/*
 * 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.
 *
 * HIERARCHY
 *
 * The following hierarchy 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 hierarchy-
 *
 * 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 because 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, successful 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 <linux/delay.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <asm/unaligned.h>

#include <scsi/fc/fc_gs.h>

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

#include "fc_libfc.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 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_ns(struct fc_lport *, enum fc_lport_state);
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 void fc_lport_enter_fdmi(struct fc_lport *lport);
static void fc_lport_enter_ms(struct fc_lport *, enum fc_lport_state);

static const char *fc_lport_state_names[] = {
        [LPORT_ST_DISABLED] = "disabled",
        [LPORT_ST_FLOGI] =    "FLOGI",
        [LPORT_ST_DNS] =      "dNS",
        [LPORT_ST_RNN_ID] =   "RNN_ID",
        [LPORT_ST_RSNN_NN] =  "RSNN_NN",
        [LPORT_ST_RSPN_ID] =  "RSPN_ID",
        [LPORT_ST_RFT_ID] =   "RFT_ID",
        [LPORT_ST_RFF_ID] =   "RFF_ID",
        [LPORT_ST_FDMI] =     "FDMI",
        [LPORT_ST_RHBA] =     "RHBA",
        [LPORT_ST_RPA] =      "RPA",
        [LPORT_ST_DHBA] =     "DHBA",
        [LPORT_ST_DPRT] =     "DPRT",
        [LPORT_ST_SCR] =      "SCR",
        [LPORT_ST_READY] =    "Ready",
        [LPORT_ST_LOGO] =     "LOGO",
        [LPORT_ST_RESET] =    "reset",
};

/**
 * struct fc_bsg_info - FC Passthrough managemet structure
 * @job:      The passthrough job
 * @lport:    The local port to pass through a command
 * @rsp_code: The expected response code
 * @sg:       job->reply_payload.sg_list
 * @nents:    job->reply_payload.sg_cnt
 * @offset:   The offset into the response data
 */
struct fc_bsg_info {
        struct bsg_job *job;
        struct fc_lport *lport;
        u16 rsp_code;
        struct scatterlist *sg;
        u32 nents;
        size_t offset;
};

/**
 * fc_frame_drop() - Dummy frame handler
 * @lport: The local port the frame was received on
 * @fp:    The received frame
 */
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
 * @rdata: private remote port data
 * @event: The event that occurred
 *
 * 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_priv *rdata,
                                    enum fc_rport_event event)
{
        FC_LPORT_DBG(lport, "Received a %d event for port (%6.6x)\n", event,
                     rdata->ids.port_id);

        mutex_lock(&lport->lp_mutex);
        switch (event) {
        case RPORT_EV_READY:
                if (lport->state == LPORT_ST_DNS) {
                        lport->dns_rdata = rdata;
                        fc_lport_enter_ns(lport, LPORT_ST_RNN_ID);
                } else if (lport->state == LPORT_ST_FDMI) {
                        lport->ms_rdata = rdata;
                        fc_lport_enter_ms(lport, LPORT_ST_DHBA);
                } else {
                        FC_LPORT_DBG(lport, "Received an READY event "
                                     "on port (%6.6x) for the directory "
                                     "server, but the lport is not "
                                     "in the DNS or FDMI state, it's in the "
                                     "%d state", rdata->ids.port_id,
                                     lport->state);
                        fc_rport_logoff(rdata);
                }
                break;
        case RPORT_EV_LOGO:
        case RPORT_EV_FAILED:
        case RPORT_EV_STOP:
                if (rdata->ids.port_id == FC_FID_DIR_SERV)
                        lport->dns_rdata = NULL;
                else if (rdata->ids.port_id == FC_FID_MGMT_SERV)
                        lport->ms_rdata = NULL;
                break;
        case RPORT_EV_NONE:
                break;
        }
        mutex_unlock(&lport->lp_mutex);
}

/**
 * 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
 * @remote_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)
{
        lockdep_assert_held(&lport->lp_mutex);

        if (lport->ptp_rdata) {
                fc_rport_logoff(lport->ptp_rdata);
                kref_put(&lport->ptp_rdata->kref, fc_rport_destroy);
        }
        mutex_lock(&lport->disc.disc_mutex);
        lport->ptp_rdata = fc_rport_create(lport, remote_fid);
        kref_get(&lport->ptp_rdata->kref);
        lport->ptp_rdata->ids.port_name = remote_wwpn;
        lport->ptp_rdata->ids.node_name = remote_wwnn;
        mutex_unlock(&lport->disc.disc_mutex);

        fc_rport_login(lport->ptp_rdata);

        fc_lport_enter_ready(lport);
}

/**
 * fc_get_host_port_state() - Return the port state of the given Scsi_Host
 * @shost:  The SCSI host whose port state is to be determined
 */
void fc_get_host_port_state(struct Scsi_Host *shost)
{
        struct fc_lport *lport = shost_priv(shost);

        mutex_lock(&lport->lp_mutex);
        if (!lport->link_up)
                fc_host_port_state(shost) = FC_PORTSTATE_LINKDOWN;
        else
                switch (lport->state) {
                case LPORT_ST_READY:
                        fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
                        break;
                default:
                        fc_host_port_state(shost) = FC_PORTSTATE_OFFLINE;
                }
        mutex_unlock(&lport->lp_mutex);
}
EXPORT_SYMBOL(fc_get_host_port_state);

/**
 * fc_get_host_speed() - Return the speed of the given Scsi_Host
 * @shost: The SCSI host whose port speed is to be determined
 */
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);

