Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 :This series consists of the usual driver updates (qla2xxx, ufs, zfcp,
  target, scsi_debug, lpfc, qedi, qedf, hisi_sas, mpt3sas) plus a host
  of other minor updates.

  There are no major core changes in this series apart from a
  refactoring in scsi_lib.c"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (207 commits)
  scsi: ufs: ti-j721e-ufs: Fix unwinding of pm_runtime changes
  scsi: cxgb3i: Fix some leaks in init_act_open()
  scsi: ibmvscsi: Make some functions static
  scsi: iscsi: Fix deadlock on recovery path during GFP_IO reclaim
  scsi: ufs: Fix WriteBooster flush during runtime suspend
  scsi: ufs: Fix index of attributes query for WriteBooster feature
  scsi: ufs: Allow WriteBooster on UFS 2.2 devices
  scsi: ufs: Remove unnecessary memset for dev_info
  scsi: ufs-qcom: Fix scheduling while atomic issue
  scsi: mpt3sas: Fix reply queue count in non RDPQ mode
  scsi: lpfc: Fix lpfc_nodelist leak when processing unsolicited event
  scsi: target: tcmu: Fix a use after free in tcmu_check_expired_queue_cmd()
  scsi: vhost: Notify TCM about the maximum sg entries supported per command
  scsi: qla2xxx: Remove return value from qla_nvme_ls()
  scsi: qla2xxx: Remove an unused function
  scsi: iscsi: Register sysfs for iscsi workqueue
  scsi: scsi_debug: Parser tables and code interaction
  scsi: core: Refactor scsi_mq_setup_tags function
  scsi: core: Fix incorrect usage of shost_for_each_device
  scsi: qla2xxx: Fix endianness annotations in source files
  ...

8 files changed, 265 insertions, 83 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 09ec846fe01d..18b713a616de 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -4,7 +4,7 @@
  *
  * Module interface and handling of zfcp data structures.
  *
- * Copyright IBM Corp. 2002, 2018
+ * Copyright IBM Corp. 2002, 2020
  */
 
 /*
@@ -415,8 +415,7 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 
 	adapter->stat_read_buf_num = FSF_STATUS_READS_RECOM;
 
-	if (!zfcp_scsi_adapter_register(adapter))
-		return adapter;
+	return adapter;
 
 failed:
 	zfcp_adapter_unregister(adapter);
diff --git a/drivers/s390/scsi/zfcp_diag.h b/drivers/s390/scsi/zfcp_diag.h
index b9c93d15f67c..3852367f15f6 100644
--- a/drivers/s390/scsi/zfcp_diag.h
+++ b/drivers/s390/scsi/zfcp_diag.h
@@ -4,7 +4,7 @@
  *
  * Definitions for handling diagnostics in the the zfcp device driver.
  *
- * Copyright IBM Corp. 2018
+ * Copyright IBM Corp. 2018, 2020
  */
 
 #ifndef ZFCP_DIAG_H
@@ -56,11 +56,11 @@ struct zfcp_diag_adapter {
 
 	unsigned long	max_age;
 
-	struct {
+	struct zfcp_diag_adapter_port_data {
 		struct zfcp_diag_header		header;
 		struct fsf_qtcb_bottom_port	data;
 	} port_data;
-	struct {
+	struct zfcp_diag_adapter_config_data {
 		struct zfcp_diag_header		header;
 		struct fsf_qtcb_bottom_config	data;
 	} config_data;
diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index 3d0bc000f500..db320dab1fee 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -4,7 +4,7 @@
  *
  * Error Recovery Procedures (ERP).
  *
- * Copyright IBM Corp. 2002, 2017
+ * Copyright IBM Corp. 2002, 2020
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -14,6 +14,7 @@
 #include <linux/bug.h>
 #include "zfcp_ext.h"
 #include "zfcp_reqlist.h"
+#include "zfcp_diag.h"
 
 #define ZFCP_MAX_ERPS                   3
 
@@ -768,10 +769,14 @@ static enum zfcp_erp_act_result zfcp_erp_adapter_strat_fsf_xconf(
 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_XCONFIG_OK))
 		return ZFCP_ERP_FAILED;
 
