/*
 * 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/slab.h>
#include <linux/of.h>
#include <linux/pm.h>
#include <linux/stringify.h>
#include <linux/bsg-lib.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 <scsi/scsi_bsg_fc.h>
#include "ibmvfc.h"

static unsigned int init_timeout = IBMVFC_INIT_TIMEOUT;
static unsigned int default_timeout = IBMVFC_DEFAULT_TIMEOUT;
static u64 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 ibmvfc_debug = IBMVFC_DEBUG;
static unsigned int log_level = IBMVFC_DEFAULT_LOG_LEVEL;
static unsigned int cls3_error = IBMVFC_CLS3_ERROR;
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, ullong, 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(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) "]");
module_param_named(cls3_error, cls3_error, uint, 0);
MODULE_PARM_DESC(cls3_error, "Enable FC Class 3 Error Recovery. "
                 "[Default=" __stringify(IBMVFC_CLS3_ERROR) "]");

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, 1, 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 void ibmvfc_npiv_logout(struct ibmvfc_host *);

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 = be64_to_cpu(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 = be32_to_cpu(vfc_cmd->iu.xfer_len);
                break;
        case IBMVFC_MAD_FORMAT:
                entry->op_code = be32_to_cpu(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 = be64_to_cpu(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 = be16_to_cpu(vfc_cmd->status);
                entry->u.end.error = be16_to_cpu(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 = be32_to_cpu(mad->opcode);
                entry->u.end.status = be16_to_cpu(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 = be32_to_cpu(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(be16_to_cpu(vfc_cmd->status), be16_to_cpu(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:
                if (action == IBMVFC_TGT_ACTION_DELETED_RPORT)
                        tgt->action = action;
        case IBMVFC_TGT_ACTION_DELETED_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_LOGO_WAIT:
                if (vhost->action == IBMVFC_HOST_ACTION_LOGO)
                        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:
                switch (vhost->action) {
                case IBMVFC_HOST_ACTION_RESET:
                case IBMVFC_HOST_ACTION_REENABLE:
                        break;
                default:
                        vhost->action = action;
                        break;
                }
                break;
        case IBMVFC_HOST_ACTION_LOGO:
        case IBMVFC_HOST_ACTION_QUERY_TGTS:
        case IBMVFC_HOST_ACTION_TGT_DEL_FAILED:
        case IBMVFC_HOST_ACTION_NONE:
        case IBMVFC_HOST_ACTION_RESET:
        case IBMVFC_HOST_ACTION_REENABLE:
        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
 *
 * Return value:
 *      nothing
 **/
static void ibmvfc_init_host(struct ibmvfc_host *vhost)
{
        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)) {
                memset(vhost->async_crq.msgs, 0, PAGE_SIZE);
                vhost->async_crq.cur = 0;

                list_for_each_entry(tgt, &vhost->targets, queue)
                        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
                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 = 0;
        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 {
                if (rc)
                        msleep(100);
                rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
        } while (rc == H_BUSY || H_IS_LONG_BUSY(rc));

        vhost->state = IBMVFC_NO_CRQ;
        vhost->logged_in = 0;
        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 = 0;
        struct vio_dev *vdev = to_vio_dev(vhost->dev);

        /* Re-enable the CRQ */
        do {
                if (rc)
                        msleep(100);
                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 = 0;
        unsigned long flags;
        struct vio_dev *vdev = to_vio_dev(vhost->dev);
        struct ibmvfc_crq_queue *crq = &vhost->crq;

        /* Close the CRQ */
        do {
                if (rc)
                        msleep(100);
                rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
        } while (rc == H_BUSY || H_IS_LONG_BUSY(rc));

        spin_lock_irqsave(vhost->host->host_lock, flags);
        vhost->state = IBMVFC_NO_CRQ;
        vhost->logged_in = 0;

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

        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 = cpu_to_be16(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_hard_reset_host - Reset the connection to the server by breaking the CRQ
 * @vhost:      struct ibmvfc host to reset
 **/
static void ibmvfc_hard_reset_host(struct ibmvfc_host *vhost)
{
        ibmvfc_purge_requests(vhost, DID_ERROR);
        ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_RESET);
}

/**
 * __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)
{
        if (vhost->logged_in && vhost->action != IBMVFC_HOST_ACTION_LOGO_WAIT &&
            !ibmvfc_set_host_state(vhost, IBMVFC_INITIALIZING)) {
                scsi_block_requests(vhost->host);
                ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_LOGO);
                vhost->job_step = ibmvfc_npiv_logout;
                wake_up(&vhost->work_wait_q);
        } else
                ibmvfc_hard_reset_host(vhost);
}