/**
 * fc_get_host_stats() - Return the Scsi_Host's statistics
 * @shost: The SCSI host whose statistics are to be returned
 */
struct fc_host_statistics *fc_get_host_stats(struct Scsi_Host *shost)
{
        struct fc_host_statistics *fc_stats;
        struct fc_lport *lport = shost_priv(shost);
        unsigned int cpu;
        u64 fcp_in_bytes = 0;
        u64 fcp_out_bytes = 0;

        fc_stats = &lport->host_stats;
        memset(fc_stats, 0, sizeof(struct fc_host_statistics));

        fc_stats->seconds_since_last_reset = (jiffies - lport->boot_time) / HZ;

        for_each_possible_cpu(cpu) {
                struct fc_stats *stats;

                stats = per_cpu_ptr(lport->stats, cpu);

                fc_stats->tx_frames += stats->TxFrames;
                fc_stats->tx_words += stats->TxWords;
                fc_stats->rx_frames += stats->RxFrames;
                fc_stats->rx_words += stats->RxWords;
                fc_stats->error_frames += stats->ErrorFrames;
                fc_stats->invalid_crc_count += stats->InvalidCRCCount;
                fc_stats->fcp_input_requests += stats->InputRequests;
                fc_stats->fcp_output_requests += stats->OutputRequests;
                fc_stats->fcp_control_requests += stats->ControlRequests;
                fcp_in_bytes += stats->InputBytes;
                fcp_out_bytes += stats->OutputBytes;
                fc_stats->fcp_packet_alloc_failures += stats->FcpPktAllocFails;
                fc_stats->fcp_packet_aborts += stats->FcpPktAborts;
                fc_stats->fcp_frame_alloc_failures += stats->FcpFrameAllocFails;
                fc_stats->link_failure_count += stats->LinkFailureCount;
        }
        fc_stats->fcp_input_megabytes = div_u64(fcp_in_bytes, 1000000);
        fc_stats->fcp_output_megabytes = div_u64(fcp_out_bytes, 1000000);
        fc_stats->lip_count = -1;
        fc_stats->nos_count = -1;
        fc_stats->loss_of_sync_count = -1;
        fc_stats->loss_of_signal_count = -1;
        fc_stats->prim_seq_protocol_err_count = -1;
        fc_stats->dumped_frames = -1;

        /* update exches stats */
        fc_exch_update_stats(lport);

        return fc_stats;
}
EXPORT_SYMBOL(fc_get_host_stats);

/**
 * fc_lport_flogi_fill() - Fill in FLOGI command for request
 * @lport: The local port the FLOGI is for
 * @flogi: The FLOGI command
 * @op:    The opcode
 */
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;
        }
}

/**
 * fc_lport_add_fc4_type() - Add a supported FC-4 type to a local port
 * @lport: The local port to add a new FC-4 type to
 * @type:  The new 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 receiving the RLIR
 * @fp:    The RLIR request frame
 */
static void fc_lport_recv_rlir_req(struct fc_lport *lport, struct fc_frame *fp)
{
        lockdep_assert_held(&lport->lp_mutex);

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

        fc_seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
        fc_frame_free(fp);
}

/**
 * fc_lport_recv_echo_req() - Handle received ECHO request
 * @lport: The local port receiving the ECHO
 * @fp:    ECHO request frame
 */
static void fc_lport_recv_echo_req(struct fc_lport *lport,
                                   struct fc_frame *in_fp)
{
        struct fc_frame *fp;
        unsigned int len;
        void *pp;
        void *dp;

        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Received ECHO 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);
                *((__be32 *)dp) = htonl(ELS_LS_ACC << 24);
                fc_fill_reply_hdr(fp, in_fp, FC_RCTL_ELS_REP, 0);
                lport->tt.frame_send(lport, fp);
        }
        fc_frame_free(in_fp);
}

/**
 * fc_lport_recv_rnid_req() - Handle received Request Node ID data request
 * @lport: The local port receiving the RNID
 * @fp:    The RNID request frame
 */
static void fc_lport_recv_rnid_req(struct fc_lport *lport,
                                   struct fc_frame *in_fp)
{
        struct fc_frame *fp;
        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;

        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(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.reason = ELS_RJT_LOGIC;
                rjt_data.explan = ELS_EXPL_NONE;
                fc_seq_els_rsp_send(in_fp, 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));
                        }
                        fc_fill_reply_hdr(fp, in_fp, FC_RCTL_ELS_REP, 0);
                        lport->tt.frame_send(lport, fp);
                }
        }
        fc_frame_free(in_fp);
}

/**
 * fc_lport_recv_logo_req() - Handle received fabric LOGO request
 * @lport: The local port receiving the LOGO
 * @fp:    The LOGO request frame
 */
static void fc_lport_recv_logo_req(struct fc_lport *lport, struct fc_frame *fp)
{
        lockdep_assert_held(&lport->lp_mutex);

        fc_seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
        fc_lport_enter_reset(lport);
        fc_frame_free(fp);
}

/**
 * fc_fabric_login() - Start the lport state machine
 * @lport: The local port 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_DISABLED ||
            lport->state == LPORT_ST_LOGO) {
                fc_lport_state_enter(lport, LPORT_ST_RESET);
                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)
{
        lockdep_assert_held(&lport->lp_mutex);

        if (!lport->link_up) {
                lport->link_up = 1;

                if (lport->state == LPORT_ST_RESET)
                        fc_lport_enter_flogi(lport);
        }
}

/**
 * fc_linkup() - Handler for transport linkup events
 * @lport: The local port whose link is up
 */
void fc_linkup(struct fc_lport *lport)
{
        printk(KERN_INFO "host%d: libfc: Link up on port (%6.6x)\n",
               lport->host->host_no, lport->port_id);

        mutex_lock(&lport->lp_mutex);
        __fc_linkup(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)
{
        lockdep_assert_held(&lport->lp_mutex);

        if (lport->link_up) {
                lport->link_up = 0;
                fc_lport_enter_reset(lport);
                lport->tt.fcp_cleanup(lport);
        }
}

/**
 * fc_linkdown() - Handler for transport linkdown events
 * @lport: The local port whose link is down
 */
void fc_linkdown(struct fc_lport *lport)
{
        printk(KERN_INFO "host%d: libfc: Link down on port (%6.6x)\n",
               lport->host->host_no, lport->port_id);

        mutex_lock(&lport->lp_mutex);
        __fc_linkdown(lport);
        mutex_unlock(&lport->lp_mutex);
}
EXPORT_SYMBOL(fc_linkdown);

/**
 * fc_fabric_logoff() - Logout of the fabric
 * @lport: The local port 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);
        if (lport->dns_rdata)
                fc_rport_logoff(lport->dns_rdata);
        mutex_unlock(&lport->lp_mutex);
        fc_rport_flush_queue();
        mutex_lock(&lport->lp_mutex);
        fc_lport_enter_logo(lport);
        mutex_unlock(&lport->lp_mutex);
        cancel_delayed_work_sync(&lport->retry_work);
        return 0;
}
EXPORT_SYMBOL(fc_fabric_logoff);

