aic79xx_osm.c

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/*
 * Adaptec AIC79xx device driver for Linux.
 *
 * $Id: //depot/aic7xxx/linux/drivers/scsi/aic7xxx/aic79xx_osm.c#171 $
 *
 * --------------------------------------------------------------------------
 * Copyright (c) 1994-2000 Justin T. Gibbs.
 * Copyright (c) 1997-1999 Doug Ledford
 * Copyright (c) 2000-2003 Adaptec Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include "aic79xx_osm.h"
#include "aic79xx_inline.h"
#include <scsi/scsicam.h>

static struct scsi_transport_template *ahd_linux_transport_template = NULL;

#include <linux/init.h>     /* __setup */
#include <linux/mm.h>       /* For fetching system memory size */
#include <linux/blkdev.h>       /* For block_size() */
#include <linux/delay.h>    /* For ssleep/msleep */
#include <linux/device.h>
#include <linux/slab.h>

/*
 * Bucket size for counting good commands in between bad ones.
 */
#define AHD_LINUX_ERR_THRESH    1000

/*
 * Set this to the delay in seconds after SCSI bus reset.
 * Note, we honor this only for the initial bus reset.
 * The scsi error recovery code performs its own bus settle
 * delay handling for error recovery actions.
 */
#ifdef CONFIG_AIC79XX_RESET_DELAY_MS
#define AIC79XX_RESET_DELAY CONFIG_AIC79XX_RESET_DELAY_MS
#else
#define AIC79XX_RESET_DELAY 5000
#endif

/*
 * To change the default number of tagged transactions allowed per-device,
 * add a line to the lilo.conf file like:
 * append="aic79xx=verbose,tag_info:{{32,32,32,32},{32,32,32,32}}"
 * which will result in the first four devices on the first two
 * controllers being set to a tagged queue depth of 32.
 *
 * The tag_commands is an array of 16 to allow for wide and twin adapters.
 * Twin adapters will use indexes 0-7 for channel 0, and indexes 8-15
 * for channel 1.
 */
typedef struct {
    uint16_t tag_commands[16];  /* Allow for wide/twin adapters. */
} adapter_tag_info_t;

/*
 * Modify this as you see fit for your system.
 *
 * 0            tagged queuing disabled
 * 1 <= n <= 253    n == max tags ever dispatched.
 *
 * The driver will throttle the number of commands dispatched to a
 * device if it returns queue full.  For devices with a fixed maximum
 * queue depth, the driver will eventually determine this depth and
 * lock it in (a console message is printed to indicate that a lock
 * has occurred).  On some devices, queue full is returned for a temporary
 * resource shortage.  These devices will return queue full at varying
 * depths.  The driver will throttle back when the queue fulls occur and
 * attempt to slowly increase the depth over time as the device recovers
 * from the resource shortage.
 *
 * In this example, the first line will disable tagged queueing for all
 * the devices on the first probed aic79xx adapter.
 *
 * The second line enables tagged queueing with 4 commands/LUN for IDs
 * (0, 2-11, 13-15), disables tagged queueing for ID 12, and tells the
 * driver to attempt to use up to 64 tags for ID 1.
 *
 * The third line is the same as the first line.
 *
 * The fourth line disables tagged queueing for devices 0 and 3.  It
 * enables tagged queueing for the other IDs, with 16 commands/LUN
 * for IDs 1 and 4, 127 commands/LUN for ID 8, and 4 commands/LUN for
 * IDs 2, 5-7, and 9-15.
 */

/*
 * NOTE: The below structure is for reference only, the actual structure
 *       to modify in order to change things is just below this comment block.
adapter_tag_info_t aic79xx_tag_info[] =
{
    {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
    {{4, 64, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 4, 4, 4}},
    {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
    {{0, 16, 4, 0, 16, 4, 4, 4, 127, 4, 4, 4, 4, 4, 4, 4}}
};
*/

#ifdef CONFIG_AIC79XX_CMDS_PER_DEVICE
#define AIC79XX_CMDS_PER_DEVICE CONFIG_AIC79XX_CMDS_PER_DEVICE
#else
#define AIC79XX_CMDS_PER_DEVICE AHD_MAX_QUEUE
#endif

#define AIC79XX_CONFIGED_TAG_COMMANDS {                 \
    AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,       \
    AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,       \
    AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,       \
    AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,       \
    AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,       \
    AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,       \
    AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,       \
    AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE        \
}

/*
 * By default, use the number of commands specified by
 * the users kernel configuration.
 */
static adapter_tag_info_t aic79xx_tag_info[] =
{
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS},
    {AIC79XX_CONFIGED_TAG_COMMANDS}
};

/*
 * The I/O cell on the chip is very configurable in respect to its analog
 * characteristics.  Set the defaults here; they can be overriden with
 * the proper insmod parameters.
 */
struct ahd_linux_iocell_opts
{
    uint8_t precomp;
    uint8_t slewrate;
    uint8_t amplitude;
};
#define AIC79XX_DEFAULT_PRECOMP     0xFF
#define AIC79XX_DEFAULT_SLEWRATE    0xFF
#define AIC79XX_DEFAULT_AMPLITUDE   0xFF
#define AIC79XX_DEFAULT_IOOPTS          \
{                       \
    AIC79XX_DEFAULT_PRECOMP,        \
    AIC79XX_DEFAULT_SLEWRATE,       \
    AIC79XX_DEFAULT_AMPLITUDE       \
}
#define AIC79XX_PRECOMP_INDEX   0
#define AIC79XX_SLEWRATE_INDEX  1
#define AIC79XX_AMPLITUDE_INDEX 2
static const struct ahd_linux_iocell_opts aic79xx_iocell_info[] =
{
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS,
    AIC79XX_DEFAULT_IOOPTS
};

/*
 * There should be a specific return value for this in scsi.h, but
 * it seems that most drivers ignore it.
 */
#define DID_UNDERFLOW   DID_ERROR

void
ahd_print_path(struct ahd_softc *ahd, struct scb *scb)
{
    printk("(scsi%d:%c:%d:%d): ",
           ahd->platform_data->host->host_no,
           scb != NULL ? SCB_GET_CHANNEL(ahd, scb) : 'X',
           scb != NULL ? SCB_GET_TARGET(ahd, scb) : -1,
           scb != NULL ? SCB_GET_LUN(scb) : -1);
}

/*
 * XXX - these options apply unilaterally to _all_ adapters
 *       cards in the system.  This should be fixed.  Exceptions to this
 *       rule are noted in the comments.
 */

/*
 * Skip the scsi bus reset.  Non 0 make us skip the reset at startup.  This
 * has no effect on any later resets that might occur due to things like
 * SCSI bus timeouts.
 */
static uint32_t aic79xx_no_reset;

/*
 * Should we force EXTENDED translation on a controller.
 *     0 == Use whatever is in the SEEPROM or default to off
 *     1 == Use whatever is in the SEEPROM or default to on
 */
static uint32_t aic79xx_extended;

/*
 * PCI bus parity checking of the Adaptec controllers.  This is somewhat
 * dubious at best.  To my knowledge, this option has never actually
 * solved a PCI parity problem, but on certain machines with broken PCI
 * chipset configurations, it can generate tons of false error messages.
 * It's included in the driver for completeness.
 *   0     = Shut off PCI parity check
 *   non-0 = Enable PCI parity check
 *
 * NOTE: you can't actually pass -1 on the lilo prompt.  So, to set this
 * variable to -1 you would actually want to simply pass the variable
 * name without a number.  That will invert the 0 which will result in
 * -1.
 */
static uint32_t aic79xx_pci_parity = ~0;

/*
 * There are lots of broken chipsets in the world.  Some of them will
 * violate the PCI spec when we issue byte sized memory writes to our
 * controller.  I/O mapped register access, if allowed by the given
 * platform, will work in almost all cases.
 */
uint32_t aic79xx_allow_memio = ~0;

/*
 * So that we can set how long each device is given as a selection timeout.
 * The table of values goes like this:
 *   0 - 256ms
 *   1 - 128ms
 *   2 - 64ms
 *   3 - 32ms
 * We default to 256ms because some older devices need a longer time
 * to respond to initial selection.
 */
static uint32_t aic79xx_seltime;

/*
 * Certain devices do not perform any aging on commands.  Should the
 * device be saturated by commands in one portion of the disk, it is
 * possible for transactions on far away sectors to never be serviced.
 * To handle these devices, we can periodically send an ordered tag to
 * force all outstanding transactions to be serviced prior to a new
 * transaction.
 */
static uint32_t aic79xx_periodic_otag;

/* Some storage boxes are using an LSI chip which has a bug making it
 * impossible to use aic79xx Rev B chip in 320 speeds.  The following
 * storage boxes have been reported to be buggy:
 * EonStor 3U 16-Bay: U16U-G3A3
 * EonStor 2U 12-Bay: U12U-G3A3
 * SentinelRAID: 2500F R5 / R6
 * SentinelRAID: 2500F R1
 * SentinelRAID: 2500F/1500F
 * SentinelRAID: 150F
 * 
 * To get around this LSI bug, you can set your board to 160 mode
 * or you can enable the SLOWCRC bit.
 */
uint32_t aic79xx_slowcrc;

/*
 * Module information and settable options.
 */
static char *aic79xx = NULL;

MODULE_AUTHOR("Maintainer: Hannes Reinecke <[email protected]>");
MODULE_DESCRIPTION("Adaptec AIC790X U320 SCSI Host Bus Adapter driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION(AIC79XX_DRIVER_VERSION);
module_param(aic79xx, charp, 0444);
MODULE_PARM_DESC(aic79xx,
"period-delimited options string:\n"
"   verbose         Enable verbose/diagnostic logging\n"
"   allow_memio     Allow device registers to be memory mapped\n"
"   debug           Bitmask of debug values to enable\n"
"   no_reset        Suppress initial bus resets\n"
"   extended        Enable extended geometry on all controllers\n"
"   periodic_otag       Send an ordered tagged transaction\n"
"               periodically to prevent tag starvation.\n"
"               This may be required by some older disk\n"
"               or drives/RAID arrays.\n"
"   tag_info:<tag_str>  Set per-target tag depth\n"
"   global_tag_depth:<int>  Global tag depth for all targets on all buses\n"
"   slewrate:<slewrate_list>Set the signal slew rate (0-15).\n"
"   precomp:<pcomp_list>    Set the signal precompensation (0-7).\n"
"   amplitude:<int>     Set the signal amplitude (0-7).\n"
"   seltime:<int>       Selection Timeout:\n"
"               (0/256ms,1/128ms,2/64ms,3/32ms)\n"
"   slowcrc         Turn on the SLOWCRC bit (Rev B only)\n"      
"\n"
"   Sample modprobe configuration file:\n"
"   #   Enable verbose logging\n"
"   #   Set tag depth on Controller 2/Target 2 to 10 tags\n"
"   #   Shorten the selection timeout to 128ms\n"
"\n"
"   options aic79xx 'aic79xx=verbose.tag_info:{{}.{}.{..10}}.seltime:1'\n"
);

static void ahd_linux_handle_scsi_status(struct ahd_softc *,
                     struct scsi_device *,
                     struct scb *);
static void ahd_linux_queue_cmd_complete(struct ahd_softc *ahd,
                     struct scsi_cmnd *cmd);
static int ahd_linux_queue_abort_cmd(struct scsi_cmnd *cmd);
static void ahd_linux_initialize_scsi_bus(struct ahd_softc *ahd);
static u_int ahd_linux_user_tagdepth(struct ahd_softc *ahd,
                     struct ahd_devinfo *devinfo);
static void ahd_linux_device_queue_depth(struct scsi_device *);
static int ahd_linux_run_command(struct ahd_softc*,
                 struct ahd_linux_device *,
                 struct scsi_cmnd *);
static void ahd_linux_setup_tag_info_global(char *p);
static int  aic79xx_setup(char *c);
static void ahd_freeze_simq(struct ahd_softc *ahd);
static void ahd_release_simq(struct ahd_softc *ahd);

static int ahd_linux_unit;


