scsi_transport_spi.c

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/* 
 *  Parallel SCSI (SPI) transport specific attributes exported to sysfs.
 *
 *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
 *  Copyright (c) 2004, 2005 James Bottomley <[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 of the License, 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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/blkdev.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <scsi/scsi.h>
#include "scsi_priv.h"
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_spi.h>

#define SPI_NUM_ATTRS 14    /* increase this if you add attributes */
#define SPI_OTHER_ATTRS 1   /* Increase this if you add "always
                 * on" attributes */
#define SPI_HOST_ATTRS  1

#define SPI_MAX_ECHO_BUFFER_SIZE    4096

#define DV_LOOPS    3
#define DV_TIMEOUT  (10*HZ)
#define DV_RETRIES  3   /* should only need at most 
                 * two cc/ua clears */

/* Our blacklist flags */
enum {
    SPI_BLIST_NOIUS = 0x1,
};

/* blacklist table, modelled on scsi_devinfo.c */
static struct {
    char *vendor;
    char *model;
    unsigned flags;
} spi_static_device_list[] __initdata = {
    {"HP", "Ultrium 3-SCSI", SPI_BLIST_NOIUS },
    {"IBM", "ULTRIUM-TD3", SPI_BLIST_NOIUS },
    {NULL, NULL, 0}
};

/* Private data accessors (keep these out of the header file) */
#define spi_dv_in_progress(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_in_progress)
#define spi_dv_mutex(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_mutex)

struct spi_internal {
    struct scsi_transport_template t;
    struct spi_function_template *f;
};

#define to_spi_internal(tmpl)   container_of(tmpl, struct spi_internal, t)

static const int ppr_to_ps[] = {
    /* The PPR values 0-6 are reserved, fill them in when
     * the committee defines them */
    -1,         /* 0x00 */
    -1,         /* 0x01 */
    -1,         /* 0x02 */
    -1,         /* 0x03 */
    -1,         /* 0x04 */
    -1,         /* 0x05 */
    -1,         /* 0x06 */
     3125,          /* 0x07 */
     6250,          /* 0x08 */
    12500,          /* 0x09 */
    25000,          /* 0x0a */
    30300,          /* 0x0b */
    50000,          /* 0x0c */
};
/* The PPR values at which you calculate the period in ns by multiplying
 * by 4 */
#define SPI_STATIC_PPR  0x0c

static int sprint_frac(char *dest, int value, int denom)
{
    int frac = value % denom;
    int result = sprintf(dest, "%d", value / denom);

    if (frac == 0)
        return result;
    dest[result++] = '.';

    do {
        denom /= 10;
        sprintf(dest + result, "%d", frac / denom);
        result++;
        frac %= denom;
    } while (frac);

    dest[result++] = '\0';
    return result;
}

static int spi_execute(struct scsi_device *sdev, const void *cmd,
               enum dma_data_direction dir,
               void *buffer, unsigned bufflen,
               struct scsi_sense_hdr *sshdr)
{
    int i, result;
    unsigned char sense[SCSI_SENSE_BUFFERSIZE];

    for(i = 0; i < DV_RETRIES; i++) {
        result = scsi_execute(sdev, cmd, dir, buffer, bufflen,
                      sense, DV_TIMEOUT, /* retries */ 1,
                      REQ_FAILFAST_DEV |
                      REQ_FAILFAST_TRANSPORT |
                      REQ_FAILFAST_DRIVER,
                      NULL);
        if (driver_byte(result) & DRIVER_SENSE) {
            struct scsi_sense_hdr sshdr_tmp;
            if (!sshdr)
                sshdr = &sshdr_tmp;

            if (scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE,
                         sshdr)
                && sshdr->sense_key == UNIT_ATTENTION)
                continue;
        }
        break;
    }
    return result;
}

static struct {
    enum spi_signal_type    value;
    char            *name;
} signal_types[] = {
    { SPI_SIGNAL_UNKNOWN, "unknown" },
    { SPI_SIGNAL_SE, "SE" },
    { SPI_SIGNAL_LVD, "LVD" },
    { SPI_SIGNAL_HVD, "HVD" },
};

static inline const char *spi_signal_to_string(enum spi_signal_type type)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(signal_types); i++) {
        if (type == signal_types[i].value)
            return signal_types[i].name;
    }
    return NULL;
}
static inline enum spi_signal_type spi_signal_to_value(const char *name)
{
    int i, len;

    for (i = 0; i < ARRAY_SIZE(signal_types); i++) {
        len =  strlen(signal_types[i].name);
        if (strncmp(name, signal_types[i].name, len) == 0 &&
            (name[len] == '\n' || name[len] == '\0'))
            return signal_types[i].value;
    }
    return SPI_SIGNAL_UNKNOWN;
}

static int spi_host_setup(struct transport_container *tc, struct device *dev,
              struct device *cdev)
{
    struct Scsi_Host *shost = dev_to_shost(dev);

    spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;

    return 0;
}

static int spi_host_configure(struct transport_container *tc,
                  struct device *dev,
                  struct device *cdev);

static DECLARE_TRANSPORT_CLASS(spi_host_class,
                   "spi_host",
                   spi_host_setup,
                   NULL,
                   spi_host_configure);

static int spi_host_match(struct attribute_container *cont,
              struct device *dev)
{
    struct Scsi_Host *shost;

    if (!scsi_is_host_device(dev))
        return 0;

    shost = dev_to_shost(dev);
    if (!shost->transportt  || shost->transportt->host_attrs.ac.class
        != &spi_host_class.class)
        return 0;

    return &shost->transportt->host_attrs.ac == cont;
}

static int spi_target_configure(struct transport_container *tc,
                struct device *dev,
                struct device *cdev);

static int spi_device_configure(struct transport_container *tc,
                struct device *dev,
                struct device *cdev)
{
    struct scsi_device *sdev = to_scsi_device(dev);
    struct scsi_target *starget = sdev->sdev_target;
    unsigned bflags = scsi_get_device_flags_keyed(sdev, &sdev->inquiry[8],
                              &sdev->inquiry[16],
                              SCSI_DEVINFO_SPI);

