sched: avoid large irq-latencies in smp-balancing

[linux-2.6] / drivers / scsi / wd33c93.c

/*
 * Copyright (c) 1996 John Shifflett, GeoLog Consulting
 *    john@geolog.com
 *    jshiffle@netcom.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

/*
 * Drew Eckhardt's excellent 'Generic NCR5380' sources from Linux-PC
 * provided much of the inspiration and some of the code for this
 * driver. Everything I know about Amiga DMA was gleaned from careful
 * reading of Hamish Mcdonald's original wd33c93 driver; in fact, I
 * borrowed shamelessly from all over that source. Thanks Hamish!
 *
 * _This_ driver is (I feel) an improvement over the old one in
 * several respects:
 *
 *    -  Target Disconnection/Reconnection  is now supported. Any
 *          system with more than one device active on the SCSI bus
 *          will benefit from this. The driver defaults to what I
 *          call 'adaptive disconnect' - meaning that each command
 *          is evaluated individually as to whether or not it should
 *          be run with the option to disconnect/reselect (if the
 *          device chooses), or as a "SCSI-bus-hog".
 *
 *    -  Synchronous data transfers are now supported. Because of
 *          a few devices that choke after telling the driver that
 *          they can do sync transfers, we don't automatically use
 *          this faster protocol - it can be enabled via the command-
 *          line on a device-by-device basis.
 *
 *    -  Runtime operating parameters can now be specified through
 *       the 'amiboot' or the 'insmod' command line. For amiboot do:
 *          "amiboot [usual stuff] wd33c93=blah,blah,blah"
 *       The defaults should be good for most people. See the comment
 *       for 'setup_strings' below for more details.
 *
 *    -  The old driver relied exclusively on what the Western Digital
 *          docs call "Combination Level 2 Commands", which are a great
 *          idea in that the CPU is relieved of a lot of interrupt
 *          overhead. However, by accepting a certain (user-settable)
 *          amount of additional interrupts, this driver achieves
 *          better control over the SCSI bus, and data transfers are
 *          almost as fast while being much easier to define, track,
 *          and debug.
 *
 *
 * TODO:
 *       more speed. linked commands.
 *
 *
 * People with bug reports, wish-lists, complaints, comments,
 * or improvements are asked to pah-leeez email me (John Shifflett)
 * at john@geolog.com or jshiffle@netcom.com! I'm anxious to get
 * this thing into as good a shape as possible, and I'm positive
 * there are lots of lurking bugs and "Stupid Places".
 *
 * Updates:
 *
 * Added support for pre -A chips, which don't have advanced features
 * and will generate CSR_RESEL rather than CSR_RESEL_AM.
 *      Richard Hirst <richard@sleepie.demon.co.uk>  August 2000
 *
 * Added support for Burst Mode DMA and Fast SCSI. Enabled the use of
 * default_sx_per for asynchronous data transfers. Added adjustment
 * of transfer periods in sx_table to the actual input-clock.
 *  peter fuerst <post@pfrst.de>  February 2007
 */

#include <linux/module.h>

#include <linux/string.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/blkdev.h>

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

#include <asm/irq.h>

#include "wd33c93.h"

#define optimum_sx_per(hostdata) (hostdata)->sx_table[1].period_ns


#define WD33C93_VERSION    "1.26++"
#define WD33C93_DATE       "10/Feb/2007"

MODULE_AUTHOR("John Shifflett");
MODULE_DESCRIPTION("Generic WD33C93 SCSI driver");
MODULE_LICENSE("GPL");

/*
 * 'setup_strings' is a single string used to pass operating parameters and
 * settings from the kernel/module command-line to the driver. 'setup_args[]'
 * is an array of strings that define the compile-time default values for
 * these settings. If Linux boots with an amiboot or insmod command-line,
 * those settings are combined with 'setup_args[]'. Note that amiboot
 * command-lines are prefixed with "wd33c93=" while insmod uses a
 * "setup_strings=" prefix. The driver recognizes the following keywords
 * (lower case required) and arguments:
 *
 * -  nosync:bitmask -bitmask is a byte where the 1st 7 bits correspond with
 *                    the 7 possible SCSI devices. Set a bit to negotiate for
 *                    asynchronous transfers on that device. To maintain
 *                    backwards compatibility, a command-line such as
 *                    "wd33c93=255" will be automatically translated to
 *                    "wd33c93=nosync:0xff".
 * -  nodma:x        -x = 1 to disable DMA, x = 0 to enable it. Argument is
 *                    optional - if not present, same as "nodma:1".
 * -  period:ns      -ns is the minimum # of nanoseconds in a SCSI data transfer
 *                    period. Default is 500; acceptable values are 250 - 1000.
 * -  disconnect:x   -x = 0 to never allow disconnects, 2 to always allow them.
 *                    x = 1 does 'adaptive' disconnects, which is the default
 *                    and generally the best choice.
 * -  debug:x        -If 'DEBUGGING_ON' is defined, x is a bit mask that causes
 *                    various types of debug output to printed - see the DB_xxx
 *                    defines in wd33c93.h
 * -  clock:x        -x = clock input in MHz for WD33c93 chip. Normal values
 *                    would be from 8 through 20. Default is 8.
 * -  burst:x        -x = 1 to use Burst Mode (or Demand-Mode) DMA, x = 0 to use
 *                    Single Byte DMA, which is the default. Argument is
 *                    optional - if not present, same as "burst:1".
 * -  fast:x         -x = 1 to enable Fast SCSI, which is only effective with
 *                    input-clock divisor 4 (WD33C93_FS_16_20), x = 0 to disable
 *                    it, which is the default.  Argument is optional - if not
 *                    present, same as "fast:1".
 * -  next           -No argument. Used to separate blocks of keywords when
 *                    there's more than one host adapter in the system.
 *
 * Syntax Notes:
 * -  Numeric arguments can be decimal or the '0x' form of hex notation. There
 *    _must_ be a colon between a keyword and its numeric argument, with no
 *    spaces.
 * -  Keywords are separated by commas, no spaces, in the standard kernel
 *    command-line manner.
 * -  A keyword in the 'nth' comma-separated command-line member will overwrite
 *    the 'nth' element of setup_args[]. A blank command-line member (in
 *    other words, a comma with no preceding keyword) will _not_ overwrite
 *    the corresponding setup_args[] element.
 * -  If a keyword is used more than once, the first one applies to the first
 *    SCSI host found, the second to the second card, etc, unless the 'next'
 *    keyword is used to change the order.
 *
 * Some amiboot examples (for insmod, use 'setup_strings' instead of 'wd33c93'):
 * -  wd33c93=nosync:255
 * -  wd33c93=nodma
 * -  wd33c93=nodma:1
 * -  wd33c93=disconnect:2,nosync:0x08,period:250
 * -  wd33c93=debug:0x1c
 */

/* Normally, no defaults are specified */
static char *setup_args[] = { "", "", "", "", "", "", "", "", "", "" };

static char *setup_strings;
module_param(setup_strings, charp, 0);

static void wd33c93_execute(struct Scsi_Host *instance);

#ifdef CONFIG_WD33C93_PIO
static inline uchar
read_wd33c93(const wd33c93_regs regs, uchar reg_num)
{
        uchar data;

        outb(reg_num, regs.SASR);
        data = inb(regs.SCMD);
        return data;
}

static inline unsigned long
read_wd33c93_count(const wd33c93_regs regs)
{
        unsigned long value;

        outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
        value = inb(regs.SCMD) << 16;
        value |= inb(regs.SCMD) << 8;
        value |= inb(regs.SCMD);
        return value;
}

static inline uchar
read_aux_stat(const wd33c93_regs regs)
{
        return inb(regs.SASR);
}

static inline void
write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
{
      outb(reg_num, regs.SASR);
      outb(value, regs.SCMD);
}

static inline void
write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
{
        outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
        outb((value >> 16) & 0xff, regs.SCMD);
        outb((value >> 8) & 0xff, regs.SCMD);
        outb( value & 0xff, regs.SCMD);
}

#define write_wd33c93_cmd(regs, cmd) \
        write_wd33c93((regs), WD_COMMAND, (cmd))

static inline void
write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
{
        int i;

        outb(WD_CDB_1, regs.SASR);
        for (i=0; i<len; i++)
                outb(cmnd[i], regs.SCMD);
}

#else /* CONFIG_WD33C93_PIO */
static inline uchar
read_wd33c93(const wd33c93_regs regs, uchar reg_num)
{
        *regs.SASR = reg_num;
        mb();
        return (*regs.SCMD);
}

static unsigned long
read_wd33c93_count(const wd33c93_regs regs)
{
        unsigned long value;

        *regs.SASR = WD_TRANSFER_COUNT_MSB;
        mb();
        value = *regs.SCMD << 16;
        value |= *regs.SCMD << 8;
        value |= *regs.SCMD;
        mb();
        return value;
}

static inline uchar
read_aux_stat(const wd33c93_regs regs)
{
        return *regs.SASR;
}

static inline void
write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
{
        *regs.SASR = reg_num;
        mb();
        *regs.SCMD = value;
        mb();
}

static void
write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
{
        *regs.SASR = WD_TRANSFER_COUNT_MSB;
        mb();
        *regs.SCMD = value >> 16;
        *regs.SCMD = value >> 8;
        *regs.SCMD = value;
        mb();
}

static inline void
write_wd33c93_cmd(const wd33c93_regs regs, uchar cmd)
{
        *regs.SASR = WD_COMMAND;
        mb();
        *regs.SCMD = cmd;
        mb();
}

static inline void
write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
{
        int i;

        *regs.SASR = WD_CDB_1;
        for (i = 0; i < len; i++)
                *regs.SCMD = cmnd[i];
}
#endif /* CONFIG_WD33C93_PIO */

static inline uchar
read_1_byte(const wd33c93_regs regs)
{
        uchar asr;
        uchar x = 0;

        write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
        write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO | 0x80);
        do {
                asr = read_aux_stat(regs);
                if (asr & ASR_DBR)
                        x = read_wd33c93(regs, WD_DATA);
        } while (!(asr & ASR_INT));
        return x;
}

static int
round_period(unsigned int period, const struct sx_period *sx_table)
{
        int x;

        for (x = 1; sx_table[x].period_ns; x++) {
                if ((period <= sx_table[x - 0].period_ns) &&
                    (period > sx_table[x - 1].period_ns)) {
                        return x;
                }
        }
        return 7;
}