+	return ZFCP_ERP_SUCCEEDED;
+}
+
+static void
+zfcp_erp_adapter_strategy_open_ptp_port(struct zfcp_adapter *const adapter)
+{
 	if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP)
 		zfcp_erp_enqueue_ptp_port(adapter);
-
-	return ZFCP_ERP_SUCCEEDED;
 }
 
 static enum zfcp_erp_act_result zfcp_erp_adapter_strategy_open_fsf_xport(
@@ -800,6 +805,59 @@ static enum zfcp_erp_act_result zfcp_erp_adapter_strategy_open_fsf_xport(
 	return ZFCP_ERP_SUCCEEDED;
 }
 
+static enum zfcp_erp_act_result
+zfcp_erp_adapter_strategy_alloc_shost(struct zfcp_adapter *const adapter)
+{
+	struct zfcp_diag_adapter_config_data *const config_data =
+		&adapter->diagnostics->config_data;
+	struct zfcp_diag_adapter_port_data *const port_data =
+		&adapter->diagnostics->port_data;
+	unsigned long flags;
+	int rc;
+
+	rc = zfcp_scsi_adapter_register(adapter);
+	if (rc == -EEXIST)
+		return ZFCP_ERP_SUCCEEDED;
+	else if (rc)
+		return ZFCP_ERP_FAILED;
+
+	/*
+	 * We allocated the shost for the first time. Before it was NULL,
+	 * and so we deferred all updates in the xconf- and xport-data
+	 * handlers. We need to make up for that now, and make all the updates
+	 * that would have been done before.
+	 *
+	 * We can be sure that xconf- and xport-data succeeded, because
+	 * otherwise this function is not called. But they might have been
+	 * incomplete.
+	 */
+
+	spin_lock_irqsave(&config_data->header.access_lock, flags);
+	zfcp_scsi_shost_update_config_data(adapter, &config_data->data,
+					   !!config_data->header.incomplete);
+	spin_unlock_irqrestore(&config_data->header.access_lock, flags);
+
+	if (adapter->adapter_features & FSF_FEATURE_HBAAPI_MANAGEMENT) {
+		spin_lock_irqsave(&port_data->header.access_lock, flags);
+		zfcp_scsi_shost_update_port_data(adapter, &port_data->data);
+		spin_unlock_irqrestore(&port_data->header.access_lock, flags);
+	}
+
+	/*
+	 * There is a remote possibility that the 'Exchange Port Data' request
+	 * reports a different connectivity status than 'Exchange Config Data'.
+	 * But any change to the connectivity status of the local optic that
+	 * happens after the initial xconf request is expected to be reported
+	 * to us, as soon as we post Status Read Buffers to the FCP channel
+	 * firmware after this function. So any resulting inconsistency will
+	 * only be momentary.
+	 */
+	if (config_data->header.incomplete)
+		zfcp_fsf_fc_host_link_down(adapter);
+
+	return ZFCP_ERP_SUCCEEDED;
+}
+
 static enum zfcp_erp_act_result zfcp_erp_adapter_strategy_open_fsf(
 	struct zfcp_erp_action *act)
 {
@@ -809,6 +867,12 @@ static enum zfcp_erp_act_result zfcp_erp_adapter_strategy_open_fsf(
 	if (zfcp_erp_adapter_strategy_open_fsf_xport(act) == ZFCP_ERP_FAILED)
 		return ZFCP_ERP_FAILED;
 
+	if (zfcp_erp_adapter_strategy_alloc_shost(act->adapter) ==
+	    ZFCP_ERP_FAILED)
+		return ZFCP_ERP_FAILED;
+
+	zfcp_erp_adapter_strategy_open_ptp_port(act->adapter);
+
 	if (mempool_resize(act->adapter->pool.sr_data,
 			   act->adapter->stat_read_buf_num))
 		return ZFCP_ERP_FAILED;
@@ -1636,6 +1700,13 @@ void zfcp_erp_set_adapter_status(struct zfcp_adapter *adapter, u32 mask)
 		atomic_or(common_mask, &port->status);
 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
 
