/*
 * zfcp device driver
 *
 * Fibre Channel related functions for the zfcp device driver.
 *
 * Copyright IBM Corporation 2008, 2009
 */

#define KMSG_COMPONENT "zfcp"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include "zfcp_ext.h"

enum rscn_address_format {
        RSCN_PORT_ADDRESS       = 0x0,
        RSCN_AREA_ADDRESS       = 0x1,
        RSCN_DOMAIN_ADDRESS     = 0x2,
        RSCN_FABRIC_ADDRESS     = 0x3,
};

static u32 rscn_range_mask[] = {
        [RSCN_PORT_ADDRESS]             = 0xFFFFFF,
        [RSCN_AREA_ADDRESS]             = 0xFFFF00,
        [RSCN_DOMAIN_ADDRESS]           = 0xFF0000,
        [RSCN_FABRIC_ADDRESS]           = 0x000000,
};

struct ct_iu_gpn_ft_req {
        struct ct_hdr header;
        u8 flags;
        u8 domain_id_scope;
        u8 area_id_scope;
        u8 fc4_type;
} __attribute__ ((packed));

struct gpn_ft_resp_acc {
        u8 control;
        u8 port_id[3];
        u8 reserved[4];
        u64 wwpn;
} __attribute__ ((packed));

#define ZFCP_CT_SIZE_ONE_PAGE   (PAGE_SIZE - sizeof(struct ct_hdr))
#define ZFCP_GPN_FT_ENTRIES     (ZFCP_CT_SIZE_ONE_PAGE \
                                        / sizeof(struct gpn_ft_resp_acc))
#define ZFCP_GPN_FT_BUFFERS 4
#define ZFCP_GPN_FT_MAX_SIZE (ZFCP_GPN_FT_BUFFERS * PAGE_SIZE \
                                - sizeof(struct ct_hdr))
#define ZFCP_GPN_FT_MAX_ENTRIES ZFCP_GPN_FT_BUFFERS * (ZFCP_GPN_FT_ENTRIES + 1)

struct ct_iu_gpn_ft_resp {
        struct ct_hdr header;
        struct gpn_ft_resp_acc accept[ZFCP_GPN_FT_ENTRIES];
} __attribute__ ((packed));

struct zfcp_gpn_ft {
        struct zfcp_send_ct ct;
        struct scatterlist sg_req;
        struct scatterlist sg_resp[ZFCP_GPN_FT_BUFFERS];
};

struct zfcp_fc_ns_handler_data {
        struct completion done;
        void (*handler)(unsigned long);
        unsigned long handler_data;
};

static int zfcp_wka_port_get(struct zfcp_wka_port *wka_port)
{
        if (mutex_lock_interruptible(&wka_port->mutex))
                return -ERESTARTSYS;

        if (wka_port->status == ZFCP_WKA_PORT_OFFLINE ||
            wka_port->status == ZFCP_WKA_PORT_CLOSING) {
                wka_port->status = ZFCP_WKA_PORT_OPENING;
                if (zfcp_fsf_open_wka_port(wka_port))
                        wka_port->status = ZFCP_WKA_PORT_OFFLINE;
        }

        mutex_unlock(&wka_port->mutex);

        wait_event_timeout(
                wka_port->completion_wq,
                wka_port->status == ZFCP_WKA_PORT_ONLINE ||
                wka_port->status == ZFCP_WKA_PORT_OFFLINE,
                HZ >> 1);

        if (wka_port->status == ZFCP_WKA_PORT_ONLINE) {
                atomic_inc(&wka_port->refcount);
                return 0;
        }
        return -EIO;
}

static void zfcp_wka_port_offline(struct work_struct *work)
{
        struct delayed_work *dw = to_delayed_work(work);
        struct zfcp_wka_port *wka_port =
                        container_of(dw, struct zfcp_wka_port, work);

        mutex_lock(&wka_port->mutex);
        if ((atomic_read(&wka_port->refcount) != 0) ||
            (wka_port->status != ZFCP_WKA_PORT_ONLINE))
                goto out;

        wka_port->status = ZFCP_WKA_PORT_CLOSING;
        if (zfcp_fsf_close_wka_port(wka_port)) {
                wka_port->status = ZFCP_WKA_PORT_OFFLINE;
                wake_up(&wka_port->completion_wq);
        }
out:
        mutex_unlock(&wka_port->mutex);
}

