fc_rport.c

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/*
 * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Maintained at www.Open-FCoE.org
 */

/*
 * RPORT GENERAL INFO
 *
 * This file contains all processing regarding fc_rports. It contains the
 * rport state machine and does all rport interaction with the transport class.
 * There should be no other places in libfc that interact directly with the
 * transport class in regards to adding and deleting rports.
 *
 * fc_rport's represent N_Port's within the fabric.
 */

/*
 * RPORT LOCKING
 *
 * The rport should never hold the rport mutex and then attempt to acquire
 * either the lport or disc mutexes. The rport's mutex is considered lesser
 * than both the lport's mutex and the disc mutex. Refer to fc_lport.c for
 * more comments on the hierarchy.
 *
 * The locking strategy is similar to the lport's strategy. The lock protects
 * the rport's states and is held and released by the entry points to the rport
 * block. All _enter_* functions correspond to rport states and expect the rport
 * mutex to be locked before calling them. This means that rports only handle
 * one request or response at a time, since they're not critical for the I/O
 * path this potential over-use of the mutex is acceptable.
 */

#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/export.h>
#include <asm/unaligned.h>

#include <scsi/libfc.h>
#include <scsi/fc_encode.h>

#include "fc_libfc.h"

static struct workqueue_struct *rport_event_queue;

static void fc_rport_enter_flogi(struct fc_rport_priv *);
static void fc_rport_enter_plogi(struct fc_rport_priv *);
static void fc_rport_enter_prli(struct fc_rport_priv *);
static void fc_rport_enter_rtv(struct fc_rport_priv *);
static void fc_rport_enter_ready(struct fc_rport_priv *);
static void fc_rport_enter_logo(struct fc_rport_priv *);
static void fc_rport_enter_adisc(struct fc_rport_priv *);

static void fc_rport_recv_plogi_req(struct fc_lport *, struct fc_frame *);
static void fc_rport_recv_prli_req(struct fc_rport_priv *, struct fc_frame *);
static void fc_rport_recv_prlo_req(struct fc_rport_priv *, struct fc_frame *);
static void fc_rport_recv_logo_req(struct fc_lport *, struct fc_frame *);
static void fc_rport_timeout(struct work_struct *);
static void fc_rport_error(struct fc_rport_priv *, struct fc_frame *);
static void fc_rport_error_retry(struct fc_rport_priv *, struct fc_frame *);
static void fc_rport_work(struct work_struct *);

static const char *fc_rport_state_names[] = {
    [RPORT_ST_INIT] = "Init",
    [RPORT_ST_FLOGI] = "FLOGI",
    [RPORT_ST_PLOGI_WAIT] = "PLOGI_WAIT",
    [RPORT_ST_PLOGI] = "PLOGI",
    [RPORT_ST_PRLI] = "PRLI",
    [RPORT_ST_RTV] = "RTV",
    [RPORT_ST_READY] = "Ready",
    [RPORT_ST_ADISC] = "ADISC",
    [RPORT_ST_DELETE] = "Delete",
};

static struct fc_rport_priv *fc_rport_lookup(const struct fc_lport *lport,
                         u32 port_id)
{
    struct fc_rport_priv *rdata;

    list_for_each_entry_rcu(rdata, &lport->disc.rports, peers)
        if (rdata->ids.port_id == port_id)
            return rdata;
    return NULL;
}

static struct fc_rport_priv *fc_rport_create(struct fc_lport *lport,
                         u32 port_id)
{
    struct fc_rport_priv *rdata;

    rdata = lport->tt.rport_lookup(lport, port_id);
    if (rdata)
        return rdata;

    rdata = kzalloc(sizeof(*rdata) + lport->rport_priv_size, GFP_KERNEL);
    if (!rdata)
        return NULL;

    rdata->ids.node_name = -1;
    rdata->ids.port_name = -1;
    rdata->ids.port_id = port_id;
    rdata->ids.roles = FC_RPORT_ROLE_UNKNOWN;

    kref_init(&rdata->kref);
    mutex_init(&rdata->rp_mutex);
    rdata->local_port = lport;
    rdata->rp_state = RPORT_ST_INIT;
    rdata->event = RPORT_EV_NONE;
    rdata->flags = FC_RP_FLAGS_REC_SUPPORTED;
    rdata->e_d_tov = lport->e_d_tov;
    rdata->r_a_tov = lport->r_a_tov;
    rdata->maxframe_size = FC_MIN_MAX_PAYLOAD;
    INIT_DELAYED_WORK(&rdata->retry_work, fc_rport_timeout);
    INIT_WORK(&rdata->event_work, fc_rport_work);
    if (port_id != FC_FID_DIR_SERV) {
        rdata->lld_event_callback = lport->tt.rport_event_callback;
        list_add_rcu(&rdata->peers, &lport->disc.rports);
    }
    return rdata;
}

static void fc_rport_destroy(struct kref *kref)
{
    struct fc_rport_priv *rdata;

    rdata = container_of(kref, struct fc_rport_priv, kref);
    kfree_rcu(rdata, rcu);
}

static const char *fc_rport_state(struct fc_rport_priv *rdata)
{
    const char *cp;

    cp = fc_rport_state_names[rdata->rp_state];
    if (!cp)
        cp = "Unknown";
    return cp;
}

void fc_set_rport_loss_tmo(struct fc_rport *rport, u32 timeout)
{
    if (timeout)
        rport->dev_loss_tmo = timeout;
    else
        rport->dev_loss_tmo = 1;
}
EXPORT_SYMBOL(fc_set_rport_loss_tmo);

static unsigned int fc_plogi_get_maxframe(struct fc_els_flogi *flp,
                      unsigned int maxval)
{
    unsigned int mfs;

    /*
     * Get max payload from the common service parameters and the
     * class 3 receive data field size.
     */
    mfs = ntohs(flp->fl_csp.sp_bb_data) & FC_SP_BB_DATA_MASK;
    if (mfs >= FC_SP_MIN_MAX_PAYLOAD && mfs < maxval)
        maxval = mfs;
    mfs = ntohs(flp->fl_cssp[3 - 1].cp_rdfs);
    if (mfs >= FC_SP_MIN_MAX_PAYLOAD && mfs < maxval)
        maxval = mfs;
    return maxval;
}

static void fc_rport_state_enter(struct fc_rport_priv *rdata,
                 enum fc_rport_state new)
{
    if (rdata->rp_state != new)
        rdata->retries = 0;
    rdata->rp_state = new;
}

static void fc_rport_work(struct work_struct *work)
{
    u32 port_id;
    struct fc_rport_priv *rdata =
        container_of(work, struct fc_rport_priv, event_work);
    struct fc_rport_libfc_priv *rpriv;
    enum fc_rport_event event;
    struct fc_lport *lport = rdata->local_port;
    struct fc_rport_operations *rport_ops;
    struct fc_rport_identifiers ids;
    struct fc_rport *rport;
    struct fc4_prov *prov;
    u8 type;

    mutex_lock(&rdata->rp_mutex);
    event = rdata->event;
    rport_ops = rdata->ops;
    rport = rdata->rport;

