[safe/jmp/linux-2.6] / drivers / scsi / libfc / fc_rport.c

/*
 * 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 heirarchy.
 *
 * 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/rcupdate.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <asm/unaligned.h>

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

static int fc_rport_debug;

#define FC_DEBUG_RPORT(fmt...)                  \
        do {                                    \
                if (fc_rport_debug)             \
                        FC_DBG(fmt);            \
        } while (0)

struct workqueue_struct *rport_event_queue;

static void fc_rport_enter_plogi(struct fc_rport *);
static void fc_rport_enter_prli(struct fc_rport *);
static void fc_rport_enter_rtv(struct fc_rport *);
static void fc_rport_enter_ready(struct fc_rport *);
static void fc_rport_enter_logo(struct fc_rport *);

static void fc_rport_recv_plogi_req(struct fc_rport *,
                                    struct fc_seq *, struct fc_frame *);
static void fc_rport_recv_prli_req(struct fc_rport *,
                                   struct fc_seq *, struct fc_frame *);
static void fc_rport_recv_prlo_req(struct fc_rport *,
                                   struct fc_seq *, struct fc_frame *);
static void fc_rport_recv_logo_req(struct fc_rport *,
                                   struct fc_seq *, struct fc_frame *);
static void fc_rport_timeout(struct work_struct *);
static void fc_rport_error(struct fc_rport *, struct fc_frame *);
static void fc_rport_work(struct work_struct *);

static const char *fc_rport_state_names[] = {
        [RPORT_ST_NONE] = "None",
        [RPORT_ST_INIT] = "Init",
        [RPORT_ST_PLOGI] = "PLOGI",
        [RPORT_ST_PRLI] = "PRLI",
        [RPORT_ST_RTV] = "RTV",
        [RPORT_ST_READY] = "Ready",
        [RPORT_ST_LOGO] = "LOGO",
};

static void fc_rport_rogue_destroy(struct device *dev)
{
        struct fc_rport *rport = dev_to_rport(dev);
        FC_DEBUG_RPORT("Destroying rogue rport (%6x)\n", rport->port_id);
        kfree(rport);
}

struct fc_rport *fc_rport_rogue_create(struct fc_disc_port *dp)
{
        struct fc_rport *rport;
        struct fc_rport_libfc_priv *rdata;
        rport = kzalloc(sizeof(*rport) + sizeof(*rdata), GFP_KERNEL);

        if (!rport)
                return NULL;

        rdata = RPORT_TO_PRIV(rport);

        rport->dd_data = rdata;
        rport->port_id = dp->ids.port_id;
        rport->port_name = dp->ids.port_name;
        rport->node_name = dp->ids.node_name;
        rport->roles = dp->ids.roles;
        rport->maxframe_size = FC_MIN_MAX_PAYLOAD;
        /*
         * Note: all this libfc rogue rport code will be removed for
         * upstream so it fine that this is really ugly and hacky right now.
         */
        device_initialize(&rport->dev);
        rport->dev.release = fc_rport_rogue_destroy;

        mutex_init(&rdata->rp_mutex);
        rdata->local_port = dp->lp;
        rdata->trans_state = FC_PORTSTATE_ROGUE;
        rdata->rp_state = RPORT_ST_INIT;
        rdata->event = RPORT_EV_NONE;
        rdata->flags = FC_RP_FLAGS_REC_SUPPORTED;
        rdata->ops = NULL;
        rdata->e_d_tov = dp->lp->e_d_tov;
        rdata->r_a_tov = dp->lp->r_a_tov;
        INIT_DELAYED_WORK(&rdata->retry_work, fc_rport_timeout);
        INIT_WORK(&rdata->event_work, fc_rport_work);
        /*
         * For good measure, but not necessary as we should only
         * add REAL rport to the lport list.
         */
        INIT_LIST_HEAD(&rdata->peers);

        return rport;
}

/**
 * fc_rport_state - return a string for the state the rport is in
 * @rport: The rport whose state we want to get a string for
 */
static const char *fc_rport_state(struct fc_rport *rport)
{
        const char *cp;
        struct fc_rport_libfc_priv *rdata = rport->dd_data;

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

/**
 * fc_set_rport_loss_tmo - Set the remote port loss timeout in seconds.
 * @rport: Pointer to Fibre Channel remote port structure
 * @timeout: timeout in seconds
 */
void fc_set_rport_loss_tmo(struct fc_rport *rport, u32 timeout)
{
        if (timeout)
                rport->dev_loss_tmo = timeout + 5;
        else
                rport->dev_loss_tmo = 30;
}
EXPORT_SYMBOL(fc_set_rport_loss_tmo);

