1 /*
2  * processor_throttling.c - Throttling submodule of the ACPI processor driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8  *  			- Added processor hotplug support
9  *
10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2 of the License, or (at
15  *  your option) any later version.
16  *
17  *  This program is distributed in the hope that it will be useful, but
18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20  *  General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License along
23  *  with this program; if not, write to the Free Software Foundation, Inc.,
24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
25  *
26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27  */
28 
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/slab.h>
32 #include <linux/init.h>
33 #include <linux/sched.h>
34 #include <linux/cpufreq.h>
35 
36 #include <asm/io.h>
37 #include <asm/uaccess.h>
38 
39 #include <acpi/acpi_bus.h>
40 #include <acpi/acpi_drivers.h>
41 #include <acpi/processor.h>
42 
43 #define PREFIX "ACPI: "
44 
45 #define ACPI_PROCESSOR_CLASS            "processor"
46 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
47 ACPI_MODULE_NAME("processor_throttling");
48 
49 /* ignore_tpc:
50  *  0 -> acpi processor driver doesn't ignore _TPC values
51  *  1 -> acpi processor driver ignores _TPC values
52  */
53 static int ignore_tpc;
54 module_param(ignore_tpc, int, 0644);
55 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
56 
57 struct throttling_tstate {
58 	unsigned int cpu;		/* cpu nr */
59 	int target_state;		/* target T-state */
60 };
61 
62 #define THROTTLING_PRECHANGE       (1)
63 #define THROTTLING_POSTCHANGE      (2)
64 
65 static int acpi_processor_get_throttling(struct acpi_processor *pr);
66 int acpi_processor_set_throttling(struct acpi_processor *pr,
67 						int state, bool force);
68 
69 static int acpi_processor_update_tsd_coord(void)
70 {
71 	int count, count_target;
72 	int retval = 0;
73 	unsigned int i, j;
74 	cpumask_var_t covered_cpus;
75 	struct acpi_processor *pr, *match_pr;
76 	struct acpi_tsd_package *pdomain, *match_pdomain;
77 	struct acpi_processor_throttling *pthrottling, *match_pthrottling;
78 
79 	if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
80 		return -ENOMEM;
81 
82 	/*
83 	 * Now that we have _TSD data from all CPUs, lets setup T-state
84 	 * coordination between all CPUs.
85 	 */
86 	for_each_possible_cpu(i) {
87 		pr = per_cpu(processors, i);
88 		if (!pr)
89 			continue;
90 
91 		/* Basic validity check for domain info */
92 		pthrottling = &(pr->throttling);
93 
94 		/*
95 		 * If tsd package for one cpu is invalid, the coordination
96 		 * among all CPUs is thought as invalid.
97 		 * Maybe it is ugly.
98 		 */
99 		if (!pthrottling->tsd_valid_flag) {
100 			retval = -EINVAL;
101 			break;
102 		}
103 	}
104 	if (retval)
105 		goto err_ret;
106 
107 	for_each_possible_cpu(i) {
108 		pr = per_cpu(processors, i);
109 		if (!pr)
110 			continue;
111 
112 		if (cpumask_test_cpu(i, covered_cpus))
113 			continue;
114 		pthrottling = &pr->throttling;
115 
116 		pdomain = &(pthrottling->domain_info);
117 		cpumask_set_cpu(i, pthrottling->shared_cpu_map);
118 		cpumask_set_cpu(i, covered_cpus);
119 		/*
120 		 * If the number of processor in the TSD domain is 1, it is
121 		 * unnecessary to parse the coordination for this CPU.
122 		 */
123 		if (pdomain->num_processors <= 1)
124 			continue;
125 
126 		/* Validate the Domain info */
127 		count_target = pdomain->num_processors;
128 		count = 1;
129 
130 		for_each_possible_cpu(j) {
131 			if (i == j)
132 				continue;
133 
134 			match_pr = per_cpu(processors, j);
135 			if (!match_pr)
136 				continue;
137 
138 			match_pthrottling = &(match_pr->throttling);
139 			match_pdomain = &(match_pthrottling->domain_info);
140 			if (match_pdomain->domain != pdomain->domain)
141 				continue;
142 
143 			/* Here i and j are in the same domain.
144 			 * If two TSD packages have the same domain, they
145 			 * should have the same num_porcessors and
146 			 * coordination type. Otherwise it will be regarded
147 			 * as illegal.