/**
 * ibmvfc_reset_host - Reset the connection to the server
 * @vhost:      ibmvfc host struct
 **/
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 (be64_to_cpu(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",
                                   be64_to_cpu(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->of_node;
        const char *location;

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

        login_info->ostype = cpu_to_be32(IBMVFC_OS_LINUX);
        login_info->max_dma_len = cpu_to_be64(IBMVFC_MAX_SECTORS << 9);
        login_info->max_payload = cpu_to_be32(sizeof(struct ibmvfc_fcp_cmd_iu));
        login_info->max_response = cpu_to_be32(sizeof(struct ibmvfc_fcp_rsp));
        login_info->partition_num = cpu_to_be32(vhost->partition_number);
        login_info->vfc_frame_version = cpu_to_be32(1);
        login_info->fcp_version = cpu_to_be16(3);
        login_info->flags = cpu_to_be16(IBMVFC_FLUSH_ON_HALT);
        if (vhost->client_migrated)
                login_info->flags |= cpu_to_be16(IBMVFC_CLIENT_MIGRATED);

        login_info->max_cmds = cpu_to_be32(max_requests + IBMVFC_NUM_INTERNAL_REQ);
        login_info->capabilities = cpu_to_be64(IBMVFC_CAN_MIGRATE);
        login_info->async.va = cpu_to_be64(vhost->async_crq.msg_token);
        login_info->async.len = cpu_to_be32(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 = cpu_to_be64(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 = cpu_to_be64(sg_dma_address(sg));
                md[i].len = cpu_to_be32(sg_dma_len(sg));
                md[i].key = 0;
        }
}

/**
 * ibmvfc_map_sg_data - Maps dma for a scatterlist and initializes decriptor fields
 * @scmd:               struct 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);

        if (cls3_error)
                vfc_cmd->flags |= cpu_to_be16(IBMVFC_CLASS_3_ERR);

        sg_mapped = scsi_dma_map(scmd);
        if (!sg_mapped) {
                vfc_cmd->flags |= cpu_to_be16(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 |= cpu_to_be16(IBMVFC_WRITE);
                vfc_cmd->iu.add_cdb_len |= IBMVFC_WRDATA;
        } else {
                vfc_cmd->flags |= cpu_to_be16(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 |= cpu_to_be16(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 = cpu_to_be64(evt->ext_list_token);
        data->len = cpu_to_be32(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 timer_list *t)
{
        struct ibmvfc_event *evt = from_timer(evt, t, timer);
        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)
{
        __be64 *crq_as_u64 = (__be64 *) &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 = cpu_to_be64((u64)evt);
        else if (evt->crq.format == IBMVFC_MAD_FORMAT)
                evt->xfer_iu->mad_common.tag = cpu_to_be64((u64)evt);
        else
                BUG();

        list_add_tail(&evt->queue, &vhost->sent);
        timer_setup(&evt->timer, ibmvfc_timeout, 0);

        if (timeout) {
                evt->timer.expires = jiffies + (timeout * HZ);
                add_timer(&evt->timer);
        }

        mb();

        if ((rc = ibmvfc_send_crq(vhost, be64_to_cpu(crq_as_u64[0]),
                                  be64_to_cpu(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 = cpu_to_be16(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(be16_to_cpu(vfc_cmd->status), be16_to_cpu(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_relogin - Log back into the specified device
 * @sdev:       scsi device struct
 *
 **/
static void ibmvfc_relogin(struct scsi_device *sdev)
{
        struct ibmvfc_host *vhost = shost_priv(sdev->host);
        struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
        struct ibmvfc_target *tgt;

        list_for_each_entry(tgt, &vhost->targets, queue) {
                if (rport == tgt->rport) {
                        ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
                        break;
                }
        }

        ibmvfc_reinit_host(vhost);
}

/**
 * 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 = be32_to_cpu(rsp->fcp_sense_len);

        if (cmnd) {
                if (be16_to_cpu(vfc_cmd->response_flags) & IBMVFC_ADAPTER_RESID_VALID)
                        scsi_set_resid(cmnd, be32_to_cpu(vfc_cmd->adapter_resid));
                else if (rsp->flags & FCP_RESID_UNDER)
                        scsi_set_resid(cmnd, be32_to_cpu(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 = be32_to_cpu(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 ((be16_to_cpu(vfc_cmd->status) & IBMVFC_VIOS_FAILURE) &&
                            (be16_to_cpu(vfc_cmd->error) == IBMVFC_PLOGI_REQUIRED))
                                ibmvfc_relogin(cmnd->device);