+	/*
+	 * if `scsi_host` is missing, xconfig/xport data has never completed
+	 * yet, so we can't access it, but there are also no SDEVs yet
+	 */
+	if (adapter->scsi_host == NULL)
+		return;
+
 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
 	__shost_for_each_device(sdev, adapter->scsi_host)
 		atomic_or(common_mask, &sdev_to_zfcp(sdev)->status);
@@ -1673,6 +1744,13 @@ void zfcp_erp_clear_adapter_status(struct zfcp_adapter *adapter, u32 mask)
 	}
 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
 
+	/*
+	 * if `scsi_host` is missing, xconfig/xport data has never completed
+	 * yet, so we can't access it, but there are also no SDEVs yet
+	 */
+	if (adapter->scsi_host == NULL)
+		return;
+
 	spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
 	__shost_for_each_device(sdev, adapter->scsi_host) {
 		atomic_andnot(common_mask, &sdev_to_zfcp(sdev)->status);
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index 88294ca0e2ea..3ef5d74331c3 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -125,6 +125,7 @@ extern int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *,
 extern int zfcp_fsf_exchange_port_data(struct zfcp_erp_action *);
 extern int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *,
 					    struct fsf_qtcb_bottom_port *);
+extern u32 zfcp_fsf_convert_portspeed(u32 fsf_speed);
 extern void zfcp_fsf_req_dismiss_all(struct zfcp_adapter *);
 extern int zfcp_fsf_status_read(struct zfcp_qdio *);
 extern int zfcp_status_read_refill(struct zfcp_adapter *adapter);
@@ -134,6 +135,7 @@ extern int zfcp_fsf_send_els(struct zfcp_adapter *, u32,
 			     struct zfcp_fsf_ct_els *, unsigned int);
 extern int zfcp_fsf_fcp_cmnd(struct scsi_cmnd *);
 extern void zfcp_fsf_req_free(struct zfcp_fsf_req *);
+extern void zfcp_fsf_fc_host_link_down(struct zfcp_adapter *adapter);
 extern struct zfcp_fsf_req *zfcp_fsf_fcp_task_mgmt(struct scsi_device *sdev,
 						   u8 tm_flags);
 extern struct zfcp_fsf_req *zfcp_fsf_abort_fcp_cmnd(struct scsi_cmnd *);
@@ -153,6 +155,8 @@ extern int zfcp_qdio_sbal_get(struct zfcp_qdio *);
 extern int zfcp_qdio_send(struct zfcp_qdio *, struct zfcp_qdio_req *);
 extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *, struct zfcp_qdio_req *,
 				   struct scatterlist *);
+extern void zfcp_qdio_shost_update(struct zfcp_adapter *const adapter,
+				   const struct zfcp_qdio *const qdio);
 extern int zfcp_qdio_open(struct zfcp_qdio *);
 extern void zfcp_qdio_close(struct zfcp_qdio *);
 extern void zfcp_qdio_siosl(struct zfcp_adapter *);
@@ -169,6 +173,13 @@ extern void zfcp_scsi_schedule_rport_block(struct zfcp_port *);
 extern void zfcp_scsi_schedule_rports_block(struct zfcp_adapter *);
 extern void zfcp_scsi_set_prot(struct zfcp_adapter *);
 extern void zfcp_scsi_dif_sense_error(struct scsi_cmnd *, int);
+extern void zfcp_scsi_shost_update_config_data(
+	struct zfcp_adapter *const adapter,
+	const struct fsf_qtcb_bottom_config *const bottom,
+	const bool bottom_incomplete);
+extern void zfcp_scsi_shost_update_port_data(
+	struct zfcp_adapter *const adapter,
+	const struct fsf_qtcb_bottom_port *const bottom);
 
 /* zfcp_sysfs.c */
 extern const struct attribute_group *zfcp_unit_attr_groups[];
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 111fe3fc32d7..c795f22249d8 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -120,21 +120,25 @@ static void zfcp_fsf_status_read_port_closed(struct zfcp_fsf_req *req)
 	read_unlock_irqrestore(&adapter->port_list_lock, flags);
 }
 
