/*-
 * Copyright (c) 2017 Broadcom. All rights reserved.
 * The term "Broadcom" refers to Broadcom Limited and/or its subsidiaries.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file
 * Functions to build and send ELS/CT/BLS commands and responses.
 */

/*!
@defgroup els_api ELS/BLS/CT Command and Response Functions
*/

#include "ocs.h"
#include "ocs_els.h"
#include "ocs_scsi.h"
#include "ocs_device.h"

#define ELS_IOFMT "[i:%04x t:%04x h:%04x]"
#define ELS_IOFMT_ARGS(els) els->init_task_tag, els->tgt_task_tag, els->hw_tag

#define node_els_trace()  \
        do { \
                if (OCS_LOG_ENABLE_ELS_TRACE(ocs)) \
                        ocs_log_info(ocs, "[%s] %-20s\n", node->display_name, __func__); \
        } while (0)

#define els_io_printf(els, fmt, ...) \
        ocs_log_debug(els->node->ocs, "[%s]" ELS_IOFMT " %-8s " fmt, els->node->display_name, ELS_IOFMT_ARGS(els), els->display_name, ##__VA_ARGS__);

static int32_t ocs_els_send(ocs_io_t *els, uint32_t reqlen, uint32_t timeout_sec, ocs_hw_srrs_cb_t cb);
static int32_t ocs_els_send_rsp(ocs_io_t *els, uint32_t rsplen);
static int32_t ocs_els_acc_cb(ocs_hw_io_t *hio, ocs_remote_node_t *rnode, uint32_t length, int32_t status, uint32_t ext_status, void *arg);
static ocs_io_t *ocs_bls_send_acc(ocs_io_t *io, uint32_t s_id, uint16_t ox_id, uint16_t rx_id);
static int32_t ocs_bls_send_acc_cb(ocs_hw_io_t *hio, ocs_remote_node_t *rnode, uint32_t length,
        int32_t status, uint32_t ext_status, void *app);
static void ocs_io_transition(ocs_io_t *els, ocs_sm_function_t state, void *data);
static ocs_io_t *ocs_els_abort_io(ocs_io_t *els, int send_abts);
static void _ocs_els_io_free(void *arg);
static void ocs_els_delay_timer_cb(void *arg);

/**
 * @ingroup els_api
 * @brief ELS state machine transition wrapper.
 *
 * <h3 class="desc">Description</h3>
 * This function is the transition wrapper for the ELS state machine. It grabs
 * the node lock prior to making the transition to protect
 * against multiple threads accessing a particular ELS. For example,
 * one thread transitioning from __els_init to
 * __ocs_els_wait_resp and another thread (tasklet) handling the
 * completion of that ELS request.
 *
 * @param els Pointer to the IO context.
 * @param state State to transition to.
 * @param data Data to pass in with the transition.
 *
 * @return None.
 */
static void
ocs_io_transition(ocs_io_t *els, ocs_sm_function_t state, void *data)
{
        /* protect ELS events with node lock */
        ocs_node_t *node = els->node;
        ocs_node_lock(node);
                ocs_sm_transition(&els->els_sm, state, data);
        ocs_node_unlock(node);
}

/**
 * @ingroup els_api
 * @brief ELS state machine post event wrapper.
 *
 * <h3 class="desc">Description</h3>
 * Post an event wrapper for the ELS state machine. This function grabs
 * the node lock prior to posting the event.
 *
 * @param els Pointer to the IO context.
 * @param evt Event to process.
 * @param data Data to pass in with the transition.
 *
 * @return None.
 */
void
ocs_els_post_event(ocs_io_t *els, ocs_sm_event_t evt, void *data)
{
        /* protect ELS events with node lock */
        ocs_node_t *node = els->node;
        ocs_node_lock(node);
                els->els_evtdepth ++;
                ocs_sm_post_event(&els->els_sm, evt, data);
                els->els_evtdepth --;
        ocs_node_unlock(node);
        if (els->els_evtdepth == 0 && els->els_req_free) {
                ocs_els_io_free(els);
        }
}

/**
 * @ingroup els_api
 * @brief Allocate an IO structure for an ELS IO context.
 *
 * <h3 class="desc">Description</h3>
 * Allocate an IO for an ELS context.  Uses OCS_ELS_RSP_LEN as response size.
 *
 * @param node node to associate ELS IO with
 * @param reqlen Length of ELS request
 * @param role Role of ELS (originator/responder)
 *
 * @return pointer to IO structure allocated
 */

ocs_io_t *
ocs_els_io_alloc(ocs_node_t *node, uint32_t reqlen, ocs_els_role_e role)
{
        return ocs_els_io_alloc_size(node, reqlen, OCS_ELS_RSP_LEN, role);
}

/**
 * @ingroup els_api
 * @brief Allocate an IO structure for an ELS IO context.
 *
 * <h3 class="desc">Description</h3>
 * Allocate an IO for an ELS context, allowing the caller to specify the size of the response.
 *
 * @param node node to associate ELS IO with
 * @param reqlen Length of ELS request
 * @param rsplen Length of ELS response
 * @param role Role of ELS (originator/responder)
 *
 * @return pointer to IO structure allocated
 */

ocs_io_t *
ocs_els_io_alloc_size(ocs_node_t *node, uint32_t reqlen, uint32_t rsplen, ocs_els_role_e role)
{

        ocs_t *ocs;
        ocs_xport_t *xport;
        ocs_io_t *els;
        ocs_assert(node, NULL);
        ocs_assert(node->ocs, NULL);
        ocs = node->ocs;
        ocs_assert(ocs->xport, NULL);
        xport = ocs->xport;

        ocs_lock(&node->active_ios_lock);
                if (!node->io_alloc_enabled) {
                        ocs_log_debug(ocs, "called with io_alloc_enabled = FALSE\n");
                        ocs_unlock(&node->active_ios_lock);
                        return NULL;
                }

                els = ocs_io_alloc(ocs);
                if (els == NULL) {
                        ocs_atomic_add_return(&xport->io_alloc_failed_count, 1);
                        ocs_unlock(&node->active_ios_lock);
                        return NULL;
                }

                /* initialize refcount */
                ocs_ref_init(&els->ref, _ocs_els_io_free, els);

                switch (role) {
                case OCS_ELS_ROLE_ORIGINATOR:
                        els->cmd_ini = TRUE;
                        els->cmd_tgt = FALSE;
                        break;
                case OCS_ELS_ROLE_RESPONDER:
                        els->cmd_ini = FALSE;
                        els->cmd_tgt = TRUE;
                        break;
                }

                /* IO should not have an associated HW IO yet.  Assigned below. */
                if (els->hio != NULL) {
                        ocs_log_err(ocs, "assertion failed.  HIO is not null\n");
                        ocs_io_free(ocs, els);
                        ocs_unlock(&node->active_ios_lock);
                        return NULL;
                }

                /* populate generic io fields */
                els->ocs = ocs;
                els->node = node;

                /* set type and ELS-specific fields */
                els->io_type = OCS_IO_TYPE_ELS;
                els->display_name = "pending";

                if (reqlen > OCS_ELS_REQ_LEN) {
                        ocs_log_err(ocs, "ELS command request len greater than allocated\n");
                        ocs_io_free(ocs, els);
                        ocs_unlock(&node->active_ios_lock);
                        return NULL;
                }

                if (rsplen > OCS_ELS_GID_PT_RSP_LEN) {
                        ocs_log_err(ocs, "ELS command response len: %d "
                                "greater than allocated\n", rsplen);
                        ocs_io_free(ocs, els);
                        ocs_unlock(&node->active_ios_lock);
                        return NULL;
                }

                els->els_req.size = reqlen;
                els->els_rsp.size = rsplen;

                if (els != NULL) {
                        ocs_memset(&els->els_sm, 0, sizeof(els->els_sm));
                        els->els_sm.app = els;

                        /* initialize fields */
                        els->els_retries_remaining = OCS_FC_ELS_DEFAULT_RETRIES;
                        els->els_evtdepth = 0;
                        els->els_pend = 0;
                        els->els_active = 0;

                        /* add els structure to ELS IO list */
                        ocs_list_add_tail(&node->els_io_pend_list, els);
                        els->els_pend = 1;
                }
        ocs_unlock(&node->active_ios_lock);
        return els;
}

/**
 * @ingroup els_api
 * @brief Free IO structure for an ELS IO context.
 *
 * <h3 class="desc">Description</h3> Free IO for an ELS
 * IO context
 *
 * @param els ELS IO structure for which IO is allocated
 *
 * @return None
 */

void
ocs_els_io_free(ocs_io_t *els)
{
        ocs_ref_put(&els->ref);
}

/**
 * @ingroup els_api
 * @brief Free IO structure for an ELS IO context.
 *
 * <h3 class="desc">Description</h3> Free IO for an ELS
 * IO context
 *
 * @param arg ELS IO structure for which IO is allocated
 *
 * @return None
 */

static void
_ocs_els_io_free(void *arg)
{
        ocs_io_t *els = (ocs_io_t *)arg;
        ocs_t *ocs;
        ocs_node_t *node;
        int send_empty_event = FALSE;

        ocs_assert(els);
        ocs_assert(els->node);
        ocs_assert(els->node->ocs);
        ocs = els->node->ocs;

        node = els->node;
        ocs = node->ocs;

        ocs_lock(&node->active_ios_lock);
                if (els->els_active) {
                        /* if active, remove from active list and check empty */
                        ocs_list_remove(&node->els_io_active_list, els);
                        /* Send list empty event if the IO allocator is disabled, and the list is empty
                         * If node->io_alloc_enabled was not checked, the event would be posted continually
                         */
                        send_empty_event = (!node->io_alloc_enabled) && ocs_list_empty(&node->els_io_active_list);
                        els->els_active = 0;
                } else if (els->els_pend) {
                        /* if pending, remove from pending list; node shutdown isn't
                         * gated off the pending list (only the active list), so no
                         * need to check if pending list is empty
                         */
                        ocs_list_remove(&node->els_io_pend_list, els);
                        els->els_pend = 0;
                } else {
                        ocs_log_err(ocs, "assertion failed: neither els->els_pend nor els->active set\n");
                        ocs_unlock(&node->active_ios_lock);
                        return;
                }

        ocs_unlock(&node->active_ios_lock);

        ocs_io_free(ocs, els);

        if (send_empty_event) {
                ocs_node_post_event(node, OCS_EVT_ALL_CHILD_NODES_FREE, NULL);
        }

        ocs_scsi_check_pending(ocs);
}

/**
 * @ingroup els_api
 * @brief Make ELS IO active
 *
 * @param els Pointer to the IO context to make active.
 *
 * @return Returns 0 on success; or a negative error code value on failure.
 */

static void
ocs_els_make_active(ocs_io_t *els)
{
        ocs_node_t *node = els->node;

