[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / scsi / ibmvscsi / ibmvfc.c

/*
 * ibmvfc.c -- driver for IBM Power Virtual Fibre Channel Adapter
 *
 * Written By: Brian King <brking@linux.vnet.ibm.com>, IBM Corporation
 *
 * Copyright (C) IBM Corporation, 2008
 *
 * 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/module.h>
#include <linux/moduleparam.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/kthread.h>
#include <linux/of.h>
#include <linux/stringify.h>
#include <asm/firmware.h>
#include <asm/irq.h>
#include <asm/vio.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_transport_fc.h>
#include "ibmvfc.h"

static unsigned int init_timeout = IBMVFC_INIT_TIMEOUT;
static unsigned int default_timeout = IBMVFC_DEFAULT_TIMEOUT;
static unsigned int max_lun = IBMVFC_MAX_LUN;
static unsigned int max_targets = IBMVFC_MAX_TARGETS;
static unsigned int max_requests = IBMVFC_MAX_REQUESTS_DEFAULT;
static unsigned int disc_threads = IBMVFC_MAX_DISC_THREADS;
static unsigned int dev_loss_tmo = IBMVFC_DEV_LOSS_TMO;
static unsigned int ibmvfc_debug = IBMVFC_DEBUG;
static unsigned int log_level = IBMVFC_DEFAULT_LOG_LEVEL;
static LIST_HEAD(ibmvfc_head);
static DEFINE_SPINLOCK(ibmvfc_driver_lock);
static struct scsi_transport_template *ibmvfc_transport_template;

MODULE_DESCRIPTION("IBM Virtual Fibre Channel Driver");
MODULE_AUTHOR("Brian King <brking@linux.vnet.ibm.com>");
MODULE_LICENSE("GPL");
MODULE_VERSION(IBMVFC_DRIVER_VERSION);

module_param_named(init_timeout, init_timeout, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds. "
                 "[Default=" __stringify(IBMVFC_INIT_TIMEOUT) "]");
module_param_named(default_timeout, default_timeout, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(default_timeout,
                 "Default timeout in seconds for initialization and EH commands. "
                 "[Default=" __stringify(IBMVFC_DEFAULT_TIMEOUT) "]");
module_param_named(max_requests, max_requests, uint, S_IRUGO);
MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter. "
                 "[Default=" __stringify(IBMVFC_MAX_REQUESTS_DEFAULT) "]");
module_param_named(max_lun, max_lun, uint, S_IRUGO);
MODULE_PARM_DESC(max_lun, "Maximum allowed LUN. "
                 "[Default=" __stringify(IBMVFC_MAX_LUN) "]");
module_param_named(max_targets, max_targets, uint, S_IRUGO);
MODULE_PARM_DESC(max_targets, "Maximum allowed targets. "
                 "[Default=" __stringify(IBMVFC_MAX_TARGETS) "]");
module_param_named(disc_threads, disc_threads, uint, S_IRUGO);
MODULE_PARM_DESC(disc_threads, "Number of device discovery threads to use. "
                 "[Default=" __stringify(IBMVFC_MAX_DISC_THREADS) "]");
module_param_named(debug, ibmvfc_debug, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Enable driver debug information. "
                 "[Default=" __stringify(IBMVFC_DEBUG) "]");
module_param_named(dev_loss_tmo, dev_loss_tmo, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(dev_loss_tmo, "Maximum number of seconds that the FC "
                 "transport should insulate the loss of a remote port. Once this "
                 "value is exceeded, the scsi target is removed. "
                 "[Default=" __stringify(IBMVFC_DEV_LOSS_TMO) "]");
module_param_named(log_level, log_level, uint, 0);
MODULE_PARM_DESC(log_level, "Set to 0 - 4 for increasing verbosity of device driver. "
                 "[Default=" __stringify(IBMVFC_DEFAULT_LOG_LEVEL) "]");

static const struct {
        u16 status;
        u16 error;
        u8 result;
        u8 retry;
        int log;
        char *name;
} cmd_status [] = {
        { IBMVFC_FABRIC_MAPPED, IBMVFC_UNABLE_TO_ESTABLISH, DID_ERROR, 1, 1, "unable to establish" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_XPORT_FAULT, DID_OK, 1, 0, "transport fault" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_CMD_TIMEOUT, DID_TIME_OUT, 1, 1, "command timeout" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_ENETDOWN, DID_TRANSPORT_DISRUPTED, 1, 1, "network down" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_HW_FAILURE, DID_ERROR, 1, 1, "hardware failure" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_LINK_DOWN_ERR, DID_REQUEUE, 0, 0, "link down" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_LINK_DEAD_ERR, DID_ERROR, 0, 0, "link dead" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_UNABLE_TO_REGISTER, DID_ERROR, 1, 1, "unable to register" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_XPORT_BUSY, DID_BUS_BUSY, 1, 0, "transport busy" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_XPORT_DEAD, DID_ERROR, 0, 1, "transport dead" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_CONFIG_ERROR, DID_ERROR, 1, 1, "configuration error" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_NAME_SERVER_FAIL, DID_ERROR, 1, 1, "name server failure" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_LINK_HALTED, DID_REQUEUE, 0, 0, "link halted" },
        { IBMVFC_FABRIC_MAPPED, IBMVFC_XPORT_GENERAL, DID_OK, 1, 0, "general transport error" },

        { IBMVFC_VIOS_FAILURE, IBMVFC_CRQ_FAILURE, DID_REQUEUE, 1, 1, "CRQ failure" },
        { IBMVFC_VIOS_FAILURE, IBMVFC_SW_FAILURE, DID_ERROR, 0, 1, "software failure" },
        { IBMVFC_VIOS_FAILURE, IBMVFC_INVALID_PARAMETER, DID_ERROR, 0, 1, "invalid parameter" },
        { IBMVFC_VIOS_FAILURE, IBMVFC_MISSING_PARAMETER, DID_ERROR, 0, 1, "missing parameter" },
        { IBMVFC_VIOS_FAILURE, IBMVFC_HOST_IO_BUS, DID_ERROR, 1, 1, "host I/O bus failure" },
        { IBMVFC_VIOS_FAILURE, IBMVFC_TRANS_CANCELLED, DID_ERROR, 0, 1, "transaction cancelled" },
        { IBMVFC_VIOS_FAILURE, IBMVFC_TRANS_CANCELLED_IMPLICIT, DID_ERROR, 0, 1, "transaction cancelled implicit" },
        { IBMVFC_VIOS_FAILURE, IBMVFC_INSUFFICIENT_RESOURCE, DID_REQUEUE, 1, 1, "insufficient resources" },
        { IBMVFC_VIOS_FAILURE, IBMVFC_PLOGI_REQUIRED, DID_ERROR, 0, 1, "port login required" },
        { IBMVFC_VIOS_FAILURE, IBMVFC_COMMAND_FAILED, DID_ERROR, 1, 1, "command failed" },

        { IBMVFC_FC_FAILURE, IBMVFC_INVALID_ELS_CMD_CODE, DID_ERROR, 0, 1, "invalid ELS command code" },
        { IBMVFC_FC_FAILURE, IBMVFC_INVALID_VERSION, DID_ERROR, 0, 1, "invalid version level" },
        { IBMVFC_FC_FAILURE, IBMVFC_LOGICAL_ERROR, DID_ERROR, 1, 1, "logical error" },
        { IBMVFC_FC_FAILURE, IBMVFC_INVALID_CT_IU_SIZE, DID_ERROR, 0, 1, "invalid CT_IU size" },
        { IBMVFC_FC_FAILURE, IBMVFC_LOGICAL_BUSY, DID_REQUEUE, 1, 0, "logical busy" },
        { IBMVFC_FC_FAILURE, IBMVFC_PROTOCOL_ERROR, DID_ERROR, 1, 1, "protocol error" },
        { IBMVFC_FC_FAILURE, IBMVFC_UNABLE_TO_PERFORM_REQ, DID_ERROR, 1, 1, "unable to perform request" },
        { IBMVFC_FC_FAILURE, IBMVFC_CMD_NOT_SUPPORTED, DID_ERROR, 0, 0, "command not supported" },
        { IBMVFC_FC_FAILURE, IBMVFC_SERVER_NOT_AVAIL, DID_ERROR, 0, 1, "server not available" },
        { IBMVFC_FC_FAILURE, IBMVFC_CMD_IN_PROGRESS, DID_ERROR, 0, 1, "command already in progress" },
        { IBMVFC_FC_FAILURE, IBMVFC_VENDOR_SPECIFIC, DID_ERROR, 1, 1, "vendor specific" },

        { IBMVFC_FC_SCSI_ERROR, 0, DID_OK, 1, 0, "SCSI error" },
};

static void ibmvfc_npiv_login(struct ibmvfc_host *);
static void ibmvfc_tgt_send_prli(struct ibmvfc_target *);
static void ibmvfc_tgt_send_plogi(struct ibmvfc_target *);
static void ibmvfc_tgt_query_target(struct ibmvfc_target *);

static const char *unknown_error = "unknown error";

#ifdef CONFIG_SCSI_IBMVFC_TRACE
/**
 * ibmvfc_trc_start - Log a start trace entry
 * @evt:                ibmvfc event struct
 *
 **/
static void ibmvfc_trc_start(struct ibmvfc_event *evt)
{
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_cmd *vfc_cmd = &evt->iu.cmd;
        struct ibmvfc_mad_common *mad = &evt->iu.mad_common;
        struct ibmvfc_trace_entry *entry;

        entry = &vhost->trace[vhost->trace_index++];
        entry->evt = evt;
        entry->time = jiffies;
        entry->fmt = evt->crq.format;
        entry->type = IBMVFC_TRC_START;

        switch (entry->fmt) {
        case IBMVFC_CMD_FORMAT:
                entry->op_code = vfc_cmd->iu.cdb[0];
                entry->scsi_id = vfc_cmd->tgt_scsi_id;
                entry->lun = scsilun_to_int(&vfc_cmd->iu.lun);
                entry->tmf_flags = vfc_cmd->iu.tmf_flags;
                entry->u.start.xfer_len = vfc_cmd->iu.xfer_len;
                break;
        case IBMVFC_MAD_FORMAT:
                entry->op_code = mad->opcode;
                break;
        default:
                break;
        };
}

/**
 * ibmvfc_trc_end - Log an end trace entry
 * @evt:                ibmvfc event struct
 *
 **/
static void ibmvfc_trc_end(struct ibmvfc_event *evt)
{
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_cmd *vfc_cmd = &evt->xfer_iu->cmd;
        struct ibmvfc_mad_common *mad = &evt->xfer_iu->mad_common;
        struct ibmvfc_trace_entry *entry = &vhost->trace[vhost->trace_index++];

        entry->evt = evt;
        entry->time = jiffies;
        entry->fmt = evt->crq.format;
        entry->type = IBMVFC_TRC_END;

        switch (entry->fmt) {
        case IBMVFC_CMD_FORMAT:
                entry->op_code = vfc_cmd->iu.cdb[0];
                entry->scsi_id = vfc_cmd->tgt_scsi_id;
                entry->lun = scsilun_to_int(&vfc_cmd->iu.lun);
                entry->tmf_flags = vfc_cmd->iu.tmf_flags;
                entry->u.end.status = vfc_cmd->status;
                entry->u.end.error = vfc_cmd->error;
                entry->u.end.fcp_rsp_flags = vfc_cmd->rsp.flags;
                entry->u.end.rsp_code = vfc_cmd->rsp.data.info.rsp_code;
                entry->u.end.scsi_status = vfc_cmd->rsp.scsi_status;
                break;
        case IBMVFC_MAD_FORMAT:
                entry->op_code = mad->opcode;
                entry->u.end.status = mad->status;
                break;
        default:
                break;

        };
}

#else
#define ibmvfc_trc_start(evt) do { } while (0)
#define ibmvfc_trc_end(evt) do { } while (0)
#endif

/**
 * ibmvfc_get_err_index - Find the index into cmd_status for the fcp response
 * @status:             status / error class
 * @error:              error
 *
 * Return value:
 *      index into cmd_status / -EINVAL on failure
 **/
static int ibmvfc_get_err_index(u16 status, u16 error)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(cmd_status); i++)
                if ((cmd_status[i].status & status) == cmd_status[i].status &&
                    cmd_status[i].error == error)
                        return i;

        return -EINVAL;
}

/**
 * ibmvfc_get_cmd_error - Find the error description for the fcp response
 * @status:             status / error class
 * @error:              error
 *
 * Return value:
 *      error description string
 **/
static const char *ibmvfc_get_cmd_error(u16 status, u16 error)
{
        int rc = ibmvfc_get_err_index(status, error);
        if (rc >= 0)
                return cmd_status[rc].name;
        return unknown_error;
}

/**
 * ibmvfc_get_err_result - Find the scsi status to return for the fcp response
 * @vfc_cmd:    ibmvfc command struct
 *
 * Return value:
 *      SCSI result value to return for completed command
 **/
static int ibmvfc_get_err_result(struct ibmvfc_cmd *vfc_cmd)
{
        int err;
        struct ibmvfc_fcp_rsp *rsp = &vfc_cmd->rsp;
        int fc_rsp_len = rsp->fcp_rsp_len;

        if ((rsp->flags & FCP_RSP_LEN_VALID) &&
            ((fc_rsp_len && fc_rsp_len != 4 && fc_rsp_len != 8) ||
             rsp->data.info.rsp_code))
                return DID_ERROR << 16;

        err = ibmvfc_get_err_index(vfc_cmd->status, vfc_cmd->error);
        if (err >= 0)
                return rsp->scsi_status | (cmd_status[err].result << 16);
        return rsp->scsi_status | (DID_ERROR << 16);
}

/**
 * ibmvfc_retry_cmd - Determine if error status is retryable
 * @status:             status / error class
 * @error:              error
 *
 * Return value:
 *      1 if error should be retried / 0 if it should not
 **/
static int ibmvfc_retry_cmd(u16 status, u16 error)
{
        int rc = ibmvfc_get_err_index(status, error);

        if (rc >= 0)
                return cmd_status[rc].retry;
        return 1;
}

static const char *unknown_fc_explain = "unknown fc explain";

static const struct {
        u16 fc_explain;
        char *name;
} ls_explain [] = {
        { 0x00, "no additional explanation" },
        { 0x01, "service parameter error - options" },
        { 0x03, "service parameter error - initiator control" },
        { 0x05, "service parameter error - recipient control" },
        { 0x07, "service parameter error - received data field size" },
        { 0x09, "service parameter error - concurrent seq" },
        { 0x0B, "service parameter error - credit" },
        { 0x0D, "invalid N_Port/F_Port_Name" },
        { 0x0E, "invalid node/Fabric Name" },
        { 0x0F, "invalid common service parameters" },
        { 0x11, "invalid association header" },
        { 0x13, "association header required" },
        { 0x15, "invalid originator S_ID" },
        { 0x17, "invalid OX_ID-RX-ID combination" },
        { 0x19, "command (request) already in progress" },
        { 0x1E, "N_Port Login requested" },
        { 0x1F, "Invalid N_Port_ID" },
};

static const struct {
        u16 fc_explain;
        char *name;
} gs_explain [] = {
        { 0x00, "no additional explanation" },
        { 0x01, "port identifier not registered" },
        { 0x02, "port name not registered" },
        { 0x03, "node name not registered" },
        { 0x04, "class of service not registered" },
        { 0x06, "initial process associator not registered" },
        { 0x07, "FC-4 TYPEs not registered" },
        { 0x08, "symbolic port name not registered" },
        { 0x09, "symbolic node name not registered" },
        { 0x0A, "port type not registered" },
        { 0xF0, "authorization exception" },
        { 0xF1, "authentication exception" },
        { 0xF2, "data base full" },
        { 0xF3, "data base empty" },
        { 0xF4, "processing request" },
        { 0xF5, "unable to verify connection" },
        { 0xF6, "devices not in a common zone" },
};

/**
 * ibmvfc_get_ls_explain - Return the FC Explain description text
 * @status:     FC Explain status
 *
 * Returns:
 *      error string
 **/
static const char *ibmvfc_get_ls_explain(u16 status)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(ls_explain); i++)
                if (ls_explain[i].fc_explain == status)
                        return ls_explain[i].name;

        return unknown_fc_explain;
}

/**
 * ibmvfc_get_gs_explain - Return the FC Explain description text
 * @status:     FC Explain status
 *
 * Returns:
 *      error string
 **/
static const char *ibmvfc_get_gs_explain(u16 status)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(gs_explain); i++)
                if (gs_explain[i].fc_explain == status)
                        return gs_explain[i].name;

        return unknown_fc_explain;
}

static const struct {
        enum ibmvfc_fc_type fc_type;
        char *name;
} fc_type [] = {
        { IBMVFC_FABRIC_REJECT, "fabric reject" },
        { IBMVFC_PORT_REJECT, "port reject" },
        { IBMVFC_LS_REJECT, "ELS reject" },
        { IBMVFC_FABRIC_BUSY, "fabric busy" },
        { IBMVFC_PORT_BUSY, "port busy" },
        { IBMVFC_BASIC_REJECT, "basic reject" },
};

static const char *unknown_fc_type = "unknown fc type";

/**
 * ibmvfc_get_fc_type - Return the FC Type description text
 * @status:     FC Type error status
 *
 * Returns:
 *      error string
 **/
static const char *ibmvfc_get_fc_type(u16 status)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(fc_type); i++)
                if (fc_type[i].fc_type == status)
                        return fc_type[i].name;

        return unknown_fc_type;
}

/**
 * ibmvfc_set_tgt_action - Set the next init action for the target
 * @tgt:                ibmvfc target struct
 * @action:             action to perform
 *
 **/
static void ibmvfc_set_tgt_action(struct ibmvfc_target *tgt,
                                  enum ibmvfc_target_action action)
{
        switch (tgt->action) {
        case IBMVFC_TGT_ACTION_DEL_RPORT:
                break;
        default:
                if (action == IBMVFC_TGT_ACTION_DEL_RPORT)
                        tgt->add_rport = 0;
                tgt->action = action;
                break;
        }
}

/**
 * ibmvfc_set_host_state - Set the state for the host
 * @vhost:              ibmvfc host struct
 * @state:              state to set host to
 *
 * Returns:
 *      0 if state changed / non-zero if not changed
 **/
static int ibmvfc_set_host_state(struct ibmvfc_host *vhost,
                                  enum ibmvfc_host_state state)
{
        int rc = 0;

        switch (vhost->state) {
        case IBMVFC_HOST_OFFLINE:
                rc = -EINVAL;
                break;
        default:
                vhost->state = state;
                break;
        };

        return rc;
}

/**
 * ibmvfc_set_host_action - Set the next init action for the host
 * @vhost:              ibmvfc host struct
 * @action:             action to perform
 *
 **/
static void ibmvfc_set_host_action(struct ibmvfc_host *vhost,
                                   enum ibmvfc_host_action action)
{
        switch (action) {
        case IBMVFC_HOST_ACTION_ALLOC_TGTS:
                if (vhost->action == IBMVFC_HOST_ACTION_INIT_WAIT)
                        vhost->action = action;
                break;
        case IBMVFC_HOST_ACTION_INIT_WAIT:
                if (vhost->action == IBMVFC_HOST_ACTION_INIT)
                        vhost->action = action;
                break;
        case IBMVFC_HOST_ACTION_QUERY:
                switch (vhost->action) {
                case IBMVFC_HOST_ACTION_INIT_WAIT:
                case IBMVFC_HOST_ACTION_NONE:
                case IBMVFC_HOST_ACTION_TGT_DEL_FAILED:
                        vhost->action = action;
                        break;
                default:
                        break;
                };
                break;
        case IBMVFC_HOST_ACTION_TGT_INIT:
                if (vhost->action == IBMVFC_HOST_ACTION_ALLOC_TGTS)
                        vhost->action = action;
                break;
        case IBMVFC_HOST_ACTION_INIT:
        case IBMVFC_HOST_ACTION_TGT_DEL:
        case IBMVFC_HOST_ACTION_QUERY_TGTS:
        case IBMVFC_HOST_ACTION_TGT_DEL_FAILED:
        case IBMVFC_HOST_ACTION_NONE:
        default:
                vhost->action = action;
                break;
        };
}

