diff --git a/arch/loongarch/include/asm/numa.h b/arch/loongarch/include/asm/numa.h
index 27f319b498625718d2349618d39008327b2f9935..564c27d2de726b0a09ad7958190fa341b2dd9693 100644
--- a/arch/loongarch/include/asm/numa.h
+++ b/arch/loongarch/include/asm/numa.h
@@ -12,6 +12,7 @@
 #include <linux/nodemask.h>
 
 #define NODE_ADDRSPACE_SHIFT 44
+#define NODES_PER_FLATMODE_NODE 4
 
 #define pa_to_nid(addr)		(((addr) & 0xf00000000000) >> NODE_ADDRSPACE_SHIFT)
 #define nid_to_addrbase(nid)	(_ULCAST_(nid) << NODE_ADDRSPACE_SHIFT)
diff --git a/drivers/irqchip/irq-loongson-eiointc.c b/drivers/irqchip/irq-loongson-eiointc.c
index c5c26b8e8d0c5cd6ca29d3ad9928f94d33ab3b48..488951a740cde11d0a50d76ce3b00a419fffd531 100644
--- a/drivers/irqchip/irq-loongson-eiointc.c
+++ b/drivers/irqchip/irq-loongson-eiointc.c
@@ -375,7 +375,7 @@ int __init pch_msi_parse_madt(union acpi_subtable_headers *header,
 	int node;
 
 	if (cpu_has_flatmode)
-		node = cpu_to_node(eiointc_priv[nr_pics - 1]->node * CORES_PER_EIO_NODE);
+		node = eiointc_priv[nr_pics - 1]->node / NODES_PER_FLATMODE_NODE;
 	else
 		node = eiointc_priv[nr_pics - 1]->node;
 
@@ -478,7 +478,7 @@ int __init eiointc_acpi_init(struct irq_domain *parent,
 		goto out_free_handle;
 
 	if (cpu_has_flatmode)
-		node = cpu_to_node(acpi_eiointc->node * CORES_PER_EIO_NODE);
+		node = acpi_eiointc->node / NODES_PER_FLATMODE_NODE;
 	else
 		node = acpi_eiointc->node;
 	acpi_set_vec_parent(node, priv->eiointc_domain, pch_group);