smp_call_function_single(): be slightly less stupid, fix #2

[linux-2.6/mini2440.git] / drivers / scsi / libfc / fc_lport.c

/*
 * Copyright(c) 2007 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
 */

/*
 * PORT LOCKING NOTES
 *
 * These comments only apply to the 'port code' which consists of the lport,
 * disc and rport blocks.
 *
 * MOTIVATION
 *
 * The lport, disc and rport blocks all have mutexes that are used to protect
 * those objects. The main motivation for these locks is to prevent from
 * having an lport reset just before we send a frame. In that scenario the
 * lport's FID would get set to zero and then we'd send a frame with an
 * invalid SID. We also need to ensure that states don't change unexpectedly
 * while processing another state.
 *
 * HEIRARCHY
 *
 * The following heirarchy defines the locking rules. A greater lock
 * may be held before acquiring a lesser lock, but a lesser lock should never
 * be held while attempting to acquire a greater lock. Here is the heirarchy-
 *
 * lport > disc, lport > rport, disc > rport
 *
 * CALLBACKS
 *
 * The callbacks cause complications with this scheme. There is a callback
 * from the rport (to either lport or disc) and a callback from disc
 * (to the lport).
 *
 * As rports exit the rport state machine a callback is made to the owner of
 * the rport to notify success or failure. Since the callback is likely to
 * cause the lport or disc to grab its lock we cannot hold the rport lock
 * while making the callback. To ensure that the rport is not free'd while
 * processing the callback the rport callbacks are serialized through a
 * single-threaded workqueue. An rport would never be free'd while in a
 * callback handler becuase no other rport work in this queue can be executed
 * at the same time.
 *
 * When discovery succeeds or fails a callback is made to the lport as
 * notification. Currently, succesful discovery causes the lport to take no
 * action. A failure will cause the lport to reset. There is likely a circular
 * locking problem with this implementation.
 */

/*
 * LPORT LOCKING
 *
 * The critical sections protected by the lport's mutex are quite broad and
 * may be improved upon in the future. The lport code and its locking doesn't
 * influence the I/O path, so excessive locking doesn't penalize I/O
 * performance.
 *
 * The strategy is to lock whenever processing a request or response. Note
 * that every _enter_* function corresponds to a state change. They generally
 * change the lports state and then send a request out on the wire. We lock
 * before calling any of these functions to protect that state change. This
 * means that the entry points into the lport block manage the locks while
 * the state machine can transition between states (i.e. _enter_* functions)
 * while always staying protected.
 *
 * When handling responses we also hold the lport mutex broadly. When the
 * lport receives the response frame it locks the mutex and then calls the
 * appropriate handler for the particuar response. Generally a response will
 * trigger a state change and so the lock must already be held.
 *
 * Retries also have to consider the locking. The retries occur from a work
 * context and the work function will lock the lport and then retry the state
 * (i.e. _enter_* function).
 */

#include <linux/timer.h>
#include <asm/unaligned.h>

#include <scsi/fc/fc_gs.h>

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

/* Fabric IDs to use for point-to-point mode, chosen on whims. */
#define FC_LOCAL_PTP_FID_LO   0x010101
#define FC_LOCAL_PTP_FID_HI   0x010102

#define DNS_DELAY             3 /* Discovery delay after RSCN (in seconds)*/

static int fc_lport_debug;

#define FC_DEBUG_LPORT(fmt...)                  \
        do {                                    \
                if (fc_lport_debug)             \
                        FC_DBG(fmt);            \
        } while (0)

static void fc_lport_error(struct fc_lport *, struct fc_frame *);

static void fc_lport_enter_reset(struct fc_lport *);
static void fc_lport_enter_flogi(struct fc_lport *);
static void fc_lport_enter_dns(struct fc_lport *);
static void fc_lport_enter_rpn_id(struct fc_lport *);
static void fc_lport_enter_rft_id(struct fc_lport *);
static void fc_lport_enter_scr(struct fc_lport *);
static void fc_lport_enter_ready(struct fc_lport *);
static void fc_lport_enter_logo(struct fc_lport *);

static const char *fc_lport_state_names[] = {
        [LPORT_ST_NONE] =     "none",
        [LPORT_ST_FLOGI] =    "FLOGI",
        [LPORT_ST_DNS] =      "dNS",
        [LPORT_ST_RPN_ID] =   "RPN_ID",
        [LPORT_ST_RFT_ID] =   "RFT_ID",
        [LPORT_ST_SCR] =      "SCR",
        [LPORT_ST_READY] =    "Ready",
        [LPORT_ST_LOGO] =     "LOGO",
        [LPORT_ST_RESET] =    "reset",
};

static int fc_frame_drop(struct fc_lport *lport, struct fc_frame *fp)
{
        fc_frame_free(fp);
        return 0;
}

/**
 * fc_lport_rport_callback - Event handler for rport events
 * @lport: The lport which is receiving the event
 * @rport: The rport which the event has occured on
 * @event: The event that occured
 *
 * Locking Note: The rport lock should not be held when calling
 *               this function.
 */
static void fc_lport_rport_callback(struct fc_lport *lport,
                                    struct fc_rport *rport,
                                    enum fc_rport_event event)
{
        FC_DEBUG_LPORT("Received a %d event for port (%6x)\n", event,
                       rport->port_id);

        switch (event) {
        case RPORT_EV_CREATED:
                if (rport->port_id == FC_FID_DIR_SERV) {
                        mutex_lock(&lport->lp_mutex);
                        if (lport->state == LPORT_ST_DNS) {
                                lport->dns_rp = rport;
                                fc_lport_enter_rpn_id(lport);
                        } else {
                                FC_DEBUG_LPORT("Received an CREATED event on "
                                               "port (%6x) for the directory "
                                               "server, but the lport is not "
                                               "in the DNS state, it's in the "
                                               "%d state", rport->port_id,
                                               lport->state);
                                lport->tt.rport_logoff(rport);
                        }
                        mutex_unlock(&lport->lp_mutex);
                } else
                        FC_DEBUG_LPORT("Received an event for port (%6x) "
                                       "which is not the directory server\n",
                                       rport->port_id);
                break;
        case RPORT_EV_LOGO:
        case RPORT_EV_FAILED:
        case RPORT_EV_STOP:
                if (rport->port_id == FC_FID_DIR_SERV) {
                        mutex_lock(&lport->lp_mutex);
                        lport->dns_rp = NULL;
                        mutex_unlock(&lport->lp_mutex);

                } else
                        FC_DEBUG_LPORT("Received an event for port (%6x) "
                                       "which is not the directory server\n",
                                       rport->port_id);
                break;
        case RPORT_EV_NONE:
                break;
        }
}

