// SPDX-License-Identifier: GPL-2.0-only
/*
 *  qla_target.c SCSI LLD infrastructure for QLogic 22xx/23xx/24xx/25xx
 *
 *  based on qla2x00t.c code:
 *
 *  Copyright (C) 2004 - 2010 Vladislav Bolkhovitin <vst@vlnb.net>
 *  Copyright (C) 2004 - 2005 Leonid Stoljar
 *  Copyright (C) 2006 Nathaniel Clark <nate@misrule.us>
 *  Copyright (C) 2006 - 2010 ID7 Ltd.
 *
 *  Forward port and refactoring to modern qla2xxx and target/configfs
 *
 *  Copyright (C) 2010-2013 Nicholas A. Bellinger <nab@kernel.org>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/list.h>
#include <linux/workqueue.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>

#include "qla_def.h"
#include "qla_target.h"

static int ql2xtgt_tape_enable;
module_param(ql2xtgt_tape_enable, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(ql2xtgt_tape_enable,
                "Enables Sequence level error recovery (aka FC Tape). Default is 0 - no SLER. 1 - Enable SLER.");

static char *qlini_mode = QLA2XXX_INI_MODE_STR_ENABLED;
module_param(qlini_mode, charp, S_IRUGO);
MODULE_PARM_DESC(qlini_mode,
        "Determines when initiator mode will be enabled. Possible values: "
        "\"exclusive\" - initiator mode will be enabled on load, "
        "disabled on enabling target mode and then on disabling target mode "
        "enabled back; "
        "\"disabled\" - initiator mode will never be enabled; "
        "\"dual\" - Initiator Modes will be enabled. Target Mode can be activated "
        "when ready "
        "\"enabled\" (default) - initiator mode will always stay enabled.");

static int ql_dm_tgt_ex_pct = 0;
module_param(ql_dm_tgt_ex_pct, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(ql_dm_tgt_ex_pct,
        "For Dual Mode (qlini_mode=dual), this parameter determines "
        "the percentage of exchanges/cmds FW will allocate resources "
        "for Target mode.");

int ql2xuctrlirq = 1;
module_param(ql2xuctrlirq, int, 0644);
MODULE_PARM_DESC(ql2xuctrlirq,
    "User to control IRQ placement via smp_affinity."
    "Valid with qlini_mode=disabled."
    "1(default): enable");

int ql2x_ini_mode = QLA2XXX_INI_MODE_EXCLUSIVE;

static int qla_sam_status = SAM_STAT_BUSY;
static int tc_sam_status = SAM_STAT_TASK_SET_FULL; /* target core */

/*
 * From scsi/fc/fc_fcp.h
 */
enum fcp_resp_rsp_codes {
        FCP_TMF_CMPL = 0,
        FCP_DATA_LEN_INVALID = 1,
        FCP_CMND_FIELDS_INVALID = 2,
        FCP_DATA_PARAM_MISMATCH = 3,
        FCP_TMF_REJECTED = 4,
        FCP_TMF_FAILED = 5,
        FCP_TMF_INVALID_LUN = 9,
};

/*
 * fc_pri_ta from scsi/fc/fc_fcp.h
 */
#define FCP_PTA_SIMPLE      0   /* simple task attribute */
#define FCP_PTA_HEADQ       1   /* head of queue task attribute */
#define FCP_PTA_ORDERED     2   /* ordered task attribute */
#define FCP_PTA_ACA         4   /* auto. contingent allegiance */
#define FCP_PTA_MASK        7   /* mask for task attribute field */
#define FCP_PRI_SHIFT       3   /* priority field starts in bit 3 */
#define FCP_PRI_RESVD_MASK  0x80        /* reserved bits in priority field */

/*
 * This driver calls qla2x00_alloc_iocbs() and qla2x00_issue_marker(), which
 * must be called under HW lock and could unlock/lock it inside.
 * It isn't an issue, since in the current implementation on the time when
 * those functions are called:
 *
 *   - Either context is IRQ and only IRQ handler can modify HW data,
 *     including rings related fields,
 *
 *   - Or access to target mode variables from struct qla_tgt doesn't
 *     cross those functions boundaries, except tgt_stop, which
 *     additionally protected by irq_cmd_count.
 */
/* Predefs for callbacks handed to qla2xxx LLD */
static void qlt_24xx_atio_pkt(struct scsi_qla_host *ha,
        struct atio_from_isp *pkt, uint8_t);
static void qlt_response_pkt(struct scsi_qla_host *ha, struct rsp_que *rsp,
        response_t *pkt);
static int qlt_issue_task_mgmt(struct fc_port *sess, u64 lun,
        int fn, void *iocb, int flags);
static void qlt_send_term_exchange(struct qla_qpair *, struct qla_tgt_cmd
        *cmd, struct atio_from_isp *atio, int ha_locked, int ul_abort);
static void qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
        struct atio_from_isp *atio, uint16_t status, int qfull);
static void qlt_disable_vha(struct scsi_qla_host *vha);
static void qlt_clear_tgt_db(struct qla_tgt *tgt);
static void qlt_send_notify_ack(struct qla_qpair *qpair,
        struct imm_ntfy_from_isp *ntfy,
        uint32_t add_flags, uint16_t resp_code, int resp_code_valid,
        uint16_t srr_flags, uint16_t srr_reject_code, uint8_t srr_explan);
static void qlt_send_term_imm_notif(struct scsi_qla_host *vha,
        struct imm_ntfy_from_isp *imm, int ha_locked);
static struct fc_port *qlt_create_sess(struct scsi_qla_host *vha,
        fc_port_t *fcport, bool local);
void qlt_unreg_sess(struct fc_port *sess);
static void qlt_24xx_handle_abts(struct scsi_qla_host *,
        struct abts_recv_from_24xx *);
static void qlt_send_busy(struct qla_qpair *, struct atio_from_isp *,
    uint16_t);
static int qlt_check_reserve_free_req(struct qla_qpair *qpair, uint32_t);
static inline uint32_t qlt_make_handle(struct qla_qpair *);

/*
 * Global Variables
 */
static struct kmem_cache *qla_tgt_mgmt_cmd_cachep;
struct kmem_cache *qla_tgt_plogi_cachep;
static mempool_t *qla_tgt_mgmt_cmd_mempool;
static struct workqueue_struct *qla_tgt_wq;
static DEFINE_MUTEX(qla_tgt_mutex);
static LIST_HEAD(qla_tgt_glist);

static const char *prot_op_str(u32 prot_op)
{
        switch (prot_op) {
        case TARGET_PROT_NORMAL:        return "NORMAL";
        case TARGET_PROT_DIN_INSERT:    return "DIN_INSERT";
        case TARGET_PROT_DOUT_INSERT:   return "DOUT_INSERT";
        case TARGET_PROT_DIN_STRIP:     return "DIN_STRIP";
        case TARGET_PROT_DOUT_STRIP:    return "DOUT_STRIP";
        case TARGET_PROT_DIN_PASS:      return "DIN_PASS";
        case TARGET_PROT_DOUT_PASS:     return "DOUT_PASS";
        default:                        return "UNKNOWN";
        }
}

/* This API intentionally takes dest as a parameter, rather than returning
 * int value to avoid caller forgetting to issue wmb() after the store */
void qlt_do_generation_tick(struct scsi_qla_host *vha, int *dest)
{
        scsi_qla_host_t *base_vha = pci_get_drvdata(vha->hw->pdev);
        *dest = atomic_inc_return(&base_vha->generation_tick);
        /* memory barrier */
        wmb();
}

/* Might release hw lock, then reaquire!! */
static inline int qlt_issue_marker(struct scsi_qla_host *vha, int vha_locked)
{
        /* Send marker if required */
        if (unlikely(vha->marker_needed != 0)) {
                int rc = qla2x00_issue_marker(vha, vha_locked);

                if (rc != QLA_SUCCESS) {
                        ql_dbg(ql_dbg_tgt, vha, 0xe03d,
                            "qla_target(%d): issue_marker() failed\n",
                            vha->vp_idx);
                }
                return rc;
        }
        return QLA_SUCCESS;
}

static inline
struct scsi_qla_host *qlt_find_host_by_d_id(struct scsi_qla_host *vha,
        uint8_t *d_id)
{
        struct scsi_qla_host *host;
        uint32_t key = 0;

        if ((vha->d_id.b.area == d_id[1]) && (vha->d_id.b.domain == d_id[0]) &&
            (vha->d_id.b.al_pa == d_id[2]))
                return vha;

        key  = (uint32_t)d_id[0] << 16;
        key |= (uint32_t)d_id[1] <<  8;
        key |= (uint32_t)d_id[2];

        host = btree_lookup32(&vha->hw->tgt.host_map, key);
        if (!host)
                ql_dbg(ql_dbg_tgt_mgt + ql_dbg_verbose, vha, 0xf005,
                    "Unable to find host %06x\n", key);

        return host;
}

static inline
struct scsi_qla_host *qlt_find_host_by_vp_idx(struct scsi_qla_host *vha,
        uint16_t vp_idx)
{
        struct qla_hw_data *ha = vha->hw;

        if (vha->vp_idx == vp_idx)
                return vha;

        BUG_ON(ha->tgt.tgt_vp_map == NULL);
        if (likely(test_bit(vp_idx, ha->vp_idx_map)))
                return ha->tgt.tgt_vp_map[vp_idx].vha;

        return NULL;
}

static inline void qlt_incr_num_pend_cmds(struct scsi_qla_host *vha)
{
        unsigned long flags;

        spin_lock_irqsave(&vha->hw->tgt.q_full_lock, flags);

        vha->hw->tgt.num_pend_cmds++;
        if (vha->hw->tgt.num_pend_cmds > vha->qla_stats.stat_max_pend_cmds)
                vha->qla_stats.stat_max_pend_cmds =
                        vha->hw->tgt.num_pend_cmds;
        spin_unlock_irqrestore(&vha->hw->tgt.q_full_lock, flags);
}
static inline void qlt_decr_num_pend_cmds(struct scsi_qla_host *vha)
{
        unsigned long flags;

        spin_lock_irqsave(&vha->hw->tgt.q_full_lock, flags);
        vha->hw->tgt.num_pend_cmds--;
        spin_unlock_irqrestore(&vha->hw->tgt.q_full_lock, flags);
}


static void qlt_queue_unknown_atio(scsi_qla_host_t *vha,
        struct atio_from_isp *atio, uint8_t ha_locked)
{
        struct qla_tgt_sess_op *u;
        struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
        unsigned long flags;

        if (tgt->tgt_stop) {
                ql_dbg(ql_dbg_async, vha, 0x502c,
                    "qla_target(%d): dropping unknown ATIO_TYPE7, because tgt is being stopped",
                    vha->vp_idx);
                goto out_term;
        }

        u = kzalloc(sizeof(*u), GFP_ATOMIC);
        if (u == NULL)
                goto out_term;

        u->vha = vha;
        memcpy(&u->atio, atio, sizeof(*atio));
        INIT_LIST_HEAD(&u->cmd_list);

        spin_lock_irqsave(&vha->cmd_list_lock, flags);
        list_add_tail(&u->cmd_list, &vha->unknown_atio_list);
        spin_unlock_irqrestore(&vha->cmd_list_lock, flags);

        schedule_delayed_work(&vha->unknown_atio_work, 1);

out:
        return;

out_term:
        qlt_send_term_exchange(vha->hw->base_qpair, NULL, atio, ha_locked, 0);
        goto out;
}

static void qlt_try_to_dequeue_unknown_atios(struct scsi_qla_host *vha,
        uint8_t ha_locked)
{
        struct qla_tgt_sess_op *u, *t;
        scsi_qla_host_t *host;
        struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
        unsigned long flags;
        uint8_t queued = 0;

        list_for_each_entry_safe(u, t, &vha->unknown_atio_list, cmd_list) {
                if (u->aborted) {
                        ql_dbg(ql_dbg_async, vha, 0x502e,
                            "Freeing unknown %s %p, because of Abort\n",
                            "ATIO_TYPE7", u);
                        qlt_send_term_exchange(vha->hw->base_qpair, NULL,
                            &u->atio, ha_locked, 0);
                        goto abort;
                }

                host = qlt_find_host_by_d_id(vha, u->atio.u.isp24.fcp_hdr.d_id);
                if (host != NULL) {
                        ql_dbg(ql_dbg_async + ql_dbg_verbose, vha, 0x502f,
                            "Requeuing unknown ATIO_TYPE7 %p\n", u);
                        qlt_24xx_atio_pkt(host, &u->atio, ha_locked);
                } else if (tgt->tgt_stop) {
                        ql_dbg(ql_dbg_async + ql_dbg_verbose, vha, 0x503a,
                            "Freeing unknown %s %p, because tgt is being stopped\n",
                            "ATIO_TYPE7", u);
                        qlt_send_term_exchange(vha->hw->base_qpair, NULL,
                            &u->atio, ha_locked, 0);
                } else {
                        ql_dbg(ql_dbg_async + ql_dbg_verbose, vha, 0x503d,
                            "Reschedule u %p, vha %p, host %p\n", u, vha, host);
                        if (!queued) {
                                queued = 1;
                                schedule_delayed_work(&vha->unknown_atio_work,
                                    1);
                        }
                        continue;
                }

abort:
                spin_lock_irqsave(&vha->cmd_list_lock, flags);
                list_del(&u->cmd_list);
                spin_unlock_irqrestore(&vha->cmd_list_lock, flags);
                kfree(u);
        }
}

void qlt_unknown_atio_work_fn(struct work_struct *work)
{
        struct scsi_qla_host *vha = container_of(to_delayed_work(work),
            struct scsi_qla_host, unknown_atio_work);

        qlt_try_to_dequeue_unknown_atios(vha, 0);
}

static bool qlt_24xx_atio_pkt_all_vps(struct scsi_qla_host *vha,
        struct atio_from_isp *atio, uint8_t ha_locked)
{
        ql_dbg(ql_dbg_tgt, vha, 0xe072,
                "%s: qla_target(%d): type %x ox_id %04x\n",
                __func__, vha->vp_idx, atio->u.raw.entry_type,
                be16_to_cpu(atio->u.isp24.fcp_hdr.ox_id));

        switch (atio->u.raw.entry_type) {
        case ATIO_TYPE7:
        {
                struct scsi_qla_host *host = qlt_find_host_by_d_id(vha,
                    atio->u.isp24.fcp_hdr.d_id);
                if (unlikely(NULL == host)) {
                        ql_dbg(ql_dbg_tgt, vha, 0xe03e,
                            "qla_target(%d): Received ATIO_TYPE7 "
                            "with unknown d_id %x:%x:%x\n", vha->vp_idx,
                            atio->u.isp24.fcp_hdr.d_id[0],
                            atio->u.isp24.fcp_hdr.d_id[1],
                            atio->u.isp24.fcp_hdr.d_id[2]);