        /* move ELS from pending list to active list */
        ocs_lock(&node->active_ios_lock);
                if (els->els_pend) {
                        if (els->els_active) {
                                ocs_log_err(node->ocs, "assertion failed: both els->els_pend and els->active set\n");
                                ocs_unlock(&node->active_ios_lock);
                                return;
                        } else {
                                /* remove from pending list */
                                ocs_list_remove(&node->els_io_pend_list, els);
                                els->els_pend = 0;

                                /* add els structure to ELS IO list */
                                ocs_list_add_tail(&node->els_io_active_list, els);
                                els->els_active = 1;
                        }
                } else {
                        /* must be retrying; make sure it's already active */
                        if (!els->els_active) {
                                ocs_log_err(node->ocs, "assertion failed: neither els->els_pend nor els->active set\n");
                        }
                }
        ocs_unlock(&node->active_ios_lock);
}

/**
 * @ingroup els_api
 * @brief Send the ELS command.
 *
 * <h3 class="desc">Description</h3>
 * The command, given by the \c els IO context, is sent to the node that the IO was
 * configured with, using ocs_hw_srrs_send(). Upon completion,
 * the \c cb callback is invoked,
 * with the application-specific argument set to the \c els IO context.
 *
 * @param els Pointer to the IO context.
 * @param reqlen Byte count in the payload to send.
 * @param timeout_sec Command timeout, in seconds (0 -> 2*R_A_TOV).
 * @param cb Completion callback.
 *
 * @return Returns 0 on success; or a negative error code value on failure.
 */

static int32_t
ocs_els_send(ocs_io_t *els, uint32_t reqlen, uint32_t timeout_sec, ocs_hw_srrs_cb_t cb)
{
        ocs_node_t *node = els->node;

        /* update ELS request counter */
        node->els_req_cnt++;

        /* move ELS from pending list to active list */
        ocs_els_make_active(els);

        els->wire_len = reqlen;
        return ocs_scsi_io_dispatch(els, cb);
}

/**
 * @ingroup els_api
 * @brief Send the ELS response.
 *
 * <h3 class="desc">Description</h3>
 * The ELS response, given by the \c els IO context, is sent to the node
 * that the IO was configured with, using ocs_hw_srrs_send().
 *
 * @param els Pointer to the IO context.
 * @param rsplen Byte count in the payload to send.
 *
 * @return Returns 0 on success; or a negative error value on failure.
 */

static int32_t
ocs_els_send_rsp(ocs_io_t *els, uint32_t rsplen)
{
        ocs_node_t *node = els->node;

        /* increment ELS completion counter */
        node->els_cmpl_cnt++;

        /* move ELS from pending list to active list */
        ocs_els_make_active(els);

        els->wire_len = rsplen;
        return ocs_scsi_io_dispatch(els, ocs_els_acc_cb);
}

/**
 * @ingroup els_api
 * @brief Handle ELS IO request completions.
 *
 * <h3 class="desc">Description</h3>
 * This callback is used for several ELS send operations.
 *
 * @param hio Pointer to the HW IO context that completed.
 * @param rnode Pointer to the remote node.
 * @param length Length of the returned payload data.
 * @param status Status of the completion.
 * @param ext_status Extended status of the completion.
 * @param arg Application-specific argument (generally a pointer to the ELS IO context).
 *
 * @return Returns 0 on success; or a negative error value on failure.
 */

static int32_t
ocs_els_req_cb(ocs_hw_io_t *hio, ocs_remote_node_t *rnode, uint32_t length, int32_t status, uint32_t ext_status, void *arg)
{
        ocs_io_t *els;
        ocs_node_t *node;
        ocs_t *ocs;
        ocs_node_cb_t cbdata;
        ocs_io_t *io;

        ocs_assert(arg, -1);
        io = arg;
        els = io;
        ocs_assert(els, -1);
        ocs_assert(els->node, -1);
        node = els->node;
        ocs_assert(node->ocs, -1);
        ocs = node->ocs;

        ocs_assert(io->hio, -1);
        ocs_assert(hio == io->hio, -1);

        if (status != 0) {
                els_io_printf(els, "status x%x ext x%x\n", status, ext_status);
        }

        /* set the response len element of els->rsp */
        els->els_rsp.len = length;

        cbdata.status = status;
        cbdata.ext_status = ext_status;
        cbdata.header = NULL;
        cbdata.els = els;

        /* FW returns the number of bytes received on the link in
         * the WCQE, not the amount placed in the buffer; use this info to
         * check if there was an overrun.
         */
        if (length > els->els_rsp.size) {
                ocs_log_warn(ocs, "ELS response returned len=%d > buflen=%zu\n",
                                length, els->els_rsp.size);
                ocs_els_post_event(els, OCS_EVT_SRRS_ELS_REQ_FAIL, &cbdata);
                return 0;
        }

        /* Post event to ELS IO object */
        switch (status) {
        case SLI4_FC_WCQE_STATUS_SUCCESS:
                ocs_els_post_event(els, OCS_EVT_SRRS_ELS_REQ_OK, &cbdata);
                break;

        case SLI4_FC_WCQE_STATUS_LS_RJT:
                ocs_els_post_event(els, OCS_EVT_SRRS_ELS_REQ_RJT, &cbdata);
                break;

        case SLI4_FC_WCQE_STATUS_LOCAL_REJECT:
                switch (ext_status) {
                case SLI4_FC_LOCAL_REJECT_SEQUENCE_TIMEOUT:
                        ocs_els_post_event(els, OCS_EVT_ELS_REQ_TIMEOUT, &cbdata);
                        break;
                case SLI4_FC_LOCAL_REJECT_ABORT_REQUESTED:
                        ocs_els_post_event(els, OCS_EVT_ELS_REQ_ABORTED, &cbdata);
                        break;
                default:
                        ocs_els_post_event(els, OCS_EVT_SRRS_ELS_REQ_FAIL, &cbdata);
                        break;
                }
                break;
        default:
                ocs_log_warn(ocs, "els req complete: failed status x%x, ext_status, x%x\n", status, ext_status);
                ocs_els_post_event(els, OCS_EVT_SRRS_ELS_REQ_FAIL, &cbdata);
                break;
        }

        return 0;
}

/**
 * @ingroup els_api
 * @brief Handle ELS IO accept/response completions.
 *
 * <h3 class="desc">Description</h3>
 * This callback is used for several ELS send operations.
 *
 * @param hio Pointer to the HW IO context that completed.
 * @param rnode Pointer to the remote node.
 * @param length Length of the returned payload data.
 * @param status Status of the completion.
 * @param ext_status Extended status of the completion.
 * @param arg Application-specific argument (generally a pointer to the ELS IO context).
 *
 * @return Returns 0 on success; or a negative error value on failure.
 */

static int32_t
ocs_els_acc_cb(ocs_hw_io_t *hio, ocs_remote_node_t *rnode, uint32_t length, int32_t status, uint32_t ext_status, void *arg)
{
        ocs_io_t *els;
        ocs_node_t *node;
        ocs_t *ocs;
        ocs_node_cb_t cbdata;
        ocs_io_t *io;

        ocs_assert(arg, -1);
        io = arg;
        els = io;
        ocs_assert(els, -1);
        ocs_assert(els->node, -1);
        node = els->node;
        ocs_assert(node->ocs, -1);
        ocs = node->ocs;

        ocs_assert(io->hio, -1);
        ocs_assert(hio == io->hio, -1);

        cbdata.status = status;
        cbdata.ext_status = ext_status;
        cbdata.header = NULL;
        cbdata.els = els;

        /* Post node event */
        switch (status) {
        case SLI4_FC_WCQE_STATUS_SUCCESS:
                ocs_node_post_event(node, OCS_EVT_SRRS_ELS_CMPL_OK, &cbdata);
                break;

        default:
                ocs_log_warn(ocs, "[%s] %-8s failed status x%x, ext_status x%x\n",
                        node->display_name, els->display_name, status, ext_status);
                ocs_log_warn(ocs, "els acc complete: failed status x%x, ext_status, x%x\n", status, ext_status);
                ocs_node_post_event(node, OCS_EVT_SRRS_ELS_CMPL_FAIL, &cbdata);
                break;
        }

        /* If this IO has a callback, invoke it */
        if (els->els_callback) {
                (*els->els_callback)(node, &cbdata, els->els_callback_arg);
        }

        ocs_els_io_free(els);

        return 0;
}

/**
 * @ingroup els_api
 * @brief Format and send a PLOGI ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Construct a PLOGI payload using the domain SLI port service parameters,
 * and send to the \c node.
 *
 * @param node Node to which the PLOGI is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_plogi(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        void (*cb)(ocs_node_t *node, ocs_node_cb_t *cbdata, void *arg), void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs = node->ocs;
        fc_plogi_payload_t *plogi;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*plogi), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "plogi";

