s390/airq: remove lsi_mask from airq_struct

Remove the field `lsi_mask` from `struct airq_struct` as it is not
utilized for any adapter interrupt, other than setting it to the default
value of 0xff.

Because nobody is using this functionality, all it does is cost a little
bit of time with each delivered adapter interrupt.

Reviewed-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

Author: Benjamin-Block

arch/s390/include/asm/airq.h

@@ -18,7 +18,6 @@ struct airq_struct {
 	struct hlist_node list;		/* Handler queueing. */
 	void (*handler)(struct airq_struct *airq, struct tpi_info *tpi_info);
 	u8 *lsi_ptr;			/* Local-Summary-Indicator pointer */
-	u8 lsi_mask;			/* Local-Summary-Indicator mask */
 	u8 isc;				/* Interrupt-subclass */
 	u8 flags;
 };

arch/s390/kvm/interrupt.c

@@ -3398,7 +3398,6 @@ static void gib_alert_irq_handler(struct airq_struct *airq,
 
 static struct airq_struct gib_alert_irq = {
 	.handler = gib_alert_irq_handler,
-	.lsi_ptr = &gib_alert_irq.lsi_mask,
 };
 
 void kvm_s390_gib_destroy(void)
@@ -3438,6 +3437,8 @@ int __init kvm_s390_gib_init(u8 nisc)
 		rc = -EIO;
 		goto out_free_gib;
 	}
+	/* adapter interrupts used for AP (applicable here) don't use the LSI */
+	*gib_alert_irq.lsi_ptr = 0xff;
 
 	gib->nisc = nisc;
 	gib_origin = virt_to_phys(gib);

drivers/s390/cio/airq.c

@@ -49,8 +49,6 @@ int register_adapter_interrupt(struct airq_struct *airq)
 			return -ENOMEM;
 		airq->flags |= AIRQ_PTR_ALLOCATED;
 	}
-	if (!airq->lsi_mask)
-		airq->lsi_mask = 0xff;
 	snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%p", airq);
 	CIO_TRACE_EVENT(4, dbf_txt);
 	isc_register(airq->isc);
@@ -98,7 +96,7 @@ static irqreturn_t do_airq_interrupt(int irq, void *dummy)
 	head = &airq_lists[tpi_info->isc];
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(airq, head, list)
-		if ((*airq->lsi_ptr & airq->lsi_mask) != 0)
+		if (*airq->lsi_ptr != 0)
 			airq->handler(airq, tpi_info);
 	rcu_read_unlock();
 

drivers/s390/virtio/virtio_ccw.c

@@ -250,7 +250,6 @@ static struct airq_info *new_airq_info(int index)
 	info->airq.handler = virtio_airq_handler;
 	info->summary_indicator_idx = index;
 	info->airq.lsi_ptr = get_summary_indicator(info);
-	info->airq.lsi_mask = 0xff;
 	info->airq.isc = VIRTIO_AIRQ_ISC;
 	rc = register_adapter_interrupt(&info->airq);
 	if (rc) {