/**
 * fc_plogi_get_maxframe - Get max payload from the common service parameters
 * @flp: FLOGI payload structure
 * @maxval: upper limit, may be less than what is in the service parameters
 */
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;
}

/**
 * fc_rport_state_enter - Change the rport's state
 * @rport: The rport whose state should change
 * @new: The new state of the rport
 *
 * Locking Note: Called with the rport lock held
 */
static void fc_rport_state_enter(struct fc_rport *rport,
                                 enum fc_rport_state new)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        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_libfc_priv *rdata =
                container_of(work, struct fc_rport_libfc_priv, event_work);
        enum fc_rport_event event;
        enum fc_rport_trans_state trans_state;
        struct fc_lport *lport = rdata->local_port;
        struct fc_rport_operations *rport_ops;
        struct fc_rport *rport = PRIV_TO_RPORT(rdata);

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

        if (event == RPORT_EV_CREATED) {
                struct fc_rport *new_rport;
                struct fc_rport_libfc_priv *new_rdata;
                struct fc_rport_identifiers ids;

                ids.port_id = rport->port_id;
                ids.roles = rport->roles;
                ids.port_name = rport->port_name;
                ids.node_name = rport->node_name;

                mutex_unlock(&rdata->rp_mutex);

                new_rport = fc_remote_port_add(lport->host, 0, &ids);
                if (new_rport) {
                        /*
                         * Switch from the rogue rport to the rport
                         * returned by the FC class.
                         */
                        new_rport->maxframe_size = rport->maxframe_size;

                        new_rdata = new_rport->dd_data;
                        new_rdata->e_d_tov = rdata->e_d_tov;
                        new_rdata->r_a_tov = rdata->r_a_tov;
                        new_rdata->ops = rdata->ops;
                        new_rdata->local_port = rdata->local_port;
                        new_rdata->flags = FC_RP_FLAGS_REC_SUPPORTED;
                        new_rdata->trans_state = FC_PORTSTATE_REAL;
                        mutex_init(&new_rdata->rp_mutex);
                        INIT_DELAYED_WORK(&new_rdata->retry_work,
                                          fc_rport_timeout);
                        INIT_LIST_HEAD(&new_rdata->peers);
                        INIT_WORK(&new_rdata->event_work, fc_rport_work);

                        fc_rport_state_enter(new_rport, RPORT_ST_READY);
                } else {
                        FC_DBG("Failed to create the rport for port "
                               "(%6x).\n", ids.port_id);
                        event = RPORT_EV_FAILED;
                }
                put_device(&rport->dev);
                rport = new_rport;
                rdata = new_rport->dd_data;
                if (rport_ops->event_callback)
                        rport_ops->event_callback(lport, rport, event);
        } else if ((event == RPORT_EV_FAILED) ||
                   (event == RPORT_EV_LOGO) ||
                   (event == RPORT_EV_STOP)) {
                trans_state = rdata->trans_state;
                mutex_unlock(&rdata->rp_mutex);
                if (rport_ops->event_callback)
                        rport_ops->event_callback(lport, rport, event);
                if (trans_state == FC_PORTSTATE_ROGUE)
                        put_device(&rport->dev);
                else {
                        port_id = rport->port_id;
                        fc_remote_port_delete(rport);
                        lport->tt.exch_mgr_reset(lport, 0, port_id);
                        lport->tt.exch_mgr_reset(lport, port_id, 0);
                }
        } else
                mutex_unlock(&rdata->rp_mutex);
}

/**
 * fc_rport_login - Start the remote port login state machine
 * @rport: Fibre Channel remote port
 *
 * Locking Note: Called without the rport lock held. This
 * function will hold the rport lock, call an _enter_*
 * function and then unlock the rport.
 */
int fc_rport_login(struct fc_rport *rport)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;

        mutex_lock(&rdata->rp_mutex);

        FC_DEBUG_RPORT("Login to port (%6x)\n", rport->port_id);

        fc_rport_enter_plogi(rport);

        mutex_unlock(&rdata->rp_mutex);

        return 0;
}

/**
 * fc_rport_logoff - Logoff and remove an rport
 * @rport: Fibre Channel remote port to be removed
 *
 * Locking Note: Called without the rport lock held. This
 * function will hold the rport lock, call an _enter_*
 * function and then unlock the rport.
 */
int fc_rport_logoff(struct fc_rport *rport)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;

        mutex_lock(&rdata->rp_mutex);

