x86: Rework arch_disable_smp_support() for x86

Currently arch_disable_smp_support() on x86 disables only the
support for the IOAPIC and is also compiled in if SMP-support is
not.

Therefore this function is renamed to disable_ioapic_support(),
which meets its purpose and is only compiled in the kernel
when IOAPIC support is also.

A new arch_disable_smp_support() is created in smpboot.c,
which calls disable_ioapic_support() and gets only compiled
in the kernel when SMP support is also.

Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
LKML-Reference: <1298385487-4708-3-git-send-email-henne@nachtwindheim.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 10 insertions, 1 deletions

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 08776a953487..09d0172a0059 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -64,6 +64,7 @@
 #include <asm/mtrr.h>
 #include <asm/mwait.h>
 #include <asm/apic.h>
+#include <asm/io_apic.h>
 #include <asm/setup.h>
 #include <asm/uv/uv.h>
 #include <linux/mc146818rtc.h>
@@ -945,6 +946,14 @@ int __cpuinit native_cpu_up(unsigned int cpu)
         return 0;
 }
 
+/**
+ * arch_disable_smp_support() - disables SMP support for x86 at runtime
+ */
+void arch_disable_smp_support(void)
+{
+        disable_ioapic_support();
+}
+
 /*
  * Fall back to non SMP mode after errors.
  *
@@ -1045,7 +1054,7 @@ static int __init smp_sanity_check(unsigned max_cpus)
                                 "(tell your hw vendor)\n");
                 }
                 smpboot_clear_io_apic();
-                arch_disable_smp_support();
+                disable_ioapic_support();
                 return -1;
         }