[PATCH v2 5/9] irqdomain: Let irq_find_host default to DOMAIN_BUS_WIRED

From: Marc Zyngier
Date: Tue May 08 2018 - 08:15:14 EST

At the beginning of times, irq_find_host() was simple. Each device node
implemented at most one irq domain, and we were happy. Over time, things
have become more complex, and we now have nodes implementing a plurality
of domains, tagged by "bus_token".

Crutially, users of irq_find_host() all expect the most basic domain
to be returned, and not any other domain such as a bus-specific MSI

So let's change irq_find_host() to first look for a DOMAIN_BUS_WIRED
domain, and only if this fails fallback to DOMAIN_BUS_ANY. Note that
this is consistent with what irq_create_fwspec_mapping is already
doing, see 530cbe100ef7 ("irqdomain: Allow domain lookup with

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
include/linux/irqdomain.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 48c7e86bb556..dccfa65aee96 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -301,7 +301,13 @@ static inline struct irq_domain *irq_find_matching_host(struct device_node *node

static inline struct irq_domain *irq_find_host(struct device_node *node)
- return irq_find_matching_host(node, DOMAIN_BUS_ANY);
+ struct irq_domain *d;
+ d = irq_find_matching_host(node, DOMAIN_BUS_WIRED);
+ if (!d)
+ d = irq_find_matching_host(node, DOMAIN_BUS_ANY);
+ return d;