        FC_DEBUG_RPORT("Remove port (%6x)\n", rport->port_id);

        fc_rport_enter_logo(rport);

        /*
         * Change the state to NONE so that we discard
         * the response.
         */
        fc_rport_state_enter(rport, RPORT_ST_NONE);

        mutex_unlock(&rdata->rp_mutex);

        cancel_delayed_work_sync(&rdata->retry_work);

        mutex_lock(&rdata->rp_mutex);

        rdata->event = RPORT_EV_STOP;
        queue_work(rport_event_queue, &rdata->event_work);

        mutex_unlock(&rdata->rp_mutex);

        return 0;
}

/**
 * fc_rport_enter_ready - The rport is ready
 * @rport: Fibre Channel remote port that is ready
 *
 * Locking Note: The rport lock is expected to be held before calling
 * this routine.
 */
static void fc_rport_enter_ready(struct fc_rport *rport)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;

        fc_rport_state_enter(rport, RPORT_ST_READY);

        FC_DEBUG_RPORT("Port (%6x) is Ready\n", rport->port_id);

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

/**
 * fc_rport_timeout - Handler for the retry_work timer.
 * @work: The work struct of the fc_rport_libfc_priv
 *
 * Locking Note: Called without the rport lock held. This
 * function will hold the rport lock, call an _enter_*
 * function and then unlock the rport.
 */
static void fc_rport_timeout(struct work_struct *work)
{
        struct fc_rport_libfc_priv *rdata =
                container_of(work, struct fc_rport_libfc_priv, retry_work.work);
        struct fc_rport *rport = PRIV_TO_RPORT(rdata);

        mutex_lock(&rdata->rp_mutex);

        switch (rdata->rp_state) {
        case RPORT_ST_PLOGI:
                fc_rport_enter_plogi(rport);
                break;
        case RPORT_ST_PRLI:
                fc_rport_enter_prli(rport);
                break;
        case RPORT_ST_RTV:
                fc_rport_enter_rtv(rport);
                break;
        case RPORT_ST_LOGO:
                fc_rport_enter_logo(rport);
                break;
        case RPORT_ST_READY:
        case RPORT_ST_INIT:
        case RPORT_ST_NONE:
                break;
        }

        mutex_unlock(&rdata->rp_mutex);
        put_device(&rport->dev);
}

/**
 * fc_rport_error - Handler for any errors
 * @rport: The fc_rport object
 * @fp: The frame pointer
 *
 * If the error was caused by a resource allocation failure
 * then wait for half a second and retry, otherwise retry
 * immediately.
 *
 * Locking Note: The rport lock is expected to be held before
 * calling this routine
 */
static void fc_rport_error(struct fc_rport *rport, struct fc_frame *fp)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        unsigned long delay = 0;

        FC_DEBUG_RPORT("Error %ld in state %s, retries %d\n",
                       PTR_ERR(fp), fc_rport_state(rport), rdata->retries);

        if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
                /*
                 * Memory allocation failure, or the exchange timed out.
                 *  Retry after delay
                 */
                if (rdata->retries < rdata->local_port->max_retry_count) {
                        rdata->retries++;
                        if (!fp)
                                delay = msecs_to_jiffies(500);
                        get_device(&rport->dev);
                        schedule_delayed_work(&rdata->retry_work, delay);
                } else {
                        switch (rdata->rp_state) {
                        case RPORT_ST_PLOGI:
                        case RPORT_ST_PRLI:
                        case RPORT_ST_LOGO:
                                rdata->event = RPORT_EV_FAILED;
                                queue_work(rport_event_queue,
                                           &rdata->event_work);
                                break;
                        case RPORT_ST_RTV:
                                fc_rport_enter_ready(rport);
                                break;
                        case RPORT_ST_NONE:
                        case RPORT_ST_READY:
                        case RPORT_ST_INIT:
                                break;
                        }
                }
        }
}

/**
 * fc_rport_plogi_recv_resp - Handle incoming ELS PLOGI response
 * @sp: current sequence in the PLOGI exchange
 * @fp: response frame
 * @rp_arg: Fibre Channel remote port
 *
 * Locking Note: This function will be called without the rport lock
 * held, but it will lock, call an _enter_* function or fc_rport_error
 * and then unlock the rport.
 */
static void fc_rport_plogi_resp(struct fc_seq *sp, struct fc_frame *fp,
                                void *rp_arg)
{
        struct fc_rport *rport = rp_arg;
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;
        struct fc_els_flogi *plp;
        unsigned int tov;
        u16 csp_seq;
        u16 cssp_seq;
        u8 op;

        mutex_lock(&rdata->rp_mutex);