/*
 * Calculate Synchronous Transfer Register value from SDTR code.
 */
static uchar
calc_sync_xfer(unsigned int period, unsigned int offset, unsigned int fast,
               const struct sx_period *sx_table)
{
        /* When doing Fast SCSI synchronous data transfers, the corresponding
         * value in 'sx_table' is two times the actually used transfer period.
         */
        uchar result;

        if (offset && fast) {
                fast = STR_FSS;
                period *= 2;
        } else {
                fast = 0;
        }
        period *= 4;            /* convert SDTR code to ns */
        result = sx_table[round_period(period,sx_table)].reg_value;
        result |= (offset < OPTIMUM_SX_OFF) ? offset : OPTIMUM_SX_OFF;
        result |= fast;
        return result;
}

/*
 * Calculate SDTR code bytes [3],[4] from period and offset.
 */
static inline void
calc_sync_msg(unsigned int period, unsigned int offset, unsigned int fast,
                uchar  msg[2])
{
        /* 'period' is a "normal"-mode value, like the ones in 'sx_table'. The
         * actually used transfer period for Fast SCSI synchronous data
         * transfers is half that value.
         */
        period /= 4;
        if (offset && fast)
                period /= 2;
        msg[0] = period;
        msg[1] = offset;
}

int
wd33c93_queuecommand(struct scsi_cmnd *cmd,
                void (*done)(struct scsi_cmnd *))
{
        struct WD33C93_hostdata *hostdata;
        struct scsi_cmnd *tmp;

        hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;

        DB(DB_QUEUE_COMMAND,
           printk("Q-%d-%02x-%ld( ", cmd->device->id, cmd->cmnd[0], cmd->serial_number))

/* Set up a few fields in the scsi_cmnd structure for our own use:
 *  - host_scribble is the pointer to the next cmd in the input queue
 *  - scsi_done points to the routine we call when a cmd is finished
 *  - result is what you'd expect
 */
        cmd->host_scribble = NULL;
        cmd->scsi_done = done;
        cmd->result = 0;

/* We use the Scsi_Pointer structure that's included with each command
 * as a scratchpad (as it's intended to be used!). The handy thing about
 * the SCp.xxx fields is that they're always associated with a given
 * cmd, and are preserved across disconnect-reselect. This means we
 * can pretty much ignore SAVE_POINTERS and RESTORE_POINTERS messages
 * if we keep all the critical pointers and counters in SCp:
 *  - SCp.ptr is the pointer into the RAM buffer
 *  - SCp.this_residual is the size of that buffer
 *  - SCp.buffer points to the current scatter-gather buffer
 *  - SCp.buffers_residual tells us how many S.G. buffers there are
 *  - SCp.have_data_in is not used
 *  - SCp.sent_command is not used
 *  - SCp.phase records this command's SRCID_ER bit setting
 */

        if (cmd->use_sg) {
                cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
                cmd->SCp.buffers_residual = cmd->use_sg - 1;
                cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
                cmd->SCp.this_residual = cmd->SCp.buffer->length;
        } else {
                cmd->SCp.buffer = NULL;
                cmd->SCp.buffers_residual = 0;
                cmd->SCp.ptr = (char *) cmd->request_buffer;
                cmd->SCp.this_residual = cmd->request_bufflen;
        }

/* WD docs state that at the conclusion of a "LEVEL2" command, the
 * status byte can be retrieved from the LUN register. Apparently,
 * this is the case only for *uninterrupted* LEVEL2 commands! If
 * there are any unexpected phases entered, even if they are 100%
 * legal (different devices may choose to do things differently),
 * the LEVEL2 command sequence is exited. This often occurs prior
 * to receiving the status byte, in which case the driver does a
 * status phase interrupt and gets the status byte on its own.
 * While such a command can then be "resumed" (ie restarted to
 * finish up as a LEVEL2 command), the LUN register will NOT be
 * a valid status byte at the command's conclusion, and we must
 * use the byte obtained during the earlier interrupt. Here, we
 * preset SCp.Status to an illegal value (0xff) so that when
 * this command finally completes, we can tell where the actual
 * status byte is stored.
 */

        cmd->SCp.Status = ILLEGAL_STATUS_BYTE;

        /*
         * Add the cmd to the end of 'input_Q'. Note that REQUEST SENSE
         * commands are added to the head of the queue so that the desired
         * sense data is not lost before REQUEST_SENSE executes.
         */

        spin_lock_irq(&hostdata->lock);

        if (!(hostdata->input_Q) || (cmd->cmnd[0] == REQUEST_SENSE)) {
                cmd->host_scribble = (uchar *) hostdata->input_Q;
                hostdata->input_Q = cmd;
        } else {                /* find the end of the queue */
                for (tmp = (struct scsi_cmnd *) hostdata->input_Q;
                     tmp->host_scribble;
                     tmp = (struct scsi_cmnd *) tmp->host_scribble) ;
                tmp->host_scribble = (uchar *) cmd;
        }

/* We know that there's at least one command in 'input_Q' now.
 * Go see if any of them are runnable!
 */

        wd33c93_execute(cmd->device->host);

        DB(DB_QUEUE_COMMAND, printk(")Q-%ld ", cmd->serial_number))

        spin_unlock_irq(&hostdata->lock);
        return 0;
}

/*
 * This routine attempts to start a scsi command. If the host_card is
 * already connected, we give up immediately. Otherwise, look through
 * the input_Q, using the first command we find that's intended
 * for a currently non-busy target/lun.
 *
 * wd33c93_execute() is always called with interrupts disabled or from
 * the wd33c93_intr itself, which means that a wd33c93 interrupt
 * cannot occur while we are in here.
 */
static void
wd33c93_execute(struct Scsi_Host *instance)
{
        struct WD33C93_hostdata *hostdata =
            (struct WD33C93_hostdata *) instance->hostdata;
        const wd33c93_regs regs = hostdata->regs;
        struct scsi_cmnd *cmd, *prev;

        DB(DB_EXECUTE, printk("EX("))
        if (hostdata->selecting || hostdata->connected) {
                DB(DB_EXECUTE, printk(")EX-0 "))
                return;
        }

        /*
         * Search through the input_Q for a command destined
         * for an idle target/lun.
         */

        cmd = (struct scsi_cmnd *) hostdata->input_Q;
        prev = NULL;
        while (cmd) {
                if (!(hostdata->busy[cmd->device->id] & (1 << cmd->device->lun)))
                        break;
                prev = cmd;
                cmd = (struct scsi_cmnd *) cmd->host_scribble;
        }

        /* quit if queue empty or all possible targets are busy */

        if (!cmd) {
                DB(DB_EXECUTE, printk(")EX-1 "))
                return;
        }

        /*  remove command from queue */

        if (prev)
                prev->host_scribble = cmd->host_scribble;
        else
                hostdata->input_Q = (struct scsi_cmnd *) cmd->host_scribble;

#ifdef PROC_STATISTICS
        hostdata->cmd_cnt[cmd->device->id]++;
#endif

        /*
         * Start the selection process
         */

        if (cmd->sc_data_direction == DMA_TO_DEVICE)
                write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
        else
                write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id | DSTID_DPD);

/* Now we need to figure out whether or not this command is a good
 * candidate for disconnect/reselect. We guess to the best of our
 * ability, based on a set of hierarchical rules. When several
 * devices are operating simultaneously, disconnects are usually
 * an advantage. In a single device system, or if only 1 device
 * is being accessed, transfers usually go faster if disconnects
 * are not allowed:
 *
 * + Commands should NEVER disconnect if hostdata->disconnect =
 *   DIS_NEVER (this holds for tape drives also), and ALWAYS
 *   disconnect if hostdata->disconnect = DIS_ALWAYS.
 * + Tape drive commands should always be allowed to disconnect.
 * + Disconnect should be allowed if disconnected_Q isn't empty.
 * + Commands should NOT disconnect if input_Q is empty.
 * + Disconnect should be allowed if there are commands in input_Q
 *   for a different target/lun. In this case, the other commands
 *   should be made disconnect-able, if not already.
 *
 * I know, I know - this code would flunk me out of any
 * "C Programming 101" class ever offered. But it's easy
 * to change around and experiment with for now.
 */

        cmd->SCp.phase = 0;     /* assume no disconnect */
        if (hostdata->disconnect == DIS_NEVER)
                goto no;
        if (hostdata->disconnect == DIS_ALWAYS)
                goto yes;
        if (cmd->device->type == 1)     /* tape drive? */
                goto yes;
        if (hostdata->disconnected_Q)   /* other commands disconnected? */
                goto yes;
        if (!(hostdata->input_Q))       /* input_Q empty? */
                goto no;
        for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
             prev = (struct scsi_cmnd *) prev->host_scribble) {
                if ((prev->device->id != cmd->device->id) ||
                    (prev->device->lun != cmd->device->lun)) {
                        for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
                             prev = (struct scsi_cmnd *) prev->host_scribble)
                                prev->SCp.phase = 1;
                        goto yes;
                }
        }

        goto no;

 yes:
        cmd->SCp.phase = 1;

#ifdef PROC_STATISTICS
        hostdata->disc_allowed_cnt[cmd->device->id]++;
#endif

 no:

        write_wd33c93(regs, WD_SOURCE_ID, ((cmd->SCp.phase) ? SRCID_ER : 0));

        write_wd33c93(regs, WD_TARGET_LUN, cmd->device->lun);
        write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
                      hostdata->sync_xfer[cmd->device->id]);
        hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);

        if ((hostdata->level2 == L2_NONE) ||
            (hostdata->sync_stat[cmd->device->id] == SS_UNSET)) {

                /*
                 * Do a 'Select-With-ATN' command. This will end with
                 * one of the following interrupts:
                 *    CSR_RESEL_AM:  failure - can try again later.
                 *    CSR_TIMEOUT:   failure - give up.
                 *    CSR_SELECT:    success - proceed.
                 */

                hostdata->selecting = cmd;