    /* Populate the target capability fields with the values
     * gleaned from the device inquiry */

    spi_support_sync(starget) = scsi_device_sync(sdev);
    spi_support_wide(starget) = scsi_device_wide(sdev);
    spi_support_dt(starget) = scsi_device_dt(sdev);
    spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
    spi_support_ius(starget) = scsi_device_ius(sdev);
    if (bflags & SPI_BLIST_NOIUS) {
        dev_info(dev, "Information Units disabled by blacklist\n");
        spi_support_ius(starget) = 0;
    }
    spi_support_qas(starget) = scsi_device_qas(sdev);

    return 0;
}

static int spi_setup_transport_attrs(struct transport_container *tc,
                     struct device *dev,
                     struct device *cdev)
{
    struct scsi_target *starget = to_scsi_target(dev);

    spi_period(starget) = -1;   /* illegal value */
    spi_min_period(starget) = 0;
    spi_offset(starget) = 0;    /* async */
    spi_max_offset(starget) = 255;
    spi_width(starget) = 0; /* narrow */
    spi_max_width(starget) = 1;
    spi_iu(starget) = 0;    /* no IU */
    spi_max_iu(starget) = 1;
    spi_dt(starget) = 0;    /* ST */
    spi_qas(starget) = 0;
    spi_max_qas(starget) = 1;
    spi_wr_flow(starget) = 0;
    spi_rd_strm(starget) = 0;
    spi_rti(starget) = 0;
    spi_pcomp_en(starget) = 0;
    spi_hold_mcs(starget) = 0;
    spi_dv_pending(starget) = 0;
    spi_dv_in_progress(starget) = 0;
    spi_initial_dv(starget) = 0;
    mutex_init(&spi_dv_mutex(starget));

    return 0;
}

#define spi_transport_show_simple(field, format_string)         \
                                    \
static ssize_t                              \
show_spi_transport_##field(struct device *dev,          \
               struct device_attribute *attr, char *buf)    \
{                                   \
    struct scsi_target *starget = transport_class_to_starget(dev);  \
    struct spi_transport_attrs *tp;                 \
                                    \
    tp = (struct spi_transport_attrs *)&starget->starget_data;  \
    return snprintf(buf, 20, format_string, tp->field);     \
}

#define spi_transport_store_simple(field, format_string)        \
                                    \
static ssize_t                              \
store_spi_transport_##field(struct device *dev,             \
                struct device_attribute *attr,      \
                const char *buf, size_t count)      \
{                                   \
    int val;                            \
    struct scsi_target *starget = transport_class_to_starget(dev);  \
    struct spi_transport_attrs *tp;                 \
                                    \
    tp = (struct spi_transport_attrs *)&starget->starget_data;  \
    val = simple_strtoul(buf, NULL, 0);             \
    tp->field = val;                        \
    return count;                           \
}

#define spi_transport_show_function(field, format_string)       \
                                    \
static ssize_t                              \
show_spi_transport_##field(struct device *dev,          \
               struct device_attribute *attr, char *buf)    \
{                                   \
    struct scsi_target *starget = transport_class_to_starget(dev);  \
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
    struct spi_transport_attrs *tp;                 \
    struct spi_internal *i = to_spi_internal(shost->transportt);    \
    tp = (struct spi_transport_attrs *)&starget->starget_data;  \
    if (i->f->get_##field)                      \
        i->f->get_##field(starget);             \
    return snprintf(buf, 20, format_string, tp->field);     \
}

#define spi_transport_store_function(field, format_string)      \
static ssize_t                              \
store_spi_transport_##field(struct device *dev,             \
                struct device_attribute *attr,      \
                const char *buf, size_t count)      \
{                                   \
    int val;                            \
    struct scsi_target *starget = transport_class_to_starget(dev);  \
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
    struct spi_internal *i = to_spi_internal(shost->transportt);    \
                                    \
    if (!i->f->set_##field)                     \
        return -EINVAL;                     \
    val = simple_strtoul(buf, NULL, 0);             \
    i->f->set_##field(starget, val);                \
    return count;                           \
}

#define spi_transport_store_max(field, format_string)           \
static ssize_t                              \
store_spi_transport_##field(struct device *dev,             \
                struct device_attribute *attr,      \
                const char *buf, size_t count)      \
{                                   \
    int val;                            \
    struct scsi_target *starget = transport_class_to_starget(dev);  \
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
    struct spi_internal *i = to_spi_internal(shost->transportt);    \
    struct spi_transport_attrs *tp                  \
        = (struct spi_transport_attrs *)&starget->starget_data; \
                                    \
    if (i->f->set_##field)                      \
        return -EINVAL;                     \
    val = simple_strtoul(buf, NULL, 0);             \
    if (val > tp->max_##field)                  \
        val = tp->max_##field;                  \
    i->f->set_##field(starget, val);                \
    return count;                           \
}

#define spi_transport_rd_attr(field, format_string)         \
    spi_transport_show_function(field, format_string)       \
    spi_transport_store_function(field, format_string)      \
static DEVICE_ATTR(field, S_IRUGO,              \
           show_spi_transport_##field,          \
           store_spi_transport_##field);

#define spi_transport_simple_attr(field, format_string)         \
    spi_transport_show_simple(field, format_string)         \
    spi_transport_store_simple(field, format_string)        \
static DEVICE_ATTR(field, S_IRUGO,              \
           show_spi_transport_##field,          \
           store_spi_transport_##field);

#define spi_transport_max_attr(field, format_string)            \
    spi_transport_show_function(field, format_string)       \
    spi_transport_store_max(field, format_string)           \
    spi_transport_simple_attr(max_##field, format_string)       \
static DEVICE_ATTR(field, S_IRUGO,              \
           show_spi_transport_##field,          \
           store_spi_transport_##field);

/* The Parallel SCSI Tranport Attributes: */
spi_transport_max_attr(offset, "%d\n");
spi_transport_max_attr(width, "%d\n");
spi_transport_max_attr(iu, "%d\n");
spi_transport_rd_attr(dt, "%d\n");
spi_transport_max_attr(qas, "%d\n");
spi_transport_rd_attr(wr_flow, "%d\n");
spi_transport_rd_attr(rd_strm, "%d\n");
spi_transport_rd_attr(rti, "%d\n");
spi_transport_rd_attr(pcomp_en, "%d\n");
spi_transport_rd_attr(hold_mcs, "%d\n");

/* we only care about the first child device that's a real SCSI device
 * so we return 1 to terminate the iteration when we find it */
static int child_iter(struct device *dev, void *data)
{
    if (!scsi_is_sdev_device(dev))
        return 0;

    spi_dv_device(to_scsi_device(dev));
    return 1;
}

static ssize_t
store_spi_revalidate(struct device *dev, struct device_attribute *attr,
             const char *buf, size_t count)
{
    struct scsi_target *starget = transport_class_to_starget(dev);

    device_for_each_child(&starget->dev, NULL, child_iter);
    return count;
}
static DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);

