arch/x86/kernel/cpu/mcheck/therm_throt.c - linux - Git at Google

 /*
  * 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 and mcelog 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/sysdev.h>
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/smp.h>
 #include <linux/cpu.h>

 #include <asm/processor.h>
 #include <asm/system.h>
 #include <asm/apic.h>
 #include <asm/idle.h>
 #include <asm/mce.h>
 #include <asm/msr.h>

 /* How long to wait between reporting thermal events */
 #define CHECK_INTERVAL		(300 * HZ)

 static DEFINE_PER_CPU(__u64, next_check) = INITIAL_JIFFIES;
 static DEFINE_PER_CPU(unsigned long, thermal_throttle_count);
 static DEFINE_PER_CPU(bool, thermal_throttle_active);

 static atomic_t therm_throt_en		= ATOMIC_INIT(0);

 #ifdef CONFIG_SYSFS
 #define define_therm_throt_sysdev_one_ro(_name)				\
 	static SYSDEV_ATTR(_name, 0444, therm_throt_sysdev_show_##_name, NULL)

 #define define_therm_throt_sysdev_show_func(name)			\
 static ssize_t therm_throt_sysdev_show_##name(struct sys_device *dev,	\
 					struct sysdev_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_throttle_##name, cpu));	\
 	else								\
 		ret = 0;						\
 	preempt_enable();						\
 									\
 	return ret;							\
 }

 define_therm_throt_sysdev_show_func(count);
 define_therm_throt_sysdev_one_ro(count);

 static struct attribute *thermal_throttle_attrs[] = {
 	&attr_count.attr,
 	NULL
 };

 static struct attribute_group thermal_throttle_attr_group = {
 	.attrs	= thermal_throttle_attrs,
 	.name	= "thermal_throttle"
 };
 #endif /* CONFIG_SYSFS */

 /***
  * 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.
  *
  * Returns: 0 : Event should NOT be further logged, i.e. still in
  *              "timeout" from previous log message.
  *          1 : Event should be logged further, and a message has been
  *              printed to the syslog.
  */
 static int therm_throt_process(int curr)
 {
 	unsigned int cpu = smp_processor_id();
 	__u64 tmp_jiffs = get_jiffies_64();
 	bool was_throttled = __get_cpu_var(thermal_throttle_active);
 	bool is_throttled = __get_cpu_var(thermal_throttle_active) = curr;

 	if (is_throttled)
 		__get_cpu_var(thermal_throttle_count)++;

 	if (!(was_throttled ^ is_throttled) &&
 	    time_before64(tmp_jiffs, __get_cpu_var(next_check)))
 		return 0;

 	__get_cpu_var(next_check) = tmp_jiffs + CHECK_INTERVAL;

 	/* if we just entered the thermal event */
 	if (is_throttled) {
 		printk(KERN_CRIT "CPU%d: Temperature above threshold, "
 		       "cpu clock throttled (total events = %lu)\n",
 		       cpu, __get_cpu_var(thermal_throttle_count));

 		add_taint(TAINT_MACHINE_CHECK);
 		return 1;
 	}
 	if (was_throttled) {
 		printk(KERN_INFO "CPU%d: Temperature/speed normal\n", cpu);
 		return 1;
 	}

 	return 0;
 }

 #ifdef CONFIG_SYSFS
 /* Add/Remove thermal_throttle interface for CPU device: */
 static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev)
 {
 	return sysfs_create_group(&sys_dev->kobj,
 				  &thermal_throttle_attr_group);
 }

 static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev)
 {
 	sysfs_remove_group(&sys_dev->kobj, &thermal_throttle_attr_group);
 }

 /* Mutex protecting device creation against CPU hotplug: */
 static DEFINE_MUTEX(therm_cpu_lock);

 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
 static __cpuinit int
 thermal_throttle_cpu_callback(struct notifier_block *nfb,
 			      unsigned long action,
 			      void *hcpu)
 {
 	unsigned int cpu = (unsigned long)hcpu;
 	struct sys_device *sys_dev;
 	int err = 0;

 	sys_dev = get_cpu_sysdev(cpu);

 	switch (action) {
 	case CPU_UP_PREPARE:
 	case CPU_UP_PREPARE_FROZEN:
 		mutex_lock(&therm_cpu_lock);
 		err = thermal_throttle_add_dev(sys_dev);
 		mutex_unlock(&therm_cpu_lock);
 		WARN_ON(err);
 		break;
 	case CPU_UP_CANCELED:
 	case CPU_UP_CANCELED_FROZEN:
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
 		mutex_lock(&therm_cpu_lock);
 		thermal_throttle_remove_dev(sys_dev);
 		mutex_unlock(&therm_cpu_lock);
 		break;
 	}
 	return err ? NOTIFY_BAD : NOTIFY_OK;
 }

 static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
 {
 	.notifier_call = thermal_throttle_cpu_callback,
 };

 static __init int thermal_throttle_init_device(void)
 {
 	unsigned int cpu = 0;
 	int err;

 	if (!atomic_read(&therm_throt_en))
 		return 0;

 	register_hotcpu_notifier(&thermal_throttle_cpu_notifier);

