irqdomain: Look for existing mapping only once
Avoid looking for an existing mapping twice when creating a new mapping
using irq_create_fwspec_mapping() by factoring out the actual allocation
which is shared with irq_create_mapping_affinity().
The new helper function will also be used to fix a shared-interrupt
mapping race, hence the Fixes tag.
Fixes: b62b2cf5759b ("irqdomain: Fix handling of type settings for existing mappings")
Cc: stable@vger.kernel.org # 4.8
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-5-johan+linaro@kernel.org
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 9f5b96c..9f95047 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -682,44 +682,15 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
#endif
-/**
- * irq_create_mapping_affinity() - Map a hardware interrupt into linux irq space
- * @domain: domain owning this hardware interrupt or NULL for default domain
- * @hwirq: hardware irq number in that domain space
- * @affinity: irq affinity
- *
- * Only one mapping per hardware interrupt is permitted. Returns a linux
- * irq number.
- * If the sense/trigger is to be specified, set_irq_type() should be called
- * on the number returned from that call.
- */
-unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
- irq_hw_number_t hwirq,
- const struct irq_affinity_desc *affinity)
+static unsigned int __irq_create_mapping_affinity(struct irq_domain *domain,
+ irq_hw_number_t hwirq,
+ const struct irq_affinity_desc *affinity)
{
- struct device_node *of_node;
+ struct device_node *of_node = irq_domain_get_of_node(domain);
int virq;
pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
- /* Look for default domain if necessary */
- if (domain == NULL)
- domain = irq_default_domain;
- if (domain == NULL) {
- WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
- return 0;
- }
- pr_debug("-> using domain @%p\n", domain);
-
- of_node = irq_domain_get_of_node(domain);
-
- /* Check if mapping already exists */
- virq = irq_find_mapping(domain, hwirq);
- if (virq) {
- pr_debug("-> existing mapping on virq %d\n", virq);
- return virq;
- }
-
/* Allocate a virtual interrupt number */
virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node),
affinity);
@@ -738,6 +709,41 @@ unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
return virq;
}
+
+/**
+ * irq_create_mapping_affinity() - Map a hardware interrupt into linux irq space
+ * @domain: domain owning this hardware interrupt or NULL for default domain
+ * @hwirq: hardware irq number in that domain space
+ * @affinity: irq affinity
+ *
+ * Only one mapping per hardware interrupt is permitted. Returns a linux
+ * irq number.
+ * If the sense/trigger is to be specified, set_irq_type() should be called
+ * on the number returned from that call.
+ */
+unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
+ irq_hw_number_t hwirq,
+ const struct irq_affinity_desc *affinity)
+{
+ int virq;
+
+ /* Look for default domain if necessary */
+ if (domain == NULL)
+ domain = irq_default_domain;
+ if (domain == NULL) {
+ WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
+ return 0;
+ }
+
+ /* Check if mapping already exists */
+ virq = irq_find_mapping(domain, hwirq);
+ if (virq) {
+ pr_debug("existing mapping on virq %d\n", virq);
+ return virq;
+ }
+
+ return __irq_create_mapping_affinity(domain, hwirq, affinity);
+}
EXPORT_SYMBOL_GPL(irq_create_mapping_affinity);
static int irq_domain_translate(struct irq_domain *d,
@@ -841,7 +847,7 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
return 0;
} else {
/* Create mapping */
- virq = irq_create_mapping(domain, hwirq);
+ virq = __irq_create_mapping_affinity(domain, hwirq, NULL);
if (!virq)
return virq;
}