/************************** OS Utility Wrappers *******************************/
void ahd_delay(long);
void
ahd_delay(long usec)
{
    /*
     * udelay on Linux can have problems for
     * multi-millisecond waits.  Wait at most
     * 1024us per call.
     */
    while (usec > 0) {
        udelay(usec % 1024);
        usec -= 1024;
    }
}


/***************************** Low Level I/O **********************************/
uint8_t ahd_inb(struct ahd_softc * ahd, long port);
void ahd_outb(struct ahd_softc * ahd, long port, uint8_t val);
void ahd_outw_atomic(struct ahd_softc * ahd,
                     long port, uint16_t val);
void ahd_outsb(struct ahd_softc * ahd, long port,
                   uint8_t *, int count);
void ahd_insb(struct ahd_softc * ahd, long port,
                   uint8_t *, int count);

uint8_t
ahd_inb(struct ahd_softc * ahd, long port)
{
    uint8_t x;

    if (ahd->tags[0] == BUS_SPACE_MEMIO) {
        x = readb(ahd->bshs[0].maddr + port);
    } else {
        x = inb(ahd->bshs[(port) >> 8].ioport + ((port) & 0xFF));
    }
    mb();
    return (x);
}

#if 0 /* unused */
static uint16_t
ahd_inw_atomic(struct ahd_softc * ahd, long port)
{
    uint8_t x;

    if (ahd->tags[0] == BUS_SPACE_MEMIO) {
        x = readw(ahd->bshs[0].maddr + port);
    } else {
        x = inw(ahd->bshs[(port) >> 8].ioport + ((port) & 0xFF));
    }
    mb();
    return (x);
}
#endif

void
ahd_outb(struct ahd_softc * ahd, long port, uint8_t val)
{
    if (ahd->tags[0] == BUS_SPACE_MEMIO) {
        writeb(val, ahd->bshs[0].maddr + port);
    } else {
        outb(val, ahd->bshs[(port) >> 8].ioport + (port & 0xFF));
    }
    mb();
}

void
ahd_outw_atomic(struct ahd_softc * ahd, long port, uint16_t val)
{
    if (ahd->tags[0] == BUS_SPACE_MEMIO) {
        writew(val, ahd->bshs[0].maddr + port);
    } else {
        outw(val, ahd->bshs[(port) >> 8].ioport + (port & 0xFF));
    }
    mb();
}

void
ahd_outsb(struct ahd_softc * ahd, long port, uint8_t *array, int count)
{
    int i;

    /*
     * There is probably a more efficient way to do this on Linux
     * but we don't use this for anything speed critical and this
     * should work.
     */
    for (i = 0; i < count; i++)
        ahd_outb(ahd, port, *array++);
}

void
ahd_insb(struct ahd_softc * ahd, long port, uint8_t *array, int count)
{
    int i;

    /*
     * There is probably a more efficient way to do this on Linux
     * but we don't use this for anything speed critical and this
     * should work.
     */
    for (i = 0; i < count; i++)
        *array++ = ahd_inb(ahd, port);
}

/******************************* PCI Routines *********************************/
uint32_t
ahd_pci_read_config(ahd_dev_softc_t pci, int reg, int width)
{
    switch (width) {
    case 1:
    {
        uint8_t retval;

        pci_read_config_byte(pci, reg, &retval);
        return (retval);
    }
    case 2:
    {
        uint16_t retval;
        pci_read_config_word(pci, reg, &retval);
        return (retval);
    }
    case 4:
    {
        uint32_t retval;
        pci_read_config_dword(pci, reg, &retval);
        return (retval);
    }
    default:
        panic("ahd_pci_read_config: Read size too big");
        /* NOTREACHED */
        return (0);
    }
}

void
ahd_pci_write_config(ahd_dev_softc_t pci, int reg, uint32_t value, int width)
{
    switch (width) {
    case 1:
        pci_write_config_byte(pci, reg, value);
        break;
    case 2:
        pci_write_config_word(pci, reg, value);
        break;
    case 4:
        pci_write_config_dword(pci, reg, value);
        break;
    default:
        panic("ahd_pci_write_config: Write size too big");
        /* NOTREACHED */
    }
}

/****************************** Inlines ***************************************/
static void ahd_linux_unmap_scb(struct ahd_softc*, struct scb*);

static void
ahd_linux_unmap_scb(struct ahd_softc *ahd, struct scb *scb)
{
    struct scsi_cmnd *cmd;

    cmd = scb->io_ctx;
    ahd_sync_sglist(ahd, scb, BUS_DMASYNC_POSTWRITE);
    scsi_dma_unmap(cmd);
}

/******************************** Macros **************************************/
#define BUILD_SCSIID(ahd, cmd)                      \
    (((scmd_id(cmd) << TID_SHIFT) & TID) | (ahd)->our_id)

/*
 * Return a string describing the driver.
 */
static const char *
ahd_linux_info(struct Scsi_Host *host)
{
    static char buffer[512];
    char    ahd_info[256];
    char   *bp;
    struct ahd_softc *ahd;

    bp = &buffer[0];
    ahd = *(struct ahd_softc **)host->hostdata;
    memset(bp, 0, sizeof(buffer));
    strcpy(bp, "Adaptec AIC79XX PCI-X SCSI HBA DRIVER, Rev " AIC79XX_DRIVER_VERSION "\n"
            "        <");
    strcat(bp, ahd->description);
    strcat(bp, ">\n"
            "        ");
    ahd_controller_info(ahd, ahd_info);
    strcat(bp, ahd_info);

    return (bp);
}

/*
 * Queue an SCB to the controller.
 */
static int
ahd_linux_queue_lck(struct scsi_cmnd * cmd, void (*scsi_done) (struct scsi_cmnd *))
{
    struct   ahd_softc *ahd;
    struct   ahd_linux_device *dev = scsi_transport_device_data(cmd->device);
    int rtn = SCSI_MLQUEUE_HOST_BUSY;

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

    cmd->scsi_done = scsi_done;
    cmd->result = CAM_REQ_INPROG << 16;
    rtn = ahd_linux_run_command(ahd, dev, cmd);

    return rtn;
}

static DEF_SCSI_QCMD(ahd_linux_queue)

static struct scsi_target **
ahd_linux_target_in_softc(struct scsi_target *starget)
{
    struct  ahd_softc *ahd =
        *((struct ahd_softc **)dev_to_shost(&starget->dev)->hostdata);
    unsigned int target_offset;

    target_offset = starget->id;
    if (starget->channel != 0)
        target_offset += 8;

    return &ahd->platform_data->starget[target_offset];
}

static int
ahd_linux_target_alloc(struct scsi_target *starget)
{
    struct  ahd_softc *ahd =
        *((struct ahd_softc **)dev_to_shost(&starget->dev)->hostdata);
    struct seeprom_config *sc = ahd->seep_config;
    unsigned long flags;
    struct scsi_target **ahd_targp = ahd_linux_target_in_softc(starget);
    struct ahd_devinfo devinfo;
    struct ahd_initiator_tinfo *tinfo;
    struct ahd_tmode_tstate *tstate;
    char channel = starget->channel + 'A';

    ahd_lock(ahd, &flags);

    BUG_ON(*ahd_targp != NULL);

    *ahd_targp = starget;

    if (sc) {
        int flags = sc->device_flags[starget->id];

        tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
                        starget->id, &tstate);

        if ((flags  & CFPACKETIZED) == 0) {
            /* don't negotiate packetized (IU) transfers */
            spi_max_iu(starget) = 0;
        } else {
            if ((ahd->features & AHD_RTI) == 0)
                spi_rti(starget) = 0;
        }

        if ((flags & CFQAS) == 0)
            spi_max_qas(starget) = 0;

        /* Transinfo values have been set to BIOS settings */
        spi_max_width(starget) = (flags & CFWIDEB) ? 1 : 0;
        spi_min_period(starget) = tinfo->user.period;
        spi_max_offset(starget) = tinfo->user.offset;
    }

    tinfo = ahd_fetch_transinfo(ahd, channel, ahd->our_id,
                    starget->id, &tstate);
    ahd_compile_devinfo(&devinfo, ahd->our_id, starget->id,
                CAM_LUN_WILDCARD, channel,
                ROLE_INITIATOR);
    ahd_set_syncrate(ahd, &devinfo, 0, 0, 0,
             AHD_TRANS_GOAL, /*paused*/FALSE);
    ahd_set_width(ahd, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,
              AHD_TRANS_GOAL, /*paused*/FALSE);
    ahd_unlock(ahd, &flags);

    return 0;
}

static void
ahd_linux_target_destroy(struct scsi_target *starget)
{
    struct scsi_target **ahd_targp = ahd_linux_target_in_softc(starget);

    *ahd_targp = NULL;
}

static int
ahd_linux_slave_alloc(struct scsi_device *sdev)
{
    struct  ahd_softc *ahd =
        *((struct ahd_softc **)sdev->host->hostdata);
    struct ahd_linux_device *dev;

    if (bootverbose)
        printk("%s: Slave Alloc %d\n", ahd_name(ahd), sdev->id);

    dev = scsi_transport_device_data(sdev);
    memset(dev, 0, sizeof(*dev));

    /*
     * We start out life using untagged
     * transactions of which we allow one.
     */
    dev->openings = 1;

    /*
     * Set maxtags to 0.  This will be changed if we
     * later determine that we are dealing with
     * a tagged queuing capable device.
     */
    dev->maxtags = 0;
    
    return (0);
}

static int
ahd_linux_slave_configure(struct scsi_device *sdev)
{
    struct  ahd_softc *ahd;

    ahd = *((struct ahd_softc **)sdev->host->hostdata);
    if (bootverbose)
        sdev_printk(KERN_INFO, sdev, "Slave Configure\n");

    ahd_linux_device_queue_depth(sdev);

    /* Initial Domain Validation */
    if (!spi_initial_dv(sdev->sdev_target))
        spi_dv_device(sdev);

    return 0;
}

#if defined(__i386__)
/*
 * Return the disk geometry for the given SCSI device.
 */
static int
ahd_linux_biosparam(struct scsi_device *sdev, struct block_device *bdev,
            sector_t capacity, int geom[])
{
    uint8_t *bh;
    int  heads;
    int  sectors;
    int  cylinders;
    int  ret;
    int  extended;
    struct   ahd_softc *ahd;

    ahd = *((struct ahd_softc **)sdev->host->hostdata);

    bh = scsi_bios_ptable(bdev);
    if (bh) {
        ret = scsi_partsize(bh, capacity,
                    &geom[2], &geom[0], &geom[1]);
        kfree(bh);
        if (ret != -1)
            return (ret);
    }
    heads = 64;
    sectors = 32;
    cylinders = aic_sector_div(capacity, heads, sectors);

    if (aic79xx_extended != 0)
        extended = 1;
    else
        extended = (ahd->flags & AHD_EXTENDED_TRANS_A) != 0;
    if (extended && cylinders >= 1024) {
        heads = 255;
        sectors = 63;
        cylinders = aic_sector_div(capacity, heads, sectors);
    }
    geom[0] = heads;
    geom[1] = sectors;
    geom[2] = cylinders;
    return (0);
}
#endif

