1 files changed, 752 insertions, 0 deletions

diff --git a/drivers/thermal/intel/therm_throt.c b/drivers/thermal/intel/therm_throt.c
new file mode 100644
index 000000000..8352083b8
--- /dev/null
+++ b/drivers/thermal/intel/therm_throt.c
@@ -0,0 +1,752 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Thermal throttle event support code (such as syslog messaging and rate
+ * limiting) that was factored out from x86_64 (mce_intel.c) and i386 (p4.c).
+ *
+ * This allows consistent reporting of CPU thermal throttle events.
+ *
+ * Maintains a counter in /sys that keeps track of the number of thermal
+ * events, such that the user knows how bad the thermal problem might be
+ * (since the logging to syslog is rate limited).
+ *
+ * Author: Dmitriy Zavin (dmitriyz@google.com)
+ *
+ * Credits: Adapted from Zwane Mwaikambo's original code in mce_intel.c.
+ *          Inspired by Ross Biro's and Al Borchers' counter code.
+ */
+#include <linux/interrupt.h>
+#include <linux/notifier.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/percpu.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+
+#include <asm/processor.h>
+#include <asm/thermal.h>
+#include <asm/traps.h>
+#include <asm/apic.h>
+#include <asm/irq.h>
+#include <asm/msr.h>
+
+#include "intel_hfi.h"
+#include "thermal_interrupt.h"
+
+/* How long to wait between reporting thermal events */
+#define CHECK_INTERVAL		(300 * HZ)
+
+#define THERMAL_THROTTLING_EVENT	0
+#define POWER_LIMIT_EVENT		1
+
+/**
+ * struct _thermal_state - Represent the current thermal event state
+ * @next_check:			Stores the next timestamp, when it is allowed
+ *				to log the next warning message.
+ * @last_interrupt_time:	Stores the timestamp for the last threshold
+ *				high event.
+ * @therm_work:			Delayed workqueue structure
+ * @count:			Stores the current running count for thermal
+ *				or power threshold interrupts.
+ * @last_count:			Stores the previous running count for thermal
+ *				or power threshold interrupts.
+ * @max_time_ms:		This shows the maximum amount of time CPU was
+ *				in throttled state for a single thermal
+ *				threshold high to low state.
+ * @total_time_ms:		This is a cumulative time during which CPU was
+ *				in the throttled state.
+ * @rate_control_active:	Set when a throttling message is logged.
+ *				This is used for the purpose of rate-control.
+ * @new_event:			Stores the last high/low status of the
+ *				THERM_STATUS_PROCHOT or
+ *				THERM_STATUS_POWER_LIMIT.
+ * @level:			Stores whether this _thermal_state instance is
+ *				for a CORE level or for PACKAGE level.
+ * @sample_index:		Index for storing the next sample in the buffer
+ *				temp_samples[].
+ * @sample_count:		Total number of samples collected in the buffer
+ *				temp_samples[].
+ * @average:			The last moving average of temperature samples
+ * @baseline_temp:		Temperature at which thermal threshold high
+ *				interrupt was generated.
+ * @temp_samples:		Storage for temperature samples to calculate
+ *				moving average.
+ *
+ * This structure is used to represent data related to thermal state for a CPU.
+ * There is a separate storage for core and package level for each CPU.