/**
 * fc_lport_destroy() - Unregister a fc_lport
 * @lport: The local port to unregister
 *
 * 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)
{
        mutex_lock(&lport->lp_mutex);
        lport->state = LPORT_ST_DISABLED;
        lport->link_up = 0;
        lport->tt.frame_send = fc_frame_drop;
        mutex_unlock(&lport->lp_mutex);

        lport->tt.fcp_abort_io(lport);
        lport->tt.disc_stop_final(lport);
        lport->tt.exch_mgr_reset(lport, 0, 0);
        cancel_delayed_work_sync(&lport->retry_work);
        fc_fc4_del_lport(lport);
        return 0;
}
EXPORT_SYMBOL(fc_lport_destroy);

/**
 * fc_set_mfs() - Set the maximum frame size for a local port
 * @lport: The local port to set the MFS for
 * @mfs:   The new MFS
 */
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: The local port receiving the event
 * @event: The discovery event
 */
static void fc_lport_disc_callback(struct fc_lport *lport,
                                   enum fc_disc_event event)
{
        switch (event) {
        case DISC_EV_SUCCESS:
                FC_LPORT_DBG(lport, "Discovery succeeded\n");
                break;
        case DISC_EV_FAILED:
                printk(KERN_ERR "host%d: libfc: "
                       "Discovery failed for port (%6.6x)\n",
                       lport->host->host_no, lport->port_id);
                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: The local port that is ready
 */
static void fc_lport_enter_ready(struct fc_lport *lport)
{
        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered READY from state %s\n",
                     fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_READY);
        if (lport->vport)
                fc_vport_set_state(lport->vport, FC_VPORT_ACTIVE);
        fc_vports_linkchange(lport);

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

/**
 * fc_lport_set_port_id() - set the local port Port ID
 * @lport: The local port which will have its Port ID set.
 * @port_id: The new port ID.
 * @fp: The frame containing the incoming request, or NULL.
 */
static void fc_lport_set_port_id(struct fc_lport *lport, u32 port_id,
                                 struct fc_frame *fp)
{
        lockdep_assert_held(&lport->lp_mutex);

        if (port_id)
                printk(KERN_INFO "host%d: Assigned Port ID %6.6x\n",
                       lport->host->host_no, port_id);

        lport->port_id = port_id;

        /* Update the fc_host */
        fc_host_port_id(lport->host) = port_id;

        if (lport->tt.lport_set_port_id)
                lport->tt.lport_set_port_id(lport, port_id, fp);
}

/**
 * fc_lport_set_port_id() - set the local port Port ID for point-to-multipoint
 * @lport: The local port which will have its Port ID set.
 * @port_id: The new port ID.
 *
 * Called by the lower-level driver when transport sets the local port_id.
 * This is used in VN_port to VN_port mode for FCoE, and causes FLOGI and
 * discovery to be skipped.
 */
void fc_lport_set_local_id(struct fc_lport *lport, u32 port_id)
{
        mutex_lock(&lport->lp_mutex);

        fc_lport_set_port_id(lport, port_id, NULL);

        switch (lport->state) {
        case LPORT_ST_RESET:
        case LPORT_ST_FLOGI:
                if (port_id)
                        fc_lport_enter_ready(lport);
                break;
        default:
                break;
        }
        mutex_unlock(&lport->lp_mutex);
}
EXPORT_SYMBOL(fc_lport_set_local_id);

/**
 * fc_lport_recv_flogi_req() - Receive a FLOGI request
 * @lport: The local port that received the request
 * @rx_fp: The FLOGI frame
 *
 * 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.
 */
static void fc_lport_recv_flogi_req(struct fc_lport *lport,
                                    struct fc_frame *rx_fp)
{
        struct fc_frame *fp;
        struct fc_frame_header *fh;
        struct fc_els_flogi *flp;
        struct fc_els_flogi *new_flp;
        u64 remote_wwpn;
        u32 remote_fid;
        u32 local_fid;

        lockdep_assert_held(&lport->lp_mutex);

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

        remote_fid = fc_frame_sid(rx_fp);
        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) {
                printk(KERN_WARNING "host%d: libfc: Received FLOGI from port "
                       "with same WWPN %16.16llx\n",
                       lport->host->host_no, remote_wwpn);
                goto out;
        }
        FC_LPORT_DBG(lport, "FLOGI from port WWPN %16.16llx\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_lport_set_port_id(lport, local_fid, rx_fp);

        fp = fc_frame_alloc(lport, sizeof(*flp));
        if (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.
                 */
                fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
                fh = fc_frame_header_get(fp);
                hton24(fh->fh_s_id, local_fid);
                hton24(fh->fh_d_id, remote_fid);
                lport->tt.frame_send(lport, fp);

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

/**
 * fc_lport_recv_els_req() - The generic lport ELS request handler
 * @lport: The local port that received the request
 * @fp:    The request frame
 *
 * 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 because it will grab the lock.
 */
static void fc_lport_recv_els_req(struct fc_lport *lport,
                                  struct fc_frame *fp)
{
        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 (!lport->link_up)
                fc_frame_free(fp);
        else {
                /*
                 * Check opcode.
                 */
                switch (fc_frame_payload_op(fp)) {
                case ELS_FLOGI:
                        if (!lport->point_to_multipoint)
                                fc_lport_recv_flogi_req(lport, fp);
                        else
                                fc_rport_recv_req(lport, fp);
                        break;
                case ELS_LOGO:
                        if (fc_frame_sid(fp) == FC_FID_FLOGI)
                                fc_lport_recv_logo_req(lport, fp);
                        else
                                fc_rport_recv_req(lport, fp);
                        break;
                case ELS_RSCN:
                        lport->tt.disc_recv_req(lport, fp);
                        break;
                case ELS_ECHO:
                        fc_lport_recv_echo_req(lport, fp);
                        break;
                case ELS_RLIR:
                        fc_lport_recv_rlir_req(lport, fp);
                        break;
                case ELS_RNID:
                        fc_lport_recv_rnid_req(lport, fp);
                        break;
                default:
                        fc_rport_recv_req(lport, fp);
                        break;
                }
        }
        mutex_unlock(&lport->lp_mutex);
}

static int fc_lport_els_prli(struct fc_rport_priv *rdata, u32 spp_len,
                             const struct fc_els_spp *spp_in,
                             struct fc_els_spp *spp_out)
{
        return FC_SPP_RESP_INVL;
}

struct fc4_prov fc_lport_els_prov = {
        .prli = fc_lport_els_prli,
        .recv = fc_lport_recv_els_req,
};