/**
 * fc_lport_state - Return a string which represents the lport's state
 * @lport: The lport whose state is to converted to a string
 */
static const char *fc_lport_state(struct fc_lport *lport)
{
        const char *cp;

        cp = fc_lport_state_names[lport->state];
        if (!cp)
                cp = "unknown";
        return cp;
}

/**
 * fc_lport_ptp_setup - Create an rport for point-to-point mode
 * @lport: The lport to attach the ptp rport to
 * @fid: The FID of the ptp rport
 * @remote_wwpn: The WWPN of the ptp rport
 * @remote_wwnn: The WWNN of the ptp rport
 */
static void fc_lport_ptp_setup(struct fc_lport *lport,
                               u32 remote_fid, u64 remote_wwpn,
                               u64 remote_wwnn)
{
        struct fc_disc_port dp;

        dp.lp = lport;
        dp.ids.port_id = remote_fid;
        dp.ids.port_name = remote_wwpn;
        dp.ids.node_name = remote_wwnn;
        dp.ids.roles = FC_RPORT_ROLE_UNKNOWN;

        if (lport->ptp_rp) {
                lport->tt.rport_logoff(lport->ptp_rp);
                lport->ptp_rp = NULL;
        }

        lport->ptp_rp = fc_rport_rogue_create(&dp);

        lport->tt.rport_login(lport->ptp_rp);

        fc_lport_enter_ready(lport);
}

void fc_get_host_port_type(struct Scsi_Host *shost)
{
        /* TODO - currently just NPORT */
        fc_host_port_type(shost) = FC_PORTTYPE_NPORT;
}
EXPORT_SYMBOL(fc_get_host_port_type);

void fc_get_host_port_state(struct Scsi_Host *shost)
{
        struct fc_lport *lp = shost_priv(shost);

        if ((lp->link_status & FC_LINK_UP) == FC_LINK_UP)
                fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
        else
                fc_host_port_state(shost) = FC_PORTSTATE_OFFLINE;
}
EXPORT_SYMBOL(fc_get_host_port_state);

void fc_get_host_speed(struct Scsi_Host *shost)
{
        struct fc_lport *lport = shost_priv(shost);

        fc_host_speed(shost) = lport->link_speed;
}
EXPORT_SYMBOL(fc_get_host_speed);

struct fc_host_statistics *fc_get_host_stats(struct Scsi_Host *shost)
{
        int i;
        struct fc_host_statistics *fcoe_stats;
        struct fc_lport *lp = shost_priv(shost);
        struct timespec v0, v1;

        fcoe_stats = &lp->host_stats;
        memset(fcoe_stats, 0, sizeof(struct fc_host_statistics));

        jiffies_to_timespec(jiffies, &v0);
        jiffies_to_timespec(lp->boot_time, &v1);
        fcoe_stats->seconds_since_last_reset = (v0.tv_sec - v1.tv_sec);

        for_each_online_cpu(i) {
                struct fcoe_dev_stats *stats = lp->dev_stats[i];
                if (stats == NULL)
                        continue;
                fcoe_stats->tx_frames += stats->TxFrames;
                fcoe_stats->tx_words += stats->TxWords;
                fcoe_stats->rx_frames += stats->RxFrames;
                fcoe_stats->rx_words += stats->RxWords;
                fcoe_stats->error_frames += stats->ErrorFrames;
                fcoe_stats->invalid_crc_count += stats->InvalidCRCCount;
                fcoe_stats->fcp_input_requests += stats->InputRequests;
                fcoe_stats->fcp_output_requests += stats->OutputRequests;
                fcoe_stats->fcp_control_requests += stats->ControlRequests;
                fcoe_stats->fcp_input_megabytes += stats->InputMegabytes;
                fcoe_stats->fcp_output_megabytes += stats->OutputMegabytes;
                fcoe_stats->link_failure_count += stats->LinkFailureCount;
        }
        fcoe_stats->lip_count = -1;
        fcoe_stats->nos_count = -1;
        fcoe_stats->loss_of_sync_count = -1;
        fcoe_stats->loss_of_signal_count = -1;
        fcoe_stats->prim_seq_protocol_err_count = -1;
        fcoe_stats->dumped_frames = -1;
        return fcoe_stats;
}
EXPORT_SYMBOL(fc_get_host_stats);

/*
 * Fill in FLOGI command for request.
 */
static void
fc_lport_flogi_fill(struct fc_lport *lport, struct fc_els_flogi *flogi,
                    unsigned int op)
{
        struct fc_els_csp *sp;
        struct fc_els_cssp *cp;

        memset(flogi, 0, sizeof(*flogi));
        flogi->fl_cmd = (u8) op;
        put_unaligned_be64(lport->wwpn, &flogi->fl_wwpn);
        put_unaligned_be64(lport->wwnn, &flogi->fl_wwnn);
        sp = &flogi->fl_csp;
        sp->sp_hi_ver = 0x20;
        sp->sp_lo_ver = 0x20;
        sp->sp_bb_cred = htons(10);     /* this gets set by gateway */
        sp->sp_bb_data = htons((u16) lport->mfs);
        cp = &flogi->fl_cssp[3 - 1];    /* class 3 parameters */
        cp->cp_class = htons(FC_CPC_VALID | FC_CPC_SEQ);
        if (op != ELS_FLOGI) {
                sp->sp_features = htons(FC_SP_FT_CIRO);
                sp->sp_tot_seq = htons(255);    /* seq. we accept */
                sp->sp_rel_off = htons(0x1f);
                sp->sp_e_d_tov = htonl(lport->e_d_tov);

                cp->cp_rdfs = htons((u16) lport->mfs);
                cp->cp_con_seq = htons(255);
                cp->cp_open_seq = 1;
        }
}

/*
 * Add a supported FC-4 type.
 */
static void fc_lport_add_fc4_type(struct fc_lport *lport, enum fc_fh_type type)
{
        __be32 *mp;

        mp = &lport->fcts.ff_type_map[type / FC_NS_BPW];
        *mp = htonl(ntohl(*mp) | 1UL << (type % FC_NS_BPW));
}

/**
 * fc_lport_recv_rlir_req - Handle received Registered Link Incident Report.
 * @lport: Fibre Channel local port recieving the RLIR
 * @sp: current sequence in the RLIR exchange
 * @fp: RLIR request frame
 *
 * Locking Note: The lport lock is exected to be held before calling
 * this function.
 */
static void fc_lport_recv_rlir_req(struct fc_seq *sp, struct fc_frame *fp,
                                   struct fc_lport *lport)
{
        FC_DEBUG_LPORT("Received RLIR request while in state %s\n",
                       fc_lport_state(lport));

