// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2021 Broadcom. All Rights Reserved. The term
 * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
 */

/*
 * This file implements remote node state machines for:
 * - Fabric logins.
 * - Fabric controller events.
 * - Name/directory services interaction.
 * - Point-to-point logins.
 */

/*
 * fabric_sm Node State Machine: Fabric States
 * ns_sm Node State Machine: Name/Directory Services States
 * p2p_sm Node State Machine: Point-to-Point Node States
 */

#include "efc.h"

static void
efc_fabric_initiate_shutdown(struct efc_node *node)
{
        struct efc *efc = node->efc;

        node->els_io_enabled = false;

        if (node->attached) {
                int rc;

                /* issue hw node free; don't care if succeeds right away
                 * or sometime later, will check node->attached later in
                 * shutdown process
                 */
                rc = efc_cmd_node_detach(efc, &node->rnode);
                if (rc < 0) {
                        node_printf(node, "Failed freeing HW node, rc=%d\n",
                                    rc);
                }
        }
        /*
         * node has either been detached or is in the process of being detached,
         * call common node's initiate cleanup function
         */
        efc_node_initiate_cleanup(node);
}

static void
__efc_fabric_common(const char *funcname, struct efc_sm_ctx *ctx,
                    enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = NULL;

        node = ctx->app;

        switch (evt) {
        case EFC_EVT_DOMAIN_ATTACH_OK:
                break;
        case EFC_EVT_SHUTDOWN:
                node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                efc_fabric_initiate_shutdown(node);
                break;

        default:
                /* call default event handler common to all nodes */
                __efc_node_common(funcname, ctx, evt, arg);
        }
}

void
__efc_fabric_init(struct efc_sm_ctx *ctx, enum efc_sm_event evt,
                  void *arg)
{
        struct efc_node *node = ctx->app;
        struct efc *efc = node->efc;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_REENTER:
                efc_log_debug(efc, ">>> reenter !!\n");
                fallthrough;

        case EFC_EVT_ENTER:
                /* send FLOGI */
                efc_send_flogi(node);
                efc_node_transition(node, __efc_fabric_flogi_wait_rsp, NULL);
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
efc_fabric_set_topology(struct efc_node *node,
                        enum efc_nport_topology topology)
{
        node->nport->topology = topology;
}

void
efc_fabric_notify_topology(struct efc_node *node)
{
        struct efc_node *tmp_node;
        enum efc_nport_topology topology = node->nport->topology;
        unsigned long index;

        /*
         * now loop through the nodes in the nport
         * and send topology notification
         */
        xa_for_each(&node->nport->lookup, index, tmp_node) {
                if (tmp_node != node) {
                        efc_node_post_event(tmp_node,
                                            EFC_EVT_NPORT_TOPOLOGY_NOTIFY,
                                            (void *)topology);
                }
        }
}

static bool efc_rnode_is_nport(struct fc_els_flogi *rsp)
{
        return !(ntohs(rsp->fl_csp.sp_features) & FC_SP_FT_FPORT);
}

void
__efc_fabric_flogi_wait_rsp(struct efc_sm_ctx *ctx,
                            enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_SRRS_ELS_REQ_OK: {
                if (efc_node_check_els_req(ctx, evt, arg, ELS_FLOGI,
                                           __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;

                memcpy(node->nport->domain->flogi_service_params,
                       cbdata->els_rsp.virt,
                       sizeof(struct fc_els_flogi));

                /* Check to see if the fabric is an F_PORT or and N_PORT */
                if (!efc_rnode_is_nport(cbdata->els_rsp.virt)) {
                        /* sm: if not nport / efc_domain_attach */
                        /* ext_status has the fc_id, attach domain */
                        efc_fabric_set_topology(node, EFC_NPORT_TOPO_FABRIC);
                        efc_fabric_notify_topology(node);
                        WARN_ON(node->nport->domain->attached);
                        efc_domain_attach(node->nport->domain,
                                          cbdata->ext_status);
                        efc_node_transition(node,
                                            __efc_fabric_wait_domain_attach,
                                            NULL);
                        break;
                }

                /*  sm: if nport and p2p_winner / efc_domain_attach */
                efc_fabric_set_topology(node, EFC_NPORT_TOPO_P2P);
                if (efc_p2p_setup(node->nport)) {
                        node_printf(node,
                                    "p2p setup failed, shutting down node\n");
                        node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                        efc_fabric_initiate_shutdown(node);
                        break;
                }

                if (node->nport->p2p_winner) {
                        efc_node_transition(node,
                                            __efc_p2p_wait_domain_attach,
                                             NULL);
                        if (node->nport->domain->attached &&
                            !node->nport->domain->domain_notify_pend) {
                                /*
                                 * already attached,
                                 * just send ATTACH_OK
                                 */
                                node_printf(node,
                                            "p2p winner, domain already attached\n");
                                efc_node_post_event(node,
                                                    EFC_EVT_DOMAIN_ATTACH_OK,
                                                    NULL);
                        }
                } else {
                        /*
                         * peer is p2p winner;
                         * PLOGI will be received on the
                         * remote SID=1 node;
                         * this node has served its purpose
                         */
                        node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                        efc_fabric_initiate_shutdown(node);
                }