static void zfcp_wka_port_put(struct zfcp_wka_port *wka_port)
{
        if (atomic_dec_return(&wka_port->refcount) != 0)
                return;
        /* wait 10 miliseconds, other reqs might pop in */
        schedule_delayed_work(&wka_port->work, HZ / 100);
}

void zfcp_fc_nameserver_init(struct zfcp_adapter *adapter)
{
        struct zfcp_wka_port *wka_port = &adapter->nsp;

        init_waitqueue_head(&wka_port->completion_wq);

        wka_port->adapter = adapter;
        wka_port->d_id = ZFCP_DID_DIRECTORY_SERVICE;

        wka_port->status = ZFCP_WKA_PORT_OFFLINE;
        atomic_set(&wka_port->refcount, 0);
        mutex_init(&wka_port->mutex);
        INIT_DELAYED_WORK(&wka_port->work, zfcp_wka_port_offline);
}

void zfcp_fc_wka_port_force_offline(struct zfcp_wka_port *wka)
{
        cancel_delayed_work_sync(&wka->work);
        mutex_lock(&wka->mutex);
        wka->status = ZFCP_WKA_PORT_OFFLINE;
        mutex_unlock(&wka->mutex);
}

static void _zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req, u32 range,
                                   struct fcp_rscn_element *elem)
{
        unsigned long flags;
        struct zfcp_port *port;

        read_lock_irqsave(&zfcp_data.config_lock, flags);
        list_for_each_entry(port, &fsf_req->adapter->port_list_head, list)
                if ((port->d_id & range) == (elem->nport_did & range))
                        zfcp_test_link(port);

        read_unlock_irqrestore(&zfcp_data.config_lock, flags);
}

static void zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req)
{
        struct fsf_status_read_buffer *status_buffer = (void *)fsf_req->data;
        struct fcp_rscn_head *fcp_rscn_head;
        struct fcp_rscn_element *fcp_rscn_element;
        u16 i;
        u16 no_entries;
        u32 range_mask;

        fcp_rscn_head = (struct fcp_rscn_head *) status_buffer->payload.data;
        fcp_rscn_element = (struct fcp_rscn_element *) fcp_rscn_head;

        /* see FC-FS */
        no_entries = fcp_rscn_head->payload_len /
                        sizeof(struct fcp_rscn_element);

        for (i = 1; i < no_entries; i++) {
                /* skip head and start with 1st element */
                fcp_rscn_element++;
                range_mask = rscn_range_mask[fcp_rscn_element->addr_format];
                _zfcp_fc_incoming_rscn(fsf_req, range_mask, fcp_rscn_element);
        }
        schedule_work(&fsf_req->adapter->scan_work);
}

static void zfcp_fc_incoming_wwpn(struct zfcp_fsf_req *req, u64 wwpn)
{
        struct zfcp_adapter *adapter = req->adapter;
        struct zfcp_port *port;
        unsigned long flags;

        read_lock_irqsave(&zfcp_data.config_lock, flags);
        list_for_each_entry(port, &adapter->port_list_head, list)
                if (port->wwpn == wwpn)
                        break;
        read_unlock_irqrestore(&zfcp_data.config_lock, flags);

        if (port && (port->wwpn == wwpn))
                zfcp_erp_port_forced_reopen(port, 0, "fciwwp1", req);
}

static void zfcp_fc_incoming_plogi(struct zfcp_fsf_req *req)
{
        struct fsf_status_read_buffer *status_buffer =
                (struct fsf_status_read_buffer *)req->data;
        struct fsf_plogi *els_plogi =
                (struct fsf_plogi *) status_buffer->payload.data;

        zfcp_fc_incoming_wwpn(req, els_plogi->serv_param.wwpn);
}

static void zfcp_fc_incoming_logo(struct zfcp_fsf_req *req)
{
        struct fsf_status_read_buffer *status_buffer =
                (struct fsf_status_read_buffer *)req->data;
        struct fcp_logo *els_logo =
                (struct fcp_logo *) status_buffer->payload.data;

        zfcp_fc_incoming_wwpn(req, els_logo->nport_wwpn);
}

/**
 * zfcp_fc_incoming_els - handle incoming ELS
 * @fsf_req - request which contains incoming ELS
 */
void zfcp_fc_incoming_els(struct zfcp_fsf_req *fsf_req)
{
        struct fsf_status_read_buffer *status_buffer =
                (struct fsf_status_read_buffer *) fsf_req->data;
        unsigned int els_type = status_buffer->payload.data[0];