/* Every target has its own synchronous transfer setting, kept in the
 * sync_xfer array, and a corresponding status byte in sync_stat[].
 * Each target's sync_stat[] entry is initialized to SX_UNSET, and its
 * sync_xfer[] entry is initialized to the default/safe value. SS_UNSET
 * means that the parameters are undetermined as yet, and that we
 * need to send an SDTR message to this device after selection is
 * complete: We set SS_FIRST to tell the interrupt routine to do so.
 * If we've been asked not to try synchronous transfers on this
 * target (and _all_ luns within it), we'll still send the SDTR message
 * later, but at that time we'll negotiate for async by specifying a
 * sync fifo depth of 0.
 */
                if (hostdata->sync_stat[cmd->device->id] == SS_UNSET)
                        hostdata->sync_stat[cmd->device->id] = SS_FIRST;
                hostdata->state = S_SELECTING;
                write_wd33c93_count(regs, 0);   /* guarantee a DATA_PHASE interrupt */
                write_wd33c93_cmd(regs, WD_CMD_SEL_ATN);
        } else {

                /*
                 * Do a 'Select-With-ATN-Xfer' command. This will end with
                 * one of the following interrupts:
                 *    CSR_RESEL_AM:  failure - can try again later.
                 *    CSR_TIMEOUT:   failure - give up.
                 *    anything else: success - proceed.
                 */

                hostdata->connected = cmd;
                write_wd33c93(regs, WD_COMMAND_PHASE, 0);

                /* copy command_descriptor_block into WD chip
                 * (take advantage of auto-incrementing)
                 */

                write_wd33c93_cdb(regs, cmd->cmd_len, cmd->cmnd);

                /* The wd33c93 only knows about Group 0, 1, and 5 commands when
                 * it's doing a 'select-and-transfer'. To be safe, we write the
                 * size of the CDB into the OWN_ID register for every case. This
                 * way there won't be problems with vendor-unique, audio, etc.
                 */

                write_wd33c93(regs, WD_OWN_ID, cmd->cmd_len);

                /* When doing a non-disconnect command with DMA, we can save
                 * ourselves a DATA phase interrupt later by setting everything
                 * up ahead of time.
                 */

                if ((cmd->SCp.phase == 0) && (hostdata->no_dma == 0)) {
                        if (hostdata->dma_setup(cmd,
                            (cmd->sc_data_direction == DMA_TO_DEVICE) ?
                             DATA_OUT_DIR : DATA_IN_DIR))
                                write_wd33c93_count(regs, 0);   /* guarantee a DATA_PHASE interrupt */
                        else {
                                write_wd33c93_count(regs,
                                                    cmd->SCp.this_residual);
                                write_wd33c93(regs, WD_CONTROL,
                                              CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
                                hostdata->dma = D_DMA_RUNNING;
                        }
                } else
                        write_wd33c93_count(regs, 0);   /* guarantee a DATA_PHASE interrupt */

                hostdata->state = S_RUNNING_LEVEL2;
                write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
        }

        /*
         * Since the SCSI bus can handle only 1 connection at a time,
         * we get out of here now. If the selection fails, or when
         * the command disconnects, we'll come back to this routine
         * to search the input_Q again...
         */

        DB(DB_EXECUTE,
           printk("%s%ld)EX-2 ", (cmd->SCp.phase) ? "d:" : "", cmd->serial_number))
}

static void
transfer_pio(const wd33c93_regs regs, uchar * buf, int cnt,
             int data_in_dir, struct WD33C93_hostdata *hostdata)
{
        uchar asr;

        DB(DB_TRANSFER,
           printk("(%p,%d,%s:", buf, cnt, data_in_dir ? "in" : "out"))

        write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
        write_wd33c93_count(regs, cnt);
        write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
        if (data_in_dir) {
                do {
                        asr = read_aux_stat(regs);
                        if (asr & ASR_DBR)
                                *buf++ = read_wd33c93(regs, WD_DATA);
                } while (!(asr & ASR_INT));
        } else {
                do {
                        asr = read_aux_stat(regs);
                        if (asr & ASR_DBR)
                                write_wd33c93(regs, WD_DATA, *buf++);
                } while (!(asr & ASR_INT));
        }

        /* Note: we are returning with the interrupt UN-cleared.
         * Since (presumably) an entire I/O operation has
         * completed, the bus phase is probably different, and
         * the interrupt routine will discover this when it
         * responds to the uncleared int.
         */

}

static void
transfer_bytes(const wd33c93_regs regs, struct scsi_cmnd *cmd,
                int data_in_dir)
{
        struct WD33C93_hostdata *hostdata;
        unsigned long length;

        hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;

/* Normally, you'd expect 'this_residual' to be non-zero here.
 * In a series of scatter-gather transfers, however, this
 * routine will usually be called with 'this_residual' equal
 * to 0 and 'buffers_residual' non-zero. This means that a
 * previous transfer completed, clearing 'this_residual', and
 * now we need to setup the next scatter-gather buffer as the
 * source or destination for THIS transfer.
 */
        if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
                ++cmd->SCp.buffer;
                --cmd->SCp.buffers_residual;
                cmd->SCp.this_residual = cmd->SCp.buffer->length;
                cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
        }
        if (!cmd->SCp.this_residual) /* avoid bogus setups */
                return;

        write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
                      hostdata->sync_xfer[cmd->device->id]);

/* 'hostdata->no_dma' is TRUE if we don't even want to try DMA.
 * Update 'this_residual' and 'ptr' after 'transfer_pio()' returns.
 */

        if (hostdata->no_dma || hostdata->dma_setup(cmd, data_in_dir)) {
#ifdef PROC_STATISTICS
                hostdata->pio_cnt++;
#endif
                transfer_pio(regs, (uchar *) cmd->SCp.ptr,
                             cmd->SCp.this_residual, data_in_dir, hostdata);
                length = cmd->SCp.this_residual;
                cmd->SCp.this_residual = read_wd33c93_count(regs);
                cmd->SCp.ptr += (length - cmd->SCp.this_residual);
        }

/* We are able to do DMA (in fact, the Amiga hardware is
 * already going!), so start up the wd33c93 in DMA mode.
 * We set 'hostdata->dma' = D_DMA_RUNNING so that when the
 * transfer completes and causes an interrupt, we're
 * reminded to tell the Amiga to shut down its end. We'll
 * postpone the updating of 'this_residual' and 'ptr'
 * until then.
 */

        else {
#ifdef PROC_STATISTICS
                hostdata->dma_cnt++;
#endif
                write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
                write_wd33c93_count(regs, cmd->SCp.this_residual);

                if ((hostdata->level2 >= L2_DATA) ||
                    (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
                        write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
                        write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
                        hostdata->state = S_RUNNING_LEVEL2;
                } else
                        write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);

                hostdata->dma = D_DMA_RUNNING;
        }
}

void
wd33c93_intr(struct Scsi_Host *instance)
{
        struct WD33C93_hostdata *hostdata =
            (struct WD33C93_hostdata *) instance->hostdata;
        const wd33c93_regs regs = hostdata->regs;
        struct scsi_cmnd *patch, *cmd;
        uchar asr, sr, phs, id, lun, *ucp, msg;
        unsigned long length, flags;

        asr = read_aux_stat(regs);
        if (!(asr & ASR_INT) || (asr & ASR_BSY))
                return;

        spin_lock_irqsave(&hostdata->lock, flags);

#ifdef PROC_STATISTICS
        hostdata->int_cnt++;
#endif

        cmd = (struct scsi_cmnd *) hostdata->connected; /* assume we're connected */
        sr = read_wd33c93(regs, WD_SCSI_STATUS);        /* clear the interrupt */
        phs = read_wd33c93(regs, WD_COMMAND_PHASE);

        DB(DB_INTR, printk("{%02x:%02x-", asr, sr))

/* After starting a DMA transfer, the next interrupt
 * is guaranteed to be in response to completion of
 * the transfer. Since the Amiga DMA hardware runs in
 * in an open-ended fashion, it needs to be told when
 * to stop; do that here if D_DMA_RUNNING is true.
 * Also, we have to update 'this_residual' and 'ptr'
 * based on the contents of the TRANSFER_COUNT register,
 * in case the device decided to do an intermediate
 * disconnect (a device may do this if it has to do a
 * seek, or just to be nice and let other devices have
 * some bus time during long transfers). After doing
 * whatever is needed, we go on and service the WD3393
 * interrupt normally.
 */
            if (hostdata->dma == D_DMA_RUNNING) {
                DB(DB_TRANSFER,
                   printk("[%p/%d:", cmd->SCp.ptr, cmd->SCp.this_residual))
                    hostdata->dma_stop(cmd->device->host, cmd, 1);
                hostdata->dma = D_DMA_OFF;
                length = cmd->SCp.this_residual;
                cmd->SCp.this_residual = read_wd33c93_count(regs);
                cmd->SCp.ptr += (length - cmd->SCp.this_residual);
                DB(DB_TRANSFER,
                   printk("%p/%d]", cmd->SCp.ptr, cmd->SCp.this_residual))
        }

/* Respond to the specific WD3393 interrupt - there are quite a few! */
        switch (sr) {
        case CSR_TIMEOUT:
                DB(DB_INTR, printk("TIMEOUT"))

                    if (hostdata->state == S_RUNNING_LEVEL2)
                        hostdata->connected = NULL;
                else {
                        cmd = (struct scsi_cmnd *) hostdata->selecting; /* get a valid cmd */
                        hostdata->selecting = NULL;
                }

                cmd->result = DID_NO_CONNECT << 16;
                hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
                hostdata->state = S_UNCONNECTED;
                cmd->scsi_done(cmd);

                /* From esp.c:
                 * There is a window of time within the scsi_done() path
                 * of execution where interrupts are turned back on full
                 * blast and left that way.  During that time we could
                 * reconnect to a disconnected command, then we'd bomb
                 * out below.  We could also end up executing two commands
                 * at _once_.  ...just so you know why the restore_flags()
                 * is here...
                 */

                spin_unlock_irqrestore(&hostdata->lock, flags);