    FC_RPORT_DBG(rdata, "work event %u\n", event);

    switch (event) {
    case RPORT_EV_READY:
        ids = rdata->ids;
        rdata->event = RPORT_EV_NONE;
        rdata->major_retries = 0;
        kref_get(&rdata->kref);
        mutex_unlock(&rdata->rp_mutex);

        if (!rport)
            rport = fc_remote_port_add(lport->host, 0, &ids);
        if (!rport) {
            FC_RPORT_DBG(rdata, "Failed to add the rport\n");
            lport->tt.rport_logoff(rdata);
            kref_put(&rdata->kref, lport->tt.rport_destroy);
            return;
        }
        mutex_lock(&rdata->rp_mutex);
        if (rdata->rport)
            FC_RPORT_DBG(rdata, "rport already allocated\n");
        rdata->rport = rport;
        rport->maxframe_size = rdata->maxframe_size;
        rport->supported_classes = rdata->supported_classes;

        rpriv = rport->dd_data;
        rpriv->local_port = lport;
        rpriv->rp_state = rdata->rp_state;
        rpriv->flags = rdata->flags;
        rpriv->e_d_tov = rdata->e_d_tov;
        rpriv->r_a_tov = rdata->r_a_tov;
        mutex_unlock(&rdata->rp_mutex);

        if (rport_ops && rport_ops->event_callback) {
            FC_RPORT_DBG(rdata, "callback ev %d\n", event);
            rport_ops->event_callback(lport, rdata, event);
        }
        if (rdata->lld_event_callback) {
            FC_RPORT_DBG(rdata, "lld callback ev %d\n", event);
            rdata->lld_event_callback(lport, rdata, event);
        }
        kref_put(&rdata->kref, lport->tt.rport_destroy);
        break;

    case RPORT_EV_FAILED:
    case RPORT_EV_LOGO:
    case RPORT_EV_STOP:
        if (rdata->prli_count) {
            mutex_lock(&fc_prov_mutex);
            for (type = 1; type < FC_FC4_PROV_SIZE; type++) {
                prov = fc_passive_prov[type];
                if (prov && prov->prlo)
                    prov->prlo(rdata);
            }
            mutex_unlock(&fc_prov_mutex);
        }
        port_id = rdata->ids.port_id;
        mutex_unlock(&rdata->rp_mutex);

        if (rport_ops && rport_ops->event_callback) {
            FC_RPORT_DBG(rdata, "callback ev %d\n", event);
            rport_ops->event_callback(lport, rdata, event);
        }
        if (rdata->lld_event_callback) {
            FC_RPORT_DBG(rdata, "lld callback ev %d\n", event);
            rdata->lld_event_callback(lport, rdata, event);
        }
        cancel_delayed_work_sync(&rdata->retry_work);

        /*
         * Reset any outstanding exchanges before freeing rport.
         */
        lport->tt.exch_mgr_reset(lport, 0, port_id);
        lport->tt.exch_mgr_reset(lport, port_id, 0);

        if (rport) {
            rpriv = rport->dd_data;
            rpriv->rp_state = RPORT_ST_DELETE;
            mutex_lock(&rdata->rp_mutex);
            rdata->rport = NULL;
            mutex_unlock(&rdata->rp_mutex);
            fc_remote_port_delete(rport);
        }

        mutex_lock(&lport->disc.disc_mutex);
        mutex_lock(&rdata->rp_mutex);
        if (rdata->rp_state == RPORT_ST_DELETE) {
            if (port_id == FC_FID_DIR_SERV) {
                rdata->event = RPORT_EV_NONE;
                mutex_unlock(&rdata->rp_mutex);
                kref_put(&rdata->kref, lport->tt.rport_destroy);
            } else if ((rdata->flags & FC_RP_STARTED) &&
                   rdata->major_retries <
                   lport->max_rport_retry_count) {
                rdata->major_retries++;
                rdata->event = RPORT_EV_NONE;
                FC_RPORT_DBG(rdata, "work restart\n");
                fc_rport_enter_flogi(rdata);
                mutex_unlock(&rdata->rp_mutex);
            } else {
                FC_RPORT_DBG(rdata, "work delete\n");
                list_del_rcu(&rdata->peers);
                mutex_unlock(&rdata->rp_mutex);
                kref_put(&rdata->kref, lport->tt.rport_destroy);
            }
        } else {
            /*
             * Re-open for events.  Reissue READY event if ready.
             */
            rdata->event = RPORT_EV_NONE;
            if (rdata->rp_state == RPORT_ST_READY)
                fc_rport_enter_ready(rdata);
            mutex_unlock(&rdata->rp_mutex);
        }
        mutex_unlock(&lport->disc.disc_mutex);
        break;

    default:
        mutex_unlock(&rdata->rp_mutex);
        break;
    }
}

static int fc_rport_login(struct fc_rport_priv *rdata)
{
    mutex_lock(&rdata->rp_mutex);

    rdata->flags |= FC_RP_STARTED;
    switch (rdata->rp_state) {
    case RPORT_ST_READY:
        FC_RPORT_DBG(rdata, "ADISC port\n");
        fc_rport_enter_adisc(rdata);
        break;
    case RPORT_ST_DELETE:
        FC_RPORT_DBG(rdata, "Restart deleted port\n");
        break;
    default:
        FC_RPORT_DBG(rdata, "Login to port\n");
        fc_rport_enter_flogi(rdata);
        break;
    }
    mutex_unlock(&rdata->rp_mutex);

    return 0;
}

static void fc_rport_enter_delete(struct fc_rport_priv *rdata,
                  enum fc_rport_event event)
{
    if (rdata->rp_state == RPORT_ST_DELETE)
        return;

    FC_RPORT_DBG(rdata, "Delete port\n");

    fc_rport_state_enter(rdata, RPORT_ST_DELETE);

    if (rdata->event == RPORT_EV_NONE)
        queue_work(rport_event_queue, &rdata->event_work);
    rdata->event = event;
}

static int fc_rport_logoff(struct fc_rport_priv *rdata)
{
    mutex_lock(&rdata->rp_mutex);

    FC_RPORT_DBG(rdata, "Remove port\n");

    rdata->flags &= ~FC_RP_STARTED;
    if (rdata->rp_state == RPORT_ST_DELETE) {
        FC_RPORT_DBG(rdata, "Port in Delete state, not removing\n");
        goto out;
    }
    fc_rport_enter_logo(rdata);

    /*
     * Change the state to Delete so that we discard
     * the response.
     */
    fc_rport_enter_delete(rdata, RPORT_EV_STOP);
out:
    mutex_unlock(&rdata->rp_mutex);
    return 0;
}

static void fc_rport_enter_ready(struct fc_rport_priv *rdata)
{
    fc_rport_state_enter(rdata, RPORT_ST_READY);

    FC_RPORT_DBG(rdata, "Port is Ready\n");

    if (rdata->event == RPORT_EV_NONE)
        queue_work(rport_event_queue, &rdata->event_work);
    rdata->event = RPORT_EV_READY;
}

static void fc_rport_timeout(struct work_struct *work)
{
    struct fc_rport_priv *rdata =
        container_of(work, struct fc_rport_priv, retry_work.work);

    mutex_lock(&rdata->rp_mutex);

    switch (rdata->rp_state) {
    case RPORT_ST_FLOGI:
        fc_rport_enter_flogi(rdata);
        break;
    case RPORT_ST_PLOGI:
        fc_rport_enter_plogi(rdata);
        break;
    case RPORT_ST_PRLI:
        fc_rport_enter_prli(rdata);
        break;
    case RPORT_ST_RTV:
        fc_rport_enter_rtv(rdata);
        break;
    case RPORT_ST_ADISC:
        fc_rport_enter_adisc(rdata);
        break;
    case RPORT_ST_PLOGI_WAIT:
    case RPORT_ST_READY:
    case RPORT_ST_INIT:
    case RPORT_ST_DELETE:
        break;
    }

    mutex_unlock(&rdata->rp_mutex);
}

static void fc_rport_error(struct fc_rport_priv *rdata, struct fc_frame *fp)
{
    FC_RPORT_DBG(rdata, "Error %ld in state %s, retries %d\n",
             IS_ERR(fp) ? -PTR_ERR(fp) : 0,
             fc_rport_state(rdata), rdata->retries);

    switch (rdata->rp_state) {
    case RPORT_ST_FLOGI:
    case RPORT_ST_PLOGI:
        rdata->flags &= ~FC_RP_STARTED;
        fc_rport_enter_delete(rdata, RPORT_EV_FAILED);
        break;
    case RPORT_ST_RTV:
        fc_rport_enter_ready(rdata);
        break;
    case RPORT_ST_PRLI:
    case RPORT_ST_ADISC:
        fc_rport_enter_logo(rdata);
        break;
    case RPORT_ST_PLOGI_WAIT:
    case RPORT_ST_DELETE:
    case RPORT_ST_READY:
    case RPORT_ST_INIT:
        break;
    }
}

static void fc_rport_error_retry(struct fc_rport_priv *rdata,
                 struct fc_frame *fp)
{
    unsigned long delay = FC_DEF_E_D_TOV;

