diff --git a/include/asm-x86_64/hardirq.h b/include/asm-x86_64/hardirq.h
index 8661b47..8689951 100644
--- a/include/asm-x86_64/hardirq.h
+++ b/include/asm-x86_64/hardirq.h
@@ -16,23 +16,6 @@
 #define set_softirq_pending(x) write_pda(__softirq_pending, (x))
 #define or_softirq_pending(x)  or_pda(__softirq_pending, (x))
 
-/*
- * 'what should we do if we get a hw irq event on an illegal vector'.
- * each architecture has to answer this themselves.
- */
-static inline void ack_bad_irq(unsigned int irq)
-{
-	printk("unexpected IRQ trap at vector %02x\n", irq);
-#ifdef CONFIG_X86_LOCAL_APIC
-	/*
-	 * Currently unexpected vectors happen only on SMP and APIC.
-	 * We _must_ ack these because every local APIC has only N
-	 * irq slots per priority level, and a 'hanging, unacked' IRQ
-	 * holds up an irq slot - in excessive cases (when multiple
-	 * unexpected vectors occur) that might lock up the APIC
-	 * completely.
-	 */
-	ack_APIC_irq();
-#endif
-}
+extern void ack_bad_irq(unsigned int irq);
+
 #endif /* __ASM_HARDIRQ_H */