        zfcp_san_dbf_event_incoming_els(fsf_req);
        if (els_type == LS_PLOGI)
                zfcp_fc_incoming_plogi(fsf_req);
        else if (els_type == LS_LOGO)
                zfcp_fc_incoming_logo(fsf_req);
        else if (els_type == LS_RSCN)
                zfcp_fc_incoming_rscn(fsf_req);
}

static void zfcp_fc_ns_handler(unsigned long data)
{
        struct zfcp_fc_ns_handler_data *compl_rec =
                        (struct zfcp_fc_ns_handler_data *) data;

        if (compl_rec->handler)
                compl_rec->handler(compl_rec->handler_data);

        complete(&compl_rec->done);
}

static void zfcp_fc_ns_gid_pn_eval(unsigned long data)
{
        struct zfcp_gid_pn_data *gid_pn = (struct zfcp_gid_pn_data *) data;
        struct zfcp_send_ct *ct = &gid_pn->ct;
        struct ct_iu_gid_pn_req *ct_iu_req = sg_virt(ct->req);
        struct ct_iu_gid_pn_resp *ct_iu_resp = sg_virt(ct->resp);
        struct zfcp_port *port = gid_pn->port;

        if (ct->status)
                return;
        if (ct_iu_resp->header.cmd_rsp_code != ZFCP_CT_ACCEPT)
                return;

        /* paranoia */
        if (ct_iu_req->wwpn != port->wwpn)
                return;
        /* looks like a valid d_id */
        port->d_id = ct_iu_resp->d_id & ZFCP_DID_MASK;
}

int static zfcp_fc_ns_gid_pn_request(struct zfcp_erp_action *erp_action,
                                     struct zfcp_gid_pn_data *gid_pn)
{
        struct zfcp_adapter *adapter = erp_action->adapter;
        struct zfcp_fc_ns_handler_data compl_rec;
        int ret;

        /* setup parameters for send generic command */
        gid_pn->port = erp_action->port;
        gid_pn->ct.wka_port = &adapter->nsp;
        gid_pn->ct.handler = zfcp_fc_ns_handler;
        gid_pn->ct.handler_data = (unsigned long) &compl_rec;
        gid_pn->ct.timeout = ZFCP_NS_GID_PN_TIMEOUT;
        gid_pn->ct.req = &gid_pn->req;
        gid_pn->ct.resp = &gid_pn->resp;
        sg_init_one(&gid_pn->req, &gid_pn->ct_iu_req,
                    sizeof(struct ct_iu_gid_pn_req));
        sg_init_one(&gid_pn->resp, &gid_pn->ct_iu_resp,
                    sizeof(struct ct_iu_gid_pn_resp));

        /* setup nameserver request */
        gid_pn->ct_iu_req.header.revision = ZFCP_CT_REVISION;
        gid_pn->ct_iu_req.header.gs_type = ZFCP_CT_DIRECTORY_SERVICE;
        gid_pn->ct_iu_req.header.gs_subtype = ZFCP_CT_NAME_SERVER;
        gid_pn->ct_iu_req.header.options = ZFCP_CT_SYNCHRONOUS;
        gid_pn->ct_iu_req.header.cmd_rsp_code = ZFCP_CT_GID_PN;
        gid_pn->ct_iu_req.header.max_res_size = ZFCP_CT_SIZE_ONE_PAGE / 4;
        gid_pn->ct_iu_req.wwpn = erp_action->port->wwpn;

        init_completion(&compl_rec.done);
        compl_rec.handler = zfcp_fc_ns_gid_pn_eval;
        compl_rec.handler_data = (unsigned long) gid_pn;
        ret = zfcp_fsf_send_ct(&gid_pn->ct, adapter->pool.fsf_req_erp,
                               erp_action);
        if (!ret)
                wait_for_completion(&compl_rec.done);
        return ret;
}

/**
 * zfcp_fc_ns_gid_pn_request - initiate GID_PN nameserver request
 * @erp_action: pointer to zfcp_erp_action where GID_PN request is needed
 * return: -ENOMEM on error, 0 otherwise
 */
int zfcp_fc_ns_gid_pn(struct zfcp_erp_action *erp_action)
{
        int ret;
        struct zfcp_gid_pn_data *gid_pn;
        struct zfcp_adapter *adapter = erp_action->adapter;

        gid_pn = mempool_alloc(adapter->pool.data_gid_pn, GFP_ATOMIC);
        if (!gid_pn)
                return -ENOMEM;