148 			 */
149 			if (match_pdomain->num_processors != count_target) {
150 				retval = -EINVAL;
151 				goto err_ret;
152 			}
153 
154 			if (pdomain->coord_type != match_pdomain->coord_type) {
155 				retval = -EINVAL;
156 				goto err_ret;
157 			}
158 
159 			cpumask_set_cpu(j, covered_cpus);
160 			cpumask_set_cpu(j, pthrottling->shared_cpu_map);
161 			count++;
162 		}
163 		for_each_possible_cpu(j) {
164 			if (i == j)
165 				continue;
166 
167 			match_pr = per_cpu(processors, j);
168 			if (!match_pr)
169 				continue;
170 
171 			match_pthrottling = &(match_pr->throttling);
172 			match_pdomain = &(match_pthrottling->domain_info);
173 			if (match_pdomain->domain != pdomain->domain)
174 				continue;
175 
176 			/*
177 			 * If some CPUS have the same domain, they
178 			 * will have the same shared_cpu_map.
179 			 */
180 			cpumask_copy(match_pthrottling->shared_cpu_map,
181 				     pthrottling->shared_cpu_map);
182 		}
183 	}
184 
185 err_ret:
186 	free_cpumask_var(covered_cpus);
187 
188 	for_each_possible_cpu(i) {
189 		pr = per_cpu(processors, i);
190 		if (!pr)
191 			continue;
192 
193 		/*
194 		 * Assume no coordination on any error parsing domain info.
195 		 * The coordination type will be forced as SW_ALL.
196 		 */
197 		if (retval) {
198 			pthrottling = &(pr->throttling);
199 			cpumask_clear(pthrottling->shared_cpu_map);
200 			cpumask_set_cpu(i, pthrottling->shared_cpu_map);
201 			pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
202 		}
203 	}
204 
205 	return retval;
206 }
207 
208 /*
209  * Update the T-state coordination after the _TSD
210  * data for all cpus is obtained.
211  */
212 void acpi_processor_throttling_init(void)
213 {
214 	if (acpi_processor_update_tsd_coord()) {
215 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
216 			"Assume no T-state coordination\n"));
217 	}
218 
219 	return;
220 }
221 
222 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
223 {
224 	struct throttling_tstate *p_tstate = data;
225 	struct acpi_processor *pr;
226 	unsigned int cpu ;
227 	int target_state;
228 	struct acpi_processor_limit *p_limit;
229 	struct acpi_processor_throttling *p_throttling;
230 
231 	cpu = p_tstate->cpu;
232 	pr = per_cpu(processors, cpu);
233 	if (!pr) {
234 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
235 		return 0;
236 	}
237 	if (!pr->flags.throttling) {
238 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
239 				"unsupported on CPU %d\n", cpu));
240 		return 0;
241 	}
242 	target_state = p_tstate->target_state;
243 	p_throttling = &(pr->throttling);
244 	switch (event) {
245 	case THROTTLING_PRECHANGE:
246 		/*
247 		 * Prechange event is used to choose one proper t-state,
248 		 * which meets the limits of thermal, user and _TPC.
249 		 */
250 		p_limit = &pr->limit;
251 		if (p_limit->thermal.tx > target_state)
252 			target_state = p_limit->thermal.tx;
253 		if (p_limit->user.tx > target_state)
254 			target_state = p_limit->user.tx;
255 		if (pr->throttling_platform_limit > target_state)
256 			target_state = pr->throttling_platform_limit;
257 		if (target_state >= p_throttling->state_count) {
258 			printk(KERN_WARNING
259 				"Exceed the limit of T-state \n");
260 			target_state = p_throttling->state_count - 1;
261 		}
262 		p_tstate->target_state = target_state;
263 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
264 				"target T-state of CPU %d is T%d\n",
265 				cpu, target_state));
266 		break;
267 	case THROTTLING_POSTCHANGE:
268 		/*
269 		 * Postchange event is only used to update the
270 		 * T-state flag of acpi_processor_throttling.
271 		 */
272 		p_throttling->state = target_state;
273 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
274 				"CPU %d is switched to T%d\n",
275 				cpu, target_state));
276 		break;
277 	default:
278 		printk(KERN_WARNING
279 			"Unsupported Throttling notifier event\n");
280 		break;
281 	}
282 
283 	return 0;
284 }
285 
286 /*
287  * _TPC - Throttling Present Capabilities
288  */
289 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
290 {
291 	acpi_status status = 0;
292 	unsigned long long tpc = 0;
293 
294 	if (!pr)
295 		return -EINVAL;
296 
297 	if (ignore_tpc)
298 		goto end;
299 
300 	status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
301 	if (ACPI_FAILURE(status)) {
302 		if (status != AE_NOT_FOUND) {
303 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
304 		}
305 		return -ENODEV;
306 	}
307 
308 end:
309 	pr->throttling_platform_limit = (int)tpc;
310 	return 0;
311 }
312 
313 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
314 {
315 	int result = 0;
316 	int throttling_limit;
317 	int current_state;
318 	struct acpi_processor_limit *limit;
319 	int target_state;
320 
321 	if (ignore_tpc)
322 		return 0;
323 
324 	result = acpi_processor_get_platform_limit(pr);
325 	if (result) {
326 		/* Throttling Limit is unsupported */
327 		return result;
328 	}
329 
330 	throttling_limit = pr->throttling_platform_limit;
331 	if (throttling_limit >= pr->throttling.state_count) {
332 		/* Uncorrect Throttling Limit */
333 		return -EINVAL;
334 	}
335 
336 	current_state = pr->throttling.state;
337 	if (current_state > throttling_limit) {
338 		/*
339 		 * The current state can meet the requirement of
340 		 * _TPC limit. But it is reasonable that OSPM changes
341 		 * t-states from high to low for better performance.