                break;
        }

        case EFC_EVT_ELS_REQ_ABORTED:
        case EFC_EVT_SRRS_ELS_REQ_RJT:
        case EFC_EVT_SRRS_ELS_REQ_FAIL: {
                struct efc_nport *nport = node->nport;
                /*
                 * with these errors, we have no recovery,
                 * so shutdown the nport, leave the link
                 * up and the domain ready
                 */
                if (efc_node_check_els_req(ctx, evt, arg, ELS_FLOGI,
                                           __efc_fabric_common, __func__)) {
                        return;
                }
                node_printf(node,
                            "FLOGI failed evt=%s, shutting down nport [%s]\n",
                            efc_sm_event_name(evt), nport->display_name);
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                efc_sm_post_event(&nport->sm, EFC_EVT_SHUTDOWN, NULL);
                break;
        }

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_vport_fabric_init(struct efc_sm_ctx *ctx,
                        enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                /* sm: / send FDISC */
                efc_send_fdisc(node);
                efc_node_transition(node, __efc_fabric_fdisc_wait_rsp, NULL);
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_fabric_fdisc_wait_rsp(struct efc_sm_ctx *ctx,
                            enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_SRRS_ELS_REQ_OK: {
                /* fc_id is in ext_status */
                if (efc_node_check_els_req(ctx, evt, arg, ELS_FDISC,
                                           __efc_fabric_common, __func__)) {
                        return;
                }

                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                /* sm: / efc_nport_attach */
                efc_nport_attach(node->nport, cbdata->ext_status);
                efc_node_transition(node, __efc_fabric_wait_domain_attach,
                                    NULL);
                break;
        }

        case EFC_EVT_SRRS_ELS_REQ_RJT:
        case EFC_EVT_SRRS_ELS_REQ_FAIL: {
                if (efc_node_check_els_req(ctx, evt, arg, ELS_FDISC,
                                           __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                efc_log_err(node->efc, "FDISC failed, shutting down nport\n");
                /* sm: / shutdown nport */
                efc_sm_post_event(&node->nport->sm, EFC_EVT_SHUTDOWN, NULL);
                break;
        }

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

static int
efc_start_ns_node(struct efc_nport *nport)
{
        struct efc_node *ns;

        /* Instantiate a name services node */
        ns = efc_node_find(nport, FC_FID_DIR_SERV);
        if (!ns) {
                ns = efc_node_alloc(nport, FC_FID_DIR_SERV, false, false);
                if (!ns)
                        return -EIO;
        }
        /*
         * for found ns, should we be transitioning from here?
         * breaks transition only
         *  1. from within state machine or
         *  2. if after alloc
         */
        if (ns->efc->nodedb_mask & EFC_NODEDB_PAUSE_NAMESERVER)
                efc_node_pause(ns, __efc_ns_init);
        else
                efc_node_transition(ns, __efc_ns_init, NULL);
        return 0;
}

static int
efc_start_fabctl_node(struct efc_nport *nport)
{
        struct efc_node *fabctl;

        fabctl = efc_node_find(nport, FC_FID_FCTRL);
        if (!fabctl) {
                fabctl = efc_node_alloc(nport, FC_FID_FCTRL,
                                        false, false);
                if (!fabctl)
                        return -EIO;
        }
        /*
         * for found ns, should we be transitioning from here?
         * breaks transition only
         *  1. from within state machine or
         *  2. if after alloc
         */
        efc_node_transition(fabctl, __efc_fabctl_init, NULL);
        return 0;
}

void
__efc_fabric_wait_domain_attach(struct efc_sm_ctx *ctx,
                                enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                efc_node_hold_frames(node);
                break;

        case EFC_EVT_EXIT:
                efc_node_accept_frames(node);
                break;
        case EFC_EVT_DOMAIN_ATTACH_OK:
        case EFC_EVT_NPORT_ATTACH_OK: {
                int rc;

                rc = efc_start_ns_node(node->nport);
                if (rc)
                        return;

                /* sm: if enable_ini / start fabctl node */
                /* Instantiate the fabric controller (sends SCR) */
                if (node->nport->enable_rscn) {
                        rc = efc_start_fabctl_node(node->nport);
                        if (rc)
                                return;
                }
                efc_node_transition(node, __efc_fabric_idle, NULL);
                break;
        }
        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_fabric_idle(struct efc_sm_ctx *ctx, enum efc_sm_event evt,
                  void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_DOMAIN_ATTACH_OK:
                break;
        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_ns_init(struct efc_sm_ctx *ctx, enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                /* sm: / send PLOGI */
                efc_send_plogi(node);
                efc_node_transition(node, __efc_ns_plogi_wait_rsp, NULL);
                break;
        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_ns_plogi_wait_rsp(struct efc_sm_ctx *ctx,
                        enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_SRRS_ELS_REQ_OK: {
                int rc;

