1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * processor_throttling.c - Throttling submodule of the ACPI processor driver
4  *
5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
8  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9  *  			- Added processor hotplug support
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/sched.h>
17 #include <linux/cpufreq.h>
18 #include <linux/acpi.h>
19 #include <acpi/processor.h>
20 #include <asm/io.h>
21 #include <linux/uaccess.h>
22 
23 #define PREFIX "ACPI: "
24 
25 #define ACPI_PROCESSOR_CLASS            "processor"
26 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
27 ACPI_MODULE_NAME("processor_throttling");
28 
29 /* ignore_tpc:
30  *  0 -> acpi processor driver doesn't ignore _TPC values
31  *  1 -> acpi processor driver ignores _TPC values
32  */
33 static int ignore_tpc;
34 module_param(ignore_tpc, int, 0644);
35 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
36 
37 struct throttling_tstate {
38 	unsigned int cpu;		/* cpu nr */
39 	int target_state;		/* target T-state */
40 };
41 
42 struct acpi_processor_throttling_arg {
43 	struct acpi_processor *pr;
44 	int target_state;
45 	bool force;
46 };
47 
48 #define THROTTLING_PRECHANGE       (1)
49 #define THROTTLING_POSTCHANGE      (2)
50 
51 static int acpi_processor_get_throttling(struct acpi_processor *pr);
52 static int __acpi_processor_set_throttling(struct acpi_processor *pr,
53 					   int state, bool force, bool direct);
54 
55 static int acpi_processor_update_tsd_coord(void)
56 {
57 	int count, count_target;
58 	int retval = 0;
59 	unsigned int i, j;
60 	cpumask_var_t covered_cpus;
61 	struct acpi_processor *pr, *match_pr;
62 	struct acpi_tsd_package *pdomain, *match_pdomain;
63 	struct acpi_processor_throttling *pthrottling, *match_pthrottling;
64 
65 	if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
66 		return -ENOMEM;
67 
68 	/*
69 	 * Now that we have _TSD data from all CPUs, lets setup T-state
70 	 * coordination between all CPUs.
71 	 */
72 	for_each_possible_cpu(i) {
73 		pr = per_cpu(processors, i);
74 		if (!pr)
75 			continue;
76 
77 		/* Basic validity check for domain info */
78 		pthrottling = &(pr->throttling);
79 
80 		/*
81 		 * If tsd package for one cpu is invalid, the coordination
82 		 * among all CPUs is thought as invalid.
83 		 * Maybe it is ugly.
84 		 */
85 		if (!pthrottling->tsd_valid_flag) {
86 			retval = -EINVAL;
87 			break;
88 		}
89 	}
90 	if (retval)
91 		goto err_ret;
92 
93 	for_each_possible_cpu(i) {
94 		pr = per_cpu(processors, i);
95 		if (!pr)
96 			continue;
97 
98 		if (cpumask_test_cpu(i, covered_cpus))
99 			continue;
100 		pthrottling = &pr->throttling;
101 
102 		pdomain = &(pthrottling->domain_info);
103 		cpumask_set_cpu(i, pthrottling->shared_cpu_map);
104 		cpumask_set_cpu(i, covered_cpus);
105 		/*
106 		 * If the number of processor in the TSD domain is 1, it is
107 		 * unnecessary to parse the coordination for this CPU.
108 		 */
109 		if (pdomain->num_processors <= 1)
110 			continue;
111 
112 		/* Validate the Domain info */
113 		count_target = pdomain->num_processors;
114 		count = 1;
115 
116 		for_each_possible_cpu(j) {
117 			if (i == j)
118 				continue;
119 
120 			match_pr = per_cpu(processors, j);
121 			if (!match_pr)
122 				continue;
123 
124 			match_pthrottling = &(match_pr->throttling);
125 			match_pdomain = &(match_pthrottling->domain_info);
126 			if (match_pdomain->domain != pdomain->domain)
127 				continue;
128 
129 			/* Here i and j are in the same domain.
130 			 * If two TSD packages have the same domain, they
131 			 * should have the same num_porcessors and
132 			 * coordination type. Otherwise it will be regarded
133 			 * as illegal.
134 			 */
135 			if (match_pdomain->num_processors != count_target) {
136 				retval = -EINVAL;
137 				goto err_ret;
138 			}
139 
140 			if (pdomain->coord_type != match_pdomain->coord_type) {
141 				retval = -EINVAL;
142 				goto err_ret;
143 			}
144 
145 			cpumask_set_cpu(j, covered_cpus);
146 			cpumask_set_cpu(j, pthrottling->shared_cpu_map);
147 			count++;
148 		}
149 		for_each_possible_cpu(j) {
150 			if (i == j)
151 				continue;
152 
153 			match_pr = per_cpu(processors, j);
154 			if (!match_pr)
155 				continue;
156 
157 			match_pthrottling = &(match_pr->throttling);
158 			match_pdomain = &(match_pthrottling->domain_info);
159 			if (match_pdomain->domain != pdomain->domain)
160 				continue;
161 
162 			/*
163 			 * If some CPUS have the same domain, they
164 			 * will have the same shared_cpu_map.