/* Translate the period into ns according to the current spec
 * for SDTR/PPR messages */
static int period_to_str(char *buf, int period)
{
    int len, picosec;

    if (period < 0 || period > 0xff) {
        picosec = -1;
    } else if (period <= SPI_STATIC_PPR) {
        picosec = ppr_to_ps[period];
    } else {
        picosec = period * 4000;
    }

    if (picosec == -1) {
        len = sprintf(buf, "reserved");
    } else {
        len = sprint_frac(buf, picosec, 1000);
    }

    return len;
}

static ssize_t
show_spi_transport_period_helper(char *buf, int period)
{
    int len = period_to_str(buf, period);
    buf[len++] = '\n';
    buf[len] = '\0';
    return len;
}

static ssize_t
store_spi_transport_period_helper(struct device *dev, const char *buf,
                  size_t count, int *periodp)
{
    int j, picosec, period = -1;
    char *endp;

    picosec = simple_strtoul(buf, &endp, 10) * 1000;
    if (*endp == '.') {
        int mult = 100;
        do {
            endp++;
            if (!isdigit(*endp))
                break;
            picosec += (*endp - '0') * mult;
            mult /= 10;
        } while (mult > 0);
    }

    for (j = 0; j <= SPI_STATIC_PPR; j++) {
        if (ppr_to_ps[j] < picosec)
            continue;
        period = j;
        break;
    }

    if (period == -1)
        period = picosec / 4000;

    if (period > 0xff)
        period = 0xff;

    *periodp = period;

    return count;
}

static ssize_t
show_spi_transport_period(struct device *dev,
              struct device_attribute *attr, char *buf)
{
    struct scsi_target *starget = transport_class_to_starget(dev);
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct spi_internal *i = to_spi_internal(shost->transportt);
    struct spi_transport_attrs *tp =
        (struct spi_transport_attrs *)&starget->starget_data;

    if (i->f->get_period)
        i->f->get_period(starget);

    return show_spi_transport_period_helper(buf, tp->period);
}

static ssize_t
store_spi_transport_period(struct device *cdev, struct device_attribute *attr,
               const char *buf, size_t count)
{
    struct scsi_target *starget = transport_class_to_starget(cdev);
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct spi_internal *i = to_spi_internal(shost->transportt);
    struct spi_transport_attrs *tp =
        (struct spi_transport_attrs *)&starget->starget_data;
    int period, retval;

    if (!i->f->set_period)
        return -EINVAL;

    retval = store_spi_transport_period_helper(cdev, buf, count, &period);

    if (period < tp->min_period)
        period = tp->min_period;

    i->f->set_period(starget, period);

    return retval;
}

static DEVICE_ATTR(period, S_IRUGO,
           show_spi_transport_period,
           store_spi_transport_period);

static ssize_t
show_spi_transport_min_period(struct device *cdev,
                  struct device_attribute *attr, char *buf)
{
    struct scsi_target *starget = transport_class_to_starget(cdev);
    struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
    struct spi_internal *i = to_spi_internal(shost->transportt);
    struct spi_transport_attrs *tp =
        (struct spi_transport_attrs *)&starget->starget_data;

    if (!i->f->set_period)
        return -EINVAL;

    return show_spi_transport_period_helper(buf, tp->min_period);
}

static ssize_t
store_spi_transport_min_period(struct device *cdev,
                   struct device_attribute *attr,
                   const char *buf, size_t count)
{
    struct scsi_target *starget = transport_class_to_starget(cdev);
    struct spi_transport_attrs *tp =
        (struct spi_transport_attrs *)&starget->starget_data;

    return store_spi_transport_period_helper(cdev, buf, count,
                         &tp->min_period);
}


static DEVICE_ATTR(min_period, S_IRUGO,
           show_spi_transport_min_period,
           store_spi_transport_min_period);


static ssize_t show_spi_host_signalling(struct device *cdev,
                    struct device_attribute *attr,
                    char *buf)
{
    struct Scsi_Host *shost = transport_class_to_shost(cdev);
    struct spi_internal *i = to_spi_internal(shost->transportt);

    if (i->f->get_signalling)
        i->f->get_signalling(shost);

    return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
}
static ssize_t store_spi_host_signalling(struct device *dev,
                     struct device_attribute *attr,
                     const char *buf, size_t count)
{
    struct Scsi_Host *shost = transport_class_to_shost(dev);
    struct spi_internal *i = to_spi_internal(shost->transportt);
    enum spi_signal_type type = spi_signal_to_value(buf);

    if (!i->f->set_signalling)
        return -EINVAL;

    if (type != SPI_SIGNAL_UNKNOWN)
        i->f->set_signalling(shost, type);

    return count;
}
static DEVICE_ATTR(signalling, S_IRUGO,
           show_spi_host_signalling,
           store_spi_host_signalling);

static ssize_t show_spi_host_width(struct device *cdev,
                      struct device_attribute *attr,
                      char *buf)
{
    struct Scsi_Host *shost = transport_class_to_shost(cdev);

    return sprintf(buf, "%s\n", shost->max_id == 16 ? "wide" : "narrow");
}
static DEVICE_ATTR(host_width, S_IRUGO,
           show_spi_host_width, NULL);

static ssize_t show_spi_host_hba_id(struct device *cdev,
                    struct device_attribute *attr,
                    char *buf)
{
    struct Scsi_Host *shost = transport_class_to_shost(cdev);

    return sprintf(buf, "%d\n", shost->this_id);
}
static DEVICE_ATTR(hba_id, S_IRUGO,
           show_spi_host_hba_id, NULL);

#define DV_SET(x, y)            \
    if(i->f->set_##x)       \
        i->f->set_##x(sdev->sdev_target, y)

enum spi_compare_returns {
    SPI_COMPARE_SUCCESS,
    SPI_COMPARE_FAILURE,
    SPI_COMPARE_SKIP_TEST,
};


/* This is for read/write Domain Validation:  If the device supports
 * an echo buffer, we do read/write tests to it */
static enum spi_compare_returns
spi_dv_device_echo_buffer(struct scsi_device *sdev, u8 *buffer,
              u8 *ptr, const int retries)
{
    int len = ptr - buffer;
    int j, k, r, result;
    unsigned int pattern = 0x0000ffff;
    struct scsi_sense_hdr sshdr;

    const char spi_write_buffer[] = {
        WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
    };
    const char spi_read_buffer[] = {
        READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
    };