    /* make sure this isn't an FC_EX_CLOSED error, never retry those */
    if (PTR_ERR(fp) == -FC_EX_CLOSED)
        goto out;

    if (rdata->retries < rdata->local_port->max_rport_retry_count) {
        FC_RPORT_DBG(rdata, "Error %ld in state %s, retrying\n",
                 PTR_ERR(fp), fc_rport_state(rdata));
        rdata->retries++;
        /* no additional delay on exchange timeouts */
        if (PTR_ERR(fp) == -FC_EX_TIMEOUT)
            delay = 0;
        schedule_delayed_work(&rdata->retry_work, delay);
        return;
    }

out:
    fc_rport_error(rdata, fp);
}

static int fc_rport_login_complete(struct fc_rport_priv *rdata,
                   struct fc_frame *fp)
{
    struct fc_lport *lport = rdata->local_port;
    struct fc_els_flogi *flogi;
    unsigned int e_d_tov;
    u16 csp_flags;

    flogi = fc_frame_payload_get(fp, sizeof(*flogi));
    if (!flogi)
        return -EINVAL;

    csp_flags = ntohs(flogi->fl_csp.sp_features);

    if (fc_frame_payload_op(fp) == ELS_FLOGI) {
        if (csp_flags & FC_SP_FT_FPORT) {
            FC_RPORT_DBG(rdata, "Fabric bit set in FLOGI\n");
            return -EINVAL;
        }
    } else {

        /*
         * E_D_TOV is not valid on an incoming FLOGI request.
         */
        e_d_tov = ntohl(flogi->fl_csp.sp_e_d_tov);
        if (csp_flags & FC_SP_FT_EDTR)
            e_d_tov /= 1000000;
        if (e_d_tov > rdata->e_d_tov)
            rdata->e_d_tov = e_d_tov;
    }
    rdata->maxframe_size = fc_plogi_get_maxframe(flogi, lport->mfs);
    return 0;
}

static void fc_rport_flogi_resp(struct fc_seq *sp, struct fc_frame *fp,
                void *rp_arg)
{
    struct fc_rport_priv *rdata = rp_arg;
    struct fc_lport *lport = rdata->local_port;
    struct fc_els_flogi *flogi;
    unsigned int r_a_tov;

    FC_RPORT_DBG(rdata, "Received a FLOGI %s\n", fc_els_resp_type(fp));

    if (fp == ERR_PTR(-FC_EX_CLOSED))
        goto put;

    mutex_lock(&rdata->rp_mutex);

    if (rdata->rp_state != RPORT_ST_FLOGI) {
        FC_RPORT_DBG(rdata, "Received a FLOGI response, but in state "
                 "%s\n", fc_rport_state(rdata));
        if (IS_ERR(fp))
            goto err;
        goto out;
    }

    if (IS_ERR(fp)) {
        fc_rport_error(rdata, fp);
        goto err;
    }

    if (fc_frame_payload_op(fp) != ELS_LS_ACC)
        goto bad;
    if (fc_rport_login_complete(rdata, fp))
        goto bad;

    flogi = fc_frame_payload_get(fp, sizeof(*flogi));
    if (!flogi)
        goto bad;
    r_a_tov = ntohl(flogi->fl_csp.sp_r_a_tov);
    if (r_a_tov > rdata->r_a_tov)
        rdata->r_a_tov = r_a_tov;

    if (rdata->ids.port_name < lport->wwpn)
        fc_rport_enter_plogi(rdata);
    else
        fc_rport_state_enter(rdata, RPORT_ST_PLOGI_WAIT);
out:
    fc_frame_free(fp);
err:
    mutex_unlock(&rdata->rp_mutex);
put:
    kref_put(&rdata->kref, rdata->local_port->tt.rport_destroy);
    return;
bad:
    FC_RPORT_DBG(rdata, "Bad FLOGI response\n");
    fc_rport_error_retry(rdata, fp);
    goto out;
}

static void fc_rport_enter_flogi(struct fc_rport_priv *rdata)
{
    struct fc_lport *lport = rdata->local_port;
    struct fc_frame *fp;

    if (!lport->point_to_multipoint)
        return fc_rport_enter_plogi(rdata);

    FC_RPORT_DBG(rdata, "Entered FLOGI state from %s state\n",
             fc_rport_state(rdata));

    fc_rport_state_enter(rdata, RPORT_ST_FLOGI);

    fp = fc_frame_alloc(lport, sizeof(struct fc_els_flogi));
    if (!fp)
        return fc_rport_error_retry(rdata, fp);

    if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, ELS_FLOGI,
                  fc_rport_flogi_resp, rdata,
                  2 * lport->r_a_tov))
        fc_rport_error_retry(rdata, NULL);
    else
        kref_get(&rdata->kref);
}

static void fc_rport_recv_flogi_req(struct fc_lport *lport,
                    struct fc_frame *rx_fp)
{
    struct fc_disc *disc;
    struct fc_els_flogi *flp;
    struct fc_rport_priv *rdata;
    struct fc_frame *fp = rx_fp;
    struct fc_seq_els_data rjt_data;
    u32 sid;

    sid = fc_frame_sid(fp);

    FC_RPORT_ID_DBG(lport, sid, "Received FLOGI request\n");

    disc = &lport->disc;
    mutex_lock(&disc->disc_mutex);

    if (!lport->point_to_multipoint) {
        rjt_data.reason = ELS_RJT_UNSUP;
        rjt_data.explan = ELS_EXPL_NONE;
        goto reject;
    }

    flp = fc_frame_payload_get(fp, sizeof(*flp));
    if (!flp) {
        rjt_data.reason = ELS_RJT_LOGIC;
        rjt_data.explan = ELS_EXPL_INV_LEN;
        goto reject;
    }

    rdata = lport->tt.rport_lookup(lport, sid);
    if (!rdata) {
        rjt_data.reason = ELS_RJT_FIP;
        rjt_data.explan = ELS_EXPL_NOT_NEIGHBOR;
        goto reject;
    }
    mutex_lock(&rdata->rp_mutex);

