irqdomain: Let irq_find_host default to DOMAIN_BUS_WIRED

Marc Zyngier · KAGA-KOKO · commit 6461934371bf · 2018-05-13T15:59:00.000+02:00
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 domain. 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 530cbe1 ("irqdomain: Allow domain lookup with DOMAIN_BUS_WIRED token"). Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Rob Herring <robh@kernel.org> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lkml.kernel.org/r/20180508121438.11301-6-marc.zyngier@arm.com
diff --git 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;
 }
 
 /**

Original file line number	Diff line number	Diff line change
`@@ -301,7 +301,13 @@ static inline struct irq_domain irq_find_matching_host(struct device_node node`
`301`	`301`
`302`	`302`	`static inline struct irq_domain irq_find_host(struct device_node node)`
`303`	`303`	`{`
`304`		`- return irq_find_matching_host(node, DOMAIN_BUS_ANY);`
	`304`	`+ struct irq_domain *d;`
	`305`	`+`
	`306`	`+ d = irq_find_matching_host(node, DOMAIN_BUS_WIRED);`
	`307`	`+ if (!d)`
	`308`	`+ d = irq_find_matching_host(node, DOMAIN_BUS_ANY);`
	`309`	`+`
	`310`	`+ return d;`
`305`	`311`	`}`
`306`	`312`
`307`	`313`	`/**`