/**
 * ibmvfc_reinit_host - Re-start host initialization (no NPIV Login)
 * @vhost:              ibmvfc host struct
 *
 * Return value:
 *      nothing
 **/
static void ibmvfc_reinit_host(struct ibmvfc_host *vhost)
{
        if (vhost->action == IBMVFC_HOST_ACTION_NONE) {
                if (!ibmvfc_set_host_state(vhost, IBMVFC_INITIALIZING)) {
                        scsi_block_requests(vhost->host);
                        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_QUERY);
                }
        } else
                vhost->reinit = 1;

        wake_up(&vhost->work_wait_q);
}

/**
 * ibmvfc_link_down - Handle a link down event from the adapter
 * @vhost:      ibmvfc host struct
 * @state:      ibmvfc host state to enter
 *
 **/
static void ibmvfc_link_down(struct ibmvfc_host *vhost,
                             enum ibmvfc_host_state state)
{
        struct ibmvfc_target *tgt;

        ENTER;
        scsi_block_requests(vhost->host);
        list_for_each_entry(tgt, &vhost->targets, queue)
                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
        ibmvfc_set_host_state(vhost, state);
        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_TGT_DEL);
        vhost->events_to_log |= IBMVFC_AE_LINKDOWN;
        wake_up(&vhost->work_wait_q);
        LEAVE;
}

/**
 * ibmvfc_init_host - Start host initialization
 * @vhost:              ibmvfc host struct
 * @relogin:    is this a re-login?
 *
 * Return value:
 *      nothing
 **/
static void ibmvfc_init_host(struct ibmvfc_host *vhost, int relogin)
{
        struct ibmvfc_target *tgt;

        if (vhost->action == IBMVFC_HOST_ACTION_INIT_WAIT) {
                if (++vhost->init_retries > IBMVFC_MAX_HOST_INIT_RETRIES) {
                        dev_err(vhost->dev,
                                "Host initialization retries exceeded. Taking adapter offline\n");
                        ibmvfc_link_down(vhost, IBMVFC_HOST_OFFLINE);
                        return;
                }
        }

        if (!ibmvfc_set_host_state(vhost, IBMVFC_INITIALIZING)) {
                if (!relogin) {
                        memset(vhost->async_crq.msgs, 0, PAGE_SIZE);
                        vhost->async_crq.cur = 0;
                }

                list_for_each_entry(tgt, &vhost->targets, queue)
                        tgt->need_login = 1;
                scsi_block_requests(vhost->host);
                ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_INIT);
                vhost->job_step = ibmvfc_npiv_login;
                wake_up(&vhost->work_wait_q);
        }
}

/**
 * ibmvfc_send_crq - Send a CRQ
 * @vhost:      ibmvfc host struct
 * @word1:      the first 64 bits of the data
 * @word2:      the second 64 bits of the data
 *
 * Return value:
 *      0 on success / other on failure
 **/
static int ibmvfc_send_crq(struct ibmvfc_host *vhost, u64 word1, u64 word2)
{
        struct vio_dev *vdev = to_vio_dev(vhost->dev);
        return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
}

/**
 * ibmvfc_send_crq_init - Send a CRQ init message
 * @vhost:      ibmvfc host struct
 *
 * Return value:
 *      0 on success / other on failure
 **/
static int ibmvfc_send_crq_init(struct ibmvfc_host *vhost)
{
        ibmvfc_dbg(vhost, "Sending CRQ init\n");
        return ibmvfc_send_crq(vhost, 0xC001000000000000LL, 0);
}

/**
 * ibmvfc_send_crq_init_complete - Send a CRQ init complete message
 * @vhost:      ibmvfc host struct
 *
 * Return value:
 *      0 on success / other on failure
 **/
static int ibmvfc_send_crq_init_complete(struct ibmvfc_host *vhost)
{
        ibmvfc_dbg(vhost, "Sending CRQ init complete\n");
        return ibmvfc_send_crq(vhost, 0xC002000000000000LL, 0);
}

/**
 * ibmvfc_release_crq_queue - Deallocates data and unregisters CRQ
 * @vhost:      ibmvfc host struct
 *
 * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
 * the crq with the hypervisor.
 **/
static void ibmvfc_release_crq_queue(struct ibmvfc_host *vhost)
{
        long rc;
        struct vio_dev *vdev = to_vio_dev(vhost->dev);
        struct ibmvfc_crq_queue *crq = &vhost->crq;

        ibmvfc_dbg(vhost, "Releasing CRQ\n");
        free_irq(vdev->irq, vhost);
        tasklet_kill(&vhost->tasklet);
        do {
                rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
        } while (rc == H_BUSY || H_IS_LONG_BUSY(rc));

        vhost->state = IBMVFC_NO_CRQ;
        dma_unmap_single(vhost->dev, crq->msg_token, PAGE_SIZE, DMA_BIDIRECTIONAL);
        free_page((unsigned long)crq->msgs);
}

/**
 * ibmvfc_reenable_crq_queue - reenables the CRQ
 * @vhost:      ibmvfc host struct
 *
 * Return value:
 *      0 on success / other on failure
 **/
static int ibmvfc_reenable_crq_queue(struct ibmvfc_host *vhost)
{
        int rc;
        struct vio_dev *vdev = to_vio_dev(vhost->dev);

        /* Re-enable the CRQ */
        do {
                rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
        } while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc));

        if (rc)
                dev_err(vhost->dev, "Error enabling adapter (rc=%d)\n", rc);

        return rc;
}

/**
 * ibmvfc_reset_crq - resets a crq after a failure
 * @vhost:      ibmvfc host struct
 *
 * Return value:
 *      0 on success / other on failure
 **/
static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)
{
        int rc;
        struct vio_dev *vdev = to_vio_dev(vhost->dev);
        struct ibmvfc_crq_queue *crq = &vhost->crq;

        /* Close the CRQ */
        do {
                rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
        } while (rc == H_BUSY || H_IS_LONG_BUSY(rc));

        vhost->state = IBMVFC_NO_CRQ;
        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_NONE);

        /* Clean out the queue */
        memset(crq->msgs, 0, PAGE_SIZE);
        crq->cur = 0;

        /* And re-open it again */
        rc = plpar_hcall_norets(H_REG_CRQ, vdev->unit_address,
                                crq->msg_token, PAGE_SIZE);

        if (rc == H_CLOSED)
                /* Adapter is good, but other end is not ready */
                dev_warn(vhost->dev, "Partner adapter not ready\n");
        else if (rc != 0)
                dev_warn(vhost->dev, "Couldn't register crq (rc=%d)\n", rc);

        return rc;
}

/**
 * ibmvfc_valid_event - Determines if event is valid.
 * @pool:       event_pool that contains the event
 * @evt:        ibmvfc event to be checked for validity
 *
 * Return value:
 *      1 if event is valid / 0 if event is not valid
 **/
static int ibmvfc_valid_event(struct ibmvfc_event_pool *pool,
                              struct ibmvfc_event *evt)
{
        int index = evt - pool->events;
        if (index < 0 || index >= pool->size)   /* outside of bounds */
                return 0;
        if (evt != pool->events + index)        /* unaligned */
                return 0;
        return 1;
}

/**
 * ibmvfc_free_event - Free the specified event
 * @evt:        ibmvfc_event to be freed
 *
 **/
static void ibmvfc_free_event(struct ibmvfc_event *evt)
{
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_event_pool *pool = &vhost->pool;

        BUG_ON(!ibmvfc_valid_event(pool, evt));
        BUG_ON(atomic_inc_return(&evt->free) != 1);
        list_add_tail(&evt->queue, &vhost->free);
}

/**
 * ibmvfc_scsi_eh_done - EH done function for queuecommand commands
 * @evt:        ibmvfc event struct
 *
 * This function does not setup any error status, that must be done
 * before this function gets called.
 **/
static void ibmvfc_scsi_eh_done(struct ibmvfc_event *evt)
{
        struct scsi_cmnd *cmnd = evt->cmnd;

        if (cmnd) {
                scsi_dma_unmap(cmnd);
                cmnd->scsi_done(cmnd);
        }

        if (evt->eh_comp)
                complete(evt->eh_comp);

        ibmvfc_free_event(evt);
}

/**
 * ibmvfc_fail_request - Fail request with specified error code
 * @evt:                ibmvfc event struct
 * @error_code: error code to fail request with
 *
 * Return value:
 *      none
 **/
static void ibmvfc_fail_request(struct ibmvfc_event *evt, int error_code)
{
        if (evt->cmnd) {
                evt->cmnd->result = (error_code << 16);
                evt->done = ibmvfc_scsi_eh_done;
        } else
                evt->xfer_iu->mad_common.status = IBMVFC_MAD_DRIVER_FAILED;

        list_del(&evt->queue);
        del_timer(&evt->timer);
        ibmvfc_trc_end(evt);
        evt->done(evt);
}

/**
 * ibmvfc_purge_requests - Our virtual adapter just shut down. Purge any sent requests
 * @vhost:              ibmvfc host struct
 * @error_code: error code to fail requests with
 *
 * Return value:
 *      none
 **/
static void ibmvfc_purge_requests(struct ibmvfc_host *vhost, int error_code)
{
        struct ibmvfc_event *evt, *pos;

        ibmvfc_dbg(vhost, "Purging all requests\n");
        list_for_each_entry_safe(evt, pos, &vhost->sent, queue)
                ibmvfc_fail_request(evt, error_code);
}

/**
 * __ibmvfc_reset_host - Reset the connection to the server (no locking)
 * @vhost:      struct ibmvfc host to reset
 **/
static void __ibmvfc_reset_host(struct ibmvfc_host *vhost)
{
        int rc;

        scsi_block_requests(vhost->host);
        ibmvfc_purge_requests(vhost, DID_ERROR);
        if ((rc = ibmvfc_reset_crq(vhost)) ||
            (rc = ibmvfc_send_crq_init(vhost)) ||
            (rc = vio_enable_interrupts(to_vio_dev(vhost->dev)))) {
                dev_err(vhost->dev, "Error after reset rc=%d\n", rc);
                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
        } else
                ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
}

/**
 * ibmvfc_reset_host - Reset the connection to the server
 * @vhost:      struct ibmvfc host to reset
 **/
static void ibmvfc_reset_host(struct ibmvfc_host *vhost)
{
        unsigned long flags;

        spin_lock_irqsave(vhost->host->host_lock, flags);
        __ibmvfc_reset_host(vhost);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
}

/**
 * ibmvfc_retry_host_init - Retry host initialization if allowed
 * @vhost:      ibmvfc host struct
 *
 * Returns: 1 if init will be retried / 0 if not
 *
 **/
static int ibmvfc_retry_host_init(struct ibmvfc_host *vhost)
{
        int retry = 0;

        if (vhost->action == IBMVFC_HOST_ACTION_INIT_WAIT) {
                vhost->delay_init = 1;
                if (++vhost->init_retries > IBMVFC_MAX_HOST_INIT_RETRIES) {
                        dev_err(vhost->dev,
                                "Host initialization retries exceeded. Taking adapter offline\n");
                        ibmvfc_link_down(vhost, IBMVFC_HOST_OFFLINE);
                } else if (vhost->init_retries == IBMVFC_MAX_HOST_INIT_RETRIES)
                        __ibmvfc_reset_host(vhost);
                else {
                        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_INIT);
                        retry = 1;
                }
        }

        wake_up(&vhost->work_wait_q);
        return retry;
}

/**
 * __ibmvfc_get_target - Find the specified scsi_target (no locking)
 * @starget:    scsi target struct
 *
 * Return value:
 *      ibmvfc_target struct / NULL if not found
 **/
static struct ibmvfc_target *__ibmvfc_get_target(struct scsi_target *starget)
{
        struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
        struct ibmvfc_host *vhost = shost_priv(shost);
        struct ibmvfc_target *tgt;

        list_for_each_entry(tgt, &vhost->targets, queue)
                if (tgt->target_id == starget->id) {
                        kref_get(&tgt->kref);
                        return tgt;
                }
        return NULL;
}

/**
 * ibmvfc_get_target - Find the specified scsi_target
 * @starget:    scsi target struct
 *
 * Return value:
 *      ibmvfc_target struct / NULL if not found
 **/
static struct ibmvfc_target *ibmvfc_get_target(struct scsi_target *starget)
{
        struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
        struct ibmvfc_target *tgt;
        unsigned long flags;

        spin_lock_irqsave(shost->host_lock, flags);
        tgt = __ibmvfc_get_target(starget);
        spin_unlock_irqrestore(shost->host_lock, flags);
        return tgt;
}

/**
 * ibmvfc_get_host_speed - Get host port speed
 * @shost:              scsi host struct
 *
 * Return value:
 *      none
 **/
static void ibmvfc_get_host_speed(struct Scsi_Host *shost)
{
        struct ibmvfc_host *vhost = shost_priv(shost);
        unsigned long flags;

        spin_lock_irqsave(shost->host_lock, flags);
        if (vhost->state == IBMVFC_ACTIVE) {
                switch (vhost->login_buf->resp.link_speed / 100) {
                case 1:
                        fc_host_speed(shost) = FC_PORTSPEED_1GBIT;
                        break;
                case 2:
                        fc_host_speed(shost) = FC_PORTSPEED_2GBIT;
                        break;
                case 4:
                        fc_host_speed(shost) = FC_PORTSPEED_4GBIT;
                        break;
                case 8:
                        fc_host_speed(shost) = FC_PORTSPEED_8GBIT;
                        break;
                case 10:
                        fc_host_speed(shost) = FC_PORTSPEED_10GBIT;
                        break;
                case 16:
                        fc_host_speed(shost) = FC_PORTSPEED_16GBIT;
                        break;
                default:
                        ibmvfc_log(vhost, 3, "Unknown port speed: %lld Gbit\n",
                                   vhost->login_buf->resp.link_speed / 100);
                        fc_host_speed(shost) = FC_PORTSPEED_UNKNOWN;
                        break;
                }
        } else
                fc_host_speed(shost) = FC_PORTSPEED_UNKNOWN;
        spin_unlock_irqrestore(shost->host_lock, flags);
}

/**
 * ibmvfc_get_host_port_state - Get host port state
 * @shost:              scsi host struct
 *
 * Return value:
 *      none
 **/
static void ibmvfc_get_host_port_state(struct Scsi_Host *shost)
{
        struct ibmvfc_host *vhost = shost_priv(shost);
        unsigned long flags;

        spin_lock_irqsave(shost->host_lock, flags);
        switch (vhost->state) {
        case IBMVFC_INITIALIZING:
        case IBMVFC_ACTIVE:
                fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
                break;
        case IBMVFC_LINK_DOWN:
                fc_host_port_state(shost) = FC_PORTSTATE_LINKDOWN;
                break;
        case IBMVFC_LINK_DEAD:
        case IBMVFC_HOST_OFFLINE:
                fc_host_port_state(shost) = FC_PORTSTATE_OFFLINE;
                break;
        case IBMVFC_HALTED:
                fc_host_port_state(shost) = FC_PORTSTATE_BLOCKED;
                break;
        case IBMVFC_NO_CRQ:
                fc_host_port_state(shost) = FC_PORTSTATE_UNKNOWN;
                break;
        default:
                ibmvfc_log(vhost, 3, "Unknown port state: %d\n", vhost->state);
                fc_host_port_state(shost) = FC_PORTSTATE_UNKNOWN;
                break;
        }
        spin_unlock_irqrestore(shost->host_lock, flags);
}

/**
 * ibmvfc_set_rport_dev_loss_tmo - Set rport's device loss timeout
 * @rport:              rport struct
 * @timeout:    timeout value
 *
 * Return value:
 *      none
 **/
static void ibmvfc_set_rport_dev_loss_tmo(struct fc_rport *rport, u32 timeout)
{
        if (timeout)
                rport->dev_loss_tmo = timeout;
        else
                rport->dev_loss_tmo = 1;
}

/**
 * ibmvfc_release_tgt - Free memory allocated for a target
 * @kref:               kref struct
 *
 **/
static void ibmvfc_release_tgt(struct kref *kref)
{
        struct ibmvfc_target *tgt = container_of(kref, struct ibmvfc_target, kref);
        kfree(tgt);
}

/**
 * ibmvfc_get_starget_node_name - Get SCSI target's node name
 * @starget:    scsi target struct
 *
 * Return value:
 *      none
 **/
static void ibmvfc_get_starget_node_name(struct scsi_target *starget)
{
        struct ibmvfc_target *tgt = ibmvfc_get_target(starget);
        fc_starget_port_name(starget) = tgt ? tgt->ids.node_name : 0;
        if (tgt)
                kref_put(&tgt->kref, ibmvfc_release_tgt);
}

/**
 * ibmvfc_get_starget_port_name - Get SCSI target's port name
 * @starget:    scsi target struct
 *
 * Return value:
 *      none
 **/
static void ibmvfc_get_starget_port_name(struct scsi_target *starget)
{
        struct ibmvfc_target *tgt = ibmvfc_get_target(starget);
        fc_starget_port_name(starget) = tgt ? tgt->ids.port_name : 0;
        if (tgt)
                kref_put(&tgt->kref, ibmvfc_release_tgt);
}

/**
 * ibmvfc_get_starget_port_id - Get SCSI target's port ID
 * @starget:    scsi target struct
 *
 * Return value:
 *      none
 **/
static void ibmvfc_get_starget_port_id(struct scsi_target *starget)
{
        struct ibmvfc_target *tgt = ibmvfc_get_target(starget);
        fc_starget_port_id(starget) = tgt ? tgt->scsi_id : -1;
        if (tgt)
                kref_put(&tgt->kref, ibmvfc_release_tgt);
}

/**
 * ibmvfc_wait_while_resetting - Wait while the host resets
 * @vhost:              ibmvfc host struct
 *
 * Return value:
 *      0 on success / other on failure
 **/
static int ibmvfc_wait_while_resetting(struct ibmvfc_host *vhost)
{
        long timeout = wait_event_timeout(vhost->init_wait_q,
                                          ((vhost->state == IBMVFC_ACTIVE ||
                                            vhost->state == IBMVFC_HOST_OFFLINE ||
                                            vhost->state == IBMVFC_LINK_DEAD) &&
                                           vhost->action == IBMVFC_HOST_ACTION_NONE),
                                          (init_timeout * HZ));

        return timeout ? 0 : -EIO;
}

/**
 * ibmvfc_issue_fc_host_lip - Re-initiate link initialization
 * @shost:              scsi host struct
 *
 * Return value:
 *      0 on success / other on failure
 **/
static int ibmvfc_issue_fc_host_lip(struct Scsi_Host *shost)
{
        struct ibmvfc_host *vhost = shost_priv(shost);

        dev_err(vhost->dev, "Initiating host LIP. Resetting connection\n");
        ibmvfc_reset_host(vhost);
        return ibmvfc_wait_while_resetting(vhost);
}

/**
 * ibmvfc_gather_partition_info - Gather info about the LPAR
 *
 * Return value:
 *      none
 **/
static void ibmvfc_gather_partition_info(struct ibmvfc_host *vhost)
{
        struct device_node *rootdn;
        const char *name;
        const unsigned int *num;

        rootdn = of_find_node_by_path("/");
        if (!rootdn)
                return;

        name = of_get_property(rootdn, "ibm,partition-name", NULL);
        if (name)
                strncpy(vhost->partition_name, name, sizeof(vhost->partition_name));
        num = of_get_property(rootdn, "ibm,partition-no", NULL);
        if (num)
                vhost->partition_number = *num;
        of_node_put(rootdn);
}

