2 * Thermal throttle event support code (such as syslog messaging and rate
3 * limiting) that was factored out from x86_64 (mce_intel.c) and i386 (p4.c).
5 * This allows consistent reporting of CPU thermal throttle events.
7 * Maintains a counter in /sys that keeps track of the number of thermal
8 * events, such that the user knows how bad the thermal problem might be
9 * (since the logging to syslog and mcelog is rate limited).
11 * Author: Dmitriy Zavin (dmitriyz@google.com)
13 * Credits: Adapted from Zwane Mwaikambo's original code in mce_intel.c.
14 * Inspired by Ross Biro's and Al Borchers' counter code.
16 #include <linux/interrupt.h>
17 #include <linux/notifier.h>
18 #include <linux/jiffies.h>
19 #include <linux/kernel.h>
20 #include <linux/percpu.h>
21 #include <linux/export.h>
22 #include <linux/types.h>
23 #include <linux/init.h>
24 #include <linux/smp.h>
25 #include <linux/cpu.h>
27 #include <asm/processor.h>
33 /* How long to wait between reporting thermal events */
34 #define CHECK_INTERVAL (300 * HZ)
36 #define THERMAL_THROTTLING_EVENT 0
37 #define POWER_LIMIT_EVENT 1
40 * Current thermal event state:
42 struct _thermal_state
{
47 unsigned long last_count
;
50 struct thermal_state
{
51 struct _thermal_state core_throttle
;
52 struct _thermal_state core_power_limit
;
53 struct _thermal_state package_throttle
;
54 struct _thermal_state package_power_limit
;
55 struct _thermal_state core_thresh0
;
56 struct _thermal_state core_thresh1
;
57 struct _thermal_state pkg_thresh0
;
58 struct _thermal_state pkg_thresh1
;
61 /* Callback to handle core threshold interrupts */
62 int (*platform_thermal_notify
)(__u64 msr_val
);
63 EXPORT_SYMBOL(platform_thermal_notify
);
65 /* Callback to handle core package threshold_interrupts */
66 int (*platform_thermal_package_notify
)(__u64 msr_val
);
67 EXPORT_SYMBOL_GPL(platform_thermal_package_notify
);
69 /* Callback support of rate control, return true, if
70 * callback has rate control */
71 bool (*platform_thermal_package_rate_control
)(void);
72 EXPORT_SYMBOL_GPL(platform_thermal_package_rate_control
);
75 static DEFINE_PER_CPU(struct thermal_state
, thermal_state
);
77 static atomic_t therm_throt_en
= ATOMIC_INIT(0);
79 static u32 lvtthmr_init __read_mostly
;
82 #define define_therm_throt_device_one_ro(_name) \
83 static DEVICE_ATTR(_name, 0444, \
84 therm_throt_device_show_##_name, \
87 #define define_therm_throt_device_show_func(event, name) \
89 static ssize_t therm_throt_device_show_##event##_##name( \
91 struct device_attribute *attr, \
94 unsigned int cpu = dev->id; \
97 preempt_disable(); /* CPU hotplug */ \
98 if (cpu_online(cpu)) { \
99 ret = sprintf(buf, "%lu\n", \
100 per_cpu(thermal_state, cpu).event.name); \
108 define_therm_throt_device_show_func(core_throttle
, count
);
109 define_therm_throt_device_one_ro(core_throttle_count
);
111 define_therm_throt_device_show_func(core_power_limit
, count
);
112 define_therm_throt_device_one_ro(core_power_limit_count
);
114 define_therm_throt_device_show_func(package_throttle
, count
);
115 define_therm_throt_device_one_ro(package_throttle_count
);
117 define_therm_throt_device_show_func(package_power_limit
, count
);
118 define_therm_throt_device_one_ro(package_power_limit_count
);
120 static struct attribute
*thermal_throttle_attrs
[] = {
121 &dev_attr_core_throttle_count
.attr
,
125 static struct attribute_group thermal_attr_group
= {
126 .attrs
= thermal_throttle_attrs
,
127 .name
= "thermal_throttle"
129 #endif /* CONFIG_SYSFS */
132 #define PACKAGE_LEVEL 1
135 * therm_throt_process - Process thermal throttling event from interrupt
136 * @curr: Whether the condition is current or not (boolean), since the
137 * thermal interrupt normally gets called both when the thermal
138 * event begins and once the event has ended.
140 * This function is called by the thermal interrupt after the
141 * IRQ has been acknowledged.
143 * It will take care of rate limiting and printing messages to the syslog.
145 * Returns: 0 : Event should NOT be further logged, i.e. still in
146 * "timeout" from previous log message.
147 * 1 : Event should be logged further, and a message has been
148 * printed to the syslog.