-static void zfcp_fsf_fc_host_link_down(struct zfcp_adapter *adapter)
+void zfcp_fsf_fc_host_link_down(struct zfcp_adapter *adapter)
 {
 	struct Scsi_Host *shost = adapter->scsi_host;
 
+	adapter->hydra_version = 0;
+	adapter->peer_wwpn = 0;
+	adapter->peer_wwnn = 0;
+	adapter->peer_d_id = 0;
+
+	/* if there is no shost yet, we have nothing to zero-out */
+	if (shost == NULL)
+		return;
+
 	fc_host_port_id(shost) = 0;
 	fc_host_fabric_name(shost) = 0;
 	fc_host_speed(shost) = FC_PORTSPEED_UNKNOWN;
 	fc_host_port_type(shost) = FC_PORTTYPE_UNKNOWN;
-	adapter->hydra_version = 0;
 	snprintf(fc_host_model(shost), FC_SYMBOLIC_NAME_SIZE, "0x%04x", 0);
 	memset(fc_host_active_fc4s(shost), 0, FC_FC4_LIST_SIZE);
-
-	adapter->peer_wwpn = 0;
-	adapter->peer_wwnn = 0;
-	adapter->peer_d_id = 0;
 }
 
 static void zfcp_fsf_link_down_info_eval(struct zfcp_fsf_req *req,
@@ -479,7 +483,7 @@ void zfcp_fsf_req_dismiss_all(struct zfcp_adapter *adapter)
 #define ZFCP_FSF_PORTSPEED_128GBIT	(1 <<  8)
 #define ZFCP_FSF_PORTSPEED_NOT_NEGOTIATED (1 << 15)
 
-static u32 zfcp_fsf_convert_portspeed(u32 fsf_speed)
+u32 zfcp_fsf_convert_portspeed(u32 fsf_speed)
 {
 	u32 fdmi_speed = 0;
 	if (fsf_speed & ZFCP_FSF_PORTSPEED_1GBIT)
@@ -509,64 +513,36 @@ static int zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *req)
 {
 	struct fsf_qtcb_bottom_config *bottom = &req->qtcb->bottom.config;
 	struct zfcp_adapter *adapter = req->adapter;
-	struct Scsi_Host *shost = adapter->scsi_host;
-	struct fc_els_flogi *nsp, *plogi;
+	struct fc_els_flogi *plogi;
 
 	/* adjust pointers for missing command code */
-	nsp = (struct fc_els_flogi *) ((u8 *)&bottom->nport_serv_param
-					- sizeof(u32));
 	plogi = (struct fc_els_flogi *) ((u8 *)&bottom->plogi_payload
 					- sizeof(u32));
 
 	if (req->data)
 		memcpy(req->data, bottom, sizeof(*bottom));
 
-	snprintf(fc_host_manufacturer(shost), FC_SERIAL_NUMBER_SIZE, "%s",
-		 "IBM");
-	fc_host_port_name(shost) = be64_to_cpu(nsp->fl_wwpn);
-	fc_host_node_name(shost) = be64_to_cpu(nsp->fl_wwnn);
-	fc_host_supported_classes(shost) = FC_COS_CLASS2 | FC_COS_CLASS3;
-
 	adapter->timer_ticks = bottom->timer_interval & ZFCP_FSF_TIMER_INT_MASK;
 	adapter->stat_read_buf_num = max(bottom->status_read_buf_num,
 					 (u16)FSF_STATUS_READS_RECOM);
 
-	zfcp_scsi_set_prot(adapter);
-
 	/* no error return above here, otherwise must fix call chains */
 	/* do not evaluate invalid fields */
 	if (req->qtcb->header.fsf_status == FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE)
 		return 0;
 