    FC_RPORT_DBG(rdata, "Received FLOGI in %s state\n",
             fc_rport_state(rdata));

    switch (rdata->rp_state) {
    case RPORT_ST_INIT:
        /*
         * If received the FLOGI request on RPORT which is INIT state
         * (means not transition to FLOGI either fc_rport timeout
         * function didn;t trigger or this end hasn;t received
         * beacon yet from other end. In that case only, allow RPORT
         * state machine to continue, otherwise fall through which
         * causes the code to send reject response.
         * NOTE; Not checking for FIP->state such as VNMP_UP or
         * VNMP_CLAIM because if FIP state is not one of those,
         * RPORT wouldn;t have created and 'rport_lookup' would have
         * failed anyway in that case.
         */
        if (lport->point_to_multipoint)
            break;
    case RPORT_ST_DELETE:
        mutex_unlock(&rdata->rp_mutex);
        rjt_data.reason = ELS_RJT_FIP;
        rjt_data.explan = ELS_EXPL_NOT_NEIGHBOR;
        goto reject;
    case RPORT_ST_FLOGI:
    case RPORT_ST_PLOGI_WAIT:
    case RPORT_ST_PLOGI:
        break;
    case RPORT_ST_PRLI:
    case RPORT_ST_RTV:
    case RPORT_ST_READY:
    case RPORT_ST_ADISC:
        /*
         * Set the remote port to be deleted and to then restart.
         * This queues work to be sure exchanges are reset.
         */
        fc_rport_enter_delete(rdata, RPORT_EV_LOGO);
        mutex_unlock(&rdata->rp_mutex);
        rjt_data.reason = ELS_RJT_BUSY;
        rjt_data.explan = ELS_EXPL_NONE;
        goto reject;
    }
    if (fc_rport_login_complete(rdata, fp)) {
        mutex_unlock(&rdata->rp_mutex);
        rjt_data.reason = ELS_RJT_LOGIC;
        rjt_data.explan = ELS_EXPL_NONE;
        goto reject;
    }

    fp = fc_frame_alloc(lport, sizeof(*flp));
    if (!fp)
        goto out;

    fc_flogi_fill(lport, fp);
    flp = fc_frame_payload_get(fp, sizeof(*flp));
    flp->fl_cmd = ELS_LS_ACC;

    fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
    lport->tt.frame_send(lport, fp);

    if (rdata->ids.port_name < lport->wwpn)
        fc_rport_enter_plogi(rdata);
    else
        fc_rport_state_enter(rdata, RPORT_ST_PLOGI_WAIT);
out:
    mutex_unlock(&rdata->rp_mutex);
    mutex_unlock(&disc->disc_mutex);
    fc_frame_free(rx_fp);
    return;

reject:
    mutex_unlock(&disc->disc_mutex);
    lport->tt.seq_els_rsp_send(rx_fp, ELS_LS_RJT, &rjt_data);
    fc_frame_free(rx_fp);
}

static void fc_rport_plogi_resp(struct fc_seq *sp, struct fc_frame *fp,
                void *rdata_arg)
{
    struct fc_rport_priv *rdata = rdata_arg;
    struct fc_lport *lport = rdata->local_port;
    struct fc_els_flogi *plp = NULL;
    u16 csp_seq;
    u16 cssp_seq;
    u8 op;

    mutex_lock(&rdata->rp_mutex);

    FC_RPORT_DBG(rdata, "Received a PLOGI %s\n", fc_els_resp_type(fp));

    if (rdata->rp_state != RPORT_ST_PLOGI) {
        FC_RPORT_DBG(rdata, "Received a PLOGI response, but in state "
                 "%s\n", fc_rport_state(rdata));
        if (IS_ERR(fp))
            goto err;
        goto out;
    }

    if (IS_ERR(fp)) {
        fc_rport_error_retry(rdata, fp);
        goto err;
    }

    op = fc_frame_payload_op(fp);
    if (op == ELS_LS_ACC &&
        (plp = fc_frame_payload_get(fp, sizeof(*plp))) != NULL) {
        rdata->ids.port_name = get_unaligned_be64(&plp->fl_wwpn);
        rdata->ids.node_name = get_unaligned_be64(&plp->fl_wwnn);

        /* save plogi response sp_features for further reference */
        rdata->sp_features = ntohs(plp->fl_csp.sp_features);

        if (lport->point_to_multipoint)
            fc_rport_login_complete(rdata, fp);
        csp_seq = ntohs(plp->fl_csp.sp_tot_seq);
        cssp_seq = ntohs(plp->fl_cssp[3 - 1].cp_con_seq);
        if (cssp_seq < csp_seq)
            csp_seq = cssp_seq;
        rdata->max_seq = csp_seq;
        rdata->maxframe_size = fc_plogi_get_maxframe(plp, lport->mfs);
        fc_rport_enter_prli(rdata);
    } else
        fc_rport_error_retry(rdata, fp);

out:
    fc_frame_free(fp);
err:
    mutex_unlock(&rdata->rp_mutex);
    kref_put(&rdata->kref, rdata->local_port->tt.rport_destroy);
}

static void fc_rport_enter_plogi(struct fc_rport_priv *rdata)
{
    struct fc_lport *lport = rdata->local_port;
    struct fc_frame *fp;

    FC_RPORT_DBG(rdata, "Port entered PLOGI state from %s state\n",
             fc_rport_state(rdata));

    fc_rport_state_enter(rdata, RPORT_ST_PLOGI);

    rdata->maxframe_size = FC_MIN_MAX_PAYLOAD;
    fp = fc_frame_alloc(lport, sizeof(struct fc_els_flogi));
    if (!fp) {
        FC_RPORT_DBG(rdata, "%s frame alloc failed\n", __func__);
        fc_rport_error_retry(rdata, fp);
        return;
    }
    rdata->e_d_tov = lport->e_d_tov;

    if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, ELS_PLOGI,
                  fc_rport_plogi_resp, rdata,
                  2 * lport->r_a_tov))
        fc_rport_error_retry(rdata, NULL);
    else
        kref_get(&rdata->kref);
}

static void fc_rport_prli_resp(struct fc_seq *sp, struct fc_frame *fp,
                   void *rdata_arg)
{
    struct fc_rport_priv *rdata = rdata_arg;
    struct {
        struct fc_els_prli prli;
        struct fc_els_spp spp;
    } *pp;
    struct fc_els_spp temp_spp;
    struct fc4_prov *prov;
    u32 roles = FC_RPORT_ROLE_UNKNOWN;
    u32 fcp_parm = 0;
    u8 op;
    u8 resp_code = 0;

    mutex_lock(&rdata->rp_mutex);

    FC_RPORT_DBG(rdata, "Received a PRLI %s\n", fc_els_resp_type(fp));

    if (rdata->rp_state != RPORT_ST_PRLI) {
        FC_RPORT_DBG(rdata, "Received a PRLI response, but in state "
                 "%s\n", fc_rport_state(rdata));
        if (IS_ERR(fp))
            goto err;
        goto out;
    }

    if (IS_ERR(fp)) {
        fc_rport_error_retry(rdata, fp);
        goto err;
    }

    /* reinitialize remote port roles */
    rdata->ids.roles = FC_RPORT_ROLE_UNKNOWN;

    op = fc_frame_payload_op(fp);
    if (op == ELS_LS_ACC) {
        pp = fc_frame_payload_get(fp, sizeof(*pp));
        if (!pp)
            goto out;

        resp_code = (pp->spp.spp_flags & FC_SPP_RESP_MASK);
        FC_RPORT_DBG(rdata, "PRLI spp_flags = 0x%x\n",
                 pp->spp.spp_flags);
        rdata->spp_type = pp->spp.spp_type;
        if (resp_code != FC_SPP_RESP_ACK) {
            if (resp_code == FC_SPP_RESP_CONF)
                fc_rport_error(rdata, fp);
            else
                fc_rport_error_retry(rdata, fp);
            goto out;
        }
        if (pp->prli.prli_spp_len < sizeof(pp->spp))
            goto out;

        fcp_parm = ntohl(pp->spp.spp_params);
        if (fcp_parm & FCP_SPPF_RETRY)
            rdata->flags |= FC_RP_FLAGS_RETRY;
        if (fcp_parm & FCP_SPPF_CONF_COMPL)
            rdata->flags |= FC_RP_FLAGS_CONF_REQ;

        prov = fc_passive_prov[FC_TYPE_FCP];
        if (prov) {
            memset(&temp_spp, 0, sizeof(temp_spp));
            prov->prli(rdata, pp->prli.prli_spp_len,
                   &pp->spp, &temp_spp);
        }

        rdata->supported_classes = FC_COS_CLASS3;
        if (fcp_parm & FCP_SPPF_INIT_FCN)
            roles |= FC_RPORT_ROLE_FCP_INITIATOR;
        if (fcp_parm & FCP_SPPF_TARG_FCN)
            roles |= FC_RPORT_ROLE_FCP_TARGET;

        rdata->ids.roles = roles;
        fc_rport_enter_rtv(rdata);