        FC_DEBUG_RPORT("Received a PLOGI response from port (%6x)\n",
                       rport->port_id);

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

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

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

                tov = ntohl(plp->fl_csp.sp_e_d_tov);
                if (ntohs(plp->fl_csp.sp_features) & FC_SP_FT_EDTR)
                        tov /= 1000;
                if (tov > rdata->e_d_tov)
                        rdata->e_d_tov = tov;
                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;
                rport->maxframe_size =
                        fc_plogi_get_maxframe(plp, lport->mfs);

                /*
                 * If the rport is one of the well known addresses
                 * we skip PRLI and RTV and go straight to READY.
                 */
                if (rport->port_id >= FC_FID_DOM_MGR)
                        fc_rport_enter_ready(rport);
                else
                        fc_rport_enter_prli(rport);
        } else
                fc_rport_error(rport, fp);

out:
        fc_frame_free(fp);
err:
        mutex_unlock(&rdata->rp_mutex);
        put_device(&rport->dev);
}

/**
 * fc_rport_enter_plogi - Send Port Login (PLOGI) request to peer
 * @rport: Fibre Channel remote port to send PLOGI to
 *
 * Locking Note: The rport lock is expected to be held before calling
 * this routine.
 */
static void fc_rport_enter_plogi(struct fc_rport *rport)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;
        struct fc_frame *fp;

        FC_DEBUG_RPORT("Port (%6x) entered PLOGI state from %s state\n",
                       rport->port_id, fc_rport_state(rport));

        fc_rport_state_enter(rport, RPORT_ST_PLOGI);

        rport->maxframe_size = FC_MIN_MAX_PAYLOAD;
        fp = fc_frame_alloc(lport, sizeof(struct fc_els_flogi));
        if (!fp) {
                fc_rport_error(rport, fp);
                return;
        }
        rdata->e_d_tov = lport->e_d_tov;

        if (!lport->tt.elsct_send(lport, rport, fp, ELS_PLOGI,
                                  fc_rport_plogi_resp, rport, lport->e_d_tov))
                fc_rport_error(rport, fp);
        else
                get_device(&rport->dev);
}

/**
 * fc_rport_prli_resp - Process Login (PRLI) response handler
 * @sp: current sequence in the PRLI exchange
 * @fp: response frame
 * @rp_arg: Fibre Channel remote port
 *
 * Locking Note: This function will be called without the rport lock
 * held, but it will lock, call an _enter_* function or fc_rport_error
 * and then unlock the rport.
 */
static void fc_rport_prli_resp(struct fc_seq *sp, struct fc_frame *fp,
                               void *rp_arg)
{
        struct fc_rport *rport = rp_arg;
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct {
                struct fc_els_prli prli;
                struct fc_els_spp spp;
        } *pp;
        u32 roles = FC_RPORT_ROLE_UNKNOWN;
        u32 fcp_parm = 0;
        u8 op;

        mutex_lock(&rdata->rp_mutex);

        FC_DEBUG_RPORT("Received a PRLI response from port (%6x)\n",
                       rport->port_id);

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

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

        op = fc_frame_payload_op(fp);
        if (op == ELS_LS_ACC) {
                pp = fc_frame_payload_get(fp, sizeof(*pp));
                if (pp && pp->prli.prli_spp_len >= sizeof(pp->spp)) {
                        fcp_parm = ntohl(pp->spp.spp_params);
                        if (fcp_parm & FCP_SPPF_RETRY)
                                rdata->flags |= FC_RP_FLAGS_RETRY;
                }

                rport->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;

                rport->roles = roles;
                fc_rport_enter_rtv(rport);

        } else {
                FC_DBG("Bad ELS response\n");
                rdata->event = RPORT_EV_FAILED;
                queue_work(rport_event_queue, &rdata->event_work);
        }

out:
        fc_frame_free(fp);
err:
        mutex_unlock(&rdata->rp_mutex);
        put_device(&rport->dev);
}

