1 files changed, 97 insertions, 41 deletions

diff --git a/drivers/s390/cio/qdio_thinint.c b/drivers/s390/cio/qdio_thinint.c
index 2a1d4dfaf859..011eadea3ee4 100644
--- a/drivers/s390/cio/qdio_thinint.c
+++ b/drivers/s390/cio/qdio_thinint.c
@@ -26,17 +26,24 @@
  */
 #define TIQDIO_NR_NONSHARED_IND		63
 #define TIQDIO_NR_INDICATORS		(TIQDIO_NR_NONSHARED_IND + 1)
+#define TIQDIO_SHARED_IND		63
+
+/* device state change indicators */
+struct indicator_t {
+	u32 ind;	/* u32 because of compare-and-swap performance */
+	atomic_t count; /* use count, 0 or 1 for non-shared indicators */
+};
 
 /* list of thin interrupt input queues */
 static LIST_HEAD(tiq_list);
-DEFINE_MUTEX(tiq_list_lock);
+static DEFINE_MUTEX(tiq_list_lock);
 
 /* adapter local summary indicator */
 static u8 *tiqdio_alsi;
 
-struct indicator_t *q_indicators;
+static struct indicator_t *q_indicators;
 
-static u64 last_ai_time;
+u64 last_ai_time;
 
 /* returns addr for the device state change indicator */
 static u32 *get_indicator(void)
@@ -67,12 +74,9 @@ static void put_indicator(u32 *addr)
 
 void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
 {
-	struct qdio_q *q;
-	int i;
-
 	mutex_lock(&tiq_list_lock);
-	for_each_input_queue(irq_ptr, q, i)
-		list_add_rcu(&q->entry, &tiq_list);
+	BUG_ON(irq_ptr->nr_input_qs < 1);
+	list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list);
 	mutex_unlock(&tiq_list_lock);
 	xchg(irq_ptr->dsci, 1 << 7);
 }
@@ -80,19 +84,54 @@ void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
 void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
 {
 	struct qdio_q *q;
-	int i;
 
-	for (i = 0; i < irq_ptr->nr_input_qs; i++) {
-		q = irq_ptr->input_qs[i];
-		/* if establish triggered an error */
-		if (!q || !q->entry.prev || !q->entry.next)
-			continue;
+	BUG_ON(irq_ptr->nr_input_qs < 1);
+	q = irq_ptr->input_qs[0];
+	/* if establish triggered an error */
+	if (!q || !q->entry.prev || !q->entry.next)
+		return;
 
-		mutex_lock(&tiq_list_lock);
-		list_del_rcu(&q->entry);
-		mutex_unlock(&tiq_list_lock);
-		synchronize_rcu();
-	}
+	mutex_lock(&tiq_list_lock);
+	list_del_rcu(&q->entry);
+	mutex_unlock(&tiq_list_lock);
+	synchronize_rcu();
+}
+
+static inline int has_multiple_inq_on_dsci(struct qdio_irq *irq_ptr)
+{
+	return irq_ptr->nr_input_qs > 1;
+}
+
+static inline int references_shared_dsci(struct qdio_irq *irq_ptr)
+{
+	return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind;
+}
+
+static inline int shared_ind(struct qdio_irq *irq_ptr)
+{
+	return references_shared_dsci(irq_ptr) ||
+		has_multiple_inq_on_dsci(irq_ptr);
+}
+
+void clear_nonshared_ind(struct qdio_irq *irq_ptr)
+{
+	if (!is_thinint_irq(irq_ptr))
+		return;
+	if (shared_ind(irq_ptr))
+		return;
+	xchg(irq_ptr->dsci, 0);
+}
+
+int test_nonshared_ind(struct qdio_irq *irq_ptr)
+{
+	if (!is_thinint_irq(irq_ptr))
+		return 0;
+	if (shared_ind(irq_ptr))
+		return 0;
+	if (*irq_ptr->dsci)
+		return 1;
+	else
+		return 0;
 }
 
 static inline u32 clear_shared_ind(void)
@@ -102,6 +141,40 @@ static inline u32 clear_shared_ind(void)
 	return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
 }
 
+static inline void tiqdio_call_inq_handlers(struct qdio_irq *irq)
+{
+	struct qdio_q *q;
+	int i;
+
+	for_each_input_queue(irq, q, i) {
+		if (!references_shared_dsci(irq) &&
+		    has_multiple_inq_on_dsci(irq))
+			xchg(q->irq_ptr->dsci, 0);
+
+		if (q->u.in.queue_start_poll) {
+			/* skip if polling is enabled or already in work */
+			if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED,
+					     &q->u.in.queue_irq_state)) {
+				qperf_inc(q, int_discarded);
+				continue;
+			}
+
+			/* avoid dsci clear here, done after processing */
+			q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr,
+						 q->irq_ptr->int_parm);
+		} else {
+			if (!shared_ind(q->irq_ptr))
+				xchg(q->irq_ptr->dsci, 0);
+
+			/*
+			 * Call inbound processing but not directly
+			 * since that could starve other thinint queues.
+			 */
+			tasklet_schedule(&q->tasklet);
+		}
+	}
+}
+
 /**
  * tiqdio_thinint_handler - thin interrupt handler for qdio
  * @alsi: pointer to adapter local summary indicator
@@ -120,35 +193,18 @@ static void tiqdio_thinint_handler(void *alsi, void *data)
 
 	/* check for work on all inbound thinint queues */
 	list_for_each_entry_rcu(q, &tiq_list, entry) {
+		struct qdio_irq *irq;
 
 		/* only process queues from changed sets */
-		if (unlikely(shared_ind(q->irq_ptr->dsci))) {
+		irq = q->irq_ptr;
+		if (unlikely(references_shared_dsci(irq))) {
 			if (!si_used)
 				continue;
-		} else if (!*q->irq_ptr->dsci)
+		} else if (!*irq->dsci)
 			continue;
 
-		if (q->u.in.queue_start_poll) {
-			/* skip if polling is enabled or already in work */
-			if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED,
-					     &q->u.in.queue_irq_state)) {
-				qperf_inc(q, int_discarded);
-				continue;
-			}
+		tiqdio_call_inq_handlers(irq);
 
-			/* avoid dsci clear here, done after processing */
-			q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr,
-						 q->irq_ptr->int_parm);
-		} else {
-			/* only clear it if the indicator is non-shared */
-			if (!shared_ind(q->irq_ptr->dsci))
-				xchg(q->irq_ptr->dsci, 0);
-			/*
-			 * Call inbound processing but not directly
-			 * since that could starve other thinint queues.
-			 */
-			tasklet_schedule(&q->tasklet);
-		}
 		qperf_inc(q, adapter_int);
 	}
 	rcu_read_unlock();