// SPDX-License-Identifier: GPL-2.0-only
/*
 *  QLogic FCoE Offload Driver
 *  Copyright (c) 2016-2018 Cavium Inc.
 */
#include "qedf.h"

/* It's assumed that the lock is held when calling this function. */
static int qedf_initiate_els(struct qedf_rport *fcport, unsigned int op,
        void *data, uint32_t data_len,
        void (*cb_func)(struct qedf_els_cb_arg *cb_arg),
        struct qedf_els_cb_arg *cb_arg, uint32_t timer_msec)
{
        struct qedf_ctx *qedf;
        struct fc_lport *lport;
        struct qedf_ioreq *els_req;
        struct qedf_mp_req *mp_req;
        struct fc_frame_header *fc_hdr;
        struct fcoe_task_context *task;
        int rc = 0;
        uint32_t did, sid;
        uint16_t xid;
        struct fcoe_wqe *sqe;
        unsigned long flags;
        u16 sqe_idx;

        if (!fcport) {
                QEDF_ERR(NULL, "fcport is NULL");
                rc = -EINVAL;
                goto els_err;
        }

        qedf = fcport->qedf;
        lport = qedf->lport;

        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Sending ELS\n");

        rc = fc_remote_port_chkready(fcport->rport);
        if (rc) {
                QEDF_ERR(&(qedf->dbg_ctx), "els 0x%x: rport not ready\n", op);
                rc = -EAGAIN;
                goto els_err;
        }
        if (lport->state != LPORT_ST_READY || !(lport->link_up)) {
                QEDF_ERR(&(qedf->dbg_ctx), "els 0x%x: link is not ready\n",
                          op);
                rc = -EAGAIN;
                goto els_err;
        }

        if (!test_bit(QEDF_RPORT_SESSION_READY, &fcport->flags)) {
                QEDF_ERR(&(qedf->dbg_ctx), "els 0x%x: fcport not ready\n", op);
                rc = -EINVAL;
                goto els_err;
        }

        els_req = qedf_alloc_cmd(fcport, QEDF_ELS);
        if (!els_req) {
                QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_ELS,
                          "Failed to alloc ELS request 0x%x\n", op);
                rc = -ENOMEM;
                goto els_err;
        }

        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "initiate_els els_req = "
                   "0x%p cb_arg = %p xid = %x\n", els_req, cb_arg,
                   els_req->xid);
        els_req->sc_cmd = NULL;
        els_req->cmd_type = QEDF_ELS;
        els_req->fcport = fcport;
        els_req->cb_func = cb_func;
        cb_arg->io_req = els_req;
        cb_arg->op = op;
        els_req->cb_arg = cb_arg;
        els_req->data_xfer_len = data_len;

        /* Record which cpu this request is associated with */
        els_req->cpu = smp_processor_id();

        mp_req = (struct qedf_mp_req *)&(els_req->mp_req);
        rc = qedf_init_mp_req(els_req);
        if (rc) {
                QEDF_ERR(&(qedf->dbg_ctx), "ELS MP request init failed\n");
                kref_put(&els_req->refcount, qedf_release_cmd);
                goto els_err;
        } else {
                rc = 0;
        }

        /* Fill ELS Payload */
        if ((op >= ELS_LS_RJT) && (op <= ELS_AUTH_ELS)) {
                memcpy(mp_req->req_buf, data, data_len);
        } else {
                QEDF_ERR(&(qedf->dbg_ctx), "Invalid ELS op 0x%x\n", op);
                els_req->cb_func = NULL;
                els_req->cb_arg = NULL;
                kref_put(&els_req->refcount, qedf_release_cmd);
                rc = -EINVAL;
        }

        if (rc)
                goto els_err;

        /* Fill FC header */
        fc_hdr = &(mp_req->req_fc_hdr);

        did = fcport->rdata->ids.port_id;
        sid = fcport->sid;

        __fc_fill_fc_hdr(fc_hdr, FC_RCTL_ELS_REQ, did, sid,
                           FC_TYPE_ELS, FC_FC_FIRST_SEQ | FC_FC_END_SEQ |
                           FC_FC_SEQ_INIT, 0);

        /* Obtain exchange id */
        xid = els_req->xid;

        spin_lock_irqsave(&fcport->rport_lock, flags);

        sqe_idx = qedf_get_sqe_idx(fcport);
        sqe = &fcport->sq[sqe_idx];
        memset(sqe, 0, sizeof(struct fcoe_wqe));

        /* Initialize task context for this IO request */
        task = qedf_get_task_mem(&qedf->tasks, xid);
        qedf_init_mp_task(els_req, task, sqe);

        /* Put timer on els request */
        if (timer_msec)
                qedf_cmd_timer_set(qedf, els_req, timer_msec);