/* We are not connected to a target - check to see if there
 * are commands waiting to be executed.
 */

                wd33c93_execute(instance);
                break;

/* Note: this interrupt should not occur in a LEVEL2 command */

        case CSR_SELECT:
                DB(DB_INTR, printk("SELECT"))
                    hostdata->connected = cmd =
                    (struct scsi_cmnd *) hostdata->selecting;
                hostdata->selecting = NULL;

                /* construct an IDENTIFY message with correct disconnect bit */

                hostdata->outgoing_msg[0] = (0x80 | 0x00 | cmd->device->lun);
                if (cmd->SCp.phase)
                        hostdata->outgoing_msg[0] |= 0x40;

                if (hostdata->sync_stat[cmd->device->id] == SS_FIRST) {

                        hostdata->sync_stat[cmd->device->id] = SS_WAITING;

/* Tack on a 2nd message to ask about synchronous transfers. If we've
 * been asked to do only asynchronous transfers on this device, we
 * request a fifo depth of 0, which is equivalent to async - should
 * solve the problems some people have had with GVP's Guru ROM.
 */

                        hostdata->outgoing_msg[1] = EXTENDED_MESSAGE;
                        hostdata->outgoing_msg[2] = 3;
                        hostdata->outgoing_msg[3] = EXTENDED_SDTR;
                        if (hostdata->no_sync & (1 << cmd->device->id)) {
                                calc_sync_msg(hostdata->default_sx_per, 0,
                                                0, hostdata->outgoing_msg + 4);
                        } else {
                                calc_sync_msg(optimum_sx_per(hostdata),
                                                OPTIMUM_SX_OFF,
                                                hostdata->fast,
                                                hostdata->outgoing_msg + 4);
                        }
                        hostdata->outgoing_len = 6;
#ifdef SYNC_DEBUG
                        ucp = hostdata->outgoing_msg + 1;
                        printk(" sending SDTR %02x03%02x%02x%02x ",
                                ucp[0], ucp[2], ucp[3], ucp[4]);
#endif
                } else
                        hostdata->outgoing_len = 1;

                hostdata->state = S_CONNECTED;
                spin_unlock_irqrestore(&hostdata->lock, flags);
                break;

        case CSR_XFER_DONE | PHS_DATA_IN:
        case CSR_UNEXP | PHS_DATA_IN:
        case CSR_SRV_REQ | PHS_DATA_IN:
                DB(DB_INTR,
                   printk("IN-%d.%d", cmd->SCp.this_residual,
                          cmd->SCp.buffers_residual))
                    transfer_bytes(regs, cmd, DATA_IN_DIR);
                if (hostdata->state != S_RUNNING_LEVEL2)
                        hostdata->state = S_CONNECTED;
                spin_unlock_irqrestore(&hostdata->lock, flags);
                break;

        case CSR_XFER_DONE | PHS_DATA_OUT:
        case CSR_UNEXP | PHS_DATA_OUT:
        case CSR_SRV_REQ | PHS_DATA_OUT:
                DB(DB_INTR,
                   printk("OUT-%d.%d", cmd->SCp.this_residual,
                          cmd->SCp.buffers_residual))
                    transfer_bytes(regs, cmd, DATA_OUT_DIR);
                if (hostdata->state != S_RUNNING_LEVEL2)
                        hostdata->state = S_CONNECTED;
                spin_unlock_irqrestore(&hostdata->lock, flags);
                break;

/* Note: this interrupt should not occur in a LEVEL2 command */

        case CSR_XFER_DONE | PHS_COMMAND:
        case CSR_UNEXP | PHS_COMMAND:
        case CSR_SRV_REQ | PHS_COMMAND:
                DB(DB_INTR, printk("CMND-%02x,%ld", cmd->cmnd[0], cmd->serial_number))
                    transfer_pio(regs, cmd->cmnd, cmd->cmd_len, DATA_OUT_DIR,
                                 hostdata);
                hostdata->state = S_CONNECTED;
                spin_unlock_irqrestore(&hostdata->lock, flags);
                break;

        case CSR_XFER_DONE | PHS_STATUS:
        case CSR_UNEXP | PHS_STATUS:
        case CSR_SRV_REQ | PHS_STATUS:
                DB(DB_INTR, printk("STATUS="))
                cmd->SCp.Status = read_1_byte(regs);
                DB(DB_INTR, printk("%02x", cmd->SCp.Status))
                    if (hostdata->level2 >= L2_BASIC) {
                        sr = read_wd33c93(regs, WD_SCSI_STATUS);        /* clear interrupt */
                        udelay(7);
                        hostdata->state = S_RUNNING_LEVEL2;
                        write_wd33c93(regs, WD_COMMAND_PHASE, 0x50);
                        write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
                } else {
                        hostdata->state = S_CONNECTED;
                }
                spin_unlock_irqrestore(&hostdata->lock, flags);
                break;

        case CSR_XFER_DONE | PHS_MESS_IN:
        case CSR_UNEXP | PHS_MESS_IN:
        case CSR_SRV_REQ | PHS_MESS_IN:
                DB(DB_INTR, printk("MSG_IN="))

                msg = read_1_byte(regs);
                sr = read_wd33c93(regs, WD_SCSI_STATUS);        /* clear interrupt */
                udelay(7);

                hostdata->incoming_msg[hostdata->incoming_ptr] = msg;
                if (hostdata->incoming_msg[0] == EXTENDED_MESSAGE)
                        msg = EXTENDED_MESSAGE;
                else
                        hostdata->incoming_ptr = 0;

                cmd->SCp.Message = msg;
                switch (msg) {

                case COMMAND_COMPLETE:
                        DB(DB_INTR, printk("CCMP-%ld", cmd->serial_number))
                            write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
                        hostdata->state = S_PRE_CMP_DISC;
                        break;

                case SAVE_POINTERS:
                        DB(DB_INTR, printk("SDP"))
                            write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
                        hostdata->state = S_CONNECTED;
                        break;

                case RESTORE_POINTERS:
                        DB(DB_INTR, printk("RDP"))
                            if (hostdata->level2 >= L2_BASIC) {
                                write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
                                write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
                                hostdata->state = S_RUNNING_LEVEL2;
                        } else {
                                write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
                                hostdata->state = S_CONNECTED;
                        }
                        break;

                case DISCONNECT:
                        DB(DB_INTR, printk("DIS"))
                            cmd->device->disconnect = 1;
                        write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
                        hostdata->state = S_PRE_TMP_DISC;
                        break;

                case MESSAGE_REJECT:
                        DB(DB_INTR, printk("REJ"))
#ifdef SYNC_DEBUG
                            printk("-REJ-");
#endif
                        if (hostdata->sync_stat[cmd->device->id] == SS_WAITING) {
                                hostdata->sync_stat[cmd->device->id] = SS_SET;
                                /* we want default_sx_per, not DEFAULT_SX_PER */
                                hostdata->sync_xfer[cmd->device->id] =
                                        calc_sync_xfer(hostdata->default_sx_per
                                                / 4, 0, 0, hostdata->sx_table);
                        }
                        write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
                        hostdata->state = S_CONNECTED;
                        break;

                case EXTENDED_MESSAGE:
                        DB(DB_INTR, printk("EXT"))

                            ucp = hostdata->incoming_msg;

#ifdef SYNC_DEBUG
                        printk("%02x", ucp[hostdata->incoming_ptr]);
#endif
                        /* Is this the last byte of the extended message? */

                        if ((hostdata->incoming_ptr >= 2) &&
                            (hostdata->incoming_ptr == (ucp[1] + 1))) {

                                switch (ucp[2]) {       /* what's the EXTENDED code? */
                                case EXTENDED_SDTR:
                                        /* default to default async period */
                                        id = calc_sync_xfer(hostdata->
                                                        default_sx_per / 4, 0,
                                                        0, hostdata->sx_table);
                                        if (hostdata->sync_stat[cmd->device->id] !=
                                            SS_WAITING) {

/* A device has sent an unsolicited SDTR message; rather than go
 * through the effort of decoding it and then figuring out what
 * our reply should be, we're just gonna say that we have a
 * synchronous fifo depth of 0. This will result in asynchronous
 * transfers - not ideal but so much easier.
 * Actually, this is OK because it assures us that if we don't
 * specifically ask for sync transfers, we won't do any.
 */

                                                write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);     /* want MESS_OUT */
                                                hostdata->outgoing_msg[0] =
                                                    EXTENDED_MESSAGE;
                                                hostdata->outgoing_msg[1] = 3;
                                                hostdata->outgoing_msg[2] =
                                                    EXTENDED_SDTR;
                                                calc_sync_msg(hostdata->
                                                        default_sx_per, 0,
                                                        0, hostdata->outgoing_msg + 3);
                                                hostdata->outgoing_len = 5;
                                        } else {
                                                if (ucp[4]) /* well, sync transfer */
                                                        id = calc_sync_xfer(ucp[3], ucp[4],
                                                                        hostdata->fast,
                                                                        hostdata->sx_table);
                                                else if (ucp[3]) /* very unlikely... */
                                                        id = calc_sync_xfer(ucp[3], ucp[4],
                                                                        0, hostdata->sx_table);
                                        }
                                        hostdata->sync_xfer[cmd->device->id] = id;
#ifdef SYNC_DEBUG
                                        printk(" sync_xfer=%02x\n",
                                               hostdata->sync_xfer[cmd->device->id]);
#endif
                                        hostdata->sync_stat[cmd->device->id] =
                                            SS_SET;
                                        write_wd33c93_cmd(regs,
                                                          WD_CMD_NEGATE_ACK);
                                        hostdata->state = S_CONNECTED;
                                        break;
                                case EXTENDED_WDTR:
                                        write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);     /* want MESS_OUT */
                                        printk("sending WDTR ");
                                        hostdata->outgoing_msg[0] =
                                            EXTENDED_MESSAGE;
                                        hostdata->outgoing_msg[1] = 2;
                                        hostdata->outgoing_msg[2] =
                                            EXTENDED_WDTR;
                                        hostdata->outgoing_msg[3] = 0;  /* 8 bit transfer width */
                                        hostdata->outgoing_len = 4;
                                        write_wd33c93_cmd(regs,
                                                          WD_CMD_NEGATE_ACK);
                                        hostdata->state = S_CONNECTED;
                                        break;
                                default:
                                        write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);     /* want MESS_OUT */
                                        printk
                                            ("Rejecting Unknown Extended Message(%02x). ",
                                             ucp[2]);
                                        hostdata->outgoing_msg[0] =
                                            MESSAGE_REJECT;
                                        hostdata->outgoing_len = 1;
                                        write_wd33c93_cmd(regs,
                                                          WD_CMD_NEGATE_ACK);
                                        hostdata->state = S_CONNECTED;
                                        break;
                                }
                                hostdata->incoming_ptr = 0;
                        }