/**
 * ibmvfc_set_login_info - Setup info for NPIV login
 * @vhost:      ibmvfc host struct
 *
 * Return value:
 *      none
 **/
static void ibmvfc_set_login_info(struct ibmvfc_host *vhost)
{
        struct ibmvfc_npiv_login *login_info = &vhost->login_info;
        struct device_node *of_node = vhost->dev->archdata.of_node;
        const char *location;

        memset(login_info, 0, sizeof(*login_info));

        login_info->ostype = IBMVFC_OS_LINUX;
        login_info->max_dma_len = IBMVFC_MAX_SECTORS << 9;
        login_info->max_payload = sizeof(struct ibmvfc_fcp_cmd_iu);
        login_info->max_response = sizeof(struct ibmvfc_fcp_rsp);
        login_info->partition_num = vhost->partition_number;
        login_info->vfc_frame_version = 1;
        login_info->fcp_version = 3;
        if (vhost->client_migrated)
                login_info->flags = IBMVFC_CLIENT_MIGRATED;

        login_info->max_cmds = max_requests + IBMVFC_NUM_INTERNAL_REQ;
        login_info->capabilities = IBMVFC_CAN_MIGRATE;
        login_info->async.va = vhost->async_crq.msg_token;
        login_info->async.len = vhost->async_crq.size * sizeof(*vhost->async_crq.msgs);
        strncpy(login_info->partition_name, vhost->partition_name, IBMVFC_MAX_NAME);
        strncpy(login_info->device_name,
                dev_name(&vhost->host->shost_gendev), IBMVFC_MAX_NAME);

        location = of_get_property(of_node, "ibm,loc-code", NULL);
        location = location ? location : dev_name(vhost->dev);
        strncpy(login_info->drc_name, location, IBMVFC_MAX_NAME);
}

/**
 * ibmvfc_init_event_pool - Allocates and initializes the event pool for a host
 * @vhost:      ibmvfc host who owns the event pool
 *
 * Returns zero on success.
 **/
static int ibmvfc_init_event_pool(struct ibmvfc_host *vhost)
{
        int i;
        struct ibmvfc_event_pool *pool = &vhost->pool;

        ENTER;
        pool->size = max_requests + IBMVFC_NUM_INTERNAL_REQ;
        pool->events = kcalloc(pool->size, sizeof(*pool->events), GFP_KERNEL);
        if (!pool->events)
                return -ENOMEM;

        pool->iu_storage = dma_alloc_coherent(vhost->dev,
                                              pool->size * sizeof(*pool->iu_storage),
                                              &pool->iu_token, 0);

        if (!pool->iu_storage) {
                kfree(pool->events);
                return -ENOMEM;
        }

        for (i = 0; i < pool->size; ++i) {
                struct ibmvfc_event *evt = &pool->events[i];
                atomic_set(&evt->free, 1);
                evt->crq.valid = 0x80;
                evt->crq.ioba = pool->iu_token + (sizeof(*evt->xfer_iu) * i);
                evt->xfer_iu = pool->iu_storage + i;
                evt->vhost = vhost;
                evt->ext_list = NULL;
                list_add_tail(&evt->queue, &vhost->free);
        }

        LEAVE;
        return 0;
}

/**
 * ibmvfc_free_event_pool - Frees memory of the event pool of a host
 * @vhost:      ibmvfc host who owns the event pool
 *
 **/
static void ibmvfc_free_event_pool(struct ibmvfc_host *vhost)
{
        int i;
        struct ibmvfc_event_pool *pool = &vhost->pool;

        ENTER;
        for (i = 0; i < pool->size; ++i) {
                list_del(&pool->events[i].queue);
                BUG_ON(atomic_read(&pool->events[i].free) != 1);
                if (pool->events[i].ext_list)
                        dma_pool_free(vhost->sg_pool,
                                      pool->events[i].ext_list,
                                      pool->events[i].ext_list_token);
        }

        kfree(pool->events);
        dma_free_coherent(vhost->dev,
                          pool->size * sizeof(*pool->iu_storage),
                          pool->iu_storage, pool->iu_token);
        LEAVE;
}

/**
 * ibmvfc_get_event - Gets the next free event in pool
 * @vhost:      ibmvfc host struct
 *
 * Returns a free event from the pool.
 **/
static struct ibmvfc_event *ibmvfc_get_event(struct ibmvfc_host *vhost)
{
        struct ibmvfc_event *evt;

        BUG_ON(list_empty(&vhost->free));
        evt = list_entry(vhost->free.next, struct ibmvfc_event, queue);
        atomic_set(&evt->free, 0);
        list_del(&evt->queue);
        return evt;
}

/**
 * ibmvfc_init_event - Initialize fields in an event struct that are always
 *                              required.
 * @evt:        The event
 * @done:       Routine to call when the event is responded to
 * @format:     SRP or MAD format
 **/
static void ibmvfc_init_event(struct ibmvfc_event *evt,
                              void (*done) (struct ibmvfc_event *), u8 format)
{
        evt->cmnd = NULL;
        evt->sync_iu = NULL;
        evt->crq.format = format;
        evt->done = done;
        evt->eh_comp = NULL;
}

/**
 * ibmvfc_map_sg_list - Initialize scatterlist
 * @scmd:       scsi command struct
 * @nseg:       number of scatterlist segments
 * @md: memory descriptor list to initialize
 **/
static void ibmvfc_map_sg_list(struct scsi_cmnd *scmd, int nseg,
                               struct srp_direct_buf *md)
{
        int i;
        struct scatterlist *sg;

        scsi_for_each_sg(scmd, sg, nseg, i) {
                md[i].va = sg_dma_address(sg);
                md[i].len = sg_dma_len(sg);
                md[i].key = 0;
        }
}

/**
 * ibmvfc_map_sg_data - Maps dma for a scatterlist and initializes decriptor fields
 * @scmd:               Scsi_Cmnd with the scatterlist
 * @evt:                ibmvfc event struct
 * @vfc_cmd:    vfc_cmd that contains the memory descriptor
 * @dev:                device for which to map dma memory
 *
 * Returns:
 *      0 on success / non-zero on failure
 **/
static int ibmvfc_map_sg_data(struct scsi_cmnd *scmd,
                              struct ibmvfc_event *evt,
                              struct ibmvfc_cmd *vfc_cmd, struct device *dev)
{

        int sg_mapped;
        struct srp_direct_buf *data = &vfc_cmd->ioba;
        struct ibmvfc_host *vhost = dev_get_drvdata(dev);

        sg_mapped = scsi_dma_map(scmd);
        if (!sg_mapped) {
                vfc_cmd->flags |= IBMVFC_NO_MEM_DESC;
                return 0;
        } else if (unlikely(sg_mapped < 0)) {
                if (vhost->log_level > IBMVFC_DEFAULT_LOG_LEVEL)
                        scmd_printk(KERN_ERR, scmd, "Failed to map DMA buffer for command\n");
                return sg_mapped;
        }

        if (scmd->sc_data_direction == DMA_TO_DEVICE) {
                vfc_cmd->flags |= IBMVFC_WRITE;
                vfc_cmd->iu.add_cdb_len |= IBMVFC_WRDATA;
        } else {
                vfc_cmd->flags |= IBMVFC_READ;
                vfc_cmd->iu.add_cdb_len |= IBMVFC_RDDATA;
        }

        if (sg_mapped == 1) {
                ibmvfc_map_sg_list(scmd, sg_mapped, data);
                return 0;
        }

        vfc_cmd->flags |= IBMVFC_SCATTERLIST;

        if (!evt->ext_list) {
                evt->ext_list = dma_pool_alloc(vhost->sg_pool, GFP_ATOMIC,
                                               &evt->ext_list_token);

                if (!evt->ext_list) {
                        scsi_dma_unmap(scmd);
                        if (vhost->log_level > IBMVFC_DEFAULT_LOG_LEVEL)
                                scmd_printk(KERN_ERR, scmd, "Can't allocate memory for scatterlist\n");
                        return -ENOMEM;
                }
        }

        ibmvfc_map_sg_list(scmd, sg_mapped, evt->ext_list);

        data->va = evt->ext_list_token;
        data->len = sg_mapped * sizeof(struct srp_direct_buf);
        data->key = 0;
        return 0;
}

/**
 * ibmvfc_timeout - Internal command timeout handler
 * @evt:        struct ibmvfc_event that timed out
 *
 * Called when an internally generated command times out
 **/
static void ibmvfc_timeout(struct ibmvfc_event *evt)
{
        struct ibmvfc_host *vhost = evt->vhost;
        dev_err(vhost->dev, "Command timed out (%p). Resetting connection\n", evt);
        ibmvfc_reset_host(vhost);
}

/**
 * ibmvfc_send_event - Transforms event to u64 array and calls send_crq()
 * @evt:                event to be sent
 * @vhost:              ibmvfc host struct
 * @timeout:    timeout in seconds - 0 means do not time command
 *
 * Returns the value returned from ibmvfc_send_crq(). (Zero for success)
 **/
static int ibmvfc_send_event(struct ibmvfc_event *evt,
                             struct ibmvfc_host *vhost, unsigned long timeout)
{
        u64 *crq_as_u64 = (u64 *) &evt->crq;
        int rc;

        /* Copy the IU into the transfer area */
        *evt->xfer_iu = evt->iu;
        if (evt->crq.format == IBMVFC_CMD_FORMAT)
                evt->xfer_iu->cmd.tag = (u64)evt;
        else if (evt->crq.format == IBMVFC_MAD_FORMAT)
                evt->xfer_iu->mad_common.tag = (u64)evt;
        else
                BUG();

        list_add_tail(&evt->queue, &vhost->sent);
        init_timer(&evt->timer);

        if (timeout) {
                evt->timer.data = (unsigned long) evt;
                evt->timer.expires = jiffies + (timeout * HZ);
                evt->timer.function = (void (*)(unsigned long))ibmvfc_timeout;
                add_timer(&evt->timer);
        }

        mb();

        if ((rc = ibmvfc_send_crq(vhost, crq_as_u64[0], crq_as_u64[1]))) {
                list_del(&evt->queue);
                del_timer(&evt->timer);

                /* If send_crq returns H_CLOSED, return SCSI_MLQUEUE_HOST_BUSY.
                 * Firmware will send a CRQ with a transport event (0xFF) to
                 * tell this client what has happened to the transport. This
                 * will be handled in ibmvfc_handle_crq()
                 */
                if (rc == H_CLOSED) {
                        if (printk_ratelimit())
                                dev_warn(vhost->dev, "Send warning. Receive queue closed, will retry.\n");
                        if (evt->cmnd)
                                scsi_dma_unmap(evt->cmnd);
                        ibmvfc_free_event(evt);
                        return SCSI_MLQUEUE_HOST_BUSY;
                }

                dev_err(vhost->dev, "Send error (rc=%d)\n", rc);
                if (evt->cmnd) {
                        evt->cmnd->result = DID_ERROR << 16;
                        evt->done = ibmvfc_scsi_eh_done;
                } else
                        evt->xfer_iu->mad_common.status = IBMVFC_MAD_CRQ_ERROR;

                evt->done(evt);
        } else
                ibmvfc_trc_start(evt);

        return 0;
}

/**
 * ibmvfc_log_error - Log an error for the failed command if appropriate
 * @evt:        ibmvfc event to log
 *
 **/
static void ibmvfc_log_error(struct ibmvfc_event *evt)
{
        struct ibmvfc_cmd *vfc_cmd = &evt->xfer_iu->cmd;
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_fcp_rsp *rsp = &vfc_cmd->rsp;
        struct scsi_cmnd *cmnd = evt->cmnd;
        const char *err = unknown_error;
        int index = ibmvfc_get_err_index(vfc_cmd->status, vfc_cmd->error);
        int logerr = 0;
        int rsp_code = 0;

        if (index >= 0) {
                logerr = cmd_status[index].log;
                err = cmd_status[index].name;
        }

        if (!logerr && (vhost->log_level <= (IBMVFC_DEFAULT_LOG_LEVEL + 1)))
                return;

        if (rsp->flags & FCP_RSP_LEN_VALID)
                rsp_code = rsp->data.info.rsp_code;

        scmd_printk(KERN_ERR, cmnd, "Command (%02X) failed: %s (%x:%x) "
                    "flags: %x fcp_rsp: %x, resid=%d, scsi_status: %x\n",
                    cmnd->cmnd[0], err, vfc_cmd->status, vfc_cmd->error,
                    rsp->flags, rsp_code, scsi_get_resid(cmnd), rsp->scsi_status);
}

/**
 * ibmvfc_scsi_done - Handle responses from commands
 * @evt:        ibmvfc event to be handled
 *
 * Used as a callback when sending scsi cmds.
 **/
static void ibmvfc_scsi_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_cmd *vfc_cmd = &evt->xfer_iu->cmd;
        struct ibmvfc_fcp_rsp *rsp = &vfc_cmd->rsp;
        struct scsi_cmnd *cmnd = evt->cmnd;
        u32 rsp_len = 0;
        u32 sense_len = rsp->fcp_sense_len;

        if (cmnd) {
                if (vfc_cmd->response_flags & IBMVFC_ADAPTER_RESID_VALID)
                        scsi_set_resid(cmnd, vfc_cmd->adapter_resid);
                else if (rsp->flags & FCP_RESID_UNDER)
                        scsi_set_resid(cmnd, rsp->fcp_resid);
                else
                        scsi_set_resid(cmnd, 0);

                if (vfc_cmd->status) {
                        cmnd->result = ibmvfc_get_err_result(vfc_cmd);

                        if (rsp->flags & FCP_RSP_LEN_VALID)
                                rsp_len = rsp->fcp_rsp_len;
                        if ((sense_len + rsp_len) > SCSI_SENSE_BUFFERSIZE)
                                sense_len = SCSI_SENSE_BUFFERSIZE - rsp_len;
                        if ((rsp->flags & FCP_SNS_LEN_VALID) && rsp->fcp_sense_len && rsp_len <= 8)
                                memcpy(cmnd->sense_buffer, rsp->data.sense + rsp_len, sense_len);
                        if ((vfc_cmd->status & IBMVFC_VIOS_FAILURE) && (vfc_cmd->error == IBMVFC_PLOGI_REQUIRED))
                                ibmvfc_reinit_host(evt->vhost);

                        if (!cmnd->result && (!scsi_get_resid(cmnd) || (rsp->flags & FCP_RESID_OVER)))
                                cmnd->result = (DID_ERROR << 16);

                        ibmvfc_log_error(evt);
                }

                if (!cmnd->result &&
                    (scsi_bufflen(cmnd) - scsi_get_resid(cmnd) < cmnd->underflow))
                        cmnd->result = (DID_ERROR << 16);

                scsi_dma_unmap(cmnd);
                cmnd->scsi_done(cmnd);
        }

        if (evt->eh_comp)
                complete(evt->eh_comp);

        ibmvfc_free_event(evt);
}

/**
 * ibmvfc_host_chkready - Check if the host can accept commands
 * @vhost:       struct ibmvfc host
 *
 * Returns:
 *      1 if host can accept command / 0 if not
 **/
static inline int ibmvfc_host_chkready(struct ibmvfc_host *vhost)
{
        int result = 0;

        switch (vhost->state) {
        case IBMVFC_LINK_DEAD:
        case IBMVFC_HOST_OFFLINE:
                result = DID_NO_CONNECT << 16;
                break;
        case IBMVFC_NO_CRQ:
        case IBMVFC_INITIALIZING:
        case IBMVFC_HALTED:
        case IBMVFC_LINK_DOWN:
                result = DID_REQUEUE << 16;
                break;
        case IBMVFC_ACTIVE:
                result = 0;
                break;
        };

        return result;
}

/**
 * ibmvfc_queuecommand - The queuecommand function of the scsi template
 * @cmnd:       struct scsi_cmnd to be executed
 * @done:       Callback function to be called when cmnd is completed
 *
 * Returns:
 *      0 on success / other on failure
 **/
static int ibmvfc_queuecommand(struct scsi_cmnd *cmnd,
                               void (*done) (struct scsi_cmnd *))
{
        struct ibmvfc_host *vhost = shost_priv(cmnd->device->host);
        struct fc_rport *rport = starget_to_rport(scsi_target(cmnd->device));
        struct ibmvfc_cmd *vfc_cmd;
        struct ibmvfc_event *evt;
        u8 tag[2];
        int rc;

        if (unlikely((rc = fc_remote_port_chkready(rport))) ||
            unlikely((rc = ibmvfc_host_chkready(vhost)))) {
                cmnd->result = rc;
                done(cmnd);
                return 0;
        }

        cmnd->result = (DID_OK << 16);
        evt = ibmvfc_get_event(vhost);
        ibmvfc_init_event(evt, ibmvfc_scsi_done, IBMVFC_CMD_FORMAT);
        evt->cmnd = cmnd;
        cmnd->scsi_done = done;
        vfc_cmd = &evt->iu.cmd;
        memset(vfc_cmd, 0, sizeof(*vfc_cmd));
        vfc_cmd->resp.va = (u64)evt->crq.ioba + offsetof(struct ibmvfc_cmd, rsp);
        vfc_cmd->resp.len = sizeof(vfc_cmd->rsp);
        vfc_cmd->frame_type = IBMVFC_SCSI_FCP_TYPE;
        vfc_cmd->payload_len = sizeof(vfc_cmd->iu);
        vfc_cmd->resp_len = sizeof(vfc_cmd->rsp);
        vfc_cmd->cancel_key = (unsigned long)cmnd->device->hostdata;
        vfc_cmd->tgt_scsi_id = rport->port_id;
        vfc_cmd->iu.xfer_len = scsi_bufflen(cmnd);
        int_to_scsilun(cmnd->device->lun, &vfc_cmd->iu.lun);
        memcpy(vfc_cmd->iu.cdb, cmnd->cmnd, cmnd->cmd_len);

        if (scsi_populate_tag_msg(cmnd, tag)) {
                vfc_cmd->task_tag = tag[1];
                switch (tag[0]) {
                case MSG_SIMPLE_TAG:
                        vfc_cmd->iu.pri_task_attr = IBMVFC_SIMPLE_TASK;
                        break;
                case MSG_HEAD_TAG:
                        vfc_cmd->iu.pri_task_attr = IBMVFC_HEAD_OF_QUEUE;
                        break;
                case MSG_ORDERED_TAG:
                        vfc_cmd->iu.pri_task_attr = IBMVFC_ORDERED_TASK;
                        break;
                };
        }

        if (likely(!(rc = ibmvfc_map_sg_data(cmnd, evt, vfc_cmd, vhost->dev))))
                return ibmvfc_send_event(evt, vhost, 0);

        ibmvfc_free_event(evt);
        if (rc == -ENOMEM)
                return SCSI_MLQUEUE_HOST_BUSY;

        if (vhost->log_level > IBMVFC_DEFAULT_LOG_LEVEL)
                scmd_printk(KERN_ERR, cmnd,
                            "Failed to map DMA buffer for command. rc=%d\n", rc);

        cmnd->result = DID_ERROR << 16;
        done(cmnd);
        return 0;
}

/**
 * ibmvfc_sync_completion - Signal that a synchronous command has completed
 * @evt:        ibmvfc event struct
 *
 **/
static void ibmvfc_sync_completion(struct ibmvfc_event *evt)
{
        /* copy the response back */
        if (evt->sync_iu)
                *evt->sync_iu = *evt->xfer_iu;

        complete(&evt->comp);
}

/**
 * ibmvfc_reset_device - Reset the device with the specified reset type
 * @sdev:       scsi device to reset
 * @type:       reset type
 * @desc:       reset type description for log messages
 *
 * Returns:
 *      0 on success / other on failure
 **/
static int ibmvfc_reset_device(struct scsi_device *sdev, int type, char *desc)
{
        struct ibmvfc_host *vhost = shost_priv(sdev->host);
        struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
        struct ibmvfc_cmd *tmf;
        struct ibmvfc_event *evt = NULL;
        union ibmvfc_iu rsp_iu;
        struct ibmvfc_fcp_rsp *fc_rsp = &rsp_iu.cmd.rsp;
        int rsp_rc = -EBUSY;
        unsigned long flags;
        int rsp_code = 0;

        spin_lock_irqsave(vhost->host->host_lock, flags);
        if (vhost->state == IBMVFC_ACTIVE) {
                evt = ibmvfc_get_event(vhost);
                ibmvfc_init_event(evt, ibmvfc_sync_completion, IBMVFC_CMD_FORMAT);

                tmf = &evt->iu.cmd;
                memset(tmf, 0, sizeof(*tmf));
                tmf->resp.va = (u64)evt->crq.ioba + offsetof(struct ibmvfc_cmd, rsp);
                tmf->resp.len = sizeof(tmf->rsp);
                tmf->frame_type = IBMVFC_SCSI_FCP_TYPE;
                tmf->payload_len = sizeof(tmf->iu);
                tmf->resp_len = sizeof(tmf->rsp);
                tmf->cancel_key = (unsigned long)sdev->hostdata;
                tmf->tgt_scsi_id = rport->port_id;
                int_to_scsilun(sdev->lun, &tmf->iu.lun);
                tmf->flags = (IBMVFC_NO_MEM_DESC | IBMVFC_TMF);
                tmf->iu.tmf_flags = type;
                evt->sync_iu = &rsp_iu;

                init_completion(&evt->comp);
                rsp_rc = ibmvfc_send_event(evt, vhost, default_timeout);
        }
        spin_unlock_irqrestore(vhost->host->host_lock, flags);

        if (rsp_rc != 0) {
                sdev_printk(KERN_ERR, sdev, "Failed to send %s reset event. rc=%d\n",
                            desc, rsp_rc);
                return -EIO;
        }

        sdev_printk(KERN_INFO, sdev, "Resetting %s\n", desc);
        wait_for_completion(&evt->comp);

        if (rsp_iu.cmd.status) {
                if (fc_rsp->flags & FCP_RSP_LEN_VALID)
                        rsp_code = fc_rsp->data.info.rsp_code;

                sdev_printk(KERN_ERR, sdev, "%s reset failed: %s (%x:%x) "
                            "flags: %x fcp_rsp: %x, scsi_status: %x\n",
                            desc, ibmvfc_get_cmd_error(rsp_iu.cmd.status, rsp_iu.cmd.error),
                            rsp_iu.cmd.status, rsp_iu.cmd.error, fc_rsp->flags, rsp_code,
                            fc_rsp->scsi_status);
                rsp_rc = -EIO;
        } else
                sdev_printk(KERN_INFO, sdev, "%s reset successful\n", desc);

        spin_lock_irqsave(vhost->host->host_lock, flags);
        ibmvfc_free_event(evt);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
        return rsp_rc;
}

