xref: /linux/drivers/thermal/intel/therm_throt.c (revision 2da68a77)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Thermal throttle event support code (such as syslog messaging and rate
4  * limiting) that was factored out from x86_64 (mce_intel.c) and i386 (p4.c).
5  *
6  * This allows consistent reporting of CPU thermal throttle events.
7  *
8  * Maintains a counter in /sys that keeps track of the number of thermal
9  * events, such that the user knows how bad the thermal problem might be
10  * (since the logging to syslog is rate limited).
11  *
12  * Author: Dmitriy Zavin (dmitriyz@google.com)
13  *
14  * Credits: Adapted from Zwane Mwaikambo's original code in mce_intel.c.
15  *          Inspired by Ross Biro's and Al Borchers' counter code.
16  */
17 #include <linux/interrupt.h>
18 #include <linux/notifier.h>
19 #include <linux/jiffies.h>
20 #include <linux/kernel.h>
21 #include <linux/percpu.h>
22 #include <linux/export.h>
23 #include <linux/types.h>
24 #include <linux/init.h>
25 #include <linux/smp.h>
26 #include <linux/cpu.h>
27 
28 #include <asm/processor.h>
29 #include <asm/thermal.h>
30 #include <asm/traps.h>
31 #include <asm/apic.h>
32 #include <asm/irq.h>
33 #include <asm/msr.h>
34 
35 #include "intel_hfi.h"
36 #include "thermal_interrupt.h"
37 
38 /* How long to wait between reporting thermal events */
39 #define CHECK_INTERVAL		(300 * HZ)
40 
41 #define THERMAL_THROTTLING_EVENT	0
42 #define POWER_LIMIT_EVENT		1
43 
44 /**
45  * struct _thermal_state - Represent the current thermal event state
46  * @next_check:			Stores the next timestamp, when it is allowed
47  *				to log the next warning message.
48  * @last_interrupt_time:	Stores the timestamp for the last threshold
49  *				high event.
50  * @therm_work:			Delayed workqueue structure
51  * @count:			Stores the current running count for thermal
52  *				or power threshold interrupts.
53  * @last_count:			Stores the previous running count for thermal
54  *				or power threshold interrupts.
55  * @max_time_ms:		This shows the maximum amount of time CPU was
56  *				in throttled state for a single thermal
57  *				threshold high to low state.
58  * @total_time_ms:		This is a cumulative time during which CPU was
59  *				in the throttled state.
60  * @rate_control_active:	Set when a throttling message is logged.
61  *				This is used for the purpose of rate-control.
62  * @new_event:			Stores the last high/low status of the
63  *				THERM_STATUS_PROCHOT or
64  *				THERM_STATUS_POWER_LIMIT.
65  * @level:			Stores whether this _thermal_state instance is
66  *				for a CORE level or for PACKAGE level.
67  * @sample_index:		Index for storing the next sample in the buffer
68  *				temp_samples[].
69  * @sample_count:		Total number of samples collected in the buffer
70  *				temp_samples[].
71  * @average:			The last moving average of temperature samples
72  * @baseline_temp:		Temperature at which thermal threshold high
73  *				interrupt was generated.
74  * @temp_samples:		Storage for temperature samples to calculate
75  *				moving average.
76  *
77  * This structure is used to represent data related to thermal state for a CPU.
78  * There is a separate storage for core and package level for each CPU.
