drivers/s390/scsi/zfcp_fc.c - kernel/msm-5.4 - Gitiles

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

 #include "zfcp_ext.h"

 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_GPN_FT_ENTRIES ((PAGE_SIZE - sizeof(struct ct_hdr)) \
 				/ sizeof(struct gpn_ft_resp_acc))
 #define ZFCP_GPN_FT_BUFFERS 4
 #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];
 };

 static struct zfcp_port *zfcp_get_port_by_did(struct zfcp_adapter *adapter,
 					      u32 d_id)
 {
 	struct zfcp_port *port;

 	list_for_each_entry(port, &adapter->port_list_head, list)
 		if ((port->d_id == d_id) &&
 		    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status))
 			return port;
 	return NULL;
 }

 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 (atomic_test_mask(ZFCP_STATUS_PORT_WKA, &port->status))
 			continue;
 		/* FIXME: ZFCP_STATUS_PORT_DID_DID check is racy */
 		if (!atomic_test_mask(ZFCP_STATUS_PORT_DID_DID, &port->status))
 			/* Try to connect to unused ports anyway. */
 			zfcp_erp_port_reopen(port,
 					     ZFCP_STATUS_COMMON_ERP_FAILED,
 					     82, fsf_req);
 		else if ((port->d_id & range) == (elem->nport_did & range))
 			/* Check connection status for connected ports */
 			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++;
 		switch (fcp_rscn_element->addr_format) {
 		case ZFCP_PORT_ADDRESS:
 			range_mask = ZFCP_PORTS_RANGE_PORT;
 			break;
 		case ZFCP_AREA_ADDRESS:
 			range_mask = ZFCP_PORTS_RANGE_AREA;
 			break;
 		case ZFCP_DOMAIN_ADDRESS:
 			range_mask = ZFCP_PORTS_RANGE_DOMAIN;
 			break;
 		case ZFCP_FABRIC_ADDRESS:
 			range_mask = ZFCP_PORTS_RANGE_FABRIC;
 			break;
 		default:
 			continue;
 		}
 		_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, wwn_t 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, 83, 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_ns_gid_pn_handler(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)
 		goto out;
 	if (ct_iu_resp->header.cmd_rsp_code != ZFCP_CT_ACCEPT) {
 		atomic_set_mask(ZFCP_STATUS_PORT_INVALID_WWPN, &port->status);
 		goto out;
 	}
 	/* paranoia */
 	if (ct_iu_req->wwpn != port->wwpn)
 		goto out;
 	/* looks like a valid d_id */
 	port->d_id = ct_iu_resp->d_id & ZFCP_DID_MASK;
 	atomic_set_mask(ZFCP_STATUS_PORT_DID_DID, &port->status);
 out:
 	mempool_free(gid_pn, port->adapter->pool.data_gid_pn);
 }

 /**
  * 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_request(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));

 	/* setup parameters for send generic command */
 	gid_pn->port = erp_action->port;
 	gid_pn->ct.port = adapter->nameserver_port;
 	gid_pn->ct.handler = zfcp_ns_gid_pn_handler;
 	gid_pn->ct.handler_data = (unsigned long) gid_pn;
 	gid_pn->ct.timeout = ZFCP_NS_GID_PN_TIMEOUT;
 	gid_pn->ct.req = &gid_pn->req;
 	gid_pn->ct.resp = &gid_pn->resp;
 	gid_pn->ct.req_count = 1;
 	gid_pn->ct.resp_count = 1;
 	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_MAX_SIZE;
 	gid_pn->ct_iu_req.wwpn = erp_action->port->wwpn;

 	ret = zfcp_fsf_send_ct(&gid_pn->ct, adapter->pool.fsf_req_erp,
 			       erp_action);
 	if (ret)
 		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_acc 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_acc *ls_adisc = &adisc->ls_adisc_acc;

 	if (adisc->els.status) {
 		/* request rejected or timed out */
 		zfcp_erp_port_forced_reopen(port, 0, 63, NULL);
 		goto out;
 	}

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

 	if (port->wwpn != ls_adisc->wwpn)
 		zfcp_erp_port_reopen(port, 0, 64, NULL);

  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_acc));

 	adisc->els.req_count = 1;
 	adisc->els.resp_count = 1;
 	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);
 }

