cr + 0x200;
	st0x_cr_sr = ioremap(cr, 0x100);
	st0x_dr = ioremap(dr, 0x100);

	DANY("%s detected. Base address = %x, cr = %x, dr = %x\n",
	      tpnt->name, base_address, cr, dr);

	/*
	 *	At all times, we will use IRQ 5.  Should also check for IRQ3
	 *	if we lose our first interrupt.
	 */
	instance = scsi_register (tpnt, 0);
	if (instance == NULL)
		return 0;

	hostno = instance->host_no;
	if (request_irq (irq, do_seagate_reconnect_intr, IRQF_DISABLED, (controller_type == SEAGATE) ? "seagate" : "tmc-8xx", instance)) {
		printk(KERN_ERR "scsi%d : unable to allocate IRQ%d\n", hostno, irq);
		return 0;
	}
	instance->irq = irq;
	instance->io_port = base_address;
#ifdef SLOW_RATE
	printk(KERN_INFO "Calibrating borken timer... ");
	borken_init();
	printk(" %d cycles per transfer\n", borken_calibration);
#endif
	printk (KERN_INFO "This is one second... ");
	{
		int clock;
		ULOOP (1 * 1000 * 1000) {
			STATUS;
			if (TIMEOUT)
				break;
		}
	}

	printk ("done, %s options:"
#ifdef ARBITRATE
		" ARBITRATE"
#endif
#ifdef DEBUG
		" DEBUG"
#endif
#ifdef FAST
		" FAST"
#ifdef FAST32
		"32"
#endif
#endif
#ifdef LINKED
		" LINKED"
#endif
#ifdef PARITY
		" PARITY"
#endif
#ifdef SEAGATE_USE_ASM
		" SEAGATE_USE_ASM"
#endif
#ifdef SLOW_RATE
		" SLOW_RATE"
#endif
#ifdef SWAPSTAT
		" SWAPSTAT"
#endif
#ifdef SWAPCNTDATA
		" SWAPCNTDATA"
#endif
		"\n", tpnt->name);
	return 1;
}

static const char *seagate_st0x_info (struct Scsi_Host *shpnt)
{
	static char buffer[64];

	snprintf(buffer, 64, "%s at irq %d, address 0x%05X",
		 (controller_type == SEAGATE) ? ST0X_ID_STR : FD_ID_STR,
		 irq, base_address);
	return buffer;
}

/*
 * These are our saved pointers for the outstanding command that is
 * waiting for a reconnect
 */

static unsigned char current_target, current_lun;
static unsigned char *current_cmnd, *current_data;
static int current_nobuffs;
static struct scatterlist *current_buffer;
static int current_bufflen;

#ifdef LINKED
/*
 * linked_connected indicates whether or not we are currently connected to
 * linked_target, linked_lun and in an INFORMATION TRANSFER phase,
 * using linked commands.
 */

static int linked_connected = 0;
static unsigned char linked_target, linked_lun;
#endif

static void (*done_fn) (struct scsi_cmnd *) = NULL;
static struct scsi_cmnd *SCint = NULL;

/*
 * These control whether or not disconnect / reconnect will be attempted,
 * or are being attempted.
 */

#define NO_RECONNECT    0
#define RECONNECT_NOW   1
#define CAN_RECONNECT   2

/*
 * LINKED_RIGHT indicates that we are currently connected to the correct target
 * for this command, LINKED_WRONG indicates that we are connected to the wrong
 * target. Note that these imply CAN_RECONNECT and require defined(LINKED).
 */

#define LINKED_RIGHT    3
#define LINKED_WRONG    4

/*
 * This determines if we are expecting to reconnect or not.
 */

static int should_reconnect = 0;

/*
 * The seagate_reconnect_intr routine is called when a target reselects the
 * host adapter.  This occurs on the interrupt triggered by the target
 * asserting SEL.
 */

static irqreturn_t do_seagate_reconnect_intr(int irq, void *dev_id)
{
	unsigned long flags;
	struct Scsi_Host *dev = dev_id;
	
	spin_lock_irqsave (dev->host_lock, flags);
	seagate_reconnect_intr (irq, dev_id);
	spin_unlock_irqrestore (dev->host_lock, flags);
	return IRQ_HANDLED;
}

static void seagate_reconnect_intr (int irq, void *dev_id)
{
	int temp;
	struct scsi_cmnd *SCtmp;

	DPRINTK (PHASE_RESELECT, "scsi%d : seagate_reconnect_intr() called\n", hostno);

	if (!should_reconnect)
		printk(KERN_WARNING "scsi%d: unexpected interrupt.\n", hostno);
	else {
		should_reconnect = 0;

		DPRINTK (PHASE_RESELECT, "scsi%d : internal_command(%d, %08x, %08x, RECONNECT_NOW\n", 
			hostno, current_target, current_data, current_bufflen);

		temp = internal_command (current_target, current_lun, current_cmnd, current_data, current_bufflen, RECONNECT_NOW);

		if (msg_byte(temp) != DISCONNECT) {
			if (done_fn) {
				DPRINTK(PHASE_RESELECT, "scsi%d : done_fn(%d,%08x)", hostno, hostno, temp);
				if (!SCint)
					panic ("SCint == NULL in seagate");
				SCtmp = SCint;
				SCint = NULL;
				SCtmp->result = temp;
				done_fn(SCtmp);
			} else
				printk(KERN_ERR "done_fn() not defined.\n");
		}
	}
}

