cobalt/intr: Add error handling to xnintr_affinity

This function should respect the supported cpu set and report an error
if the specified set has no intersection with it. It should also return
potential errors for the underlying pipeline code.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

include/cobalt/kernel/intr.h

@@ -124,8 +124,7 @@ void xnintr_enable(struct xnintr *intr);
 
 void xnintr_disable(struct xnintr *intr);
 
-void xnintr_affinity(struct xnintr *intr,
-		     const cpumask_t *cpumask);
+int xnintr_affinity(struct xnintr *intr, const cpumask_t *cpumask);
 
 #ifdef CONFIG_XENO_OPT_STATS_IRQS
 

kernel/cobalt/dovetail/intr.c

@@ -118,13 +118,16 @@ void xnintr_disable(struct xnintr *intr)
 }
 EXPORT_SYMBOL_GPL(xnintr_disable);
 
-void xnintr_affinity(struct xnintr *intr, const cpumask_t *cpumask)
+int xnintr_affinity(struct xnintr *intr, const cpumask_t *cpumask)
 {
-	int ret;
+	cpumask_t effective_mask;
 
 	secondary_mode_only();
-	ret = irq_set_affinity_hint(intr->irq, cpumask);
 
-	WARN_ON_ONCE(ret);
+	cpumask_and(&effective_mask, &xnsched_realtime_cpus, cpumask);
+	if (cpumask_empty(&effective_mask))
+		return -EINVAL;
+
+	return irq_set_affinity_hint(intr->irq, &effective_mask);
 }
 EXPORT_SYMBOL_GPL(xnintr_affinity);

kernel/cobalt/ipipe/intr.c

@@ -992,11 +992,21 @@ EXPORT_SYMBOL_GPL(xnintr_disable);
  *
  * @coretags{secondary-only}
  */
-void xnintr_affinity(struct xnintr *intr, const cpumask_t *cpumask)
+int xnintr_affinity(struct xnintr *intr, const cpumask_t *cpumask)
 {
-	secondary_mode_only();
 #ifdef CONFIG_SMP
-	ipipe_set_irq_affinity(intr->irq, *cpumask);
+	cpumask_t effective_mask;
+
+	secondary_mode_only();
+
+	cpumask_and(&effective_mask, &xnsched_realtime_cpus, cpumask);
+	if (cpumask_empty(&effective_mask))
+		return -EINVAL;
+
+	return ipipe_set_irq_affinity(intr->irq, effective_mask);
+#else
+	secondary_mode_only();
+	return 0;
 #endif
 }
 EXPORT_SYMBOL_GPL(xnintr_affinity);