                        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_lck(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;
        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 = cpu_to_be64(be64_to_cpu(evt->crq.ioba) + offsetof(struct ibmvfc_cmd, rsp));
        vfc_cmd->resp.len = cpu_to_be32(sizeof(vfc_cmd->rsp));
        vfc_cmd->frame_type = cpu_to_be32(IBMVFC_SCSI_FCP_TYPE);
        vfc_cmd->payload_len = cpu_to_be32(sizeof(vfc_cmd->iu));
        vfc_cmd->resp_len = cpu_to_be32(sizeof(vfc_cmd->rsp));
        vfc_cmd->cancel_key = cpu_to_be32((unsigned long)cmnd->device->hostdata);
        vfc_cmd->tgt_scsi_id = cpu_to_be64(rport->port_id);
        vfc_cmd->iu.xfer_len = cpu_to_be32(scsi_bufflen(cmnd));
        int_to_scsilun(cmnd->device->lun, &vfc_cmd->iu.lun);
        memcpy(vfc_cmd->iu.cdb, cmnd->cmnd, cmnd->cmd_len);

        if (cmnd->flags & SCMD_TAGGED) {
                vfc_cmd->task_tag = cpu_to_be64(cmnd->tag);
                vfc_cmd->iu.pri_task_attr = IBMVFC_SIMPLE_TASK;
        }

        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;
}

static DEF_SCSI_QCMD(ibmvfc_queuecommand)

/**
 * 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_bsg_timeout_done - Completion handler for cancelling BSG commands
 * @evt:        struct ibmvfc_event
 *
 **/
static void ibmvfc_bsg_timeout_done(struct ibmvfc_event *evt)
{
        struct ibmvfc_host *vhost = evt->vhost;

        ibmvfc_free_event(evt);
        vhost->aborting_passthru = 0;
        dev_info(vhost->dev, "Passthru command cancelled\n");
}

/**
 * ibmvfc_bsg_timeout - Handle a BSG timeout
 * @job:        struct bsg_job that timed out
 *
 * Returns:
 *      0 on success / other on failure
 **/
static int ibmvfc_bsg_timeout(struct bsg_job *job)
{
        struct ibmvfc_host *vhost = shost_priv(fc_bsg_to_shost(job));
        unsigned long port_id = (unsigned long)job->dd_data;
        struct ibmvfc_event *evt;
        struct ibmvfc_tmf *tmf;
        unsigned long flags;
        int rc;

        ENTER;
        spin_lock_irqsave(vhost->host->host_lock, flags);
        if (vhost->aborting_passthru || vhost->state != IBMVFC_ACTIVE) {
                __ibmvfc_reset_host(vhost);
                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                return 0;
        }

        vhost->aborting_passthru = 1;
        evt = ibmvfc_get_event(vhost);
        ibmvfc_init_event(evt, ibmvfc_bsg_timeout_done, IBMVFC_MAD_FORMAT);

        tmf = &evt->iu.tmf;
        memset(tmf, 0, sizeof(*tmf));
        tmf->common.version = cpu_to_be32(1);
        tmf->common.opcode = cpu_to_be32(IBMVFC_TMF_MAD);
        tmf->common.length = cpu_to_be16(sizeof(*tmf));
        tmf->scsi_id = cpu_to_be64(port_id);
        tmf->cancel_key = cpu_to_be32(IBMVFC_PASSTHRU_CANCEL_KEY);
        tmf->my_cancel_key = cpu_to_be32(IBMVFC_INTERNAL_CANCEL_KEY);
        rc = ibmvfc_send_event(evt, vhost, default_timeout);

        if (rc != 0) {
                vhost->aborting_passthru = 0;
                dev_err(vhost->dev, "Failed to send cancel event. rc=%d\n", rc);
                rc = -EIO;
        } else
                dev_info(vhost->dev, "Cancelling passthru command to port id 0x%lx\n",
                         port_id);

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

        LEAVE;
        return rc;
}

/**
 * ibmvfc_bsg_plogi - PLOGI into a target to handle a BSG command
 * @vhost:              struct ibmvfc_host to send command
 * @port_id:    port ID to send command
 *
 * Returns:
 *      0 on success / other on failure
 **/
static int ibmvfc_bsg_plogi(struct ibmvfc_host *vhost, unsigned int port_id)
{
        struct ibmvfc_port_login *plogi;
        struct ibmvfc_target *tgt;
        struct ibmvfc_event *evt;
        union ibmvfc_iu rsp_iu;
        unsigned long flags;
        int rc = 0, issue_login = 1;