150 static int therm_throt_process(bool new_event
, int event
, int level
)
152 struct _thermal_state
*state
;
153 unsigned int this_cpu
= smp_processor_id();
156 struct thermal_state
*pstate
= &per_cpu(thermal_state
, this_cpu
);
158 now
= get_jiffies_64();
159 if (level
== CORE_LEVEL
) {
160 if (event
== THERMAL_THROTTLING_EVENT
)
161 state
= &pstate
->core_throttle
;
162 else if (event
== POWER_LIMIT_EVENT
)
163 state
= &pstate
->core_power_limit
;
166 } else if (level
== PACKAGE_LEVEL
) {
167 if (event
== THERMAL_THROTTLING_EVENT
)
168 state
= &pstate
->package_throttle
;
169 else if (event
== POWER_LIMIT_EVENT
)
170 state
= &pstate
->package_power_limit
;
176 old_event
= state
->new_event
;
177 state
->new_event
= new_event
;
182 if (time_before64(now
, state
->next_check
) &&
183 state
->count
!= state
->last_count
)
186 state
->next_check
= now
+ CHECK_INTERVAL
;
187 state
->last_count
= state
->count
;
189 /* if we just entered the thermal event */
191 if (event
== THERMAL_THROTTLING_EVENT
)
192 printk(KERN_CRIT
"CPU%d: %s temperature above threshold, cpu clock throttled (total events = %lu)\n",
194 level
== CORE_LEVEL
? "Core" : "Package",
197 printk(KERN_CRIT
"CPU%d: %s power limit notification (total events = %lu)\n",
199 level
== CORE_LEVEL
? "Core" : "Package",
204 if (event
== THERMAL_THROTTLING_EVENT
)
205 printk(KERN_INFO
"CPU%d: %s temperature/speed normal\n",
207 level
== CORE_LEVEL
? "Core" : "Package");
209 printk(KERN_INFO
"CPU%d: %s power limit normal\n",
211 level
== CORE_LEVEL
? "Core" : "Package");
218 static int thresh_event_valid(int level
, int event
)
220 struct _thermal_state
*state
;
221 unsigned int this_cpu
= smp_processor_id();
222 struct thermal_state
*pstate
= &per_cpu(thermal_state
, this_cpu
);
223 u64 now
= get_jiffies_64();
225 if (level
== PACKAGE_LEVEL
)
226 state
= (event
== 0) ? &pstate
->pkg_thresh0
:
227 &pstate
->pkg_thresh1
;
229 state
= (event
== 0) ? &pstate
->core_thresh0
:
230 &pstate
->core_thresh1
;
232 if (time_before64(now
, state
->next_check
))
235 state
->next_check
= now
+ CHECK_INTERVAL
;
241 /* Add/Remove thermal_throttle interface for CPU device: */
242 static __cpuinit
int thermal_throttle_add_dev(struct device
*dev
,
246 struct cpuinfo_x86
*c
= &cpu_data(cpu
);
248 err
= sysfs_create_group(&dev
->kobj
, &thermal_attr_group
);
252 if (cpu_has(c
, X86_FEATURE_PLN
))
253 err
= sysfs_add_file_to_group(&dev
->kobj
,
254 &dev_attr_core_power_limit_count
.attr
,
255 thermal_attr_group
.name
);
256 if (cpu_has(c
, X86_FEATURE_PTS
)) {
257 err
= sysfs_add_file_to_group(&dev
->kobj
,
258 &dev_attr_package_throttle_count
.attr
,
259 thermal_attr_group
.name
);
260 if (cpu_has(c
, X86_FEATURE_PLN
))
261 err
= sysfs_add_file_to_group(&dev
->kobj
,
262 &dev_attr_package_power_limit_count
.attr
,
263 thermal_attr_group
.name
);
269 static __cpuinit
void thermal_throttle_remove_dev(struct device
*dev
)
271 sysfs_remove_group(&dev
->kobj
, &thermal_attr_group
);
274 /* Mutex protecting device creation against CPU hotplug: */
275 static DEFINE_MUTEX(therm_cpu_lock
);
277 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
279 thermal_throttle_cpu_callback(struct notifier_block
*nfb
,
280 unsigned long action
,
283 unsigned int cpu
= (unsigned long)hcpu
;
287 dev
= get_cpu_device(cpu
);
291 case CPU_UP_PREPARE_FROZEN
:
292 mutex_lock(&therm_cpu_lock
);
293 err
= thermal_throttle_add_dev(dev
, cpu
);
294 mutex_unlock(&therm_cpu_lock
);
297 case CPU_UP_CANCELED
:
298 case CPU_UP_CANCELED_FROZEN
:
300 case CPU_DEAD_FROZEN
:
301 mutex_lock(&therm_cpu_lock
);
302 thermal_throttle_remove_dev(dev
);
303 mutex_unlock(&therm_cpu_lock
);
306 return notifier_from_errno(err
);
309 static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata
=
311 .notifier_call
= thermal_throttle_cpu_callback
,
314 static __init
int thermal_throttle_init_device(void)
316 unsigned int cpu
= 0;
319 if (!atomic_read(&therm_throt_en
))
322 register_hotcpu_notifier(&thermal_throttle_cpu_notifier
);
324 #ifdef CONFIG_HOTPLUG_CPU
325 mutex_lock(&therm_cpu_lock
);