342 		 * Of course the limit condition of thermal
343 		 * and user should be considered.
344 		 */
345 		limit = &pr->limit;
346 		target_state = throttling_limit;
347 		if (limit->thermal.tx > target_state)
348 			target_state = limit->thermal.tx;
349 		if (limit->user.tx > target_state)
350 			target_state = limit->user.tx;
351 	} else if (current_state == throttling_limit) {
352 		/*
353 		 * Unnecessary to change the throttling state
354 		 */
355 		return 0;
356 	} else {
357 		/*
358 		 * If the current state is lower than the limit of _TPC, it
359 		 * will be forced to switch to the throttling state defined
360 		 * by throttling_platfor_limit.
361 		 * Because the previous state meets with the limit condition
362 		 * of thermal and user, it is unnecessary to check it again.
363 		 */
364 		target_state = throttling_limit;
365 	}
366 	return acpi_processor_set_throttling(pr, target_state, false);
367 }
368 
369 /*
370  * This function is used to reevaluate whether the T-state is valid
371  * after one CPU is onlined/offlined.
372  * It is noted that it won't reevaluate the following properties for
373  * the T-state.
374  *	1. Control method.
375  *	2. the number of supported T-state
376  *	3. TSD domain
377  */
378 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
379 					unsigned long action)
380 {
381 	int result = 0;
382 
383 	if (action == CPU_DEAD) {
384 		/* When one CPU is offline, the T-state throttling
385 		 * will be invalidated.
386 		 */
387 		pr->flags.throttling = 0;
388 		return;
389 	}
390 	/* the following is to recheck whether the T-state is valid for
391 	 * the online CPU
392 	 */
393 	if (!pr->throttling.state_count) {
394 		/* If the number of T-state is invalid, it is
395 		 * invalidated.
396 		 */
397 		pr->flags.throttling = 0;
398 		return;
399 	}
400 	pr->flags.throttling = 1;
401 
402 	/* Disable throttling (if enabled).  We'll let subsequent
403 	 * policy (e.g.thermal) decide to lower performance if it
404 	 * so chooses, but for now we'll crank up the speed.
405 	 */
406 
407 	result = acpi_processor_get_throttling(pr);
408 	if (result)
409 		goto end;
410 
411 	if (pr->throttling.state) {
412 		result = acpi_processor_set_throttling(pr, 0, false);
413 		if (result)
414 			goto end;
415 	}
416 
417 end:
418 	if (result)
419 		pr->flags.throttling = 0;
420 }
421 /*
422  * _PTC - Processor Throttling Control (and status) register location
423  */
424 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
425 {
426 	int result = 0;
427 	acpi_status status = 0;
428 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
429 	union acpi_object *ptc = NULL;
430 	union acpi_object obj = { 0 };
431 	struct acpi_processor_throttling *throttling;
432 
433 	status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
434 	if (ACPI_FAILURE(status)) {
435 		if (status != AE_NOT_FOUND) {
436 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
437 		}
438 		return -ENODEV;
439 	}
440 
441 	ptc = (union acpi_object *)buffer.pointer;
442 	if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
443 	    || (ptc->package.count != 2)) {
444 		printk(KERN_ERR PREFIX "Invalid _PTC data\n");
445 		result = -EFAULT;
446 		goto end;
447 	}
448 
449 	/*
450 	 * control_register
451 	 */
452 
453 	obj = ptc->package.elements[0];
454 
455 	if ((obj.type != ACPI_TYPE_BUFFER)
456 	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
457 	    || (obj.buffer.pointer == NULL)) {
458 		printk(KERN_ERR PREFIX
459 		       "Invalid _PTC data (control_register)\n");
460 		result = -EFAULT;
461 		goto end;
462 	}
463 	memcpy(&pr->throttling.control_register, obj.buffer.pointer,
464 	       sizeof(struct acpi_ptc_register));
465 
466 	/*
467 	 * status_register
468 	 */
469 
470 	obj = ptc->package.elements[1];
471 
472 	if ((obj.type != ACPI_TYPE_BUFFER)
473 	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
474 	    || (obj.buffer.pointer == NULL)) {
475 		printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
476 		result = -EFAULT;
477 		goto end;
478 	}
479 
480 	memcpy(&pr->throttling.status_register, obj.buffer.pointer,
481 	       sizeof(struct acpi_ptc_register));
482 
483 	throttling = &pr->throttling;
484 
485 	if ((throttling->control_register.bit_width +
486 		throttling->control_register.bit_offset) > 32) {
487 		printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
488 		result = -EFAULT;
489 		goto end;
490 	}
491 
492 	if ((throttling->status_register.bit_width +
493 		throttling->status_register.bit_offset) > 32) {
494 		printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
495 		result = -EFAULT;
496 		goto end;
497 	}
498 
499       end:
500 	kfree(buffer.pointer);
501 
502 	return result;
503 }
504 
505 /*
506  * _TSS - Throttling Supported States
507  */
508 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
509 {
510 	int result = 0;
511 	acpi_status status = AE_OK;
512 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
513 	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
514 	struct acpi_buffer state = { 0, NULL };
515 	union acpi_object *tss = NULL;
516 	int i;
517 