        ENTER;
        spin_lock_irqsave(vhost->host->host_lock, flags);
        list_for_each_entry(tgt, &vhost->targets, queue) {
                if (tgt->scsi_id == port_id) {
                        issue_login = 0;
                        break;
                }
        }

        if (!issue_login)
                goto unlock_out;
        if (unlikely((rc = ibmvfc_host_chkready(vhost))))
                goto unlock_out;

        evt = ibmvfc_get_event(vhost);
        ibmvfc_init_event(evt, ibmvfc_sync_completion, IBMVFC_MAD_FORMAT);
        plogi = &evt->iu.plogi;
        memset(plogi, 0, sizeof(*plogi));
        plogi->common.version = cpu_to_be32(1);
        plogi->common.opcode = cpu_to_be32(IBMVFC_PORT_LOGIN);
        plogi->common.length = cpu_to_be16(sizeof(*plogi));
        plogi->scsi_id = cpu_to_be64(port_id);
        evt->sync_iu = &rsp_iu;
        init_completion(&evt->comp);

        rc = ibmvfc_send_event(evt, vhost, default_timeout);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);

        if (rc)
                return -EIO;

        wait_for_completion(&evt->comp);

        if (rsp_iu.plogi.common.status)
                rc = -EIO;

        spin_lock_irqsave(vhost->host->host_lock, flags);
        ibmvfc_free_event(evt);
unlock_out:
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
        LEAVE;
        return rc;
}

/**
 * ibmvfc_bsg_request - Handle a BSG request
 * @job:        struct bsg_job to be executed
 *
 * Returns:
 *      0 on success / other on failure
 **/
static int ibmvfc_bsg_request(struct bsg_job *job)
{
        struct ibmvfc_host *vhost = shost_priv(fc_bsg_to_shost(job));
        struct fc_rport *rport = fc_bsg_to_rport(job);
        struct ibmvfc_passthru_mad *mad;
        struct ibmvfc_event *evt;
        union ibmvfc_iu rsp_iu;
        unsigned long flags, port_id = -1;
        struct fc_bsg_request *bsg_request = job->request;
        struct fc_bsg_reply *bsg_reply = job->reply;
        unsigned int code = bsg_request->msgcode;
        int rc = 0, req_seg, rsp_seg, issue_login = 0;
        u32 fc_flags, rsp_len;

        ENTER;
        bsg_reply->reply_payload_rcv_len = 0;
        if (rport)
                port_id = rport->port_id;

        switch (code) {
        case FC_BSG_HST_ELS_NOLOGIN:
                port_id = (bsg_request->rqst_data.h_els.port_id[0] << 16) |
                        (bsg_request->rqst_data.h_els.port_id[1] << 8) |
                        bsg_request->rqst_data.h_els.port_id[2];
        case FC_BSG_RPT_ELS:
                fc_flags = IBMVFC_FC_ELS;
                break;
        case FC_BSG_HST_CT:
                issue_login = 1;
                port_id = (bsg_request->rqst_data.h_ct.port_id[0] << 16) |
                        (bsg_request->rqst_data.h_ct.port_id[1] << 8) |
                        bsg_request->rqst_data.h_ct.port_id[2];
        case FC_BSG_RPT_CT:
                fc_flags = IBMVFC_FC_CT_IU;
                break;
        default:
                return -ENOTSUPP;
        }

        if (port_id == -1)
                return -EINVAL;
        if (!mutex_trylock(&vhost->passthru_mutex))
                return -EBUSY;

        job->dd_data = (void *)port_id;
        req_seg = dma_map_sg(vhost->dev, job->request_payload.sg_list,
                             job->request_payload.sg_cnt, DMA_TO_DEVICE);

        if (!req_seg) {
                mutex_unlock(&vhost->passthru_mutex);
                return -ENOMEM;
        }

        rsp_seg = dma_map_sg(vhost->dev, job->reply_payload.sg_list,
                             job->reply_payload.sg_cnt, DMA_FROM_DEVICE);

        if (!rsp_seg) {
                dma_unmap_sg(vhost->dev, job->request_payload.sg_list,
                             job->request_payload.sg_cnt, DMA_TO_DEVICE);
                mutex_unlock(&vhost->passthru_mutex);
                return -ENOMEM;
        }

        if (req_seg > 1 || rsp_seg > 1) {
                rc = -EINVAL;
                goto out;
        }

        if (issue_login)
                rc = ibmvfc_bsg_plogi(vhost, port_id);

