1 files changed, 210 insertions, 4 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel_64.c b/arch/x86/kernel/cpu/mcheck/mce_intel_64.c
index f44c3662436..aaa7d973093 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_intel_64.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_intel_64.c
@@ -1,17 +1,21 @@
 /*
  * Intel specific MCE features.
  * Copyright 2004 Zwane Mwaikambo <zwane@linuxpower.ca>
+ * Copyright (C) 2008, 2009 Intel Corporation
+ * Author: Andi Kleen
  */
 
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/percpu.h>
 #include <asm/processor.h>
+#include <asm/apic.h>
 #include <asm/msr.h>
 #include <asm/mce.h>
 #include <asm/hw_irq.h>
 #include <asm/idle.h>
 #include <asm/therm_throt.h>
+#include <asm/apic.h>
 
 asmlinkage void smp_thermal_interrupt(void)
 {
@@ -24,7 +28,7 @@ asmlinkage void smp_thermal_interrupt(void)
 
         rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
         if (therm_throt_process(msr_val & 1))
-                mce_log_therm_throt_event(smp_processor_id(), msr_val);
+                mce_log_therm_throt_event(msr_val);
 
         inc_irq_stat(irq_thermal_count);
         irq_exit();
@@ -48,13 +52,13 @@ static void intel_init_thermal(struct cpuinfo_x86 *c)
          */
         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
         h = apic_read(APIC_LVTTHMR);
-        if ((l & (1 << 3)) && (h & APIC_DM_SMI)) {
+        if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
                 printk(KERN_DEBUG
                        "CPU%d: Thermal monitoring handled by SMI\n", cpu);
                 return;
         }
 
-        if (cpu_has(c, X86_FEATURE_TM2) && (l & (1 << 13)))
+        if (cpu_has(c, X86_FEATURE_TM2) && (l & MSR_IA32_MISC_ENABLE_TM2))
                 tm2 = 1;
 
         if (h & APIC_VECTOR_MASK) {
@@ -72,7 +76,7 @@ static void intel_init_thermal(struct cpuinfo_x86 *c)
         wrmsr(MSR_IA32_THERM_INTERRUPT, l | 0x03, h);
 
         rdmsr(MSR_IA32_MISC_ENABLE, l, h);
-        wrmsr(MSR_IA32_MISC_ENABLE, l | (1 << 3), h);
+        wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
 
         l = apic_read(APIC_LVTTHMR);
         apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
@@ -84,7 +88,209 @@ static void intel_init_thermal(struct cpuinfo_x86 *c)
         return;
 }
 
