x86/ioapic/32: Decrapify phys_id_present_map operation

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>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 8c47099..ff2d27e 100644 (file)
--- 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_nocheck(void)
                        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);
                }
 
                /*