165 			 */
166 			cpumask_copy(match_pthrottling->shared_cpu_map,
167 				     pthrottling->shared_cpu_map);
168 		}
169 	}
170 
171 err_ret:
172 	free_cpumask_var(covered_cpus);
173 
174 	for_each_possible_cpu(i) {
175 		pr = per_cpu(processors, i);
176 		if (!pr)
177 			continue;
178 
179 		/*
180 		 * Assume no coordination on any error parsing domain info.
181 		 * The coordination type will be forced as SW_ALL.
182 		 */
183 		if (retval) {
184 			pthrottling = &(pr->throttling);
185 			cpumask_clear(pthrottling->shared_cpu_map);
186 			cpumask_set_cpu(i, pthrottling->shared_cpu_map);
187 			pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
188 		}
189 	}
190 
191 	return retval;
192 }
193 
194 /*
195  * Update the T-state coordination after the _TSD
196  * data for all cpus is obtained.
197  */
198 void acpi_processor_throttling_init(void)
199 {
200 	if (acpi_processor_update_tsd_coord()) {
201 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
202 			"Assume no T-state coordination\n"));
203 	}
204 
205 	return;
206 }
207 
208 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
209 {
210 	struct throttling_tstate *p_tstate = data;
211 	struct acpi_processor *pr;
212 	unsigned int cpu ;
213 	int target_state;
214 	struct acpi_processor_limit *p_limit;
215 	struct acpi_processor_throttling *p_throttling;
216 
217 	cpu = p_tstate->cpu;
218 	pr = per_cpu(processors, cpu);
219 	if (!pr) {
220 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
221 		return 0;
222 	}
223 	if (!pr->flags.throttling) {
224 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
225 				"unsupported on CPU %d\n", cpu));
226 		return 0;
227 	}
228 	target_state = p_tstate->target_state;
229 	p_throttling = &(pr->throttling);
230 	switch (event) {
231 	case THROTTLING_PRECHANGE:
232 		/*
233 		 * Prechange event is used to choose one proper t-state,
234 		 * which meets the limits of thermal, user and _TPC.
235 		 */
236 		p_limit = &pr->limit;
237 		if (p_limit->thermal.tx > target_state)
238 			target_state = p_limit->thermal.tx;
239 		if (p_limit->user.tx > target_state)
240 			target_state = p_limit->user.tx;
241 		if (pr->throttling_platform_limit > target_state)
242 			target_state = pr->throttling_platform_limit;
243 		if (target_state >= p_throttling->state_count) {
244 			printk(KERN_WARNING
245 				"Exceed the limit of T-state \n");
246 			target_state = p_throttling->state_count - 1;
247 		}
248 		p_tstate->target_state = target_state;
249 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
250 				"target T-state of CPU %d is T%d\n",
251 				cpu, target_state));
252 		break;
253 	case THROTTLING_POSTCHANGE:
254 		/*
255 		 * Postchange event is only used to update the
256 		 * T-state flag of acpi_processor_throttling.
257 		 */
258 		p_throttling->state = target_state;
259 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
260 				"CPU %d is switched to T%d\n",
261 				cpu, target_state));
262 		break;
263 	default:
264 		printk(KERN_WARNING
265 			"Unsupported Throttling notifier event\n");
266 		break;
267 	}
268 
269 	return 0;
270 }
271 
272 /*
273  * _TPC - Throttling Present Capabilities
274  */
275 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
276 {
277 	acpi_status status = 0;
278 	unsigned long long tpc = 0;
279 
280 	if (!pr)
281 		return -EINVAL;
282 
283 	if (ignore_tpc)
284 		goto end;
285 
286 	status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
287 	if (ACPI_FAILURE(status)) {
288 		if (status != AE_NOT_FOUND) {
289 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
290 		}
291 		return -ENODEV;
292 	}
293 
294 end:
295 	pr->throttling_platform_limit = (int)tpc;
296 	return 0;
297 }
298 
299 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
300 {
301 	int result = 0;
302 	int throttling_limit;
303 	int current_state;
304 	struct acpi_processor_limit *limit;
305 	int target_state;
306 
307 	if (ignore_tpc)
308 		return 0;
309 
310 	result = acpi_processor_get_platform_limit(pr);
311 	if (result) {
312 		/* Throttling Limit is unsupported */
313 		return result;
314 	}
315 
316 	throttling_limit = pr->throttling_platform_limit;
317 	if (throttling_limit >= pr->throttling.state_count) {
318 		/* Uncorrect Throttling Limit */
319 		return -EINVAL;
320 	}
321 
322 	current_state = pr->throttling.state;
323 	if (current_state > throttling_limit) {
324 		/*
325 		 * The current state can meet the requirement of
326 		 * _TPC limit. But it is reasonable that OSPM changes
327 		 * t-states from high to low for better performance.
