zfcp_scsi.c

Go to the documentation of this file.

/*
 * zfcp device driver
 *
 * Interface to Linux SCSI midlayer.
 *
 * Copyright IBM Corp. 2002, 2010
 */

#define KMSG_COMPONENT "zfcp"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <scsi/fc/fc_fcp.h>
#include <scsi/scsi_eh.h>
#include <linux/atomic.h>
#include "zfcp_ext.h"
#include "zfcp_dbf.h"
#include "zfcp_fc.h"
#include "zfcp_reqlist.h"

static unsigned int default_depth = 32;
module_param_named(queue_depth, default_depth, uint, 0600);
MODULE_PARM_DESC(queue_depth, "Default queue depth for new SCSI devices");

static bool enable_dif;
module_param_named(dif, enable_dif, bool, 0400);
MODULE_PARM_DESC(dif, "Enable DIF/DIX data integrity support");

static bool allow_lun_scan = 1;
module_param(allow_lun_scan, bool, 0600);
MODULE_PARM_DESC(allow_lun_scan, "For NPIV, scan and attach all storage LUNs");

static int zfcp_scsi_change_queue_depth(struct scsi_device *sdev, int depth,
                    int reason)
{
    switch (reason) {
    case SCSI_QDEPTH_DEFAULT:
        scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
        break;
    case SCSI_QDEPTH_QFULL:
        scsi_track_queue_full(sdev, depth);
        break;
    case SCSI_QDEPTH_RAMP_UP:
        scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
        break;
    default:
        return -EOPNOTSUPP;
    }
    return sdev->queue_depth;
}

static void zfcp_scsi_slave_destroy(struct scsi_device *sdev)
{
    struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);

    /* if previous slave_alloc returned early, there is nothing to do */
    if (!zfcp_sdev->port)
        return;

    zfcp_erp_lun_shutdown_wait(sdev, "scssd_1");
    put_device(&zfcp_sdev->port->dev);
}

static int zfcp_scsi_slave_configure(struct scsi_device *sdp)
{
    if (sdp->tagged_supported)
        scsi_adjust_queue_depth(sdp, MSG_SIMPLE_TAG, default_depth);
    else
        scsi_adjust_queue_depth(sdp, 0, 1);
    return 0;
}

static void zfcp_scsi_command_fail(struct scsi_cmnd *scpnt, int result)
{
    set_host_byte(scpnt, result);
    zfcp_dbf_scsi_fail_send(scpnt);
    scpnt->scsi_done(scpnt);
}

static
int zfcp_scsi_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scpnt)
{
    struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scpnt->device);
    struct fc_rport *rport = starget_to_rport(scsi_target(scpnt->device));
    int    status, scsi_result, ret;

    /* reset the status for this request */
    scpnt->result = 0;
    scpnt->host_scribble = NULL;

    scsi_result = fc_remote_port_chkready(rport);
    if (unlikely(scsi_result)) {
        scpnt->result = scsi_result;
        zfcp_dbf_scsi_fail_send(scpnt);
        scpnt->scsi_done(scpnt);
        return 0;
    }

    status = atomic_read(&zfcp_sdev->status);
    if (unlikely(status & ZFCP_STATUS_COMMON_ERP_FAILED) &&
             !(atomic_read(&zfcp_sdev->port->status) &
               ZFCP_STATUS_COMMON_ERP_FAILED)) {
        /* only LUN access denied, but port is good
         * not covered by FC transport, have to fail here */
        zfcp_scsi_command_fail(scpnt, DID_ERROR);
        return 0;
    }

    if (unlikely(!(status & ZFCP_STATUS_COMMON_UNBLOCKED))) {
        /* This could be either
         * open LUN pending: this is temporary, will result in
         *  open LUN or ERP_FAILED, so retry command
         * call to rport_delete pending: mimic retry from
         *  fc_remote_port_chkready until rport is BLOCKED
         */
        zfcp_scsi_command_fail(scpnt, DID_IMM_RETRY);
        return 0;
    }

    ret = zfcp_fsf_fcp_cmnd(scpnt);
    if (unlikely(ret == -EBUSY))
        return SCSI_MLQUEUE_DEVICE_BUSY;
    else if (unlikely(ret < 0))
        return SCSI_MLQUEUE_HOST_BUSY;