 /**
  * 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)
 {
 	int retval;

 	zfcp_port_get(port);
 	retval = zfcp_fc_adisc(port);
 	if (retval == 0 || retval == -EBUSY)
 		return;

 	/* send of ADISC was not possible */
 	zfcp_port_put(port);
 	zfcp_erp_port_forced_reopen(port, 0, 65, NULL);
 }

 static int zfcp_scan_get_nameserver(struct zfcp_adapter *adapter)
 {
 	int ret;

 	if (!adapter->nameserver_port)
 		return -EINTR;

 	if (!atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED,
 			       &adapter->nameserver_port->status)) {
 		ret = zfcp_erp_port_reopen(adapter->nameserver_port, 0, 148,
 					   NULL);
 		if (ret)
 			return ret;
 		zfcp_erp_wait(adapter);
 		zfcp_port_put(adapter->nameserver_port);
 	}
 	return !atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED,
 				  &adapter->nameserver_port->status);
 }

 static void zfcp_gpn_ft_handler(unsigned long _done)
 {
 	complete((struct completion *)_done);
 }

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

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

 	kfree(gpn_ft);
 }

 static struct zfcp_gpn_ft *zfcp_alloc_sg_env(void)
 {
 	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, ZFCP_GPN_FT_BUFFERS)) {
 		zfcp_free_sg_env(gpn_ft);
 		gpn_ft = NULL;
 	}
 out:
 	return gpn_ft;
 }


 static int zfcp_scan_issue_gpn_ft(struct zfcp_gpn_ft *gpn_ft,
 				  struct zfcp_adapter *adapter)
 {
 	struct zfcp_send_ct *ct = &gpn_ft->ct;
 	struct ct_iu_gpn_ft_req *req = sg_virt(&gpn_ft->sg_req);
 	struct completion done;
 	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 = (sizeof(struct gpn_ft_resp_acc) *
 					(ZFCP_GPN_FT_MAX_ENTRIES - 1)) >> 2;
 	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->port = adapter->nameserver_port;
 	ct->handler = zfcp_gpn_ft_handler;
 	ct->handler_data = (unsigned long)&done;
 	ct->timeout = 10;
 	ct->req = &gpn_ft->sg_req;
 	ct->resp = gpn_ft->sg_resp;
 	ct->req_count = 1;
 	ct->resp_count = ZFCP_GPN_FT_BUFFERS;

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

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

 	atomic_clear_mask(ZFCP_STATUS_COMMON_NOESC, &port->status);

 	if (port == adapter->nameserver_port)
 		return;
 	if ((port->supported_classes != 0) || (port->units != 0)) {
 		zfcp_port_put(port);
 		return;
 	}
 	zfcp_erp_port_shutdown(port, 0, 151, 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)
 {
 	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->port->adapter;
 	struct zfcp_port *port, *tmp;
 	u32 d_id;
 	int ret = 0, x;

 	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)
 		return -E2BIG;

 	down(&zfcp_data.config_sema);

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

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

 		/* skip the adapter's port and known remote ports */
 		if (acc->wwpn == fc_host_port_name(adapter->scsi_host) ||
 		     zfcp_get_port_by_did(adapter, d_id))
 			continue;

 		port = zfcp_port_enqueue(adapter, acc->wwpn,
 					 ZFCP_STATUS_PORT_DID_DID |
 					 ZFCP_STATUS_COMMON_NOESC, d_id);
 		if (IS_ERR(port))
 			ret = PTR_ERR(port);
 		else
 			zfcp_erp_port_reopen(port, 0, 149, NULL);
 		if (acc->control & 0x80) /* last entry */
 			break;
 	}

 	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;

 	zfcp_erp_wait(adapter); /* wait until adapter is finished with ERP */
 	if (fc_host_port_type(adapter->scsi_host) != FC_PORTTYPE_NPORT)
 		return 0;

 	ret = zfcp_scan_get_nameserver(adapter);
 	if (ret)
 		return ret;

 	gpn_ft = zfcp_alloc_sg_env();
 	if (!gpn_ft)
 		return -ENOMEM;

 	for (i = 0; i < 3; i++) {
 		ret = zfcp_scan_issue_gpn_ft(gpn_ft, adapter);
 		if (!ret) {
 			ret = zfcp_scan_eval_gpn_ft(gpn_ft);
 			if (ret == -EAGAIN)
 				ssleep(1);
 			else
 				break;
 		}
 	}
 	zfcp_free_sg_env(gpn_ft);

 	return ret;
 }


 void _zfcp_scan_ports_later(struct work_struct *work)
 {
 	zfcp_scan_ports(container_of(work, struct zfcp_adapter, scan_work));
 }
	/*
	* zfcp device driver
	*
	* Fibre Channel related functions for the zfcp device driver.
	*
	* Copyright IBM Corporation 2008
	*/