                        /* We need to read more MESS_IN bytes for the extended message */

                        else {
                                hostdata->incoming_ptr++;
                                write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
                                hostdata->state = S_CONNECTED;
                        }
                        break;

                default:
                        printk("Rejecting Unknown Message(%02x) ", msg);
                        write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);     /* want MESS_OUT */
                        hostdata->outgoing_msg[0] = MESSAGE_REJECT;
                        hostdata->outgoing_len = 1;
                        write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
                        hostdata->state = S_CONNECTED;
                }
                spin_unlock_irqrestore(&hostdata->lock, flags);
                break;

/* Note: this interrupt will occur only after a LEVEL2 command */

        case CSR_SEL_XFER_DONE:

/* Make sure that reselection is enabled at this point - it may
 * have been turned off for the command that just completed.
 */

                write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
                if (phs == 0x60) {
                        DB(DB_INTR, printk("SX-DONE-%ld", cmd->serial_number))
                            cmd->SCp.Message = COMMAND_COMPLETE;
                        lun = read_wd33c93(regs, WD_TARGET_LUN);
                        DB(DB_INTR, printk(":%d.%d", cmd->SCp.Status, lun))
                            hostdata->connected = NULL;
                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
                        hostdata->state = S_UNCONNECTED;
                        if (cmd->SCp.Status == ILLEGAL_STATUS_BYTE)
                                cmd->SCp.Status = lun;
                        if (cmd->cmnd[0] == REQUEST_SENSE
                            && cmd->SCp.Status != GOOD)
                                cmd->result =
                                    (cmd->
                                     result & 0x00ffff) | (DID_ERROR << 16);
                        else
                                cmd->result =
                                    cmd->SCp.Status | (cmd->SCp.Message << 8);
                        cmd->scsi_done(cmd);

/* We are no longer  connected to a target - check to see if
 * there are commands waiting to be executed.
 */
                        spin_unlock_irqrestore(&hostdata->lock, flags);
                        wd33c93_execute(instance);
                } else {
                        printk
                            ("%02x:%02x:%02x-%ld: Unknown SEL_XFER_DONE phase!!---",
                             asr, sr, phs, cmd->serial_number);
                        spin_unlock_irqrestore(&hostdata->lock, flags);
                }
                break;

/* Note: this interrupt will occur only after a LEVEL2 command */

        case CSR_SDP:
                DB(DB_INTR, printk("SDP"))
                    hostdata->state = S_RUNNING_LEVEL2;
                write_wd33c93(regs, WD_COMMAND_PHASE, 0x41);
                write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
                spin_unlock_irqrestore(&hostdata->lock, flags);
                break;

        case CSR_XFER_DONE | PHS_MESS_OUT:
        case CSR_UNEXP | PHS_MESS_OUT:
        case CSR_SRV_REQ | PHS_MESS_OUT:
                DB(DB_INTR, printk("MSG_OUT="))

/* To get here, we've probably requested MESSAGE_OUT and have
 * already put the correct bytes in outgoing_msg[] and filled
 * in outgoing_len. We simply send them out to the SCSI bus.
 * Sometimes we get MESSAGE_OUT phase when we're not expecting
 * it - like when our SDTR message is rejected by a target. Some
 * targets send the REJECT before receiving all of the extended
 * message, and then seem to go back to MESSAGE_OUT for a byte
 * or two. Not sure why, or if I'm doing something wrong to
 * cause this to happen. Regardless, it seems that sending
 * NOP messages in these situations results in no harm and
 * makes everyone happy.
 */
                    if (hostdata->outgoing_len == 0) {
                        hostdata->outgoing_len = 1;
                        hostdata->outgoing_msg[0] = NOP;
                }
                transfer_pio(regs, hostdata->outgoing_msg,
                             hostdata->outgoing_len, DATA_OUT_DIR, hostdata);
                DB(DB_INTR, printk("%02x", hostdata->outgoing_msg[0]))
                    hostdata->outgoing_len = 0;
                hostdata->state = S_CONNECTED;
                spin_unlock_irqrestore(&hostdata->lock, flags);
                break;

        case CSR_UNEXP_DISC:

/* I think I've seen this after a request-sense that was in response
 * to an error condition, but not sure. We certainly need to do
 * something when we get this interrupt - the question is 'what?'.
 * Let's think positively, and assume some command has finished
 * in a legal manner (like a command that provokes a request-sense),
 * so we treat it as a normal command-complete-disconnect.
 */

/* Make sure that reselection is enabled at this point - it may
 * have been turned off for the command that just completed.
 */

                write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
                if (cmd == NULL) {
                        printk(" - Already disconnected! ");
                        hostdata->state = S_UNCONNECTED;
                        spin_unlock_irqrestore(&hostdata->lock, flags);
                        return;
                }
                DB(DB_INTR, printk("UNEXP_DISC-%ld", cmd->serial_number))
                    hostdata->connected = NULL;
                hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
                hostdata->state = S_UNCONNECTED;
                if (cmd->cmnd[0] == REQUEST_SENSE && cmd->SCp.Status != GOOD)
                        cmd->result =
                            (cmd->result & 0x00ffff) | (DID_ERROR << 16);
                else
                        cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
                cmd->scsi_done(cmd);

/* We are no longer connected to a target - check to see if
 * there are commands waiting to be executed.
 */
                /* look above for comments on scsi_done() */
                spin_unlock_irqrestore(&hostdata->lock, flags);
                wd33c93_execute(instance);
                break;

        case CSR_DISC:

/* Make sure that reselection is enabled at this point - it may
 * have been turned off for the command that just completed.
 */

                write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
                DB(DB_INTR, printk("DISC-%ld", cmd->serial_number))
                    if (cmd == NULL) {
                        printk(" - Already disconnected! ");
                        hostdata->state = S_UNCONNECTED;
                }
                switch (hostdata->state) {
                case S_PRE_CMP_DISC:
                        hostdata->connected = NULL;
                        hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
                        hostdata->state = S_UNCONNECTED;
                        DB(DB_INTR, printk(":%d", cmd->SCp.Status))
                            if (cmd->cmnd[0] == REQUEST_SENSE
                                && cmd->SCp.Status != GOOD)
                                cmd->result =
                                    (cmd->
                                     result & 0x00ffff) | (DID_ERROR << 16);
                        else
                                cmd->result =
                                    cmd->SCp.Status | (cmd->SCp.Message << 8);
                        cmd->scsi_done(cmd);
                        break;
                case S_PRE_TMP_DISC:
                case S_RUNNING_LEVEL2:
                        cmd->host_scribble = (uchar *) hostdata->disconnected_Q;
                        hostdata->disconnected_Q = cmd;
                        hostdata->connected = NULL;
                        hostdata->state = S_UNCONNECTED;

#ifdef PROC_STATISTICS
                        hostdata->disc_done_cnt[cmd->device->id]++;
#endif

                        break;
                default:
                        printk("*** Unexpected DISCONNECT interrupt! ***");
                        hostdata->state = S_UNCONNECTED;
                }

/* We are no longer connected to a target - check to see if
 * there are commands waiting to be executed.
 */
                spin_unlock_irqrestore(&hostdata->lock, flags);
                wd33c93_execute(instance);
                break;

        case CSR_RESEL_AM:
        case CSR_RESEL:
                DB(DB_INTR, printk("RESEL%s", sr == CSR_RESEL_AM ? "_AM" : ""))

                    /* Old chips (pre -A ???) don't have advanced features and will
                     * generate CSR_RESEL.  In that case we have to extract the LUN the
                     * hard way (see below).
                     * First we have to make sure this reselection didn't
                     * happen during Arbitration/Selection of some other device.
                     * If yes, put losing command back on top of input_Q.
                     */
                    if (hostdata->level2 <= L2_NONE) {

                        if (hostdata->selecting) {
                                cmd = (struct scsi_cmnd *) hostdata->selecting;
                                hostdata->selecting = NULL;
                                hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
                                cmd->host_scribble =
                                    (uchar *) hostdata->input_Q;
                                hostdata->input_Q = cmd;
                        }
                }

                else {

                        if (cmd) {
                                if (phs == 0x00) {
                                        hostdata->busy[cmd->device->id] &=
                                            ~(1 << cmd->device->lun);
                                        cmd->host_scribble =
                                            (uchar *) hostdata->input_Q;
                                        hostdata->input_Q = cmd;
                                } else {
                                        printk
                                            ("---%02x:%02x:%02x-TROUBLE: Intrusive ReSelect!---",
                                             asr, sr, phs);
                                        while (1)
                                                printk("\r");
                                }
                        }

                }

                /* OK - find out which device reselected us. */

                id = read_wd33c93(regs, WD_SOURCE_ID);
                id &= SRCID_MASK;

