diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c
index 15ce75b925457eb34573f50f90518420d6eae2ff..b6b8c47b258816ecee7a5f5a5313c347f38c28c3 100644
--- a/drivers/acpi/irq.c
+++ b/drivers/acpi/irq.c
@@ -13,6 +13,7 @@
 enum acpi_irq_model_id acpi_irq_model;
 
 static struct fwnode_handle *(*acpi_get_gsi_domain_id)(u32 gsi);
+static u32 (*acpi_gsi_to_irq_fallback)(u32 gsi);
 
 /**
  * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
@@ -32,9 +33,12 @@ int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
 					DOMAIN_BUS_ANY);
 	*irq = irq_find_mapping(d, gsi);
 	/*
-	 * *irq == 0 means no mapping, that should
-	 * be reported as a failure
+	 * *irq == 0 means no mapping, that should be reported as a
+	 * failure, unless there is an arch-specific fallback handler.
 	 */
+	if (!*irq && acpi_gsi_to_irq_fallback)
+		*irq = acpi_gsi_to_irq_fallback(gsi);
+
 	return (*irq > 0) ? 0 : -EINVAL;
 }
 EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
@@ -300,6 +304,16 @@ void __init acpi_set_irq_model(enum acpi_irq_model_id model,
 	acpi_get_gsi_domain_id = fn;
 }
 
+/**
+ * acpi_set_gsi_to_irq_fallback - Register a GSI transfer
+ * callback to fallback to arch specified implementation.
+ * @fn: arch-specific fallback handler
+ */
+void __init acpi_set_gsi_to_irq_fallback(u32 (*fn)(u32))
+{
+	acpi_gsi_to_irq_fallback = fn;
+}
+
 /**
  * acpi_irq_create_hierarchy - Create a hierarchical IRQ domain with the default
  *                             GSI domain as its parent.
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index f4799d9384266acc5b6785007dba61d2ea0eb5c8..9f7f9a0d724fe6c11c8875222962812e7a0135ed 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -333,6 +333,7 @@ int acpi_isa_irq_to_gsi (unsigned isa_irq, u32 *gsi);
 
 void acpi_set_irq_model(enum acpi_irq_model_id model,
 			struct fwnode_handle *(*)(u32));
+void acpi_set_gsi_to_irq_fallback(u32 (*)(u32));
 
 struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags,
 					     unsigned int size,