diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h
index b0d5f0a97a01..343ea7c987aa 100644
--- a/arch/s390/include/asm/irq.h
+++ b/arch/s390/include/asm/irq.h
@@ -1,11 +1,11 @@
 #ifndef _ASM_IRQ_H
 #define _ASM_IRQ_H
 
-#define EXT_INTERRUPT	1
-#define IO_INTERRUPT	2
-#define THIN_INTERRUPT	3
+#define EXT_INTERRUPT	0
+#define IO_INTERRUPT	1
+#define THIN_INTERRUPT	2
 
-#define NR_IRQS_BASE	4
+#define NR_IRQS_BASE	3
 
 #ifdef CONFIG_PCI_NR_MSI
 # define NR_IRQS	(NR_IRQS_BASE + CONFIG_PCI_NR_MSI)
@@ -13,9 +13,6 @@
 # define NR_IRQS	NR_IRQS_BASE
 #endif
 
-/* This number is used when no interrupt has been assigned */
-#define NO_IRQ		0
-
 /* External interruption codes */
 #define EXT_IRQ_INTERRUPT_KEY	0x0040
 #define EXT_IRQ_CLK_COMP	0x1004
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 1b8a38ab7861..f238720690f3 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -127,13 +127,10 @@ int show_interrupts(struct seq_file *p, void *v)
 		for_each_online_cpu(cpu)
 			seq_printf(p, "CPU%d       ", cpu);
 		seq_putc(p, '\n');
-		goto out;
 	}
 	if (index < NR_IRQS) {
 		if (index >= NR_IRQS_BASE)
 			goto out;
-		/* Adjust index to process irqclass_main_desc array entries */
-		index--;
 		seq_printf(p, "%s: ", irqclass_main_desc[index].name);
 		irq = irqclass_main_desc[index].irq;
 		for_each_online_cpu(cpu)
@@ -158,7 +155,7 @@ out:
 
 unsigned int arch_dynirq_lower_bound(unsigned int from)
 {
-	return from < THIN_INTERRUPT ? THIN_INTERRUPT : from;
+	return from < NR_IRQS_BASE ? NR_IRQS_BASE : from;
 }
 
 /*