	#include "zfcp_ext.h"

	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_GPN_FT_ENTRIES ((PAGE_SIZE - sizeof(struct ct_hdr)) \
	/ sizeof(struct gpn_ft_resp_acc))
	#define ZFCP_GPN_FT_BUFFERS 4
	#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];
	};

	static struct zfcp_port zfcp_get_port_by_did(struct zfcp_adapter adapter,
	u32 d_id)
	{
	struct zfcp_port *port;

	list_for_each_entry(port, &adapter->port_list_head, list)
	if ((port->d_id == d_id) &&
	!atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status))
	return port;
	return NULL;
	}

	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 (atomic_test_mask(ZFCP_STATUS_PORT_WKA, &port->status))
	continue;
	/* FIXME: ZFCP_STATUS_PORT_DID_DID check is racy */
	if (!atomic_test_mask(ZFCP_STATUS_PORT_DID_DID, &port->status))
	/* Try to connect to unused ports anyway. */
	zfcp_erp_port_reopen(port,
	ZFCP_STATUS_COMMON_ERP_FAILED,
	82, fsf_req);
	else if ((port->d_id & range) == (elem->nport_did & range))
	/* Check connection status for connected ports */
	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++;
	switch (fcp_rscn_element->addr_format) {
	case ZFCP_PORT_ADDRESS:
	range_mask = ZFCP_PORTS_RANGE_PORT;
	break;
	case ZFCP_AREA_ADDRESS:
	range_mask = ZFCP_PORTS_RANGE_AREA;
	break;
	case ZFCP_DOMAIN_ADDRESS:
	range_mask = ZFCP_PORTS_RANGE_DOMAIN;
	break;
	case ZFCP_FABRIC_ADDRESS:
	range_mask = ZFCP_PORTS_RANGE_FABRIC;
	break;
	default:
	continue;
	}
	_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, wwn_t 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, 83, 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_ns_gid_pn_handler(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)
	goto out;
	if (ct_iu_resp->header.cmd_rsp_code != ZFCP_CT_ACCEPT) {
	atomic_set_mask(ZFCP_STATUS_PORT_INVALID_WWPN, &port->status);
	goto out;
	}
	/* paranoia */
	if (ct_iu_req->wwpn != port->wwpn)
	goto out;
	/* looks like a valid d_id */
	port->d_id = ct_iu_resp->d_id & ZFCP_DID_MASK;
	atomic_set_mask(ZFCP_STATUS_PORT_DID_DID, &port->status);
	out:
	mempool_free(gid_pn, port->adapter->pool.data_gid_pn);
	}

	/**
	* 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_request(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));

	/* setup parameters for send generic command */
	gid_pn->port = erp_action->port;
	gid_pn->ct.port = adapter->nameserver_port;
	gid_pn->ct.handler = zfcp_ns_gid_pn_handler;
	gid_pn->ct.handler_data = (unsigned long) gid_pn;
	gid_pn->ct.timeout = ZFCP_NS_GID_PN_TIMEOUT;
	gid_pn->ct.req = &gid_pn->req;
	gid_pn->ct.resp = &gid_pn->resp;
	gid_pn->ct.req_count = 1;
	gid_pn->ct.resp_count = 1;
	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_MAX_SIZE;
	gid_pn->ct_iu_req.wwpn = erp_action->port->wwpn;

	ret = zfcp_fsf_send_ct(&gid_pn->ct, adapter->pool.fsf_req_erp,
	erp_action);
	if (ret)
	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_acc 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_acc *ls_adisc = &adisc->ls_adisc_acc;

	if (adisc->els.status) {
	/* request rejected or timed out */
	zfcp_erp_port_forced_reopen(port, 0, 63, NULL);
	goto out;
	}

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

	if (port->wwpn != ls_adisc->wwpn)
	zfcp_erp_port_reopen(port, 0, 64, NULL);

	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_acc));

	adisc->els.req_count = 1;
	adisc->els.resp_count = 1;
	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);
	}