                /* Build PLOGI request */
                plogi = els->els_req.virt;

                ocs_memcpy(plogi, node->sport->service_params, sizeof(*plogi));

                plogi->command_code = FC_ELS_CMD_PLOGI;
                plogi->resv1 = 0;

                ocs_display_sparams(node->display_name, "plogi send req", 0, NULL, plogi->common_service_parameters);

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;

                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Format and send a FLOGI ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Construct an FLOGI payload, and send to the \c node.
 *
 * @param node Node to which the FLOGI is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_flogi(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs;
        fc_plogi_payload_t *flogi;

        ocs_assert(node, NULL);
        ocs_assert(node->ocs, NULL);
        ocs_assert(node->sport, NULL);
        ocs = node->ocs;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*flogi), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "flogi";

                /* Build FLOGI request */
                flogi = els->els_req.virt;

                ocs_memcpy(flogi, node->sport->service_params, sizeof(*flogi));
                flogi->command_code = FC_ELS_CMD_FLOGI;
                flogi->resv1 = 0;

                /* Priority tagging support */
                flogi->common_service_parameters[1] |= ocs_htobe32(1U << 23);

                ocs_display_sparams(node->display_name, "flogi send req", 0, NULL, flogi->common_service_parameters);

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;
                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Format and send a FDISC ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Construct an FDISC payload, and send to the \c node.
 *
 * @param node Node to which the FDISC is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_fdisc(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs;
        fc_plogi_payload_t *fdisc;

        ocs_assert(node, NULL);
        ocs_assert(node->ocs, NULL);
        ocs = node->ocs;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*fdisc), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "fdisc";

                /* Build FDISC request */
                fdisc = els->els_req.virt;

                ocs_memcpy(fdisc, node->sport->service_params, sizeof(*fdisc));
                fdisc->command_code = FC_ELS_CMD_FDISC;
                fdisc->resv1 = 0;

                ocs_display_sparams(node->display_name, "fdisc send req", 0, NULL, fdisc->common_service_parameters);

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;
                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send a PRLI ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Construct a PRLI ELS command, and send to the \c node.
 *
 * @param node Node to which the PRLI is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_prli(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_t *ocs = node->ocs;
        ocs_io_t *els;
        fc_prli_payload_t *prli;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*prli), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "prli";

                /* Build PRLI request */
                prli = els->els_req.virt;

                ocs_memset(prli, 0, sizeof(*prli));

                prli->command_code = FC_ELS_CMD_PRLI;
                prli->page_length = 16;
                prli->payload_length = ocs_htobe16(sizeof(fc_prli_payload_t));
                prli->type = FC_TYPE_FCP;
                prli->type_ext = 0;
                prli->flags = ocs_htobe16(FC_PRLI_ESTABLISH_IMAGE_PAIR);
                prli->service_params = ocs_htobe16(FC_PRLI_READ_XRDY_DISABLED |
                        (node->sport->enable_ini ? FC_PRLI_INITIATOR_FUNCTION : 0) |
                        (node->sport->enable_tgt ? FC_PRLI_TARGET_FUNCTION : 0)); 

                /* For Tape Drive support */
                prli->service_params |= ocs_htobe16(FC_PRLI_CONFIRMED_COMPLETION | FC_PRLI_RETRY |
                                 FC_PRLI_TASK_RETRY_ID_REQ| FC_PRLI_REC_SUPPORT);

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;
                ocs_io_transition(els, __ocs_els_init, NULL);
        }

        return els;
}

/**
 * @ingroup els_api
 * @brief Send a PRLO ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Construct a PRLO ELS command, and send to the \c node.
 *
 * @param node Node to which the PRLO is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_prlo(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_t *ocs = node->ocs;
        ocs_io_t *els;
        fc_prlo_payload_t *prlo;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*prlo), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "prlo";

                /* Build PRLO request */
                prlo = els->els_req.virt;

                ocs_memset(prlo, 0, sizeof(*prlo));
                prlo->command_code = FC_ELS_CMD_PRLO;
                prlo->page_length = 16;
                prlo->payload_length = ocs_htobe16(sizeof(fc_prlo_payload_t));
                prlo->type = FC_TYPE_FCP;
                prlo->type_ext = 0;

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;
                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send a LOGO ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Format a LOGO, and send to the \c node.
 *
 * @param node Node to which the LOGO is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_logo(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs;
        fc_logo_payload_t *logo;
        fc_plogi_payload_t *sparams;

        ocs = node->ocs;

        node_els_trace();

        sparams = (fc_plogi_payload_t*) node->sport->service_params;

        els = ocs_els_io_alloc(node, sizeof(*logo), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "logo";

                /* Build LOGO request */

                logo = els->els_req.virt;

                ocs_memset(logo, 0, sizeof(*logo));
                logo->command_code = FC_ELS_CMD_LOGO;
                logo->resv1 = 0;
                logo->port_id = fc_htobe24(node->rnode.sport->fc_id);
                logo->port_name_hi = sparams->port_name_hi;
                logo->port_name_lo = sparams->port_name_lo;

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;
                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send an ADISC ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Construct an ADISC ELS command, and send to the \c node.
 *
 * @param node Node to which the ADISC is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_adisc(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs;
        fc_adisc_payload_t *adisc;
        fc_plogi_payload_t *sparams;
        ocs_sport_t *sport = node->sport;

        ocs = node->ocs;

        node_els_trace();

        sparams = (fc_plogi_payload_t*) node->sport->service_params;

        els = ocs_els_io_alloc(node, sizeof(*adisc), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "adisc";

                /* Build ADISC request */

                adisc = els->els_req.virt;
                sparams = (fc_plogi_payload_t*) node->sport->service_params;

                ocs_memset(adisc, 0, sizeof(*adisc));
                adisc->command_code = FC_ELS_CMD_ADISC;
                adisc->hard_address = fc_htobe24(sport->fc_id);
                adisc->port_name_hi = sparams->port_name_hi;
                adisc->port_name_lo = sparams->port_name_lo;
                adisc->node_name_hi = sparams->node_name_hi;
                adisc->node_name_lo = sparams->node_name_lo;
                adisc->port_id = fc_htobe24(node->rnode.sport->fc_id);

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;
                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send a PDISC ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Construct a PDISC ELS command, and send to the \c node.
 *
 * @param node Node to which the PDISC is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_pdisc(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs = node->ocs;
        fc_plogi_payload_t *pdisc;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*pdisc), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "pdisc";

                pdisc = els->els_req.virt;

                ocs_memcpy(pdisc, node->sport->service_params, sizeof(*pdisc));

                pdisc->command_code = FC_ELS_CMD_PDISC;
                pdisc->resv1 = 0;

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;
                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send an SCR ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Format an SCR, and send to the \c node.
 *
 * @param node Node to which the SCR is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function
 * @param cbarg Callback function arg
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_scr(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs = node->ocs;
        fc_scr_payload_t *req;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*req), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "scr";

                req = els->els_req.virt;

                ocs_memset(req, 0, sizeof(*req));
                req->command_code = FC_ELS_CMD_SCR;
                req->function = FC_SCR_REG_FULL;

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;
                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send an RRQ ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Format an RRQ, and send to the \c node.
 *
 * @param node Node to which the RRQ is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function
 * @param cbarg Callback function arg
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_rrq(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs = node->ocs;
        fc_scr_payload_t *req;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*req), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "scr";

                req = els->els_req.virt;

                ocs_memset(req, 0, sizeof(*req));
                req->command_code = FC_ELS_CMD_RRQ;
                req->function = FC_SCR_REG_FULL;

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;
                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send an RSCN ELS command.
 *
 * <h3 class="desc">Description</h3>
 * Format an RSCN, and send to the \c node.
 *
 * @param node Node to which the RRQ is sent.
 * @param timeout_sec Command timeout, in seconds.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param port_ids Pointer to port IDs
 * @param port_ids_count Count of port IDs
 * @param cb Callback function
 * @param cbarg Callback function arg
 *
 * @return Returns pointer to IO object, or NULL if error.
 */
ocs_io_t *
ocs_send_rscn(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        void *port_ids, uint32_t port_ids_count, els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs = node->ocs;
        fc_rscn_payload_t *req;
        uint32_t payload_length = sizeof(fc_rscn_affected_port_id_page_t)*(port_ids_count - 1) +
                sizeof(fc_rscn_payload_t);

        node_els_trace();

        els = ocs_els_io_alloc(node, payload_length, OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->els_timeout_sec = timeout_sec;
                els->els_retries_remaining = retries;
                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "rscn";

                req = els->els_req.virt;

                req->command_code = FC_ELS_CMD_RSCN;
                req->page_length = sizeof(fc_rscn_affected_port_id_page_t);
                req->payload_length = ocs_htobe16(sizeof(*req) +
                        sizeof(fc_rscn_affected_port_id_page_t)*(port_ids_count-1));

                els->hio_type = OCS_HW_ELS_REQ;
                els->iparam.els.timeout = timeout_sec;

                /* copy in the payload */
                ocs_memcpy(req->port_list, port_ids, port_ids_count*sizeof(fc_rscn_affected_port_id_page_t));

                /* Submit the request */
                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @brief Send an LS_RJT ELS response.
 *
 * <h3 class="desc">Description</h3>
 * Send an LS_RJT ELS response.
 *
 * @param io Pointer to a SCSI IO object.
 * @param ox_id Originator exchange ID being responded to.
 * @param reason_code Reason code value for LS_RJT.
 * @param reason_code_expl Reason code explanation value for LS_RJT.
 * @param vendor_unique Vendor-unique value for LS_RJT.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_ls_rjt(ocs_io_t *io, uint32_t ox_id, uint32_t reason_code, uint32_t reason_code_expl,
                uint32_t vendor_unique, els_cb_t cb, void *cbarg)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        ocs_t *ocs = node->ocs;
        fc_ls_rjt_payload_t *rjt;

        node_els_trace();

        io->els_callback = cb;
        io->els_callback_arg = cbarg;
        io->display_name = "ls_rjt";
        io->init_task_tag = ox_id;