+ */
+struct _thermal_state {
+	u64			next_check;
+	u64			last_interrupt_time;
+	struct delayed_work	therm_work;
+	unsigned long		count;
+	unsigned long		last_count;
+	unsigned long		max_time_ms;
+	unsigned long		total_time_ms;
+	bool			rate_control_active;
+	bool			new_event;
+	u8			level;
+	u8			sample_index;
+	u8			sample_count;
+	u8			average;
+	u8			baseline_temp;
+	u8			temp_samples[3];
+};
+
+struct thermal_state {
+	struct _thermal_state core_throttle;
+	struct _thermal_state core_power_limit;
+	struct _thermal_state package_throttle;
+	struct _thermal_state package_power_limit;
+	struct _thermal_state core_thresh0;
+	struct _thermal_state core_thresh1;
+	struct _thermal_state pkg_thresh0;
+	struct _thermal_state pkg_thresh1;
+};
+
+/* Callback to handle core threshold interrupts */
+int (*platform_thermal_notify)(__u64 msr_val);
+EXPORT_SYMBOL(platform_thermal_notify);
+
+/* Callback to handle core package threshold_interrupts */
+int (*platform_thermal_package_notify)(__u64 msr_val);
+EXPORT_SYMBOL_GPL(platform_thermal_package_notify);
+
+/* Callback support of rate control, return true, if
+ * callback has rate control */
+bool (*platform_thermal_package_rate_control)(void);
+EXPORT_SYMBOL_GPL(platform_thermal_package_rate_control);
+
+
+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_device_one_ro(_name)				\
+	static DEVICE_ATTR(_name, 0444,					\
+			   therm_throt_device_show_##_name,		\
+				   NULL)				\
+
+#define define_therm_throt_device_show_func(event, name)		\
+									\
+static ssize_t therm_throt_device_show_##event##_##name(		\
+			struct device *dev,				\
+			struct device_attribute *attr,			\
+			char *buf)					\
+{									\
+	unsigned int cpu = dev->id;					\
+	ssize_t ret;							\
+									\
+	preempt_disable();	/* CPU hotplug */			\
+	if (cpu_online(cpu)) {						\
+		ret = sprintf(buf, "%lu\n",				\
+			      per_cpu(thermal_state, cpu).event.name);	\
+	} else								\
+		ret = 0;						\
+	preempt_enable();						\
+									\
+	return ret;							\
+}
+
+define_therm_throt_device_show_func(core_throttle, count);
+define_therm_throt_device_one_ro(core_throttle_count);
+
+define_therm_throt_device_show_func(core_power_limit, count);
+define_therm_throt_device_one_ro(core_power_limit_count);
+
+define_therm_throt_device_show_func(package_throttle, count);
+define_therm_throt_device_one_ro(package_throttle_count);
+
+define_therm_throt_device_show_func(package_power_limit, count);
+define_therm_throt_device_one_ro(package_power_limit_count);
+
+define_therm_throt_device_show_func(core_throttle, max_time_ms);
+define_therm_throt_device_one_ro(core_throttle_max_time_ms);
+
+define_therm_throt_device_show_func(package_throttle, max_time_ms);
+define_therm_throt_device_one_ro(package_throttle_max_time_ms);
+
+define_therm_throt_device_show_func(core_throttle, total_time_ms);
+define_therm_throt_device_one_ro(core_throttle_total_time_ms);
+
+define_therm_throt_device_show_func(package_throttle, total_time_ms);
+define_therm_throt_device_one_ro(package_throttle_total_time_ms);
+
+static struct attribute *thermal_throttle_attrs[] = {
+	&dev_attr_core_throttle_count.attr,
+	&dev_attr_core_throttle_max_time_ms.attr,
+	&dev_attr_core_throttle_total_time_ms.attr,
+	NULL
+};
+
+static const struct attribute_group thermal_attr_group = {
+	.attrs	= thermal_throttle_attrs,
+	.name	= "thermal_throttle"
+};
+#endif /* CONFIG_SYSFS */
+
+#define CORE_LEVEL	0
+#define PACKAGE_LEVEL	1
+
+#define THERM_THROT_POLL_INTERVAL	HZ
+#define THERM_STATUS_PROCHOT_LOG	BIT(1)
+
+#define THERM_STATUS_CLEAR_CORE_MASK (BIT(1) | BIT(3) | BIT(5) | BIT(7) | BIT(9) | BIT(11) | BIT(13) | BIT(15))
+#define THERM_STATUS_CLEAR_PKG_MASK  (BIT(1) | BIT(3) | BIT(5) | BIT(7) | BIT(9) | BIT(11))
+
+static void clear_therm_status_log(int level)
+{
+	int msr;
+	u64 mask, msr_val;
+
+	if (level == CORE_LEVEL) {
+		msr  = MSR_IA32_THERM_STATUS;
+		mask = THERM_STATUS_CLEAR_CORE_MASK;
+	} else {
+		msr  = MSR_IA32_PACKAGE_THERM_STATUS;
+		mask = THERM_STATUS_CLEAR_PKG_MASK;