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

        if (unlikely(rc || (rport && (rc = fc_remote_port_chkready(rport)))) ||
            unlikely((rc = ibmvfc_host_chkready(vhost)))) {
                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                goto out;
        }

        evt = ibmvfc_get_event(vhost);
        ibmvfc_init_event(evt, ibmvfc_sync_completion, IBMVFC_MAD_FORMAT);
        mad = &evt->iu.passthru;

        memset(mad, 0, sizeof(*mad));
        mad->common.version = cpu_to_be32(1);
        mad->common.opcode = cpu_to_be32(IBMVFC_PASSTHRU);
        mad->common.length = cpu_to_be16(sizeof(*mad) - sizeof(mad->fc_iu) - sizeof(mad->iu));

        mad->cmd_ioba.va = cpu_to_be64(be64_to_cpu(evt->crq.ioba) +
                offsetof(struct ibmvfc_passthru_mad, iu));
        mad->cmd_ioba.len = cpu_to_be32(sizeof(mad->iu));

        mad->iu.cmd_len = cpu_to_be32(job->request_payload.payload_len);
        mad->iu.rsp_len = cpu_to_be32(job->reply_payload.payload_len);
        mad->iu.flags = cpu_to_be32(fc_flags);
        mad->iu.cancel_key = cpu_to_be32(IBMVFC_PASSTHRU_CANCEL_KEY);

        mad->iu.cmd.va = cpu_to_be64(sg_dma_address(job->request_payload.sg_list));
        mad->iu.cmd.len = cpu_to_be32(sg_dma_len(job->request_payload.sg_list));
        mad->iu.rsp.va = cpu_to_be64(sg_dma_address(job->reply_payload.sg_list));
        mad->iu.rsp.len = cpu_to_be32(sg_dma_len(job->reply_payload.sg_list));
        mad->iu.scsi_id = cpu_to_be64(port_id);
        mad->iu.tag = cpu_to_be64((u64)evt);
        rsp_len = be32_to_cpu(mad->iu.rsp.len);

        evt->sync_iu = &rsp_iu;
        init_completion(&evt->comp);
        rc = ibmvfc_send_event(evt, vhost, 0);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);

        if (rc) {
                rc = -EIO;
                goto out;
        }

        wait_for_completion(&evt->comp);

        if (rsp_iu.passthru.common.status)
                rc = -EIO;
        else
                bsg_reply->reply_payload_rcv_len = rsp_len;

        spin_lock_irqsave(vhost->host->host_lock, flags);
        ibmvfc_free_event(evt);
        spin_unlock_irqrestore(vhost->host->host_lock, flags);
        bsg_reply->result = rc;
        bsg_job_done(job, bsg_reply->result,
                       bsg_reply->reply_payload_rcv_len);
        rc = 0;
out:
        dma_unmap_sg(vhost->dev, job->request_payload.sg_list,
                     job->request_payload.sg_cnt, DMA_TO_DEVICE);
        dma_unmap_sg(vhost->dev, job->reply_payload.sg_list,
                     job->reply_payload.sg_cnt, DMA_FROM_DEVICE);
        mutex_unlock(&vhost->passthru_mutex);
        LEAVE;
        return rc;
}

/**
 * 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 = cpu_to_be64(be64_to_cpu(evt->crq.ioba) + offsetof(struct ibmvfc_cmd, rsp));
                tmf->resp.len = cpu_to_be32(sizeof(tmf->rsp));
                tmf->frame_type = cpu_to_be32(IBMVFC_SCSI_FCP_TYPE);
                tmf->payload_len = cpu_to_be32(sizeof(tmf->iu));
                tmf->resp_len = cpu_to_be32(sizeof(tmf->rsp));
                tmf->cancel_key = cpu_to_be32((unsigned long)sdev->hostdata);
                tmf->tgt_scsi_id = cpu_to_be64(rport->port_id);
                int_to_scsilun(sdev->lun, &tmf->iu.lun);
                tmf->flags = cpu_to_be16((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)
                rsp_code = ibmvfc_get_err_result(&rsp_iu.cmd);

        if (rsp_code) {
                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(be16_to_cpu(rsp_iu.cmd.status), be16_to_cpu(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_match_rport - Match function for specified remote port
 * @evt:        ibmvfc event struct
 * @device:     device to match (rport)
 *
 * Returns:
 *      1 if event matches rport / 0 if event does not match rport
 **/
static int ibmvfc_match_rport(struct ibmvfc_event *evt, void *rport)
{
        struct fc_rport *cmd_rport;