        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.els.ox_id = ox_id;

        rjt = io->els_req.virt;
        ocs_memset(rjt, 0, sizeof(*rjt));

        rjt->command_code = FC_ELS_CMD_RJT;
        rjt->reason_code = reason_code;
        rjt->reason_code_exp = reason_code_expl;

        io->hio_type = OCS_HW_ELS_RSP;
        if ((rc = ocs_els_send_rsp(io, sizeof(*rjt)))) {
                ocs_els_io_free(io);
                io = NULL;
        }

        return io;
}

/**
 * @ingroup els_api
 * @brief Send a PLOGI accept response.
 *
 * <h3 class="desc">Description</h3>
 * Construct a PLOGI LS_ACC, and send to the \c node, using the originator exchange ID
 * \c ox_id.
 *
 * @param io Pointer to a SCSI IO object.
 * @param ox_id Originator exchange ID being responsed to.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */
ocs_io_t *
ocs_send_plogi_acc(ocs_io_t *io, uint32_t ox_id, els_cb_t cb, void *cbarg)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        ocs_t *ocs = node->ocs;
        fc_plogi_payload_t *plogi;
        fc_plogi_payload_t *req = (fc_plogi_payload_t *)node->service_params;

        node_els_trace();

        io->els_callback = cb;
        io->els_callback_arg = cbarg;
        io->display_name = "plog_acc";
        io->init_task_tag = ox_id;

        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.els.ox_id = ox_id;

        plogi = io->els_req.virt;

        /* copy our port's service parameters to payload */
        ocs_memcpy(plogi, node->sport->service_params, sizeof(*plogi));
        plogi->command_code = FC_ELS_CMD_ACC;
        plogi->resv1 = 0;

        /* Set Application header support bit if requested */
        if (req->common_service_parameters[1] & ocs_htobe32(1U << 24)) {
                plogi->common_service_parameters[1] |= ocs_htobe32(1U << 24);
        }

        /* Priority tagging support. */
        if (req->common_service_parameters[1] & ocs_htobe32(1U << 23)) {
                plogi->common_service_parameters[1] |= ocs_htobe32(1U << 23);
        }

        ocs_display_sparams(node->display_name, "plogi send resp", 0, NULL, plogi->common_service_parameters);

        io->hio_type = OCS_HW_ELS_RSP;
        if ((rc = ocs_els_send_rsp(io, sizeof(*plogi)))) {
                ocs_els_io_free(io);
                io = NULL;
        }
        return io;
}

/**
 * @ingroup els_api
 * @brief Send an FLOGI accept response for point-to-point negotiation.
 *
 * <h3 class="desc">Description</h3>
 * Construct an FLOGI accept response, and send to the \c node using the originator
 * exchange id \c ox_id. The \c s_id is used for the response frame source FC ID.
 *
 * @param io Pointer to a SCSI IO object.
 * @param ox_id Originator exchange ID for the response.
 * @param s_id Source FC ID to be used in the response frame.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */
ocs_io_t *
ocs_send_flogi_p2p_acc(ocs_io_t *io, uint32_t ox_id, uint32_t s_id, els_cb_t cb, void *cbarg)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        ocs_t *ocs = node->ocs;
        fc_plogi_payload_t *flogi;

        node_els_trace();

        io->els_callback = cb;
        io->els_callback_arg = cbarg;
        io->display_name = "flogi_p2p_acc";
        io->init_task_tag = ox_id;

        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.els_sid.ox_id = ox_id;
        io->iparam.els_sid.s_id = s_id;

        flogi = io->els_req.virt;

        /* copy our port's service parameters to payload */
        ocs_memcpy(flogi, node->sport->service_params, sizeof(*flogi));
        flogi->command_code = FC_ELS_CMD_ACC;
        flogi->resv1 = 0;
        ocs_memset(flogi->class1_service_parameters, 0, sizeof(flogi->class1_service_parameters));
        ocs_memset(flogi->class2_service_parameters, 0, sizeof(flogi->class1_service_parameters));
        ocs_memset(flogi->class3_service_parameters, 0, sizeof(flogi->class1_service_parameters));
        ocs_memset(flogi->class4_service_parameters, 0, sizeof(flogi->class1_service_parameters));

        io->hio_type = OCS_HW_ELS_RSP_SID;
        if ((rc = ocs_els_send_rsp(io, sizeof(*flogi)))) {
                ocs_els_io_free(io);
                io = NULL;
        }

        return io;
}

ocs_io_t *
ocs_send_flogi_acc(ocs_io_t *io, uint32_t ox_id, uint32_t is_fport, els_cb_t cb, void *cbarg)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        ocs_t *ocs = node->ocs;
        fc_plogi_payload_t *flogi;

        node_els_trace();

        io->els_callback = cb;
        io->els_callback_arg = cbarg;
        io->display_name = "flogi_acc";
        io->init_task_tag = ox_id;

        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.els_sid.ox_id = ox_id;
        io->iparam.els_sid.s_id = io->node->sport->fc_id;

        flogi = io->els_req.virt;

        /* copy our port's service parameters to payload */
        ocs_memcpy(flogi, node->sport->service_params, sizeof(*flogi));

        /* Set F_port */
        if (is_fport) {
                /* Set F_PORT and Multiple N_PORT_ID Assignment */
                flogi->common_service_parameters[1] |= ocs_be32toh(3U << 28);
        }

        flogi->command_code = FC_ELS_CMD_ACC;
        flogi->resv1 = 0;

        ocs_display_sparams(node->display_name, "flogi send resp", 0, NULL, flogi->common_service_parameters);

        ocs_memset(flogi->class1_service_parameters, 0, sizeof(flogi->class1_service_parameters));
        ocs_memset(flogi->class2_service_parameters, 0, sizeof(flogi->class1_service_parameters));
        ocs_memset(flogi->class3_service_parameters, 0, sizeof(flogi->class1_service_parameters));
        ocs_memset(flogi->class4_service_parameters, 0, sizeof(flogi->class1_service_parameters));

        io->hio_type = OCS_HW_ELS_RSP_SID;
        if ((rc = ocs_els_send_rsp(io, sizeof(*flogi)))) {
                ocs_els_io_free(io);
                io = NULL;
        }

        return io;
}

/**
 * @ingroup els_api
 * @brief Send a PRLI accept response
 *
 * <h3 class="desc">Description</h3>
 * Construct a PRLI LS_ACC response, and send to the \c node, using the originator
 * \c ox_id exchange ID.
 *
 * @param io Pointer to a SCSI IO object.
 * @param ox_id Originator exchange ID.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_prli_acc(ocs_io_t *io, uint32_t ox_id, uint8_t fc_type, els_cb_t cb, void *cbarg)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        ocs_t *ocs = node->ocs;
        fc_prli_payload_t *prli;

        node_els_trace();

        io->els_callback = cb;
        io->els_callback_arg = cbarg;
        io->display_name = "prli_acc";
        io->init_task_tag = ox_id;

        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.els.ox_id = ox_id;

        prli = io->els_req.virt;
        ocs_memset(prli, 0, sizeof(*prli));

        prli->command_code = FC_ELS_CMD_ACC;
        prli->page_length = 16;
        prli->payload_length = ocs_htobe16(sizeof(fc_prli_payload_t));
        prli->type = fc_type;
        prli->type_ext = 0;
        prli->flags = ocs_htobe16(FC_PRLI_ESTABLISH_IMAGE_PAIR | FC_PRLI_REQUEST_EXECUTED);

        prli->service_params = ocs_htobe16(FC_PRLI_READ_XRDY_DISABLED |
                                (node->sport->enable_ini ? FC_PRLI_INITIATOR_FUNCTION : 0) |
                                (node->sport->enable_tgt ? FC_PRLI_TARGET_FUNCTION : 0)); 

        io->hio_type = OCS_HW_ELS_RSP;
        if ((rc = ocs_els_send_rsp(io, sizeof(*prli)))) {
                ocs_els_io_free(io);
                io = NULL;
        }

        return io;
}

/**
 * @ingroup els_api
 * @brief Send a PRLO accept response.
 *
 * <h3 class="desc">Description</h3>
 * Construct a PRLO LS_ACC response, and send to the \c node, using the originator
 * exchange ID \c ox_id.
 *
 * @param io Pointer to a SCSI IO object.
 * @param ox_id Originator exchange ID.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_prlo_acc(ocs_io_t *io, uint32_t ox_id, uint8_t fc_type, els_cb_t cb, void *cbarg)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        ocs_t *ocs = node->ocs;
        fc_prlo_acc_payload_t *prlo_acc;

        node_els_trace();

        io->els_callback = cb;
        io->els_callback_arg = cbarg;
        io->display_name = "prlo_acc";
        io->init_task_tag = ox_id;

