x86, mce, cmci: factor out threshold interrupt handler

Impact: cleanup; preparation for feature

The mce_amd_64 code has an own private MC threshold vector with an own
interrupt handler. Since Intel needs a similar handler
it makes sense to share the vector because both can not
be active at the same time.

I factored the common APIC handler code into a separate file which can
be used by both the Intel or AMD MC code.

This is needed for the next patch which adds an Intel specific
CMCI handler.

This patch should be a nop for AMD, it just moves some code
around.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

arch/x86/Kconfig

@@ -751,6 +751,11 @@ config X86_MCE_AMD
 	   Additional support for AMD specific MCE features such as
 	   the DRAM Error Threshold.
 
+config X86_MCE_THRESHOLD
+	depends on X86_MCE_AMD || X86_MCE_INTEL
+	bool
+	default y
+
 config X86_MCE_NONFATAL
 	tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
 	depends on X86_32 && X86_MCE

arch/x86/include/asm/mce.h

@@ -135,5 +135,7 @@ extern void mcheck_init(struct cpuinfo_x86 *c);
 #define mcheck_init(c) do { } while (0)
 #endif
 
+extern void (*mce_threshold_vector)(void);
+
 #endif /* __KERNEL__ */
 #endif /* _ASM_X86_MCE_H */

arch/x86/kernel/cpu/mcheck/Makefile

@@ -4,3 +4,4 @@ obj-$(CONFIG_X86_32)		+= k7.o p4.o p5.o p6.o winchip.o
 obj-$(CONFIG_X86_MCE_INTEL)	+= mce_intel_64.o
 obj-$(CONFIG_X86_MCE_AMD)	+= mce_amd_64.o
 obj-$(CONFIG_X86_MCE_NONFATAL)	+= non-fatal.o
+obj-$(CONFIG_X86_MCE_THRESHOLD) += threshold.o

arch/x86/kernel/cpu/mcheck/mce_amd_64.c

@@ -79,6 +79,8 @@ static unsigned char shared_bank[NR_BANKS] = {
 
 static DEFINE_PER_CPU(unsigned char, bank_map);	/* see which banks are on */
 
+static void amd_threshold_interrupt(void);
+
 /*
  * CPU Initialization
  */
@@ -174,6 +176,8 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
 			tr.reset = 0;
 			tr.old_limit = 0;
 			threshold_restart_bank(&tr);
+
+			mce_threshold_vector = amd_threshold_interrupt;
 		}
 	}
 }
@@ -187,16 +191,12 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
  * the interrupt goes off when error_count reaches threshold_limit.
  * the handler will simply log mcelog w/ software defined bank number.
  */
-asmlinkage void mce_threshold_interrupt(void)
+static void amd_threshold_interrupt(void)
 {
 	unsigned int bank, block;
 	struct mce m;
 	u32 low = 0, high = 0, address = 0;
 
-	ack_APIC_irq();
-	exit_idle();
-	irq_enter();
-
 	mce_setup(&m);
 
 	/* assume first bank caused it */
@@ -241,13 +241,10 @@ asmlinkage void mce_threshold_interrupt(void)
 				       + bank * NR_BLOCKS
 				       + block;
 				mce_log(&m);
-				goto out;
+				return;
 			}
 		}
 	}
-out:
-	inc_irq_stat(irq_threshold_count);
-	irq_exit();
 }
 
 /*

arch/x86/kernel/cpu/mcheck/threshold.c

+/* Common corrected MCE threshold handler code */
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <asm/mce.h>
+#include <asm/irq_vectors.h>
+#include <asm/idle.h>
+
+static void default_threshold_interrupt(void)
+{
+	printk(KERN_ERR "Unexpected threshold interrupt at vector %x\n",
+			 THRESHOLD_APIC_VECTOR);
+}
+
+void (*mce_threshold_vector)(void) = default_threshold_interrupt;
+
+asmlinkage void mce_threshold_interrupt(void)
+{
+	ack_APIC_irq();
+	exit_idle();
+	irq_enter();
+	inc_irq_stat(irq_threshold_count);
+	mce_threshold_vector();
+	irq_exit();
+}