                        qlt_queue_unknown_atio(vha, atio, ha_locked);
                        break;
                }
                if (unlikely(!list_empty(&vha->unknown_atio_list)))
                        qlt_try_to_dequeue_unknown_atios(vha, ha_locked);

                qlt_24xx_atio_pkt(host, atio, ha_locked);
                break;
        }

        case IMMED_NOTIFY_TYPE:
        {
                struct scsi_qla_host *host = vha;
                struct imm_ntfy_from_isp *entry =
                    (struct imm_ntfy_from_isp *)atio;

                qlt_issue_marker(vha, ha_locked);

                if ((entry->u.isp24.vp_index != 0xFF) &&
                    (entry->u.isp24.nport_handle != 0xFFFF)) {
                        host = qlt_find_host_by_vp_idx(vha,
                            entry->u.isp24.vp_index);
                        if (unlikely(!host)) {
                                ql_dbg(ql_dbg_tgt, vha, 0xe03f,
                                    "qla_target(%d): Received "
                                    "ATIO (IMMED_NOTIFY_TYPE) "
                                    "with unknown vp_index %d\n",
                                    vha->vp_idx, entry->u.isp24.vp_index);
                                break;
                        }
                }
                qlt_24xx_atio_pkt(host, atio, ha_locked);
                break;
        }

        case VP_RPT_ID_IOCB_TYPE:
                qla24xx_report_id_acquisition(vha,
                        (struct vp_rpt_id_entry_24xx *)atio);
                break;

        case ABTS_RECV_24XX:
        {
                struct abts_recv_from_24xx *entry =
                        (struct abts_recv_from_24xx *)atio;
                struct scsi_qla_host *host = qlt_find_host_by_vp_idx(vha,
                        entry->vp_index);
                unsigned long flags;

                if (unlikely(!host)) {
                        ql_dbg(ql_dbg_tgt, vha, 0xe00a,
                            "qla_target(%d): Response pkt (ABTS_RECV_24XX) "
                            "received, with unknown vp_index %d\n",
                            vha->vp_idx, entry->vp_index);
                        break;
                }
                if (!ha_locked)
                        spin_lock_irqsave(&host->hw->hardware_lock, flags);
                qlt_24xx_handle_abts(host, (struct abts_recv_from_24xx *)atio);
                if (!ha_locked)
                        spin_unlock_irqrestore(&host->hw->hardware_lock, flags);
                break;
        }

        /* case PUREX_IOCB_TYPE: ql2xmvasynctoatio */

        default:
                ql_dbg(ql_dbg_tgt, vha, 0xe040,
                    "qla_target(%d): Received unknown ATIO atio "
                    "type %x\n", vha->vp_idx, atio->u.raw.entry_type);
                break;
        }

        return false;
}

void qlt_response_pkt_all_vps(struct scsi_qla_host *vha,
        struct rsp_que *rsp, response_t *pkt)
{
        switch (pkt->entry_type) {
        case CTIO_CRC2:
                ql_dbg(ql_dbg_tgt, vha, 0xe073,
                        "qla_target(%d):%s: CRC2 Response pkt\n",
                        vha->vp_idx, __func__);
                /* fall through */
        case CTIO_TYPE7:
        {
                struct ctio7_from_24xx *entry = (struct ctio7_from_24xx *)pkt;
                struct scsi_qla_host *host = qlt_find_host_by_vp_idx(vha,
                    entry->vp_index);
                if (unlikely(!host)) {
                        ql_dbg(ql_dbg_tgt, vha, 0xe041,
                            "qla_target(%d): Response pkt (CTIO_TYPE7) "
                            "received, with unknown vp_index %d\n",
                            vha->vp_idx, entry->vp_index);
                        break;
                }
                qlt_response_pkt(host, rsp, pkt);
                break;
        }

        case IMMED_NOTIFY_TYPE:
        {
                struct scsi_qla_host *host = vha;
                struct imm_ntfy_from_isp *entry =
                    (struct imm_ntfy_from_isp *)pkt;

                host = qlt_find_host_by_vp_idx(vha, entry->u.isp24.vp_index);
                if (unlikely(!host)) {
                        ql_dbg(ql_dbg_tgt, vha, 0xe042,
                            "qla_target(%d): Response pkt (IMMED_NOTIFY_TYPE) "
                            "received, with unknown vp_index %d\n",
                            vha->vp_idx, entry->u.isp24.vp_index);
                        break;
                }
                qlt_response_pkt(host, rsp, pkt);
                break;
        }

        case NOTIFY_ACK_TYPE:
        {
                struct scsi_qla_host *host = vha;
                struct nack_to_isp *entry = (struct nack_to_isp *)pkt;

                if (0xFF != entry->u.isp24.vp_index) {
                        host = qlt_find_host_by_vp_idx(vha,
                            entry->u.isp24.vp_index);
                        if (unlikely(!host)) {
                                ql_dbg(ql_dbg_tgt, vha, 0xe043,
                                    "qla_target(%d): Response "
                                    "pkt (NOTIFY_ACK_TYPE) "
                                    "received, with unknown "
                                    "vp_index %d\n", vha->vp_idx,
                                    entry->u.isp24.vp_index);
                                break;
                        }
                }
                qlt_response_pkt(host, rsp, pkt);
                break;
        }

        case ABTS_RECV_24XX:
        {
                struct abts_recv_from_24xx *entry =
                    (struct abts_recv_from_24xx *)pkt;
                struct scsi_qla_host *host = qlt_find_host_by_vp_idx(vha,
                    entry->vp_index);
                if (unlikely(!host)) {
                        ql_dbg(ql_dbg_tgt, vha, 0xe044,
                            "qla_target(%d): Response pkt "
                            "(ABTS_RECV_24XX) received, with unknown "
                            "vp_index %d\n", vha->vp_idx, entry->vp_index);
                        break;
                }
                qlt_response_pkt(host, rsp, pkt);
                break;
        }

        case ABTS_RESP_24XX:
        {
                struct abts_resp_to_24xx *entry =
                    (struct abts_resp_to_24xx *)pkt;
                struct scsi_qla_host *host = qlt_find_host_by_vp_idx(vha,
                    entry->vp_index);
                if (unlikely(!host)) {
                        ql_dbg(ql_dbg_tgt, vha, 0xe045,
                            "qla_target(%d): Response pkt "
                            "(ABTS_RECV_24XX) received, with unknown "
                            "vp_index %d\n", vha->vp_idx, entry->vp_index);
                        break;
                }
                qlt_response_pkt(host, rsp, pkt);
                break;
        }
        default:
                qlt_response_pkt(vha, rsp, pkt);
                break;
        }

}

/*
 * All qlt_plogi_ack_t operations are protected by hardware_lock
 */
static int qla24xx_post_nack_work(struct scsi_qla_host *vha, fc_port_t *fcport,
        struct imm_ntfy_from_isp *ntfy, int type)
{
        struct qla_work_evt *e;

        e = qla2x00_alloc_work(vha, QLA_EVT_NACK);
        if (!e)
                return QLA_FUNCTION_FAILED;

        e->u.nack.fcport = fcport;
        e->u.nack.type = type;
        memcpy(e->u.nack.iocb, ntfy, sizeof(struct imm_ntfy_from_isp));
        return qla2x00_post_work(vha, e);
}

static
void qla2x00_async_nack_sp_done(void *s, int res)
{
        struct srb *sp = (struct srb *)s;
        struct scsi_qla_host *vha = sp->vha;
        unsigned long flags;

        ql_dbg(ql_dbg_disc, vha, 0x20f2,
            "Async done-%s res %x %8phC  type %d\n",
            sp->name, res, sp->fcport->port_name, sp->type);

        spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);
        sp->fcport->flags &= ~FCF_ASYNC_SENT;
        sp->fcport->chip_reset = vha->hw->base_qpair->chip_reset;

        switch (sp->type) {
        case SRB_NACK_PLOGI:
                sp->fcport->login_gen++;
                sp->fcport->fw_login_state = DSC_LS_PLOGI_COMP;
                sp->fcport->logout_on_delete = 1;
                sp->fcport->plogi_nack_done_deadline = jiffies + HZ;
                sp->fcport->send_els_logo = 0;
                break;

        case SRB_NACK_PRLI:
                sp->fcport->fw_login_state = DSC_LS_PRLI_COMP;
                sp->fcport->deleted = 0;
                sp->fcport->send_els_logo = 0;

                if (!sp->fcport->login_succ &&
                    !IS_SW_RESV_ADDR(sp->fcport->d_id)) {
                        sp->fcport->login_succ = 1;

                        vha->fcport_count++;
                        spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);
                        qla24xx_sched_upd_fcport(sp->fcport);
                        spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);
                } else {
                        sp->fcport->login_retry = 0;
                        sp->fcport->disc_state = DSC_LOGIN_COMPLETE;
                        sp->fcport->deleted = 0;
                        sp->fcport->logout_on_delete = 1;
                }
                break;

        case SRB_NACK_LOGO:
                sp->fcport->login_gen++;
                sp->fcport->fw_login_state = DSC_LS_PORT_UNAVAIL;
                qlt_logo_completion_handler(sp->fcport, MBS_COMMAND_COMPLETE);
                break;
        }
        spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);

        sp->free(sp);
}

int qla24xx_async_notify_ack(scsi_qla_host_t *vha, fc_port_t *fcport,
        struct imm_ntfy_from_isp *ntfy, int type)
{
        int rval = QLA_FUNCTION_FAILED;
        srb_t *sp;
        char *c = NULL;

        fcport->flags |= FCF_ASYNC_SENT;
        switch (type) {
        case SRB_NACK_PLOGI:
                fcport->fw_login_state = DSC_LS_PLOGI_PEND;
                c = "PLOGI";
                break;
        case SRB_NACK_PRLI:
                fcport->fw_login_state = DSC_LS_PRLI_PEND;
                fcport->deleted = 0;
                c = "PRLI";
                break;
        case SRB_NACK_LOGO:
                fcport->fw_login_state = DSC_LS_LOGO_PEND;
                c = "LOGO";
                break;
        }

        sp = qla2x00_get_sp(vha, fcport, GFP_ATOMIC);
        if (!sp)
                goto done;

        sp->type = type;
        sp->name = "nack";

        sp->u.iocb_cmd.timeout = qla2x00_async_iocb_timeout;
        qla2x00_init_timer(sp, qla2x00_get_async_timeout(vha)+2);

        sp->u.iocb_cmd.u.nack.ntfy = ntfy;
        sp->done = qla2x00_async_nack_sp_done;

        ql_dbg(ql_dbg_disc, vha, 0x20f4,
            "Async-%s %8phC hndl %x %s\n",
            sp->name, fcport->port_name, sp->handle, c);

        rval = qla2x00_start_sp(sp);
        if (rval != QLA_SUCCESS)
                goto done_free_sp;

        return rval;

done_free_sp:
        sp->free(sp);
done:
        fcport->flags &= ~FCF_ASYNC_SENT;
        return rval;
}

void qla24xx_do_nack_work(struct scsi_qla_host *vha, struct qla_work_evt *e)
{
        fc_port_t *t;

        switch (e->u.nack.type) {
        case SRB_NACK_PRLI:
                t = e->u.nack.fcport;
                flush_work(&t->del_work);
                flush_work(&t->free_work);
                mutex_lock(&vha->vha_tgt.tgt_mutex);
                t = qlt_create_sess(vha, e->u.nack.fcport, 0);
                mutex_unlock(&vha->vha_tgt.tgt_mutex);
                if (t) {
                        ql_log(ql_log_info, vha, 0xd034,
                            "%s create sess success %p", __func__, t);
                        /* create sess has an extra kref */
                        vha->hw->tgt.tgt_ops->put_sess(e->u.nack.fcport);
                }
                break;
        }
        qla24xx_async_notify_ack(vha, e->u.nack.fcport,
            (struct imm_ntfy_from_isp *)e->u.nack.iocb, e->u.nack.type);
}

void qla24xx_delete_sess_fn(struct work_struct *work)
{
        fc_port_t *fcport = container_of(work, struct fc_port, del_work);
        struct qla_hw_data *ha = fcport->vha->hw;

        if (fcport->se_sess) {
                ha->tgt.tgt_ops->shutdown_sess(fcport);
                ha->tgt.tgt_ops->put_sess(fcport);
        } else {
                qlt_unreg_sess(fcport);
        }
}

/*
 * Called from qla2x00_reg_remote_port()
 */
void qlt_fc_port_added(struct scsi_qla_host *vha, fc_port_t *fcport)
{
        struct qla_hw_data *ha = vha->hw;
        struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
        struct fc_port *sess = fcport;
        unsigned long flags;

        if (!vha->hw->tgt.tgt_ops)
                return;

        spin_lock_irqsave(&ha->tgt.sess_lock, flags);
        if (tgt->tgt_stop) {
                spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
                return;
        }

        if (fcport->disc_state == DSC_DELETE_PEND) {
                spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
                return;
        }

        if (!sess->se_sess) {
                spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);

                mutex_lock(&vha->vha_tgt.tgt_mutex);
                sess = qlt_create_sess(vha, fcport, false);
                mutex_unlock(&vha->vha_tgt.tgt_mutex);

                spin_lock_irqsave(&ha->tgt.sess_lock, flags);
        } else {
                if (fcport->fw_login_state == DSC_LS_PRLI_COMP) {
                        spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
                        return;
                }

                if (!kref_get_unless_zero(&sess->sess_kref)) {
                        ql_dbg(ql_dbg_disc, vha, 0x2107,
                            "%s: kref_get fail sess %8phC \n",
                            __func__, sess->port_name);
                        spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
                        return;
                }

                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf04c,
                    "qla_target(%u): %ssession for port %8phC "
                    "(loop ID %d) reappeared\n", vha->vp_idx,
                    sess->local ? "local " : "", sess->port_name, sess->loop_id);