/**
 * fc_lport_recv() - The generic lport request handler
 * @lport: The lport that received the request
 * @fp: The frame the request is in
 *
 * Locking Note: This function should not be called with the lport
 *               lock held because it may grab the lock.
 */
void fc_lport_recv(struct fc_lport *lport, struct fc_frame *fp)
{
        struct fc_frame_header *fh = fc_frame_header_get(fp);
        struct fc_seq *sp = fr_seq(fp);
        struct fc4_prov *prov;

        /*
         * Use RCU read lock and module_lock to be sure module doesn't
         * deregister and get unloaded while we're calling it.
         * try_module_get() is inlined and accepts a NULL parameter.
         * Only ELSes and FCP target ops should come through here.
         * The locking is unfortunate, and a better scheme is being sought.
         */

        rcu_read_lock();
        if (fh->fh_type >= FC_FC4_PROV_SIZE)
                goto drop;
        prov = rcu_dereference(fc_passive_prov[fh->fh_type]);
        if (!prov || !try_module_get(prov->module))
                goto drop;
        rcu_read_unlock();
        prov->recv(lport, fp);
        module_put(prov->module);
        return;
drop:
        rcu_read_unlock();
        FC_LPORT_DBG(lport, "dropping unexpected frame type %x\n", fh->fh_type);
        fc_frame_free(fp);
        if (sp)
                fc_exch_done(sp);
}
EXPORT_SYMBOL(fc_lport_recv);

/**
 * fc_lport_reset() - Reset a local port
 * @lport: The local port 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)
{
        cancel_delayed_work_sync(&lport->retry_work);
        mutex_lock(&lport->lp_mutex);
        fc_lport_enter_reset(lport);
        mutex_unlock(&lport->lp_mutex);
        return 0;
}
EXPORT_SYMBOL(fc_lport_reset);

/**
 * fc_lport_reset_locked() - Reset the local port w/ the lport lock held
 * @lport: The local port to be reset

 */
static void fc_lport_reset_locked(struct fc_lport *lport)
{
        lockdep_assert_held(&lport->lp_mutex);

        if (lport->dns_rdata) {
                fc_rport_logoff(lport->dns_rdata);
                lport->dns_rdata = NULL;
        }

        if (lport->ptp_rdata) {
                fc_rport_logoff(lport->ptp_rdata);
                kref_put(&lport->ptp_rdata->kref, fc_rport_destroy);
                lport->ptp_rdata = NULL;
        }

        lport->tt.disc_stop(lport);

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

        if (lport->port_id && (!lport->point_to_multipoint || !lport->link_up))
                fc_lport_set_port_id(lport, 0, NULL);
}

/**
 * fc_lport_enter_reset() - Reset the local port
 * @lport: The local port to be reset
 */
static void fc_lport_enter_reset(struct fc_lport *lport)
{
        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered RESET state from %s state\n",
                     fc_lport_state(lport));

        if (lport->state == LPORT_ST_DISABLED || lport->state == LPORT_ST_LOGO)
                return;

        if (lport->vport) {
                if (lport->link_up)
                        fc_vport_set_state(lport->vport, FC_VPORT_INITIALIZING);
                else
                        fc_vport_set_state(lport->vport, FC_VPORT_LINKDOWN);
        }
        fc_lport_state_enter(lport, LPORT_ST_RESET);
        fc_host_post_event(lport->host, fc_get_event_number(),
                           FCH_EVT_LIPRESET, 0);
        fc_vports_linkchange(lport);
        fc_lport_reset_locked(lport);
        if (lport->link_up)
                fc_lport_enter_flogi(lport);
}

/**
 * fc_lport_enter_disabled() - Disable the local port
 * @lport: The local port to be reset
 */
static void fc_lport_enter_disabled(struct fc_lport *lport)
{
        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered disabled state from %s state\n",
                     fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_DISABLED);
        fc_vports_linkchange(lport);
        fc_lport_reset_locked(lport);
}

/**
 * fc_lport_error() - Handler for any errors
 * @lport: The local port that the error was on
 * @fp:    The error code encoded in a 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_LPORT_DBG(lport, "Error %ld in state %s, retries %d\n",
                     IS_ERR(fp) ? -PTR_ERR(fp) : 0, fc_lport_state(lport),
                     lport->retry_count);

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

        /*
         * Memory allocation failure, or the exchange timed out
         * or we received LS_RJT.
         * 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
                fc_lport_enter_reset(lport);
}

/**
 * fc_lport_ns_resp() - Handle response to a name server
 *                      registration exchange
 * @sp:     current sequence in 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_ns_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;

        FC_LPORT_DBG(lport, "Received a ns %s\n", fc_els_resp_type(fp));

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

        mutex_lock(&lport->lp_mutex);

        if (lport->state < LPORT_ST_RNN_ID || lport->state > LPORT_ST_RFF_ID) {
                FC_LPORT_DBG(lport, "Received a name server response, "
                             "but in state %s\n", fc_lport_state(lport));
                if (IS_ERR(fp))
                        goto err;
                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)
                switch (lport->state) {
                case LPORT_ST_RNN_ID:
                        fc_lport_enter_ns(lport, LPORT_ST_RSNN_NN);
                        break;
                case LPORT_ST_RSNN_NN:
                        fc_lport_enter_ns(lport, LPORT_ST_RSPN_ID);
                        break;
                case LPORT_ST_RSPN_ID:
                        fc_lport_enter_ns(lport, LPORT_ST_RFT_ID);
                        break;
                case LPORT_ST_RFT_ID:
                        fc_lport_enter_ns(lport, LPORT_ST_RFF_ID);
                        break;
                case LPORT_ST_RFF_ID:
                        if (lport->fdmi_enabled)
                                fc_lport_enter_fdmi(lport);
                        else
                                fc_lport_enter_scr(lport);
                        break;
                default:
                        /* should have already been caught by state checks */
                        break;
                }
        else
                fc_lport_error(lport, fp);
out:
        fc_frame_free(fp);
err:
        mutex_unlock(&lport->lp_mutex);
}