/**
 * ibmvfc_abort_task_set - Abort outstanding commands to the device
 * @sdev:       scsi device to abort commands
 *
 * This sends an Abort Task Set to the VIOS for the specified device. This does
 * NOT send any cancel to the VIOS. That must be done separately.
 *
 * Returns:
 *      0 on success / other on failure
 **/
static int ibmvfc_abort_task_set(struct scsi_device *sdev)
{
        struct ibmvfc_host *vhost = shost_priv(sdev->host);
        struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
        struct ibmvfc_cmd *tmf;
        struct ibmvfc_event *evt, *found_evt;
        union ibmvfc_iu rsp_iu;
        struct ibmvfc_fcp_rsp *fc_rsp = &rsp_iu.cmd.rsp;
        int rsp_rc = -EBUSY;
        unsigned long flags;
        int rsp_code = 0;

        spin_lock_irqsave(vhost->host->host_lock, flags);
        found_evt = NULL;
        list_for_each_entry(evt, &vhost->sent, queue) {
                if (evt->cmnd && evt->cmnd->device == sdev) {
                        found_evt = evt;
                        break;
                }
        }

        if (!found_evt) {
                if (vhost->log_level > IBMVFC_DEFAULT_LOG_LEVEL)
                        sdev_printk(KERN_INFO, sdev, "No events found to abort\n");
                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                return 0;
        }

        if (vhost->state == IBMVFC_ACTIVE) {
                evt = ibmvfc_get_event(vhost);
                ibmvfc_init_event(evt, ibmvfc_sync_completion, IBMVFC_CMD_FORMAT);

                tmf = &evt->iu.cmd;
                memset(tmf, 0, sizeof(*tmf));
                tmf->resp.va = (u64)evt->crq.ioba + offsetof(struct ibmvfc_cmd, rsp);
                tmf->resp.len = sizeof(tmf->rsp);
                tmf->frame_type = IBMVFC_SCSI_FCP_TYPE;
                tmf->payload_len = sizeof(tmf->iu);
                tmf->resp_len = sizeof(tmf->rsp);
                tmf->cancel_key = (unsigned long)sdev->hostdata;
                tmf->tgt_scsi_id = rport->port_id;
                int_to_scsilun(sdev->lun, &tmf->iu.lun);
                tmf->flags = (IBMVFC_NO_MEM_DESC | IBMVFC_TMF);
                tmf->iu.tmf_flags = IBMVFC_ABORT_TASK_SET;
                evt->sync_iu = &rsp_iu;

                init_completion(&evt->comp);
                rsp_rc = ibmvfc_send_event(evt, vhost, default_timeout);
        }

        spin_unlock_irqrestore(vhost->host->host_lock, flags);

        if (rsp_rc != 0) {
                sdev_printk(KERN_ERR, sdev, "Failed to send abort. rc=%d\n", rsp_rc);
                return -EIO;
        }

        sdev_printk(KERN_INFO, sdev, "Aborting outstanding commands\n");
        wait_for_completion(&evt->comp);

        if (rsp_iu.cmd.status) {
                if (fc_rsp->flags & FCP_RSP_LEN_VALID)
                        rsp_code = fc_rsp->data.info.rsp_code;

                sdev_printk(KERN_ERR, sdev, "Abort failed: %s (%x:%x) "
                            "flags: %x fcp_rsp: %x, scsi_status: %x\n",
                            ibmvfc_get_cmd_error(rsp_iu.cmd.status, rsp_iu.cmd.error),
                            rsp_iu.cmd.status, rsp_iu.cmd.error, fc_rsp->flags, rsp_code,
                            fc_rsp->scsi_status);
                rsp_rc = -EIO;
        } else
                sdev_printk(KERN_INFO, sdev, "Abort successful\n");

        spin_lock_irqsave(vhost->host->host_lock, flags);
        ibmvfc_free_event(evt);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
        return rsp_rc;
}

/**
 * ibmvfc_cancel_all - Cancel all outstanding commands to the device
 * @sdev:       scsi device to cancel commands
 * @type:       type of error recovery being performed
 *
 * This sends a cancel to the VIOS for the specified device. This does
 * NOT send any abort to the actual device. That must be done separately.
 *
 * Returns:
 *      0 on success / other on failure
 **/
static int ibmvfc_cancel_all(struct scsi_device *sdev, int type)
{
        struct ibmvfc_host *vhost = shost_priv(sdev->host);
        struct scsi_target *starget = scsi_target(sdev);
        struct fc_rport *rport = starget_to_rport(starget);
        struct ibmvfc_tmf *tmf;
        struct ibmvfc_event *evt, *found_evt;
        union ibmvfc_iu rsp;
        int rsp_rc = -EBUSY;
        unsigned long flags;
        u16 status;

        ENTER;
        spin_lock_irqsave(vhost->host->host_lock, flags);
        found_evt = NULL;
        list_for_each_entry(evt, &vhost->sent, queue) {
                if (evt->cmnd && evt->cmnd->device == sdev) {
                        found_evt = evt;
                        break;
                }
        }

        if (!found_evt) {
                if (vhost->log_level > IBMVFC_DEFAULT_LOG_LEVEL)
                        sdev_printk(KERN_INFO, sdev, "No events found to cancel\n");
                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                return 0;
        }

        if (vhost->state == IBMVFC_ACTIVE) {
                evt = ibmvfc_get_event(vhost);
                ibmvfc_init_event(evt, ibmvfc_sync_completion, IBMVFC_MAD_FORMAT);

                tmf = &evt->iu.tmf;
                memset(tmf, 0, sizeof(*tmf));
                tmf->common.version = 1;
                tmf->common.opcode = IBMVFC_TMF_MAD;
                tmf->common.length = sizeof(*tmf);
                tmf->scsi_id = rport->port_id;
                int_to_scsilun(sdev->lun, &tmf->lun);
                tmf->flags = (type | IBMVFC_TMF_LUA_VALID);
                tmf->cancel_key = (unsigned long)sdev->hostdata;
                tmf->my_cancel_key = (unsigned long)starget->hostdata;

                evt->sync_iu = &rsp;
                init_completion(&evt->comp);
                rsp_rc = ibmvfc_send_event(evt, vhost, default_timeout);
        }

        spin_unlock_irqrestore(vhost->host->host_lock, flags);

        if (rsp_rc != 0) {
                sdev_printk(KERN_ERR, sdev, "Failed to send cancel event. rc=%d\n", rsp_rc);
                return -EIO;
        }

        sdev_printk(KERN_INFO, sdev, "Cancelling outstanding commands.\n");

        wait_for_completion(&evt->comp);
        status = rsp.mad_common.status;
        spin_lock_irqsave(vhost->host->host_lock, flags);
        ibmvfc_free_event(evt);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);

        if (status != IBMVFC_MAD_SUCCESS) {
                sdev_printk(KERN_WARNING, sdev, "Cancel failed with rc=%x\n", status);
                return -EIO;
        }

        sdev_printk(KERN_INFO, sdev, "Successfully cancelled outstanding commands\n");
        return 0;
}

/**
 * ibmvfc_match_target - Match function for specified target
 * @evt:        ibmvfc event struct
 * @device:     device to match (starget)
 *
 * Returns:
 *      1 if event matches starget / 0 if event does not match starget
 **/
static int ibmvfc_match_target(struct ibmvfc_event *evt, void *device)
{
        if (evt->cmnd && scsi_target(evt->cmnd->device) == device)
                return 1;
        return 0;
}

/**
 * ibmvfc_match_lun - Match function for specified LUN
 * @evt:        ibmvfc event struct
 * @device:     device to match (sdev)
 *
 * Returns:
 *      1 if event matches sdev / 0 if event does not match sdev
 **/
static int ibmvfc_match_lun(struct ibmvfc_event *evt, void *device)
{
        if (evt->cmnd && evt->cmnd->device == device)
                return 1;
        return 0;
}

/**
 * ibmvfc_wait_for_ops - Wait for ops to complete
 * @vhost:      ibmvfc host struct
 * @device:     device to match (starget or sdev)
 * @match:      match function
 *
 * Returns:
 *      SUCCESS / FAILED
 **/
static int ibmvfc_wait_for_ops(struct ibmvfc_host *vhost, void *device,
                               int (*match) (struct ibmvfc_event *, void *))
{
        struct ibmvfc_event *evt;
        DECLARE_COMPLETION_ONSTACK(comp);
        int wait;
        unsigned long flags;
        signed long timeout = init_timeout * HZ;

        ENTER;
        do {
                wait = 0;
                spin_lock_irqsave(vhost->host->host_lock, flags);
                list_for_each_entry(evt, &vhost->sent, queue) {
                        if (match(evt, device)) {
                                evt->eh_comp = &comp;
                                wait++;
                        }
                }
                spin_unlock_irqrestore(vhost->host->host_lock, flags);

                if (wait) {
                        timeout = wait_for_completion_timeout(&comp, timeout);

                        if (!timeout) {
                                wait = 0;
                                spin_lock_irqsave(vhost->host->host_lock, flags);
                                list_for_each_entry(evt, &vhost->sent, queue) {
                                        if (match(evt, device)) {
                                                evt->eh_comp = NULL;
                                                wait++;
                                        }
                                }
                                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                                if (wait)
                                        dev_err(vhost->dev, "Timed out waiting for aborted commands\n");
                                LEAVE;
                                return wait ? FAILED : SUCCESS;
                        }
                }
        } while (wait);

        LEAVE;
        return SUCCESS;
}

/**
 * ibmvfc_eh_abort_handler - Abort a command
 * @cmd:        scsi command to abort
 *
 * Returns:
 *      SUCCESS / FAILED
 **/
static int ibmvfc_eh_abort_handler(struct scsi_cmnd *cmd)
{
        struct scsi_device *sdev = cmd->device;
        struct ibmvfc_host *vhost = shost_priv(sdev->host);
        int cancel_rc, abort_rc;
        int rc = FAILED;

        ENTER;
        ibmvfc_wait_while_resetting(vhost);
        cancel_rc = ibmvfc_cancel_all(sdev, IBMVFC_TMF_ABORT_TASK_SET);
        abort_rc = ibmvfc_abort_task_set(sdev);

        if (!cancel_rc && !abort_rc)
                rc = ibmvfc_wait_for_ops(vhost, sdev, ibmvfc_match_lun);

        LEAVE;
        return rc;
}

/**
 * ibmvfc_eh_device_reset_handler - Reset a single LUN
 * @cmd:        scsi command struct
 *
 * Returns:
 *      SUCCESS / FAILED
 **/
static int ibmvfc_eh_device_reset_handler(struct scsi_cmnd *cmd)
{
        struct scsi_device *sdev = cmd->device;
        struct ibmvfc_host *vhost = shost_priv(sdev->host);
        int cancel_rc, reset_rc;
        int rc = FAILED;

        ENTER;
        ibmvfc_wait_while_resetting(vhost);
        cancel_rc = ibmvfc_cancel_all(sdev, IBMVFC_TMF_LUN_RESET);
        reset_rc = ibmvfc_reset_device(sdev, IBMVFC_LUN_RESET, "LUN");

        if (!cancel_rc && !reset_rc)
                rc = ibmvfc_wait_for_ops(vhost, sdev, ibmvfc_match_lun);

        LEAVE;
        return rc;
}

/**
 * ibmvfc_dev_cancel_all - Device iterated cancel all function
 * @sdev:       scsi device struct
 * @data:       return code
 *
 **/
static void ibmvfc_dev_cancel_all(struct scsi_device *sdev, void *data)
{
        unsigned long *rc = data;
        *rc |= ibmvfc_cancel_all(sdev, IBMVFC_TMF_TGT_RESET);
}

/**
 * ibmvfc_dev_abort_all - Device iterated abort task set function
 * @sdev:       scsi device struct
 * @data:       return code
 *
 **/
static void ibmvfc_dev_abort_all(struct scsi_device *sdev, void *data)
{
        unsigned long *rc = data;
        *rc |= ibmvfc_abort_task_set(sdev);
}

/**
 * ibmvfc_eh_target_reset_handler - Reset the target
 * @cmd:        scsi command struct
 *
 * Returns:
 *      SUCCESS / FAILED
 **/
static int ibmvfc_eh_target_reset_handler(struct scsi_cmnd *cmd)
{
        struct scsi_device *sdev = cmd->device;
        struct ibmvfc_host *vhost = shost_priv(sdev->host);
        struct scsi_target *starget = scsi_target(sdev);
        int reset_rc;
        int rc = FAILED;
        unsigned long cancel_rc = 0;

        ENTER;
        ibmvfc_wait_while_resetting(vhost);
        starget_for_each_device(starget, &cancel_rc, ibmvfc_dev_cancel_all);
        reset_rc = ibmvfc_reset_device(sdev, IBMVFC_TARGET_RESET, "target");

        if (!cancel_rc && !reset_rc)
                rc = ibmvfc_wait_for_ops(vhost, starget, ibmvfc_match_target);

        LEAVE;
        return rc;
}

/**
 * ibmvfc_eh_host_reset_handler - Reset the connection to the server
 * @cmd:        struct scsi_cmnd having problems
 *
 **/
static int ibmvfc_eh_host_reset_handler(struct scsi_cmnd *cmd)
{
        int rc;
        struct ibmvfc_host *vhost = shost_priv(cmd->device->host);

        dev_err(vhost->dev, "Resetting connection due to error recovery\n");
        rc = ibmvfc_issue_fc_host_lip(vhost->host);
        return rc ? FAILED : SUCCESS;
}

/**
 * ibmvfc_terminate_rport_io - Terminate all pending I/O to the rport.
 * @rport:              rport struct
 *
 * Return value:
 *      none
 **/
static void ibmvfc_terminate_rport_io(struct fc_rport *rport)
{
        struct scsi_target *starget = to_scsi_target(&rport->dev);
        struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
        struct ibmvfc_host *vhost = shost_priv(shost);
        unsigned long cancel_rc = 0;
        unsigned long abort_rc = 0;
        int rc = FAILED;

        ENTER;
        starget_for_each_device(starget, &cancel_rc, ibmvfc_dev_cancel_all);
        starget_for_each_device(starget, &abort_rc, ibmvfc_dev_abort_all);

        if (!cancel_rc && !abort_rc)
                rc = ibmvfc_wait_for_ops(vhost, starget, ibmvfc_match_target);

        if (rc == FAILED)
                ibmvfc_issue_fc_host_lip(shost);
        LEAVE;
}

static const struct {
        enum ibmvfc_async_event ae;
        const char *desc;
} ae_desc [] = {
        { IBMVFC_AE_ELS_PLOGI,          "PLOGI" },
        { IBMVFC_AE_ELS_LOGO,           "LOGO" },
        { IBMVFC_AE_ELS_PRLO,           "PRLO" },
        { IBMVFC_AE_SCN_NPORT,          "N-Port SCN" },
        { IBMVFC_AE_SCN_GROUP,          "Group SCN" },
        { IBMVFC_AE_SCN_DOMAIN,         "Domain SCN" },
        { IBMVFC_AE_SCN_FABRIC,         "Fabric SCN" },
        { IBMVFC_AE_LINK_UP,            "Link Up" },
        { IBMVFC_AE_LINK_DOWN,          "Link Down" },
        { IBMVFC_AE_LINK_DEAD,          "Link Dead" },
        { IBMVFC_AE_HALT,                       "Halt" },
        { IBMVFC_AE_RESUME,             "Resume" },
        { IBMVFC_AE_ADAPTER_FAILED,     "Adapter Failed" },
};

static const char *unknown_ae = "Unknown async";

/**
 * ibmvfc_get_ae_desc - Get text description for async event
 * @ae: async event
 *
 **/
static const char *ibmvfc_get_ae_desc(u64 ae)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(ae_desc); i++)
                if (ae_desc[i].ae == ae)
                        return ae_desc[i].desc;

        return unknown_ae;
}

/**
 * ibmvfc_handle_async - Handle an async event from the adapter
 * @crq:        crq to process
 * @vhost:      ibmvfc host struct
 *
 **/
static void ibmvfc_handle_async(struct ibmvfc_async_crq *crq,
                                struct ibmvfc_host *vhost)
{
        const char *desc = ibmvfc_get_ae_desc(crq->event);

        ibmvfc_log(vhost, 3, "%s event received. scsi_id: %llx, wwpn: %llx,"
                   " node_name: %llx\n", desc, crq->scsi_id, crq->wwpn, crq->node_name);

        switch (crq->event) {
        case IBMVFC_AE_LINK_UP:
        case IBMVFC_AE_RESUME:
                vhost->events_to_log |= IBMVFC_AE_LINKUP;
                vhost->delay_init = 1;
                __ibmvfc_reset_host(vhost);
                break;
        case IBMVFC_AE_SCN_FABRIC:
        case IBMVFC_AE_SCN_DOMAIN:
                vhost->events_to_log |= IBMVFC_AE_RSCN;
                vhost->delay_init = 1;
                __ibmvfc_reset_host(vhost);
                break;
        case IBMVFC_AE_SCN_NPORT:
        case IBMVFC_AE_SCN_GROUP:
                vhost->events_to_log |= IBMVFC_AE_RSCN;
        case IBMVFC_AE_ELS_LOGO:
        case IBMVFC_AE_ELS_PRLO:
        case IBMVFC_AE_ELS_PLOGI:
                ibmvfc_reinit_host(vhost);
                break;
        case IBMVFC_AE_LINK_DOWN:
        case IBMVFC_AE_ADAPTER_FAILED:
                ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
                break;
        case IBMVFC_AE_LINK_DEAD:
                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
                break;
        case IBMVFC_AE_HALT:
                ibmvfc_link_down(vhost, IBMVFC_HALTED);
                break;
        default:
                dev_err(vhost->dev, "Unknown async event received: %lld\n", crq->event);
                break;
        };
}