                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf007,
                    "Reappeared sess %p\n", sess);

                ha->tgt.tgt_ops->update_sess(sess, fcport->d_id,
                    fcport->loop_id,
                    (fcport->flags & FCF_CONF_COMP_SUPPORTED));
        }

        if (sess && sess->local) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf04d,
                    "qla_target(%u): local session for "
                    "port %8phC (loop ID %d) became global\n", vha->vp_idx,
                    fcport->port_name, sess->loop_id);
                sess->local = 0;
        }
        spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);

        ha->tgt.tgt_ops->put_sess(sess);
}

/*
 * This is a zero-base ref-counting solution, since hardware_lock
 * guarantees that ref_count is not modified concurrently.
 * Upon successful return content of iocb is undefined
 */
static struct qlt_plogi_ack_t *
qlt_plogi_ack_find_add(struct scsi_qla_host *vha, port_id_t *id,
                       struct imm_ntfy_from_isp *iocb)
{
        struct qlt_plogi_ack_t *pla;

        list_for_each_entry(pla, &vha->plogi_ack_list, list) {
                if (pla->id.b24 == id->b24) {
                        ql_dbg(ql_dbg_disc + ql_dbg_verbose, vha, 0x210d,
                            "%s %d %8phC Term INOT due to new INOT",
                            __func__, __LINE__,
                            pla->iocb.u.isp24.port_name);
                        qlt_send_term_imm_notif(vha, &pla->iocb, 1);
                        memcpy(&pla->iocb, iocb, sizeof(pla->iocb));
                        return pla;
                }
        }

        pla = kmem_cache_zalloc(qla_tgt_plogi_cachep, GFP_ATOMIC);
        if (!pla) {
                ql_dbg(ql_dbg_async, vha, 0x5088,
                       "qla_target(%d): Allocation of plogi_ack failed\n",
                       vha->vp_idx);
                return NULL;
        }

        memcpy(&pla->iocb, iocb, sizeof(pla->iocb));
        pla->id = *id;
        list_add_tail(&pla->list, &vha->plogi_ack_list);

        return pla;
}

void qlt_plogi_ack_unref(struct scsi_qla_host *vha,
    struct qlt_plogi_ack_t *pla)
{
        struct imm_ntfy_from_isp *iocb = &pla->iocb;
        port_id_t port_id;
        uint16_t loop_id;
        fc_port_t *fcport = pla->fcport;

        BUG_ON(!pla->ref_count);
        pla->ref_count--;

        if (pla->ref_count)
                return;

        ql_dbg(ql_dbg_disc, vha, 0x5089,
            "Sending PLOGI ACK to wwn %8phC s_id %02x:%02x:%02x loop_id %#04x"
            " exch %#x ox_id %#x\n", iocb->u.isp24.port_name,
            iocb->u.isp24.port_id[2], iocb->u.isp24.port_id[1],
            iocb->u.isp24.port_id[0],
            le16_to_cpu(iocb->u.isp24.nport_handle),
            iocb->u.isp24.exchange_address, iocb->ox_id);

        port_id.b.domain = iocb->u.isp24.port_id[2];
        port_id.b.area   = iocb->u.isp24.port_id[1];
        port_id.b.al_pa  = iocb->u.isp24.port_id[0];
        port_id.b.rsvd_1 = 0;

        loop_id = le16_to_cpu(iocb->u.isp24.nport_handle);

        fcport->loop_id = loop_id;
        fcport->d_id = port_id;
        if (iocb->u.isp24.status_subcode == ELS_PLOGI)
                qla24xx_post_nack_work(vha, fcport, iocb, SRB_NACK_PLOGI);
        else
                qla24xx_post_nack_work(vha, fcport, iocb, SRB_NACK_PRLI);

        list_for_each_entry(fcport, &vha->vp_fcports, list) {
                if (fcport->plogi_link[QLT_PLOGI_LINK_SAME_WWN] == pla)
                        fcport->plogi_link[QLT_PLOGI_LINK_SAME_WWN] = NULL;
                if (fcport->plogi_link[QLT_PLOGI_LINK_CONFLICT] == pla)
                        fcport->plogi_link[QLT_PLOGI_LINK_CONFLICT] = NULL;
        }

        list_del(&pla->list);
        kmem_cache_free(qla_tgt_plogi_cachep, pla);
}

void
qlt_plogi_ack_link(struct scsi_qla_host *vha, struct qlt_plogi_ack_t *pla,
    struct fc_port *sess, enum qlt_plogi_link_t link)
{
        struct imm_ntfy_from_isp *iocb = &pla->iocb;
        /* Inc ref_count first because link might already be pointing at pla */
        pla->ref_count++;

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf097,
                "Linking sess %p [%d] wwn %8phC with PLOGI ACK to wwn %8phC"
                " s_id %02x:%02x:%02x, ref=%d pla %p link %d\n",
                sess, link, sess->port_name,
                iocb->u.isp24.port_name, iocb->u.isp24.port_id[2],
                iocb->u.isp24.port_id[1], iocb->u.isp24.port_id[0],
                pla->ref_count, pla, link);

        if (link == QLT_PLOGI_LINK_CONFLICT) {
                switch (sess->disc_state) {
                case DSC_DELETED:
                case DSC_DELETE_PEND:
                        pla->ref_count--;
                        return;
                default:
                        break;
                }
        }

        if (sess->plogi_link[link])
                qlt_plogi_ack_unref(vha, sess->plogi_link[link]);

        if (link == QLT_PLOGI_LINK_SAME_WWN)
                pla->fcport = sess;

        sess->plogi_link[link] = pla;
}

typedef struct {
        /* These fields must be initialized by the caller */
        port_id_t id;
        /*
         * number of cmds dropped while we were waiting for
         * initiator to ack LOGO initialize to 1 if LOGO is
         * triggered by a command, otherwise, to 0
         */
        int cmd_count;

        /* These fields are used by callee */
        struct list_head list;
} qlt_port_logo_t;

static void
qlt_send_first_logo(struct scsi_qla_host *vha, qlt_port_logo_t *logo)
{
        qlt_port_logo_t *tmp;
        int res;

        mutex_lock(&vha->vha_tgt.tgt_mutex);

        list_for_each_entry(tmp, &vha->logo_list, list) {
                if (tmp->id.b24 == logo->id.b24) {
                        tmp->cmd_count += logo->cmd_count;
                        mutex_unlock(&vha->vha_tgt.tgt_mutex);
                        return;
                }
        }

        list_add_tail(&logo->list, &vha->logo_list);

        mutex_unlock(&vha->vha_tgt.tgt_mutex);

        res = qla24xx_els_dcmd_iocb(vha, ELS_DCMD_LOGO, logo->id);

        mutex_lock(&vha->vha_tgt.tgt_mutex);
        list_del(&logo->list);
        mutex_unlock(&vha->vha_tgt.tgt_mutex);

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf098,
            "Finished LOGO to %02x:%02x:%02x, dropped %d cmds, res = %#x\n",
            logo->id.b.domain, logo->id.b.area, logo->id.b.al_pa,
            logo->cmd_count, res);
}

void qlt_free_session_done(struct work_struct *work)
{
        struct fc_port *sess = container_of(work, struct fc_port,
            free_work);
        struct qla_tgt *tgt = sess->tgt;
        struct scsi_qla_host *vha = sess->vha;
        struct qla_hw_data *ha = vha->hw;
        unsigned long flags;
        bool logout_started = false;
        scsi_qla_host_t *base_vha;
        struct qlt_plogi_ack_t *own =
                sess->plogi_link[QLT_PLOGI_LINK_SAME_WWN];

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf084,
                "%s: se_sess %p / sess %p from port %8phC loop_id %#04x"
                " s_id %02x:%02x:%02x logout %d keep %d els_logo %d\n",
                __func__, sess->se_sess, sess, sess->port_name, sess->loop_id,
                sess->d_id.b.domain, sess->d_id.b.area, sess->d_id.b.al_pa,
                sess->logout_on_delete, sess->keep_nport_handle,
                sess->send_els_logo);

        if (!IS_SW_RESV_ADDR(sess->d_id)) {
                qla2x00_mark_device_lost(vha, sess, 0, 0);

                if (sess->send_els_logo) {
                        qlt_port_logo_t logo;

                        logo.id = sess->d_id;
                        logo.cmd_count = 0;
                        if (!own)
                                qlt_send_first_logo(vha, &logo);
                        sess->send_els_logo = 0;
                }

                if (sess->logout_on_delete && sess->loop_id != FC_NO_LOOP_ID) {
                        int rc;

                        if (!own ||
                            (own &&
                             (own->iocb.u.isp24.status_subcode == ELS_PLOGI))) {
                                rc = qla2x00_post_async_logout_work(vha, sess,
                                    NULL);
                                if (rc != QLA_SUCCESS)
                                        ql_log(ql_log_warn, vha, 0xf085,
                                            "Schedule logo failed sess %p rc %d\n",
                                            sess, rc);
                                else
                                        logout_started = true;
                        } else if (own && (own->iocb.u.isp24.status_subcode ==
                                ELS_PRLI) && ha->flags.rida_fmt2) {
                                rc = qla2x00_post_async_prlo_work(vha, sess,
                                    NULL);
                                if (rc != QLA_SUCCESS)

                                        ql_log(ql_log_warn, vha, 0xf085,
                                            "Schedule PRLO failed sess %p rc %d\n",
                                            sess, rc);
                                else
                                        logout_started = true;
                        }
                } /* if sess->logout_on_delete */

                if (sess->nvme_flag & NVME_FLAG_REGISTERED &&
                    !(sess->nvme_flag & NVME_FLAG_DELETING)) {
                        sess->nvme_flag |= NVME_FLAG_DELETING;
                        qla_nvme_unregister_remote_port(sess);
                }
        }

        /*
         * Release the target session for FC Nexus from fabric module code.
         */
        if (sess->se_sess != NULL)
                ha->tgt.tgt_ops->free_session(sess);

        if (logout_started) {
                bool traced = false;

                while (!READ_ONCE(sess->logout_completed)) {
                        if (!traced) {
                                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf086,
                                        "%s: waiting for sess %p logout\n",
                                        __func__, sess);
                                traced = true;
                        }
                        msleep(100);
                }

                ql_dbg(ql_dbg_disc, vha, 0xf087,
                    "%s: sess %p logout completed\n", __func__, sess);
        }

        if (sess->logo_ack_needed) {
                sess->logo_ack_needed = 0;
                qla24xx_async_notify_ack(vha, sess,
                        (struct imm_ntfy_from_isp *)sess->iocb, SRB_NACK_LOGO);
        }

        spin_lock_irqsave(&ha->tgt.sess_lock, flags);
        if (sess->se_sess) {
                sess->se_sess = NULL;
                if (tgt && !IS_SW_RESV_ADDR(sess->d_id))
                        tgt->sess_count--;
        }

        sess->disc_state = DSC_DELETED;
        sess->fw_login_state = DSC_LS_PORT_UNAVAIL;
        sess->deleted = QLA_SESS_DELETED;

        if (sess->login_succ && !IS_SW_RESV_ADDR(sess->d_id)) {
                vha->fcport_count--;
                sess->login_succ = 0;
        }

        qla2x00_clear_loop_id(sess);

        if (sess->conflict) {
                sess->conflict->login_pause = 0;
                sess->conflict = NULL;
                if (!test_bit(UNLOADING, &vha->dpc_flags))
                        set_bit(RELOGIN_NEEDED, &vha->dpc_flags);
        }

        {
                struct qlt_plogi_ack_t *con =
                    sess->plogi_link[QLT_PLOGI_LINK_CONFLICT];
                struct imm_ntfy_from_isp *iocb;

                own = sess->plogi_link[QLT_PLOGI_LINK_SAME_WWN];

                if (con) {
                        iocb = &con->iocb;
                        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf099,
                                 "se_sess %p / sess %p port %8phC is gone,"
                                 " %s (ref=%d), releasing PLOGI for %8phC (ref=%d)\n",
                                 sess->se_sess, sess, sess->port_name,
                                 own ? "releasing own PLOGI" : "no own PLOGI pending",
                                 own ? own->ref_count : -1,
                                 iocb->u.isp24.port_name, con->ref_count);
                        qlt_plogi_ack_unref(vha, con);
                        sess->plogi_link[QLT_PLOGI_LINK_CONFLICT] = NULL;
                } else {
                        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf09a,
                            "se_sess %p / sess %p port %8phC is gone, %s (ref=%d)\n",
                            sess->se_sess, sess, sess->port_name,
                            own ? "releasing own PLOGI" :
                            "no own PLOGI pending",
                            own ? own->ref_count : -1);
                }

                if (own) {
                        sess->fw_login_state = DSC_LS_PLOGI_PEND;
                        qlt_plogi_ack_unref(vha, own);
                        sess->plogi_link[QLT_PLOGI_LINK_SAME_WWN] = NULL;
                }
        }

        spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf001,
            "Unregistration of sess %p %8phC finished fcp_cnt %d\n",
                sess, sess->port_name, vha->fcport_count);

        if (tgt && (tgt->sess_count == 0))
                wake_up_all(&tgt->waitQ);

        if (vha->fcport_count == 0)
                wake_up_all(&vha->fcport_waitQ);

        base_vha = pci_get_drvdata(ha->pdev);

        sess->free_pending = 0;

        if (test_bit(PFLG_DRIVER_REMOVING, &base_vha->pci_flags))
                return;

        if ((!tgt || !tgt->tgt_stop) && !LOOP_TRANSITION(vha)) {
                switch (vha->host->active_mode) {
                case MODE_INITIATOR:
                case MODE_DUAL:
                        set_bit(RELOGIN_NEEDED, &vha->dpc_flags);
                        qla2xxx_wake_dpc(vha);
                        break;
                case MODE_TARGET:
                default:
                        /* no-op */
                        break;
                }
        }
}

/* ha->tgt.sess_lock supposed to be held on entry */
void qlt_unreg_sess(struct fc_port *sess)
{
        struct scsi_qla_host *vha = sess->vha;
        unsigned long flags;

        ql_dbg(ql_dbg_disc, sess->vha, 0x210a,
            "%s sess %p for deletion %8phC\n",
            __func__, sess, sess->port_name);

        spin_lock_irqsave(&sess->vha->work_lock, flags);
        if (sess->free_pending) {
                spin_unlock_irqrestore(&sess->vha->work_lock, flags);
                return;
        }
        sess->free_pending = 1;
        spin_unlock_irqrestore(&sess->vha->work_lock, flags);

        if (sess->se_sess)
                vha->hw->tgt.tgt_ops->clear_nacl_from_fcport_map(sess);

        sess->deleted = QLA_SESS_DELETION_IN_PROGRESS;
        sess->disc_state = DSC_DELETE_PEND;
        sess->last_rscn_gen = sess->rscn_gen;
        sess->last_login_gen = sess->login_gen;