/*
 * The seagate_st0x_queue_command() function provides a queued interface
 * to the seagate SCSI driver.  Basically, it just passes control onto the
 * seagate_command() function, after fixing it so that the done_fn()
 * is set to the one passed to the function.  We have to be very careful,
 * because there are some commands on some devices that do not disconnect,
 * and if we simply call the done_fn when the command is done then another
 * command is started and queue_command is called again...  We end up
 * overflowing the kernel stack, and this tends not to be such a good idea.
 */

static int recursion_depth = 0;

static int seagate_st0x_queue_command(struct scsi_cmnd * SCpnt,
				      void (*done) (struct scsi_cmnd *))
{
	int result, reconnect;
	struct scsi_cmnd *SCtmp;

	DANY ("seagate: que_command");
	done_fn = done;
	current_target = SCpnt->device->id;
	current_lun = SCpnt->device->lun;
	current_cmnd = SCpnt->cmnd;
	current_data = (unsigned char *) SCpnt->request_buffer;
	current_bufflen = SCpnt->request_bufflen;
	SCint = SCpnt;
	if (recursion_depth)
		return 1;
	recursion_depth++;
	do {
#ifdef LINKED
		/*
		 * Set linked command bit in control field of SCSI command.
		 */

		current_cmnd[SCpnt->cmd_len] |= 0x01;
		if (linked_connected) {
			DPRINTK (DEBUG_LINKED, "scsi%d : using linked commands, current I_T_L nexus is ", hostno);
			if (linked_target == current_target && linked_lun == current_lun) 
			{
				DPRINTK(DEBUG_LINKED, "correct\n");
				reconnect = LINKED_RIGHT;
			} else {
				DPRINTK(DEBUG_LINKED, "incorrect\n");
				reconnect = LINKED_WRONG;
			}
		} else
#endif				/* LINKED */
			reconnect = CAN_RECONNECT;

		result = internal_command(SCint->device->id, SCint->device->lun, SCint->cmnd,
				      SCint->request_buffer, SCint->request_bufflen, reconnect);
		if (msg_byte(result) == DISCONNECT)
			break;
		SCtmp = SCint;
		SCint = NULL;
		SCtmp->result = result;
		done_fn(SCtmp);
	}
	while (SCint);
	recursion_depth--;
	return 0;
}

static int internal_command (unsigned char target, unsigned char lun,
		  const void *cmnd, void *buff, int bufflen, int reselect)
{
	unsigned char *data = NULL;
	struct scatterlist *buffer = NULL;
	int clock, temp, nobuffs = 0, done = 0, len = 0;
#ifdef DEBUG
	int transfered = 0, phase = 0, newphase;
#endif
	register unsigned char status_read;
	unsigned char tmp_data, tmp_control, status = 0, message = 0;
	unsigned transfersize = 0, underflow = 0;
#ifdef SLOW_RATE
	int borken = (int) SCint->device->borken;	/* Does the current target require
							   Very Slow I/O ?  */
#endif

	incommand = 0;
	st0x_aborted = 0;

#if (DEBUG & PRINT_COMMAND)
	printk("scsi%d : target = %d, command = ", hostno, target);
	__scsi_print_command((unsigned char *) cmnd);
#endif

#if (DEBUG & PHASE_RESELECT)
	switch (reselect) {
	case RECONNECT_NOW:
		printk("scsi%d : reconnecting\n", hostno);
		break;
#ifdef LINKED
	case LINKED_RIGHT:
		printk("scsi%d : connected, can reconnect\n", hostno);
		break;
	case LINKED_WRONG:
		printk("scsi%d : connected to wrong target, can reconnect\n",
			hostno);
		break;
#endif
	case CAN_RECONNECT:
		printk("scsi%d : allowed to reconnect\n", hostno);
		break;
	default:
		printk("scsi%d : not allowed to reconnect\n", hostno);
	}
#endif

	if (target == (controller_type == SEAGATE ? 7 : 6))
		return DID_BAD_TARGET;

	/*
	 *	We work it differently depending on if this is is "the first time,"
	 *      or a reconnect.  If this is a reselect phase, then SEL will
	 *      be asserted, and we must skip selection / arbitration phases.
	 */

	switch (reselect) {
	case RECONNECT_NOW:
		DPRINTK (PHASE_RESELECT, "scsi%d : phase RESELECT \n", hostno);
		/*
		 *	At this point, we should find the logical or of our ID
		 *	and the original target's ID on the BUS, with BSY, SEL,
		 *	and I/O signals asserted.
		 *
		 *      After ARBITRATION phase is completed, only SEL, BSY,
		 *	and the target ID are asserted.  A valid initiator ID
		 *	is not on the bus until IO is asserted, so we must wait
		 *	for that.
		 */
		ULOOP (100 * 1000) {
			temp = STATUS;
			if ((temp & STAT_IO) && !(temp & STAT_BSY))
				break;
			if (TIMEOUT) {
				DPRINTK (PHASE_RESELECT, "scsi%d : RESELECT timed out while waiting for IO .\n", hostno);
				return (DID_BAD_INTR << 16);
			}
		}