/**
 * ibmvfc_handle_crq - Handles and frees received events in the CRQ
 * @crq:        Command/Response queue
 * @vhost:      ibmvfc host struct
 *
 **/
static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost)
{
        long rc;
        struct ibmvfc_event *evt = (struct ibmvfc_event *)crq->ioba;

        switch (crq->valid) {
        case IBMVFC_CRQ_INIT_RSP:
                switch (crq->format) {
                case IBMVFC_CRQ_INIT:
                        dev_info(vhost->dev, "Partner initialized\n");
                        /* Send back a response */
                        rc = ibmvfc_send_crq_init_complete(vhost);
                        if (rc == 0)
                                ibmvfc_init_host(vhost, 0);
                        else
                                dev_err(vhost->dev, "Unable to send init rsp. rc=%ld\n", rc);
                        break;
                case IBMVFC_CRQ_INIT_COMPLETE:
                        dev_info(vhost->dev, "Partner initialization complete\n");
                        ibmvfc_init_host(vhost, 0);
                        break;
                default:
                        dev_err(vhost->dev, "Unknown crq message type: %d\n", crq->format);
                }
                return;
        case IBMVFC_CRQ_XPORT_EVENT:
                vhost->state = IBMVFC_NO_CRQ;
                ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_NONE);
                if (crq->format == IBMVFC_PARTITION_MIGRATED) {
                        /* We need to re-setup the interpartition connection */
                        dev_info(vhost->dev, "Re-enabling adapter\n");
                        vhost->client_migrated = 1;
                        ibmvfc_purge_requests(vhost, DID_REQUEUE);
                        if ((rc = ibmvfc_reenable_crq_queue(vhost)) ||
                            (rc = ibmvfc_send_crq_init(vhost))) {
                                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
                                dev_err(vhost->dev, "Error after enable (rc=%ld)\n", rc);
                        } else
                                ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
                } else {
                        dev_err(vhost->dev, "Virtual adapter failed (rc=%d)\n", crq->format);

                        ibmvfc_purge_requests(vhost, DID_ERROR);
                        if ((rc = ibmvfc_reset_crq(vhost)) ||
                            (rc = ibmvfc_send_crq_init(vhost))) {
                                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
                                dev_err(vhost->dev, "Error after reset (rc=%ld)\n", rc);
                        } else
                                ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
                }
                return;
        case IBMVFC_CRQ_CMD_RSP:
                break;
        default:
                dev_err(vhost->dev, "Got an invalid message type 0x%02x\n", crq->valid);
                return;
        }

        if (crq->format == IBMVFC_ASYNC_EVENT)
                return;

        /* The only kind of payload CRQs we should get are responses to
         * things we send. Make sure this response is to something we
         * actually sent
         */
        if (unlikely(!ibmvfc_valid_event(&vhost->pool, evt))) {
                dev_err(vhost->dev, "Returned correlation_token 0x%08llx is invalid!\n",
                        crq->ioba);
                return;
        }

        if (unlikely(atomic_read(&evt->free))) {
                dev_err(vhost->dev, "Received duplicate correlation_token 0x%08llx!\n",
                        crq->ioba);
                return;
        }

        del_timer(&evt->timer);
        list_del(&evt->queue);
        ibmvfc_trc_end(evt);
        evt->done(evt);
}

/**
 * ibmvfc_scan_finished - Check if the device scan is done.
 * @shost:      scsi host struct
 * @time:       current elapsed time
 *
 * Returns:
 *      0 if scan is not done / 1 if scan is done
 **/
static int ibmvfc_scan_finished(struct Scsi_Host *shost, unsigned long time)
{
        unsigned long flags;
        struct ibmvfc_host *vhost = shost_priv(shost);
        int done = 0;

        spin_lock_irqsave(shost->host_lock, flags);
        if (time >= (init_timeout * HZ)) {
                dev_info(vhost->dev, "Scan taking longer than %d seconds, "
                         "continuing initialization\n", init_timeout);
                done = 1;
        }

        if (vhost->scan_complete)
                done = 1;
        spin_unlock_irqrestore(shost->host_lock, flags);
        return done;
}

/**
 * ibmvfc_slave_alloc - Setup the device's task set value
 * @sdev:       struct scsi_device device to configure
 *
 * Set the device's task set value so that error handling works as
 * expected.
 *
 * Returns:
 *      0 on success / -ENXIO if device does not exist
 **/
static int ibmvfc_slave_alloc(struct scsi_device *sdev)
{
        struct Scsi_Host *shost = sdev->host;
        struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
        struct ibmvfc_host *vhost = shost_priv(shost);
        unsigned long flags = 0;

        if (!rport || fc_remote_port_chkready(rport))
                return -ENXIO;

        spin_lock_irqsave(shost->host_lock, flags);
        sdev->hostdata = (void *)(unsigned long)vhost->task_set++;
        spin_unlock_irqrestore(shost->host_lock, flags);
        return 0;
}

/**
 * ibmvfc_target_alloc - Setup the target's task set value
 * @starget:    struct scsi_target
 *
 * Set the target's task set value so that error handling works as
 * expected.
 *
 * Returns:
 *      0 on success / -ENXIO if device does not exist
 **/
static int ibmvfc_target_alloc(struct scsi_target *starget)
{
        struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
        struct ibmvfc_host *vhost = shost_priv(shost);
        unsigned long flags = 0;

        spin_lock_irqsave(shost->host_lock, flags);
        starget->hostdata = (void *)(unsigned long)vhost->task_set++;
        spin_unlock_irqrestore(shost->host_lock, flags);
        return 0;
}

/**
 * ibmvfc_slave_configure - Configure the device
 * @sdev:       struct scsi_device device to configure
 *
 * Enable allow_restart for a device if it is a disk. Adjust the
 * queue_depth here also.
 *
 * Returns:
 *      0
 **/
static int ibmvfc_slave_configure(struct scsi_device *sdev)
{
        struct Scsi_Host *shost = sdev->host;
        struct fc_rport *rport = starget_to_rport(sdev->sdev_target);
        unsigned long flags = 0;

        spin_lock_irqsave(shost->host_lock, flags);
        if (sdev->type == TYPE_DISK)
                sdev->allow_restart = 1;

        if (sdev->tagged_supported) {
                scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);
                scsi_activate_tcq(sdev, sdev->queue_depth);
        } else
                scsi_deactivate_tcq(sdev, sdev->queue_depth);

        rport->dev_loss_tmo = dev_loss_tmo;
        spin_unlock_irqrestore(shost->host_lock, flags);
        return 0;
}

/**
 * ibmvfc_change_queue_depth - Change the device's queue depth
 * @sdev:       scsi device struct
 * @qdepth:     depth to set
 *
 * Return value:
 *      actual depth set
 **/
static int ibmvfc_change_queue_depth(struct scsi_device *sdev, int qdepth)
{
        if (qdepth > IBMVFC_MAX_CMDS_PER_LUN)
                qdepth = IBMVFC_MAX_CMDS_PER_LUN;

        scsi_adjust_queue_depth(sdev, 0, qdepth);
        return sdev->queue_depth;
}

/**
 * ibmvfc_change_queue_type - Change the device's queue type
 * @sdev:               scsi device struct
 * @tag_type:   type of tags to use
 *
 * Return value:
 *      actual queue type set
 **/
static int ibmvfc_change_queue_type(struct scsi_device *sdev, int tag_type)
{
        if (sdev->tagged_supported) {
                scsi_set_tag_type(sdev, tag_type);

                if (tag_type)
                        scsi_activate_tcq(sdev, sdev->queue_depth);
                else
                        scsi_deactivate_tcq(sdev, sdev->queue_depth);
        } else
                tag_type = 0;

        return tag_type;
}

static ssize_t ibmvfc_show_host_partition_name(struct device *dev,
                                                 struct device_attribute *attr, char *buf)
{
        struct Scsi_Host *shost = class_to_shost(dev);
        struct ibmvfc_host *vhost = shost_priv(shost);

        return snprintf(buf, PAGE_SIZE, "%s\n",
                        vhost->login_buf->resp.partition_name);
}

static ssize_t ibmvfc_show_host_device_name(struct device *dev,
                                            struct device_attribute *attr, char *buf)
{
        struct Scsi_Host *shost = class_to_shost(dev);
        struct ibmvfc_host *vhost = shost_priv(shost);

        return snprintf(buf, PAGE_SIZE, "%s\n",
                        vhost->login_buf->resp.device_name);
}

static ssize_t ibmvfc_show_host_loc_code(struct device *dev,
                                         struct device_attribute *attr, char *buf)
{
        struct Scsi_Host *shost = class_to_shost(dev);
        struct ibmvfc_host *vhost = shost_priv(shost);

        return snprintf(buf, PAGE_SIZE, "%s\n",
                        vhost->login_buf->resp.port_loc_code);
}

static ssize_t ibmvfc_show_host_drc_name(struct device *dev,
                                         struct device_attribute *attr, char *buf)
{
        struct Scsi_Host *shost = class_to_shost(dev);
        struct ibmvfc_host *vhost = shost_priv(shost);

        return snprintf(buf, PAGE_SIZE, "%s\n",
                        vhost->login_buf->resp.drc_name);
}

static ssize_t ibmvfc_show_host_npiv_version(struct device *dev,
                                             struct device_attribute *attr, char *buf)
{
        struct Scsi_Host *shost = class_to_shost(dev);
        struct ibmvfc_host *vhost = shost_priv(shost);
        return snprintf(buf, PAGE_SIZE, "%d\n", vhost->login_buf->resp.version);
}

/**
 * ibmvfc_show_log_level - Show the adapter's error logging level
 * @dev:        class device struct
 * @buf:        buffer
 *
 * Return value:
 *      number of bytes printed to buffer
 **/
static ssize_t ibmvfc_show_log_level(struct device *dev,
                                     struct device_attribute *attr, char *buf)
{
        struct Scsi_Host *shost = class_to_shost(dev);
        struct ibmvfc_host *vhost = shost_priv(shost);
        unsigned long flags = 0;
        int len;

        spin_lock_irqsave(shost->host_lock, flags);
        len = snprintf(buf, PAGE_SIZE, "%d\n", vhost->log_level);
        spin_unlock_irqrestore(shost->host_lock, flags);
        return len;
}

/**
 * ibmvfc_store_log_level - Change the adapter's error logging level
 * @dev:        class device struct
 * @buf:        buffer
 *
 * Return value:
 *      number of bytes printed to buffer
 **/
static ssize_t ibmvfc_store_log_level(struct device *dev,
                                      struct device_attribute *attr,
                                      const char *buf, size_t count)
{
        struct Scsi_Host *shost = class_to_shost(dev);
        struct ibmvfc_host *vhost = shost_priv(shost);
        unsigned long flags = 0;

        spin_lock_irqsave(shost->host_lock, flags);
        vhost->log_level = simple_strtoul(buf, NULL, 10);
        spin_unlock_irqrestore(shost->host_lock, flags);
        return strlen(buf);
}

static DEVICE_ATTR(partition_name, S_IRUGO, ibmvfc_show_host_partition_name, NULL);
static DEVICE_ATTR(device_name, S_IRUGO, ibmvfc_show_host_device_name, NULL);
static DEVICE_ATTR(port_loc_code, S_IRUGO, ibmvfc_show_host_loc_code, NULL);
static DEVICE_ATTR(drc_name, S_IRUGO, ibmvfc_show_host_drc_name, NULL);
static DEVICE_ATTR(npiv_version, S_IRUGO, ibmvfc_show_host_npiv_version, NULL);
static DEVICE_ATTR(log_level, S_IRUGO | S_IWUSR,
                   ibmvfc_show_log_level, ibmvfc_store_log_level);

#ifdef CONFIG_SCSI_IBMVFC_TRACE
/**
 * ibmvfc_read_trace - Dump the adapter trace
 * @kobj:               kobject struct
 * @bin_attr:   bin_attribute struct
 * @buf:                buffer
 * @off:                offset
 * @count:              buffer size
 *
 * Return value:
 *      number of bytes printed to buffer
 **/
static ssize_t ibmvfc_read_trace(struct kobject *kobj,
                                 struct bin_attribute *bin_attr,
                                 char *buf, loff_t off, size_t count)
{
        struct device *dev = container_of(kobj, struct device, kobj);
        struct Scsi_Host *shost = class_to_shost(dev);
        struct ibmvfc_host *vhost = shost_priv(shost);
        unsigned long flags = 0;
        int size = IBMVFC_TRACE_SIZE;
        char *src = (char *)vhost->trace;

        if (off > size)
                return 0;
        if (off + count > size) {
                size -= off;
                count = size;
        }

        spin_lock_irqsave(shost->host_lock, flags);
        memcpy(buf, &src[off], count);
        spin_unlock_irqrestore(shost->host_lock, flags);
        return count;
}

static struct bin_attribute ibmvfc_trace_attr = {
        .attr = {
                .name = "trace",
                .mode = S_IRUGO,
        },
        .size = 0,
        .read = ibmvfc_read_trace,
};
#endif

static struct device_attribute *ibmvfc_attrs[] = {
        &dev_attr_partition_name,
        &dev_attr_device_name,
        &dev_attr_port_loc_code,
        &dev_attr_drc_name,
        &dev_attr_npiv_version,
        &dev_attr_log_level,
        NULL
};

static struct scsi_host_template driver_template = {
        .module = THIS_MODULE,
        .name = "IBM POWER Virtual FC Adapter",
        .proc_name = IBMVFC_NAME,
        .queuecommand = ibmvfc_queuecommand,
        .eh_abort_handler = ibmvfc_eh_abort_handler,
        .eh_device_reset_handler = ibmvfc_eh_device_reset_handler,
        .eh_target_reset_handler = ibmvfc_eh_target_reset_handler,
        .eh_host_reset_handler = ibmvfc_eh_host_reset_handler,
        .slave_alloc = ibmvfc_slave_alloc,
        .slave_configure = ibmvfc_slave_configure,
        .target_alloc = ibmvfc_target_alloc,
        .scan_finished = ibmvfc_scan_finished,
        .change_queue_depth = ibmvfc_change_queue_depth,
        .change_queue_type = ibmvfc_change_queue_type,
        .cmd_per_lun = 16,
        .can_queue = IBMVFC_MAX_REQUESTS_DEFAULT,
        .this_id = -1,
        .sg_tablesize = SG_ALL,
        .max_sectors = IBMVFC_MAX_SECTORS,
        .use_clustering = ENABLE_CLUSTERING,
        .shost_attrs = ibmvfc_attrs,
};

/**
 * ibmvfc_next_async_crq - Returns the next entry in async queue
 * @vhost:      ibmvfc host struct
 *
 * Returns:
 *      Pointer to next entry in queue / NULL if empty
 **/
static struct ibmvfc_async_crq *ibmvfc_next_async_crq(struct ibmvfc_host *vhost)
{
        struct ibmvfc_async_crq_queue *async_crq = &vhost->async_crq;
        struct ibmvfc_async_crq *crq;

        crq = &async_crq->msgs[async_crq->cur];
        if (crq->valid & 0x80) {
                if (++async_crq->cur == async_crq->size)
                        async_crq->cur = 0;
        } else
                crq = NULL;

        return crq;
}

/**
 * ibmvfc_next_crq - Returns the next entry in message queue
 * @vhost:      ibmvfc host struct
 *
 * Returns:
 *      Pointer to next entry in queue / NULL if empty
 **/
static struct ibmvfc_crq *ibmvfc_next_crq(struct ibmvfc_host *vhost)
{
        struct ibmvfc_crq_queue *queue = &vhost->crq;
        struct ibmvfc_crq *crq;

        crq = &queue->msgs[queue->cur];
        if (crq->valid & 0x80) {
                if (++queue->cur == queue->size)
                        queue->cur = 0;
        } else
                crq = NULL;

        return crq;
}

/**
 * ibmvfc_interrupt - Interrupt handler
 * @irq:                number of irq to handle, not used
 * @dev_instance: ibmvfc_host that received interrupt
 *
 * Returns:
 *      IRQ_HANDLED
 **/
static irqreturn_t ibmvfc_interrupt(int irq, void *dev_instance)
{
        struct ibmvfc_host *vhost = (struct ibmvfc_host *)dev_instance;
        unsigned long flags;

        spin_lock_irqsave(vhost->host->host_lock, flags);
        vio_disable_interrupts(to_vio_dev(vhost->dev));
        tasklet_schedule(&vhost->tasklet);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
        return IRQ_HANDLED;
}

/**
 * ibmvfc_tasklet - Interrupt handler tasklet
 * @data:               ibmvfc host struct
 *
 * Returns:
 *      Nothing
 **/
static void ibmvfc_tasklet(void *data)
{
        struct ibmvfc_host *vhost = data;
        struct vio_dev *vdev = to_vio_dev(vhost->dev);
        struct ibmvfc_crq *crq;
        struct ibmvfc_async_crq *async;
        unsigned long flags;
        int done = 0;

        spin_lock_irqsave(vhost->host->host_lock, flags);
        while (!done) {
                /* Pull all the valid messages off the CRQ */
                while ((crq = ibmvfc_next_crq(vhost)) != NULL) {
                        ibmvfc_handle_crq(crq, vhost);
                        crq->valid = 0;
                }

                /* Pull all the valid messages off the async CRQ */
                while ((async = ibmvfc_next_async_crq(vhost)) != NULL) {
                        ibmvfc_handle_async(async, vhost);
                        async->valid = 0;
                }

                vio_enable_interrupts(vdev);
                if ((crq = ibmvfc_next_crq(vhost)) != NULL) {
                        vio_disable_interrupts(vdev);
                        ibmvfc_handle_crq(crq, vhost);
                        crq->valid = 0;
                } else if ((async = ibmvfc_next_async_crq(vhost)) != NULL) {
                        vio_disable_interrupts(vdev);
                        ibmvfc_handle_async(async, vhost);
                        async->valid = 0;
                } else
                        done = 1;
        }

        spin_unlock_irqrestore(vhost->host->host_lock, flags);
}

/**
 * ibmvfc_init_tgt - Set the next init job step for the target
 * @tgt:                ibmvfc target struct
 * @job_step:   job step to perform
 *
 **/
static void ibmvfc_init_tgt(struct ibmvfc_target *tgt,
                            void (*job_step) (struct ibmvfc_target *))
{
        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_INIT);
        tgt->job_step = job_step;
        wake_up(&tgt->vhost->work_wait_q);
}

/**
 * ibmvfc_retry_tgt_init - Attempt to retry a step in target initialization
 * @tgt:                ibmvfc target struct
 * @job_step:   initialization job step
 *
 * Returns: 1 if step will be retried / 0 if not
 *
 **/
static int ibmvfc_retry_tgt_init(struct ibmvfc_target *tgt,
                                  void (*job_step) (struct ibmvfc_target *))
{
        if (++tgt->init_retries > IBMVFC_MAX_TGT_INIT_RETRIES) {
                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
                wake_up(&tgt->vhost->work_wait_q);
                return 0;
        } else
                ibmvfc_init_tgt(tgt, job_step);
        return 1;
}

/* Defined in FC-LS */
static const struct {
        int code;
        int retry;
        int logged_in;
} prli_rsp [] = {
        { 0, 1, 0 },
        { 1, 0, 1 },
        { 2, 1, 0 },
        { 3, 1, 0 },
        { 4, 0, 0 },
        { 5, 0, 0 },
        { 6, 0, 1 },
        { 7, 0, 0 },
        { 8, 1, 0 },
};