    /* set up the pattern buffer.  Doesn't matter if we spill
     * slightly beyond since that's where the read buffer is */
    for (j = 0; j < len; ) {

        /* fill the buffer with counting (test a) */
        for ( ; j < min(len, 32); j++)
            buffer[j] = j;
        k = j;
        /* fill the buffer with alternating words of 0x0 and
         * 0xffff (test b) */
        for ( ; j < min(len, k + 32); j += 2) {
            u16 *word = (u16 *)&buffer[j];
            
            *word = (j & 0x02) ? 0x0000 : 0xffff;
        }
        k = j;
        /* fill with crosstalk (alternating 0x5555 0xaaa)
                 * (test c) */
        for ( ; j < min(len, k + 32); j += 2) {
            u16 *word = (u16 *)&buffer[j];

            *word = (j & 0x02) ? 0x5555 : 0xaaaa;
        }
        k = j;
        /* fill with shifting bits (test d) */
        for ( ; j < min(len, k + 32); j += 4) {
            u32 *word = (unsigned int *)&buffer[j];
            u32 roll = (pattern & 0x80000000) ? 1 : 0;
            
            *word = pattern;
            pattern = (pattern << 1) | roll;
        }
        /* don't bother with random data (test e) */
    }

    for (r = 0; r < retries; r++) {
        result = spi_execute(sdev, spi_write_buffer, DMA_TO_DEVICE,
                     buffer, len, &sshdr);
        if(result || !scsi_device_online(sdev)) {

            scsi_device_set_state(sdev, SDEV_QUIESCE);
            if (scsi_sense_valid(&sshdr)
                && sshdr.sense_key == ILLEGAL_REQUEST
                /* INVALID FIELD IN CDB */
                && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
                /* This would mean that the drive lied
                 * to us about supporting an echo
                 * buffer (unfortunately some Western
                 * Digital drives do precisely this)
                 */
                return SPI_COMPARE_SKIP_TEST;


            sdev_printk(KERN_ERR, sdev, "Write Buffer failure %x\n", result);
            return SPI_COMPARE_FAILURE;
        }

        memset(ptr, 0, len);
        spi_execute(sdev, spi_read_buffer, DMA_FROM_DEVICE,
                ptr, len, NULL);
        scsi_device_set_state(sdev, SDEV_QUIESCE);

        if (memcmp(buffer, ptr, len) != 0)
            return SPI_COMPARE_FAILURE;
    }
    return SPI_COMPARE_SUCCESS;
}

/* This is for the simplest form of Domain Validation: a read test
 * on the inquiry data from the device */
static enum spi_compare_returns
spi_dv_device_compare_inquiry(struct scsi_device *sdev, u8 *buffer,
                  u8 *ptr, const int retries)
{
    int r, result;
    const int len = sdev->inquiry_len;
    const char spi_inquiry[] = {
        INQUIRY, 0, 0, 0, len, 0
    };

    for (r = 0; r < retries; r++) {
        memset(ptr, 0, len);

        result = spi_execute(sdev, spi_inquiry, DMA_FROM_DEVICE,
                     ptr, len, NULL);
        
        if(result || !scsi_device_online(sdev)) {
            scsi_device_set_state(sdev, SDEV_QUIESCE);
            return SPI_COMPARE_FAILURE;
        }

        /* If we don't have the inquiry data already, the
         * first read gets it */
        if (ptr == buffer) {
            ptr += len;
            --r;
            continue;
        }

        if (memcmp(buffer, ptr, len) != 0)
            /* failure */
            return SPI_COMPARE_FAILURE;
    }
    return SPI_COMPARE_SUCCESS;
}

static enum spi_compare_returns
spi_dv_retrain(struct scsi_device *sdev, u8 *buffer, u8 *ptr,
           enum spi_compare_returns 
           (*compare_fn)(struct scsi_device *, u8 *, u8 *, int))
{
    struct spi_internal *i = to_spi_internal(sdev->host->transportt);
    struct scsi_target *starget = sdev->sdev_target;
    int period = 0, prevperiod = 0; 
    enum spi_compare_returns retval;


    for (;;) {
        int newperiod;
        retval = compare_fn(sdev, buffer, ptr, DV_LOOPS);

        if (retval == SPI_COMPARE_SUCCESS
            || retval == SPI_COMPARE_SKIP_TEST)
            break;

        /* OK, retrain, fallback */
        if (i->f->get_iu)
            i->f->get_iu(starget);
        if (i->f->get_qas)
            i->f->get_qas(starget);
        if (i->f->get_period)
            i->f->get_period(sdev->sdev_target);

        /* Here's the fallback sequence; first try turning off
         * IU, then QAS (if we can control them), then finally
         * fall down the periods */
        if (i->f->set_iu && spi_iu(starget)) {
            starget_printk(KERN_ERR, starget, "Domain Validation Disabing Information Units\n");
            DV_SET(iu, 0);
        } else if (i->f->set_qas && spi_qas(starget)) {
            starget_printk(KERN_ERR, starget, "Domain Validation Disabing Quick Arbitration and Selection\n");
            DV_SET(qas, 0);
        } else {
            newperiod = spi_period(starget);
            period = newperiod > period ? newperiod : period;
            if (period < 0x0d)
                period++;
            else
                period += period >> 1;

            if (unlikely(period > 0xff || period == prevperiod)) {
                /* Total failure; set to async and return */
                starget_printk(KERN_ERR, starget, "Domain Validation Failure, dropping back to Asynchronous\n");
                DV_SET(offset, 0);
                return SPI_COMPARE_FAILURE;
            }
            starget_printk(KERN_ERR, starget, "Domain Validation detected failure, dropping back\n");
            DV_SET(period, period);
            prevperiod = period;
        }
    }
    return retval;
}

static int
spi_dv_device_get_echo_buffer(struct scsi_device *sdev, u8 *buffer)
{
    int l, result;

    /* first off do a test unit ready.  This can error out 
     * because of reservations or some other reason.  If it
     * fails, the device won't let us write to the echo buffer
     * so just return failure */
    
    const char spi_test_unit_ready[] = {
        TEST_UNIT_READY, 0, 0, 0, 0, 0
    };

    const char spi_read_buffer_descriptor[] = {
        READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
    };