        /* Ring doorbell */
        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Ringing doorbell for ELS "
                   "req\n");
        qedf_ring_doorbell(fcport);
        set_bit(QEDF_CMD_OUTSTANDING, &els_req->flags);

        spin_unlock_irqrestore(&fcport->rport_lock, flags);
els_err:
        return rc;
}

void qedf_process_els_compl(struct qedf_ctx *qedf, struct fcoe_cqe *cqe,
        struct qedf_ioreq *els_req)
{
        struct fcoe_cqe_midpath_info *mp_info;
        struct qedf_rport *fcport;

        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Entered with xid = 0x%x"
                   " cmd_type = %d.\n", els_req->xid, els_req->cmd_type);

        if ((els_req->event == QEDF_IOREQ_EV_ELS_FLUSH)
                || (els_req->event == QEDF_IOREQ_EV_CLEANUP_SUCCESS)
                || (els_req->event == QEDF_IOREQ_EV_CLEANUP_FAILED)) {
                QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_IO,
                        "ELS completion xid=0x%x after flush event=0x%x",
                        els_req->xid, els_req->event);
                return;
        }

        fcport = els_req->fcport;

        /* When flush is active,
         * let the cmds be completed from the cleanup context
         */
        if (test_bit(QEDF_RPORT_IN_TARGET_RESET, &fcport->flags) ||
                test_bit(QEDF_RPORT_IN_LUN_RESET, &fcport->flags)) {
                QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_IO,
                        "Dropping ELS completion xid=0x%x as fcport is flushing",
                        els_req->xid);
                return;
        }

        clear_bit(QEDF_CMD_OUTSTANDING, &els_req->flags);

        /* Kill the ELS timer */
        cancel_delayed_work(&els_req->timeout_work);

        /* Get ELS response length from CQE */
        mp_info = &cqe->cqe_info.midpath_info;
        els_req->mp_req.resp_len = mp_info->data_placement_size;

        /* Parse ELS response */
        if ((els_req->cb_func) && (els_req->cb_arg)) {
                els_req->cb_func(els_req->cb_arg);
                els_req->cb_arg = NULL;
        }

        kref_put(&els_req->refcount, qedf_release_cmd);
}

static void qedf_rrq_compl(struct qedf_els_cb_arg *cb_arg)
{
        struct qedf_ioreq *orig_io_req;
        struct qedf_ioreq *rrq_req;
        struct qedf_ctx *qedf;
        int refcount;

        rrq_req = cb_arg->io_req;
        qedf = rrq_req->fcport->qedf;

        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Entered.\n");

        orig_io_req = cb_arg->aborted_io_req;

        if (!orig_io_req) {
                QEDF_ERR(&qedf->dbg_ctx,
                         "Original io_req is NULL, rrq_req = %p.\n", rrq_req);
                goto out_free;
        }

        refcount = kref_read(&orig_io_req->refcount);
        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "rrq_compl: orig io = %p,"
                   " orig xid = 0x%x, rrq_xid = 0x%x, refcount=%d\n",
                   orig_io_req, orig_io_req->xid, rrq_req->xid, refcount);

        /*
         * This should return the aborted io_req to the command pool. Note that
         * we need to check the refcound in case the original request was
         * flushed but we get a completion on this xid.
         */
        if (orig_io_req && refcount > 0)
                kref_put(&orig_io_req->refcount, qedf_release_cmd);

out_free:
        /*
         * Release a reference to the rrq request if we timed out as the
         * rrq completion handler is called directly from the timeout handler
         * and not from els_compl where the reference would have normally been
         * released.
         */
        if (rrq_req->event == QEDF_IOREQ_EV_ELS_TMO)
                kref_put(&rrq_req->refcount, qedf_release_cmd);
        kfree(cb_arg);
}

/* Assumes kref is already held by caller */
int qedf_send_rrq(struct qedf_ioreq *aborted_io_req)
{

        struct fc_els_rrq rrq;
        struct qedf_rport *fcport;
        struct fc_lport *lport;
        struct qedf_els_cb_arg *cb_arg = NULL;
        struct qedf_ctx *qedf;
        uint32_t sid;
        uint32_t r_a_tov;
        int rc;
        int refcount;

        if (!aborted_io_req) {
                QEDF_ERR(NULL, "abort_io_req is NULL.\n");
                return -EINVAL;
        }

        fcport = aborted_io_req->fcport;

        if (!fcport) {
                refcount = kref_read(&aborted_io_req->refcount);
                QEDF_ERR(NULL,
                         "RRQ work was queued prior to a flush xid=0x%x, refcount=%d.\n",
                         aborted_io_req->xid, refcount);
                kref_put(&aborted_io_req->refcount, qedf_release_cmd);
                return -EINVAL;
        }

        /* Check that fcport is still offloaded */
        if (!test_bit(QEDF_RPORT_SESSION_READY, &fcport->flags)) {
                QEDF_ERR(NULL, "fcport is no longer offloaded.\n");
                return -EINVAL;
        }

        if (!fcport->qedf) {
                QEDF_ERR(NULL, "fcport->qedf is NULL.\n");
                return -EINVAL;
        }

        qedf = fcport->qedf;