	/**
	* 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)
	{
	int retval;

	zfcp_port_get(port);
	retval = zfcp_fc_adisc(port);
	if (retval == 0 \|\| retval == -EBUSY)
	return;

	/* send of ADISC was not possible */
	zfcp_port_put(port);
	zfcp_erp_port_forced_reopen(port, 0, 65, NULL);
	}

	static int zfcp_scan_get_nameserver(struct zfcp_adapter *adapter)
	{
	int ret;

	if (!adapter->nameserver_port)
	return -EINTR;

	if (!atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED,
	&adapter->nameserver_port->status)) {
	ret = zfcp_erp_port_reopen(adapter->nameserver_port, 0, 148,
	NULL);
	if (ret)
	return ret;
	zfcp_erp_wait(adapter);
	zfcp_port_put(adapter->nameserver_port);
	}
	return !atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED,
	&adapter->nameserver_port->status);
	}

	static void zfcp_gpn_ft_handler(unsigned long _done)
	{
	complete((struct completion *)_done);
	}

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

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

	kfree(gpn_ft);
	}

	static struct zfcp_gpn_ft *zfcp_alloc_sg_env(void)
	{
	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, ZFCP_GPN_FT_BUFFERS)) {
	zfcp_free_sg_env(gpn_ft);
	gpn_ft = NULL;
	}
	out:
	return gpn_ft;
	}


	static int zfcp_scan_issue_gpn_ft(struct zfcp_gpn_ft *gpn_ft,
	struct zfcp_adapter *adapter)
	{
	struct zfcp_send_ct *ct = &gpn_ft->ct;
	struct ct_iu_gpn_ft_req *req = sg_virt(&gpn_ft->sg_req);
	struct completion done;
	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 = (sizeof(struct gpn_ft_resp_acc) *
	(ZFCP_GPN_FT_MAX_ENTRIES - 1)) >> 2;
	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->port = adapter->nameserver_port;
	ct->handler = zfcp_gpn_ft_handler;
	ct->handler_data = (unsigned long)&done;
	ct->timeout = 10;
	ct->req = &gpn_ft->sg_req;
	ct->resp = gpn_ft->sg_resp;
	ct->req_count = 1;
	ct->resp_count = ZFCP_GPN_FT_BUFFERS;

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

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

	atomic_clear_mask(ZFCP_STATUS_COMMON_NOESC, &port->status);

	if (port == adapter->nameserver_port)
	return;
	if ((port->supported_classes != 0) \|\| (port->units != 0)) {
	zfcp_port_put(port);
	return;
	}
	zfcp_erp_port_shutdown(port, 0, 151, 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)
	{
	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->port->adapter;
	struct zfcp_port port, tmp;
	u32 d_id;
	int ret = 0, x;

	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)
	return -E2BIG;

	down(&zfcp_data.config_sema);

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

	d_id = acc->port_id[0] << 16 \| acc->port_id[1] << 8 \|
	acc->port_id[2];

	/* skip the adapter's port and known remote ports */
	if (acc->wwpn == fc_host_port_name(adapter->scsi_host) \|\|
	zfcp_get_port_by_did(adapter, d_id))
	continue;

	port = zfcp_port_enqueue(adapter, acc->wwpn,
	ZFCP_STATUS_PORT_DID_DID \|
	ZFCP_STATUS_COMMON_NOESC, d_id);
	if (IS_ERR(port))
	ret = PTR_ERR(port);
	else
	zfcp_erp_port_reopen(port, 0, 149, NULL);
	if (acc->control & 0x80) /* last entry */
	break;
	}

	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;

	zfcp_erp_wait(adapter); /* wait until adapter is finished with ERP */
	if (fc_host_port_type(adapter->scsi_host) != FC_PORTTYPE_NPORT)
	return 0;

	ret = zfcp_scan_get_nameserver(adapter);
	if (ret)
	return ret;

	gpn_ft = zfcp_alloc_sg_env();
	if (!gpn_ft)
	return -ENOMEM;

	for (i = 0; i < 3; i++) {
	ret = zfcp_scan_issue_gpn_ft(gpn_ft, adapter);
	if (!ret) {
	ret = zfcp_scan_eval_gpn_ft(gpn_ft);
	if (ret == -EAGAIN)
	ssleep(1);
	else
	break;
	}
	}
	zfcp_free_sg_env(gpn_ft);

	return ret;
	}


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