/*
 * Abort the current SCSI command(s).
 */
static int
ahd_linux_abort(struct scsi_cmnd *cmd)
{
    int error;
    
    error = ahd_linux_queue_abort_cmd(cmd);

    return error;
}

/*
 * Attempt to send a target reset message to the device that timed out.
 */
static int
ahd_linux_dev_reset(struct scsi_cmnd *cmd)
{
    struct ahd_softc *ahd;
    struct ahd_linux_device *dev;
    struct scb *reset_scb;
    u_int  cdb_byte;
    int    retval = SUCCESS;
    int    paused;
    int    wait;
    struct  ahd_initiator_tinfo *tinfo;
    struct  ahd_tmode_tstate *tstate;
    unsigned long flags;
    DECLARE_COMPLETION_ONSTACK(done);

    reset_scb = NULL;
    paused = FALSE;
    wait = FALSE;
    ahd = *(struct ahd_softc **)cmd->device->host->hostdata;

    scmd_printk(KERN_INFO, cmd,
            "Attempting to queue a TARGET RESET message:");

    printk("CDB:");
    for (cdb_byte = 0; cdb_byte < cmd->cmd_len; cdb_byte++)
        printk(" 0x%x", cmd->cmnd[cdb_byte]);
    printk("\n");

    /*
     * Determine if we currently own this command.
     */
    dev = scsi_transport_device_data(cmd->device);

    if (dev == NULL) {
        /*
         * No target device for this command exists,
         * so we must not still own the command.
         */
        scmd_printk(KERN_INFO, cmd, "Is not an active device\n");
        return SUCCESS;
    }

    /*
     * Generate us a new SCB
     */
    reset_scb = ahd_get_scb(ahd, AHD_NEVER_COL_IDX);
    if (!reset_scb) {
        scmd_printk(KERN_INFO, cmd, "No SCB available\n");
        return FAILED;
    }

    tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
                    cmd->device->id, &tstate);
    reset_scb->io_ctx = cmd;
    reset_scb->platform_data->dev = dev;
    reset_scb->sg_count = 0;
    ahd_set_residual(reset_scb, 0);
    ahd_set_sense_residual(reset_scb, 0);
    reset_scb->platform_data->xfer_len = 0;
    reset_scb->hscb->control = 0;
    reset_scb->hscb->scsiid = BUILD_SCSIID(ahd,cmd);
    reset_scb->hscb->lun = cmd->device->lun;
    reset_scb->hscb->cdb_len = 0;
    reset_scb->hscb->task_management = SIU_TASKMGMT_LUN_RESET;
    reset_scb->flags |= SCB_DEVICE_RESET|SCB_RECOVERY_SCB|SCB_ACTIVE;
    if ((tinfo->curr.ppr_options & MSG_EXT_PPR_IU_REQ) != 0) {
        reset_scb->flags |= SCB_PACKETIZED;
    } else {
        reset_scb->hscb->control |= MK_MESSAGE;
    }
    dev->openings--;
    dev->active++;
    dev->commands_issued++;

    ahd_lock(ahd, &flags);

    LIST_INSERT_HEAD(&ahd->pending_scbs, reset_scb, pending_links);
    ahd_queue_scb(ahd, reset_scb);

    ahd->platform_data->eh_done = &done;
    ahd_unlock(ahd, &flags);

    printk("%s: Device reset code sleeping\n", ahd_name(ahd));
    if (!wait_for_completion_timeout(&done, 5 * HZ)) {
        ahd_lock(ahd, &flags);
        ahd->platform_data->eh_done = NULL;
        ahd_unlock(ahd, &flags);
        printk("%s: Device reset timer expired (active %d)\n",
               ahd_name(ahd), dev->active);
        retval = FAILED;
    }
    printk("%s: Device reset returning 0x%x\n", ahd_name(ahd), retval);

    return (retval);
}

/*
 * Reset the SCSI bus.
 */
static int
ahd_linux_bus_reset(struct scsi_cmnd *cmd)
{
    struct ahd_softc *ahd;
    int    found;
    unsigned long flags;

    ahd = *(struct ahd_softc **)cmd->device->host->hostdata;
#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_RECOVERY) != 0)
        printk("%s: Bus reset called for cmd %p\n",
               ahd_name(ahd), cmd);
#endif
    ahd_lock(ahd, &flags);

    found = ahd_reset_channel(ahd, scmd_channel(cmd) + 'A',
                  /*initiate reset*/TRUE);
    ahd_unlock(ahd, &flags);

    if (bootverbose)
        printk("%s: SCSI bus reset delivered. "
               "%d SCBs aborted.\n", ahd_name(ahd), found);

    return (SUCCESS);
}

struct scsi_host_template aic79xx_driver_template = {
    .module         = THIS_MODULE,
    .name           = "aic79xx",
    .proc_name      = "aic79xx",
    .proc_info      = ahd_linux_proc_info,
    .info           = ahd_linux_info,
    .queuecommand       = ahd_linux_queue,
    .eh_abort_handler   = ahd_linux_abort,
    .eh_device_reset_handler = ahd_linux_dev_reset,
    .eh_bus_reset_handler   = ahd_linux_bus_reset,
#if defined(__i386__)
    .bios_param     = ahd_linux_biosparam,
#endif
    .can_queue      = AHD_MAX_QUEUE,
    .this_id        = -1,
    .max_sectors        = 8192,
    .cmd_per_lun        = 2,
    .use_clustering     = ENABLE_CLUSTERING,
    .slave_alloc        = ahd_linux_slave_alloc,
    .slave_configure    = ahd_linux_slave_configure,
    .target_alloc       = ahd_linux_target_alloc,
    .target_destroy     = ahd_linux_target_destroy,
};

/******************************** Bus DMA *************************************/
int
ahd_dma_tag_create(struct ahd_softc *ahd, bus_dma_tag_t parent,
           bus_size_t alignment, bus_size_t boundary,
           dma_addr_t lowaddr, dma_addr_t highaddr,
           bus_dma_filter_t *filter, void *filterarg,
           bus_size_t maxsize, int nsegments,
           bus_size_t maxsegsz, int flags, bus_dma_tag_t *ret_tag)
{
    bus_dma_tag_t dmat;

    dmat = kmalloc(sizeof(*dmat), GFP_ATOMIC);
    if (dmat == NULL)
        return (ENOMEM);

    /*
     * Linux is very simplistic about DMA memory.  For now don't
     * maintain all specification information.  Once Linux supplies
     * better facilities for doing these operations, or the
     * needs of this particular driver change, we might need to do
     * more here.
     */
    dmat->alignment = alignment;
    dmat->boundary = boundary;
    dmat->maxsize = maxsize;
    *ret_tag = dmat;
    return (0);
}

void
ahd_dma_tag_destroy(struct ahd_softc *ahd, bus_dma_tag_t dmat)
{
    kfree(dmat);
}

int
ahd_dmamem_alloc(struct ahd_softc *ahd, bus_dma_tag_t dmat, void** vaddr,
         int flags, bus_dmamap_t *mapp)
{
    *vaddr = pci_alloc_consistent(ahd->dev_softc,
                      dmat->maxsize, mapp);
    if (*vaddr == NULL)
        return (ENOMEM);
    return(0);
}

void
ahd_dmamem_free(struct ahd_softc *ahd, bus_dma_tag_t dmat,
        void* vaddr, bus_dmamap_t map)
{
    pci_free_consistent(ahd->dev_softc, dmat->maxsize,
                vaddr, map);
}

int
ahd_dmamap_load(struct ahd_softc *ahd, bus_dma_tag_t dmat, bus_dmamap_t map,
        void *buf, bus_size_t buflen, bus_dmamap_callback_t *cb,
        void *cb_arg, int flags)
{
    /*
     * Assume for now that this will only be used during
     * initialization and not for per-transaction buffer mapping.
     */
    bus_dma_segment_t stack_sg;

    stack_sg.ds_addr = map;
    stack_sg.ds_len = dmat->maxsize;
    cb(cb_arg, &stack_sg, /*nseg*/1, /*error*/0);
    return (0);
}

void
ahd_dmamap_destroy(struct ahd_softc *ahd, bus_dma_tag_t dmat, bus_dmamap_t map)
{
}

int
ahd_dmamap_unload(struct ahd_softc *ahd, bus_dma_tag_t dmat, bus_dmamap_t map)
{
    /* Nothing to do */
    return (0);
}

/********************* Platform Dependent Functions ***************************/
static void
ahd_linux_setup_iocell_info(u_long index, int instance, int targ, int32_t value)
{

    if ((instance >= 0)
     && (instance < ARRAY_SIZE(aic79xx_iocell_info))) {
        uint8_t *iocell_info;

        iocell_info = (uint8_t*)&aic79xx_iocell_info[instance];
        iocell_info[index] = value & 0xFFFF;
        if (bootverbose)
            printk("iocell[%d:%ld] = %d\n", instance, index, value);
    }
}

static void
ahd_linux_setup_tag_info_global(char *p)
{
    int tags, i, j;

    tags = simple_strtoul(p + 1, NULL, 0) & 0xff;
    printk("Setting Global Tags= %d\n", tags);

    for (i = 0; i < ARRAY_SIZE(aic79xx_tag_info); i++) {
        for (j = 0; j < AHD_NUM_TARGETS; j++) {
            aic79xx_tag_info[i].tag_commands[j] = tags;
        }
    }
}

static void
ahd_linux_setup_tag_info(u_long arg, int instance, int targ, int32_t value)
{

    if ((instance >= 0) && (targ >= 0)
     && (instance < ARRAY_SIZE(aic79xx_tag_info))
     && (targ < AHD_NUM_TARGETS)) {
        aic79xx_tag_info[instance].tag_commands[targ] = value & 0x1FF;
        if (bootverbose)
            printk("tag_info[%d:%d] = %d\n", instance, targ, value);
    }
}

static char *
ahd_parse_brace_option(char *opt_name, char *opt_arg, char *end, int depth,
               void (*callback)(u_long, int, int, int32_t),
               u_long callback_arg)
{
    char    *tok_end;
    char    *tok_end2;
    int      i;
    int      instance;
    int  targ;
    int  done;
    char     tok_list[] = {'.', ',', '{', '}', '\0'};

    /* All options use a ':' name/arg separator */
    if (*opt_arg != ':')
        return (opt_arg);
    opt_arg++;
    instance = -1;
    targ = -1;
    done = FALSE;
    /*
     * Restore separator that may be in
     * the middle of our option argument.
     */
    tok_end = strchr(opt_arg, '\0');
    if (tok_end < end)
        *tok_end = ',';
    while (!done) {
        switch (*opt_arg) {
        case '{':
            if (instance == -1) {
                instance = 0;
            } else {
                if (depth > 1) {
                    if (targ == -1)
                        targ = 0;
                } else {
                    printk("Malformed Option %s\n",
                           opt_name);
                    done = TRUE;
                }
            }
            opt_arg++;
            break;
        case '}':
            if (targ != -1)
                targ = -1;
            else if (instance != -1)
                instance = -1;
            opt_arg++;
            break;
        case ',':
        case '.':
            if (instance == -1)
                done = TRUE;
            else if (targ >= 0)
                targ++;
            else if (instance >= 0)
                instance++;
            opt_arg++;
            break;
        case '\0':
            done = TRUE;
            break;
        default:
            tok_end = end;
            for (i = 0; tok_list[i]; i++) {
                tok_end2 = strchr(opt_arg, tok_list[i]);
                if ((tok_end2) && (tok_end2 < tok_end))
                    tok_end = tok_end2;
            }
            callback(callback_arg, instance, targ,
                 simple_strtol(opt_arg, NULL, 0));
            opt_arg = tok_end;
            break;
        }
    }
    return (opt_arg);
}