+	}
+
+	rdmsrl(msr, msr_val);
+	msr_val &= mask;
+	wrmsrl(msr, msr_val & ~THERM_STATUS_PROCHOT_LOG);
+}
+
+static void get_therm_status(int level, bool *proc_hot, u8 *temp)
+{
+	int msr;
+	u64 msr_val;
+
+	if (level == CORE_LEVEL)
+		msr = MSR_IA32_THERM_STATUS;
+	else
+		msr = MSR_IA32_PACKAGE_THERM_STATUS;
+
+	rdmsrl(msr, msr_val);
+	if (msr_val & THERM_STATUS_PROCHOT_LOG)
+		*proc_hot = true;
+	else
+		*proc_hot = false;
+
+	*temp = (msr_val >> 16) & 0x7F;
+}
+
+static void __maybe_unused throttle_active_work(struct work_struct *work)
+{
+	struct _thermal_state *state = container_of(to_delayed_work(work),
+						struct _thermal_state, therm_work);
+	unsigned int i, avg, this_cpu = smp_processor_id();
+	u64 now = get_jiffies_64();
+	bool hot;
+	u8 temp;
+
+	get_therm_status(state->level, &hot, &temp);
+	/* temperature value is offset from the max so lesser means hotter */
+	if (!hot && temp > state->baseline_temp) {
+		if (state->rate_control_active)
+			pr_info("CPU%d: %s temperature/speed normal (total events = %lu)\n",
+				this_cpu,
+				state->level == CORE_LEVEL ? "Core" : "Package",
+				state->count);
+
+		state->rate_control_active = false;
+		return;
+	}
+
+	if (time_before64(now, state->next_check) &&
+			  state->rate_control_active)
+		goto re_arm;
+
+	state->next_check = now + CHECK_INTERVAL;
+
+	if (state->count != state->last_count) {
+		/* There was one new thermal interrupt */
+		state->last_count = state->count;
+		state->average = 0;
+		state->sample_count = 0;
+		state->sample_index = 0;
+	}
+
+	state->temp_samples[state->sample_index] = temp;
+	state->sample_count++;
+	state->sample_index = (state->sample_index + 1) % ARRAY_SIZE(state->temp_samples);
+	if (state->sample_count < ARRAY_SIZE(state->temp_samples))
+		goto re_arm;
+
+	avg = 0;
+	for (i = 0; i < ARRAY_SIZE(state->temp_samples); ++i)
+		avg += state->temp_samples[i];
+
+	avg /= ARRAY_SIZE(state->temp_samples);
+
+	if (state->average > avg) {
+		pr_warn("CPU%d: %s temperature is above threshold, cpu clock is throttled (total events = %lu)\n",
+			this_cpu,
+			state->level == CORE_LEVEL ? "Core" : "Package",
+			state->count);
+		state->rate_control_active = true;
+	}
+
+	state->average = avg;
+
+re_arm:
+	clear_therm_status_log(state->level);
+	schedule_delayed_work_on(this_cpu, &state->therm_work, THERM_THROT_POLL_INTERVAL);
+}
+
+/***
+ * therm_throt_process - Process thermal throttling event from interrupt
+ * @curr: Whether the condition is current or not (boolean), since the
+ *        thermal interrupt normally gets called both when the thermal
+ *        event begins and once the event has ended.
+ *
+ * This function is called by the thermal interrupt after the
+ * IRQ has been acknowledged.
+ *
+ * It will take care of rate limiting and printing messages to the syslog.
+ */
+static void therm_throt_process(bool new_event, int event, int level)
+{
+	struct _thermal_state *state;
+	unsigned int this_cpu = smp_processor_id();
+	bool old_event;
+	u64 now;
+	struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
+
+	now = get_jiffies_64();
+	if (level == CORE_LEVEL) {
+		if (event == THERMAL_THROTTLING_EVENT)
+			state = &pstate->core_throttle;
+		else if (event == POWER_LIMIT_EVENT)
+			state = &pstate->core_power_limit;
+		else
+			return;
+	} else if (level == PACKAGE_LEVEL) {
+		if (event == THERMAL_THROTTLING_EVENT)
+			state = &pstate->package_throttle;
+		else if (event == POWER_LIMIT_EVENT)
+			state = &pstate->package_power_limit;
+		else
+			return;
+	} else
+		return;
+
+	old_event = state->new_event;
+	state->new_event = new_event;
+
+	if (new_event)
+		state->count++;
+
+	if (event != THERMAL_THROTTLING_EVENT)
+		return;
+
+	if (new_event && !state->last_interrupt_time) {
+		bool hot;
+		u8 temp;
+
+		get_therm_status(state->level, &hot, &temp);
+		/*
+		 * Ignore short temperature spike as the system is not close
+		 * to PROCHOT. 10C offset is large enough to ignore. It is
+		 * already dropped from the high threshold temperature.