        if (evt->cmnd) {
                cmd_rport = starget_to_rport(scsi_target(evt->cmnd->device));
                if (cmd_rport == rport)
                        return 1;
        }
        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 = IBMVFC_ABORT_WAIT_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 = ∁
                                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_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->logged_in) {
                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 = cpu_to_be32(1);
                tmf->common.opcode = cpu_to_be32(IBMVFC_TMF_MAD);
                tmf->common.length = cpu_to_be16(sizeof(*tmf));
                tmf->scsi_id = cpu_to_be64(rport->port_id);
                int_to_scsilun(sdev->lun, &tmf->lun);
                if (!(be64_to_cpu(vhost->login_buf->resp.capabilities) & IBMVFC_CAN_SUPPRESS_ABTS))
                        type &= ~IBMVFC_TMF_SUPPRESS_ABTS;
                if (vhost->state == IBMVFC_ACTIVE)
                        tmf->flags = cpu_to_be32((type | IBMVFC_TMF_LUA_VALID));
                else
                        tmf->flags = cpu_to_be32(((type & IBMVFC_TMF_SUPPRESS_ABTS) | IBMVFC_TMF_LUA_VALID));
                tmf->cancel_key = cpu_to_be32((unsigned long)sdev->hostdata);
                tmf->my_cancel_key = cpu_to_be32((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);
                /* If failure is received, the host adapter is most likely going
                 through reset, return success so the caller will wait for the command
                 being cancelled to get returned */
                return 0;
        }

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

        wait_for_completion(&evt->comp);
        status = be16_to_cpu(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);
                switch (status) {
                case IBMVFC_MAD_DRIVER_FAILED:
                case IBMVFC_MAD_CRQ_ERROR:
                        /* Host adapter most likely going through reset, return success to
                         the caller will wait for the command being cancelled to get returned */
                        return 0;
                default:
                        return -EIO;
                };
        }

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

/**
 * ibmvfc_match_key - Match function for specified cancel key
 * @evt:        ibmvfc event struct
 * @key:        cancel key to match
 *
 * Returns:
 *      1 if event matches key / 0 if event does not match key
 **/
static int ibmvfc_match_key(struct ibmvfc_event *evt, void *key)
{
        unsigned long cancel_key = (unsigned long)key;

        if (evt->crq.format == IBMVFC_CMD_FORMAT &&
            be32_to_cpu(evt->iu.cmd.cancel_key) == cancel_key)
                return 1;
        return 0;
}

/**
 * ibmvfc_match_evt - Match function for specified event
 * @evt:        ibmvfc event struct
 * @match:      event to match
 *
 * Returns:
 *      1 if event matches key / 0 if event does not match key
 **/
static int ibmvfc_match_evt(struct ibmvfc_event *evt, void *match)
{
        if (evt == match)
                return 1;
        return 0;
}

/**
 * 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 rc, rsp_rc = -EBUSY;
        unsigned long flags, timeout = IBMVFC_ABORT_TIMEOUT;
        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 = cpu_to_be64(be64_to_cpu(evt->crq.ioba) + offsetof(struct ibmvfc_cmd, rsp));
                tmf->resp.len = cpu_to_be32(sizeof(tmf->rsp));
                tmf->frame_type = cpu_to_be32(IBMVFC_SCSI_FCP_TYPE);
                tmf->payload_len = cpu_to_be32(sizeof(tmf->iu));
                tmf->resp_len = cpu_to_be32(sizeof(tmf->rsp));
                tmf->cancel_key = cpu_to_be32((unsigned long)sdev->hostdata);
                tmf->tgt_scsi_id = cpu_to_be64(rport->port_id);
                int_to_scsilun(sdev->lun, &tmf->iu.lun);
                tmf->flags = cpu_to_be16((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");
        timeout = wait_for_completion_timeout(&evt->comp, timeout);

        if (!timeout) {
                rc = ibmvfc_cancel_all(sdev, 0);
                if (!rc) {
                        rc = ibmvfc_wait_for_ops(vhost, sdev->hostdata, ibmvfc_match_key);
                        if (rc == SUCCESS)
                                rc = 0;
                }

                if (rc) {
                        sdev_printk(KERN_INFO, sdev, "Cancel failed, resetting host\n");
                        ibmvfc_reset_host(vhost);
                        rsp_rc = -EIO;
                        rc = ibmvfc_wait_for_ops(vhost, sdev->hostdata, ibmvfc_match_key);

                        if (rc == SUCCESS)
                                rsp_rc = 0;

                        rc = ibmvfc_wait_for_ops(vhost, evt, ibmvfc_match_evt);
                        if (rc != SUCCESS) {
                                spin_lock_irqsave(vhost->host->host_lock, flags);
                                ibmvfc_hard_reset_host(vhost);
                                spin_unlock_irqrestore(vhost->host->host_lock, flags);
                                rsp_rc = 0;
                        }

                        goto out;
                }
        }

        if (rsp_iu.cmd.status)
                rsp_code = ibmvfc_get_err_result(&rsp_iu.cmd);

        if (rsp_code) {
                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(be16_to_cpu(rsp_iu.cmd.status), be16_to_cpu(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");

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

/**
 * ibmvfc_eh_abort_handler - Abort a command
 * @cmd:        scsi command to abort
 *
 * Returns:
 *      SUCCESS / FAST_IO_FAIL / 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, block_rc;
        int rc = FAILED;