328 		 * Of course the limit condition of thermal
329 		 * and user should be considered.
330 		 */
331 		limit = &pr->limit;
332 		target_state = throttling_limit;
333 		if (limit->thermal.tx > target_state)
334 			target_state = limit->thermal.tx;
335 		if (limit->user.tx > target_state)
336 			target_state = limit->user.tx;
337 	} else if (current_state == throttling_limit) {
338 		/*
339 		 * Unnecessary to change the throttling state
340 		 */
341 		return 0;
342 	} else {
343 		/*
344 		 * If the current state is lower than the limit of _TPC, it
345 		 * will be forced to switch to the throttling state defined
346 		 * by throttling_platfor_limit.
347 		 * Because the previous state meets with the limit condition
348 		 * of thermal and user, it is unnecessary to check it again.
349 		 */
350 		target_state = throttling_limit;
351 	}
352 	return acpi_processor_set_throttling(pr, target_state, false);
353 }
354 
355 /*
356  * This function is used to reevaluate whether the T-state is valid
357  * after one CPU is onlined/offlined.
358  * It is noted that it won't reevaluate the following properties for
359  * the T-state.
360  *	1. Control method.
361  *	2. the number of supported T-state
362  *	3. TSD domain
363  */
364 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
365 					bool is_dead)
366 {
367 	int result = 0;
368 
369 	if (is_dead) {
370 		/* When one CPU is offline, the T-state throttling
371 		 * will be invalidated.
372 		 */
373 		pr->flags.throttling = 0;
374 		return;
375 	}
376 	/* the following is to recheck whether the T-state is valid for
377 	 * the online CPU
378 	 */
379 	if (!pr->throttling.state_count) {
380 		/* If the number of T-state is invalid, it is
381 		 * invalidated.
382 		 */
383 		pr->flags.throttling = 0;
384 		return;
385 	}
386 	pr->flags.throttling = 1;
387 
388 	/* Disable throttling (if enabled).  We'll let subsequent
389 	 * policy (e.g.thermal) decide to lower performance if it
390 	 * so chooses, but for now we'll crank up the speed.
391 	 */
392 
393 	result = acpi_processor_get_throttling(pr);
394 	if (result)
395 		goto end;
396 
397 	if (pr->throttling.state) {
398 		result = acpi_processor_set_throttling(pr, 0, false);
399 		if (result)
400 			goto end;
401 	}
402 
403 end:
404 	if (result)
405 		pr->flags.throttling = 0;
406 }
407 /*
408  * _PTC - Processor Throttling Control (and status) register location
409  */
410 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
411 {
412 	int result = 0;
413 	acpi_status status = 0;
414 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
415 	union acpi_object *ptc = NULL;
416 	union acpi_object obj = { 0 };
417 	struct acpi_processor_throttling *throttling;
418 
419 	status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
420 	if (ACPI_FAILURE(status)) {
421 		if (status != AE_NOT_FOUND) {
422 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
423 		}
424 		return -ENODEV;
425 	}
426 
427 	ptc = (union acpi_object *)buffer.pointer;
428 	if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
429 	    || (ptc->package.count != 2)) {
430 		printk(KERN_ERR PREFIX "Invalid _PTC data\n");
431 		result = -EFAULT;
432 		goto end;
433 	}
434 
435 	/*
436 	 * control_register
437 	 */
438 
439 	obj = ptc->package.elements[0];
440 
441 	if ((obj.type != ACPI_TYPE_BUFFER)
442 	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
443 	    || (obj.buffer.pointer == NULL)) {
444 		printk(KERN_ERR PREFIX
445 		       "Invalid _PTC data (control_register)\n");
446 		result = -EFAULT;
447 		goto end;
448 	}
449 	memcpy(&pr->throttling.control_register, obj.buffer.pointer,
450 	       sizeof(struct acpi_ptc_register));
451 
452 	/*
453 	 * status_register
454 	 */
455 
456 	obj = ptc->package.elements[1];
457 
458 	if ((obj.type != ACPI_TYPE_BUFFER)
459 	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
460 	    || (obj.buffer.pointer == NULL)) {
461 		printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
462 		result = -EFAULT;
463 		goto end;
464 	}
465 
466 	memcpy(&pr->throttling.status_register, obj.buffer.pointer,
467 	       sizeof(struct acpi_ptc_register));
468 
469 	throttling = &pr->throttling;
470 
471 	if ((throttling->control_register.bit_width +
472 		throttling->control_register.bit_offset) > 32) {
473 		printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
474 		result = -EFAULT;
475 		goto end;
476 	}
477 
478 	if ((throttling->status_register.bit_width +
479 		throttling->status_register.bit_offset) > 32) {
480 		printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
481 		result = -EFAULT;
482 		goto end;
483 	}
484 
485       end:
486 	kfree(buffer.pointer);
487 
488 	return result;
489 }
490 
491 /*
492  * _TSS - Throttling Supported States
493  */
494 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
495 {
496 	int result = 0;
497 	acpi_status status = AE_OK;
498 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
499 	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
500 	struct acpi_buffer state = { 0, NULL };