    } else {
        FC_RPORT_DBG(rdata, "Bad ELS response for PRLI command\n");
        fc_rport_error_retry(rdata, fp);
    }

out:
    fc_frame_free(fp);
err:
    mutex_unlock(&rdata->rp_mutex);
    kref_put(&rdata->kref, rdata->local_port->tt.rport_destroy);
}

static void fc_rport_enter_prli(struct fc_rport_priv *rdata)
{
    struct fc_lport *lport = rdata->local_port;
    struct {
        struct fc_els_prli prli;
        struct fc_els_spp spp;
    } *pp;
    struct fc_frame *fp;
    struct fc4_prov *prov;

    /*
     * If the rport is one of the well known addresses
     * we skip PRLI and RTV and go straight to READY.
     */
    if (rdata->ids.port_id >= FC_FID_DOM_MGR) {
        fc_rport_enter_ready(rdata);
        return;
    }

    FC_RPORT_DBG(rdata, "Port entered PRLI state from %s state\n",
             fc_rport_state(rdata));

    fc_rport_state_enter(rdata, RPORT_ST_PRLI);

    fp = fc_frame_alloc(lport, sizeof(*pp));
    if (!fp) {
        fc_rport_error_retry(rdata, fp);
        return;
    }

    fc_prli_fill(lport, fp);

    prov = fc_passive_prov[FC_TYPE_FCP];
    if (prov) {
        pp = fc_frame_payload_get(fp, sizeof(*pp));
        prov->prli(rdata, sizeof(pp->spp), NULL, &pp->spp);
    }

    fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rdata->ids.port_id,
               fc_host_port_id(lport->host), FC_TYPE_ELS,
               FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);

    if (!lport->tt.exch_seq_send(lport, fp, fc_rport_prli_resp,
                    NULL, rdata, 2 * lport->r_a_tov))
        fc_rport_error_retry(rdata, NULL);
    else
        kref_get(&rdata->kref);
}

static void fc_rport_rtv_resp(struct fc_seq *sp, struct fc_frame *fp,
                  void *rdata_arg)
{
    struct fc_rport_priv *rdata = rdata_arg;
    u8 op;

    mutex_lock(&rdata->rp_mutex);

    FC_RPORT_DBG(rdata, "Received a RTV %s\n", fc_els_resp_type(fp));

    if (rdata->rp_state != RPORT_ST_RTV) {
        FC_RPORT_DBG(rdata, "Received a RTV response, but in state "
                 "%s\n", fc_rport_state(rdata));
        if (IS_ERR(fp))
            goto err;
        goto out;
    }

    if (IS_ERR(fp)) {
        fc_rport_error(rdata, fp);
        goto err;
    }

    op = fc_frame_payload_op(fp);
    if (op == ELS_LS_ACC) {
        struct fc_els_rtv_acc *rtv;
        u32 toq;
        u32 tov;

        rtv = fc_frame_payload_get(fp, sizeof(*rtv));
        if (rtv) {
            toq = ntohl(rtv->rtv_toq);
            tov = ntohl(rtv->rtv_r_a_tov);
            if (tov == 0)
                tov = 1;
            rdata->r_a_tov = tov;
            tov = ntohl(rtv->rtv_e_d_tov);
            if (toq & FC_ELS_RTV_EDRES)
                tov /= 1000000;
            if (tov == 0)
                tov = 1;
            rdata->e_d_tov = tov;
        }
    }

    fc_rport_enter_ready(rdata);

out:
    fc_frame_free(fp);
err:
    mutex_unlock(&rdata->rp_mutex);
    kref_put(&rdata->kref, rdata->local_port->tt.rport_destroy);
}

static void fc_rport_enter_rtv(struct fc_rport_priv *rdata)
{
    struct fc_frame *fp;
    struct fc_lport *lport = rdata->local_port;

    FC_RPORT_DBG(rdata, "Port entered RTV state from %s state\n",
             fc_rport_state(rdata));

    fc_rport_state_enter(rdata, RPORT_ST_RTV);

    fp = fc_frame_alloc(lport, sizeof(struct fc_els_rtv));
    if (!fp) {
        fc_rport_error_retry(rdata, fp);
        return;
    }

    if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, ELS_RTV,
                  fc_rport_rtv_resp, rdata,
                  2 * lport->r_a_tov))
        fc_rport_error_retry(rdata, NULL);
    else
        kref_get(&rdata->kref);
}

static void fc_rport_logo_resp(struct fc_seq *sp, struct fc_frame *fp,
                   void *lport_arg)
{
    struct fc_lport *lport = lport_arg;

    FC_RPORT_ID_DBG(lport, fc_seq_exch(sp)->did,
            "Received a LOGO %s\n", fc_els_resp_type(fp));
    if (IS_ERR(fp))
        return;
    fc_frame_free(fp);
}

static void fc_rport_enter_logo(struct fc_rport_priv *rdata)
{
    struct fc_lport *lport = rdata->local_port;
    struct fc_frame *fp;

    FC_RPORT_DBG(rdata, "Port sending LOGO from %s state\n",
             fc_rport_state(rdata));

    fp = fc_frame_alloc(lport, sizeof(struct fc_els_logo));
    if (!fp)
        return;
    (void)lport->tt.elsct_send(lport, rdata->ids.port_id, fp, ELS_LOGO,
                   fc_rport_logo_resp, lport, 0);
}

static void fc_rport_adisc_resp(struct fc_seq *sp, struct fc_frame *fp,
                void *rdata_arg)
{
    struct fc_rport_priv *rdata = rdata_arg;
    struct fc_els_adisc *adisc;
    u8 op;

    mutex_lock(&rdata->rp_mutex);

    FC_RPORT_DBG(rdata, "Received a ADISC response\n");

    if (rdata->rp_state != RPORT_ST_ADISC) {
        FC_RPORT_DBG(rdata, "Received a ADISC resp but in state %s\n",
                 fc_rport_state(rdata));
        if (IS_ERR(fp))
            goto err;
        goto out;
    }

    if (IS_ERR(fp)) {
        fc_rport_error(rdata, fp);
        goto err;
    }

    /*
     * If address verification failed.  Consider us logged out of the rport.
     * Since the rport is still in discovery, we want to be
     * logged in, so go to PLOGI state.  Otherwise, go back to READY.
     */
    op = fc_frame_payload_op(fp);
    adisc = fc_frame_payload_get(fp, sizeof(*adisc));
    if (op != ELS_LS_ACC || !adisc ||
        ntoh24(adisc->adisc_port_id) != rdata->ids.port_id ||
        get_unaligned_be64(&adisc->adisc_wwpn) != rdata->ids.port_name ||
        get_unaligned_be64(&adisc->adisc_wwnn) != rdata->ids.node_name) {
        FC_RPORT_DBG(rdata, "ADISC error or mismatch\n");
        fc_rport_enter_flogi(rdata);
    } else {
        FC_RPORT_DBG(rdata, "ADISC OK\n");
        fc_rport_enter_ready(rdata);
    }
out:
    fc_frame_free(fp);
err:
    mutex_unlock(&rdata->rp_mutex);
    kref_put(&rdata->kref, rdata->local_port->tt.rport_destroy);
}

static void fc_rport_enter_adisc(struct fc_rport_priv *rdata)
{
    struct fc_lport *lport = rdata->local_port;
    struct fc_frame *fp;

