irqdomain: Add irq domain MSI and MSI_REMAP flags

We introduce two new enum values for the irq domain flag:
- IRQ_DOMAIN_FLAG_MSI indicates the irq domain corresponds to
  an MSI domain
- IRQ_DOMAIN_FLAG_MSI_REMAP indicates the irq domain has MSI
  remapping capabilities.

Those values will be useful to check all MSI irq domains have
MSI remapping support when assessing the safety of IRQ assignment
to a guest.

irq_domain_hierarchical_is_msi_remap() allows to check if an
irq domain or any parent implements MSI remapping.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com>
Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com>
Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 8c0a0ae43521..876e13172dc8 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1392,6 +1392,20 @@ static void irq_domain_check_hierarchy(struct irq_domain *domain)
 	if (domain->ops->alloc)
 		domain->flags |= IRQ_DOMAIN_FLAG_HIERARCHY;
 }
+
+/**
+ * irq_domain_hierarchical_is_msi_remap - Check if the domain or any
+ * parent has MSI remapping support
+ * @domain: domain pointer
+ */
+bool irq_domain_hierarchical_is_msi_remap(struct irq_domain *domain)
+{
+	for (; domain; domain = domain->parent) {
+		if (irq_domain_is_msi_remap(domain))
+			return true;
+	}
+	return false;
+}
 #else	/* CONFIG_IRQ_DOMAIN_HIERARCHY */
 /**
  * irq_domain_get_irq_data - Get irq_data associated with @virq and @domain