                /* Save service parameters */
                if (efc_node_check_els_req(ctx, evt, arg, ELS_PLOGI,
                                           __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                /* sm: / save sparams, efc_node_attach */
                efc_node_save_sparms(node, cbdata->els_rsp.virt);
                rc = efc_node_attach(node);
                efc_node_transition(node, __efc_ns_wait_node_attach, NULL);
                if (rc < 0)
                        efc_node_post_event(node, EFC_EVT_NODE_ATTACH_FAIL,
                                            NULL);
                break;
        }
        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_ns_wait_node_attach(struct efc_sm_ctx *ctx,
                          enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                efc_node_hold_frames(node);
                break;

        case EFC_EVT_EXIT:
                efc_node_accept_frames(node);
                break;

        case EFC_EVT_NODE_ATTACH_OK:
                node->attached = true;
                /* sm: / send RFTID */
                efc_ns_send_rftid(node);
                efc_node_transition(node, __efc_ns_rftid_wait_rsp, NULL);
                break;

        case EFC_EVT_NODE_ATTACH_FAIL:
                /* node attach failed, shutdown the node */
                node->attached = false;
                node_printf(node, "Node attach failed\n");
                node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                efc_fabric_initiate_shutdown(node);
                break;

        case EFC_EVT_SHUTDOWN:
                node_printf(node, "Shutdown event received\n");
                node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                efc_node_transition(node,
                                    __efc_fabric_wait_attach_evt_shutdown,
                                     NULL);
                break;

        /*
         * if receive RSCN just ignore,
         * we haven't sent GID_PT yet (ACC sent by fabctl node)
         */
        case EFC_EVT_RSCN_RCVD:
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_fabric_wait_attach_evt_shutdown(struct efc_sm_ctx *ctx,
                                      enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                efc_node_hold_frames(node);
                break;

        case EFC_EVT_EXIT:
                efc_node_accept_frames(node);
                break;

        /* wait for any of these attach events and then shutdown */
        case EFC_EVT_NODE_ATTACH_OK:
                node->attached = true;
                node_printf(node, "Attach evt=%s, proceed to shutdown\n",
                            efc_sm_event_name(evt));
                efc_fabric_initiate_shutdown(node);
                break;

        case EFC_EVT_NODE_ATTACH_FAIL:
                node->attached = false;
                node_printf(node, "Attach evt=%s, proceed to shutdown\n",
                            efc_sm_event_name(evt));
                efc_fabric_initiate_shutdown(node);
                break;

        /* ignore shutdown event as we're already in shutdown path */
        case EFC_EVT_SHUTDOWN:
                node_printf(node, "Shutdown event received\n");
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_ns_rftid_wait_rsp(struct efc_sm_ctx *ctx,
                        enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_SRRS_ELS_REQ_OK:
                if (efc_node_check_ns_req(ctx, evt, arg, FC_NS_RFT_ID,
                                          __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                /* sm: / send RFFID */
                efc_ns_send_rffid(node);
                efc_node_transition(node, __efc_ns_rffid_wait_rsp, NULL);
                break;

        /*
         * if receive RSCN just ignore,
         * we haven't sent GID_PT yet (ACC sent by fabctl node)
         */
        case EFC_EVT_RSCN_RCVD:
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_ns_rffid_wait_rsp(struct efc_sm_ctx *ctx,
                        enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        /*
         * Waits for an RFFID response event;
         * if rscn enabled, a GIDPT name services request is issued.
         */
        switch (evt) {
        case EFC_EVT_SRRS_ELS_REQ_OK:   {
                if (efc_node_check_ns_req(ctx, evt, arg, FC_NS_RFF_ID,
                                          __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                if (node->nport->enable_rscn) {
                        /* sm: if enable_rscn / send GIDPT */
                        efc_ns_send_gidpt(node);

                        efc_node_transition(node, __efc_ns_gidpt_wait_rsp,
                                            NULL);
                } else {
                        /* if 'T' only, we're done, go to idle */
                        efc_node_transition(node, __efc_ns_idle, NULL);
                }
                break;
        }
        /*
         * if receive RSCN just ignore,
         * we haven't sent GID_PT yet (ACC sent by fabctl node)
         */
        case EFC_EVT_RSCN_RCVD:
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

static int
efc_process_gidpt_payload(struct efc_node *node,
                          void *data, u32 gidpt_len)
{
        u32 i, j;
        struct efc_node *newnode;
        struct efc_nport *nport = node->nport;
        struct efc *efc = node->efc;
        u32 port_id = 0, port_count, plist_count;
        struct efc_node *n;
        struct efc_node **active_nodes;
        int residual;
        struct {
                struct fc_ct_hdr hdr;
                struct fc_gid_pn_resp pn_rsp;
        } *rsp;
        struct fc_gid_pn_resp *gidpt;
        unsigned long index;