518 	status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
519 	if (ACPI_FAILURE(status)) {
520 		if (status != AE_NOT_FOUND) {
521 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
522 		}
523 		return -ENODEV;
524 	}
525 
526 	tss = buffer.pointer;
527 	if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
528 		printk(KERN_ERR PREFIX "Invalid _TSS data\n");
529 		result = -EFAULT;
530 		goto end;
531 	}
532 
533 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
534 			  tss->package.count));
535 
536 	pr->throttling.state_count = tss->package.count;
537 	pr->throttling.states_tss =
538 	    kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
539 		    GFP_KERNEL);
540 	if (!pr->throttling.states_tss) {
541 		result = -ENOMEM;
542 		goto end;
543 	}
544 
545 	for (i = 0; i < pr->throttling.state_count; i++) {
546 
547 		struct acpi_processor_tx_tss *tx =
548 		    (struct acpi_processor_tx_tss *)&(pr->throttling.
549 						      states_tss[i]);
550 
551 		state.length = sizeof(struct acpi_processor_tx_tss);
552 		state.pointer = tx;
553 
554 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
555 
556 		status = acpi_extract_package(&(tss->package.elements[i]),
557 					      &format, &state);
558 		if (ACPI_FAILURE(status)) {
559 			ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
560 			result = -EFAULT;
561 			kfree(pr->throttling.states_tss);
562 			goto end;
563 		}
564 
565 		if (!tx->freqpercentage) {
566 			printk(KERN_ERR PREFIX
567 			       "Invalid _TSS data: freq is zero\n");
568 			result = -EFAULT;
569 			kfree(pr->throttling.states_tss);
570 			goto end;
571 		}
572 	}
573 
574       end:
575 	kfree(buffer.pointer);
576 
577 	return result;
578 }
579 
580 /*
581  * _TSD - T-State Dependencies
582  */
583 static int acpi_processor_get_tsd(struct acpi_processor *pr)
584 {
585 	int result = 0;
586 	acpi_status status = AE_OK;
587 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
588 	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
589 	struct acpi_buffer state = { 0, NULL };
590 	union acpi_object *tsd = NULL;
591 	struct acpi_tsd_package *pdomain;
592 	struct acpi_processor_throttling *pthrottling;
593 
594 	pthrottling = &pr->throttling;
595 	pthrottling->tsd_valid_flag = 0;
596 
597 	status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
598 	if (ACPI_FAILURE(status)) {
599 		if (status != AE_NOT_FOUND) {
600 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
601 		}
602 		return -ENODEV;
603 	}
604 
605 	tsd = buffer.pointer;
606 	if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
607 		printk(KERN_ERR PREFIX "Invalid _TSD data\n");
608 		result = -EFAULT;
609 		goto end;
610 	}
611 
612 	if (tsd->package.count != 1) {
613 		printk(KERN_ERR PREFIX "Invalid _TSD data\n");
614 		result = -EFAULT;
615 		goto end;
616 	}
617 
618 	pdomain = &(pr->throttling.domain_info);
619 
620 	state.length = sizeof(struct acpi_tsd_package);
621 	state.pointer = pdomain;
622 
623 	status = acpi_extract_package(&(tsd->package.elements[0]),
624 				      &format, &state);
625 	if (ACPI_FAILURE(status)) {
626 		printk(KERN_ERR PREFIX "Invalid _TSD data\n");
627 		result = -EFAULT;
628 		goto end;
629 	}
630 
631 	if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
632 		printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
633 		result = -EFAULT;
634 		goto end;
635 	}
636 
637 	if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
638 		printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
639 		result = -EFAULT;
640 		goto end;
641 	}
642 
643 	pthrottling = &pr->throttling;
644 	pthrottling->tsd_valid_flag = 1;
645 	pthrottling->shared_type = pdomain->coord_type;
646 	cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
647 	/*
648 	 * If the coordination type is not defined in ACPI spec,
649 	 * the tsd_valid_flag will be clear and coordination type
650 	 * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
651 	 */
652 	if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
653 		pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
654 		pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
655 		pthrottling->tsd_valid_flag = 0;
656 		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
657 	}
658 
659       end:
660 	kfree(buffer.pointer);
661 	return result;
662 }
663 
664 /* --------------------------------------------------------------------------
665                               Throttling Control
666    -------------------------------------------------------------------------- */
667 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
668 {
669 	int state = 0;
670 	u32 value = 0;
671 	u32 duty_mask = 0;
672 	u32 duty_value = 0;
673 
674 	if (!pr)
675 		return -EINVAL;
676 
677 	if (!pr->flags.throttling)
678 		return -ENODEV;
679 
680 	pr->throttling.state = 0;
681 
682 	duty_mask = pr->throttling.state_count - 1;
683 
684 	duty_mask <<= pr->throttling.duty_offset;
685 
686 	local_irq_disable();
687 
688 	value = inl(pr->throttling.address);
689 
690 	/*
691 	 * Compute the current throttling state when throttling is enabled
692 	 * (bit 4 is on).