/**
 * fc_rport_logo_resp - Logout (LOGO) response handler
 * @sp: current sequence in the LOGO exchange
 * @fp: response frame
 * @rp_arg: Fibre Channel remote port
 *
 * Locking Note: This function will be called without the rport lock
 * held, but it will lock, call an _enter_* function or fc_rport_error
 * and then unlock the rport.
 */
static void fc_rport_logo_resp(struct fc_seq *sp, struct fc_frame *fp,
                               void *rp_arg)
{
        struct fc_rport *rport = rp_arg;
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        u8 op;

        mutex_lock(&rdata->rp_mutex);

        FC_DEBUG_RPORT("Received a LOGO response from port (%6x)\n",
                       rport->port_id);

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

        if (rdata->rp_state != RPORT_ST_LOGO) {
                FC_DEBUG_RPORT("Received a LOGO response, but in state %s\n",
                               fc_rport_state(rport));
                goto out;
        }

        op = fc_frame_payload_op(fp);
        if (op == ELS_LS_ACC) {
                fc_rport_enter_rtv(rport);
        } else {
                FC_DBG("Bad ELS response\n");
                rdata->event = RPORT_EV_LOGO;
                queue_work(rport_event_queue, &rdata->event_work);
        }

out:
        fc_frame_free(fp);
err:
        mutex_unlock(&rdata->rp_mutex);
        put_device(&rport->dev);
}

/**
 * fc_rport_enter_prli - Send Process Login (PRLI) request to peer
 * @rport: Fibre Channel remote port to send PRLI to
 *
 * Locking Note: The rport lock is expected to be held before calling
 * this routine.
 */
static void fc_rport_enter_prli(struct fc_rport *rport)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;
        struct {
                struct fc_els_prli prli;
                struct fc_els_spp spp;
        } *pp;
        struct fc_frame *fp;

        FC_DEBUG_RPORT("Port (%6x) entered PRLI state from %s state\n",
                       rport->port_id, fc_rport_state(rport));

        fc_rport_state_enter(rport, RPORT_ST_PRLI);

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

        if (!lport->tt.elsct_send(lport, rport, fp, ELS_PRLI,
                                  fc_rport_prli_resp, rport, lport->e_d_tov))
                fc_rport_error(rport, fp);
        else
                get_device(&rport->dev);
}

/**
 * fc_rport_els_rtv_resp - Request Timeout Value response handler
 * @sp: current sequence in the RTV exchange
 * @fp: response frame
 * @rp_arg: Fibre Channel remote port
 *
 * Many targets don't seem to support this.
 *
 * Locking Note: This function will be called without the rport lock
 * held, but it will lock, call an _enter_* function or fc_rport_error
 * and then unlock the rport.
 */
static void fc_rport_rtv_resp(struct fc_seq *sp, struct fc_frame *fp,
                              void *rp_arg)
{
        struct fc_rport *rport = rp_arg;
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        u8 op;

        mutex_lock(&rdata->rp_mutex);

        FC_DEBUG_RPORT("Received a RTV response from port (%6x)\n",
                       rport->port_id);

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

        if (IS_ERR(fp)) {
                fc_rport_error(rport, 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(rport);

out:
        fc_frame_free(fp);
err:
        mutex_unlock(&rdata->rp_mutex);
        put_device(&rport->dev);
}

/**
 * fc_rport_enter_rtv - Send Request Timeout Value (RTV) request to peer
 * @rport: Fibre Channel remote port to send RTV to
 *
 * Locking Note: The rport lock is expected to be held before calling
 * this routine.
 */
static void fc_rport_enter_rtv(struct fc_rport *rport)
{
        struct fc_frame *fp;
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;

        FC_DEBUG_RPORT("Port (%6x) entered RTV state from %s state\n",
                       rport->port_id, fc_rport_state(rport));

        fc_rport_state_enter(rport, RPORT_ST_RTV);

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

        if (!lport->tt.elsct_send(lport, rport, fp, ELS_RTV,
                                     fc_rport_rtv_resp, rport, lport->e_d_tov))
                fc_rport_error(rport, fp);
        else
                get_device(&rport->dev);
}

/**
 * fc_rport_enter_logo - Send Logout (LOGO) request to peer
 * @rport: Fibre Channel remote port to send LOGO to
 *
 * Locking Note: The rport lock is expected to be held before calling
 * this routine.
 */
static void fc_rport_enter_logo(struct fc_rport *rport)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;
        struct fc_frame *fp;