        INIT_WORK(&sess->free_work, qlt_free_session_done);
        schedule_work(&sess->free_work);
}
EXPORT_SYMBOL(qlt_unreg_sess);

static int qlt_reset(struct scsi_qla_host *vha, void *iocb, int mcmd)
{
        struct qla_hw_data *ha = vha->hw;
        struct fc_port *sess = NULL;
        uint16_t loop_id;
        int res = 0;
        struct imm_ntfy_from_isp *n = (struct imm_ntfy_from_isp *)iocb;
        unsigned long flags;

        loop_id = le16_to_cpu(n->u.isp24.nport_handle);
        if (loop_id == 0xFFFF) {
                /* Global event */
                atomic_inc(&vha->vha_tgt.qla_tgt->tgt_global_resets_count);
                spin_lock_irqsave(&ha->tgt.sess_lock, flags);
                qlt_clear_tgt_db(vha->vha_tgt.qla_tgt);
                spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
        } else {
                spin_lock_irqsave(&ha->tgt.sess_lock, flags);
                sess = ha->tgt.tgt_ops->find_sess_by_loop_id(vha, loop_id);
                spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
        }

        ql_dbg(ql_dbg_tgt, vha, 0xe000,
            "Using sess for qla_tgt_reset: %p\n", sess);
        if (!sess) {
                res = -ESRCH;
                return res;
        }

        ql_dbg(ql_dbg_tgt, vha, 0xe047,
            "scsi(%ld): resetting (session %p from port %8phC mcmd %x, "
            "loop_id %d)\n", vha->host_no, sess, sess->port_name,
            mcmd, loop_id);

        return qlt_issue_task_mgmt(sess, 0, mcmd, iocb, QLA24XX_MGMT_SEND_NACK);
}

static void qla24xx_chk_fcp_state(struct fc_port *sess)
{
        if (sess->chip_reset != sess->vha->hw->base_qpair->chip_reset) {
                sess->logout_on_delete = 0;
                sess->logo_ack_needed = 0;
                sess->fw_login_state = DSC_LS_PORT_UNAVAIL;
                sess->scan_state = 0;
        }
}

void qlt_schedule_sess_for_deletion(struct fc_port *sess)
{
        struct qla_tgt *tgt = sess->tgt;
        unsigned long flags;
        u16 sec;

        switch (sess->disc_state) {
        case DSC_DELETE_PEND:
                return;
        case DSC_DELETED:
                if (tgt && tgt->tgt_stop && (tgt->sess_count == 0))
                        wake_up_all(&tgt->waitQ);
                if (sess->vha->fcport_count == 0)
                        wake_up_all(&sess->vha->fcport_waitQ);

                if (!sess->plogi_link[QLT_PLOGI_LINK_SAME_WWN] &&
                        !sess->plogi_link[QLT_PLOGI_LINK_CONFLICT])
                        return;
                break;
        case DSC_UPD_FCPORT:
                /*
                 * This port is not done reporting to upper layer.
                 * let it finish
                 */
                sess->next_disc_state = DSC_DELETE_PEND;
                sec = jiffies_to_msecs(jiffies -
                    sess->jiffies_at_registration)/1000;
                if (sess->sec_since_registration < sec && sec && !(sec % 5)) {
                        sess->sec_since_registration = sec;
                        ql_dbg(ql_dbg_disc, sess->vha, 0xffff,
                            "%s %8phC : Slow Rport registration(%d Sec)\n",
                            __func__, sess->port_name, sec);
                }
                return;
        default:
                break;
        }

        spin_lock_irqsave(&sess->vha->work_lock, flags);
        if (sess->deleted == QLA_SESS_DELETION_IN_PROGRESS) {
                spin_unlock_irqrestore(&sess->vha->work_lock, flags);
                return;
        }
        sess->deleted = QLA_SESS_DELETION_IN_PROGRESS;
        spin_unlock_irqrestore(&sess->vha->work_lock, flags);

        sess->disc_state = DSC_DELETE_PEND;

        qla24xx_chk_fcp_state(sess);

        ql_dbg(ql_dbg_tgt, sess->vha, 0xe001,
            "Scheduling sess %p for deletion %8phC\n",
            sess, sess->port_name);

        INIT_WORK(&sess->del_work, qla24xx_delete_sess_fn);
        WARN_ON(!queue_work(sess->vha->hw->wq, &sess->del_work));
}

static void qlt_clear_tgt_db(struct qla_tgt *tgt)
{
        struct fc_port *sess;
        scsi_qla_host_t *vha = tgt->vha;

        list_for_each_entry(sess, &vha->vp_fcports, list) {
                if (sess->se_sess)
                        qlt_schedule_sess_for_deletion(sess);
        }

        /* At this point tgt could be already dead */
}

static int qla24xx_get_loop_id(struct scsi_qla_host *vha, const uint8_t *s_id,
        uint16_t *loop_id)
{
        struct qla_hw_data *ha = vha->hw;
        dma_addr_t gid_list_dma;
        struct gid_list_info *gid_list;
        char *id_iter;
        int res, rc, i;
        uint16_t entries;

        gid_list = dma_alloc_coherent(&ha->pdev->dev, qla2x00_gid_list_size(ha),
            &gid_list_dma, GFP_KERNEL);
        if (!gid_list) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf044,
                    "qla_target(%d): DMA Alloc failed of %u\n",
                    vha->vp_idx, qla2x00_gid_list_size(ha));
                return -ENOMEM;
        }

        /* Get list of logged in devices */
        rc = qla24xx_gidlist_wait(vha, gid_list, gid_list_dma, &entries);
        if (rc != QLA_SUCCESS) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf045,
                    "qla_target(%d): get_id_list() failed: %x\n",
                    vha->vp_idx, rc);
                res = -EBUSY;
                goto out_free_id_list;
        }

        id_iter = (char *)gid_list;
        res = -ENOENT;
        for (i = 0; i < entries; i++) {
                struct gid_list_info *gid = (struct gid_list_info *)id_iter;

                if ((gid->al_pa == s_id[2]) &&
                    (gid->area == s_id[1]) &&
                    (gid->domain == s_id[0])) {
                        *loop_id = le16_to_cpu(gid->loop_id);
                        res = 0;
                        break;
                }
                id_iter += ha->gid_list_info_size;
        }

out_free_id_list:
        dma_free_coherent(&ha->pdev->dev, qla2x00_gid_list_size(ha),
            gid_list, gid_list_dma);
        return res;
}

/*
 * Adds an extra ref to allow to drop hw lock after adding sess to the list.
 * Caller must put it.
 */
static struct fc_port *qlt_create_sess(
        struct scsi_qla_host *vha,
        fc_port_t *fcport,
        bool local)
{
        struct qla_hw_data *ha = vha->hw;
        struct fc_port *sess = fcport;
        unsigned long flags;

        if (vha->vha_tgt.qla_tgt->tgt_stop)
                return NULL;

        if (fcport->se_sess) {
                if (!kref_get_unless_zero(&sess->sess_kref)) {
                        ql_dbg(ql_dbg_disc, vha, 0x20f6,
                            "%s: kref_get_unless_zero failed for %8phC\n",
                            __func__, sess->port_name);
                        return NULL;
                }
                return fcport;
        }
        sess->tgt = vha->vha_tgt.qla_tgt;
        sess->local = local;

        /*
         * Under normal circumstances we want to logout from firmware when
         * session eventually ends and release corresponding nport handle.
         * In the exception cases (e.g. when new PLOGI is waiting) corresponding
         * code will adjust these flags as necessary.
         */
        sess->logout_on_delete = 1;
        sess->keep_nport_handle = 0;
        sess->logout_completed = 0;

        if (ha->tgt.tgt_ops->check_initiator_node_acl(vha,
            &fcport->port_name[0], sess) < 0) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf015,
                    "(%d) %8phC check_initiator_node_acl failed\n",
                    vha->vp_idx, fcport->port_name);
                return NULL;
        } else {
                kref_init(&fcport->sess_kref);
                /*
                 * Take an extra reference to ->sess_kref here to handle
                 * fc_port access across ->tgt.sess_lock reaquire.
                 */
                if (!kref_get_unless_zero(&sess->sess_kref)) {
                        ql_dbg(ql_dbg_disc, vha, 0x20f7,
                            "%s: kref_get_unless_zero failed for %8phC\n",
                            __func__, sess->port_name);
                        return NULL;
                }

                spin_lock_irqsave(&ha->tgt.sess_lock, flags);
                if (!IS_SW_RESV_ADDR(sess->d_id))
                        vha->vha_tgt.qla_tgt->sess_count++;

                qlt_do_generation_tick(vha, &sess->generation);
                spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
        }

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf006,
            "Adding sess %p se_sess %p  to tgt %p sess_count %d\n",
            sess, sess->se_sess, vha->vha_tgt.qla_tgt,
            vha->vha_tgt.qla_tgt->sess_count);

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf04b,
            "qla_target(%d): %ssession for wwn %8phC (loop_id %d, "
            "s_id %x:%x:%x, confirmed completion %ssupported) added\n",
            vha->vp_idx, local ?  "local " : "", fcport->port_name,
            fcport->loop_id, sess->d_id.b.domain, sess->d_id.b.area,
            sess->d_id.b.al_pa, sess->conf_compl_supported ?  "" : "not ");

        return sess;
}

/*
 * max_gen - specifies maximum session generation
 * at which this deletion requestion is still valid
 */
void
qlt_fc_port_deleted(struct scsi_qla_host *vha, fc_port_t *fcport, int max_gen)
{
        struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
        struct fc_port *sess = fcport;
        unsigned long flags;

        if (!vha->hw->tgt.tgt_ops)
                return;

        if (!tgt)
                return;

        spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);
        if (tgt->tgt_stop) {
                spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);
                return;
        }
        if (!sess->se_sess) {
                spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);
                return;
        }

        if (max_gen - sess->generation < 0) {
                spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf092,
                    "Ignoring stale deletion request for se_sess %p / sess %p"
                    " for port %8phC, req_gen %d, sess_gen %d\n",
                    sess->se_sess, sess, sess->port_name, max_gen,
                    sess->generation);
                return;
        }

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf008, "qla_tgt_fc_port_deleted %p", sess);

        sess->local = 1;
        spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);
        qlt_schedule_sess_for_deletion(sess);
}

static inline int test_tgt_sess_count(struct qla_tgt *tgt)
{
        struct qla_hw_data *ha = tgt->ha;
        unsigned long flags;
        int res;
        /*
         * We need to protect against race, when tgt is freed before or
         * inside wake_up()
         */
        spin_lock_irqsave(&ha->tgt.sess_lock, flags);
        ql_dbg(ql_dbg_tgt, tgt->vha, 0xe002,
            "tgt %p, sess_count=%d\n",
            tgt, tgt->sess_count);
        res = (tgt->sess_count == 0);
        spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);

        return res;
}

/* Called by tcm_qla2xxx configfs code */
int qlt_stop_phase1(struct qla_tgt *tgt)
{
        struct scsi_qla_host *vha = tgt->vha;
        struct qla_hw_data *ha = tgt->ha;
        unsigned long flags;

        mutex_lock(&ha->optrom_mutex);
        mutex_lock(&qla_tgt_mutex);

        if (tgt->tgt_stop || tgt->tgt_stopped) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf04e,
                    "Already in tgt->tgt_stop or tgt_stopped state\n");
                mutex_unlock(&qla_tgt_mutex);
                mutex_unlock(&ha->optrom_mutex);
                return -EPERM;
        }

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xe003, "Stopping target for host %ld(%p)\n",
            vha->host_no, vha);
        /*
         * Mutex needed to sync with qla_tgt_fc_port_[added,deleted].
         * Lock is needed, because we still can get an incoming packet.
         */
        mutex_lock(&vha->vha_tgt.tgt_mutex);
        tgt->tgt_stop = 1;
        qlt_clear_tgt_db(tgt);
        mutex_unlock(&vha->vha_tgt.tgt_mutex);
        mutex_unlock(&qla_tgt_mutex);

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf009,
            "Waiting for sess works (tgt %p)", tgt);
        spin_lock_irqsave(&tgt->sess_work_lock, flags);
        while (!list_empty(&tgt->sess_works_list)) {
                spin_unlock_irqrestore(&tgt->sess_work_lock, flags);
                flush_scheduled_work();
                spin_lock_irqsave(&tgt->sess_work_lock, flags);
        }
        spin_unlock_irqrestore(&tgt->sess_work_lock, flags);

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf00a,
            "Waiting for tgt %p: sess_count=%d\n", tgt, tgt->sess_count);

        wait_event_timeout(tgt->waitQ, test_tgt_sess_count(tgt), 10*HZ);

        /* Big hammer */
        if (!ha->flags.host_shutting_down &&
            (qla_tgt_mode_enabled(vha) || qla_dual_mode_enabled(vha)))
                qlt_disable_vha(vha);

        /* Wait for sessions to clear out (just in case) */
        wait_event_timeout(tgt->waitQ, test_tgt_sess_count(tgt), 10*HZ);
        mutex_unlock(&ha->optrom_mutex);

        return 0;
}
EXPORT_SYMBOL(qlt_stop_phase1);

/* Called by tcm_qla2xxx configfs code */
void qlt_stop_phase2(struct qla_tgt *tgt)
{
        scsi_qla_host_t *vha = tgt->vha;

        if (tgt->tgt_stopped) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf04f,
                    "Already in tgt->tgt_stopped state\n");
                dump_stack();
                return;
        }
        if (!tgt->tgt_stop) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf00b,
                    "%s: phase1 stop is not completed\n", __func__);
                dump_stack();
                return;
        }

        mutex_lock(&vha->vha_tgt.tgt_mutex);
        tgt->tgt_stop = 0;
        tgt->tgt_stopped = 1;
        mutex_unlock(&vha->vha_tgt.tgt_mutex);

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf00c, "Stop of tgt %p finished\n",
            tgt);

        switch (vha->qlini_mode) {
        case QLA2XXX_INI_MODE_EXCLUSIVE:
                vha->flags.online = 1;
                set_bit(ISP_ABORT_NEEDED, &vha->dpc_flags);
                break;
        default:
                break;
        }
}
EXPORT_SYMBOL(qlt_stop_phase2);

/* Called from qlt_remove_target() -> qla2x00_remove_one() */
static void qlt_release(struct qla_tgt *tgt)
{
        scsi_qla_host_t *vha = tgt->vha;
        void *node;
        u64 key = 0;
        u16 i;
        struct qla_qpair_hint *h;
        struct qla_hw_data *ha = vha->hw;

        if ((vha->vha_tgt.qla_tgt != NULL) && !tgt->tgt_stop &&
            !tgt->tgt_stopped)
                qlt_stop_phase1(tgt);

        if ((vha->vha_tgt.qla_tgt != NULL) && !tgt->tgt_stopped)
                qlt_stop_phase2(tgt);

        for (i = 0; i < vha->hw->max_qpairs + 1; i++) {
                unsigned long flags;

                h = &tgt->qphints[i];
                if (h->qpair) {
                        spin_lock_irqsave(h->qpair->qp_lock_ptr, flags);
                        list_del(&h->hint_elem);
                        spin_unlock_irqrestore(h->qpair->qp_lock_ptr, flags);
                        h->qpair = NULL;
                }
        }
        kfree(tgt->qphints);
        mutex_lock(&qla_tgt_mutex);
        list_del(&vha->vha_tgt.qla_tgt->tgt_list_entry);
        mutex_unlock(&qla_tgt_mutex);

        btree_for_each_safe64(&tgt->lun_qpair_map, key, node)
                btree_remove64(&tgt->lun_qpair_map, key);

        btree_destroy64(&tgt->lun_qpair_map);

        if (vha->vp_idx)
                if (ha->tgt.tgt_ops &&
                    ha->tgt.tgt_ops->remove_target &&
                    vha->vha_tgt.target_lport_ptr)
                        ha->tgt.tgt_ops->remove_target(vha);

        vha->vha_tgt.qla_tgt = NULL;