    
    /* We send a set of three TURs to clear any outstanding 
     * unit attention conditions if they exist (Otherwise the
     * buffer tests won't be happy).  If the TUR still fails
     * (reservation conflict, device not ready, etc) just
     * skip the write tests */
    for (l = 0; ; l++) {
        result = spi_execute(sdev, spi_test_unit_ready, DMA_NONE, 
                     NULL, 0, NULL);

        if(result) {
            if(l >= 3)
                return 0;
        } else {
            /* TUR succeeded */
            break;
        }
    }

    result = spi_execute(sdev, spi_read_buffer_descriptor, 
                 DMA_FROM_DEVICE, buffer, 4, NULL);

    if (result)
        /* Device has no echo buffer */
        return 0;

    return buffer[3] + ((buffer[2] & 0x1f) << 8);
}

static void
spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
{
    struct spi_internal *i = to_spi_internal(sdev->host->transportt);
    struct scsi_target *starget = sdev->sdev_target;
    struct Scsi_Host *shost = sdev->host;
    int len = sdev->inquiry_len;
    int min_period = spi_min_period(starget);
    int max_width = spi_max_width(starget);
    /* first set us up for narrow async */
    DV_SET(offset, 0);
    DV_SET(width, 0);

    if (spi_dv_device_compare_inquiry(sdev, buffer, buffer, DV_LOOPS)
        != SPI_COMPARE_SUCCESS) {
        starget_printk(KERN_ERR, starget, "Domain Validation Initial Inquiry Failed\n");
        /* FIXME: should probably offline the device here? */
        return;
    }

    if (!spi_support_wide(starget)) {
        spi_max_width(starget) = 0;
        max_width = 0;
    }

    /* test width */
    if (i->f->set_width && max_width) {
        i->f->set_width(starget, 1);

        if (spi_dv_device_compare_inquiry(sdev, buffer,
                           buffer + len,
                           DV_LOOPS)
            != SPI_COMPARE_SUCCESS) {
            starget_printk(KERN_ERR, starget, "Wide Transfers Fail\n");
            i->f->set_width(starget, 0);
            /* Make sure we don't force wide back on by asking
             * for a transfer period that requires it */
            max_width = 0;
            if (min_period < 10)
                min_period = 10;
        }
    }

    if (!i->f->set_period)
        return;

    /* device can't handle synchronous */
    if (!spi_support_sync(starget) && !spi_support_dt(starget))
        return;

    /* len == -1 is the signal that we need to ascertain the
     * presence of an echo buffer before trying to use it.  len ==
     * 0 means we don't have an echo buffer */
    len = -1;

 retry:

    /* now set up to the maximum */
    DV_SET(offset, spi_max_offset(starget));
    DV_SET(period, min_period);

    /* try QAS requests; this should be harmless to set if the
     * target supports it */
    if (spi_support_qas(starget) && spi_max_qas(starget)) {
        DV_SET(qas, 1);
    } else {
        DV_SET(qas, 0);
    }

    if (spi_support_ius(starget) && spi_max_iu(starget) &&
        min_period < 9) {
        /* This u320 (or u640). Set IU transfers */
        DV_SET(iu, 1);
        /* Then set the optional parameters */
        DV_SET(rd_strm, 1);
        DV_SET(wr_flow, 1);
        DV_SET(rti, 1);
        if (min_period == 8)
            DV_SET(pcomp_en, 1);
    } else {
        DV_SET(iu, 0);
    }

    /* now that we've done all this, actually check the bus
     * signal type (if known).  Some devices are stupid on
     * a SE bus and still claim they can try LVD only settings */
    if (i->f->get_signalling)
        i->f->get_signalling(shost);
    if (spi_signalling(shost) == SPI_SIGNAL_SE ||
        spi_signalling(shost) == SPI_SIGNAL_HVD ||
        !spi_support_dt(starget)) {
        DV_SET(dt, 0);
    } else {
        DV_SET(dt, 1);
    }
    /* set width last because it will pull all the other
     * parameters down to required values */
    DV_SET(width, max_width);

    /* Do the read only INQUIRY tests */
    spi_dv_retrain(sdev, buffer, buffer + sdev->inquiry_len,
               spi_dv_device_compare_inquiry);
    /* See if we actually managed to negotiate and sustain DT */
    if (i->f->get_dt)
        i->f->get_dt(starget);

    /* see if the device has an echo buffer.  If it does we can do
     * the SPI pattern write tests.  Because of some broken
     * devices, we *only* try this on a device that has actually
     * negotiated DT */

    if (len == -1 && spi_dt(starget))
        len = spi_dv_device_get_echo_buffer(sdev, buffer);

    if (len <= 0) {
        starget_printk(KERN_INFO, starget, "Domain Validation skipping write tests\n");
        return;
    }

    if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
        starget_printk(KERN_WARNING, starget, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
        len = SPI_MAX_ECHO_BUFFER_SIZE;
    }

    if (spi_dv_retrain(sdev, buffer, buffer + len,
               spi_dv_device_echo_buffer)
        == SPI_COMPARE_SKIP_TEST) {
        /* OK, the stupid drive can't do a write echo buffer
         * test after all, fall back to the read tests */
        len = 0;
        goto retry;
    }
}


void
spi_dv_device(struct scsi_device *sdev)
{
    struct scsi_target *starget = sdev->sdev_target;
    u8 *buffer;
    const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;

    if (unlikely(spi_dv_in_progress(starget)))
        return;

    if (unlikely(scsi_device_get(sdev)))
        return;
    spi_dv_in_progress(starget) = 1;

    buffer = kzalloc(len, GFP_KERNEL);

    if (unlikely(!buffer))
        goto out_put;