        /*
         * Sanity check that we can send a RRQ to make sure that refcount isn't
         * 0
         */
        refcount = kref_read(&aborted_io_req->refcount);
        if (refcount != 1) {
                QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_ELS,
                          "refcount for xid=%x io_req=%p refcount=%d is not 1.\n",
                          aborted_io_req->xid, aborted_io_req, refcount);
                return -EINVAL;
        }

        lport = qedf->lport;
        sid = fcport->sid;
        r_a_tov = lport->r_a_tov;

        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Sending RRQ orig "
                   "io = %p, orig_xid = 0x%x\n", aborted_io_req,
                   aborted_io_req->xid);
        memset(&rrq, 0, sizeof(rrq));

        cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
        if (!cb_arg) {
                QEDF_ERR(&(qedf->dbg_ctx), "Unable to allocate cb_arg for "
                          "RRQ\n");
                rc = -ENOMEM;
                goto rrq_err;
        }

        cb_arg->aborted_io_req = aborted_io_req;

        rrq.rrq_cmd = ELS_RRQ;
        hton24(rrq.rrq_s_id, sid);
        rrq.rrq_ox_id = htons(aborted_io_req->xid);
        rrq.rrq_rx_id =
            htons(aborted_io_req->task->tstorm_st_context.read_write.rx_id);

        rc = qedf_initiate_els(fcport, ELS_RRQ, &rrq, sizeof(rrq),
            qedf_rrq_compl, cb_arg, r_a_tov);

rrq_err:
        if (rc) {
                QEDF_ERR(&(qedf->dbg_ctx), "RRQ failed - release orig io "
                          "req 0x%x\n", aborted_io_req->xid);
                kfree(cb_arg);
                kref_put(&aborted_io_req->refcount, qedf_release_cmd);
        }
        return rc;
}

static void qedf_process_l2_frame_compl(struct qedf_rport *fcport,
                                        struct fc_frame *fp,
                                        u16 l2_oxid)
{
        struct fc_lport *lport = fcport->qedf->lport;
        struct fc_frame_header *fh;
        u32 crc;

        fh = (struct fc_frame_header *)fc_frame_header_get(fp);

        /* Set the OXID we return to what libfc used */
        if (l2_oxid != FC_XID_UNKNOWN)
                fh->fh_ox_id = htons(l2_oxid);

        /* Setup header fields */
        fh->fh_r_ctl = FC_RCTL_ELS_REP;
        fh->fh_type = FC_TYPE_ELS;
        /* Last sequence, end sequence */
        fh->fh_f_ctl[0] = 0x98;
        hton24(fh->fh_d_id, lport->port_id);
        hton24(fh->fh_s_id, fcport->rdata->ids.port_id);
        fh->fh_rx_id = 0xffff;

        /* Set frame attributes */
        crc = fcoe_fc_crc(fp);
        fc_frame_init(fp);
        fr_dev(fp) = lport;
        fr_sof(fp) = FC_SOF_I3;
        fr_eof(fp) = FC_EOF_T;
        fr_crc(fp) = cpu_to_le32(~crc);

        /* Send completed request to libfc */
        fc_exch_recv(lport, fp);
}

/*
 * In instances where an ELS command times out we may need to restart the
 * rport by logging out and then logging back in.
 */
void qedf_restart_rport(struct qedf_rport *fcport)
{
        struct fc_lport *lport;
        struct fc_rport_priv *rdata;
        u32 port_id;
        unsigned long flags;

        if (!fcport) {
                QEDF_ERR(NULL, "fcport is NULL.\n");
                return;
        }

        spin_lock_irqsave(&fcport->rport_lock, flags);
        if (test_bit(QEDF_RPORT_IN_RESET, &fcport->flags) ||
            !test_bit(QEDF_RPORT_SESSION_READY, &fcport->flags) ||
            test_bit(QEDF_RPORT_UPLOADING_CONNECTION, &fcport->flags)) {
                QEDF_ERR(&(fcport->qedf->dbg_ctx), "fcport %p already in reset or not offloaded.\n",
                    fcport);
                spin_unlock_irqrestore(&fcport->rport_lock, flags);
                return;
        }