/**
 * ibmvfc_get_prli_rsp - Find PRLI response index
 * @flags:      PRLI response flags
 *
 **/
static int ibmvfc_get_prli_rsp(u16 flags)
{
        int i;
        int code = (flags & 0x0f00) >> 8;

        for (i = 0; i < ARRAY_SIZE(prli_rsp); i++)
                if (prli_rsp[i].code == code)
                        return i;

        return 0;
}

/**
 * ibmvfc_tgt_prli_done - Completion handler for Process Login
 * @evt:        ibmvfc event struct
 *
 **/
static void ibmvfc_tgt_prli_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_target *tgt = evt->tgt;
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_process_login *rsp = &evt->xfer_iu->prli;
        struct ibmvfc_prli_svc_parms *parms = &rsp->parms;
        u32 status = rsp->common.status;
        int index, level = IBMVFC_DEFAULT_LOG_LEVEL;

        vhost->discovery_threads--;
        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
        switch (status) {
        case IBMVFC_MAD_SUCCESS:
                tgt_dbg(tgt, "Process Login succeeded: %X %02X %04X\n",
                        parms->type, parms->flags, parms->service_parms);

                if (parms->type == IBMVFC_SCSI_FCP_TYPE) {
                        index = ibmvfc_get_prli_rsp(parms->flags);
                        if (prli_rsp[index].logged_in) {
                                if (parms->flags & IBMVFC_PRLI_EST_IMG_PAIR) {
                                        tgt->need_login = 0;
                                        tgt->ids.roles = 0;
                                        if (parms->service_parms & IBMVFC_PRLI_TARGET_FUNC)
                                                tgt->ids.roles |= FC_PORT_ROLE_FCP_TARGET;
                                        if (parms->service_parms & IBMVFC_PRLI_INITIATOR_FUNC)
                                                tgt->ids.roles |= FC_PORT_ROLE_FCP_INITIATOR;
                                        tgt->add_rport = 1;
                                } else
                                        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
                        } else if (prli_rsp[index].retry)
                                ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_send_prli);
                        else
                                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
                } else
                        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
                break;
        case IBMVFC_MAD_DRIVER_FAILED:
                break;
        case IBMVFC_MAD_CRQ_ERROR:
                ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_send_prli);
                break;
        case IBMVFC_MAD_FAILED:
        default:
                if (ibmvfc_retry_cmd(rsp->status, rsp->error))
                        level += ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_send_prli);
                else
                        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);

                tgt_log(tgt, level, "Process Login failed: %s (%x:%x) rc=0x%02X\n",
                        ibmvfc_get_cmd_error(rsp->status, rsp->error),
                        rsp->status, rsp->error, status);
                break;
        };

        kref_put(&tgt->kref, ibmvfc_release_tgt);
        ibmvfc_free_event(evt);
        wake_up(&vhost->work_wait_q);
}

/**
 * ibmvfc_tgt_send_prli - Send a process login
 * @tgt:        ibmvfc target struct
 *
 **/
static void ibmvfc_tgt_send_prli(struct ibmvfc_target *tgt)
{
        struct ibmvfc_process_login *prli;
        struct ibmvfc_host *vhost = tgt->vhost;
        struct ibmvfc_event *evt;

        if (vhost->discovery_threads >= disc_threads)
                return;

        kref_get(&tgt->kref);
        evt = ibmvfc_get_event(vhost);
        vhost->discovery_threads++;
        ibmvfc_init_event(evt, ibmvfc_tgt_prli_done, IBMVFC_MAD_FORMAT);
        evt->tgt = tgt;
        prli = &evt->iu.prli;
        memset(prli, 0, sizeof(*prli));
        prli->common.version = 1;
        prli->common.opcode = IBMVFC_PROCESS_LOGIN;
        prli->common.length = sizeof(*prli);
        prli->scsi_id = tgt->scsi_id;

        prli->parms.type = IBMVFC_SCSI_FCP_TYPE;
        prli->parms.flags = IBMVFC_PRLI_EST_IMG_PAIR;
        prli->parms.service_parms = IBMVFC_PRLI_INITIATOR_FUNC;

        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_INIT_WAIT);
        if (ibmvfc_send_event(evt, vhost, default_timeout)) {
                vhost->discovery_threads--;
                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
                kref_put(&tgt->kref, ibmvfc_release_tgt);
        } else
                tgt_dbg(tgt, "Sent process login\n");
}

/**
 * ibmvfc_tgt_plogi_done - Completion handler for Port Login
 * @evt:        ibmvfc event struct
 *
 **/
static void ibmvfc_tgt_plogi_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_target *tgt = evt->tgt;
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_port_login *rsp = &evt->xfer_iu->plogi;
        u32 status = rsp->common.status;
        int level = IBMVFC_DEFAULT_LOG_LEVEL;

        vhost->discovery_threads--;
        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
        switch (status) {
        case IBMVFC_MAD_SUCCESS:
                tgt_dbg(tgt, "Port Login succeeded\n");
                if (tgt->ids.port_name &&
                    tgt->ids.port_name != wwn_to_u64(rsp->service_parms.port_name)) {
                        vhost->reinit = 1;
                        tgt_dbg(tgt, "Port re-init required\n");
                        break;
                }
                tgt->ids.node_name = wwn_to_u64(rsp->service_parms.node_name);
                tgt->ids.port_name = wwn_to_u64(rsp->service_parms.port_name);
                tgt->ids.port_id = tgt->scsi_id;
                memcpy(&tgt->service_parms, &rsp->service_parms,
                       sizeof(tgt->service_parms));
                memcpy(&tgt->service_parms_change, &rsp->service_parms_change,
                       sizeof(tgt->service_parms_change));
                ibmvfc_init_tgt(tgt, ibmvfc_tgt_send_prli);
                break;
        case IBMVFC_MAD_DRIVER_FAILED:
                break;
        case IBMVFC_MAD_CRQ_ERROR:
                ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_send_plogi);
                break;
        case IBMVFC_MAD_FAILED:
        default:
                if (ibmvfc_retry_cmd(rsp->status, rsp->error))
                        level += ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_send_plogi);
                else
                        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);

                tgt_log(tgt, level, "Port Login failed: %s (%x:%x) %s (%x) %s (%x) rc=0x%02X\n",
                        ibmvfc_get_cmd_error(rsp->status, rsp->error), rsp->status, rsp->error,
                        ibmvfc_get_fc_type(rsp->fc_type), rsp->fc_type,
                        ibmvfc_get_ls_explain(rsp->fc_explain), rsp->fc_explain, status);
                break;
        };

        kref_put(&tgt->kref, ibmvfc_release_tgt);
        ibmvfc_free_event(evt);
        wake_up(&vhost->work_wait_q);
}

/**
 * ibmvfc_tgt_send_plogi - Send PLOGI to the specified target
 * @tgt:        ibmvfc target struct
 *
 **/
static void ibmvfc_tgt_send_plogi(struct ibmvfc_target *tgt)
{
        struct ibmvfc_port_login *plogi;
        struct ibmvfc_host *vhost = tgt->vhost;
        struct ibmvfc_event *evt;

        if (vhost->discovery_threads >= disc_threads)
                return;

        kref_get(&tgt->kref);
        evt = ibmvfc_get_event(vhost);
        vhost->discovery_threads++;
        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_INIT_WAIT);
        ibmvfc_init_event(evt, ibmvfc_tgt_plogi_done, IBMVFC_MAD_FORMAT);
        evt->tgt = tgt;
        plogi = &evt->iu.plogi;
        memset(plogi, 0, sizeof(*plogi));
        plogi->common.version = 1;
        plogi->common.opcode = IBMVFC_PORT_LOGIN;
        plogi->common.length = sizeof(*plogi);
        plogi->scsi_id = tgt->scsi_id;

        if (ibmvfc_send_event(evt, vhost, default_timeout)) {
                vhost->discovery_threads--;
                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
                kref_put(&tgt->kref, ibmvfc_release_tgt);
        } else
                tgt_dbg(tgt, "Sent port login\n");
}

/**
 * ibmvfc_tgt_implicit_logout_done - Completion handler for Implicit Logout MAD
 * @evt:        ibmvfc event struct
 *
 **/
static void ibmvfc_tgt_implicit_logout_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_target *tgt = evt->tgt;
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_implicit_logout *rsp = &evt->xfer_iu->implicit_logout;
        u32 status = rsp->common.status;

        vhost->discovery_threads--;
        ibmvfc_free_event(evt);
        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);

        switch (status) {
        case IBMVFC_MAD_SUCCESS:
                tgt_dbg(tgt, "Implicit Logout succeeded\n");
                break;
        case IBMVFC_MAD_DRIVER_FAILED:
                kref_put(&tgt->kref, ibmvfc_release_tgt);
                wake_up(&vhost->work_wait_q);
                return;
        case IBMVFC_MAD_FAILED:
        default:
                tgt_err(tgt, "Implicit Logout failed: rc=0x%02X\n", status);
                break;
        };

        if (vhost->action == IBMVFC_HOST_ACTION_TGT_INIT)
                ibmvfc_init_tgt(tgt, ibmvfc_tgt_send_plogi);
        else if (vhost->action == IBMVFC_HOST_ACTION_QUERY_TGTS &&
                 tgt->scsi_id != tgt->new_scsi_id)
                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
        kref_put(&tgt->kref, ibmvfc_release_tgt);
        wake_up(&vhost->work_wait_q);
}

/**
 * ibmvfc_tgt_implicit_logout - Initiate an Implicit Logout for specified target
 * @tgt:                ibmvfc target struct
 *
 **/
static void ibmvfc_tgt_implicit_logout(struct ibmvfc_target *tgt)
{
        struct ibmvfc_implicit_logout *mad;
        struct ibmvfc_host *vhost = tgt->vhost;
        struct ibmvfc_event *evt;

        if (vhost->discovery_threads >= disc_threads)
                return;

        kref_get(&tgt->kref);
        evt = ibmvfc_get_event(vhost);
        vhost->discovery_threads++;
        ibmvfc_init_event(evt, ibmvfc_tgt_implicit_logout_done, IBMVFC_MAD_FORMAT);
        evt->tgt = tgt;
        mad = &evt->iu.implicit_logout;
        memset(mad, 0, sizeof(*mad));
        mad->common.version = 1;
        mad->common.opcode = IBMVFC_IMPLICIT_LOGOUT;
        mad->common.length = sizeof(*mad);
        mad->old_scsi_id = tgt->scsi_id;

        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_INIT_WAIT);
        if (ibmvfc_send_event(evt, vhost, default_timeout)) {
                vhost->discovery_threads--;
                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
                kref_put(&tgt->kref, ibmvfc_release_tgt);
        } else
                tgt_dbg(tgt, "Sent Implicit Logout\n");
}

/**
 * ibmvfc_adisc_needs_plogi - Does device need PLOGI?
 * @mad:        ibmvfc passthru mad struct
 * @tgt:        ibmvfc target struct
 *
 * Returns:
 *      1 if PLOGI needed / 0 if PLOGI not needed
 **/
static int ibmvfc_adisc_needs_plogi(struct ibmvfc_passthru_mad *mad,
                                    struct ibmvfc_target *tgt)
{
        if (memcmp(&mad->fc_iu.response[2], &tgt->ids.port_name,
                   sizeof(tgt->ids.port_name)))
                return 1;
        if (memcmp(&mad->fc_iu.response[4], &tgt->ids.node_name,
                   sizeof(tgt->ids.node_name)))
                return 1;
        if (mad->fc_iu.response[6] != tgt->scsi_id)
                return 1;
        return 0;
}

/**
 * ibmvfc_tgt_adisc_done - Completion handler for ADISC
 * @evt:        ibmvfc event struct
 *
 **/
static void ibmvfc_tgt_adisc_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_target *tgt = evt->tgt;
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_passthru_mad *mad = &evt->xfer_iu->passthru;
        u32 status = mad->common.status;
        u8 fc_reason, fc_explain;

        vhost->discovery_threads--;
        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
        del_timer(&tgt->timer);

        switch (status) {
        case IBMVFC_MAD_SUCCESS:
                tgt_dbg(tgt, "ADISC succeeded\n");
                if (ibmvfc_adisc_needs_plogi(mad, tgt))
                        tgt->need_login = 1;
                break;
        case IBMVFC_MAD_DRIVER_FAILED:
                break;
        case IBMVFC_MAD_FAILED:
        default:
                tgt->need_login = 1;
                fc_reason = (mad->fc_iu.response[1] & 0x00ff0000) >> 16;
                fc_explain = (mad->fc_iu.response[1] & 0x0000ff00) >> 8;
                tgt_info(tgt, "ADISC failed: %s (%x:%x) %s (%x) %s (%x) rc=0x%02X\n",
                         ibmvfc_get_cmd_error(mad->iu.status, mad->iu.error),
                         mad->iu.status, mad->iu.error,
                         ibmvfc_get_fc_type(fc_reason), fc_reason,
                         ibmvfc_get_ls_explain(fc_explain), fc_explain, status);
                break;
        };

        kref_put(&tgt->kref, ibmvfc_release_tgt);
        ibmvfc_free_event(evt);
        wake_up(&vhost->work_wait_q);
}

/**
 * ibmvfc_init_passthru - Initialize an event struct for FC passthru
 * @evt:                ibmvfc event struct
 *
 **/
static void ibmvfc_init_passthru(struct ibmvfc_event *evt)
{
        struct ibmvfc_passthru_mad *mad = &evt->iu.passthru;

        memset(mad, 0, sizeof(*mad));
        mad->common.version = 1;
        mad->common.opcode = IBMVFC_PASSTHRU;
        mad->common.length = sizeof(*mad) - sizeof(mad->fc_iu) - sizeof(mad->iu);
        mad->cmd_ioba.va = (u64)evt->crq.ioba +
                offsetof(struct ibmvfc_passthru_mad, iu);
        mad->cmd_ioba.len = sizeof(mad->iu);
        mad->iu.cmd_len = sizeof(mad->fc_iu.payload);
        mad->iu.rsp_len = sizeof(mad->fc_iu.response);
        mad->iu.cmd.va = (u64)evt->crq.ioba +
                offsetof(struct ibmvfc_passthru_mad, fc_iu) +
                offsetof(struct ibmvfc_passthru_fc_iu, payload);
        mad->iu.cmd.len = sizeof(mad->fc_iu.payload);
        mad->iu.rsp.va = (u64)evt->crq.ioba +
                offsetof(struct ibmvfc_passthru_mad, fc_iu) +
                offsetof(struct ibmvfc_passthru_fc_iu, response);
        mad->iu.rsp.len = sizeof(mad->fc_iu.response);
}

/**
 * ibmvfc_tgt_adisc_cancel_done - Completion handler when cancelling an ADISC
 * @evt:                ibmvfc event struct
 *
 * Just cleanup this event struct. Everything else is handled by
 * the ADISC completion handler. If the ADISC never actually comes
 * back, we still have the timer running on the ADISC event struct
 * which will fire and cause the CRQ to get reset.
 *
 **/
static void ibmvfc_tgt_adisc_cancel_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_target *tgt = evt->tgt;

        tgt_dbg(tgt, "ADISC cancel complete\n");
        vhost->abort_threads--;
        ibmvfc_free_event(evt);
        kref_put(&tgt->kref, ibmvfc_release_tgt);
        wake_up(&vhost->work_wait_q);
}

/**
 * ibmvfc_adisc_timeout - Handle an ADISC timeout
 * @tgt:                ibmvfc target struct
 *
 * If an ADISC times out, send a cancel. If the cancel times
 * out, reset the CRQ. When the ADISC comes back as cancelled,
 * log back into the target.
 **/
static void ibmvfc_adisc_timeout(struct ibmvfc_target *tgt)
{
        struct ibmvfc_host *vhost = tgt->vhost;
        struct ibmvfc_event *evt;
        struct ibmvfc_tmf *tmf;
        unsigned long flags;
        int rc;

        tgt_dbg(tgt, "ADISC timeout\n");
        spin_lock_irqsave(vhost->host->host_lock, flags);
        if (vhost->abort_threads >= disc_threads ||
            tgt->action != IBMVFC_TGT_ACTION_INIT_WAIT ||
            vhost->state != IBMVFC_INITIALIZING ||
            vhost->action != IBMVFC_HOST_ACTION_QUERY_TGTS) {
                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                return;
        }

        vhost->abort_threads++;
        kref_get(&tgt->kref);
        evt = ibmvfc_get_event(vhost);
        ibmvfc_init_event(evt, ibmvfc_tgt_adisc_cancel_done, IBMVFC_MAD_FORMAT);

        evt->tgt = tgt;
        tmf = &evt->iu.tmf;
        memset(tmf, 0, sizeof(*tmf));
        tmf->common.version = 1;
        tmf->common.opcode = IBMVFC_TMF_MAD;
        tmf->common.length = sizeof(*tmf);
        tmf->scsi_id = tgt->scsi_id;
        tmf->cancel_key = tgt->cancel_key;

        rc = ibmvfc_send_event(evt, vhost, default_timeout);

        if (rc) {
                tgt_err(tgt, "Failed to send cancel event for ADISC. rc=%d\n", rc);
                vhost->abort_threads--;
                kref_put(&tgt->kref, ibmvfc_release_tgt);
                __ibmvfc_reset_host(vhost);
        } else
                tgt_dbg(tgt, "Attempting to cancel ADISC\n");
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
}

/**
 * ibmvfc_tgt_adisc - Initiate an ADISC for specified target
 * @tgt:                ibmvfc target struct
 *
 * When sending an ADISC we end up with two timers running. The
 * first timer is the timer in the ibmvfc target struct. If this
 * fires, we send a cancel to the target. The second timer is the
 * timer on the ibmvfc event for the ADISC, which is longer. If that
 * fires, it means the ADISC timed out and our attempt to cancel it
 * also failed, so we need to reset the CRQ.
 **/
static void ibmvfc_tgt_adisc(struct ibmvfc_target *tgt)
{
        struct ibmvfc_passthru_mad *mad;
        struct ibmvfc_host *vhost = tgt->vhost;
        struct ibmvfc_event *evt;

        if (vhost->discovery_threads >= disc_threads)
                return;

        kref_get(&tgt->kref);
        evt = ibmvfc_get_event(vhost);
        vhost->discovery_threads++;
        ibmvfc_init_event(evt, ibmvfc_tgt_adisc_done, IBMVFC_MAD_FORMAT);
        evt->tgt = tgt;

        ibmvfc_init_passthru(evt);
        mad = &evt->iu.passthru;
        mad->iu.flags = IBMVFC_FC_ELS;
        mad->iu.scsi_id = tgt->scsi_id;
        mad->iu.cancel_key = tgt->cancel_key;

        mad->fc_iu.payload[0] = IBMVFC_ADISC;
        memcpy(&mad->fc_iu.payload[2], &vhost->login_buf->resp.port_name,
               sizeof(vhost->login_buf->resp.port_name));
        memcpy(&mad->fc_iu.payload[4], &vhost->login_buf->resp.node_name,
               sizeof(vhost->login_buf->resp.node_name));
        mad->fc_iu.payload[6] = vhost->login_buf->resp.scsi_id & 0x00ffffff;

        if (timer_pending(&tgt->timer))
                mod_timer(&tgt->timer, jiffies + (IBMVFC_ADISC_TIMEOUT * HZ));
        else {
                tgt->timer.data = (unsigned long) tgt;
                tgt->timer.expires = jiffies + (IBMVFC_ADISC_TIMEOUT * HZ);
                tgt->timer.function = (void (*)(unsigned long))ibmvfc_adisc_timeout;
                add_timer(&tgt->timer);
        }