/*
 * Handle Linux boot parameters. This routine allows for assigning a value
 * to a parameter with a ':' between the parameter and the value.
 * ie. aic79xx=stpwlev:1,extended
 */
static int
aic79xx_setup(char *s)
{
    int i, n;
    char   *p;
    char   *end;

    static const struct {
        const char *name;
        uint32_t *flag;
    } options[] = {
        { "extended", &aic79xx_extended },
        { "no_reset", &aic79xx_no_reset },
        { "verbose", &aic79xx_verbose },
        { "allow_memio", &aic79xx_allow_memio},
#ifdef AHD_DEBUG
        { "debug", &ahd_debug },
#endif
        { "periodic_otag", &aic79xx_periodic_otag },
        { "pci_parity", &aic79xx_pci_parity },
        { "seltime", &aic79xx_seltime },
        { "tag_info", NULL },
        { "global_tag_depth", NULL},
        { "slewrate", NULL },
        { "precomp", NULL },
        { "amplitude", NULL },
        { "slowcrc", &aic79xx_slowcrc },
    };

    end = strchr(s, '\0');

    /*
     * XXX ia64 gcc isn't smart enough to know that ARRAY_SIZE
     * will never be 0 in this case.
     */
    n = 0;

    while ((p = strsep(&s, ",.")) != NULL) {
        if (*p == '\0')
            continue;
        for (i = 0; i < ARRAY_SIZE(options); i++) {

            n = strlen(options[i].name);
            if (strncmp(options[i].name, p, n) == 0)
                break;
        }
        if (i == ARRAY_SIZE(options))
            continue;

        if (strncmp(p, "global_tag_depth", n) == 0) {
            ahd_linux_setup_tag_info_global(p + n);
        } else if (strncmp(p, "tag_info", n) == 0) {
            s = ahd_parse_brace_option("tag_info", p + n, end,
                2, ahd_linux_setup_tag_info, 0);
        } else if (strncmp(p, "slewrate", n) == 0) {
            s = ahd_parse_brace_option("slewrate",
                p + n, end, 1, ahd_linux_setup_iocell_info,
                AIC79XX_SLEWRATE_INDEX);
        } else if (strncmp(p, "precomp", n) == 0) {
            s = ahd_parse_brace_option("precomp",
                p + n, end, 1, ahd_linux_setup_iocell_info,
                AIC79XX_PRECOMP_INDEX);
        } else if (strncmp(p, "amplitude", n) == 0) {
            s = ahd_parse_brace_option("amplitude",
                p + n, end, 1, ahd_linux_setup_iocell_info,
                AIC79XX_AMPLITUDE_INDEX);
        } else if (p[n] == ':') {
            *(options[i].flag) = simple_strtoul(p + n + 1, NULL, 0);
        } else if (!strncmp(p, "verbose", n)) {
            *(options[i].flag) = 1;
        } else {
            *(options[i].flag) ^= 0xFFFFFFFF;
        }
    }
    return 1;
}

__setup("aic79xx=", aic79xx_setup);

uint32_t aic79xx_verbose;

int
ahd_linux_register_host(struct ahd_softc *ahd, struct scsi_host_template *template)
{
    char    buf[80];
    struct  Scsi_Host *host;
    char    *new_name;
    u_long  s;
    int retval;

    template->name = ahd->description;
    host = scsi_host_alloc(template, sizeof(struct ahd_softc *));
    if (host == NULL)
        return (ENOMEM);

    *((struct ahd_softc **)host->hostdata) = ahd;
    ahd->platform_data->host = host;
    host->can_queue = AHD_MAX_QUEUE;
    host->cmd_per_lun = 2;
    host->sg_tablesize = AHD_NSEG;
    host->this_id = ahd->our_id;
    host->irq = ahd->platform_data->irq;
    host->max_id = (ahd->features & AHD_WIDE) ? 16 : 8;
    host->max_lun = AHD_NUM_LUNS;
    host->max_channel = 0;
    host->sg_tablesize = AHD_NSEG;
    ahd_lock(ahd, &s);
    ahd_set_unit(ahd, ahd_linux_unit++);
    ahd_unlock(ahd, &s);
    sprintf(buf, "scsi%d", host->host_no);
    new_name = kmalloc(strlen(buf) + 1, GFP_ATOMIC);
    if (new_name != NULL) {
        strcpy(new_name, buf);
        ahd_set_name(ahd, new_name);
    }
    host->unique_id = ahd->unit;
    ahd_linux_initialize_scsi_bus(ahd);
    ahd_intr_enable(ahd, TRUE);

    host->transportt = ahd_linux_transport_template;

    retval = scsi_add_host(host, &ahd->dev_softc->dev);
    if (retval) {
        printk(KERN_WARNING "aic79xx: scsi_add_host failed\n");
        scsi_host_put(host);
        return retval;
    }

    scsi_scan_host(host);
    return 0;
}

/*
 * Place the SCSI bus into a known state by either resetting it,
 * or forcing transfer negotiations on the next command to any
 * target.
 */
static void
ahd_linux_initialize_scsi_bus(struct ahd_softc *ahd)
{
    u_int target_id;
    u_int numtarg;
    unsigned long s;

    target_id = 0;
    numtarg = 0;

    if (aic79xx_no_reset != 0)
        ahd->flags &= ~AHD_RESET_BUS_A;

    if ((ahd->flags & AHD_RESET_BUS_A) != 0)
        ahd_reset_channel(ahd, 'A', /*initiate_reset*/TRUE);
    else
        numtarg = (ahd->features & AHD_WIDE) ? 16 : 8;

    ahd_lock(ahd, &s);

    /*
     * Force negotiation to async for all targets that
     * will not see an initial bus reset.
     */
    for (; target_id < numtarg; target_id++) {
        struct ahd_devinfo devinfo;
        struct ahd_initiator_tinfo *tinfo;
        struct ahd_tmode_tstate *tstate;

        tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
                        target_id, &tstate);
        ahd_compile_devinfo(&devinfo, ahd->our_id, target_id,
                    CAM_LUN_WILDCARD, 'A', ROLE_INITIATOR);
        ahd_update_neg_request(ahd, &devinfo, tstate,
                       tinfo, AHD_NEG_ALWAYS);
    }
    ahd_unlock(ahd, &s);
    /* Give the bus some time to recover */
    if ((ahd->flags & AHD_RESET_BUS_A) != 0) {
        ahd_freeze_simq(ahd);
        msleep(AIC79XX_RESET_DELAY);
        ahd_release_simq(ahd);
    }
}

int
ahd_platform_alloc(struct ahd_softc *ahd, void *platform_arg)
{
    ahd->platform_data =
        kmalloc(sizeof(struct ahd_platform_data), GFP_ATOMIC);
    if (ahd->platform_data == NULL)
        return (ENOMEM);
    memset(ahd->platform_data, 0, sizeof(struct ahd_platform_data));
    ahd->platform_data->irq = AHD_LINUX_NOIRQ;
    ahd_lockinit(ahd);
    ahd->seltime = (aic79xx_seltime & 0x3) << 4;
    return (0);
}

void
ahd_platform_free(struct ahd_softc *ahd)
{
    struct scsi_target *starget;
    int i;

    if (ahd->platform_data != NULL) {
        /* destroy all of the device and target objects */
        for (i = 0; i < AHD_NUM_TARGETS; i++) {
            starget = ahd->platform_data->starget[i];
            if (starget != NULL) {
                ahd->platform_data->starget[i] = NULL;
            }
        }

        if (ahd->platform_data->irq != AHD_LINUX_NOIRQ)
            free_irq(ahd->platform_data->irq, ahd);
        if (ahd->tags[0] == BUS_SPACE_PIO
         && ahd->bshs[0].ioport != 0)
            release_region(ahd->bshs[0].ioport, 256);
        if (ahd->tags[1] == BUS_SPACE_PIO
         && ahd->bshs[1].ioport != 0)
            release_region(ahd->bshs[1].ioport, 256);
        if (ahd->tags[0] == BUS_SPACE_MEMIO
         && ahd->bshs[0].maddr != NULL) {
            iounmap(ahd->bshs[0].maddr);
            release_mem_region(ahd->platform_data->mem_busaddr,
                       0x1000);
        }
        if (ahd->platform_data->host)
            scsi_host_put(ahd->platform_data->host);

        kfree(ahd->platform_data);
    }
}

void
ahd_platform_init(struct ahd_softc *ahd)
{
    /*
     * Lookup and commit any modified IO Cell options.
     */
    if (ahd->unit < ARRAY_SIZE(aic79xx_iocell_info)) {
        const struct ahd_linux_iocell_opts *iocell_opts;

        iocell_opts = &aic79xx_iocell_info[ahd->unit];
        if (iocell_opts->precomp != AIC79XX_DEFAULT_PRECOMP)
            AHD_SET_PRECOMP(ahd, iocell_opts->precomp);
        if (iocell_opts->slewrate != AIC79XX_DEFAULT_SLEWRATE)
            AHD_SET_SLEWRATE(ahd, iocell_opts->slewrate);
        if (iocell_opts->amplitude != AIC79XX_DEFAULT_AMPLITUDE)
            AHD_SET_AMPLITUDE(ahd, iocell_opts->amplitude);
    }