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf00d,
            "Release of tgt %p finished\n", tgt);

        kfree(tgt);
}

/* ha->hardware_lock supposed to be held on entry */
static int qlt_sched_sess_work(struct qla_tgt *tgt, int type,
        const void *param, unsigned int param_size)
{
        struct qla_tgt_sess_work_param *prm;
        unsigned long flags;

        prm = kzalloc(sizeof(*prm), GFP_ATOMIC);
        if (!prm) {
                ql_dbg(ql_dbg_tgt_mgt, tgt->vha, 0xf050,
                    "qla_target(%d): Unable to create session "
                    "work, command will be refused", 0);
                return -ENOMEM;
        }

        ql_dbg(ql_dbg_tgt_mgt, tgt->vha, 0xf00e,
            "Scheduling work (type %d, prm %p)"
            " to find session for param %p (size %d, tgt %p)\n",
            type, prm, param, param_size, tgt);

        prm->type = type;
        memcpy(&prm->tm_iocb, param, param_size);

        spin_lock_irqsave(&tgt->sess_work_lock, flags);
        list_add_tail(&prm->sess_works_list_entry, &tgt->sess_works_list);
        spin_unlock_irqrestore(&tgt->sess_work_lock, flags);

        schedule_work(&tgt->sess_work);

        return 0;
}

/*
 * ha->hardware_lock supposed to be held on entry. Might drop it, then reaquire
 */
static void qlt_send_notify_ack(struct qla_qpair *qpair,
        struct imm_ntfy_from_isp *ntfy,
        uint32_t add_flags, uint16_t resp_code, int resp_code_valid,
        uint16_t srr_flags, uint16_t srr_reject_code, uint8_t srr_explan)
{
        struct scsi_qla_host *vha = qpair->vha;
        struct qla_hw_data *ha = vha->hw;
        request_t *pkt;
        struct nack_to_isp *nack;

        if (!ha->flags.fw_started)
                return;

        ql_dbg(ql_dbg_tgt, vha, 0xe004, "Sending NOTIFY_ACK (ha=%p)\n", ha);

        pkt = (request_t *)__qla2x00_alloc_iocbs(qpair, NULL);
        if (!pkt) {
                ql_dbg(ql_dbg_tgt, vha, 0xe049,
                    "qla_target(%d): %s failed: unable to allocate "
                    "request packet\n", vha->vp_idx, __func__);
                return;
        }

        if (vha->vha_tgt.qla_tgt != NULL)
                vha->vha_tgt.qla_tgt->notify_ack_expected++;

        pkt->entry_type = NOTIFY_ACK_TYPE;
        pkt->entry_count = 1;

        nack = (struct nack_to_isp *)pkt;
        nack->ox_id = ntfy->ox_id;

        nack->u.isp24.handle = QLA_TGT_SKIP_HANDLE;
        nack->u.isp24.nport_handle = ntfy->u.isp24.nport_handle;
        if (le16_to_cpu(ntfy->u.isp24.status) == IMM_NTFY_ELS) {
                nack->u.isp24.flags = ntfy->u.isp24.flags &
                        cpu_to_le32(NOTIFY24XX_FLAGS_PUREX_IOCB);
        }
        nack->u.isp24.srr_rx_id = ntfy->u.isp24.srr_rx_id;
        nack->u.isp24.status = ntfy->u.isp24.status;
        nack->u.isp24.status_subcode = ntfy->u.isp24.status_subcode;
        nack->u.isp24.fw_handle = ntfy->u.isp24.fw_handle;
        nack->u.isp24.exchange_address = ntfy->u.isp24.exchange_address;
        nack->u.isp24.srr_rel_offs = ntfy->u.isp24.srr_rel_offs;
        nack->u.isp24.srr_ui = ntfy->u.isp24.srr_ui;
        nack->u.isp24.srr_flags = cpu_to_le16(srr_flags);
        nack->u.isp24.srr_reject_code = srr_reject_code;
        nack->u.isp24.srr_reject_code_expl = srr_explan;
        nack->u.isp24.vp_index = ntfy->u.isp24.vp_index;

        ql_dbg(ql_dbg_tgt, vha, 0xe005,
            "qla_target(%d): Sending 24xx Notify Ack %d\n",
            vha->vp_idx, nack->u.isp24.status);

        /* Memory Barrier */
        wmb();
        qla2x00_start_iocbs(vha, qpair->req);
}

static int qlt_build_abts_resp_iocb(struct qla_tgt_mgmt_cmd *mcmd)
{
        struct scsi_qla_host *vha = mcmd->vha;
        struct qla_hw_data *ha = vha->hw;
        struct abts_resp_to_24xx *resp;
        uint32_t f_ctl, h;
        uint8_t *p;
        int rc;
        struct abts_recv_from_24xx *abts = &mcmd->orig_iocb.abts;
        struct qla_qpair *qpair = mcmd->qpair;

        ql_dbg(ql_dbg_tgt, vha, 0xe006,
            "Sending task mgmt ABTS response (ha=%p, status=%x)\n",
            ha, mcmd->fc_tm_rsp);

        rc = qlt_check_reserve_free_req(qpair, 1);
        if (rc) {
                ql_dbg(ql_dbg_tgt, vha, 0xe04a,
                    "qla_target(%d): %s failed: unable to allocate request packet\n",
                    vha->vp_idx, __func__);
                return -EAGAIN;
        }

        resp = (struct abts_resp_to_24xx *)qpair->req->ring_ptr;
        memset(resp, 0, sizeof(*resp));

        h = qlt_make_handle(qpair);
        if (unlikely(h == QLA_TGT_NULL_HANDLE)) {
                /*
                 * CTIO type 7 from the firmware doesn't provide a way to
                 * know the initiator's LOOP ID, hence we can't find
                 * the session and, so, the command.
                 */
                return -EAGAIN;
        } else {
                qpair->req->outstanding_cmds[h] = (srb_t *)mcmd;
        }

        resp->handle = MAKE_HANDLE(qpair->req->id, h);
        resp->entry_type = ABTS_RESP_24XX;
        resp->entry_count = 1;
        resp->nport_handle = abts->nport_handle;
        resp->vp_index = vha->vp_idx;
        resp->sof_type = abts->sof_type;
        resp->exchange_address = abts->exchange_address;
        resp->fcp_hdr_le = abts->fcp_hdr_le;
        f_ctl = cpu_to_le32(F_CTL_EXCH_CONTEXT_RESP |
            F_CTL_LAST_SEQ | F_CTL_END_SEQ |
            F_CTL_SEQ_INITIATIVE);
        p = (uint8_t *)&f_ctl;
        resp->fcp_hdr_le.f_ctl[0] = *p++;
        resp->fcp_hdr_le.f_ctl[1] = *p++;
        resp->fcp_hdr_le.f_ctl[2] = *p;

        resp->fcp_hdr_le.d_id[0] = abts->fcp_hdr_le.s_id[0];
        resp->fcp_hdr_le.d_id[1] = abts->fcp_hdr_le.s_id[1];
        resp->fcp_hdr_le.d_id[2] = abts->fcp_hdr_le.s_id[2];
        resp->fcp_hdr_le.s_id[0] = abts->fcp_hdr_le.d_id[0];
        resp->fcp_hdr_le.s_id[1] = abts->fcp_hdr_le.d_id[1];
        resp->fcp_hdr_le.s_id[2] = abts->fcp_hdr_le.d_id[2];

        resp->exchange_addr_to_abort = abts->exchange_addr_to_abort;
        if (mcmd->fc_tm_rsp == FCP_TMF_CMPL) {
                resp->fcp_hdr_le.r_ctl = R_CTL_BASIC_LINK_SERV | R_CTL_B_ACC;
                resp->payload.ba_acct.seq_id_valid = SEQ_ID_INVALID;
                resp->payload.ba_acct.low_seq_cnt = 0x0000;
                resp->payload.ba_acct.high_seq_cnt = 0xFFFF;
                resp->payload.ba_acct.ox_id = abts->fcp_hdr_le.ox_id;
                resp->payload.ba_acct.rx_id = abts->fcp_hdr_le.rx_id;
        } else {
                resp->fcp_hdr_le.r_ctl = R_CTL_BASIC_LINK_SERV | R_CTL_B_RJT;
                resp->payload.ba_rjt.reason_code =
                        BA_RJT_REASON_CODE_UNABLE_TO_PERFORM;
                /* Other bytes are zero */
        }

        vha->vha_tgt.qla_tgt->abts_resp_expected++;

        /* Memory Barrier */
        wmb();
        if (qpair->reqq_start_iocbs)
                qpair->reqq_start_iocbs(qpair);
        else
                qla2x00_start_iocbs(vha, qpair->req);

        return rc;
}

/*
 * ha->hardware_lock supposed to be held on entry. Might drop it, then reaquire
 */
static void qlt_24xx_send_abts_resp(struct qla_qpair *qpair,
        struct abts_recv_from_24xx *abts, uint32_t status,
        bool ids_reversed)
{
        struct scsi_qla_host *vha = qpair->vha;
        struct qla_hw_data *ha = vha->hw;
        struct abts_resp_to_24xx *resp;
        uint32_t f_ctl;
        uint8_t *p;

        ql_dbg(ql_dbg_tgt, vha, 0xe006,
            "Sending task mgmt ABTS response (ha=%p, atio=%p, status=%x\n",
            ha, abts, status);

        resp = (struct abts_resp_to_24xx *)qla2x00_alloc_iocbs_ready(qpair,
            NULL);
        if (!resp) {
                ql_dbg(ql_dbg_tgt, vha, 0xe04a,
                    "qla_target(%d): %s failed: unable to allocate "
                    "request packet", vha->vp_idx, __func__);
                return;
        }

        resp->entry_type = ABTS_RESP_24XX;
        resp->handle = QLA_TGT_SKIP_HANDLE;
        resp->entry_count = 1;
        resp->nport_handle = abts->nport_handle;
        resp->vp_index = vha->vp_idx;
        resp->sof_type = abts->sof_type;
        resp->exchange_address = abts->exchange_address;
        resp->fcp_hdr_le = abts->fcp_hdr_le;
        f_ctl = cpu_to_le32(F_CTL_EXCH_CONTEXT_RESP |
            F_CTL_LAST_SEQ | F_CTL_END_SEQ |
            F_CTL_SEQ_INITIATIVE);
        p = (uint8_t *)&f_ctl;
        resp->fcp_hdr_le.f_ctl[0] = *p++;
        resp->fcp_hdr_le.f_ctl[1] = *p++;
        resp->fcp_hdr_le.f_ctl[2] = *p;
        if (ids_reversed) {
                resp->fcp_hdr_le.d_id[0] = abts->fcp_hdr_le.d_id[0];
                resp->fcp_hdr_le.d_id[1] = abts->fcp_hdr_le.d_id[1];
                resp->fcp_hdr_le.d_id[2] = abts->fcp_hdr_le.d_id[2];
                resp->fcp_hdr_le.s_id[0] = abts->fcp_hdr_le.s_id[0];
                resp->fcp_hdr_le.s_id[1] = abts->fcp_hdr_le.s_id[1];
                resp->fcp_hdr_le.s_id[2] = abts->fcp_hdr_le.s_id[2];
        } else {
                resp->fcp_hdr_le.d_id[0] = abts->fcp_hdr_le.s_id[0];
                resp->fcp_hdr_le.d_id[1] = abts->fcp_hdr_le.s_id[1];
                resp->fcp_hdr_le.d_id[2] = abts->fcp_hdr_le.s_id[2];
                resp->fcp_hdr_le.s_id[0] = abts->fcp_hdr_le.d_id[0];
                resp->fcp_hdr_le.s_id[1] = abts->fcp_hdr_le.d_id[1];
                resp->fcp_hdr_le.s_id[2] = abts->fcp_hdr_le.d_id[2];
        }
        resp->exchange_addr_to_abort = abts->exchange_addr_to_abort;
        if (status == FCP_TMF_CMPL) {
                resp->fcp_hdr_le.r_ctl = R_CTL_BASIC_LINK_SERV | R_CTL_B_ACC;
                resp->payload.ba_acct.seq_id_valid = SEQ_ID_INVALID;
                resp->payload.ba_acct.low_seq_cnt = 0x0000;
                resp->payload.ba_acct.high_seq_cnt = 0xFFFF;
                resp->payload.ba_acct.ox_id = abts->fcp_hdr_le.ox_id;
                resp->payload.ba_acct.rx_id = abts->fcp_hdr_le.rx_id;
        } else {
                resp->fcp_hdr_le.r_ctl = R_CTL_BASIC_LINK_SERV | R_CTL_B_RJT;
                resp->payload.ba_rjt.reason_code =
                        BA_RJT_REASON_CODE_UNABLE_TO_PERFORM;
                /* Other bytes are zero */
        }

        vha->vha_tgt.qla_tgt->abts_resp_expected++;

        /* Memory Barrier */
        wmb();
        if (qpair->reqq_start_iocbs)
                qpair->reqq_start_iocbs(qpair);
        else
                qla2x00_start_iocbs(vha, qpair->req);
}

/*
 * ha->hardware_lock supposed to be held on entry. Might drop it, then reaquire
 */
static void qlt_24xx_retry_term_exchange(struct scsi_qla_host *vha,
    struct qla_qpair *qpair, response_t *pkt, struct qla_tgt_mgmt_cmd *mcmd)
{
        struct ctio7_to_24xx *ctio;
        u16 tmp;
        struct abts_recv_from_24xx *entry;

        ctio = (struct ctio7_to_24xx *)qla2x00_alloc_iocbs_ready(qpair, NULL);
        if (ctio == NULL) {
                ql_dbg(ql_dbg_tgt, vha, 0xe04b,
                    "qla_target(%d): %s failed: unable to allocate "
                    "request packet\n", vha->vp_idx, __func__);
                return;
        }

        if (mcmd)
                /* abts from remote port */
                entry = &mcmd->orig_iocb.abts;
        else
                /* abts from this driver.  */
                entry = (struct abts_recv_from_24xx *)pkt;