		/*
		 *	After I/O is asserted by the target, we can read our ID
		 *	and its ID off of the BUS.
		 */

		if (!((temp = DATA) & (controller_type == SEAGATE ? 0x80 : 0x40))) {
			DPRINTK (PHASE_RESELECT, "scsi%d : detected reconnect request to different target.\n\tData bus = %d\n", hostno, temp);
			return (DID_BAD_INTR << 16);
		}

		if (!(temp & (1 << current_target))) {
			printk(KERN_WARNING "scsi%d : Unexpected reselect interrupt.  Data bus = %d\n", hostno, temp);
			return (DID_BAD_INTR << 16);
		}

		buffer = current_buffer;
		cmnd = current_cmnd;	/* WDE add */
		data = current_data;	/* WDE add */
		len = current_bufflen;	/* WDE add */
		nobuffs = current_nobuffs;

		/*
		 *	We have determined that we have been selected.  At this
		 *	point, we must respond to the reselection by asserting
		 *	BSY ourselves
		 */

#if 1
		WRITE_CONTROL (BASE_CMD | CMD_DRVR_ENABLE | CMD_BSY);
#else
		WRITE_CONTROL (BASE_CMD | CMD_BSY);
#endif

		/*
		 *	The target will drop SEL, and raise BSY, at which time
		 *	we must drop BSY.
		 */

		ULOOP (100 * 1000) {
			if (!(STATUS & STAT_SEL))
				break;
			if (TIMEOUT) {
				WRITE_CONTROL (BASE_CMD | CMD_INTR);
				DPRINTK (PHASE_RESELECT, "scsi%d : RESELECT timed out while waiting for SEL.\n", hostno);
				return (DID_BAD_INTR << 16);
			}
		}
		WRITE_CONTROL (BASE_CMD);
		/*
		 *	At this point, we have connected with the target
		 *	and can get on with our lives.
		 */
		break;
	case CAN_RECONNECT:
#ifdef LINKED
		/*
		 * This is a bletcherous hack, just as bad as the Unix #!
		 * interpreter stuff. If it turns out we are using the wrong
		 * I_T_L nexus, the easiest way to deal with it is to go into
		 *  our INFORMATION TRANSFER PHASE code, send a ABORT
		 * message on MESSAGE OUT phase, and then loop back to here.
		 */
connect_loop:
#endif
		DPRINTK (PHASE_BUS_FREE, "scsi%d : phase = BUS FREE \n", hostno);

		/*
		 *    BUS FREE PHASE
		 *
		 *      On entry, we make sure that the BUS is in a BUS FREE
		 *      phase, by insuring that both BSY and SEL are low for
		 *      at least one bus settle delay.  Several reads help
		 *      eliminate wire glitch.
		 */

#ifndef ARBITRATE
#error FIXME: this is broken: we may not use jiffies here - we are under cli(). It will hardlock.
		clock = jiffies + ST0X_BUS_FREE_DELAY;

		while (((STATUS | STATUS | STATUS) & (STAT_BSY | STAT_SEL)) && (!st0x_aborted) && time_before (jiffies, clock))
			cpu_relax();

		if (time_after (jiffies, clock))
			return retcode (DID_BUS_BUSY);
		else if (st0x_aborted)
			return retcode (st0x_aborted);
#endif
		DPRINTK (PHASE_SELECTION, "scsi%d : phase = SELECTION\n", hostno);

		clock = jiffies + ST0X_SELECTION_DELAY;

		/*
		 * Arbitration/selection procedure :
		 * 1.  Disable drivers
		 * 2.  Write HOST adapter address bit
		 * 3.  Set start arbitration.
		 * 4.  We get either ARBITRATION COMPLETE or SELECT at this
		 *     point.
		 * 5.  OR our ID and targets on bus.
		 * 6.  Enable SCSI drivers and asserted SEL and ATTN
		 */

#ifdef ARBITRATE
		/* FIXME: verify host lock is always held here */
		WRITE_CONTROL(0);
		WRITE_DATA((controller_type == SEAGATE) ? 0x80 : 0x40);
		WRITE_CONTROL(CMD_START_ARB);

		ULOOP (ST0X_SELECTION_DELAY * 10000) {
			status_read = STATUS;
			if (status_read & STAT_ARB_CMPL)
				break;
			if (st0x_aborted)	/* FIXME: What? We are going to do something even after abort? */
				break;
			if (TIMEOUT || (status_read & STAT_SEL)) {
				printk(KERN_WARNING "scsi%d : arbitration lost or timeout.\n", hostno);
				WRITE_CONTROL (BASE_CMD);
				return retcode (DID_NO_CONNECT);
			}
		}
		DPRINTK (PHASE_SELECTION, "scsi%d : arbitration complete\n", hostno);
#endif