+		 */
+		if (temp > 10)
+			return;
+
+		state->baseline_temp = temp;
+		state->last_interrupt_time = now;
+		schedule_delayed_work_on(this_cpu, &state->therm_work, THERM_THROT_POLL_INTERVAL);
+	} else if (old_event && state->last_interrupt_time) {
+		unsigned long throttle_time;
+
+		throttle_time = jiffies_delta_to_msecs(now - state->last_interrupt_time);
+		if (throttle_time > state->max_time_ms)
+			state->max_time_ms = throttle_time;
+		state->total_time_ms += throttle_time;
+		state->last_interrupt_time = 0;
+	}
+}
+
+static int thresh_event_valid(int level, int event)
+{
+	struct _thermal_state *state;
+	unsigned int this_cpu = smp_processor_id();
+	struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
+	u64 now = get_jiffies_64();
+
+	if (level == PACKAGE_LEVEL)
+		state = (event == 0) ? &pstate->pkg_thresh0 :
+						&pstate->pkg_thresh1;
+	else
+		state = (event == 0) ? &pstate->core_thresh0 :
+						&pstate->core_thresh1;
+
+	if (time_before64(now, state->next_check))
+		return 0;
+
+	state->next_check = now + CHECK_INTERVAL;
+
+	return 1;
+}
+
+static bool int_pln_enable;
+static int __init int_pln_enable_setup(char *s)
+{
+	int_pln_enable = true;
+
+	return 1;
+}
+__setup("int_pln_enable", int_pln_enable_setup);
+
+#ifdef CONFIG_SYSFS
+/* Add/Remove thermal_throttle interface for CPU device: */
+static int thermal_throttle_add_dev(struct device *dev, unsigned int cpu)
+{
+	int err;
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+
+	err = sysfs_create_group(&dev->kobj, &thermal_attr_group);
+	if (err)
+		return err;
+
+	if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable) {
+		err = sysfs_add_file_to_group(&dev->kobj,
+					      &dev_attr_core_power_limit_count.attr,
+					      thermal_attr_group.name);
+		if (err)
+			goto del_group;
+	}
+
+	if (cpu_has(c, X86_FEATURE_PTS)) {
+		err = sysfs_add_file_to_group(&dev->kobj,
+					      &dev_attr_package_throttle_count.attr,
+					      thermal_attr_group.name);
+		if (err)
+			goto del_group;
+
+		err = sysfs_add_file_to_group(&dev->kobj,
+					      &dev_attr_package_throttle_max_time_ms.attr,
+					      thermal_attr_group.name);
+		if (err)
+			goto del_group;
+
+		err = sysfs_add_file_to_group(&dev->kobj,
+					      &dev_attr_package_throttle_total_time_ms.attr,
+					      thermal_attr_group.name);
+		if (err)
+			goto del_group;
+
+		if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable) {
+			err = sysfs_add_file_to_group(&dev->kobj,
+					&dev_attr_package_power_limit_count.attr,
+					thermal_attr_group.name);
+			if (err)
+				goto del_group;
+		}
+	}
+
+	return 0;
+
+del_group:
+	sysfs_remove_group(&dev->kobj, &thermal_attr_group);
+
+	return err;
+}
+
+static void thermal_throttle_remove_dev(struct device *dev)
+{
+	sysfs_remove_group(&dev->kobj, &thermal_attr_group);
+}
+
+/* Get notified when a cpu comes on/off. Be hotplug friendly. */
+static int thermal_throttle_online(unsigned int cpu)
+{
+	struct thermal_state *state = &per_cpu(thermal_state, cpu);
+	struct device *dev = get_cpu_device(cpu);
+	u32 l;
+
+	state->package_throttle.level = PACKAGE_LEVEL;
+	state->core_throttle.level = CORE_LEVEL;
+
+	INIT_DELAYED_WORK(&state->package_throttle.therm_work, throttle_active_work);
+	INIT_DELAYED_WORK(&state->core_throttle.therm_work, throttle_active_work);
+
+	/*
+	 * The first CPU coming online will enable the HFI. Usually this causes
+	 * hardware to issue an HFI thermal interrupt. Such interrupt will reach
+	 * the CPU once we enable the thermal vector in the local APIC.