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

/**
 * fc_lport_recv_echo_req - Handle received ECHO request
 * @lport: Fibre Channel local port recieving the ECHO
 * @sp: current sequence in the ECHO exchange
 * @fp: ECHO request frame
 *
 * Locking Note: The lport lock is exected to be held before calling
 * this function.
 */
static void fc_lport_recv_echo_req(struct fc_seq *sp, struct fc_frame *in_fp,
                                   struct fc_lport *lport)
{
        struct fc_frame *fp;
        struct fc_exch *ep = fc_seq_exch(sp);
        unsigned int len;
        void *pp;
        void *dp;
        u32 f_ctl;

        FC_DEBUG_LPORT("Received RLIR request while in state %s\n",
                       fc_lport_state(lport));

        len = fr_len(in_fp) - sizeof(struct fc_frame_header);
        pp = fc_frame_payload_get(in_fp, len);

        if (len < sizeof(__be32))
                len = sizeof(__be32);

        fp = fc_frame_alloc(lport, len);
        if (fp) {
                dp = fc_frame_payload_get(fp, len);
                memcpy(dp, pp, len);
                *((u32 *)dp) = htonl(ELS_LS_ACC << 24);
                sp = lport->tt.seq_start_next(sp);
                f_ctl = FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ;
                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);
        }
        fc_frame_free(in_fp);
}

/**
 * fc_lport_recv_echo_req - Handle received Request Node ID data request
 * @lport: Fibre Channel local port recieving the RNID
 * @sp: current sequence in the RNID exchange
 * @fp: RNID request frame
 *
 * Locking Note: The lport lock is exected to be held before calling
 * this function.
 */
static void fc_lport_recv_rnid_req(struct fc_seq *sp, struct fc_frame *in_fp,
                                   struct fc_lport *lport)
{
        struct fc_frame *fp;
        struct fc_exch *ep = fc_seq_exch(sp);
        struct fc_els_rnid *req;
        struct {
                struct fc_els_rnid_resp rnid;
                struct fc_els_rnid_cid cid;
                struct fc_els_rnid_gen gen;
        } *rp;
        struct fc_seq_els_data rjt_data;
        u8 fmt;
        size_t len;
        u32 f_ctl;

        FC_DEBUG_LPORT("Received RNID request while in state %s\n",
                       fc_lport_state(lport));

        req = fc_frame_payload_get(in_fp, sizeof(*req));
        if (!req) {
                rjt_data.fp = NULL;
                rjt_data.reason = ELS_RJT_LOGIC;
                rjt_data.explan = ELS_EXPL_NONE;
                lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
        } else {
                fmt = req->rnid_fmt;
                len = sizeof(*rp);
                if (fmt != ELS_RNIDF_GEN ||
                    ntohl(lport->rnid_gen.rnid_atype) == 0) {
                        fmt = ELS_RNIDF_NONE;   /* nothing to provide */
                        len -= sizeof(rp->gen);
                }
                fp = fc_frame_alloc(lport, len);
                if (fp) {
                        rp = fc_frame_payload_get(fp, len);
                        memset(rp, 0, len);
                        rp->rnid.rnid_cmd = ELS_LS_ACC;
                        rp->rnid.rnid_fmt = fmt;
                        rp->rnid.rnid_cid_len = sizeof(rp->cid);
                        rp->cid.rnid_wwpn = htonll(lport->wwpn);
                        rp->cid.rnid_wwnn = htonll(lport->wwnn);
                        if (fmt == ELS_RNIDF_GEN) {
                                rp->rnid.rnid_sid_len = sizeof(rp->gen);
                                memcpy(&rp->gen, &lport->rnid_gen,
                                       sizeof(rp->gen));
                        }
                        sp = lport->tt.seq_start_next(sp);
                        f_ctl = FC_FC_EX_CTX | FC_FC_LAST_SEQ;
                        f_ctl |= FC_FC_END_SEQ | FC_FC_SEQ_INIT;
                        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);
                }
        }
        fc_frame_free(in_fp);
}

/**
 * fc_lport_recv_adisc_req - Handle received Address Discovery Request
 * @lport: Fibre Channel local port recieving the ADISC
 * @sp: current sequence in the ADISC exchange
 * @fp: ADISC request frame
 *
 * Locking Note: The lport lock is expected to be held before calling
 * this function.
 */
static void fc_lport_recv_adisc_req(struct fc_seq *sp, struct fc_frame *in_fp,
                                    struct fc_lport *lport)
{
        struct fc_frame *fp;
        struct fc_exch *ep = fc_seq_exch(sp);
        struct fc_els_adisc *req, *rp;
        struct fc_seq_els_data rjt_data;
        size_t len;
        u32 f_ctl;

        FC_DEBUG_LPORT("Received ADISC request while in state %s\n",
                       fc_lport_state(lport));

        req = fc_frame_payload_get(in_fp, sizeof(*req));
        if (!req) {
                rjt_data.fp = NULL;
                rjt_data.reason = ELS_RJT_LOGIC;
                rjt_data.explan = ELS_EXPL_NONE;
                lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
        } else {
                len = sizeof(*rp);
                fp = fc_frame_alloc(lport, len);
                if (fp) {
                        rp = fc_frame_payload_get(fp, len);
                        memset(rp, 0, len);
                        rp->adisc_cmd = ELS_LS_ACC;
                        rp->adisc_wwpn = htonll(lport->wwpn);
                        rp->adisc_wwnn = htonll(lport->wwnn);
                        hton24(rp->adisc_port_id,
                               fc_host_port_id(lport->host));
                        sp = lport->tt.seq_start_next(sp);
                        f_ctl = FC_FC_EX_CTX | FC_FC_LAST_SEQ;
                        f_ctl |= FC_FC_END_SEQ | FC_FC_SEQ_INIT;
                        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);
                }
        }
        fc_frame_free(in_fp);
}

/**
 * fc_lport_recv_logo_req - Handle received fabric LOGO request
 * @lport: Fibre Channel local port recieving the LOGO
 * @sp: current sequence in the LOGO exchange
 * @fp: LOGO request frame
 *
 * Locking Note: The lport lock is exected to be held before calling
 * this function.
 */
static void fc_lport_recv_logo_req(struct fc_seq *sp, struct fc_frame *fp,
                                   struct fc_lport *lport)
{
        lport->tt.seq_els_rsp_send(sp, ELS_LS_ACC, NULL);
        fc_lport_enter_reset(lport);
        fc_frame_free(fp);
}

/**
 * fc_fabric_login - Start the lport state machine
 * @lport: The lport that should log into the fabric
 *
 * Locking Note: This function should not be called
 *               with the lport lock held.
 */
int fc_fabric_login(struct fc_lport *lport)
{
        int rc = -1;

        mutex_lock(&lport->lp_mutex);
        if (lport->state == LPORT_ST_NONE) {
                fc_lport_enter_reset(lport);
                rc = 0;
        }
        mutex_unlock(&lport->lp_mutex);

        return rc;
}
EXPORT_SYMBOL(fc_fabric_login);