		/*
		 *    When the SCSI device decides that we're gawking at it, 
		 *    it will respond by asserting BUSY on the bus.
		 *
		 *    Note : the Seagate ST-01/02 product manual says that we
		 *    should twiddle the DATA register before the control
		 *    register. However, this does not work reliably so we do
		 *    it the other way around.
		 *
		 *    Probably could be a problem with arbitration too, we
		 *    really should try this with a SCSI protocol or logic 
		 *    analyzer to see what is going on.
		 */
		tmp_data = (unsigned char) ((1 << target) | (controller_type == SEAGATE ? 0x80 : 0x40));
		tmp_control = BASE_CMD | CMD_DRVR_ENABLE | CMD_SEL | (reselect ? CMD_ATTN : 0);

		/* FIXME: verify host lock is always held here */
#ifdef OLDCNTDATASCEME
#ifdef SWAPCNTDATA
		WRITE_CONTROL (tmp_control);
		WRITE_DATA (tmp_data);
#else
		WRITE_DATA (tmp_data);
		WRITE_CONTROL (tmp_control);
#endif
#else
		tmp_control ^= CMD_BSY;	/* This is guesswork. What used to be in driver    */
		WRITE_CONTROL (tmp_control);	/* could never work: it sent data into control     */
		WRITE_DATA (tmp_data);	/* register and control info into data. Hopefully  */
		tmp_control ^= CMD_BSY;	/* fixed, but order of first two may be wrong.     */
		WRITE_CONTROL (tmp_control);	/* -- pavel@ucw.cz   */
#endif

		ULOOP (250 * 1000) {
			if (st0x_aborted) {
				/*
				 *	If we have been aborted, and we have a
				 *	command in progress, IE the target 
				 *	still has BSY asserted, then we will
				 *	reset the bus, and notify the midlevel
				 *	driver to expect sense.
				 */

				WRITE_CONTROL (BASE_CMD);
				if (STATUS & STAT_BSY) {
					printk(KERN_WARNING "scsi%d : BST asserted after we've been aborted.\n", hostno);
					seagate_st0x_bus_reset(NULL);
					return retcode (DID_RESET);
				}
				return retcode (st0x_aborted);
			}
			if (STATUS & STAT_BSY)
				break;
			if (TIMEOUT) {
				DPRINTK (PHASE_SELECTION, "scsi%d : NO CONNECT with target %d, stat = %x \n", hostno, target, STATUS);
				return retcode (DID_NO_CONNECT);
			}
		}

		/* Establish current pointers.  Take into account scatter / gather */

		if ((nobuffs = SCint->use_sg)) {
#if (DEBUG & DEBUG_SG)
			{
				int i;
				printk("scsi%d : scatter gather requested, using %d buffers.\n", hostno, nobuffs);
				for (i = 0; i < nobuffs; ++i)
					printk("scsi%d : buffer %d address = %p length = %d\n",
					     hostno, i,
					     page_address(buffer[i].page) + buffer[i].offset,
					     buffer[i].length);
			}
#endif

			buffer = (struct scatterlist *) SCint->request_buffer;
			len = buffer->length;
			data = page_address(buffer->page) + buffer->offset;
		} else {
			DPRINTK (DEBUG_SG, "scsi%d : scatter gather not requested.\n", hostno);
			buffer = NULL;
			len = SCint->request_bufflen;
			data = (unsigned char *) SCint->request_buffer;
		}

		DPRINTK (PHASE_DATAIN | PHASE_DATAOUT, "scsi%d : len = %d\n",
			 hostno, len);

		break;
#ifdef LINKED
	case LINKED_RIGHT:
		break;
	case LINKED_WRONG:
		break;
#endif
	}			/* end of switch(reselect) */

	/*
	 *    There are several conditions under which we wish to send a message :
	 *      1.  When we are allowing disconnect / reconnect, and need to
	 *	establish the I_T_L nexus via an IDENTIFY with the DiscPriv bit
	 *	set.
	 *
	 *      2.  When we are doing linked commands, are have the wrong I_T_L
	 *	nexus established and want to send an ABORT message.
	 */

	/* GCC does not like an ifdef inside a macro, so do it the hard way. */
#ifdef LINKED
	WRITE_CONTROL (BASE_CMD | CMD_DRVR_ENABLE | (((reselect == CAN_RECONNECT)|| (reselect == LINKED_WRONG))? CMD_ATTN : 0));
#else
	WRITE_CONTROL (BASE_CMD | CMD_DRVR_ENABLE | (((reselect == CAN_RECONNECT))? CMD_ATTN : 0));
#endif

	/*
	 *    INFORMATION TRANSFER PHASE
	 *
	 *      The nasty looking read / write inline assembler loops we use for
	 *      DATAIN and DATAOUT phases are approximately 4-5 times as fast as
	 *      the 'C' versions - since we're moving 1024 bytes of data, this
	 *      really adds up.
	 *
	 *      SJT: The nasty-looking assembler is gone, so it's slower.
	 *
	 */

	DPRINTK (PHASE_ETC, "scsi%d : phase = INFORMATION TRANSFER\n", hostno);

	incommand = 1;
	transfersize = SCint->transfersize;
	underflow = SCint->underflow;