        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.els.ox_id = ox_id;

        prlo_acc = io->els_req.virt;
        ocs_memset(prlo_acc, 0, sizeof(*prlo_acc));

        prlo_acc->command_code = FC_ELS_CMD_ACC;
        prlo_acc->page_length = 16;
        prlo_acc->payload_length = ocs_htobe16(sizeof(fc_prlo_acc_payload_t));
        prlo_acc->type = fc_type;
        prlo_acc->type_ext = 0;
        prlo_acc->response_code = FC_PRLO_REQUEST_EXECUTED;

        io->hio_type = OCS_HW_ELS_RSP;
        if ((rc = ocs_els_send_rsp(io, sizeof(*prlo_acc)))) {
                ocs_els_io_free(io);
                io = NULL;
        }

        return io;
}

/**
 * @ingroup els_api
 * @brief Send a generic LS_ACC response without a payload.
 *
 * <h3 class="desc">Description</h3>
 * A generic LS_ACC response is sent to the \c node using the originator exchange ID
 * \c ox_id.
 *
 * @param io Pointer to a SCSI IO object.
 * @param ox_id Originator exchange id.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */
ocs_io_t *
ocs_send_ls_acc(ocs_io_t *io, uint32_t ox_id, els_cb_t cb, void *cbarg)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        ocs_t *ocs = node->ocs;
        fc_acc_payload_t *acc;

        node_els_trace();

        io->els_callback = cb;
        io->els_callback_arg = cbarg;
        io->display_name = "ls_acc";
        io->init_task_tag = ox_id;

        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.els.ox_id = ox_id;

        acc = io->els_req.virt;
        ocs_memset(acc, 0, sizeof(*acc));

        acc->command_code = FC_ELS_CMD_ACC;

        io->hio_type = OCS_HW_ELS_RSP;
        if ((rc = ocs_els_send_rsp(io, sizeof(*acc)))) {
                ocs_els_io_free(io);
                io = NULL;
        }

        return io;
}

/**
 * @ingroup els_api
 * @brief Send a LOGO accept response.
 *
 * <h3 class="desc">Description</h3>
 * Construct a LOGO LS_ACC response, and send to the \c node, using the originator
 * exchange ID \c ox_id.
 *
 * @param io Pointer to a SCSI IO object.
 * @param ox_id Originator exchange ID.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */
ocs_io_t *
ocs_send_logo_acc(ocs_io_t *io, uint32_t ox_id, els_cb_t cb, void *cbarg)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        ocs_t *ocs = node->ocs;
        fc_acc_payload_t *logo;

        node_els_trace();

        io->els_callback = cb;
        io->els_callback_arg = cbarg;
        io->display_name = "logo_acc";
        io->init_task_tag = ox_id;

        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.els.ox_id = ox_id;

        logo = io->els_req.virt;
        ocs_memset(logo, 0, sizeof(*logo));

        logo->command_code = FC_ELS_CMD_ACC;
        logo->resv1 = 0;

        io->hio_type = OCS_HW_ELS_RSP;
        if ((rc = ocs_els_send_rsp(io, sizeof(*logo)))) {
                ocs_els_io_free(io);
                io = NULL;
        }

        return io;
}

/**
 * @ingroup els_api
 * @brief Send an ADISC accept response.
 *
 * <h3 class="desc">Description</h3>
 * Construct an ADISC LS__ACC, and send to the \c node, using the originator
 * exchange id \c ox_id.
 *
 * @param io Pointer to a SCSI IO object.
 * @param ox_id Originator exchange ID.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_send_adisc_acc(ocs_io_t *io, uint32_t ox_id, els_cb_t cb, void *cbarg)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        fc_adisc_payload_t *adisc;
        fc_plogi_payload_t *sparams;
        ocs_t *ocs;

        ocs_assert(node, NULL);
        ocs_assert(node->ocs, NULL);
        ocs = node->ocs;

        node_els_trace();

        io->els_callback = cb;
        io->els_callback_arg = cbarg;
        io->display_name = "adisc_acc";
        io->init_task_tag = ox_id;

        /* Go ahead and send the ELS_ACC */
        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.els.ox_id = ox_id;

        sparams = (fc_plogi_payload_t*) node->sport->service_params;
        adisc = io->els_req.virt;
        ocs_memset(adisc, 0, sizeof(fc_adisc_payload_t));
        adisc->command_code = FC_ELS_CMD_ACC;
        adisc->hard_address = 0;
        adisc->port_name_hi = sparams->port_name_hi;
        adisc->port_name_lo = sparams->port_name_lo;
        adisc->node_name_hi = sparams->node_name_hi;
        adisc->node_name_lo = sparams->node_name_lo;
        adisc->port_id = fc_htobe24(node->rnode.sport->fc_id);

        io->hio_type = OCS_HW_ELS_RSP;
        if ((rc = ocs_els_send_rsp(io, sizeof(*adisc)))) {
                ocs_els_io_free(io);
                io = NULL;
        }

        return io;
}

/**
 * @ingroup els_api
 * @brief Send a RFTID CT request.
 *
 * <h3 class="desc">Description</h3>
 * Construct an RFTID CT request, and send to the \c node.
 *
 * @param node Node to which the RFTID request is sent.
 * @param timeout_sec Time, in seconds, to wait before timing out the ELS.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */
ocs_io_t *
ocs_ns_send_rftid(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs = node->ocs;
        fcct_rftid_req_t *rftid;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*rftid), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->iparam.fc_ct.r_ctl = FC_RCTL_ELS;
                els->iparam.fc_ct.type = FC_TYPE_GS;
                els->iparam.fc_ct.df_ctl = 0;
                els->iparam.fc_ct.timeout = timeout_sec;

                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "rftid";

                rftid = els->els_req.virt;

                ocs_memset(rftid, 0, sizeof(*rftid));
                fcct_build_req_header(&rftid->hdr, FC_GS_NAMESERVER_RFT_ID, (OCS_ELS_RSP_LEN - sizeof(rftid->hdr)));
                rftid->port_id = ocs_htobe32(node->rnode.sport->fc_id);
                rftid->fc4_types[FC_GS_TYPE_WORD(FC_TYPE_FCP)] = ocs_htobe32(1 << FC_GS_TYPE_BIT(FC_TYPE_FCP));

                els->hio_type = OCS_HW_FC_CT;

                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send a RFFID CT request.
 *
 * <h3 class="desc">Description</h3>
 * Construct an RFFID CT request, and send to the \c node.
 *
 * @param node Node to which the RFFID request is sent.
 * @param timeout_sec Time, in seconds, to wait before timing out the ELS.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */
ocs_io_t *
ocs_ns_send_rffid(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs = node->ocs;
        fcct_rffid_req_t *rffid;

        node_els_trace();

        els = ocs_els_io_alloc(node, sizeof(*rffid), OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->iparam.fc_ct.r_ctl = FC_RCTL_ELS;
                els->iparam.fc_ct.type = FC_TYPE_GS;
                els->iparam.fc_ct.df_ctl = 0;
                els->iparam.fc_ct.timeout = timeout_sec;

                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "rffid";

                rffid = els->els_req.virt;

                ocs_memset(rffid, 0, sizeof(*rffid));

                fcct_build_req_header(&rffid->hdr, FC_GS_NAMESERVER_RFF_ID, (OCS_ELS_RSP_LEN - sizeof(rffid->hdr)));
                rffid->port_id = ocs_htobe32(node->rnode.sport->fc_id);
                if (node->sport->enable_ini) {
                        rffid->fc4_feature_bits |= FC4_FEATURE_INITIATOR;
                }
                if (node->sport->enable_tgt) {
                        rffid->fc4_feature_bits |= FC4_FEATURE_TARGET;
                }
                rffid->type = FC_TYPE_FCP;

                els->hio_type = OCS_HW_FC_CT;

                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send a GIDPT CT request.
 *
 * <h3 class="desc">Description</h3>
 * Construct a GIDPT CT request, and send to the \c node.
 *
 * @param node Node to which the GIDPT request is sent.
 * @param timeout_sec Time, in seconds, to wait before timing out the ELS.
 * @param retries Number of times to retry errors before reporting a failure.
 * @param cb Callback function.
 * @param cbarg Callback function argument.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_ns_send_gidpt(ocs_node_t *node, uint32_t timeout_sec, uint32_t retries,
        els_cb_t cb, void *cbarg)
{
        ocs_io_t *els;
        ocs_t *ocs = node->ocs;
        fcct_gidpt_req_t *gidpt;

        node_els_trace();

        els = ocs_els_io_alloc_size(node, sizeof(*gidpt), OCS_ELS_GID_PT_RSP_LEN, OCS_ELS_ROLE_ORIGINATOR);
        if (els == NULL) {
                ocs_log_err(ocs, "IO alloc failed\n");
        } else {
                els->iparam.fc_ct.r_ctl = FC_RCTL_ELS;
                els->iparam.fc_ct.type = FC_TYPE_GS;
                els->iparam.fc_ct.df_ctl = 0;
                els->iparam.fc_ct.timeout = timeout_sec;

                els->els_callback = cb;
                els->els_callback_arg = cbarg;
                els->display_name = "gidpt";

                gidpt = els->els_req.virt;

                ocs_memset(gidpt, 0, sizeof(*gidpt));
                fcct_build_req_header(&gidpt->hdr, FC_GS_NAMESERVER_GID_PT, (OCS_ELS_GID_PT_RSP_LEN - sizeof(gidpt->hdr)) );
                gidpt->domain_id_scope = 0;
                gidpt->area_id_scope = 0;
                gidpt->port_type = 0x7f;

                els->hio_type = OCS_HW_FC_CT;

                ocs_io_transition(els, __ocs_els_init, NULL);
        }
        return els;
}

/**
 * @ingroup els_api
 * @brief Send a BA_ACC given the request's FC header
 *
 * <h3 class="desc">Description</h3>
 * Using the S_ID/D_ID from the request's FC header, generate a BA_ACC.
 *
 * @param io Pointer to a SCSI IO object.
 * @param hdr Pointer to the FC header.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

ocs_io_t *
ocs_bls_send_acc_hdr(ocs_io_t *io, fc_header_t *hdr)
{
        uint16_t ox_id = ocs_be16toh(hdr->ox_id);
        uint16_t rx_id = ocs_be16toh(hdr->rx_id);
        uint32_t d_id = fc_be24toh(hdr->d_id);

        return ocs_bls_send_acc(io, d_id, ox_id, rx_id);
}

/**
 * @ingroup els_api
 * @brief Send a BLS BA_ACC response.
 *
 * <h3 class="desc">Description</h3>
 * Construct a BLS BA_ACC response, and send to the \c node.
 *
 * @param io Pointer to a SCSI IO object.
 * @param s_id S_ID to use for the response. If UINT32_MAX, then use our SLI port
 * (sport) S_ID.
 * @param ox_id Originator exchange ID.
 * @param rx_id Responder exchange ID.
 *
 * @return Returns pointer to IO object, or NULL if error.
 */

static ocs_io_t *
ocs_bls_send_acc(ocs_io_t *io, uint32_t s_id, uint16_t ox_id, uint16_t rx_id)
{
        ocs_node_t *node = io->node;
        int32_t rc;
        fc_ba_acc_payload_t *acc;
        ocs_t *ocs;

        ocs_assert(node, NULL);
        ocs_assert(node->ocs, NULL);
        ocs = node->ocs;

        if (node->rnode.sport->fc_id == s_id) {
                s_id = UINT32_MAX;
        }

