5 files changed, 18 insertions, 2 deletions

diff --git a/arch/x86/include/asm/mach_traps.h b/arch/x86/include/asm/mach_traps.h
index 72a8b52e7dfd..a01e7ec7d237 100644
--- a/arch/x86/include/asm/mach_traps.h
+++ b/arch/x86/include/asm/mach_traps.h
@@ -17,7 +17,7 @@
 #define NMI_REASON_CLEAR_IOCHK  0x08
 #define NMI_REASON_CLEAR_MASK   0x0f
 
-static inline unsigned char get_nmi_reason(void)
+static inline unsigned char default_get_nmi_reason(void)
 {
         return inb(NMI_REASON_PORT);
 }
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index f864fbe474c6..1971e652d24b 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -167,6 +167,7 @@ struct x86_platform_ops {
         void (*iommu_shutdown)(void);
         bool (*is_untracked_pat_range)(u64 start, u64 end);
         void (*nmi_init)(void);
+        unsigned char (*get_nmi_reason)(void);
         int (*i8042_detect)(void);
 };
 
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index b9c8628974af..27d1e7cbdb6c 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -348,7 +348,7 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
 
         /* Non-CPU-specific NMI: NMI sources can be processed on any CPU */
         raw_spin_lock(&nmi_reason_lock);
-        reason = get_nmi_reason();
+        reason = x86_platform.get_nmi_reason();
 
         if (reason & NMI_REASON_MASK) {
                 if (reason & NMI_REASON_SERR)
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index 701c7be442f1..c1d6cd549397 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -21,6 +21,7 @@
 #include <asm/pat.h>
 #include <asm/tsc.h>
 #include <asm/iommu.h>
+#include <asm/mach_traps.h>
 
 void __cpuinit x86_init_noop(void) { }
 void __init x86_init_uint_noop(unsigned int unused) { }
@@ -104,6 +105,7 @@ struct x86_platform_ops x86_platform = {
         .iommu_shutdown                 = iommu_shutdown_noop,
         .is_untracked_pat_range         = is_ISA_range,
         .nmi_init                       = default_nmi_init,
+        .get_nmi_reason                 = default_get_nmi_reason,
         .i8042_detect                   = default_i8042_detect
 };
 
diff --git a/arch/x86/platform/mrst/mrst.c b/arch/x86/platform/mrst/mrst.c
index b7f14e5b2c66..9b9ee292c107 100644
--- a/arch/x86/platform/mrst/mrst.c
+++ b/arch/x86/platform/mrst/mrst.c
@@ -277,6 +277,17 @@ static void mrst_reboot(void)
 }
 
 /*
+ * Moorestown does not have external NMI source nor port 0x61 to report
+ * NMI status. The possible NMI sources are from pmu as a result of NMI
+ * watchdog or lock debug. Reading io port 0x61 results in 0xff which
+ * misled NMI handler.
+ */
+static unsigned char mrst_get_nmi_reason(void)
+{
+        return 0;
+}
+
+/*
  * Moorestown specific x86_init function overrides and early setup
  * calls.
  */
@@ -297,6 +308,8 @@ void __init x86_mrst_early_setup(void)
         x86_platform.calibrate_tsc = mrst_calibrate_tsc;
         x86_platform.i8042_detect = mrst_i8042_detect;
         x86_init.timers.wallclock_init = mrst_rtc_init;
+        x86_platform.get_nmi_reason = mrst_get_nmi_reason;
+
         x86_init.pci.init = pci_mrst_init;
         x86_init.pci.fixup_irqs = x86_init_noop;