79  */
80 struct _thermal_state {
81 	u64			next_check;
82 	u64			last_interrupt_time;
83 	struct delayed_work	therm_work;
84 	unsigned long		count;
85 	unsigned long		last_count;
86 	unsigned long		max_time_ms;
87 	unsigned long		total_time_ms;
88 	bool			rate_control_active;
89 	bool			new_event;
90 	u8			level;
91 	u8			sample_index;
92 	u8			sample_count;
93 	u8			average;
94 	u8			baseline_temp;
95 	u8			temp_samples[3];
96 };
97 
98 struct thermal_state {
99 	struct _thermal_state core_throttle;
100 	struct _thermal_state core_power_limit;
101 	struct _thermal_state package_throttle;
102 	struct _thermal_state package_power_limit;
103 	struct _thermal_state core_thresh0;
104 	struct _thermal_state core_thresh1;
105 	struct _thermal_state pkg_thresh0;
106 	struct _thermal_state pkg_thresh1;
107 };
108 
109 /* Callback to handle core threshold interrupts */
110 int (*platform_thermal_notify)(__u64 msr_val);
111 EXPORT_SYMBOL(platform_thermal_notify);
112 
113 /* Callback to handle core package threshold_interrupts */
114 int (*platform_thermal_package_notify)(__u64 msr_val);
115 EXPORT_SYMBOL_GPL(platform_thermal_package_notify);
116 
117 /* Callback support of rate control, return true, if
118  * callback has rate control */
119 bool (*platform_thermal_package_rate_control)(void);
120 EXPORT_SYMBOL_GPL(platform_thermal_package_rate_control);
121 
122 
123 static DEFINE_PER_CPU(struct thermal_state, thermal_state);
124 
125 static atomic_t therm_throt_en	= ATOMIC_INIT(0);
126 
127 static u32 lvtthmr_init __read_mostly;
128 
129 #ifdef CONFIG_SYSFS
130 #define define_therm_throt_device_one_ro(_name)				\
131 	static DEVICE_ATTR(_name, 0444,					\
132 			   therm_throt_device_show_##_name,		\
133 				   NULL)				\
134 
135 #define define_therm_throt_device_show_func(event, name)		\
136 									\
137 static ssize_t therm_throt_device_show_##event##_##name(		\
138 			struct device *dev,				\
139 			struct device_attribute *attr,			\
140 			char *buf)					\
141 {									\
142 	unsigned int cpu = dev->id;					\
143 	ssize_t ret;							\
144 									\
145 	preempt_disable();	/* CPU hotplug */			\
146 	if (cpu_online(cpu)) {						\
147 		ret = sprintf(buf, "%lu\n",				\
148 			      per_cpu(thermal_state, cpu).event.name);	\
149 	} else								\
150 		ret = 0;						\
151 	preempt_enable();						\
152 									\
153 	return ret;							\
154 }
155 
156 define_therm_throt_device_show_func(core_throttle, count);
157 define_therm_throt_device_one_ro(core_throttle_count);
158 
159 define_therm_throt_device_show_func(core_power_limit, count);
160 define_therm_throt_device_one_ro(core_power_limit_count);
161 
162 define_therm_throt_device_show_func(package_throttle, count);
163 define_therm_throt_device_one_ro(package_throttle_count);
164 
165 define_therm_throt_device_show_func(package_power_limit, count);
166 define_therm_throt_device_one_ro(package_power_limit_count);
167 
168 define_therm_throt_device_show_func(core_throttle, max_time_ms);
169 define_therm_throt_device_one_ro(core_throttle_max_time_ms);
170 
171 define_therm_throt_device_show_func(package_throttle, max_time_ms);
172 define_therm_throt_device_one_ro(package_throttle_max_time_ms);
173 
174 define_therm_throt_device_show_func(core_throttle, total_time_ms);
175 define_therm_throt_device_one_ro(core_throttle_total_time_ms);
176 
177 define_therm_throt_device_show_func(package_throttle, total_time_ms);
178 define_therm_throt_device_one_ro(package_throttle_total_time_ms);
179 
180 static struct attribute *thermal_throttle_attrs[] = {
181 	&dev_attr_core_throttle_count.attr,
182 	&dev_attr_core_throttle_max_time_ms.attr,
183 	&dev_attr_core_throttle_total_time_ms.attr,
184 	NULL
185 };
186 
187 static const struct attribute_group thermal_attr_group = {
188 	.attrs	= thermal_throttle_attrs,
189 	.name	= "thermal_throttle"
190 };