    return ret;
}

static int zfcp_scsi_slave_alloc(struct scsi_device *sdev)
{
    struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
    struct zfcp_adapter *adapter =
        (struct zfcp_adapter *) sdev->host->hostdata[0];
    struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
    struct zfcp_port *port;
    struct zfcp_unit *unit;
    int npiv = adapter->connection_features & FSF_FEATURE_NPIV_MODE;

    port = zfcp_get_port_by_wwpn(adapter, rport->port_name);
    if (!port)
        return -ENXIO;

    unit = zfcp_unit_find(port, zfcp_scsi_dev_lun(sdev));
    if (unit)
        put_device(&unit->dev);

    if (!unit && !(allow_lun_scan && npiv)) {
        put_device(&port->dev);
        return -ENXIO;
    }

    zfcp_sdev->port = port;
    zfcp_sdev->latencies.write.channel.min = 0xFFFFFFFF;
    zfcp_sdev->latencies.write.fabric.min = 0xFFFFFFFF;
    zfcp_sdev->latencies.read.channel.min = 0xFFFFFFFF;
    zfcp_sdev->latencies.read.fabric.min = 0xFFFFFFFF;
    zfcp_sdev->latencies.cmd.channel.min = 0xFFFFFFFF;
    zfcp_sdev->latencies.cmd.fabric.min = 0xFFFFFFFF;
    spin_lock_init(&zfcp_sdev->latencies.lock);

    zfcp_erp_set_lun_status(sdev, ZFCP_STATUS_COMMON_RUNNING);
    zfcp_erp_lun_reopen(sdev, 0, "scsla_1");
    zfcp_erp_wait(port->adapter);

    return 0;
}

static int zfcp_scsi_eh_abort_handler(struct scsi_cmnd *scpnt)
{
    struct Scsi_Host *scsi_host = scpnt->device->host;
    struct zfcp_adapter *adapter =
        (struct zfcp_adapter *) scsi_host->hostdata[0];
    struct zfcp_fsf_req *old_req, *abrt_req;
    unsigned long flags;
    unsigned long old_reqid = (unsigned long) scpnt->host_scribble;
    int retval = SUCCESS, ret;
    int retry = 3;
    char *dbf_tag;

    /* avoid race condition between late normal completion and abort */
    write_lock_irqsave(&adapter->abort_lock, flags);

    old_req = zfcp_reqlist_find(adapter->req_list, old_reqid);
    if (!old_req) {
        write_unlock_irqrestore(&adapter->abort_lock, flags);
        zfcp_dbf_scsi_abort("abrt_or", scpnt, NULL);
        return FAILED; /* completion could be in progress */
    }
    old_req->data = NULL;

    /* don't access old fsf_req after releasing the abort_lock */
    write_unlock_irqrestore(&adapter->abort_lock, flags);

    while (retry--) {
        abrt_req = zfcp_fsf_abort_fcp_cmnd(scpnt);
        if (abrt_req)
            break;

        zfcp_erp_wait(adapter);
        ret = fc_block_scsi_eh(scpnt);
        if (ret) {
            zfcp_dbf_scsi_abort("abrt_bl", scpnt, NULL);
            return ret;
        }
        if (!(atomic_read(&adapter->status) &
              ZFCP_STATUS_COMMON_RUNNING)) {
            zfcp_dbf_scsi_abort("abrt_ru", scpnt, NULL);
            return SUCCESS;
        }
    }
    if (!abrt_req) {
        zfcp_dbf_scsi_abort("abrt_ar", scpnt, NULL);
        return FAILED;
    }

    wait_for_completion(&abrt_req->completion);

    if (abrt_req->status & ZFCP_STATUS_FSFREQ_ABORTSUCCEEDED)
        dbf_tag = "abrt_ok";
    else if (abrt_req->status & ZFCP_STATUS_FSFREQ_ABORTNOTNEEDED)
        dbf_tag = "abrt_nn";
    else {
        dbf_tag = "abrt_fa";
        retval = FAILED;
    }
    zfcp_dbf_scsi_abort(dbf_tag, scpnt, abrt_req);
    zfcp_fsf_req_free(abrt_req);
    return retval;
}

static int zfcp_task_mgmt_function(struct scsi_cmnd *scpnt, u8 tm_flags)
{
    struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scpnt->device);
    struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
    struct zfcp_fsf_req *fsf_req = NULL;
    int retval = SUCCESS, ret;
    int retry = 3;