	/*
	 *	Now, we poll the device for status information,
	 *      and handle any requests it makes.  Note that since we are unsure
	 *	of how much data will be flowing across the system, etc and
	 *	cannot make reasonable timeouts, that we will instead have the
	 *	midlevel driver handle any timeouts that occur in this phase.
	 */

	while (((status_read = STATUS) & STAT_BSY) && !st0x_aborted && !done) {
#ifdef PARITY
		if (status_read & STAT_PARITY) {
			printk(KERN_ERR "scsi%d : got parity error\n", hostno);
			st0x_aborted = DID_PARITY;
		}
#endif
		if (status_read & STAT_REQ) {
#if ((DEBUG & PHASE_ETC) == PHASE_ETC)
			if ((newphase = (status_read & REQ_MASK)) != phase) {
				phase = newphase;
				switch (phase) {
				case REQ_DATAOUT:
					printk ("scsi%d : phase = DATA OUT\n", hostno);
					break;
				case REQ_DATAIN:
					printk ("scsi%d : phase = DATA IN\n", hostno);
					break;
				case REQ_CMDOUT:
					printk
					    ("scsi%d : phase = COMMAND OUT\n", hostno);
					break;
				case REQ_STATIN:
					printk ("scsi%d : phase = STATUS IN\n",	hostno);
					break;
				case REQ_MSGOUT:
					printk
					    ("scsi%d : phase = MESSAGE OUT\n", hostno);
					break;
				case REQ_MSGIN:
					printk ("scsi%d : phase = MESSAGE IN\n", hostno);
					break;
				default:
					printk ("scsi%d : phase = UNKNOWN\n", hostno);
					st0x_aborted = DID_ERROR;
				}
			}
#endif
			switch (status_read & REQ_MASK) {
			case REQ_DATAOUT:
				/*
				 * If we are in fast mode, then we simply splat
				 * the data out in word-sized chunks as fast as
				 * we can.
				 */

				if (!len) {
#if 0
					printk("scsi%d: underflow to target %d lun %d \n", hostno, target, lun);
					st0x_aborted = DID_ERROR;
					fast = 0;
#endif
					break;
				}

				if (fast && transfersize
				    && !(len % transfersize)
				    && (len >= transfersize)
#ifdef FAST32
				    && !(transfersize % 4)
#endif
				    ) {
					DPRINTK (DEBUG_FAST,
						 "scsi%d : FAST transfer, underflow = %d, transfersize = %d\n"
						 "         len = %d, data = %08x\n",
						 hostno, SCint->underflow,
						 SCint->transfersize, len,
						 data);

			/* SJT: Start. Fast Write */
#ifdef SEAGATE_USE_ASM
					__asm__ ("cld\n\t"
#ifdef FAST32
						 "shr $2, %%ecx\n\t"
						 "1:\t"
						 "lodsl\n\t"
						 "movl %%eax, (%%edi)\n\t"
#else
						 "1:\t"
						 "lodsb\n\t"
						 "movb %%al, (%%edi)\n\t"
#endif
						 "loop 1b;"
				      /* output */ :
				      /* input */ :"D" (st0x_dr),
						 "S"
						 (data),
						 "c" (SCint->transfersize)
/* clobbered */
				      :	 "eax", "ecx",
						 "esi");
#else				/* SEAGATE_USE_ASM */
					memcpy_toio(st0x_dr, data, transfersize);
#endif				/* SEAGATE_USE_ASM */
/* SJT: End */
					len -= transfersize;
					data += transfersize;
					DPRINTK (DEBUG_FAST, "scsi%d : FAST transfer complete len = %d data = %08x\n", hostno, len, data);
				} else {
					/*
					 *    We loop as long as we are in a 
					 *    data out phase, there is data to
					 *    send, and BSY is still active.
					 */

/* SJT: Start. Slow Write. */
#ifdef SEAGATE_USE_ASM

					int __dummy_1, __dummy_2;

/*
 *      We loop as long as we are in a data out phase, there is data to send, 
 *      and BSY is still active.
 */
/* Local variables : len = ecx , data = esi, 
                     st0x_cr_sr = ebx, st0x_dr =  edi
*/
					__asm__ (
							/* Test for any data here at all. */
							"orl %%ecx, %%ecx\n\t"
							"jz 2f\n\t" "cld\n\t"
/*                    "movl st0x_cr_sr, %%ebx\n\t"  */
/*                    "movl st0x_dr, %%edi\n\t"  */
							"1:\t"
							"movb (%%ebx), %%al\n\t"
							/* Test for BSY */
							"test $1, %%al\n\t"
							"jz 2f\n\t"
							/* Test for data out phase - STATUS & REQ_MASK should be 
							   REQ_DATAOUT, which is 0. */
							"test $0xe, %%al\n\t"
							"jnz 2f\n\t"
							/* Test for REQ */
							"test $0x10, %%al\n\t"
							"jz 1b\n\t"
							"lodsb\n\t"
							"movb %%al, (%%edi)\n\t"
							"loop 1b\n\t" "2:\n"
				      /* output */ :"=S" (data), "=c" (len),
							"=b"
							(__dummy_1),
							"=D" (__dummy_2)
/* input */
				      :		"0" (data), "1" (len),
							"2" (st0x_cr_sr),
							"3" (st0x_dr)
/* clobbered */
				      :		"eax");
#else				/* SEAGATE_USE_ASM */
					while (len) {
						unsigned char stat;