191 #endif /* CONFIG_SYSFS */
192 
193 #define THERM_THROT_POLL_INTERVAL	HZ
194 #define THERM_STATUS_PROCHOT_LOG	BIT(1)
195 
196 #define THERM_STATUS_CLEAR_CORE_MASK (BIT(1) | BIT(3) | BIT(5) | BIT(7) | BIT(9) | BIT(11) | BIT(13) | BIT(15))
197 #define THERM_STATUS_CLEAR_PKG_MASK  (BIT(1) | BIT(3) | BIT(5) | BIT(7) | BIT(9) | BIT(11) | BIT(26))
198 
199 /*
200  * Clear the bits in package thermal status register for bit = 1
201  * in bitmask
202  */
203 void thermal_clear_package_intr_status(int level, u64 bit_mask)
204 {
205 	u64 msr_val;
206 	int msr;
207 
208 	if (level == CORE_LEVEL) {
209 		msr  = MSR_IA32_THERM_STATUS;
210 		msr_val = THERM_STATUS_CLEAR_CORE_MASK;
211 	} else {
212 		msr  = MSR_IA32_PACKAGE_THERM_STATUS;
213 		msr_val = THERM_STATUS_CLEAR_PKG_MASK;
214 	}
215 
216 	msr_val &= ~bit_mask;
217 	wrmsrl(msr, msr_val);
218 }
219 EXPORT_SYMBOL_GPL(thermal_clear_package_intr_status);
220 
221 static void get_therm_status(int level, bool *proc_hot, u8 *temp)
222 {
223 	int msr;
224 	u64 msr_val;
225 
226 	if (level == CORE_LEVEL)
227 		msr = MSR_IA32_THERM_STATUS;
228 	else
229 		msr = MSR_IA32_PACKAGE_THERM_STATUS;
230 
231 	rdmsrl(msr, msr_val);
232 	if (msr_val & THERM_STATUS_PROCHOT_LOG)
233 		*proc_hot = true;
234 	else
235 		*proc_hot = false;
236 
237 	*temp = (msr_val >> 16) & 0x7F;
238 }
239 
240 static void __maybe_unused throttle_active_work(struct work_struct *work)
241 {
242 	struct _thermal_state *state = container_of(to_delayed_work(work),
243 						struct _thermal_state, therm_work);
244 	unsigned int i, avg, this_cpu = smp_processor_id();
245 	u64 now = get_jiffies_64();
246 	bool hot;
247 	u8 temp;
248 
249 	get_therm_status(state->level, &hot, &temp);
250 	/* temperature value is offset from the max so lesser means hotter */
251 	if (!hot && temp > state->baseline_temp) {
252 		if (state->rate_control_active)
253 			pr_info("CPU%d: %s temperature/speed normal (total events = %lu)\n",
254 				this_cpu,
255 				state->level == CORE_LEVEL ? "Core" : "Package",
256 				state->count);
257 
258 		state->rate_control_active = false;
259 		return;
260 	}
261 
262 	if (time_before64(now, state->next_check) &&
263 			  state->rate_control_active)
264 		goto re_arm;
265 
266 	state->next_check = now + CHECK_INTERVAL;
267 
268 	if (state->count != state->last_count) {
269 		/* There was one new thermal interrupt */
270 		state->last_count = state->count;
271 		state->average = 0;
272 		state->sample_count = 0;
273 		state->sample_index = 0;
274 	}
275 
276 	state->temp_samples[state->sample_index] = temp;
277 	state->sample_count++;
278 	state->sample_index = (state->sample_index + 1) % ARRAY_SIZE(state->temp_samples);
279 	if (state->sample_count < ARRAY_SIZE(state->temp_samples))
280 		goto re_arm;
281 
282 	avg = 0;
283 	for (i = 0; i < ARRAY_SIZE(state->temp_samples); ++i)
284 		avg += state->temp_samples[i];
285 
286 	avg /= ARRAY_SIZE(state->temp_samples);
287 
288 	if (state->average > avg) {
289 		pr_warn("CPU%d: %s temperature is above threshold, cpu clock is throttled (total events = %lu)\n",
290 			this_cpu,
291 			state->level == CORE_LEVEL ? "Core" : "Package",
292 			state->count);
293 		state->rate_control_active = true;
294 	}
295 
296 	state->average = avg;
297 
298 re_arm:
299 	thermal_clear_package_intr_status(state->level, THERM_STATUS_PROCHOT_LOG);
300 	schedule_delayed_work_on(this_cpu, &state->therm_work, THERM_THROT_POLL_INTERVAL);
301 }
302 
303 /***
304  * therm_throt_process - Process thermal throttling event from interrupt
305  * @curr: Whether the condition is current or not (boolean), since the
306  *        thermal interrupt normally gets called both when the thermal
307  *        event begins and once the event has ended.
308  *
309  * This function is called by the thermal interrupt after the
310  * IRQ has been acknowledged.
