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authorJacob Pan <jacob.jun.pan@linux.intel.com>2011-11-10 13:43:05 +0000
committerIngo Molnar <mingo@elte.hu>2011-11-10 16:21:01 +0100
commit064a59b6dd1f341cc478c212bb436e3da9cb8d04 (patch)
tree44a5075e6b913493391911a57ebbe3cc6a25c26e
parent0a9153261d54c432bc0bdc88607f24c835ac729c (diff)
x86/mrst: Avoid reporting wrong nmi status
Moorestown/Medfield platform does not have port 0x61 to report NMI status, nor does it have external NMI sources. The only NMI sources are from lapic, as results of perf counter overflow or IPI, e.g. NMI watchdog or spin lock debug. Reading port 0x61 on Moorestown will return 0xff which misled NMI handlers to false critical errors such memory parity error. The subsequent ioport access for NMI handling can also cause undefined behavior on Moorestown. This patch allows kernel process NMI due to watchdog or backrace dump without unnecessary hangs. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> [hand applied] Signed-off-by: Alan Cox <alan@linux.intel.com>
-rw-r--r--arch/x86/include/asm/mach_traps.h2
-rw-r--r--arch/x86/include/asm/x86_init.h1
-rw-r--r--arch/x86/kernel/nmi.c2
-rw-r--r--arch/x86/kernel/x86_init.c2
-rw-r--r--arch/x86/platform/mrst/mrst.c13
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;