						stat = STATUS;
						if (!(stat & STAT_BSY)
						    || ((stat & REQ_MASK) !=
							REQ_DATAOUT))
							break;
						if (stat & STAT_REQ) {
							WRITE_DATA (*data++);
							--len;
						}
					}
#endif				/* SEAGATE_USE_ASM */
/* SJT: End. */
				}

				if (!len && nobuffs) {
					--nobuffs;
					++buffer;
					len = buffer->length;
					data = page_address(buffer->page) + buffer->offset;
					DPRINTK (DEBUG_SG,
						 "scsi%d : next scatter-gather buffer len = %d address = %08x\n",
						 hostno, len, data);
				}
				break;

			case REQ_DATAIN:
#ifdef SLOW_RATE
				if (borken) {
#if (DEBUG & (PHASE_DATAIN))
					transfered += len;
#endif
					for (; len && (STATUS & (REQ_MASK | STAT_REQ)) == (REQ_DATAIN | STAT_REQ); --len) {
						*data++ = DATA;
						borken_wait();
					}
#if (DEBUG & (PHASE_DATAIN))
					transfered -= len;
#endif
				} else
#endif

					if (fast && transfersize
					    && !(len % transfersize)
					    && (len >= transfersize)
#ifdef FAST32
					    && !(transfersize % 4)
#endif
				    ) {
					DPRINTK (DEBUG_FAST,
						 "scsi%d : FAST transfer, underflow = %d, transfersize = %d\n"
						 "         len = %d, data = %08x\n",
						 hostno, SCint->underflow,
						 SCint->transfersize, len,
						 data);

/* SJT: Start. Fast Read */
#ifdef SEAGATE_USE_ASM
					__asm__ ("cld\n\t"
#ifdef FAST32
						 "shr $2, %%ecx\n\t"
						 "1:\t"
						 "movl (%%esi), %%eax\n\t"
						 "stosl\n\t"
#else
						 "1:\t"
						 "movb (%%esi), %%al\n\t"
						 "stosb\n\t"
#endif
						 "loop 1b\n\t"
				      /* output */ :
				      /* input */ :"S" (st0x_dr),
						 "D"
						 (data),
						 "c" (SCint->transfersize)
/* clobbered */
				      :	 "eax", "ecx",
						 "edi");
#else				/* SEAGATE_USE_ASM */
					memcpy_fromio(data, st0x_dr, len);
#endif				/* SEAGATE_USE_ASM */
/* SJT: End */
					len -= transfersize;
					data += transfersize;
#if (DEBUG & PHASE_DATAIN)
					printk ("scsi%d: transfered += %d\n", hostno, transfersize);
					transfered += transfersize;
#endif

					DPRINTK (DEBUG_FAST, "scsi%d : FAST transfer complete len = %d data = %08x\n", hostno, len, data);
				} else {

#if (DEBUG & PHASE_DATAIN)
					printk ("scsi%d: transfered += %d\n", hostno, len);
					transfered += len;	/* Assume we'll transfer it all, then
								   subtract what we *didn't* transfer */
#endif

/*
 *	We loop as long as we are in a data in phase, there is room to read,
 *      and BSY is still active
 */

/* SJT: Start. */
#ifdef SEAGATE_USE_ASM

					int __dummy_3, __dummy_4;

/* Dummy clobbering variables for the new gcc-2.95 */

/*
 *      We loop as long as we are in a data in phase, there is room to read, 
 *      and BSY is still active
 */
					/* Local variables : ecx = len, edi = data
					   esi = st0x_cr_sr, ebx = st0x_dr */
					__asm__ (
							/* Test for room to read */
							"orl %%ecx, %%ecx\n\t"
							"jz 2f\n\t" "cld\n\t"
/*                "movl st0x_cr_sr, %%esi\n\t"  */
/*                "movl st0x_dr, %%ebx\n\t"  */
							"1:\t"
							"movb (%%esi), %%al\n\t"
							/* Test for BSY */
							"test $1, %%al\n\t"
							"jz 2f\n\t"
							/* Test for data in phase - STATUS & REQ_MASK should be REQ_DATAIN, 
							   = STAT_IO, which is 4. */
							"movb $0xe, %%ah\n\t"
							"andb %%al, %%ah\n\t"
							"cmpb $0x04, %%ah\n\t"
							"jne 2f\n\t"
							/* Test for REQ */
							"test $0x10, %%al\n\t"
							"jz 1b\n\t"
							"movb (%%ebx), %%al\n\t"
							"stosb\n\t"
							"loop 1b\n\t" "2:\n"
				      /* output */ :"=D" (data), "=c" (len),
							"=S"
							(__dummy_3),
							"=b" (__dummy_4)
/* input */
				      :		"0" (data), "1" (len),
							"2" (st0x_cr_sr),
							"3" (st0x_dr)
/* clobbered */
				      :		"eax");
#else				/* SEAGATE_USE_ASM */
					while (len) {
						unsigned char stat;