/**
 * fc_lport_ms_resp() - Handle response to a management server
 *                      exchange
 * @sp:     current sequence in 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_ms_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;

        FC_LPORT_DBG(lport, "Received a ms %s\n", fc_els_resp_type(fp));

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

        mutex_lock(&lport->lp_mutex);

        if (lport->state < LPORT_ST_RHBA || lport->state > LPORT_ST_DPRT) {
                FC_LPORT_DBG(lport, "Received a management server response, "
                             "but in state %s\n", fc_lport_state(lport));
                if (IS_ERR(fp))
                        goto err;
                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_MGMT &&
            ct->ct_fs_subtype == FC_FDMI_SUBTYPE) {
                FC_LPORT_DBG(lport, "Received a management server response, "
                                    "reason=%d explain=%d\n",
                                    ct->ct_reason,
                                    ct->ct_explan);

                switch (lport->state) {
                case LPORT_ST_RHBA:
                        if (ntohs(ct->ct_cmd) == FC_FS_ACC)
                                fc_lport_enter_ms(lport, LPORT_ST_RPA);
                        else /* Error Skip RPA */
                                fc_lport_enter_scr(lport);
                        break;
                case LPORT_ST_RPA:
                        fc_lport_enter_scr(lport);
                        break;
                case LPORT_ST_DPRT:
                        fc_lport_enter_ms(lport, LPORT_ST_RHBA);
                        break;
                case LPORT_ST_DHBA:
                        fc_lport_enter_ms(lport, LPORT_ST_DPRT);
                        break;
                default:
                        /* should have already been caught by state checks */
                        break;
                }
        } else {
                /* Invalid Frame? */
                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;

        FC_LPORT_DBG(lport, "Received a SCR %s\n", fc_els_resp_type(fp));

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

        mutex_lock(&lport->lp_mutex);

        if (lport->state != LPORT_ST_SCR) {
                FC_LPORT_DBG(lport, "Received a SCR response, but in state "
                             "%s\n", fc_lport_state(lport));
                if (IS_ERR(fp))
                        goto err;
                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 SCR (State Change Register) request
 * @lport: The local port to register for state changes
 */
static void fc_lport_enter_scr(struct fc_lport *lport)
{
        struct fc_frame *fp;

        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered SCR state from %s state\n",
                     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, FC_FID_FCTRL, fp, ELS_SCR,
                                  fc_lport_scr_resp, lport,
                                  2 * lport->r_a_tov))
                fc_lport_error(lport, NULL);
}

/**
 * fc_lport_enter_ns() - register some object with the name server
 * @lport: Fibre Channel local port to register
 */
static void fc_lport_enter_ns(struct fc_lport *lport, enum fc_lport_state state)
{
        struct fc_frame *fp;
        enum fc_ns_req cmd;
        int size = sizeof(struct fc_ct_hdr);
        size_t len;

        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered %s state from %s state\n",
                     fc_lport_state_names[state],
                     fc_lport_state(lport));

        fc_lport_state_enter(lport, state);

        switch (state) {
        case LPORT_ST_RNN_ID:
                cmd = FC_NS_RNN_ID;
                size += sizeof(struct fc_ns_rn_id);
                break;
        case LPORT_ST_RSNN_NN:
                len = strnlen(fc_host_symbolic_name(lport->host), 255);
                /* if there is no symbolic name, skip to RFT_ID */
                if (!len)
                        return fc_lport_enter_ns(lport, LPORT_ST_RFT_ID);
                cmd = FC_NS_RSNN_NN;
                size += sizeof(struct fc_ns_rsnn) + len;
                break;
        case LPORT_ST_RSPN_ID:
                len = strnlen(fc_host_symbolic_name(lport->host), 255);
                /* if there is no symbolic name, skip to RFT_ID */
                if (!len)
                        return fc_lport_enter_ns(lport, LPORT_ST_RFT_ID);
                cmd = FC_NS_RSPN_ID;
                size += sizeof(struct fc_ns_rspn) + len;
                break;
        case LPORT_ST_RFT_ID:
                cmd = FC_NS_RFT_ID;
                size += sizeof(struct fc_ns_rft);
                break;
        case LPORT_ST_RFF_ID:
                cmd = FC_NS_RFF_ID;
                size += sizeof(struct fc_ns_rff_id);
                break;
        default:
                fc_lport_error(lport, NULL);
                return;
        }

        fp = fc_frame_alloc(lport, size);
        if (!fp) {
                fc_lport_error(lport, fp);
                return;
        }

        if (!lport->tt.elsct_send(lport, FC_FID_DIR_SERV, fp, cmd,
                                  fc_lport_ns_resp,
                                  lport, 3 * lport->r_a_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 fc_rport for the name server
 * @lport: The local port requesting a remote port for the name server
 */
static void fc_lport_enter_dns(struct fc_lport *lport)
{
        struct fc_rport_priv *rdata;

        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered DNS state from %s state\n",
                     fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_DNS);

        mutex_lock(&lport->disc.disc_mutex);
        rdata = fc_rport_create(lport, FC_FID_DIR_SERV);
        mutex_unlock(&lport->disc.disc_mutex);
        if (!rdata)
                goto err;

        rdata->ops = &fc_lport_rport_ops;
        fc_rport_login(rdata);
        return;

err:
        fc_lport_error(lport, NULL);
}

/**
 * fc_lport_enter_ms() - management server commands
 * @lport: Fibre Channel local port to register
 */
static void fc_lport_enter_ms(struct fc_lport *lport, enum fc_lport_state state)
{
        struct fc_frame *fp;
        enum fc_fdmi_req cmd;
        int size = sizeof(struct fc_ct_hdr);
        size_t len;
        int numattrs;