        /*
         * We've got on entrance firmware's response on by us generated
         * ABTS response. So, in it ID fields are reversed.
         */

        ctio->entry_type = CTIO_TYPE7;
        ctio->entry_count = 1;
        ctio->nport_handle = entry->nport_handle;
        ctio->handle = QLA_TGT_SKIP_HANDLE |    CTIO_COMPLETION_HANDLE_MARK;
        ctio->timeout = cpu_to_le16(QLA_TGT_TIMEOUT);
        ctio->vp_index = vha->vp_idx;
        ctio->exchange_addr = entry->exchange_addr_to_abort;
        tmp = (CTIO7_FLAGS_STATUS_MODE_1 | CTIO7_FLAGS_TERMINATE);

        if (mcmd) {
                ctio->initiator_id[0] = entry->fcp_hdr_le.s_id[0];
                ctio->initiator_id[1] = entry->fcp_hdr_le.s_id[1];
                ctio->initiator_id[2] = entry->fcp_hdr_le.s_id[2];

                if (mcmd->flags & QLA24XX_MGMT_ABORT_IO_ATTR_VALID)
                        tmp |= (mcmd->abort_io_attr << 9);
                else if (qpair->retry_term_cnt & 1)
                        tmp |= (0x4 << 9);
        } else {
                ctio->initiator_id[0] = entry->fcp_hdr_le.d_id[0];
                ctio->initiator_id[1] = entry->fcp_hdr_le.d_id[1];
                ctio->initiator_id[2] = entry->fcp_hdr_le.d_id[2];

                if (qpair->retry_term_cnt & 1)
                        tmp |= (0x4 << 9);
        }
        ctio->u.status1.flags = cpu_to_le16(tmp);
        ctio->u.status1.ox_id = entry->fcp_hdr_le.ox_id;

        ql_dbg(ql_dbg_tgt, vha, 0xe007,
            "Sending retry TERM EXCH CTIO7 flags %04xh oxid %04xh attr valid %x\n",
            le16_to_cpu(ctio->u.status1.flags),
            le16_to_cpu(ctio->u.status1.ox_id),
            (mcmd && mcmd->flags & QLA24XX_MGMT_ABORT_IO_ATTR_VALID) ? 1 : 0);

        /* Memory Barrier */
        wmb();
        if (qpair->reqq_start_iocbs)
                qpair->reqq_start_iocbs(qpair);
        else
                qla2x00_start_iocbs(vha, qpair->req);

        if (mcmd)
                qlt_build_abts_resp_iocb(mcmd);
        else
                qlt_24xx_send_abts_resp(qpair,
                    (struct abts_recv_from_24xx *)entry, FCP_TMF_CMPL, true);

}

/* drop cmds for the given lun
 * XXX only looks for cmds on the port through which lun reset was recieved
 * XXX does not go through the list of other port (which may have cmds
 *     for the same lun)
 */
static void abort_cmds_for_lun(struct scsi_qla_host *vha,
                                u64 lun, uint8_t *s_id)
{
        struct qla_tgt_sess_op *op;
        struct qla_tgt_cmd *cmd;
        uint32_t key;
        unsigned long flags;

        key = sid_to_key(s_id);
        spin_lock_irqsave(&vha->cmd_list_lock, flags);
        list_for_each_entry(op, &vha->qla_sess_op_cmd_list, cmd_list) {
                uint32_t op_key;
                u64 op_lun;

                op_key = sid_to_key(op->atio.u.isp24.fcp_hdr.s_id);
                op_lun = scsilun_to_int(
                        (struct scsi_lun *)&op->atio.u.isp24.fcp_cmnd.lun);
                if (op_key == key && op_lun == lun)
                        op->aborted = true;
        }

        list_for_each_entry(op, &vha->unknown_atio_list, cmd_list) {
                uint32_t op_key;
                u64 op_lun;

                op_key = sid_to_key(op->atio.u.isp24.fcp_hdr.s_id);

                op_lun = scsilun_to_int(
                        (struct scsi_lun *)&op->atio.u.isp24.fcp_cmnd.lun);
                if (op_key == key && op_lun == lun)
                        op->aborted = true;
        }

        list_for_each_entry(cmd, &vha->qla_cmd_list, cmd_list) {
                uint32_t cmd_key;
                u64 cmd_lun;

                cmd_key = sid_to_key(cmd->atio.u.isp24.fcp_hdr.s_id);
                cmd_lun = scsilun_to_int(
                        (struct scsi_lun *)&cmd->atio.u.isp24.fcp_cmnd.lun);
                if (cmd_key == key && cmd_lun == lun)
                        cmd->aborted = 1;
        }
        spin_unlock_irqrestore(&vha->cmd_list_lock, flags);
}

static struct qla_qpair_hint *qlt_find_qphint(struct scsi_qla_host *vha,
    uint64_t unpacked_lun)
{
        struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
        struct qla_qpair_hint *h = NULL;

        if (vha->flags.qpairs_available) {
                h = btree_lookup64(&tgt->lun_qpair_map, unpacked_lun);
                if (!h)
                        h = &tgt->qphints[0];
        } else {
                h = &tgt->qphints[0];
        }

        return h;
}

static void qlt_do_tmr_work(struct work_struct *work)
{
        struct qla_tgt_mgmt_cmd *mcmd =
                container_of(work, struct qla_tgt_mgmt_cmd, work);
        struct qla_hw_data *ha = mcmd->vha->hw;
        int rc = EIO;
        uint32_t tag;
        unsigned long flags;

        switch (mcmd->tmr_func) {
        case QLA_TGT_ABTS:
                tag = mcmd->orig_iocb.abts.exchange_addr_to_abort;
                break;
        default:
                tag = 0;
                break;
        }

        rc = ha->tgt.tgt_ops->handle_tmr(mcmd, mcmd->unpacked_lun,
            mcmd->tmr_func, tag);

        if (rc != 0) {
                spin_lock_irqsave(mcmd->qpair->qp_lock_ptr, flags);
                switch (mcmd->tmr_func) {
                case QLA_TGT_ABTS:
                        mcmd->fc_tm_rsp = FCP_TMF_REJECTED;
                        qlt_build_abts_resp_iocb(mcmd);
                        break;
                case QLA_TGT_LUN_RESET:
                case QLA_TGT_CLEAR_TS:
                case QLA_TGT_ABORT_TS:
                case QLA_TGT_CLEAR_ACA:
                case QLA_TGT_TARGET_RESET:
                        qlt_send_busy(mcmd->qpair, &mcmd->orig_iocb.atio,
                            qla_sam_status);
                        break;

                case QLA_TGT_ABORT_ALL:
                case QLA_TGT_NEXUS_LOSS_SESS:
                case QLA_TGT_NEXUS_LOSS:
                        qlt_send_notify_ack(mcmd->qpair,
                            &mcmd->orig_iocb.imm_ntfy, 0, 0, 0, 0, 0, 0);
                        break;
                }
                spin_unlock_irqrestore(mcmd->qpair->qp_lock_ptr, flags);

                ql_dbg(ql_dbg_tgt_mgt, mcmd->vha, 0xf052,
                    "qla_target(%d):  tgt_ops->handle_tmr() failed: %d\n",
                    mcmd->vha->vp_idx, rc);
                mempool_free(mcmd, qla_tgt_mgmt_cmd_mempool);
        }
}

/* ha->hardware_lock supposed to be held on entry */
static int __qlt_24xx_handle_abts(struct scsi_qla_host *vha,
        struct abts_recv_from_24xx *abts, struct fc_port *sess)
{
        struct qla_hw_data *ha = vha->hw;
        struct qla_tgt_mgmt_cmd *mcmd;
        struct qla_qpair_hint *h = &vha->vha_tgt.qla_tgt->qphints[0];

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf00f,
            "qla_target(%d): task abort (tag=%d)\n",
            vha->vp_idx, abts->exchange_addr_to_abort);

        mcmd = mempool_alloc(qla_tgt_mgmt_cmd_mempool, GFP_ATOMIC);
        if (mcmd == NULL) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf051,
                    "qla_target(%d): %s: Allocation of ABORT cmd failed",
                    vha->vp_idx, __func__);
                return -ENOMEM;
        }
        memset(mcmd, 0, sizeof(*mcmd));
        mcmd->cmd_type = TYPE_TGT_TMCMD;
        mcmd->sess = sess;
        memcpy(&mcmd->orig_iocb.abts, abts, sizeof(mcmd->orig_iocb.abts));
        mcmd->reset_count = ha->base_qpair->chip_reset;
        mcmd->tmr_func = QLA_TGT_ABTS;
        mcmd->qpair = h->qpair;
        mcmd->vha = vha;

        /*
         * LUN is looked up by target-core internally based on the passed
         * abts->exchange_addr_to_abort tag.
         */
        mcmd->se_cmd.cpuid = h->cpuid;

        if (ha->tgt.tgt_ops->find_cmd_by_tag) {
                struct qla_tgt_cmd *abort_cmd;

                abort_cmd = ha->tgt.tgt_ops->find_cmd_by_tag(sess,
                    abts->exchange_addr_to_abort);
                if (abort_cmd && abort_cmd->qpair) {
                        mcmd->qpair = abort_cmd->qpair;
                        mcmd->se_cmd.cpuid = abort_cmd->se_cmd.cpuid;
                        mcmd->abort_io_attr = abort_cmd->atio.u.isp24.attr;
                        mcmd->flags = QLA24XX_MGMT_ABORT_IO_ATTR_VALID;
                }
        }

        INIT_WORK(&mcmd->work, qlt_do_tmr_work);
        queue_work_on(mcmd->se_cmd.cpuid, qla_tgt_wq, &mcmd->work);

        return 0;
}

/*
 * ha->hardware_lock supposed to be held on entry. Might drop it, then reaquire
 */
static void qlt_24xx_handle_abts(struct scsi_qla_host *vha,
        struct abts_recv_from_24xx *abts)
{
        struct qla_hw_data *ha = vha->hw;
        struct fc_port *sess;
        uint32_t tag = abts->exchange_addr_to_abort;
        uint8_t s_id[3];
        int rc;
        unsigned long flags;

        if (le32_to_cpu(abts->fcp_hdr_le.parameter) & ABTS_PARAM_ABORT_SEQ) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf053,
                    "qla_target(%d): ABTS: Abort Sequence not "
                    "supported\n", vha->vp_idx);
                qlt_24xx_send_abts_resp(ha->base_qpair, abts, FCP_TMF_REJECTED,
                    false);
                return;
        }

        if (tag == ATIO_EXCHANGE_ADDRESS_UNKNOWN) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf010,
                    "qla_target(%d): ABTS: Unknown Exchange "
                    "Address received\n", vha->vp_idx);
                qlt_24xx_send_abts_resp(ha->base_qpair, abts, FCP_TMF_REJECTED,
                    false);
                return;
        }

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf011,
            "qla_target(%d): task abort (s_id=%x:%x:%x, "
            "tag=%d, param=%x)\n", vha->vp_idx, abts->fcp_hdr_le.s_id[2],
            abts->fcp_hdr_le.s_id[1], abts->fcp_hdr_le.s_id[0], tag,
            le32_to_cpu(abts->fcp_hdr_le.parameter));

        s_id[0] = abts->fcp_hdr_le.s_id[2];
        s_id[1] = abts->fcp_hdr_le.s_id[1];
        s_id[2] = abts->fcp_hdr_le.s_id[0];

        spin_lock_irqsave(&ha->tgt.sess_lock, flags);
        sess = ha->tgt.tgt_ops->find_sess_by_s_id(vha, s_id);
        if (!sess) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf012,
                    "qla_target(%d): task abort for non-existent session\n",
                    vha->vp_idx);
                spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);

                qlt_24xx_send_abts_resp(ha->base_qpair, abts, FCP_TMF_REJECTED,
                            false);
                return;
        }
        spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);


        if (sess->deleted) {
                qlt_24xx_send_abts_resp(ha->base_qpair, abts, FCP_TMF_REJECTED,
                    false);
                return;
        }

        rc = __qlt_24xx_handle_abts(vha, abts, sess);
        if (rc != 0) {
                ql_dbg(ql_dbg_tgt_mgt, vha, 0xf054,
                    "qla_target(%d): __qlt_24xx_handle_abts() failed: %d\n",
                    vha->vp_idx, rc);
                qlt_24xx_send_abts_resp(ha->base_qpair, abts, FCP_TMF_REJECTED,
                    false);
                return;
        }
}

/*
 * ha->hardware_lock supposed to be held on entry. Might drop it, then reaquire
 */
static void qlt_24xx_send_task_mgmt_ctio(struct qla_qpair *qpair,
        struct qla_tgt_mgmt_cmd *mcmd, uint32_t resp_code)
{
        struct scsi_qla_host *ha = mcmd->vha;
        struct atio_from_isp *atio = &mcmd->orig_iocb.atio;
        struct ctio7_to_24xx *ctio;
        uint16_t temp;

        ql_dbg(ql_dbg_tgt, ha, 0xe008,
            "Sending task mgmt CTIO7 (ha=%p, atio=%p, resp_code=%x\n",
            ha, atio, resp_code);


        ctio = (struct ctio7_to_24xx *)__qla2x00_alloc_iocbs(qpair, NULL);
        if (ctio == NULL) {
                ql_dbg(ql_dbg_tgt, ha, 0xe04c,
                    "qla_target(%d): %s failed: unable to allocate "
                    "request packet\n", ha->vp_idx, __func__);
                return;
        }

        ctio->entry_type = CTIO_TYPE7;
        ctio->entry_count = 1;
        ctio->handle = QLA_TGT_SKIP_HANDLE | CTIO_COMPLETION_HANDLE_MARK;
        ctio->nport_handle = mcmd->sess->loop_id;
        ctio->timeout = cpu_to_le16(QLA_TGT_TIMEOUT);
        ctio->vp_index = ha->vp_idx;
        ctio->initiator_id[0] = atio->u.isp24.fcp_hdr.s_id[2];
        ctio->initiator_id[1] = atio->u.isp24.fcp_hdr.s_id[1];
        ctio->initiator_id[2] = atio->u.isp24.fcp_hdr.s_id[0];
        ctio->exchange_addr = atio->u.isp24.exchange_addr;
        temp = (atio->u.isp24.attr << 9)|
                CTIO7_FLAGS_STATUS_MODE_1 | CTIO7_FLAGS_SEND_STATUS;
        ctio->u.status1.flags = cpu_to_le16(temp);
        temp = be16_to_cpu(atio->u.isp24.fcp_hdr.ox_id);
        ctio->u.status1.ox_id = cpu_to_le16(temp);
        ctio->u.status1.scsi_status =
            cpu_to_le16(SS_RESPONSE_INFO_LEN_VALID);
        ctio->u.status1.response_len = cpu_to_le16(8);
        ctio->u.status1.sense_data[0] = resp_code;

        /* Memory Barrier */
        wmb();
        if (qpair->reqq_start_iocbs)
                qpair->reqq_start_iocbs(qpair);
        else
                qla2x00_start_iocbs(ha, qpair->req);
}

void qlt_free_mcmd(struct qla_tgt_mgmt_cmd *mcmd)
{
        mempool_free(mcmd, qla_tgt_mgmt_cmd_mempool);
}
EXPORT_SYMBOL(qlt_free_mcmd);

