From be71b8553d0522aba535a815baaebb1f0bb9a9ec Mon Sep 17 00:00:00 2001
From: Andi Kleen <andi@firstfloor.org>
Date: Thu, 12 Feb 2009 13:49:38 +0100
Subject: [PATCH] x86, mce, cmci: recheck CMCI banks after APIC has been
 enabled on CPU #0

Impact: Fix marginal race condition

One the first CPU the machine checks are enabled early before
the local APIC is enabled. This could in theory lead
to some lost CMCI events very early during boot because
CMCIs cannot be delivered with disabled LAPIC.

The poller also doesn't recover from this because it doesn't
check CMCI banks.

Add an explicit CMCI banks check after the LAPIC is enabled.
This is only done for CPU #0, the other CPUs only initialize
machine checks after the LAPIC is on.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/kernel/apic.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index 648676f0b50a..57b53774d986 100644
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -48,6 +48,7 @@
 #include <asm/apic.h>
 #include <asm/i8259.h>
 #include <asm/smp.h>
+#include <asm/mce.h>
 
 #include <mach_apic.h>
 #include <mach_apicdef.h>
@@ -1270,6 +1271,12 @@ void __cpuinit setup_local_APIC(void)
 	apic_write(APIC_LVT1, value);
 
 	preempt_enable();
+
+#ifdef CONFIG_X86_MCE_INTEL
+	/* Recheck CMCI information after local APIC is up on CPU #0 */
+	if (smp_processor_id() == 0)
+		cmci_recheck();
+#endif
 }
 
 void __cpuinit end_local_APIC_setup(void)