        /* fill out generic fields */
        io->ocs = ocs;
        io->node = node;
        io->cmd_tgt = TRUE;

        /* fill out BLS Response-specific fields */
        io->io_type = OCS_IO_TYPE_BLS_RESP;
        io->display_name = "ba_acc";
        io->hio_type = OCS_HW_BLS_ACC_SID;
        io->init_task_tag = ox_id;

        /* fill out iparam fields */
        ocs_memset(&io->iparam, 0, sizeof(io->iparam));
        io->iparam.bls_sid.s_id = s_id;
        io->iparam.bls_sid.ox_id = ox_id;
        io->iparam.bls_sid.rx_id = rx_id;

        acc = (void *)io->iparam.bls_sid.payload;

        ocs_memset(io->iparam.bls_sid.payload, 0, sizeof(io->iparam.bls_sid.payload));
        acc->ox_id = io->iparam.bls_sid.ox_id;
        acc->rx_id = io->iparam.bls_sid.rx_id;
        acc->high_seq_cnt = UINT16_MAX;

        if ((rc = ocs_scsi_io_dispatch(io, ocs_bls_send_acc_cb))) {
                ocs_log_err(ocs, "ocs_scsi_io_dispatch() failed: %d\n", rc);
                ocs_scsi_io_free(io);
                io = NULL;
        }
        return io;
}

/**
 * @brief Handle the BLS accept completion.
 *
 * <h3 class="desc">Description</h3>
 * Upon completion of sending a BA_ACC, this callback is invoked by the HW.
 *
 * @param hio Pointer to the HW IO object.
 * @param rnode Pointer to the HW remote node.
 * @param length Length of the response payload, in bytes.
 * @param status Completion status.
 * @param ext_status Extended completion status.
 * @param app Callback private argument.
 *
 * @return Returns 0 on success; or a negative error value on failure.
 */

static int32_t
ocs_bls_send_acc_cb(ocs_hw_io_t *hio, ocs_remote_node_t *rnode, uint32_t length, int32_t status, uint32_t ext_status, void *app)
{
        ocs_io_t *io = app;

        ocs_assert(io, -1);

        ocs_scsi_io_free(io);
        return 0;
}

/**
 * @brief ELS abort callback.
 *
 * <h3 class="desc">Description</h3>
 * This callback is invoked by the HW when an ELS IO is aborted.
 *
 * @param hio Pointer to the HW IO object.
 * @param rnode Pointer to the HW remote node.
 * @param length Length of the response payload, in bytes.
 * @param status Completion status.
 * @param ext_status Extended completion status.
 * @param app Callback private argument.
 *
 * @return Returns 0 on success; or a negative error value on failure.
 */

static int32_t
ocs_els_abort_cb(ocs_hw_io_t *hio, ocs_remote_node_t *rnode, uint32_t length, int32_t status, uint32_t ext_status, void *app)
{
        ocs_io_t *els;
        ocs_io_t *abort_io = NULL; /* IO structure used to abort ELS */
        ocs_t *ocs;

        ocs_assert(app, -1);
        abort_io = app;
        els = abort_io->io_to_abort;
        ocs_assert(els->node, -1);
        ocs_assert(els->node->ocs, -1);

        ocs = els->node->ocs;

        if (status != 0) {
                ocs_log_warn(ocs, "status x%x ext x%x\n", status, ext_status);
        }

        /* now free the abort IO */
        ocs_io_free(ocs, abort_io);

        /* send completion event to indicate abort process is complete
         * Note: The ELS SM will already be receiving ELS_REQ_OK/FAIL/RJT/ABORTED
         */
        ocs_els_post_event(els, OCS_EVT_ELS_ABORT_CMPL, NULL);

        /* done with ELS IO to abort */
        ocs_ref_put(&els->ref); /* ocs_ref_get(): ocs_els_abort_io() */
        return 0;
}

/**
 * @brief Abort an ELS IO.
 *
 * <h3 class="desc">Description</h3>
 * The ELS IO is aborted by making a HW abort IO request,
 * optionally requesting that an ABTS is sent.
 *
 * \b Note: This function allocates a HW IO, and associates the HW IO
 * with the ELS IO that it is aborting. It does not associate
 * the HW IO with the node directly, like for ELS requests. The
 * abort completion is propagated up to the node once the
 * original WQE and the abort WQE are complete (the original WQE
 * completion is not propagated up to node).
 *
 * @param els Pointer to the ELS IO.
 * @param send_abts Boolean to indicate if hardware will automatically generate an ABTS.
 *
 * @return Returns pointer to Abort IO object, or NULL if error.
 */

static ocs_io_t *
ocs_els_abort_io(ocs_io_t *els, int send_abts)
{
        ocs_t *ocs;
        ocs_xport_t *xport;
        int32_t rc;
        ocs_io_t *abort_io = NULL;

        ocs_assert(els, NULL);
        ocs_assert(els->node, NULL);
        ocs_assert(els->node->ocs, NULL);

        ocs = els->node->ocs;
        ocs_assert(ocs->xport, NULL);
        xport = ocs->xport;

        /* take a reference on IO being aborted */
        if ((ocs_ref_get_unless_zero(&els->ref) == 0)) {
                /* command no longer active */
                ocs_log_debug(ocs, "els no longer active\n");
                return NULL;
        }

        /* allocate IO structure to send abort */
        abort_io = ocs_io_alloc(ocs);
        if (abort_io == NULL) {
                ocs_atomic_add_return(&xport->io_alloc_failed_count, 1);
        } else {
                ocs_assert(abort_io->hio == NULL, NULL);

                /* set generic fields */
                abort_io->ocs = ocs;
                abort_io->node = els->node;
                abort_io->cmd_ini = TRUE;

                /* set type and ABORT-specific fields */
                abort_io->io_type = OCS_IO_TYPE_ABORT;
                abort_io->display_name = "abort_els";
                abort_io->io_to_abort = els;
                abort_io->send_abts = send_abts;

                /* now dispatch IO */
                if ((rc = ocs_scsi_io_dispatch_abort(abort_io, ocs_els_abort_cb))) {
                        ocs_log_err(ocs, "ocs_scsi_io_dispatch failed: %d\n", rc);
                        ocs_io_free(ocs, abort_io);
                        abort_io = NULL;
                }
        }

        /* if something failed, put reference on ELS to abort */
        if (abort_io == NULL) {
                ocs_ref_put(&els->ref); /* ocs_ref_get(): same function */
        }
        return abort_io;
}

/*
 * ELS IO State Machine
 */

#define std_els_state_decl(...) \
        ocs_io_t *els = NULL; \
        ocs_node_t *node = NULL; \
        ocs_t *ocs = NULL; \
        ocs_assert(ctx != NULL, NULL); \
        els = ctx->app; \
        ocs_assert(els != NULL, NULL); \
        node = els->node; \
        ocs_assert(node != NULL, NULL); \
        ocs = node->ocs; \
        ocs_assert(ocs != NULL, NULL);

#define els_sm_trace(...) \
        do { \
                if (OCS_LOG_ENABLE_ELS_TRACE(ocs)) \
                        ocs_log_info(ocs, "[%s] %-8s %-20s %-20s\n", node->display_name, els->display_name, \
                                __func__, ocs_sm_event_name(evt)); \
        } while (0)

/**
 * @brief Cleanup an ELS IO
 *
 * <h3 class="desc">Description</h3>
 * Cleans up an ELS IO by posting the requested event to the owning node object;
 * invoking the callback, if one is provided; and then freeing the
 * ELS IO object.
 *
 * @param els Pointer to the ELS IO.
 * @param node_evt Node SM event to post.
 * @param arg Node SM event argument.
 *
 * @return None.
 */

void
ocs_els_io_cleanup(ocs_io_t *els, ocs_sm_event_t node_evt, void *arg)
{
        ocs_assert(els);

        /* don't want further events that could come; e.g. abort requests
         * from the node state machine; thus, disable state machine
         */
        ocs_sm_disable(&els->els_sm);
        ocs_node_post_event(els->node, node_evt, arg);

        /* If this IO has a callback, invoke it */
        if (els->els_callback) {
                (*els->els_callback)(els->node, arg, els->els_callback_arg);
        }
        els->els_req_free = 1;
}

/**
 * @brief Common event handler for the ELS IO state machine.
 *
 * <h3 class="desc">Description</h3>
 * Provide handler for events for which default actions are desired.
 *
 * @param funcname Name of the calling function (for logging).
 * @param ctx Remote node SM context.
 * @param evt Event to process.
 * @param arg Per event optional argument.
 *
 * @return Returns NULL.
 */

void *
__ocs_els_common(const char *funcname, ocs_sm_ctx_t *ctx, ocs_sm_event_t evt, void *arg)
{
        std_els_state_decl();

        switch(evt) {
        case OCS_EVT_ENTER:
        case OCS_EVT_REENTER:
        case OCS_EVT_EXIT:
                break;