        /* Set that we are now in reset */
        set_bit(QEDF_RPORT_IN_RESET, &fcport->flags);
        spin_unlock_irqrestore(&fcport->rport_lock, flags);

        rdata = fcport->rdata;
        if (rdata && !kref_get_unless_zero(&rdata->kref)) {
                fcport->rdata = NULL;
                rdata = NULL;
        }

        if (rdata && rdata->rp_state == RPORT_ST_READY) {
                lport = fcport->qedf->lport;
                port_id = rdata->ids.port_id;
                QEDF_ERR(&(fcport->qedf->dbg_ctx),
                    "LOGO port_id=%x.\n", port_id);
                fc_rport_logoff(rdata);
                kref_put(&rdata->kref, fc_rport_destroy);
                mutex_lock(&lport->disc.disc_mutex);
                /* Recreate the rport and log back in */
                rdata = fc_rport_create(lport, port_id);
                mutex_unlock(&lport->disc.disc_mutex);
                if (rdata)
                        fc_rport_login(rdata);
                fcport->rdata = rdata;
        }
        clear_bit(QEDF_RPORT_IN_RESET, &fcport->flags);
}

static void qedf_l2_els_compl(struct qedf_els_cb_arg *cb_arg)
{
        struct qedf_ioreq *els_req;
        struct qedf_rport *fcport;
        struct qedf_mp_req *mp_req;
        struct fc_frame *fp;
        struct fc_frame_header *fh, *mp_fc_hdr;
        void *resp_buf, *fc_payload;
        u32 resp_len;
        u16 l2_oxid;

        l2_oxid = cb_arg->l2_oxid;
        els_req = cb_arg->io_req;

        if (!els_req) {
                QEDF_ERR(NULL, "els_req is NULL.\n");
                goto free_arg;
        }

        /*
         * If we are flushing the command just free the cb_arg as none of the
         * response data will be valid.
         */
        if (els_req->event == QEDF_IOREQ_EV_ELS_FLUSH) {
                QEDF_ERR(NULL, "els_req xid=0x%x event is flush.\n",
                         els_req->xid);
                goto free_arg;
        }

        fcport = els_req->fcport;
        mp_req = &(els_req->mp_req);
        mp_fc_hdr = &(mp_req->resp_fc_hdr);
        resp_len = mp_req->resp_len;
        resp_buf = mp_req->resp_buf;

        /*
         * If a middle path ELS command times out, don't try to return
         * the command but rather do any internal cleanup and then libfc
         * timeout the command and clean up its internal resources.
         */
        if (els_req->event == QEDF_IOREQ_EV_ELS_TMO) {
                /*
                 * If ADISC times out, libfc will timeout the exchange and then
                 * try to send a PLOGI which will timeout since the session is
                 * still offloaded.  Force libfc to logout the session which
                 * will offload the connection and allow the PLOGI response to
                 * flow over the LL2 path.
                 */
                if (cb_arg->op == ELS_ADISC)
                        qedf_restart_rport(fcport);
                return;
        }

        if (sizeof(struct fc_frame_header) + resp_len > QEDF_PAGE_SIZE) {
                QEDF_ERR(&(fcport->qedf->dbg_ctx), "resp_len is "
                   "beyond page size.\n");
                goto free_arg;
        }

        fp = fc_frame_alloc(fcport->qedf->lport, resp_len);
        if (!fp) {
                QEDF_ERR(&(fcport->qedf->dbg_ctx),
                    "fc_frame_alloc failure.\n");
                return;
        }

        /* Copy frame header from firmware into fp */
        fh = (struct fc_frame_header *)fc_frame_header_get(fp);
        memcpy(fh, mp_fc_hdr, sizeof(struct fc_frame_header));

        /* Copy payload from firmware into fp */
        fc_payload = fc_frame_payload_get(fp, resp_len);
        memcpy(fc_payload, resp_buf, resp_len);

        QEDF_INFO(&(fcport->qedf->dbg_ctx), QEDF_LOG_ELS,
            "Completing OX_ID 0x%x back to libfc.\n", l2_oxid);
        qedf_process_l2_frame_compl(fcport, fp, l2_oxid);

free_arg:
        kfree(cb_arg);
}

int qedf_send_adisc(struct qedf_rport *fcport, struct fc_frame *fp)
{
        struct fc_els_adisc *adisc;
        struct fc_frame_header *fh;
        struct fc_lport *lport = fcport->qedf->lport;
        struct qedf_els_cb_arg *cb_arg = NULL;
        struct qedf_ctx *qedf;
        uint32_t r_a_tov = lport->r_a_tov;
        int rc;

        qedf = fcport->qedf;
        fh = fc_frame_header_get(fp);

        cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
        if (!cb_arg) {
                QEDF_ERR(&(qedf->dbg_ctx), "Unable to allocate cb_arg for "
                          "ADISC\n");
                rc = -ENOMEM;
                goto adisc_err;
        }
        cb_arg->l2_oxid = ntohs(fh->fh_ox_id);