-	fc_host_port_id(shost) = ntoh24(bottom->s_id);
-	fc_host_speed(shost) =
-		zfcp_fsf_convert_portspeed(bottom->fc_link_speed);
-
 	adapter->hydra_version = bottom->adapter_type;
-	snprintf(fc_host_model(shost), FC_SYMBOLIC_NAME_SIZE, "0x%04x",
-		 bottom->adapter_type);
 
 	switch (bottom->fc_topology) {
 	case FSF_TOPO_P2P:
 		adapter->peer_d_id = ntoh24(bottom->peer_d_id);
 		adapter->peer_wwpn = be64_to_cpu(plogi->fl_wwpn);
 		adapter->peer_wwnn = be64_to_cpu(plogi->fl_wwnn);
-		fc_host_port_type(shost) = FC_PORTTYPE_PTP;
-		fc_host_fabric_name(shost) = 0;
 		break;
 	case FSF_TOPO_FABRIC:
-		fc_host_fabric_name(shost) = be64_to_cpu(plogi->fl_wwnn);
-		if (bottom->connection_features & FSF_FEATURE_NPIV_MODE)
-			fc_host_port_type(shost) = FC_PORTTYPE_NPIV;
-		else
-			fc_host_port_type(shost) = FC_PORTTYPE_NPORT;
 		break;
 	case FSF_TOPO_AL:
-		fc_host_port_type(shost) = FC_PORTTYPE_NLPORT;
-		fc_host_fabric_name(shost) = 0;
-		fallthrough;
 	default:
-		fc_host_fabric_name(shost) = 0;
 		dev_err(&adapter->ccw_device->dev,
 			"Unknown or unsupported arbitrated loop "
 			"fibre channel topology detected\n");
@@ -584,13 +560,10 @@ static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req)
 		&adapter->diagnostics->config_data.header;
 	struct fsf_qtcb *qtcb = req->qtcb;
 	struct fsf_qtcb_bottom_config *bottom = &qtcb->bottom.config;
-	struct Scsi_Host *shost = adapter->scsi_host;
 
 	if (req->status & ZFCP_STATUS_FSFREQ_ERROR)
 		return;
 
-	snprintf(fc_host_firmware_version(shost), FC_VERSION_STRING_SIZE,
-		 "0x%08x", bottom->lic_version);
 	adapter->fsf_lic_version = bottom->lic_version;
 	adapter->adapter_features = bottom->adapter_features;
 	adapter->connection_features = bottom->connection_features;
@@ -606,6 +579,7 @@ static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req)
 		 */
 		zfcp_diag_update_xdata(diag_hdr, bottom, false);
 
+		zfcp_scsi_shost_update_config_data(adapter, bottom, false);
 		if (zfcp_fsf_exchange_config_evaluate(req))
 			return;
 
@@ -630,6 +604,8 @@ static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req)
 				&adapter->status);
 		zfcp_fsf_link_down_info_eval(req,
 			&qtcb->header.fsf_status_qual.link_down_info);
+
+		zfcp_scsi_shost_update_config_data(adapter, bottom, true);
 		if (zfcp_fsf_exchange_config_evaluate(req))
 			return;
 		break;
@@ -638,16 +614,8 @@ static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req)
 		return;
 	}
 
-	if (adapter->adapter_features & FSF_FEATURE_HBAAPI_MANAGEMENT) {
+	if (adapter->adapter_features & FSF_FEATURE_HBAAPI_MANAGEMENT)
 		adapter->hardware_version = bottom->hardware_version;
-		snprintf(fc_host_hardware_version(shost),
-			 FC_VERSION_STRING_SIZE,
-			 "0x%08x", bottom->hardware_version);
-		memcpy(fc_host_serial_number(shost), bottom->serial_number,
-		       min(FC_SERIAL_NUMBER_SIZE, 17));
-		EBCASC(fc_host_serial_number(shost),
-		       min(FC_SERIAL_NUMBER_SIZE, 17));
-	}
 
 	if (FSF_QTCB_CURRENT_VERSION < bottom->low_qtcb_version) {
 		dev_err(&adapter->ccw_device->dev,
@@ -761,19 +729,10 @@ static void zfcp_fsf_exchange_port_evaluate(struct zfcp_fsf_req *req)
 {
 	struct zfcp_adapter *adapter = req->adapter;
 	struct fsf_qtcb_bottom_port *bottom = &req->qtcb->bottom.port;
-	struct Scsi_Host *shost = adapter->scsi_host;
 
 	if (req->data)
 		memcpy(req->data, bottom, sizeof(*bottom));
 