                /* and extract the lun from the ID message. (Note that we don't
                 * bother to check for a valid message here - I guess this is
                 * not the right way to go, but...)
                 */

                if (sr == CSR_RESEL_AM) {
                        lun = read_wd33c93(regs, WD_DATA);
                        if (hostdata->level2 < L2_RESELECT)
                                write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
                        lun &= 7;
                } else {
                        /* Old chip; wait for msgin phase to pick up the LUN. */
                        for (lun = 255; lun; lun--) {
                                if ((asr = read_aux_stat(regs)) & ASR_INT)
                                        break;
                                udelay(10);
                        }
                        if (!(asr & ASR_INT)) {
                                printk
                                    ("wd33c93: Reselected without IDENTIFY\n");
                                lun = 0;
                        } else {
                                /* Verify this is a change to MSG_IN and read the message */
                                sr = read_wd33c93(regs, WD_SCSI_STATUS);
                                udelay(7);
                                if (sr == (CSR_ABORT | PHS_MESS_IN) ||
                                    sr == (CSR_UNEXP | PHS_MESS_IN) ||
                                    sr == (CSR_SRV_REQ | PHS_MESS_IN)) {
                                        /* Got MSG_IN, grab target LUN */
                                        lun = read_1_byte(regs);
                                        /* Now we expect a 'paused with ACK asserted' int.. */
                                        asr = read_aux_stat(regs);
                                        if (!(asr & ASR_INT)) {
                                                udelay(10);
                                                asr = read_aux_stat(regs);
                                                if (!(asr & ASR_INT))
                                                        printk
                                                            ("wd33c93: No int after LUN on RESEL (%02x)\n",
                                                             asr);
                                        }
                                        sr = read_wd33c93(regs, WD_SCSI_STATUS);
                                        udelay(7);
                                        if (sr != CSR_MSGIN)
                                                printk
                                                    ("wd33c93: Not paused with ACK on RESEL (%02x)\n",
                                                     sr);
                                        lun &= 7;
                                        write_wd33c93_cmd(regs,
                                                          WD_CMD_NEGATE_ACK);
                                } else {
                                        printk
                                            ("wd33c93: Not MSG_IN on reselect (%02x)\n",
                                             sr);
                                        lun = 0;
                                }
                        }
                }

                /* Now we look for the command that's reconnecting. */

                cmd = (struct scsi_cmnd *) hostdata->disconnected_Q;
                patch = NULL;
                while (cmd) {
                        if (id == cmd->device->id && lun == cmd->device->lun)
                                break;
                        patch = cmd;
                        cmd = (struct scsi_cmnd *) cmd->host_scribble;
                }

                /* Hmm. Couldn't find a valid command.... What to do? */

                if (!cmd) {
                        printk
                            ("---TROUBLE: target %d.%d not in disconnect queue---",
                             id, lun);
                        spin_unlock_irqrestore(&hostdata->lock, flags);
                        return;
                }

                /* Ok, found the command - now start it up again. */

                if (patch)
                        patch->host_scribble = cmd->host_scribble;
                else
                        hostdata->disconnected_Q =
                            (struct scsi_cmnd *) cmd->host_scribble;
                hostdata->connected = cmd;

                /* We don't need to worry about 'initialize_SCp()' or 'hostdata->busy[]'
                 * because these things are preserved over a disconnect.
                 * But we DO need to fix the DPD bit so it's correct for this command.
                 */

                if (cmd->sc_data_direction == DMA_TO_DEVICE)
                        write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
                else
                        write_wd33c93(regs, WD_DESTINATION_ID,
                                      cmd->device->id | DSTID_DPD);
                if (hostdata->level2 >= L2_RESELECT) {
                        write_wd33c93_count(regs, 0);   /* we want a DATA_PHASE interrupt */
                        write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
                        write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
                        hostdata->state = S_RUNNING_LEVEL2;
                } else
                        hostdata->state = S_CONNECTED;

                DB(DB_INTR, printk("-%ld", cmd->serial_number))
                    spin_unlock_irqrestore(&hostdata->lock, flags);
                break;

        default:
                printk("--UNKNOWN INTERRUPT:%02x:%02x:%02x--", asr, sr, phs);
                spin_unlock_irqrestore(&hostdata->lock, flags);
        }

        DB(DB_INTR, printk("} "))

}

static void
reset_wd33c93(struct Scsi_Host *instance)
{
        struct WD33C93_hostdata *hostdata =
            (struct WD33C93_hostdata *) instance->hostdata;
        const wd33c93_regs regs = hostdata->regs;
        uchar sr;

#ifdef CONFIG_SGI_IP22
        {
                int busycount = 0;
                extern void sgiwd93_reset(unsigned long);
                /* wait 'til the chip gets some time for us */
                while ((read_aux_stat(regs) & ASR_BSY) && busycount++ < 100)
                        udelay (10);
        /*
         * there are scsi devices out there, which manage to lock up
         * the wd33c93 in a busy condition. In this state it won't
         * accept the reset command. The only way to solve this is to
         * give the chip a hardware reset (if possible). The code below
         * does this for the SGI Indy, where this is possible
         */
        /* still busy ? */
        if (read_aux_stat(regs) & ASR_BSY)
                sgiwd93_reset(instance->base); /* yeah, give it the hard one */
        }
#endif

        write_wd33c93(regs, WD_OWN_ID, OWNID_EAF | OWNID_RAF |
                      instance->this_id | hostdata->clock_freq);
        write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
        write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
                      calc_sync_xfer(hostdata->default_sx_per / 4,
                                     DEFAULT_SX_OFF, 0, hostdata->sx_table));
        write_wd33c93(regs, WD_COMMAND, WD_CMD_RESET);


#ifdef CONFIG_MVME147_SCSI
        udelay(25);             /* The old wd33c93 on MVME147 needs this, at least */
#endif

        while (!(read_aux_stat(regs) & ASR_INT))
                ;
        sr = read_wd33c93(regs, WD_SCSI_STATUS);

        hostdata->microcode = read_wd33c93(regs, WD_CDB_1);
        if (sr == 0x00)
                hostdata->chip = C_WD33C93;
        else if (sr == 0x01) {
                write_wd33c93(regs, WD_QUEUE_TAG, 0xa5);        /* any random number */
                sr = read_wd33c93(regs, WD_QUEUE_TAG);
                if (sr == 0xa5) {
                        hostdata->chip = C_WD33C93B;
                        write_wd33c93(regs, WD_QUEUE_TAG, 0);
                } else
                        hostdata->chip = C_WD33C93A;
        } else
                hostdata->chip = C_UNKNOWN_CHIP;

        if (hostdata->chip != C_WD33C93B)       /* Fast SCSI unavailable */
                hostdata->fast = 0;

        write_wd33c93(regs, WD_TIMEOUT_PERIOD, TIMEOUT_PERIOD_VALUE);
        write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
}

int
wd33c93_host_reset(struct scsi_cmnd * SCpnt)
{
        struct Scsi_Host *instance;
        struct WD33C93_hostdata *hostdata;
        int i;

        instance = SCpnt->device->host;
        hostdata = (struct WD33C93_hostdata *) instance->hostdata;

        printk("scsi%d: reset. ", instance->host_no);
        disable_irq(instance->irq);

        hostdata->dma_stop(instance, NULL, 0);
        for (i = 0; i < 8; i++) {
                hostdata->busy[i] = 0;
                hostdata->sync_xfer[i] =
                        calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
                                        0, hostdata->sx_table);
                hostdata->sync_stat[i] = SS_UNSET;      /* using default sync values */
        }
        hostdata->input_Q = NULL;
        hostdata->selecting = NULL;
        hostdata->connected = NULL;
        hostdata->disconnected_Q = NULL;
        hostdata->state = S_UNCONNECTED;
        hostdata->dma = D_DMA_OFF;
        hostdata->incoming_ptr = 0;
        hostdata->outgoing_len = 0;

        reset_wd33c93(instance);
        SCpnt->result = DID_RESET << 16;
        enable_irq(instance->irq);
        return SUCCESS;
}

int
wd33c93_abort(struct scsi_cmnd * cmd)
{
        struct Scsi_Host *instance;
        struct WD33C93_hostdata *hostdata;
        wd33c93_regs regs;
        struct scsi_cmnd *tmp, *prev;

        disable_irq(cmd->device->host->irq);

        instance = cmd->device->host;
        hostdata = (struct WD33C93_hostdata *) instance->hostdata;
        regs = hostdata->regs;

/*
 * Case 1 : If the command hasn't been issued yet, we simply remove it
 *     from the input_Q.
 */

        tmp = (struct scsi_cmnd *) hostdata->input_Q;
        prev = NULL;
        while (tmp) {
                if (tmp == cmd) {
                        if (prev)
                                prev->host_scribble = cmd->host_scribble;
                        else
                                hostdata->input_Q =
                                    (struct scsi_cmnd *) cmd->host_scribble;
                        cmd->host_scribble = NULL;
                        cmd->result = DID_ABORT << 16;
                        printk
                            ("scsi%d: Abort - removing command %ld from input_Q. ",
                             instance->host_no, cmd->serial_number);
                        enable_irq(cmd->device->host->irq);
                        cmd->scsi_done(cmd);
                        return SUCCESS;
                }
                prev = tmp;
                tmp = (struct scsi_cmnd *) tmp->host_scribble;
        }

/*
 * Case 2 : If the command is connected, we're going to fail the abort
 *     and let the high level SCSI driver retry at a later time or
 *     issue a reset.
 *
 *     Timeouts, and therefore aborted commands, will be highly unlikely
 *     and handling them cleanly in this situation would make the common
 *     case of noresets less efficient, and would pollute our code.  So,
 *     we fail.
 */

        if (hostdata->connected == cmd) {
                uchar sr, asr;
                unsigned long timeout;

                printk("scsi%d: Aborting connected command %ld - ",
                       instance->host_no, cmd->serial_number);

                printk("stopping DMA - ");
                if (hostdata->dma == D_DMA_RUNNING) {
                        hostdata->dma_stop(instance, cmd, 0);
                        hostdata->dma = D_DMA_OFF;
                }

                printk("sending wd33c93 ABORT command - ");
                write_wd33c93(regs, WD_CONTROL,
                              CTRL_IDI | CTRL_EDI | CTRL_POLLED);
                write_wd33c93_cmd(regs, WD_CMD_ABORT);

/* Now we have to attempt to flush out the FIFO... */

                printk("flushing fifo - ");
                timeout = 1000000;
                do {
                        asr = read_aux_stat(regs);
                        if (asr & ASR_DBR)
                                read_wd33c93(regs, WD_DATA);
                } while (!(asr & ASR_INT) && timeout-- > 0);
                sr = read_wd33c93(regs, WD_SCSI_STATUS);
                printk
                    ("asr=%02x, sr=%02x, %ld bytes un-transferred (timeout=%ld) - ",
                     asr, sr, read_wd33c93_count(regs), timeout);