    while (retry--) {
        fsf_req = zfcp_fsf_fcp_task_mgmt(scpnt, tm_flags);
        if (fsf_req)
            break;

        zfcp_erp_wait(adapter);
        ret = fc_block_scsi_eh(scpnt);
        if (ret)
            return ret;

        if (!(atomic_read(&adapter->status) &
              ZFCP_STATUS_COMMON_RUNNING)) {
            zfcp_dbf_scsi_devreset("nres", scpnt, tm_flags);
            return SUCCESS;
        }
    }
    if (!fsf_req)
        return FAILED;

    wait_for_completion(&fsf_req->completion);

    if (fsf_req->status & ZFCP_STATUS_FSFREQ_TMFUNCFAILED) {
        zfcp_dbf_scsi_devreset("fail", scpnt, tm_flags);
        retval = FAILED;
    } else
        zfcp_dbf_scsi_devreset("okay", scpnt, tm_flags);

    zfcp_fsf_req_free(fsf_req);
    return retval;
}

static int zfcp_scsi_eh_device_reset_handler(struct scsi_cmnd *scpnt)
{
    return zfcp_task_mgmt_function(scpnt, FCP_TMF_LUN_RESET);
}

static int zfcp_scsi_eh_target_reset_handler(struct scsi_cmnd *scpnt)
{
    return zfcp_task_mgmt_function(scpnt, FCP_TMF_TGT_RESET);
}

static int zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *scpnt)
{
    struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scpnt->device);
    struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
    int ret;

    zfcp_erp_adapter_reopen(adapter, 0, "schrh_1");
    zfcp_erp_wait(adapter);
    ret = fc_block_scsi_eh(scpnt);
    if (ret)
        return ret;

    return SUCCESS;
}

struct scsi_transport_template *zfcp_scsi_transport_template;

static struct scsi_host_template zfcp_scsi_host_template = {
    .module          = THIS_MODULE,
    .name            = "zfcp",
    .queuecommand        = zfcp_scsi_queuecommand,
    .eh_abort_handler    = zfcp_scsi_eh_abort_handler,
    .eh_device_reset_handler = zfcp_scsi_eh_device_reset_handler,
    .eh_target_reset_handler = zfcp_scsi_eh_target_reset_handler,
    .eh_host_reset_handler   = zfcp_scsi_eh_host_reset_handler,
    .slave_alloc         = zfcp_scsi_slave_alloc,
    .slave_configure     = zfcp_scsi_slave_configure,
    .slave_destroy       = zfcp_scsi_slave_destroy,
    .change_queue_depth  = zfcp_scsi_change_queue_depth,
    .proc_name       = "zfcp",
    .can_queue       = 4096,
    .this_id         = -1,
    .sg_tablesize        = 1, /* adjusted later */
    .max_sectors         = 8, /* adjusted later */
    .dma_boundary        = ZFCP_QDIO_SBALE_LEN - 1,
    .cmd_per_lun         = 1,
    .use_clustering      = 1,
    .shost_attrs         = zfcp_sysfs_shost_attrs,
    .sdev_attrs      = zfcp_sysfs_sdev_attrs,
};

int zfcp_scsi_adapter_register(struct zfcp_adapter *adapter)
{
    struct ccw_dev_id dev_id;

    if (adapter->scsi_host)
        return 0;

    ccw_device_get_id(adapter->ccw_device, &dev_id);
    /* register adapter as SCSI host with mid layer of SCSI stack */
    adapter->scsi_host = scsi_host_alloc(&zfcp_scsi_host_template,
                         sizeof (struct zfcp_adapter *));
    if (!adapter->scsi_host) {
        dev_err(&adapter->ccw_device->dev,
            "Registering the FCP device with the "
            "SCSI stack failed\n");
        return -EIO;
    }

    /* tell the SCSI stack some characteristics of this adapter */
    adapter->scsi_host->max_id = 511;
    adapter->scsi_host->max_lun = 0xFFFFFFFF;
    adapter->scsi_host->max_channel = 0;
    adapter->scsi_host->unique_id = dev_id.devno;
    adapter->scsi_host->max_cmd_len = 16; /* in struct fcp_cmnd */
    adapter->scsi_host->transportt = zfcp_scsi_transport_template;

    adapter->scsi_host->hostdata[0] = (unsigned long) adapter;

    if (scsi_add_host(adapter->scsi_host, &adapter->ccw_device->dev)) {
        scsi_host_put(adapter->scsi_host);
        return -EIO;
    }