-	fc_host_permanent_port_name(shost) = bottom->wwpn;
-	fc_host_maxframe_size(shost) = bottom->maximum_frame_size;
-	fc_host_supported_speeds(shost) =
-		zfcp_fsf_convert_portspeed(bottom->supported_speed);
-	memcpy(fc_host_supported_fc4s(shost), bottom->supported_fc4_types,
-	       FC_FC4_LIST_SIZE);
-	memcpy(fc_host_active_fc4s(shost), bottom->active_fc4_types,
-	       FC_FC4_LIST_SIZE);
 	if (adapter->adapter_features & FSF_FEATURE_FC_SECURITY)
 		adapter->fc_security_algorithms =
 			bottom->fc_security_algorithms;
@@ -800,6 +759,7 @@ static void zfcp_fsf_exchange_port_data_handler(struct zfcp_fsf_req *req)
 		 */
 		zfcp_diag_update_xdata(diag_hdr, bottom, false);
 
+		zfcp_scsi_shost_update_port_data(req->adapter, bottom);
 		zfcp_fsf_exchange_port_evaluate(req);
 		break;
 	case FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE:
@@ -808,6 +768,8 @@ static void zfcp_fsf_exchange_port_data_handler(struct zfcp_fsf_req *req)
 
 		zfcp_fsf_link_down_info_eval(req,
 			&qtcb->header.fsf_status_qual.link_down_info);
+
+		zfcp_scsi_shost_update_port_data(req->adapter, bottom);
 		zfcp_fsf_exchange_port_evaluate(req);
 		break;
 	}
diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index 26702b56a7ab..3a7f3374d10a 100644
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -4,7 +4,7 @@
  *
  * Setup and helper functions to access QDIO.
  *
- * Copyright IBM Corp. 2002, 2017
+ * Copyright IBM Corp. 2002, 2020
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -342,6 +342,18 @@ void zfcp_qdio_close(struct zfcp_qdio *qdio)
 	atomic_set(&qdio->req_q_free, 0);
 }
 
+void zfcp_qdio_shost_update(struct zfcp_adapter *const adapter,
+			    const struct zfcp_qdio *const qdio)
+{
+	struct Scsi_Host *const shost = adapter->scsi_host;
+
+	if (shost == NULL)
+		return;
+
+	shost->sg_tablesize = qdio->max_sbale_per_req;
+	shost->max_sectors = qdio->max_sbale_per_req * 8;
+}
+
 /**
  * zfcp_qdio_open - prepare and initialize response queue
  * @qdio: pointer to struct zfcp_qdio
@@ -420,10 +432,7 @@ int zfcp_qdio_open(struct zfcp_qdio *qdio)
 	atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
 	atomic_or(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
 
-	if (adapter->scsi_host) {
-		adapter->scsi_host->sg_tablesize = qdio->max_sbale_per_req;
-		adapter->scsi_host->max_sectors = qdio->max_sbale_per_req * 8;
-	}
+	zfcp_qdio_shost_update(adapter, qdio);
 
 	return 0;
 
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 13d873f806e4..d58bf79892f2 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -4,7 +4,7 @@
  *
  * Interface to Linux SCSI midlayer.
  *
- * Copyright IBM Corp. 2002, 2018
+ * Copyright IBM Corp. 2002, 2020
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -451,26 +451,39 @@ static struct scsi_host_template zfcp_scsi_host_template = {
 };
 