    /* We need to verify that the actual device will quiesce; the
     * later target quiesce is just a nice to have */
    if (unlikely(scsi_device_quiesce(sdev)))
        goto out_free;

    scsi_target_quiesce(starget);

    spi_dv_pending(starget) = 1;
    mutex_lock(&spi_dv_mutex(starget));

    starget_printk(KERN_INFO, starget, "Beginning Domain Validation\n");

    spi_dv_device_internal(sdev, buffer);

    starget_printk(KERN_INFO, starget, "Ending Domain Validation\n");

    mutex_unlock(&spi_dv_mutex(starget));
    spi_dv_pending(starget) = 0;

    scsi_target_resume(starget);

    spi_initial_dv(starget) = 1;

 out_free:
    kfree(buffer);
 out_put:
    spi_dv_in_progress(starget) = 0;
    scsi_device_put(sdev);
}
EXPORT_SYMBOL(spi_dv_device);

struct work_queue_wrapper {
    struct work_struct  work;
    struct scsi_device  *sdev;
};

static void
spi_dv_device_work_wrapper(struct work_struct *work)
{
    struct work_queue_wrapper *wqw =
        container_of(work, struct work_queue_wrapper, work);
    struct scsi_device *sdev = wqw->sdev;

    kfree(wqw);
    spi_dv_device(sdev);
    spi_dv_pending(sdev->sdev_target) = 0;
    scsi_device_put(sdev);
}


void
spi_schedule_dv_device(struct scsi_device *sdev)
{
    struct work_queue_wrapper *wqw =
        kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);

    if (unlikely(!wqw))
        return;

    if (unlikely(spi_dv_pending(sdev->sdev_target))) {
        kfree(wqw);
        return;
    }
    /* Set pending early (dv_device doesn't check it, only sets it) */
    spi_dv_pending(sdev->sdev_target) = 1;
    if (unlikely(scsi_device_get(sdev))) {
        kfree(wqw);
        spi_dv_pending(sdev->sdev_target) = 0;
        return;
    }

    INIT_WORK(&wqw->work, spi_dv_device_work_wrapper);
    wqw->sdev = sdev;

    schedule_work(&wqw->work);
}
EXPORT_SYMBOL(spi_schedule_dv_device);

void spi_display_xfer_agreement(struct scsi_target *starget)
{
    struct spi_transport_attrs *tp;
    tp = (struct spi_transport_attrs *)&starget->starget_data;

    if (tp->offset > 0 && tp->period > 0) {
        unsigned int picosec, kb100;
        char *scsi = "FAST-?";
        char tmp[8];

        if (tp->period <= SPI_STATIC_PPR) {
            picosec = ppr_to_ps[tp->period];
            switch (tp->period) {
                case  7: scsi = "FAST-320"; break;
                case  8: scsi = "FAST-160"; break;
                case  9: scsi = "FAST-80"; break;
                case 10:
                case 11: scsi = "FAST-40"; break;
                case 12: scsi = "FAST-20"; break;
            }
        } else {
            picosec = tp->period * 4000;
            if (tp->period < 25)
                scsi = "FAST-20";
            else if (tp->period < 50)
                scsi = "FAST-10";
            else
                scsi = "FAST-5";
        }

        kb100 = (10000000 + picosec / 2) / picosec;
        if (tp->width)
            kb100 *= 2;
        sprint_frac(tmp, picosec, 1000);

        dev_info(&starget->dev,
             "%s %sSCSI %d.%d MB/s %s%s%s%s%s%s%s%s (%s ns, offset %d)\n",
             scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
             tp->dt ? "DT" : "ST",
             tp->iu ? " IU" : "",
             tp->qas  ? " QAS" : "",
             tp->rd_strm ? " RDSTRM" : "",
             tp->rti ? " RTI" : "",
             tp->wr_flow ? " WRFLOW" : "",
             tp->pcomp_en ? " PCOMP" : "",
             tp->hold_mcs ? " HMCS" : "",
             tmp, tp->offset);
    } else {
        dev_info(&starget->dev, "%sasynchronous\n",
                tp->width ? "wide " : "");
    }
}
EXPORT_SYMBOL(spi_display_xfer_agreement);

int spi_populate_width_msg(unsigned char *msg, int width)
{
    msg[0] = EXTENDED_MESSAGE;
    msg[1] = 2;
    msg[2] = EXTENDED_WDTR;
    msg[3] = width;
    return 4;
}
EXPORT_SYMBOL_GPL(spi_populate_width_msg);

int spi_populate_sync_msg(unsigned char *msg, int period, int offset)
{
    msg[0] = EXTENDED_MESSAGE;
    msg[1] = 3;
    msg[2] = EXTENDED_SDTR;
    msg[3] = period;
    msg[4] = offset;
    return 5;
}
EXPORT_SYMBOL_GPL(spi_populate_sync_msg);

int spi_populate_ppr_msg(unsigned char *msg, int period, int offset,
        int width, int options)
{
    msg[0] = EXTENDED_MESSAGE;
    msg[1] = 6;
    msg[2] = EXTENDED_PPR;
    msg[3] = period;
    msg[4] = 0;
    msg[5] = offset;
    msg[6] = width;
    msg[7] = options;
    return 8;
}
EXPORT_SYMBOL_GPL(spi_populate_ppr_msg);

#ifdef CONFIG_SCSI_CONSTANTS
static const char * const one_byte_msgs[] = {
/* 0x00 */ "Task Complete", NULL /* Extended Message */, "Save Pointers",
/* 0x03 */ "Restore Pointers", "Disconnect", "Initiator Error", 
/* 0x06 */ "Abort Task Set", "Message Reject", "Nop", "Message Parity Error",
/* 0x0a */ "Linked Command Complete", "Linked Command Complete w/flag",
/* 0x0c */ "Target Reset", "Abort Task", "Clear Task Set", 
/* 0x0f */ "Initiate Recovery", "Release Recovery",
/* 0x11 */ "Terminate Process", "Continue Task", "Target Transfer Disable",
/* 0x14 */ NULL, NULL, "Clear ACA", "LUN Reset"
};

static const char * const two_byte_msgs[] = {
/* 0x20 */ "Simple Queue Tag", "Head of Queue Tag", "Ordered Queue Tag",
/* 0x23 */ "Ignore Wide Residue", "ACA"
};

static const char * const extended_msgs[] = {
/* 0x00 */ "Modify Data Pointer", "Synchronous Data Transfer Request",
/* 0x02 */ "SCSI-I Extended Identify", "Wide Data Transfer Request",
/* 0x04 */ "Parallel Protocol Request", "Modify Bidirectional Data Pointer"
};

static void print_nego(const unsigned char *msg, int per, int off, int width)
{
    if (per) {
        char buf[20];
        period_to_str(buf, msg[per]);
        printk("period = %s ns ", buf);
    }

    if (off)
        printk("offset = %d ", msg[off]);
    if (width)
        printk("width = %d ", 8 << msg[width]);
}