    return 0;
}

void zfcp_scsi_adapter_unregister(struct zfcp_adapter *adapter)
{
    struct Scsi_Host *shost;
    struct zfcp_port *port;

    shost = adapter->scsi_host;
    if (!shost)
        return;

    read_lock_irq(&adapter->port_list_lock);
    list_for_each_entry(port, &adapter->port_list, list)
        port->rport = NULL;
    read_unlock_irq(&adapter->port_list_lock);

    fc_remove_host(shost);
    scsi_remove_host(shost);
    scsi_host_put(shost);
    adapter->scsi_host = NULL;
}

static struct fc_host_statistics*
zfcp_init_fc_host_stats(struct zfcp_adapter *adapter)
{
    struct fc_host_statistics *fc_stats;

    if (!adapter->fc_stats) {
        fc_stats = kmalloc(sizeof(*fc_stats), GFP_KERNEL);
        if (!fc_stats)
            return NULL;
        adapter->fc_stats = fc_stats; /* freed in adapter_release */
    }
    memset(adapter->fc_stats, 0, sizeof(*adapter->fc_stats));
    return adapter->fc_stats;
}

static void zfcp_adjust_fc_host_stats(struct fc_host_statistics *fc_stats,
                      struct fsf_qtcb_bottom_port *data,
                      struct fsf_qtcb_bottom_port *old)
{
    fc_stats->seconds_since_last_reset =
        data->seconds_since_last_reset - old->seconds_since_last_reset;
    fc_stats->tx_frames = data->tx_frames - old->tx_frames;
    fc_stats->tx_words = data->tx_words - old->tx_words;
    fc_stats->rx_frames = data->rx_frames - old->rx_frames;
    fc_stats->rx_words = data->rx_words - old->rx_words;
    fc_stats->lip_count = data->lip - old->lip;
    fc_stats->nos_count = data->nos - old->nos;
    fc_stats->error_frames = data->error_frames - old->error_frames;
    fc_stats->dumped_frames = data->dumped_frames - old->dumped_frames;
    fc_stats->link_failure_count = data->link_failure - old->link_failure;
    fc_stats->loss_of_sync_count = data->loss_of_sync - old->loss_of_sync;
    fc_stats->loss_of_signal_count =
        data->loss_of_signal - old->loss_of_signal;
    fc_stats->prim_seq_protocol_err_count =
        data->psp_error_counts - old->psp_error_counts;
    fc_stats->invalid_tx_word_count =
        data->invalid_tx_words - old->invalid_tx_words;
    fc_stats->invalid_crc_count = data->invalid_crcs - old->invalid_crcs;
    fc_stats->fcp_input_requests =
        data->input_requests - old->input_requests;
    fc_stats->fcp_output_requests =
        data->output_requests - old->output_requests;
    fc_stats->fcp_control_requests =
        data->control_requests - old->control_requests;
    fc_stats->fcp_input_megabytes = data->input_mb - old->input_mb;
    fc_stats->fcp_output_megabytes = data->output_mb - old->output_mb;
}

static void zfcp_set_fc_host_stats(struct fc_host_statistics *fc_stats,
                   struct fsf_qtcb_bottom_port *data)
{
    fc_stats->seconds_since_last_reset = data->seconds_since_last_reset;
    fc_stats->tx_frames = data->tx_frames;
    fc_stats->tx_words = data->tx_words;
    fc_stats->rx_frames = data->rx_frames;
    fc_stats->rx_words = data->rx_words;
    fc_stats->lip_count = data->lip;
    fc_stats->nos_count = data->nos;
    fc_stats->error_frames = data->error_frames;
    fc_stats->dumped_frames = data->dumped_frames;
    fc_stats->link_failure_count = data->link_failure;
    fc_stats->loss_of_sync_count = data->loss_of_sync;
    fc_stats->loss_of_signal_count = data->loss_of_signal;
    fc_stats->prim_seq_protocol_err_count = data->psp_error_counts;
    fc_stats->invalid_tx_word_count = data->invalid_tx_words;
    fc_stats->invalid_crc_count = data->invalid_crcs;
    fc_stats->fcp_input_requests = data->input_requests;
    fc_stats->fcp_output_requests = data->output_requests;
    fc_stats->fcp_control_requests = data->control_requests;
    fc_stats->fcp_input_megabytes = data->input_mb;
    fc_stats->fcp_output_megabytes = data->output_mb;
}

