genirq/msi: Check for invalid MSI parent domain usage

In the upcoming per device MSI domain concept the MSI parent domains are not allowed to be used as regular MSI domains where the MSI allocation/free operations are applicable. Add appropriate checks. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Kevin Tian <[email protected]> Acked-by: Marc Zyngier <[email protected]> Link: https://lore.kernel.org/r/[email protected]
chewitt · Dec 5, 2022 · 3e86a3a · 3e86a3a
1 parent e71c5d0
commit 3e86a3a
Showing 1 changed file with 14 additions and 3 deletions.
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
@@ -937,13 +937,21 @@ int msi_domain_alloc_irqs_descs_locked(struct irq_domain *domain, struct device
 
 	lockdep_assert_held(&dev->msi.data->mutex);
 
+	if (WARN_ON_ONCE(irq_domain_is_msi_parent(domain))) {
+		ret = -EINVAL;
+		goto free;
+	}
+
+	/* Frees allocated descriptors in case of failure. */
 	ret = msi_domain_add_simple_msi_descs(info, dev, nvec);
 	if (ret)
-		return ret;
+		goto free;
 
 	ret = ops->domain_alloc_irqs(domain, dev, nvec);
-	if (ret)
-		msi_domain_free_irqs_descs_locked(domain, dev);
+	if (!ret)
+		return 0;
+free:
+	msi_domain_free_irqs_descs_locked(domain, dev);
 	return ret;
 }
 
@@ -1013,6 +1021,9 @@ void msi_domain_free_irqs_descs_locked(struct irq_domain *domain, struct device
 
 	lockdep_assert_held(&dev->msi.data->mutex);
 
+	if (WARN_ON_ONCE(irq_domain_is_msi_parent(domain)))
+		return;
+
 	ops->domain_free_irqs(domain, dev);
 	if (ops->msi_post_free)
 		ops->msi_post_free(domain, dev);