/**
 * fc_linkup - Handler for transport linkup events
 * @lport: The lport whose link is up
 */
void fc_linkup(struct fc_lport *lport)
{
        FC_DEBUG_LPORT("Link is up for port (%6x)\n",
                       fc_host_port_id(lport->host));

        mutex_lock(&lport->lp_mutex);
        if ((lport->link_status & FC_LINK_UP) != FC_LINK_UP) {
                lport->link_status |= FC_LINK_UP;

                if (lport->state == LPORT_ST_RESET)
                        fc_lport_enter_flogi(lport);
        }
        mutex_unlock(&lport->lp_mutex);
}
EXPORT_SYMBOL(fc_linkup);

/**
 * fc_linkdown - Handler for transport linkdown events
 * @lport: The lport whose link is down
 */
void fc_linkdown(struct fc_lport *lport)
{
        mutex_lock(&lport->lp_mutex);
        FC_DEBUG_LPORT("Link is down for port (%6x)\n",
                       fc_host_port_id(lport->host));

        if ((lport->link_status & FC_LINK_UP) == FC_LINK_UP) {
                lport->link_status &= ~(FC_LINK_UP);
                fc_lport_enter_reset(lport);
                lport->tt.fcp_cleanup(lport);
        }
        mutex_unlock(&lport->lp_mutex);
}
EXPORT_SYMBOL(fc_linkdown);

/**
 * fc_pause - Pause the flow of frames
 * @lport: The lport to be paused
 */
void fc_pause(struct fc_lport *lport)
{
        mutex_lock(&lport->lp_mutex);
        lport->link_status |= FC_PAUSE;
        mutex_unlock(&lport->lp_mutex);
}
EXPORT_SYMBOL(fc_pause);

/**
 * fc_unpause - Unpause the flow of frames
 * @lport: The lport to be unpaused
 */
void fc_unpause(struct fc_lport *lport)
{
        mutex_lock(&lport->lp_mutex);
        lport->link_status &= ~(FC_PAUSE);
        mutex_unlock(&lport->lp_mutex);
}
EXPORT_SYMBOL(fc_unpause);

/**
 * fc_fabric_logoff - Logout of the fabric
 * @lport:            fc_lport pointer to logoff the fabric
 *
 * Return value:
 *      0 for success, -1 for failure
 **/
int fc_fabric_logoff(struct fc_lport *lport)
{
        lport->tt.disc_stop_final(lport);
        mutex_lock(&lport->lp_mutex);
        fc_lport_enter_logo(lport);
        mutex_unlock(&lport->lp_mutex);
        return 0;
}
EXPORT_SYMBOL(fc_fabric_logoff);

/**
 * fc_lport_destroy - unregister a fc_lport
 * @lport:            fc_lport pointer to unregister
 *
 * Return value:
 *      None
 * Note:
 * exit routine for fc_lport instance
 * clean-up all the allocated memory
 * and free up other system resources.
 *
 **/
int fc_lport_destroy(struct fc_lport *lport)
{
        lport->tt.frame_send = fc_frame_drop;
        lport->tt.fcp_abort_io(lport);
        lport->tt.exch_mgr_reset(lport->emp, 0, 0);
        return 0;
}
EXPORT_SYMBOL(fc_lport_destroy);

/**
 * fc_set_mfs - sets up the mfs for the corresponding fc_lport
 * @lport: fc_lport pointer to unregister
 * @mfs: the new mfs for fc_lport
 *
 * Set mfs for the given fc_lport to the new mfs.
 *
 * Return: 0 for success
 *
 **/
int fc_set_mfs(struct fc_lport *lport, u32 mfs)
{
        unsigned int old_mfs;
        int rc = -EINVAL;

        mutex_lock(&lport->lp_mutex);

        old_mfs = lport->mfs;

        if (mfs >= FC_MIN_MAX_FRAME) {
                mfs &= ~3;
                if (mfs > FC_MAX_FRAME)
                        mfs = FC_MAX_FRAME;
                mfs -= sizeof(struct fc_frame_header);
                lport->mfs = mfs;
                rc = 0;
        }

        if (!rc && mfs < old_mfs)
                fc_lport_enter_reset(lport);

        mutex_unlock(&lport->lp_mutex);

        return rc;
}
EXPORT_SYMBOL(fc_set_mfs);

/**
 * fc_lport_disc_callback - Callback for discovery events
 * @lport: FC local port
 * @event: The discovery event
 */
void fc_lport_disc_callback(struct fc_lport *lport, enum fc_disc_event event)
{
        switch (event) {
        case DISC_EV_SUCCESS:
                FC_DEBUG_LPORT("Got a SUCCESS event for port (%6x)\n",
                               fc_host_port_id(lport->host));
                break;
        case DISC_EV_FAILED:
                FC_DEBUG_LPORT("Got a FAILED event for port (%6x)\n",
                               fc_host_port_id(lport->host));
                mutex_lock(&lport->lp_mutex);
                fc_lport_enter_reset(lport);
                mutex_unlock(&lport->lp_mutex);
                break;
        case DISC_EV_NONE:
                WARN_ON(1);
                break;
        }
}

/**
 * fc_rport_enter_ready - Enter the ready state and start discovery
 * @lport: Fibre Channel local port that is ready
 *
 * Locking Note: The lport lock is expected to be held before calling
 * this routine.
 */
static void fc_lport_enter_ready(struct fc_lport *lport)
{
        FC_DEBUG_LPORT("Port (%6x) entered Ready from state %s\n",
                       fc_host_port_id(lport->host), fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_READY);

        lport->tt.disc_start(fc_lport_disc_callback, lport);
}

/**
 * fc_lport_recv_flogi_req - Receive a FLOGI request
 * @sp_in: The sequence the FLOGI is on
 * @rx_fp: The frame the FLOGI is in
 * @lport: The lport that recieved the request
 *
 * A received FLOGI request indicates a point-to-point connection.
 * Accept it with the common service parameters indicating our N port.
 * Set up to do a PLOGI if we have the higher-number WWPN.
 *
 * Locking Note: The lport lock is exected to be held before calling
 * this function.
 */
static void fc_lport_recv_flogi_req(struct fc_seq *sp_in,
                                    struct fc_frame *rx_fp,
                                    struct fc_lport *lport)
{
        struct fc_frame *fp;
        struct fc_frame_header *fh;
        struct fc_seq *sp;
        struct fc_exch *ep;
        struct fc_els_flogi *flp;
        struct fc_els_flogi *new_flp;
        u64 remote_wwpn;
        u32 remote_fid;
        u32 local_fid;
        u32 f_ctl;