						stat = STATUS;
						if (!(stat & STAT_BSY)
						    || ((stat & REQ_MASK) !=
							REQ_DATAIN))
							break;
						if (stat & STAT_REQ) {
							*data++ = DATA;
							--len;
						}
					}
#endif				/* SEAGATE_USE_ASM */
/* SJT: End. */
#if (DEBUG & PHASE_DATAIN)
					printk ("scsi%d: transfered -= %d\n", hostno, len);
					transfered -= len;	/* Since we assumed all of Len got  *
								   transfered, correct our mistake */
#endif
				}

				if (!len && nobuffs) {
					--nobuffs;
					++buffer;
					len = buffer->length;
					data = page_address(buffer->page) + buffer->offset;
					DPRINTK (DEBUG_SG, "scsi%d : next scatter-gather buffer len = %d address = %08x\n", hostno, len, data);
				}
				break;

			case REQ_CMDOUT:
				while (((status_read = STATUS) & STAT_BSY) &&
				       ((status_read & REQ_MASK) == REQ_CMDOUT))
					if (status_read & STAT_REQ) {
						WRITE_DATA (*(const unsigned char *) cmnd);
						cmnd = 1 + (const unsigned char *)cmnd;
#ifdef SLOW_RATE
						if (borken)
							borken_wait ();
#endif
					}
				break;

			case REQ_STATIN:
				status = DATA;
				break;

			case REQ_MSGOUT:
				/*
				 *	We can only have sent a MSG OUT if we
				 *	requested to do this by raising ATTN.
				 *	So, we must drop ATTN.
				 */
				WRITE_CONTROL (BASE_CMD | CMD_DRVR_ENABLE);
				/*
				 *	If we are reconnecting, then we must 
				 *	send an IDENTIFY message in response
				 *	to MSGOUT.
				 */
				switch (reselect) {
				case CAN_RECONNECT:
					WRITE_DATA (IDENTIFY (1, lun));
					DPRINTK (PHASE_RESELECT | PHASE_MSGOUT, "scsi%d : sent IDENTIFY message.\n", hostno);
					break;
#ifdef LINKED
				case LINKED_WRONG:
					WRITE_DATA (ABORT);
					linked_connected = 0;
					reselect = CAN_RECONNECT;
					goto connect_loop;
					DPRINTK (PHASE_MSGOUT | DEBUG_LINKED, "scsi%d : sent ABORT message to cancel incorrect I_T_L nexus.\n", hostno);
#endif					/* LINKED */
					DPRINTK (DEBUG_LINKED, "correct\n");
				default:
					WRITE_DATA (NOP);
					printk("scsi%d : target %d requested MSGOUT, sent NOP message.\n", hostno, target);
				}
				break;

			case REQ_MSGIN:
				switch (message = DATA) {
				case DISCONNECT:
					DANY("seagate: deciding to disconnect\n");
					should_reconnect = 1;
					current_data = data;	/* WDE add */
					current_buffer = buffer;
					current_bufflen = len;	/* WDE add */
					current_nobuffs = nobuffs;
#ifdef LINKED
					linked_connected = 0;
#endif
					done = 1;
					DPRINTK ((PHASE_RESELECT | PHASE_MSGIN), "scsi%d : disconnected.\n", hostno);
					break;

#ifdef LINKED
				case LINKED_CMD_COMPLETE:
				case LINKED_FLG_CMD_COMPLETE:
#endif
				case COMMAND_COMPLETE:
					/*
					 * Note : we should check for underflow here.
					 */
					DPRINTK(PHASE_MSGIN, "scsi%d : command complete.\n", hostno);
					done = 1;
					break;
				case ABORT:
					DPRINTK(PHASE_MSGIN, "scsi%d : abort message.\n", hostno);
					done = 1;
					break;
				case SAVE_POINTERS:
					current_buffer = buffer;
					current_bufflen = len;	/* WDE add */
					current_data = data;	/* WDE mod */
					current_nobuffs = nobuffs;
					DPRINTK (PHASE_MSGIN, "scsi%d : pointers saved.\n", hostno);
					break;
				case RESTORE_POINTERS:
					buffer = current_buffer;
					cmnd = current_cmnd;
					data = current_data;	/* WDE mod */
					len = current_bufflen;
					nobuffs = current_nobuffs;
					DPRINTK(PHASE_MSGIN, "scsi%d : pointers restored.\n", hostno);
					break;
				default:

					/*
					 *	IDENTIFY distinguishes itself
					 *	from the other messages by 
					 *	setting the high bit.
					 *
					 *      Note : we need to handle at 
					 *	least one outstanding command
					 *	per LUN, and need to hash the 
					 *	SCSI command for that I_T_L
					 *	nexus based on the known ID 
					 *	(at this point) and LUN.
					 */

					if (message & 0x80) {
						DPRINTK (PHASE_MSGIN, "scsi%d : IDENTIFY message received from id %d, lun %d.\n", hostno, target, message & 7);
					} else {
						/*
						 *      We should go into a
						 *	MESSAGE OUT phase, and
						 *	send  a MESSAGE_REJECT
						 *      if we run into a message 
						 *	that we don't like.  The
						 *	seagate driver needs 
						 *	some serious 
						 *	restructuring first
						 *	though.
						 */
						DPRINTK (PHASE_MSGIN, "scsi%d : unknown message %d from target %d.\n", hostno, message, target);
					}
				}
				break;
			default:
				printk(KERN_ERR "scsi%d : unknown phase.\n", hostno);
				st0x_aborted = DID_ERROR;
			}	/* end of switch (status_read &  REQ_MASK) */
#ifdef SLOW_RATE
			/*
			 * I really don't care to deal with borken devices in
			 * each single byte transfer case (ie, message in,
			 * message out, status), so I'll do the wait here if 
			 * necessary.
			 */
			if(borken)
				borken_wait();
#endif

		}		/* if(status_read & STAT_REQ) ends */
	}			/* while(((status_read = STATUS)...) ends */

	DPRINTK(PHASE_DATAIN | PHASE_DATAOUT | PHASE_EXIT, "scsi%d : Transfered %d bytes\n", hostno, transfered);

#if (DEBUG & PHASE_EXIT)
#if 0				/* Doesn't work for scatter/gather */
	printk("Buffer : \n");
	for(i = 0; i < 20; ++i)
		printk("%02x  ", ((unsigned char *) data)[i]);	/* WDE mod */
	printk("\n");
#endif
	printk("scsi%d : status = ", hostno);
	scsi_print_status(status);
	printk(" message = %02x\n", message);
#endif

	/* We shouldn't reach this until *after* BSY has been deasserted */

#ifdef LINKED
	else
	{
		/*
		 * Fix the message byte so that unsuspecting high level drivers
		 * don't puke when they see a LINKED COMMAND message in place of
		 * the COMMAND COMPLETE they may be expecting.  Shouldn't be
		 * necessary, but it's better to be on the safe side.
		 *
		 * A non LINKED* message byte will indicate that the command
		 * completed, and we are now disconnected.
		 */

		switch (message) {
		case LINKED_CMD_COMPLETE:
		case LINKED_FLG_CMD_COMPLETE:
			message = COMMAND_COMPLETE;
			linked_target = current_target;
			linked_lun = current_lun;
			linked_connected = 1;
			DPRINTK (DEBUG_LINKED, "scsi%d : keeping I_T_L nexus established for linked command.\n", hostno);
			/* We also will need to adjust status to accommodate intermediate
			   conditions. */
			if ((status == INTERMEDIATE_GOOD) || (status == INTERMEDIATE_C_GOOD))
				status = GOOD;
			break;
			/*
			 * We should also handle what are "normal" termination
			 * messages here (ABORT, BUS_DEVICE_RESET?, and
			 * COMMAND_COMPLETE individually, and flake if things
			 * aren't right.
			 */
		default:
			DPRINTK (DEBUG_LINKED, "scsi%d : closing I_T_L nexus.\n", hostno);
			linked_connected = 0;
		}
	}
#endif	/* LINKED */

	if (should_reconnect) {
		DPRINTK (PHASE_RESELECT, "scsi%d : exiting seagate_st0x_queue_command() with reconnect enabled.\n", hostno);
		WRITE_CONTROL (BASE_CMD | CMD_INTR);
	} else
		WRITE_CONTROL (BASE_CMD);

	return retcode (st0x_aborted);
}				/* end of internal_command */

static int seagate_st0x_abort(struct scsi_cmnd * SCpnt)
{
	st0x_aborted = DID_ABORT;
	return SUCCESS;
}

#undef ULOOP
#undef TIMEOUT

/*
 * the seagate_st0x_reset function resets the SCSI bus 
 *
 * May be called with SCpnt = NULL
 */

static int seagate_st0x_bus_reset(struct scsi_cmnd * SCpnt)
{
	/* No timeouts - this command is going to fail because it was reset. */
	DANY ("scsi%d: Reseting bus... ", hostno);

	/* assert  RESET signal on SCSI bus.  */
	WRITE_CONTROL (BASE_CMD | CMD_RST);

	mdelay (20);

	WRITE_CONTROL (BASE_CMD);
	st0x_aborted = DID_RESET;

	DANY ("done.\n");
	return SUCCESS;
}

static int seagate_st0x_release(struct Scsi_Host *shost)
{
	if (shost->irq)
		free_irq(shost->irq, shost);
	release_region(shost->io_port, shost->n_io_port);
	return 0;
}

static struct scsi_host_template driver_template = {
	.detect         	= seagate_st0x_detect,
	.release        	= seagate_st0x_release,
	.info           	= seagate_st0x_info,
	.queuecommand   	= seagate_st0x_queue_command,
	.eh_abort_handler	= seagate_st0x_abort,
	.eh_bus_reset_handler	= seagate_st0x_bus_reset,
	.can_queue      	= 1,
	.this_id        	= 7,
	.sg_tablesize   	= SG_ALL,
	.cmd_per_lun    	= 1,
	.use_clustering		= DISABLE_CLUSTERING,
};
#include "scsi_module.c"