static void print_ptr(const unsigned char *msg, int msb, const char *desc)
{
    int ptr = (msg[msb] << 24) | (msg[msb+1] << 16) | (msg[msb+2] << 8) |
            msg[msb+3];
    printk("%s = %d ", desc, ptr);
}

int spi_print_msg(const unsigned char *msg)
{
    int len = 1, i;
    if (msg[0] == EXTENDED_MESSAGE) {
        len = 2 + msg[1];
        if (len == 2)
            len += 256;
        if (msg[2] < ARRAY_SIZE(extended_msgs))
            printk ("%s ", extended_msgs[msg[2]]); 
        else 
            printk ("Extended Message, reserved code (0x%02x) ",
                (int) msg[2]);
        switch (msg[2]) {
        case EXTENDED_MODIFY_DATA_POINTER:
            print_ptr(msg, 3, "pointer");
            break;
        case EXTENDED_SDTR:
            print_nego(msg, 3, 4, 0);
            break;
        case EXTENDED_WDTR:
            print_nego(msg, 0, 0, 3);
            break;
        case EXTENDED_PPR:
            print_nego(msg, 3, 5, 6);
            break;
        case EXTENDED_MODIFY_BIDI_DATA_PTR:
            print_ptr(msg, 3, "out");
            print_ptr(msg, 7, "in");
            break;
        default:
        for (i = 2; i < len; ++i) 
            printk("%02x ", msg[i]);
        }
    /* Identify */
    } else if (msg[0] & 0x80) {
        printk("Identify disconnect %sallowed %s %d ",
            (msg[0] & 0x40) ? "" : "not ",
            (msg[0] & 0x20) ? "target routine" : "lun",
            msg[0] & 0x7);
    /* Normal One byte */
    } else if (msg[0] < 0x1f) {
        if (msg[0] < ARRAY_SIZE(one_byte_msgs) && one_byte_msgs[msg[0]])
            printk("%s ", one_byte_msgs[msg[0]]);
        else
            printk("reserved (%02x) ", msg[0]);
    } else if (msg[0] == 0x55) {
        printk("QAS Request ");
    /* Two byte */
    } else if (msg[0] <= 0x2f) {
        if ((msg[0] - 0x20) < ARRAY_SIZE(two_byte_msgs))
            printk("%s %02x ", two_byte_msgs[msg[0] - 0x20], 
                msg[1]);
        else 
            printk("reserved two byte (%02x %02x) ", 
                msg[0], msg[1]);
        len = 2;
    } else 
        printk("reserved ");
    return len;
}
EXPORT_SYMBOL(spi_print_msg);

#else  /* ifndef CONFIG_SCSI_CONSTANTS */

int spi_print_msg(const unsigned char *msg)
{
    int len = 1, i;

    if (msg[0] == EXTENDED_MESSAGE) {
        len = 2 + msg[1];
        if (len == 2)
            len += 256;
        for (i = 0; i < len; ++i)
            printk("%02x ", msg[i]);
    /* Identify */
    } else if (msg[0] & 0x80) {
        printk("%02x ", msg[0]);
    /* Normal One byte */
    } else if ((msg[0] < 0x1f) || (msg[0] == 0x55)) {
        printk("%02x ", msg[0]);
    /* Two byte */
    } else if (msg[0] <= 0x2f) {
        printk("%02x %02x", msg[0], msg[1]);
        len = 2;
    } else 
        printk("%02x ", msg[0]);
    return len;
}
EXPORT_SYMBOL(spi_print_msg);
#endif /* ! CONFIG_SCSI_CONSTANTS */

static int spi_device_match(struct attribute_container *cont,
                struct device *dev)
{
    struct scsi_device *sdev;
    struct Scsi_Host *shost;
    struct spi_internal *i;

    if (!scsi_is_sdev_device(dev))
        return 0;

    sdev = to_scsi_device(dev);
    shost = sdev->host;
    if (!shost->transportt  || shost->transportt->host_attrs.ac.class
        != &spi_host_class.class)
        return 0;
    /* Note: this class has no device attributes, so it has
     * no per-HBA allocation and thus we don't need to distinguish
     * the attribute containers for the device */
    i = to_spi_internal(shost->transportt);
    if (i->f->deny_binding && i->f->deny_binding(sdev->sdev_target))
        return 0;
    return 1;
}

static int spi_target_match(struct attribute_container *cont,
                struct device *dev)
{
    struct Scsi_Host *shost;
    struct scsi_target *starget;
    struct spi_internal *i;

    if (!scsi_is_target_device(dev))
        return 0;

    shost = dev_to_shost(dev->parent);
    if (!shost->transportt  || shost->transportt->host_attrs.ac.class
        != &spi_host_class.class)
        return 0;

    i = to_spi_internal(shost->transportt);
    starget = to_scsi_target(dev);

    if (i->f->deny_binding && i->f->deny_binding(starget))
        return 0;

    return &i->t.target_attrs.ac == cont;
}

static DECLARE_TRANSPORT_CLASS(spi_transport_class,
                   "spi_transport",
                   spi_setup_transport_attrs,
                   NULL,
                   spi_target_configure);

static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
                    spi_device_match,
                    spi_device_configure);

static struct attribute *host_attributes[] = {
    &dev_attr_signalling.attr,
    &dev_attr_host_width.attr,
    &dev_attr_hba_id.attr,
    NULL
};

static struct attribute_group host_attribute_group = {
    .attrs = host_attributes,
};

static int spi_host_configure(struct transport_container *tc,
                  struct device *dev,
                  struct device *cdev)
{
    struct kobject *kobj = &cdev->kobj;
    struct Scsi_Host *shost = transport_class_to_shost(cdev);
    struct spi_internal *si = to_spi_internal(shost->transportt);
    struct attribute *attr = &dev_attr_signalling.attr;
    int rc = 0;

    if (si->f->set_signalling)
        rc = sysfs_chmod_file(kobj, attr, attr->mode | S_IWUSR);

    return rc;
}

/* returns true if we should be showing the variable.  Also
 * overloads the return by setting 1<<1 if the attribute should
 * be writeable */
#define TARGET_ATTRIBUTE_HELPER(name) \
    (si->f->show_##name ? S_IRUGO : 0) | \
    (si->f->set_##name ? S_IWUSR : 0)

static umode_t target_attribute_is_visible(struct kobject *kobj,
                      struct attribute *attr, int i)
{
    struct device *cdev = container_of(kobj, struct device, kobj);
    struct scsi_target *starget = transport_class_to_starget(cdev);
    struct Scsi_Host *shost = transport_class_to_shost(cdev);
    struct spi_internal *si = to_spi_internal(shost->transportt);