501 	union acpi_object *tss = NULL;
502 	int i;
503 
504 	status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
505 	if (ACPI_FAILURE(status)) {
506 		if (status != AE_NOT_FOUND) {
507 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
508 		}
509 		return -ENODEV;
510 	}
511 
512 	tss = buffer.pointer;
513 	if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
514 		printk(KERN_ERR PREFIX "Invalid _TSS data\n");
515 		result = -EFAULT;
516 		goto end;
517 	}
518 
519 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
520 			  tss->package.count));
521 
522 	pr->throttling.state_count = tss->package.count;
523 	pr->throttling.states_tss =
524 	    kmalloc_array(tss->package.count,
525 			  sizeof(struct acpi_processor_tx_tss),
526 			  GFP_KERNEL);
527 	if (!pr->throttling.states_tss) {
528 		result = -ENOMEM;
529 		goto end;
530 	}
531 
532 	for (i = 0; i < pr->throttling.state_count; i++) {
533 
534 		struct acpi_processor_tx_tss *tx =
535 		    (struct acpi_processor_tx_tss *)&(pr->throttling.
536 						      states_tss[i]);
537 
538 		state.length = sizeof(struct acpi_processor_tx_tss);
539 		state.pointer = tx;
540 
541 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
542 
543 		status = acpi_extract_package(&(tss->package.elements[i]),
544 					      &format, &state);
545 		if (ACPI_FAILURE(status)) {
546 			ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
547 			result = -EFAULT;
548 			kfree(pr->throttling.states_tss);
549 			goto end;
550 		}
551 
552 		if (!tx->freqpercentage) {
553 			printk(KERN_ERR PREFIX
554 			       "Invalid _TSS data: freq is zero\n");
555 			result = -EFAULT;
556 			kfree(pr->throttling.states_tss);
557 			goto end;
558 		}
559 	}
560 
561       end:
562 	kfree(buffer.pointer);
563 
564 	return result;
565 }
566 
567 /*
568  * _TSD - T-State Dependencies
569  */
570 static int acpi_processor_get_tsd(struct acpi_processor *pr)
571 {
572 	int result = 0;
573 	acpi_status status = AE_OK;
574 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
575 	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
576 	struct acpi_buffer state = { 0, NULL };
577 	union acpi_object *tsd = NULL;
578 	struct acpi_tsd_package *pdomain;
579 	struct acpi_processor_throttling *pthrottling;
580 
581 	pthrottling = &pr->throttling;
582 	pthrottling->tsd_valid_flag = 0;
583 
584 	status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
585 	if (ACPI_FAILURE(status)) {
586 		if (status != AE_NOT_FOUND) {
587 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
588 		}
589 		return -ENODEV;
590 	}
591 
592 	tsd = buffer.pointer;
593 	if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
594 		printk(KERN_ERR PREFIX "Invalid _TSD data\n");
595 		result = -EFAULT;
596 		goto end;
597 	}
598 
599 	if (tsd->package.count != 1) {
600 		printk(KERN_ERR PREFIX "Invalid _TSD data\n");
601 		result = -EFAULT;
602 		goto end;
603 	}
604 
605 	pdomain = &(pr->throttling.domain_info);
606 
607 	state.length = sizeof(struct acpi_tsd_package);
608 	state.pointer = pdomain;
609 
610 	status = acpi_extract_package(&(tsd->package.elements[0]),
611 				      &format, &state);
612 	if (ACPI_FAILURE(status)) {
613 		printk(KERN_ERR PREFIX "Invalid _TSD data\n");
614 		result = -EFAULT;
615 		goto end;
616 	}
617 
618 	if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
619 		printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
620 		result = -EFAULT;
621 		goto end;
622 	}
623 
624 	if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
625 		printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
626 		result = -EFAULT;
627 		goto end;
628 	}
629 
630 	pthrottling = &pr->throttling;
631 	pthrottling->tsd_valid_flag = 1;
632 	pthrottling->shared_type = pdomain->coord_type;
633 	cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
634 	/*
635 	 * If the coordination type is not defined in ACPI spec,
636 	 * the tsd_valid_flag will be clear and coordination type
637 	 * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
638 	 */
639 	if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
640 		pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
641 		pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
642 		pthrottling->tsd_valid_flag = 0;
643 		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
644 	}
645 
646       end:
647 	kfree(buffer.pointer);
648 	return result;
649 }
650 
651 /* --------------------------------------------------------------------------
652                               Throttling Control
653    -------------------------------------------------------------------------- */
654 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
655 {
656 	int state = 0;
657 	u32 value = 0;
658 	u32 duty_mask = 0;
659 	u32 duty_value = 0;
660 
661 	if (!pr)
662 		return -EINVAL;
663 
664 	if (!pr->flags.throttling)
665 		return -ENODEV;
666 
667 	/*
668 	 * We don't care about error returns - we just try to mark
669 	 * these reserved so that nobody else is confused into thinking
670 	 * that this region might be unused..