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

        ret = zfcp_wka_port_get(&adapter->nsp);
        if (ret)
                goto out;

        ret = zfcp_fc_ns_gid_pn_request(erp_action, gid_pn);

        zfcp_wka_port_put(&adapter->nsp);
out:
        mempool_free(gid_pn, adapter->pool.data_gid_pn);
        return ret;
}

/**
 * zfcp_fc_plogi_evaluate - evaluate PLOGI playload
 * @port: zfcp_port structure
 * @plogi: plogi payload
 *
 * Evaluate PLOGI playload and copy important fields into zfcp_port structure
 */
void zfcp_fc_plogi_evaluate(struct zfcp_port *port, struct fsf_plogi *plogi)
{
        port->maxframe_size = plogi->serv_param.common_serv_param[7] |
                ((plogi->serv_param.common_serv_param[6] & 0x0F) << 8);
        if (plogi->serv_param.class1_serv_param[0] & 0x80)
                port->supported_classes |= FC_COS_CLASS1;
        if (plogi->serv_param.class2_serv_param[0] & 0x80)
                port->supported_classes |= FC_COS_CLASS2;
        if (plogi->serv_param.class3_serv_param[0] & 0x80)
                port->supported_classes |= FC_COS_CLASS3;
        if (plogi->serv_param.class4_serv_param[0] & 0x80)
                port->supported_classes |= FC_COS_CLASS4;
}

struct zfcp_els_adisc {
        struct zfcp_send_els els;
        struct scatterlist req;
        struct scatterlist resp;
        struct zfcp_ls_adisc ls_adisc;
        struct zfcp_ls_adisc ls_adisc_acc;
};

static void zfcp_fc_adisc_handler(unsigned long data)
{
        struct zfcp_els_adisc *adisc = (struct zfcp_els_adisc *) data;
        struct zfcp_port *port = adisc->els.port;
        struct zfcp_ls_adisc *ls_adisc = &adisc->ls_adisc_acc;

        if (adisc->els.status) {
                /* request rejected or timed out */
                zfcp_erp_port_forced_reopen(port, ZFCP_STATUS_COMMON_ERP_FAILED,
                                            "fcadh_1", NULL);
                goto out;
        }

        if (!port->wwnn)
                port->wwnn = ls_adisc->wwnn;

        if ((port->wwpn != ls_adisc->wwpn) ||
            !(atomic_read(&port->status) & ZFCP_STATUS_COMMON_OPEN)) {
                zfcp_erp_port_reopen(port, ZFCP_STATUS_COMMON_ERP_FAILED,
                                     "fcadh_2", NULL);
                goto out;
        }

        /* port is good, unblock rport without going through erp */
        zfcp_scsi_schedule_rport_register(port);
 out:
        zfcp_port_put(port);
        kfree(adisc);
}

static int zfcp_fc_adisc(struct zfcp_port *port)
{
        struct zfcp_els_adisc *adisc;
        struct zfcp_adapter *adapter = port->adapter;

        adisc = kzalloc(sizeof(struct zfcp_els_adisc), GFP_ATOMIC);
        if (!adisc)
                return -ENOMEM;

        adisc->els.req = &adisc->req;
        adisc->els.resp = &adisc->resp;
        sg_init_one(adisc->els.req, &adisc->ls_adisc,
                    sizeof(struct zfcp_ls_adisc));
        sg_init_one(adisc->els.resp, &adisc->ls_adisc_acc,
                    sizeof(struct zfcp_ls_adisc));

        adisc->els.adapter = adapter;
        adisc->els.port = port;
        adisc->els.d_id = port->d_id;
        adisc->els.handler = zfcp_fc_adisc_handler;
        adisc->els.handler_data = (unsigned long) adisc;
        adisc->els.ls_code = adisc->ls_adisc.code = ZFCP_LS_ADISC;

        /* acc. to FC-FS, hard_nport_id in ADISC should not be set for ports
           without FC-AL-2 capability, so we don't set it */
        adisc->ls_adisc.wwpn = fc_host_port_name(adapter->scsi_host);
        adisc->ls_adisc.wwnn = fc_host_node_name(adapter->scsi_host);
        adisc->ls_adisc.nport_id = fc_host_port_id(adapter->scsi_host);

        return zfcp_fsf_send_els(&adisc->els);
}

void zfcp_fc_link_test_work(struct work_struct *work)
{
        struct zfcp_port *port =
                container_of(work, struct zfcp_port, test_link_work);
        int retval;

        zfcp_port_get(port);
        port->rport_task = RPORT_DEL;
        zfcp_scsi_rport_work(&port->rport_work);

        retval = zfcp_fc_adisc(port);
        if (retval == 0)
                return;