311  *
312  * It will take care of rate limiting and printing messages to the syslog.
313  */
314 static void therm_throt_process(bool new_event, int event, int level)
315 {
316 	struct _thermal_state *state;
317 	unsigned int this_cpu = smp_processor_id();
318 	bool old_event;
319 	u64 now;
320 	struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
321 
322 	now = get_jiffies_64();
323 	if (level == CORE_LEVEL) {
324 		if (event == THERMAL_THROTTLING_EVENT)
325 			state = &pstate->core_throttle;
326 		else if (event == POWER_LIMIT_EVENT)
327 			state = &pstate->core_power_limit;
328 		else
329 			return;
330 	} else if (level == PACKAGE_LEVEL) {
331 		if (event == THERMAL_THROTTLING_EVENT)
332 			state = &pstate->package_throttle;
333 		else if (event == POWER_LIMIT_EVENT)
334 			state = &pstate->package_power_limit;
335 		else
336 			return;
337 	} else
338 		return;
339 
340 	old_event = state->new_event;
341 	state->new_event = new_event;
342 
343 	if (new_event)
344 		state->count++;
345 
346 	if (event != THERMAL_THROTTLING_EVENT)
347 		return;
348 
349 	if (new_event && !state->last_interrupt_time) {
350 		bool hot;
351 		u8 temp;
352 
353 		get_therm_status(state->level, &hot, &temp);
354 		/*
355 		 * Ignore short temperature spike as the system is not close
356 		 * to PROCHOT. 10C offset is large enough to ignore. It is
357 		 * already dropped from the high threshold temperature.
358 		 */
359 		if (temp > 10)
360 			return;
361 
362 		state->baseline_temp = temp;
363 		state->last_interrupt_time = now;
364 		schedule_delayed_work_on(this_cpu, &state->therm_work, THERM_THROT_POLL_INTERVAL);
365 	} else if (old_event && state->last_interrupt_time) {
366 		unsigned long throttle_time;
367 
368 		throttle_time = jiffies_delta_to_msecs(now - state->last_interrupt_time);
369 		if (throttle_time > state->max_time_ms)
370 			state->max_time_ms = throttle_time;
371 		state->total_time_ms += throttle_time;
372 		state->last_interrupt_time = 0;
373 	}
374 }
375 
376 static int thresh_event_valid(int level, int event)
377 {
378 	struct _thermal_state *state;
379 	unsigned int this_cpu = smp_processor_id();
380 	struct thermal_state *pstate = &per_cpu(thermal_state, this_cpu);
381 	u64 now = get_jiffies_64();
382 
383 	if (level == PACKAGE_LEVEL)
384 		state = (event == 0) ? &pstate->pkg_thresh0 :
385 						&pstate->pkg_thresh1;
386 	else
387 		state = (event == 0) ? &pstate->core_thresh0 :
388 						&pstate->core_thresh1;
389 
390 	if (time_before64(now, state->next_check))
391 		return 0;
392 
393 	state->next_check = now + CHECK_INTERVAL;
394 
395 	return 1;
396 }
397 
398 static bool int_pln_enable;
399 static int __init int_pln_enable_setup(char *s)
400 {
401 	int_pln_enable = true;
402 
403 	return 1;
404 }
405 __setup("int_pln_enable", int_pln_enable_setup);
406 
407 #ifdef CONFIG_SYSFS
408 /* Add/Remove thermal_throttle interface for CPU device: */
409 static int thermal_throttle_add_dev(struct device *dev, unsigned int cpu)
410 {
411 	int err;
412 	struct cpuinfo_x86 *c = &cpu_data(cpu);
413 
414 	err = sysfs_create_group(&dev->kobj, &thermal_attr_group);
415 	if (err)
416 		return err;
417 
418 	if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable) {
419 		err = sysfs_add_file_to_group(&dev->kobj,
420 					      &dev_attr_core_power_limit_count.attr,
421 					      thermal_attr_group.name);
422 		if (err)
423 			goto del_group;
424 	}
425 
426 	if (cpu_has(c, X86_FEATURE_PTS)) {
427 		err = sysfs_add_file_to_group(&dev->kobj,
428 					      &dev_attr_package_throttle_count.attr,
429 					      thermal_attr_group.name);
430 		if (err)
431 			goto del_group;
432 
433 		err = sysfs_add_file_to_group(&dev->kobj,
434 					      &dev_attr_package_throttle_max_time_ms.attr,