        rsp = data;
        gidpt = &rsp->pn_rsp;
        residual = be16_to_cpu(rsp->hdr.ct_mr_size);

        if (residual != 0)
                efc_log_debug(node->efc, "residual is %u words\n", residual);

        if (be16_to_cpu(rsp->hdr.ct_cmd) == FC_FS_RJT) {
                node_printf(node,
                            "GIDPT request failed: rsn x%x rsn_expl x%x\n",
                            rsp->hdr.ct_reason, rsp->hdr.ct_explan);
                return -EIO;
        }

        plist_count = (gidpt_len - sizeof(struct fc_ct_hdr)) / sizeof(*gidpt);

        /* Count the number of nodes */
        port_count = 0;
        xa_for_each(&nport->lookup, index, n) {
                port_count++;
        }

        /* Allocate a buffer for all nodes */
        active_nodes = kzalloc(port_count * sizeof(*active_nodes), GFP_ATOMIC);
        if (!active_nodes) {
                node_printf(node, "efc_malloc failed\n");
                return -EIO;
        }

        /* Fill buffer with fc_id of active nodes */
        i = 0;
        xa_for_each(&nport->lookup, index, n) {
                port_id = n->rnode.fc_id;
                switch (port_id) {
                case FC_FID_FLOGI:
                case FC_FID_FCTRL:
                case FC_FID_DIR_SERV:
                        break;
                default:
                        if (port_id != FC_FID_DOM_MGR)
                                active_nodes[i++] = n;
                        break;
                }
        }

        /* update the active nodes buffer */
        for (i = 0; i < plist_count; i++) {
                hton24(gidpt[i].fp_fid, port_id);

                for (j = 0; j < port_count; j++) {
                        if (active_nodes[j] &&
                            port_id == active_nodes[j]->rnode.fc_id) {
                                active_nodes[j] = NULL;
                        }
                }

                if (gidpt[i].fp_resvd & FC_NS_FID_LAST)
                        break;
        }

        /* Those remaining in the active_nodes[] are now gone ! */
        for (i = 0; i < port_count; i++) {
                /*
                 * if we're an initiator and the remote node
                 * is a target, then post the node missing event.
                 * if we're target and we have enabled
                 * target RSCN, then post the node missing event.
                 */
                if (!active_nodes[i])
                        continue;

                if ((node->nport->enable_ini && active_nodes[i]->targ) ||
                    (node->nport->enable_tgt && enable_target_rscn(efc))) {
                        efc_node_post_event(active_nodes[i],
                                            EFC_EVT_NODE_MISSING, NULL);
                } else {
                        node_printf(node,
                                    "GID_PT: skipping non-tgt port_id x%06x\n",
                                    active_nodes[i]->rnode.fc_id);
                }
        }
        kfree(active_nodes);

        for (i = 0; i < plist_count; i++) {
                hton24(gidpt[i].fp_fid, port_id);

                /* Don't create node for ourselves */
                if (port_id == node->rnode.nport->fc_id) {
                        if (gidpt[i].fp_resvd & FC_NS_FID_LAST)
                                break;
                        continue;
                }

                newnode = efc_node_find(nport, port_id);
                if (!newnode) {
                        if (!node->nport->enable_ini)
                                continue;

                        newnode = efc_node_alloc(nport, port_id, false, false);
                        if (!newnode) {
                                efc_log_err(efc, "efc_node_alloc() failed\n");
                                return -EIO;
                        }
                        /*
                         * send PLOGI automatically
                         * if initiator
                         */
                        efc_node_init_device(newnode, true);
                }

                if (node->nport->enable_ini && newnode->targ) {
                        efc_node_post_event(newnode, EFC_EVT_NODE_REFOUND,
                                            NULL);
                }

                if (gidpt[i].fp_resvd & FC_NS_FID_LAST)
                        break;
        }
        return 0;
}

void
__efc_ns_gidpt_wait_rsp(struct efc_sm_ctx *ctx,
                        enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();
        /*
         * Wait for a GIDPT response from the name server. Process the FC_IDs
         * that are reported by creating new remote ports, as needed.
         */

        switch (evt) {
        case EFC_EVT_SRRS_ELS_REQ_OK:   {
                if (efc_node_check_ns_req(ctx, evt, arg, FC_NS_GID_PT,
                                          __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                /* sm: / process GIDPT payload */
                efc_process_gidpt_payload(node, cbdata->els_rsp.virt,
                                          cbdata->els_rsp.len);
                efc_node_transition(node, __efc_ns_idle, NULL);
                break;
        }

        case EFC_EVT_SRRS_ELS_REQ_FAIL: {
                /* not much we can do; will retry with the next RSCN */
                node_printf(node, "GID_PT failed to complete\n");
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                efc_node_transition(node, __efc_ns_idle, NULL);
                break;
        }

