[PATCH] x86: default to physical mode on hotplug CPU kernels

Default to physical mode on hotplug CPU kernels.  Furher simplify and clean up
the APIC initialization code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 3 insertions, 13 deletions

diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c
index 025f26ebb8d7..c08650a427e2 100644
--- a/arch/x86_64/kernel/genapic.c
+++ b/arch/x86_64/kernel/genapic.c
@@ -35,11 +35,8 @@ struct genapic __read_mostly *genapic = &apic_flat;
 /*
  * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
  */
-void __init clustered_apic_check(void)
+void __init setup_apic_routing(void)
 {
-        unsigned int i, max_apic = 0;
-        u8 id;
-
 #ifdef CONFIG_ACPI
         /*
          * Quirk: some x86_64 machines can only use physical APIC mode
@@ -49,17 +46,10 @@ void __init clustered_apic_check(void)
         if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID &&
                         (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL))
                 genapic = &apic_physflat;
+        else
 #endif
 
-        for (i = 0; i < NR_CPUS; i++) {
-                id = bios_cpu_apicid[i];
-                if (id == BAD_APICID)
-                        continue;
-                if (id > max_apic)
-                        max_apic = id;
-        }
-
-        if (max_apic < 8)
+        if (cpus_weight(cpu_possible_map) <= 8)
                 genapic = &apic_flat;
         else
                 genapic = &apic_physflat;