 #ifdef CONFIG_HOTPLUG_CPU
 	mutex_lock(&therm_cpu_lock);
 #endif
 	/* connect live CPUs to sysfs */
 	for_each_online_cpu(cpu) {
 		err = thermal_throttle_add_dev(get_cpu_sysdev(cpu));
 		WARN_ON(err);
 	}
 #ifdef CONFIG_HOTPLUG_CPU
 	mutex_unlock(&therm_cpu_lock);
 #endif

 	return 0;
 }
 device_initcall(thermal_throttle_init_device);

 #endif /* CONFIG_SYSFS */

 /* Thermal transition interrupt handler */
 static void intel_thermal_interrupt(void)
 {
 	__u64 msr_val;

 	rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
 	if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT))
 		mce_log_therm_throt_event(msr_val);
 }

 static void unexpected_thermal_interrupt(void)
 {
 	printk(KERN_ERR "CPU%d: Unexpected LVT TMR interrupt!\n",
 			smp_processor_id());
 	add_taint(TAINT_MACHINE_CHECK);
 }

 static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;

 asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
 {
 	exit_idle();
 	irq_enter();
 	inc_irq_stat(irq_thermal_count);
 	smp_thermal_vector();
 	irq_exit();
 	/* Ack only at the end to avoid potential reentry */
 	ack_APIC_irq();
 }

 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))
 		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 = apic_read(APIC_LVTTHMR);
 	if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
 		printk(KERN_DEBUG
 		       "CPU%d: Thermal monitoring handled by SMI\n", cpu);
 		return;
 	}

 	/* Check whether a vector already exists */
 	if (h & APIC_VECTOR_MASK) {
 		printk(KERN_DEBUG
 		       "CPU%d: Thermal LVT vector (%#x) already installed\n",
 		       cpu, (h & APIC_VECTOR_MASK));
 		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);
 	wrmsr(MSR_IA32_THERM_INTERRUPT,
 		l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);

 	smp_thermal_vector = intel_thermal_interrupt;

 	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
 	wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);

 	/* Unmask the thermal vector: */
 	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");

 	/* enable thermal throttle processing */
 	atomic_set(&therm_throt_en, 1);
 }
	/*
	* 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 and mcelog 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/sysdev.h>
	#include <linux/types.h>
	#include <linux/init.h>
	#include <linux/smp.h>
	#include <linux/cpu.h>

	#include <asm/processor.h>
	#include <asm/system.h>
	#include <asm/apic.h>
	#include <asm/idle.h>
	#include <asm/mce.h>
	#include <asm/msr.h>

	/* How long to wait between reporting thermal events */
	#define CHECK_INTERVAL (300 * HZ)

	static DEFINE_PER_CPU(__u64, next_check) = INITIAL_JIFFIES;
	static DEFINE_PER_CPU(unsigned long, thermal_throttle_count);
	static DEFINE_PER_CPU(bool, thermal_throttle_active);

	static atomic_t therm_throt_en = ATOMIC_INIT(0);

	#ifdef CONFIG_SYSFS
	#define define_therm_throt_sysdev_one_ro(_name) \
	static SYSDEV_ATTR(_name, 0444, therm_throt_sysdev_show_##_name, NULL)

	#define define_therm_throt_sysdev_show_func(name) \
	static ssize_t therm_throt_sysdev_show_##name(struct sys_device *dev, \
	struct sysdev_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_throttle_##name, cpu)); \
	else \
	ret = 0; \
	preempt_enable(); \
	\
	return ret; \
	}

	define_therm_throt_sysdev_show_func(count);
	define_therm_throt_sysdev_one_ro(count);

	static struct attribute *thermal_throttle_attrs[] = {
	&attr_count.attr,
	NULL
	};

	static struct attribute_group thermal_throttle_attr_group = {
	.attrs = thermal_throttle_attrs,
	.name = "thermal_throttle"
	};
	#endif /* CONFIG_SYSFS */

	/***
	* 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.
	*
	* Returns: 0 : Event should NOT be further logged, i.e. still in
	* "timeout" from previous log message.
	* 1 : Event should be logged further, and a message has been
	* printed to the syslog.
	*/
	static int therm_throt_process(int curr)
	{
	unsigned int cpu = smp_processor_id();
	__u64 tmp_jiffs = get_jiffies_64();
	bool was_throttled = __get_cpu_var(thermal_throttle_active);
	bool is_throttled = __get_cpu_var(thermal_throttle_active) = curr;

	if (is_throttled)
	__get_cpu_var(thermal_throttle_count)++;

	if (!(was_throttled ^ is_throttled) &&
	time_before64(tmp_jiffs, __get_cpu_var(next_check)))
	return 0;