static struct fc_host_statistics *zfcp_get_fc_host_stats(struct Scsi_Host *host)
{
    struct zfcp_adapter *adapter;
    struct fc_host_statistics *fc_stats;
    struct fsf_qtcb_bottom_port *data;
    int ret;

    adapter = (struct zfcp_adapter *)host->hostdata[0];
    fc_stats = zfcp_init_fc_host_stats(adapter);
    if (!fc_stats)
        return NULL;

    data = kzalloc(sizeof(*data), GFP_KERNEL);
    if (!data)
        return NULL;

    ret = zfcp_fsf_exchange_port_data_sync(adapter->qdio, data);
    if (ret) {
        kfree(data);
        return NULL;
    }

    if (adapter->stats_reset &&
        ((jiffies/HZ - adapter->stats_reset) <
         data->seconds_since_last_reset))
        zfcp_adjust_fc_host_stats(fc_stats, data,
                      adapter->stats_reset_data);
    else
        zfcp_set_fc_host_stats(fc_stats, data);

    kfree(data);
    return fc_stats;
}

static void zfcp_reset_fc_host_stats(struct Scsi_Host *shost)
{
    struct zfcp_adapter *adapter;
    struct fsf_qtcb_bottom_port *data;
    int ret;

    adapter = (struct zfcp_adapter *)shost->hostdata[0];
    data = kzalloc(sizeof(*data), GFP_KERNEL);
    if (!data)
        return;

    ret = zfcp_fsf_exchange_port_data_sync(adapter->qdio, data);
    if (ret)
        kfree(data);
    else {
        adapter->stats_reset = jiffies/HZ;
        kfree(adapter->stats_reset_data);
        adapter->stats_reset_data = data; /* finally freed in
                             adapter_release */
    }
}

static void zfcp_get_host_port_state(struct Scsi_Host *shost)
{
    struct zfcp_adapter *adapter =
        (struct zfcp_adapter *)shost->hostdata[0];
    int status = atomic_read(&adapter->status);

    if ((status & ZFCP_STATUS_COMMON_RUNNING) &&
        !(status & ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED))
        fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
    else if (status & ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED)
        fc_host_port_state(shost) = FC_PORTSTATE_LINKDOWN;
    else if (status & ZFCP_STATUS_COMMON_ERP_FAILED)
        fc_host_port_state(shost) = FC_PORTSTATE_ERROR;
    else
        fc_host_port_state(shost) = FC_PORTSTATE_UNKNOWN;
}

static void zfcp_set_rport_dev_loss_tmo(struct fc_rport *rport, u32 timeout)
{
    rport->dev_loss_tmo = timeout;
}

static void zfcp_scsi_terminate_rport_io(struct fc_rport *rport)
{
    struct zfcp_port *port;
    struct Scsi_Host *shost = rport_to_shost(rport);
    struct zfcp_adapter *adapter =
        (struct zfcp_adapter *)shost->hostdata[0];

    port = zfcp_get_port_by_wwpn(adapter, rport->port_name);

    if (port) {
        zfcp_erp_port_forced_reopen(port, 0, "sctrpi1");
        put_device(&port->dev);
    }
}

static void zfcp_scsi_rport_register(struct zfcp_port *port)
{
    struct fc_rport_identifiers ids;
    struct fc_rport *rport;

    if (port->rport)
        return;

    ids.node_name = port->wwnn;
    ids.port_name = port->wwpn;
    ids.port_id = port->d_id;
    ids.roles = FC_RPORT_ROLE_FCP_TARGET;

    rport = fc_remote_port_add(port->adapter->scsi_host, 0, &ids);
    if (!rport) {
        dev_err(&port->adapter->ccw_device->dev,
            "Registering port 0x%016Lx failed\n",
            (unsigned long long)port->wwpn);
        return;
    }

    rport->maxframe_size = port->maxframe_size;
    rport->supported_classes = port->supported_classes;
    port->rport = rport;
    port->starget_id = rport->scsi_target_id;

    zfcp_unit_queue_scsi_scan(port);
}

static void zfcp_scsi_rport_block(struct zfcp_port *port)
{
    struct fc_rport *rport = port->rport;

    if (rport) {
        fc_remote_port_delete(rport);
        port->rport = NULL;
    }
}

void zfcp_scsi_schedule_rport_register(struct zfcp_port *port)
{
    get_device(&port->dev);
    port->rport_task = RPORT_ADD;