        FC_DEBUG_LPORT("Received FLOGI request while in state %s\n",
                       fc_lport_state(lport));

        fh = fc_frame_header_get(rx_fp);
        remote_fid = ntoh24(fh->fh_s_id);
        flp = fc_frame_payload_get(rx_fp, sizeof(*flp));
        if (!flp)
                goto out;
        remote_wwpn = get_unaligned_be64(&flp->fl_wwpn);
        if (remote_wwpn == lport->wwpn) {
                FC_DBG("FLOGI from port with same WWPN %llx "
                       "possible configuration error\n", remote_wwpn);
                goto out;
        }
        FC_DBG("FLOGI from port WWPN %llx\n", remote_wwpn);

        /*
         * XXX what is the right thing to do for FIDs?
         * The originator might expect our S_ID to be 0xfffffe.
         * But if so, both of us could end up with the same FID.
         */
        local_fid = FC_LOCAL_PTP_FID_LO;
        if (remote_wwpn < lport->wwpn) {
                local_fid = FC_LOCAL_PTP_FID_HI;
                if (!remote_fid || remote_fid == local_fid)
                        remote_fid = FC_LOCAL_PTP_FID_LO;
        } else if (!remote_fid) {
                remote_fid = FC_LOCAL_PTP_FID_HI;
        }

        fc_host_port_id(lport->host) = local_fid;

        fp = fc_frame_alloc(lport, sizeof(*flp));
        if (fp) {
                sp = lport->tt.seq_start_next(fr_seq(rx_fp));
                new_flp = fc_frame_payload_get(fp, sizeof(*flp));
                fc_lport_flogi_fill(lport, new_flp, ELS_FLOGI);
                new_flp->fl_cmd = (u8) ELS_LS_ACC;

                /*
                 * Send the response.  If this fails, the originator should
                 * repeat the sequence.
                 */
                f_ctl = FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ;
                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);

        } else {
                fc_lport_error(lport, fp);
        }
        fc_lport_ptp_setup(lport, remote_fid, remote_wwpn,
                           get_unaligned_be64(&flp->fl_wwnn));

        lport->tt.disc_start(fc_lport_disc_callback, lport);

out:
        sp = fr_seq(rx_fp);
        fc_frame_free(rx_fp);
}

/**
 * fc_lport_recv_req - The generic lport request handler
 * @lport: The lport that received the request
 * @sp: The sequence the request is on
 * @fp: The frame the request is in
 *
 * This function will see if the lport handles the request or
 * if an rport should handle the request.
 *
 * Locking Note: This function should not be called with the lport
 *               lock held becuase it will grab the lock.
 */
static void fc_lport_recv_req(struct fc_lport *lport, struct fc_seq *sp,
                              struct fc_frame *fp)
{
        struct fc_frame_header *fh = fc_frame_header_get(fp);
        void (*recv) (struct fc_seq *, struct fc_frame *, struct fc_lport *);
        struct fc_rport *rport;
        u32 s_id;
        u32 d_id;
        struct fc_seq_els_data rjt_data;

        mutex_lock(&lport->lp_mutex);

        /*
         * Handle special ELS cases like FLOGI, LOGO, and
         * RSCN here.  These don't require a session.
         * Even if we had a session, it might not be ready.
         */
        if (fh->fh_type == FC_TYPE_ELS && fh->fh_r_ctl == FC_RCTL_ELS_REQ) {
                /*
                 * Check opcode.
                 */
                recv = NULL;
                switch (fc_frame_payload_op(fp)) {
                case ELS_FLOGI:
                        recv = fc_lport_recv_flogi_req;
                        break;
                case ELS_LOGO:
                        fh = fc_frame_header_get(fp);
                        if (ntoh24(fh->fh_s_id) == FC_FID_FLOGI)
                                recv = fc_lport_recv_logo_req;
                        break;
                case ELS_RSCN:
                        recv = lport->tt.disc_recv_req;
                        break;
                case ELS_ECHO:
                        recv = fc_lport_recv_echo_req;
                        break;
                case ELS_RLIR:
                        recv = fc_lport_recv_rlir_req;
                        break;
                case ELS_RNID:
                        recv = fc_lport_recv_rnid_req;
                        break;
                case ELS_ADISC:
                        recv = fc_lport_recv_adisc_req;
                        break;
                }

                if (recv)
                        recv(sp, fp, lport);
                else {
                        /*
                         * Find session.
                         * If this is a new incoming PLOGI, we won't find it.
                         */
                        s_id = ntoh24(fh->fh_s_id);
                        d_id = ntoh24(fh->fh_d_id);

                        rport = lport->tt.rport_lookup(lport, s_id);
                        if (rport)
                                lport->tt.rport_recv_req(sp, fp, rport);
                        else {
                                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);
                        }
                }
        } else {
                FC_DBG("dropping invalid frame (eof %x)\n", fr_eof(fp));
                fc_frame_free(fp);
        }
        mutex_unlock(&lport->lp_mutex);

        /*
         *  The common exch_done for all request may not be good
         *  if any request requires longer hold on exhange. XXX
         */
        lport->tt.exch_done(sp);
}

/**
 * fc_lport_reset - Reset an lport
 * @lport: The lport which should be reset
 *
 * Locking Note: This functions should not be called with the
 *               lport lock held.
 */
int fc_lport_reset(struct fc_lport *lport)
{
        mutex_lock(&lport->lp_mutex);
        fc_lport_enter_reset(lport);
        mutex_unlock(&lport->lp_mutex);
        return 0;
}
EXPORT_SYMBOL(fc_lport_reset);

/**
 * fc_rport_enter_reset - Reset the local port
 * @lport: Fibre Channel local port to be reset
 *
 * Locking Note: The lport lock is expected to be held before calling
 * this routine.
 */
static void fc_lport_enter_reset(struct fc_lport *lport)
{
        FC_DEBUG_LPORT("Port (%6x) entered RESET state from %s state\n",
                       fc_host_port_id(lport->host), fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_RESET);

        if (lport->dns_rp)
                lport->tt.rport_logoff(lport->dns_rp);

        if (lport->ptp_rp) {
                lport->tt.rport_logoff(lport->ptp_rp);
                lport->ptp_rp = NULL;
        }

        lport->tt.disc_stop(lport);

        lport->tt.exch_mgr_reset(lport->emp, 0, 0);
        fc_host_fabric_name(lport->host) = 0;
        fc_host_port_id(lport->host) = 0;

        if ((lport->link_status & FC_LINK_UP) == FC_LINK_UP)
                fc_lport_enter_flogi(lport);
}