435 					      thermal_attr_group.name);
436 		if (err)
437 			goto del_group;
438 
439 		err = sysfs_add_file_to_group(&dev->kobj,
440 					      &dev_attr_package_throttle_total_time_ms.attr,
441 					      thermal_attr_group.name);
442 		if (err)
443 			goto del_group;
444 
445 		if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable) {
446 			err = sysfs_add_file_to_group(&dev->kobj,
447 					&dev_attr_package_power_limit_count.attr,
448 					thermal_attr_group.name);
449 			if (err)
450 				goto del_group;
451 		}
452 	}
453 
454 	return 0;
455 
456 del_group:
457 	sysfs_remove_group(&dev->kobj, &thermal_attr_group);
458 
459 	return err;
460 }
461 
462 static void thermal_throttle_remove_dev(struct device *dev)
463 {
464 	sysfs_remove_group(&dev->kobj, &thermal_attr_group);
465 }
466 
467 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
468 static int thermal_throttle_online(unsigned int cpu)
469 {
470 	struct thermal_state *state = &per_cpu(thermal_state, cpu);
471 	struct device *dev = get_cpu_device(cpu);
472 	u32 l;
473 
474 	state->package_throttle.level = PACKAGE_LEVEL;
475 	state->core_throttle.level = CORE_LEVEL;
476 
477 	INIT_DELAYED_WORK(&state->package_throttle.therm_work, throttle_active_work);
478 	INIT_DELAYED_WORK(&state->core_throttle.therm_work, throttle_active_work);
479 
480 	/*
481 	 * The first CPU coming online will enable the HFI. Usually this causes
482 	 * hardware to issue an HFI thermal interrupt. Such interrupt will reach
483 	 * the CPU once we enable the thermal vector in the local APIC.
484 	 */
485 	intel_hfi_online(cpu);
486 
487 	/* Unmask the thermal vector after the above workqueues are initialized. */
488 	l = apic_read(APIC_LVTTHMR);
489 	apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
490 
491 	return thermal_throttle_add_dev(dev, cpu);
492 }
493 
494 static int thermal_throttle_offline(unsigned int cpu)
495 {
496 	struct thermal_state *state = &per_cpu(thermal_state, cpu);
497 	struct device *dev = get_cpu_device(cpu);
498 	u32 l;
499 
500 	/* Mask the thermal vector before draining evtl. pending work */
501 	l = apic_read(APIC_LVTTHMR);
502 	apic_write(APIC_LVTTHMR, l | APIC_LVT_MASKED);
503 
504 	intel_hfi_offline(cpu);
505 
506 	cancel_delayed_work_sync(&state->package_throttle.therm_work);
507 	cancel_delayed_work_sync(&state->core_throttle.therm_work);
508 
509 	state->package_throttle.rate_control_active = false;
510 	state->core_throttle.rate_control_active = false;
511 
512 	thermal_throttle_remove_dev(dev);
513 	return 0;
514 }
515 
516 static __init int thermal_throttle_init_device(void)
517 {
518 	int ret;
519 
520 	if (!atomic_read(&therm_throt_en))
521 		return 0;
522 
523 	intel_hfi_init();
524 
525 	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/therm:online",
526 				thermal_throttle_online,
527 				thermal_throttle_offline);
528 	return ret < 0 ? ret : 0;
529 }
530 device_initcall(thermal_throttle_init_device);
531 
532 #endif /* CONFIG_SYSFS */
533 
534 static void notify_package_thresholds(__u64 msr_val)
535 {
536 	bool notify_thres_0 = false;
537 	bool notify_thres_1 = false;
538 
539 	if (!platform_thermal_package_notify)
540 		return;
541 
542 	/* lower threshold check */
543 	if (msr_val & THERM_LOG_THRESHOLD0)
544 		notify_thres_0 = true;
545 	/* higher threshold check */
546 	if (msr_val & THERM_LOG_THRESHOLD1)
547 		notify_thres_1 = true;
548 
549 	if (!notify_thres_0 && !notify_thres_1)
550 		return;
551 
552 	if (platform_thermal_package_rate_control &&
553 		platform_thermal_package_rate_control()) {
554 		/* Rate control is implemented in callback */
555 		platform_thermal_package_notify(msr_val);
556 		return;
557 	}
558 
559 	/* lower threshold reached */
