wd33c93.c

Go to the documentation of this file.

/*
 * Copyright (c) 1996 John Shifflett, GeoLog Consulting
 *    [email protected]
 *    [email protected]
 *
 * 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 [email protected] or [email protected]! 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 <[email protected]>  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 <[email protected]>  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;
}

static int
wd33c93_queuecommand_lck(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( ", cmd->device->id, cmd->cmnd[0]))

/* 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 (scsi_bufflen(cmd)) {
        cmd->SCp.buffer = scsi_sglist(cmd);
        cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 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 = NULL;
        cmd->SCp.this_residual = 0;
    }

/* 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 "))

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

DEF_SCSI_QCMD(wd33c93_queuecommand)

/*
 * 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)EX-2 ", (cmd->SCp.phase) ? "d:" : ""))
}

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", cmd->cmnd[0]))
            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"))
                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"))
                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: Unknown SEL_XFER_DONE phase!!---",
                 asr, sr, phs);
            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"))
            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"))
            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;

            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 from input_Q. ",
                 instance->host_no);
            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 - ",
               instance->host_no);

        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 found on disconnected_Q - ",
                 instance->host_no);
            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 occurred 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_dma = 0;   /* default is DMA enabled */

#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\n", WD33C93_VERSION, WD33C93_DATE);
}

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.",
            WD33C93_VERSION, WD33C93_DATE);
        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, " %d:%d(%02x)",
                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, " %d:%d(%02x)",
                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, " %d:%d(%02x)",
                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 */

}

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