}

void
ahd_platform_freeze_devq(struct ahd_softc *ahd, struct scb *scb)
{
    ahd_platform_abort_scbs(ahd, SCB_GET_TARGET(ahd, scb),
                SCB_GET_CHANNEL(ahd, scb),
                SCB_GET_LUN(scb), SCB_LIST_NULL,
                ROLE_UNKNOWN, CAM_REQUEUE_REQ);
}

void
ahd_platform_set_tags(struct ahd_softc *ahd, struct scsi_device *sdev,
              struct ahd_devinfo *devinfo, ahd_queue_alg alg)
{
    struct ahd_linux_device *dev;
    int was_queuing;
    int now_queuing;

    if (sdev == NULL)
        return;

    dev = scsi_transport_device_data(sdev);

    if (dev == NULL)
        return;
    was_queuing = dev->flags & (AHD_DEV_Q_BASIC|AHD_DEV_Q_TAGGED);
    switch (alg) {
    default:
    case AHD_QUEUE_NONE:
        now_queuing = 0;
        break; 
    case AHD_QUEUE_BASIC:
        now_queuing = AHD_DEV_Q_BASIC;
        break;
    case AHD_QUEUE_TAGGED:
        now_queuing = AHD_DEV_Q_TAGGED;
        break;
    }
    if ((dev->flags & AHD_DEV_FREEZE_TIL_EMPTY) == 0
     && (was_queuing != now_queuing)
     && (dev->active != 0)) {
        dev->flags |= AHD_DEV_FREEZE_TIL_EMPTY;
        dev->qfrozen++;
    }

    dev->flags &= ~(AHD_DEV_Q_BASIC|AHD_DEV_Q_TAGGED|AHD_DEV_PERIODIC_OTAG);
    if (now_queuing) {
        u_int usertags;

        usertags = ahd_linux_user_tagdepth(ahd, devinfo);
        if (!was_queuing) {
            /*
             * Start out aggressively and allow our
             * dynamic queue depth algorithm to take
             * care of the rest.
             */
            dev->maxtags = usertags;
            dev->openings = dev->maxtags - dev->active;
        }
        if (dev->maxtags == 0) {
            /*
             * Queueing is disabled by the user.
             */
            dev->openings = 1;
        } else if (alg == AHD_QUEUE_TAGGED) {
            dev->flags |= AHD_DEV_Q_TAGGED;
            if (aic79xx_periodic_otag != 0)
                dev->flags |= AHD_DEV_PERIODIC_OTAG;
        } else
            dev->flags |= AHD_DEV_Q_BASIC;
    } else {
        /* We can only have one opening. */
        dev->maxtags = 0;
        dev->openings =  1 - dev->active;
    }

    switch ((dev->flags & (AHD_DEV_Q_BASIC|AHD_DEV_Q_TAGGED))) {
    case AHD_DEV_Q_BASIC:
        scsi_set_tag_type(sdev, MSG_SIMPLE_TASK);
        scsi_activate_tcq(sdev, dev->openings + dev->active);
        break;
    case AHD_DEV_Q_TAGGED:
        scsi_set_tag_type(sdev, MSG_ORDERED_TASK);
        scsi_activate_tcq(sdev, dev->openings + dev->active);
        break;
    default:
        /*
         * We allow the OS to queue 2 untagged transactions to
         * us at any time even though we can only execute them
         * serially on the controller/device.  This should
         * remove some latency.
         */
        scsi_deactivate_tcq(sdev, 1);
        break;
    }
}

int
ahd_platform_abort_scbs(struct ahd_softc *ahd, int target, char channel,
            int lun, u_int tag, role_t role, uint32_t status)
{
    return 0;
}

static u_int
ahd_linux_user_tagdepth(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
{
    static int warned_user;
    u_int tags;

    tags = 0;
    if ((ahd->user_discenable & devinfo->target_mask) != 0) {
        if (ahd->unit >= ARRAY_SIZE(aic79xx_tag_info)) {

            if (warned_user == 0) {
                printk(KERN_WARNING
"aic79xx: WARNING: Insufficient tag_info instances\n"
"aic79xx: for installed controllers.  Using defaults\n"
"aic79xx: Please update the aic79xx_tag_info array in\n"
"aic79xx: the aic79xx_osm.c source file.\n");
                warned_user++;
            }
            tags = AHD_MAX_QUEUE;
        } else {
            adapter_tag_info_t *tag_info;

            tag_info = &aic79xx_tag_info[ahd->unit];
            tags = tag_info->tag_commands[devinfo->target_offset];
            if (tags > AHD_MAX_QUEUE)
                tags = AHD_MAX_QUEUE;
        }
    }
    return (tags);
}

/*
 * Determines the queue depth for a given device.
 */
static void
ahd_linux_device_queue_depth(struct scsi_device *sdev)
{
    struct  ahd_devinfo devinfo;
    u_int   tags;
    struct ahd_softc *ahd = *((struct ahd_softc **)sdev->host->hostdata);

    ahd_compile_devinfo(&devinfo,
                ahd->our_id,
                sdev->sdev_target->id, sdev->lun,
                sdev->sdev_target->channel == 0 ? 'A' : 'B',
                ROLE_INITIATOR);
    tags = ahd_linux_user_tagdepth(ahd, &devinfo);
    if (tags != 0 && sdev->tagged_supported != 0) {

        ahd_platform_set_tags(ahd, sdev, &devinfo, AHD_QUEUE_TAGGED);
        ahd_send_async(ahd, devinfo.channel, devinfo.target,
                   devinfo.lun, AC_TRANSFER_NEG);
        ahd_print_devinfo(ahd, &devinfo);
        printk("Tagged Queuing enabled.  Depth %d\n", tags);
    } else {
        ahd_platform_set_tags(ahd, sdev, &devinfo, AHD_QUEUE_NONE);
        ahd_send_async(ahd, devinfo.channel, devinfo.target,
                   devinfo.lun, AC_TRANSFER_NEG);
    }
}

static int
ahd_linux_run_command(struct ahd_softc *ahd, struct ahd_linux_device *dev,
              struct scsi_cmnd *cmd)
{
    struct   scb *scb;
    struct   hardware_scb *hscb;
    struct   ahd_initiator_tinfo *tinfo;
    struct   ahd_tmode_tstate *tstate;
    u_int    col_idx;
    uint16_t mask;
    unsigned long flags;
    int nseg;

    nseg = scsi_dma_map(cmd);
    if (nseg < 0)
        return SCSI_MLQUEUE_HOST_BUSY;

    ahd_lock(ahd, &flags);

    /*
     * Get an scb to use.
     */
    tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
                    cmd->device->id, &tstate);
    if ((dev->flags & (AHD_DEV_Q_TAGGED|AHD_DEV_Q_BASIC)) == 0
     || (tinfo->curr.ppr_options & MSG_EXT_PPR_IU_REQ) != 0) {
        col_idx = AHD_NEVER_COL_IDX;
    } else {
        col_idx = AHD_BUILD_COL_IDX(cmd->device->id,
                        cmd->device->lun);
    }
    if ((scb = ahd_get_scb(ahd, col_idx)) == NULL) {
        ahd->flags |= AHD_RESOURCE_SHORTAGE;
        ahd_unlock(ahd, &flags);
        scsi_dma_unmap(cmd);
        return SCSI_MLQUEUE_HOST_BUSY;
    }

    scb->io_ctx = cmd;
    scb->platform_data->dev = dev;
    hscb = scb->hscb;
    cmd->host_scribble = (char *)scb;

    /*
     * Fill out basics of the HSCB.
     */
    hscb->control = 0;
    hscb->scsiid = BUILD_SCSIID(ahd, cmd);
    hscb->lun = cmd->device->lun;
    scb->hscb->task_management = 0;
    mask = SCB_GET_TARGET_MASK(ahd, scb);

    if ((ahd->user_discenable & mask) != 0)
        hscb->control |= DISCENB;

    if ((tinfo->curr.ppr_options & MSG_EXT_PPR_IU_REQ) != 0)
        scb->flags |= SCB_PACKETIZED;

    if ((tstate->auto_negotiate & mask) != 0) {
        scb->flags |= SCB_AUTO_NEGOTIATE;
        scb->hscb->control |= MK_MESSAGE;
    }

    if ((dev->flags & (AHD_DEV_Q_TAGGED|AHD_DEV_Q_BASIC)) != 0) {
        int msg_bytes;
        uint8_t tag_msgs[2];

        msg_bytes = scsi_populate_tag_msg(cmd, tag_msgs);
        if (msg_bytes && tag_msgs[0] != MSG_SIMPLE_TASK) {
            hscb->control |= tag_msgs[0];
            if (tag_msgs[0] == MSG_ORDERED_TASK)
                dev->commands_since_idle_or_otag = 0;
        } else
        if (dev->commands_since_idle_or_otag == AHD_OTAG_THRESH
         && (dev->flags & AHD_DEV_Q_TAGGED) != 0) {
            hscb->control |= MSG_ORDERED_TASK;
            dev->commands_since_idle_or_otag = 0;
        } else {
            hscb->control |= MSG_SIMPLE_TASK;
        }
    }

    hscb->cdb_len = cmd->cmd_len;
    memcpy(hscb->shared_data.idata.cdb, cmd->cmnd, hscb->cdb_len);

    scb->platform_data->xfer_len = 0;
    ahd_set_residual(scb, 0);
    ahd_set_sense_residual(scb, 0);
    scb->sg_count = 0;

    if (nseg > 0) {
        void *sg = scb->sg_list;
        struct scatterlist *cur_seg;
        int i;

        scb->platform_data->xfer_len = 0;

        scsi_for_each_sg(cmd, cur_seg, nseg, i) {
            dma_addr_t addr;
            bus_size_t len;

            addr = sg_dma_address(cur_seg);
            len = sg_dma_len(cur_seg);
            scb->platform_data->xfer_len += len;
            sg = ahd_sg_setup(ahd, scb, sg, addr, len,
                      i == (nseg - 1));
        }
    }

    LIST_INSERT_HEAD(&ahd->pending_scbs, scb, pending_links);
    dev->openings--;
    dev->active++;
    dev->commands_issued++;

    if ((dev->flags & AHD_DEV_PERIODIC_OTAG) != 0)
        dev->commands_since_idle_or_otag++;
    scb->flags |= SCB_ACTIVE;
    ahd_queue_scb(ahd, scb);

    ahd_unlock(ahd, &flags);

    return 0;
}

/*
 * SCSI controller interrupt handler.
 */
irqreturn_t
ahd_linux_isr(int irq, void *dev_id)
{
    struct  ahd_softc *ahd;
    u_long  flags;
    int ours;

    ahd = (struct ahd_softc *) dev_id;
    ahd_lock(ahd, &flags); 
    ours = ahd_intr(ahd);
    ahd_unlock(ahd, &flags);
    return IRQ_RETVAL(ours);
}

void
ahd_send_async(struct ahd_softc *ahd, char channel,
           u_int target, u_int lun, ac_code code)
{
    switch (code) {
    case AC_TRANSFER_NEG:
    {
        char    buf[80];
        struct  scsi_target *starget;
        struct  info_str info;
        struct  ahd_initiator_tinfo *tinfo;
        struct  ahd_tmode_tstate *tstate;
        unsigned int target_ppr_options;

        BUG_ON(target == CAM_TARGET_WILDCARD);

        info.buffer = buf;
        info.length = sizeof(buf);
        info.offset = 0;
        info.pos = 0;
        tinfo = ahd_fetch_transinfo(ahd, channel, ahd->our_id,
                        target, &tstate);

        /*
         * Don't bother reporting results while
         * negotiations are still pending.
         */
        if (tinfo->curr.period != tinfo->goal.period
         || tinfo->curr.width != tinfo->goal.width
         || tinfo->curr.offset != tinfo->goal.offset
         || tinfo->curr.ppr_options != tinfo->goal.ppr_options)
            if (bootverbose == 0)
                break;