/*
 * ha->hardware_lock supposed to be held on entry. Might drop it, then
 * reacquire
 */
void qlt_send_resp_ctio(struct qla_qpair *qpair, struct qla_tgt_cmd *cmd,
    uint8_t scsi_status, uint8_t sense_key, uint8_t asc, uint8_t ascq)
{
        struct atio_from_isp *atio = &cmd->atio;
        struct ctio7_to_24xx *ctio;
        uint16_t temp;
        struct scsi_qla_host *vha = cmd->vha;

        ql_dbg(ql_dbg_tgt_dif, vha, 0x3066,
            "Sending response CTIO7 (vha=%p, atio=%p, scsi_status=%02x, "
            "sense_key=%02x, asc=%02x, ascq=%02x",
            vha, atio, scsi_status, sense_key, asc, ascq);

        ctio = (struct ctio7_to_24xx *)qla2x00_alloc_iocbs(vha, NULL);
        if (!ctio) {
                ql_dbg(ql_dbg_async, vha, 0x3067,
                    "qla2x00t(%ld): %s failed: unable to allocate request packet",
                    vha->host_no, __func__);
                goto out;
        }

        ctio->entry_type = CTIO_TYPE7;
        ctio->entry_count = 1;
        ctio->handle = QLA_TGT_SKIP_HANDLE;
        ctio->nport_handle = cmd->sess->loop_id;
        ctio->timeout = cpu_to_le16(QLA_TGT_TIMEOUT);
        ctio->vp_index = vha->vp_idx;
        ctio->initiator_id[0] = atio->u.isp24.fcp_hdr.s_id[2];
        ctio->initiator_id[1] = atio->u.isp24.fcp_hdr.s_id[1];
        ctio->initiator_id[2] = atio->u.isp24.fcp_hdr.s_id[0];
        ctio->exchange_addr = atio->u.isp24.exchange_addr;
        temp = (atio->u.isp24.attr << 9) |
            CTIO7_FLAGS_STATUS_MODE_1 | CTIO7_FLAGS_SEND_STATUS;
        ctio->u.status1.flags = cpu_to_le16(temp);
        temp = be16_to_cpu(atio->u.isp24.fcp_hdr.ox_id);
        ctio->u.status1.ox_id = cpu_to_le16(temp);
        ctio->u.status1.scsi_status =
            cpu_to_le16(SS_RESPONSE_INFO_LEN_VALID | scsi_status);
        ctio->u.status1.response_len = cpu_to_le16(18);
        ctio->u.status1.residual = cpu_to_le32(get_datalen_for_atio(atio));

        if (ctio->u.status1.residual != 0)
                ctio->u.status1.scsi_status |=
                    cpu_to_le16(SS_RESIDUAL_UNDER);

        /* Fixed format sense data. */
        ctio->u.status1.sense_data[0] = 0x70;
        ctio->u.status1.sense_data[2] = sense_key;
        /* Additional sense length */
        ctio->u.status1.sense_data[7] = 0xa;
        /* ASC and ASCQ */
        ctio->u.status1.sense_data[12] = asc;
        ctio->u.status1.sense_data[13] = ascq;

        /* Memory Barrier */
        wmb();

        if (qpair->reqq_start_iocbs)
                qpair->reqq_start_iocbs(qpair);
        else
                qla2x00_start_iocbs(vha, qpair->req);

out:
        return;
}

/* callback from target fabric module code */
void qlt_xmit_tm_rsp(struct qla_tgt_mgmt_cmd *mcmd)
{
        struct scsi_qla_host *vha = mcmd->sess->vha;
        struct qla_hw_data *ha = vha->hw;
        unsigned long flags;
        struct qla_qpair *qpair = mcmd->qpair;
        bool free_mcmd = true;

        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf013,
            "TM response mcmd (%p) status %#x state %#x",
            mcmd, mcmd->fc_tm_rsp, mcmd->flags);

        spin_lock_irqsave(qpair->qp_lock_ptr, flags);

        if (!vha->flags.online || mcmd->reset_count != qpair->chip_reset) {
                /*
                 * Either the port is not online or this request was from
                 * previous life, just abort the processing.
                 */
                ql_dbg(ql_dbg_async, vha, 0xe100,
                        "RESET-TMR online/active/old-count/new-count = %d/%d/%d/%d.\n",
                        vha->flags.online, qla2x00_reset_active(vha),
                        mcmd->reset_count, qpair->chip_reset);
                ha->tgt.tgt_ops->free_mcmd(mcmd);
                spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
                return;
        }

        if (mcmd->flags == QLA24XX_MGMT_SEND_NACK) {
                switch (mcmd->orig_iocb.imm_ntfy.u.isp24.status_subcode) {
                case ELS_LOGO:
                case ELS_PRLO:
                case ELS_TPRLO:
                        ql_dbg(ql_dbg_disc, vha, 0x2106,
                            "TM response logo %8phC status %#x state %#x",
                            mcmd->sess->port_name, mcmd->fc_tm_rsp,
                            mcmd->flags);
                        qlt_schedule_sess_for_deletion(mcmd->sess);
                        break;
                default:
                        qlt_send_notify_ack(vha->hw->base_qpair,
                            &mcmd->orig_iocb.imm_ntfy, 0, 0, 0, 0, 0, 0);
                        break;
                }
        } else {
                if (mcmd->orig_iocb.atio.u.raw.entry_type == ABTS_RECV_24XX) {
                        qlt_build_abts_resp_iocb(mcmd);
                        free_mcmd = false;
                } else
                        qlt_24xx_send_task_mgmt_ctio(qpair, mcmd,
                            mcmd->fc_tm_rsp);
        }
        /*
         * Make the callback for ->free_mcmd() to queue_work() and invoke
         * target_put_sess_cmd() to drop cmd_kref to 1.  The final
         * target_put_sess_cmd() call will be made from TFO->check_stop_free()
         * -> tcm_qla2xxx_check_stop_free() to release the TMR associated se_cmd
         * descriptor after TFO->queue_tm_rsp() -> tcm_qla2xxx_queue_tm_rsp() ->
         * qlt_xmit_tm_rsp() returns here..
         */
        if (free_mcmd)
                ha->tgt.tgt_ops->free_mcmd(mcmd);

        spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
}
EXPORT_SYMBOL(qlt_xmit_tm_rsp);

/* No locks */
static int qlt_pci_map_calc_cnt(struct qla_tgt_prm *prm)
{
        struct qla_tgt_cmd *cmd = prm->cmd;

        BUG_ON(cmd->sg_cnt == 0);

        prm->sg = (struct scatterlist *)cmd->sg;
        prm->seg_cnt = dma_map_sg(&cmd->qpair->pdev->dev, cmd->sg,
            cmd->sg_cnt, cmd->dma_data_direction);
        if (unlikely(prm->seg_cnt == 0))
                goto out_err;

        prm->cmd->sg_mapped = 1;

        if (cmd->se_cmd.prot_op == TARGET_PROT_NORMAL) {
                /*
                 * If greater than four sg entries then we need to allocate
                 * the continuation entries
                 */
                if (prm->seg_cnt > QLA_TGT_DATASEGS_PER_CMD_24XX)
                        prm->req_cnt += DIV_ROUND_UP(prm->seg_cnt -
                        QLA_TGT_DATASEGS_PER_CMD_24XX,
                        QLA_TGT_DATASEGS_PER_CONT_24XX);
        } else {
                /* DIF */
                if ((cmd->se_cmd.prot_op == TARGET_PROT_DIN_INSERT) ||
                    (cmd->se_cmd.prot_op == TARGET_PROT_DOUT_STRIP)) {
                        prm->seg_cnt = DIV_ROUND_UP(cmd->bufflen, cmd->blk_sz);
                        prm->tot_dsds = prm->seg_cnt;
                } else
                        prm->tot_dsds = prm->seg_cnt;

                if (cmd->prot_sg_cnt) {
                        prm->prot_sg      = cmd->prot_sg;
                        prm->prot_seg_cnt = dma_map_sg(&cmd->qpair->pdev->dev,
                                cmd->prot_sg, cmd->prot_sg_cnt,
                                cmd->dma_data_direction);
                        if (unlikely(prm->prot_seg_cnt == 0))
                                goto out_err;

                        if ((cmd->se_cmd.prot_op == TARGET_PROT_DIN_INSERT) ||
                            (cmd->se_cmd.prot_op == TARGET_PROT_DOUT_STRIP)) {
                                /* Dif Bundling not support here */
                                prm->prot_seg_cnt = DIV_ROUND_UP(cmd->bufflen,
                                                                cmd->blk_sz);
                                prm->tot_dsds += prm->prot_seg_cnt;
                        } else
                                prm->tot_dsds += prm->prot_seg_cnt;
                }
        }

        return 0;

out_err:
        ql_dbg_qp(ql_dbg_tgt, prm->cmd->qpair, 0xe04d,
            "qla_target(%d): PCI mapping failed: sg_cnt=%d",
            0, prm->cmd->sg_cnt);
        return -1;
}

static void qlt_unmap_sg(struct scsi_qla_host *vha, struct qla_tgt_cmd *cmd)
{
        struct qla_hw_data *ha;
        struct qla_qpair *qpair;

        if (!cmd->sg_mapped)
                return;

        qpair = cmd->qpair;

        dma_unmap_sg(&qpair->pdev->dev, cmd->sg, cmd->sg_cnt,
            cmd->dma_data_direction);
        cmd->sg_mapped = 0;

        if (cmd->prot_sg_cnt)
                dma_unmap_sg(&qpair->pdev->dev, cmd->prot_sg, cmd->prot_sg_cnt,
                        cmd->dma_data_direction);

        if (!cmd->ctx)
                return;
        ha = vha->hw;
        if (cmd->ctx_dsd_alloced)
                qla2x00_clean_dsd_pool(ha, cmd->ctx);

        dma_pool_free(ha->dl_dma_pool, cmd->ctx, cmd->ctx->crc_ctx_dma);
}

static int qlt_check_reserve_free_req(struct qla_qpair *qpair,
        uint32_t req_cnt)
{
        uint32_t cnt;
        struct req_que *req = qpair->req;

        if (req->cnt < (req_cnt + 2)) {
                cnt = (uint16_t)(qpair->use_shadow_reg ? *req->out_ptr :
                    RD_REG_DWORD_RELAXED(req->req_q_out));

                if  (req->ring_index < cnt)
                        req->cnt = cnt - req->ring_index;
                else
                        req->cnt = req->length - (req->ring_index - cnt);

                if (unlikely(req->cnt < (req_cnt + 2)))
                        return -EAGAIN;
        }

        req->cnt -= req_cnt;

        return 0;
}

/*
 * ha->hardware_lock supposed to be held on entry. Might drop it, then reaquire
 */
static inline void *qlt_get_req_pkt(struct req_que *req)
{
        /* Adjust ring index. */
        req->ring_index++;
        if (req->ring_index == req->length) {
                req->ring_index = 0;
                req->ring_ptr = req->ring;
        } else {
                req->ring_ptr++;
        }
        return (cont_entry_t *)req->ring_ptr;
}

/* ha->hardware_lock supposed to be held on entry */
static inline uint32_t qlt_make_handle(struct qla_qpair *qpair)
{
        uint32_t h;
        int index;
        uint8_t found = 0;
        struct req_que *req = qpair->req;

        h = req->current_outstanding_cmd;

        for (index = 1; index < req->num_outstanding_cmds; index++) {
                h++;
                if (h == req->num_outstanding_cmds)
                        h = 1;

                if (h == QLA_TGT_SKIP_HANDLE)
                        continue;

                if (!req->outstanding_cmds[h]) {
                        found = 1;
                        break;
                }
        }

        if (found) {
                req->current_outstanding_cmd = h;
        } else {
                ql_dbg(ql_dbg_io, qpair->vha, 0x305b,
                    "qla_target(%d): Ran out of empty cmd slots\n",
                    qpair->vha->vp_idx);
                h = QLA_TGT_NULL_HANDLE;
        }

        return h;
}

/* ha->hardware_lock supposed to be held on entry */
static int qlt_24xx_build_ctio_pkt(struct qla_qpair *qpair,
        struct qla_tgt_prm *prm)
{
        uint32_t h;
        struct ctio7_to_24xx *pkt;
        struct atio_from_isp *atio = &prm->cmd->atio;
        uint16_t temp;

        pkt = (struct ctio7_to_24xx *)qpair->req->ring_ptr;
        prm->pkt = pkt;
        memset(pkt, 0, sizeof(*pkt));

        pkt->entry_type = CTIO_TYPE7;
        pkt->entry_count = (uint8_t)prm->req_cnt;
        pkt->vp_index = prm->cmd->vp_idx;

        h = qlt_make_handle(qpair);
        if (unlikely(h == QLA_TGT_NULL_HANDLE)) {
                /*
                 * CTIO type 7 from the firmware doesn't provide a way to
                 * know the initiator's LOOP ID, hence we can't find
                 * the session and, so, the command.
                 */
                return -EAGAIN;
        } else
                qpair->req->outstanding_cmds[h] = (srb_t *)prm->cmd;

        pkt->handle = MAKE_HANDLE(qpair->req->id, h);
        pkt->handle |= CTIO_COMPLETION_HANDLE_MARK;
        pkt->nport_handle = cpu_to_le16(prm->cmd->loop_id);
        pkt->timeout = cpu_to_le16(QLA_TGT_TIMEOUT);
        pkt->initiator_id[0] = atio->u.isp24.fcp_hdr.s_id[2];
        pkt->initiator_id[1] = atio->u.isp24.fcp_hdr.s_id[1];
        pkt->initiator_id[2] = atio->u.isp24.fcp_hdr.s_id[0];
        pkt->exchange_addr = atio->u.isp24.exchange_addr;
        temp = atio->u.isp24.attr << 9;
        pkt->u.status0.flags |= cpu_to_le16(temp);
        temp = be16_to_cpu(atio->u.isp24.fcp_hdr.ox_id);
        pkt->u.status0.ox_id = cpu_to_le16(temp);
        pkt->u.status0.relative_offset = cpu_to_le32(prm->cmd->offset);

        return 0;
}

/*
 * ha->hardware_lock supposed to be held on entry. We have already made sure
 * that there is sufficient amount of request entries to not drop it.
 */
static void qlt_load_cont_data_segments(struct qla_tgt_prm *prm)
{
        int cnt;
        struct dsd64 *cur_dsd;

        /* Build continuation packets */
        while (prm->seg_cnt > 0) {
                cont_a64_entry_t *cont_pkt64 =
                        (cont_a64_entry_t *)qlt_get_req_pkt(
                           prm->cmd->qpair->req);

