s390/qdio: put thinint indicator after early error

BugLink: https://bugs.launchpad.net/bugs/1885932

[ Upstream commit 75e82bec ]

qdio_establish() calls qdio_setup_thinint() via qdio_setup_irq().
If the subsequent qdio_establish_thinint() fails, we miss to put the
DSCI again. Thus the DSCI isn't available for re-use. Given enough of
such errors, we could end up with having only the shared DSCI available.

Merge qdio_setup_thinint() into qdio_establish_thinint(), and deal with
such an error internally.

Fixes: 779e6e1c ("[S390] qdio: new qdio driver.")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

drivers/s390/cio/qdio.h

@@ -376,7 +376,6 @@ static inline int multicast_outbound(struct qdio_q *q)
 extern u64 last_ai_time;
 
 /* prototypes for thin interrupt */
-void qdio_setup_thinint(struct qdio_irq *irq_ptr);
 int qdio_establish_thinint(struct qdio_irq *irq_ptr);
 void qdio_shutdown_thinint(struct qdio_irq *irq_ptr);
 void tiqdio_add_input_queues(struct qdio_irq *irq_ptr);

drivers/s390/cio/qdio_setup.c

@@ -479,7 +479,6 @@ int qdio_setup_irq(struct qdio_initialize *init_data)
 	setup_queues(irq_ptr, init_data);
 
 	setup_qib(irq_ptr, init_data);
-	qdio_setup_thinint(irq_ptr);
 	set_impl_params(irq_ptr, init_data->qib_param_field_format,
 			init_data->qib_param_field,
 			init_data->input_slib_elements,

drivers/s390/cio/qdio_thinint.c

@@ -268,17 +268,19 @@ int __init tiqdio_register_thinints(void)
 
 int qdio_establish_thinint(struct qdio_irq *irq_ptr)
 {
+	int rc;
+
 	if (!is_thinint_irq(irq_ptr))
 		return 0;
-	return set_subchannel_ind(irq_ptr, 0);
-}
 
-void qdio_setup_thinint(struct qdio_irq *irq_ptr)
-{
-	if (!is_thinint_irq(irq_ptr))
-		return;
 	irq_ptr->dsci = get_indicator();
 	DBF_HEX(&irq_ptr->dsci, sizeof(void *));
+
+	rc = set_subchannel_ind(irq_ptr, 0);
+	if (rc)
+		put_indicator(irq_ptr->dsci);
+
+	return rc;
 }
 
 void qdio_shutdown_thinint(struct qdio_irq *irq_ptr)