327 /* connect live CPUs to sysfs */
328 for_each_online_cpu(cpu
) {
329 err
= thermal_throttle_add_dev(get_cpu_device(cpu
), cpu
);
332 #ifdef CONFIG_HOTPLUG_CPU
333 mutex_unlock(&therm_cpu_lock
);
338 device_initcall(thermal_throttle_init_device
);
340 #endif /* CONFIG_SYSFS */
342 static void notify_package_thresholds(__u64 msr_val
)
344 bool notify_thres_0
= false;
345 bool notify_thres_1
= false;
347 if (!platform_thermal_package_notify
)
350 /* lower threshold check */
351 if (msr_val
& THERM_LOG_THRESHOLD0
)
352 notify_thres_0
= true;
353 /* higher threshold check */
354 if (msr_val
& THERM_LOG_THRESHOLD1
)
355 notify_thres_1
= true;
357 if (!notify_thres_0
&& !notify_thres_1
)
360 if (platform_thermal_package_rate_control
&&
361 platform_thermal_package_rate_control()) {
362 /* Rate control is implemented in callback */
363 platform_thermal_package_notify(msr_val
);
367 /* lower threshold reached */
368 if (notify_thres_0
&& thresh_event_valid(PACKAGE_LEVEL
, 0))
369 platform_thermal_package_notify(msr_val
);
370 /* higher threshold reached */
371 if (notify_thres_1
&& thresh_event_valid(PACKAGE_LEVEL
, 1))
372 platform_thermal_package_notify(msr_val
);
375 static void notify_thresholds(__u64 msr_val
)
377 /* check whether the interrupt handler is defined;
378 * otherwise simply return
380 if (!platform_thermal_notify
)
383 /* lower threshold reached */
384 if ((msr_val
& THERM_LOG_THRESHOLD0
) &&
385 thresh_event_valid(CORE_LEVEL
, 0))
386 platform_thermal_notify(msr_val
);
387 /* higher threshold reached */
388 if ((msr_val
& THERM_LOG_THRESHOLD1
) &&
389 thresh_event_valid(CORE_LEVEL
, 1))
390 platform_thermal_notify(msr_val
);
393 /* Thermal transition interrupt handler */
394 static void intel_thermal_interrupt(void)
398 rdmsrl(MSR_IA32_THERM_STATUS
, msr_val
);
400 /* Check for violation of core thermal thresholds*/
401 notify_thresholds(msr_val
);
403 if (therm_throt_process(msr_val
& THERM_STATUS_PROCHOT
,
404 THERMAL_THROTTLING_EVENT
,
406 mce_log_therm_throt_event(msr_val
);
408 if (this_cpu_has(X86_FEATURE_PLN
))
409 therm_throt_process(msr_val
& THERM_STATUS_POWER_LIMIT
,
413 if (this_cpu_has(X86_FEATURE_PTS
)) {
414 rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS
, msr_val
);
415 /* check violations of package thermal thresholds */
416 notify_package_thresholds(msr_val
);
417 therm_throt_process(msr_val
& PACKAGE_THERM_STATUS_PROCHOT
,
418 THERMAL_THROTTLING_EVENT
,
420 if (this_cpu_has(X86_FEATURE_PLN
))
421 therm_throt_process(msr_val
&
422 PACKAGE_THERM_STATUS_POWER_LIMIT
,
428 static void unexpected_thermal_interrupt(void)
430 printk(KERN_ERR
"CPU%d: Unexpected LVT thermal interrupt!\n",
434 static void (*smp_thermal_vector
)(void) = unexpected_thermal_interrupt
;
436 asmlinkage
void smp_thermal_interrupt(struct pt_regs
*regs
)
440 inc_irq_stat(irq_thermal_count
);
441 smp_thermal_vector();
443 /* Ack only at the end to avoid potential reentry */
447 /* Thermal monitoring depends on APIC, ACPI and clock modulation */
448 static int intel_thermal_supported(struct cpuinfo_x86
*c
)
452 if (!cpu_has(c
, X86_FEATURE_ACPI
) || !cpu_has(c
, X86_FEATURE_ACC
))
457 void __init
mcheck_intel_therm_init(void)
460 * This function is only called on boot CPU. Save the init thermal
461 * LVT value on BSP and use that value to restore APs' thermal LVT
462 * entry BIOS programmed later
464 if (intel_thermal_supported(&boot_cpu_data
))
465 lvtthmr_init
= apic_read(APIC_LVTTHMR
);
468 void intel_init_thermal(struct cpuinfo_x86
*c
)
470 unsigned int cpu
= smp_processor_id();
474 if (!intel_thermal_supported(c
))
478 * First check if its enabled already, in which case there might
479 * be some SMM goo which handles it, so we can't even put a handler
480 * since it might be delivered via SMI already:
482 rdmsr(MSR_IA32_MISC_ENABLE
, l
, h
);
486 * The initial value of thermal LVT entries on all APs always reads
487 * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI
488 * sequence to them and LVT registers are reset to 0s except for
489 * the mask bits which are set to 1s when APs receive INIT IPI.
