x86: apic - unify disable_local_APIC

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 46acb9b47ae7..4fb903b2fc39 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -691,6 +691,20 @@ void disable_local_APIC(void)
         value = apic_read(APIC_SPIV);
         value &= ~APIC_SPIV_APIC_ENABLED;
         apic_write(APIC_SPIV, value);
+
+#ifdef CONFIG_X86_32
+        /*
+         * When LAPIC was disabled by the BIOS and enabled by the kernel,
+         * restore the disabled state.
+         */
+        if (enabled_via_apicbase) {
+                unsigned int l, h;
+
+                rdmsr(MSR_IA32_APICBASE, l, h);
+                l &= ~MSR_IA32_APICBASE_ENABLE;
+                wrmsr(MSR_IA32_APICBASE, l, h);
+        }
+#endif
 }
 
 void lapic_shutdown(void)