        /*
         * Don't bother reporting results that
         * are identical to those last reported.
         */
        starget = ahd->platform_data->starget[target];
        if (starget == NULL)
            break;

        target_ppr_options =
            (spi_dt(starget) ? MSG_EXT_PPR_DT_REQ : 0)
            + (spi_qas(starget) ? MSG_EXT_PPR_QAS_REQ : 0)
            + (spi_iu(starget) ?  MSG_EXT_PPR_IU_REQ : 0)
            + (spi_rd_strm(starget) ? MSG_EXT_PPR_RD_STRM : 0)
            + (spi_pcomp_en(starget) ? MSG_EXT_PPR_PCOMP_EN : 0)
            + (spi_rti(starget) ? MSG_EXT_PPR_RTI : 0)
            + (spi_wr_flow(starget) ? MSG_EXT_PPR_WR_FLOW : 0)
            + (spi_hold_mcs(starget) ? MSG_EXT_PPR_HOLD_MCS : 0);

        if (tinfo->curr.period == spi_period(starget)
            && tinfo->curr.width == spi_width(starget)
            && tinfo->curr.offset == spi_offset(starget)
         && tinfo->curr.ppr_options == target_ppr_options)
            if (bootverbose == 0)
                break;

        spi_period(starget) = tinfo->curr.period;
        spi_width(starget) = tinfo->curr.width;
        spi_offset(starget) = tinfo->curr.offset;
        spi_dt(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_DT_REQ ? 1 : 0;
        spi_qas(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_QAS_REQ ? 1 : 0;
        spi_iu(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_IU_REQ ? 1 : 0;
        spi_rd_strm(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_RD_STRM ? 1 : 0;
        spi_pcomp_en(starget) =  tinfo->curr.ppr_options & MSG_EXT_PPR_PCOMP_EN ? 1 : 0;
        spi_rti(starget) =  tinfo->curr.ppr_options &  MSG_EXT_PPR_RTI ? 1 : 0;
        spi_wr_flow(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_WR_FLOW ? 1 : 0;
        spi_hold_mcs(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_HOLD_MCS ? 1 : 0;
        spi_display_xfer_agreement(starget);
        break;
    }
        case AC_SENT_BDR:
    {
        WARN_ON(lun != CAM_LUN_WILDCARD);
        scsi_report_device_reset(ahd->platform_data->host,
                     channel - 'A', target);
        break;
    }
        case AC_BUS_RESET:
        if (ahd->platform_data->host != NULL) {
            scsi_report_bus_reset(ahd->platform_data->host,
                          channel - 'A');
        }
                break;
        default:
                panic("ahd_send_async: Unexpected async event");
        }
}

/*
 * Calls the higher level scsi done function and frees the scb.
 */
void
ahd_done(struct ahd_softc *ahd, struct scb *scb)
{
    struct scsi_cmnd *cmd;
    struct    ahd_linux_device *dev;

    if ((scb->flags & SCB_ACTIVE) == 0) {
        printk("SCB %d done'd twice\n", SCB_GET_TAG(scb));
        ahd_dump_card_state(ahd);
        panic("Stopping for safety");
    }
    LIST_REMOVE(scb, pending_links);
    cmd = scb->io_ctx;
    dev = scb->platform_data->dev;
    dev->active--;
    dev->openings++;
    if ((cmd->result & (CAM_DEV_QFRZN << 16)) != 0) {
        cmd->result &= ~(CAM_DEV_QFRZN << 16);
        dev->qfrozen--;
    }
    ahd_linux_unmap_scb(ahd, scb);

    /*
     * Guard against stale sense data.
     * The Linux mid-layer assumes that sense
     * was retrieved anytime the first byte of
     * the sense buffer looks "sane".
     */
    cmd->sense_buffer[0] = 0;
    if (ahd_get_transaction_status(scb) == CAM_REQ_INPROG) {
        uint32_t amount_xferred;

        amount_xferred =
            ahd_get_transfer_length(scb) - ahd_get_residual(scb);
        if ((scb->flags & SCB_TRANSMISSION_ERROR) != 0) {
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MISC) != 0) {
                ahd_print_path(ahd, scb);
                printk("Set CAM_UNCOR_PARITY\n");
            }
#endif
            ahd_set_transaction_status(scb, CAM_UNCOR_PARITY);
#ifdef AHD_REPORT_UNDERFLOWS
        /*
         * This code is disabled by default as some
         * clients of the SCSI system do not properly
         * initialize the underflow parameter.  This
         * results in spurious termination of commands
         * that complete as expected (e.g. underflow is
         * allowed as command can return variable amounts
         * of data.
         */
        } else if (amount_xferred < scb->io_ctx->underflow) {
            u_int i;

            ahd_print_path(ahd, scb);
            printk("CDB:");
            for (i = 0; i < scb->io_ctx->cmd_len; i++)
                printk(" 0x%x", scb->io_ctx->cmnd[i]);
            printk("\n");
            ahd_print_path(ahd, scb);
            printk("Saw underflow (%ld of %ld bytes). "
                   "Treated as error\n",
                ahd_get_residual(scb),
                ahd_get_transfer_length(scb));
            ahd_set_transaction_status(scb, CAM_DATA_RUN_ERR);
#endif
        } else {
            ahd_set_transaction_status(scb, CAM_REQ_CMP);
        }
    } else if (ahd_get_transaction_status(scb) == CAM_SCSI_STATUS_ERROR) {
        ahd_linux_handle_scsi_status(ahd, cmd->device, scb);
    }

    if (dev->openings == 1
     && ahd_get_transaction_status(scb) == CAM_REQ_CMP
     && ahd_get_scsi_status(scb) != SCSI_STATUS_QUEUE_FULL)
        dev->tag_success_count++;
    /*
     * Some devices deal with temporary internal resource
     * shortages by returning queue full.  When the queue
     * full occurrs, we throttle back.  Slowly try to get
     * back to our previous queue depth.
     */
    if ((dev->openings + dev->active) < dev->maxtags
     && dev->tag_success_count > AHD_TAG_SUCCESS_INTERVAL) {
        dev->tag_success_count = 0;
        dev->openings++;
    }

    if (dev->active == 0)
        dev->commands_since_idle_or_otag = 0;

    if ((scb->flags & SCB_RECOVERY_SCB) != 0) {
        printk("Recovery SCB completes\n");
        if (ahd_get_transaction_status(scb) == CAM_BDR_SENT
         || ahd_get_transaction_status(scb) == CAM_REQ_ABORTED)
            ahd_set_transaction_status(scb, CAM_CMD_TIMEOUT);

        if (ahd->platform_data->eh_done)
            complete(ahd->platform_data->eh_done);
    }

    ahd_free_scb(ahd, scb);
    ahd_linux_queue_cmd_complete(ahd, cmd);
}

static void
ahd_linux_handle_scsi_status(struct ahd_softc *ahd,
                 struct scsi_device *sdev, struct scb *scb)
{
    struct  ahd_devinfo devinfo;
    struct ahd_linux_device *dev = scsi_transport_device_data(sdev);

    ahd_compile_devinfo(&devinfo,
                ahd->our_id,
                sdev->sdev_target->id, sdev->lun,
                sdev->sdev_target->channel == 0 ? 'A' : 'B',
                ROLE_INITIATOR);
    
    /*
     * We don't currently trust the mid-layer to
     * properly deal with queue full or busy.  So,
     * when one occurs, we tell the mid-layer to
     * unconditionally requeue the command to us
     * so that we can retry it ourselves.  We also
     * implement our own throttling mechanism so
     * we don't clobber the device with too many
     * commands.
     */
    switch (ahd_get_scsi_status(scb)) {
    default:
        break;
    case SCSI_STATUS_CHECK_COND:
    case SCSI_STATUS_CMD_TERMINATED:
    {
        struct scsi_cmnd *cmd;

        /*
         * Copy sense information to the OS's cmd
         * structure if it is available.
         */
        cmd = scb->io_ctx;
        if ((scb->flags & (SCB_SENSE|SCB_PKT_SENSE)) != 0) {
            struct scsi_status_iu_header *siu;
            u_int sense_size;
            u_int sense_offset;

            if (scb->flags & SCB_SENSE) {
                sense_size = min(sizeof(struct scsi_sense_data)
                           - ahd_get_sense_residual(scb),
                         (u_long)SCSI_SENSE_BUFFERSIZE);
                sense_offset = 0;
            } else {
                /*
                 * Copy only the sense data into the provided
                 * buffer.
                 */
                siu = (struct scsi_status_iu_header *)
                    scb->sense_data;
                sense_size = min_t(size_t,
                        scsi_4btoul(siu->sense_length),
                        SCSI_SENSE_BUFFERSIZE);
                sense_offset = SIU_SENSE_OFFSET(siu);
            }

            memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
            memcpy(cmd->sense_buffer,
                   ahd_get_sense_buf(ahd, scb)
                   + sense_offset, sense_size);
            cmd->result |= (DRIVER_SENSE << 24);

#ifdef AHD_DEBUG
            if (ahd_debug & AHD_SHOW_SENSE) {
                int i;

                printk("Copied %d bytes of sense data at %d:",
                       sense_size, sense_offset);
                for (i = 0; i < sense_size; i++) {
                    if ((i & 0xF) == 0)
                        printk("\n");
                    printk("0x%x ", cmd->sense_buffer[i]);
                }
                printk("\n");
            }
#endif
        }
        break;
    }
    case SCSI_STATUS_QUEUE_FULL:
        /*
         * By the time the core driver has returned this
         * command, all other commands that were queued
         * to us but not the device have been returned.
         * This ensures that dev->active is equal to
         * the number of commands actually queued to
         * the device.
         */
        dev->tag_success_count = 0;
        if (dev->active != 0) {
            /*
             * Drop our opening count to the number
             * of commands currently outstanding.
             */
            dev->openings = 0;
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_QFULL) != 0) {
                ahd_print_path(ahd, scb);
                printk("Dropping tag count to %d\n",
                       dev->active);
            }
#endif
            if (dev->active == dev->tags_on_last_queuefull) {

                dev->last_queuefull_same_count++;
                /*
                 * If we repeatedly see a queue full
                 * at the same queue depth, this
                 * device has a fixed number of tag
                 * slots.  Lock in this tag depth
                 * so we stop seeing queue fulls from
                 * this device.
                 */
                if (dev->last_queuefull_same_count
                 == AHD_LOCK_TAGS_COUNT) {
                    dev->maxtags = dev->active;
                    ahd_print_path(ahd, scb);
                    printk("Locking max tag count at %d\n",
                           dev->active);
                }
            } else {
                dev->tags_on_last_queuefull = dev->active;
                dev->last_queuefull_same_count = 0;
            }
            ahd_set_transaction_status(scb, CAM_REQUEUE_REQ);
            ahd_set_scsi_status(scb, SCSI_STATUS_OK);
            ahd_platform_set_tags(ahd, sdev, &devinfo,
                     (dev->flags & AHD_DEV_Q_BASIC)
                   ? AHD_QUEUE_BASIC : AHD_QUEUE_TAGGED);
            break;
        }
        /*
         * Drop down to a single opening, and treat this
         * as if the target returned BUSY SCSI status.
         */
        dev->openings = 1;
        ahd_platform_set_tags(ahd, sdev, &devinfo,
                 (dev->flags & AHD_DEV_Q_BASIC)
               ? AHD_QUEUE_BASIC : AHD_QUEUE_TAGGED);
        ahd_set_scsi_status(scb, SCSI_STATUS_BUSY);
    }
}

static void
ahd_linux_queue_cmd_complete(struct ahd_softc *ahd, struct scsi_cmnd *cmd)
{
    int status;
    int new_status = DID_OK;
    int do_fallback = 0;
    int scsi_status;