671 	 *
672 	 * (In particular, allocating the IO range for Cardbus)
673 	 */
674 	request_region(pr->throttling.address, 6, "ACPI CPU throttle");
675 
676 	pr->throttling.state = 0;
677 
678 	duty_mask = pr->throttling.state_count - 1;
679 
680 	duty_mask <<= pr->throttling.duty_offset;
681 
682 	local_irq_disable();
683 
684 	value = inl(pr->throttling.address);
685 
686 	/*
687 	 * Compute the current throttling state when throttling is enabled
688 	 * (bit 4 is on).
689 	 */
690 	if (value & 0x10) {
691 		duty_value = value & duty_mask;
692 		duty_value >>= pr->throttling.duty_offset;
693 
694 		if (duty_value)
695 			state = pr->throttling.state_count - duty_value;
696 	}
697 
698 	pr->throttling.state = state;
699 
700 	local_irq_enable();
701 
702 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
703 			  "Throttling state is T%d (%d%% throttling applied)\n",
704 			  state, pr->throttling.states[state].performance));
705 
706 	return 0;
707 }
708 
709 #ifdef CONFIG_X86
710 static int acpi_throttling_rdmsr(u64 *value)
711 {
712 	u64 msr_high, msr_low;
713 	u64 msr = 0;
714 	int ret = -1;
715 
716 	if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
717 		!this_cpu_has(X86_FEATURE_ACPI)) {
718 		printk(KERN_ERR PREFIX
719 			"HARDWARE addr space,NOT supported yet\n");
720 	} else {
721 		msr_low = 0;
722 		msr_high = 0;
723 		rdmsr_safe(MSR_IA32_THERM_CONTROL,
724 			(u32 *)&msr_low , (u32 *) &msr_high);
725 		msr = (msr_high << 32) | msr_low;
726 		*value = (u64) msr;
727 		ret = 0;
728 	}
729 	return ret;
730 }
731 
732 static int acpi_throttling_wrmsr(u64 value)
733 {
734 	int ret = -1;
735 	u64 msr;
736 
737 	if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
738 		!this_cpu_has(X86_FEATURE_ACPI)) {
739 		printk(KERN_ERR PREFIX
740 			"HARDWARE addr space,NOT supported yet\n");
741 	} else {
742 		msr = value;
743 		wrmsr_safe(MSR_IA32_THERM_CONTROL,
744 			msr & 0xffffffff, msr >> 32);
745 		ret = 0;
746 	}
747 	return ret;
748 }
749 #else
750 static int acpi_throttling_rdmsr(u64 *value)
751 {
752 	printk(KERN_ERR PREFIX
753 		"HARDWARE addr space,NOT supported yet\n");
754 	return -1;
755 }
756 
757 static int acpi_throttling_wrmsr(u64 value)
758 {
759 	printk(KERN_ERR PREFIX
760 		"HARDWARE addr space,NOT supported yet\n");
761 	return -1;
762 }
763 #endif
764 
765 static int acpi_read_throttling_status(struct acpi_processor *pr,
766 					u64 *value)
767 {
768 	u32 bit_width, bit_offset;
769 	u32 ptc_value;
770 	u64 ptc_mask;
771 	struct acpi_processor_throttling *throttling;
772 	int ret = -1;
773 
774 	throttling = &pr->throttling;
775 	switch (throttling->status_register.space_id) {
776 	case ACPI_ADR_SPACE_SYSTEM_IO:
777 		bit_width = throttling->status_register.bit_width;
778 		bit_offset = throttling->status_register.bit_offset;
779 
780 		acpi_os_read_port((acpi_io_address) throttling->status_register.