    FC_RPORT_DBG(rdata, "sending ADISC from %s state\n",
             fc_rport_state(rdata));

    fc_rport_state_enter(rdata, RPORT_ST_ADISC);

    fp = fc_frame_alloc(lport, sizeof(struct fc_els_adisc));
    if (!fp) {
        fc_rport_error_retry(rdata, fp);
        return;
    }
    if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, ELS_ADISC,
                  fc_rport_adisc_resp, rdata,
                  2 * lport->r_a_tov))
        fc_rport_error_retry(rdata, NULL);
    else
        kref_get(&rdata->kref);
}

static void fc_rport_recv_adisc_req(struct fc_rport_priv *rdata,
                    struct fc_frame *in_fp)
{
    struct fc_lport *lport = rdata->local_port;
    struct fc_frame *fp;
    struct fc_els_adisc *adisc;
    struct fc_seq_els_data rjt_data;

    FC_RPORT_DBG(rdata, "Received ADISC request\n");

    adisc = fc_frame_payload_get(in_fp, sizeof(*adisc));
    if (!adisc) {
        rjt_data.reason = ELS_RJT_PROT;
        rjt_data.explan = ELS_EXPL_INV_LEN;
        lport->tt.seq_els_rsp_send(in_fp, ELS_LS_RJT, &rjt_data);
        goto drop;
    }

    fp = fc_frame_alloc(lport, sizeof(*adisc));
    if (!fp)
        goto drop;
    fc_adisc_fill(lport, fp);
    adisc = fc_frame_payload_get(fp, sizeof(*adisc));
    adisc->adisc_cmd = ELS_LS_ACC;
    fc_fill_reply_hdr(fp, in_fp, FC_RCTL_ELS_REP, 0);
    lport->tt.frame_send(lport, fp);
drop:
    fc_frame_free(in_fp);
}

static void fc_rport_recv_rls_req(struct fc_rport_priv *rdata,
                  struct fc_frame *rx_fp)

{
    struct fc_lport *lport = rdata->local_port;
    struct fc_frame *fp;
    struct fc_els_rls *rls;
    struct fc_els_rls_resp *rsp;
    struct fc_els_lesb *lesb;
    struct fc_seq_els_data rjt_data;
    struct fc_host_statistics *hst;

    FC_RPORT_DBG(rdata, "Received RLS request while in state %s\n",
             fc_rport_state(rdata));

    rls = fc_frame_payload_get(rx_fp, sizeof(*rls));
    if (!rls) {
        rjt_data.reason = ELS_RJT_PROT;
        rjt_data.explan = ELS_EXPL_INV_LEN;
        goto out_rjt;
    }

    fp = fc_frame_alloc(lport, sizeof(*rsp));
    if (!fp) {
        rjt_data.reason = ELS_RJT_UNAB;
        rjt_data.explan = ELS_EXPL_INSUF_RES;
        goto out_rjt;
    }

    rsp = fc_frame_payload_get(fp, sizeof(*rsp));
    memset(rsp, 0, sizeof(*rsp));
    rsp->rls_cmd = ELS_LS_ACC;
    lesb = &rsp->rls_lesb;
    if (lport->tt.get_lesb) {
        /* get LESB from LLD if it supports it */
        lport->tt.get_lesb(lport, lesb);
    } else {
        fc_get_host_stats(lport->host);
        hst = &lport->host_stats;
        lesb->lesb_link_fail = htonl(hst->link_failure_count);
        lesb->lesb_sync_loss = htonl(hst->loss_of_sync_count);
        lesb->lesb_sig_loss = htonl(hst->loss_of_signal_count);
        lesb->lesb_prim_err = htonl(hst->prim_seq_protocol_err_count);
        lesb->lesb_inv_word = htonl(hst->invalid_tx_word_count);
        lesb->lesb_inv_crc = htonl(hst->invalid_crc_count);
    }

    fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
    lport->tt.frame_send(lport, fp);
    goto out;

out_rjt:
    lport->tt.seq_els_rsp_send(rx_fp, ELS_LS_RJT, &rjt_data);
out:
    fc_frame_free(rx_fp);
}

static void fc_rport_recv_els_req(struct fc_lport *lport, struct fc_frame *fp)
{
    struct fc_rport_priv *rdata;
    struct fc_seq_els_data els_data;

    mutex_lock(&lport->disc.disc_mutex);
    rdata = lport->tt.rport_lookup(lport, fc_frame_sid(fp));
    if (!rdata) {
        mutex_unlock(&lport->disc.disc_mutex);
        goto reject;
    }
    mutex_lock(&rdata->rp_mutex);
    mutex_unlock(&lport->disc.disc_mutex);

    switch (rdata->rp_state) {
    case RPORT_ST_PRLI:
    case RPORT_ST_RTV:
    case RPORT_ST_READY:
    case RPORT_ST_ADISC:
        break;
    default:
        mutex_unlock(&rdata->rp_mutex);
        goto reject;
    }

    switch (fc_frame_payload_op(fp)) {
    case ELS_PRLI:
        fc_rport_recv_prli_req(rdata, fp);
        break;
    case ELS_PRLO:
        fc_rport_recv_prlo_req(rdata, fp);
        break;
    case ELS_ADISC:
        fc_rport_recv_adisc_req(rdata, fp);
        break;
    case ELS_RRQ:
        lport->tt.seq_els_rsp_send(fp, ELS_RRQ, NULL);
        fc_frame_free(fp);
        break;
    case ELS_REC:
        lport->tt.seq_els_rsp_send(fp, ELS_REC, NULL);
        fc_frame_free(fp);
        break;
    case ELS_RLS:
        fc_rport_recv_rls_req(rdata, fp);
        break;
    default:
        fc_frame_free(fp);  /* can't happen */
        break;
    }

    mutex_unlock(&rdata->rp_mutex);
    return;

reject:
    els_data.reason = ELS_RJT_UNAB;
    els_data.explan = ELS_EXPL_PLOGI_REQD;
    lport->tt.seq_els_rsp_send(fp, ELS_LS_RJT, &els_data);
    fc_frame_free(fp);
}

static void fc_rport_recv_req(struct fc_lport *lport, struct fc_frame *fp)
{
    struct fc_seq_els_data els_data;

    /*
     * Handle FLOGI, PLOGI and LOGO requests separately, since they
     * don't require prior login.
     * Check for unsupported opcodes first and reject them.
     * For some ops, it would be incorrect to reject with "PLOGI required".
     */
    switch (fc_frame_payload_op(fp)) {
    case ELS_FLOGI:
        fc_rport_recv_flogi_req(lport, fp);
        break;
    case ELS_PLOGI:
        fc_rport_recv_plogi_req(lport, fp);
        break;
    case ELS_LOGO:
        fc_rport_recv_logo_req(lport, fp);
        break;
    case ELS_PRLI:
    case ELS_PRLO:
    case ELS_ADISC:
    case ELS_RRQ:
    case ELS_REC:
    case ELS_RLS:
        fc_rport_recv_els_req(lport, fp);
        break;
    default:
        els_data.reason = ELS_RJT_UNSUP;
        els_data.explan = ELS_EXPL_NONE;
        lport->tt.seq_els_rsp_send(fp, ELS_LS_RJT, &els_data);
        fc_frame_free(fp);
        break;
    }
}

static void fc_rport_recv_plogi_req(struct fc_lport *lport,
                    struct fc_frame *rx_fp)
{
    struct fc_disc *disc;
    struct fc_rport_priv *rdata;
    struct fc_frame *fp = rx_fp;
    struct fc_els_flogi *pl;
    struct fc_seq_els_data rjt_data;
    u32 sid;

    sid = fc_frame_sid(fp);