/**
 * fc_lport_error - Handler for any errors
 * @lport: The fc_lport 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
 * after the e_d_tov time.
 */
static void fc_lport_error(struct fc_lport *lport, struct fc_frame *fp)
{
        unsigned long delay = 0;
        FC_DEBUG_LPORT("Error %ld in state %s, retries %d\n",
                       PTR_ERR(fp), fc_lport_state(lport),
                       lport->retry_count);

        if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
                /*
                 * Memory allocation failure, or the exchange timed out.
                 *  Retry after delay
                 */
                if (lport->retry_count < lport->max_retry_count) {
                        lport->retry_count++;
                        if (!fp)
                                delay = msecs_to_jiffies(500);
                        else
                                delay = msecs_to_jiffies(lport->e_d_tov);

                        schedule_delayed_work(&lport->retry_work, delay);
                } else {
                        switch (lport->state) {
                        case LPORT_ST_NONE:
                        case LPORT_ST_READY:
                        case LPORT_ST_RESET:
                        case LPORT_ST_RPN_ID:
                        case LPORT_ST_RFT_ID:
                        case LPORT_ST_SCR:
                        case LPORT_ST_DNS:
                        case LPORT_ST_FLOGI:
                        case LPORT_ST_LOGO:
                                fc_lport_enter_reset(lport);
                                break;
                        }
                }
        }
}

/**
 * fc_lport_rft_id_resp - Handle response to Register Fibre
 *                        Channel Types by ID (RPN_ID) request
 * @sp: current sequence in RPN_ID exchange
 * @fp: response frame
 * @lp_arg: Fibre Channel host port instance
 *
 * Locking Note: This function will be called without the lport lock
 * held, but it will lock, call an _enter_* function or fc_lport_error
 * and then unlock the lport.
 */
static void fc_lport_rft_id_resp(struct fc_seq *sp, struct fc_frame *fp,
                                 void *lp_arg)
{
        struct fc_lport *lport = lp_arg;
        struct fc_frame_header *fh;
        struct fc_ct_hdr *ct;

        if (fp == ERR_PTR(-FC_EX_CLOSED))
                return;

        mutex_lock(&lport->lp_mutex);

        FC_DEBUG_LPORT("Received a RFT_ID response\n");

        if (lport->state != LPORT_ST_RFT_ID) {
                FC_DBG("Received a RFT_ID response, but in state %s\n",
                       fc_lport_state(lport));
                goto out;
        }

        if (IS_ERR(fp)) {
                fc_lport_error(lport, fp);
                goto err;
        }

        fh = fc_frame_header_get(fp);
        ct = fc_frame_payload_get(fp, sizeof(*ct));

        if (fh && ct && fh->fh_type == FC_TYPE_CT &&
            ct->ct_fs_type == FC_FST_DIR &&
            ct->ct_fs_subtype == FC_NS_SUBTYPE &&
            ntohs(ct->ct_cmd) == FC_FS_ACC)
                fc_lport_enter_scr(lport);
        else
                fc_lport_error(lport, fp);
out:
        fc_frame_free(fp);
err:
        mutex_unlock(&lport->lp_mutex);
}

/**
 * fc_lport_rpn_id_resp - Handle response to Register Port
 *                        Name by ID (RPN_ID) request
 * @sp: current sequence in RPN_ID exchange
 * @fp: response frame
 * @lp_arg: Fibre Channel host port instance
 *
 * Locking Note: This function will be called without the lport lock
 * held, but it will lock, call an _enter_* function or fc_lport_error
 * and then unlock the lport.
 */
static void fc_lport_rpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
                                 void *lp_arg)
{
        struct fc_lport *lport = lp_arg;
        struct fc_frame_header *fh;
        struct fc_ct_hdr *ct;

        if (fp == ERR_PTR(-FC_EX_CLOSED))
                return;

        mutex_lock(&lport->lp_mutex);

        FC_DEBUG_LPORT("Received a RPN_ID response\n");

        if (lport->state != LPORT_ST_RPN_ID) {
                FC_DBG("Received a RPN_ID response, but in state %s\n",
                       fc_lport_state(lport));
                goto out;
        }

        if (IS_ERR(fp)) {
                fc_lport_error(lport, fp);
                goto err;
        }

        fh = fc_frame_header_get(fp);
        ct = fc_frame_payload_get(fp, sizeof(*ct));
        if (fh && ct && fh->fh_type == FC_TYPE_CT &&
            ct->ct_fs_type == FC_FST_DIR &&
            ct->ct_fs_subtype == FC_NS_SUBTYPE &&
            ntohs(ct->ct_cmd) == FC_FS_ACC)
                fc_lport_enter_rft_id(lport);
        else
                fc_lport_error(lport, fp);

out:
        fc_frame_free(fp);
err:
        mutex_unlock(&lport->lp_mutex);
}

/**
 * fc_lport_scr_resp - Handle response to State Change Register (SCR) request
 * @sp: current sequence in SCR exchange
 * @fp: response frame
 * @lp_arg: Fibre Channel lport port instance that sent the registration request
 *
 * Locking Note: This function will be called without the lport lock
 * held, but it will lock, call an _enter_* function or fc_lport_error
 * and then unlock the lport.
 */
static void fc_lport_scr_resp(struct fc_seq *sp, struct fc_frame *fp,
                              void *lp_arg)
{
        struct fc_lport *lport = lp_arg;
        u8 op;

        if (fp == ERR_PTR(-FC_EX_CLOSED))
                return;

        mutex_lock(&lport->lp_mutex);

        FC_DEBUG_LPORT("Received a SCR response\n");

        if (lport->state != LPORT_ST_SCR) {
                FC_DBG("Received a SCR response, but in state %s\n",
                       fc_lport_state(lport));
                goto out;
        }

        if (IS_ERR(fp)) {
                fc_lport_error(lport, fp);
                goto err;
        }

        op = fc_frame_payload_op(fp);
        if (op == ELS_LS_ACC)
                fc_lport_enter_ready(lport);
        else
                fc_lport_error(lport, fp);

out:
        fc_frame_free(fp);
err:
        mutex_unlock(&lport->lp_mutex);
}

/**
 * fc_lport_enter_scr - Send a State Change Register (SCR) request
 * @lport: Fibre Channel local port to register for state changes
 *
 * Locking Note: The lport lock is expected to be held before calling
 * this routine.
 */
static void fc_lport_enter_scr(struct fc_lport *lport)
{
        struct fc_frame *fp;

        FC_DEBUG_LPORT("Port (%6x) entered SCR state from %s state\n",
                       fc_host_port_id(lport->host), fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_SCR);

        fp = fc_frame_alloc(lport, sizeof(struct fc_els_scr));
        if (!fp) {
                fc_lport_error(lport, fp);
                return;
        }

        if (!lport->tt.elsct_send(lport, NULL, fp, ELS_SCR,
                                  fc_lport_scr_resp, lport, lport->e_d_tov))
                fc_lport_error(lport, fp);
}