781 				  address, &ptc_value,
782 				  (u32) (bit_width + bit_offset));
783 		ptc_mask = (1 << bit_width) - 1;
784 		*value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
785 		ret = 0;
786 		break;
787 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
788 		ret = acpi_throttling_rdmsr(value);
789 		break;
790 	default:
791 		printk(KERN_ERR PREFIX "Unknown addr space %d\n",
792 		       (u32) (throttling->status_register.space_id));
793 	}
794 	return ret;
795 }
796 
797 static int acpi_write_throttling_state(struct acpi_processor *pr,
798 				u64 value)
799 {
800 	u32 bit_width, bit_offset;
801 	u64 ptc_value;
802 	u64 ptc_mask;
803 	struct acpi_processor_throttling *throttling;
804 	int ret = -1;
805 
806 	throttling = &pr->throttling;
807 	switch (throttling->control_register.space_id) {
808 	case ACPI_ADR_SPACE_SYSTEM_IO:
809 		bit_width = throttling->control_register.bit_width;
810 		bit_offset = throttling->control_register.bit_offset;
811 		ptc_mask = (1 << bit_width) - 1;
812 		ptc_value = value & ptc_mask;
813 
814 		acpi_os_write_port((acpi_io_address) throttling->
815 					control_register.address,
816 					(u32) (ptc_value << bit_offset),
817 					(u32) (bit_width + bit_offset));
818 		ret = 0;
819 		break;
820 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
821 		ret = acpi_throttling_wrmsr(value);
822 		break;
823 	default:
824 		printk(KERN_ERR PREFIX "Unknown addr space %d\n",
825 		       (u32) (throttling->control_register.space_id));
826 	}
827 	return ret;
828 }
829 
830 static int acpi_get_throttling_state(struct acpi_processor *pr,
831 				u64 value)
832 {
833 	int i;
834 
835 	for (i = 0; i < pr->throttling.state_count; i++) {
836 		struct acpi_processor_tx_tss *tx =
837 		    (struct acpi_processor_tx_tss *)&(pr->throttling.
838 						      states_tss[i]);
839 		if (tx->control == value)
840 			return i;
841 	}
842 	return -1;
843 }
844 
845 static int acpi_get_throttling_value(struct acpi_processor *pr,
846 			int state, u64 *value)
847 {
848 	int ret = -1;
849 
850 	if (state >= 0 && state <= pr->throttling.state_count) {
851 		struct acpi_processor_tx_tss *tx =
852 		    (struct acpi_processor_tx_tss *)&(pr->throttling.
853 						      states_tss[state]);
854 		*value = tx->control;
855 		ret = 0;
856 	}
857 	return ret;
858 }
859 
860 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
861 {
862 	int state = 0;
863 	int ret;
864 	u64 value;
865 
866 	if (!pr)
867 		return -EINVAL;
868 
869 	if (!pr->flags.throttling)
870 		return -ENODEV;
871 
872 	pr->throttling.state = 0;
873 
874 	value = 0;
875 	ret = acpi_read_throttling_status(pr, &value);
876 	if (ret >= 0) {
877 		state = acpi_get_throttling_state(pr, value);
878 		if (state == -1) {
879 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
880 				"Invalid throttling state, reset\n"));
881 			state = 0;
882 			ret = __acpi_processor_set_throttling(pr, state, true,
883 							      true);
884 			if (ret)
885 				return ret;
886 		}
887 		pr->throttling.state = state;
888 	}
889 
890 	return 0;
891 }
892 
893 static long __acpi_processor_get_throttling(void *data)
894 {
895 	struct acpi_processor *pr = data;
896 
897 	return pr->throttling.acpi_processor_get_throttling(pr);
898 }
899 
900 static int acpi_processor_get_throttling(struct acpi_processor *pr)
901 {
902 	if (!pr)
903 		return -EINVAL;
904 
905 	if (!pr->flags.throttling)
906 		return -ENODEV;
907 
908 	/*
909 	 * This is either called from the CPU hotplug callback of
910 	 * processor_driver or via the ACPI probe function. In the latter
911 	 * case the CPU is not guaranteed to be online. Both call sites are
912 	 * protected against CPU hotplug.
913 	 */
914 	if (!cpu_online(pr->id))
915 		return -ENODEV;
916 
917 	return call_on_cpu(pr->id, __acpi_processor_get_throttling, pr, false);
918 }
919 
920 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
921 {
922 	int i, step;
923 
924 	if (!pr->throttling.address) {
925 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
926 		return -EINVAL;
927 	} else if (!pr->throttling.duty_width) {
928 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
929 		return -EINVAL;
930 	}
931 	/* TBD: Support duty_cycle values that span bit 4. */
932 	else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
933 		printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
934 		return -EINVAL;
935 	}
936 
937 	pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
938 
939 	/*
940 	 * Compute state values. Note that throttling displays a linear power
941 	 * performance relationship (at 50% performance the CPU will consume
942 	 * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
943 	 */
944 
945 	step = (1000 / pr->throttling.state_count);
946 
947 	for (i = 0; i < pr->throttling.state_count; i++) {
948 		pr->throttling.states[i].performance = 1000 - step * i;
949 		pr->throttling.states[i].power = 1000 - step * i;
950 	}
951 	return 0;
952 }
953 
954 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
955 					      int state, bool force)
956 {
957 	u32 value = 0;
958 	u32 duty_mask = 0;
959 	u32 duty_value = 0;
960 
961 	if (!pr)
962 		return -EINVAL;
963 
964 	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
965 		return -EINVAL;
966 
967 	if (!pr->flags.throttling)
968 		return -ENODEV;
969 
970 	if (!force && (state == pr->throttling.state))
971 		return 0;
972 
973 	if (state < pr->throttling_platform_limit)
974 		return -EPERM;
975 	/*
976 	 * Calculate the duty_value and duty_mask.