 /**
- * zfcp_scsi_adapter_register - Register SCSI and FC host with SCSI midlayer
+ * zfcp_scsi_adapter_register() - Allocate and register SCSI and FC host with
+ *				  SCSI midlayer
  * @adapter: The zfcp adapter to register with the SCSI midlayer
+ *
+ * Allocates the SCSI host object for the given adapter, sets basic properties
+ * (such as the transport template, QDIO limits, ...), and registers it with
+ * the midlayer.
+ *
+ * During registration with the midlayer the corresponding FC host object for
+ * the referenced transport class is also implicitely allocated.
+ *
+ * Upon success adapter->scsi_host is set, and upon failure it remains NULL. If
+ * adapter->scsi_host is already set, nothing is done.
+ *
+ * Return:
+ * * 0	     - Allocation and registration was successful
+ * * -EEXIST - SCSI and FC host did already exist, nothing was done, nothing
+ *	       was changed
+ * * -EIO    - Allocation or registration failed
  */
 int zfcp_scsi_adapter_register(struct zfcp_adapter *adapter)
 {
 	struct ccw_dev_id dev_id;
 
 	if (adapter->scsi_host)
-		return 0;
+		return -EEXIST;
 
 	ccw_device_get_id(adapter->ccw_device, &dev_id);
 	/* register adapter as SCSI host with mid layer of SCSI stack */
 	adapter->scsi_host = scsi_host_alloc(&zfcp_scsi_host_template,
 					     sizeof (struct zfcp_adapter *));
-	if (!adapter->scsi_host) {
-		dev_err(&adapter->ccw_device->dev,
-			"Registering the FCP device with the "
-			"SCSI stack failed\n");
-		return -EIO;
-	}
+	if (!adapter->scsi_host)
+		goto err_out;
 
 	/* tell the SCSI stack some characteristics of this adapter */
 	adapter->scsi_host->max_id = 511;
@@ -480,14 +493,23 @@ int zfcp_scsi_adapter_register(struct zfcp_adapter *adapter)
 	adapter->scsi_host->max_cmd_len = 16; /* in struct fcp_cmnd */
 	adapter->scsi_host->transportt = zfcp_scsi_transport_template;
 
+	/* make all basic properties known at registration time */
+	zfcp_qdio_shost_update(adapter, adapter->qdio);
+	zfcp_scsi_set_prot(adapter);
+
 	adapter->scsi_host->hostdata[0] = (unsigned long) adapter;
 
 	if (scsi_add_host(adapter->scsi_host, &adapter->ccw_device->dev)) {
 		scsi_host_put(adapter->scsi_host);
-		return -EIO;
+		goto err_out;
 	}
 
 	return 0;
+err_out:
+	adapter->scsi_host = NULL;
+	dev_err(&adapter->ccw_device->dev,
+		"Registering the FCP device with the SCSI stack failed\n");
+	return -EIO;
 }
 
 /**
@@ -841,6 +863,95 @@ void zfcp_scsi_dif_sense_error(struct scsi_cmnd *scmd, int ascq)
 	set_host_byte(scmd, DID_SOFT_ERROR);
 }
 