693 	 */
694 	if (value & 0x10) {
695 		duty_value = value & duty_mask;
696 		duty_value >>= pr->throttling.duty_offset;
697 
698 		if (duty_value)
699 			state = pr->throttling.state_count - duty_value;
700 	}
701 
702 	pr->throttling.state = state;
703 
704 	local_irq_enable();
705 
706 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
707 			  "Throttling state is T%d (%d%% throttling applied)\n",
708 			  state, pr->throttling.states[state].performance));
709 
710 	return 0;
711 }
712 
713 #ifdef CONFIG_X86
714 static int acpi_throttling_rdmsr(u64 *value)
715 {
716 	u64 msr_high, msr_low;
717 	u64 msr = 0;
718 	int ret = -1;
719 
720 	if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
721 		!this_cpu_has(X86_FEATURE_ACPI)) {
722 		printk(KERN_ERR PREFIX
723 			"HARDWARE addr space,NOT supported yet\n");
724 	} else {
725 		msr_low = 0;
726 		msr_high = 0;
727 		rdmsr_safe(MSR_IA32_THERM_CONTROL,
728 			(u32 *)&msr_low , (u32 *) &msr_high);
729 		msr = (msr_high << 32) | msr_low;
730 		*value = (u64) msr;
731 		ret = 0;
732 	}
733 	return ret;
734 }
735 
736 static int acpi_throttling_wrmsr(u64 value)
737 {
738 	int ret = -1;
739 	u64 msr;
740 
741 	if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
742 		!this_cpu_has(X86_FEATURE_ACPI)) {
743 		printk(KERN_ERR PREFIX
744 			"HARDWARE addr space,NOT supported yet\n");
745 	} else {
746 		msr = value;
747 		wrmsr_safe(MSR_IA32_THERM_CONTROL,
748 			msr & 0xffffffff, msr >> 32);
749 		ret = 0;
750 	}
751 	return ret;
752 }
753 #else
754 static int acpi_throttling_rdmsr(u64 *value)
755 {
756 	printk(KERN_ERR PREFIX
757 		"HARDWARE addr space,NOT supported yet\n");
758 	return -1;
759 }
760 
761 static int acpi_throttling_wrmsr(u64 value)
762 {
763 	printk(KERN_ERR PREFIX
764 		"HARDWARE addr space,NOT supported yet\n");
765 	return -1;
766 }
767 #endif
768 
769 static int acpi_read_throttling_status(struct acpi_processor *pr,
770 					u64 *value)
771 {
772 	u32 bit_width, bit_offset;
773 	u32 ptc_value;
774 	u64 ptc_mask;
775 	struct acpi_processor_throttling *throttling;
776 	int ret = -1;
777 
778 	throttling = &pr->throttling;
779 	switch (throttling->status_register.space_id) {
780 	case ACPI_ADR_SPACE_SYSTEM_IO:
781 		bit_width = throttling->status_register.bit_width;
782 		bit_offset = throttling->status_register.bit_offset;
783 
784 		acpi_os_read_port((acpi_io_address) throttling->status_register.