977 	 */
978 	if (state) {
979 		duty_value = pr->throttling.state_count - state;
980 
981 		duty_value <<= pr->throttling.duty_offset;
982 
983 		/* Used to clear all duty_value bits */
984 		duty_mask = pr->throttling.state_count - 1;
985 
986 		duty_mask <<= acpi_gbl_FADT.duty_offset;
987 		duty_mask = ~duty_mask;
988 	}
989 
990 	local_irq_disable();
991 
992 	/*
993 	 * Disable throttling by writing a 0 to bit 4.  Note that we must
994 	 * turn it off before you can change the duty_value.
995 	 */
996 	value = inl(pr->throttling.address);
997 	if (value & 0x10) {
998 		value &= 0xFFFFFFEF;
999 		outl(value, pr->throttling.address);
1000 	}
1001 
1002 	/*
1003 	 * Write the new duty_value and then enable throttling.  Note
1004 	 * that a state value of 0 leaves throttling disabled.
1005 	 */
1006 	if (state) {
1007 		value &= duty_mask;
1008 		value |= duty_value;
1009 		outl(value, pr->throttling.address);
1010 
1011 		value |= 0x00000010;
1012 		outl(value, pr->throttling.address);
1013 	}
1014 
1015 	pr->throttling.state = state;
1016 
1017 	local_irq_enable();
1018 
1019 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1020 			  "Throttling state set to T%d (%d%%)\n", state,
1021 			  (pr->throttling.states[state].performance ? pr->
1022 			   throttling.states[state].performance / 10 : 0)));
1023 
1024 	return 0;
1025 }
1026 
1027 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1028 					     int state, bool force)
1029 {
1030 	int ret;
1031 	u64 value;
1032 
1033 	if (!pr)
1034 		return -EINVAL;
1035 
1036 	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1037 		return -EINVAL;
1038 
1039 	if (!pr->flags.throttling)
1040 		return -ENODEV;
1041 
1042 	if (!force && (state == pr->throttling.state))
1043 		return 0;
1044 
1045 	if (state < pr->throttling_platform_limit)
1046 		return -EPERM;
1047 
1048 	value = 0;
1049 	ret = acpi_get_throttling_value(pr, state, &value);
1050 	if (ret >= 0) {
1051 		acpi_write_throttling_state(pr, value);
1052 		pr->throttling.state = state;
1053 	}
1054 
1055 	return 0;
1056 }
1057 
1058 static long acpi_processor_throttling_fn(void *data)
1059 {
1060 	struct acpi_processor_throttling_arg *arg = data;
1061 	struct acpi_processor *pr = arg->pr;
1062 
1063 	return pr->throttling.acpi_processor_set_throttling(pr,
1064 			arg->target_state, arg->force);
1065 }
1066 
1067 static int __acpi_processor_set_throttling(struct acpi_processor *pr,
1068 					   int state, bool force, bool direct)
1069 {
1070 	int ret = 0;
1071 	unsigned int i;
1072 	struct acpi_processor *match_pr;
1073 	struct acpi_processor_throttling *p_throttling;
1074 	struct acpi_processor_throttling_arg arg;
1075 	struct throttling_tstate t_state;
1076 
1077 	if (!pr)
1078 		return -EINVAL;
1079 
1080 	if (!pr->flags.throttling)
1081 		return -ENODEV;
1082 
1083 	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1084 		return -EINVAL;
1085 
1086 	if (cpu_is_offline(pr->id)) {
1087 		/*
1088 		 * the cpu pointed by pr->id is offline. Unnecessary to change
1089 		 * the throttling state any more.
1090 		 */
1091 		return -ENODEV;
1092 	}
1093 
1094 	t_state.target_state = state;
1095 	p_throttling = &(pr->throttling);
1096 
1097 	/*
1098 	 * The throttling notifier will be called for every
1099 	 * affected cpu in order to get one proper T-state.
1100 	 * The notifier event is THROTTLING_PRECHANGE.
1101 	 */
1102 	for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1103 		t_state.cpu = i;
1104 		acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1105 							&t_state);
1106 	}
1107 	/*
1108 	 * The function of acpi_processor_set_throttling will be called
1109 	 * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1110 	 * it is necessary to call it for every affected cpu. Otherwise
1111 	 * it can be called only for the cpu pointed by pr.