490 * If BIOS takes over the thermal interrupt and sets its interrupt
491 * delivery mode to SMI (not fixed), it restores the value that the
492 * BIOS has programmed on AP based on BSP's info we saved since BIOS
493 * is always setting the same value for all threads/cores.
495 if ((h
& APIC_DM_FIXED_MASK
) != APIC_DM_FIXED
)
496 apic_write(APIC_LVTTHMR
, lvtthmr_init
);
499 if ((l
& MSR_IA32_MISC_ENABLE_TM1
) && (h
& APIC_DM_SMI
)) {
501 "CPU%d: Thermal monitoring handled by SMI\n", cpu
);
505 /* Check whether a vector already exists */
506 if (h
& APIC_VECTOR_MASK
) {
508 "CPU%d: Thermal LVT vector (%#x) already installed\n",
509 cpu
, (h
& APIC_VECTOR_MASK
));
513 /* early Pentium M models use different method for enabling TM2 */
514 if (cpu_has(c
, X86_FEATURE_TM2
)) {
515 if (c
->x86
== 6 && (c
->x86_model
== 9 || c
->x86_model
== 13)) {
516 rdmsr(MSR_THERM2_CTL
, l
, h
);
517 if (l
& MSR_THERM2_CTL_TM_SELECT
)
519 } else if (l
& MSR_IA32_MISC_ENABLE_TM2
)
523 /* We'll mask the thermal vector in the lapic till we're ready: */
524 h
= THERMAL_APIC_VECTOR
| APIC_DM_FIXED
| APIC_LVT_MASKED
;
525 apic_write(APIC_LVTTHMR
, h
);
527 rdmsr(MSR_IA32_THERM_INTERRUPT
, l
, h
);
528 if (cpu_has(c
, X86_FEATURE_PLN
))
529 wrmsr(MSR_IA32_THERM_INTERRUPT
,
530 l
| (THERM_INT_LOW_ENABLE
531 | THERM_INT_HIGH_ENABLE
| THERM_INT_PLN_ENABLE
), h
);
533 wrmsr(MSR_IA32_THERM_INTERRUPT
,
534 l
| (THERM_INT_LOW_ENABLE
| THERM_INT_HIGH_ENABLE
), h
);
536 if (cpu_has(c
, X86_FEATURE_PTS
)) {
537 rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT
, l
, h
);
538 if (cpu_has(c
, X86_FEATURE_PLN
))
539 wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT
,
540 l
| (PACKAGE_THERM_INT_LOW_ENABLE
541 | PACKAGE_THERM_INT_HIGH_ENABLE
542 | PACKAGE_THERM_INT_PLN_ENABLE
), h
);
544 wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT
,
545 l
| (PACKAGE_THERM_INT_LOW_ENABLE
546 | PACKAGE_THERM_INT_HIGH_ENABLE
), h
);
549 smp_thermal_vector
= intel_thermal_interrupt
;
551 rdmsr(MSR_IA32_MISC_ENABLE
, l
, h
);
552 wrmsr(MSR_IA32_MISC_ENABLE
, l
| MSR_IA32_MISC_ENABLE_TM1
, h
);
554 /* Unmask the thermal vector: */
555 l
= apic_read(APIC_LVTTHMR
);
556 apic_write(APIC_LVTTHMR
, l
& ~APIC_LVT_MASKED
);
558 printk_once(KERN_INFO
"CPU0: Thermal monitoring enabled (%s)\n",
559 tm2
? "TM2" : "TM1");
561 /* enable thermal throttle processing */
562 atomic_set(&therm_throt_en
, 1);