[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>

4 files changed, 6 insertions, 16 deletions

diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index 9ea5b8ecc7e1..280898b045b2 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -874,7 +874,7 @@ static void __init acpi_process_madt(void)
                                 acpi_ioapic = 1;
 
                                 smp_found_config = 1;
-                                clustered_apic_check();
+                                setup_apic_routing();
                         }
                 }
                 if (error == -EINVAL) {
diff --git a/arch/i386/kernel/mpparse.c b/arch/i386/kernel/mpparse.c
index 4f5983c98669..0952eccd8f28 100644
--- a/arch/i386/kernel/mpparse.c
+++ b/arch/i386/kernel/mpparse.c
@@ -477,7 +477,7 @@ static int __init smp_read_mpc(struct mp_config_table *mpc)
                 }
                 ++mpc_record;
         }
-        clustered_apic_check();
+        setup_apic_routing();
         if (!num_processors)
                 printk(KERN_ERR "SMP mptable: no processors registered!\n");
         return num_processors;
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;
diff --git a/arch/x86_64/kernel/mpparse.c b/arch/x86_64/kernel/mpparse.c
index 455aa0b932f0..d0dc4891599b 100644
--- a/arch/x86_64/kernel/mpparse.c
+++ b/arch/x86_64/kernel/mpparse.c
@@ -300,7 +300,7 @@ static int __init smp_read_mpc(struct mp_config_table *mpc)
                         }
                 }
         }
-        clustered_apic_check();
+        setup_apic_routing();
         if (!num_processors)
                 printk(KERN_ERR "MPTABLE: no processors registered!\n");
         return num_processors;