1112 	 */
1113 	if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1114 		arg.pr = pr;
1115 		arg.target_state = state;
1116 		arg.force = force;
1117 		ret = call_on_cpu(pr->id, acpi_processor_throttling_fn, &arg,
1118 				  direct);
1119 	} else {
1120 		/*
1121 		 * When the T-state coordination is SW_ALL or HW_ALL,
1122 		 * it is necessary to set T-state for every affected
1123 		 * cpus.
1124 		 */
1125 		for_each_cpu_and(i, cpu_online_mask,
1126 		    p_throttling->shared_cpu_map) {
1127 			match_pr = per_cpu(processors, i);
1128 			/*
1129 			 * If the pointer is invalid, we will report the
1130 			 * error message and continue.
1131 			 */
1132 			if (!match_pr) {
1133 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1134 					"Invalid Pointer for CPU %d\n", i));
1135 				continue;
1136 			}
1137 			/*
1138 			 * If the throttling control is unsupported on CPU i,
1139 			 * we will report the error message and continue.
1140 			 */
1141 			if (!match_pr->flags.throttling) {
1142 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1143 					"Throttling Control is unsupported "
1144 					"on CPU %d\n", i));
1145 				continue;
1146 			}
1147 
1148 			arg.pr = match_pr;
1149 			arg.target_state = state;
1150 			arg.force = force;
1151 			ret = call_on_cpu(pr->id, acpi_processor_throttling_fn,
1152 					  &arg, direct);
1153 		}
1154 	}
1155 	/*
1156 	 * After the set_throttling is called, the
1157 	 * throttling notifier is called for every
1158 	 * affected cpu to update the T-states.
1159 	 * The notifier event is THROTTLING_POSTCHANGE
1160 	 */
1161 	for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1162 		t_state.cpu = i;
1163 		acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1164 							&t_state);
1165 	}
1166 
1167 	return ret;
1168 }
1169 
1170 int acpi_processor_set_throttling(struct acpi_processor *pr, int state,
1171 				  bool force)
1172 {
1173 	return __acpi_processor_set_throttling(pr, state, force, false);
1174 }
1175 
1176 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1177 {
1178 	int result = 0;
1179 	struct acpi_processor_throttling *pthrottling;
1180 
1181 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1182 			  "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1183 			  pr->throttling.address,
1184 			  pr->throttling.duty_offset,
1185 			  pr->throttling.duty_width));
1186 
1187 	/*
1188 	 * Evaluate _PTC, _TSS and _TPC
1189 	 * They must all be present or none of them can be used.
1190 	 */
1191 	if (acpi_processor_get_throttling_control(pr) ||
1192 		acpi_processor_get_throttling_states(pr) ||
1193 		acpi_processor_get_platform_limit(pr))
1194 	{
1195 		pr->throttling.acpi_processor_get_throttling =
1196 		    &acpi_processor_get_throttling_fadt;
1197 		pr->throttling.acpi_processor_set_throttling =
1198 		    &acpi_processor_set_throttling_fadt;
1199 		if (acpi_processor_get_fadt_info(pr))
1200 			return 0;
1201 	} else {
1202 		pr->throttling.acpi_processor_get_throttling =
1203 		    &acpi_processor_get_throttling_ptc;
1204 		pr->throttling.acpi_processor_set_throttling =
1205 		    &acpi_processor_set_throttling_ptc;
1206 	}
1207 
1208 	/*
1209 	 * If TSD package for one CPU can't be parsed successfully, it means
1210 	 * that this CPU will have no coordination with other CPUs.
1211 	 */
1212 	if (acpi_processor_get_tsd(pr)) {
1213 		pthrottling = &pr->throttling;
1214 		pthrottling->tsd_valid_flag = 0;
1215 		cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1216 		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1217 	}
1218 
1219 	/*
1220 	 * PIIX4 Errata: We don't support throttling on the original PIIX4.
1221 	 * This shouldn't be an issue as few (if any) mobile systems ever
1222 	 * used this part.
1223 	 */
1224 	if (errata.piix4.throttle) {
1225 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1226 				  "Throttling not supported on PIIX4 A- or B-step\n"));
1227 		return 0;
1228 	}
1229 
1230 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1231 			  pr->throttling.state_count));
1232 
1233 	pr->flags.throttling = 1;
1234 
1235 	/*
1236 	 * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1237 	 * thermal) decide to lower performance if it so chooses, but for now
1238 	 * we'll crank up the speed.
1239 	 */
1240 
1241 	result = acpi_processor_get_throttling(pr);
1242 	if (result)
1243 		goto end;
1244 
1245 	if (pr->throttling.state) {
1246 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1247 				  "Disabling throttling (was T%d)\n",
1248 				  pr->throttling.state));
1249 		result = acpi_processor_set_throttling(pr, 0, false);
1250 		if (result)
1251 			goto end;
1252 	}
1253 
1254       end:
1255 	if (result)
1256 		pr->flags.throttling = 0;
1257 
1258 	return result;
1259 }
1260 
1261