        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered %s state from %s state\n",
                     fc_lport_state_names[state],
                     fc_lport_state(lport));

        fc_lport_state_enter(lport, state);

        switch (state) {
        case LPORT_ST_RHBA:
                cmd = FC_FDMI_RHBA;
                /* Number of HBA Attributes */
                numattrs = 10;
                len = sizeof(struct fc_fdmi_rhba);
                len -= sizeof(struct fc_fdmi_attr_entry);
                len += (numattrs * FC_FDMI_ATTR_ENTRY_HEADER_LEN);
                len += FC_FDMI_HBA_ATTR_NODENAME_LEN;
                len += FC_FDMI_HBA_ATTR_MANUFACTURER_LEN;
                len += FC_FDMI_HBA_ATTR_SERIALNUMBER_LEN;
                len += FC_FDMI_HBA_ATTR_MODEL_LEN;
                len += FC_FDMI_HBA_ATTR_MODELDESCR_LEN;
                len += FC_FDMI_HBA_ATTR_HARDWAREVERSION_LEN;
                len += FC_FDMI_HBA_ATTR_DRIVERVERSION_LEN;
                len += FC_FDMI_HBA_ATTR_OPTIONROMVERSION_LEN;
                len += FC_FDMI_HBA_ATTR_FIRMWAREVERSION_LEN;
                len += FC_FDMI_HBA_ATTR_OSNAMEVERSION_LEN;

                size += len;
                break;
        case LPORT_ST_RPA:
                cmd = FC_FDMI_RPA;
                /* Number of Port Attributes */
                numattrs = 6;
                len = sizeof(struct fc_fdmi_rpa);
                len -= sizeof(struct fc_fdmi_attr_entry);
                len += (numattrs * FC_FDMI_ATTR_ENTRY_HEADER_LEN);
                len += FC_FDMI_PORT_ATTR_FC4TYPES_LEN;
                len += FC_FDMI_PORT_ATTR_SUPPORTEDSPEED_LEN;
                len += FC_FDMI_PORT_ATTR_CURRENTPORTSPEED_LEN;
                len += FC_FDMI_PORT_ATTR_MAXFRAMESIZE_LEN;
                len += FC_FDMI_PORT_ATTR_OSDEVICENAME_LEN;
                len += FC_FDMI_PORT_ATTR_HOSTNAME_LEN;

                size += len;
                break;
        case LPORT_ST_DPRT:
                cmd = FC_FDMI_DPRT;
                len = sizeof(struct fc_fdmi_dprt);
                size += len;
                break;
        case LPORT_ST_DHBA:
                cmd = FC_FDMI_DHBA;
                len = sizeof(struct fc_fdmi_dhba);
                size += len;
                break;
        default:
                fc_lport_error(lport, NULL);
                return;
        }

        FC_LPORT_DBG(lport, "Cmd=0x%x Len %d size %d\n",
                             cmd, (int)len, size);
        fp = fc_frame_alloc(lport, size);
        if (!fp) {
                fc_lport_error(lport, fp);
                return;
        }

        if (!lport->tt.elsct_send(lport, FC_FID_MGMT_SERV, fp, cmd,
                                  fc_lport_ms_resp,
                                  lport, 3 * lport->r_a_tov))
                fc_lport_error(lport, fp);
}

/**
 * fc_rport_enter_fdmi() - Create a fc_rport for the management server
 * @lport: The local port requesting a remote port for the management server
 */
static void fc_lport_enter_fdmi(struct fc_lport *lport)
{
        struct fc_rport_priv *rdata;

        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered FDMI state from %s state\n",
                     fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_FDMI);

        mutex_lock(&lport->disc.disc_mutex);
        rdata = fc_rport_create(lport, FC_FID_MGMT_SERV);
        mutex_unlock(&lport->disc.disc_mutex);
        if (!rdata)
                goto err;

        rdata->ops = &fc_lport_rport_ops;
        fc_rport_login(rdata);
        return;

err:
        fc_lport_error(lport, NULL);
}

/**
 * fc_lport_timeout() - Handler for the retry_work timer
 * @work: The work struct of the local port
 */
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_DISABLED:
                break;
        case LPORT_ST_READY:
                break;
        case LPORT_ST_RESET:
                break;
        case LPORT_ST_FLOGI:
                fc_lport_enter_flogi(lport);
                break;
        case LPORT_ST_DNS:
                fc_lport_enter_dns(lport);
                break;
        case LPORT_ST_RNN_ID:
        case LPORT_ST_RSNN_NN:
        case LPORT_ST_RSPN_ID:
        case LPORT_ST_RFT_ID:
        case LPORT_ST_RFF_ID:
                fc_lport_enter_ns(lport, lport->state);
                break;
        case LPORT_ST_FDMI:
                fc_lport_enter_fdmi(lport);
                break;
        case LPORT_ST_RHBA:
        case LPORT_ST_RPA:
        case LPORT_ST_DHBA:
        case LPORT_ST_DPRT:
                FC_LPORT_DBG(lport, "Skipping lport state %s to SCR\n",
                             fc_lport_state(lport));
                /* fall thru */
        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:     The sequence that the LOGO was on
 * @fp:     The LOGO frame
 * @lp_arg: The lport port that received 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.
 */
void fc_lport_logo_resp(struct fc_seq *sp, struct fc_frame *fp,
                        void *lp_arg)
{
        struct fc_lport *lport = lp_arg;
        u8 op;

        FC_LPORT_DBG(lport, "Received a LOGO %s\n", fc_els_resp_type(fp));

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

        mutex_lock(&lport->lp_mutex);

        if (lport->state != LPORT_ST_LOGO) {
                FC_LPORT_DBG(lport, "Received a LOGO response, but in state "
                             "%s\n", fc_lport_state(lport));
                if (IS_ERR(fp))
                        goto err;
                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_disabled(lport);
        else
                fc_lport_error(lport, fp);

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

/**
 * fc_rport_enter_logo() - Logout of the fabric
 * @lport: The local port to be logged out
 */
static void fc_lport_enter_logo(struct fc_lport *lport)
{
        struct fc_frame *fp;
        struct fc_els_logo *logo;

        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered LOGO state from %s state\n",
                     fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_LOGO);
        fc_vports_linkchange(lport);

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

        if (!lport->tt.elsct_send(lport, FC_FID_FLOGI, fp, ELS_LOGO,
                                  fc_lport_logo_resp, lport,
                                  2 * lport->r_a_tov))
                fc_lport_error(lport, NULL);
}

/**
 * fc_lport_flogi_resp() - Handle response to FLOGI request
 * @sp:     The sequence that the FLOGI was on
 * @fp:     The FLOGI response frame
 * @lp_arg: The lport port that received the FLOGI response
 *
 * 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.
 */
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;

        FC_LPORT_DBG(lport, "Received a FLOGI %s\n", fc_els_resp_type(fp));

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

        mutex_lock(&lport->lp_mutex);