        /* if receive RSCN here, queue up another discovery processing */
        case EFC_EVT_RSCN_RCVD: {
                node_printf(node, "RSCN received during GID_PT processing\n");
                node->rscn_pending = true;
                break;
        }

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_ns_idle(struct efc_sm_ctx *ctx, enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;
        struct efc *efc = node->efc;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        /*
         * Wait for RSCN received events (posted from the fabric controller)
         * and restart the GIDPT name services query and processing.
         */

        switch (evt) {
        case EFC_EVT_ENTER:
                if (!node->rscn_pending)
                        break;

                node_printf(node, "RSCN pending, restart discovery\n");
                node->rscn_pending = false;
                fallthrough;

        case EFC_EVT_RSCN_RCVD: {
                /* sm: / send GIDPT */
                /*
                 * If target RSCN processing is enabled,
                 * and this is target only (not initiator),
                 * and tgt_rscn_delay is non-zero,
                 * then we delay issuing the GID_PT
                 */
                if (efc->tgt_rscn_delay_msec != 0 &&
                    !node->nport->enable_ini && node->nport->enable_tgt &&
                    enable_target_rscn(efc)) {
                        efc_node_transition(node, __efc_ns_gidpt_delay, NULL);
                } else {
                        efc_ns_send_gidpt(node);
                        efc_node_transition(node, __efc_ns_gidpt_wait_rsp,
                                            NULL);
                }
                break;
        }

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

static void
gidpt_delay_timer_cb(struct timer_list *t)
{
        struct efc_node *node = from_timer(node, t, gidpt_delay_timer);

        del_timer(&node->gidpt_delay_timer);

        efc_node_post_event(node, EFC_EVT_GIDPT_DELAY_EXPIRED, NULL);
}

void
__efc_ns_gidpt_delay(struct efc_sm_ctx *ctx,
                     enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;
        struct efc *efc = node->efc;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER: {
                u64 delay_msec, tmp;

                /*
                 * Compute the delay time.
                 * Set to tgt_rscn_delay, if the time since last GIDPT
                 * is less than tgt_rscn_period, then use tgt_rscn_period.
                 */
                delay_msec = efc->tgt_rscn_delay_msec;
                tmp = jiffies_to_msecs(jiffies) - node->time_last_gidpt_msec;
                if (tmp < efc->tgt_rscn_period_msec)
                        delay_msec = efc->tgt_rscn_period_msec;

                timer_setup(&node->gidpt_delay_timer, &gidpt_delay_timer_cb,
                            0);
                mod_timer(&node->gidpt_delay_timer,
                          jiffies + msecs_to_jiffies(delay_msec));

                break;
        }

        case EFC_EVT_GIDPT_DELAY_EXPIRED:
                node->time_last_gidpt_msec = jiffies_to_msecs(jiffies);

                efc_ns_send_gidpt(node);
                efc_node_transition(node, __efc_ns_gidpt_wait_rsp, NULL);
                break;

        case EFC_EVT_RSCN_RCVD: {
                efc_log_debug(efc,
                              "RSCN received while in GIDPT delay - no action\n");
                break;
        }

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_fabctl_init(struct efc_sm_ctx *ctx,
                  enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                /* no need to login to fabric controller, just send SCR */
                efc_send_scr(node);
                efc_node_transition(node, __efc_fabctl_wait_scr_rsp, NULL);
                break;

        case EFC_EVT_NODE_ATTACH_OK:
                node->attached = true;
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_fabctl_wait_scr_rsp(struct efc_sm_ctx *ctx,
                          enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        /*
         * Fabric controller node state machine:
         * Wait for an SCR response from the fabric controller.
         */
        switch (evt) {
        case EFC_EVT_SRRS_ELS_REQ_OK:
                if (efc_node_check_els_req(ctx, evt, arg, ELS_SCR,
                                           __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                efc_node_transition(node, __efc_fabctl_ready, NULL);
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

static void
efc_process_rscn(struct efc_node *node, struct efc_node_cb *cbdata)
{
        struct efc *efc = node->efc;
        struct efc_nport *nport = node->nport;
        struct efc_node *ns;

        /* Forward this event to the name-services node */
        ns = efc_node_find(nport, FC_FID_DIR_SERV);
        if (ns)
                efc_node_post_event(ns, EFC_EVT_RSCN_RCVD, cbdata);
        else
                efc_log_warn(efc, "can't find name server node\n");
}

void
__efc_fabctl_ready(struct efc_sm_ctx *ctx,
                   enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        /*
         * Fabric controller node state machine: Ready.
         * In this state, the fabric controller sends a RSCN, which is received
         * by this node and is forwarded to the name services node object; and
         * the RSCN LS_ACC is sent.
         */
        switch (evt) {
        case EFC_EVT_RSCN_RCVD: {
                struct fc_frame_header *hdr = cbdata->header->dma.virt;

