[PATCH] x86_64: Support for AMD specific MCE Threshold.

MC4_MISC - DRAM Errors Threshold Register realized under AMD K8 Rev F.
This register is used to count correctable and uncorrectable ECC errors that occur during DRAM read operations.
The user may interface through sysfs files in order to change the threshold configuration.

bank%d/error_count - reads current error count, write to clear.
bank%d/interrupt_enable - set/clear interrupt enable.
bank%d/threshold_limit - read/write the threshold limit.

APIC vector 0xF9 in hw_irq.h.
5 software defined bank ids in mce.h.
new apic.c function to setup threshold apic lvt.
defaults to interrupt off, count enabled, and threshold limit max.
sysfs interface created on /sys/devices/system/threshold.

AK: added some ifdefs to make it compile on UP

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/Kconfig

@@ -374,6 +374,14 @@ config X86_MCE_INTEL
 	   Additional support for intel specific MCE features such as
 	   the thermal monitor.
 
+config X86_MCE_AMD
+	bool "AMD MCE features"
+	depends on X86_MCE && X86_LOCAL_APIC
+	default y
+	help
+	   Additional support for AMD specific MCE features such as
+	   the DRAM Error Threshold.
+
 config PHYSICAL_START
 	hex "Physical address where the kernel is loaded" if EMBEDDED
 	default "0x100000"

arch/x86_64/kernel/Makefile

@@ -11,6 +11,7 @@ obj-y	:= process.o signal.o entry.o traps.o irq.o \
 
 obj-$(CONFIG_X86_MCE)         += mce.o
 obj-$(CONFIG_X86_MCE_INTEL)	+= mce_intel.o
+obj-$(CONFIG_X86_MCE_AMD)	+= mce_amd.o
 obj-$(CONFIG_MTRR)		+= ../../i386/kernel/cpu/mtrr/
 obj-$(CONFIG_ACPI)		+= acpi/
 obj-$(CONFIG_X86_MSR)		+= msr.o

arch/x86_64/kernel/apic.c

@@ -833,6 +833,16 @@ int setup_profiling_timer(unsigned int multiplier)
 	return 0;
 }
 
+#ifdef CONFIG_X86_MCE_AMD
+void setup_threshold_lvt(unsigned long lvt_off)
+{
+	unsigned int v = 0;
+	unsigned long reg = (lvt_off << 4) + 0x500;
+	v |= THRESHOLD_APIC_VECTOR;
+	apic_write(reg, v);
+}
+#endif /* CONFIG_X86_MCE_AMD */
+
 #undef APIC_DIVISOR
 
 /*

arch/x86_64/kernel/entry.S

@@ -612,6 +612,9 @@ retint_kernel:
 ENTRY(thermal_interrupt)
 	apicinterrupt THERMAL_APIC_VECTOR,smp_thermal_interrupt
 
+ENTRY(threshold_interrupt)
+	apicinterrupt THRESHOLD_APIC_VECTOR,mce_threshold_interrupt
+
 #ifdef CONFIG_SMP	
 ENTRY(reschedule_interrupt)
 	apicinterrupt RESCHEDULE_VECTOR,smp_reschedule_interrupt

arch/x86_64/kernel/i8259.c

@@ -492,6 +492,7 @@ void invalidate_interrupt5(void);
 void invalidate_interrupt6(void);
 void invalidate_interrupt7(void);
 void thermal_interrupt(void);
+void threshold_interrupt(void);
 void i8254_timer_resume(void);
 
 static void setup_timer_hardware(void)
@@ -580,6 +581,7 @@ void __init init_IRQ(void)
 	set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
 #endif	
 	set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
+	set_intr_gate(THRESHOLD_APIC_VECTOR, threshold_interrupt);
 
 #ifdef CONFIG_X86_LOCAL_APIC
 	/* self generated IPI for local APIC timer */

arch/x86_64/kernel/mce.c

@@ -356,6 +356,9 @@ static void __cpuinit mce_cpu_features(struct cpuinfo_x86 *c)
 	case X86_VENDOR_INTEL:
 		mce_intel_feature_init(c);
 		break;
+	case X86_VENDOR_AMD:
+		mce_amd_feature_init(c);
+		break;
 	default:
 		break;
 	}

arch/x86_64/kernel/traps.c

@@ -888,6 +888,10 @@ asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
 {
 }
 
+asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
+{
+}
+
 /*
  *  'math_state_restore()' saves the current math information in the
  * old math state array, and gets the new ones from the current task

include/asm-x86_64/apic.h

@@ -111,6 +111,8 @@ extern unsigned int nmi_watchdog;
 
 extern int disable_timer_pin_1;
 
+extern void setup_threshold_lvt(unsigned long lvt_off);
+
 #endif /* CONFIG_X86_LOCAL_APIC */
 
 extern unsigned boot_cpu_id;

include/asm-x86_64/hw_irq.h

@@ -55,7 +55,7 @@ struct hw_interrupt_type;
 #define CALL_FUNCTION_VECTOR	0xfc
 #define KDB_VECTOR		0xfb	/* reserved for KDB */
 #define THERMAL_APIC_VECTOR	0xfa
-/* 0xf9 free */
+#define THRESHOLD_APIC_VECTOR   0xf9
 #define INVALIDATE_TLB_VECTOR_END	0xf8
 #define INVALIDATE_TLB_VECTOR_START	0xf0	/* f0-f8 used for TLB flush */
 

include/asm-x86_64/mce.h

@@ -67,6 +67,8 @@ struct mce_log {
 /* Software defined banks */
 #define MCE_EXTENDED_BANK	128
 #define MCE_THERMAL_BANK	MCE_EXTENDED_BANK + 0
+#define MCE_THRESHOLD_BASE      MCE_EXTENDED_BANK + 1 /* MCE_AMD */
+#define MCE_THRESHOLD_DRAM_ECC  MCE_THRESHOLD_BASE + 4
 
 void mce_log(struct mce *m);
 #ifdef CONFIG_X86_MCE_INTEL
@@ -77,4 +79,12 @@ static inline void mce_intel_feature_init(struct cpuinfo_x86 *c)
 }
 #endif
 
+#ifdef CONFIG_X86_MCE_AMD
+void mce_amd_feature_init(struct cpuinfo_x86 *c);
+#else
+static inline void mce_amd_feature_init(struct cpuinfo_x86 *c)
+{
+}
+#endif
+
 #endif