    if (!queue_work(port->adapter->work_queue, &port->rport_work))
        put_device(&port->dev);
}

void zfcp_scsi_schedule_rport_block(struct zfcp_port *port)
{
    get_device(&port->dev);
    port->rport_task = RPORT_DEL;

    if (port->rport && queue_work(port->adapter->work_queue,
                      &port->rport_work))
        return;

    put_device(&port->dev);
}

void zfcp_scsi_schedule_rports_block(struct zfcp_adapter *adapter)
{
    unsigned long flags;
    struct zfcp_port *port;

    read_lock_irqsave(&adapter->port_list_lock, flags);
    list_for_each_entry(port, &adapter->port_list, list)
        zfcp_scsi_schedule_rport_block(port);
    read_unlock_irqrestore(&adapter->port_list_lock, flags);
}

void zfcp_scsi_rport_work(struct work_struct *work)
{
    struct zfcp_port *port = container_of(work, struct zfcp_port,
                          rport_work);

    while (port->rport_task) {
        if (port->rport_task == RPORT_ADD) {
            port->rport_task = RPORT_NONE;
            zfcp_scsi_rport_register(port);
        } else {
            port->rport_task = RPORT_NONE;
            zfcp_scsi_rport_block(port);
        }
    }

    put_device(&port->dev);
}

void zfcp_scsi_set_prot(struct zfcp_adapter *adapter)
{
    unsigned int mask = 0;
    unsigned int data_div;
    struct Scsi_Host *shost = adapter->scsi_host;

    data_div = atomic_read(&adapter->status) &
           ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED;

    if (enable_dif &&
        adapter->adapter_features & FSF_FEATURE_DIF_PROT_TYPE1)
        mask |= SHOST_DIF_TYPE1_PROTECTION;

    if (enable_dif && data_div &&
        adapter->adapter_features & FSF_FEATURE_DIX_PROT_TCPIP) {
        mask |= SHOST_DIX_TYPE1_PROTECTION;
        scsi_host_set_guard(shost, SHOST_DIX_GUARD_IP);
        shost->sg_prot_tablesize = adapter->qdio->max_sbale_per_req / 2;
        shost->sg_tablesize = adapter->qdio->max_sbale_per_req / 2;
        shost->max_sectors = shost->sg_tablesize * 8;
    }

    scsi_host_set_prot(shost, mask);
}

void zfcp_scsi_dif_sense_error(struct scsi_cmnd *scmd, int ascq)
{
    scsi_build_sense_buffer(1, scmd->sense_buffer,
                ILLEGAL_REQUEST, 0x10, ascq);
    set_driver_byte(scmd, DRIVER_SENSE);
    scmd->result |= SAM_STAT_CHECK_CONDITION;
    set_host_byte(scmd, DID_SOFT_ERROR);
}

struct fc_function_template zfcp_transport_functions = {
    .show_starget_port_id = 1,
    .show_starget_port_name = 1,
    .show_starget_node_name = 1,
    .show_rport_supported_classes = 1,
    .show_rport_maxframe_size = 1,
    .show_rport_dev_loss_tmo = 1,
    .show_host_node_name = 1,
    .show_host_port_name = 1,
    .show_host_permanent_port_name = 1,
    .show_host_supported_classes = 1,
    .show_host_supported_fc4s = 1,
    .show_host_supported_speeds = 1,
    .show_host_maxframe_size = 1,
    .show_host_serial_number = 1,
    .get_fc_host_stats = zfcp_get_fc_host_stats,
    .reset_fc_host_stats = zfcp_reset_fc_host_stats,
    .set_rport_dev_loss_tmo = zfcp_set_rport_dev_loss_tmo,
    .get_host_port_state = zfcp_get_host_port_state,
    .terminate_rport_io = zfcp_scsi_terminate_rport_io,
    .show_host_port_state = 1,
    .show_host_active_fc4s = 1,
    .bsg_request = zfcp_fc_exec_bsg_job,
    .bsg_timeout = zfcp_fc_timeout_bsg_job,
    /* no functions registered for following dynamic attributes but
       directly set by LLDD */
    .show_host_port_type = 1,
    .show_host_symbolic_name = 1,
    .show_host_speed = 1,
    .show_host_port_id = 1,
    .dd_bsg_size = sizeof(struct zfcp_fsf_ct_els),
};