        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
            "Sending ADISC ox_id=0x%x.\n", cb_arg->l2_oxid);

        adisc = fc_frame_payload_get(fp, sizeof(*adisc));

        rc = qedf_initiate_els(fcport, ELS_ADISC, adisc, sizeof(*adisc),
            qedf_l2_els_compl, cb_arg, r_a_tov);

adisc_err:
        if (rc) {
                QEDF_ERR(&(qedf->dbg_ctx), "ADISC failed.\n");
                kfree(cb_arg);
        }
        return rc;
}

static void qedf_srr_compl(struct qedf_els_cb_arg *cb_arg)
{
        struct qedf_ioreq *orig_io_req;
        struct qedf_ioreq *srr_req;
        struct qedf_mp_req *mp_req;
        struct fc_frame_header *mp_fc_hdr, *fh;
        struct fc_frame *fp;
        void *resp_buf, *fc_payload;
        u32 resp_len;
        struct fc_lport *lport;
        struct qedf_ctx *qedf;
        int refcount;
        u8 opcode;

        srr_req = cb_arg->io_req;
        qedf = srr_req->fcport->qedf;
        lport = qedf->lport;

        orig_io_req = cb_arg->aborted_io_req;

        if (!orig_io_req) {
                QEDF_ERR(NULL, "orig_io_req is NULL.\n");
                goto out_free;
        }

        clear_bit(QEDF_CMD_SRR_SENT, &orig_io_req->flags);

        if (srr_req->event != QEDF_IOREQ_EV_ELS_TMO &&
            srr_req->event != QEDF_IOREQ_EV_ELS_ERR_DETECT)
                cancel_delayed_work_sync(&orig_io_req->timeout_work);

        refcount = kref_read(&orig_io_req->refcount);
        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Entered: orig_io=%p,"
                   " orig_io_xid=0x%x, rec_xid=0x%x, refcount=%d\n",
                   orig_io_req, orig_io_req->xid, srr_req->xid, refcount);

        /* If a SRR times out, simply free resources */
        if (srr_req->event == QEDF_IOREQ_EV_ELS_TMO) {
                QEDF_ERR(&qedf->dbg_ctx,
                         "ELS timeout rec_xid=0x%x.\n", srr_req->xid);
                goto out_put;
        }

        /* Normalize response data into struct fc_frame */
        mp_req = &(srr_req->mp_req);
        mp_fc_hdr = &(mp_req->resp_fc_hdr);
        resp_len = mp_req->resp_len;
        resp_buf = mp_req->resp_buf;

        fp = fc_frame_alloc(lport, resp_len);
        if (!fp) {
                QEDF_ERR(&(qedf->dbg_ctx),
                    "fc_frame_alloc failure.\n");
                goto out_put;
        }

        /* Copy frame header from firmware into fp */
        fh = (struct fc_frame_header *)fc_frame_header_get(fp);
        memcpy(fh, mp_fc_hdr, sizeof(struct fc_frame_header));

        /* Copy payload from firmware into fp */
        fc_payload = fc_frame_payload_get(fp, resp_len);
        memcpy(fc_payload, resp_buf, resp_len);

        opcode = fc_frame_payload_op(fp);
        switch (opcode) {
        case ELS_LS_ACC:
                QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                    "SRR success.\n");
                break;
        case ELS_LS_RJT:
                QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_ELS,
                    "SRR rejected.\n");
                qedf_initiate_abts(orig_io_req, true);
                break;
        }

        fc_frame_free(fp);
out_put:
        /* Put reference for original command since SRR completed */
        kref_put(&orig_io_req->refcount, qedf_release_cmd);
out_free:
        kfree(cb_arg);
}

static int qedf_send_srr(struct qedf_ioreq *orig_io_req, u32 offset, u8 r_ctl)
{
        struct fcp_srr srr;
        struct qedf_ctx *qedf;
        struct qedf_rport *fcport;
        struct fc_lport *lport;
        struct qedf_els_cb_arg *cb_arg = NULL;
        u32 r_a_tov;
        int rc;

        if (!orig_io_req) {
                QEDF_ERR(NULL, "orig_io_req is NULL.\n");
                return -EINVAL;
        }

        fcport = orig_io_req->fcport;

        /* Check that fcport is still offloaded */
        if (!test_bit(QEDF_RPORT_SESSION_READY, &fcport->flags)) {
                QEDF_ERR(NULL, "fcport is no longer offloaded.\n");
                return -EINVAL;
        }

        if (!fcport->qedf) {
                QEDF_ERR(NULL, "fcport->qedf is NULL.\n");
                return -EINVAL;
        }

        /* Take reference until SRR command completion */
        kref_get(&orig_io_req->refcount);

        qedf = fcport->qedf;
        lport = qedf->lport;
        r_a_tov = lport->r_a_tov;