        /* send of ADISC was not possible */
        zfcp_erp_port_forced_reopen(port, 0, "fcltwk1", NULL);

        zfcp_port_put(port);
}

/**
 * zfcp_test_link - lightweight link test procedure
 * @port: port to be tested
 *
 * Test status of a link to a remote port using the ELS command ADISC.
 * If there is a problem with the remote port, error recovery steps
 * will be triggered.
 */
void zfcp_test_link(struct zfcp_port *port)
{
        zfcp_port_get(port);
        if (!queue_work(zfcp_data.work_queue, &port->test_link_work))
                zfcp_port_put(port);
}

static void zfcp_free_sg_env(struct zfcp_gpn_ft *gpn_ft, int buf_num)
{
        struct scatterlist *sg = &gpn_ft->sg_req;

        kfree(sg_virt(sg)); /* free request buffer */
        zfcp_sg_free_table(gpn_ft->sg_resp, buf_num);

        kfree(gpn_ft);
}

static struct zfcp_gpn_ft *zfcp_alloc_sg_env(int buf_num)
{
        struct zfcp_gpn_ft *gpn_ft;
        struct ct_iu_gpn_ft_req *req;

        gpn_ft = kzalloc(sizeof(*gpn_ft), GFP_KERNEL);
        if (!gpn_ft)
                return NULL;

        req = kzalloc(sizeof(struct ct_iu_gpn_ft_req), GFP_KERNEL);
        if (!req) {
                kfree(gpn_ft);
                gpn_ft = NULL;
                goto out;
        }
        sg_init_one(&gpn_ft->sg_req, req, sizeof(*req));

        if (zfcp_sg_setup_table(gpn_ft->sg_resp, buf_num)) {
                zfcp_free_sg_env(gpn_ft, buf_num);
                gpn_ft = NULL;
        }
out:
        return gpn_ft;
}


static int zfcp_scan_issue_gpn_ft(struct zfcp_gpn_ft *gpn_ft,
                                  struct zfcp_adapter *adapter,
                                  int max_bytes)
{
        struct zfcp_send_ct *ct = &gpn_ft->ct;
        struct ct_iu_gpn_ft_req *req = sg_virt(&gpn_ft->sg_req);
        struct zfcp_fc_ns_handler_data compl_rec;
        int ret;

        /* prepare CT IU for GPN_FT */
        req->header.revision = ZFCP_CT_REVISION;
        req->header.gs_type = ZFCP_CT_DIRECTORY_SERVICE;
        req->header.gs_subtype = ZFCP_CT_NAME_SERVER;
        req->header.options = ZFCP_CT_SYNCHRONOUS;
        req->header.cmd_rsp_code = ZFCP_CT_GPN_FT;
        req->header.max_res_size = max_bytes / 4;
        req->flags = 0;
        req->domain_id_scope = 0;
        req->area_id_scope = 0;
        req->fc4_type = ZFCP_CT_SCSI_FCP;

        /* prepare zfcp_send_ct */
        ct->wka_port = &adapter->nsp;
        ct->handler = zfcp_fc_ns_handler;
        ct->handler_data = (unsigned long)&compl_rec;
        ct->timeout = 10;
        ct->req = &gpn_ft->sg_req;
        ct->resp = gpn_ft->sg_resp;

        init_completion(&compl_rec.done);
        compl_rec.handler = NULL;
        ret = zfcp_fsf_send_ct(ct, NULL, NULL);
        if (!ret)
                wait_for_completion(&compl_rec.done);
        return ret;
}

static void zfcp_validate_port(struct zfcp_port *port)
{
        struct zfcp_adapter *adapter = port->adapter;

        if (!(atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC))
                return;

        atomic_clear_mask(ZFCP_STATUS_COMMON_NOESC, &port->status);

        if ((port->supported_classes != 0) ||
            !list_empty(&port->unit_list_head)) {
                zfcp_port_put(port);
                return;
        }
        zfcp_erp_port_shutdown(port, 0, "fcpval1", NULL);
        zfcp_erp_wait(adapter);
        zfcp_port_put(port);
        zfcp_port_dequeue(port);
}