                /*
                 * sm: / process RSCN (forward to name services node),
                 * send LS_ACC
                 */
                efc_process_rscn(node, cbdata);
                efc_send_ls_acc(node, be16_to_cpu(hdr->fh_ox_id));
                efc_node_transition(node, __efc_fabctl_wait_ls_acc_cmpl,
                                    NULL);
                break;
        }

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_fabctl_wait_ls_acc_cmpl(struct efc_sm_ctx *ctx,
                              enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                efc_node_hold_frames(node);
                break;

        case EFC_EVT_EXIT:
                efc_node_accept_frames(node);
                break;

        case EFC_EVT_SRRS_ELS_CMPL_OK:
                WARN_ON(!node->els_cmpl_cnt);
                node->els_cmpl_cnt--;
                efc_node_transition(node, __efc_fabctl_ready, NULL);
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

static uint64_t
efc_get_wwpn(struct fc_els_flogi *sp)
{
        return be64_to_cpu(sp->fl_wwnn);
}

static int
efc_rnode_is_winner(struct efc_nport *nport)
{
        struct fc_els_flogi *remote_sp;
        u64 remote_wwpn;
        u64 local_wwpn = nport->wwpn;
        u64 wwn_bump = 0;

        remote_sp = (struct fc_els_flogi *)nport->domain->flogi_service_params;
        remote_wwpn = efc_get_wwpn(remote_sp);

        local_wwpn ^= wwn_bump;

        efc_log_debug(nport->efc, "r: %llx\n",
                      be64_to_cpu(remote_sp->fl_wwpn));
        efc_log_debug(nport->efc, "l: %llx\n", local_wwpn);

        if (remote_wwpn == local_wwpn) {
                efc_log_warn(nport->efc,
                             "WWPN of remote node [%08x %08x] matches local WWPN\n",
                             (u32)(local_wwpn >> 32ll),
                             (u32)local_wwpn);
                return -1;
        }

        return (remote_wwpn > local_wwpn);
}

void
__efc_p2p_wait_domain_attach(struct efc_sm_ctx *ctx,
                             enum efc_sm_event evt, void *arg)
{
        struct efc_node *node = ctx->app;
        struct efc *efc = node->efc;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                efc_node_hold_frames(node);
                break;

        case EFC_EVT_EXIT:
                efc_node_accept_frames(node);
                break;

        case EFC_EVT_DOMAIN_ATTACH_OK: {
                struct efc_nport *nport = node->nport;
                struct efc_node *rnode;

                /*
                 * this transient node (SID=0 (recv'd FLOGI)
                 * or DID=fabric (sent FLOGI))
                 * is the p2p winner, will use a separate node
                 * to send PLOGI to peer
                 */
                WARN_ON(!node->nport->p2p_winner);

                rnode = efc_node_find(nport, node->nport->p2p_remote_port_id);
                if (rnode) {
                        /*
                         * the "other" transient p2p node has
                         * already kicked off the
                         * new node from which PLOGI is sent
                         */
                        node_printf(node,
                                    "Node with fc_id x%x already exists\n",
                                    rnode->rnode.fc_id);
                } else {
                        /*
                         * create new node (SID=1, DID=2)
                         * from which to send PLOGI
                         */
                        rnode = efc_node_alloc(nport,
                                               nport->p2p_remote_port_id,
                                                false, false);
                        if (!rnode) {
                                efc_log_err(efc, "node alloc failed\n");
                                return;
                        }

                        efc_fabric_notify_topology(node);
                        /* sm: / allocate p2p remote node */
                        efc_node_transition(rnode, __efc_p2p_rnode_init,
                                            NULL);
                }

                /*
                 * the transient node (SID=0 or DID=fabric)
                 * has served its purpose
                 */
                if (node->rnode.fc_id == 0) {
                        /*
                         * if this is the SID=0 node,
                         * move to the init state in case peer
                         * has restarted FLOGI discovery and FLOGI is pending
                         */
                        /* don't send PLOGI on efc_d_init entry */
                        efc_node_init_device(node, false);
                } else {
                        /*
                         * if this is the DID=fabric node
                         * (we initiated FLOGI), shut it down
                         */
                        node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                        efc_fabric_initiate_shutdown(node);
                }
                break;
        }

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_p2p_rnode_init(struct efc_sm_ctx *ctx,
                     enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                /* sm: / send PLOGI */
                efc_send_plogi(node);
                efc_node_transition(node, __efc_p2p_wait_plogi_rsp, NULL);
                break;

        case EFC_EVT_ABTS_RCVD:
                /* sm: send BA_ACC */
                efc_send_bls_acc(node, cbdata->header->dma.virt);