	__get_cpu_var(next_check) = tmp_jiffs + CHECK_INTERVAL;

	/* if we just entered the thermal event */
	if (is_throttled) {
	printk(KERN_CRIT "CPU%d: Temperature above threshold, "
	"cpu clock throttled (total events = %lu)\n",
	cpu, __get_cpu_var(thermal_throttle_count));

	add_taint(TAINT_MACHINE_CHECK);
	return 1;
	}
	if (was_throttled) {
	printk(KERN_INFO "CPU%d: Temperature/speed normal\n", cpu);
	return 1;
	}

	return 0;
	}

	#ifdef CONFIG_SYSFS
	/* Add/Remove thermal_throttle interface for CPU device: */
	static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev)
	{
	return sysfs_create_group(&sys_dev->kobj,
	&thermal_throttle_attr_group);
	}

	static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev)
	{
	sysfs_remove_group(&sys_dev->kobj, &thermal_throttle_attr_group);
	}

	/* Mutex protecting device creation against CPU hotplug: */
	static DEFINE_MUTEX(therm_cpu_lock);

	/* Get notified when a cpu comes on/off. Be hotplug friendly. */
	static __cpuinit int
	thermal_throttle_cpu_callback(struct notifier_block *nfb,
	unsigned long action,
	void *hcpu)
	{
	unsigned int cpu = (unsigned long)hcpu;
	struct sys_device *sys_dev;
	int err = 0;

	sys_dev = get_cpu_sysdev(cpu);

	switch (action) {
	case CPU_UP_PREPARE:
	case CPU_UP_PREPARE_FROZEN:
	mutex_lock(&therm_cpu_lock);
	err = thermal_throttle_add_dev(sys_dev);
	mutex_unlock(&therm_cpu_lock);
	WARN_ON(err);
	break;
	case CPU_UP_CANCELED:
	case CPU_UP_CANCELED_FROZEN:
	case CPU_DEAD:
	case CPU_DEAD_FROZEN:
	mutex_lock(&therm_cpu_lock);
	thermal_throttle_remove_dev(sys_dev);
	mutex_unlock(&therm_cpu_lock);
	break;
	}
	return err ? NOTIFY_BAD : NOTIFY_OK;
	}

	static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
	{
	.notifier_call = thermal_throttle_cpu_callback,
	};

	static __init int thermal_throttle_init_device(void)
	{
	unsigned int cpu = 0;
	int err;

	if (!atomic_read(&therm_throt_en))
	return 0;

	register_hotcpu_notifier(&thermal_throttle_cpu_notifier);

	#ifdef CONFIG_HOTPLUG_CPU
	mutex_lock(&therm_cpu_lock);
	#endif
	/* connect live CPUs to sysfs */
	for_each_online_cpu(cpu) {
	err = thermal_throttle_add_dev(get_cpu_sysdev(cpu));
	WARN_ON(err);
	}
	#ifdef CONFIG_HOTPLUG_CPU
	mutex_unlock(&therm_cpu_lock);
	#endif

	return 0;
	}
	device_initcall(thermal_throttle_init_device);

	#endif /* CONFIG_SYSFS */

	/* Thermal transition interrupt handler */
	static void intel_thermal_interrupt(void)
	{
	__u64 msr_val;

	rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
	if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT))
	mce_log_therm_throt_event(msr_val);
	}

	static void unexpected_thermal_interrupt(void)
	{
	printk(KERN_ERR "CPU%d: Unexpected LVT TMR interrupt!\n",
	smp_processor_id());
	add_taint(TAINT_MACHINE_CHECK);
	}

	static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;

	asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
	{
	exit_idle();
	irq_enter();
	inc_irq_stat(irq_thermal_count);
	smp_thermal_vector();
	irq_exit();
	/* Ack only at the end to avoid potential reentry */
	ack_APIC_irq();
	}

	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))
	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 = apic_read(APIC_LVTTHMR);
	if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
	printk(KERN_DEBUG
	"CPU%d: Thermal monitoring handled by SMI\n", cpu);
	return;
	}

	/* Check whether a vector already exists */
	if (h & APIC_VECTOR_MASK) {
	printk(KERN_DEBUG
	"CPU%d: Thermal LVT vector (%#x) already installed\n",
	cpu, (h & APIC_VECTOR_MASK));
	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);
	wrmsr(MSR_IA32_THERM_INTERRUPT,
	l \| (THERM_INT_LOW_ENABLE \| THERM_INT_HIGH_ENABLE), h);

	smp_thermal_vector = intel_thermal_interrupt;

	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
	wrmsr(MSR_IA32_MISC_ENABLE, l \| MSR_IA32_MISC_ENABLE_TM1, h);

	/* Unmask the thermal vector: */
	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");

	/* enable thermal throttle processing */
	atomic_set(&therm_throt_en, 1);
	}