static int zfcp_scan_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft, int max_entries)
{
        struct zfcp_send_ct *ct = &gpn_ft->ct;
        struct scatterlist *sg = gpn_ft->sg_resp;
        struct ct_hdr *hdr = sg_virt(sg);
        struct gpn_ft_resp_acc *acc = sg_virt(sg);
        struct zfcp_adapter *adapter = ct->wka_port->adapter;
        struct zfcp_port *port, *tmp;
        u32 d_id;
        int ret = 0, x, last = 0;

        if (ct->status)
                return -EIO;

        if (hdr->cmd_rsp_code != ZFCP_CT_ACCEPT) {
                if (hdr->reason_code == ZFCP_CT_UNABLE_TO_PERFORM_CMD)
                        return -EAGAIN; /* might be a temporary condition */
                return -EIO;
        }

        if (hdr->max_res_size) {
                dev_warn(&adapter->ccw_device->dev,
                         "The name server reported %d words residual data\n",
                         hdr->max_res_size);
                return -E2BIG;
        }

        down(&zfcp_data.config_sema);

        /* first entry is the header */
        for (x = 1; x < max_entries && !last; x++) {
                if (x % (ZFCP_GPN_FT_ENTRIES + 1))
                        acc++;
                else
                        acc = sg_virt(++sg);

                last = acc->control & 0x80;
                d_id = acc->port_id[0] << 16 | acc->port_id[1] << 8 |
                       acc->port_id[2];

                /* don't attach ports with a well known address */
                if ((d_id & ZFCP_DID_WKA) == ZFCP_DID_WKA)
                        continue;
                /* skip the adapter's port and known remote ports */
                if (acc->wwpn == fc_host_port_name(adapter->scsi_host))
                        continue;
                port = zfcp_get_port_by_wwpn(adapter, acc->wwpn);
                if (port)
                        continue;

                port = zfcp_port_enqueue(adapter, acc->wwpn,
                                         ZFCP_STATUS_COMMON_NOESC, d_id);
                if (IS_ERR(port))
                        ret = PTR_ERR(port);
                else
                        zfcp_erp_port_reopen(port, 0, "fcegpf1", NULL);
        }

        zfcp_erp_wait(adapter);
        list_for_each_entry_safe(port, tmp, &adapter->port_list_head, list)
                zfcp_validate_port(port);
        up(&zfcp_data.config_sema);
        return ret;
}

/**
 * zfcp_scan_ports - scan remote ports and attach new ports
 * @adapter: pointer to struct zfcp_adapter
 */
int zfcp_scan_ports(struct zfcp_adapter *adapter)
{
        int ret, i;
        struct zfcp_gpn_ft *gpn_ft;
        int chain, max_entries, buf_num, max_bytes;

        chain = adapter->adapter_features & FSF_FEATURE_ELS_CT_CHAINED_SBALS;
        buf_num = chain ? ZFCP_GPN_FT_BUFFERS : 1;
        max_entries = chain ? ZFCP_GPN_FT_MAX_ENTRIES : ZFCP_GPN_FT_ENTRIES;
        max_bytes = chain ? ZFCP_GPN_FT_MAX_SIZE : ZFCP_CT_SIZE_ONE_PAGE;

        if (fc_host_port_type(adapter->scsi_host) != FC_PORTTYPE_NPORT &&
            fc_host_port_type(adapter->scsi_host) != FC_PORTTYPE_NPIV)
                return 0;

        ret = zfcp_wka_port_get(&adapter->nsp);
        if (ret)
                return ret;

        gpn_ft = zfcp_alloc_sg_env(buf_num);
        if (!gpn_ft) {
                ret = -ENOMEM;
                goto out;
        }

        for (i = 0; i < 3; i++) {
                ret = zfcp_scan_issue_gpn_ft(gpn_ft, adapter, max_bytes);
                if (!ret) {
                        ret = zfcp_scan_eval_gpn_ft(gpn_ft, max_entries);
                        if (ret == -EAGAIN)
                                ssleep(1);
                        else
                                break;
                }
        }
        zfcp_free_sg_env(gpn_ft, buf_num);
out:
        zfcp_wka_port_put(&adapter->nsp);
        return ret;
}


void _zfcp_scan_ports_later(struct work_struct *work)
{
        zfcp_scan_ports(container_of(work, struct zfcp_adapter, scan_work));
}