[SCSI] zfcp: Simplify latency lock handling

The lock only needs to protect the softirq context called from qdio
against the userspace context called from sysfs. spin_lock and
spin_lock_bh is enough.

Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/s390/scsi/zfcp_fsf.c

@@ -2069,7 +2069,6 @@ static void zfcp_fsf_req_latency(struct zfcp_fsf_req *req)
 	struct fsf_qual_latency_info *lat_inf;
 	struct latency_cont *lat;
 	struct zfcp_unit *unit = req->unit;
-	unsigned long flags;
 
 	lat_inf = &req->qtcb->prefix.prot_status_qual.latency_info;
 
@@ -2087,11 +2086,11 @@ static void zfcp_fsf_req_latency(struct zfcp_fsf_req *req)
 		return;
 	}
 
-	spin_lock_irqsave(&unit->latencies.lock, flags);
+	spin_lock(&unit->latencies.lock);
 	zfcp_fsf_update_lat(&lat->channel, lat_inf->channel_lat);
 	zfcp_fsf_update_lat(&lat->fabric, lat_inf->fabric_lat);
 	lat->counter++;
-	spin_unlock_irqrestore(&unit->latencies.lock, flags);
+	spin_unlock(&unit->latencies.lock);
 }
 
 #ifdef CONFIG_BLK_DEV_IO_TRACE

drivers/s390/scsi/zfcp_sysfs.c

@@ -318,10 +318,9 @@ zfcp_sysfs_unit_##_name##_latency_show(struct device *dev,		\
 	struct zfcp_unit *unit = sdev->hostdata;			\
 	struct zfcp_latencies *lat = &unit->latencies;			\
 	struct zfcp_adapter *adapter = unit->port->adapter;		\
-	unsigned long flags;						\
 	unsigned long long fsum, fmin, fmax, csum, cmin, cmax, cc;	\
 									\
-	spin_lock_irqsave(&lat->lock, flags);				\
+	spin_lock_bh(&lat->lock);					\
 	fsum = lat->_name.fabric.sum * adapter->timer_ticks;		\
 	fmin = lat->_name.fabric.min * adapter->timer_ticks;		\
 	fmax = lat->_name.fabric.max * adapter->timer_ticks;		\
@@ -329,7 +328,7 @@ zfcp_sysfs_unit_##_name##_latency_show(struct device *dev,		\
 	cmin = lat->_name.channel.min * adapter->timer_ticks;		\
 	cmax = lat->_name.channel.max * adapter->timer_ticks;		\
 	cc  = lat->_name.counter;					\
-	spin_unlock_irqrestore(&lat->lock, flags);			\
+	spin_unlock_bh(&lat->lock);					\
 									\
 	do_div(fsum, 1000);						\
 	do_div(fmin, 1000);						\