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

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

        fh = fc_frame_header_get(fp);
        did = fc_frame_did(fp);
        if (fh->fh_r_ctl != FC_RCTL_ELS_REP || did == 0 ||
            fc_frame_payload_op(fp) != ELS_LS_ACC) {
                FC_LPORT_DBG(lport, "FLOGI not accepted or bad response\n");
                fc_lport_error(lport, fp);
                goto out;
        }

        flp = fc_frame_payload_get(fp, sizeof(*flp));
        if (!flp) {
                FC_LPORT_DBG(lport, "FLOGI bad response\n");
                fc_lport_error(lport, fp);
                goto out;
        }

        mfs = ntohs(flp->fl_csp.sp_bb_data) &
                FC_SP_BB_DATA_MASK;

        if (mfs < FC_SP_MIN_MAX_PAYLOAD || mfs > FC_SP_MAX_MAX_PAYLOAD) {
                FC_LPORT_DBG(lport, "FLOGI bad mfs:%hu response, "
                             "lport->mfs:%hu\n", mfs, lport->mfs);
                fc_lport_error(lport, fp);
                goto out;
        }

        if (mfs <= lport->mfs) {
                lport->mfs = mfs;
                fc_host_maxframe_size(lport->host) = 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;

        lport->npiv_enabled = !!(csp_flags & FC_SP_FT_NPIV_ACC);

        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 * lport->e_d_tov;
                fc_lport_set_port_id(lport, did, fp);
                printk(KERN_INFO "host%d: libfc: "
                       "Port (%6.6x) entered "
                       "point-to-point mode\n",
                       lport->host->host_no, did);
                fc_lport_ptp_setup(lport, fc_frame_sid(fp),
                                   get_unaligned_be64(
                                           &flp->fl_wwpn),
                                   get_unaligned_be64(
                                           &flp->fl_wwnn));
        } else {
                if (e_d_tov > lport->e_d_tov)
                        lport->e_d_tov = e_d_tov;
                if (r_a_tov > lport->r_a_tov)
                        lport->r_a_tov = r_a_tov;
                fc_host_fabric_name(lport->host) =
                        get_unaligned_be64(&flp->fl_wwnn);
                fc_lport_set_port_id(lport, did, fp);
                fc_lport_enter_dns(lport);
        }

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

/**
 * fc_rport_enter_flogi() - Send a FLOGI request to the fabric manager
 * @lport: Fibre Channel local port to be logged in to the fabric
 */
static void fc_lport_enter_flogi(struct fc_lport *lport)
{
        struct fc_frame *fp;

        lockdep_assert_held(&lport->lp_mutex);

        FC_LPORT_DBG(lport, "Entered FLOGI state from %s state\n",
                     fc_lport_state(lport));

        fc_lport_state_enter(lport, LPORT_ST_FLOGI);

        if (lport->point_to_multipoint) {
                if (lport->port_id)
                        fc_lport_enter_ready(lport);
                return;
        }

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

        if (!lport->tt.elsct_send(lport, FC_FID_FLOGI, fp,
                                  lport->vport ? ELS_FDISC : ELS_FLOGI,
                                  fc_lport_flogi_resp, lport,
                                  lport->vport ? 2 * lport->r_a_tov :
                                  lport->e_d_tov))
                fc_lport_error(lport, NULL);
}

/**
 * fc_lport_config() - Configure a fc_lport
 * @lport: The local port to be configured
 */
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_DISABLED);

        fc_lport_add_fc4_type(lport, FC_TYPE_FCP);
        fc_lport_add_fc4_type(lport, FC_TYPE_CT);
        fc_fc4_conf_lport_params(lport, FC_TYPE_FCP);

        return 0;
}
EXPORT_SYMBOL(fc_lport_config);

/**
 * fc_lport_init() - Initialize the lport layer for a local port
 * @lport: The local port to initialize the exchange layer for
 */
int fc_lport_init(struct fc_lport *lport)
{
        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;
        fc_fc4_add_lport(lport);

        return 0;
}
EXPORT_SYMBOL(fc_lport_init);

/**
 * fc_lport_bsg_resp() - The common response handler for FC Passthrough requests
 * @sp:       The sequence for the FC Passthrough response
 * @fp:       The response frame
 * @info_arg: The BSG info that the response is for
 */
static void fc_lport_bsg_resp(struct fc_seq *sp, struct fc_frame *fp,
                              void *info_arg)
{
        struct fc_bsg_info *info = info_arg;
        struct bsg_job *job = info->job;
        struct fc_bsg_reply *bsg_reply = job->reply;
        struct fc_lport *lport = info->lport;
        struct fc_frame_header *fh;
        size_t len;
        void *buf;

        if (IS_ERR(fp)) {
                bsg_reply->result = (PTR_ERR(fp) == -FC_EX_CLOSED) ?
                        -ECONNABORTED : -ETIMEDOUT;
                job->reply_len = sizeof(uint32_t);
                bsg_job_done(job, bsg_reply->result,
                               bsg_reply->reply_payload_rcv_len);
                kfree(info);
                return;
        }

        mutex_lock(&lport->lp_mutex);
        fh = fc_frame_header_get(fp);
        len = fr_len(fp) - sizeof(*fh);
        buf = fc_frame_payload_get(fp, 0);

        if (fr_sof(fp) == FC_SOF_I3 && !ntohs(fh->fh_seq_cnt)) {
                /* Get the response code from the first frame payload */
                unsigned short cmd = (info->rsp_code == FC_FS_ACC) ?
                        ntohs(((struct fc_ct_hdr *)buf)->ct_cmd) :
                        (unsigned short)fc_frame_payload_op(fp);

                /* Save the reply status of the job */
                bsg_reply->reply_data.ctels_reply.status =
                        (cmd == info->rsp_code) ?
                        FC_CTELS_STATUS_OK : FC_CTELS_STATUS_REJECT;
        }

        bsg_reply->reply_payload_rcv_len +=
                fc_copy_buffer_to_sglist(buf, len, info->sg, &info->nents,
                                         &info->offset, NULL);

        if (fr_eof(fp) == FC_EOF_T &&
            (ntoh24(fh->fh_f_ctl) & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
            (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
                if (bsg_reply->reply_payload_rcv_len >
                    job->reply_payload.payload_len)
                        bsg_reply->reply_payload_rcv_len =
                                job->reply_payload.payload_len;
                bsg_reply->result = 0;
                bsg_job_done(job, bsg_reply->result,
                               bsg_reply->reply_payload_rcv_len);
                kfree(info);
        }
        fc_frame_free(fp);
        mutex_unlock(&lport->lp_mutex);
}