785 				  address, &ptc_value,
786 				  (u32) (bit_width + bit_offset));
787 		ptc_mask = (1 << bit_width) - 1;
788 		*value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
789 		ret = 0;
790 		break;
791 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
792 		ret = acpi_throttling_rdmsr(value);
793 		break;
794 	default:
795 		printk(KERN_ERR PREFIX "Unknown addr space %d\n",
796 		       (u32) (throttling->status_register.space_id));
797 	}
798 	return ret;
799 }
800 
801 static int acpi_write_throttling_state(struct acpi_processor *pr,
802 				u64 value)
803 {
804 	u32 bit_width, bit_offset;
805 	u64 ptc_value;
806 	u64 ptc_mask;
807 	struct acpi_processor_throttling *throttling;
808 	int ret = -1;
809 
810 	throttling = &pr->throttling;
811 	switch (throttling->control_register.space_id) {
812 	case ACPI_ADR_SPACE_SYSTEM_IO:
813 		bit_width = throttling->control_register.bit_width;
814 		bit_offset = throttling->control_register.bit_offset;
815 		ptc_mask = (1 << bit_width) - 1;
816 		ptc_value = value & ptc_mask;
817 
818 		acpi_os_write_port((acpi_io_address) throttling->
819 					control_register.address,
820 					(u32) (ptc_value << bit_offset),
821 					(u32) (bit_width + bit_offset));
822 		ret = 0;
823 		break;
824 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
825 		ret = acpi_throttling_wrmsr(value);
826 		break;
827 	default:
828 		printk(KERN_ERR PREFIX "Unknown addr space %d\n",
829 		       (u32) (throttling->control_register.space_id));
830 	}
831 	return ret;
832 }
833 
834 static int acpi_get_throttling_state(struct acpi_processor *pr,
835 				u64 value)
836 {
837 	int i;
838 
839 	for (i = 0; i < pr->throttling.state_count; i++) {
840 		struct acpi_processor_tx_tss *tx =
841 		    (struct acpi_processor_tx_tss *)&(pr->throttling.
842 						      states_tss[i]);
843 		if (tx->control == value)
844 			return i;
845 	}
846 	return -1;
847 }
848 
849 static int acpi_get_throttling_value(struct acpi_processor *pr,
850 			int state, u64 *value)
851 {
852 	int ret = -1;
853 
854 	if (state >= 0 && state <= pr->throttling.state_count) {
855 		struct acpi_processor_tx_tss *tx =
856 		    (struct acpi_processor_tx_tss *)&(pr->throttling.
857 						      states_tss[state]);
858 		*value = tx->control;
859 		ret = 0;
860 	}
861 	return ret;
862 }
863 
864 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
865 {
866 	int state = 0;
867 	int ret;
868 	u64 value;
869 
870 	if (!pr)
871 		return -EINVAL;
872 
873 	if (!pr->flags.throttling)
874 		return -ENODEV;
875 
876 	pr->throttling.state = 0;
877 
878 	value = 0;
879 	ret = acpi_read_throttling_status(pr, &value);
880 	if (ret >= 0) {
881 		state = acpi_get_throttling_state(pr, value);
882 		if (state == -1) {
883 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
884 				"Invalid throttling state, reset\n"));
885 			state = 0;
886 			ret = acpi_processor_set_throttling(pr, state, true);
887 			if (ret)
888 				return ret;
889 		}
890 		pr->throttling.state = state;
891 	}
892 
893 	return 0;
894 }
895 
896 static int acpi_processor_get_throttling(struct acpi_processor *pr)
897 {
898 	cpumask_var_t saved_mask;
899 	int ret;
900 
901 	if (!pr)
902 		return -EINVAL;
903 
904 	if (!pr->flags.throttling)
905 		return -ENODEV;
906 
907 	if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
908 		return -ENOMEM;
909 
910 	/*
911 	 * Migrate task to the cpu pointed by pr.
912 	 */
913 	cpumask_copy(saved_mask, &current->cpus_allowed);
914 	/* FIXME: use work_on_cpu() */
915 	if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
916 		/* Can't migrate to the target pr->id CPU. Exit */
917 		free_cpumask_var(saved_mask);
918 		return -ENODEV;
919 	}
920 	ret = pr->throttling.acpi_processor_get_throttling(pr);
921 	/* restore the previous state */
922 	set_cpus_allowed_ptr(current, saved_mask);
923 	free_cpumask_var(saved_mask);
924 
925 	return ret;
926 }
927 
928 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
929 {
930 	int i, step;
931 
932 	if (!pr->throttling.address) {
933 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
934 		return -EINVAL;
935 	} else if (!pr->throttling.duty_width) {
936 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
937 		return -EINVAL;
938 	}
939 	/* TBD: Support duty_cycle values that span bit 4. */
940 	else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
941 		printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
942 		return -EINVAL;
943 	}
944 
945 	pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
946 
947 	/*
948 	 * Compute state values. Note that throttling displays a linear power
949 	 * performance relationship (at 50% performance the CPU will consume
950 	 * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
951 	 */
952 
953 	step = (1000 / pr->throttling.state_count);
954 
955 	for (i = 0; i < pr->throttling.state_count; i++) {
956 		pr->throttling.states[i].performance = 1000 - step * i;
957 		pr->throttling.states[i].power = 1000 - step * i;
958 	}
959 	return 0;
960 }
961 
962 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
963 					      int state, bool force)
964 {
965 	u32 value = 0;
966 	u32 duty_mask = 0;
967 	u32 duty_value = 0;
968 
969 	if (!pr)
970 		return -EINVAL;
971 
972 	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
973 		return -EINVAL;
974 
975 	if (!pr->flags.throttling)
976 		return -ENODEV;
977 
978 	if (!force && (state == pr->throttling.state))
979 		return 0;
980 
981 	if (state < pr->throttling_platform_limit)
982 		return -EPERM;
983 	/*
984 	 * Calculate the duty_value and duty_mask.