                /*
                 * Abort command processed.
                 * Still connected.
                 * We must disconnect.
                 */

                printk("sending wd33c93 DISCONNECT command - ");
                write_wd33c93_cmd(regs, WD_CMD_DISCONNECT);

                timeout = 1000000;
                asr = read_aux_stat(regs);
                while ((asr & ASR_CIP) && timeout-- > 0)
                        asr = read_aux_stat(regs);
                sr = read_wd33c93(regs, WD_SCSI_STATUS);
                printk("asr=%02x, sr=%02x.", asr, sr);

                hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
                hostdata->connected = NULL;
                hostdata->state = S_UNCONNECTED;
                cmd->result = DID_ABORT << 16;

/*      sti();*/
                wd33c93_execute(instance);

                enable_irq(cmd->device->host->irq);
                cmd->scsi_done(cmd);
                return SUCCESS;
        }

/*
 * Case 3: If the command is currently disconnected from the bus,
 * we're not going to expend much effort here: Let's just return
 * an ABORT_SNOOZE and hope for the best...
 */

        tmp = (struct scsi_cmnd *) hostdata->disconnected_Q;
        while (tmp) {
                if (tmp == cmd) {
                        printk
                            ("scsi%d: Abort - command %ld found on disconnected_Q - ",
                             instance->host_no, cmd->serial_number);
                        printk("Abort SNOOZE. ");
                        enable_irq(cmd->device->host->irq);
                        return FAILED;
                }
                tmp = (struct scsi_cmnd *) tmp->host_scribble;
        }

/*
 * Case 4 : If we reached this point, the command was not found in any of
 *     the queues.
 *
 * We probably reached this point because of an unlikely race condition
 * between the command completing successfully and the abortion code,
 * so we won't panic, but we will notify the user in case something really
 * broke.
 */

/*   sti();*/
        wd33c93_execute(instance);

        enable_irq(cmd->device->host->irq);
        printk("scsi%d: warning : SCSI command probably completed successfully"
               "         before abortion. ", instance->host_no);
        return FAILED;
}

#define MAX_WD33C93_HOSTS 4
#define MAX_SETUP_ARGS ARRAY_SIZE(setup_args)
#define SETUP_BUFFER_SIZE 200
static char setup_buffer[SETUP_BUFFER_SIZE];
static char setup_used[MAX_SETUP_ARGS];
static int done_setup = 0;

static int
wd33c93_setup(char *str)
{
        int i;
        char *p1, *p2;

        /* The kernel does some processing of the command-line before calling
         * this function: If it begins with any decimal or hex number arguments,
         * ints[0] = how many numbers found and ints[1] through [n] are the values
         * themselves. str points to where the non-numeric arguments (if any)
         * start: We do our own parsing of those. We construct synthetic 'nosync'
         * keywords out of numeric args (to maintain compatibility with older
         * versions) and then add the rest of the arguments.
         */

        p1 = setup_buffer;
        *p1 = '\0';
        if (str)
                strncpy(p1, str, SETUP_BUFFER_SIZE - strlen(setup_buffer));
        setup_buffer[SETUP_BUFFER_SIZE - 1] = '\0';
        p1 = setup_buffer;
        i = 0;
        while (*p1 && (i < MAX_SETUP_ARGS)) {
                p2 = strchr(p1, ',');
                if (p2) {
                        *p2 = '\0';
                        if (p1 != p2)
                                setup_args[i] = p1;
                        p1 = p2 + 1;
                        i++;
                } else {
                        setup_args[i] = p1;
                        break;
                }
        }
        for (i = 0; i < MAX_SETUP_ARGS; i++)
                setup_used[i] = 0;
        done_setup = 1;

        return 1;
}
__setup("wd33c93=", wd33c93_setup);

/* check_setup_args() returns index if key found, 0 if not
 */
static int
check_setup_args(char *key, int *flags, int *val, char *buf)
{
        int x;
        char *cp;

        for (x = 0; x < MAX_SETUP_ARGS; x++) {
                if (setup_used[x])
                        continue;
                if (!strncmp(setup_args[x], key, strlen(key)))
                        break;
                if (!strncmp(setup_args[x], "next", strlen("next")))
                        return 0;
        }
        if (x == MAX_SETUP_ARGS)
                return 0;
        setup_used[x] = 1;
        cp = setup_args[x] + strlen(key);
        *val = -1;
        if (*cp != ':')
                return ++x;
        cp++;
        if ((*cp >= '0') && (*cp <= '9')) {
                *val = simple_strtoul(cp, NULL, 0);
        }
        return ++x;
}

/*
 * Calculate internal data-transfer-clock cycle from input-clock
 * frequency (/MHz) and fill 'sx_table'.
 *
 * The original driver used to rely on a fixed sx_table, containing periods
 * for (only) the lower limits of the respective input-clock-frequency ranges
 * (8-10/12-15/16-20 MHz). Although it seems, that no problems ocurred with
 * this setting so far, it might be desirable to adjust the transfer periods
 * closer to the really attached, possibly 25% higher, input-clock, since
 * - the wd33c93 may really use a significant shorter period, than it has
 *   negotiated (eg. thrashing the target, which expects 4/8MHz, with 5/10MHz
 *   instead).
 * - the wd33c93 may ask the target for a lower transfer rate, than the target
 *   is capable of (eg. negotiating for an assumed minimum of 252ns instead of
 *   possible 200ns, which indeed shows up in tests as an approx. 10% lower
 *   transfer rate).
 */
static inline unsigned int
round_4(unsigned int x)
{
        switch (x & 3) {
                case 1: --x;
                        break;
                case 2: ++x;
                case 3: ++x;
        }
        return x;
}

static void
calc_sx_table(unsigned int mhz, struct sx_period sx_table[9])
{
        unsigned int d, i;
        if (mhz < 11)
                d = 2;  /* divisor for  8-10 MHz input-clock */
        else if (mhz < 16)
                d = 3;  /* divisor for 12-15 MHz input-clock */
        else
                d = 4;  /* divisor for 16-20 MHz input-clock */

        d = (100000 * d) / 2 / mhz; /* 100 x DTCC / nanosec */

        sx_table[0].period_ns = 1;
        sx_table[0].reg_value = 0x20;
        for (i = 1; i < 8; i++) {
                sx_table[i].period_ns = round_4((i+1)*d / 100);
                sx_table[i].reg_value = (i+1)*0x10;
        }
        sx_table[7].reg_value = 0;
        sx_table[8].period_ns = 0;
        sx_table[8].reg_value = 0;
}

/*
 * check and, maybe, map an init- or "clock:"- argument.
 */
static uchar
set_clk_freq(int freq, int *mhz)
{
        int x = freq;
        if (WD33C93_FS_8_10 == freq)
                freq = 8;
        else if (WD33C93_FS_12_15 == freq)
                freq = 12;
        else if (WD33C93_FS_16_20 == freq)
                freq = 16;
        else if (freq > 7 && freq < 11)
                x = WD33C93_FS_8_10;
                else if (freq > 11 && freq < 16)
                x = WD33C93_FS_12_15;
                else if (freq > 15 && freq < 21)
                x = WD33C93_FS_16_20;
        else {
                        /* Hmm, wouldn't it be safer to assume highest freq here? */
                x = WD33C93_FS_8_10;
                freq = 8;
        }
        *mhz = freq;
        return x;
}

/*
 * to be used with the resync: fast: ... options
 */
static inline void set_resync ( struct WD33C93_hostdata *hd, int mask )
{
        int i;
        for (i = 0; i < 8; i++)
                if (mask & (1 << i))
                        hd->sync_stat[i] = SS_UNSET;
}

void
wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
             dma_setup_t setup, dma_stop_t stop, int clock_freq)
{
        struct WD33C93_hostdata *hostdata;
        int i;
        int flags;
        int val;
        char buf[32];

        if (!done_setup && setup_strings)
                wd33c93_setup(setup_strings);

        hostdata = (struct WD33C93_hostdata *) instance->hostdata;

        hostdata->regs = regs;
        hostdata->clock_freq = set_clk_freq(clock_freq, &i);
        calc_sx_table(i, hostdata->sx_table);
        hostdata->dma_setup = setup;
        hostdata->dma_stop = stop;
        hostdata->dma_bounce_buffer = NULL;
        hostdata->dma_bounce_len = 0;
        for (i = 0; i < 8; i++) {
                hostdata->busy[i] = 0;
                hostdata->sync_xfer[i] =
                        calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
                                        0, hostdata->sx_table);
                hostdata->sync_stat[i] = SS_UNSET;      /* using default sync values */
#ifdef PROC_STATISTICS
                hostdata->cmd_cnt[i] = 0;
                hostdata->disc_allowed_cnt[i] = 0;
                hostdata->disc_done_cnt[i] = 0;
#endif
        }
        hostdata->input_Q = NULL;
        hostdata->selecting = NULL;
        hostdata->connected = NULL;
        hostdata->disconnected_Q = NULL;
        hostdata->state = S_UNCONNECTED;
        hostdata->dma = D_DMA_OFF;
        hostdata->level2 = L2_BASIC;
        hostdata->disconnect = DIS_ADAPTIVE;
        hostdata->args = DEBUG_DEFAULTS;
        hostdata->incoming_ptr = 0;
        hostdata->outgoing_len = 0;
        hostdata->default_sx_per = DEFAULT_SX_PER;
        hostdata->no_sync = 0xff;       /* sync defaults to off */
        hostdata->no_dma = 0;   /* default is DMA enabled */
        hostdata->fast = 0;     /* default is Fast SCSI transfers disabled */
        hostdata->dma_mode = CTRL_DMA;  /* default is Single Byte DMA */