560 	if (notify_thres_0 && thresh_event_valid(PACKAGE_LEVEL, 0))
561 		platform_thermal_package_notify(msr_val);
562 	/* higher threshold reached */
563 	if (notify_thres_1 && thresh_event_valid(PACKAGE_LEVEL, 1))
564 		platform_thermal_package_notify(msr_val);
565 }
566 
567 static void notify_thresholds(__u64 msr_val)
568 {
569 	/* check whether the interrupt handler is defined;
570 	 * otherwise simply return
571 	 */
572 	if (!platform_thermal_notify)
573 		return;
574 
575 	/* lower threshold reached */
576 	if ((msr_val & THERM_LOG_THRESHOLD0) &&
577 			thresh_event_valid(CORE_LEVEL, 0))
578 		platform_thermal_notify(msr_val);
579 	/* higher threshold reached */
580 	if ((msr_val & THERM_LOG_THRESHOLD1) &&
581 			thresh_event_valid(CORE_LEVEL, 1))
582 		platform_thermal_notify(msr_val);
583 }
584 
585 void __weak notify_hwp_interrupt(void)
586 {
587 	wrmsrl_safe(MSR_HWP_STATUS, 0);
588 }
589 
590 /* Thermal transition interrupt handler */
591 void intel_thermal_interrupt(void)
592 {
593 	__u64 msr_val;
594 
595 	if (static_cpu_has(X86_FEATURE_HWP))
596 		notify_hwp_interrupt();
597 
598 	rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
599 
600 	/* Check for violation of core thermal thresholds*/
601 	notify_thresholds(msr_val);
602 
603 	therm_throt_process(msr_val & THERM_STATUS_PROCHOT,
604 			    THERMAL_THROTTLING_EVENT,
605 			    CORE_LEVEL);
606 
607 	if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)
608 		therm_throt_process(msr_val & THERM_STATUS_POWER_LIMIT,
609 					POWER_LIMIT_EVENT,
610 					CORE_LEVEL);
611 
612 	if (this_cpu_has(X86_FEATURE_PTS)) {
613 		rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
614 		/* check violations of package thermal thresholds */
615 		notify_package_thresholds(msr_val);
616 		therm_throt_process(msr_val & PACKAGE_THERM_STATUS_PROCHOT,
617 					THERMAL_THROTTLING_EVENT,
618 					PACKAGE_LEVEL);
619 		if (this_cpu_has(X86_FEATURE_PLN) && int_pln_enable)
620 			therm_throt_process(msr_val &
621 					PACKAGE_THERM_STATUS_POWER_LIMIT,
622 					POWER_LIMIT_EVENT,
623 					PACKAGE_LEVEL);
624 
625 		if (this_cpu_has(X86_FEATURE_HFI))
626 			intel_hfi_process_event(msr_val &
627 						PACKAGE_THERM_STATUS_HFI_UPDATED);
628 	}
629 }
630 
631 /* Thermal monitoring depends on APIC, ACPI and clock modulation */
632 static int intel_thermal_supported(struct cpuinfo_x86 *c)
633 {
634 	if (!boot_cpu_has(X86_FEATURE_APIC))
635 		return 0;
636 	if (!cpu_has(c, X86_FEATURE_ACPI) || !cpu_has(c, X86_FEATURE_ACC))
637 		return 0;
638 	return 1;
639 }
640 
641 bool x86_thermal_enabled(void)
642 {
643 	return atomic_read(&therm_throt_en);
644 }
645 
646 void __init therm_lvt_init(void)
647 {
648 	/*
649 	 * This function is only called on boot CPU. Save the init thermal
650 	 * LVT value on BSP and use that value to restore APs' thermal LVT
651 	 * entry BIOS programmed later
652 	 */
653 	if (intel_thermal_supported(&boot_cpu_data))
654 		lvtthmr_init = apic_read(APIC_LVTTHMR);
655 }
656 
657 void intel_init_thermal(struct cpuinfo_x86 *c)
658 {
659 	unsigned int cpu = smp_processor_id();
660 	int tm2 = 0;
661 	u32 l, h;
662 
663 	if (!intel_thermal_supported(c))
664 		return;
665 
666 	/*
667 	 * First check if its enabled already, in which case there might
668 	 * be some SMM goo which handles it, so we can't even put a handler
669 	 * since it might be delivered via SMI already:
670 	 */
671 	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
672 
673 	h = lvtthmr_init;
674 	/*
675 	 * The initial value of thermal LVT entries on all APs always reads
676 	 * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI
677 	 * sequence to them and LVT registers are reset to 0s except for
678 	 * the mask bits which are set to 1s when APs receive INIT IPI.