        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_INIT_WAIT);
        if (ibmvfc_send_event(evt, vhost, IBMVFC_ADISC_PLUS_CANCEL_TIMEOUT)) {
                vhost->discovery_threads--;
                del_timer(&tgt->timer);
                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
                kref_put(&tgt->kref, ibmvfc_release_tgt);
        } else
                tgt_dbg(tgt, "Sent ADISC\n");
}

/**
 * ibmvfc_tgt_query_target_done - Completion handler for Query Target MAD
 * @evt:        ibmvfc event struct
 *
 **/
static void ibmvfc_tgt_query_target_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_target *tgt = evt->tgt;
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_query_tgt *rsp = &evt->xfer_iu->query_tgt;
        u32 status = rsp->common.status;
        int level = IBMVFC_DEFAULT_LOG_LEVEL;

        vhost->discovery_threads--;
        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
        switch (status) {
        case IBMVFC_MAD_SUCCESS:
                tgt_dbg(tgt, "Query Target succeeded\n");
                tgt->new_scsi_id = rsp->scsi_id;
                if (rsp->scsi_id != tgt->scsi_id)
                        ibmvfc_init_tgt(tgt, ibmvfc_tgt_implicit_logout);
                else
                        ibmvfc_init_tgt(tgt, ibmvfc_tgt_adisc);
                break;
        case IBMVFC_MAD_DRIVER_FAILED:
                break;
        case IBMVFC_MAD_CRQ_ERROR:
                ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_query_target);
                break;
        case IBMVFC_MAD_FAILED:
        default:
                if ((rsp->status & IBMVFC_FABRIC_MAPPED) == IBMVFC_FABRIC_MAPPED &&
                    rsp->error == IBMVFC_UNABLE_TO_PERFORM_REQ &&
                    rsp->fc_explain == IBMVFC_PORT_NAME_NOT_REG)
                        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
                else if (ibmvfc_retry_cmd(rsp->status, rsp->error))
                        level += ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_query_target);
                else
                        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);

                tgt_log(tgt, level, "Query Target failed: %s (%x:%x) %s (%x) %s (%x) rc=0x%02X\n",
                        ibmvfc_get_cmd_error(rsp->status, rsp->error), rsp->status, rsp->error,
                        ibmvfc_get_fc_type(rsp->fc_type), rsp->fc_type,
                        ibmvfc_get_gs_explain(rsp->fc_explain), rsp->fc_explain, status);
                break;
        };

        kref_put(&tgt->kref, ibmvfc_release_tgt);
        ibmvfc_free_event(evt);
        wake_up(&vhost->work_wait_q);
}

/**
 * ibmvfc_tgt_query_target - Initiate a Query Target for specified target
 * @tgt:        ibmvfc target struct
 *
 **/
static void ibmvfc_tgt_query_target(struct ibmvfc_target *tgt)
{
        struct ibmvfc_query_tgt *query_tgt;
        struct ibmvfc_host *vhost = tgt->vhost;
        struct ibmvfc_event *evt;

        if (vhost->discovery_threads >= disc_threads)
                return;

        kref_get(&tgt->kref);
        evt = ibmvfc_get_event(vhost);
        vhost->discovery_threads++;
        evt->tgt = tgt;
        ibmvfc_init_event(evt, ibmvfc_tgt_query_target_done, IBMVFC_MAD_FORMAT);
        query_tgt = &evt->iu.query_tgt;
        memset(query_tgt, 0, sizeof(*query_tgt));
        query_tgt->common.version = 1;
        query_tgt->common.opcode = IBMVFC_QUERY_TARGET;
        query_tgt->common.length = sizeof(*query_tgt);
        query_tgt->wwpn = tgt->ids.port_name;

        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_INIT_WAIT);
        if (ibmvfc_send_event(evt, vhost, default_timeout)) {
                vhost->discovery_threads--;
                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
                kref_put(&tgt->kref, ibmvfc_release_tgt);
        } else
                tgt_dbg(tgt, "Sent Query Target\n");
}

/**
 * ibmvfc_alloc_target - Allocate and initialize an ibmvfc target
 * @vhost:              ibmvfc host struct
 * @scsi_id:    SCSI ID to allocate target for
 *
 * Returns:
 *      0 on success / other on failure
 **/
static int ibmvfc_alloc_target(struct ibmvfc_host *vhost, u64 scsi_id)
{
        struct ibmvfc_target *tgt;
        unsigned long flags;

        spin_lock_irqsave(vhost->host->host_lock, flags);
        list_for_each_entry(tgt, &vhost->targets, queue) {
                if (tgt->scsi_id == scsi_id) {
                        if (tgt->need_login)
                                ibmvfc_init_tgt(tgt, ibmvfc_tgt_implicit_logout);
                        goto unlock_out;
                }
        }
        spin_unlock_irqrestore(vhost->host->host_lock, flags);

        tgt = mempool_alloc(vhost->tgt_pool, GFP_NOIO);
        if (!tgt) {
                dev_err(vhost->dev, "Target allocation failure for scsi id %08llx\n",
                        scsi_id);
                return -ENOMEM;
        }

        memset(tgt, 0, sizeof(*tgt));
        tgt->scsi_id = scsi_id;
        tgt->new_scsi_id = scsi_id;
        tgt->vhost = vhost;
        tgt->need_login = 1;
        tgt->cancel_key = vhost->task_set++;
        init_timer(&tgt->timer);
        kref_init(&tgt->kref);
        ibmvfc_init_tgt(tgt, ibmvfc_tgt_implicit_logout);
        spin_lock_irqsave(vhost->host->host_lock, flags);
        list_add_tail(&tgt->queue, &vhost->targets);

unlock_out:
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
        return 0;
}

/**
 * ibmvfc_alloc_targets - Allocate and initialize ibmvfc targets
 * @vhost:              ibmvfc host struct
 *
 * Returns:
 *      0 on success / other on failure
 **/
static int ibmvfc_alloc_targets(struct ibmvfc_host *vhost)
{
        int i, rc;

        for (i = 0, rc = 0; !rc && i < vhost->num_targets; i++)
                rc = ibmvfc_alloc_target(vhost,
                                         vhost->disc_buf->scsi_id[i] & IBMVFC_DISC_TGT_SCSI_ID_MASK);

        return rc;
}

/**
 * ibmvfc_discover_targets_done - Completion handler for discover targets MAD
 * @evt:        ibmvfc event struct
 *
 **/
static void ibmvfc_discover_targets_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_host *vhost = evt->vhost;
        struct ibmvfc_discover_targets *rsp = &evt->xfer_iu->discover_targets;
        u32 mad_status = rsp->common.status;
        int level = IBMVFC_DEFAULT_LOG_LEVEL;

        switch (mad_status) {
        case IBMVFC_MAD_SUCCESS:
                ibmvfc_dbg(vhost, "Discover Targets succeeded\n");
                vhost->num_targets = rsp->num_written;
                ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_ALLOC_TGTS);
                break;
        case IBMVFC_MAD_FAILED:
                level += ibmvfc_retry_host_init(vhost);
                ibmvfc_log(vhost, level, "Discover Targets failed: %s (%x:%x)\n",
                           ibmvfc_get_cmd_error(rsp->status, rsp->error), rsp->status, rsp->error);
                break;
        case IBMVFC_MAD_DRIVER_FAILED:
                break;
        default:
                dev_err(vhost->dev, "Invalid Discover Targets response: 0x%x\n", mad_status);
                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
                break;
        }

        ibmvfc_free_event(evt);
        wake_up(&vhost->work_wait_q);
}

/**
 * ibmvfc_discover_targets - Send Discover Targets MAD
 * @vhost:      ibmvfc host struct
 *
 **/
static void ibmvfc_discover_targets(struct ibmvfc_host *vhost)
{
        struct ibmvfc_discover_targets *mad;
        struct ibmvfc_event *evt = ibmvfc_get_event(vhost);

        ibmvfc_init_event(evt, ibmvfc_discover_targets_done, IBMVFC_MAD_FORMAT);
        mad = &evt->iu.discover_targets;
        memset(mad, 0, sizeof(*mad));
        mad->common.version = 1;
        mad->common.opcode = IBMVFC_DISC_TARGETS;
        mad->common.length = sizeof(*mad);
        mad->bufflen = vhost->disc_buf_sz;
        mad->buffer.va = vhost->disc_buf_dma;
        mad->buffer.len = vhost->disc_buf_sz;
        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_INIT_WAIT);

        if (!ibmvfc_send_event(evt, vhost, default_timeout))
                ibmvfc_dbg(vhost, "Sent discover targets\n");
        else
                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
}

/**
 * ibmvfc_npiv_login_done - Completion handler for NPIV Login
 * @evt:        ibmvfc event struct
 *
 **/
static void ibmvfc_npiv_login_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_host *vhost = evt->vhost;
        u32 mad_status = evt->xfer_iu->npiv_login.common.status;
        struct ibmvfc_npiv_login_resp *rsp = &vhost->login_buf->resp;
        unsigned int npiv_max_sectors;
        int level = IBMVFC_DEFAULT_LOG_LEVEL;

        switch (mad_status) {
        case IBMVFC_MAD_SUCCESS:
                ibmvfc_free_event(evt);
                break;
        case IBMVFC_MAD_FAILED:
                if (ibmvfc_retry_cmd(rsp->status, rsp->error))
                        level += ibmvfc_retry_host_init(vhost);
                else
                        ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
                ibmvfc_log(vhost, level, "NPIV Login failed: %s (%x:%x)\n",
                           ibmvfc_get_cmd_error(rsp->status, rsp->error), rsp->status, rsp->error);
                ibmvfc_free_event(evt);
                return;
        case IBMVFC_MAD_CRQ_ERROR:
                ibmvfc_retry_host_init(vhost);
        case IBMVFC_MAD_DRIVER_FAILED:
                ibmvfc_free_event(evt);
                return;
        default:
                dev_err(vhost->dev, "Invalid NPIV Login response: 0x%x\n", mad_status);
                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
                ibmvfc_free_event(evt);
                return;
        }

        vhost->client_migrated = 0;

        if (!(rsp->flags & IBMVFC_NATIVE_FC)) {
                dev_err(vhost->dev, "Virtual adapter does not support FC. %x\n",
                        rsp->flags);
                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
                wake_up(&vhost->work_wait_q);
                return;
        }

        if (rsp->max_cmds <= IBMVFC_NUM_INTERNAL_REQ) {
                dev_err(vhost->dev, "Virtual adapter supported queue depth too small: %d\n",
                        rsp->max_cmds);
                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
                wake_up(&vhost->work_wait_q);
                return;
        }

        npiv_max_sectors = min((uint)(rsp->max_dma_len >> 9), IBMVFC_MAX_SECTORS);
        dev_info(vhost->dev, "Host partition: %s, device: %s %s %s max sectors %u\n",
                 rsp->partition_name, rsp->device_name, rsp->port_loc_code,
                 rsp->drc_name, npiv_max_sectors);

        fc_host_fabric_name(vhost->host) = rsp->node_name;
        fc_host_node_name(vhost->host) = rsp->node_name;
        fc_host_port_name(vhost->host) = rsp->port_name;
        fc_host_port_id(vhost->host) = rsp->scsi_id;
        fc_host_port_type(vhost->host) = FC_PORTTYPE_NPIV;
        fc_host_supported_classes(vhost->host) = 0;
        if (rsp->service_parms.class1_parms[0] & 0x80000000)
                fc_host_supported_classes(vhost->host) |= FC_COS_CLASS1;
        if (rsp->service_parms.class2_parms[0] & 0x80000000)
                fc_host_supported_classes(vhost->host) |= FC_COS_CLASS2;
        if (rsp->service_parms.class3_parms[0] & 0x80000000)
                fc_host_supported_classes(vhost->host) |= FC_COS_CLASS3;
        fc_host_maxframe_size(vhost->host) =
                rsp->service_parms.common.bb_rcv_sz & 0x0fff;

        vhost->host->can_queue = rsp->max_cmds - IBMVFC_NUM_INTERNAL_REQ;
        vhost->host->max_sectors = npiv_max_sectors;
        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_QUERY);
        wake_up(&vhost->work_wait_q);
}

/**
 * ibmvfc_npiv_login - Sends NPIV login
 * @vhost:      ibmvfc host struct
 *
 **/
static void ibmvfc_npiv_login(struct ibmvfc_host *vhost)
{
        struct ibmvfc_npiv_login_mad *mad;
        struct ibmvfc_event *evt = ibmvfc_get_event(vhost);

        ibmvfc_gather_partition_info(vhost);
        ibmvfc_set_login_info(vhost);
        ibmvfc_init_event(evt, ibmvfc_npiv_login_done, IBMVFC_MAD_FORMAT);

        memcpy(vhost->login_buf, &vhost->login_info, sizeof(vhost->login_info));
        mad = &evt->iu.npiv_login;
        memset(mad, 0, sizeof(struct ibmvfc_npiv_login_mad));
        mad->common.version = 1;
        mad->common.opcode = IBMVFC_NPIV_LOGIN;
        mad->common.length = sizeof(struct ibmvfc_npiv_login_mad);
        mad->buffer.va = vhost->login_buf_dma;
        mad->buffer.len = sizeof(*vhost->login_buf);

        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_INIT_WAIT);

        if (!ibmvfc_send_event(evt, vhost, default_timeout))
                ibmvfc_dbg(vhost, "Sent NPIV login\n");
        else
                ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
};

/**
 * ibmvfc_dev_init_to_do - Is there target initialization work to do?
 * @vhost:              ibmvfc host struct
 *
 * Returns:
 *      1 if work to do / 0 if not
 **/
static int ibmvfc_dev_init_to_do(struct ibmvfc_host *vhost)
{
        struct ibmvfc_target *tgt;

        list_for_each_entry(tgt, &vhost->targets, queue) {
                if (tgt->action == IBMVFC_TGT_ACTION_INIT ||
                    tgt->action == IBMVFC_TGT_ACTION_INIT_WAIT)
                        return 1;
        }

        return 0;
}

/**
 * __ibmvfc_work_to_do - Is there task level work to do? (no locking)
 * @vhost:              ibmvfc host struct
 *
 * Returns:
 *      1 if work to do / 0 if not
 **/
static int __ibmvfc_work_to_do(struct ibmvfc_host *vhost)
{
        struct ibmvfc_target *tgt;

        if (kthread_should_stop())
                return 1;
        switch (vhost->action) {
        case IBMVFC_HOST_ACTION_NONE:
        case IBMVFC_HOST_ACTION_INIT_WAIT:
                return 0;
        case IBMVFC_HOST_ACTION_TGT_INIT:
        case IBMVFC_HOST_ACTION_QUERY_TGTS:
                if (vhost->discovery_threads == disc_threads)
                        return 0;
                list_for_each_entry(tgt, &vhost->targets, queue)
                        if (tgt->action == IBMVFC_TGT_ACTION_INIT)
                                return 1;
                list_for_each_entry(tgt, &vhost->targets, queue)
                        if (tgt->action == IBMVFC_TGT_ACTION_INIT_WAIT)
                                return 0;
                return 1;
        case IBMVFC_HOST_ACTION_INIT:
        case IBMVFC_HOST_ACTION_ALLOC_TGTS:
        case IBMVFC_HOST_ACTION_TGT_DEL:
        case IBMVFC_HOST_ACTION_TGT_DEL_FAILED:
        case IBMVFC_HOST_ACTION_QUERY:
        default:
                break;
        };

        return 1;
}

/**
 * ibmvfc_work_to_do - Is there task level work to do?
 * @vhost:              ibmvfc host struct
 *
 * Returns:
 *      1 if work to do / 0 if not
 **/
static int ibmvfc_work_to_do(struct ibmvfc_host *vhost)
{
        unsigned long flags;
        int rc;

        spin_lock_irqsave(vhost->host->host_lock, flags);
        rc = __ibmvfc_work_to_do(vhost);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
        return rc;
}

/**
 * ibmvfc_log_ae - Log async events if necessary
 * @vhost:              ibmvfc host struct
 * @events:             events to log
 *
 **/
static void ibmvfc_log_ae(struct ibmvfc_host *vhost, int events)
{
        if (events & IBMVFC_AE_RSCN)
                fc_host_post_event(vhost->host, fc_get_event_number(), FCH_EVT_RSCN, 0);
        if ((events & IBMVFC_AE_LINKDOWN) &&
            vhost->state >= IBMVFC_HALTED)
                fc_host_post_event(vhost->host, fc_get_event_number(), FCH_EVT_LINKDOWN, 0);
        if ((events & IBMVFC_AE_LINKUP) &&
            vhost->state == IBMVFC_INITIALIZING)
                fc_host_post_event(vhost->host, fc_get_event_number(), FCH_EVT_LINKUP, 0);
}

/**
 * ibmvfc_tgt_add_rport - Tell the FC transport about a new remote port
 * @tgt:                ibmvfc target struct
 *
 **/
static void ibmvfc_tgt_add_rport(struct ibmvfc_target *tgt)
{
        struct ibmvfc_host *vhost = tgt->vhost;
        struct fc_rport *rport;
        unsigned long flags;

        tgt_dbg(tgt, "Adding rport\n");
        rport = fc_remote_port_add(vhost->host, 0, &tgt->ids);
        spin_lock_irqsave(vhost->host->host_lock, flags);

        if (rport && tgt->action == IBMVFC_TGT_ACTION_DEL_RPORT) {
                tgt_dbg(tgt, "Deleting rport\n");
                list_del(&tgt->queue);
                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                fc_remote_port_delete(rport);
                del_timer_sync(&tgt->timer);
                kref_put(&tgt->kref, ibmvfc_release_tgt);
                return;
        }

        if (rport) {
                tgt_dbg(tgt, "rport add succeeded\n");
                tgt->rport = rport;
                rport->maxframe_size = tgt->service_parms.common.bb_rcv_sz & 0x0fff;
                rport->supported_classes = 0;
                tgt->target_id = rport->scsi_target_id;
                if (tgt->service_parms.class1_parms[0] & 0x80000000)
                        rport->supported_classes |= FC_COS_CLASS1;
                if (tgt->service_parms.class2_parms[0] & 0x80000000)
                        rport->supported_classes |= FC_COS_CLASS2;
                if (tgt->service_parms.class3_parms[0] & 0x80000000)
                        rport->supported_classes |= FC_COS_CLASS3;
        } else
                tgt_dbg(tgt, "rport add failed\n");
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
}

/**
 * ibmvfc_do_work - Do task level work
 * @vhost:              ibmvfc host struct
 *
 **/
static void ibmvfc_do_work(struct ibmvfc_host *vhost)
{
        struct ibmvfc_target *tgt;
        unsigned long flags;
        struct fc_rport *rport;

        ibmvfc_log_ae(vhost, vhost->events_to_log);
        spin_lock_irqsave(vhost->host->host_lock, flags);
        vhost->events_to_log = 0;
        switch (vhost->action) {
        case IBMVFC_HOST_ACTION_NONE:
        case IBMVFC_HOST_ACTION_INIT_WAIT:
                break;
        case IBMVFC_HOST_ACTION_INIT:
                BUG_ON(vhost->state != IBMVFC_INITIALIZING);
                if (vhost->delay_init) {
                        vhost->delay_init = 0;
                        spin_unlock_irqrestore(vhost->host->host_lock, flags);
                        ssleep(15);
                        return;
                } else
                        vhost->job_step(vhost);
                break;
        case IBMVFC_HOST_ACTION_QUERY:
                list_for_each_entry(tgt, &vhost->targets, queue)
                        ibmvfc_init_tgt(tgt, ibmvfc_tgt_query_target);
                ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_QUERY_TGTS);
                break;
        case IBMVFC_HOST_ACTION_QUERY_TGTS:
                list_for_each_entry(tgt, &vhost->targets, queue) {
                        if (tgt->action == IBMVFC_TGT_ACTION_INIT) {
                                tgt->job_step(tgt);
                                break;
                        }
                }

                if (!ibmvfc_dev_init_to_do(vhost))
                        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_TGT_DEL);
                break;
        case IBMVFC_HOST_ACTION_TGT_DEL:
        case IBMVFC_HOST_ACTION_TGT_DEL_FAILED:
                list_for_each_entry(tgt, &vhost->targets, queue) {
                        if (tgt->action == IBMVFC_TGT_ACTION_DEL_RPORT) {
                                tgt_dbg(tgt, "Deleting rport\n");
                                rport = tgt->rport;
                                tgt->rport = NULL;
                                list_del(&tgt->queue);
                                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                                if (rport)
                                        fc_remote_port_delete(rport);
                                del_timer_sync(&tgt->timer);
                                kref_put(&tgt->kref, ibmvfc_release_tgt);
                                return;
                        }
                }

                if (vhost->state == IBMVFC_INITIALIZING) {
                        if (vhost->action == IBMVFC_HOST_ACTION_TGT_DEL_FAILED) {
                                if (vhost->reinit) {
                                        vhost->reinit = 0;
                                        scsi_block_requests(vhost->host);
                                        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_QUERY);
                                        spin_unlock_irqrestore(vhost->host->host_lock, flags);
                                } else {
                                        ibmvfc_set_host_state(vhost, IBMVFC_ACTIVE);
                                        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_NONE);
                                        wake_up(&vhost->init_wait_q);
                                        schedule_work(&vhost->rport_add_work_q);
                                        vhost->init_retries = 0;
                                        spin_unlock_irqrestore(vhost->host->host_lock, flags);
                                        scsi_unblock_requests(vhost->host);
                                }

