[patch 06/20] genirq/msi: Check for invalid MSI parent domain usage

Thomas Gleixner
2022-11-11T14:01:24Z

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 <tglx@linutronix.de>
---
kernel/irq/msi.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -937,13 +937,21 @@ int msi_domain_alloc_irqs_descs_locked(s

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;

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(s

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);