        FC_DEBUG_RPORT("Port (%6x) entered LOGO state from %s state\n",
                       rport->port_id, fc_rport_state(rport));

        fc_rport_state_enter(rport, RPORT_ST_LOGO);

        fp = fc_frame_alloc(lport, sizeof(struct fc_els_logo));
        if (!fp) {
                fc_rport_error(rport, fp);
                return;
        }

        if (!lport->tt.elsct_send(lport, rport, fp, ELS_LOGO,
                                  fc_rport_logo_resp, rport, lport->e_d_tov))
                fc_rport_error(rport, fp);
        else
                get_device(&rport->dev);
}


/**
 * fc_rport_recv_req - Receive a request from a rport
 * @sp: current sequence in the PLOGI exchange
 * @fp: response frame
 * @rp_arg: Fibre Channel remote port
 *
 * Locking Note: Called without the rport lock held. This
 * function will hold the rport lock, call an _enter_*
 * function and then unlock the rport.
 */
void fc_rport_recv_req(struct fc_seq *sp, struct fc_frame *fp,
                       struct fc_rport *rport)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;

        struct fc_frame_header *fh;
        struct fc_seq_els_data els_data;
        u8 op;

        mutex_lock(&rdata->rp_mutex);

        els_data.fp = NULL;
        els_data.explan = ELS_EXPL_NONE;
        els_data.reason = ELS_RJT_NONE;

        fh = fc_frame_header_get(fp);

        if (fh->fh_r_ctl == FC_RCTL_ELS_REQ && fh->fh_type == FC_TYPE_ELS) {
                op = fc_frame_payload_op(fp);
                switch (op) {
                case ELS_PLOGI:
                        fc_rport_recv_plogi_req(rport, sp, fp);
                        break;
                case ELS_PRLI:
                        fc_rport_recv_prli_req(rport, sp, fp);
                        break;
                case ELS_PRLO:
                        fc_rport_recv_prlo_req(rport, sp, fp);
                        break;
                case ELS_LOGO:
                        fc_rport_recv_logo_req(rport, sp, fp);
                        break;
                case ELS_RRQ:
                        els_data.fp = fp;
                        lport->tt.seq_els_rsp_send(sp, ELS_RRQ, &els_data);
                        break;
                case ELS_REC:
                        els_data.fp = fp;
                        lport->tt.seq_els_rsp_send(sp, ELS_REC, &els_data);
                        break;
                default:
                        els_data.reason = ELS_RJT_UNSUP;
                        lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &els_data);
                        break;
                }
        }

        mutex_unlock(&rdata->rp_mutex);
}

/**
 * fc_rport_recv_plogi_req - Handle incoming Port Login (PLOGI) request
 * @rport: Fibre Channel remote port that initiated PLOGI
 * @sp: current sequence in the PLOGI exchange
 * @fp: PLOGI request frame
 *
 * Locking Note: The rport lock is exected to be held before calling
 * this function.
 */
static void fc_rport_recv_plogi_req(struct fc_rport *rport,
                                    struct fc_seq *sp, struct fc_frame *rx_fp)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;
        struct fc_frame *fp = rx_fp;
        struct fc_exch *ep;
        struct fc_frame_header *fh;
        struct fc_els_flogi *pl;
        struct fc_seq_els_data rjt_data;
        u32 sid;
        u64 wwpn;
        u64 wwnn;
        enum fc_els_rjt_reason reject = 0;
        u32 f_ctl;
        rjt_data.fp = NULL;

        fh = fc_frame_header_get(fp);

        FC_DEBUG_RPORT("Received PLOGI request from port (%6x) "
                       "while in state %s\n", ntoh24(fh->fh_s_id),
                       fc_rport_state(rport));

        sid = ntoh24(fh->fh_s_id);
        pl = fc_frame_payload_get(fp, sizeof(*pl));
        if (!pl) {
                FC_DBG("incoming PLOGI from %x too short\n", sid);
                WARN_ON(1);
                /* XXX TBD: send reject? */
                fc_frame_free(fp);
                return;
        }
        wwpn = get_unaligned_be64(&pl->fl_wwpn);
        wwnn = get_unaligned_be64(&pl->fl_wwnn);