                                return;
                        } else {
                                ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_INIT);
                                vhost->job_step = ibmvfc_discover_targets;
                        }
                } else {
                        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_NONE);
                        spin_unlock_irqrestore(vhost->host->host_lock, flags);
                        scsi_unblock_requests(vhost->host);
                        wake_up(&vhost->init_wait_q);
                        return;
                }
                break;
        case IBMVFC_HOST_ACTION_ALLOC_TGTS:
                ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_TGT_INIT);
                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                ibmvfc_alloc_targets(vhost);
                spin_lock_irqsave(vhost->host->host_lock, flags);
                break;
        case IBMVFC_HOST_ACTION_TGT_INIT:
                list_for_each_entry(tgt, &vhost->targets, queue) {
                        if (tgt->action == IBMVFC_TGT_ACTION_INIT) {
                                tgt->job_step(tgt);
                                break;
                        }
                }

                if (!ibmvfc_dev_init_to_do(vhost))
                        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_TGT_DEL_FAILED);
                break;
        default:
                break;
        };

        spin_unlock_irqrestore(vhost->host->host_lock, flags);
}

/**
 * ibmvfc_work - Do task level work
 * @data:               ibmvfc host struct
 *
 * Returns:
 *      zero
 **/
static int ibmvfc_work(void *data)
{
        struct ibmvfc_host *vhost = data;
        int rc;

        set_user_nice(current, -20);

        while (1) {
                rc = wait_event_interruptible(vhost->work_wait_q,
                                              ibmvfc_work_to_do(vhost));

                BUG_ON(rc);

                if (kthread_should_stop())
                        break;

                ibmvfc_do_work(vhost);
        }

        ibmvfc_dbg(vhost, "ibmvfc kthread exiting...\n");
        return 0;
}

/**
 * ibmvfc_init_crq - Initializes and registers CRQ with hypervisor
 * @vhost:      ibmvfc host struct
 *
 * Allocates a page for messages, maps it for dma, and registers
 * the crq with the hypervisor.
 *
 * Return value:
 *      zero on success / other on failure
 **/
static int ibmvfc_init_crq(struct ibmvfc_host *vhost)
{
        int rc, retrc = -ENOMEM;
        struct device *dev = vhost->dev;
        struct vio_dev *vdev = to_vio_dev(dev);
        struct ibmvfc_crq_queue *crq = &vhost->crq;

        ENTER;
        crq->msgs = (struct ibmvfc_crq *)get_zeroed_page(GFP_KERNEL);

        if (!crq->msgs)
                return -ENOMEM;

        crq->size = PAGE_SIZE / sizeof(*crq->msgs);
        crq->msg_token = dma_map_single(dev, crq->msgs,
                                        PAGE_SIZE, DMA_BIDIRECTIONAL);

        if (dma_mapping_error(dev, crq->msg_token))
                goto map_failed;

        retrc = rc = plpar_hcall_norets(H_REG_CRQ, vdev->unit_address,
                                        crq->msg_token, PAGE_SIZE);

        if (rc == H_RESOURCE)
                /* maybe kexecing and resource is busy. try a reset */
                retrc = rc = ibmvfc_reset_crq(vhost);

        if (rc == H_CLOSED)
                dev_warn(dev, "Partner adapter not ready\n");
        else if (rc) {
                dev_warn(dev, "Error %d opening adapter\n", rc);
                goto reg_crq_failed;
        }

        retrc = 0;

        tasklet_init(&vhost->tasklet, (void *)ibmvfc_tasklet, (unsigned long)vhost);

        if ((rc = request_irq(vdev->irq, ibmvfc_interrupt, 0, IBMVFC_NAME, vhost))) {
                dev_err(dev, "Couldn't register irq 0x%x. rc=%d\n", vdev->irq, rc);
                goto req_irq_failed;
        }

        if ((rc = vio_enable_interrupts(vdev))) {
                dev_err(dev, "Error %d enabling interrupts\n", rc);
                goto req_irq_failed;
        }

        crq->cur = 0;
        LEAVE;
        return retrc;

req_irq_failed:
        tasklet_kill(&vhost->tasklet);
        do {
                rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
        } while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
reg_crq_failed:
        dma_unmap_single(dev, crq->msg_token, PAGE_SIZE, DMA_BIDIRECTIONAL);
map_failed:
        free_page((unsigned long)crq->msgs);
        return retrc;
}

/**
 * ibmvfc_free_mem - Free memory for vhost
 * @vhost:      ibmvfc host struct
 *
 * Return value:
 *      none
 **/
static void ibmvfc_free_mem(struct ibmvfc_host *vhost)
{
        struct ibmvfc_async_crq_queue *async_q = &vhost->async_crq;

        ENTER;
        mempool_destroy(vhost->tgt_pool);
        kfree(vhost->trace);
        dma_free_coherent(vhost->dev, vhost->disc_buf_sz, vhost->disc_buf,
                          vhost->disc_buf_dma);
        dma_free_coherent(vhost->dev, sizeof(*vhost->login_buf),
                          vhost->login_buf, vhost->login_buf_dma);
        dma_pool_destroy(vhost->sg_pool);
        dma_unmap_single(vhost->dev, async_q->msg_token,
                         async_q->size * sizeof(*async_q->msgs), DMA_BIDIRECTIONAL);
        free_page((unsigned long)async_q->msgs);
        LEAVE;
}

/**
 * ibmvfc_alloc_mem - Allocate memory for vhost
 * @vhost:      ibmvfc host struct
 *
 * Return value:
 *      0 on success / non-zero on failure
 **/
static int ibmvfc_alloc_mem(struct ibmvfc_host *vhost)
{
        struct ibmvfc_async_crq_queue *async_q = &vhost->async_crq;
        struct device *dev = vhost->dev;

        ENTER;
        async_q->msgs = (struct ibmvfc_async_crq *)get_zeroed_page(GFP_KERNEL);
        if (!async_q->msgs) {
                dev_err(dev, "Couldn't allocate async queue.\n");
                goto nomem;
        }

        async_q->size = PAGE_SIZE / sizeof(struct ibmvfc_async_crq);
        async_q->msg_token = dma_map_single(dev, async_q->msgs,
                                            async_q->size * sizeof(*async_q->msgs),
                                            DMA_BIDIRECTIONAL);

        if (dma_mapping_error(dev, async_q->msg_token)) {
                dev_err(dev, "Failed to map async queue\n");
                goto free_async_crq;
        }

        vhost->sg_pool = dma_pool_create(IBMVFC_NAME, dev,
                                         SG_ALL * sizeof(struct srp_direct_buf),
                                         sizeof(struct srp_direct_buf), 0);

        if (!vhost->sg_pool) {
                dev_err(dev, "Failed to allocate sg pool\n");
                goto unmap_async_crq;
        }

        vhost->login_buf = dma_alloc_coherent(dev, sizeof(*vhost->login_buf),
                                              &vhost->login_buf_dma, GFP_KERNEL);

        if (!vhost->login_buf) {
                dev_err(dev, "Couldn't allocate NPIV login buffer\n");
                goto free_sg_pool;
        }

        vhost->disc_buf_sz = sizeof(vhost->disc_buf->scsi_id[0]) * max_targets;
        vhost->disc_buf = dma_alloc_coherent(dev, vhost->disc_buf_sz,
                                             &vhost->disc_buf_dma, GFP_KERNEL);

        if (!vhost->disc_buf) {
                dev_err(dev, "Couldn't allocate Discover Targets buffer\n");
                goto free_login_buffer;
        }

        vhost->trace = kcalloc(IBMVFC_NUM_TRACE_ENTRIES,
                               sizeof(struct ibmvfc_trace_entry), GFP_KERNEL);

        if (!vhost->trace)
                goto free_disc_buffer;

        vhost->tgt_pool = mempool_create_kzalloc_pool(IBMVFC_TGT_MEMPOOL_SZ,
                                                      sizeof(struct ibmvfc_target));

        if (!vhost->tgt_pool) {
                dev_err(dev, "Couldn't allocate target memory pool\n");
                goto free_trace;
        }

        LEAVE;
        return 0;

free_trace:
        kfree(vhost->trace);
free_disc_buffer:
        dma_free_coherent(dev, vhost->disc_buf_sz, vhost->disc_buf,
                          vhost->disc_buf_dma);
free_login_buffer:
        dma_free_coherent(dev, sizeof(*vhost->login_buf),
                          vhost->login_buf, vhost->login_buf_dma);
free_sg_pool:
        dma_pool_destroy(vhost->sg_pool);
unmap_async_crq:
        dma_unmap_single(dev, async_q->msg_token,
                         async_q->size * sizeof(*async_q->msgs), DMA_BIDIRECTIONAL);
free_async_crq:
        free_page((unsigned long)async_q->msgs);
nomem:
        LEAVE;
        return -ENOMEM;
}

/**
 * ibmvfc_rport_add_thread - Worker thread for rport adds
 * @work:       work struct
 *
 **/
static void ibmvfc_rport_add_thread(struct work_struct *work)
{
        struct ibmvfc_host *vhost = container_of(work, struct ibmvfc_host,
                                                 rport_add_work_q);
        struct ibmvfc_target *tgt;
        struct fc_rport *rport;
        unsigned long flags;
        int did_work;

        ENTER;
        spin_lock_irqsave(vhost->host->host_lock, flags);
        do {
                did_work = 0;
                if (vhost->state != IBMVFC_ACTIVE)
                        break;

                list_for_each_entry(tgt, &vhost->targets, queue) {
                        if (tgt->add_rport) {
                                did_work = 1;
                                tgt->add_rport = 0;
                                kref_get(&tgt->kref);
                                rport = tgt->rport;
                                if (!rport) {
                                        spin_unlock_irqrestore(vhost->host->host_lock, flags);
                                        ibmvfc_tgt_add_rport(tgt);
                                } else if (get_device(&rport->dev)) {
                                        spin_unlock_irqrestore(vhost->host->host_lock, flags);
                                        tgt_dbg(tgt, "Setting rport roles\n");
                                        fc_remote_port_rolechg(rport, tgt->ids.roles);
                                        put_device(&rport->dev);
                                }

                                kref_put(&tgt->kref, ibmvfc_release_tgt);
                                spin_lock_irqsave(vhost->host->host_lock, flags);
                                break;
                        }
                }
        } while(did_work);

        if (vhost->state == IBMVFC_ACTIVE)
                vhost->scan_complete = 1;
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
        LEAVE;
}

/**
 * ibmvfc_probe - Adapter hot plug add entry point
 * @vdev:       vio device struct
 * @id: vio device id struct
 *
 * Return value:
 *      0 on success / non-zero on failure
 **/
static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
{
        struct ibmvfc_host *vhost;
        struct Scsi_Host *shost;
        struct device *dev = &vdev->dev;
        int rc = -ENOMEM;

        ENTER;
        shost = scsi_host_alloc(&driver_template, sizeof(*vhost));
        if (!shost) {
                dev_err(dev, "Couldn't allocate host data\n");
                goto out;
        }

        shost->transportt = ibmvfc_transport_template;
        shost->can_queue = max_requests;
        shost->max_lun = max_lun;
        shost->max_id = max_targets;
        shost->max_sectors = IBMVFC_MAX_SECTORS;
        shost->max_cmd_len = IBMVFC_MAX_CDB_LEN;
        shost->unique_id = shost->host_no;

        vhost = shost_priv(shost);
        INIT_LIST_HEAD(&vhost->sent);
        INIT_LIST_HEAD(&vhost->free);
        INIT_LIST_HEAD(&vhost->targets);
        sprintf(vhost->name, IBMVFC_NAME);
        vhost->host = shost;
        vhost->dev = dev;
        vhost->partition_number = -1;
        vhost->log_level = log_level;
        vhost->task_set = 1;
        strcpy(vhost->partition_name, "UNKNOWN");
        init_waitqueue_head(&vhost->work_wait_q);
        init_waitqueue_head(&vhost->init_wait_q);
        INIT_WORK(&vhost->rport_add_work_q, ibmvfc_rport_add_thread);

        if ((rc = ibmvfc_alloc_mem(vhost)))
                goto free_scsi_host;

        vhost->work_thread = kthread_run(ibmvfc_work, vhost, "%s_%d", IBMVFC_NAME,
                                         shost->host_no);

        if (IS_ERR(vhost->work_thread)) {
                dev_err(dev, "Couldn't create kernel thread: %ld\n",
                        PTR_ERR(vhost->work_thread));
                goto free_host_mem;
        }

        if ((rc = ibmvfc_init_crq(vhost))) {
                dev_err(dev, "Couldn't initialize crq. rc=%d\n", rc);
                goto kill_kthread;
        }

        if ((rc = ibmvfc_init_event_pool(vhost))) {
                dev_err(dev, "Couldn't initialize event pool. rc=%d\n", rc);
                goto release_crq;
        }

        if ((rc = scsi_add_host(shost, dev)))
                goto release_event_pool;

        if ((rc = ibmvfc_create_trace_file(&shost->shost_dev.kobj,
                                           &ibmvfc_trace_attr))) {
                dev_err(dev, "Failed to create trace file. rc=%d\n", rc);
                goto remove_shost;
        }

        dev_set_drvdata(dev, vhost);
        spin_lock(&ibmvfc_driver_lock);
        list_add_tail(&vhost->queue, &ibmvfc_head);
        spin_unlock(&ibmvfc_driver_lock);

        ibmvfc_send_crq_init(vhost);
        scsi_scan_host(shost);
        return 0;

remove_shost:
        scsi_remove_host(shost);
release_event_pool:
        ibmvfc_free_event_pool(vhost);
release_crq:
        ibmvfc_release_crq_queue(vhost);
kill_kthread:
        kthread_stop(vhost->work_thread);
free_host_mem:
        ibmvfc_free_mem(vhost);
free_scsi_host:
        scsi_host_put(shost);
out:
        LEAVE;
        return rc;
}

/**
 * ibmvfc_remove - Adapter hot plug remove entry point
 * @vdev:       vio device struct
 *
 * Return value:
 *      0
 **/
static int ibmvfc_remove(struct vio_dev *vdev)
{
        struct ibmvfc_host *vhost = dev_get_drvdata(&vdev->dev);
        unsigned long flags;

        ENTER;
        ibmvfc_remove_trace_file(&vhost->host->shost_dev.kobj, &ibmvfc_trace_attr);
        ibmvfc_link_down(vhost, IBMVFC_HOST_OFFLINE);
        ibmvfc_wait_while_resetting(vhost);
        ibmvfc_release_crq_queue(vhost);
        kthread_stop(vhost->work_thread);
        fc_remove_host(vhost->host);
        scsi_remove_host(vhost->host);

        spin_lock_irqsave(vhost->host->host_lock, flags);
        ibmvfc_purge_requests(vhost, DID_ERROR);
        ibmvfc_free_event_pool(vhost);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);

        ibmvfc_free_mem(vhost);
        spin_lock(&ibmvfc_driver_lock);
        list_del(&vhost->queue);
        spin_unlock(&ibmvfc_driver_lock);
        scsi_host_put(vhost->host);
        LEAVE;
        return 0;
}

/**
 * ibmvfc_get_desired_dma - Calculate DMA resources needed by the driver
 * @vdev:       vio device struct
 *
 * Return value:
 *      Number of bytes the driver will need to DMA map at the same time in
 *      order to perform well.
 */
static unsigned long ibmvfc_get_desired_dma(struct vio_dev *vdev)
{
        unsigned long pool_dma = max_requests * sizeof(union ibmvfc_iu);
        return pool_dma + ((512 * 1024) * driver_template.cmd_per_lun);
}

static struct vio_device_id ibmvfc_device_table[] __devinitdata = {
        {"fcp", "IBM,vfc-client"},
        { "", "" }
};
MODULE_DEVICE_TABLE(vio, ibmvfc_device_table);

static struct vio_driver ibmvfc_driver = {
        .id_table = ibmvfc_device_table,
        .probe = ibmvfc_probe,
        .remove = ibmvfc_remove,
        .get_desired_dma = ibmvfc_get_desired_dma,
        .driver = {
                .name = IBMVFC_NAME,
                .owner = THIS_MODULE,
        }
};

static struct fc_function_template ibmvfc_transport_functions = {
        .show_host_fabric_name = 1,
        .show_host_node_name = 1,
        .show_host_port_name = 1,
        .show_host_supported_classes = 1,
        .show_host_port_type = 1,
        .show_host_port_id = 1,
        .show_host_maxframe_size = 1,

        .get_host_port_state = ibmvfc_get_host_port_state,
        .show_host_port_state = 1,

        .get_host_speed = ibmvfc_get_host_speed,
        .show_host_speed = 1,

        .issue_fc_host_lip = ibmvfc_issue_fc_host_lip,
        .terminate_rport_io = ibmvfc_terminate_rport_io,

        .show_rport_maxframe_size = 1,
        .show_rport_supported_classes = 1,

        .set_rport_dev_loss_tmo = ibmvfc_set_rport_dev_loss_tmo,
        .show_rport_dev_loss_tmo = 1,

        .get_starget_node_name = ibmvfc_get_starget_node_name,
        .show_starget_node_name = 1,

        .get_starget_port_name = ibmvfc_get_starget_port_name,
        .show_starget_port_name = 1,

        .get_starget_port_id = ibmvfc_get_starget_port_id,
        .show_starget_port_id = 1,
};

/**
 * ibmvfc_module_init - Initialize the ibmvfc module
 *
 * Return value:
 *      0 on success / other on failure
 **/
static int __init ibmvfc_module_init(void)
{
        int rc;

        if (!firmware_has_feature(FW_FEATURE_VIO))
                return -ENODEV;

        printk(KERN_INFO IBMVFC_NAME": IBM Virtual Fibre Channel Driver version: %s %s\n",
               IBMVFC_DRIVER_VERSION, IBMVFC_DRIVER_DATE);

        ibmvfc_transport_template = fc_attach_transport(&ibmvfc_transport_functions);
        if (!ibmvfc_transport_template)
                return -ENOMEM;

        rc = vio_register_driver(&ibmvfc_driver);
        if (rc)
                fc_release_transport(ibmvfc_transport_template);
        return rc;
}

/**
 * ibmvfc_module_exit - Teardown the ibmvfc module
 *
 * Return value:
 *      nothing
 **/
static void __exit ibmvfc_module_exit(void)
{
        vio_unregister_driver(&ibmvfc_driver);
        fc_release_transport(ibmvfc_transport_template);
}

module_init(ibmvfc_module_init);
module_exit(ibmvfc_module_exit);