+void zfcp_scsi_shost_update_config_data(
+	struct zfcp_adapter *const adapter,
+	const struct fsf_qtcb_bottom_config *const bottom,
+	const bool bottom_incomplete)
+{
+	struct Scsi_Host *const shost = adapter->scsi_host;
+	const struct fc_els_flogi *nsp, *plogi;
+
+	if (shost == NULL)
+		return;
+
+	snprintf(fc_host_firmware_version(shost), FC_VERSION_STRING_SIZE,
+		 "0x%08x", bottom->lic_version);
+
+	if (adapter->adapter_features & FSF_FEATURE_HBAAPI_MANAGEMENT) {
+		snprintf(fc_host_hardware_version(shost),
+			 FC_VERSION_STRING_SIZE,
+			 "0x%08x", bottom->hardware_version);
+		memcpy(fc_host_serial_number(shost), bottom->serial_number,
+		       min(FC_SERIAL_NUMBER_SIZE, 17));
+		EBCASC(fc_host_serial_number(shost),
+		       min(FC_SERIAL_NUMBER_SIZE, 17));
+	}
+
+	/* adjust pointers for missing command code */
+	nsp = (struct fc_els_flogi *) ((u8 *)&bottom->nport_serv_param
+					- sizeof(u32));
+	plogi = (struct fc_els_flogi *) ((u8 *)&bottom->plogi_payload
+					- sizeof(u32));
+
+	snprintf(fc_host_manufacturer(shost), FC_SERIAL_NUMBER_SIZE, "%s",
+		 "IBM");
+	fc_host_port_name(shost) = be64_to_cpu(nsp->fl_wwpn);
+	fc_host_node_name(shost) = be64_to_cpu(nsp->fl_wwnn);
+	fc_host_supported_classes(shost) = FC_COS_CLASS2 | FC_COS_CLASS3;
+
+	zfcp_scsi_set_prot(adapter);
+
+	/* do not evaluate invalid fields */
+	if (bottom_incomplete)
+		return;
+
+	fc_host_port_id(shost) = ntoh24(bottom->s_id);
+	fc_host_speed(shost) =
+		zfcp_fsf_convert_portspeed(bottom->fc_link_speed);
+
+	snprintf(fc_host_model(shost), FC_SYMBOLIC_NAME_SIZE, "0x%04x",
+		 bottom->adapter_type);
+
+	switch (bottom->fc_topology) {
+	case FSF_TOPO_P2P:
+		fc_host_port_type(shost) = FC_PORTTYPE_PTP;
+		fc_host_fabric_name(shost) = 0;
+		break;
+	case FSF_TOPO_FABRIC:
+		fc_host_fabric_name(shost) = be64_to_cpu(plogi->fl_wwnn);
+		if (bottom->connection_features & FSF_FEATURE_NPIV_MODE)
+			fc_host_port_type(shost) = FC_PORTTYPE_NPIV;
+		else
+			fc_host_port_type(shost) = FC_PORTTYPE_NPORT;
+		break;
+	case FSF_TOPO_AL:
+		fc_host_port_type(shost) = FC_PORTTYPE_NLPORT;
+		fallthrough;
+	default:
+		fc_host_fabric_name(shost) = 0;
+		break;
+	}
+}
+
+void zfcp_scsi_shost_update_port_data(
+	struct zfcp_adapter *const adapter,
+	const struct fsf_qtcb_bottom_port *const bottom)
+{
+	struct Scsi_Host *const shost = adapter->scsi_host;
+
+	if (shost == NULL)
+		return;
+
+	fc_host_permanent_port_name(shost) = bottom->wwpn;
+	fc_host_maxframe_size(shost) = bottom->maximum_frame_size;
+	fc_host_supported_speeds(shost) =
+		zfcp_fsf_convert_portspeed(bottom->supported_speed);
+	memcpy(fc_host_supported_fc4s(shost), bottom->supported_fc4_types,
+	       FC_FC4_LIST_SIZE);
+	memcpy(fc_host_active_fc4s(shost), bottom->active_fc4_types,
+	       FC_FC4_LIST_SIZE);
+}
+
 struct fc_function_template zfcp_transport_functions = {
 	.show_starget_port_id = 1,
 	.show_starget_port_name = 1,
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 7ec30ded0169..8d9662e8b717 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -216,20 +216,32 @@ static ssize_t zfcp_sysfs_port_rescan_store(struct device *dev,
 {
 	struct ccw_device *cdev = to_ccwdev(dev);
 	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
+	int retval = 0;
 
 	if (!adapter)
 		return -ENODEV;
 
 	/*
+	 * If `scsi_host` is missing, we can't schedule `scan_work`, as it
+	 * makes use of the corresponding fc_host object. But this state is
+	 * only possible if xconfig/xport data has never completed yet,
+	 * and we couldn't successfully scan for ports anyway.
+	 */
+	if (adapter->scsi_host == NULL) {
+		retval = -ENODEV;
+		goto out;
+	}
+
+	/*
 	 * Users wish is our command: immediately schedule and flush a
 	 * worker to conduct a synchronous port scan, that is, neither
 	 * a random delay nor a rate limit is applied here.
 	 */
 	queue_delayed_work(adapter->work_queue, &adapter->scan_work, 0);
 	flush_delayed_work(&adapter->scan_work);
+out:
 	zfcp_ccw_adapter_put(adapter);
-
-	return (ssize_t) count;
+	return retval ? retval : (ssize_t) count;
 }
 static ZFCP_DEV_ATTR(adapter, port_rescan, S_IWUSR, NULL,
 		     zfcp_sysfs_port_rescan_store);