+	 */
+	intel_hfi_online(cpu);
+
+	/* Unmask the thermal vector after the above workqueues are initialized. */
+	l = apic_read(APIC_LVTTHMR);
+	apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
+
+	return thermal_throttle_add_dev(dev, cpu);
+}
+
+static int thermal_throttle_offline(unsigned int cpu)
+{
+	struct thermal_state *state = &per_cpu(thermal_state, cpu);
+	struct device *dev = get_cpu_device(cpu);
+	u32 l;
+
+	/* Mask the thermal vector before draining evtl. pending work */
+	l = apic_read(APIC_LVTTHMR);
+	apic_write(APIC_LVTTHMR, l | APIC_LVT_MASKED);
+
+	intel_hfi_offline(cpu);
+
+	cancel_delayed_work_sync(&state->package_throttle.therm_work);
+	cancel_delayed_work_sync(&state->core_throttle.therm_work);
+
+	state->package_throttle.rate_control_active = false;
+	state->core_throttle.rate_control_active = false;
+
+	thermal_throttle_remove_dev(dev);
+	return 0;
+}
+
+static __init int thermal_throttle_init_device(void)
+{
+	int ret;
+
+	if (!atomic_read(&therm_throt_en))
+		return 0;
+
+	intel_hfi_init();
+
+	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/therm:online",
+				thermal_throttle_online,
+				thermal_throttle_offline);
+	return ret < 0 ? ret : 0;
+}
+device_initcall(thermal_throttle_init_device);
+
+#endif /* CONFIG_SYSFS */
+
+static void notify_package_thresholds(__u64 msr_val)
+{
+	bool notify_thres_0 = false;
+	bool notify_thres_1 = false;
+
+	if (!platform_thermal_package_notify)
+		return;
+
+	/* lower threshold check */
+	if (msr_val & THERM_LOG_THRESHOLD0)
+		notify_thres_0 = true;
+	/* higher threshold check */
+	if (msr_val & THERM_LOG_THRESHOLD1)
+		notify_thres_1 = true;
+
+	if (!notify_thres_0 && !notify_thres_1)
+		return;
+
+	if (platform_thermal_package_rate_control &&
+		platform_thermal_package_rate_control()) {
+		/* Rate control is implemented in callback */
+		platform_thermal_package_notify(msr_val);
+		return;
+	}
+
+	/* lower threshold reached */
+	if (notify_thres_0 && thresh_event_valid(PACKAGE_LEVEL, 0))
+		platform_thermal_package_notify(msr_val);
+	/* higher threshold reached */
+	if (notify_thres_1 && thresh_event_valid(PACKAGE_LEVEL, 1))
+		platform_thermal_package_notify(msr_val);
+}
+
+static void notify_thresholds(__u64 msr_val)
+{
+	/* check whether the interrupt handler is defined;
+	 * otherwise simply return
+	 */
+	if (!platform_thermal_notify)
+		return;
+
+	/* lower threshold reached */
+	if ((msr_val & THERM_LOG_THRESHOLD0) &&
+			thresh_event_valid(CORE_LEVEL, 0))
+		platform_thermal_notify(msr_val);
+	/* higher threshold reached */
+	if ((msr_val & THERM_LOG_THRESHOLD1) &&
+			thresh_event_valid(CORE_LEVEL, 1))
+		platform_thermal_notify(msr_val);
+}
+
+void __weak notify_hwp_interrupt(void)
+{
+	wrmsrl_safe(MSR_HWP_STATUS, 0);
+}
+
+/* Thermal transition interrupt handler */
+void intel_thermal_interrupt(void)
+{
+	__u64 msr_val;
+
+	if (static_cpu_has(X86_FEATURE_HWP))
+		notify_hwp_interrupt();
+
+	rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
+
+	/* Check for violation of core thermal thresholds*/
+	notify_thresholds(msr_val);
+
+	therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
+			    THERMAL_THROTTLING_EVENT,
+			    CORE_LEVEL);
+
+	if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)
+		therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,
+					POWER_LIMIT_EVENT,
+					CORE_LEVEL);
+
+	if (this_cpu_has(X86_FEATURE_PTS)) {
+		rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
+		/* check violations of package thermal thresholds */
+		notify_package_thresholds(msr_val);
+		therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,
+					THERMAL_THROTTLING_EVENT,
+					PACKAGE_LEVEL);
+		if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)
+			therm_throt_process(msr_val &
+					PACKAGE_THERM_STATUS_POWER_LIMIT,
+					POWER_LIMIT_EVENT,
+					PACKAGE_LEVEL);
+
+		if (this_cpu_has(X86_FEATURE_HFI))
+			intel_hfi_process_event(msr_val &
+						PACKAGE_THERM_STATUS_HFI_UPDATED);
+	}
+}
+
+/* Thermal monitoring depends on APIC, ACPI and clock modulation */
+static int intel_thermal_supported(struct cpuinfo_x86 *c)
+{
+	if (!boot_cpu_has(X86_FEATURE_APIC))
+		return 0;
+	if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
+		return 0;
+	return 1;
+}
+
+bool x86_thermal_enabled(void)
+{
+	return atomic_read(&therm_throt_en);
+}
+
+void __init therm_lvt_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;
+
+	if (!intel_thermal_supported(c))
+		return;
+
+	/*
+	 * First check if its enabled already, in which case there might
+	 * be some SMM goo which handles it, so we can't even put a handler
+	 * since it might be delivered via SMI already:
+	 */
+	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
+
+	h = lvtthmr_init;
+	/*
+	 * 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.