#ifdef PROC_INTERFACE
        hostdata->proc = PR_VERSION | PR_INFO | PR_STATISTICS |
            PR_CONNECTED | PR_INPUTQ | PR_DISCQ | PR_STOP;
#ifdef PROC_STATISTICS
        hostdata->dma_cnt = 0;
        hostdata->pio_cnt = 0;
        hostdata->int_cnt = 0;
#endif
#endif

        if (check_setup_args("clock", &flags, &val, buf)) {
                hostdata->clock_freq = set_clk_freq(val, &val);
                calc_sx_table(val, hostdata->sx_table);
        }

        if (check_setup_args("nosync", &flags, &val, buf))
                hostdata->no_sync = val;

        if (check_setup_args("nodma", &flags, &val, buf))
                hostdata->no_dma = (val == -1) ? 1 : val;

        if (check_setup_args("period", &flags, &val, buf))
                hostdata->default_sx_per =
                    hostdata->sx_table[round_period((unsigned int) val,
                                                    hostdata->sx_table)].period_ns;

        if (check_setup_args("disconnect", &flags, &val, buf)) {
                if ((val >= DIS_NEVER) && (val <= DIS_ALWAYS))
                        hostdata->disconnect = val;
                else
                        hostdata->disconnect = DIS_ADAPTIVE;
        }

        if (check_setup_args("level2", &flags, &val, buf))
                hostdata->level2 = val;

        if (check_setup_args("debug", &flags, &val, buf))
                hostdata->args = val & DB_MASK;

        if (check_setup_args("burst", &flags, &val, buf))
                hostdata->dma_mode = val ? CTRL_BURST:CTRL_DMA;

        if (WD33C93_FS_16_20 == hostdata->clock_freq /* divisor 4 */
                && check_setup_args("fast", &flags, &val, buf))
                hostdata->fast = !!val;

        if ((i = check_setup_args("next", &flags, &val, buf))) {
                while (i)
                        setup_used[--i] = 1;
        }
#ifdef PROC_INTERFACE
        if (check_setup_args("proc", &flags, &val, buf))
                hostdata->proc = val;
#endif

        spin_lock_irq(&hostdata->lock);
        reset_wd33c93(instance);
        spin_unlock_irq(&hostdata->lock);

        printk("wd33c93-%d: chip=%s/%d no_sync=0x%x no_dma=%d",
               instance->host_no,
               (hostdata->chip == C_WD33C93) ? "WD33c93" : (hostdata->chip ==
                                                            C_WD33C93A) ?
               "WD33c93A" : (hostdata->chip ==
                             C_WD33C93B) ? "WD33c93B" : "unknown",
               hostdata->microcode, hostdata->no_sync, hostdata->no_dma);
#ifdef DEBUGGING_ON
        printk(" debug_flags=0x%02x\n", hostdata->args);
#else
        printk(" debugging=OFF\n");
#endif
        printk("           setup_args=");
        for (i = 0; i < MAX_SETUP_ARGS; i++)
                printk("%s,", setup_args[i]);
        printk("\n");
        printk("           Version %s - %s, Compiled %s at %s\n",
               WD33C93_VERSION, WD33C93_DATE, __DATE__, __TIME__);
}

int
wd33c93_proc_info(struct Scsi_Host *instance, char *buf, char **start, off_t off, int len, int in)
{

#ifdef PROC_INTERFACE

        char *bp;
        char tbuf[128];
        struct WD33C93_hostdata *hd;
        struct scsi_cmnd *cmd;
        int x;
        static int stop = 0;

        hd = (struct WD33C93_hostdata *) instance->hostdata;

/* If 'in' is TRUE we need to _read_ the proc file. We accept the following
 * keywords (same format as command-line, but arguments are not optional):
 *    debug
 *    disconnect
 *    period
 *    resync
 *    proc
 *    nodma
 *    level2
 *    burst
 *    fast
 *    nosync
 */

        if (in) {
                buf[len] = '\0';
                for (bp = buf; *bp; ) {
                        while (',' == *bp || ' ' == *bp)
                                ++bp;
                if (!strncmp(bp, "debug:", 6)) {
                                hd->args = simple_strtoul(bp+6, &bp, 0) & DB_MASK;
                } else if (!strncmp(bp, "disconnect:", 11)) {
                                x = simple_strtoul(bp+11, &bp, 0);
                        if (x < DIS_NEVER || x > DIS_ALWAYS)
                                x = DIS_ADAPTIVE;
                        hd->disconnect = x;
                } else if (!strncmp(bp, "period:", 7)) {
                        x = simple_strtoul(bp+7, &bp, 0);
                        hd->default_sx_per =
                                hd->sx_table[round_period((unsigned int) x,
                                                          hd->sx_table)].period_ns;
                } else if (!strncmp(bp, "resync:", 7)) {
                                set_resync(hd, (int)simple_strtoul(bp+7, &bp, 0));
                } else if (!strncmp(bp, "proc:", 5)) {
                                hd->proc = simple_strtoul(bp+5, &bp, 0);
                } else if (!strncmp(bp, "nodma:", 6)) {
                                hd->no_dma = simple_strtoul(bp+6, &bp, 0);
                } else if (!strncmp(bp, "level2:", 7)) {
                                hd->level2 = simple_strtoul(bp+7, &bp, 0);
                        } else if (!strncmp(bp, "burst:", 6)) {
                                hd->dma_mode =
                                        simple_strtol(bp+6, &bp, 0) ? CTRL_BURST:CTRL_DMA;
                        } else if (!strncmp(bp, "fast:", 5)) {
                                x = !!simple_strtol(bp+5, &bp, 0);
                                if (x != hd->fast)
                                        set_resync(hd, 0xff);
                                hd->fast = x;
                        } else if (!strncmp(bp, "nosync:", 7)) {
                                x = simple_strtoul(bp+7, &bp, 0);
                                set_resync(hd, x ^ hd->no_sync);
                                hd->no_sync = x;
                        } else {
                                break; /* unknown keyword,syntax-error,... */
                        }
                }
                return len;
        }

        spin_lock_irq(&hd->lock);
        bp = buf;
        *bp = '\0';
        if (hd->proc & PR_VERSION) {
                sprintf(tbuf, "\nVersion %s - %s. Compiled %s %s",
                        WD33C93_VERSION, WD33C93_DATE, __DATE__, __TIME__);
                strcat(bp, tbuf);
        }
        if (hd->proc & PR_INFO) {
                sprintf(tbuf, "\nclock_freq=%02x no_sync=%02x no_dma=%d"
                        " dma_mode=%02x fast=%d",
                        hd->clock_freq, hd->no_sync, hd->no_dma, hd->dma_mode, hd->fast);
                strcat(bp, tbuf);
                strcat(bp, "\nsync_xfer[] =       ");
                for (x = 0; x < 7; x++) {
                        sprintf(tbuf, "\t%02x", hd->sync_xfer[x]);
                        strcat(bp, tbuf);
                }
                strcat(bp, "\nsync_stat[] =       ");
                for (x = 0; x < 7; x++) {
                        sprintf(tbuf, "\t%02x", hd->sync_stat[x]);
                        strcat(bp, tbuf);
                }
        }
#ifdef PROC_STATISTICS
        if (hd->proc & PR_STATISTICS) {
                strcat(bp, "\ncommands issued:    ");
                for (x = 0; x < 7; x++) {
                        sprintf(tbuf, "\t%ld", hd->cmd_cnt[x]);
                        strcat(bp, tbuf);
                }
                strcat(bp, "\ndisconnects allowed:");
                for (x = 0; x < 7; x++) {
                        sprintf(tbuf, "\t%ld", hd->disc_allowed_cnt[x]);
                        strcat(bp, tbuf);
                }
                strcat(bp, "\ndisconnects done:   ");
                for (x = 0; x < 7; x++) {
                        sprintf(tbuf, "\t%ld", hd->disc_done_cnt[x]);
                        strcat(bp, tbuf);
                }
                sprintf(tbuf,
                        "\ninterrupts: %ld, DATA_PHASE ints: %ld DMA, %ld PIO",
                        hd->int_cnt, hd->dma_cnt, hd->pio_cnt);
                strcat(bp, tbuf);
        }
#endif
        if (hd->proc & PR_CONNECTED) {
                strcat(bp, "\nconnected:     ");
                if (hd->connected) {
                        cmd = (struct scsi_cmnd *) hd->connected;
                        sprintf(tbuf, " %ld-%d:%d(%02x)",
                                cmd->serial_number, cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
                        strcat(bp, tbuf);
                }
        }
        if (hd->proc & PR_INPUTQ) {
                strcat(bp, "\ninput_Q:       ");
                cmd = (struct scsi_cmnd *) hd->input_Q;
                while (cmd) {
                        sprintf(tbuf, " %ld-%d:%d(%02x)",
                                cmd->serial_number, cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
                        strcat(bp, tbuf);
                        cmd = (struct scsi_cmnd *) cmd->host_scribble;
                }
        }
        if (hd->proc & PR_DISCQ) {
                strcat(bp, "\ndisconnected_Q:");
                cmd = (struct scsi_cmnd *) hd->disconnected_Q;
                while (cmd) {
                        sprintf(tbuf, " %ld-%d:%d(%02x)",
                                cmd->serial_number, cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
                        strcat(bp, tbuf);
                        cmd = (struct scsi_cmnd *) cmd->host_scribble;
                }
        }
        strcat(bp, "\n");
        spin_unlock_irq(&hd->lock);
        *start = buf;
        if (stop) {
                stop = 0;
                return 0;
        }
        if (off > 0x40000)      /* ALWAYS stop after 256k bytes have been read */
                stop = 1;
        if (hd->proc & PR_STOP) /* stop every other time */
                stop = 1;
        return strlen(bp);

#else                           /* PROC_INTERFACE */

        return 0;

#endif                          /* PROC_INTERFACE */

}

void
wd33c93_release(void)
{
}

EXPORT_SYMBOL(wd33c93_host_reset);
EXPORT_SYMBOL(wd33c93_init);
EXPORT_SYMBOL(wd33c93_release);
EXPORT_SYMBOL(wd33c93_abort);
EXPORT_SYMBOL(wd33c93_queuecommand);
EXPORT_SYMBOL(wd33c93_intr);
EXPORT_SYMBOL(wd33c93_proc_info);