[PATCH] x86_64: fix interrupt routing with nosmp

Fix interaction between nosmp and pcibios_fixup_irqs().

Originally from Oleg Nesterov via i386

   When we boot with nosmp we dont have all the mptable info, so
   IO_APIC_get_PCI_irq_vector() doesnt work and devices just end up getting a
   wrong interrupt.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-x86_64/io_apic.h

@@ -199,7 +199,7 @@ extern int skip_ioapic_setup;
  * If we use the IO-APIC for IRQ routing, disable automatic
  * assignment of PCI IRQ's.
  */
-#define io_apic_assign_pci_irqs (mp_irq_entries && !skip_ioapic_setup)
+#define io_apic_assign_pci_irqs (mp_irq_entries && !skip_ioapic_setup && io_apic_irqs)
 
 #ifdef CONFIG_ACPI_BOOT
 extern int io_apic_get_unique_id (int ioapic, int apic_id);