/**
 * fc_lport_enter_rft_id - Register FC4-types with the name server
 * @lport: Fibre Channel local port to register
 *
 * Locking Note: The lport lock is expected to be held before calling
 * this routine.
 */
static void fc_lport_enter_rft_id(struct fc_lport *lport)
{
        struct fc_frame *fp;
        struct fc_ns_fts *lps;
        int i;

        FC_DEBUG_LPORT("Port (%6x) entered RFT_ID state from %s state\n",
                       fc_host_port_id(lport->host), fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_RFT_ID);

        lps = &lport->fcts;
        i = sizeof(lps->ff_type_map) / sizeof(lps->ff_type_map[0]);
        while (--i >= 0)
                if (ntohl(lps->ff_type_map[i]) != 0)
                        break;
        if (i < 0) {
                /* nothing to register, move on to SCR */
                fc_lport_enter_scr(lport);
                return;
        }

        fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
                            sizeof(struct fc_ns_rft));
        if (!fp) {
                fc_lport_error(lport, fp);
                return;
        }

        if (!lport->tt.elsct_send(lport, NULL, fp, FC_NS_RFT_ID,
                                  fc_lport_rft_id_resp,
                                  lport, lport->e_d_tov))
                fc_lport_error(lport, fp);
}

/**
 * fc_rport_enter_rft_id - Register port name with the name server
 * @lport: Fibre Channel local port to register
 *
 * Locking Note: The lport lock is expected to be held before calling
 * this routine.
 */
static void fc_lport_enter_rpn_id(struct fc_lport *lport)
{
        struct fc_frame *fp;

        FC_DEBUG_LPORT("Port (%6x) entered RPN_ID state from %s state\n",
                       fc_host_port_id(lport->host), fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_RPN_ID);

        fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
                            sizeof(struct fc_ns_rn_id));
        if (!fp) {
                fc_lport_error(lport, fp);
                return;
        }

        if (!lport->tt.elsct_send(lport, NULL, fp, FC_NS_RPN_ID,
                                  fc_lport_rpn_id_resp,
                                  lport, lport->e_d_tov))
                fc_lport_error(lport, fp);
}

static struct fc_rport_operations fc_lport_rport_ops = {
        .event_callback = fc_lport_rport_callback,
};

/**
 * fc_rport_enter_dns - Create a rport to the name server
 * @lport: Fibre Channel local port requesting a rport for the name server
 *
 * Locking Note: The lport lock is expected to be held before calling
 * this routine.
 */
static void fc_lport_enter_dns(struct fc_lport *lport)
{
        struct fc_rport *rport;
        struct fc_rport_libfc_priv *rdata;
        struct fc_disc_port dp;

        dp.ids.port_id = FC_FID_DIR_SERV;
        dp.ids.port_name = -1;
        dp.ids.node_name = -1;
        dp.ids.roles = FC_RPORT_ROLE_UNKNOWN;
        dp.lp = lport;

        FC_DEBUG_LPORT("Port (%6x) entered DNS state from %s state\n",
                       fc_host_port_id(lport->host), fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_DNS);

        rport = fc_rport_rogue_create(&dp);
        if (!rport)
                goto err;

        rdata = rport->dd_data;
        rdata->ops = &fc_lport_rport_ops;
        lport->tt.rport_login(rport);
        return;

err:
        fc_lport_error(lport, NULL);
}

/**
 * fc_lport_timeout - Handler for the retry_work timer.
 * @work: The work struct of the fc_lport
 */
static void fc_lport_timeout(struct work_struct *work)
{
        struct fc_lport *lport =
                container_of(work, struct fc_lport,
                             retry_work.work);

        mutex_lock(&lport->lp_mutex);

        switch (lport->state) {
        case LPORT_ST_NONE:
        case LPORT_ST_READY:
        case LPORT_ST_RESET:
                WARN_ON(1);
                break;
        case LPORT_ST_FLOGI:
                fc_lport_enter_flogi(lport);
                break;
        case LPORT_ST_DNS:
                fc_lport_enter_dns(lport);
                break;
        case LPORT_ST_RPN_ID:
                fc_lport_enter_rpn_id(lport);
                break;
        case LPORT_ST_RFT_ID:
                fc_lport_enter_rft_id(lport);
                break;
        case LPORT_ST_SCR:
                fc_lport_enter_scr(lport);
                break;
        case LPORT_ST_LOGO:
                fc_lport_enter_logo(lport);
                break;
        }

        mutex_unlock(&lport->lp_mutex);
}

/**
 * fc_lport_logo_resp - Handle response to LOGO request
 * @sp: current sequence in LOGO exchange
 * @fp: response frame
 * @lp_arg: Fibre Channel lport port instance that sent the LOGO request
 *
 * Locking Note: This function will be called without the lport lock
 * held, but it will lock, call an _enter_* function or fc_lport_error
 * and then unlock the lport.
 */
static void fc_lport_logo_resp(struct fc_seq *sp, struct fc_frame *fp,
                               void *lp_arg)
{
        struct fc_lport *lport = lp_arg;
        u8 op;

        if (fp == ERR_PTR(-FC_EX_CLOSED))
                return;

        mutex_lock(&lport->lp_mutex);

        FC_DEBUG_LPORT("Received a LOGO response\n");

        if (lport->state != LPORT_ST_LOGO) {
                FC_DBG("Received a LOGO response, but in state %s\n",
                       fc_lport_state(lport));
                goto out;
        }

        if (IS_ERR(fp)) {
                fc_lport_error(lport, fp);
                goto err;
        }

        op = fc_frame_payload_op(fp);
        if (op == ELS_LS_ACC)
                fc_lport_enter_reset(lport);
        else
                fc_lport_error(lport, fp);

out:
        fc_frame_free(fp);
err:
        mutex_unlock(&lport->lp_mutex);
}

/**
 * fc_rport_enter_logo - Logout of the fabric
 * @lport: Fibre Channel local port to be logged out
 *
 * Locking Note: The lport lock is expected to be held before calling
 * this routine.
 */
static void fc_lport_enter_logo(struct fc_lport *lport)
{
        struct fc_frame *fp;
        struct fc_els_logo *logo;

        FC_DEBUG_LPORT("Port (%6x) entered LOGO state from %s state\n",
                       fc_host_port_id(lport->host), fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_LOGO);