/**
 * fc_lport_els_request() - Send ELS passthrough request
 * @job:   The BSG Passthrough job
 * @lport: The local port sending the request
 * @did:   The destination port id
 */
static int fc_lport_els_request(struct bsg_job *job,
                                struct fc_lport *lport,
                                u32 did, u32 tov)
{
        struct fc_bsg_info *info;
        struct fc_frame *fp;
        struct fc_frame_header *fh;
        char *pp;
        int len;

        lockdep_assert_held(&lport->lp_mutex);

        fp = fc_frame_alloc(lport, job->request_payload.payload_len);
        if (!fp)
                return -ENOMEM;

        len = job->request_payload.payload_len;
        pp = fc_frame_payload_get(fp, len);

        sg_copy_to_buffer(job->request_payload.sg_list,
                          job->request_payload.sg_cnt,
                          pp, len);

        fh = fc_frame_header_get(fp);
        fh->fh_r_ctl = FC_RCTL_ELS_REQ;
        hton24(fh->fh_d_id, did);
        hton24(fh->fh_s_id, lport->port_id);
        fh->fh_type = FC_TYPE_ELS;
        hton24(fh->fh_f_ctl, FC_FCTL_REQ);
        fh->fh_cs_ctl = 0;
        fh->fh_df_ctl = 0;
        fh->fh_parm_offset = 0;

        info = kzalloc(sizeof(struct fc_bsg_info), GFP_KERNEL);
        if (!info) {
                fc_frame_free(fp);
                return -ENOMEM;
        }

        info->job = job;
        info->lport = lport;
        info->rsp_code = ELS_LS_ACC;
        info->nents = job->reply_payload.sg_cnt;
        info->sg = job->reply_payload.sg_list;

        if (!fc_exch_seq_send(lport, fp, fc_lport_bsg_resp,
                              NULL, info, tov)) {
                kfree(info);
                return -ECOMM;
        }
        return 0;
}

/**
 * fc_lport_ct_request() - Send CT Passthrough request
 * @job:   The BSG Passthrough job
 * @lport: The local port sending the request
 * @did:   The destination FC-ID
 * @tov:   The timeout period to wait for the response
 */
static int fc_lport_ct_request(struct bsg_job *job,
                               struct fc_lport *lport, u32 did, u32 tov)
{
        struct fc_bsg_info *info;
        struct fc_frame *fp;
        struct fc_frame_header *fh;
        struct fc_ct_req *ct;
        size_t len;

        lockdep_assert_held(&lport->lp_mutex);

        fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
                            job->request_payload.payload_len);
        if (!fp)
                return -ENOMEM;

        len = job->request_payload.payload_len;
        ct = fc_frame_payload_get(fp, len);

        sg_copy_to_buffer(job->request_payload.sg_list,
                          job->request_payload.sg_cnt,
                          ct, len);

        fh = fc_frame_header_get(fp);
        fh->fh_r_ctl = FC_RCTL_DD_UNSOL_CTL;
        hton24(fh->fh_d_id, did);
        hton24(fh->fh_s_id, lport->port_id);
        fh->fh_type = FC_TYPE_CT;
        hton24(fh->fh_f_ctl, FC_FCTL_REQ);
        fh->fh_cs_ctl = 0;
        fh->fh_df_ctl = 0;
        fh->fh_parm_offset = 0;

        info = kzalloc(sizeof(struct fc_bsg_info), GFP_KERNEL);
        if (!info) {
                fc_frame_free(fp);
                return -ENOMEM;
        }

        info->job = job;
        info->lport = lport;
        info->rsp_code = FC_FS_ACC;
        info->nents = job->reply_payload.sg_cnt;
        info->sg = job->reply_payload.sg_list;

        if (!fc_exch_seq_send(lport, fp, fc_lport_bsg_resp,
                              NULL, info, tov)) {
                kfree(info);
                return -ECOMM;
        }
        return 0;
}

/**
 * fc_lport_bsg_request() - The common entry point for sending
 *                          FC Passthrough requests
 * @job: The BSG passthrough job
 */
int fc_lport_bsg_request(struct bsg_job *job)
{
        struct fc_bsg_request *bsg_request = job->request;
        struct fc_bsg_reply *bsg_reply = job->reply;
        struct Scsi_Host *shost = fc_bsg_to_shost(job);
        struct fc_lport *lport = shost_priv(shost);
        struct fc_rport *rport;
        struct fc_rport_priv *rdata;
        int rc = -EINVAL;
        u32 did, tov;

        bsg_reply->reply_payload_rcv_len = 0;

        mutex_lock(&lport->lp_mutex);

        switch (bsg_request->msgcode) {
        case FC_BSG_RPT_ELS:
                rport = fc_bsg_to_rport(job);
                if (!rport)
                        break;

                rdata = rport->dd_data;
                rc = fc_lport_els_request(job, lport, rport->port_id,
                                          rdata->e_d_tov);
                break;

        case FC_BSG_RPT_CT:
                rport = fc_bsg_to_rport(job);
                if (!rport)
                        break;

                rdata = rport->dd_data;
                rc = fc_lport_ct_request(job, lport, rport->port_id,
                                         rdata->e_d_tov);
                break;

        case FC_BSG_HST_CT:
                did = ntoh24(bsg_request->rqst_data.h_ct.port_id);
                if (did == FC_FID_DIR_SERV) {
                        rdata = lport->dns_rdata;
                        if (!rdata)
                                break;
                        tov = rdata->e_d_tov;
                } else {
                        rdata = fc_rport_lookup(lport, did);
                        if (!rdata)
                                break;
                        tov = rdata->e_d_tov;
                        kref_put(&rdata->kref, fc_rport_destroy);
                }

                rc = fc_lport_ct_request(job, lport, did, tov);
                break;

        case FC_BSG_HST_ELS_NOLOGIN:
                did = ntoh24(bsg_request->rqst_data.h_els.port_id);
                rc = fc_lport_els_request(job, lport, did, lport->e_d_tov);
                break;
        }

        mutex_unlock(&lport->lp_mutex);
        return rc;
}
EXPORT_SYMBOL(fc_lport_bsg_request);