        ENTER;
        block_rc = fc_block_scsi_eh(cmd);
        ibmvfc_wait_while_resetting(vhost);
        if (block_rc != FAST_IO_FAIL) {
                cancel_rc = ibmvfc_cancel_all(sdev, IBMVFC_TMF_ABORT_TASK_SET);
                ibmvfc_abort_task_set(sdev);
        } else
                cancel_rc = ibmvfc_cancel_all(sdev, IBMVFC_TMF_SUPPRESS_ABTS);

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

        if (block_rc == FAST_IO_FAIL && rc != FAILED)
                rc = FAST_IO_FAIL;

        LEAVE;
        return rc;
}

/**
 * ibmvfc_eh_device_reset_handler - Reset a single LUN
 * @cmd:        scsi command struct
 *
 * Returns:
 *      SUCCESS / FAST_IO_FAIL / 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, block_rc, reset_rc = 0;
        int rc = FAILED;

        ENTER;
        block_rc = fc_block_scsi_eh(cmd);
        ibmvfc_wait_while_resetting(vhost);
        if (block_rc != FAST_IO_FAIL) {
                cancel_rc = ibmvfc_cancel_all(sdev, IBMVFC_TMF_LUN_RESET);
                reset_rc = ibmvfc_reset_device(sdev, IBMVFC_LUN_RESET, "LUN");
        } else
                cancel_rc = ibmvfc_cancel_all(sdev, IBMVFC_TMF_SUPPRESS_ABTS);

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

        if (block_rc == FAST_IO_FAIL && rc != FAILED)
                rc = FAST_IO_FAIL;

        LEAVE;
        return rc;
}

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

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

/**
 * ibmvfc_eh_target_reset_handler - Reset the target
 * @cmd:        scsi command struct
 *
 * Returns:
 *      SUCCESS / FAST_IO_FAIL / 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 block_rc;
        int reset_rc = 0;
        int rc = FAILED;
        unsigned long cancel_rc = 0;

        ENTER;
        block_rc = fc_block_scsi_eh(cmd);
        ibmvfc_wait_while_resetting(vhost);
        if (block_rc != FAST_IO_FAIL) {
                starget_for_each_device(starget, &cancel_rc, ibmvfc_dev_cancel_all_reset);
                reset_rc = ibmvfc_reset_device(sdev, IBMVFC_TARGET_RESET, "target");
        } else
                starget_for_each_device(starget, &cancel_rc, ibmvfc_dev_cancel_all_noreset);

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

        if (block_rc == FAST_IO_FAIL && rc != FAILED)
                rc = FAST_IO_FAIL;

        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_Host *shost = rport_to_shost(rport);
        struct ibmvfc_host *vhost = shost_priv(shost);
        struct fc_rport *dev_rport;
        struct scsi_device *sdev;
        unsigned long rc;

        ENTER;
        shost_for_each_device(sdev, shost) {
                dev_rport = starget_to_rport(scsi_target(sdev));
                if (dev_rport != rport)
                        continue;
                ibmvfc_cancel_all(sdev, IBMVFC_TMF_SUPPRESS_ABTS);
        }

        rc = ibmvfc_wait_for_ops(vhost, rport, ibmvfc_match_rport);

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

static const struct ibmvfc_async_desc ae_desc [] = {
        { "PLOGI",      IBMVFC_AE_ELS_PLOGI,    IBMVFC_DEFAULT_LOG_LEVEL + 1 },
        { "LOGO",       IBMVFC_AE_ELS_LOGO,     IBMVFC_DEFAULT_LOG_LEVEL + 1 },
        { "PRLO",       IBMVFC_AE_ELS_PRLO,     IBMVFC_DEFAULT_LOG_LEVEL + 1 },
        { "N-Port SCN", IBMVFC_AE_SCN_NPORT,    IBMVFC_DEFAULT_LOG_LEVEL + 1 },
        { "Group SCN",  IBMVFC_AE_SCN_GROUP,    IBMVFC_DEFAULT_LOG_LEVEL + 1 },
        { "Domain SCN", IBMVFC_AE_SCN_DOMAIN,   IBMVFC_DEFAULT_LOG_LEVEL },
        { "Fabric SCN", IBMVFC_AE_SCN_FABRIC,   IBMVFC_DEFAULT_LOG_LEVEL },
        { "Link Up",    IBMVFC_AE_LINK_UP,      IBMVFC_DEFAULT_LOG_LEVEL },
        { "Link Down",  IBMVFC_AE_LINK_DOWN,    IBMVFC_DEFAULT_LOG_LEVEL },
        { "Link Dead",  IBMVFC_AE_LINK_DEAD,    IBMVFC_DEFAULT_LOG_LEVEL },
        { "Halt",       IBMVFC_AE_HALT,         IBMVFC_DEFAULT_LOG_LEVEL },
        { "Resume",     IBMVFC_AE_RESUME,       IBMVFC_DEFAULT_LOG_LEVEL },
        { "Adapter Failed", IBMVFC_AE_ADAPTER_FAILED, IBMVFC_DEFAULT_LOG_LEVEL },
};

static const struct ibmvfc_async_desc unknown_ae = {
        "Unknown async", 0, IBMVFC_DEFAULT_LOG_LEVEL
};

