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Diffstat (limited to 'arch/x86/kernel/cpu/mcheck/therm_throt.c')
-rw-r--r--arch/x86/kernel/cpu/mcheck/therm_throt.c29
1 files changed, 28 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index b3a1dba7533..4fef985fc22 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -49,6 +49,8 @@ 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)
@@ -254,6 +256,18 @@ asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
ack_APIC_irq();
}
+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 (cpu_has(&boot_cpu_data, X86_FEATURE_ACPI) &&
+ cpu_has(&boot_cpu_data, X86_FEATURE_ACC))
+ lvtthmr_init = apic_read(APIC_LVTTHMR);
+}
+
void intel_init_thermal(struct cpuinfo_x86 *c)
{
unsigned int cpu = smp_processor_id();
@@ -270,7 +284,20 @@ 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);