diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 7c7c16cde1f8f3b5ddcf65f6a2f40d537368ad86..84fdd5110948b71b3fe42774498f88cc19b0b63c 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -143,8 +143,6 @@ extern int noioapicreroute;
 /* 1 if the timer IRQ uses the '8259A Virtual Wire' mode */
 extern int timer_through_8259;
 
-extern void io_apic_disable_legacy(void);
-
 /*
  * If we use the IO-APIC for IRQ routing, disable automatic
  * assignment of PCI IRQ's.
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 1704cd82db5f073fadb8aff83138c0af086d47f6..3592a72f3f0abef8eb81b6d1fbd878027d57ea38 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -143,11 +143,6 @@ static struct irq_cfg irq_cfgx[NR_IRQS_LEGACY];
 static struct irq_cfg irq_cfgx[NR_IRQS];
 #endif
 
-void __init io_apic_disable_legacy(void)
-{
-	nr_irqs_gsi = 0;
-}
-
 int __init arch_early_irq_init(void)
 {
 	struct irq_cfg *cfg;
@@ -156,6 +151,11 @@ int __init arch_early_irq_init(void)
 	int node;
 	int i;
 
+	if (!legacy_pic->nr_legacy_irqs) {
+		nr_irqs_gsi = 0;
+		io_apic_irqs = ~0UL;
+	}
+
 	cfg = irq_cfgx;
 	count = ARRAY_SIZE(irq_cfgx);
 	node= cpu_to_node(boot_cpu_id);