    if (attr == &dev_attr_period.attr &&
        spi_support_sync(starget))
        return TARGET_ATTRIBUTE_HELPER(period);
    else if (attr == &dev_attr_min_period.attr &&
         spi_support_sync(starget))
        return TARGET_ATTRIBUTE_HELPER(period);
    else if (attr == &dev_attr_offset.attr &&
         spi_support_sync(starget))
        return TARGET_ATTRIBUTE_HELPER(offset);
    else if (attr == &dev_attr_max_offset.attr &&
         spi_support_sync(starget))
        return TARGET_ATTRIBUTE_HELPER(offset);
    else if (attr == &dev_attr_width.attr &&
         spi_support_wide(starget))
        return TARGET_ATTRIBUTE_HELPER(width);
    else if (attr == &dev_attr_max_width.attr &&
         spi_support_wide(starget))
        return TARGET_ATTRIBUTE_HELPER(width);
    else if (attr == &dev_attr_iu.attr &&
         spi_support_ius(starget))
        return TARGET_ATTRIBUTE_HELPER(iu);
    else if (attr == &dev_attr_max_iu.attr &&
         spi_support_ius(starget))
        return TARGET_ATTRIBUTE_HELPER(iu);
    else if (attr == &dev_attr_dt.attr &&
         spi_support_dt(starget))
        return TARGET_ATTRIBUTE_HELPER(dt);
    else if (attr == &dev_attr_qas.attr &&
         spi_support_qas(starget))
        return TARGET_ATTRIBUTE_HELPER(qas);
    else if (attr == &dev_attr_max_qas.attr &&
         spi_support_qas(starget))
        return TARGET_ATTRIBUTE_HELPER(qas);
    else if (attr == &dev_attr_wr_flow.attr &&
         spi_support_ius(starget))
        return TARGET_ATTRIBUTE_HELPER(wr_flow);
    else if (attr == &dev_attr_rd_strm.attr &&
         spi_support_ius(starget))
        return TARGET_ATTRIBUTE_HELPER(rd_strm);
    else if (attr == &dev_attr_rti.attr &&
         spi_support_ius(starget))
        return TARGET_ATTRIBUTE_HELPER(rti);
    else if (attr == &dev_attr_pcomp_en.attr &&
         spi_support_ius(starget))
        return TARGET_ATTRIBUTE_HELPER(pcomp_en);
    else if (attr == &dev_attr_hold_mcs.attr &&
         spi_support_ius(starget))
        return TARGET_ATTRIBUTE_HELPER(hold_mcs);
    else if (attr == &dev_attr_revalidate.attr)
        return S_IWUSR;

    return 0;
}

static struct attribute *target_attributes[] = {
    &dev_attr_period.attr,
    &dev_attr_min_period.attr,
    &dev_attr_offset.attr,
    &dev_attr_max_offset.attr,
    &dev_attr_width.attr,
    &dev_attr_max_width.attr,
    &dev_attr_iu.attr,
    &dev_attr_max_iu.attr,
    &dev_attr_dt.attr,
    &dev_attr_qas.attr,
    &dev_attr_max_qas.attr,
    &dev_attr_wr_flow.attr,
    &dev_attr_rd_strm.attr,
    &dev_attr_rti.attr,
    &dev_attr_pcomp_en.attr,
    &dev_attr_hold_mcs.attr,
    &dev_attr_revalidate.attr,
    NULL
};

static struct attribute_group target_attribute_group = {
    .attrs = target_attributes,
    .is_visible = target_attribute_is_visible,
};

static int spi_target_configure(struct transport_container *tc,
                struct device *dev,
                struct device *cdev)
{
    struct kobject *kobj = &cdev->kobj;

    /* force an update based on parameters read from the device */
    sysfs_update_group(kobj, &target_attribute_group);

    return 0;
}

struct scsi_transport_template *
spi_attach_transport(struct spi_function_template *ft)
{
    struct spi_internal *i = kzalloc(sizeof(struct spi_internal),
                     GFP_KERNEL);

    if (unlikely(!i))
        return NULL;

    i->t.target_attrs.ac.class = &spi_transport_class.class;
    i->t.target_attrs.ac.grp = &target_attribute_group;
    i->t.target_attrs.ac.match = spi_target_match;
    transport_container_register(&i->t.target_attrs);
    i->t.target_size = sizeof(struct spi_transport_attrs);
    i->t.host_attrs.ac.class = &spi_host_class.class;
    i->t.host_attrs.ac.grp = &host_attribute_group;
    i->t.host_attrs.ac.match = spi_host_match;
    transport_container_register(&i->t.host_attrs);
    i->t.host_size = sizeof(struct spi_host_attrs);
    i->f = ft;

    return &i->t;
}
EXPORT_SYMBOL(spi_attach_transport);

void spi_release_transport(struct scsi_transport_template *t)
{
    struct spi_internal *i = to_spi_internal(t);

    transport_container_unregister(&i->t.target_attrs);
    transport_container_unregister(&i->t.host_attrs);

    kfree(i);
}
EXPORT_SYMBOL(spi_release_transport);

static __init int spi_transport_init(void)
{
    int error = scsi_dev_info_add_list(SCSI_DEVINFO_SPI,
                       "SCSI Parallel Transport Class");
    if (!error) {
        int i;

        for (i = 0; spi_static_device_list[i].vendor; i++)
            scsi_dev_info_list_add_keyed(1, /* compatible */
                             spi_static_device_list[i].vendor,
                             spi_static_device_list[i].model,
                             NULL,
                             spi_static_device_list[i].flags,
                             SCSI_DEVINFO_SPI);
    }

    error = transport_class_register(&spi_transport_class);
    if (error)
        return error;
    error = anon_transport_class_register(&spi_device_class);
    return transport_class_register(&spi_host_class);
}

static void __exit spi_transport_exit(void)
{
    transport_class_unregister(&spi_transport_class);
    anon_transport_class_unregister(&spi_device_class);
    transport_class_unregister(&spi_host_class);
    scsi_dev_info_remove_list(SCSI_DEVINFO_SPI);
}

MODULE_AUTHOR("Martin Hicks");
MODULE_DESCRIPTION("SPI Transport Attributes");
MODULE_LICENSE("GPL");

module_init(spi_transport_init);
module_exit(spi_transport_exit);