                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_p2p_wait_flogi_acc_cmpl(struct efc_sm_ctx *ctx,
                              enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                efc_node_hold_frames(node);
                break;

        case EFC_EVT_EXIT:
                efc_node_accept_frames(node);
                break;

        case EFC_EVT_SRRS_ELS_CMPL_OK:
                WARN_ON(!node->els_cmpl_cnt);
                node->els_cmpl_cnt--;

                /* sm: if p2p_winner / domain_attach */
                if (node->nport->p2p_winner) {
                        efc_node_transition(node,
                                            __efc_p2p_wait_domain_attach,
                                        NULL);
                        if (!node->nport->domain->attached) {
                                node_printf(node, "Domain not attached\n");
                                efc_domain_attach(node->nport->domain,
                                                  node->nport->p2p_port_id);
                        } else {
                                node_printf(node, "Domain already attached\n");
                                efc_node_post_event(node,
                                                    EFC_EVT_DOMAIN_ATTACH_OK,
                                                    NULL);
                        }
                } else {
                        /* this node has served its purpose;
                         * we'll expect a PLOGI on a separate
                         * node (remote SID=0x1); return this node
                         * to init state in case peer
                         * restarts discovery -- it may already
                         * have (pending frames may exist).
                         */
                        /* don't send PLOGI on efc_d_init entry */
                        efc_node_init_device(node, false);
                }
                break;

        case EFC_EVT_SRRS_ELS_CMPL_FAIL:
                /*
                 * LS_ACC failed, possibly due to link down;
                 * shutdown node and wait
                 * for FLOGI discovery to restart
                 */
                node_printf(node, "FLOGI LS_ACC failed, shutting down\n");
                WARN_ON(!node->els_cmpl_cnt);
                node->els_cmpl_cnt--;
                node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                efc_fabric_initiate_shutdown(node);
                break;

        case EFC_EVT_ABTS_RCVD: {
                /* sm: / send BA_ACC */
                efc_send_bls_acc(node, cbdata->header->dma.virt);
                break;
        }

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_p2p_wait_plogi_rsp(struct efc_sm_ctx *ctx,
                         enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_SRRS_ELS_REQ_OK: {
                int rc;

                if (efc_node_check_els_req(ctx, evt, arg, ELS_PLOGI,
                                           __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                /* sm: / save sparams, efc_node_attach */
                efc_node_save_sparms(node, cbdata->els_rsp.virt);
                rc = efc_node_attach(node);
                efc_node_transition(node, __efc_p2p_wait_node_attach, NULL);
                if (rc < 0)
                        efc_node_post_event(node, EFC_EVT_NODE_ATTACH_FAIL,
                                            NULL);
                break;
        }
        case EFC_EVT_SRRS_ELS_REQ_FAIL: {
                if (efc_node_check_els_req(ctx, evt, arg, ELS_PLOGI,
                                           __efc_fabric_common, __func__)) {
                        return;
                }
                node_printf(node, "PLOGI failed, shutting down\n");
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                efc_fabric_initiate_shutdown(node);
                break;
        }

        case EFC_EVT_PLOGI_RCVD: {
                struct fc_frame_header *hdr = cbdata->header->dma.virt;
                /* if we're in external loopback mode, just send LS_ACC */
                if (node->efc->external_loopback) {
                        efc_send_plogi_acc(node, be16_to_cpu(hdr->fh_ox_id));
                } else {
                        /*
                         * if this isn't external loopback,
                         * pass to default handler
                         */
                        __efc_fabric_common(__func__, ctx, evt, arg);
                }
                break;
        }
        case EFC_EVT_PRLI_RCVD:
                /* I, or I+T */
                /* sent PLOGI and before completion was seen, received the
                 * PRLI from the remote node (WCQEs and RCQEs come in on
                 * different queues and order of processing cannot be assumed)
                 * Save OXID so PRLI can be sent after the attach and continue
                 * to wait for PLOGI response
                 */
                efc_process_prli_payload(node, cbdata->payload->dma.virt);
                efc_send_ls_acc_after_attach(node,
                                             cbdata->header->dma.virt,
                                             EFC_NODE_SEND_LS_ACC_PRLI);
                efc_node_transition(node, __efc_p2p_wait_plogi_rsp_recvd_prli,
                                    NULL);
                break;
        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_p2p_wait_plogi_rsp_recvd_prli(struct efc_sm_ctx *ctx,
                                    enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                /*
                 * Since we've received a PRLI, we have a port login and will
                 * just need to wait for the PLOGI response to do the node
                 * attach and then we can send the LS_ACC for the PRLI. If,
                 * during this time, we receive FCP_CMNDs (which is possible
                 * since we've already sent a PRLI and our peer may have
                 * accepted).
                 * At this time, we are not waiting on any other unsolicited
                 * frames to continue with the login process. Thus, it will not
                 * hurt to hold frames here.
                 */
                efc_node_hold_frames(node);
                break;

        case EFC_EVT_EXIT:
                efc_node_accept_frames(node);
                break;

        case EFC_EVT_SRRS_ELS_REQ_OK: { /* PLOGI response received */
                int rc;

