FreeBSD/Linux Kernel Cross Reference
sys/dev/ocs_fc/ocs_els.c

     /*-
      * 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.
     *
     * $FreeBSD$
     */
    
    /**
     * @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: niether 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: niether 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);
          }
  }

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