    /*
     * Map CAM error codes into Linux Error codes.  We
     * avoid the conversion so that the DV code has the
     * full error information available when making
     * state change decisions.
     */

    status = ahd_cmd_get_transaction_status(cmd);
    switch (status) {
    case CAM_REQ_INPROG:
    case CAM_REQ_CMP:
        new_status = DID_OK;
        break;
    case CAM_AUTOSENSE_FAIL:
        new_status = DID_ERROR;
        /* Fallthrough */
    case CAM_SCSI_STATUS_ERROR:
        scsi_status = ahd_cmd_get_scsi_status(cmd);

        switch(scsi_status) {
        case SCSI_STATUS_CMD_TERMINATED:
        case SCSI_STATUS_CHECK_COND:
            if ((cmd->result >> 24) != DRIVER_SENSE) {
                do_fallback = 1;
            } else {
                struct scsi_sense_data *sense;
                
                sense = (struct scsi_sense_data *)
                    cmd->sense_buffer;
                if (sense->extra_len >= 5 &&
                    (sense->add_sense_code == 0x47
                     || sense->add_sense_code == 0x48))
                    do_fallback = 1;
            }
            break;
        default:
            break;
        }
        break;
    case CAM_REQ_ABORTED:
        new_status = DID_ABORT;
        break;
    case CAM_BUSY:
        new_status = DID_BUS_BUSY;
        break;
    case CAM_REQ_INVALID:
    case CAM_PATH_INVALID:
        new_status = DID_BAD_TARGET;
        break;
    case CAM_SEL_TIMEOUT:
        new_status = DID_NO_CONNECT;
        break;
    case CAM_SCSI_BUS_RESET:
    case CAM_BDR_SENT:
        new_status = DID_RESET;
        break;
    case CAM_UNCOR_PARITY:
        new_status = DID_PARITY;
        do_fallback = 1;
        break;
    case CAM_CMD_TIMEOUT:
        new_status = DID_TIME_OUT;
        do_fallback = 1;
        break;
    case CAM_REQ_CMP_ERR:
    case CAM_UNEXP_BUSFREE:
    case CAM_DATA_RUN_ERR:
        new_status = DID_ERROR;
        do_fallback = 1;
        break;
    case CAM_UA_ABORT:
    case CAM_NO_HBA:
    case CAM_SEQUENCE_FAIL:
    case CAM_CCB_LEN_ERR:
    case CAM_PROVIDE_FAIL:
    case CAM_REQ_TERMIO:
    case CAM_UNREC_HBA_ERROR:
    case CAM_REQ_TOO_BIG:
        new_status = DID_ERROR;
        break;
    case CAM_REQUEUE_REQ:
        new_status = DID_REQUEUE;
        break;
    default:
        /* We should never get here */
        new_status = DID_ERROR;
        break;
    }

    if (do_fallback) {
        printk("%s: device overrun (status %x) on %d:%d:%d\n",
               ahd_name(ahd), status, cmd->device->channel,
               cmd->device->id, cmd->device->lun);
    }

    ahd_cmd_set_transaction_status(cmd, new_status);

    cmd->scsi_done(cmd);
}

static void
ahd_freeze_simq(struct ahd_softc *ahd)
{
    scsi_block_requests(ahd->platform_data->host);
}

static void
ahd_release_simq(struct ahd_softc *ahd)
{
    scsi_unblock_requests(ahd->platform_data->host);
}

static int
ahd_linux_queue_abort_cmd(struct scsi_cmnd *cmd)
{
    struct ahd_softc *ahd;
    struct ahd_linux_device *dev;
    struct scb *pending_scb;
    u_int  saved_scbptr;
    u_int  active_scbptr;
    u_int  last_phase;
    u_int  saved_scsiid;
    u_int  cdb_byte;
    int    retval;
    int    was_paused;
    int    paused;
    int    wait;
    int    disconnected;
    ahd_mode_state saved_modes;
    unsigned long flags;

    pending_scb = NULL;
    paused = FALSE;
    wait = FALSE;
    ahd = *(struct ahd_softc **)cmd->device->host->hostdata;

    scmd_printk(KERN_INFO, cmd,
            "Attempting to queue an ABORT message:");

    printk("CDB:");
    for (cdb_byte = 0; cdb_byte < cmd->cmd_len; cdb_byte++)
        printk(" 0x%x", cmd->cmnd[cdb_byte]);
    printk("\n");

    ahd_lock(ahd, &flags);

    /*
     * First determine if we currently own this command.
     * Start by searching the device queue.  If not found
     * there, check the pending_scb list.  If not found
     * at all, and the system wanted us to just abort the
     * command, return success.
     */
    dev = scsi_transport_device_data(cmd->device);

    if (dev == NULL) {
        /*
         * No target device for this command exists,
         * so we must not still own the command.
         */
        scmd_printk(KERN_INFO, cmd, "Is not an active device\n");
        retval = SUCCESS;
        goto no_cmd;
    }

    /*
     * See if we can find a matching cmd in the pending list.
     */
    LIST_FOREACH(pending_scb, &ahd->pending_scbs, pending_links) {
        if (pending_scb->io_ctx == cmd)
            break;
    }

    if (pending_scb == NULL) {
        scmd_printk(KERN_INFO, cmd, "Command not found\n");
        goto no_cmd;
    }

    if ((pending_scb->flags & SCB_RECOVERY_SCB) != 0) {
        /*
         * We can't queue two recovery actions using the same SCB
         */
        retval = FAILED;
        goto  done;
    }

    /*
     * Ensure that the card doesn't do anything
     * behind our back.  Also make sure that we
     * didn't "just" miss an interrupt that would
     * affect this cmd.
     */
    was_paused = ahd_is_paused(ahd);
    ahd_pause_and_flushwork(ahd);
    paused = TRUE;

    if ((pending_scb->flags & SCB_ACTIVE) == 0) {
        scmd_printk(KERN_INFO, cmd, "Command already completed\n");
        goto no_cmd;
    }

    printk("%s: At time of recovery, card was %spaused\n",
           ahd_name(ahd), was_paused ? "" : "not ");
    ahd_dump_card_state(ahd);

    disconnected = TRUE;
    if (ahd_search_qinfifo(ahd, cmd->device->id, 
                   cmd->device->channel + 'A',
                   cmd->device->lun, 
                   pending_scb->hscb->tag,
                   ROLE_INITIATOR, CAM_REQ_ABORTED,
                   SEARCH_COMPLETE) > 0) {
        printk("%s:%d:%d:%d: Cmd aborted from QINFIFO\n",
               ahd_name(ahd), cmd->device->channel, 
               cmd->device->id, cmd->device->lun);
        retval = SUCCESS;
        goto done;
    }

    saved_modes = ahd_save_modes(ahd);
    ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
    last_phase = ahd_inb(ahd, LASTPHASE);
    saved_scbptr = ahd_get_scbptr(ahd);
    active_scbptr = saved_scbptr;
    if (disconnected && (ahd_inb(ahd, SEQ_FLAGS) & NOT_IDENTIFIED) == 0) {
        struct scb *bus_scb;

        bus_scb = ahd_lookup_scb(ahd, active_scbptr);
        if (bus_scb == pending_scb)
            disconnected = FALSE;
    }

    /*
     * At this point, pending_scb is the scb associated with the
     * passed in command.  That command is currently active on the
     * bus or is in the disconnected state.
     */
    saved_scsiid = ahd_inb(ahd, SAVED_SCSIID);
    if (last_phase != P_BUSFREE
        && SCB_GET_TAG(pending_scb) == active_scbptr) {

        /*
         * We're active on the bus, so assert ATN
         * and hope that the target responds.
         */
        pending_scb = ahd_lookup_scb(ahd, active_scbptr);
        pending_scb->flags |= SCB_RECOVERY_SCB|SCB_ABORT;
        ahd_outb(ahd, MSG_OUT, HOST_MSG);
        ahd_outb(ahd, SCSISIGO, last_phase|ATNO);
        scmd_printk(KERN_INFO, cmd, "Device is active, asserting ATN\n");
        wait = TRUE;
    } else if (disconnected) {

        /*
         * Actually re-queue this SCB in an attempt
         * to select the device before it reconnects.
         */
        pending_scb->flags |= SCB_RECOVERY_SCB|SCB_ABORT;
        ahd_set_scbptr(ahd, SCB_GET_TAG(pending_scb));
        pending_scb->hscb->cdb_len = 0;
        pending_scb->hscb->task_attribute = 0;
        pending_scb->hscb->task_management = SIU_TASKMGMT_ABORT_TASK;

        if ((pending_scb->flags & SCB_PACKETIZED) != 0) {
            /*
             * Mark the SCB has having an outstanding
             * task management function.  Should the command
             * complete normally before the task management
             * function can be sent, the host will be notified
             * to abort our requeued SCB.
             */
            ahd_outb(ahd, SCB_TASK_MANAGEMENT,
                 pending_scb->hscb->task_management);
        } else {
            /*
             * If non-packetized, set the MK_MESSAGE control
             * bit indicating that we desire to send a message.
             * We also set the disconnected flag since there is
             * no guarantee that our SCB control byte matches
             * the version on the card.  We don't want the
             * sequencer to abort the command thinking an
             * unsolicited reselection occurred.
             */
            pending_scb->hscb->control |= MK_MESSAGE|DISCONNECTED;

            /*
             * The sequencer will never re-reference the
             * in-core SCB.  To make sure we are notified
             * during reselection, set the MK_MESSAGE flag in
             * the card's copy of the SCB.
             */
            ahd_outb(ahd, SCB_CONTROL,
                 ahd_inb(ahd, SCB_CONTROL)|MK_MESSAGE);
        }

        /*
         * Clear out any entries in the QINFIFO first
         * so we are the next SCB for this target
         * to run.
         */
        ahd_search_qinfifo(ahd, cmd->device->id,
                   cmd->device->channel + 'A', cmd->device->lun,
                   SCB_LIST_NULL, ROLE_INITIATOR,
                   CAM_REQUEUE_REQ, SEARCH_COMPLETE);
        ahd_qinfifo_requeue_tail(ahd, pending_scb);
        ahd_set_scbptr(ahd, saved_scbptr);
        ahd_print_path(ahd, pending_scb);
        printk("Device is disconnected, re-queuing SCB\n");
        wait = TRUE;
    } else {
        scmd_printk(KERN_INFO, cmd, "Unable to deliver message\n");
        retval = FAILED;
        goto done;
    }

no_cmd:
    /*
     * Our assumption is that if we don't have the command, no
     * recovery action was required, so we return success.  Again,
     * the semantics of the mid-layer recovery engine are not
     * well defined, so this may change in time.
     */
    retval = SUCCESS;
done:
    if (paused)
        ahd_unpause(ahd);
    if (wait) {
        DECLARE_COMPLETION_ONSTACK(done);

        ahd->platform_data->eh_done = &done;
        ahd_unlock(ahd, &flags);

        printk("%s: Recovery code sleeping\n", ahd_name(ahd));
        if (!wait_for_completion_timeout(&done, 5 * HZ)) {
            ahd_lock(ahd, &flags);
            ahd->platform_data->eh_done = NULL;
            ahd_unlock(ahd, &flags);
            printk("%s: Timer Expired (active %d)\n",
                   ahd_name(ahd), dev->active);
            retval = FAILED;
        }
        printk("Recovery code awake\n");
    } else
        ahd_unlock(ahd, &flags);

    if (retval != SUCCESS)
        printk("%s: Command abort returning 0x%x\n",
               ahd_name(ahd), retval);

    return retval;
}

static void ahd_linux_set_width(struct scsi_target *starget, int width)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_devinfo devinfo;
    unsigned long flags;

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    ahd_lock(ahd, &flags);
    ahd_set_width(ahd, &devinfo, width, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_period(struct scsi_target *starget, int period)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = tinfo->goal.ppr_options;
    unsigned int dt;
    unsigned long flags;
    unsigned long offset = tinfo->goal.offset;