    FC_RPORT_ID_DBG(lport, sid, "Received PLOGI request\n");

    pl = fc_frame_payload_get(fp, sizeof(*pl));
    if (!pl) {
        FC_RPORT_ID_DBG(lport, sid, "Received PLOGI too short\n");
        rjt_data.reason = ELS_RJT_PROT;
        rjt_data.explan = ELS_EXPL_INV_LEN;
        goto reject;
    }

    disc = &lport->disc;
    mutex_lock(&disc->disc_mutex);
    rdata = lport->tt.rport_create(lport, sid);
    if (!rdata) {
        mutex_unlock(&disc->disc_mutex);
        rjt_data.reason = ELS_RJT_UNAB;
        rjt_data.explan = ELS_EXPL_INSUF_RES;
        goto reject;
    }

    mutex_lock(&rdata->rp_mutex);
    mutex_unlock(&disc->disc_mutex);

    rdata->ids.port_name = get_unaligned_be64(&pl->fl_wwpn);
    rdata->ids.node_name = get_unaligned_be64(&pl->fl_wwnn);

    /*
     * If the rport was just created, possibly due to the incoming PLOGI,
     * set the state appropriately and accept the PLOGI.
     *
     * If we had also sent a PLOGI, and if the received PLOGI is from a
     * higher WWPN, we accept it, otherwise an LS_RJT is sent with reason
     * "command already in progress".
     *
     * XXX TBD: If the session was ready before, the PLOGI should result in
     * all outstanding exchanges being reset.
     */
    switch (rdata->rp_state) {
    case RPORT_ST_INIT:
        FC_RPORT_DBG(rdata, "Received PLOGI in INIT state\n");
        break;
    case RPORT_ST_PLOGI_WAIT:
        FC_RPORT_DBG(rdata, "Received PLOGI in PLOGI_WAIT state\n");
        break;
    case RPORT_ST_PLOGI:
        FC_RPORT_DBG(rdata, "Received PLOGI in PLOGI state\n");
        if (rdata->ids.port_name < lport->wwpn) {
            mutex_unlock(&rdata->rp_mutex);
            rjt_data.reason = ELS_RJT_INPROG;
            rjt_data.explan = ELS_EXPL_NONE;
            goto reject;
        }
        break;
    case RPORT_ST_PRLI:
    case RPORT_ST_RTV:
    case RPORT_ST_READY:
    case RPORT_ST_ADISC:
        FC_RPORT_DBG(rdata, "Received PLOGI in logged-in state %d "
                 "- ignored for now\n", rdata->rp_state);
        /* XXX TBD - should reset */
        break;
    case RPORT_ST_FLOGI:
    case RPORT_ST_DELETE:
        FC_RPORT_DBG(rdata, "Received PLOGI in state %s - send busy\n",
                 fc_rport_state(rdata));
        mutex_unlock(&rdata->rp_mutex);
        rjt_data.reason = ELS_RJT_BUSY;
        rjt_data.explan = ELS_EXPL_NONE;
        goto reject;
    }

    /*
     * Get session payload size from incoming PLOGI.
     */
    rdata->maxframe_size = fc_plogi_get_maxframe(pl, lport->mfs);

    /*
     * Send LS_ACC.  If this fails, the originator should retry.
     */
    fp = fc_frame_alloc(lport, sizeof(*pl));
    if (!fp)
        goto out;

    fc_plogi_fill(lport, fp, ELS_LS_ACC);
    fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
    lport->tt.frame_send(lport, fp);
    fc_rport_enter_prli(rdata);
out:
    mutex_unlock(&rdata->rp_mutex);
    fc_frame_free(rx_fp);
    return;

reject:
    lport->tt.seq_els_rsp_send(fp, ELS_LS_RJT, &rjt_data);
    fc_frame_free(fp);
}

static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
                   struct fc_frame *rx_fp)
{
    struct fc_lport *lport = rdata->local_port;
    struct fc_frame *fp;
    struct {
        struct fc_els_prli prli;
        struct fc_els_spp spp;
    } *pp;
    struct fc_els_spp *rspp;    /* request service param page */
    struct fc_els_spp *spp; /* response spp */
    unsigned int len;
    unsigned int plen;
    enum fc_els_spp_resp resp;
    enum fc_els_spp_resp passive;
    struct fc_seq_els_data rjt_data;
    struct fc4_prov *prov;

    FC_RPORT_DBG(rdata, "Received PRLI request while in state %s\n",
             fc_rport_state(rdata));

    len = fr_len(rx_fp) - sizeof(struct fc_frame_header);
    pp = fc_frame_payload_get(rx_fp, sizeof(*pp));
    if (!pp)
        goto reject_len;
    plen = ntohs(pp->prli.prli_len);
    if ((plen % 4) != 0 || plen > len || plen < 16)
        goto reject_len;
    if (plen < len)
        len = plen;
    plen = pp->prli.prli_spp_len;
    if ((plen % 4) != 0 || plen < sizeof(*spp) ||
        plen > len || len < sizeof(*pp) || plen < 12)
        goto reject_len;
    rspp = &pp->spp;

    fp = fc_frame_alloc(lport, len);
    if (!fp) {
        rjt_data.reason = ELS_RJT_UNAB;
        rjt_data.explan = ELS_EXPL_INSUF_RES;
        goto reject;
    }
    pp = fc_frame_payload_get(fp, len);
    WARN_ON(!pp);
    memset(pp, 0, len);
    pp->prli.prli_cmd = ELS_LS_ACC;
    pp->prli.prli_spp_len = plen;
    pp->prli.prli_len = htons(len);
    len -= sizeof(struct fc_els_prli);

    /*
     * Go through all the service parameter pages and build
     * response.  If plen indicates longer SPP than standard,
     * use that.  The entire response has been pre-cleared above.
     */
    spp = &pp->spp;
    mutex_lock(&fc_prov_mutex);
    while (len >= plen) {
        rdata->spp_type = rspp->spp_type;
        spp->spp_type = rspp->spp_type;
        spp->spp_type_ext = rspp->spp_type_ext;
        resp = 0;

        if (rspp->spp_type < FC_FC4_PROV_SIZE) {
            prov = fc_active_prov[rspp->spp_type];
            if (prov)
                resp = prov->prli(rdata, plen, rspp, spp);
            prov = fc_passive_prov[rspp->spp_type];
            if (prov) {
                passive = prov->prli(rdata, plen, rspp, spp);
                if (!resp || passive == FC_SPP_RESP_ACK)
                    resp = passive;
            }
        }
        if (!resp) {
            if (spp->spp_flags & FC_SPP_EST_IMG_PAIR)
                resp |= FC_SPP_RESP_CONF;
            else
                resp |= FC_SPP_RESP_INVL;
        }
        spp->spp_flags |= resp;
        len -= plen;
        rspp = (struct fc_els_spp *)((char *)rspp + plen);
        spp = (struct fc_els_spp *)((char *)spp + plen);
    }
    mutex_unlock(&fc_prov_mutex);