        /*
         * If the session 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_DEBUG_RPORT("incoming PLOGI from %6x wwpn %llx state INIT "
                               "- reject\n", sid, wwpn);
                reject = ELS_RJT_UNSUP;
                break;
        case RPORT_ST_PLOGI:
                FC_DEBUG_RPORT("incoming PLOGI from %x in PLOGI state %d\n",
                               sid, rdata->rp_state);
                if (wwpn < lport->wwpn)
                        reject = ELS_RJT_INPROG;
                break;
        case RPORT_ST_PRLI:
        case RPORT_ST_READY:
                FC_DEBUG_RPORT("incoming PLOGI from %x in logged-in state %d "
                               "- ignored for now\n", sid, rdata->rp_state);
                /* XXX TBD - should reset */
                break;
        case RPORT_ST_NONE:
        default:
                FC_DEBUG_RPORT("incoming PLOGI from %x in unexpected "
                               "state %d\n", sid, rdata->rp_state);
                break;
        }

        if (reject) {
                rjt_data.reason = reject;
                rjt_data.explan = ELS_EXPL_NONE;
                lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
                fc_frame_free(fp);
        } else {
                fp = fc_frame_alloc(lport, sizeof(*pl));
                if (fp == NULL) {
                        fp = rx_fp;
                        rjt_data.reason = ELS_RJT_UNAB;
                        rjt_data.explan = ELS_EXPL_NONE;
                        lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
                        fc_frame_free(fp);
                } else {
                        sp = lport->tt.seq_start_next(sp);
                        WARN_ON(!sp);
                        fc_rport_set_name(rport, wwpn, wwnn);

                        /*
                         * Get session payload size from incoming PLOGI.
                         */
                        rport->maxframe_size =
                                fc_plogi_get_maxframe(pl, lport->mfs);
                        fc_frame_free(rx_fp);
                        fc_plogi_fill(lport, fp, ELS_LS_ACC);

                        /*
                         * Send LS_ACC.  If this fails,
                         * the originator should retry.
                         */
                        f_ctl = FC_FC_EX_CTX | FC_FC_LAST_SEQ;
                        f_ctl |= FC_FC_END_SEQ | FC_FC_SEQ_INIT;
                        ep = fc_seq_exch(sp);
                        fc_fill_fc_hdr(fp, FC_RCTL_ELS_REP, ep->did, ep->sid,
                                       FC_TYPE_ELS, f_ctl, 0);
                        lport->tt.seq_send(lport, sp, fp);
                        if (rdata->rp_state == RPORT_ST_PLOGI)
                                fc_rport_enter_prli(rport);
                }
        }
}

/**
 * fc_rport_recv_prli_req - Handle incoming Process Login (PRLI) request
 * @rport: Fibre Channel remote port that initiated PRLI
 * @sp: current sequence in the PRLI exchange
 * @fp: PRLI request frame
 *
 * Locking Note: The rport lock is exected to be held before calling
 * this function.
 */
static void fc_rport_recv_prli_req(struct fc_rport *rport,
                                   struct fc_seq *sp, struct fc_frame *rx_fp)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;
        struct fc_exch *ep;
        struct fc_frame *fp;
        struct fc_frame_header *fh;
        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_rjt_reason reason = ELS_RJT_UNAB;
        enum fc_els_rjt_explan explan = ELS_EXPL_NONE;
        enum fc_els_spp_resp resp;
        struct fc_seq_els_data rjt_data;
        u32 f_ctl;
        u32 fcp_parm;
        u32 roles = FC_RPORT_ROLE_UNKNOWN;
        rjt_data.fp = NULL;

        fh = fc_frame_header_get(rx_fp);

        FC_DEBUG_RPORT("Received PRLI request from port (%6x) "
                       "while in state %s\n", ntoh24(fh->fh_s_id),
                       fc_rport_state(rport));

