[SCSI] zfcp: Post events through FC transport class

Post FC transport class netlink events for usage in the userspace,
e.g. for HBAAPI. Supported events are those required for the
polled events in HBAAPI.
- link up
- link down
- incoming RSCN
(events related to FC-AL are not supported, as zfcp has no support for FC-AL)

Signed-off-by: Sven Schuetz <sven@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/s390/scsi/zfcp_aux.c

@@ -524,6 +524,10 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 	rwlock_init(&adapter->port_list_lock);
 	INIT_LIST_HEAD(&adapter->port_list);
 
+	INIT_LIST_HEAD(&adapter->events.list);
+	INIT_WORK(&adapter->events.work, zfcp_fc_post_event);
+	spin_lock_init(&adapter->events.list_lock);
+
 	init_waitqueue_head(&adapter->erp_ready_wq);
 	init_waitqueue_head(&adapter->erp_done_wqh);
 

drivers/s390/scsi/zfcp_def.h

@@ -37,6 +37,7 @@
 #include <asm/ebcdic.h>
 #include <asm/sysinfo.h>
 #include "zfcp_fsf.h"
+#include "zfcp_fc.h"
 #include "zfcp_qdio.h"
 
 struct zfcp_reqlist;
@@ -190,6 +191,7 @@ struct zfcp_adapter {
 	struct service_level	service_level;
 	struct workqueue_struct	*work_queue;
 	struct device_dma_parameters dma_parms;
+	struct zfcp_fc_events events;
 };
 
 struct zfcp_port {

drivers/s390/scsi/zfcp_ext.h

@@ -96,6 +96,9 @@ extern void zfcp_erp_adapter_access_changed(struct zfcp_adapter *, char *,
 extern void zfcp_erp_timeout_handler(unsigned long);
 
 /* zfcp_fc.c */
+extern void zfcp_fc_enqueue_event(struct zfcp_adapter *,
+				enum fc_host_event_code event_code, u32);
+extern void zfcp_fc_post_event(struct work_struct *);
 extern void zfcp_fc_scan_ports(struct work_struct *);
 extern void zfcp_fc_incoming_els(struct zfcp_fsf_req *);
 extern void zfcp_fc_port_did_lookup(struct work_struct *);

drivers/s390/scsi/zfcp_fc.c

@@ -23,6 +23,58 @@ static u32 zfcp_fc_rscn_range_mask[] = {
 	[ELS_ADDR_FMT_FAB]		= 0x000000,
 };
 
+/**
+ * zfcp_fc_post_event - post event to userspace via fc_transport
+ * @work: work struct with enqueued events
+ */
+void zfcp_fc_post_event(struct work_struct *work)
+{
+	struct zfcp_fc_event *event = NULL, *tmp = NULL;
+	LIST_HEAD(tmp_lh);
+	struct zfcp_fc_events *events = container_of(work,
+					struct zfcp_fc_events, work);
+	struct zfcp_adapter *adapter = container_of(events, struct zfcp_adapter,
+						events);
+
+	spin_lock_bh(&events->list_lock);
+	list_splice_init(&events->list, &tmp_lh);
+	spin_unlock_bh(&events->list_lock);
+
+	list_for_each_entry_safe(event, tmp, &tmp_lh, list) {
+		fc_host_post_event(adapter->scsi_host, fc_get_event_number(),
+				event->code, event->data);
+		list_del(&event->list);
+		kfree(event);
+	}
+
+}
+
+/**
+ * zfcp_fc_enqueue_event - safely enqueue FC HBA API event from irq context
+ * @adapter: The adapter where to enqueue the event
+ * @event_code: The event code (as defined in fc_host_event_code in
+ *		scsi_transport_fc.h)
+ * @event_data: The event data (e.g. n_port page in case of els)
+ */
+void zfcp_fc_enqueue_event(struct zfcp_adapter *adapter,
+			enum fc_host_event_code event_code, u32 event_data)
+{
+	struct zfcp_fc_event *event;
+
+	event = kmalloc(sizeof(struct zfcp_fc_event), GFP_ATOMIC);
+	if (!event)
+		return;
+
+	event->code = event_code;
+	event->data = event_data;
+
+	spin_lock(&adapter->events.list_lock);
+	list_add_tail(&event->list, &adapter->events.list);
+	spin_unlock(&adapter->events.list_lock);
+
+	queue_work(adapter->work_queue, &adapter->events.work);
+}
+
 static int zfcp_fc_wka_port_get(struct zfcp_fc_wka_port *wka_port)
 {
 	if (mutex_lock_interruptible(&wka_port->mutex))
@@ -148,6 +200,8 @@ static void zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req)
 		afmt = page->rscn_page_flags & ELS_RSCN_ADDR_FMT_MASK;
 		_zfcp_fc_incoming_rscn(fsf_req, zfcp_fc_rscn_range_mask[afmt],
 				       page);
+		zfcp_fc_enqueue_event(fsf_req->adapter, FCH_EVT_RSCN,
+				      *(u32 *)page);
 	}
 	queue_work(fsf_req->adapter->work_queue, &fsf_req->adapter->scan_work);
 }

drivers/s390/scsi/zfcp_fc.h

@@ -29,6 +29,30 @@
 
 #define ZFCP_FC_CTELS_TMO	(2 * FC_DEF_R_A_TOV / 1000)
 
+/**
+ * struct zfcp_fc_event - FC HBAAPI event for internal queueing from irq context
+ * @code: Event code
+ * @data: Event data
+ * @list: list_head for zfcp_fc_events list
+ */
+struct zfcp_fc_event {
+	enum fc_host_event_code code;
+	u32 data;
+	struct list_head list;
+};
+
+/**
+ * struct zfcp_fc_events - Infrastructure for posting FC events from irq context
+ * @list: List for queueing of events from irq context to workqueue
+ * @list_lock: Lock for event list
+ * @work: work_struct for forwarding events in workqueue
+*/
+struct zfcp_fc_events {
+	struct list_head list;
+	spinlock_t list_lock;
+	struct work_struct work;
+};
+
 /**
  * struct zfcp_fc_gid_pn_req - container for ct header plus gid_pn request
  * @ct_hdr: FC GS common transport header

drivers/s390/scsi/zfcp_fsf.c

@@ -274,6 +274,7 @@ static void zfcp_fsf_status_read_handler(struct zfcp_fsf_req *req)
 		break;
 	case FSF_STATUS_READ_LINK_DOWN:
 		zfcp_fsf_status_read_link_down(req);
+		zfcp_fc_enqueue_event(adapter, FCH_EVT_LINKDOWN, 0);
 		break;
 	case FSF_STATUS_READ_LINK_UP:
 		dev_info(&adapter->ccw_device->dev,
@@ -286,6 +287,8 @@ static void zfcp_fsf_status_read_handler(struct zfcp_fsf_req *req)
 					ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
 					ZFCP_STATUS_COMMON_ERP_FAILED,
 					"fssrh_2", req);
+		zfcp_fc_enqueue_event(adapter, FCH_EVT_LINKUP, 0);
+
 		break;
 	case FSF_STATUS_READ_NOTIFICATION_LOST:
 		if (sr_buf->status_subtype & FSF_STATUS_READ_SUB_ACT_UPDATED)