                /* Completion from PLOGI sent */
                if (efc_node_check_els_req(ctx, evt, arg, ELS_PLOGI,
                                           __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                /* sm: / save sparams, efc_node_attach */
                efc_node_save_sparms(node, cbdata->els_rsp.virt);
                rc = efc_node_attach(node);
                efc_node_transition(node, __efc_p2p_wait_node_attach, NULL);
                if (rc < 0)
                        efc_node_post_event(node, EFC_EVT_NODE_ATTACH_FAIL,
                                            NULL);
                break;
        }
        case EFC_EVT_SRRS_ELS_REQ_FAIL: /* PLOGI response received */
        case EFC_EVT_SRRS_ELS_REQ_RJT:
                /* PLOGI failed, shutdown the node */
                if (efc_node_check_els_req(ctx, evt, arg, ELS_PLOGI,
                                           __efc_fabric_common, __func__)) {
                        return;
                }
                WARN_ON(!node->els_req_cnt);
                node->els_req_cnt--;
                node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                efc_fabric_initiate_shutdown(node);
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

void
__efc_p2p_wait_node_attach(struct efc_sm_ctx *ctx,
                           enum efc_sm_event evt, void *arg)
{
        struct efc_node_cb *cbdata = arg;
        struct efc_node *node = ctx->app;

        efc_node_evt_set(ctx, evt, __func__);

        node_sm_trace();

        switch (evt) {
        case EFC_EVT_ENTER:
                efc_node_hold_frames(node);
                break;

        case EFC_EVT_EXIT:
                efc_node_accept_frames(node);
                break;

        case EFC_EVT_NODE_ATTACH_OK:
                node->attached = true;
                switch (node->send_ls_acc) {
                case EFC_NODE_SEND_LS_ACC_PRLI: {
                        efc_d_send_prli_rsp(node->ls_acc_io,
                                            node->ls_acc_oxid);
                        node->send_ls_acc = EFC_NODE_SEND_LS_ACC_NONE;
                        node->ls_acc_io = NULL;
                        break;
                }
                case EFC_NODE_SEND_LS_ACC_PLOGI: /* Can't happen in P2P */
                case EFC_NODE_SEND_LS_ACC_NONE:
                default:
                        /* Normal case for I */
                        /* sm: send_plogi_acc is not set / send PLOGI acc */
                        efc_node_transition(node, __efc_d_port_logged_in,
                                            NULL);
                        break;
                }
                break;

        case EFC_EVT_NODE_ATTACH_FAIL:
                /* node attach failed, shutdown the node */
                node->attached = false;
                node_printf(node, "Node attach failed\n");
                node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                efc_fabric_initiate_shutdown(node);
                break;

        case EFC_EVT_SHUTDOWN:
                node_printf(node, "%s received\n", efc_sm_event_name(evt));
                node->shutdown_reason = EFC_NODE_SHUTDOWN_DEFAULT;
                efc_node_transition(node,
                                    __efc_fabric_wait_attach_evt_shutdown,
                                     NULL);
                break;
        case EFC_EVT_PRLI_RCVD:
                node_printf(node, "%s: PRLI received before node is attached\n",
                            efc_sm_event_name(evt));
                efc_process_prli_payload(node, cbdata->payload->dma.virt);
                efc_send_ls_acc_after_attach(node,
                                             cbdata->header->dma.virt,
                                EFC_NODE_SEND_LS_ACC_PRLI);
                break;

        default:
                __efc_fabric_common(__func__, ctx, evt, arg);
        }
}

int
efc_p2p_setup(struct efc_nport *nport)
{
        struct efc *efc = nport->efc;
        int rnode_winner;

        rnode_winner = efc_rnode_is_winner(nport);

        /* set nport flags to indicate p2p "winner" */
        if (rnode_winner == 1) {
                nport->p2p_remote_port_id = 0;
                nport->p2p_port_id = 0;
                nport->p2p_winner = false;
        } else if (rnode_winner == 0) {
                nport->p2p_remote_port_id = 2;
                nport->p2p_port_id = 1;
                nport->p2p_winner = true;
        } else {
                /* no winner; only okay if external loopback enabled */
                if (nport->efc->external_loopback) {
                        /*
                         * External loopback mode enabled;
                         * local nport and remote node
                         * will be registered with an NPortID = 1;
                         */
                        efc_log_debug(efc,
                                      "External loopback mode enabled\n");
                        nport->p2p_remote_port_id = 1;
                        nport->p2p_port_id = 1;
                        nport->p2p_winner = true;
                } else {
                        efc_log_warn(efc,
                                     "failed to determine p2p winner\n");
                        return rnode_winner;
                }
        }
        return 0;
}