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