679 	 * If BIOS takes over the thermal interrupt and sets its interrupt
680 	 * delivery mode to SMI (not fixed), it restores the value that the
681 	 * BIOS has programmed on AP based on BSP's info we saved since BIOS
682 	 * is always setting the same value for all threads/cores.
683 	 */
684 	if ((h & APIC_DM_FIXED_MASK) != APIC_DM_FIXED)
685 		apic_write(APIC_LVTTHMR, lvtthmr_init);
686 
687 
688 	if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) {
689 		if (system_state == SYSTEM_BOOTING)
690 			pr_debug("CPU%d: Thermal monitoring handled by SMI\n", cpu);
691 		return;
692 	}
693 
694 	/* early Pentium M models use different method for enabling TM2 */
695 	if (cpu_has(c, X86_FEATURE_TM2)) {
696 		if (c->x86 == 6 && (c->x86_model == 9 || c->x86_model == 13)) {
697 			rdmsr(MSR_THERM2_CTL, l, h);
698 			if (l & MSR_THERM2_CTL_TM_SELECT)
699 				tm2 = 1;
700 		} else if (l & MSR_IA32_MISC_ENABLE_TM2)
701 			tm2 = 1;
702 	}
703 
704 	/* We'll mask the thermal vector in the lapic till we're ready: */
705 	h = THERMAL_APIC_VECTOR | APIC_DM_FIXED | APIC_LVT_MASKED;
706 	apic_write(APIC_LVTTHMR, h);
707 
708 	rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
709 	if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)
710 		wrmsr(MSR_IA32_THERM_INTERRUPT,
711 			(l | (THERM_INT_LOW_ENABLE
712 			| THERM_INT_HIGH_ENABLE)) & ~THERM_INT_PLN_ENABLE, h);
713 	else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
714 		wrmsr(MSR_IA32_THERM_INTERRUPT,
715 			l | (THERM_INT_LOW_ENABLE
716 			| THERM_INT_HIGH_ENABLE | THERM_INT_PLN_ENABLE), h);
717 	else
718 		wrmsr(MSR_IA32_THERM_INTERRUPT,
719 		      l | (THERM_INT_LOW_ENABLE | THERM_INT_HIGH_ENABLE), h);
720 
721 	if (cpu_has(c, X86_FEATURE_PTS)) {
722 		rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
723 		if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)
724 			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
725 				(l | (PACKAGE_THERM_INT_LOW_ENABLE
726 				| PACKAGE_THERM_INT_HIGH_ENABLE))
727 				& ~PACKAGE_THERM_INT_PLN_ENABLE, h);
728 		else if (cpu_has(c, X86_FEATURE_PLN) && int_pln_enable)
729 			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
730 				l | (PACKAGE_THERM_INT_LOW_ENABLE
731 				| PACKAGE_THERM_INT_HIGH_ENABLE
732 				| PACKAGE_THERM_INT_PLN_ENABLE), h);
733 		else
734 			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
735 			      l | (PACKAGE_THERM_INT_LOW_ENABLE
736 				| PACKAGE_THERM_INT_HIGH_ENABLE), h);
737 
738 		if (cpu_has(c, X86_FEATURE_HFI)) {
739 			rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
740 			wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
741 			      l | PACKAGE_THERM_INT_HFI_ENABLE, h);
742 		}
743 	}
744 
745 	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
746 	wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
747 
748 	pr_info_once("CPU0: Thermal monitoring enabled (%s)\n",
749 		      tm2 ? "TM2" : "TM1");
750 
751 	/* enable thermal throttle processing */
752 	atomic_set(&therm_throt_en, 1);
753 }
754