                /*
                 * Make sure that from cont_pkt64 none of
                 * 64-bit specific fields used for 32-bit
                 * addressing. Cast to (cont_entry_t *) for
                 * that.
                 */

                memset(cont_pkt64, 0, sizeof(*cont_pkt64));

                cont_pkt64->entry_count = 1;
                cont_pkt64->sys_define = 0;

                cont_pkt64->entry_type = CONTINUE_A64_TYPE;
                cur_dsd = cont_pkt64->dsd;

                /* Load continuation entry data segments */
                for (cnt = 0;
                    cnt < QLA_TGT_DATASEGS_PER_CONT_24XX && prm->seg_cnt;
                    cnt++, prm->seg_cnt--) {
                        append_dsd64(&cur_dsd, prm->sg);
                        prm->sg = sg_next(prm->sg);
                }
        }
}

/*
 * ha->hardware_lock supposed to be held on entry. We have already made sure
 * that there is sufficient amount of request entries to not drop it.
 */
static void qlt_load_data_segments(struct qla_tgt_prm *prm)
{
        int cnt;
        struct dsd64 *cur_dsd;
        struct ctio7_to_24xx *pkt24 = (struct ctio7_to_24xx *)prm->pkt;

        pkt24->u.status0.transfer_length = cpu_to_le32(prm->cmd->bufflen);

        /* Setup packet address segment pointer */
        cur_dsd = &pkt24->u.status0.dsd;

        /* Set total data segment count */
        if (prm->seg_cnt)
                pkt24->dseg_count = cpu_to_le16(prm->seg_cnt);

        if (prm->seg_cnt == 0) {
                /* No data transfer */
                cur_dsd->address = 0;
                cur_dsd->length = 0;
                return;
        }

        /* If scatter gather */

        /* Load command entry data segments */
        for (cnt = 0;
            (cnt < QLA_TGT_DATASEGS_PER_CMD_24XX) && prm->seg_cnt;
            cnt++, prm->seg_cnt--) {
                append_dsd64(&cur_dsd, prm->sg);
                prm->sg = sg_next(prm->sg);
        }

        qlt_load_cont_data_segments(prm);
}

static inline int qlt_has_data(struct qla_tgt_cmd *cmd)
{
        return cmd->bufflen > 0;
}

static void qlt_print_dif_err(struct qla_tgt_prm *prm)
{
        struct qla_tgt_cmd *cmd;
        struct scsi_qla_host *vha;

        /* asc 0x10=dif error */
        if (prm->sense_buffer && (prm->sense_buffer[12] == 0x10)) {
                cmd = prm->cmd;
                vha = cmd->vha;
                /* ASCQ */
                switch (prm->sense_buffer[13]) {
                case 1:
                        ql_dbg(ql_dbg_tgt_dif, vha, 0xe00b,
                            "BE detected Guard TAG ERR: lba[0x%llx|%lld] len[0x%x] "
                            "se_cmd=%p tag[%x]",
                            cmd->lba, cmd->lba, cmd->num_blks, &cmd->se_cmd,
                            cmd->atio.u.isp24.exchange_addr);
                        break;
                case 2:
                        ql_dbg(ql_dbg_tgt_dif, vha, 0xe00c,
                            "BE detected APP TAG ERR: lba[0x%llx|%lld] len[0x%x] "
                            "se_cmd=%p tag[%x]",
                            cmd->lba, cmd->lba, cmd->num_blks, &cmd->se_cmd,
                            cmd->atio.u.isp24.exchange_addr);
                        break;
                case 3:
                        ql_dbg(ql_dbg_tgt_dif, vha, 0xe00f,
                            "BE detected REF TAG ERR: lba[0x%llx|%lld] len[0x%x] "
                            "se_cmd=%p tag[%x]",
                            cmd->lba, cmd->lba, cmd->num_blks, &cmd->se_cmd,
                            cmd->atio.u.isp24.exchange_addr);
                        break;
                default:
                        ql_dbg(ql_dbg_tgt_dif, vha, 0xe010,
                            "BE detected Dif ERR: lba[%llx|%lld] len[%x] "
                            "se_cmd=%p tag[%x]",
                            cmd->lba, cmd->lba, cmd->num_blks, &cmd->se_cmd,
                            cmd->atio.u.isp24.exchange_addr);
                        break;
                }
                ql_dump_buffer(ql_dbg_tgt_dif, vha, 0xe011, cmd->cdb, 16);
        }
}

/*
 * Called without ha->hardware_lock held
 */
static int qlt_pre_xmit_response(struct qla_tgt_cmd *cmd,
        struct qla_tgt_prm *prm, int xmit_type, uint8_t scsi_status,
        uint32_t *full_req_cnt)
{
        struct se_cmd *se_cmd = &cmd->se_cmd;
        struct qla_qpair *qpair = cmd->qpair;

        prm->cmd = cmd;
        prm->tgt = cmd->tgt;
        prm->pkt = NULL;
        prm->rq_result = scsi_status;
        prm->sense_buffer = &cmd->sense_buffer[0];
        prm->sense_buffer_len = TRANSPORT_SENSE_BUFFER;
        prm->sg = NULL;
        prm->seg_cnt = -1;
        prm->req_cnt = 1;
        prm->residual = 0;
        prm->add_status_pkt = 0;
        prm->prot_sg = NULL;
        prm->prot_seg_cnt = 0;
        prm->tot_dsds = 0;

        if ((xmit_type & QLA_TGT_XMIT_DATA) && qlt_has_data(cmd)) {
                if  (qlt_pci_map_calc_cnt(prm) != 0)
                        return -EAGAIN;
        }

        *full_req_cnt = prm->req_cnt;

        if (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
                prm->residual = se_cmd->residual_count;
                ql_dbg_qp(ql_dbg_io + ql_dbg_verbose, qpair, 0x305c,
                    "Residual underflow: %d (tag %lld, op %x, bufflen %d, rq_result %x)\n",
                       prm->residual, se_cmd->tag,
                       se_cmd->t_task_cdb ? se_cmd->t_task_cdb[0] : 0,
                       cmd->bufflen, prm->rq_result);
                prm->rq_result |= SS_RESIDUAL_UNDER;
        } else if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
                prm->residual = se_cmd->residual_count;
                ql_dbg_qp(ql_dbg_io, qpair, 0x305d,
                    "Residual overflow: %d (tag %lld, op %x, bufflen %d, rq_result %x)\n",
                       prm->residual, se_cmd->tag, se_cmd->t_task_cdb ?
                       se_cmd->t_task_cdb[0] : 0, cmd->bufflen, prm->rq_result);
                prm->rq_result |= SS_RESIDUAL_OVER;
        }

        if (xmit_type & QLA_TGT_XMIT_STATUS) {
                /*
                 * If QLA_TGT_XMIT_DATA is not set, add_status_pkt will be
                 * ignored in *xmit_response() below
                 */
                if (qlt_has_data(cmd)) {
                        if (QLA_TGT_SENSE_VALID(prm->sense_buffer) ||
                            (IS_FWI2_CAPABLE(cmd->vha->hw) &&
                            (prm->rq_result != 0))) {
                                prm->add_status_pkt = 1;
                                (*full_req_cnt)++;
                        }
                }
        }

        return 0;
}

static inline int qlt_need_explicit_conf(struct qla_tgt_cmd *cmd,
    int sending_sense)
{
        if (cmd->qpair->enable_class_2)
                return 0;

        if (sending_sense)
                return cmd->conf_compl_supported;
        else
                return cmd->qpair->enable_explicit_conf &&
                    cmd->conf_compl_supported;
}

static void qlt_24xx_init_ctio_to_isp(struct ctio7_to_24xx *ctio,
        struct qla_tgt_prm *prm)
{
        prm->sense_buffer_len = min_t(uint32_t, prm->sense_buffer_len,
            (uint32_t)sizeof(ctio->u.status1.sense_data));
        ctio->u.status0.flags |= cpu_to_le16(CTIO7_FLAGS_SEND_STATUS);
        if (qlt_need_explicit_conf(prm->cmd, 0)) {
                ctio->u.status0.flags |= cpu_to_le16(
                    CTIO7_FLAGS_EXPLICIT_CONFORM |
                    CTIO7_FLAGS_CONFORM_REQ);
        }
        ctio->u.status0.residual = cpu_to_le32(prm->residual);
        ctio->u.status0.scsi_status = cpu_to_le16(prm->rq_result);
        if (QLA_TGT_SENSE_VALID(prm->sense_buffer)) {
                int i;

                if (qlt_need_explicit_conf(prm->cmd, 1)) {
                        if ((prm->rq_result & SS_SCSI_STATUS_BYTE) != 0) {
                                ql_dbg_qp(ql_dbg_tgt, prm->cmd->qpair, 0xe017,
                                    "Skipping EXPLICIT_CONFORM and "
                                    "CTIO7_FLAGS_CONFORM_REQ for FCP READ w/ "
                                    "non GOOD status\n");
                                goto skip_explict_conf;
                        }
                        ctio->u.status1.flags |= cpu_to_le16(
                            CTIO7_FLAGS_EXPLICIT_CONFORM |
                            CTIO7_FLAGS_CONFORM_REQ);
                }
skip_explict_conf:
                ctio->u.status1.flags &=
                    ~cpu_to_le16(CTIO7_FLAGS_STATUS_MODE_0);
                ctio->u.status1.flags |=
                    cpu_to_le16(CTIO7_FLAGS_STATUS_MODE_1);
                ctio->u.status1.scsi_status |=
                    cpu_to_le16(SS_SENSE_LEN_VALID);
                ctio->u.status1.sense_length =
                    cpu_to_le16(prm->sense_buffer_len);
                for (i = 0; i < prm->sense_buffer_len/4; i++)
                        ((uint32_t *)ctio->u.status1.sense_data)[i] =
                                cpu_to_be32(((uint32_t *)prm->sense_buffer)[i]);

                qlt_print_dif_err(prm);

        } else {
                ctio->u.status1.flags &=
                    ~cpu_to_le16(CTIO7_FLAGS_STATUS_MODE_0);
                ctio->u.status1.flags |=
                    cpu_to_le16(CTIO7_FLAGS_STATUS_MODE_1);
                ctio->u.status1.sense_length = 0;
                memset(ctio->u.status1.sense_data, 0,
                    sizeof(ctio->u.status1.sense_data));
        }

        /* Sense with len > 24, is it possible ??? */
}

static inline int
qlt_hba_err_chk_enabled(struct se_cmd *se_cmd)
{
        switch (se_cmd->prot_op) {
        case TARGET_PROT_DOUT_INSERT:
        case TARGET_PROT_DIN_STRIP:
                if (ql2xenablehba_err_chk >= 1)
                        return 1;
                break;
        case TARGET_PROT_DOUT_PASS:
        case TARGET_PROT_DIN_PASS:
                if (ql2xenablehba_err_chk >= 2)
                        return 1;
                break;
        case TARGET_PROT_DIN_INSERT:
        case TARGET_PROT_DOUT_STRIP:
                return 1;
        default:
                break;
        }
        return 0;
}

static inline int
qla_tgt_ref_mask_check(struct se_cmd *se_cmd)
{
        switch (se_cmd->prot_op) {
        case TARGET_PROT_DIN_INSERT:
        case TARGET_PROT_DOUT_INSERT:
        case TARGET_PROT_DIN_STRIP:
        case TARGET_PROT_DOUT_STRIP:
        case TARGET_PROT_DIN_PASS:
        case TARGET_PROT_DOUT_PASS:
            return 1;
        default:
            return 0;
        }
        return 0;
}

/*
 * qla_tgt_set_dif_tags - Extract Ref and App tags from SCSI command
 */
static void
qla_tgt_set_dif_tags(struct qla_tgt_cmd *cmd, struct crc_context *ctx,
    uint16_t *pfw_prot_opts)
{
        struct se_cmd *se_cmd = &cmd->se_cmd;
        uint32_t lba = 0xffffffff & se_cmd->t_task_lba;
        scsi_qla_host_t *vha = cmd->tgt->vha;
        struct qla_hw_data *ha = vha->hw;
        uint32_t t32 = 0;

        /*
         * wait till Mode Sense/Select cmd, modepage Ah, subpage 2
         * have been immplemented by TCM, before AppTag is avail.
         * Look for modesense_handlers[]
         */
        ctx->app_tag = 0;
        ctx->app_tag_mask[0] = 0x0;
        ctx->app_tag_mask[1] = 0x0;

        if (IS_PI_UNINIT_CAPABLE(ha)) {
                if ((se_cmd->prot_type == TARGET_DIF_TYPE1_PROT) ||
                    (se_cmd->prot_type == TARGET_DIF_TYPE2_PROT))
                        *pfw_prot_opts |= PO_DIS_VALD_APP_ESC;
                else if (se_cmd->prot_type == TARGET_DIF_TYPE3_PROT)
                        *pfw_prot_opts |= PO_DIS_VALD_APP_REF_ESC;
        }

        t32 = ha->tgt.tgt_ops->get_dif_tags(cmd, pfw_prot_opts);

        switch (se_cmd->prot_type) {
        case TARGET_DIF_TYPE0_PROT:
                /*
                 * No check for ql2xenablehba_err_chk, as it
                 * would be an I/O error if hba tag generation
                 * is not done.
                 */
                ctx->ref_tag = cpu_to_le32(lba);
                /* enable ALL bytes of the ref tag */
                ctx->ref_tag_mask[0] = 0xff;
                ctx->ref_tag_mask[1] = 0xff;
                ctx->ref_tag_mask[2] = 0xff;
                ctx->ref_tag_mask[3] = 0xff;
                break;
        case TARGET_DIF_TYPE1_PROT:
            /*
             * For TYPE 1 protection: 16 bit GUARD tag, 32 bit
             * REF tag, and 16 bit app tag.
             */
            ctx->ref_tag = cpu_to_le32(lba);
            if (!qla_tgt_ref_mask_check(se_cmd) ||
                !(ha->tgt.tgt_ops->chk_dif_tags(t32))) {
                    *pfw_prot_opts |= PO_DIS_REF_TAG_VALD;
                    break;
            }
            /* enable ALL bytes of the ref tag */
            ctx->ref_tag_mask[0] = 0xff;
            ctx->ref_tag_mask[1] = 0xff;
            ctx->ref_tag_mask[2] = 0xff;
            ctx->ref_tag_mask[3] = 0xff;
            break;
        case TARGET_DIF_TYPE2_PROT:
            /*
             * For TYPE 2 protection: 16 bit GUARD + 32 bit REF
             * tag has to match LBA in CDB + N
             */
            ctx->ref_tag = cpu_to_le32(lba);
            if (!qla_tgt_ref_mask_check(se_cmd) ||
                !(ha->tgt.tgt_ops->chk_dif_tags(t32))) {
                    *pfw_prot_opts |= PO_DIS_REF_TAG_VALD;
                    break;
            }
            /* enable ALL bytes of the ref tag */
            ctx->ref_tag_mask[0] = 0xff;