985 	 */
986 	if (state) {
987 		duty_value = pr->throttling.state_count - state;
988 
989 		duty_value <<= pr->throttling.duty_offset;
990 
991 		/* Used to clear all duty_value bits */
992 		duty_mask = pr->throttling.state_count - 1;
993 
994 		duty_mask <<= acpi_gbl_FADT.duty_offset;
995 		duty_mask = ~duty_mask;
996 	}
997 
998 	local_irq_disable();
999 
1000 	/*
1001 	 * Disable throttling by writing a 0 to bit 4.  Note that we must
1002 	 * turn it off before you can change the duty_value.
1003 	 */
1004 	value = inl(pr->throttling.address);
1005 	if (value & 0x10) {
1006 		value &= 0xFFFFFFEF;
1007 		outl(value, pr->throttling.address);
1008 	}
1009 
1010 	/*
1011 	 * Write the new duty_value and then enable throttling.  Note
1012 	 * that a state value of 0 leaves throttling disabled.
1013 	 */
1014 	if (state) {
1015 		value &= duty_mask;
1016 		value |= duty_value;
1017 		outl(value, pr->throttling.address);
1018 
1019 		value |= 0x00000010;
1020 		outl(value, pr->throttling.address);
1021 	}
1022 
1023 	pr->throttling.state = state;
1024 
1025 	local_irq_enable();
1026 
1027 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1028 			  "Throttling state set to T%d (%d%%)\n", state,
1029 			  (pr->throttling.states[state].performance ? pr->
1030 			   throttling.states[state].performance / 10 : 0)));
1031 
1032 	return 0;
1033 }
1034 
1035 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1036 					     int state, bool force)
1037 {
1038 	int ret;
1039 	u64 value;
1040 
1041 	if (!pr)
1042 		return -EINVAL;
1043 
1044 	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1045 		return -EINVAL;
1046 
1047 	if (!pr->flags.throttling)
1048 		return -ENODEV;
1049 
1050 	if (!force && (state == pr->throttling.state))
1051 		return 0;
1052 
1053 	if (state < pr->throttling_platform_limit)
1054 		return -EPERM;
1055 
1056 	value = 0;
1057 	ret = acpi_get_throttling_value(pr, state, &value);
1058 	if (ret >= 0) {
1059 		acpi_write_throttling_state(pr, value);
1060 		pr->throttling.state = state;
1061 	}
1062 
1063 	return 0;
1064 }
1065 
1066 int acpi_processor_set_throttling(struct acpi_processor *pr,
1067 						int state, bool force)
1068 {
1069 	cpumask_var_t saved_mask;
1070 	int ret = 0;
1071 	unsigned int i;
1072 	struct acpi_processor *match_pr;
1073 	struct acpi_processor_throttling *p_throttling;
1074 	struct throttling_tstate t_state;
1075 	cpumask_var_t online_throttling_cpus;
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 (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
1087 		return -ENOMEM;
1088 
1089 	if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
1090 		free_cpumask_var(saved_mask);
1091 		return -ENOMEM;
1092 	}
1093 
1094 	if (cpu_is_offline(pr->id)) {
1095 		/*
1096 		 * the cpu pointed by pr->id is offline. Unnecessary to change
1097 		 * the throttling state any more.
1098 		 */
1099 		return -ENODEV;
1100 	}
1101 
1102 	cpumask_copy(saved_mask, &current->cpus_allowed);
1103 	t_state.target_state = state;
1104 	p_throttling = &(pr->throttling);
1105 	cpumask_and(online_throttling_cpus, cpu_online_mask,
1106 		    p_throttling->shared_cpu_map);
1107 	/*
1108 	 * The throttling notifier will be called for every
1109 	 * affected cpu in order to get one proper T-state.
1110 	 * The notifier event is THROTTLING_PRECHANGE.
1111 	 */
1112 	for_each_cpu(i, online_throttling_cpus) {
1113 		t_state.cpu = i;
1114 		acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1115 							&t_state);
1116 	}
1117 	/*
1118 	 * The function of acpi_processor_set_throttling will be called
1119 	 * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1120 	 * it is necessary to call it for every affected cpu. Otherwise
1121 	 * it can be called only for the cpu pointed by pr.
1122 	 */
1123 	if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1124 		/* FIXME: use work_on_cpu() */
1125 		if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
1126 			/* Can't migrate to the pr->id CPU. Exit */
1127 			ret = -ENODEV;
1128 			goto exit;
1129 		}
1130 		ret = p_throttling->acpi_processor_set_throttling(pr,
1131 						t_state.target_state, force);
1132 	} else {
1133 		/*
1134 		 * When the T-state coordination is SW_ALL or HW_ALL,
1135 		 * it is necessary to set T-state for every affected
1136 		 * cpus.