        /* DNS session should be closed so we can release it here */
        if (lport->dns_rp)
                lport->tt.rport_logoff(lport->dns_rp);

        fp = fc_frame_alloc(lport, sizeof(*logo));
        if (!fp) {
                fc_lport_error(lport, fp);
                return;
        }

        if (!lport->tt.elsct_send(lport, NULL, fp, ELS_LOGO, fc_lport_logo_resp,
                                  lport, lport->e_d_tov))
                fc_lport_error(lport, fp);
}

/**
 * fc_lport_flogi_resp - Handle response to FLOGI request
 * @sp: current sequence in FLOGI exchange
 * @fp: response frame
 * @lp_arg: Fibre Channel lport port instance that sent the FLOGI request
 *
 * Locking Note: This function will be called without the lport lock
 * held, but it will lock, call an _enter_* function or fc_lport_error
 * and then unlock the lport.
 */
static void fc_lport_flogi_resp(struct fc_seq *sp, struct fc_frame *fp,
                                void *lp_arg)
{
        struct fc_lport *lport = lp_arg;
        struct fc_frame_header *fh;
        struct fc_els_flogi *flp;
        u32 did;
        u16 csp_flags;
        unsigned int r_a_tov;
        unsigned int e_d_tov;
        u16 mfs;

        if (fp == ERR_PTR(-FC_EX_CLOSED))
                return;

        mutex_lock(&lport->lp_mutex);

        FC_DEBUG_LPORT("Received a FLOGI response\n");

        if (lport->state != LPORT_ST_FLOGI) {
                FC_DBG("Received a FLOGI response, but in state %s\n",
                       fc_lport_state(lport));
                goto out;
        }

        if (IS_ERR(fp)) {
                fc_lport_error(lport, fp);
                goto err;
        }

        fh = fc_frame_header_get(fp);
        did = ntoh24(fh->fh_d_id);
        if (fc_frame_payload_op(fp) == ELS_LS_ACC && did != 0) {

                FC_DEBUG_LPORT("Assigned fid %x\n", did);
                fc_host_port_id(lport->host) = did;

                flp = fc_frame_payload_get(fp, sizeof(*flp));
                if (flp) {
                        mfs = ntohs(flp->fl_csp.sp_bb_data) &
                                FC_SP_BB_DATA_MASK;
                        if (mfs >= FC_SP_MIN_MAX_PAYLOAD &&
                            mfs < lport->mfs)
                                lport->mfs = mfs;
                        csp_flags = ntohs(flp->fl_csp.sp_features);
                        r_a_tov = ntohl(flp->fl_csp.sp_r_a_tov);
                        e_d_tov = ntohl(flp->fl_csp.sp_e_d_tov);
                        if (csp_flags & FC_SP_FT_EDTR)
                                e_d_tov /= 1000000;
                        if ((csp_flags & FC_SP_FT_FPORT) == 0) {
                                if (e_d_tov > lport->e_d_tov)
                                        lport->e_d_tov = e_d_tov;
                                lport->r_a_tov = 2 * e_d_tov;
                                FC_DBG("Point-to-Point mode\n");
                                fc_lport_ptp_setup(lport, ntoh24(fh->fh_s_id),
                                                   get_unaligned_be64(
                                                           &flp->fl_wwpn),
                                                   get_unaligned_be64(
                                                           &flp->fl_wwnn));
                        } else {
                                lport->e_d_tov = e_d_tov;
                                lport->r_a_tov = r_a_tov;
                                fc_host_fabric_name(lport->host) =
                                        get_unaligned_be64(&flp->fl_wwnn);
                                fc_lport_enter_dns(lport);
                        }
                }

                if (flp) {
                        csp_flags = ntohs(flp->fl_csp.sp_features);
                        if ((csp_flags & FC_SP_FT_FPORT) == 0) {
                                lport->tt.disc_start(fc_lport_disc_callback,
                                                     lport);
                        }
                }
        } else {
                FC_DBG("bad FLOGI response\n");
        }

out:
        fc_frame_free(fp);
err:
        mutex_unlock(&lport->lp_mutex);
}

/**
 * fc_rport_enter_flogi - Send a FLOGI request to the fabric manager
 * @lport: Fibre Channel local port to be logged in to the fabric
 *
 * Locking Note: The lport lock is expected to be held before calling
 * this routine.
 */
void fc_lport_enter_flogi(struct fc_lport *lport)
{
        struct fc_frame *fp;

        FC_DEBUG_LPORT("Processing FLOGI state\n");

        fc_lport_state_enter(lport, LPORT_ST_FLOGI);

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

        if (!lport->tt.elsct_send(lport, NULL, fp, ELS_FLOGI,
                                  fc_lport_flogi_resp, lport, lport->e_d_tov))
                fc_lport_error(lport, fp);
}

/* Configure a fc_lport */
int fc_lport_config(struct fc_lport *lport)
{
        INIT_DELAYED_WORK(&lport->retry_work, fc_lport_timeout);
        mutex_init(&lport->lp_mutex);

        fc_lport_state_enter(lport, LPORT_ST_NONE);

        fc_lport_add_fc4_type(lport, FC_TYPE_FCP);
        fc_lport_add_fc4_type(lport, FC_TYPE_CT);

        return 0;
}
EXPORT_SYMBOL(fc_lport_config);

int fc_lport_init(struct fc_lport *lport)
{
        if (!lport->tt.lport_recv)
                lport->tt.lport_recv = fc_lport_recv_req;

        if (!lport->tt.lport_reset)
                lport->tt.lport_reset = fc_lport_reset;

        fc_host_port_type(lport->host) = FC_PORTTYPE_NPORT;
        fc_host_node_name(lport->host) = lport->wwnn;
        fc_host_port_name(lport->host) = lport->wwpn;
        fc_host_supported_classes(lport->host) = FC_COS_CLASS3;
        memset(fc_host_supported_fc4s(lport->host), 0,
               sizeof(fc_host_supported_fc4s(lport->host)));
        fc_host_supported_fc4s(lport->host)[2] = 1;
        fc_host_supported_fc4s(lport->host)[7] = 1;

        /* This value is also unchanging */
        memset(fc_host_active_fc4s(lport->host), 0,
               sizeof(fc_host_active_fc4s(lport->host)));
        fc_host_active_fc4s(lport->host)[2] = 1;
        fc_host_active_fc4s(lport->host)[7] = 1;
        fc_host_maxframe_size(lport->host) = lport->mfs;
        fc_host_supported_speeds(lport->host) = 0;
        if (lport->link_supported_speeds & FC_PORTSPEED_1GBIT)
                fc_host_supported_speeds(lport->host) |= FC_PORTSPEED_1GBIT;
        if (lport->link_supported_speeds & FC_PORTSPEED_10GBIT)
                fc_host_supported_speeds(lport->host) |= FC_PORTSPEED_10GBIT;

        return 0;
}
EXPORT_SYMBOL(fc_lport_init);