        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Sending SRR orig_io=%p, "
                   "orig_xid=0x%x\n", orig_io_req, orig_io_req->xid);
        memset(&srr, 0, sizeof(srr));

        cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
        if (!cb_arg) {
                QEDF_ERR(&(qedf->dbg_ctx), "Unable to allocate cb_arg for "
                          "SRR\n");
                rc = -ENOMEM;
                goto srr_err;
        }

        cb_arg->aborted_io_req = orig_io_req;

        srr.srr_op = ELS_SRR;
        srr.srr_ox_id = htons(orig_io_req->xid);
        srr.srr_rx_id = htons(orig_io_req->rx_id);
        srr.srr_rel_off = htonl(offset);
        srr.srr_r_ctl = r_ctl;

        rc = qedf_initiate_els(fcport, ELS_SRR, &srr, sizeof(srr),
            qedf_srr_compl, cb_arg, r_a_tov);

srr_err:
        if (rc) {
                QEDF_ERR(&(qedf->dbg_ctx), "SRR failed - release orig_io_req"
                          "=0x%x\n", orig_io_req->xid);
                kfree(cb_arg);
                /* If we fail to queue SRR, send ABTS to orig_io */
                qedf_initiate_abts(orig_io_req, true);
                kref_put(&orig_io_req->refcount, qedf_release_cmd);
        } else
                /* Tell other threads that SRR is in progress */
                set_bit(QEDF_CMD_SRR_SENT, &orig_io_req->flags);

        return rc;
}

static void qedf_initiate_seq_cleanup(struct qedf_ioreq *orig_io_req,
        u32 offset, u8 r_ctl)
{
        struct qedf_rport *fcport;
        unsigned long flags;
        struct qedf_els_cb_arg *cb_arg;
        struct fcoe_wqe *sqe;
        u16 sqe_idx;

        fcport = orig_io_req->fcport;

        QEDF_INFO(&(fcport->qedf->dbg_ctx), QEDF_LOG_ELS,
            "Doing sequence cleanup for xid=0x%x offset=%u.\n",
            orig_io_req->xid, offset);

        cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
        if (!cb_arg) {
                QEDF_ERR(&(fcport->qedf->dbg_ctx), "Unable to allocate cb_arg "
                          "for sequence cleanup\n");
                return;
        }

        /* Get reference for cleanup request */
        kref_get(&orig_io_req->refcount);

        orig_io_req->cmd_type = QEDF_SEQ_CLEANUP;
        cb_arg->offset = offset;
        cb_arg->r_ctl = r_ctl;
        orig_io_req->cb_arg = cb_arg;

        qedf_cmd_timer_set(fcport->qedf, orig_io_req,
            QEDF_CLEANUP_TIMEOUT * HZ);

        spin_lock_irqsave(&fcport->rport_lock, flags);

        sqe_idx = qedf_get_sqe_idx(fcport);
        sqe = &fcport->sq[sqe_idx];
        memset(sqe, 0, sizeof(struct fcoe_wqe));
        orig_io_req->task_params->sqe = sqe;

        init_initiator_sequence_recovery_fcoe_task(orig_io_req->task_params,
                                                   offset);
        qedf_ring_doorbell(fcport);

        spin_unlock_irqrestore(&fcport->rport_lock, flags);
}

void qedf_process_seq_cleanup_compl(struct qedf_ctx *qedf,
        struct fcoe_cqe *cqe, struct qedf_ioreq *io_req)
{
        int rc;
        struct qedf_els_cb_arg *cb_arg;

        cb_arg = io_req->cb_arg;

        /* If we timed out just free resources */
        if (io_req->event == QEDF_IOREQ_EV_ELS_TMO || !cqe) {
                QEDF_ERR(&qedf->dbg_ctx,
                         "cqe is NULL or timeout event (0x%x)", io_req->event);
                goto free;
        }

        /* Kill the timer we put on the request */
        cancel_delayed_work_sync(&io_req->timeout_work);

        rc = qedf_send_srr(io_req, cb_arg->offset, cb_arg->r_ctl);
        if (rc)
                QEDF_ERR(&(qedf->dbg_ctx), "Unable to send SRR, I/O will "
                    "abort, xid=0x%x.\n", io_req->xid);
free:
        kfree(cb_arg);
        kref_put(&io_req->refcount, qedf_release_cmd);
}

static bool qedf_requeue_io_req(struct qedf_ioreq *orig_io_req)
{
        struct qedf_rport *fcport;
        struct qedf_ioreq *new_io_req;
        unsigned long flags;
        bool rc = false;

        fcport = orig_io_req->fcport;
        if (!fcport) {
                QEDF_ERR(NULL, "fcport is NULL.\n");
                goto out;
        }

        if (!orig_io_req->sc_cmd) {
                QEDF_ERR(&(fcport->qedf->dbg_ctx), "sc_cmd is NULL for "
                    "xid=0x%x.\n", orig_io_req->xid);
                goto out;
        }

        new_io_req = qedf_alloc_cmd(fcport, QEDF_SCSI_CMD);
        if (!new_io_req) {
                QEDF_ERR(&(fcport->qedf->dbg_ctx), "Could not allocate new "
                    "io_req.\n");
                goto out;
        }

        new_io_req->sc_cmd = orig_io_req->sc_cmd;