        switch (rdata->rp_state) {
        case RPORT_ST_PRLI:
        case RPORT_ST_READY:
                reason = ELS_RJT_NONE;
                break;
        default:
                break;
        }
        len = fr_len(rx_fp) - sizeof(*fh);
        pp = fc_frame_payload_get(rx_fp, sizeof(*pp));
        if (pp == NULL) {
                reason = ELS_RJT_PROT;
                explan = ELS_EXPL_INV_LEN;
        } else {
                plen = ntohs(pp->prli.prli_len);
                if ((plen % 4) != 0 || plen > len) {
                        reason = ELS_RJT_PROT;
                        explan = ELS_EXPL_INV_LEN;
                } else if (plen < len) {
                        len = plen;
                }
                plen = pp->prli.prli_spp_len;
                if ((plen % 4) != 0 || plen < sizeof(*spp) ||
                    plen > len || len < sizeof(*pp)) {
                        reason = ELS_RJT_PROT;
                        explan = ELS_EXPL_INV_LEN;
                }
                rspp = &pp->spp;
        }
        if (reason != ELS_RJT_NONE ||
            (fp = fc_frame_alloc(lport, len)) == NULL) {
                rjt_data.reason = reason;
                rjt_data.explan = explan;
                lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
        } else {
                sp = lport->tt.seq_start_next(sp);
                WARN_ON(!sp);
                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;
                while (len >= plen) {
                        spp->spp_type = rspp->spp_type;
                        spp->spp_type_ext = rspp->spp_type_ext;
                        spp->spp_flags = rspp->spp_flags & FC_SPP_EST_IMG_PAIR;
                        resp = FC_SPP_RESP_ACK;
                        if (rspp->spp_flags & FC_SPP_RPA_VAL)
                                resp = FC_SPP_RESP_NO_PA;
                        switch (rspp->spp_type) {
                        case 0: /* common to all FC-4 types */
                                break;
                        case FC_TYPE_FCP:
                                fcp_parm = ntohl(rspp->spp_params);
                                if (fcp_parm * FCP_SPPF_RETRY)
                                        rdata->flags |= FC_RP_FLAGS_RETRY;
                                rport->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;
                                rport->roles = roles;

                                spp->spp_params =
                                        htonl(lport->service_params);
                                break;
                        default:
                                resp = FC_SPP_RESP_INVL;
                                break;
                        }
                        spp->spp_flags |= resp;
                        len -= plen;
                        rspp = (struct fc_els_spp *)((char *)rspp + plen);
                        spp = (struct fc_els_spp *)((char *)spp + plen);
                }

                /*
                 * Send LS_ACC.  If this fails, the originator should retry.
                 */
                f_ctl = FC_FC_EX_CTX | FC_FC_LAST_SEQ;
                f_ctl |= FC_FC_END_SEQ | FC_FC_SEQ_INIT;
                ep = fc_seq_exch(sp);
                fc_fill_fc_hdr(fp, FC_RCTL_ELS_REP, ep->did, ep->sid,
                               FC_TYPE_ELS, f_ctl, 0);
                lport->tt.seq_send(lport, sp, fp);

                /*
                 * Get lock and re-check state.
                 */
                switch (rdata->rp_state) {
                case RPORT_ST_PRLI:
                        fc_rport_enter_ready(rport);
                        break;
                case RPORT_ST_READY:
                        break;
                default:
                        break;
                }
        }
        fc_frame_free(rx_fp);
}

/**
 * fc_rport_recv_prlo_req - Handle incoming Process Logout (PRLO) request
 * @rport: Fibre Channel remote port that initiated PRLO
 * @sp: current sequence in the PRLO exchange
 * @fp: PRLO request frame
 *
 * Locking Note: The rport lock is exected to be held before calling
 * this function.
 */
static void fc_rport_recv_prlo_req(struct fc_rport *rport, struct fc_seq *sp,
                                   struct fc_frame *fp)
{
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;

        struct fc_frame_header *fh;
        struct fc_seq_els_data rjt_data;

        fh = fc_frame_header_get(fp);

        FC_DEBUG_RPORT("Received PRLO request from port (%6x) "
                       "while in state %s\n", ntoh24(fh->fh_s_id),
                       fc_rport_state(rport));

        rjt_data.fp = NULL;
        rjt_data.reason = ELS_RJT_UNAB;
        rjt_data.explan = ELS_EXPL_NONE;
        lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
        fc_frame_free(fp);
}

/**
 * fc_rport_recv_logo_req - Handle incoming Logout (LOGO) request
 * @rport: Fibre Channel remote port that initiated LOGO
 * @sp: current sequence in the LOGO exchange
 * @fp: LOGO request frame
 *
 * Locking Note: The rport lock is exected to be held before calling
 * this function.
 */
static void fc_rport_recv_logo_req(struct fc_rport *rport, struct fc_seq *sp,
                                   struct fc_frame *fp)
{
        struct fc_frame_header *fh;
        struct fc_rport_libfc_priv *rdata = rport->dd_data;
        struct fc_lport *lport = rdata->local_port;

        fh = fc_frame_header_get(fp);

        FC_DEBUG_RPORT("Received LOGO request from port (%6x) "
                       "while in state %s\n", ntoh24(fh->fh_s_id),
                       fc_rport_state(rport));

        rdata->event = RPORT_EV_LOGO;
        queue_work(rport_event_queue, &rdata->event_work);

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

        return 0;
}
EXPORT_SYMBOL(fc_rport_init);

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

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

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