Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6

[safe/jmp/linux-2.6] / arch / x86 / kernel / cpu / mcheck / therm_throt.c

diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index db80b57..e1a0a3b 100644 (file)
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -42,12 +42,15 @@ struct thermal_state {
 
        u64                     next_check;
        unsigned long           throttle_count;
+       unsigned long           last_throttle_count;
 };
 
 static DEFINE_PER_CPU(struct thermal_state, thermal_state);
 
 static atomic_t therm_throt_en = ATOMIC_INIT(0);
 
+static u32 lvtthmr_init __read_mostly;
+
 #ifdef CONFIG_SYSFS
 #define define_therm_throt_sysdev_one_ro(_name)                                \
        static SYSDEV_ATTR(_name, 0444, therm_throt_sysdev_show_##_name, NULL)
@@ -120,11 +123,12 @@ static int therm_throt_process(bool is_throttled)
        if (is_throttled)
                state->throttle_count++;
 
-       if (!(was_throttled ^ is_throttled) &&
-                       time_before64(now, state->next_check))
+       if (time_before64(now, state->next_check) &&
+                       state->throttle_count != state->last_throttle_count)
                return 0;
 
        state->next_check = now + CHECK_INTERVAL;
+       state->last_throttle_count = state->throttle_count;
 
        /* if we just entered the thermal event */
        if (is_throttled) {
@@ -186,7 +190,7 @@ thermal_throttle_cpu_callback(struct notifier_block *nfb,
                mutex_unlock(&therm_cpu_lock);
                break;
        }
-       return err ? NOTIFY_BAD : NOTIFY_OK;
+       return notifier_from_errno(err);
 }
 
 static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
@@ -252,14 +256,34 @@ asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
        ack_APIC_irq();
 }
 
+/* Thermal monitoring depends on APIC, ACPI and clock modulation */
+static int intel_thermal_supported(struct cpuinfo_x86 *c)
+{
+       if (!cpu_has_apic)
+               return 0;
+       if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
+               return 0;
+       return 1;
+}
+
+void __init mcheck_intel_therm_init(void)
+{
+       /*
+        * This function is only called on boot CPU. Save the init thermal
+        * LVT value on BSP and use that value to restore APs' thermal LVT
+        * entry BIOS programmed later
+        */
+       if (intel_thermal_supported(&boot_cpu_data))
+               lvtthmr_init = apic_read(APIC_LVTTHMR);
+}
+
 void intel_init_thermal(struct cpuinfo_x86 *c)
 {
        unsigned int cpu = smp_processor_id();
        int tm2 = 0;
        u32 l, h;
 
-       /* Thermal monitoring depends on ACPI and clock modulation*/
-       if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
+       if (!intel_thermal_supported(c))
                return;
 
        /*
@@ -268,7 +292,20 @@ void intel_init_thermal(struct cpuinfo_x86 *c)
         * since it might be delivered via SMI already:
         */
        rdmsr(MSR_IA32_MISC_ENABLE, l, h);
-       h = apic_read(APIC_LVTTHMR);
+
+       /*
+        * The initial value of thermal LVT entries on all APs always reads
+        * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI
+        * sequence to them and LVT registers are reset to 0s except for
+        * the mask bits which are set to 1s when APs receive INIT IPI.
+        * Always restore the value that BIOS has programmed on AP based on
+        * BSP's info we saved since BIOS is always setting the same value
+        * for all threads/cores
+        */
+       apic_write(APIC_LVTTHMR, lvtthmr_init);
+
+       h = lvtthmr_init;
+
        if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
                printk(KERN_DEBUG
                       "CPU%d: Thermal monitoring handled by SMI\n", cpu);
@@ -310,8 +347,8 @@ void intel_init_thermal(struct cpuinfo_x86 *c)
        l = apic_read(APIC_LVTTHMR);
        apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
 
-       printk(KERN_INFO "CPU%d: Thermal monitoring enabled (%s)\n",
-              cpu, tm2 ? "TM2" : "TM1");
+       printk_once(KERN_INFO "CPU0: Thermal monitoring enabled (%s)\n",
+                      tm2 ? "TM2" : "TM1");
 
        /* enable thermal throttle processing */
        atomic_set(&therm_throt_en, 1);