The operation to set the IOAPIC ID in phys_id_present_map is as convoluted
as it can be.

  1) Allocate a bitmap of 32byte size on the stack
  2) Zero the bitmap and set the IOAPIC ID bit
  3) Or the temporary bitmap over phys_id_present_map

The same functionality can be achieved by setting the IOAPIC ID bit
directly in the phys_id_present_map.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/kernel/apic/io_apic.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1511,12 +1511,9 @@ void __init setup_ioapic_ids_from_mpc_no
 			physid_set(i, phys_id_present_map);
 			ioapics[ioapic_idx].mp_config.apicid = i;
 		} else {
-			physid_mask_t tmp;
-
-			physid_set_mask_of_physid(mpc_ioapic_id(ioapic_idx), &tmp);
 			apic_printk(APIC_VERBOSE, "Setting %d in the phys_id_present_map\n",
 				    mpc_ioapic_id(ioapic_idx));
-			physids_or(phys_id_present_map, phys_id_present_map, tmp);
+			physid_set(mpc_ioapic_id(ioapic_idx), phys_id_present_map);
 		}
 
 		/*