1137 		 */
1138 		for_each_cpu(i, online_throttling_cpus) {
1139 			match_pr = per_cpu(processors, i);
1140 			/*
1141 			 * If the pointer is invalid, we will report the
1142 			 * error message and continue.
1143 			 */
1144 			if (!match_pr) {
1145 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1146 					"Invalid Pointer for CPU %d\n", i));
1147 				continue;
1148 			}
1149 			/*
1150 			 * If the throttling control is unsupported on CPU i,
1151 			 * we will report the error message and continue.
1152 			 */
1153 			if (!match_pr->flags.throttling) {
1154 				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1155 					"Throttling Control is unsupported "
1156 					"on CPU %d\n", i));
1157 				continue;
1158 			}
1159 			t_state.cpu = i;
1160 			/* FIXME: use work_on_cpu() */
1161 			if (set_cpus_allowed_ptr(current, cpumask_of(i)))
1162 				continue;
1163 			ret = match_pr->throttling.
1164 				acpi_processor_set_throttling(
1165 				match_pr, t_state.target_state, force);
1166 		}
1167 	}
1168 	/*
1169 	 * After the set_throttling is called, the
1170 	 * throttling notifier is called for every
1171 	 * affected cpu to update the T-states.
1172 	 * The notifier event is THROTTLING_POSTCHANGE
1173 	 */
1174 	for_each_cpu(i, online_throttling_cpus) {
1175 		t_state.cpu = i;
1176 		acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1177 							&t_state);
1178 	}
1179 	/* restore the previous state */
1180 	/* FIXME: use work_on_cpu() */
1181 	set_cpus_allowed_ptr(current, saved_mask);
1182 exit:
1183 	free_cpumask_var(online_throttling_cpus);
1184 	free_cpumask_var(saved_mask);
1185 	return ret;
1186 }
1187 
1188 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1189 {
1190 	int result = 0;
1191 	struct acpi_processor_throttling *pthrottling;
1192 
1193 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1194 			  "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1195 			  pr->throttling.address,
1196 			  pr->throttling.duty_offset,
1197 			  pr->throttling.duty_width));
1198 
1199 	/*
1200 	 * Evaluate _PTC, _TSS and _TPC
1201 	 * They must all be present or none of them can be used.
1202 	 */
1203 	if (acpi_processor_get_throttling_control(pr) ||
1204 		acpi_processor_get_throttling_states(pr) ||
1205 		acpi_processor_get_platform_limit(pr))
1206 	{
1207 		pr->throttling.acpi_processor_get_throttling =
1208 		    &acpi_processor_get_throttling_fadt;
1209 		pr->throttling.acpi_processor_set_throttling =
1210 		    &acpi_processor_set_throttling_fadt;
1211 		if (acpi_processor_get_fadt_info(pr))
1212 			return 0;
1213 	} else {
1214 		pr->throttling.acpi_processor_get_throttling =
1215 		    &acpi_processor_get_throttling_ptc;
1216 		pr->throttling.acpi_processor_set_throttling =
1217 		    &acpi_processor_set_throttling_ptc;
1218 	}
1219 
1220 	/*
1221 	 * If TSD package for one CPU can't be parsed successfully, it means
1222 	 * that this CPU will have no coordination with other CPUs.
1223 	 */
1224 	if (acpi_processor_get_tsd(pr)) {
1225 		pthrottling = &pr->throttling;
1226 		pthrottling->tsd_valid_flag = 0;
1227 		cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1228 		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1229 	}
1230 
1231 	/*
1232 	 * PIIX4 Errata: We don't support throttling on the original PIIX4.
1233 	 * This shouldn't be an issue as few (if any) mobile systems ever
1234 	 * used this part.
1235 	 */
1236 	if (errata.piix4.throttle) {
1237 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1238 				  "Throttling not supported on PIIX4 A- or B-step\n"));
1239 		return 0;
1240 	}
1241 
1242 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1243 			  pr->throttling.state_count));
1244 
1245 	pr->flags.throttling = 1;
1246 
1247 	/*
1248 	 * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1249 	 * thermal) decide to lower performance if it so chooses, but for now
1250 	 * we'll crank up the speed.
1251 	 */
1252 
1253 	result = acpi_processor_get_throttling(pr);
1254 	if (result)
1255 		goto end;
1256 
1257 	if (pr->throttling.state) {
1258 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1259 				  "Disabling throttling (was T%d)\n",
1260 				  pr->throttling.state));
1261 		result = acpi_processor_set_throttling(pr, 0, false);
1262 		if (result)
1263 			goto end;
1264 	}
1265 
1266       end:
1267 	if (result)
1268 		pr->flags.throttling = 0;
1269 
1270 	return result;
1271 }
1272 
1273