+	 * If BIOS takes over the thermal interrupt and sets its interrupt
+	 * delivery mode to SMI (not fixed), it restores the value that the
+	 * BIOS has programmed on AP based on BSP's info we saved since BIOS
+	 * is always setting the same value for all threads/cores.
+	 */
+	if ((h & APIC_DM_FIXED_MASK) != APIC_DM_FIXED)
+		apic_write(APIC_LVTTHMR, lvtthmr_init);
+
+
+	if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
+		if (system_state == SYSTEM_BOOTING)
+			pr_debug("CPU%d: Thermal monitoring handled by SMI\n", cpu);
+		return;
+	}
+
+	/* early Pentium M models use different method for enabling TM2 */
+	if (cpu_has(c, X86_FEATURE_TM2)) {
+		if (c->x86 == 6 && (c->x86_model == 9 || c->x86_model == 13)) {
+			rdmsr(MSR_THERM2_CTL, l, h);
+			if (l & MSR_THERM2_CTL_TM_SELECT)
+				tm2 = 1;
+		} else if (l & MSR_IA32_MISC_ENABLE_TM2)
+			tm2 = 1;
+	}
+
+	/* We'll mask the thermal vector in the lapic till we're ready: */
+	h = THERMAL_APIC_VECTOR | APIC_DM_FIXED | APIC_LVT_MASKED;
+	apic_write(APIC_LVTTHMR, h);
+
+	rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
+	if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)
+		wrmsr(MSR_IA32_THERM_INTERRUPT,
+			(l | (THERM_INT_LOW_ENABLE
+			| THERM_INT_HIGH_ENABLE)) & ~THERM_INT_PLN_ENABLE, h);
+	else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
+		wrmsr(MSR_IA32_THERM_INTERRUPT,
+			l | (THERM_INT_LOW_ENABLE
+			| THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
+	else
+		wrmsr(MSR_IA32_THERM_INTERRUPT,
+		      l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);
+
+	if (cpu_has(c, X86_FEATURE_PTS)) {
+		rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
+		if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)
+			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+				(l | (PACKAGE_THERM_INT_LOW_ENABLE
+				| PACKAGE_THERM_INT_HIGH_ENABLE))
+				& ~PACKAGE_THERM_INT_PLN_ENABLE, h);
+		else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
+			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+				l | (PACKAGE_THERM_INT_LOW_ENABLE
+				| PACKAGE_THERM_INT_HIGH_ENABLE
+				| PACKAGE_THERM_INT_PLN_ENABLE), h);
+		else
+			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+			      l | (PACKAGE_THERM_INT_LOW_ENABLE
+				| PACKAGE_THERM_INT_HIGH_ENABLE), h);
+
+		if (cpu_has(c, X86_FEATURE_HFI)) {
+			rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
+			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+			      l | PACKAGE_THERM_INT_HFI_ENABLE, h);
+		}
+	}
+
+	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
+	wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
+
+	pr_info_once("CPU0: Thermal monitoring enabled (%s)\n",
+		      tm2 ? "TM2" : "TM1");
+
+	/* enable thermal throttle processing */
+	atomic_set(&therm_throt_en, 1);
+}