        /* If ELS_REQ_FAIL is not handled in state, then we'll terminate this ELS and
         * pass the event to the node
         */
        case OCS_EVT_SRRS_ELS_REQ_FAIL:
                ocs_log_warn(els->node->ocs, "[%s] %-20s %-20s not handled - terminating ELS\n", node->display_name, funcname,
                        ocs_sm_event_name(evt));
                ocs_els_io_cleanup(els, OCS_EVT_SRRS_ELS_REQ_FAIL, arg);
                break;
        default:
                ocs_log_warn(els->node->ocs, "[%s] %-20s %-20s not handled\n", node->display_name, funcname,
                        ocs_sm_event_name(evt));
                break;
        }
        return NULL;
}

/**
 * @brief Initial ELS IO state
 *
 * <h3 class="desc">Description</h3>
 * This is the initial ELS IO state. Upon entry, the requested ELS/CT is submitted to
 * the hardware.
 *
 * @param ctx Remote node SM context.
 * @param evt Event to process.
 * @param arg Per event optional argument.
 *
 * @return Returns NULL.
 */

void *
__ocs_els_init(ocs_sm_ctx_t *ctx, ocs_sm_event_t evt, void *arg)
{
        int32_t rc = 0;
        std_els_state_decl();

        els_sm_trace();

        switch(evt) {
        case OCS_EVT_ENTER: {
                rc = ocs_els_send(els, els->els_req.size, els->els_timeout_sec, ocs_els_req_cb);
                if (rc) {
                        ocs_node_cb_t cbdata;
                        cbdata.status = cbdata.ext_status = (~0);
                        cbdata.els = els;
                        ocs_log_err(ocs, "ocs_els_send failed: %d\n", rc);
                        ocs_els_io_cleanup(els, OCS_EVT_SRRS_ELS_REQ_FAIL, &cbdata);
                } else {
                        ocs_io_transition(els, __ocs_els_wait_resp, NULL);
                }
                break;
        }
        default:
                __ocs_els_common(__func__, ctx, evt, arg);
                break;
        }

        return NULL;
}

/**
 * @brief Wait for the ELS request to complete.
 *
 * <h3 class="desc">Description</h3>
 * This is the ELS IO state that waits for the submitted ELS event to complete.
 * If an error completion event is received, the requested ELS is aborted.
 *
 * @param ctx Remote node SM context.
 * @param evt Event to process.
 * @param arg Per event optional argument.
 *
 * @return Returns NULL.
 */

void *
__ocs_els_wait_resp(ocs_sm_ctx_t *ctx, ocs_sm_event_t evt, void *arg)
{
        ocs_io_t *io;
        std_els_state_decl();

        els_sm_trace();

        switch(evt) {
        case OCS_EVT_SRRS_ELS_REQ_OK: {
                ocs_els_io_cleanup(els, OCS_EVT_SRRS_ELS_REQ_OK, arg);
                break;
        }

        case OCS_EVT_SRRS_ELS_REQ_FAIL: {
                ocs_els_io_cleanup(els, OCS_EVT_SRRS_ELS_REQ_FAIL, arg);
                break;
        }

        case OCS_EVT_ELS_REQ_TIMEOUT: {
                els_io_printf(els, "Timed out, retry (%d tries remaining)\n",
                                els->els_retries_remaining-1);
                ocs_io_transition(els, __ocs_els_retry, NULL);
                break;
        }

        case OCS_EVT_SRRS_ELS_REQ_RJT: {
                ocs_node_cb_t *cbdata = arg;
                uint32_t reason_code = (cbdata->ext_status >> 16) & 0xff;

                /* delay and retry if reason code is Logical Busy */
                switch (reason_code) {
                case FC_REASON_LOGICAL_BUSY:
                        els->node->els_req_cnt--;
                        els_io_printf(els, "LS_RJT Logical Busy response, delay and retry\n");
                        ocs_io_transition(els, __ocs_els_delay_retry, NULL);
                        break;
                default:
                        ocs_els_io_cleanup(els, evt, arg);
                        break;
                }
                break;
        }

        case OCS_EVT_ABORT_ELS: {
                /* request to abort this ELS without an ABTS */
                els_io_printf(els, "ELS abort requested\n");
                els->els_retries_remaining = 0;         /* Set retries to zero, we are done */
                io = ocs_els_abort_io(els, FALSE);
                if (io == NULL) {
                        ocs_log_err(ocs, "ocs_els_send failed\n");
                        ocs_els_io_cleanup(els, OCS_EVT_SRRS_ELS_REQ_FAIL, arg);
                } else {
                        ocs_io_transition(els, __ocs_els_aborting, NULL);
                }
                break;
        }

        default:
                __ocs_els_common(__func__, ctx, evt, arg);
                break;
        }
        return NULL;
}

/**
 * @brief Wait for the ELS IO abort request to complete, and retry the ELS.
 *
 * <h3 class="desc">Description</h3>
 * This state is entered when waiting for an abort of an ELS
 * request to complete so the request can be retried.
 *
 * @param ctx Remote node SM context.
 * @param evt Event to process.
 * @param arg Per event optional argument.
 *
 * @return Returns NULL.
 */

void *
__ocs_els_retry(ocs_sm_ctx_t *ctx, ocs_sm_event_t evt, void *arg)
{
        int32_t rc = 0;
        std_els_state_decl();

        els_sm_trace();

        switch(evt) {
        case OCS_EVT_ENTER: {
                /* handle event for ABORT_XRI WQE
                 * once abort is complete, retry if retries left;
                 * don't need to wait for OCS_EVT_SRRS_ELS_REQ_* event because we got
                 * by receiving OCS_EVT_ELS_REQ_TIMEOUT
                 */
                ocs_node_cb_t node_cbdata;
                node_cbdata.status = node_cbdata.ext_status = (~0);
                node_cbdata.els = els;
                if (els->els_retries_remaining && --els->els_retries_remaining) {
                        /* Use a different XRI for the retry (would like a new oxid),
                         * so free the HW IO (dispatch will allocate a new one). It's an
                         * optimization to only free the HW IO here and not the ocs_io_t;
                         * Freeing the ocs_io_t object would require copying all the necessary
                         * info from the old ocs_io_t object to the * new one; and allocating
                         * a new ocs_io_t could fail.
                         */
                        ocs_assert(els->hio, NULL);
                        ocs_hw_io_free(&ocs->hw, els->hio);
                        els->hio = NULL;

                        /* result isn't propagated up to node sm, need to decrement req cnt */
                        ocs_assert(els->node->els_req_cnt, NULL);
                        els->node->els_req_cnt--;
                        rc = ocs_els_send(els, els->els_req.size, els->els_timeout_sec, ocs_els_req_cb);
                        if (rc) {
                                ocs_log_err(ocs, "ocs_els_send failed: %d\n", rc);
                                ocs_els_io_cleanup(els, OCS_EVT_SRRS_ELS_REQ_FAIL, &node_cbdata);
                        }
                        ocs_io_transition(els, __ocs_els_wait_resp, NULL);
                } else {
                        els_io_printf(els, "Retries exhausted\n");
                        ocs_els_io_cleanup(els, OCS_EVT_SRRS_ELS_REQ_FAIL, &node_cbdata);
                }
                break;
        }

        default:
                __ocs_els_common(__func__, ctx, evt, arg);
                break;
        }
        return NULL;
}

/**
 * @brief Wait for a retry timer to expire having received an abort request
 *
 * <h3 class="desc">Description</h3>
 * This state is entered when waiting for a timer event, after having received
 * an abort request, to avoid a race condition with the timer handler
 *
 * @param ctx Remote node SM context.
 * @param evt Event to process.
 * @param arg Per event optional argument.
 *
 * @return Returns NULL.
 */
void *
__ocs_els_aborted_delay_retry(ocs_sm_ctx_t *ctx, ocs_sm_event_t evt, void *arg)
{
        std_els_state_decl();

        els_sm_trace();

        switch(evt) {
        case OCS_EVT_ENTER:
                /* mod/resched the timer for a short duration */
                ocs_mod_timer(&els->delay_timer, 1);
                break;
        case OCS_EVT_TIMER_EXPIRED:
                /* Cancel the timer, skip post node event, and free the io */
                node->els_req_cnt++;
                ocs_els_io_cleanup(els, OCS_EVT_SRRS_ELS_REQ_FAIL, arg);
                break;
        default:
                __ocs_els_common(__func__, ctx, evt, arg);
                break;
        }
        return NULL;
}

/**
 * @brief Wait for a retry timer to expire
 *
 * <h3 class="desc">Description</h3>
 * This state is entered when waiting for a timer event, so that
 * the ELS request can be retried.
 *
 * @param ctx Remote node SM context.
 * @param evt Event to process.
 * @param arg Per event optional argument.
 *
 * @return Returns NULL.
 */
void *
__ocs_els_delay_retry(ocs_sm_ctx_t *ctx, ocs_sm_event_t evt, void *arg)
{
        std_els_state_decl();

        els_sm_trace();

        switch(evt) {
        case OCS_EVT_ENTER:
                ocs_setup_timer(ocs, &els->delay_timer, ocs_els_delay_timer_cb, els, 5000);
                break;
        case OCS_EVT_TIMER_EXPIRED:
                /* Retry delay timer expired, retry the ELS request, Free the HW IO so
                 * that a new oxid is used.
                 */
                if (els->hio != NULL) {
                        ocs_hw_io_free(&ocs->hw, els->hio);
                        els->hio = NULL;
                }
                ocs_io_transition(els, __ocs_els_init, NULL);
                break;
        case OCS_EVT_ABORT_ELS:
                ocs_io_transition(els, __ocs_els_aborted_delay_retry, NULL);
                break;
        default:
                __ocs_els_common(__func__, ctx, evt, arg);
                break;
        }
        return NULL;
}