/**
 * ibmvfc_get_ae_desc - Get text description for async event
 * @ae: async event
 *
 **/
static const struct ibmvfc_async_desc *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];

        return &unknown_ae;
}

static const struct {
        enum ibmvfc_ae_link_state state;
        const char *desc;
} link_desc [] = {
        { IBMVFC_AE_LS_LINK_UP,         " link up" },
        { IBMVFC_AE_LS_LINK_BOUNCED,    " link bounced" },
        { IBMVFC_AE_LS_LINK_DOWN,       " link down" },
        { IBMVFC_AE_LS_LINK_DEAD,       " link dead" },
};

/**
 * ibmvfc_get_link_state - Get text description for link state
 * @state:      link state
 *
 **/
static const char *ibmvfc_get_link_state(enum ibmvfc_ae_link_state state)
{
        int i;

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

        return "";
}

/**
 * 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 struct ibmvfc_async_desc *desc = ibmvfc_get_ae_desc(be64_to_cpu(crq->event));
        struct ibmvfc_target *tgt;

        ibmvfc_log(vhost, desc->log_level, "%s event received. scsi_id: %llx, wwpn: %llx,"
                   " node_name: %llx%s\n", desc->desc, be64_to_cpu(crq->scsi_id),
                   be64_to_cpu(crq->wwpn), be64_to_cpu(crq->node_name),
                   ibmvfc_get_link_state(crq->link_state));

        switch (be64_to_cpu(crq->event)) {
        case IBMVFC_AE_RESUME:
                switch (crq->link_state) {
                case IBMVFC_AE_LS_LINK_DOWN:
                        ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
                        break;
                case IBMVFC_AE_LS_LINK_DEAD:
                        ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD);
                        break;
                case IBMVFC_AE_LS_LINK_UP:
                case IBMVFC_AE_LS_LINK_BOUNCED:
                default:
                        vhost->events_to_log |= IBMVFC_AE_LINKUP;
                        vhost->delay_init = 1;
                        __ibmvfc_reset_host(vhost);
                        break;
                }

                break;
        case IBMVFC_AE_LINK_UP:
                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;
                if (vhost->state < IBMVFC_HALTED) {
                        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;
                ibmvfc_reinit_host(vhost);
                break;
        case IBMVFC_AE_ELS_LOGO:
        case IBMVFC_AE_ELS_PRLO:
        case IBMVFC_AE_ELS_PLOGI:
                list_for_each_entry(tgt, &vhost->targets, queue) {
                        if (!crq->scsi_id && !crq->wwpn && !crq->node_name)
                                break;
                        if (crq->scsi_id && cpu_to_be64(tgt->scsi_id) != crq->scsi_id)
                                continue;
                        if (crq->wwpn && cpu_to_be64(tgt->ids.port_name) != crq->wwpn)
                                continue;
                        if (crq->node_name && cpu_to_be64(tgt->ids.node_name) != crq->node_name)
                                continue;
                        if (tgt->need_login && be64_to_cpu(crq->event) == IBMVFC_AE_ELS_LOGO)
                                tgt->logo_rcvd = 1;
                        if (!tgt->need_login || be64_to_cpu(crq->event) == IBMVFC_AE_ELS_PLOGI) {
                                ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
                                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 *)be64_to_cpu(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);
                        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);
                        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;
                vhost->logged_in = 0;
                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);
                        ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
                        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_REENABLE);
                } else {
                        dev_err(vhost->dev, "Virtual adapter failed (rc=%d)\n", crq->format);
                        ibmvfc_purge_requests(vhost, DID_ERROR);
                        ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
                        ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_RESET);
                }
                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;
        unsigned long flags = 0;

        spin_lock_irqsave(shost->host_lock, flags);
        if (sdev->type == TYPE_DISK)
                sdev->allow_restart = 1;
        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
 * @reason:     calling context
 *
 * 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;

        return scsi_change_queue_depth(sdev, qdepth);
}

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);
}

static ssize_t ibmvfc_show_host_capabilities(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, "%llx\n", vhost->login_buf->resp.capabilities);
}

/**
 * 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