+/*
+ * Support for Intel Correct Machine Check Interrupts. This allows
+ * the CPU to raise an interrupt when a corrected machine check happened.
+ * Normally we pick those up using a regular polling timer.
+ * Also supports reliable discovery of shared banks.
+ */
+
+static DEFINE_PER_CPU(mce_banks_t, mce_banks_owned);
+
+/*
+ * cmci_discover_lock protects against parallel discovery attempts
+ * which could race against each other.
+ */
+static DEFINE_SPINLOCK(cmci_discover_lock);
+
+#define CMCI_THRESHOLD 1
+
+static int cmci_supported(int *banks)
+{
+        u64 cap;
+
+        /*
+         * Vendor check is not strictly needed, but the initial
+         * initialization is vendor keyed and this
+         * makes sure none of the backdoors are entered otherwise.
+         */
+        if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+                return 0;
+        if (!cpu_has_apic || lapic_get_maxlvt() < 6)
+                return 0;
+        rdmsrl(MSR_IA32_MCG_CAP, cap);
+        *banks = min_t(unsigned, MAX_NR_BANKS, cap & 0xff);
+        return !!(cap & MCG_CMCI_P);
+}
+
+/*
+ * The interrupt handler. This is called on every event.
+ * Just call the poller directly to log any events.
+ * This could in theory increase the threshold under high load,
+ * but doesn't for now.
+ */
+static void intel_threshold_interrupt(void)
+{
+        machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
+        mce_notify_user();
+}
+
+static void print_update(char *type, int *hdr, int num)
+{
+        if (*hdr == 0)
+                printk(KERN_INFO "CPU %d MCA banks", smp_processor_id());
+        *hdr = 1;
+        printk(KERN_CONT " %s:%d", type, num);
+}
+
+/*
+ * Enable CMCI (Corrected Machine Check Interrupt) for available MCE banks
+ * on this CPU. Use the algorithm recommended in the SDM to discover shared
+ * banks.
+ */
+static void cmci_discover(int banks, int boot)
+{
+        unsigned long *owned = (void *)&__get_cpu_var(mce_banks_owned);
+        int hdr = 0;
+        int i;
+
+        spin_lock(&cmci_discover_lock);
+        for (i = 0; i < banks; i++) {
+                u64 val;
+
+                if (test_bit(i, owned))
+                        continue;
+
+                rdmsrl(MSR_IA32_MC0_CTL2 + i, val);
+
+                /* Already owned by someone else? */
+                if (val & CMCI_EN) {
+                        if (test_and_clear_bit(i, owned) || boot)
+                                print_update("SHD", &hdr, i);
+                        __clear_bit(i, __get_cpu_var(mce_poll_banks));
+                        continue;
+                }
+
+                val |= CMCI_EN | CMCI_THRESHOLD;
+                wrmsrl(MSR_IA32_MC0_CTL2 + i, val);
+                rdmsrl(MSR_IA32_MC0_CTL2 + i, val);
+
+                /* Did the enable bit stick? -- the bank supports CMCI */
+                if (val & CMCI_EN) {
+                        if (!test_and_set_bit(i, owned) || boot)
+                                print_update("CMCI", &hdr, i);
+                        __clear_bit(i, __get_cpu_var(mce_poll_banks));
+                } else {
+                        WARN_ON(!test_bit(i, __get_cpu_var(mce_poll_banks)));
+                }
+        }
+        spin_unlock(&cmci_discover_lock);
+        if (hdr)
+                printk(KERN_CONT "\n");
+}
+
+/*
+ * Just in case we missed an event during initialization check
+ * all the CMCI owned banks.
+ */
+void cmci_recheck(void)
+{
+        unsigned long flags;
+        int banks;
+
+        if (!mce_available(&current_cpu_data) || !cmci_supported(&banks))
+                return;
+        local_irq_save(flags);
+        machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
+        local_irq_restore(flags);
+}
+
+/*
+ * Disable CMCI on this CPU for all banks it owns when it goes down.
+ * This allows other CPUs to claim the banks on rediscovery.
+ */
+void cmci_clear(void)
+{
+        int i;
+        int banks;
+        u64 val;
+
+        if (!cmci_supported(&banks))
+                return;
+        spin_lock(&cmci_discover_lock);
+        for (i = 0; i < banks; i++) {
+                if (!test_bit(i, __get_cpu_var(mce_banks_owned)))
+                        continue;
+                /* Disable CMCI */
+                rdmsrl(MSR_IA32_MC0_CTL2 + i, val);
+                val &= ~(CMCI_EN|CMCI_THRESHOLD_MASK);
+                wrmsrl(MSR_IA32_MC0_CTL2 + i, val);
+                __clear_bit(i, __get_cpu_var(mce_banks_owned));
+        }
+        spin_unlock(&cmci_discover_lock);
+}
+
+/*
+ * After a CPU went down cycle through all the others and rediscover
+ * Must run in process context.
+ */
+void cmci_rediscover(int dying)
+{
+        int banks;
+        int cpu;
+        cpumask_var_t old;
+
+        if (!cmci_supported(&banks))
+                return;
+        if (!alloc_cpumask_var(&old, GFP_KERNEL))
+                return;
+        cpumask_copy(old, &current->cpus_allowed);
+
+        for_each_online_cpu (cpu) {
+                if (cpu == dying)
+                        continue;
+                if (set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu)))
+                        continue;
+                /* Recheck banks in case CPUs don't all have the same */
+                if (cmci_supported(&banks))
+                        cmci_discover(banks, 0);
+        }
+
+        set_cpus_allowed_ptr(current, old);
+        free_cpumask_var(old);
+}
+
+/*
+ * Reenable CMCI on this CPU in case a CPU down failed.
+ */
+void cmci_reenable(void)
+{
+        int banks;
+        if (cmci_supported(&banks))
+                cmci_discover(banks, 0);
+}
+
+static __cpuinit void intel_init_cmci(void)
+{
+        int banks;
+
+        if (!cmci_supported(&banks))
+                return;
+
+        mce_threshold_vector = intel_threshold_interrupt;
+        cmci_discover(banks, 1);
+        /*
+         * For CPU #0 this runs with still disabled APIC, but that's
+         * ok because only the vector is set up. We still do another
+         * check for the banks later for CPU #0 just to make sure
+         * to not miss any events.
+         */
+        apic_write(APIC_LVTCMCI, THRESHOLD_APIC_VECTOR|APIC_DM_FIXED);
+        cmci_recheck();
+}
+
 void mce_intel_feature_init(struct cpuinfo_x86 *c)
 {
         intel_init_thermal(c);
+        intel_init_cmci();
 }