        /*
         * This keeps the sc_cmd struct from being returned to the tape
         * driver and being requeued twice. We do need to put a reference
         * for the original I/O request since we will not do a SCSI completion
         * for it.
         */
        orig_io_req->sc_cmd = NULL;
        kref_put(&orig_io_req->refcount, qedf_release_cmd);

        spin_lock_irqsave(&fcport->rport_lock, flags);

        /* kref for new command released in qedf_post_io_req on error */
        if (qedf_post_io_req(fcport, new_io_req)) {
                QEDF_ERR(&(fcport->qedf->dbg_ctx), "Unable to post io_req\n");
                /* Return SQE to pool */
                atomic_inc(&fcport->free_sqes);
        } else {
                QEDF_INFO(&(fcport->qedf->dbg_ctx), QEDF_LOG_ELS,
                    "Reissued SCSI command from  orig_xid=0x%x on "
                    "new_xid=0x%x.\n", orig_io_req->xid, new_io_req->xid);
                /*
                 * Abort the original I/O but do not return SCSI command as
                 * it has been reissued on another OX_ID.
                 */
                spin_unlock_irqrestore(&fcport->rport_lock, flags);
                qedf_initiate_abts(orig_io_req, false);
                goto out;
        }

        spin_unlock_irqrestore(&fcport->rport_lock, flags);
out:
        return rc;
}


static void qedf_rec_compl(struct qedf_els_cb_arg *cb_arg)
{
        struct qedf_ioreq *orig_io_req;
        struct qedf_ioreq *rec_req;
        struct qedf_mp_req *mp_req;
        struct fc_frame_header *mp_fc_hdr, *fh;
        struct fc_frame *fp;
        void *resp_buf, *fc_payload;
        u32 resp_len;
        struct fc_lport *lport;
        struct qedf_ctx *qedf;
        int refcount;
        enum fc_rctl r_ctl;
        struct fc_els_ls_rjt *rjt;
        struct fc_els_rec_acc *acc;
        u8 opcode;
        u32 offset, e_stat;
        struct scsi_cmnd *sc_cmd;
        bool srr_needed = false;

        rec_req = cb_arg->io_req;
        qedf = rec_req->fcport->qedf;
        lport = qedf->lport;

        orig_io_req = cb_arg->aborted_io_req;

        if (!orig_io_req) {
                QEDF_ERR(NULL, "orig_io_req is NULL.\n");
                goto out_free;
        }

        if (rec_req->event != QEDF_IOREQ_EV_ELS_TMO &&
            rec_req->event != QEDF_IOREQ_EV_ELS_ERR_DETECT)
                cancel_delayed_work_sync(&orig_io_req->timeout_work);

        refcount = kref_read(&orig_io_req->refcount);
        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Entered: orig_io=%p,"
                   " orig_io_xid=0x%x, rec_xid=0x%x, refcount=%d\n",
                   orig_io_req, orig_io_req->xid, rec_req->xid, refcount);

        /* If a REC times out, free resources */
        if (rec_req->event == QEDF_IOREQ_EV_ELS_TMO) {
                QEDF_ERR(&qedf->dbg_ctx,
                         "Got TMO event, orig_io_req %p orig_io_xid=0x%x.\n",
                         orig_io_req, orig_io_req->xid);
                goto out_put;
        }

        /* Normalize response data into struct fc_frame */
        mp_req = &(rec_req->mp_req);
        mp_fc_hdr = &(mp_req->resp_fc_hdr);
        resp_len = mp_req->resp_len;
        acc = resp_buf = mp_req->resp_buf;

        fp = fc_frame_alloc(lport, resp_len);
        if (!fp) {
                QEDF_ERR(&(qedf->dbg_ctx),
                    "fc_frame_alloc failure.\n");
                goto out_put;
        }

        /* Copy frame header from firmware into fp */
        fh = (struct fc_frame_header *)fc_frame_header_get(fp);
        memcpy(fh, mp_fc_hdr, sizeof(struct fc_frame_header));

        /* Copy payload from firmware into fp */
        fc_payload = fc_frame_payload_get(fp, resp_len);
        memcpy(fc_payload, resp_buf, resp_len);

        opcode = fc_frame_payload_op(fp);
        if (opcode == ELS_LS_RJT) {
                rjt = fc_frame_payload_get(fp, sizeof(*rjt));
                if (!rjt) {
                        QEDF_ERR(&qedf->dbg_ctx, "payload get failed");
                        goto out_free_frame;
                }

                QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                    "Received LS_RJT for REC: er_reason=0x%x, "
                    "er_explan=0x%x.\n", rjt->er_reason, rjt->er_explan);
                /*
                 * The following response(s) mean that we need to reissue the
                 * request on another exchange.  We need to do this without
                 * informing the upper layers lest it cause an application
                 * error.
                 */
                if ((rjt->er_reason == ELS_RJT_LOGIC ||
                    rjt->er_reason == ELS_RJT_UNAB) &&
                    rjt->er_explan == ELS_EXPL_OXID_RXID) {
                        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                            "Handle CMD LOST case.\n");
                        qedf_requeue_io_req(orig_io_req);
                }
        } else if (opcode == ELS_LS_ACC) {
                offset = ntohl(acc->reca_fc4value);
                e_stat = ntohl(acc->reca_e_stat);
                QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                    "Received LS_ACC for REC: offset=0x%x, e_stat=0x%x.\n",
                    offset, e_stat);
                if (e_stat & ESB_ST_SEQ_INIT)  {
                        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                            "Target has the seq init\n");
                        goto out_free_frame;
                }
                sc_cmd = orig_io_req->sc_cmd;
                if (!sc_cmd) {
                        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                            "sc_cmd is NULL for xid=0x%x.\n",
                            orig_io_req->xid);
                        goto out_free_frame;
                }
                /* SCSI write case */
                if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
                        if (offset == orig_io_req->data_xfer_len) {
                                QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                                    "WRITE - response lost.\n");
                                r_ctl = FC_RCTL_DD_CMD_STATUS;
                                srr_needed = true;
                                offset = 0;
                        } else {
                                QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                                    "WRITE - XFER_RDY/DATA lost.\n");
                                r_ctl = FC_RCTL_DD_DATA_DESC;
                                /* Use data from warning CQE instead of REC */
                                offset = orig_io_req->tx_buf_off;
                        }
                /* SCSI read case */
                } else {
                        if (orig_io_req->rx_buf_off ==
                            orig_io_req->data_xfer_len) {
                                QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                                    "READ - response lost.\n");
                                srr_needed = true;
                                r_ctl = FC_RCTL_DD_CMD_STATUS;
                                offset = 0;
                        } else {
                                QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
                                    "READ - DATA lost.\n");
                                /*
                                 * For read case we always set the offset to 0
                                 * for sequence recovery task.
                                 */
                                offset = 0;
                                r_ctl = FC_RCTL_DD_SOL_DATA;
                        }
                }

                if (srr_needed)
                        qedf_send_srr(orig_io_req, offset, r_ctl);
                else
                        qedf_initiate_seq_cleanup(orig_io_req, offset, r_ctl);
        }

out_free_frame:
        fc_frame_free(fp);
out_put:
        /* Put reference for original command since REC completed */
        kref_put(&orig_io_req->refcount, qedf_release_cmd);
out_free:
        kfree(cb_arg);
}

/* Assumes kref is already held by caller */
int qedf_send_rec(struct qedf_ioreq *orig_io_req)
{

        struct fc_els_rec rec;
        struct qedf_rport *fcport;

        struct fc_lport *lport;
        struct qedf_els_cb_arg *cb_arg = NULL;
        struct qedf_ctx *qedf;
        uint32_t sid;
        uint32_t r_a_tov;
        int rc;

        if (!orig_io_req) {
                QEDF_ERR(NULL, "orig_io_req is NULL.\n");
                return -EINVAL;
        }

        fcport = orig_io_req->fcport;

        /* Check that fcport is still offloaded */
        if (!test_bit(QEDF_RPORT_SESSION_READY, &fcport->flags)) {
                QEDF_ERR(NULL, "fcport is no longer offloaded.\n");
                return -EINVAL;
        }

        if (!fcport->qedf) {
                QEDF_ERR(NULL, "fcport->qedf is NULL.\n");
                return -EINVAL;
        }

        /* Take reference until REC command completion */
        kref_get(&orig_io_req->refcount);

        qedf = fcport->qedf;
        lport = qedf->lport;
        sid = fcport->sid;
        r_a_tov = lport->r_a_tov;

        memset(&rec, 0, sizeof(rec));

        cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
        if (!cb_arg) {
                QEDF_ERR(&(qedf->dbg_ctx), "Unable to allocate cb_arg for "
                          "REC\n");
                rc = -ENOMEM;
                goto rec_err;
        }

        cb_arg->aborted_io_req = orig_io_req;

        rec.rec_cmd = ELS_REC;
        hton24(rec.rec_s_id, sid);
        rec.rec_ox_id = htons(orig_io_req->xid);
        rec.rec_rx_id =
            htons(orig_io_req->task->tstorm_st_context.read_write.rx_id);

        QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Sending REC orig_io=%p, "
           "orig_xid=0x%x rx_id=0x%x\n", orig_io_req,
           orig_io_req->xid, rec.rec_rx_id);
        rc = qedf_initiate_els(fcport, ELS_REC, &rec, sizeof(rec),
            qedf_rec_compl, cb_arg, r_a_tov);

rec_err:
        if (rc) {
                QEDF_ERR(&(qedf->dbg_ctx), "REC failed - release orig_io_req"
                          "=0x%x\n", orig_io_req->xid);
                kfree(cb_arg);
                kref_put(&orig_io_req->refcount, qedf_release_cmd);
        }
        return rc;
}