    /*
     * Send LS_ACC.  If this fails, the originator should retry.
     */
    fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
    lport->tt.frame_send(lport, fp);

    switch (rdata->rp_state) {
    case RPORT_ST_PRLI:
        fc_rport_enter_ready(rdata);
        break;
    default:
        break;
    }
    goto drop;

reject_len:
    rjt_data.reason = ELS_RJT_PROT;
    rjt_data.explan = ELS_EXPL_INV_LEN;
reject:
    lport->tt.seq_els_rsp_send(rx_fp, ELS_LS_RJT, &rjt_data);
drop:
    fc_frame_free(rx_fp);
}

static void fc_rport_recv_prlo_req(struct fc_rport_priv *rdata,
                   struct fc_frame *rx_fp)
{
    struct fc_lport *lport = rdata->local_port;
    struct fc_frame *fp;
    struct {
        struct fc_els_prlo prlo;
        struct fc_els_spp spp;
    } *pp;
    struct fc_els_spp *rspp;    /* request service param page */
    struct fc_els_spp *spp;     /* response spp */
    unsigned int len;
    unsigned int plen;
    struct fc_seq_els_data rjt_data;

    FC_RPORT_DBG(rdata, "Received PRLO request while in state %s\n",
             fc_rport_state(rdata));

    len = fr_len(rx_fp) - sizeof(struct fc_frame_header);
    pp = fc_frame_payload_get(rx_fp, sizeof(*pp));
    if (!pp)
        goto reject_len;
    plen = ntohs(pp->prlo.prlo_len);
    if (plen != 20)
        goto reject_len;
    if (plen < len)
        len = plen;

    rspp = &pp->spp;

    fp = fc_frame_alloc(lport, len);
    if (!fp) {
        rjt_data.reason = ELS_RJT_UNAB;
        rjt_data.explan = ELS_EXPL_INSUF_RES;
        goto reject;
    }

    pp = fc_frame_payload_get(fp, len);
    WARN_ON(!pp);
    memset(pp, 0, len);
    pp->prlo.prlo_cmd = ELS_LS_ACC;
    pp->prlo.prlo_obs = 0x10;
    pp->prlo.prlo_len = htons(len);
    spp = &pp->spp;
    spp->spp_type = rspp->spp_type;
    spp->spp_type_ext = rspp->spp_type_ext;
    spp->spp_flags = FC_SPP_RESP_ACK;

    fc_rport_enter_delete(rdata, RPORT_EV_LOGO);

    fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
    lport->tt.frame_send(lport, fp);
    goto drop;

reject_len:
    rjt_data.reason = ELS_RJT_PROT;
    rjt_data.explan = ELS_EXPL_INV_LEN;
reject:
    lport->tt.seq_els_rsp_send(rx_fp, ELS_LS_RJT, &rjt_data);
drop:
    fc_frame_free(rx_fp);
}

static void fc_rport_recv_logo_req(struct fc_lport *lport, struct fc_frame *fp)
{
    struct fc_rport_priv *rdata;
    u32 sid;

    lport->tt.seq_els_rsp_send(fp, ELS_LS_ACC, NULL);

    sid = fc_frame_sid(fp);

    mutex_lock(&lport->disc.disc_mutex);
    rdata = lport->tt.rport_lookup(lport, sid);
    if (rdata) {
        mutex_lock(&rdata->rp_mutex);
        FC_RPORT_DBG(rdata, "Received LOGO request while in state %s\n",
                 fc_rport_state(rdata));

        fc_rport_enter_delete(rdata, RPORT_EV_LOGO);
        mutex_unlock(&rdata->rp_mutex);
    } else
        FC_RPORT_ID_DBG(lport, sid,
                "Received LOGO from non-logged-in port\n");
    mutex_unlock(&lport->disc.disc_mutex);
    fc_frame_free(fp);
}

static void fc_rport_flush_queue(void)
{
    flush_workqueue(rport_event_queue);
}

int fc_rport_init(struct fc_lport *lport)
{
    if (!lport->tt.rport_lookup)
        lport->tt.rport_lookup = fc_rport_lookup;

    if (!lport->tt.rport_create)
        lport->tt.rport_create = fc_rport_create;

    if (!lport->tt.rport_login)
        lport->tt.rport_login = fc_rport_login;

    if (!lport->tt.rport_logoff)
        lport->tt.rport_logoff = fc_rport_logoff;

    if (!lport->tt.rport_recv_req)
        lport->tt.rport_recv_req = fc_rport_recv_req;

    if (!lport->tt.rport_flush_queue)
        lport->tt.rport_flush_queue = fc_rport_flush_queue;

    if (!lport->tt.rport_destroy)
        lport->tt.rport_destroy = fc_rport_destroy;

    return 0;
}
EXPORT_SYMBOL(fc_rport_init);

static int fc_rport_fcp_prli(struct fc_rport_priv *rdata, u32 spp_len,
                 const struct fc_els_spp *rspp,
                 struct fc_els_spp *spp)
{
    struct fc_lport *lport = rdata->local_port;
    u32 fcp_parm;

    fcp_parm = ntohl(rspp->spp_params);
    rdata->ids.roles = FC_RPORT_ROLE_UNKNOWN;
    if (fcp_parm & FCP_SPPF_INIT_FCN)
        rdata->ids.roles |= FC_RPORT_ROLE_FCP_INITIATOR;
    if (fcp_parm & FCP_SPPF_TARG_FCN)
        rdata->ids.roles |= FC_RPORT_ROLE_FCP_TARGET;
    if (fcp_parm & FCP_SPPF_RETRY)
        rdata->flags |= FC_RP_FLAGS_RETRY;
    rdata->supported_classes = FC_COS_CLASS3;

    if (!(lport->service_params & FC_RPORT_ROLE_FCP_INITIATOR))
        return 0;

    spp->spp_flags |= rspp->spp_flags & FC_SPP_EST_IMG_PAIR;

    /*
     * OR in our service parameters with other providers (target), if any.
     */
    fcp_parm = ntohl(spp->spp_params);
    spp->spp_params = htonl(fcp_parm | lport->service_params);
    return FC_SPP_RESP_ACK;
}

/*
 * FC-4 provider ops for FCP initiator.
 */
struct fc4_prov fc_rport_fcp_init = {
    .prli = fc_rport_fcp_prli,
};

static int fc_rport_t0_prli(struct fc_rport_priv *rdata, u32 spp_len,
                const struct fc_els_spp *rspp,
                struct fc_els_spp *spp)
{
    if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR)
        return FC_SPP_RESP_INVL;
    return FC_SPP_RESP_ACK;
}

/*
 * FC-4 provider ops for type 0 service parameters.
 *
 * This handles the special case of type 0 which is always successful
 * but doesn't do anything otherwise.
 */
struct fc4_prov fc_rport_t0_prov = {
    .prli = fc_rport_t0_prli,
};

int fc_setup_rport(void)
{
    rport_event_queue = create_singlethread_workqueue("fc_rport_eq");
    if (!rport_event_queue)
        return -ENOMEM;
    return 0;
}

void fc_destroy_rport(void)
{
    destroy_workqueue(rport_event_queue);
}

void fc_rport_terminate_io(struct fc_rport *rport)
{
    struct fc_rport_libfc_priv *rpriv = rport->dd_data;
    struct fc_lport *lport = rpriv->local_port;

    lport->tt.exch_mgr_reset(lport, 0, rport->port_id);
    lport->tt.exch_mgr_reset(lport, rport->port_id, 0);
}
EXPORT_SYMBOL(fc_rport_terminate_io);