#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_DV) != 0)
        printk("%s: set period to %d\n", ahd_name(ahd), period);
#endif
    if (offset == 0)
        offset = MAX_OFFSET;

    if (period < 8)
        period = 8;
    if (period < 10) {
        if (spi_max_width(starget)) {
            ppr_options |= MSG_EXT_PPR_DT_REQ;
            if (period == 8)
                ppr_options |= MSG_EXT_PPR_IU_REQ;
        } else
            period = 10;
    }

    dt = ppr_options & MSG_EXT_PPR_DT_REQ;

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);

    /* all PPR requests apart from QAS require wide transfers */
    if (ppr_options & ~MSG_EXT_PPR_QAS_REQ) {
        if (spi_width(starget) == 0)
            ppr_options &= MSG_EXT_PPR_QAS_REQ;
    }

    ahd_find_syncrate(ahd, &period, &ppr_options,
              dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, offset,
             ppr_options, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_offset(struct scsi_target *starget, int offset)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = 0;
    unsigned int period = 0;
    unsigned int dt = ppr_options & MSG_EXT_PPR_DT_REQ;
    unsigned long flags;

#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_DV) != 0)
        printk("%s: set offset to %d\n", ahd_name(ahd), offset);
#endif

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    if (offset != 0) {
        period = tinfo->goal.period;
        ppr_options = tinfo->goal.ppr_options;
        ahd_find_syncrate(ahd, &period, &ppr_options, 
                  dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);
    }

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, offset, ppr_options,
             AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_dt(struct scsi_target *starget, int dt)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = tinfo->goal.ppr_options
        & ~MSG_EXT_PPR_DT_REQ;
    unsigned int period = tinfo->goal.period;
    unsigned int width = tinfo->goal.width;
    unsigned long flags;

#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_DV) != 0)
        printk("%s: %s DT\n", ahd_name(ahd),
               dt ? "enabling" : "disabling");
#endif
    if (dt && spi_max_width(starget)) {
        ppr_options |= MSG_EXT_PPR_DT_REQ;
        if (!width)
            ahd_linux_set_width(starget, 1);
    } else {
        if (period <= 9)
            period = 10; /* If resetting DT, period must be >= 25ns */
        /* IU is invalid without DT set */
        ppr_options &= ~MSG_EXT_PPR_IU_REQ;
    }
    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    ahd_find_syncrate(ahd, &period, &ppr_options,
              dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, tinfo->goal.offset,
             ppr_options, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_qas(struct scsi_target *starget, int qas)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = tinfo->goal.ppr_options
        & ~MSG_EXT_PPR_QAS_REQ;
    unsigned int period = tinfo->goal.period;
    unsigned int dt;
    unsigned long flags;

#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_DV) != 0)
        printk("%s: %s QAS\n", ahd_name(ahd),
               qas ? "enabling" : "disabling");
#endif

    if (qas) {
        ppr_options |= MSG_EXT_PPR_QAS_REQ; 
    }

    dt = ppr_options & MSG_EXT_PPR_DT_REQ;

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    ahd_find_syncrate(ahd, &period, &ppr_options,
              dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, tinfo->goal.offset,
             ppr_options, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_iu(struct scsi_target *starget, int iu)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = tinfo->goal.ppr_options
        & ~MSG_EXT_PPR_IU_REQ;
    unsigned int period = tinfo->goal.period;
    unsigned int dt;
    unsigned long flags;

#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_DV) != 0)
        printk("%s: %s IU\n", ahd_name(ahd),
               iu ? "enabling" : "disabling");
#endif

    if (iu && spi_max_width(starget)) {
        ppr_options |= MSG_EXT_PPR_IU_REQ;
        ppr_options |= MSG_EXT_PPR_DT_REQ; /* IU requires DT */
    }

    dt = ppr_options & MSG_EXT_PPR_DT_REQ;

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    ahd_find_syncrate(ahd, &period, &ppr_options,
              dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, tinfo->goal.offset,
             ppr_options, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_rd_strm(struct scsi_target *starget, int rdstrm)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = tinfo->goal.ppr_options
        & ~MSG_EXT_PPR_RD_STRM;
    unsigned int period = tinfo->goal.period;
    unsigned int dt = ppr_options & MSG_EXT_PPR_DT_REQ;
    unsigned long flags;

#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_DV) != 0)
        printk("%s: %s Read Streaming\n", ahd_name(ahd),
               rdstrm  ? "enabling" : "disabling");
#endif

    if (rdstrm && spi_max_width(starget))
        ppr_options |= MSG_EXT_PPR_RD_STRM;

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    ahd_find_syncrate(ahd, &period, &ppr_options,
              dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, tinfo->goal.offset,
             ppr_options, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_wr_flow(struct scsi_target *starget, int wrflow)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = tinfo->goal.ppr_options
        & ~MSG_EXT_PPR_WR_FLOW;
    unsigned int period = tinfo->goal.period;
    unsigned int dt = ppr_options & MSG_EXT_PPR_DT_REQ;
    unsigned long flags;

#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_DV) != 0)
        printk("%s: %s Write Flow Control\n", ahd_name(ahd),
               wrflow ? "enabling" : "disabling");
#endif

    if (wrflow && spi_max_width(starget))
        ppr_options |= MSG_EXT_PPR_WR_FLOW;

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    ahd_find_syncrate(ahd, &period, &ppr_options,
              dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, tinfo->goal.offset,
             ppr_options, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_rti(struct scsi_target *starget, int rti)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = tinfo->goal.ppr_options
        & ~MSG_EXT_PPR_RTI;
    unsigned int period = tinfo->goal.period;
    unsigned int dt = ppr_options & MSG_EXT_PPR_DT_REQ;
    unsigned long flags;

    if ((ahd->features & AHD_RTI) == 0) {
#ifdef AHD_DEBUG
        if ((ahd_debug & AHD_SHOW_DV) != 0)
            printk("%s: RTI not available\n", ahd_name(ahd));
#endif
        return;
    }

#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_DV) != 0)
        printk("%s: %s RTI\n", ahd_name(ahd),
               rti ? "enabling" : "disabling");
#endif

    if (rti && spi_max_width(starget))
        ppr_options |= MSG_EXT_PPR_RTI;

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    ahd_find_syncrate(ahd, &period, &ppr_options,
              dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, tinfo->goal.offset,
             ppr_options, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_pcomp_en(struct scsi_target *starget, int pcomp)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = tinfo->goal.ppr_options
        & ~MSG_EXT_PPR_PCOMP_EN;
    unsigned int period = tinfo->goal.period;
    unsigned int dt = ppr_options & MSG_EXT_PPR_DT_REQ;
    unsigned long flags;

#ifdef AHD_DEBUG
    if ((ahd_debug & AHD_SHOW_DV) != 0)
        printk("%s: %s Precompensation\n", ahd_name(ahd),
               pcomp ? "Enable" : "Disable");
#endif

    if (pcomp && spi_max_width(starget)) {
        uint8_t precomp;

        if (ahd->unit < ARRAY_SIZE(aic79xx_iocell_info)) {
            const struct ahd_linux_iocell_opts *iocell_opts;

            iocell_opts = &aic79xx_iocell_info[ahd->unit];
            precomp = iocell_opts->precomp;
        } else {
            precomp = AIC79XX_DEFAULT_PRECOMP;
        }
        ppr_options |= MSG_EXT_PPR_PCOMP_EN;
        AHD_SET_PRECOMP(ahd, precomp);
    } else {
        AHD_SET_PRECOMP(ahd, 0);
    }

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    ahd_find_syncrate(ahd, &period, &ppr_options,
              dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, tinfo->goal.offset,
             ppr_options, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_set_hold_mcs(struct scsi_target *starget, int hold)
{
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct ahd_softc *ahd = *((struct ahd_softc **)shost->hostdata);
    struct ahd_tmode_tstate *tstate;
    struct ahd_initiator_tinfo *tinfo 
        = ahd_fetch_transinfo(ahd,
                      starget->channel + 'A',
                      shost->this_id, starget->id, &tstate);
    struct ahd_devinfo devinfo;
    unsigned int ppr_options = tinfo->goal.ppr_options
        & ~MSG_EXT_PPR_HOLD_MCS;
    unsigned int period = tinfo->goal.period;
    unsigned int dt = ppr_options & MSG_EXT_PPR_DT_REQ;
    unsigned long flags;

    if (hold && spi_max_width(starget))
        ppr_options |= MSG_EXT_PPR_HOLD_MCS;

    ahd_compile_devinfo(&devinfo, shost->this_id, starget->id, 0,
                starget->channel + 'A', ROLE_INITIATOR);
    ahd_find_syncrate(ahd, &period, &ppr_options,
              dt ? AHD_SYNCRATE_MAX : AHD_SYNCRATE_ULTRA2);

    ahd_lock(ahd, &flags);
    ahd_set_syncrate(ahd, &devinfo, period, tinfo->goal.offset,
             ppr_options, AHD_TRANS_GOAL, FALSE);
    ahd_unlock(ahd, &flags);
}

static void ahd_linux_get_signalling(struct Scsi_Host *shost)
{
    struct ahd_softc *ahd = *(struct ahd_softc **)shost->hostdata;
    unsigned long flags;
    u8 mode;

    ahd_lock(ahd, &flags);
    ahd_pause(ahd);
    mode = ahd_inb(ahd, SBLKCTL);
    ahd_unpause(ahd);
    ahd_unlock(ahd, &flags);

    if (mode & ENAB40)
        spi_signalling(shost) = SPI_SIGNAL_LVD;
    else if (mode & ENAB20)
        spi_signalling(shost) = SPI_SIGNAL_SE;
    else
        spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
}

static struct spi_function_template ahd_linux_transport_functions = {
    .set_offset = ahd_linux_set_offset,
    .show_offset    = 1,
    .set_period = ahd_linux_set_period,
    .show_period    = 1,
    .set_width  = ahd_linux_set_width,
    .show_width = 1,
    .set_dt     = ahd_linux_set_dt,
    .show_dt    = 1,
    .set_iu     = ahd_linux_set_iu,
    .show_iu    = 1,
    .set_qas    = ahd_linux_set_qas,
    .show_qas   = 1,
    .set_rd_strm    = ahd_linux_set_rd_strm,
    .show_rd_strm   = 1,
    .set_wr_flow    = ahd_linux_set_wr_flow,
    .show_wr_flow   = 1,
    .set_rti    = ahd_linux_set_rti,
    .show_rti   = 1,
    .set_pcomp_en   = ahd_linux_set_pcomp_en,
    .show_pcomp_en  = 1,
    .set_hold_mcs   = ahd_linux_set_hold_mcs,
    .show_hold_mcs  = 1,
    .get_signalling = ahd_linux_get_signalling,
};

static int __init
ahd_linux_init(void)
{
    int error = 0;

    /*
     * If we've been passed any parameters, process them now.
     */
    if (aic79xx)
        aic79xx_setup(aic79xx);

    ahd_linux_transport_template =
        spi_attach_transport(&ahd_linux_transport_functions);
    if (!ahd_linux_transport_template)
        return -ENODEV;

    scsi_transport_reserve_device(ahd_linux_transport_template,
                      sizeof(struct ahd_linux_device));

    error = ahd_linux_pci_init();
    if (error)
        spi_release_transport(ahd_linux_transport_template);
    return error;
}

static void __exit
ahd_linux_exit(void)
{
    ahd_linux_pci_exit();
    spi_release_transport(ahd_linux_transport_template);
}

module_init(ahd_linux_init);
module_exit(ahd_linux_exit);