/**
 * @brief Wait for the ELS IO abort request to complete.
 *
 * <h3 class="desc">Description</h3>
 * This state is entered after we abort an ELS WQE and are
 * waiting for either the original ELS WQE request or the abort
 * to complete.
 *
 * @param ctx Remote node SM context.
 * @param evt Event to process.
 * @param arg Per event optional argument.
 *
 * @return Returns NULL.
 */

void *
__ocs_els_aborting(ocs_sm_ctx_t *ctx, ocs_sm_event_t evt, void *arg)
{
        std_els_state_decl();

        els_sm_trace();

        switch(evt) {
        case OCS_EVT_SRRS_ELS_REQ_OK:
        case OCS_EVT_SRRS_ELS_REQ_FAIL:
        case OCS_EVT_SRRS_ELS_REQ_RJT:
        case OCS_EVT_ELS_REQ_TIMEOUT:
        case OCS_EVT_ELS_REQ_ABORTED: {
                /* completion for ELS received first, transition to wait for abort cmpl */
                els_io_printf(els, "request cmpl evt=%s\n", ocs_sm_event_name(evt));
                ocs_io_transition(els, __ocs_els_aborting_wait_abort_cmpl, NULL);
                break;
        }
        case OCS_EVT_ELS_ABORT_CMPL: {
                /* completion for abort was received first, transition to wait for req cmpl */
                els_io_printf(els, "abort cmpl evt=%s\n", ocs_sm_event_name(evt));
                ocs_io_transition(els, __ocs_els_aborting_wait_req_cmpl, NULL);
                break;
        }
        case OCS_EVT_ABORT_ELS:
                /* nothing we can do but wait */
                break;

        default:
                __ocs_els_common(__func__, ctx, evt, arg);
                break;
        }
        return NULL;
}

/**
 * @brief cleanup ELS after abort
 *
 * @param els ELS IO to cleanup
 *
 * @return Returns None.
 */

static void
ocs_els_abort_cleanup(ocs_io_t *els)
{
        /* handle event for ABORT_WQE
         * whatever state ELS happened to be in, propagate aborted event up
         * to node state machine in lieu of OCS_EVT_SRRS_ELS_* event
         */
        ocs_node_cb_t cbdata;
        cbdata.status = cbdata.ext_status = 0;
        cbdata.els = els;
        els_io_printf(els, "Request aborted\n");
        ocs_els_io_cleanup(els, OCS_EVT_ELS_REQ_ABORTED, &cbdata);
}

/**
 * @brief Wait for the ELS IO abort request to complete.
 *
 * <h3 class="desc">Description</h3>
 * This state is entered after we abort an ELS WQE, we received
 * the abort completion first and are waiting for the original
 * ELS WQE request to complete.
 *
 * @param ctx Remote node SM context.
 * @param evt Event to process.
 * @param arg Per event optional argument.
 *
 * @return Returns NULL.
 */

void *
__ocs_els_aborting_wait_req_cmpl(ocs_sm_ctx_t *ctx, ocs_sm_event_t evt, void *arg)
{
        std_els_state_decl();

        els_sm_trace();

        switch(evt) {
        case OCS_EVT_SRRS_ELS_REQ_OK:
        case OCS_EVT_SRRS_ELS_REQ_FAIL:
        case OCS_EVT_SRRS_ELS_REQ_RJT:
        case OCS_EVT_ELS_REQ_TIMEOUT:
        case OCS_EVT_ELS_REQ_ABORTED: {
                /* completion for ELS that was aborted */
                ocs_els_abort_cleanup(els);
                break;
        }
        case OCS_EVT_ABORT_ELS:
                /* nothing we can do but wait */
                break;

        default:
                __ocs_els_common(__func__, ctx, evt, arg);
                break;
        }
        return NULL;
}

/**
 * @brief Wait for the ELS IO abort request to complete.
 *
 * <h3 class="desc">Description</h3>
 * This state is entered after we abort an ELS WQE, we received
 * the original ELS WQE request completion first and are waiting
 * for the abort to complete.
 *
 * @param ctx Remote node SM context.
 * @param evt Event to process.
 * @param arg Per event optional argument.
 *
 * @return Returns NULL.
 */

void *
__ocs_els_aborting_wait_abort_cmpl(ocs_sm_ctx_t *ctx, ocs_sm_event_t evt, void *arg)
{
        std_els_state_decl();

        els_sm_trace();

        switch(evt) {
        case OCS_EVT_ELS_ABORT_CMPL: {
                ocs_els_abort_cleanup(els);
                break;
        }
        case OCS_EVT_ABORT_ELS:
                /* nothing we can do but wait */
                break;

        default:
                __ocs_els_common(__func__, ctx, evt, arg);
                break;
        }
        return NULL;
}

/**
 * @brief Generate ELS context ddump data.
 *
 * <h3 class="desc">Description</h3>
 * Generate the ddump data for an ELS context.
 *
 * @param textbuf Pointer to the text buffer.
 * @param els Pointer to the ELS context.
 *
 * @return None.
 */

void
ocs_ddump_els(ocs_textbuf_t *textbuf, ocs_io_t *els)
{
        ocs_ddump_section(textbuf, "els", -1);
        ocs_ddump_value(textbuf, "req_free", "%d", els->els_req_free);
        ocs_ddump_value(textbuf, "evtdepth", "%d", els->els_evtdepth);
        ocs_ddump_value(textbuf, "pend", "%d", els->els_pend);
        ocs_ddump_value(textbuf, "active", "%d", els->els_active);
        ocs_ddump_io(textbuf, els);
        ocs_ddump_endsection(textbuf, "els", -1);
}

/**
 * @brief return TRUE if given ELS list is empty (while taking proper locks)
 *
 * Test if given ELS list is empty while holding the node->active_ios_lock.
 *
 * @param node pointer to node object
 * @param list pointer to list
 *
 * @return TRUE if els_io_list is empty
 */

int32_t
ocs_els_io_list_empty(ocs_node_t *node, ocs_list_t *list)
{
        int empty;
        ocs_lock(&node->active_ios_lock);
                empty = ocs_list_empty(list);
        ocs_unlock(&node->active_ios_lock);
        return empty;
}

/**
 * @brief Handle CT send response completion
 *
 * Called when CT response completes, free IO
 *
 * @param hio Pointer to the HW IO context that completed.
 * @param rnode Pointer to the remote node.
 * @param length Length of the returned payload data.
 * @param status Status of the completion.
 * @param ext_status Extended status of the completion.
 * @param arg Application-specific argument (generally a pointer to the ELS IO context).
 *
 * @return returns 0
 */
static int32_t
ocs_ct_acc_cb(ocs_hw_io_t *hio, ocs_remote_node_t *rnode, uint32_t length, int32_t status, uint32_t ext_status, void *arg)
{
        ocs_io_t *io = arg;

        ocs_els_io_free(io);

        return 0;
}

/**
 * @brief Send CT response
 *
 * Sends a CT response frame with payload
 *
 * @param io Pointer to the IO context.
 * @param ox_id Originator exchange ID
 * @param ct_hdr Pointer to the CT IU
 * @param cmd_rsp_code CT response code
 * @param reason_code Reason code
 * @param reason_code_explanation Reason code explanation
 *
 * @return returns 0 for success, a negative error code value for failure.
 */
int32_t
ocs_send_ct_rsp(ocs_io_t *io, uint32_t ox_id, fcct_iu_header_t *ct_hdr, uint32_t cmd_rsp_code, uint32_t reason_code, uint32_t reason_code_explanation)
{
        fcct_iu_header_t *rsp = io->els_rsp.virt;

        io->io_type = OCS_IO_TYPE_CT_RESP;

        *rsp = *ct_hdr;

        fcct_build_req_header(rsp, cmd_rsp_code, 0);
        rsp->reason_code = reason_code;
        rsp->reason_code_explanation = reason_code_explanation;

        io->display_name = "ct response";
        io->init_task_tag = ox_id;
        io->wire_len += sizeof(*rsp);

        ocs_memset(&io->iparam, 0, sizeof(io->iparam));

        io->io_type = OCS_IO_TYPE_CT_RESP;
        io->hio_type = OCS_HW_FC_CT_RSP;
        io->iparam.fc_ct_rsp.ox_id = ocs_htobe16(ox_id);
        io->iparam.fc_ct_rsp.r_ctl = 3;
        io->iparam.fc_ct_rsp.type = FC_TYPE_GS;
        io->iparam.fc_ct_rsp.df_ctl = 0;
        io->iparam.fc_ct_rsp.timeout = 5;

        if (ocs_scsi_io_dispatch(io, ocs_ct_acc_cb) < 0) {
                ocs_els_io_free(io);
                return -1;
        }
        return 0;
}

/**
 * @brief Handle delay retry timeout
 *
 * Callback is invoked when the delay retry timer expires.
 *
 * @param arg pointer to the ELS IO object
 *
 * @return none
 */
static void
ocs_els_delay_timer_cb(void *arg)
{
        ocs_io_t *els = arg;
        ocs_node_t *node = els->node;

        /*
         * There is a potential deadlock here since is Linux executes timers
         * in a soft IRQ context. The lock may be aready locked by the interrupt
         * thread. Handle this case by attempting to take the node lock and reset the
         * timer if we fail to acquire the lock.
         *
         * Note: This code relies on the fact that the node lock is recursive.
         */
        if (ocs_node_lock_try(node)) {
                ocs_els_post_event(els, OCS_EVT_TIMER_EXPIRED, NULL);
                ocs_node_unlock(node);
        } else {
                ocs_setup_timer(els->ocs, &els->delay_timer, ocs_els_delay_timer_cb, els, 1);
        }
}